Two research teams led by Dr. Michael Verkhovsky and Prof. Mårten Wikström of the Institute of Biotechnology of the University of Helsinki have for the first time succeeded in monitoring electron transfer by Complex I in real time. In the future, this work might, for example, have medical relevance, because most of the maternally inherited so-called mitochondrial diseases are caused by dysfunction of Complex I.

This achievement required developing and building of a special device by which the enzyme-catalysed electron transfer could be captured at different time points by stopping the reaction at liquid nitrogen temperatures, on a microsecond (one millionth of a second) time scale. The electrons are very small elementary particles, which is why their transfer is very fast. This work is published this week in the prestigious journal of the American National Academy of Sciences (Proc. Natl. Acad. Sci.). The results give certain hints of the function of Complex I at the molecular level.

Researchers writing in the March issue of Archives of General Psychiatry have discovered evidence linking variation in a particular gene with anxiety-related traits.

The team describes finding that particular versions of the RGS2 protein, which affects the activity of important neurotransmitter receptors, were more common in both children and adults assessed as being inhibited or introverted and also were associated with increased activity of brain regions involved in emotional processing.

“We found that variations in this gene were associated with shy, inhibited behavior in children, introverted personality in adults and the reactivity of brain regions involved in processing fear and anxiety,” says Jordan Smoller, MD, ScD, of the MGH Department of Psychiatry, the report’s lead author. “Each of these traits appears to be a risk factor for social anxiety disorder, the most common type of anxiety disorder in the U.S.”

Older men with lower free testosterone levels in their blood appear to have higher prevalence of depression, according to a new report.

Depression affects between 2 percent and 5 percent of the population at any given time, according to background information in the article. Women are more likely to be depressed than men until age 65, when sex differences almost disappear. Several studies have suggested that sex hormones might be responsible for this phenomenon.

Polyaromatic hydrocarbon benzo(a)pyrene (BaP), a toxic pollutant spread by oil spills, forest fires and car exhaust is also present in cigarette smoke and may represent a second way in which smoking delays bone healing, according to research presented today at the annual meeting of the Orthopaedic Research Society in San Francisco.

In 2005, researchers from the University of Rochester Medical Center identified one ingredient in smoke, nicotine, that delays bone growth by influencing gene expression in the two-step bone healing process: stem cells become cartilage; cartilage matures into bone. In the current study, some of the same researchers found that a second smoke ingredient, BaP, also slows bone healing, but in a different way.

Smoking has been shown to delay skeletal healing by as much as 60 percent following fractures. Slower healing means a greater chance of re-injury and can lead to chronic pain and disability. The obvious solution is for smokers to quit when they get hurt, but studies show that just 15 percent can.

Researchers from Northwestern University and the University of Haifa say they have shown that areas of the brain associated with language work harder in girls than in boys during language tasks, and that boys and girls rely on different parts of the brain when performing these tasks.

Researchers have long believed that girls have superior language abilities to boys but no one has clearly provided a biological basis that may account for their differences.

“Our findings – which suggest that language processing is more sensory in boys and more abstract in girls -- could have major implications for teaching children and even provide support for advocates of single sex classrooms,” said Douglas D. Burman, research associate in Northwestern’s Roxelyn and Richard Pepper Department of Communication Sciences and Disorders.

The discovery of three-billion-year-old zircon microcrystals in northern Ontario by an international research team is providing a new record of the processes that form continents and their natural resources, including gold and diamonds.

Measuring no more than the width of a human hair, the 200-million-year growth span of these ancient microcrystals is longer than any previously discovered.