Biologists have long believed that bigger is better when it comes to body size, since many lineages of animals, from horses to dinosaurs, have evolved into larger species over time.
But a study published this week by two biologists at the University of California, San Diego in an early online edition of the Proceedings of the National Academy of Sciences suggests that maxim, known as “Cope’s Rule,” may be only partly true.
The scientists found that populations of tiny
Data strikingly similar to Finnish studies
Using technology that allows DNA from thousands of genes to be collected and surveyed on a 3 x 1½-inch chip, University of Utah medical researchers have confirmed that a region on a single chromosome probably harbors a gene that causes autism. The researchers at the U School of Medicine made the finding by tracing variations in the DNA of an extended Utah family that has a high occurrence of the disorder and whose members are descended
By deleting a single gene in a small portion of the brains of mice, researchers at UT Southwestern Medical Center found that the animals were affected in a way resembling schizophrenia in humans.
After the gene was removed, the animals, which had been trained to use external cues to look for chocolate treats buried in sand, couldn’t learn a similar task, the researchers report in a paper appearing in today’s issue of The Journal of Neuroscience.
The resear
Numbers high among older women, women who have had several babies and women who have major depression
It’s a topic that is discussed so infrequently – for reasons that are easy to understand – that it may seem it isn’t much of a problem. But new research shows that fecal incontinence is prevalent among U.S. women, especially those in older age groups, those who have had numerous babies, women whose deliveries were assisted by forceps or vacuum devices, and those who ha
Max Planck researchers in Jena, Germany have identified a gene which produces a chemical ’cry for help’ that attracts beneficial insects to damaged plants
Corn plants emit a cocktail of scents when they are attacked by certain pests, such as a caterpillar known as the Egyptian cotton leaf worm. Parasitic wasps use these plant scents to localize the caterpillar and deposit their eggs on it, so that their offspring can feed on the caterpillar. Soon after, the caterpillar di
When medics are treating trauma patients, every second counts. Yet bruises, burns, and other physical conditions often make it difficult to locate veins and administer lifesaving drugs or solutions.
A team of Georgia Tech researchers, including research engineer Francois Guillot in the School of Mechanical Engineering, is developing an inexpensive, handheld device that uses Doppler ultrasound technology to find veins quickly.
In response, a team of Georgia Institute of T
To prevent possible pandemic, new methods of prevention needed
In 1918, nearly 40 million people died in a flu pandemic. Three such pandemics have occurred during the last 100 years.
When a new strain of flu infects people, the infection can spread around the world quickly. This is what could potentially happen with some new human flu viruses that come from bird flu viruses.
“Recently, some strains of bird flu viruses have infected people in Asia,” said Rob
People who lack a cell surface protein called CCR5 are highly resistant to infection by HIV but may be at increased risk of developing West Nile virus (WNV) illness when exposed to the mosquito-borne virus, report researchers from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH). The study, by Philip M. Murphy, M.D., and colleagues, appears online today in The Journal of Experimental Medicine. The findings may have cautionary implica
Overactive growth controller could become drug target
Researchers at Dana-Farber Cancer Institute have identified a molecular interaction that triggers a particularly aggressive form of breast cancer, and suggest that attacking this target with selective drugs might improve treatment.
In the January issue of Cancer Cell, a team led by Qunyan Yu, MD, and Peter Sicinski, MD, PhD, of Dana-Farber report that the interaction of a certain mutated oncogene and the newly describe
Results available in physician’s office
A simple urine test that can be interpreted in a doctor’s office can help detect nearly all recurrences of bladder cancers with a higher accuracy rate than conventional laboratory analysis of urine tests. The BladderChek test, used in conjunction with a diagnostic scope, detected 99 percent of recurring bladder cancers, according to a study in the Jan. 18 issue of JAMA.
“This is good news for patients. If you have been treated for b
Men who delay surgical repair of a hernia until the hernia becomes uncomfortable fare as well those who undergo immediate surgery, according to a study at five North American medical centers.
In the study, published in the Jan. 18 issue of JAMA, a journal of the American Medical Association, 720 men with inguinal hernia (a small part of the large or small intestine protruding into the groin) were randomly assigned to either “watchful waiting” or standard hernia repair surgery an
A new study in mice suggests that Alzheimer’s disease (AD) may be triggered when adult neurons try to divide. The finding helps researchers understand what goes wrong in the disease and may lead to new ways of treating it. The study was funded in part by the National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health, and appears in the January 18, 2006 issue of The Journal of Neuroscience.*
For unknown reasons, nerve cells (neurons) aff
Scientists have developed a novel mouse model for leukemia that reveals critical information about the mechanisms involved in leukemia progression and provides a model system for evaluation of new drugs for treatment of leukemia. The research, published in the January issue of Cancer Cell, utilizes a technique that allows induction and study of a key oncoprotein in adult mice. Previously, it was difficult to investigate this oncoprotein in the mouse, as the expression of this gene is associated w
Batteries could soon replace standard nickel-metal hydride batteries in hybrid vehicles
As part of the Department of Energy-funded FreedomCAR program, Sandia National Laboratories’ Power Sources Technology Group is researching ways to make lithium-ion batteries work longer and safer. The research could lead to these batteries being used in new hybrid electric vehicles (HEVs) in the next five to ten years.
“Batteries are a necessary part of hybrid electric-gasoli
Researchers identify a compound in cocoa responsible for improving blood flow
While a growing number of studies has shown a link between flavanol-rich cocoa and cardiovascular health, scientists have now substantiated a causal relationship between specific compounds present in cocoa and cardiovascular health. Published today in the Proceedings of the National Academy of Sciences of the United States of America (PNAS) , this new study identifies the flavanol, (-)epicatechin, as o
Enhancing the thermal conductivity of â-Si 3N 4 ceramics
Silicon nitride ceramics are important engineering materials due to their excellent properties such as fracture toughness, wear resistance and high temperature strength. They were originally developed to compete with metallic parts and now find application in such areas as engine components, glow plugs for diesel engines, cutting tools, bearings, nozzles and kiln furniture.
Thermal conductivity is an important physi
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