Even if you don't feel tired, a lack of sleep may slow you down on the job and affect how well you work, and that drag on performance tends to snowball the longer and later you stay awake, a new study finds.

Researchers set out to study how workers' productivity is affected if they sleep on an irregular schedule and get less than the recommended 8 hours of shut-eye per night. During the first week of the study at Brigham and Women's Hospital in Boston, participants slept 10 to 12 hours per night. But for the next three weeks, they were allotted only five to six hours of slumber on a 28-hour cycle that mirrored chronic jet lag, according to the hospital.

Throughout the research, participants were unaware of the time and they took visual search tests on a computer that recorded how quickly and accurately they could find important information. The team tested visual search performance because those tasks are common in jobs such as air-traffic control, baggage screening and monitoring power plant operations, Jeanne Duffy, a neuroscientist at BWH, explained in a statement. "These types of jobs involve processes that require repeated, quick memory encoding and retrieval of visual information, in combination with decision making about the information."

The longer the participants were awake, the more slowly they identified the important information in the test, according to the hospital. Participants also performed tasks more slowly from 12 a.m. to 6 a.m. considered the biological nighttime than they did during the daytime.

"The longer someone is awake, the more the ability to perform a task, in this case a visual search, is hindered, and this impact of being awake is even stronger at night," said Duffy, who published her results in the Journal of Vision.

As the weeks went on, the participants were increasingly slower to identify the important information in the tests. And though their test scores were getting worse during their sleep-deprived schedule, the participants only rated themselves to be slightly sleepier than their first well-rested week. Duffy said this suggests your perception of how tired you are does not always match your actual ability.

Sleep deprivation and an irregular sleep cycle have been linked to health problems. Previous research at Brigham and Women's Hospital found that a skewed sleep schedule similar to the one used in this new study may increase your risk of developing Type 2 diabetes. That said, scientists admit they don't really know how much sleep you need, as each person's requirements vary based on many factors.

If you are trying to slim down, you may have crossed cheese off the menu.

But scientists have discovered it may actually help prevent diabetes an illness often triggered by being overweight.

They claim that eating just two slices of cheese a day cuts the risk of type 2 diabetes by 12 per cent.

The findings go against current health guidelines, which advise cutting back on dairy products and other high-fat foods to help prevent the illness.

Around 2.5million Britons have diabetes. Of these, 90 per cent suffer from type 2, which is often caused by being very overweight.

But experts fear another million have the condition, which can cause heart attacks, strokes, blindness and nerve problems, without yet having been diagnosed.

British and Dutch researchers looked at the diets of 16,800 healthy adults and 12,400 patients with type 2 diabetes from eight European countries, including the UK.

The study, published in the American Journal of Clinical Nutrition, found that those who ate at least 55g of cheese a day around two slices were 12 per cent less likely to develop type 2 diabetes. The risk fell by the same amount for those who ate 55g of yoghurt a day.

For years NHS guidelines have advised against eating too much dairy, cake or red meat as they are high in saturated fat. This is thought to increase cholesterol and raise the risk of diabetes.

But the researchers including academics from the Medical Research Council, Cambridge say not all saturated fats are as harmful as others, and some may even be beneficial.

One theory is that the so-called 'probiotic' bacteria in cheese and yoghurt lower cholesterol and produce certain vitamins which prevent diabetes.

And cheese, milk and yoghurt are also high in vitamin D, calcium and magnesium, which may help protect against the condition.

Diabetes occurs when the body does not produce enough of the hormone insulin to control its blood sugar levels. Symptoms of type 2 diabetes include feeling very thirsty, needing to pass water frequently and constant tiredness.

Although the illness is treatable through methods such as dietary changes, tablets and injections, it can cause serious complications if not properly looked after.

But despite the latest findings, campaigners warned against gorging on cheese and other dairy products in the hope of warding off diabetes.

Dr Iain Frame, director of research at the charity Diabetes UK, said: 'It is too simplistic to concentrate on individual foods.

'We recommend a healthy balanced diet, rich in fruit and vegetables and low in salt and fat.

'This study gives us no reason to believe that people should change their dairy intake in an attempt to avoid the condition.'

A loving family helps a child's brain to grow and increases their intelligence and mental abilities, a study suggests.

Researchers found that children in care have less grey and white matter - the two components of the central nervous system - than those brought up in a typical home environment.

Children in foster families have normal levels of white matter, which relays messages in the brain, but less of the grey matter which contains nerve cells and controls muscles, memory, emotions and speech.

Scientists believe the findings could explain why children who spend time in care are statistically more likely to develop issues such as attention deficit hyperactivity disorder and mental health problems.

People who have been in care also have, on average, lower IQ and language skills than those who grew up in loving homes.

The differences in levels of grey and white matter is most likely to be due to varying levels of stimulation required for normal brain development, researchers said.

Many children in care have been exposed to deprivation and neglect, which could be linked to their lower levels of grey and white matter.

The improvement among those who were moved to foster families, however, indicates that it is possible to recover in terms of white matter, which affects learning ability.

The study team, led by researchers from Harvard University and Boston Children's Hospital, examined MRI scans from Romanian orphans aged between eight and 11, some of whom had been transferred to quality foster care homes.

It has published almost 50 research papers since the project began.

Reporting their latest findings in the journal Proceedings of the National Academy of Sciences, the reesearchers wrote: 'In most forms of institutional rearing, the ratio of caregivers to children is low, care is highly regimented and caregiver investment in children is low.

'One of the most likely explanations for the wide range of developmental problems observed among children exposed to institutional rearing is that the deprived environment of an institution does not provide adequate experience on which to scaffold normal brain development.'

One of the study's authors, Dr Charles Nelson, a developmental neuroscientist in Boston, said the findings suggested that there was a sensitive period in the first two years of a child's life, when foster care has the greatest impact on their progress.

'The younger a child is when placed in foster care, the better,' he added.

Indians are among the most physically active people in the world

Are Indians some of the most physically unfit people in the world?

Well, doctors will tell you that with the country riding a diabetes and heart disease epidemic, most Indians are physically unfit. As the middle class swells, more Indians are leading desk-bound sedentary lives in cities, where pavements are scarce and there is no culture of walking. Fat-rich diets don't help matters.

But an exhaustive new study by the medical journal Lancet measuring global physical activity explodes the "myth" about the unfit Indian. The study measured physical activity in adults - aged 15 years or older - from 122 countries, comprising over 88% of the world's population.

India, according to the study, is agile and kicking. Only 15.6% of Indians were found to be physically inactive. The British (63.3%), Japanese (60.2%), Italians (54.7%), Irish (53.2%) and Americans (40.5%) were found to be more physically inactive than Indians.

Is it any surprise that Indians appear to be more physically fit than their counterparts in more prosperous parts of the world?

Not really. As the study suggests, physical inactivity is more common in countries of high income than in those of low income. In high income countries, physical activity dwindles as people use more technology and are less engaged in labour-intensive work.

In India, where the overwhelming majority of people are engaged in back-breaking farming, it is little wonder that they are more physically active than their counterparts in more prosperous countries.

More women (18.4%) in India were found to be more physically inactive than men (12.7%), perhaps pointing to a society moored in traditions where men work and women look after the home.

So which, according to the Lancet study, is the most physically active country in the world?

No prizes for guessing this, but yes, it is Bangladesh where only 4.7% are physically unfit.

About 44.3% adults in Karnataka are exposed to passive smoking at their home and 37.2% have to put up with passive smoking in public places, says a new survey.

Global Audit Tobacco Survey (GATS) conducted the survey, whose report was released in the banquet hall of Vidhana Soudha on Tuesday. Chief minister Jagadish Shettar, deputy chief minister R Ashoka, cabinet ministers and opposition leaders attended the function.

The survey indicates that more than 28% adults in Karnataka consume tobacco in one form or the other. About 40% male adults and 16% female adults consume tobacco in the state. The estimate puts the number of tobacco users at more than one-and-a-half crore.

On the occasion of the release of the survey report, a few tobacco users who survived cancer narrated their sufferings and pleaded with political leaders to introduce strict norms to discourage the use of tobacco. They said a high-power committee should be set up in this regard and the chief minister/chief secretary should head it. The committee should take a call on issues like controlling the sale of tobacco, raising tax on tobacco products, putting an end to advertising of tobacco products and chalking out strong policies.

Shettar said an alarming number of people lose their life every year because of smoking-induced cancer. He said the state government was spending `3.7 crore to control the use of tobacco products. He said the government had arranged for facilities at Kidwai Hospital to diagnose cancer and treat it.

Former minister Roshan Baig advised parents and adults not to smoke at home or in front of children. He said he himself was a smoker and had picked up the habit after emulating elders. He said he quit smoking owing to health complications, and was feeling better since stopping.