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.