| Science news |
[Aug. 28th, 2003|04:40 pm] |
Childhood mental health linked to birth date
The youngest children in a school year group have a higher risk of developing mental health problems than the oldest children, according to a new study.
A survey of more than 10,000 British schoolchildren aged five to 15 years old, found that those with birthdays in the last three months of the school year were more prone to psychiatric problems, such as hyperactivity and behavioural difficulties, compared to those born in the earlier in the school year.
"Our study shows that those born in the first third of the school year have an 8.3 per cent chance of having a psychiatric disorder, whereas the youngest third have a 9.9 per cent chance," says psychologist Robert Goodman, who led the research team at King's College London.
He suggests that the effects may be due to teachers having the same academic and behavioural expectations for all the children in a year group, even though there may be up to 12 months' difference in their ages.
Comment: I think the difference is not that significant. Noise, but worth checking out.
Computer game boosts children's' language skills
A simple computer program that teaches children to distinguish between sounds can dramatically boost their listening skills. It can allow them to progress by the equivalent of two years in just a few weeks, the game's creator claims.
The game, called Phonomena, was devised by David Moore of the University of Oxford, UK, as an aid for children with language problems, but he says his latest trials also show that it can help any child. Other experts, however, are reserving judgement until independent tests are carried out.
Phonomena is designed to improve children's ability to distinguish between different phonemes, the basic sounds that form the building blocks of language. Up to a fifth of all children are thought to have problems hearing the differences between some sounds, says Moore, who heads the UK Medical Research Council's Institute of Hearing Research.
In the game, children have to distinguish between pairs of phonemes such as the "i" sound from the word "bit" and the "e" from "bet". They are played one phoneme followed by two more examples, and asked which one matches the first sound. As the game progresses the phonemes are gradually "morphed" to make them more and more similar, making it increasingly difficult to distinguish between them.
Gene variant linked to athletic performance
A specific gene linked to athletic performance has been discovered by Australian sports scientists. The announcement comes as elite athletes vie for glory at the World Athletics Championships in Paris, and reopens the debate about whether top athletes can be screened and nurtured from birth.
The gene comes in two variants. People with one variant are predisposed to become sprinters. Those with the second are more likely to excel in endurance events. This is the second gene to be shown to confer athletic ability. The first, angiotensin-converting enzyme, or ACE, makes an enzyme which influences how efficiently our muscles burn oxygen, and the rate at which some muscles grow (New Scientist print edition, 23 May 1998).
The gene discovered by the Australian team is called alpha-actinin-3, or ACTN3. One version, the R allele, makes actinin, a protein found only in fast muscle fibres. These fibres help to produce the explosive bursts of speed and power that sprinters need. The other allele, called X, does not produce actinin-3.
Winning formula
The researchers studied the genetic profiles of over 300 athletes, 50 of whom had represented Australia at Olympic or international level at various sports. They found that 95 per cent of elite sprinters possessed at least one copy of the R allele while 50 per cent had two copies, one inherited from each parent ( American Journal of Human Genetics, vol 73, p 627).
But just 76 per cent of endurance athletes possessed an R allele, with only 31 per cent inheriting both (see graphic). Out of over 400 controls taken from the general population, 82 per cent had one R allele and 30 per cent had two Rs.
Dark chocolate boosts antioxidant levels
Eating chocolate can boost the level of heart-protecting antioxidants in the blood, but consuming milk at the same time cancels the potential health benefits, according to a new study.
The researchers speculate that milk may also have the same effect on other antioxidant-rich foods, including fruit and green vegetables.
Dark chocolate contains about twice the amount of flavonoids as milk chocolate, so 12 healthy volunteers were given either 100 grams of plain chocolate or 200 grams of milk chocolate. Some were also given 200 ml of milk to drink in the double-blind experiment. The levels of antioxidant in their blood plasma were tested after one, two and four hours.
Four hours after eating the chocolate, all the volunteers' blood antioxidant levels had returned to normal. To gain the maximum potential benefits from chocolate, Crozier suggests it may be advisable to refrain from milk products during that period.
NASA culture key to Columbia shuttle disaster
...the accident was caused in large part by the way NASA manages its operations. And this NASA "culture", as the 248-page report terms it, extended to, and to some extent emanated from, the very top: NASA chief Sean O'Keefe.
In one of its sharpest criticisms, which had not been detailed prior to the final report, the CAIB makes it clear that schedule pressure imposed by O'Keefe in order to appease the US Congress apparently played a significant role in causing managers all the way down the line to downplay risks and sweep aside clear warning signs.
According to the CAIB, the cultural problems extended through most of NASA's upper management. The attitudes throughout the Columbia flight, and the months leading up to it, showed clear signs that schedule pressures were forcing ever-greater compromises and leading managers to override the judgment of their own engineers.
The report reveals no less than eight "missed opportunities" after Columbia's launch to gain understanding of the damage. Beginning on the mission's second day, requests were passed up through the line of command to get spy-satellite images of the shuttle to assess the foam impact's damage - every one of these requests was blocked by management. Requests to ask the crew to perform an in-orbit inspection were also ignored.
In part, this stemmed from an attitude that even if a breach of the wing's thermal insulation had been discovered, nothing could have been done about it. The board strongly disputes that notion, concluding that with timely information, it was "challenging but feasible" to launch a rescue mission and save the entire crew (New Scientist print editions, March 22, p 36).
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