Research led by UK and Australian scientists sheds new light on the role that our ancestors played in the extinction of Australia's prehistoric animals.

The study in the Proceedings of the National Academy of Sciences provides the first evidence that Tasmania's giant kangaroos and marsupial 'rhinos' and 'leopards' were still roaming the island when humans first arrived. The findings suggest that the mass extinction of Tasmania's large prehistoric animals was the result of human hunting, and not climate change as previously believed.

Scientists have long argued over the reasons behind the worldwide mass extinctions that took place towards the end of the last ice age. The main culprits are generally thought to be climate change or some form of human impact. People only arrived in Tasmania around 43,000 years ago, when the island became temporarily connected by a land bridge to mainland Australia. None of Tasmania's giant animals, known as 'megafauna' were known to have survived until this time. This appeared to clear humans of any involvement in the disappearance of the island's large megafauna.

Small, specially designed bits of ribonucleic acid (RNA) can interfere with cholesterol metabolism, reducing harmful cholesterol by two-thirds in pre-clinical tests, according to a new study by researchers at UT Southwestern Medical Center in collaboration with Alnylam Pharmaceuticals and the Massachusetts Institute of Technology.

In a study that appears on the Proceedings of the National Academy of Sciences, researchers found that a single dose of a small interfering RNA (siRNA), a chemical cousin of DNA, lowered cholesterol levels up to 60 percent in rodents, with the effects lasting for weeks. This result indicated that the RNA interference, or RNAi, mechanism could provide a new tactic for treating high cholesterol. Similar treatments in four nonhuman primates, conducted off-site by a certified contract research organization, produced an average 56 percent drop in low-density lipoprotein cholesterol levels in the animals’ blood.

A new report on severe sporting injuries among high school and college athletes shows cheerleading appears to account for a larger proportion of all such injuries than previously thought.

The latest annual report from the University of North Carolina at Chapel Hill-based National Center for Catastrophic Sports Injury Research shows high school cheerleading accounted for 65.1 percent of all catastrophic sports injuries among high school females over the past 25 years.

According to the report, almost 95,200 female students take part in high school cheerleading annually, along with about 2,150 males. College participation numbers are hard to find since cheerleading is not an NCAA sport. The report also notes that according to the NCAA Insurance program, 25 percent of money spent on student athlete injuries in 2005 resulted from cheerleading.

Some obese individuals do not appear to have an increased risk for heart disease, while some normal-weight individuals experience a cluster of heart risks, according to two reports in the August 11/25 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

"The prevalence of obesity is increasing worldwide, and this epidemic is accompanied by a high incidence of type 2 diabetes mellitus and cardiovascular disease," the authors write as background information in one of the articles. Research indicates that in addition to overall obesity, the way body fat is distributed may influence risk for heart disease and diabetes. For instance, individuals with fat within the abdominal cavity—estimated by measuring waist size—appear to be at higher risk for insulin resistance (a pre-diabetic condition that occurs when the body fails to respond to the hormone insulin) and for having an unhealthy cardiovascular risk profile.

The traditional view of individual brain areas involved in perception of different sensory stimuli, with one brain region involved in hearing and another involved in seeing, has been thrown into doubt in recent years.

A new study published in BMC Neuroscience shows that, in monkeys, the region involved in hearing can directly improve perception in the visual region, without the involvement of other structures to integrate the senses.

Ruins of a Roman temple from the second century CE have recently been unearthed in the Zippori National Park in Israel. Above the temple are foundations of a church from the Byzantine period.

The discovery indicated that Zippori, the Jewish capital of the Galilee during the Roman period, had a significant pagan population which built a temple in the heart of the city center. The central location of the temple which is positioned within a walled courtyard and its architectural relation to the surrounding buildings enhance our knowledge regarding the planning of Zippori in the Roman era.