Does playing violent video games lead to aggressive behaviour?
Critics of the games often point to the now infamous example of the two teenage boys who went on a killing spree in 1999 at Columbine High School in Colorado before committing suicide. Both teens were reportedly obsessed with games such as Doom.
But a paper published in the International Journal of Liability and Scientific Enquiry challenges the common notion that these games fuel juvenile delinquency, aggressive behaviour and even murder.
"It is only speculation that violent video games were a factor in their actions," said the paper's author, Patrick Kierkegaard, a doctoral student at the University of Essex in Britain. He said many things probably influenced the boys including "a history of depression and mental conditions that resulted from being bullied."
Millions of people play the games and yet do not show any pathological tendencies, he said, adding that there is no obvious link between violence statistics and the advent of video games.
"Violent crime, particularly among the young, has decreased dramatically since the early 1990s, while video games have steadily increased in popularity and use," he writes.
"The actual trend from the U.S. Department of Justice is that over the 10 years from 1995 to 2005 violence has measurably declined in the United States from around 50 violent crimes per 1,000 citizens to around 20. This is a significant decline and occurs over the exact same period that the violent video games increased in number, explicitness and use," he added in an e-mail interview.
Still, that doesn't mean all these games are suitable for kids of every age. "Parents need to monitor what games their children play and how long they play." He noted a descriptive labelling system ranks video games based on age appropriateness.
COLD SORE CURE?
There's good news for people who suffer from frequent outbreaks of cold sores - those painful, unsightly blemishes around the mouth. Scientists think they may have found a way to eradicate them once and for all.
Cold sores are caused by an infection of herpes simplex virus 1, or HSV1. During the initial infection, the virus rapidly multiplies and then all the new viruses take refuge in cells of the trigeminal nerve in the face. From time to time, some of these viruses become active, causing a cold sore. But the vast majority of them remain dormant - and out of reach of antiviral drug treatments.
"Inactive virus is completely untouchable by any treatment we have," said lead researcher Bryan Cullen at Duke University Medical Center in Durham, N.C.
"Unless you can activate the virus, you can't kill it."
But now his research team has figured out how the vast majority of HSV1 remains dormant most of the time. In their study, they discovered HSV1 produces microbits of genetic material, called LAT RNA, which can keep most of the viruses silent and undetected while a few cause an active outbreak.
The researchers suggest they may be able to develop a drug that would neutralize the LAT RNA so that all the viruses wake up at once and start replicating.
And at that moment of vulnerability, a patient could take another drug - such as the antiviral medication acyclovir - that would then kill all the replicating HSV1.
"This would completely cure a person and you would never get another cold sore," Dr. Cullen said in a statement released with the study published in the journal Nature.
He added that a similar technique may also work against other strains of the virus family - including HSV2, which causes genital herpes.
Dr. Cullen cautions that it could take many years to develop a drug that blocks LAT RNA. Even so, he added, understanding how the virus works is the first step to developing an effective treatment against it.
ORAL HEALTH STARTS EARLY
A good set of choppers may start in the womb, according to a study by researchers at the University of Manitoba.
They found that children born to women with low levels of vitamin D are at an elevated risk of suffering from tooth decay at an early age.
For the study, the researchers collected blood samples from a group of pregnant women to measure their vitamin D levels. They later compared these figures with rates of tooth decay in the offspring at about 16 months of age.
"The data suggest that the kids whose mothers had low levels of vitamin D during pregnancy were more likely to have cavities during preschool years," said Robert Schroth, one of the authors of the study, which was presented in Toronto at a meeting of the International Association for Dental Research.
Dr. Schroth, who is both a dentist and a researcher, pointed out that a baby's teeth begin to take shape during the early stages of pregnancy.
Many factors, including diet and hygiene, can later contribute to oral health - or undermine it. But, he added, "good vitamin D levels during pregnancy can certainly help to ensure that enamel is stronger and less vulnerable to cavities."