Researchers at Queensland University of Technology have had good results with a trial vaccine for chlamydia, a disease which is decimating koala populations in the wild.

Chlamydia in koalas was a significant cause of infertility, urinary tract infections, and inflammation in the lining of the eye that often led to blindness.

Professors Peter Timms and Ken Beagley from Queensland University of Technology's Institute of Health and Biomedical Innovation (IHBI) said the vaccinated koalas, which are at Brisbane's Lone Pine Koala Sanctuary, were mounting a good response to the vaccine.

“If you want to be happy for the rest of your life you need to make an ugly woman your wife,” or “if your rent is late and you might have to litigate, don’t worry, be happy,” are a few of the ways some popular singers verbalize ways to stay happy. The role that genes and environment play on happiness and the choices a person makes in life have been regularly investigated in studies involving criminals and twins.

A genetic variation which evolved to protect people of African descent against malaria has now been shown to increase their susceptibility to HIV infection by up to 40 per cent, according to new research published today in Cell Host & Microbe. The work analyzed data from a 25-year study of thousands of Americans of different ethnic backgrounds.

Conversely, the same variation also appears to prolong survival of those infected with HIV by approximately two years.

The discovery marks the first genetic risk factor for HIV found only in people of African descent, and sheds light on the differences in genetic makeup that play a crucial role in susceptibility to HIV and AIDS.

Mars once hosted vast lakes, flowing rivers and a variety of other wet environments that had the potential to support life, according to two new studies based on data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) and other instruments on board NASA's Mars Reconnaissance Orbiter (MRO).

"The big surprise from these new results is how pervasive and long-lasting Mars' water was, and how diverse the wet environments were," says Scott Murchie, CRISM's principal investigator at the Johns Hopkins University Applied Physics Laboratory (APL), in Laurel, Md.

The key to good health is to be physically active. The key to being active is ... to be born that way?

The well-documented importance of exercise in maintaining fitness has created the idea that individuals can manage their health by increasing their activity. But what if the inclination to engage in physical activity is itself significantly affected by factors that are predetermined? Two new studies suggest that the inclination to exercise may be strongly affected by genetics.

Controlled experiments into the effects of genetics on human activity have yet to be attempted, but recent studies on mice – the standard test species for mammalian genetics – have found genetic influences.

Hydrogen has three times more potential energy by weight than petrol, making it the highest energy-content fuel available. Research into using bacteria to produce hydrogen has been revived thanks to the rising profile of energy issues.

Researchers have combined the efforts of two kinds of bacteria to produce hydrogen in a bioreactor, with the product from one providing food for the other.

According to the outline in Microbiology Today, this technology has an added bonus: leftover enzymes can be used to scavenge precious metals from spent automotive catalysts to help make fuel cells that convert hydrogen into energy.

In the remote desert highlands of southern Yemen, a team of archaeologists have discovered new evidence of ancient transitions from hunting and herding to irrigation agriculture 5,200 years ago.

As part of a larger program of archaeological research, Michael Harrower from the University of Toronto and The Roots of Agriculture in Southern Arabia (RASA) team explored the Wadi Sana watershed documenting 174 ancient irrigation structures, modeled topography and hydrology, and interviewed contemporary camel and goat herders and irrigation farmers.

By measuring a peak in the temperature of hot gas in the center of the giant elliptical galaxy NGC 4649, scientists have determined the mass of the galaxy's supermassive black hole. The method, applied for the first time, gives results that are consistent with a traditional technique.

Astronomers have been seeking different, independent ways of precisely weighing the largest supermassive black holes, that is, those that are billions of times more massive than the sun. Until now, methods based on observing the motions of stars or of gas in a disk near such large black holes had been used.

"This is tremendously important work since black holes can be elusive, and there are only a couple of ways to weigh them accurately," said Philip Humphrey, leader of the study and an assistant project scientist in the Department of Physics and Astronomy at UCI. David Buote, associate professor of physics and astronomy at UCI, also worked on this study.

Women exposed to high levels of PCBs (polychlorinated biphenyls – a group of banned environmental pollutants) are less likely to give birth to male children, according to a study published today in Environmental Health.

The researchers found that among women from the San Francisco Bay Area, those exposed to higher levels of PCBs during the 50s and 60s, were significantly more likely to give birth to female children.

Similar exposure is thought to have occurred in Wales, after a quarry on the edge of Groesfaen village near Cardiff was used as a toxic dumping ground from 1965 to 1972.

A two-year study led by researchers from Ben-Gurion University of the Negev (BGU) reveals that low-carbohydrate and Mediterranean diets may be just as safe and effective in achieving weight loss as the standard, medically prescribed low-fat diet, according to a new study published in the prestigious New England Journal of Medicine.

In the study, 322 moderately obese people were intensively monitored and were randomly assigned one of three diets: a low-fat, calorie-restricted diet; a Mediterranean calorie-restricted diet with the highest level of dietary fiber and monounsaturated/saturated fat; or a low-carbohydrate diet with the least amount of carbohydrates, highest fat, protein, and dietary cholesterol. The low-carb dieters had no caloric intake restrictions.