Press Releases 2013

In researching neural pathways, it helps to establish an analogous relationship between a region of the human brain and the brains of more-easily studied animal species. New work from a team led by Carnegie’s Marnie Halpern hones in on one particular region of the zebrafish brain that could help us understand the circuitry underlying nicotine addiction.

Around 250 million years ago, at the end of the Permian period, there was a mass extinction so severe that it remains the most traumatic known species die-off in Earth’s history. Some researchers have suggested that this extinction was triggered by contemporaneous volcanic eruptions in Siberia. New results from a team including Director of Carnegie's Department of Terrestrial Magnetism Linda Elkins-Tanton show that the atmospheric effects of these eruptions could have been devastating. 

Government calculations of total U.S. methane emissions may underestimate the true values by 50 percent, a new study finds. The results cast doubt on a recent Environmental Protection Agency decision to downscale its emissions estimate. 

Life originated as a result of natural processes that exploited early Earth’s raw materials. Scientific models of life’s origins almost always look to minerals for such essential tasks as the synthesis of life’s molecular building blocks or the supply of metabolic energy. But this assumes that the mineral species found on Earth today are much the same as they were during Earth’s first 550 million years—the Hadean Eon—when life emerged. A new analysis of Hadean mineralogy challenges that assumption. 

Inside every plant cell, a cytoskeleton provides an interior scaffolding to direct construction of the cell’s walls, and thus the growth of the organism as a whole. Environmental and hormonal signals that modulate cell growth cause reorganization of this scaffolding. New research led by Carnegie’s David Ehrhardt provides surprising evidence as to how this reorganization process works, with important evidence as to how the direction of a light source influences a plant’s growth pattern.  

A team of researchers including two Carnegie scientists used a novel astronomical survey software system—the intermediate Palomar Transient Factory (iPTF)—to link a new stripped-envelope supernova, named iPTF13bvn, to the star from which it exploded, which is a first for this type of supernova, called Type Ib. The iPTF team also pinpointed the first afterglow of an explosion called a gamma-ray burst that was found by the Fermi satellite.

For the first time, researchers have been able to map the true extent of gold mining in the biologically diverse region of Madre De Dios in the Peruvian Amazon. The team, led by Greg Asner, combined field surveys with airborne mapping and high-resolution satellite monitoring to show that the geographic extent of mining has increased 400% from 1999 to 2012 and that the average annual rate of forest loss has tripled since the Great Recession of 2008. Until this study, thousands of small, clandestine mines that have boomed since the economic crisis have gone unmonitored.

Reconstructing the rise of life during the period of Earth’s history when it first evolved is challenging. Earth’s oldest sedimentary rocks are not only rare, but also almost always altered by hydrothermal and tectonic activity. A new study from a team including Carnegie’s Nora Noffke, a visiting investigator, and Robert Hazen revealed the well-preserved remnants of a complex ecosystem in a nearly 3.5 billion-year-old sedimentary rock sequence in Australia. 

A great deal of research has focused on the amount of global warming resulting from increased greenhouse gas concentrations. But there has been relatively little study of the pace of the change following these increases. A new study by Carnegie’s Ken Caldeira and Nathan Myhrvold of Intellectual Ventures concludes that about half of the warming occurs within the first 10 years after an instantaneous step increase in atmospheric CO2 concentration, but about one-quarter of the warming occurs more than a century after the step increase.

A new planet-hunting survey has revealed planetary candidates with orbital periods as short as four hours and so close to their host stars that they are nearly skimming the stellar surface. If confirmed, these candidates would be among the closest planets to their stars discovered so far. Brian Jackson of the Carnegie Institution for Science’s Department of Terrestrial Magnetism will present his team’s findings, which are based on data from NASA’s Kepler mission, at the American Astronomical Society’s Division of Planetary Sciences meeting.

Coral reefs are tremendously important for ocean biodiversity, as well as for the economic and aesthetic value they provide to their surrounding communities. Unfortunately they have been in great decline in recent years, much of it due to the effects of global climate change. One such effect, called bleaching, occurs when the symbiotic algae that are essential for providing nutrients to the coral either lose their identifying photosynthetic pigmentation and their ability to perform photosynthesis or disappear entirely from the coral’s tissue. Without a healthy population of these algae, the coral cannot survive.

The Arabidopsis Information Resource (TAIR), a database of genetic and molecular biology data for the laboratory plant Arabidopsis thaliana, is one of the most widely used plant databases in the world. Some 60,000 scientists visit the site and view over 1,000,000 pages per month, and usage continues to climb. Funding from the National Science Foundation is ending soon and the program will begin transitioning to a subscription-based service in October.

Cells in the body wear down over time and die. In many organs, like the small intestine, adult stem cells play a vital role in maintaining function by replacing old cells with new ones. Learning about the nature of tissue stem cells can help scientists understand exactly how our organs are built, and why some organs generate cancer frequently, but others only rarely. New work from Carnegie’s Alexis Marianes and Allan Spradling used some of the most experimentally accessible tissue stem cells, the adult stem cells in the midsection of the fruit fly gut, with surprising results.

Researchers, including Alex Goncharov, have for the first time experimentally mimicked the pressure conditions of Earths’ deep mantle to measure thermal conductivity using a new measurement technique on the mantle material magnesium oxide (MgO). They found that heat transfer is lower than other predictions, with total heat flow across the Earth of about 10.4 terawatts, about 60 % of the power used today by civilization. They also found that conductivity has less dependence on pressure conditions than predicted.

Transport proteins are responsible for moving materials such as nutrients and metabolic products through a cell’s outer membrane, which seals and protects all living cells, to the cell’s interior. These transported molecules include sugars, which can be used to fuel growth or to respond to chemical signals of activity or stress outside of the cell. Measuring the activity of transporter proteins in a living organism has been a challenge for scientists, because the methods are difficult, often require the use of radioactive tracers, and are hard to use in intact tissues and organs. A team led by Wolf Frommer, director of Carnegie’s Plant Biology Department, has now developed a groundbreaking new way to overcome this technology gap.

Researchers reviewed the likelihood of continued changes to the terrestrial climate, including an analysis of a collection of 27 climate models. If emissions of heat-trapping gases continue along the recent trajectory, 21st century mean annual global warming could exceed 3.6 °F ( 2 °C) over most terrestrial regions during 2046 to 2065 and 7.2 °F (4 °C) during 2081-2100.At this pace, it will probably be the most rapid large climate change in the last 65 million years.

Hydrogen is deceptively simple. It has only a single electron per atom, but it powers the sun and forms the majority of the observed universe. As such, it is naturally exposed to the entire range of pressures and temperatures available in the whole cosmos. But researchers are still struggling to understand even basic aspects of its various forms under high-pressure conditions. New work from a team at Carnegie’s Geophysical Laboratory makes significant additions to our understanding of this vital element’s high-pressure behavior.

Proper tissue function and regeneration is supported by stem cells, which reside in so-called niches. New work from Carnegie’s Yixian Zheng and Haiyang Chen identifies an important component for regulating stem cell niches, with impacts on tissue building and function. The results could have implications for disease research.

Comets and meteorites contain clues to our solar system's earliest days. But some of the findings are puzzle pieces that don't seem to fit well together. A new set of theoretical models from Carnegie's Alan Boss shows how an outburst event in the Sun's formative years could explain some of this disparate evidence. His work could have implications for the hunt for habitable planets outside of our solar system.

A study published in the July 17, issue of the journal PLOS ONE found that more than 80% of tropical forests in Malaysian Borneo have been heavily impacted by logging.

A team of scientists led by Carnegie’s Lin Wang has observed a new form of very hard carbon clusters, which are unusual in their mix of crystalline and disordered structure. The material is capable of indenting diamond. This finding has potential applications for a range of mechanical, electronic, and electrochemical uses.

For years, scientists have debated how big a role elephants play in toppling trees in South African savannas. Tree loss is a natural process, but it is increasing in some regions, with cascading effects on the habitat for many other species. Using high resolution 3-D mapping, Carnegie scientists have for the first time quantitatively determined tree losses across savannas of Kruger National Park. They found that elephants are the primary agents.

For decades it has been thought that a shock wave from a supernova explosion triggered the formation of our Solar System. According to this theory, the shock wave also injected material from the exploding star into a cloud of dust and gas, and the newly polluted cloud collapsed to form the Sun and its surrounding planets. New work provides the first fully three-dimensional (3-D) models for how this process could have happened.

Type Ia supernovae are violent stellar explosions. Observations of their brightness are used to determine distances in the universe and have shown scientists that the universe is expanding at an accelerating rate. But there is still too little known about the specifics of the processes by which these supernovae form. New research led by Carnegie identifies a star, prior to explosion, which will possibly become a type Ia supernova.

Carnegie scientists are the first to discover the conditions under which nickel oxide can turn into an electricity-conducting metal. Nickel oxide is one of the first compounds to be studied for its electronic properties, but until now scientists have not been able to induce a metallic state. The compound becomes metallic at enormous pressures of 2.4 million times the atmospheric pressure (240 gigapascals).

The study of muscular system protein myostatin has been of great interest to researchers as a potential therapeutic target for people with muscular disorders. Although much is known about how myostatin affects muscle growth, there has been disagreement about what types of muscle cells it acts upon. New research from a team including Carnegie's Chen-Ming Fan and Christoph Lepper narrows down the field to one likely type of cell.

How did icy comets obtain particles that formed at high temperatures, and how did the particles acquire rims with different compositions? Carnegie scientists are the first to model the trajectories of refractory particles in the unstable disk that formed the Solar System. They found particles could have been processed in the hot inner disk, and then traveled to the frigid outer regions to end up in icy comets. Their meanderings could help explain the different rims.

Using new techniques, Carnegie and Colombian scientists have developed ultra-high resolution maps of the carbon stocks locked in tropical vegetation for 40% of the Colombian Amazon, an area about four times the size of Switzerland. Until now, the inability to accurately quantify carbon stocks at high spatial resolution over large areas has hindered the United Nations’ Reducing Emissions from Deforestation and Forest Degradation (REDD+) program aimed at creating a financial value for storing carbon in tropical forests.

In order to understand Earth's earliest history--its formation from Solar System material into the present-day layering of metal core and mantle, and crust--scientists look to meteorites. New research from a team including Carnegie scientists focuses on one particularly old type of meteorite called diogenites. These samples were examined using an array of techniques, including precise analysis of certain elements for important clues to some of the Solar System's earliest chemical processing.

When evaluating the historic contributions made by different countries to the greenhouse gasses found in Earth's atmosphere, calculations generally go back no further than the year 1840. New research from Carnegie's Julia Pongratz and Ken Caldeira shows that carbon dioxide contributions from the pre-industrial era still have an impact on our climate today.

Light is not only the source of a plant’s energy, but also an environmental signal that instructs the growth behavior of plants. As a result, a plant’s sensitivity to light is of great interest to scientists and their research on this issue could help improve crop yields down the road. Similarly understanding a plant’s temperature sensitivity could also help improve agriculture and feed more people. Two new papers identify key aspects of the hormonal responses of plants to changes in light and heat in their environments.

Scientists have long believed that comets and, or a type of very primitive meteorite called carbonaceous chondrites were the sources of early Earth's volatile elements—which include hydrogen, nitrogen, and carbon—and possibly organic material, too. Understanding where these volatiles came from is crucial for determining the origins of both water and life on the planet. New research focuses on frozen water that was distributed throughout much of the early Solar System, but probably not in the materials that aggregated to initially form Earth.

Mineral evolution posits that Earth's near-surface mineral diversity gradually increased through an array of chemical and biological processes. A dozen different species in interstellar dust particles that formed the solar system have evolved to more than 4500 species today. New work from Carnegie's Bob Hazen demonstrates that the creation of most minerals containing mercury is fundamentally linked to several episodes of supercontinent assembly over the last 3 billion years.

Although there have been about 800 extra-solar planets discovered so far in our galaxy, the precise masses of the majority of them are still unknown, as the most-common planet-finding technique provides only a general idea of an object’s mass. Previously, the only way to determine a planet’s exact mass was if it transits—has an orbit that periodically eclipses that of its host star. Former Carnegie scientist Mercedes López-Morales has, for the first time, determined the mass of a non-transiting planet.

In mammals, most lipids (such as fatty acids and cholesterol) are absorbed into the body via the small intestine. The complexity of the cells and fluids that inhabit this organ make it very difficult to study in a laboratory setting. New research from Carnegie’s Steven Farber, James Walters and Jennifer Anderson reveals a technique that allows scientists to watch lipid metabolism in live zebrafish. This method enabled them to describe new aspects of lipid absorption that could have broad applications for human health.

The scientific community needs to make a 10-year, $100 billion investment in food and energy security, says Carnegie’s Wolf Frommer and Tom Brutnell of the Donald Danforth Plant Science Center in an opinion piece published in the June issue of The Scientist. They say the importance of addressing these concerns in light of a rapidly growing global population is on par with President John Kennedy’s promise to put man on the moon—a project that took a decade and cost $24 billion.