Bubonic plague has killed hundreds of millions of people during the course of history. It is the most devastating acute infectious disease known to man. Scientists remain uncertain about the molecular basis of its extraordinary virulence.

Bacteria that cause the bubonic plague may be more virulent than their close relatives because of a single genetic mutation, according to research published in the May issue of the journal Microbiology.

“The plague bacterium Yersinia pestis needs calcium in order to grow at body temperature. When there is no calcium available, it produces a large amount of an amino acid called aspartic acid,” said Professor Brubaker from the University of Chicago, USA. “We found that this is because Y. pestis is missing an important enzyme.”

Marine scientists led by Dr. Lothar Stramma from the Leibniz Institute of Marine Sciences (IFM-GEOMAR) in Kiel, Germany say they have made an alarming new discovery - in some regions of the world oceans, oxygen essential for marine organisms is declining.

The new study documents that the oxygen values in tropical oceans at a depth of 300 to 700 meters have declined during the past 50 years. As large marine organisms can either no longer exist in these areas or they would avoid them, the expanding oxygen minimum zones may have substantial biological and economical consequences.

The oxygen distribution in the ocean is not homogenous. At the eastern boundaries of the tropical oceans at depths between 200 and 800 metres, there are areas with reduced oxygen, the so-called oxygen minimum zones (OMZ). Rising CO2 levels are causing a temperature increase of the ocean and a general decline of oxygen solubility in the water.

"Random lasers" are not what chooses the songs in your CD player in shuffle mode, they are a class of microlasers which use the principle of random light scattering as an integral part of the their operation.

In conventional lasers light is trapped between two highly reflecting mirrors where it is amplified by pumping from outside. When this amplification process is efficient enough, the laser begins to operate.

After the initiation of the modern study of random lasers by Nabil M. Lawandy at Brown University, it was demonstrated by Hui Cao (Northwestern and Yale) and coworkers that you don't actually elaborate mirrors to confine light long enough for lasing from micron sized devices. All you need to do is to put light into a highly disordered medium where scattering in random directions takes place.

A study of 90,000 people has uncovered new genetic variants that influence fat mass, weight and risk of obesity. The variants act in addition to the recently described variants of the FTO gene: adults carrying variants in both genes are, on average, 3.8 kg (or 8.5 lb) heavier. The research could lead to better ways of treating obesity.

The variants map close to a gene called MC4R: mutations in this gene are the most common genetic cause of severe familial obesity. The study also highlights the power of large collections of volunteer samples to uncover common variants that influence health.

The study also shows that the gene sequence is significantly more common in those with Indian Asian than European ancestry.

Parents of children with autism were roughly twice as likely to have been hospitalized for a mental disorder, such as schizophrenia, than parents of other children, according to an analysis of Swedish birth and hospital records by a University of North Carolina at Chapel Hill researcher and colleagues in the U.S. and Europe.

The study examined 1,237 children born between 1977 and 2003 who were diagnosed with autism before age 10, and compared them with 30,925 control subjects matched for gender, year of birth and hospital. The large sample size enabled researchers to distinguish between psychiatric histories of mothers versus fathers in relation to autism. The association was present regardless of the timing of the parent’s diagnosis relative to the child’s diagnosis.

The genome analysis of a champion biomass-degrading fungus has revealed a surprisingly minimal repertoire of genes that it employs to break down plant cell walls, highlighting opportunities for further improvements in enzymes customized for biofuels production.

The discovery of Trichoderma reesei, the target of the published analysis, dates back to World War II, when it was identified as the culprit responsible for the deterioration of fatigues and tents in the South Pacific. This progenitor strain has since yielded variants for broad industrial applications and is known today as an abundant source of enzymes, particularly cellulases and hemicellulases, currently being explored to catalyze the deconstruction of plant cell walls as a first step towards the production of biofuels from lignocellulose.

A process of self-digestion called autophagy prompts the maturation of red blood cells. Without a protein called Nix, the cells would not effectively rid themselves of organelles called mitochondria and consequently become short-lived, leading to anemia, said researchers at Baylor College of Medicine in Houston.

“It’s changed our thinking on autophagy,” said Dr. Jin Wang, assistant professor of immunology at BCM and senior author of the report in Nature. During autophagy, the cell forms an envelope or vesicle around components of the cell that need to be degraded and removed. The vesicle then fuses with a cellular component called a lysosome that degrades its contents. The inclusion of components in the cell by autophagy vesicles was generally considered to be nonspecific.

Cross-sectional studies, which collect information at a single point in time, generally find that young Americans report having more lifetime alcohol problems than older Americans, despite having had less time to develop these problems.

But these studies are hampered by the fact that people of different ages may remember or report problems to different degrees. A new examination of data, collected on similarly aged groups one decade apart, has found substantial increases in drinking and alcohol dependence among women – particularly white and Hispanic women – beginning with those born in the United States after World War II.

Leptospirosis is a serious but neglected emerging disease that infects humans through contaminated water. It is a major public health problem in South East Asia and South America, with over 500,000 severe cases every year. Between 5% and 20% of these cases are fatal.

Rats and other mammals carry the disease-causing pathogen Leptospira interrogans in their kidneys and when they urinate, they contaminate surface water with the bacteria, which can survive in the environment for long periods.

Now research published in the May issue of the journal Microbiology shows for the first time how bacteria that cause the disease survive in the environment.