Cool articles on some exciting developments on the science and technology scene.
- Can you 'daydream' your way out of a coma?
- Longevity gene keeps the brain ticking over
- Smoking gene protects against cocaine addiction
- Tequila is surprise raw material for diamond films
- Google plans to become net-access nanny
- Surgeons may get Minority Report-style display
- The Worms Crawl In
Can you 'daydream' your way out of a coma?
Date: 13 June 2008
Daydreaming your way out of a coma? Unlikely as it sounds, keeping track of a wandering mind may one day help doctors to discover whether a brain-damaged individual is still 'in there'.
When a healthy person is daydreaming, their brain is not occupied with specific tasks and the 'default network', a series of specific, connected regions in the brain's cortex, kicks in. The network's purpose is still hotly debated but recent evidence suggests it keeps the brain primed and ready to take on new tasks. Problems activating the default network have been linked to cognitive diseases like Alzheimer's and schizophrenia.
Now Steven Laureys and colleagues at the University of Liège in Belgium have used brain scans to measure the activity of the default network in 13 brain-damaged people whose levels of consciousness were different.
Their study, presented at this week's meeting of the European Neurology Society in Nice, France, found that activity varied in proportion to the amount of brain damage. Minimally conscious patients had a ten per cent reduction compared with healthy individuals, while activity was reduced by 35 per cent in coma patients and those in a persistent vegetative state (PVS). There was no activity at all in the default network of a brain-dead patient.
Laureys concludes that such a scan could act as a 'consciousness meter'. "This could turn into an utterly useful way to diagnose residual consciousness in brain-damaged patients," he says. Such a test could dramatically affect the fate of brain-damaged patients, by helping to determine whether to treat them with drugs or therapies, and in some cases, whether to keep them alive at all, says Laureys.
Usually, consciousness is measured by running a battery of behavioural tests. But these may miss some people who are minimally conscious. Two years ago, researchers at the University of Cambridge, together with Laureys's group, investigated an alternative. They found that the correct brain areas lit up in someone they thought was in a PVS when she was asked to imagine playing tennis. This indicated that she must in fact be conscious (New Scientist, 7 July 2007, p 40).
However, the test is difficult to carry out and negative results are hard to interpret as the patient may simply not be able to think about a particular task. Measuring activity in the resting brain is quicker - and doesn't depend on the patient responding. "We just scan someone for ten minutes and get an easily quantifiable read-out," says Laureys.
John Whyte at the Moss Rehabilitation Research Institute in Philadelphia, Pennsylvania, who is testing drugs that may help restore consciousness, says that although larger studies are needed to determine how reliably the default network indicates consciousness, assessing awareness in the resting brain is crucial to treating unresponsive, brain-damaged patients: "To find the right treatments, we need to be able to classify patients better, and resting assessments like this one should help with that."
Joseph Giacino at the JFK Medical Center in Edison, New Jersey, agrees: "If this can help us to sort patients by how well connected their brains are, we might be able to use it one day to better predict who will wake up and who won't." source:NewScientist full article
Longevity gene keeps the brain ticking over
- 18 June 2008
A GENE linked to IQ might also help to prolong life.
The gene codes for an enzyme called succinic semialdehyde dehydrogenase (SSADH), which destroys GABA, a neurotransmitter that dampens brain activity and causes drowsiness. The gene comes in two common forms: the so-called "T" version is 20 per cent less efficient than the "C" version. In previous studies, young people with two copies of the T version performed slightly worse on IQ tests.
SSADH also detoxifies the brain by getting rid of excess acid, helping to protect cells from the free-radical damage that accelerates ageing.
So to study the effects of the gene on ageing and longevity, Giuseppe Passarino of the University of Calabria, Italy, and his colleagues took a representative sample of 514 Italians aged between 18 and 107 and identified which gene variants they carried. Of these they also evaluated 115 people aged 65 to 85 using a ... source
The team then used the ages and gene information to reconstruct a survival “snapshot”
for the entire group. Their model showed that people carrying two Ts were unlikely to live past the age of 85; the maximum age for those carrying at least one C copy was approximately 100 years (Annals of Human Genetics, DOI: 10.1111/j.1469-1890.2008.00450.x).
My comment: Nice! So, they don't live more because they are smarter, but because their brains clean up the stress better. Sounds reasonable. And it's particularly close to the explanation why meditation is good for you health.
Smoking gene protects against cocaine addiction
- 25 June 2008
- Magazine issue 2661
IT MAY be a small consolation, but a mutation in a gene that makes you more likely to smoke also offers some protection against cocaine dependence.
An earlier study showed that people with two copies of a mutation in the CHRNA5 gene are twice as likely to become heavy smokers. The assumption was that genes for nicotine addiction would also increase the risk of addiction to other drugs. "Most cocaine users are also smokers, so we expected the same gene to increase the risk for both," says Rick Grucza of Washington University in Saint Louis, Missouri.But when his team scanned the genes of 260 cocaine addicts and 244 non-addicts, they found that only 48 per cent of addicts had at least one copy of the CHRNA5 mutation compared to 64 per cent of the non-addicts. Using the number of copies of the mutation that people in each group had, source group had, the researchers calculated that two copies of the mutation reduce the risk of addiction by 55 per cent and one copy by 35 per cent (Biological Psychiatry, DOI: 10.1016/j.
How might the same gene make people more likely to smoke yet less vulnerable to cocaine addiction? The CHRNA5 mutation damps down the function of a receptor found on both
reward and inhibitory neurons. As cocaine only affects the reward neurons, the researchers speculate that decreased receptor function means people with the mutation get less of a kick out of cocaine, making them less susceptible to addiction.
But as nicotine affects inhibitory neurons as well as reward ones, a decrease in receptor function reduces inhibition as well as reward. The team says this reduced inhibition causes people with the mutated gene to get more reward from nicotine than those with a normal one.
My comment: This isn't to make smokers go try drugs or to give them another reason not to quit cigarettes. I just think it's interesting how our behaviour is so well defined by our genes. Not completely, we still have out choices, but still, it has a huge impact. I love our bodies!
Tequila is surprise raw material for diamond films
- 20 June 2008
- From New Scientist Print Edition. Subscribe and get 4 free issues
If you were looking for a new way to make semiconducting diamond, you might not have thought of starting with tequila. But the potent spirit turns out to be excellent raw material.
Diamond is normally an electrical insulator, but becomes a semiconductor when doped with the right impurities. Diamond film is tougher than silicon, so it could be useful for devices that must operate at high temperatures or under other harsh conditions.
However, diamond films are expensive and difficult to make. They are produced by vaporising organic material, and then controlling how the carbon atoms crystallise onto a surface. The process works best if the material contains carbon and oxygen in roughly equal parts, as well as some hydrogen.
Now a team of researchers led by Javier Morales of the University of Nuevo León near Monterrey in Mexico have shown that ordinary tequila does the job nicely. They injected the heated vapour from 80-proof "tequila blanco" into a low-pressure chamber. Measurements confirmed that the carbon deposited on test surfaces had a diamond structure (www.arxiv.org/abs/0806.1485).
"The result is certainly funny, but the process seems reasonable," says physicist Rudolf Pfeiffer of the University of Vienna in Austria. "I don't know of any previous attempts to make diamonds from drinks." source
My comment: Lol, really really funny. So, tequila isn't made just to help boys take the flowers of drunk girls. Nice! :)
Google plans to become net-access nanny
It is the latest round of the net neutrality debate. Net neutrals like Google say the the internet should be a straightforward commodity. Although you may pay more or less for access, what you get is always the same - freedom to use and access the internet as you wish, with all those potential activities being treated the same by your ISP.
In the opposite corner are those who think ISPs should be able to choose which services they support, and which they don't. For example, under this scheme an ISP could slow all traffic to pizza delivery sites except those it had commercial agreements with.
Google's planned software will let you know when that is happening, by presenting an easy-to-understand breakdown of how your connection has been performing. Exactly how has not been revealed. I'm guessing one way would be to let you know if certain applications or websites consistently perform badly on your connection, compared to Google's own data on how they usually perform.
Google is one of the most influential pro-neutrality organisations. But its as-yet-unnamed tool (Throottle, Nootral?) is unlikely to be downloaded by large numbers of people.
If Google wanted to push it to more than just principled geeks it could throw it in with Google Toolbar, which already comes bundled with other software. Adding the neutrality nanny into that mix could dramatically increase its impact. source
My comment: I don't think people understand why the privacy of our data is really really important. But my bf gave me a very good example. So, your provider shares your interests with another party. Then suddenly, you see ads saying "You like Star Trek? Check this, this is just as good!" using the movie you like. And after you check 20 of this every day, because they attract their attention by a way you cannot turn off-your interests, you'll loose say minimum 15 seconds on each ad-so it makes 300 seconds. Which is 5 minutes. Not much. But if you add the lost concentration , make it 30 minutes. Also the impulsive purchases. Just like in Youtube. You go to see one video and end up spending hours on the "related videos".
As for why your provider shouldnot filter your internet, I hope it's clear enough. If you happen to like another pizza, you're screwed. And you cannot always simply change the provider, because it might be like one! Think of it!
Surgeons may get Minority Report-style display
- 16 June 2008
In Steven Spielberg's movie Minority Report, the agents of a police state monitor people's lives to stop crimes before they are committed, using giant computer screens that they operate using mid-air hand gestures. But in the real world surgeons, not spies, may be the first to handle data in this way. It appears to be a great way to avoid hospital-acquired infections like MRSA, which can easily be spread via a keyboard or mouse.
Writing in the Journal of the American Medical Informatics Association (vol 15, p 321), engineer Juan Wachs and colleagues at Ben Gurion University of the Negev, in Israel, describe a screen and gesture-recognition system that allows surgeons to flip back and forth through radiology images, such as MRI and CT scans, by simply groping in mid-air. Their system, called Gestix, comprises a colour video camera above a flat, widescreen monitor placed next to the operating table. The video signal from the camera is fed to a PC, where software trained to detect the colour of the surgeon's gloves tracks the movements of their hand.
Unlike the EyeToy and Wii gaming systems, which require the user to hit target areas on a screen or hold a controller, Gestix simply requires the surgeon to learn eight gestures. These include swishing the hand right or left to go back or forth through a preloaded image sequence, or clockwise and counterclockwise to zoom in and out.
In tests of the sterile browsing system during brain surgery, the researchers say the system did what it was asked to do 96 per cent of the time. source
My comment: Awesome! Like really awesome! I'm kind of jelous of the sergeons they get to try the cool new tech first. But then-all for the science!
The Worms Crawl In
In 2004, David Pritchard applied a dressing to his arm that was crawling with pin-size hookworm larvae, like maggots on the surface of meat. He left the wrap on for several days to make sure that the squirming freeloaders would infiltrate his system.“The itch when they cross through your skin is indescribable,” he said.
Dr. Pritchard, an immunologist-biologist at the University of Nottingham, is.
While carrying out field work in Papua New Guinea in the late 1980s, he noticed that Papuans infected with the Necator americanus hookworm, a parasite that lives in the human gut, did not suffer much from an assortment of autoimmune-related illnesses, including hay fever and asthma. Over the years, Dr. Pritchard has developed a theory to explain the phenomenon.
“The allergic response evolved to help expel parasites, and we think the worms have found a way of switching off the immune system in order to survive,” he said. “That’s why infected people have fewer allergic symptoms.”
To test his theory, and to see whether he can translate it into therapeutic pay dirt, Dr. Pritchard is recruiting clinical trial participants willing to be infected with 10 hookworms each in hopes of banishing their allergies and asthma.
Dr. Pritchard initially used himself as a subject to secure approval from the National Health Services ethics committee in Britain.
In the tropics, where it is common, hookworm kills 65,000 people a year and afflicts hundreds of thousands with anemia. In low numbers in adults in a controlled experiment, Dr. Pritchard said, the worms have not caused problems.
In the late 1980s, the Wellcome Trust issued a grant, and Dr. Pritchard and his Nottingham team set up camp on Karkar Island, Papua New Guinea.
Hookworm infiltrates a victim’s system when the larvae, hatched from eggs in infected people’s excrement, penetrate the skin, often through the soles of the feet. From there, they enter the bloodstream, travel to the heart and lungs, and are swallowed when they reach the pharynx. They mature into adults once they reach the small intestine, where they can subsist for years by latching onto the intestinal wall and siphoning off blood. After sieving the fecal samples to extract hookworms eliminated when the worm treatment pill was given, the team reached an intriguing conclusion: Villagers with the highest levels of allergy-related antibodies in their blood had the smallest and least fertile parasites, indicating that these antibodies conferred a degree of protection against parasite infection.
And the hookworms seemed equipped to retaliate. After colonizing a digestive tract, the host often showed signs of a blunted immune response, leading Dr. Pritchard to suspect that the worms were reducing the potency of the body’s defenses to make their environment more hospitable.
Nearly 20 years later, his musing began to come to fruition. After Dr. Pritchard’s self-infection experiment, the National Health Services ethics committee let him conduct a study in 2006 with 30 participants, 15 of whom received 10 hookworms each. Tests showed that after six weeks, the T-cells of the 15 worm recipients began to produce lower levels of chemicals associated with inflammatory response, indicating that their immune systems were more suppressed than those of the 15 placebo recipients. Despite playing host to small numbers of parasites, worm recipients reported little discomfort.
Trial participants raved about their allergy symptoms disappearing. Word about the study soon appeared online among chronic allergy sufferers, and a Yahoo group on “helminthic therapy” sprung up.
Now he is recruiting patients for a larger-scale trial of the therapy, and he said he hoped to publish his results within the next year.
Dr. Pritchard is the first scientist to infect patients with hookworms in a laboratory setting, but he is not the first to conclude that parasite infection might ease allergy symptoms. Previous studies have lent support to the idea.
In 2000, Maria Yazdanbakhsh, an immunologist at Leiden University in the Netherlands, studied 520 Gabonese children and found that those with Schistosoma haematobium, one of a family of parasites that cause schistosomiasis, had lower levels of allergic responses to dust mites, one of the most common environmental allergens.It was not until 2005 that Rick Maizels, a biologist at Edinburgh University, uncovered a possible biological explanation.
When Dr. Maizels and his colleagues infected a group of mice with the Heligmosomoides polygyrus parasite, a nematode similar to the hookworm that infects humans, they found that the mice started churning out more regulatory T cells for reasons that remain unclear.
The T cells, Dr. Maizels said, modulate the immune response by secreting interleukin-10, a compound that counteracts inflammatory effects that other immune system cells generate at the site of an allergic reaction.
Some scientists say Dr. Pritchard is walking a fine ethical line by infecting patients with a parasite known to risk hosts’ health. Peter Hotez, a microbiologist at George Washington University who is developing a hookworm vaccine, said the parasite was among the primary causes of stunted growth and malnutrition in developing countries.
“If a kid is infected with 25 hookworms, he’s being robbed of his daily iron requirement, and because the worms suppress the immune system, they can increase the host’s susceptibility to diseases like AIDS and malaria,” Dr. Hotez said. “So in its current form, I think this therapy is too risky.”
Because of the potential side effects, Dr. Pritchard does not envision thousands of patients lined up at clinics to receive parasites along with flu shots.His long-term goal, he added, is to figure out exactly how the worms turn down the immune-system radar, so he can borrow the tactics to develop alternatives to immune-suppressant and allergy-fighting drugs.
“We’re looking at the molecular mechanisms the worms are using, and we’re hoping to find molecules that veer the immune response away from allergy,” he said.
Though he eventually hopes to eliminate hookworms entirely from his allergy treatment, Dr. Pritchard has few qualms about venturing where no parasite researcher has gone before.source
My comment: Not exactly a technology but it's interesting and promising!