Looking at the chemical composition of stars that host planets, astronomers have found that while dwarf stars often show iron enrichment on their surface, giant stars do not. The astronomers think that the planetary debris falling onto the outer layer of the star produces a detectable effect in a dwarf star, but this pollution is diluted by the giant star and mixed into its interior.

"It is a little bit like a Tiramisu or a Capuccino," says Luca Pasquini from ESO, lead-author of the paper reporting the results. "There is cocoa powder only on the top!'

Just a few years after the discovery of the first exoplanet it became evident that planets are preferentially found around stars that are enriched in iron.

Johns Hopkins researchers have added to the growing mound of evidence that many of the genetic bits and pieces that drive evolutionary changes do not confer any advantages or disadvantages to humans or other animals.

“For a long time, the basic belief of evolution was that all random genetic changes that manage to stick around have some selective advantage,” says Nicholas Katsanis, Ph.D., Associate Professor at Hopkins’ Institute of Genetic Medicine. “But our work adds to the case that frequently, we are what we are largely due to random changes that are completely neutral.”

By looking at temperature fluctuations and reduced agricultural production in eastern China's past, David Zhang from the University of Hong Kong and his colleagues say they can predict the geopolitics of global warming's future.

They found that warfare frequency in eastern China, and the southern part in particular, significantly correlated with temperature oscillations. Almost all peaks of warfare and dynastic changes coincided with cold phases.

Looking to the future and applying their findings, Zhang and colleagues suggest that shortages of essential resources, such as fresh water, agricultural land, energy sources and minerals may trigger more armed conflicts among human societies.

Fossilised midges have helped scientists at the University of Liverpool identify two episodes of abrupt climate change that suggest the UK climate is not as stable as previously thought.

The episodes were discovered at a study in Hawes Water in Northern Lancashire, where the team used a unique combination of isotope studies and analysis of fossilised midge heads. Together they indicated where the climate shifts occurred and the temperature of the atmosphere at the time.

The first shift detected occurred around 9,000 years ago and the second around 8,000 years ago. Evidence suggests that these shifts were due to changes in the Gulf Stream, which normally keeps the UK climate warm and wet.

A few years ago, the low-carb diet craze was in full force and it looked like sugar might never return to society's good graces.

Sugar substitutes are a billion-dollar business. According to a national survey conducted by the Calorie Control Council, a sugar-substitute industry group based in Atlanta, 80 percent of adults use low-calorie and sugar-free foods and beverages.

Yet you can't really count sugar out. For one thing, every diet program recommends sugar substitutes, which keeps the taste of sugar in the minds of its dieters, and though that doesn't make a lot of sense because it's like Alcoholics Anonymous telling its members to drink non-alcoholic beer, it means that people prefer it.

As I've recently commented, there has been media interest in the use of the virtual online world Second Life for chemistry. We also recently demonstrated on Drexel Island that it was possible to visualize molecular docking using the molecular rezzer developed by Andrew Lang. Nature Island also hosts several common molecules, including buckyballs.

First the obesity problem in humans alarmed physicians and then veterinarians worried about fat cags ( and dogs) but now a team of researchers in the Virginia-Maryland Regional College of Veterinary Medicine and Virginia Tech has determined that horses are also facing serious health risks because of obesity.

Fifty-one percent of the horses evaluated during the pioneering research were determined to be overweight or obese – and may be subject to serious health problems like laminitis and hyperinsulinemia. And just like people, it appears as though the culprits are over-eating and lack of exercise.

Unlike moths and butterflies that are often brilliantly colored to warn potential predators that they carry toxins, flowers and the fruits they produce have brilliant colors to attract the attention of pollinators and frugivores who will disperse their pollen and seed, thus guaranteeing the next generation.

The appearance of flowering plants on earth about 150 million years ago had a profound effect on the evolution of many other kinds of organisms like insects, birds, and mammals, who became the pollinators and consumers of those plants, thus ensuring the continuity of both the plant and its animal partner.

A study of more than 2,200 women at the Kimmel Cancer Center at Jefferson in Philadelphia shows that African American women have more advanced breast cancer at the time of diagnosis than Caucasian women.

In addition, African American women tend to have breast cancer tumor types that are more aggressive and have poorer prognoses.

The disease that causes tremors, rigidity and slowed movements in a million Americans also targets another brain network that regulates cognitive thought and the ability to carry out everyday tasks.

David Eidelberg, MD, head of the Center for Neurosciences at The Feinstein Institute for Medical Research, and his colleagues measured and quantified this network of brain regions during a five-year study of newly diagnosed Parkinson’s patients who agreed to be followed several times over the course of the study. This is the first longitudinal study of Parkinson’s disease using a brain scan to follow these Parkinson’s network over time.