Human activities are releasing carbon dioxide faster than ever, while the natural processes that normally slow its build up in the atmosphere appear to be weakening, according to a new report. The report states that “together, these effects characterize a carbon cycle that is generating stronger-than-expected climate forcing sooner than expected.”

Between 2000 to 2006, human activities such as burning fossil fuels, manufacturing cement, and tropical deforestation contributed an average of 4.1 billion metric tons of carbon to the atmosphere each year, yielding an annual growth rate for atmospheric carbon dioxide of 1.93 parts per million (ppm). “This is the highest since the beginning of continuous monitoring in 1959,” states the report.

The Autism Consortium has completed the first genome scan for Autism Spectrum Disorders (ASD) through its Autism Gene Discovery Project and has released the reference data set to a database that autism researchers around the world can use. The scan was conducted using new, high resolution technology developed by Affymetrix on genetic data from more than 3,000 children with ASD and their families.

People with medium levels of HIV in their blood are likely to contribute most to the spread of the virus, according to new research published today in the journal Proceedings of the National Academy of Sciences.

The study, by researchers from Imperial College London, looked at several groups of HIV-positive people in Europe, the USA and sub-Saharan Africa. It found that those with a high viral load are the most infectious group, but have only limited time to infect others, because they generally progress to AIDS quite quickly.

Viral load - a count of how many viral particles are in a person’s blood – varies hugely between individuals. The higher the viral load, the more infectious a person is but the shorter their life expectancy.

“Being a coral reef scientist these days can be depressing. So many reefs around the world have collapsed before our eyes in the past few years,” says Professor Terry Hughes, Director of the ARC’s Centre of Excellence for Coral Reef Studies. “But we’ve got to get past the gloom-and-doom, and use the best science to find practical ways to protect reefs from global warming.”

The world has a narrow window of opportunity to save coral reefs from the destruction caused by extreme climate change, according to a unanimous statement issued today by leading Australian scientists (see communiqué, above). The call for action is the outcome of a National Forum on Coral Reef Futures, held at the Australian Academy of Science, in Canberra.

Without sleep, the emotional centers of the brain dramatically overreact to negative experiences, reveals a new brain imaging study in Current Biology.   The reason for that hyperactive emotional response in sleep-deprived people stems from a shutdown of the prefrontal lobe—a region that normally keeps emotions under control.

The new study from Harvard Medical School and the University of California, Berkeley is the first to explain, at the neural level, what seems to be a universal phenomenon: that sleep loss leads to emotionally irrational behavior, according to the researchers. The findings might also offer some insight into the clinical connection between sleep disruptions and psychiatric disorders.

Philosophers and scientists have long been interested in how the mind processes the inevitability of death, both cognitively and emotionally. One would expect, for example, that reminders of our mortality - like the sudden death of a loved one - would throw us into a state of disabling fear of the unknown. But that doesn't happen. If the prospect of death is so incomprehensible, why are we not trembling in a constant state of terror over this fact?

Psychologists have some ideas about how we cope with existential dread. One emerging idea--"terror management theory" --holds that the brain is hard-wired to keep us from being paralyzed by fear.

Researchers at Tufts University School of Medicine in collaboration with the Virginia Bioinformatics Institute at Virginia Tech have created a computer program called Pathogen Simulation (PathSim) to study the progression of Epstein-Barr virus (EBV) in humans. David Thorley-Lawson, PhD, professor of pathology at Tufts University School of Medicine, is combining PathSim, laboratory methods, and clinical studies to provide a new and powerful approach to understanding EBV and ultimately designing anti-viral therapies.

“PathSim is an agent-based computer program. The agents are the virus itself, and the T and B cells of the patient’s immune system,” explains Thorley-Lawson. Using PathSim, Thorley-Lawson can manipulate these agents to simulate EBV infection and persistence in humans.

With an eye on curing diabetes, scientists at Washington University School of Medicine in St. Louis have successfully transplanted embryonic pig pancreatic cells destined to produce insulin into diabetic macaque monkeys – all without the need for risky immune suppression drugs that prevent rejection.

The transplanted cells, known as primordia, are in the earliest stages of developing into pancreatic tissues. Within several weeks of the transplants, the cells became engrafted, or established, within the three rhesus macaque monkeys that received them. The cells also released pig insulin in response to rising blood glucose levels, as would be expected in healthy animals and humans.

A clinical trial evaluating a brain cancer vaccine in patients with newly diagnosed brain cancer has begun at NYU Medical Center. The study will evaluate the addition of the vaccine following standard therapy with surgery and chemotherapy in patients with glioblastoma multiforme, a deadly form of brain cancer.

The vaccine, called DCVax-Brain, incorporates proteins found in patients’ tumors and is designed to attack cancer cells containing these proteins. The study underway at NYU Medical Center is an expansion of an earlier phase I trial of the vaccine. The vaccine is made by the Northwest Biotherapeutics, Inc., based in Bothell, Washington.

“We are really excited about the promise of this vaccine,” said Patrick J.