One copy of the human genome is more than 3 billion nucleotides in length, and weighs in at about 3.5 picograms (pg, or trillionths of a gram). Only about 1.5% of this is composed of our 20,000 or so protein-coding genes, though other data suggest that at least 5% has been conserved by natural selection, suggesting that a notable portion of the non-coding majority is also functional. On the other hand, it is now apparent that much of the genome residing in our cells is made up of sequences like transposable elements -- "parasites" of the genome that can move about wwithin and be copied independently of the "host" genome -- and especially their extinct remnants. One such element, Alu, is present in more than one million copies.

The discovery of four families in which some members only walk on all fours (quadrupedality) may help us understand how humans, unlike other primates, are able to walk for long periods on only two legs, according to professor Tayfun Ozcelik, of Bilkent University, Ankara, Turkey, who presented his study at the annual conference of the European Society of Human Genetics tomorrow.

The quadrupedal families in Turkey previously attracted attention in 2005, when they were discovered. Now the Turkish team reports that they have found the first gene implicated in quadrupedal locomotion in these families.

Ozcelik and colleagues, studied four unrelated families where some members were affected by the rare quadrupedic condition, Unertan syndrome, which is also associated with imperfect articulation of speech, mental retardation, and defects in the cerebellum, a part of the brain involved in motor control. They found that the affected individuals in two families had mutations in the gene responsible for the expression of very low density lipoprotein receptor (VLDLR), a protein which is known to be critical to the proper functioning of the cerebellum during development.

Prenatal biochemical screening tests are widely used to look for chromosomal abnormalities in the fetus which can lead to serious handicap, or even death during gestation or in the first few days after birth. But these tests are only able to detect fewer than half of the total chromosomal abnormalities in the fetus.

Dr. Francesca R. Grati, of the TOMA Laboratory, Busto Arsizio, Italy, says women should be better informed before deciding to undertake it.

The researchers studied 115,576 prenatal diagnoses carried out during the last fourteen years. 84,847 were amniocenteses, usually carried out around the 16th week of pregnancy, and 30,729 chorionic villus samplings, which can be undertaken from 12 weeks into the pregnancy. Both these tests carry an increased risk of miscarriage, so the decision on whether or not to undertake them can be difficult to weigh up.

It’s stronger than steel and nylon, and more extensible than Kevlar.

What is this super-tough material? Spider silk; and learning how to spin it is one of the materials industries’ Holy Grails.

John Gosline has been fascinated by spider silks and their remarkable toughness for most of his scientific career. He explains that if we’re to learn how to manufacture spider silk, we have to understand the relationship between the components and the spun fibre’s mechanical properties; which is why he is focusing on major ampullate silk, one of the many silks that spiders spin. According to Gosline, spiders use major ampullate silk for draglines and to build the frame and radial structures in webs, all of which have to deform and absorb enormous amounts of energy without fracturing.

Researchers at Columbia University Medical Center have illuminated a window into how abnormalities in microRNAs, a family of molecules that regulate expression of numerous genes, may contribute to the behavioral and neuronal deficits associated with schizophrenia and possibly other brain disorders.

Maria Karayiorgou, M.D., professor of psychiatry, and Joseph A. Gogos, M.D., Ph.D., associate professor of physiology and neuroscience at Columbia University Medical Center explain how they uncovered a previously unknown alteration in the production of microRNAs of a mouse modeled to have the same chromosome 22q11.2 deletions previously identified in humans with schizophrenia.

Ecosystems are constantly exchanging materials through the movement of air in the atmosphere, the flow of water in rivers and the migration of animals across the landscape. People, however, have also established themselves as another major driver of connectivity among ecosystems.

In the June 2008 Special Issue of Frontiers in Ecology and the Environment, titled “Continental-scale ecology in an increasingly connected world,” ecologists discuss how human influences interact with natural processes to influence connectivity at the continental scale. The authors conclude that networks of large-scale experiments are needed to predict long-term ecological change.

The transport of many types of materials, including gases, minerals and even organisms, can affect natural systems. This movement results in “greenlash,” which occurs when environmental changes localized to a small geographic area have far-reaching effects in other areas. For example, a drought in the 1930’s caused small-scale farmers to abandon their farms across the U.S. Midwest. The absence of crops intensified local soil erosion, leading to powerful dust storms. Large amounts of wind-swept dust traveled across the continent, causing the infamous Dust Bowl and affecting air quality, public health and patterns of human settlement throughout the country.

A whole generation of World War II soldiers endured the same trauma as soldiers in any war but for the most part kept quiet about it with little ill effect. Somewhere after that it became normal and healthy to relive bad experiences, like war or a school shooting or terrorist attack, by discussing it publicly or in therapy.

A new study says it is okay not to express one's thoughts and feelings after experiencing a collective trauma. In fact, people who choose not to express their feelings after such an event may be better off than those who do talk about their feelings, according to University at Buffalo psychologist Mark Seery, Ph.D., lead author of a study to appear in the June issue of Journal of Consulting and Clinical Psychology.

The study investigated the mental and physical effects of collective traumas on people who are exposed to a tragedy but who do not experience a direct loss of a friend or family member. It focused on people's responses to the terrorist attacks of Sept. 11, 2001, but the results may generalize to include responses to other collective traumas.

MUNICH, Germany and CHICAGO, May 31 /PRNewswire/ --

- Data presented at 44th Annual ASCO Congress, Chicago, USA

We are advised by Merck Serono that journalists and other readers should disregard the news release "Erbitux Significantly Prolongs Survival in 1st-Line Treatment of Non-Small Cell Lung Cancer" NYSE:SRA, issued today due to premature release. This release will be reissued at a later date.

Contact: Dr. Raphaela Farrenkopf, Phone +49-6151-72-2274