Body

A well-done analysis by Chen WY et al, published in JAMA assesses the association of moderate alcohol consumption during adult life, drinking patterns, and breast cancer risk. The authors use prospectively collected data from the 105,986 women enrolled in the Nurses' Health Study followed up from 1980 until 2008 with an early adult alcohol assessment and 8 follow ups.

PASADENA, Calif.—If the changing seasons are making it chilly inside your house, you might just turn the heater on. That's a reasonable response to a cold environment: switching to a toastier and more comfortable state until it warms up outside. And so it's no surprise that biologists have long thought cells would respond to their environment in a similar way.

CORVALLIS, Ore. – A huge "migration" of trees has begun across much of the West due to global warming, insect attack, diseases and fire, and many tree species are projected to decline or die out in regions where they have been present for centuries, while others move in and replace them.

In an enormous display of survival of the fittest, the forests of the future are taking a new shape.

One of the few reliable ways to extend an organism's lifespan, be it a fruit fly or a mouse, is to restrict calorie intake. Now, a new study in fruit flies is helping to explain why such minimal diets are linked to longevity and offering clues to the effects of aging on stem cell behavior.

Scientists at the Salk Institute for Biological Studies and their collaborators found that tweaking a gene known as PGC-1, which is also found in human DNA, in the intestinal stem cells of fruit flies delayed the aging of their intestine and extended their lifespan by as much as 50 percent.

Unusual features of the human placenta may be the underlying cause of postpartum hemorrhage, the leading cause of maternal deaths during childbirth, according to evolutionary research at the University of Illinois at Chicago.

Defined as the loss of more than a pint of blood during or just after vaginal delivery, postpartum hemorrhage accounts for nearly 35 percent, or 125,000, of the 358,000 worldwide annual maternal deaths during childbirth.

SALT LAKE CITY, Nov. 2, 2011 – When lions and tigers roar loudly and deeply – terrifying every creature within earshot – they are somewhat like human babies crying for attention, although their voices are much deeper.

So says the senior author of a new study that shows lions' and tigers' loud, low-frequency roars are predetermined by physical properties of their vocal fold tissue – namely, the ability to stretch and shear – and not by nerve impulses from the brain.

Lions' and tigers' fearsome roars are due to their unusual vocal cords, according to a study published in the Nov. 2 issue of the online journal PLoS ONE.

The authors report that the big cats' vocal cards have an odd square shape and can withstand strong stretching and shearing. That shape "makes it easier for the tissue to respond to the passing airflow," allowing louder roars at lower lung pressure, says University of Utah researcher Tobias Riede, one of the researchers involved in the project.

An international research team led by Dr. Cindy Leissinger of Tulane University School of Medicine, along with Dr. Alessandro Gringeri from the University of Milan, has found that a drug commonly used to treat bleeding events in people with a type of severe hemophilia can also be used to prevent such events from happening in the first place. The study, the first to confirm the efficacy and safety of the drug FEIBA™ in bleed prevention is published in the Nov. 3, 2011 issue of the New England Journal of Medicine.

WHAT:Epstein-Barr virus (EBV) infects nine out of ten people worldwide at some point during their lifetimes. Infections in early childhood often cause no disease symptoms, but people infected during adolescence or young adulthood may develop infectious mononucleosis, a disease characterized by swollen lymph nodes, fever and severe fatigue. EBV also is associated with several kinds of cancer, including Hodgkin lymphoma and stomach and nasal cancers.

Was it humans or climate change that caused the extinctions of the iconic Ice Age mammals (megafauna) such as the woolly rhinoceros and woolly mammoth?

For decades, scientists have been debating the reasons behind these enigmatic Ice Age mass extinctions, which caused the loss of a third of the large mammal species in Eurasia and two thirds of the species in North America.

The history of six large herbivores -- the woolly rhinoceros, woolly mammoth, wild horse, reindeer, bison, and musk ox -- is the subject of a study by an international group of scientists investigating how climate fluctuations and human activity affected mammal populations at the end of the last ice age. According to Beth Shapiro, the Shaffer Associate Professor of Biology at Penn State University and a member of the research team, both climate change and humans were responsible for the extinction of some cold-adapted animals and the near extinction of others.

ROCHESTER, Minn. — Mayo Clinic researchers have discovered why measles, perhaps the most contagious viral disease in the world, spreads so quickly. The virus emerges in the trachea of its host, provoking a cough that fills the air with particles ready to infect the next host. The findings may also help in the fight against ovarian, breast and lung cancers.

Honey bee populations have been mysteriously falling for at least five years in the United States, but the cause of so-called colony collapse disorder (CCD) is still largely unknown.

In a report published Nov. 2 in the online journal PLoS ONE, researchers report that a widely used in-hive medication may make bees more susceptible to toxicity of commonly used pesticides, and that this interaction may be at least partially responsible for the continuing honey bee population loss.

ROCHESTER, Minn. -- Researchers at Mayo Clinic (http://www.mayoclinic.org) have shown that eliminating cells that accumulate with age could prevent or delay the onset of age-related disorders and disabilities. The study, performed in mouse models, provides the first evidence that these "deadbeat" cells could contribute to aging and suggests a way to help people stay healthier as they age.

A piece of jawbone excavated from a prehistoric cave in England is the earliest evidence for modern humans in Europe, according to an international team of scientists. The bone first was believed to be about 35,000 years old, but the new research study shows it to be significantly older -- between 44,000 and 41,000 years old, according to the findings that will be published in the journal Nature. The new dating of the bone is expected to help scientists pin down how quickly the modern humans spread across Europe during the last Ice Age.