In the past ten years, researchers in genome stability have observed that many kinds of cancer are associated with areas where human chromosomes break. They have hypothesized – but never proven – that slow or altered replication led to the chromosomes breaking.

In a Tufts University study, two molecular biologists have used yeast artificial chromosomes to prove the hypothesis. They have found a highly flexible DNA sequence that increases fragility and stalls replication, which then causes the chromosome to break.

Catherine Freudenreich, associate professor of biology at Tufts University, and doctoral student Haihua Zhang focused on one particular human common fragile site – an area that is a normal part of chromosome structure but is prone to breaking.

The causes of depression have not been fully identified but scientists acknowledge that genetic and environmental factors play a role in the onset of the disorder. One of the environmental risk factors more often related to depression is exposure to threatening life events. From a genetic point of view, the serotonin transporter gene, with its crucial role in communication between neurons, could also predispose people to depression.

An international group of scientists, headed by professors Jorge Cervilla Ballesteros and Blanca Gutiérrez Martínez, from University of Granada, has recently published the study PREDICT-gene, confirming the relationship between alleles in the serotonin transporter gene and exposure to threatening life events in the onset of depression.

The new planet was identified by astronomers looking for transiting planets – that is, planets that pass in front of their home star – using a network of small automated telescopes in Arizona, California, and the Canary Islands. TrES-4 was discovered less than half a degree (about the size of the full Moon) from the team’s third planet, TrES-3.

"TrES-4 is the largest known exoplanet," said Georgi Mandushev, Lowell Observatory astronomer and the lead author of the paper announcing the discovery. "It is about 70 percent bigger than Jupiter, the Solar System’s largest planet, but less massive, making it a planet of extremely low density. Its mean density is only about 0.2 grams per cubic centimeter, or about the density of balsa wood!

A new study reveals correlations between plentiful sunspots and periods of heavy rain in East Africa. Intense rainfall in the region often leads to flooding and disease outbreaks.

The analysis by a team of U.S. and British researchers shows that unusually heavy rainfalls in East Africa over the past century preceded peak sunspot activity by about one year. Because periods of peak sunspot activity, known as solar maxima, are predictable, so too are the associated heavy rains that precede them, the researchers propose.

“With the help of these findings, we can now say when especially rainy seasons are likely to occur, several years in advance," says paleoclimatologist and study leader Curt Stager of Paul Smith's College in Paul Smiths, New York.

For every man with a migraine, three women are struck by the severe headaches that often come with nausea, sensitivity to light and sound, and aura. That means a staggering 18 to 25 percent of women suffer from migraines, making it one of the most common disabling conditions faced by women around the globe.

This 3-to-1 ratio raises the obvious question: Why? The reason, suggest researchers at UCLA, is that women may have a faster trigger than men for activating the waves of brain activity thought to underlie migraines. If the theory is correct, this triggering mechanism may be a new target for migraine treatment.

Glycine is a non-essential amino acid used by the organism to synthesise proteins and is present in foods such as fish, meat or dairy products.