News Articles

A new study in Nature Geoscience suggests that an asteroid strike may not only account for the demise of ocean and land life 65 million years ago; the resulting dust, darkness and toxic metal contamination may also explain the geographic unevenness of extinctions and recovery.Using 823 samples from 17 drilling sites in both the Northern and Southern Hemispheres, researchers analyzed the community structure of calcareous nannoplankton. Included in their study were two sites -- one in the Pacific and one in the South Atlantic -- with reliable, accurate dating.

The longer an individual uses marijuana, the more likely that person is to meet criteria for psychosis, according to a report to appear in the May print issue of the Archives of General Psychiatry. Previous studies have identified an association between cannabis use and psychosis, but the authors of the current study say concerns remain that earlier research has not adequately accounted for confounding variables.

Geologists at the Woods Hole Oceanographic Institution (WHOI) say the massive, 8.8-magnitude earthquake that struck Chile last week occurred in an offshore zone that was under increased stress caused by a 1960 magnitude 9.5 earthquake. Some 300-500 times more powerful than the magnitude 7.0 quake in Haiti Jan. 12,  the earthquake ruptured at the boundary between the Nazca and South American tectonic plates. The temblor was triggered when the "subducting" Nazca plate was thrust under the South American plate, uplifting a large patch of the seafloor and prompting tsunami warnings throughout the Pacific Ocean. The two plates are converging at a rate of 80 mm per year, says WHOI geologist Jian Lin, "which is one of the fastest rates on Earth."

Researchers analyzing mitochondrial DNA extracted from a polar bear fossil discovered in Norway in 2004 say the species is relatively young, splitting off from brown bears approximately 150,000 years ago and rapidly evolving during the late Pleistocene. The findings are published in the Proceedings of The National Academy of Sciences"Very few polar bear fossils have been found, leading to widely varying estimates of exactly when and how polar bears evolved," explains Øystein Wiig, polar bear expert and co-author at the University of Oslo's Natural History Museum. "Because polar bears live on the ice, their dead remains fall to the bottom of the ocean or get scavenged. They don't get deposited in the sediments like other mammals."

A possible new
solution to a 163-year-old biology puzzle - why animals grow bigger in cold climates - may have been found, according to researchers who say ecological factors can now be added to
physiological ones.
The results were published
in The
American Naturalist and they say it offers new
insight into 'Bergmann’s rule', an ecogeographic notion that correlates latitude with body mass in animals - animals grow larger at high, cold latitudes than their counterparts closer to

Most people believe the individual is the best judge of his or her own personality. But a Washington University Psychologist says that we are not the know-it-alls that we think we are.Simine Vazire, Ph.D., Washington University assistant professor of psychology, says that the individual is more accurate in assessing one's own internal, or neurotic traits, such as anxiety, while friends are better barometers of intellect-related traits, such as intelligence and creativity, and even strangers are equally adept as our friends and ourselves at spotting the extrovert in us all.

While much attention has been given to the potential global impact of climate change, less has been paid to how a warmer planet would affect regional climates. The Intergovernmental Panel on Climate Change (IPCC) projects that the global average temperature will rise about 1°C by the middle of the century, but the global average does not tell us anything about what will happen to regional climates, for example rainfall in the western United States or Hawaiian Islands.Analyzing warming projections in models used by the IPCC, a team of scientists claim that ocean temperature patterns in the tropics and subtropics will change in ways that will lead to significant changes in rainfall patterns. The study will be published in the Journal of Climate this month.

Researchers at UT Southwestern Medical Center say that increasing the normally occurring process of making nerve cells might prevent addiction. The conclusion is based on a rodent study demonstrating that blocking new growth of specific brain nerve cells increases vulnerability for cocaine addiction and relapse.Published in Journal of Neuroscience, the study's findings are the first to directly link addiction with the process, called neurogenesis, in the region of the brain called the hippocampus.While the research specifically focused on what happens when neurogenesis is blocked, the scientists said the results suggest that increasing adult neurogenesis might be a potential way to combat drug addiction and relapse.

The flowering plant purple loosestrife - Lythrum salicaria - has been heading north since it was first introduced to the eastern seaboard from Europe 150 years ago. This exotic invader chokes out native species and has dramatically altered wetland habitats in North America. But as this invasive plant has spread north it has run into challenges posed by a shorter growing season, according to a study conducted by researchers from the University of Toronto's Department of Ecology and Evolutionary Ecology. Scientists have found that adapting to the Great White North carries a severe reproductive penalty that may limit its spread. The results are highlighted this week in Nature.  

Cigarette smoking may increase the risk of experiencing an aneurysm for people who carry common gene variants, according to research presented at the American Stroke Association's International Stroke Conference 2010.In one study, researchers found that the chance of an intracranial aneurysm increased between 37 percent and 48 percent for people who carried one copy of an identified risky gene variation. However, when the gene variant was combined with smoking the equivalent of one pack a day for 20 years, the risk increased more than five-fold. People with two copies of the gene variant were at even higher risk.

University of Pennsylvania scientists have found that mixed lineage leukemia (MLL), has an unusual way to keep the molecular motors running. The cancer cells rely on the normal version of an associated protein to stay alive. MLL happens when a piece of chromosome 11 breaks off at the normal MLL-associated gene. The broken gene attaches itself to another chromosome, resulting in a fusion protein that eventually causes uncontrolled growth of blood cells.Researchers discovered that this runaway growth triggered by the fusion protein is blocked when the gene for the normal protein is deleted from leukemia cells. This indicates that the normal protein is required for MLL to proliferate.

Comets are thought to be some of the oldest, most primitive bodies in the solar system, but new research on the comet Wild 2 indicates that inner solar system material was transported to the comet-forming region at least 1.7 million years after the formation of the oldest solar system solids.Published in Science, the research provides the first constraint on the age of cometary material from a known comet. The findings are published in the Feb. 25 edition of Science Express.The NASA Stardust mission to comet Wild 2, which launched in 1999, was designed around the premise that comets preserve pristine remnants of materials that helped form the solar system. In 2006, Stardust returned with the first samples from a comet.