Viral infections passed by humans are causing some wild African chimpanzees to get sick and die. Scientists had suspected it for some time, but now German researchers have proven it.

Using evidence gathered about populations of chimps hit by five different respiratory outbreaks between 1999 and 2006 in the Ivory Coast, Africa, the researchers found that tissue samples from all that died tested positive for one of two human respiratory viruses.

The study examined chimps that lived in protected parks where researchers are active but local people don’t travel. As a result, researchers concluded, the sources of the viruses were most likely the researchers themselves or possibly poachers.

Aspirin cuts cancer risk

According to a new study, regular and long-term use of aspirin and Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) cuts down the risk linked with colorectal cancer.

However, use of aspirin for chemoprevention of colorectal cancer might require using the drug at doses that are higher than recommended over a long period of time. This might cause serious side effects including gastrointestinal bleeding.

In the study, the participants were enrolled in the Health Professionals Follow-up Study, a large prospective cohort study, which has provided detailed and updated information on aspirin use.

The study has been conducted on 51,529 male dentists, optometrists, osteopaths, podiatrists, pharmacists and veterinarians, who returned a mailed health questionnaire in 1986.

The questionnaire consisted of questions based on diet, aspirin use and medical diagnoses, including cancer.

Sex and survival theory

Australian researchers have unearthed proof that an almost three-decade old theory about reptile sex and survival is correct. Rick Shine of the University of Sydney, and his former student Daniel Warner have shown that the temperature at which a reptile egg is incubated not only determines sex, but also optimises the number of offspring in future generations.

This is the first time that a team of researchers has made “unequivocal” demonstration that incubation temperatures affect the reproductive success of males and females. About 30 years ago, US biologists Ric Charnov and Jim Bull of the University of Texas had said that this “environmental sex determination” was not just a quirk of nature.

Indeed, they believed that males or females incubated at certain temperatures had an evolutionary advantage, especially, that they would have an optimised number of offspring.

Making foods taste better

A team of scientists from the Monell Centre and Tokyo University of Agriculture has used a new molecular way to find chemical compounds from common foods that activate bitter taste receptors in humans.

The study provides a practical means to manipulate food flavour in general and bitter taste in particular.

Scientists have identified 25 different human bitter receptors from human genome sequences.

But, only some of these can be activated by known chemical compounds. The remainders are 'orphan receptors,' meaning that the compounds that bind to and activate them have not been identified. Therefore, it is not clear how these orphan receptors add to bitter taste perception.

Exercise to look younger

Sorry, couch potatoes — the verdict is in: People who exercise regularly do look at least a decade younger than those who don’t.

A team of international researchers has carried out a study and found that half-an-hour of exercise daily can not only slow the ageing process but also makes a person appear ten years younger than an obese of the same age.

In fact, the researchers came to the conclusion after monitoring a group of over 2,000 twins — they measured the length of the telomeres of the participants, which cap the chromosomes in cells and protect the same from damage.

The telemores shorten with age, meaning more damage occurs. The team found that people who were active had longer telomeres than those of the same age who were sedentary.