Podcasts about lotka volterra

On episode 28 of CheloniaCast Ken and Michael sit down with ecologist Dr. Luca Luiselli of Rivers State University and Roma Tre University and Pearson McGovern of the African Chelonian Institute to discuss turtle conservation in West Africa and using mathematical models to make predictions about turtle populations. The discussion ranges from what it was like to discover the Nubian Flapshell in South Sudan and Uganda, use of Lotka-Volterra models to understand turtle population dynamics, Kinixys conservation, and what it is like to do conservation work in Africa.    Learn more about the CheloniaCast Podcast and Student Research Fund at theturtleroom.org/cheloniacast - 100% of proceeds from donations to the CheloniaCast Fund go towards enhancing turtle conservation programs.    You can learn more about Dr. Luiselli's work at: https://www.researchgate.net/profile/Luca-Luiselli You can learn more about Pearson's work at: https://www.researchgate.net/profile/Pearson-Mcgovern Learn more about the African Chelonian Institute at: https://africanchelonian.org/   Follow the CheloniaCast Podcast on Instagram/Facebook @cheloniacast    Host social media (Instagram/Facebook) - Jason Wills (@chelonian.carter) / Michael Skibsted (@michael.skibstedd) / Jack Thompson (@jack_reptile_naturalist_302) / Ken Wang (@americanmamushi)

Authors of the new book, Make: Calculus, Joan Horvath and Rich Cameron talk about using Legos and 3D printed models to create visualizations that help anyone learn calculus. After we talk about the book, Joan and Rich show some of the models that demonstrate Lotka Volterra equations, for instance. You might prefer to see that portion as a video, which is available at: https://youtu.be/a0v4fUSFl2UFor a transcript and additional info, go to https://makezine.com/article/education/a-better-way-to-learn-calculus/Make: Education Forum link: https://make.co/educationforum/

Puntata 415, che voi lo vogliate o no. In apertura – su richiesta da Telegram – Marco e Romina descrivono il funzionamento dei vari tipi di rivelatori di particelle e di come vadano adattati ai vari contesti di misura (spazio, terra, sottoterra).Kuna intervista Martina Carnio, laureata in ingegneria aeronautica e una tra i molti organizzatori del festival Galactic Park ( http://www.galacticpark.it/ ) che si svolgerà tra il Civico Planetario Ulrico Hoepli ( https://lofficina.eu/ ) e i Giardini di Porta Venezia di Milano, il prossimo 24 settembre. Martina ci svela un po' l'evento, racconta l'esperienza di organizzare un festival a tema scientifico per la prima volta e dà qualche consiglio a un appassionato che volesse cimentarsi a fare lo stesso. Dopo la solita barza, Romina ci racconta di come l'equazione di Lotka-Volterra descrive il rapporto tra prede e predatori.

Topological phases were discovered in condensed matter physics and recently extended to classical physics such as topological mechanical metamaterials. Their study and realization in soft-matter and biological systems has only started to develop. In this talk we discuss how topological phases may determine the behavior of nonlinear dynamical systems that arise, for example, in population dynamics. We have shown that topological phases can be realized with the anti-symmetric Lotka-Volterra equation (ALVE). The ALVE is a paradigmatic model system in population dynamics and governs, for example, the evolutionary dynamics of zero-sum games, such as the rock-paper-scissors game [1], but also describes the condensation of non-interacting bosons in driven-dissipative set-ups [2]. We have shown that for the ALVE, defined on a one-dimensional chain of rock-paper-scissors cycles, robust polarization emerges at the chain’s edge [3]. The system undergoes a transition from left to right polarization as the control parameter passes through a critical value. At the critical point, solitary waves are observed. We found that the polarization states are topological phases and that this transition is indeed a topological phase transition. Remarkably, this phase transition falls into symmetry class D within the “ten-fold way” classification scheme of gapped free-fermion systems, which also applies, for example, to one-dimensional topological superconductors. Beyond the observation of topological phases in the ALVE, it might be possible to generalize the approach of our work to other dynamical systems in biological physics whose attractors are nonlinear oscillators or limit cycles. [1] J. Knebel, T. Krüger, M. F. Weber, and E. Frey, Phys. Rev. Lett. 110, 168106 (2013). [2] J. Knebel, M. F. Weber, T. Krüger, and E. Frey, Nature Communications 6, 6977 (2015). [3] J. Knebel, P. M. Geiger, and E. Frey, Phys. Rev. Lett. (in press) [arXiv:2009.01780].

Hallo, schön, dass Du wieder mit mir gemeinsam für das Abitur lernen möchtest. Deshalb werden wir beide uns noch einmal das Thema Ökologie anschauen, um auch dort einen guten Überblick gewinnen zu können. :) Heute werden wir uns den Lotka-Volterra-Regeln widmen, bevor ich Dir diese aber erkläre, möchte ich Dir zunächst die Räuber-Beute-Beziehung näherbringen, weil diese für die Lotka-Volterra-Regeln maßgeblich sind. Anschließend schauen wir uns die Lotka-Volterra-Regeln an, die insgesamt drei Regeln umfassen. Ich werde sie Dir an einem Beispiel veranschaulichen und oft wiederholen, damit Du auch alles verstehst. Dein Name als Unterstützer am Anfang jeder Podcast-Folge? Ich werde Dich am Anfang der nächsten Podcast-Folge namentlich aufführen. Wenn Dir der Podcast zu einem besseren Gefühl oder einer besseren Note verholfen hat, dann freue ich mich über Deine Unterstützung, damit können wir sicherstellen, dass wir weiterhin für Dich tolle Lerninhalte präsentieren können. Mit Paypal kannst Du uns mit folgendem Link unterstützen: paypal.me/abiturcrashkurs Auch mit einer Bewertung bei Apple Podcasts oder einer lieben Nachricht von Dir kannst Du uns gern unterstützen ❤ Audiovisuelle Direktion & Produktion: Christian Horn

การอธิบายเหตุการณ์ในสังคม หรือมุมมองเรื่องการเดินทางของชีวิต จากมุมมอง The Lotka-Volterra and Wator simulation predator and prey models

Tillbaka till Prolog! Samuel samtalar med Alma Johansson(Som medverkade både i avsnitten om Lotka-Volterra och Tundlaheim.  Idag pratar de om Almas nya lajv Projekt Midgård. Ett nutida lajv om halvgudar i den nordiska mytologin som samlas för att förbereda sig på ragnarök. DOWNOLAD

Sup?! This is an episode in English. Weird! But then again so was Lotka-Volterra. In English that is, not weird. Although… Ok. I’m derailing. Podcast wonderchild Samuel Pontén and Friend of Lajvpodden Alma Johansson got together after Lotka-Volterra to talk about our thoughts and feelings about the bunker experience. We also managed to get some… Fortsätt läsa Episode 43: Bombshell or Bunkertastic?

Kan hända att du sitter där ute i världen och panikpatinerar i detta nu. Fixar det sista på din outfit till eventet som du betalat typ flera pengar för att åka på. Då passar detta avsnitt perfekt! På prolog hann vi även med att prata med Olle Nyman och Sebastian Utbult om Lotka-Volterra. Det är… Fortsätt läsa Avsnitt 41,5: Liten kort Bunkerspecial

The classic Lotka-Volterra model of predator-prey competition is a nonlinear system of two equations, where one species grows exponentially and the other decays exponentially in the absence of the other. The program "predprey" studies this model.

How do populations evolve? This question inspired Alberto Saldaña to his PhD thesis on Partial symmetries of solutions to nonlinear elliptic and parabolic problems in bounded radial domains. He considered an extended Lotka-Volterra models which is describing the dynamics of two species such as wolves in a bounded radial domain: For each species, the model contains the diffusion of a individual beings, the birth rate , the saturation rate or concentration , and the aggressiveness rate . Starting from an initial condition, a distribution of and in the regarded domain, above equations with additional constraints for well-posedness will describe the future outcome. In the long run, this could either be co-existence, or extinction of one or both species. In case of co-existence, the question is how they will separate on the assumed radial bounded domain. For this, he adapted a moving plane method. On a bounded domain, the given boundary conditions are an important aspect for the mathematical model: In this setup, a homogeneous Neumann boundary condition can represent a fence, which no-one, or no wolve, can cross, wereas a homogeneous Dirichlet boundary condition assumes a lethal boundary, such as an electric fence or cliff, which sets the density of living, or surviving, individuals touching the boundary to zero. The initial conditions, that is the distribution of the wolf species, were quite general but assumed to be nearly reflectional symmetric. The analytical treatment of the system was less tedious in the case of Neumann boundary conditions due to reflection symmetry at the boundary, similar to the method of image charges in electrostatics. The case of Dirichlet boundary conditions needed more analytical results, such as the Serrin's boundary point lemma. It turned out, that asymtotically in both cases the two species will separate into two symmetric functions. Here, Saldaña introduced a new aspect to this problem: He let the birth rate, saturation rate and agressiveness rate vary in time. This time-dependence modelled seasons, such as wolves behaviour depends on food availability. The Lotka-Volterra model can also be adapted to a predator-prey setting or a cooperative setting, where the two species live symbiotically. In the latter case, there also is an asymptotical solution, in which the two species do not separate- they stay together. Alberto Saldaña startet his academic career in Mexico where he found his love for mathematical analysis. He then did his Ph.D. in Frankfurt, and now he is a Post-Doc in the Mathematical Department at the University of Brussels. Literature and additional material A. Saldaña, T. Weth: On the asymptotic shape of solutions to Neumann problems for non-cooperative parabolic systems, Journal of Dynamics and Differential Equations,Volume 27, Issue 2, pp 307-332, 2015. A. Saldaña: Qualitative properties of coexistence and semi-trivial limit profiles of nonautonomous nonlinear parabolic Dirichlet systems, Nonlinear Analysis: Theory, Methods and Applications, 130:31 46, 2016. A. Saldaña: Partial symmetries of solutions to nonlinear elliptic and parabolic problems in bounded radial domains, PhD thesis, Johann Wolfgang Goethe-Universität Frankfurt am Main, Germany, 2014. A. Saldaña, T. Weth: Asymptotic axial symmetry of solutions of parabolic equations in bounded radial domains, Journal of Evolution Equations 12.3: 697-712, 2012.

How do populations evolve? This question inspired Alberto Saldaña to his PhD thesis on Partial symmetries of solutions to nonlinear elliptic and parabolic problems in bounded radial domains. He considered an extended Lotka-Volterra models which is describing the dynamics of two species such as wolves in a bounded radial domain: For each species, the model contains the diffusion of a individual beings, the birth rate , the saturation rate or concentration , and the aggressiveness rate . Starting from an initial condition, a distribution of and in the regarded domain, above equations with additional constraints for well-posedness will describe the future outcome. In the long run, this could either be co-existence, or extinction of one or both species. In case of co-existence, the question is how they will separate on the assumed radial bounded domain. For this, he adapted a moving plane method. On a bounded domain, the given boundary conditions are an important aspect for the mathematical model: In this setup, a homogeneous Neumann boundary condition can represent a fence, which no-one, or no wolve, can cross, wereas a homogeneous Dirichlet boundary condition assumes a lethal boundary, such as an electric fence or cliff, which sets the density of living, or surviving, individuals touching the boundary to zero. The initial conditions, that is the distribution of the wolf species, were quite general but assumed to be nearly reflectional symmetric. The analytical treatment of the system was less tedious in the case of Neumann boundary conditions due to reflection symmetry at the boundary, similar to the method of image charges in electrostatics. The case of Dirichlet boundary conditions needed more analytical results, such as the Serrin's boundary point lemma. It turned out, that asymtotically in both cases the two species will separate into two symmetric functions. Here, Saldaña introduced a new aspect to this problem: He let the birth rate, saturation rate and agressiveness rate vary in time. This time-dependence modelled seasons, such as wolves behaviour depends on food availability. The Lotka-Volterra model can also be adapted to a predator-prey setting or a cooperative setting, where the two species live symbiotically. In the latter case, there also is an asymptotical solution, in which the two species do not separate- they stay together. Alberto Saldaña startet his academic career in Mexico where he found his love for mathematical analysis. He then did his Ph.D. in Frankfurt, and now he is a Post-Doc in the Mathematical Department at the University of Brussels. Literature and additional material A. Saldaña, T. Weth: On the asymptotic shape of solutions to Neumann problems for non-cooperative parabolic systems, Journal of Dynamics and Differential Equations,Volume 27, Issue 2, pp 307-332, 2015. A. Saldaña: Qualitative properties of coexistence and semi-trivial limit profiles of nonautonomous nonlinear parabolic Dirichlet systems, Nonlinear Analysis: Theory, Methods and Applications, 130:31 46, 2016. A. Saldaña: Partial symmetries of solutions to nonlinear elliptic and parabolic problems in bounded radial domains, PhD thesis, Johann Wolfgang Goethe-Universität Frankfurt am Main, Germany, 2014. A. Saldaña, T. Weth: Asymptotic axial symmetry of solutions of parabolic equations in bounded radial domains, Journal of Evolution Equations 12.3: 697-712, 2012.

In this lecture, Prof. Jeff Gore finishes the discussion of the Lotka-Volterra competition model. He then moves on to the topic of non-transitive interactions, what he calls rock-paper-scissor interactions.

Transitions to absorbing states are of fundamental importance in nonequilibrium physics as well as ecology. In ecology, absorbing states correspond to the extinction of species. We here study the spatial population dynamics of three cyclically interacting species. The interaction scheme comprises both direct competition between species as in the cyclic Lotka-Volterra model, and separated selection and reproduction processes as in the May-Leonard model. We show that the dynamic processes leading to the transient maintenance of biodiversity are closely linked to attractors of the nonlinear dynamics for the overall species' concentrations. The characteristics of these global attractors change qualitatively at certain threshold values of the mobility and depend on the relative strength of the different types of competition between species. They give information about the scaling of extinction times with the system size and thereby the stability of biodiversity. We define an effective free energy as the negative logarithm of the probability to find the system in a specific global state before reaching one of the absorbing states. The global attractors then correspond to minima of this effective energy landscape and determine the most probable values for the species' global concentrations. As in equilibrium thermodynamics, qualitative changes in the effective free energy landscape indicate and characterize the underlying nonequilibrium phase transitions. We provide the complete phase diagrams for the population dynamics and give a comprehensive analysis of the spatio-temporal dynamics and routes to extinction in the respective phases.

Analyzing coexistence and survival scenarios of Lotka-Volterra (LV) networks in which the total biomass is conserved is of vital importance for the characterization of long-term dynamics of ecological communities. Here, we introduce a classification scheme for coexistence scenarios in these conservative LV models and quantify the extinction process by employing the Pfaffian of the network's interaction matrix. We illustrate our findings on global stability properties for general systems of four and five species and find a generalized scaling law for the extinction time.

Populations of competing biological species exhibit a fascinating interplay between the nonlinear dynamics of evolutionary selection forces and random fluctuations arising from the stochastic nature of the interactions. The processes leading to extinction of species, whose understanding is a key component in the study of evolution and biodiversity, are influenced by both of these factors. Here, we investigate a class of stochastic population dynamics models based on generalized Lotka-Volterra systems. In the case of neutral stability of the underlying deterministic model, the impact of intrinsic noise on the survival of species is dramatic: It destroys coexistence of interacting species on a time scale proportional to the population size. We introduce a new method based on stochastic averaging which allows one to understand this extinction process quantitatively by reduction to a lower-dimensional effective dynamics. This is performed analytically for two highly symmetrical models and can be generalized numerically to more complex situations. The extinction probability distributions and other quantities of interest we obtain show excellent agreement with simulations.

Title: “Analysing Language Shift: the Example of Scottish Gaelic" Abstract: ‘Language shift’ is the process whereby members of a community in which more than one language is spoken abandon their original vernacular language in favour of another. We model the dynamic of language shift as a Lotka-Volterra type competition process in which the numbers of speakers of each language and of the bilingual sub-population vary as a function both of internal recruitment (as the net outcome of birth, death, immigration and emigration), and of gains and losses due to language shift. In order to test the model we apply our approach to the English-Gaelic competition in Western Scotland. We are able to replicate the main dynamic of the shift process and give predictions about the future of the Gaelic language under unchanged environmental conditions. However, the Gaelic language is subject to recent governmental interventions whose objective are stable societal bilingualism - by creating or preserving segregated sociolinguistic domains, in each of which one or other language is the preferred medium of communication. To consider these effects we examine a second model in which bilingualism is no longer simply a transitional state. Superimposed on the basic shift dynamic there is an additional demand for the endangered language as the preferred medium of communication in some restricted sociolinguistic domains. The creation of segregated sociolinguistic domains can lead to stable co-existence and therewith be a successful maintenance strategy. Our model enables us to estimate e.g. for the English-Gaelic competition the strength of interventions needed in order to maintain the bilingual sub-population. Further, we analyse the crucial role of random drift for small numbers of speakers of the endangered languages and selective migration on the maintenance success.

Title: “Analysing Language Shift: the Example of Scottish Gaelic" Abstract: ‘Language shift’ is the process whereby members of a community in which more than one language is spoken abandon their original vernacular language in favour of another. We model the dynamic of language shift as a Lotka-Volterra type competition process in which the numbers of speakers of each language and of the bilingual sub-population vary as a function both of internal recruitment (as the net outcome of birth, death, immigration and emigration), and of gains and losses due to language shift. In order to test the model we apply our approach to the English-Gaelic competition in Western Scotland. We are able to replicate the main dynamic of the shift process and give predictions about the future of the Gaelic language under unchanged environmental conditions. However, the Gaelic language is subject to recent governmental interventions whose objective are stable societal bilingualism - by creating or preserving segregated sociolinguistic domains, in each of which one or other language is the preferred medium of communication. To consider these effects we examine a second model in which bilingualism is no longer simply a transitional state. Superimposed on the basic shift dynamic there is an additional demand for the endangered language as the preferred medium of communication in some restricted sociolinguistic domains. The creation of segregated sociolinguistic domains can lead to stable co-existence and therewith be a successful maintenance strategy. Our model enables us to estimate e.g. for the English-Gaelic competition the strength of interventions needed in order to maintain the bilingual sub-population. Further, we analyse the crucial role of random drift for small numbers of speakers of the endangered languages and selective migration on the maintenance success.

Cyclic dominance of species has been identified as a potential mechanism to maintain biodiversity, see, e.g., B. Kerr, M. A. Riley, M. W. Feldman and B. J. M. Bohannan Nature 418, 171 (2002)] and B. Kirkup and M. A. Riley Nature 428, 412 (2004)]. Through analytical methods supported by numerical simulations, we address this issue by studying the properties of a paradigmatic non-spatial three-species stochastic system, namely, the "rock-paper-scissors" or cyclic Lotka-Volterra model. While the deterministic approach (rate equations) predicts the coexistence of the species resulting in regular (yet neutrally stable) oscillations of the population densities, we demonstrate that fluctuations arising in the system with a finite number of agents drastically alter this picture and are responsible for extinction: After long enough time, two of the three species die out. As main findings we provide analytic estimates and numerical computation of the extinction probability at a given time. We also discuss the implications of our results for a broad class of competing population systems.