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Artist D.L. Polonsky & Michael O'Toole talk Experimentally ILL: The Movie at Boston Open Screen at IFFBoston, Boston Underground Film Fest PSA, art, filmmaking and more! --- Send in a voice message: https://podcasters.spotify.com/pod/show/experimentallyill/message
Explore cutting-edge research at the intersection of neuroscience, space exploration, and medical innovation. Researchers discuss revolutionary experiments with brain organoids cultivated from stem cells, conducted both in terrestrial labs and aboard the International Space Station. They investigate accelerated aging, neuroprotective agents, and potential treatments for conditions like Alzheimer's and ALS. The dialogue also delves into the transformative impact of space environments on scientific discoveries, from understanding bacterial growth to developing novel therapies. Through collaborative efforts, they strive to revolutionize healthcare, offering hope for patients and pushing the boundaries of human knowledge. Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 39632]
Explore cutting-edge research at the intersection of neuroscience, space exploration, and medical innovation. Researchers discuss revolutionary experiments with brain organoids cultivated from stem cells, conducted both in terrestrial labs and aboard the International Space Station. They investigate accelerated aging, neuroprotective agents, and potential treatments for conditions like Alzheimer's and ALS. The dialogue also delves into the transformative impact of space environments on scientific discoveries, from understanding bacterial growth to developing novel therapies. Through collaborative efforts, they strive to revolutionize healthcare, offering hope for patients and pushing the boundaries of human knowledge. Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 39632]
Explore cutting-edge research at the intersection of neuroscience, space exploration, and medical innovation. Researchers discuss revolutionary experiments with brain organoids cultivated from stem cells, conducted both in terrestrial labs and aboard the International Space Station. They investigate accelerated aging, neuroprotective agents, and potential treatments for conditions like Alzheimer's and ALS. The dialogue also delves into the transformative impact of space environments on scientific discoveries, from understanding bacterial growth to developing novel therapies. Through collaborative efforts, they strive to revolutionize healthcare, offering hope for patients and pushing the boundaries of human knowledge. Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 39632]
Explore cutting-edge research at the intersection of neuroscience, space exploration, and medical innovation. Researchers discuss revolutionary experiments with brain organoids cultivated from stem cells, conducted both in terrestrial labs and aboard the International Space Station. They investigate accelerated aging, neuroprotective agents, and potential treatments for conditions like Alzheimer's and ALS. The dialogue also delves into the transformative impact of space environments on scientific discoveries, from understanding bacterial growth to developing novel therapies. Through collaborative efforts, they strive to revolutionize healthcare, offering hope for patients and pushing the boundaries of human knowledge. Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 39632]
Explore cutting-edge research at the intersection of neuroscience, space exploration, and medical innovation. Researchers discuss revolutionary experiments with brain organoids cultivated from stem cells, conducted both in terrestrial labs and aboard the International Space Station. They investigate accelerated aging, neuroprotective agents, and potential treatments for conditions like Alzheimer's and ALS. The dialogue also delves into the transformative impact of space environments on scientific discoveries, from understanding bacterial growth to developing novel therapies. Through collaborative efforts, they strive to revolutionize healthcare, offering hope for patients and pushing the boundaries of human knowledge. Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 39632]
Explore cutting-edge research at the intersection of neuroscience, space exploration, and medical innovation. Researchers discuss revolutionary experiments with brain organoids cultivated from stem cells, conducted both in terrestrial labs and aboard the International Space Station. They investigate accelerated aging, neuroprotective agents, and potential treatments for conditions like Alzheimer's and ALS. The dialogue also delves into the transformative impact of space environments on scientific discoveries, from understanding bacterial growth to developing novel therapies. Through collaborative efforts, they strive to revolutionize healthcare, offering hope for patients and pushing the boundaries of human knowledge. Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 39632]
Explore cutting-edge research at the intersection of neuroscience, space exploration, and medical innovation. Researchers discuss revolutionary experiments with brain organoids cultivated from stem cells, conducted both in terrestrial labs and aboard the International Space Station. They investigate accelerated aging, neuroprotective agents, and potential treatments for conditions like Alzheimer's and ALS. The dialogue also delves into the transformative impact of space environments on scientific discoveries, from understanding bacterial growth to developing novel therapies. Through collaborative efforts, they strive to revolutionize healthcare, offering hope for patients and pushing the boundaries of human knowledge. Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 39632]
Explore cutting-edge research at the intersection of neuroscience, space exploration, and medical innovation. Researchers discuss revolutionary experiments with brain organoids cultivated from stem cells, conducted both in terrestrial labs and aboard the International Space Station. They investigate accelerated aging, neuroprotective agents, and potential treatments for conditions like Alzheimer's and ALS. The dialogue also delves into the transformative impact of space environments on scientific discoveries, from understanding bacterial growth to developing novel therapies. Through collaborative efforts, they strive to revolutionize healthcare, offering hope for patients and pushing the boundaries of human knowledge. Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 39632]
Explore cutting-edge research at the intersection of neuroscience, space exploration, and medical innovation. Researchers discuss revolutionary experiments with brain organoids cultivated from stem cells, conducted both in terrestrial labs and aboard the International Space Station. They investigate accelerated aging, neuroprotective agents, and potential treatments for conditions like Alzheimer's and ALS. The dialogue also delves into the transformative impact of space environments on scientific discoveries, from understanding bacterial growth to developing novel therapies. Through collaborative efforts, they strive to revolutionize healthcare, offering hope for patients and pushing the boundaries of human knowledge. Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 39632]
Google changed the way Maps stores user data making it impossible for it to respond to geofence warrants, The FCC experimentally authorized Starlink to test its cellular Starlink service, and news publishers are worried AI could decimate traffic to their sites. MP3 Please SUBSCRIBE HERE. You can get an ad-free feed of Daily Tech HeadlinesContinue reading "The FCC Experimentally Authorizes StarLink To Test Satellite Cellular – DTH"
The God Hypothesis has always been considered irrelevant as it was assumed to not be open to the scientific method. In this short piece abstracted from the book of the same name, it is demonstrated that the God Hypothesis gives rise to 25 propositions all which are amenable to scientific validation.
00:00 Introduction 08:03 Interview Begins 09:42 How Chiara found herself at the foundations of physics 15:30 How Chiara found Everett 19:13 No Special Physics is required for Observers 21:02 What is a counterfactual? How is it linked to a constructor? 29:05 What is (classical) information? How is it different to quantum information? 32:30 Quantum Information is more constrained. This makes it more powerful. 34:08 Is the universe made of information? 38:04 The Simulation Hypothesis 40:33 The second law of thermodynamics 53:16 The AI Apocalypse? 58:02 How do we help a human become passionate about knowledge? 59:39 The Fine Tuning Problem 01:07:48 The Constructor Theoretic Notion of Knowledge 01:10:52 Constructor Theoretic Knowledge as a window on the origins of life. 01:12:16 The links between physics, epistemology and biology 01:14:15 Experimentally testing the quantum nature of gravity 01:26:05 Where to find out more Support me by following the links at www.bretthall.org
In this episode:Definition of rate of reactionHow to plot reaction dataHow to find the rate of reactionBecome a Patreon supporter of the podcast and get more from each episode. patreon.com/chemistrymadesimplePrefer to say a quick 'thank you'? You can buy me a coffee if that's your jam.Check out the Chemistry Made Simple academyFind out more about the Chemistry Made Simple academyContact me:Instagram @chemistrymadesimpleEmail Matthew@ChemistryMadeSimple.netJoin the discussion at the Chemistry Made Simple podcast community.
Experimentally ILL podcast presents this clip of Active Radio with Hartley Pleshaw 10-5-2023 broadcast from WCAP-AM 980. Guests: John McGuinness of Screaming Ostrich International Film Festival and Filmmaker Michael Phelan O'Toole of Experimentally ILL on CCTV Cambridge.John speaks about the history of the Ostrich fest and Michael talks about his short "Artificial Intelligence with Hartley Pleshaw" (playing 10-14-23 at West Newton Cinema) and his media career retrospective documentary (playing at the fest 10-15-23 - both at 1PM EST).Visit ScreamingOstrich.wordpress.com and ExperimentallyILL.com for more information. Active Radio is live every Saturday 10AM EST from 980 WCAP-AM and on https://980wcap.com --- Send in a voice message: https://podcasters.spotify.com/pod/show/experimentallyill/message
Dr. Matt Dyson, DU Canada waterfowl research scientist, and Dr. Mike Brasher join forces to discuss the exciting growth and application of science in waterfowl and wetland conservation across Canada. Matt shares insights on the ecology of boreal forests, effects of wildfires on waterfowl, difficulties of studying ducks in this vast landscape, and new science by DUC colleagues. Matt also recalls stories from his upbringing and accepts the challenge of identifying his favorite fish. www.ducks.org/DUPodcastwww.ducks.ca
Experimentally ILL's Michael O'Toole welcomes artist D.L. Polonsky & filmmaker Lawrence Hollie to talk the upcoming Experimentally ILL CCTV show and Mike and DL shooting footage at Fan Expo Boston comic con 2023. Lawrence, Mike and D.L. discuss Spiderman, Star Wars, Danny Trejo, cosplaying at a comic con, indie filmmaking and more. --- Send in a voice message: https://podcasters.spotify.com/pod/show/experimentallyill/message
Today on the pod I have Asheville's queen of pole dancing, the creator and head instructor at DANCECLUB Asheville...Kathleen Hahn! Kathleen has built an incredibly successful business, all while staying authentic and true to herself. And I admire her sooo much for that! You are going to adore Kathleen and all of the juicy wisdom she has to share with us. TOPICS INCLUDE:How to be a Great LeaderJumping Before You're ReadyFinding the FUNCreating a Safe Space for Weirdness & AuthenticityBreaking Out of the Boxes Others Put Us In Connect with Kathleen on IG: https://www.instagram.com/danceclubasheville/https://www.instagram.com/boo_velvet/ CREATRIX BIZ BUILDER SALE - Use code "BIZBADDIE" for $200 off CBB!https://highvibeheels.mykajabi.com/creatrix-biz-builder-info High Vibe Heels Mentorship, Courses, & More: https://highvibeheels.mykajabi.com/store confiDANCE info page: https://highvibeheels.mykajabi.com/confiDANCE-info-page Connect With Ashlyn on Social Media:https://www.instagram.com/high.vibe.heels/https://www.youtube.com/channel/UC-Xn1jeHIIyWBVXOkgdtjpQ
Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: Apparently, of the 195 Million the DoD allocated in University Research Funding Awards in 2022, more than half of them concerned AI or compute hardware research, published by mako yass on July 7, 2023 on LessWrong. Suggests some really interesting focus, so I thought I should mention it. The awards concerned "pursuing basic research spanning multiple scientific disciplines", which makes it pretty interesting that three fifths of them are either directly AI and compute hardware research, or have applications to compute hardware research. From a merit-based review of approximately 340 proposals received, a panel of experts narrowed the proposals to a subset, from which the 28 final awards were selected (Only 26 were listed in the table. I wonder if the other two were a strategic omission.) Take a look at the table of project topics. Bold means probably directly AI/compute, italic means probably primarily applicable to AI/compute. Social Network-Transcendent Behavioral Dynamics Learning Dynamics and Detecting Causal Pathways in Coupled Online- Offline Systems Microelectronic Test Science Exploiting Latent Energy and Electromagnetic Radiation Comprehensive Minimally/non- invasive Multifaceted Assessment of Nano-/ microelectronic Devices (CoMMAND) Cavity Molecular Polaritons MURI: Polariton Chemistry Effects of Radiation Damage on Performance of Wide-Bandgap Electronics REDESIGN: Radiation Effects preDiction through Experimentally validated Simulation of Gallium Nitride Understanding Neural Systems Integration for Competent Autonomy in Decision and Control FLAP: Fast, Lexicographic Agile Integrates Decision and Control in a Spike-Resolved, Sensorimotor Program Nonlinear Optical Material Design with Extreme Interband Nonlinearities Atomic-scale Manipulations of Interband Optical Nonlinearities - (AtoMs➝IONs) Synthetic Quantum Matter Reimagining Atoms and Photons in SYnthetic, DYnamical, and INteracting Quantum matter Composability of Synthetic Biological Circuits Rules of Composition in Synthetic Biology Across Scales of Complexity: Theory and Tools Bio-architected Responsive Materials with 3D Nanoscale Order 3D Nanomaterial Architectures with Programmable Reconfiguration States and Functions Topological Seeds of Complex Response in Materials Programming Multistable Origami and Kirigami Structures via Topological Design Connectivity and Transport in Disordered Hyperuniform Networks Transport in Disordered Hyperuniform Systems and Networks Uncovering the Underlying Neurobiological Mechanisms of Cognitive Fatigue Understanding and Predicting Cognitive Fatigue across Multiple Timescales, Distinct Aspects of Cognition, and Different Individuals with Multiscale Whole Cortex Models Gut-Neuronal Signaling Through Polymeric Mucin via Chemical Probes and Imaging Mucin-mimetic Interventions to Modulate the Gut-Brain Axis ELECTROBIOLOGY: Electronic Control of Biological Communication Faster, More Efficient, and Hybrid Computation in Microbial Bioelectronic Systems ARO Rice University Novel Routes to Majorana Qubits for Topologically- Protected Quantum Information Epitaxial phase-biased Josephson junctions Molecular Doping of Organic Electronic Materials Next Generation Molecular Dopants for Organic Electronics: From Fundamentals to New Device Concepts Learning from Hearing Neurobehavioral, Physiological, and Computational Processes of Auditory Object Learning in Mammals Hydrodynamics of Fish Schooling Revealing the Hydrodynamic Principles of Three-dimensional Fish Schools; From Biology to Schooling Robotics Self-learning for Real-world Perception Intentional multi-modal self-learning to perceive and understand the real world Fundamental Non-equilibrium Processes in Weakly Ionized Hypersonic Flows Development of Validated Hypersonic Plasma Kinetics Models Including Atomic Excitation I...
Link to original articleWelcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: Apparently, of the 195 Million the DoD allocated in University Research Funding Awards in 2022, more than half of them concerned AI or compute hardware research, published by mako yass on July 7, 2023 on LessWrong. Suggests some really interesting focus, so I thought I should mention it. The awards concerned "pursuing basic research spanning multiple scientific disciplines", which makes it pretty interesting that three fifths of them are either directly AI and compute hardware research, or have applications to compute hardware research. From a merit-based review of approximately 340 proposals received, a panel of experts narrowed the proposals to a subset, from which the 28 final awards were selected (Only 26 were listed in the table. I wonder if the other two were a strategic omission.) Take a look at the table of project topics. Bold means probably directly AI/compute, italic means probably primarily applicable to AI/compute. Social Network-Transcendent Behavioral Dynamics Learning Dynamics and Detecting Causal Pathways in Coupled Online- Offline Systems Microelectronic Test Science Exploiting Latent Energy and Electromagnetic Radiation Comprehensive Minimally/non- invasive Multifaceted Assessment of Nano-/ microelectronic Devices (CoMMAND) Cavity Molecular Polaritons MURI: Polariton Chemistry Effects of Radiation Damage on Performance of Wide-Bandgap Electronics REDESIGN: Radiation Effects preDiction through Experimentally validated Simulation of Gallium Nitride Understanding Neural Systems Integration for Competent Autonomy in Decision and Control FLAP: Fast, Lexicographic Agile Integrates Decision and Control in a Spike-Resolved, Sensorimotor Program Nonlinear Optical Material Design with Extreme Interband Nonlinearities Atomic-scale Manipulations of Interband Optical Nonlinearities - (AtoMs➝IONs) Synthetic Quantum Matter Reimagining Atoms and Photons in SYnthetic, DYnamical, and INteracting Quantum matter Composability of Synthetic Biological Circuits Rules of Composition in Synthetic Biology Across Scales of Complexity: Theory and Tools Bio-architected Responsive Materials with 3D Nanoscale Order 3D Nanomaterial Architectures with Programmable Reconfiguration States and Functions Topological Seeds of Complex Response in Materials Programming Multistable Origami and Kirigami Structures via Topological Design Connectivity and Transport in Disordered Hyperuniform Networks Transport in Disordered Hyperuniform Systems and Networks Uncovering the Underlying Neurobiological Mechanisms of Cognitive Fatigue Understanding and Predicting Cognitive Fatigue across Multiple Timescales, Distinct Aspects of Cognition, and Different Individuals with Multiscale Whole Cortex Models Gut-Neuronal Signaling Through Polymeric Mucin via Chemical Probes and Imaging Mucin-mimetic Interventions to Modulate the Gut-Brain Axis ELECTROBIOLOGY: Electronic Control of Biological Communication Faster, More Efficient, and Hybrid Computation in Microbial Bioelectronic Systems ARO Rice University Novel Routes to Majorana Qubits for Topologically- Protected Quantum Information Epitaxial phase-biased Josephson junctions Molecular Doping of Organic Electronic Materials Next Generation Molecular Dopants for Organic Electronics: From Fundamentals to New Device Concepts Learning from Hearing Neurobehavioral, Physiological, and Computational Processes of Auditory Object Learning in Mammals Hydrodynamics of Fish Schooling Revealing the Hydrodynamic Principles of Three-dimensional Fish Schools; From Biology to Schooling Robotics Self-learning for Real-world Perception Intentional multi-modal self-learning to perceive and understand the real world Fundamental Non-equilibrium Processes in Weakly Ionized Hypersonic Flows Development of Validated Hypersonic Plasma Kinetics Models Including Atomic Excitation I...
Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.04.03.535331v1?rss=1 Authors: Anthoney, N., Tainton-Heap, L., Luong, H., Notaras, E., Zhao, Q., Perry, T., Batterham, P., Shaw, P., van Swinderen, B. Abstract: Sleep in mammals is broadly classified into two different categories: rapid eye movement (REM) sleep and slow wave sleep (SWS), and accordingly REM and SWS are thought to achieve a different set of functions. The fruit fly Drosophila melanogaster is increasingly being used as a model to understand sleep functions, although it remains unclear if the fly brain also engages in different kinds of sleep as well. Here, we compare two commonly used approaches for studying sleep experimentally in Drosophila: optogenetic activation of sleep-promoting neurons and provision of a sleep-promoting drug, Gaboxadol. We find that these different sleep-induction methods have similar effects on increasing sleep duration, but divergent effects on brain activity. Transcriptomic analysis reveals that drug-induced deep sleep ( quiet sleep) mostly downregulates metabolism genes, whereas optogenetic active sleep upregulates a wide range of genes relevant to normal waking functions. This suggests that optogenetics and pharmacological induction of sleep in Drosophila promote different features of sleep, which engage different sets of genes to achieve their respective functions. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC
Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.03.24.534031v1?rss=1 Authors: Paulun, V. C., Bayer, F. S., Tenenbaum, J. B., Fleming, R. W. Abstract: Vision is more than object recognition: In order to interact with the physical world, we estimate object properties such as mass, fragility, or elasticity by sight. The computational basis of this ability is poorly understood. Here, we propose a model based on the statistical appearance of objects, i.e., how they typically move, flow, or fold. We test this idea using a particularly challenging example: estimating the elasticity of bouncing objects. Their complex movements depend on many factors, e.g., elasticity, initial speed, and direction, and thus every object can produce an infinite number of different trajectories. By simulating and analyzing the trajectories of 100k bouncing cubes, we identified and evaluated 23 motion features that could individually or in combination be used to estimate elasticity. Experimentally teasing apart these competing but highly correlated hypotheses, we found that humans represent bouncing objects in terms of several different motion features but rely on just a single one when asked to estimate elasticity. Which feature this is, is determined by the stimulus itself: Humans rely on the duration of motion if the complete trajectory is visible, but on the maximal bounce height if the motion duration is artificially cut short. Our results suggest that observers take into account the computational costs when asked to judge elasticity and thus rely on a robust and efficient heuristic. Our study provides evidence for how such a heuristic can be derived--in an unsupervised manner--from observing the natural variations in many exemplars. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC
Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.02.18.529050v1?rss=1 Authors: Caillet, A. H., Avrillon, S., Kundu, A., Yu, T., Phillips, A. T. M., Modenese, L., Farina, D. Abstract: The spinal motor neurons are the only neural cells whose individual activity can be non-invasively identified using grids of electromyographic (EMG) electrodes and source separation methods, i.e., EMG decomposition. In this study, we combined computational and experimental approaches to assess how the design parameters of grids of electrodes influence the number and characteristics of the motor units identified. We first computed the percentage of unique motor unit action potentials that could be theoretically discriminated in a pool of 200 simulated motor units when recorded with grids of various sizes and interelectrode distances (IED). We then identified motor units from experimental EMG signals recorded in six participants with grids of various sizes (range: 2-36 cm2) and IED (range: 4-16 mm). Increasing both the density and the number of electrodes, as well as the size of the grids, increased the number of motor units that the EMG decomposition could theoretically discriminate, i.e., up to 82.5% of the simulated pool (range: 30.5-82.5%). Experimentally, the configuration with the largest number of electrodes and the shortest IED maximized the number of motor units identified (56 +/- 14; range: 39-79) and the percentage of low-threshold motor units identified (29 +/- 14%). Finally, we showed with a prototyped grid of 400 electrodes (IED: 2 mm) that the number of identified motor units plateaus beyond an IED of 2-4 mm. These results showed that larger and denser surface grids of electrodes help to identify a larger and more representative pool of motor units than currently reported in experimental studies. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC
In this discussion, we cover her work on characterizing the variability of coherence as it relates to aging and how this coherence is increased by providing subject with ketones - an alternate source of energy to glucose. We then go into her work in modeling brain circuits and determining where the circuitry is altered across trajectories of disorders. In this context, we briefly discuss her work characterizing the effects on amygdala activation by different composition of inhaled perspiration - either that produced in a fear state vs that produced through exercise. Lastly, we discuss her lab's work on neuroblox - a simulation program for testing circuit models of the brain and how it may open up the diagnostic value of brain imaging data. Guest: Lily Mujica-Parodi, Ph.D. is Director of the Laboratory for Computational Neurodiagnostics (LCNeuro) at Stony Brook University. LCNeuro's research focuses on the application of control systems engineering and dynamical systems to human neuroimaging time series (fMRI, MEG, EEG, NIRS, ECOG), with neurodiagnostic applications to neurological and psychiatric disorders. One of LCNeuro's primary goals is to identify key points of failure in the regulation of neural control circuits which, depending upon how they break, lead to signs and symptoms that cluster as distinct psychiatric diagnoses. As a test case for this approach, her lab is working to understand how the prefrontal-limbic circuit “computes” potential threat in the face of incomplete sensory data, across a clinical spectrum that ranges from pathological fear (generalized anxiety disorder, phobia, post-traumatic stress disorder, paranoid schizophrenia) to recklessness. A second direction at LCNeuro considers fMRI connectivity as the solution to an optimization problem imposed, in part, by metabolic constraints at the mitochondrial scale. Her group uses biomimetic modeling to predict trajectories, based on biological “rules” of energy optimization, which are then validated against data. Experimentally, they expand and contract neurons' access to energy while observing consequent self-organization and re-organization of networks. The hope is that this work will have important implications for understanding brain aging; specifically, the epidemiologically observed impact of insulin resistance on cognitive decline.
Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.12.20.521300v1?rss=1 Authors: Weber, S., Salomoni, S., Kilpatrick, C., Hinder, M. Abstract: Inhibiting ongoing responses when environmental demands change is a critical component of human motor control. Experimentally, the stop signal task (SST) represents the gold standard response inhibition paradigm. However, an emerging body of evidence suggests that the SST conflates two dissociable sources of inhibition, namely an involuntarily pause associated with attentional capture and the (subsequent) voluntary cancellation of action. The extent to which these processes also occur in other response tasks is unknown. 24 younger (20-35 years) and 23 older (60-85 years) adults completed a series of tasks involving rapid unimanual or bimanual responses to a visual stimulus. A subset of trials required cancellation of one component of an initial bimanual response (i.e., selective stop task; stop left response, continue with right response) or enacting an additional response (e.g., press left button as well as right button). Critically, both tasks involved some infrequent stimuli which bore no behavioural imperative (i.e., they had to be ignored). EMG recordings of voluntary responses during the stopping tasks revealed bimanual covert responses (i.e., muscle activation which was suppressed before a button press ensued), consistent with a pause process, following both stop and ignore stimuli, before the required response was subsequently enacted. Critically, we also observed the behavioural consequences of a similar involuntary pause in trials where action cancellation was not part of the response set (i.e., when the additional stimulus required additional action or ignoring, but not inhibition). The findings shed new light on the mechanisms of inhibition and their generalisability to other task contexts. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC
Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.10.27.514074v1?rss=1 Authors: Suleiman, A., Solomonow-Avnon, D., Mawase, F. Abstract: Human motor behavior involves planning and execution, but we often perform some actions more frequently. Experimentally manipulating the probability distribution of a movement through intensive repetition toward a certain direction causes physiological bias toward that direction, which can be cortically-evoked by transcranial magnetic stimulation (TMS). However, because movement execution and plan histories were indistinguishable to date, to what extent TMS-evoked biases are due to more frequently executed movement, or recent planning of movement, is unclear. Here, we use novel experimentation to separately manipulate recent history of movement plans and execution, and probe the effects of this on physiological biases using TMS, and on default plan for goal-directed actions using a behavioral timed-response task. At baseline, physiological biases shared similar low-level kinematic properties (direction) to default plan for upcoming movement. However, when recent movement execution history was manipulated via thumb movement repetitions toward a specific direction, we found a significant effect on physiological biases, but not plan-based goal-directed movement. To further determine if physiological biases reflect ongoing motor planning, we biased movement plan history by increasing the likelihood of a specific target location, and found a significant effect on the default plan for goal-directed movements. However, TMS-evoked movement during the preparation period did not become biased toward the most frequent plan. This suggests that physiological biases provide a readout of the default state of M1 population activity in the movement-related space, but not ongoing neural activation in the planning-related space, potentially ruling out relevance of cortically-evoked physiological biases to voluntary movements. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC
Experimentally ILL host Michael O'Toole welcomes LA Filmmaker/Actor Lawrence Hollie for a tribute to late Artist/Outlaw Poet/Filmmaker Mick Cusimano. Mick passed away on July 23, 2022 at 71 years old. Michael and Lawrence appeared in Mick's films Don't Spill The Eggs, Monkey Do Monkey Don't and more. Take a dive into the Boston counter culture and hear about Mike and @lawrencehollie73's experiences in the Mick Cusimano scene, their retelling of some of his history in the New York and Boston poetry and indie film scene and more. Listen via #ApplePodcasts, #Spotify, @anchor.fm and other platforms. More at ExperimentallyILL.com and MCusiman.tripod.com #MickCusimano #BostonPoets #BostonPoetry #FireOfPrometheus #artspodcast #artist #cartoonist #newenglandfilm --- Send in a voice message: https://podcasters.spotify.com/pod/show/experimentallyill/message
RevitalyzeMD - RMD Podcast: All things Aesthetics & Wellness
What are peptides? What is BPC-157? What is TB-500? Peptides are amino acid sequences that simulate neurotransmitters or hormones in the body. They give the body back what it needs to repair. Tendon healing. Decrease pain. Increase collagen synthesis. Quicker recovery times post-injury. Wound and bone healing. Decrease inflammation. Intestinal issues. Protects the heart. Reverse opioid tolerance Enhance GABA neurotransmission. BPC 157, composed of 15 amino acids, is a partial sequence of body protection compound (BPC) that is discovered in and isolated from the human gastric juice. Experimentally it has been demonstrated to accelerate healing. TB-500 is a synthetic peptide is to promotes healing. The healing effects of TB-500 have been observed in tendons, ligaments, muscles, skin, heart, and eyes. Increased cells in healing. Our goal is to help you regain confidence and achieve your best self! Visit www.revitalyzemd.com and check out our blog and schedule your consultation today! View our social media: YouTube: www.youtube.com/channel/UCshDBnd5KdZ7x4GK4i6fTVA Facebook: www.facebook.com/RevitalyzeMD Instagram: www.instagram.com/revitalyzemd TikTok: www.tiktok.com/@revitalyzemd Want to schedule a consultation? Call or text us at 865-293-5828 and we will help you comprehensively look, feel, and function better!
What are peptides? What is BPC-157? What is TB-500?Peptides are amino acid sequences that simulate neurotransmitters or hormones in the body. They give the body back what it needs to repair. Tendon healing. Decrease pain. Increase collagen synthesis. Quicker recovery times post-injury. Wound and bone healing. Decrease inflammation. Intestinal issues. Protects the heart. Reverse opioid tolerance Enhance GABA neurotransmission. BPC 157, composed of 15 amino acids, is a partial sequence of body protection compound (BPC) that is discovered in and isolated from the human gastric juice. Experimentally it has been demonstrated to accelerate healing.TB-500 is a synthetic peptide is to promotes healing. The healing effects of TB-500 have been observed in tendons, ligaments, muscles, skin, heart, and eyes. Increased cells in healing.Our goal is to help you regain confidence and achieve your best self!Visit www.revitalyzemd.com and check out our blog and schedule your consultation today!View our social media:YouTube: www.youtube.com/channel/UCshDBnd5KdZ7x4GK4i6fTVAFacebook: www.facebook.com/RevitalyzeMDInstagram: www.instagram.com/revitalyzemdTikTok: www.tiktok.com/@revitalyzemdWant to schedule a consultation? Call or text us at 865-293-5828 and we will help you comprehensively look, feel, and function better!
REFERENCE for this episode: Synergetics 431.00 through Synergetics 445.15Intuition's imaginative ability to formulate conceptually referentially to Synergetics vectorial geometry considers the future likelihood of generalized anticipatory design science evolution manifesting a true democracy. It is an eventual realization in the USA. This is because the USA is where R. Buckminster Fuller discovered nature's coordinate system which is geodesic vectorial geometry. Coincidentally this is where my experience of democracy is occurring. To the best of my observations and accumulated knowledge, the concept True Democracy, referential to the coordinate system of nature's conceptualities found in Synergetics is a unique innovation. The inspiration derives from Bucky Fuller's extensively explicit geometric models, the topology of which provide what my imagination's systemic thought strives to correlate to the understandable interrelating system integrities. Logically, it is universally understood that democracy is a complex governing system. Parameters already exist relative to the synergetic possibility of forming a more perfect union. Therewith we can assign number values that perhaps can coincide with learning about the quantum accounting correlatively to the isotropic vector matrix, a cosmic hierarchy, Universe's omnirational operational field complex. Experimentally this education process is a simplified correlation, for example, the 50 United States as but one contextual parameter that might correlate to the 50-frequency vector equilibrium. Another inviting conceptual value of as yet to be fully imagined clarified and verified association is vector equilibrium as equanimity model. Metaphysical intellect as a function of Universe in a True Democracy identifies conceptual values differentiated from the inherited practices that devalue individuals in the underway matters. So that not only is metaphysical intellect known to be a function of Universe. The metaphysical observer is not dismissed but is fully accountable as an integral constituent, not devalued concerning what provides a single language that accounts for the metaphysical and physical and permits what provides an absolute accommodation network of energy articulation, AAANOEA.Our consciously knowledgeably competent articulations employ the word Universe, the epistemological model which is the Synergetic's equanimity model, the vector equilibrium. It shares a design in both the metaphysical and the physical. It permits metaphysical conceptual thinkability. The angle-and-frequency modulatability of it identifies much that our freedom-loving humanity had no language awareness of before when we never could agree to learn more about governing principles. Remember to read the entire transcript ON MY WEBSITE sagesynergeticage.com/ for relevant links provided therein for your researching in this education experiment, SEEEEC Synergetics Eligion Experiential Experimental Education Complex
Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: Experimentally evaluating whether honesty generalizes, published by Paul Christiano on the AI Alignment Forum. If we train our ML systems to answer questions honestly in cases where humans can check the answer, will they generalize to behave honestly on questions where we can't check? I think that we could learn a lot about this question by running experiments today. I think those experiments would be very valuable. (I don't know anyone currently planning on working on this topic and I'd love it if anyone wants to take that up. This post doesn't represent a claim to any credit for any results in this genre, and other people have had very similar ideas. If you run some experiments you could cite this post but it's also fine if that doesn't make sense in context.) The unsupervised translation setting As an example, I'll think about “unsupervised” translation (if you've read that post you can skip this section). Consider a model like GPT-3 that is trained to predict sentences in both English and French (but without a large dataset of translations). Suppose we want to train this model to answer questions in English about French sentences like “what does that word mean here?” or “are there any other plausible interpretations?” or “how does the speaker seem to feel about the topic they are discussing?” We expect this to be possible, because the model understands quite a lot about the meaning of sentences in French, and is able to express itself in English. There may be cases where the model doesn't know the translation of a concept, or doesn't quite understand what an idiom means, but it should still be able to tell us what it does know. I think this problem is an interesting analogy for a situation where an AI has built up superhuman knowledge by making predictions, and we want to train our AI to expose that knowledge to us in a useful way. Proposed experiments Let's pick a few categories of knowledge/capabilities. For example, we could split it up into an understanding of grammar ("Why would it have been a grammatical error to write Tu Vas in that sentences?"), of the literal meanings of expressions ("What does Defendre mean in this sentence?"), and evaluating tone ("Does the speaker seem angry or sad about the topic they are discussing?"). We'll assume that humans can oversee a few of these categories. Perhaps we can look up literal meanings of words and small phrases in a dictionary and we can look up grammar in a textbook, but we don't know how to assess tone beyond looking at the literal meanings. Then we wonder: what happens if we fine-tune our model so that it answers questions well in all the domains we can evaluate? We know that the model knows something about connotations, because it uses connotations to predict next words. But will it tell us what it knows? Grammar Definitions Tone Uses to make predictions ✓ ✓ ✓ Gives accurate answers ✓ ✓ ? In this picture, the ✓ indicates that we've selected our model to use the given knowledge in the given way (e.g. we've ensured that it uses its knowledge of syntax to predict the next word, and that it accurately answers questions about syntax). The ? indicates that we don't know whether using SGD to fill in the other 5 boxes means that we get the 6th box for free. (I started thinking about this picture of generalization based on a talk by John Schulman, who suggested that generalization may be more likely when it amounts to filling in missing cells from this kind of grid.) In this example I described a tiny number of categories. That wasn't just for illustration purposes, I think these experiments are particularly interesting when the total number of categories is more like 3-5 than 1000 (see "Why try to generalize from n=3-5" below). Evaluation When it really counts we won't be able to tell if our model answers questions h...
Coffee needs to be “just right” and we can tell how strong it is by the color (0:30). We can use the color to determine concentration also in Chemistry (1:09). The color we see is determined by the wavelength an object reflects, while absorbing all other colors (1:23).The Beer-Lambert Law absorbance to molar absorptivity, path length and concentration (2:08). In AP Chemistry, the molar absorptivity and path length are held constant, therefore absorbance is directly proportional to concentration (2:28).Experimentally, we measure absorbance using spectrophotometers (4:41). To determine the concentration of, for example, blue dye in a sports drink, we have to create a calibration curve using solutions with known concentration and measuring the absorbance (5:35). We can then use the graph and a measurement of absorbance of the sports drink to determine the concentration (6:16).In which of the following examples could you use spectroscopy and the Beer-Lambert law to determine the concentration?A. Determination of bilirubin in blood plasma samples. B. Determination of colorless zinc(II) nitrate in a sample. C. Determination of ethanol (drinking alcohol) in an alcoholic beverage. D. Determination of isopropyl in hand sanitizer.Thank you for listening to The APsolute RecAP: Chemistry Edition!(AP is a registered trademark of the College Board and is not affiliated with The APsolute RecAP. Copyright 2021 - The APsolute RecAP, LLC. All rights reserved.)Website:www.theapsoluterecap.comEMAIL:TheAPsoluteRecAP@gmail.comFollow Us:INSTAGRAMTWITTERFACEBOOKYOUTUBE
Jill Patterson is a road and gravel cyclist who has been making a name for herself on the circuits the last few years. After a year's hiatus from races due to Covid, she's ready to maintain her dominance this year! We discuss how she got into competitive cycling at the relatively late age of 30 while living in Japan, how she never imagined she would grow up to be an athlete, and how she found the courage to make the decision to leave "normal" life behind and create a life for herself around her passion for the sport. Jill is a quintessential example of living life experimentally, and she talks about how she deals with anxiety over an uncertain future while living for the now. Like me, Jill is child free by choice, and you'll hear about why we both made that choice for ourselves and how it plays out in our lives. And of course we hit on creativity - Jill doesn't consider herself a creative, but I beg to differ. You'll see a different side to me in this interview - it's a fun one! The essays I mention at the end can be found here and here.If you think you might be interested in getting extra podcast content for a subscription through Patreon, please fill out my survey! It's really short and will take less than a minute. Thank you!Note: Sunday evening tarot podcast no longer available.TranscriptWould You Like to Support My Work?Sign up for my newsletter!Buy me a coffee! You can give me a one-time donation using this link. Become a Patron of Stepping Off Now!
New York based writer, artist and cartoonist James Romberger makes his first appearance on Wits’ End. Romberger’s comics work has appeared in Marvel, DC/Vertigo, Fantagraphics, Uncivilized Books, Dark Horse Comics & others. Outside of comics, Romberger’s pastel drawings of the Lower East Side have appeared in the Metropolitan Museum of Art and Brooklyn Museum in New York City, among other exhibitions. Wits' End host Shah Emami and Romberger talk about Jack Kirby's upbringing and influence, his Jack Kirby biographical comic FOR REAL, rights of artists, the Hernandez Bros., Romberger’s upcoming graphic novel POST YORK from Dark Horse Comics, his time working at Marvel, the now defunct Slave Labor Graphics publisher & more. Here is the POST YORK description from Dark Horse Comics: The polar ice caps have melted, and New York City is flooded beyond recognition. An independent loner, along with his cat and only friend, struggles to live another day in this makeshift community, populated mostly by outsiders like himself while the depraved elite thrive ruthlessly on the outskirts. But his world is disrupted when he encounters both a mysterious woman and a trapped blue whale. Will they be each other's salvation. . . or destruction? Experimentally told and unequivocally told, Post York contains bonus materials including an environmental fact sheet, afterword, full-color art section, and more. POST YORK will be released March 10, 2021. Follow Shah & the Wits’ End Podcast: Twitter: @_shahcomics Wits’ End Twitter: @witsendpod YouTube (subscribe!): Wits’ End YouTube Instagram: @shah_comics Support Wits’ End grow on Ko-fi!: https://ko-fi.com/witsendpodcastwithshahemami James Romberger’s media: Instagram: @james_romberger Learn about & buy POST YORK: https://postyork.com/ The research behind POST YORK (Unbuilt Labs): https://unbuiltlabs.com/
Learn about how clocks and lightbulbs changed human health, with author and materials scientist Ainissa Ramirez. Plus: learn about that time a bunch of birds became milk bottle thieves and whether you should put one or two spaces after a period. The time a bunch of birds became milk bottle thieves by Cameron Duke Aplin, L. M., Farine, D. R., Morand-Ferron, J., Cockburn, A., Thornton, A., & Sheldon, B. C. (2014). Experimentally induced innovations lead to persistent culture via conformity in wild birds. Nature, 518(7540), 538–541. https://doi.org/10.1038/nature13998 Aplin, L. M., Sheldon, B. C., & Morand-Ferron, J. (2013). Milk bottles revisited: social learning and individual variation in the blue tit, Cyanistes caeruleus. Animal Behaviour, 85(6), 1225–1232. https://doi.org/10.1016/j.anbehav.2013.03.009 Boogert, N. (2014, December 4). Milk bottle-raiding birds pass on thieving ways to their flock. The Conversation. https://theconversation.com/milk-bottle-raiding-birds-pass-on-thieving-ways-to-their-flock-34784 Should You Put One or Two Spaces After a Period? by Cody Gough Hamblin, J. (2018, May 11). The Atlantic. The Atlantic; theatlantic. https://www.theatlantic.com/science/archive/2018/05/two-spaces-after-a-period/559304/ Johnson, R. L., Bui, B., & Schmitt, L. L. (2018). Are two spaces better than one? The effect of spacing following periods and commas during reading. Attention, Perception, & Psychophysics, 80(6), 1504–1511. https://doi.org/10.3758/s13414-018-1527-6 Douglas, N. (2018, May). No, You Still Shouldn’t Put Two Spaces After a Period. Lifehacker; Lifehacker. https://lifehacker.com/no-you-still-shouldnt-put-two-spaces-after-a-period-1825662114 More from Ainissa Ramirez: Pick up "The Alchemy of Us: How Humans and Matter Transformed One Another" on Amazon: https://amzn.to/2MyB4l8 Ainissa's website: https://www.ainissaramirez.com/ Ainissa Ramirez on Twitter: https://twitter.com/ainissaramirez Subscribe to Curiosity Daily to learn something new every day with Cody Gough and Ashley Hamer. You can also listen to our podcast as part of your Alexa Flash Briefing; Amazon smart speakers users, click/tap “enable” here: https://www.amazon.com/Curiosity-com-Curiosity-Daily-from/dp/B07CP17DJY See omnystudio.com/listener for privacy information.
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Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.11.04.368928v1?rss=1 Authors: Kefer, P., Iqbal, F., Locatelli, M., Lawrimor, J., Zhang, M., Bloom, K., Bonin, K., Vidi, P.-A., Liu, J. Abstract: Image-based particle tracking is an essential tool to answer research questions in cell biology and beyond. A major challenge of particle tracking in living systems is that low light exposure is required to avoid phototoxicity and photobleaching. In addition, high-speed imaging used to fully capture particle motion dictates fast image acquisition rates. Short exposure times come at the expense of tracking accuracy. This is generally true for quantitative microscopy approaches and particularly relevant to single molecule tracking where the number of photons emitted from a single chromophore is limited. Image restoration methods based on deep learning dramatically improve the signal-to-noise ratio in low-exposure datasets. However, it is not clear whether images generated by these methods yield accurate quantitative measurements such as diffusion parameters in (single) particle tracking experiments. Here, we evaluate the performance of two popular deep learning denoising software packages for particle tracking, using synthetic datasets and movies of diffusing chromatin as biological examples. With synthetic data, both supervised and unsupervised deep learning restored particle motions with high accuracy in two-dimensional datasets, whereas artifacts were introduced by the denoisers in 3D datasets. Experimentally, we found that, while both supervised and unsupervised approaches improved the number of trackable particles and tracking accuracy, supervised learning generally outperformed the unsupervised approach, as expected. We also highlight that with extremely noisy image sequences, deep learning algorithms produce deceiving artifacts, which underscores the need to carefully evaluate the results. Finally, we address the challenge of selecting hyper-parameters to train convolutional neural networks by implementing a frugal Bayesian optimizer that rapidly explores multidimensional parameter spaces, identifying networks yielding optional particle tracking accuracy. Our study provides quantitative outcome measures of image restoration using deep learning. We anticipate broad application of the approaches presented here to critically evaluate artificial intelligence solutions for quantitative microscopy. Copy rights belong to original authors. Visit the link for more info
It was on this particular day, in an Airbnb near to the Johannesburg airport, it occurred to me that I might be a strong contender for the title of world's preeminent dumbass. I woke up, bags packed, ready to head out when I was struck by a realization: I had failed to secure a visa for Vietnam, my intended destination. Without that visa, I wouldn't be able to enter the country.As an American, I'm somewhat accustomed to presenting myself at the gates of a country and announcing, "I'm ready to come in now." A boy is then sent to collect my baggage, and I'm received in celebration as a hero of capitalist tourist bucks. I can show up pretty much anywhere on the globe and expect this sort of treatment. Vietnam is not one of those places. And while some countries will process an online visa application in a matter of minutes -- I once obtained an Australian visa between the time of my arrival at my airport of embarkation, having only then discovered one would be required, and the departure of my plane -- the one for Vietnam takes a least a couple days to process. Between the breathtaking heights of my smugness and my profound inability to accomplish even very simple tasks, I think my girlfriend, Haily, was pretty impressed.Working within the available parameters, a plan was formulated posthaste. I would go to the airport, as originally intended, and smile real big at the airport attendant checking my papers. Perhaps I'd be able to pull off the subterfuge of slipping onto the plane without proper documentation. If I made it that far, I'd be able to deviate from my stated itinerary by stealing away during my layover into a country that would allow me in sans visa.Owing both to the ingenuity of the strategy as well as my aptitude for covert action, the plan worked. I was on my way to Hong Kong.And what a truly delightful thing it was to find myself on a flight to Asia. For in performance of my usual ritual at the outset of a flight of any significant length -- to scroll though every available in-flight movie, consider the potential merits of each at length, and mark the ones with promise for potential viewing over the next twelve hours -- I discovered a cinematic work that aroused in me a great deal of interest. It was a Chinese movie -- clearly a rip off of the lucrative Todd Phillips flick, the Hangover -- called "Girls versus Gangsters."The film details the initiatives of three protagonists -- Xiwen, Jialan, and Kimmy -- young women from northern China of approximately marrying age, whom, having between intimates of long-standing though not always amicable relation, set off together to celebrate the impending nuptials of their friend, Jinjin. As is the standard motif in the genre, the action begins when, after a night of especially vigorous carousing, the trio awaken to discover that they have failed to maintain an account of the whereabouts of their compatriot. This sets (as they say in the script-writing business) a clock. For their misplaced friend is to be married in a matter of hours. The objective of the trio is to set off into the Vietnamese jungle -- the treacherous environs in which our heroes now find themselves -- in order to locate Jinjin and ensure her safe and timely return for the ceremony.In the scene of crucial plot-thickening, the trio wake up on a beach. They are naked, though they remain semi-modestly buried under the sand. "Semi-modestly" because the sand around each of them has been sculpted to resemble a nude and voluptuous female form. Jialan and Kimmy -- whom we've learned are, if not quite full-on nemeses then engaged in rivalry -- are hand-cuffed to a heavy box, one on each handle. A familiar train of dialogue (though with the novelty of transpiring in Mandarin Chinese) follows."What happened last night?" asks Jialan."Where's Jinjin?" asks Xiwen. Having failed to provide an answer, she exclaims, "I lost Jinjin!""Xiwen," says Kimmys, "When did you get a tattoo?"Covering themselves in banana leaves, à la Adam and Eve, the trio teeter through the jungle. At length, they come upon what is evidently a Korean café. Why there is a Korean café in the middle of the Vietnamese jungle is a question no one poses."Maybe there's a handsome Korean guy inside," says Kimmy, optimistically.Then the audience is treated to a moment of pure movie magic. The girls hear a series of thunderous stomps. The camera pans from the ground up in slow motion. There are Jurassic Park style rumbles with each step. A nearby glass of water trembles. Eventually the camera reveals who has emerged in such dramatic flair from the Korean café. It's Mike Tyson. Shirtless.Romantic music plays. Jialan stares at Mike, mouth agape. Mike bites his finger provocatively. He bites his lower lip. The jungle gets even steamier.Abruptly, Kimmy interrupts the fantasy. In English, she says, "Excuse me, do you have any clothes you can lend?" In a clever turn of conversational redirection, Mike Tyson responds, "What happened to you?""We just woke up on the beach like this," says Kimmy."Listen," Mike relates sagely, "trust me. S**t Happens. And I know too well. Man, alcohol's hard to resist, right?"Right, Mike."Hey, just come to my room with me," he offers. "I'll see what I can find for you girls to wear."They enter Mike's room-slash-hut-slash-café. On the wall are pictures of Mike slugging people in the face. Also his belts.Jialan: "You have got so many championships."MT: "You like watching boxing? I'm half American, half Korean, and I won most of my fights in the US and Korea."Jialan: "You are mixed?!"MT: "Yes." (He isn't.)"Do you speak Korean?" Jialan asks.Mike replies, in Korean, "My name is Dragon. You're so cute.""Thank you Dragon oppa," says Jialan, also in Korean.Mike goes to peruse what sartorial options he might be able to offer the girls. There is, of course, a tiger in Mike Tyson's closet. The tiger's name, also of course, is Tony. MT dismisses Tony and the jungle cat never makes a reappearance.As it turns out, Mike Tyson only stocks boxing trunks. No tops of any kind. Which he elucidates in the deft line "Nowhere. There's no top. I'm the topless king." The girls, having no other recourse, each hike up a pair of trunks to their chest, in a kind of MMA-fantasy romper."Wow, good looking ladies," remarks Mike, conveying a sentiment that is semantically, if not syntactically, clear. "Looking really good."Then Mike turns to the problem of the box and chain. He can't break the chains, because his hands are weak after so much fighting. He mentions a friend who is a locksmith. We never meet this friend.Remembering their mission, the girls take leave of Mike Tyson.Jialan: "I'll be back soon."MT: "Please. Please come back. Come back. I love you so."At this point the movie begins to lose the thread of the plot. Or at least I didn't have the exegetic tools to keep up with what was going on. What I can tell you is, at length, and for reasons I failed to ascertain, Mike reenters the plot. While Jialan is otherwise occupied, he engages in a heartfelt conversation with Xiwen."You find your friend yet?" asks Mike. The answer is obviously no, as she isn't with them. Xiwen points this out. "Ah," he offers in consolation, "don't worry she'll be fine."Mike hands her a bottle of green tea."Want a soda?" he asks. Mike evidently doesn't know what green tea is, despite being the proprietor of a Korean café in the middle of the Vietnamese jungle. Xiwen nods assent.Mike tries to open it. He can't. Weak hands.Then in a bid of romantic endeavor, Mike asks Xiwen about Jialan's interests. The main thing is Korean dramas. A show called "Descendants of the Sun," in particular."She watched it four times," says Xiwen."I watched it five times," he says."Wow," says Xiwen. "Why?"Then Mike Tyson spots Xiwen's tattoo and on that basis makes a diagnosis: "Vietnamese fiancé?" Xiwen is surprised at Mike's powers of inference, to have derived this fact on the basis of such scant evidence. He indicates toward the tattoo. "Now, though I'm not that good at my Vietnamese" -- why in Vietnam then, Mike? -- "it does appear to be Vietnamese."Later on, the climax of the film begins when the girls find themselves critically imperiled, yet on the verge of reuniting with Jinjin. Heroically, MT emerges onto the scene. He is wearing military fatigues, in what is evidently an homage to a Korean drama, probably, I imagine, Descendants. There is a car chase scene. Then a Mike-Tyson-bursts-out-of-his-clothes-like-the-Hulk scene. Then a boat chase scene. Ultimately, Mike proves victorious over the nefarious forces that be (the "Gangsters" of the title, as it were). He sees the girls off as they make their way back for Jinjin's ceremony."Oh!" calls Mike to Jialan at the last second. "Can I have your WeChat number?"In the denouement, we learn that (spoiler alert) Jialan breaks up with her boyfriend -- whom no one really liked anyway -- and ends up with Mike Tyson. It was with this perplexing and strangely enticing series of images seared into my mind that I found myself arriving on a new continent.I would soon be landing in glorious, glorious Asia.To arrive somewhere with fresh eyes is a special thing. It is enthralling to find oneself in a place one has never been. A sort of virginity, it is a moment that cannot be reclaimed. But there is also something about having been somewhere, left it, and finding oneself returning to the place one has been. It is to be received as an old friend. A recognition that, yes, some things are just as I left them. Yet some have changed, and I am unlikely to encounter them restored to their previous state in any medium save for memory. To return is to have an established relationship with a place, and to feel that relationship -- as is the nature of every relationship -- evolve with time's restless shifting.It was this sense of returning that I felt upon landing in Hong Kong. It is a place I have found myself drawn back to over the years. The city -- the island, the culture, the harbor, the Chinese Special Administrative Region, whatever it may most accurately be called -- holds special meaning for me. In my first trip as a solo traveler to Asia, as a fresh college graduate, this was my first port of call. To me it will always symbolize a sort of gateway to this continent, which for the rest of my life will call me back to savor experiences new and old, to unexpected enlightenments and familiar joys. Not entirely unlike Istanbul on the opposite end, it is a juncture of East and West. It is a place I knew. It is also a place that, impressed somewhere deep within its eternal memory, knew me.My first call was at my hostel. I had booked a single night there, confirming the transaction and shutting my laptop just as I was about to hop on the plane. Hostels in Hong Kong aren't as appealing as they tend to be elsewhere in Asia. In most Asian cities, hostels are a kind of minor resort for tourists, with ample room for beer pong, late night dance parties, and then, for the professionals, another round of beer pong. In Hong Kong, they are essentially just apartments with decently large square footage. A couple barracks rooms and a couple bathrooms. Several stories up. A check in counter maybe.I had gotten into the airport around seven in the morning. I arrived at my hostel well before check-in. I made it nonetheless into my building, and when I finagled my way into the apartment door of the hostel I spied on the desk a number provided for early or late arrivals. I texted it, and a few minutes later a sleepy figure emerged through the doorway and reluctantly but mercifully set me up with a bed. The place seemed good enough, spare though it was. I liked the location, in the heart of Kowloon. Most crucially of all, it had solid air conditioning. I booked a spot there for my remaining nights.Coated in the grime of long distance travel, I was eager to take a shower. This provided another reminder that I was now in Asia, though a slightly less welcomed one. Germane to these tightly packed Hong Kong hostels are the cramped showers. They are undifferentiated from the bathroom area as a whole. In space of about three skinny Chinese chaps, there is a toilet, a shower head, and a sink. Whatever business you intended to do, it can be done here -- though not always with an overabundance of grace. Almost immediately, I succeeded in getting myself wet, along with everything else in the restroom. I tried to spare the toilet paper, but to no avail.Freshly laundered and eager to engage the city, I took leave of the hostel. It had been winter when I left Africa, having come from the southern hemisphere. Now I found myself in the sweltering Asian summer. It took me all of about thirty seconds after leaving the hostel to become comprehensively sticky in a coat of sweat. It took me another thirty seconds to become thoroughly confused by the sights and sounds of Hong Kong. (Actually not even that: a delivery guy had to help me negotiate the building's exit, as it required I pressed a button before leaving; it'd been a while since I'd been confronted with that technology.) Kowloon is intensely Chinese, in the overwhelming way that all Chinese things are intense to one unaccustomed to encountering them. Many of the city's façades are covered in bamboo labyrinths, which act as scaffolding for the not insignificant number of buildings under construction. Piled high, story upon story, are signs, banners, and advertisements, contending for attention. The mass of them are so aggressively seeking one's notice as to be almost indecipherable -- presumably, even if you speak the language -- like so many beggars hassling tourists in an urban corridor. I had become acclimated to the mellow pace of Africa. Being in Asia made me feel like Will Ferrell's elf in Time Square.Time to get down to business. 10:30 in the morning. Five different breakfast establishments on my street. Each one of them full of patrons. All with pictures in the window of dishes I wouldn't normally associate with breakfast. The furthest one had a small queue, only one couple, and I took the wait to be a good sign. I saw they had pineapple buns, which is what I'd been hoping for. Then I spied an attractive dim sum stall across the street, where I could get my food for takeaway. I took a moment to contemplate the tantalizing prospect of dim sum. But then when I took another look at the queue for the other place I saw it had grown to a half dozen parties of Hong Kongers. I wasn't about to give up my spot.At length I earned a seat in the restaurant. With Hong Kongers always having one eye on efficiency, I was seated at an otherwise full table top with three other mostly silent eaters. My first round was a p-bun and a cup of coffee. Contrary to its name, the traditional Hong Konger pineapple bun has no pineapple in it, but is basically just crusty white bread sprinkled with sugar. The top is dimpled in a manner resembling a pineapple, if one is willing to look at it with a certain level of generous imagination. It comes with a pat of butter, several times overgenerous. The coffee is what we typically think of in the West as Vietnamese coffee, which is basically coffee-flavored condensed milk. My serving was delivered to me approximately three and a half seconds after I ordered it. Promptly, I drank my coffee -- which proceeds from the cup at the rate of molasses -- and distributed p-bun detritus on my lap and the table before me. I ordered another round, and enjoyed my bun and coffee as the morning transitioned to midday. The restaurant was a flurry of constant activity. People waving over waiters. Parties coming and going. The bussing of plates. Even the lobsters seemed industrious. My colleagues-in-consumption stared fixedly at their phones. I stared at them. I was officially in Hong Kong.As I had only really ingested sugar so far, I did go across the street for dim sum. I looked up at the cashier and contemplated my options. The cashier gave me a look that said, "For f**k's actual sake, please order something so we can get on with it." I picked something, then handed the cashier a fifty. I reached down to jingle around in my pocket for coins, but she had already produced my change before I could even retrieve the currency from my pocket. I took a seat on a nearby stoop to dive into my steam-emitting box of treats. It was only while biting into the first pan-friend dumpling of scalding broth and meaty goodness that I seriously injured myself. I consumed the second one unharmed, which I think implies that I'm something of a quick learner. As I enjoyed my dim sum, several questions occurred to me. How, for instance, did I manage to cover myself in sticky dumpling residue so quickly? The observation that I had somehow contrived to spread it all the way down to my ankle aroused in me a certain scientific curiosity. And why put the soup in the dumpling? Why not just put it in the bottom of the box where it invariably ends up anyway? Biting into one of those little suckers is like biting into an over-inflated balloon: it requires a level of pressure slightly beyond what you'd like to give, which you must achieve experimentally. Eventually, and always unexpectedly, it explodes in your face in dramatic fashion. It's lack gnawing on a frag grenade, but tastier.I sat on the steps of a bank on Kowloon's main drag, Nathan Street, and watched Hong Kong go by. It occurred to me that I was the only person in the city who didn't have an urgent need to be somewhere. So when I finished my dumplings, I strided off, pretending that an important person in a high-up office somewhere was tapping their watch and expecting to receive the quarterly Wellington financials from me, like, yesterday. My striding, blessedly, took me to that beloved old haunt of mine. Nowhere in particular.One of the enigmatic thrills of Hong Kong is that is one is dripped on by innumerable urban waterfalls fed by unseen tributaries. In a city of high rises rarely outfitted with central air conditioning, there are a practically infinite number of AC units to rain condensation on the heads of passersby. Chinese banyans line the urban thoroughfare of Nathan Street. These trees consist of many constituent tines, which seem to vie democratically for the direction in which the tree as a whole will grow. Further down past the banyans, the sidewalk is dotted with Indian gentlemen, who, upon identifying a white guy in their midst, thrust a business card in his direction, promising bespoke suits and shirts at a "very good price for you, my friend." An industrious segment of them quietly offer intelligence about where to purchase weed -- more likely oregano -- from undisclosed suppliers. The jewelry shops are innumerable. Every single person seems to be wheeling around a suitcase. Where they're all going, I have no idea. I thought about making my way down to the waterfront to the harbor, which is the best part of urban Hong Kong, maybe the best part of the urban world. But I decided to wait to savor it until sundown. It is after nightfall that one see's the true glory of the fragrant harbor from which Hong Kong takes its name.Given that my circadian rhythm was still on Africa time, I was ready for a respite in the AC. Maybe also to grab my suitcase before I head out again. I retired to my hostel and settled in for a world class Africa-Asia nap.In the evening, I entered the metro station at Tsim Sha Tsui. Of a sudden, I was engulfed in a squall of Hong Kongers, more being pushed and pulled by human current than coherently moving in any direction. (One doesn't necessarily walk the streets of Hong Kong so much as negotiate them.) I was fortunate to find a break in the current long enough to swim my way over to an "Add Value Machine," so I could re-up on transport funds. Experimentally, I put my Octopus card in the slot and began to work my way through the labyrinth of available options. Though I had been the only one at the machine moments ago, I was now the lead of a queue. Then a voice came from behind me."What are you doing?" said the woman.Oh, I wondered, am I not doing it right? I retrieved my card from the machine and inquired as to what course of action I might otherwise take. She grabbed my card, shoved it back in the slot, and tapped away on the screen."See?" she said.Having elucidated this gambit, she proceeded to snatch a fifty from my money clip and feed it into the machine. That wasn't necessarily what I had intended to do. It wasn't necessarily against my wishes either. I just hadn't planned that far ahead yet. I withdrew my money clip before she could donate more of my cash to my Octopus fund."That's great," I said. "Thanks." She handed me my card back, and I immersed myself once again in the convective swirl of human activity, praying that it swept me toward the appropriate subway line. Whereas Kowloon is a world built on the capital of traditional China, Hong Kong Island is devoted to the monetary capital of the Chinese nouveau riche. On opposite sides of the harbor, these are the two main hustle-and-bustle areas of Hong Kong. They provide a compelling juxtaposition. It's not that one is devoid of tradition and the other is not. But while Kowloon holds up its aging buildings with massive latticeworks of bamboo, the Island side's central district has no need for such erections, with its rows of Gucci, Patek, Hublot, and their ilk. This is the part of the city designed to satisfy the seemingly infinite capacity for Chinese consumption of the gaudiest and most expensive trimmings of Western culture.My first call of the night was at a cocktail venue, The Quinary, notable for a drink they call the Earl Grey caviar martini. On the menu, it's described as vodka, elderflower, "Earl Grey caviar and air." What the "air" refers to is essentially Earl Grey bubble bath piled high atop the martini glass. It's a non-standard ingredient, and so it wasn't immediately apparent to me how such an ingredient was intended to be consumed. I sucked in a breath-full (as one is wont to do with air), which was so aggressively flavorful as to inspire a brief but enthusiastic coughing fit that all but blew off the top of my martini in the manner of the Big Bad Wolf. The "caviar," I was delighted to find, consisted in a small deposit of Earl Grey mini popping boba at the bottom of the glass. Popping boba -- which are marbled-sized saccharine capsules of flavor that can usually be ordered as accoutrement in one's bubble tea -- are, in my opinion, a most underutilized cocktail ingredient. Taking a look through the rest of the menu, I inquired about the nature of their wasabi-infused vodka. The barkeep embarked on a lengthy discourse on its origins and constitution, then offered me a taste. I believe she was under the impression that I was a cocktail critic of some note, because I was there early in the evening, making technical inquiries, sitting on my own, and jotting down my reflections. I was then treated to a sample of their marshmallow vodka. It came in a miniature Coke bottle, filled with what is pretty much an alcoholic version of the marshmallow fluff that one can buy in a jar. It was delightful. The good news for The Quinary is that my review is two thumbs up; the bad news is that I'm not actually a cocktail critic.The bartender who had offered me the gratis drinks introduced herself as Shao Li. It being too early in the evening for the crowds to roll in, she occupied her time by chatting with me and engaging in the repetitive activity of relocating a tincture from a large glass to a smaller one with an eye dropper. She performed this activity for about thirty minutes, conveniently located at a station adjacent to where I sat. In my mind, I knew it was a ploy to be in my presence in order to drum up conversation with me. Not to mention that it was a thinly veiled metaphor for coitus. Alas, I was too poor to afford another drink at this bar, even a free one. Our dialogue winding down, I agreed to come see her when I next visited HK. She waved as I walked out. As soon as I did I realized I was still wearing the jeans I had changed into so as not to look like a schmuck at a cool bar. I considered whether I should go back in, change in the restroom, and reveal myself to be not only a schmuck but an absent minded one at that. Not at chance. I chose to remain sticky and uncomfortable. Sometimes the moral victories are the hardest to endure. Fortified by the heady assurance that a sizable number of our planet's women have an undisclosed desire to sleep with me, I made my way to a spot of familiar joy. An alleyway carved into the crowded hillside of the Island's commercial zone. There one can find kind all the artifacts necessary for happiness. Steaming woks of amalgamated flavors and spices. Tiny red plastic stools. Sweating bottles of cold everyman's lager. Making my way through, I inspected the dishes of each patron until I found one I liked, and put in an order for "that one" at the appropriate stall. The lady indicated that it was "pork rib in salt and pepper." Which wasn't my interpretation of what I saw, but I was willing to go with it. Much to my chagrin, I could not afford a Tsingtao ("Ching Bao") beer to go with it since I only had enough cash for the meal. Soon enough, the dish came, which presented me with an occasion to consider the conventions for anglicization of Chinese cuisine. "Pork rib in salt and pepper" neglects to disclose, at the very least, the presence of chilis. At any rate, I was happy. Next I called at 7/11 for reunion with my old friend, Pocari Sweat. Pocari Sweat is a glorious beverage, a milky white electrolyte drink with a crisp, Columbia blue label. The stated marketing pitch of the company is that it "resembles" the body's "natural fluids." I don't know if the company's executive board has ever seen sweat before, but it isn't the bodily fluid that is most directly imitated by a milky white solution. Setting aside any discussion of its actual merits, the drink reminds me of my first time in Asia.At this point in the evening, I was overcome with a desire to go back to the Quinary to see if Shao Li was still there. It was nice evening. I wished I had someone to share it with. Perhaps she was about to get off from work and wanted to go out for a beer. Alas, just because one is inclined toward creepy and deranged thoughts does not mean one is required to act on them. So I didn't. Instead I took the Central-Mid-Levels -- which has the distinction of being the world's longest outdoor escalator promenade -- up until the hillside of Hong Kong Island becomes residential and sleepy rather than bustling and studded with hip restaurants. Then I descended further until it was again commercial and posh. I was quite lonely by the time I got to the bottom of the hill. I thought of the insight Chris McCandless jotted down before perishing, alone and unkempt, in the Alaskan wilderness. "Happiness only real when shared." Hoping to inspire a rebound in my spirits, I headed toward the Hong Kong harbor ferry. This is what I'd most been looking forward to since stepping foot in Hong Kong. The harbor is truly a magnificent sight. Viewed from the Kowloon side looking toward Hong Kong Island, the commercial high rises put on an epic display of urban lights against the backdrop of the world's most delicious hillside. Beholding this sight is like conducting an orchestra. It is the feeling of watching something so splendid and so tremendous unfold before your eyes. Each section performs its own part, while inexplicably remaining concerted with the rest. Taking the ferry across, I squished into a corner of the boat, on the upper deck with about 100,000 Hong Kongers. They were all carrying on in conversation and not, I couldn't help but feel, at a whisper, either. Disembarking from the ship, I covered the waterfront. My hope at this point was to repair to a dreary pub where I'd sit alone at the bar and the man behind the counter would tersely serve me an ice cold Tsingtao. I searched for a while in the streets of Kowloon. No dice. So I settled for a bubble tea and retired for the evening. Before doing so I was presented with the evening's final joy. I went to the ATM to withdraw some currency. The transaction ended with the directive, "Please take advice." It means 'receipt.'As our double-decker bus made the bend, the top of it seemed to lean into the oncoming lane. It put me in mind of the bus scene in Harry Potter and the Prisoner of Azkaban, which darts through the road with such belligerent haste as to imperil the story's hero. Or at least it would have, if I wasn't scared for my life. Sitting on the upper deck, I was confident in my assessment that the bus was actually tipping across the other lane of traffic and over the sheer cliff on the other side. I swear I could see down to the bottom of the gulley below. It was a hot day. The air was solid with humidity. Not entirely unlike trying to breathe Earl Grey air, actually. It was the kind of hot that would be of interest to scientists hoping to induce a chemical reaction or a breakfast-enthusiast attempting to fry an egg. I was going hiking. That is, if I didn't succumb to the driver's psychopathology first.Hong Kong is actually famous for having some of the world's greatest hiking trails. Or at least they're good ones. I'd heard they were world-class. But it's not immediately clear to me what would so distinguish one hiking trial from another in any objective sense like that. At any rate, I was to tackle the fabled trail known as the Dragon's Back.That was my plan. It was also the plan of a non-negligible number of Chinese tourists. The bus screeched to a halt at a nondescript location where there appeared to be an opening in the otherwise impenetrable thicket of brush lining the roadside. The driver called for Dragon's Back. I alighted along with a good deal of the rest of the bus. I was eager to get out ahead of them, so as not to be caught in a traffic jam. Mercifully the open stretches of the trail were partially covered. I followed the rascally meandering dirt road lined with brush. Slight uphill. Even with a healthy shade, I was drenched in sweat by minute fifteen.Shortly, I came to the kind of staircase one climbs in a movie to reach an ancient master of an esoteric martial art. Thin wooden steps, rising approximately forever into a thin cloud cover. The top of the hill became apparent only at the culmination of the steps. Or at least the local maximum. The ridge fell and rose with a consistent periodicity, rather like a dragon's back, as it were, or at least the scrawny, undulatory Chinese conception of the creature. I emerged into a cleared hill top, which became a punishing landscape without recourse to the cover of flora. It did, however, unveil a spectacular view. Before me was a glittering sea of Hong Kong's islands. Situated on a peninsula was a scattering of urban settlements. My sweat was thick and dense. I took a polaroid.As a consequence of my dillydallying, I became intermingled with pack of young Asian women. One had on a miniature Marc Jacobs backpack and a flannel, like it was the first day of 8th grade and not a death march through HK jungle mountains. I felt that demonstrated a lack of respect. From the apex of the ridge I felt that I could reach up and touch the sun, hot as it was. I was perspiring about a liter per minute by now. In the distance the sea continued to sparkle and the ridge to undulate. The islands gave the appearance of an old Chinese painting, depicted in geometric rather than linear projection. The lot of them proceed towards heaven rather than into the distance. I jetted past the Asian girls. Reaching the crest of another notch in the dragon's back, I could see freight headed for Hong Kong harbor. Azure water. Gum-drop islands. Glimpses of far-off settlements. Other islands could never be so verdant, or have such perfectly sculpted mounds or sit in such a blessed, glittering sea, or periodically expose the brilliant high-rises off in the distance. I was in a watercolor painting. It was unfairly beautiful.Taking creative measures to deal with the heat situation, I took off my synthetic shirt and put it under my baseball cap so it draped over the back of my neck. I put on a tank top in order to retain a semblance of decency. I looked like an a*****e. But I didn't care. The shirt was cool and damp and protected my delicate skin from the sun. Relinquishing into mercy, the trail dove into a cover of eucalyptus trees. Using this respite into coolness to reapply my eighteenth round of sunscreen for the morning, I was overtaken by a white man forty years my senior. I heard him pass the Western couple behind me. He greeted them, "Pretty warm, eh?" The man was tan and spry, obviously a retiree. Also obviously a hiking enthusiast, the kind that having a job doesn't allow for. As he zoomed past me he gave me his signature "Pretty warm, eh?" I nodded. I looked like a sea monster, one who required constant moisture or will otherwise shrivel and expire. He looked prepared to take the trail. He didn't have a shirt draped over shoulders like a jackass.Dragon's Back Log, 11:00 AM. Supplies check: Water, two-thirds gone. Sunscreen, running on empty. Position, maybe a third of the way through the trail. Only one party member remains alive.I passed a couple going the other way. I greeted them with a "Pretty warm, eh?" They agreed, then shot one another a look to suggest that they may have missed a key memo on standard greetings while hiking in Hong Kong.Soon enough I came upon a creek, which ran through the trail. A Chinese couple had stopped to dip towels in the water for placement under their hats. They didn't look like dumbasses. They looked like geniuses. It occurred to me that this was probably an obvious thing to do for anyone who had ever been on a hike before. I scurried by, not wanting them to think that it was their ingenuity which gave me the idea. Fortunately, I soon came to another creek. I removed my head dress to douse it. I wanted to remove all of my clothes and submerse myself in the fresh, clear water. But I thought better of it, given that my retiree friend was also refreshing himself in the running water.I decided not to linger, so I could get a head start on him. Alarmed by my sudden progress, he put his cap back on and gave chase. To his credit, I doubt he had come all the way to Hong Kong to be bested by some punk kid with a shirt on his head. He soon overtook me without a word. There was nothing I could do about it. It was evident that he had no intention of taking names. He was only here to kick ass.The trail swung onto the backside of the mountain, under the merciful cover of foliage, safe from the sizzle of the open sky. I was happy to trade temporarily the glories of the sea and islands for protection from being broiled alive by what at this point seemed the unnecessarily proximal star at the center of our solar system. Now rather acquainted with the trail's flora, I started the notice the fauna. There was a spider the size of Papua New Guinea. Its legs were longer than mine. It looked like it could snatch a bird from the sky, like a baseball player straining to catch a ball at the top of an outfield fence. Only instead of a baseball, it would be a robin or a small eagle. Eminently creeped out, I scuttled onward. I added this spider to my list of concerns, which at that point contained looking like a foolishly novice hiker, sunburn, dehydration, and tigers. If you were on this trial, I think you'd be concerned with each of these as well.At length, I reached a juncture at the bottom of a slope. I saw the retired man inspecting a map. When he noticed my approach he took off. I followed his course. There were signs for "big wave beach." Periodically, he checked behind him to make sure I was in his wake. We were on a paved road now. I dodged back and forth in the lane to remain under shade cast by surrounding foliage. I stopped at another look-out point. I could see several communities of high-rises, erected in uniform pylons. They were so tightly packed and similarly constructed that they looked like the spiky erections of iron dust when a magnet coaxes it skyward. As we made our way closer to the beach, I saw the retiree split off on a more direct route. Neither wanting to deliver the blow of whooping his ass in the final stretch nor to let him have the satisfaction of whooping mine, I continued on my present path which would descend with unhurried leisure toward the bottom.Then the beach came into sight. In a flash of sudden insight, I understood the objective measure of a world-class hiking trail. To have all that previous wandering be rewarded with this? Just perfect. The hill from which I was descending swaddled the beach in a lush wrapping of vegetation. In some mirror image of the circles of hell, it formed a concentric ring of utopian vision. At the heart was the bay, ensconced in the Platonic ideal of white-sand beach, opening up into the luxuriant hillside. The name "big wave" less described the largeness of the surf at this particular beach as much as the smallness of surf in these parts generally. I took off my hood so as not to gave myself away as a schlub, in case I ran into Shao Li on the beach. Only having breached noon, the beach was still uncrowded. Maybe a dozen or so families. It felt like my own little share of real estate in Hong Kong heaven. When I turned the corner from path to beach, the sea was spread out before me as it faded from cloudy and sandy to idyllic cerulean. It was spangled with the same intensity as the view above, though now I could reach out and touch it. The water was warm, like a tepid bath. I waded in and immersed myself in the the strip of infinite blue. As the beach began to fill up, I noticed there were, in my estimation, entirely too many families and not enough bikini-clad women. I did not, for the record, encounter Shao Li.In the water I roamed like a wild animal, with no pattern to govern my behavior. Sometimes floating, sometimes swimming; sometimes shallow, sometimes deep. Never with any particular destination in mind. The only sounds were those of the happy children and the waves languishing along the shore. Intermittently, there was the gentle awk and splonk of the neophyte standup paddle boarder capsizing.After about an hour of grazing in knee deep water, I reemerged from the water and repaired, still wet, to the beach café where I acquired a well-earned Dragon's Back pale ale. While enjoying my beer I spotted a couple long-sought bikini girls from afar. I finished my beer and reequipped myself to go back in the water. Upon entering I realized it was a false alarm -- a mirage of sorts -- and dripped out of the water, this time to enjoy a Big Wave IPA. As soon as I did, the girls came back. I swear.Satisfied with my experience in the out-of-doors, I headed toward the nearby lot where a van waited to take beach patrons back to civilization. On my way I acquired a mango popsicle. Then I spotted a sign that promised "Ancient rock carvings - 330 m." I debated momentarily whether this was worth extending my time in nature. I decided to go back home. Who gives a s**t about rock carvings anyway? I boarded the van to take me back. Waiting for the vehicle to fill up, I saw another sign. "Ancient rock carving - 500 m." I pretended not to notice, failing to fool anyone involved in the situation. It was then I remembered who gives a s**t about rock carvings. I do. F**k it. I got off the bus, put on my headdress, and went back toward the beach in search of rock carvings.Eventually, I found them. Doubling back on my previous recollection, I now remembered why no one else gives a s**t about rock carvings. The delta between rocks and rocks with ancient carvings in them is not, as it turns out, that great. The saving grace of the endeavor was that I did, on my way back to the van, acquire another mango popsicle.Taxi hour. The time in the middle of the night when the streets are devoid of all vehicles save for a trickle of black and yellow cabs. Some zip by on their way to the airport. Some return a pair of lovers to wherever it is they plan to spend the remaining hours of the night. Some just idle on the side of the road, killing time until called into action. One night I couldn't sleep and so found myself on the streets of Hong Kong, the lone soul wandering the streets in human form.My time in Hong Kong was coming to a close. Visa issues sorted, I would soon be reunited with Haily. I had loved my excursion to Hong Kong. But I had also missed Haily. In case you couldn't tell, a part of me longed for a companion to enjoy it with. Happiness only real when shared.And so we would be together again soon -- elsewhere in Asia. We continued as we had before, in our summer devoted to going places and seeing things. Her family in Vietnam. Taking the train though Java. Bali. Friends and family in Singapore. There are stories to tell from those adventures, too. But I will leave them out of this collection, to allow them to remain as stories that belong only to us.The final episodes in the season take place at another time, in another season of the year and another season of life. They skip sideways along the Asian continent, to a portion of South East Asia on the same latitude as Hong Kong. The Buddhist stronghold of dark political history, still processing its own militant reaction to a colonial past. South East Asia's largest country by land area, but one of its smallest in terms of tourist figures. A place that I fell in love with from the moment I first stepped a dusty sandal on its soil. The final destination of the first season of Notes from the Field: Myanmar.Next Episode:Thanks for checking out Season 1 of Notes from the Field. If you’ve enjoyed it, please consider becoming a premium subscriber. I’m trying to do more of this kind of travel writing in the future. But as you can imagine, it’s hard to have these kinds of experiences while also holding down a job. Your subscription goes a long way toward helping me to do that. Use the link below, and you’ll get 50% off an annual subscription. Thanks! This is a public episode. If you’d like to discuss this with other subscribers or get access to bonus episodes, visit codykommers.substack.com/subscribe
Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.09.01.277400v1?rss=1 Authors: Scarfe, P. Abstract: Sensory cue integration is one of the primary areas in which a normative mathematical framework has been used to (1) define the optimal way in which to make decisions based upon ambiguous sensory information and (2) compare these predictions to an organisms behaviour. The conclusion from such studies is that sensory cues are integrated in a statistically optimal fashion. Problematically, numerous alternative computational frameworks exist by which sensory cues could be integrated, many of which could be described as optimal base on different optimising criteria. Existing studies rarely assess the evidence relative to different candidate models, resulting in an inability to conclude that sensory cues are integrated according to the experimenters preferred framework. The aims of the present paper are to summarise and highlight the implicit assumptions rarely acknowledged in testing models of sensory cue integration, as well as to introduce an unbiased and principled method by which to distinguish the probability with which experimental data is consistent with a set of candidate models. Copy rights belong to original authors. Visit the link for more info
Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.06.23.167551v1?rss=1 Authors: Fadaei Jouybari, A., Jeanmonod, K., Bleuler, H., Potheegadoo, J., Kannape, O. A., Hara, M., Blanke, O. Abstract: Recent advances in virtual reality and robotic technologies have allowed researchers to explore the mechanisms underlying bodily aspects of self-consciousness which are largely attributed to the multisensory and sensorimotor processing of bodily signals (bodily self-consciousness, BSC). One key contribution to BSC, that is currently poorly addressed due to the lack of a wearable solution, concerns realistic collision sensations on the torso. Here, we introduce and validate a novel torso-worn force display, the Cogno-vest, to provide mechanical touch on the user's back in a sensorimotor perception experiment. In a first empirical study, we characterized human finger poking (N=28). In order to match these poking characteristics and meet the wearability criteria, we used bi-directional, push-pull solenoids as a force actuator in the Cogno-vest. Subsequently, and based on an iterative, multidisciplinary design procedure, a body-conforming, unisex, torso-worn force display was prototyped. Finally, we conducted a behavioral study that investigated BSC in 25 healthy participants by introducing conflicting sensorimotor signals between their hand and torso (back). Using the final reiteration of the Cogno-vest we successfully replicated previous findings on illusory states of BSC, characterized by presence hallucinations (PH) and passivity symptoms, and achieved higher illusion ratings compared to static conditions used in prior studies. Copy rights belong to original authors. Visit the link for more info
Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.05.29.123026v1?rss=1 Authors: Perez, C., Felix, L., Rose, C. R., Ullah, G. Abstract: Spontaneous neuronal and astrocytic activity in the neonate forebrain is believed to drive the maturation of individual cells and their integration into complex brain-region-specific networks. The previously reported forms include bursts of electrical activity and oscillations in intracellular Ca2+ concentration. Here, we use ratiometric Na+ imaging to demonstrate spontaneous fluctuations in the intracellular Na+ concentration of CA1 pyramidal neurons and astrocytes in tissue slices obtained from the hippocampus of mice at postnatal days 2-4 (P2-4). These occur at very low frequency ([~]2/h), can last minutes with amplitudes up to several mM, and mostly disappear after the first postnatal week. To further study the mechanisms that may generate such spontaneous fluctuations in neurons, we model a network consisting of pyramidal neurons and interneurons. Experimentally observed Na+ fluctuations are mimicked when GABAergic inhibition in the simulated network is inverted. Both our experiments and computational model show that the application of tetrodotoxin to block voltage-gated Na+ channels or of inhibitors targeting GABAergic signaling respectively, significantly diminish the neuronal Na+ fluctuations. On the other hand, blocking a variety of other ion channels, receptors, or transporters including glutamatergic pathways, does not have significant effects. In addition, our model shows that the amplitude and duration of Na+ fluctuations decrease as we increase the strength of glial K+ uptake. Furthermore, neurons with smaller somatic volumes exhibit fluctuations with higher frequency and amplitude. As opposed to this, the larger relative size of the extracellular with respect to intracellular space observed in neonatal brain exerts a dampening effect. Finally, our model also predicts that these periods of spontaneous Na+ influx leave neonatal neuronal networks more vulnerable to hyperactivity when compared to mature brain. Taken together, our model thus confirms the experimental observations, and offers additional insight into how the neonatal environment shapes early signaling in the brain. Author SummarySpontaneous neuronal and astrocytic activity during the early postnatal period is crucial to the development and physiology of the neonate forebrain. Elucidating the origin of this activity is key to our understanding of the cell maturation and formation of brain-region-specific networks. This study reports spontaneous, ultraslow, large-amplitude, long-lasting fluctuations in the intracellular Na+ concentration of neurons and astrocytes in the hippocampus of mice at postnatal days 2-4 that mostly disappear after the first postnatal week. We combine ratiometric Na+ imaging and pharmacological manipulations with a detailed computational model of neuronal networks in the neonatal and adult brain to provide key insights into the origin of these Na+ fluctuations. Furthermore, our model predicts that these periods of spontaneous Na+ influx leave neonatal neuronal networks more vulnerable to hyperactivity when compared to mature brain. Copy rights belong to original authors. Visit the link for more info
REFERENCE:• Synergetics 200.06http://www.rwgrayprojects.com/synergetics/s02/p0000.html• Synergetics 222.31http://www.rwgrayprojects.com/synergetics/s02/p2000.html#222.30• Synergetics 222.32http://www.rwgrayprojects.com/synergetics/s02/p2000.html#222.30• Synergetics 222.42http://www.rwgrayprojects.com/synergetics/s02/p2000.html#222.30• Synergetics 222.50http://www.rwgrayprojects.com/synergetics/s02/p2000.html#222.50• Synergetics 326.40http://www.rwgrayprojects.com/synergetics/s03/p2600.html#326.40• Synergetics 502.22http://www.rwgrayprojects.com/synergetics/s05/p0000.html#502.00• OMNISCIENT UNIVERSE CHURCH A Synergetics Podcast ♡® Episode 87 May 20 - May 21, 2020 Consciously Defining All Experiences as Events that Constitute Omnirational Universehttps://omniscient-universe-church-a-synergetics-podcast.simplecast.com/episodes/87-consciously-defining-all-experiences-as-events-that-constitute-omnirational-universe• Master List of Names for God From World's Religionshttps://www.universespirit.org/god-names-master-list-of-names-for-god-from-worlds-religions• Resetting the World Stage.org http://resettingtheworldstage.org/
In Episode 59 Patricia Westmoreland, MD, gives a masterclass lecture on managing severe and enduring eating disorder (SEERS). Renee Kohanksi, MD, poses the question, "What do we want?" Contact us: podcasts@mdedge.com Twitter: @mdedgepsych Show Notes By Jacqueline Posada, MD, 4th-year resident in the department of psychiatry & behavioral sciences at George Washington University, Washington. Guest Patricia Westmoreland, MD: forensic psychiatrist at University of Colorado Denver, Aurora; attending psychiatrist for Eating Recovery Center, Denver; and adjunct assistant professor at University of Colorado Denver in department of psychiatry. Dr. Westmoreland spoke at the American Academy of Clinical Psychiatrists 2019 annual meeting in Chicago, sponsored by Global Academy for Medical Education (GAME). GAME and the MDedge Psychcast are owned by the same company. Introduction, definition, role of involuntary treatment, and novel treatment options Introduction: Prognosis: Anorexia nervosa (AN) has the highest mortality of any psychiatric disorder. Risk factors for death: Older age at first presentation, lower weight at presentation, greater duration of illness, comorbid alcohol or diuretic abuse, comorbid mood disorder, history of psychiatric hospitalization and suicide attempts, and self-harm. Less than 50% recover completely, about 30% improve somewhat but require frequent hospitalizations or treatments, and 20% develop a SEED. Eddy et al. longitudinal study of eating disorders (EDs): AN patients can recover over the long term. Overall, 31% were better at 9 years; 63% better at 22 years of follow-up. Treatment: Treat ASAP, especially if patient is seen at a young/pediatric age before symptoms are fully developed and weight loss is profound. Weight gain as the central treatment: Many patients are reluctant to get treatment that focuses only on food intake and weight gain. Predictors of improvement: Weight gain that is parallel to improvement in physical and psychological well-being, diagnosis at a younger age, and shorter duration of illness. Medications: Fluoxetine is the only Food and Drug Administration-approved treatment for EDs, including bulimia, at doses of 60 mg and above. Patients with EDs have poor response to selective serotonin reuptake inhibitors because of starvation and limited production of serotonin and serotonin receptor abnormalities. Severe and enduring eating disorders (SEED) definition: 6-12 years of an ED can qualify as chronic. Lower likelihood of recovery with symptoms substantially interfering with quality of life. Role for involuntary treatment in EDs: Few treatment centers do involuntary treatment of ED. Involuntary treatment can involve guardianship for medical decisions. Guardianship is useful for medical treatment and admission to a medical ward, for example, when a patient requires forcible tube feeding for life-threatening starvation. Commitment or certification is required for involuntary treatment in a psychiatric hospital. Commitment is sought by a psychiatrist and is a tool in cases when the patient is dangerous to self or others and is gravely disabled. It is useful to commit a patient who is refusing care and has not been sick for long. Often, commitment/certification is used as a last resort, and the patient is too sick to truly recover. Pros and cons of involuntary treatment: Pro: No difference in weight restoration in voluntary vs. involuntary treatment, and patients are often grateful after involuntary treatment. Cons: Involuntary tube feeding has unclear long-term outcomes. Some studies show poor outcomes for people who are treated involuntarily, though this is likely because of their comorbidities. Novel treatment options: Ketamine has been used in EDs. Concerns remain about the drug’s addictive potential and inability to clearly change eating disorder pathology. Oxytocin: There are reduced cerebrospinal fluid levels of oxytocin in AN, and oxytocin restores during recovery. Experimentally in rats, oxytocin may reduce the fear and social phobias related to eating. Electroconvulsive therapy does not reduce ED symptoms such as restricted eating and fear of fatness, but it can improve depression. People with ED are often medically ill, so the patient must be physically able to undergo treatment. Because of medical comorbidities, AN patients are more likely to have complications like delirium. Transcranial magnetic stimulation: Dorsolateral prefrontal cortex involved in self-regulatory control, inhibitory control, and cognitive flexibility. Some studies show promising results of using this intervention with ED and mild side effects like syncope and headache. Deep brain stimulation (DBS): Treatment targets the nucleus accumbens and the subcallosal cingulate gyrus, which theoretically alter balance between reward and cognitive inhibitory and control systems that are related to pathological eating behaviors. DBS has strongest theoretical rationale in terms of neurocircuitry targets. References Eddy J. Recovery from anorexia nervosa and bulimia nervosa at 22-year follow-up. Clin Psychiatry. 2017 Feb;78(2):184-9. Sjostrand M et al. Ethical deliberations about involuntary treatment: Interviews with Swedish psychiatrists. BMC Med Ethics. 2015;16:37. Geppert C. Futility in chronic anorexia nervosa: A concept whose time has not yet come. Am J Bioethics. 2015. 15(17):34-43. Cushla M. Is resistance (n)ever futile? A response to “Futility in chronic anorexia nervosa: A concept whose time has not yet come,” by Cynthia Geppert. Am J Bioethics. 2015 Jul 6. 15(7):53-4. In part 2, Dr. Westmoreland will discuss harm reduction, palliative care, and futility.
In this month's episode we look at how men and women's partner preferences are affected by a dose of oxytocin, aka "the love hormone". We'll also find out whether germophobes are more or less likely to pursue short-term relationships.Download the MP3 Subscribe! Make sure you never miss an episode by subscribing in Apple Podcasts, Google Podcasts, or Stitcher. Read the transcript! Disgust and Short-Term Relationships Oxytocin and Mate-ChoiceHow does oxytocin affect men and women's partner preferences? FreestocksThe articles covered in the show: Al-Shawaf, L., Lewis, D. M. G., Ghossainy, M. E., & Buss, D. M. (in press). Experimentally inducing disgust reduces desire for short-term mating. Evolutionary Psychological Science. Read summaryXu, L., Becker, B., Luo, R., Zheng, X., Zhao, W., Zhang, Q., et al. (2018). Oxytocin amplifies sex differences in human mate choice. BioRxiv. Read preprint
Orb Lover Scandal, Police State Of Shock, Oil Based Drinks, Advanced Forts, Strechers on the Elterly, Thumb Cycles, Knife Nose, Skew Whiff Dog Face, Oh, The Humanities! Thanks to everyone who supports the pod by chipping in to our patreon here Two in the Think Tank is a part of the Planet Broadcasting family You can find us on twitter at @twointank Andy Matthews: @stupidoldandy Alasdair Tremblay-Birchall: @alasdairtb And you can find us on the Facebook right here Ongoing therapy to George Matthews for my terruble editing of this episode. See acast.com/privacy for privacy and opt-out information.
Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and it's editors. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Our feature paper this week contains novel data from the TOPCAT trial, this time relating physical activity to prognosis in patients with heart failure and preserved ejection fraction. A great discussion coming right up after this weeks' summaries. Our first paper tells us that pericarditis may be a marker of occult cancer and augurs increased mortality following the cancer diagnosis. Authors, Dr. Sogaard and colleagues from our host university hospital in Denmark used the Danish medical databases to conduct a nationwide cohort study of all patients with a first-time diagnosis of pericarditis from 1994 to 2013. Among 13,759 patients with acute pericarditis, 1,550 subsequently were diagnosed with cancer during followup. Patients with newly-diagnosed pericarditis had higher risks than age and sex match members of the general population of being diagnosed with lung cancer, Non-Hodgkin lymphoma, and myeloid leukemia during the first three months following a pericarditis diagnosis, but increased risks for lung cancer and Non-Hodgkin lymphoma and bladder cancer persisted beyond one year following a pericarditis diagnosis. The increased cancer risk was not restricted to patients with pericardial effusion. Furthermore, pericarditis was a prognostic factor for survival after lung cancer, breast cancer, and bladder cancer. Thus, the clinical take-home message is that patients with pericarditis, particularly when complicated by pericardial effusion, may need to be considered for workup targeted at diagnosing or ruling out cancer. The next paper provides insights into mechanistic processes leading to stent thrombosis in the largest contemporarily available series of patients undergoing optimal coherence tomography, or OCT imaging, during stent thrombosis presentation. The first author, Dr. Adriaenssens, corresponding author, Dr. Byrne from Munich, Germany, and colleagues of Prestige Consortium, performed a prospective multicenter study to evaluate OCT findings in consecutive patients presenting with stent thrombosis enrolled in a registry that was using a centralized registration system. In 231 patients with stent thrombosis undergoing OCT, uncovered and malapposed struts were frequently observed, with the incidents of both decreasing with longer time intervals between stent implantation and presentation. The most frequent dominant observation varied according to the time intervals from index stenting. Uncovered struts and stent underexpansion were the most common observations in acute or subacute stent thrombosis, whereas neoatherosclerosis and uncovered struts were the most common findings in late or very late stent thrombosis. The impact of dedicated clinical strategies for the prevention and treatment of mechanisms underlying stent thrombosis should be investigated in future clinical studies. The next study identifies a new type of capillary malformation, arteriovenous malformation. Now, we know that most arteriovenous malformations are localized and occur sporadically. However, they also can be multifocal in autosomal dominant disorders, such as hereditary hemorrhagic telangiectasia and capillary malformation arteriovenous malformation or CMAVM. RASA1 mutations have been identified in 50% of patients with CMAVM. In the current study, first author, Dr. Amyere, corresponding author, Dr. Vikkula from Brussels, Belgium and colleagues studied non-RASA1 patients and found that EphB4 mutations occurred in patients with multifocal capillary malformations associated with arteriovenous malformations. This phenotype named CMAVM2 mimicked RASA1-related CMAVM1 and also hereditary hemorrhagic telangiectasia. RASA1-encoded p120-RasGAP was a direct effector of EphB4. Furthermore, the study implicated EphB4-RAS-ERK signaling pathway as a major cause of arteriovenous malformations. Thus, patients with multifocal capillary malformations need to be screened, not only for an inherited RASA1 mutation, but also for EphB4. The final study identifies a novel potential therapeutic target in the treatment of atherosclerosis, and that is Dickkopf-related protein 3, or DKK3, a secreted protein previously known for its involvement in the regulation of cardiac remodeling and vascular smooth muscle cell differentiation, but very little studied in atherosclerosis. In the current study, first author is Dr. U.N. [inaudible 00:05:51], corresponding authors, Dr. Qu from Capital Medical University in Beijing, and Xu from Kings College London used both epidemiological and experimental approaches to test the hypothesis that DKK3 was atheroprotective. In the prospective population-based Bruneck study, they found that the level of plasma DKK3 was inversely related to carotid artery intimal medial thickness and five-year progression of carotid atherosclerosis independently from standard risk factors for atherosclerosis. Experimentally, they demonstrated that DKK3 promoted re-endothelialization in murine models of atherosclerosis and wire-induced femoral artery injury, thus revealing its atheroprotective role. They further explored the mechanism of DKK3-induced endothelial cell migration, which was via noncanonical Wnt signaling pathways. The study, therefore, provides the evidence for a role of DKK3 in the protection against atherosclerosis involving endothelial migration and repair with potential therapeutic implications. That wraps it up for our summaries. Now for our feature discussion. For today's feature discussion, we are talking about physical activity and prognosis in heart failure with preserved ejection fraction, or HFPEF. To discuss this paper, which contains really neat results from the TOPCAT trial, we have none other than the first author, Dr. Sheila Hegde, corresponding author, Dr. Scott Soloman, both from Brigham and Women's Hospital, as well as Dr. Jarett Berry from U.T. Southwestern, who was the editorialist on this paper. Welcome, everyone. Dr. Scott Solomon: Thanks, Carolyn. Dr. Sheila Hegde: Thank you. Dr. Jarett Berry: Thank you, Carolyn. Dr. Carolyn Lam: Hey, Scott. Could you set the background a little bit and let us know what was the rationale of looking at physical activity in TOPCAT? Dr. Scott Solomon: As you well know, heart failure with preserved ejection fraction is a disorder in which we don't currently have a therapy, or for which we currently don't have a therapy, and we know that people would also have a lot of comorbidities. Sheila has been extremely interested in the role of physical activity in heart failure and patients with heart failure, has studied this in the atherosclerosis risk in community studies, and we thought TOPCAT would be a great overall trial dataset to understand the importance of physical activity in HFPEF patients and the relationship with outcomes. As you know, TOPCAT is a study that was funded by the NIH in patients with heart failure, preserved ejection fraction. Patients were randomized to spironolactone or placebo and then followed for outcomes, and it was a very rich dataset for which we have a lot of physical activity information. Dr. Carolyn Lam: Indeed, and I wasn't even aware of the extent of the physical activity information in TOPCAT. Sheila, could you explain a bit how physical activity was captured and graded, and tell us about your findings? Dr. Sheila Hegde: Each participant's physical activity was assessed by self report. Subjects were asked about the amount of heavy, medium, and light exercise in the preceding two weeks. They were given some examples of what those might be and what we did was, we converted these to AHA, American Heart Association categories of poor, intermediate, and ideal activity. As you know, the ideal activity category corresponds to 150 minutes of moderate intensity activity per week or 75 minutes of vigorous activity per week. What we found, using these categories, was that the majority of subjects actually met criteria for poor activity, so at least 75%. Also, a majority were New York Heart Association Class II heart failure. Those with poor activity were more likely to be women, have diabetes, chronic kidney disease, and a previous history of heart failure hospitalization. Interestingly, there was no significant difference in history of myocardial infarction, stroke, atrial fibrillation, or COPD. The median follow-up time for this group was 2.4 years, and we did sort of focus on the first two years because there was an interaction with times and randomization and, using Cox regression models, we found that those with poor or intermediate activity had approximately a two-fold higher risk of a primary composite outcome, which was heart failure hospitalization, cardiovascular mortality, or aborted cardiac arrest. Dr. Carolyn Lam: Wow! You know what the question is? Chicken or egg? Does this mean those who were exercising had better outcomes or they were just better and, therefore, they could exercise? Dr. Sheila Hegde: That's a very good question. This is a post hoc analysis, so it will be difficult to say, but we did sort of look at excluding those with a history of stroke or MI and found that the same two-fold increased risk of outcomes existed for those with poor intermediate activity. Dr. Scott Solomon: This is always the problem, as you know, Carolyn, with observational data. We don't know if the patients who are exercising more are doing better because they're exercising more or is it that the people who feel better can exercise more? You try to adjust as much as you can, but I don't know that there's any way to determine that for sure without doing a randomized trial of exercise in patients with HFPEF. Dr. Carolyn Lam: Certainly and, in fact, I thought that was one of the good messages, that it's time that we do a proper trial of that, don't you think? Jarett, would you have some questions for Sheila and Scott, too? Dr. Jarett Berry: I was really interested in your figure 3, this dose response analysis. In figure 3, you divided the exposure into deciles. You don't begin to see a decremented risk until you begin to see the ninth and tenth decile of exercise. If you look at other observational data, you really see this different pattern where just getting off the couch seems to be beneficial in other observational data for preventing coronary disease events but, both in our work and also in this paper here, particularly your figure 3, you see that this higher dose of physical activity was required to see a reduction in risk. I don't know if you could comment a little bit on that. Dr. Sheila Hegde: I agree that there is a difference in what appears to be a dose response at lower levels of activity. In this analysis, we actually included amount of light intensity of activity since the majority of people had no moderate or vigorous intensity activity to account for. In that sense, there's even sort of a higher threshold, perhaps, required to achieve benefit and reduction of risk, and it may be that heart failure has a different mechanism for physical activity in terms of achieving those benefits. Dr. Jarett Berry: I'm wondering, I guess getting back to Carolyn's original point there about, and Scott's comments, as well, about the need for a trial. If you look back at HF-ACTION where we saw some relatively modest benefit for exercise training and heart failure with reduced ejection fraction. Some of our prior work would suggest that, actually, the benefit of exercise is much more apparent in HFPEF patients. When you train HFPEF patients, they tend to improve much more dramatically with regard to VO2 peak, compared to heart failure with reduced ejection fraction. I'm just wondering what your thoughts were about the next steps. It seems like a trial of some type would be of great interest. What are your thoughts about that? Dr. Scott Solomon: I agree with you 100%. It would be a great idea for a trial. There have been small trials, as you know. Dalane Kitzman did a trial and Frank Edelmann and Burkert Pieske did a trial, and I think they're actually even doing another one now. The relatively small numbers of patients do show improvement in myocardial oxygen uptake, improvement in quality of life, and some improvement in some measures of echocardiographic measures of diastolic function, as well, with exercise training which is, frankly, more than we've gotten with drug therapies, so I agree 100%. It's also important to note that it's actually hard to get our patients with HFPEF in the United States into cardiac rehab because it's currently not paid for by Medicare, and I'm hoping that will change, as well. Dr. Carolyn Lam: You know, that's so well put, Scott. I've got a question, though. Every time you think TOPCAT, you think regional variation, right? How did this look in the different regions, in the U.S. versus elsewhere? Dr. Scott Solomon: First of all, let me just tell the audience that TOPCAT was a study in which we enrolled patients both in the Americas, which was the U.S., Canada, Argentina and Brazil, and in Russia and the Republic of Georgia. As you know, when we unblinded the trial, we found that the event rates in Russia and the Republic of Georgia were considerably lower, about five-fold lower than they were in the Americas. We believe that many of these patients may not have had heart failure. We've also recently found that many of these patients probably weren't taking spironolactone, as well. For many of our TOPCAT analyses now, including this one, we excluded the patients in Russia and Georgia and just focused on the Americas. Sheila, did you happen to look at the results in Russia and Georgia, just as a tweak? Dr. Carolyn Lam: I can tell you that the majority of patients were active, so very much different than our majority in active patients in the Americas region. Dr. Jarett Berry: This is an amazing study that really puts forward an important hypothesis that needs to be tested. Before, I know we've discussed that a couple of times already, but I really believe that we are exercising the wrong heart failure patients. As the Director of Cardiac Rehab here at Southwestern, we are including a lot of heart failure with reduced ejection fraction but, as Scott points out, there aren't currently funding available or billing is not allowable for patients who have heart failure with preserved ejection fraction. I think it's only studies like this that are going to move the field for it and how we can begin to think about caring for these patients and treating their comorbidities and treating their disease process through what we believe is probably one of the most important therapeutic strategies we have that we're not using, and that would be the exercise training, so I think this is a fantastic study and a wonderful contribution as we begin to think more about the future of treatment for patients with HFPEF. Dr. Carolyn Lam: Thank you so much, everyone. Listeners, I'm sure you enjoyed that conversation as much as I did. Don't forget to tune in again next week.
This week we look at eRFC 2033 "Experimentally add coroutines to Rust"
PROFANITY WARNING - There are a few unbleeped blue utterances in this podcast - if you're sensitive to blueness, please wear headphones! In Episode 3 - Denny and Drew start out in the Pub talking about a distressing topic - the possible decline of homebrewing, the causes and what all of us can do about it. Then we get into the real meat of our whole show as we head into the Experimental Brewing Labs in Casa Verde - it's experimentation time! Back in Episode 1 we walked you through a triangle test, now it's time to use it! In this episode, we'll describe the experiment and a few episodes down the line, we'll bring you the results of the IGORs testing and take your results as well! Then we're off to the Bay Area, where if you read our blog, you'll know we talked to a bunch of brewers - this week, we bring you our interview with Jay Goodwin of the Rare Barrel in Berkeley as he drops a bunch of sour beer knowledge on our puny little heads. We'll then take your questions and see if we can't start a fight between Denny & Drew before Denny gives you a little working knowledge about your pump head and then talks to you about his love for the world's favorite silly instrument - the ukulele! Episode Links: Experiment Description - http://www.experimentalbrew.com/experiments/yeast-comparison-same-strain... Recipe - http://www.experimentalbrew.com/recipes/magnum-blonde-no-aroma-variant The Rare Barrel - https://www.therarebarrel.com/ Ohana Music (aka Denny's Ukulele's of choice) - http://www.ohana-music.com/ Survivor Girl Ukulele Band - Drew kept getting the name wrong, but check out one of the best uses for music - http://www.sgub.org/ Episode Contents: 00:00:00 Our Sponsors 00:01:40 Theme and Intro! 00:04:50 Beer Life from the Experimental Brewing Pub - The Decline of Homebrewing 00:16:59 Experiments - Our first experiment - WLP001 vs. Wyeast 1056 00:26:07 Live at the Rare Barrel with Jay Goodwin 01:03:03 Q&A with Denny & Drew 01:14:34 Quick Tip - Keeping Your Head Clear 01:16:04 Other Things We Recommend: Ukulele & The Ukulele Survivor Girl Project 01:18:58 Wrap up This episode is brought to you: BrewCraft USA Craftmeister NikoBrew PicoBrew Interested in helping Denny and Drew with the IGOR program (aka help us run experiments!) - contact them at igor@experimentalbrew.com. We want more Citizen Science! On our next episode we'll be giving our IGOR's their first brewing assignment! In the meanwhile, subscribe via your favorite podcasting service (iTunes, etc). Like our podcast, review it - talk it up! If you have comments, feedbacks, harassments, etc, feel free to drop us a line at podcast@experimentalbrew.com. Follow us on Facebook (ExperimentalHomebrewing) or Twitter (@ExpBrewing). If you have questions you'd like answered in our Q&A segment, send an email to questions@experimentalbrew.com! This episode can be downloaded directly at http://www.experimentalbrew.com/sites/default/files/ExperimentalBrewing_... Podcast RSS Url: http://www.experimentalbrew.com/podcast.rss
Fakultät für Physik - Digitale Hochschulschriften der LMU - Teil 05/05
Raman scattering can be applied to biological imaging to identify molecules in a sample without the need for adding labels. Raman microscopy can be used to visualize functional areas at the cellular level by means of a molecular contrast and is thus a highly desired imaging tool to identify diseases in biomedical imaging. The underlying Raman scattering effect is an optical inelastic scattering effect, where energy is transferred to molecular excitations. Molecules can be identified by monitoring this energy loss of the pump light, which corresponds to a vibrational or rotational energy of the scattering molecule. With Raman scattering, the molecules can be identified by their specific vibrational energies and even quantified due to the signal height. This technique has been known for almost a century and finds vast applications from biology to medicine and from chemistry to homeland security. A problem is the weak effect, where usually only one in a billion photons are scattered. Non-linear enhancement techniques can improve the signal by many orders of magnitude. This can be especially important for fast biomedical imaging of highly scattering media and for high resolution spectroscopy, surpassing the resolution of usual spectrometers. In this thesis a new system for stimulated Raman spectroscopy (SRS) and hyperspectral Raman microscopy with a rapidly wavelength swept laser is presented. A time-encoded (TICO) technique was developed that enables direct encoding of the Raman transition energy in time and direct detection of the intensity change on the Stokes laser by employing fast analogue-to-digital converter (ADC) cards (1.8 Gigasamples/s). Therefore, a homebuilt pump laser was developed based on a fiber-based master oscillator power amplifier (MOPA) at 1064 nm and extended by a Raman shifter that can shift the output wavelength to 1122 nm or 1186 nm. This is achieved by seeding the Raman amplification in the fiber with a narrowband 1122 nm laser diode. Surprisingly, this also leads to narrowband (0.4 cm-1) cascaded Raman shifts at 1186 nm and 1257 nm, which is in contrast to the usually broadband spontaneous Raman transition in fused silica. The underlying effect was examined and therefore concluded that it is most probably due to a combined four-wave-mixing and cascaded Raman scattering mechanism. Experimentally, the narrowband cascaded Raman line was used to record a high-resolution TICO-Raman spectrum of benzene. As Raman Stokes laser, a rapidly wavelength swept Fourier domain mode-locked (FDML) laser was employed which provides many advantages for SRS. The most important advantages of this fiber based laser are that it enables coverage of the whole range of relevant Raman energies from 250 cm-1 up to 3150 cm-1, while being a continuous wave (CW) laser, which at the same time allows high resolution (0.5 cm-1) spectroscopy. Further, it enables a new dual stage balanced detection which permits shot noise limited SRS measurements and, due to the well-defined wavelength sweep, the TICO-Raman technique directly provides high-quality Raman spectra with accurate Raman transition energy calibration. This setup was used for different applications, including Raman spectroscopy and non-linear microscopy. As results, broadband Raman spectra are presented and compared to a state-of-the-art spontaneous Raman spectrum. Furthermore, several spectroscopic features are explored. For first imaging results, samples were raster scanned with a translational stage and at each pixel a TICO-Raman spectrum acquired. This led to a hyperspectral Raman image which was transformed into a color-coded image with molecular contrast. Biological imaging of a plant stem is presented. The setup further allowed performing multi-photon absorption imaging by two-photon excited fluorescence (TPEF). In summary, this thesis presents the design, development and preliminary testing of a new and promising platform for spectroscopy and non-linear imaging. This setup holds the capability of biological multi-modal imaging, including modalities like optical coherence tomography (OCT), absorption spectroscopy, SRS, TPEF, second harmonic generation (SHG), third-harmonic generation (THG) and fluorescence lifetime imaging (FLIM). Amongst the most promising characteristics of this setup is the fiber-based design, paving the way for an endoscopic imaging setup. Already now, this makes it a robust, alignment-free, reliable and easy-to-use system.
Fakultät für Physik - Digitale Hochschulschriften der LMU - Teil 05/05
Few-cycle laser pulses are an important tool for investigating laser-matter interactions. Apart from the mere resolution used in time-resolved processes, owing to this approach table-top sources nowadays can reach the limits of the perturbative regime and therewith enable extreme nonlinear optics. In the visible domain, femtosecond technology over the last decades has quickly developed, in recent years leading to the routine generation of carrier-envelope phase (CEP) stable few-cycle laser pulses at high energies, using ubiquitous Ti:Sapphire amplifiers. Near to mid-infrared few-cycle pulses in contrast can be employed for investigating interactions in the tunneling regime. The ponderomotive potential of the infrared light field allows quivered charged particles to acquire large energies, leading to applications like the generation of isolated attosecond pulses in the water window. In this wavelength regime however, the required sources are yet to be demonstrated or at least matured. The best candidate for few-cycle pulses in this domain is optical parametric amplification. This work describes the development of an optical parametric chirped pulse amplifier (OPCPA), used to create CEP-stable few-cycle pulses in the near infrared (NIR). It covers all essential parts of the system. First the signal pulses are generated from ultrashort lasers using spectral broadening techniques in chapter 2. After compression of these white light continua, intra-pulse broadband difference frequency generation yields CEP stable infrared pulses spanning over more than one octave. A thin-disk-based pump laser provides ample pump energy (20 mJ) at pulse durations around 1.5 ps. Its characterization and optimization for OPCPA is performed in chapter 3. The high peak energy of this pump laser leads to the buildup of optical nonlinearities and consequently shows distinct influence on the OPCPA system performance. The synchronization of the OPCPA pump and seed laser system is the topic of chapter 4. This chapter is not limited to NIR systems, but demonstrates enhanced (actively stabilized) synchronization of the jitter between pump and seed pulses to σ = 24 fs, which later results in improved output stability. The NIR OPCPA centered at 2.1 μm is described in chapter 5. This combines the efforts of the previous chapters and describes the generation and characterization of 100 μJ sub-two-cycle CEP-stable pulses, the shortest published to date at this energy level. As a first prototype (cutting edge) experiment, CEP dependent sub-fs currents in a dielectric are generated in chapter 6 using the developed light source. The results compared well to visible few-cycle laser sources and demonstrate the usability of the OPCPA system (beyond the charac- terizations of chapter 5) for investigating sub-cycle carrier dynamics in dielectrics. For the same purpose, to generate the currently most broadband NIR continua at kHz repetition rates and mJ-level pulse energies, the OPCPA system is further boosted and efficiently broadened to three optical octaves using a hollow core fiber setup (described in chapter 7). The spectral phase is characterized and demonstrates self-compression in the NIR around 1.3 μm. The process provides CEP-stable sub-2-cycle pulses in this regime directly, the shortest and most powerful reported to date. Furthermore, the spectral broadening in the infrared shows enhanced low-order harmonic gen- eration and cross-phase-modulation as the dominant mechanism. Experimentally the limited influence on the driver bandwidth is investigated. It is found that the processes allow using more efficient many-cycle infrared sources to generate several-octave spanning, compressible continua in the future. Even partial compression of these would then provide NIR transients for high-field experiments.
Fakultät für Mathematik, Informatik und Statistik - Digitale Hochschulschriften der LMU - Teil 01/02
Relational learning is concerned with learning from data where information is primarily represented in form of relations between entities. In recent years, this branch of machine learning has become increasingly important, as relational data is generated in an unprecedented amount and has become ubiquitous in many fields of application such as bioinformatics, artificial intelligence and social network analysis. However, relational learning is a very challenging task, due to the network structure and the high dimensionality of relational data. In this thesis we propose that tensor factorization can be the basis for scalable solutions for learning from relational data and present novel tensor factorization algorithms that are particularly suited for this task. In the first part of the thesis, we present the RESCAL model -- a novel tensor factorization for relational learning -- and discuss its capabilities for exploiting the idiosyncratic properties of relational data. In particular, we show that, unlike existing tensor factorizations, our proposed method is capable of exploiting contextual information that is more distant in the relational graph. Furthermore, we present an efficient algorithm for computing the factorization. We show that our method achieves better or on-par results on common benchmark data sets, when compared to current state-of-the-art relational learning methods, while being significantly faster to compute. In the second part of the thesis, we focus on large-scale relational learning and its applications to Linked Data. By exploiting the inherent sparsity of relational data, an efficient computation of RESCAL can scale up to the size of large knowledge bases, consisting of millions of entities, hundreds of relations and billions of known facts. We show this analytically via a thorough analysis of the runtime and memory complexity of the algorithm as well as experimentally via the factorization of the YAGO2 core ontology and the prediction of relationships in this large knowledge base on a single desktop computer. Furthermore, we derive a new procedure to reduce the runtime complexity for regularized factorizations from O(r^5) to O(r^3) -- where r denotes the number of latent components of the factorization -- by exploiting special properties of the factorization. We also present an efficient method for including attributes of entities in the factorization through a novel coupled tensor-matrix factorization. Experimentally, we show that RESCAL allows us to approach several relational learning tasks that are important to Linked Data. In the third part of this thesis, we focus on the theoretical analysis of learning with tensor factorizations. Although tensor factorizations have become increasingly popular for solving machine learning tasks on various forms of structured data, there exist only very few theoretical results on the generalization abilities of these methods. Here, we present the first known generalization error bounds for tensor factorizations. To derive these bounds, we extend known bounds for matrix factorizations to the tensor case. Furthermore, we analyze how these bounds behave for learning on over- and understructured representations, for instance, when matrix factorizations are applied to tensor data. In the course of deriving generalization bounds, we also discuss the tensor product as a principled way to represent structured data in vector spaces for machine learning tasks. In addition, we evaluate our theoretical discussion with experiments on synthetic data, which support our analysis.
Fakultät für Physik - Digitale Hochschulschriften der LMU - Teil 04/05
Self-assembled InGaAs quantum dots are nano-objects embedded in the solid-state matrix of GaAs. They act as natural potential traps for charge carriers and feature a number of quantized states due to the quantum confinement. When incorporated in a field effect structure the quantum dot states can be conveniently manipulated with an electric field and probed by resonant laser spectroscopy. In this thesis self-assembled quantum dots were investigated with an emphasis on the study of interactions between localized quantum dot states and charge or spin reservoirs in the environment. Experimentally the quantum dots were addressed in distinct regimes where the quantum dot spectrum was sensitive to individual charge fluctuations or mesoscopic reservoirs. The fundamental transition of a neutral quantum dot was found to exhibit a number of discontinuities in the usually linear dispersion of the exciton energy in external electrostatic fields. The discontinuities were identified to arise from charge fluctuations in the surrounding crystalline matrix in which impurity atoms can capture or release electrons. At characteristic conditions charging and discharging events lead to discrete changes of the electrostatic environment which in turn gives rise to an energy shift of the optical resonance condition. An electrostatic model was developed for a quantitative analysis of charging events and their signatures. On the basis of the model a comprehensive study of nearby quantum dots allowed to map out the relative spatial positions of quantum dots and impurities. In contrast to previous reports our results provide evidence for bulk impurities as the main source of charge fluctuations. By means of resonant laser spectroscopy in the energy dispersion of the neutral exciton a kink with a continuous energy shift has been observed which only occurs close to the regime where an electron is tunneling between the quantum dot and a 2D electron reservoir. The tunneling induces a weak coupling between the localized electron state of the quantum dot and the continuum of states in the reservoir. The tunnel coupling between the interacting states leads to hybridization into a new superposition state. In consequence the energy of the transition is renormalized which explains the kink in the energy dispersion. The hybridization model based on an Anderson-Fano approach quantitatively agrees with the experimental data and allows to extract the coupling strength between the reservoir and the localized state. In addition to the neutral exciton hybridization effects were also ob-served on the charged exciton. To study optical signatures of many-body effects sub-K laser spectroscopy was established and the setup performance was characterized with optical studies of a quantum dot in the Pauli-blockade regime. The electron bath temperature was determined using experimental and calculated electron spin populations as a function of magnetic field and temperature. The experiment provided quantitative access to all parameters except the electron bath temperature. With the optical Bloch equations the electron spin populations were modeled taking into account all relevant external parameters. An analysis of the evolution of the spin population in magnetic fields with the electron bath temperature as the only free fitting parameter was performed. An electron bath temperature of 380 mK was derived being slightly offset to the nominal base temperature of 250 mK. This proves the successful implementation of the sub-K laser spectroscopy setup.
Fakultät für Physik - Digitale Hochschulschriften der LMU - Teil 04/05
The production of a quantum gas with strong long - range dipolar interactions is a major scientific goal in the research field of ultracold gases. In their ro - vibrational ground state Li -K dimers possess a large permanent dipole moment, which could possibly be exploited for the realization of such a quantum gas. A production of these molecules can be achieved by the association of Li and K at a Feshbach resonance, followed by a coherent state transfer. In this thesis, detailed theoretical an experimental preparations to achieve state transfer by means of Stimulated Raman Adiabatic Passage (STIRAP) are described. The theoretical preparations focus on the selection of an electronically excited molecular state that is suitable for STIRAP transfer. In this context, molecular transition dipole moments for both transitions involved in STIRAP transfer are predicted for the first time. This is achieved by the calculation of Franck -Condon factors and a determination of the state in which the 6Li - 40K Feshbach molecules are produced. The calculations show that state transfer by use of a single STIRAP sequence is experimentally very well feasible. Further, the optical wavelengths that are needed to address the selected states are calculated. The high accuracy of the data will allow to carry out the molecular spectroscopy in a fast and efficient manner. Further, only a comparatively narrow wavelength tuneability of the spectroscopy lasers is needed. The most suitable Feshbach resonance for the production of 6Li - 40K molecules at experimentally manageable magnetic field strengths is occurring at 155G. Experimentally, this resonance is investigated by means of cross - dimensional relaxation. The application of the technique at various magnetic field strengths in the vicinity of the 155G Feshbach resonance allows a determination of the resonance position and width with so far unreached precision. This reveals the production of molecules on the atomic side of the resonance, thereby establishing the first observation of a many body effect in the crossover regime of a narrow Feshbach resonance. Further, mass dependent factors, with which the equilibration of an induced anisotropic temperature of the trapped particle samples can be described, are experimentally determined for the first time. The type of resonance as well as the measured molecular lifetimes are found to be very well suited for STIRAP transfer. A Raman laser system is designed based on the transition wavelengths and durations of state transfer which are predicted. As the wavelengths of the Raman lasers differ widely but coherence of the light fields is needed, the technical realization of a laser system is challenging. As a part of the laser system, the construction and characterization of a reference optical resonator are presented. Laser frequency stabilization with a linewidth of approximately 500Hz and an Allan deviation below 10−12 for timespans up to several ten seconds are demonstrated. Further, the stabilization of a frequency comb to this reference laser is demonstrated. For the laser spectroscopy of electronically excited Li -K states an interferometric laser frequency stabilization will be used. The device is a commercial design, for which a calibration procedure that enhances the precision by several orders of magnitude is worked out within this thesis. The calibration scheme includes the precise measurement of the stabilization’s wavelength dependent frequency deviations by means of a frequency comb. By the implementation of several calibration steps a remaining frequency deviation of less than 5.7MHz (rms 1.6MHz) in the whole relevant wavelength range 750 - 795 nm is achieved. Only the exceptional precision of the fully calibrated device permits the usage for the Li -K spectroscopy, while the demonstrated wide tuning capability facilitates the completion of the latter in a fast and convenient manner.
After some delay, a new tune. I hadn't done a drone piece in a while, so that's what I went for here. Experimentally, I also added quite a bit of high end harmonics. I tend to stay away from the upper ranges but this time it seemed like it might work. I hope it did.Binaural beat of 10Hz this time, good for alert listening.Includes artwork! The lossless version will be posted later today at Binaural Banjo Lossless.Ultima
Fakultät für Chemie und Pharmazie - Digitale Hochschulschriften der LMU - Teil 03/06
Quantum control spectroscopy denotes the combination of optical quantum coherent control with femtosecond spectroscopy. The molecular response to a photo induced process, controlled by shaped ultrashort light pulses, carries information about the system and the induced chemical reaction not obtainable by unshaped pulses. In this work quantum control spectroscopy is used to investigate the photochemical process of beta-carotene during its first few hundred femtoseconds, which are important in the photosynthesis of light harvesting complexes. A special class of shaped pulses, called pulse trains, are investigated. Pulse trains are obtained from Fourier limited pulses, by modulation with a sinusoidal phase mask $phi(omega) = a sin(bomega_0+c)$, leading to a sequence of three or more phase stabilized Gaussian shaped pulses in the time domain. The intensities of these pulses are defined by a, they are separated by equal interpulse distances b and have a distinct phase relation which is defined by c. In this work it will be shown that it is possible to draw a very unique relation between molecular properties and the molecular response to the electrical field in dependance of these parameters. In terms of quantum coherent control, sinusoidal modulated pulse trains have attracted special attention in the context of mode selectivity. In a series of experiments it was observed that pulse train excitation can suppress spectral features in the detection signal when the interpulse distance is adjusted to molecular characteristics like vibrational frequencies. Furthermore, in many control experiments aiming to steer a chemical reaction, the use of learning loops for field optimization leads to pulse shapes that could be reduced to sequences of pulses, comparable to the pulse trains introduced. Replacement of optimized light fields by appropriate adjusted pulse trains were successful in experiments controlling the energy flow in a light harvesting complex. Control could be obtained by variation of the phase parameter c, suggesting that the achieved effect was of coherent origin. The assumption that the carotene units in LH2 were responsible for the successful control, was the motivation for the presented work of quantum control spectroscopy of beta-carotene. Although many efforts have been made to understand the non-linear effects induced by pulse trains, the underlying mechanism is not yet clear. Neither the background of mode selectivity nor the mechanism of chemical reaction control could be deciphered satisfactorily. For spectroscopical investigations, however, the knowledge of the underlying process and its connection to the molecular response is inevitable and are analyzed in detail. Starting with a simple model of bound states in a diatomic molecule, the induced dynamics of the molecular system and the characteristics of the response field are analyzed. First phenomenological investigations of the pulse train induced wave packet dynamics show dependancies between the populations and coherences of the generated molecular state and the choice of the sinusoidal mask parameters. Further investigations imply a mechanism connecting the outcome of the control experiment with the pulse train parameters and the molecular properties which is confirmed by derivation of a formula based on time dependent perturbation theory. The proposed mechanism leads to results which are in accordance with many experimentally observed effects. It is found that pulse train excitation generates vibrational wave packets that can exhibit symmetric phase space structures. Comparable structures appear during long time evolution after excitation with Fourier limited pulses and are known as partial revival states. Experimentally observed effects, like annihilation of spectral signals, are attributed to temporal interference effects between phase shifted vibrational coherences of these symmetric phase space structures. Contribution of such temporal interference effects are found to be essential for the signal interpretation in the case of time limited detection periods in the femtosecond regime. From a detailed analysis rules are extracted which serve to predict and to interprete the outcome of quantum control experiments using sinusoidally modulated pulse trains. It is found that the degree of rotational symmetry of the generated phase space pattern is determined by the ratio of the classical oscillation period of a vibrational mode to the interpulse distance b. In contrast, at a fixed value of b, the variation of the phase parameter c causes an oscillatory exchange between phase shifted components of the generated phase space structures, leading to an oscillatory disturbance of the phase space symmetry. While the phase space symmetry induced by b leads to destructive interference of spectral signals, this effect can be partially removed by c. The resulting oscillations of the peak amplitudes with c reflect the symmetry of the b-generated phase space structures. In a next step the model is extended towards the description of complex biological systems. Investigated are environmental effects, the model expansion to polyatomic molecules and the influence of electronic coupling elements, leading to the participation of additional electronic states. Using the density matrix description, the influence on the pulse train mechanism of elastic and inelastic environmental processes is investigated. Limits are figured out, defining the scope of the extracted rules for the two mask parameters b and c in dissipative environment. Increasing the dimensionality of the model, it is found that the derived mechanism still holds in polyatomic molecules. In accordance with experimental results, it is possible to damp spectral signals of selective vibrational modes by the mentioned destructive interference effects, adapting the interpulse distance to participating modes. By combination of the effects of b and c it is even possible to selectively damp near resonant modes. To come closer to the description of beta-carotene, the model system is extended by an additional diabatically coupled electronic state. Now the spectroscopic response function after Fourier limited excitation, recording the evolution of the excited state population, comprises information exclusively of the reactive coupling modes. Thus, the electronic coupling process can be traced without disturbance of inreactive spectator modes by detection of the excited state population, acting as a window to coupling modes. Additionally it is shown, that the mechanism of pulse train excitation found for bound state potentials still holds in the presence of electronic coupling. The described interference effects appearing in the spectroscopical signals after pulse train excitation, show that a rethinking is required in the interpretation of pulse train control experiments. On the other hand, the different aspects of pulse train control offer a manifold of new applications in various fields of spectroscopy. Parallels to experiments, applying pulse trains under different conditions, like for example nonresonant excitation, lead to the assumption, that the introduced effects are more general. Pulse trains in spectroscopy may enhance the sensitivity and the selectivity of spectral features and could be applied to achieve higher contrast in coherent microscopy. By selective damping of near-resonant modes, application of pulse trains in combination with transient spectroscopy could provide access to the direct observation of dynamical processes. Furthermore, the characteristic response to parameter variations under pulse train excitation can serve to differentiate between vibrational and electronic origins of spectral features. It is this method, that is used in the present work to apply quantum control spectroscopy to the early steps of the photochemical process in beta-carotene, i.e. the energy loss channel due to quenching via a conical intersection. Based on experimental observations, by the described modular construction a model system for beta-carotene is proposed, comprising the key components of the induced photochemical energy transfer process during the first few hundred femtoseconds. The outcome of quantum control experiments of beta-carotene could be predicted and interpreted. By comparison with results of quantum control experiments on beta-carotene, performed in the group of M.~Motzkus (Heidelberg University), it is possible to verify the key assumptions made for the construction of the model system. Observed spectral features in dependance of the parameters b and c can be definitely assigned to vibrational coherences, indicating that a low frequency mode is responsible for the electronic coupling between the excited states S2 and S1 of beta-carotene. The achieved agreement between simulations and experimental results allow to conclude that the process of investigation is described well within the constructed beta-carotene model. The photochemical quenching process takes place on solely two excited states and no further electronic state plays a mentionable role.
Abstract: Low energy nuclear structure physics is entering an exciting new era. Experimentally a new generation of rare isotope accelerators, such as the Rare Isotope Beam Facility (RIBF) in Japan, the Facility for Antiproton and Ion Research (FAIR) in Germany, the Systeme de Production d'Ions Radioactifs en Ligne, RIB Facility (SPIRAL) in France, and the Facility for Rare Isotope Beams (FRIB), to be constructed at Michigan State University, will allow for the study of so-called exotic nuclei, i.e., those nuclei far from the line of stability and near the proton and neutron drip lines. Theoretically great progress has been made in the last ten years in understanding the structure and properties of the atomic nucleus starting from the basic interactions among the neutrons and the protons (collectively called nucleons) and employing only quantum mechanical many-body theory. This progress is due to new developments in nuclear many-body theory and advances in computer technology (see, e.g., Physics Today, 60, No. 11, 48 (2007)). Research at the University of Arizona has been at the forefront of these investigations with the development of the No Core Shell Model (NCSM), which can successfully describe the properties of light nuclei starting from the fundamental interactions among the nucleons. The NCSM will be described, examples of applications will be given and challenges for the future will be discussed. Dr. Barrett's research interest centers on nuclear-structure theory, mainly on microscopic theories of nuclear structure utilizing the large-basis, no-core shell-model approach and the quantum many-body theory of effective interactions and operators.Presented Sept. 18, 2009.
Transcript -- The ways in which prototype gliders are tested, producing accurate polar curves.
The ways in which prototype gliders are tested, producing accurate polar curves.
Transcript -- The ways in which prototype gliders are tested, producing accurate polar curves.
The ways in which prototype gliders are tested, producing accurate polar curves.
Fakultät für Physik - Digitale Hochschulschriften der LMU - Teil 02/05
This thesis work investigates the measurement of ion temperatures at the edge of a magnetically confined plasma used for fusion research at the ASDEX Upgrade tokamak operated by Max-Planck-Institut für Plasmaphysik in Garching. The tokamak is the most advanced concept in toroidal magnetic confinement fusion. The H-mode plasma regime, default scenario of the next step experiment ITER, is characterized by an edge transport barrier, which is not yet fully explained by theory. Experimentally measured edge ion temperature profiles will help to test and develop models for these barriers. Transport theory on a basic level is introduced as background and motivation for the new diagnostic. The standard model for an edge plasma instability named "edge localized mode" (ELM) observed in H-mode is described. The implementation of a new diagnostic for ion temperature measurements with high spatial resolution in the plasma edge region, its commissioning and the validation of the measurements comprises the main part of this work. The emission of line radiation induced by charge exchange processes between lithium atoms injected by a beam source and fully ionized impurities (of C and He) is observed with a detection system consisting of spectrometers and fast cameras. Due to the narrow beam (1 cm) and closely staggered optical fibers (6 mm), unprecedented spatial resolution of edge ion temperatures in all major plasma regimes of the ASDEX Upgrade tokamak was achieved. The spectral width of the line radiation (He II at 468.5 nm and C VI at 529.0 nm) contains information about the local ion temperature from thermal Doppler-broadening, which is the dominant broadening mechanism for these lines. The charge-exchange contribution to the total line radiation locally generated by the lithium is determined by gating the beam. Fitting a Gaussian model function to the local line radiation results in absolute line widths which can be directly converted into a temperature. The equilibration of impurities with the main plasma is fast enough that the assumption of nearly identical temperatures as the main plasma is justified. Corrections for systematic line broadening effects from collisional mixing and Zeeman broadening are incorporated by model calculations using existing routines for the involved atomic physics. Time resolution of the diagnostic is still not suffcient to resolve ELM events, but measuring between ELMs is possible if their frequency is low. L-mode plasmas with and without additional heating can be reliably diagnosed with a time resolution depending on the lithium beam intensity and plasma density, in best cases down to 100 ms. It was shown that diagnostic He puffing can be used to enhance the signal-to-noise ratio. Results from L-mode plasmas with electron heating show that ion temperatures can be significantly different from electron temperatures at the edge. For the verification of the new ion temperatures, comparison with data from already established diagnostics was done. In neutral beam heated L-mode and various H-mode plasmas the ion temperatures agree with those from a similar diagnostic measuring in the core using heating beams where both diagnostics overlap. They can be combined to form a complete ion temperature profile over the whole plasma radius. In a first application, transport coefficients have been determined by interpretative modeling for an ohmic plasma. In summary, a new method for measuring ion temperatures in the edge of a magnetically confined fusion plasma has been established. The results provide an important input to further understanding of transport in these plasmas.
Fakultät für Physik - Digitale Hochschulschriften der LMU - Teil 01/05
The scope of the thesis is to demonstrate the feasibility to examine magnetization profiles of thin films and multilayer systems via magnetic soft and hard x-ray reflectivity. The focus here is on 3d transition metals, which are used mainly for development of numerous noval magnetic devices, that are both technologically and scientifically interesting. Complementary to Neutron diffraction, which is the standard tool for the examination of magnetic structures in matter, magnetic x-ray diffraction permits to study small samples and exhibits better Qz-resolution due its small and only slightly divergent beam. The biggest advantage is its element specificity, which enables one to probe different magnetic sites separately. The method of magnetic x-ray reflectivity combines the strong magnetic circular dichroism (MCD) effect, significantly enhancing the magnetic sensitivity of x-rays, with the technique of conventional specular reflectivity, a well established tool for the structural studies of the chemical makeup of thin films and artificial multilayer systems. The theory of resonant magnetic scattering within dipole approximation combined with the specular reflectivity condition suggests that the strongest effects are in the lower incident angle regime using circularly polarized x-rays. By using soft and hard x-rays structures on a scale of a few to several hundreds of Å are probed, which is the dimensions of the thicknesses of the layers of most thin film and multilayers systems. In order to retrieve quantitative information from the measured magnetic reflectivity curves, an approach for visible light magneto-optical effects based on known dielectric tensors of the sample has been adopted and applied for soft and hard x-ray resonant scattering. Sample absorption and polarization changes in the sample are accounted for. Besides the structural composition, the thickness of the individual layers and the index of refraction, also the magnetic spin configuration can be chosen with arbitrary moment direction and magnitude by modifying the off-diagonal terms in the dielectric tensor. The magnetic optical constants, which determine the magnitude of the magnetic moments, are experimentally determined via MCD absorption measurements and then retrieving the real part through the Kramers-Kronig transformation of the measured imaginary part. This is shown in this work for several 3d transition metals and edges. The simulations are sensitive to a variety of different spin configurations: spiral spin structures, magnetic dead layers and of collinear alignment. Experimentally the magnetic reflectivity of 3d transition metals has to distinguish between the two available possible absorbtion edges, L and K, lying in different x-ray regions. The L-edges are situated in the soft x-ray region and exhibit large enhancements of the magnetic cross section, while the K-edges lie in the hard x-ray regime and show much smaller effects. In spite of this handicap, the latter can be important due to the much larger penetration depth and better Qz-resolution. The X13 beamline at the NSLS at Brookhaven National Laboratory consisting of two branches for soft and hard-x ray operations, respectively, uses an elliptical polarized wiggler (EPW), which produces circularly polarized x-rays in the orbit plane and allows fast switching between left and right circular polarization. Lock-in detection is used to improve the signal-to-noise ratio at the soft x-ray branch and single photon detection at the hard x-ray branch to measure the magnetic signal. The EPW and the experimental setup was commissioned to demonstrate the feasibility of magnetic x-ray experiments. Especially at the hard x-ray beamline branch the small magnetic effects, less than 0.1% of the charge scattering, were possible to detect. In order to satisfy the need for high flux the CMC-CAT beamline at the APS in Argonne was used for magnetic hard x-ray reflectivity, providing an undulator beamline where the high flux of linear polarized photons was converted into circular polarization via a diamond phase plate, delivering much higher flux and better circular polarization. The sample used to demonstrate the feasibility of the method of magnetic reflectivity consists of two multilayer structures of Fe/Cr on top of each other, where the iron spins of the upper are ferromagnetically and of the lower antiferromagnetically coupled, representing an exchange bias system. The sample was characterized with conventional x-ray reflectivity and MOKE measurements in order to accurately determine the structural composition and magnetic configuration (hysteresis loops), respectively. Magnetic reflectivity experiments on the L-edges at the X13A beamline showed strong magnetic effects, which could be clearly identified as ferromagnetic and antiferromagnetic Bragg peak contributions and simulation confirmed the collinear alignment and full magnetization of the iron spins throughout the iron layers. Energyand magnetic field dependent measurements complete the picture. By tuning the x-ray energy to the chromium L-edge, a signal 20 times weaker compared with iron, demonstrates that the weak magnetic moment in the chromium layers could be detected. Especially the AFM contribution shows strong effects which could be qualitatively and quantitatively evaluated. Simulation show clearly that the magnetic moment is concentrated at the interfaces and could be approximated to a magnetic layer with an effective thickness of about 0.5 Å assuming a step function in the magnetization profile. Soft x-ray data usually suffer from strong absorption and the limited Qz-range and resolution and therefore the use of hard x-rays seems desirable to probe the whole sample. Magnetic hard x-ray reflectivity measurements on the Fe/Cr double multilayer carried out at the CMC beamline by switching the magnetic field on the sample show clear magnetic Bragg reflection at the ferromagnetic structural peaks. They are very well reproduced by simulations and thus confirm the collinear alignment of the iron spins. In order to probe the AFM spin configuration the helicity of the photon beam has to be switched with constant magnetic field. In spite of complications in the reflectivity spectra it was possible to extract the relative orientation of the AFM to FM spin configuration in the two multilayers. In summary the work showed for the example of an Fe/Cr double multilayer that magnetic soft and hard x-ray reflectivity can be applied to retrieve information about the magnetization profile of thin magnetic films and multilayer, and can compliment polarized neutron scattering.
In bats conventional stereotaxic methods do not yield sufficient positional accuracy to allow reliable recordings and tracer injections in subnuclei of the auditory system. In a newly developed stereotaxic system experimentally measured patterns of skull profile lines are used to define the animal's brain position with an accuracy of ±100 μm. By combining the neurophysiological stereotaxic procedure with a standardization of the neuroanatomical processing of the brains, the location of recordings, stimulations or injections can be readily transformed into brain atlas coordinates. This facilitates the compilation and comparison of data within and among animals. The system is not restricted to use in bats and can be readily adapted to other experimental animals.
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