In a geological moment about 66 million years ago, something killed off almost all the dinosaurs and some 70 percent of all other species living on Earth. Only those dinosaurs related to birds appear to have survived. Most scientists agree that the culprit in this extinction was extraterrestrial, and the prevailing opinion has been that the party crasher was an asteroid. Not so, say two Dartmouth researchers. Professors Jason Moore and Mukul Sharma of the Department of Earth Sciences favor another explanation, asserting that a high-velocity comet led to the demise of ...

SOUTH BEND, IND. – Scientists from the University of Notre Dame, The Nature Conservancy, and Central Michigan University presented their findings of Asian carp DNA throughout the Great Lakes in a study published in the Canadian Journal of Fisheries and Aquatic Sciences. "The good news is that we have found no evidence that Asian carp are widespread in the Great Lakes basin, despite extensive surveys in Southern Lake Michigan and parts of lakes Erie and St Clair," said Dr. Christopher Jerde, the paper's lead author and a scientist at the University of Notre Dame, "Looking ...

The genus Megachile is a cosmopolitan group of solitary bees, often called leafcutter bees. This is one of the largest genera of bees, with well over 1,500 species in over 50 subgenera. A new species, Megachile chomskyi, has been found only in Texas, US. What is specific and interesting about this bee is the fact that it is among those insects which exhibit a narrow, specialized preference for pollen sources. Presumably, the irreplaceable host of M. chomskyi are the beautiful flowers of the widespread Onagraceae, or the so-called Evening-Primrose Family. The study has been ...

Owing to the huge array of applications, catalysis has long been dubbed as one of the most significant areas of process and synthetic chemistry. In fact, the vast majority of all chemical industrial products – be it in the field of pharmaceutical, agricultural or polymer chemistry – involve catalysts at some stage of the manufacturing process. Catalytic processes are generally conducted in homogeneous phase using anhydrous organic solvents (e.g. halogenated solvents, toluene, etc.) which are very toxic and hard to eliminate. The development of environmentally friendly ...

The supernova, designated SN UDS10Wil [1], belongs to a special class of exploding stars known as Type Ia supernovae. These bright beacons are prized by astronomers because they can be used as a yardstick for measuring cosmic distances, thereby yielding clues to the nature of dark energy, the mysterious force accelerating the rate of expansion of the Universe. "This new distance record holder opens a window into the early Universe, offering important new insights into how these supernovae form," said astronomer David O. Jones of The Johns Hopkins University in Baltimore, ...

New Rochelle, NY, April 4, 2013—Pet therapy can help patients cope with the pain, stress, and emotional effects of a serious illness, but access to a companion animal is not always possible. Robotic animals may offer the same benefits, as explored in a fascinating study presented in Cyberpsychology, Behavior, and Social Networking, a peer-reviewed journal from Mary Ann Liebert, Inc., publishers. The article is available free online on the Cyberpsychology, Behavior, and Social Networking website. Sandra Okita, PhD, Columbia University (New York, NY) evaluated the effectiveness ...

CHAPEL HILL, N.C – Viruses have historically been classified into one of two types – those with an outer lipid-containing envelope and those without an envelope. For the first time, researchers at the University of North Carolina have discovered that hepatitis A virus, a common cause of enterically-transmitted hepatitis, takes on characteristics of both virus types depending on whether it is in a host or in the environment. "The whole universe of virology is divided into two types of viruses – viruses that are enveloped and viruses that are not enveloped. If you look ...

The observation that males appear to be superior to females in some fields of academic study has prompted a wealth of research hoping to shed light on whether this is attributable to nature or nurture. Although there is no difference in general intelligence between the sexes, studies over the past 35 years have consistently found that overall men do much better in tests of spatial ability than women. This difference may have something to do with why there are still fewer women in tertiary education studying science, technology, engineering and math – all subjects where ...

A new study which was performed jointly at Umeå University and the University of Washington in Seattle, USA, discovered that bacteria can degrade the cell membrane of bacterial competitors with enzymes that do not harm their own membrane. This exciting finding opens the way for the development of new antibacterial drugs to fight bacteria using their own weapons. (NATURE, 2013). During the infection of a host organism, pathogenic bacteria can excrete toxins that cause damage to host cells and tissue. Interestingly, bacteria also use similar mechanisms in competition with ...

Results from an anonymous survey of U.S. transplant providers report that incarceration, marijuana use, and psychiatric diagnoses, particularly suicide attempts, may lower patients' eligibility for liver transplantation. The study published in the April issue of Liver Transplantation, a journal of the American Association for the Study of Liver Diseases and the International Liver Transplantation Society, also found that most providers would not offer transplants to patients with advanced age, those severely obese, or with lifetime imprisonment. "For patients with end-stage ...

Analysis of a bronze battering ram from a 2000 year-old warship sheds light on how such an object would have been made in ancient times. Known as the Belgammel Ram, the 20kg artefact was discovered by a group of British divers off the coast of Libya near Tobruk in 1964. The ram is from a small Greek or Roman warship – a "tesseraria". These ships were equipped with massive bronze rams on the bow at the waterline and were used for ramming the side timbers of enemy ships. At 65cm long, the Belgammel Ram is smaller in size and would have been sited on the upper level on the ...

Scientists from the University of Notre Dame, The Nature Conservancy, and Central Michigan University have presented their findings of Asian carp DNA throughout the Great Lakes in a study published in the Canadian Journal of Fisheries and Aquatic Sciences. "The good news is that we have found no evidence that Asian carp are widespread in the Great Lakes basin, despite extensive surveys in Southern Lake Michigan and parts of lakes Erie and St Clair," Christopher Jerde, the paper's lead author and a scientist at the University of Notre Dame, said. "Looking at the overall ...

Amsterdam, NL, April 4, 2013 – In a study designed to differentiate why some stroke patients recover from aphasia and others do not, investigators have found that a compensatory reorganization of language function to right hemispheric brain regions bodes poorly for language recovery. Patients who recovered from aphasia showed a return to normal left-hemispheric language activation patterns. These results, which may open up new rehabilitation strategies, are available in the current issue of Restorative Neurology and Neuroscience. "Overall, approximately 30% of patients ...

Children's sense of having and owning a body differs from that of adults, indicating that our sense of physical self develops over time, according to a new study published in Psychological Science, a journal of the Association for Psychological Science. Many of our senses — vision, touch, and body orientation — come together to inform our perception of having and owning a body. Psychological scientist Dorothy Cowie of Goldsmiths, University of London and colleagues hypothesized that there might be age differences in how these processes come together. To test this hypothesis, ...

NASA's Hubble Space Telescope has found the farthest supernova so far of the type used to measure cosmic distances. Supernova UDS10Wil, nicknamed SN Wilson after American President Woodrow Wilson, exploded more than 10 billion years ago. SN Wilson belongs to a special class called Type Ia supernovae. These bright beacons are prized by astronomers because they provide a consistent level of brightness that can be used to measure the expansion of space. They also yield clues to the nature of dark energy, the mysterious force accelerating the rate of expansion. "This new ...

A technology being developed at Oak Ridge National Laboratory promises to provide clear images of the brains of children, the elderly and people with Parkinson's and other diseases without the use of uncomfortable or intrusive restraints. Awake imaging provides motion compensation reconstruction, which removes blur caused by motion, allowing physicians to get a transparent picture of the functioning brain without anesthetics that can mask conditions and alter test results. The use of anesthetics, patient restraints or both is not ideal because they can trigger brain activities ...

CHAPEL HILL, N.C. – For the first time, researchers at the University of North Carolina at Chapel Hill have isolated adult stem cells from human intestinal tissue. The accomplishment provides a much-needed resource for scientists eager to uncover the true mechanisms of human stem cell biology. It also enables them to explore new tactics to treat inflammatory bowel disease or to ameliorate the side effects of chemotherapy and radiation, which often damage the gut. "Not having these cells to study has been a significant roadblock to research," said senior study author ...

WASHINGTON -- Significant investments over the past decade into disease surveillance and notification systems appear to have "paid off" and the systems "work remarkably well," says a Georgetown University Medical Center researcher who examined the public health response systems during the 2009 H1N1 influenza pandemic. The findings are published online today in PLOS ONE. After the Sept. 11 terrorist attacks in the U.S. and the potential threat of bioterrorism, many new advanced systems for disease surveillance and notification have been developed and implemented throughout ...

The monetary cost of dementia in the United States ranges from $157 billion to $215 billion annually, making the disease more costly to the nation than either heart disease or cancer, according to a new RAND Corporation study. The greatest economic cost of dementia is associated with providing institutional and home-based long-term care rather than medical services, according to the findings published in the April 4 edition of the New England Journal of Medicine. The study, funded by the National Institute on Aging, is the most-detailed examination done in recent decades ...

Treating patients with cells may one day become as common as it is now to treat the sick with drugs made from engineered proteins, antibodies or smaller chemicals, according to UC San Francisco researchers. They outlined their vision of cell-based therapeutics as a "third pillar of medicine" in an article published online April 3 in Science Translational Medicine. "Today, biomedical science sits on the cusp of a revolution: the use of human and microbial cells as therapeutic entities," said Wendell Lim, PhD, a UCSF professor and director of the UCSF Center for Systems ...

Wikipedia users who proclaim their political affiliations within the online community consider their identity as "Wikipedian" stronger than potentially divisive political affiliations, according to research published April 3 in the open access journal PLOS ONE by David Laniado and colleagues from Barcelona Media, Spain, and University of Southern California. Previous studies of blog networks have revealed that liberal and conservative blogs tend to link to others with similar political slants rather than to one another, described by researchers as "divided they blog". ...

Stable, specific 'breathprints' unique to an individual exist and may have applications as diagnostic tools in personalized medicine, according to research published April 3 in the open access journal PLOS ONE by Renato Zenobi and colleagues from the Swiss Federal Institute of Technology (ETH) and the University Hospital Zürich, Switzerland. The researchers studied the chemicals present in exhaled breath from eleven participants, collected at different times of the day over an 11-day period. They found significant differences in the chemicals present in each person's ...

A new system for isolating rare circulating tumor cells (CTCs) – living solid tumor cells found at low levels in the bloodstream – shows significant improvement over previously developed devices and does not require prior identification of tumor-specific target molecules. Developed at the Massachusetts General Hospital (MGH) Center for Engineering in Medicine and the MGH Cancer Center, the device rapidly delivers a population of unlabeled tumor cells that can be analyzed with both standard clinical diagnostic cytopathology and advanced genetic and molecular technology. ...

STANFORD, Calif. — Amyloids — clumps of misfolded proteins found in the brains of people with Alzheimer's disease and other neurodegenerative disorders — are the quintessential bad boys of neurobiology. They're thought to muck up the seamless workings of the neurons responsible for memory and movement, and researchers around the world have devoted themselves to devising ways of blocking their production or accumulation in humans. But now a pair of recent research studies from the Stanford University School of Medicine sets a solid course toward rehabilitating the reputation ...

Humans favor speech as the primary means of linguistic communication. Spoken languages are so common many think language and speech are one and the same. But the prevalence of sign languages suggests otherwise. Not only can Deaf communities generate language using manual gestures, but their languages share some of their design and neural mechanisms with spoken languages. New research by Northeastern University's Prof. Iris Berent further underscores the flexibility of human language and its robustness across both spoken and signed channels of communication. In a paper ...