Cholera is an infectious disease caused by a bacterium, the bacillus Vibrio cholerae. In 2004 there were 101,383 cases - 95,000 in Africa - resulting in 2,345 deaths, according to the World Health Organization. Increases in the frequency of torrential rain, floods and periods of drought, said by some to result from global climate change, has contributed to the spread of cholera.

In studies aiming to understand better the emergence and persistence of cholera in Africa, IRD and CNRS researchers showed the strong correlation that exists between outbreaks and the different parameters linked to climate changes in West Africa.

A recent simulation has shown that thin layers of ice could persist on specially treated diamond coatings at temperatures well above body temperature, which could make ice-coated-diamond films an ideal coating for artificial heart valves, joint replacements, and wear-resistant prosthetics.

Physicists Alexander D. Wissner-Gross and Efthimios Kaxiras of Harvard modeled water ice on top of a diamond surface coated with sodium ions. They found that ice layers should persist on the treated diamond up to temperatures of 108 degrees Fahrenheit (42 Celsius), and in some circumstances could remain frozen beyond the boiling point of water.

It's hardly surprising that clinically depressed people act differently than healthy people. Quantifying the difference, however, can be difficult. Now a collaboration of physicists and psychiatrists in Japan has found a way to clearly and objectively measure depression.

The researchers outfitted both healthy control subjects and depressed patients with accelerometers to continuously measure their motions over 5-day periods. Although activity levels in all of the subjects followed power-law patterns (a type of distribution that often turns up in physics studies of natural systems) the activity levels of depressed patients were clearly distinguished from healthy subjects by a number known as the scaling parameter.

While we are a long way off from the lightweight, high-performance, magical cloak of Harry Potter, physicists have been busy designing ways to make invisibility possible.

A recent theoretical analysis of a column-shaped invisibility cloak, by a collaboration of researchers from Sweden and China, showed that a cloak made to ideal specifications could render an object (or wizard) hidden inside perfectly invisible. However, even slight deviations from these specifications will cause the invisibility to break down.

The researchers analyzed the properties of a simulated tube of special metamaterials (manmade materials with intricate, microscopic structures) that can force light to follow a specified path.

Several genes with strong associations to schizophrenia have evolved rapidly due to selection during human evolution, according to researchers who found a higher prevalence of the influence of so-called positive selection on genes or gene regions known to be associated with the disorder than a comparable control set of non-associated genes, functioning in similar neuronal processes.

This is consistent with the theory that positive selection may play a role in the persistence of schizophrenia at a frequency of one per cent in human populations around the world, despite its strong effects on reproductive fitness and its high heritability from generation-to-generation.

It also provides genetic evidence consistent with the long-standing theory that schizophrenia represents, in part, a ma

According to new research at the University of Virginia Health System, N-acetylcysteine (NAC), an anti-oxidant commonly used in nutritional and body-building supplements, can form a red blood cell-derived molecule that makes blood vessels think they are not getting enough oxygen. This leads to pulmonary arterial hypertension (PAH), a serious condition characterized by high blood pressure in the arteries that carry blood to the lungs.

“NAC fools the body into thinking that it has an oxygen shortage,” said Dr. Ben Gaston, UVa Children’s Hospital pediatrician and researcher who led the study. “We found that an NAC product formed by red blood cells, know as a nitrosothiol, bypasses the normal regulation of oxygen sensing.