Archive for April 2010

Comments Off Posted on Sunday 25 April 2010 at 7:25 pm by Jacob Aron
In Biology, Health & Medicine, Inventions & Technology, Weekly Roundup, Yes, But When?

Print your own skin

Researchers funded by the US military are working on a way of printing new human skin as a treatment for burn victims. What’s more, they’ve using a regular inkjet printer and cartridges filled with human skill cells:

Grow your own font

Typographer Craig Ward has developed a typeface with a difference – each letter was grown from live cells and moulded into the correct shape.

Comments Off

Comments Off Posted on Saturday 24 April 2010 at 4:53 pm by Jacob Aron
In Getting It Wrong, Health & Medicine

Forensic experts are unable to accurately determine the age of bruises on the bodies of crime victims, say researchers at Queen Mary, University of London. A study published in the Journal of Forensic and Legal Medicine, suggests that sentencing of criminal cases involving bruising, such as child abuse or assault, could be based on flawed conclusions.

The researchers evaluated the bruise-judging abilities of 15 forensic experts with the aid of 11 willing volunteers and a suction pump. Each subject used the pump to inflict bruises on themselves, which the researchers photographed daily until they had faded completely. The photos were digitally altered to remove any hints that might aid the experts in estimating their age, such as marks from the suction pump, then randomly presented for them to judge. They were also asked to place a series of photos in chronological order, identifying how the bruise faded over time.

While we’re used to seeing experts on TV pin down the time of a crime to the nearest minute, the reality is somewhat different. The median difference between the expert’s assessment and the true age of a bruise was 26 hours, but some were even further out, with one expert getting it wrong by 454 hours or nearly 19 days.

Fresher bruises were easier to identify, with a 52% success rate for injuries under 12 hours old, but accuracy fell as the bruises faded. There was a slight increase in accuracy for injuries over 6 days old, but this could be due to chance as there were only a few bruises that lasted this long.

The experts fared better at the second task, placing the bruise images in chronological order without too many mistakes. The results seemed to depend on the nature of each bruise rather than the skill of the experts, because some bruises showed clearer changes in size and colouration than others.

Incorrectly judging the age of a bruise could have significant effects on a criminal trial, either by allowing perpetrators to get away with their crime or placing the blame on an innocent suspect. The study authors conclude that forensic experts’ estimates are unreliable at best, which calls into question whether they should be used in court at all.

Pilling, M., Vanezis, P., Perrett, D., & Johnston, A. (2010). Visual assessment of the timing of bruising by forensic experts Journal of Forensic and Legal Medicine, 17 (3), 143-149 DOI: 10.1016/j.jflm.2009.10.002

Comments Off

Comments Off Posted on Monday 19 April 2010 at 7:19 pm by Jacob Aron
In Health & Medicine, Inventions & Technology, Psychology, Weekly Roundup

Not really, I’ve just been ill, but that sounds less dramatic. On with the roundup!

Emailers or e-liars?

It’s more tempting to lie when you’re sending a message via email compared with using pen and paper, say psychologists at DePaul University in Chicago. They asked 48 students to split an imaginary pot of $89 by choosing the amount in the pot they would tell their partner and how much they were willing to share. Some conveyed their choice using email, while the rest wrote it down.

Nearly all of the emailers (92%) lied about the amount of money available, versus just 62% of letter writers. Participants reported they felt more justified in this deception, and also kept more of the money for themselves. Next time you’re doing a financial deal, be sure to get it in writing of the non-digital variety…

Don’t drink and drag

Everyone knows that smoking and drinking is bad for your health, but it seems that doing both at once could be even worse. Drinking moderate amounts of alcohol, such as two small glass of wine per day, has previously been linked to a reduced risk of stroke, but a 12-year study has found that smoking may counteract this benefit.

The study followed the drinking and smoking habits of 22,524 people in the UK. Moderate drinkers who didn’t smoke were 37% less likely to have a strike than non-drinkers, but the same wasn’t true of smokers.

Less is more when it comes to dating

Speed dating is increasingly popular these days, but it may not be the best way to find “the one”. When meeting a large number of potential partners, the brain may become overwhelmed by choice and end up resorting to surface values, instead of what’s inside.

A study published in Psychological Science found that people at speed dating events with 24 or more dates were more likely to pick a partner based on their weight or height, while those at smaller events took a deeper look, taking in into account attributes such as education and employment.

Comments Off

Comments Off Posted on Thursday 8 April 2010 at 7:14 am by Jacob Aron
In Biology, Psychology

Guest blog time! My fellow Imperial alumni Mia Kukathasan tells us how mice show some people may have depressive tendencies in our genes. Look out for more from Mia soon…

Scientists have genetically engineered mice with a predisposition for depression. The study aims to find out why, when faced with stressful situations, some people’s are genetically more prone to fall to depression. The mice were altered to carry a genetic change that affects serotonin transport in the brain, mimicking a change that occurs in people with the condition.

“There is a clear relationship between a short form of the serotonin transporter and a very high vulnerability to develop clinical depression when people are exposed to increasing levels of stressful life events.” says Dr. Allesandro Bartolomucci of Parma university, Italy.

Brain imaging of people with depression shows that they have greater activity in some brain areas, but the link with genetics is not as well understood. Chemical changes could be seen in these ‘knock’out’ mice in areas of the brain that regulate memory formation, emotional responses to stimuli and social interactions, such as meeting new mice. They showed physical signs of stress with changes in body temperature, body weight gain, higher levels of the ‘stress’ hormone corticosterone and lower levels of the ‘feel good’ hormone serotonin.

Depression is the number one cause of ‘disability’ worldwide, according to the World Health Organisation with 120 million people affected globally. The increased risk of hormone imbalances, heart disease, digestive problems and reduced immune response faced by depressed people makes it a formidable foe for the health services. The work from this study will help to find out how this genetic change in people affects serotonin turnover in the brain. The results published in the journal Disease Models and Mechanisms suggest that the genetic mutation causes an exaggerated response to stress.

Comments Off

Comments Off Posted on Sunday 4 April 2010 at 2:05 pm by Jacob Aron
In About Just A Theory, Space & Astronomy, Weekly Roundup

Pac-Man in the moon

Mimas is fast shaping up to be the nerdiest object in the solar system. The tiny moon of Saturn has already been compared to the Death Star from Star Wars, but the Cassini probe has revealed another geek-culture icon – Pac-Man.

Nom nom nom
Nom nom nom

The appearance of the classic video game character during a thermal scan of Mimas has baffled scientists. It could be due to differences in texture on the moon’s icey surface. Old, densely packed ice conducts heat away from the surface, while recently fallen snow acts as an insulator, trapping heat to create the distinctive Pac-Man shape.

Just A Review: Just A Theory

Physics World has published a rather nice review of Just A Theory. You’ll have to register on their site to see it in full, but here’s an excerpt:

Just A Theory offers a moderately UK-centric perspective on science news for interested members of the public and busy professional researchers alike. You will not find too many detailed, hard-science articles here, but sometimes that is not the point. As a student or professional physicist, it is easy to develop tunnel vision as you dig ever deeper into a relatively narrow research topic, but keeping the “bigger picture” in sight can be a time-consuming process in an ever-more-crowded media world.

Comments Off