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.

A study published by Nutrition Journal says they can demonstrate substantial advances in long term weight management and blood glucose levels as a result of personalizing patients' diets based on their genetic information (nutrigenetics).  They found significant improvement in long term (more than 300 days) weight management for individuals whose nutrient requirements were tailored to individual variations in the genes known to affect nutrient metabolism and transport.

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.

There has been a decline in the efficiency of natural land and ocean sinks which soak up carbon dioxide (CO2) emitted to the atmosphere by human activities, according to findings published this week in the Proceedings of the National Academy of Sciences of the US (PNAS).

The swift increase in atmospheric CO2 is due to faster economic growth coupled with a halt in carbon intensity reductions, in addition to natural sinks removing a smaller proportion of emissions from the air. Carbon intensity is the amount of carbon emitted to produce one dollar of global wealth.

The study’s lead author, Dr Pep Canadell, executive director of the Global Carbon Project, explained “Fifty years ago, for every tonne of CO2 emitted, 600kg were removed by natural sinks.

“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.

Hospitalized patients who smoke may be more likely to quit smoking through the use of hypnotherapy than patients using other smoking cessation methods according to a new study presented at CHEST 2007,the annual meeting of the American College of Chest Physicians (ACCP).

Smoking patients who participated in one hypnotherapy session were more likely to be nonsmokers at 6 months compared with patients using nicotine replacement therapy (NRT) alone or patients who quit “cold turkey”. The study also shows that patients admitted to the hospital with a cardiac diagnosis are three times more likely to quit smoking at 6 months than patients admitted with a pulmonary diagnosis.

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.

Height may point to a biological basis for pedophilia, according to new research released by the Centre for Addiction and Mental Health (CAMH). The study found that pedophilic males were shorter on average than males without a sexual attraction to children.

The study, published in Sexual Abuse: A Journal of Research and Treatment, suggests that pedophiles may have been exposed to pre-birth conditions that affected their physical development. The researchers observed this height difference by analyzing the files of over 1,000 men who were assessed for pedophilia or other sexual disorders between 1995 and 2006 at the Kurt Freund Laboratory in Toronto, Canada.

A difference in average height is a trait found in other illnesses with biological links.

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.