Saturday, February 27, 2010

Scientists Unravel Mysteries of Intelligence

FRIDAY, Feb. 26 (HealthDay News) -- It's not a particular brain region that makes someone smart or not smart.

Nor is it the strength and speed of the connections throughout the brain or such features as total brain volume.

Instead, new research shows, it's the connections between very specific areas of the brain that determine intelligence and often, by extension, how well someone does in life.

"General intelligence actually relies on a specific network inside the brain, and this is the connections between the gray matter, or cell bodies, and the white matter, or connecting fibers between neurons," said Jan Glascher, lead author of a paper appearing in this week's issue of the Proceedings of the National Academy of Sciences. "General intelligence relies on the connection between the frontal and the parietal [situated behind the frontal] parts of the brain."

The results weren't entirely unexpected, said Keith Young, vice chairman of research in psychiatry and behavioral science at Texas A&M Health Science Center College of Medicine in Temple, but "it is confirmation of the idea that good communication between various parts of brain are very important for this generalized intelligence."

General intelligence is an abstract notion developed in 1904 that has always been somewhat controversial.

"People noticed a long time ago that, in general, people who are good test-takers did well in a lot of different subjects," explained Young. "If you're good in mathematics, you're also usually good in English. Researchers came up with this idea that this represented a kind of overall intelligence."

"General intelligence is this notion that smart people tend to be smart across all different kinds of domains," added Glascher, who is a postdoctoral fellow in the department of humanities and social sciences at the California Institute of Technology in Pasadena.

Hoping to learn more, the authors located 241 patients who had some sort of brain lesion. They then diagrammed the location of their lesions and had them take IQ tests.

"We took patients who had damaged parts of their brain, tested them on intelligence to see where they were good and where they were bad, then we correlated those scores across all the patients with the location of the brain lesions," Glascher explained. "That way, you can highlight the areas that are associated with reduced performance on these tests which, by the reverse inference, means these areas are really important for general intelligence."

"These studies infer results based on the absence of brain tissue," added Paul Sanberg, distinguished professor of neurosurgery and director of the University of South Florida Center for Aging and Brain Repair in Tampa. "It allows them to systemize and pinpoint areas important to intelligence."

Young said the findings echo what's come before. "The map they came up with was what we expected and involves areas of the cortex we thought would be involved -- the parietal and frontal cortex. They're important for language and mathematics," he said.

In an earlier study, the same team of investigators found that this brain network was also important for working memory, "the ability to hold a certain number of items [in your mind]," Glascher said. "In the past, people have associated general intelligence very strongly with enhanced working memory capacity so there's a close theoretical connection with that."

Wednesday, February 17, 2010

Canadian curler is five months pregnant

As with all curling teams, Team Canada features five members. Well, six, if you really want to get technical with it.

Alternate Kristie Moore, 30, is 5½ months pregnant, making her just the third athlete known to be with child during Olympic competition. Ninety years ago, Swedish figure skater Magda Julin won a gold medal at the Antwerp Games while in her first trimester and Germany’s Diana Sartor took fourth in the skeleton in 2006.

Though she is showing (as evidenced in the picture above), Moore says that her pregnancy has not affected her ability to deliver rocks ... yet. "[In] the eighth month or so, that might be an issue," she said.

Moore found out about her pregnancy weeks before team officials invited her to join Team Canada as an alternate. When she divulged her secret, the team was more than supportive. Said team leader Cheryl Bernard, "she is young and fit. There's no reason we'll have any problems, and she'll be out there."

Barring unforeseen problems with the other four members of the team, it's unlikely Moore will see any Olympic action. During competition her role as an alternate is much like a backup quarterback in football: She'll be called on if needed. Moore has said that although she'd like to get out on the ice, doing so would mean having to play at the expense of someone else's injury.

Team Canada is the gold-medal favorite in the women's curling event, which begins Tuesday and runs through Friday of next week. Even if Moore doesn't play, she will receive any medal Canada wins.

Saturday, February 13, 2010

Can a Healthy Heart Help Create a Healthy Relationship (or is it the other way around)?

Your heart swells, sings, skips a beat, races, goes pitter patter… oh yes, that feeling of effervescent love and its physical effects on the body. You better believe that for the entire month of February you’re going to be hearing a lot about matters of the heart, how it feels to fall in love, and what to do to stay in love. But what about the health of the heart and it's effects on your ability to express that love?
Studies have shown that happy relationships can improve heart health. More than a healthy heart, the Kinsey Institute for Research in Sex, Gender and Reproduction has found a link between healthy people and frequency in sexual activity. But the question that has yet to be proven is this: is it thathealthy people are more sexually activity, or does sexual activity improve health? Regardless of the final statistical outcome, what we do know is this- healthy and regular sexual activity helps your health, and therefore the potential longevity and health of your relationship by:

-Boosting Cardiovascular Healthby getting the heart beating, lowering blood pressure, and, this may be a shocker, Dutch scientists found that ingesting (yes, swallowing) semen lowers the risk of preeclampsia (high blood pressure) in pregnant women.

-Minimizes Stress, both emotionally and physically; in fact, according to the Kinsey Institute, semen is like a shot of zinc, calcium, potassium, fructose, proteins, translation: vitality!

-Relieves Pain, thanks to the oxytocin and endorphins released during orgasm.

-Decrease Prostate Cancer risk for men who regularly ejaculate.

-Healing Cuts and Wounds another effect of the oxytocin said to help heal wounds faster, helping to regenerate skin cells.

3 simple tests that can predict and prevent a heart attack

Your doctor can order a host of complex tests to gauge the health of your heart, but Prevention’s resident cardiologist, Arthur Agatston, MD, shared three new methods of predicting heart disease that are surprisingly simple and effective. One can be done with your eyes closed—literally. Another can be ordered the next time you have a blood test, and the third involves taking the temperature of your finger. Here's a rundown of how each one works:

1. The Sleep Test

Answer this question: Do you feel drowsy during the day? If so, you may be harming your heart. Every extra hour of sleep middle-aged adults can add to their nightly average reduces their risk of coronary artery calcification by 33%, according to a study reported in the Journal of the American Medical Association. When you're even a little sleep deprived, your body releases stress hormones that constrict arteries and cause inflammation. If you routinely wake up feeling tired or need an afternoon nap, then you're probably sleep deprived. Try either changing your sleep habits (darker room, TV off, earplugs) or going to bed 30 minutes earlier until symptoms disappear. If your spouse complains about your snoring or you often wake up with a headache, get checked for sleep apnea disorder.

2. The Vitamin D Test

Low levels of vitamin D, found in nearly 80% of US adults, can cause a rise in blood pressure and increased arterial inflammation. Fortunately, it's easy to test for and remedy any deficiency. Ask your doctor to order a vitamin-D analysis as part of your next blood test. Optimal levels are 30 to 40 ng/mL, but some doctors contend 50-plus ng/mL is even better. If yours is low, get 10 to 15 more minutes of sunlight per day (without sunblock), eat more vitamin D–rich foods (salmon, tuna, fortified orange juice), or take a D supplement (as recommended by your doctor). It's one of the simplest things you can do to protect your heart.

3. The Finger Test

Lining all your blood vessels—even those in your index finger—is a single layer of cells, called the endothelium, that produce chemicals that affect the vessels' function, causing dilation, constriction, clotting, etc. Negative changes in the endothelium occur years before any other measurable signs of heart trouble appear, so researchers have believed that if the health of the endothelium could be tested, we just might lick heart disease and stroke.

Now that test exists. The one Dr. Agatston uses, called Vendys, involves attaching a fingertip-temperature detector to your index finger and wrapping a blood-pressure cuff around your arm. As the cuff is inflated, blood flow to the hand decreases and finger temperature drops. After 5 minutes, the cuff is deflated and blood flow returns. The faster and more completely finger temperature rebounds, the healthier the endothelium.

The great thing about this test is that your doctor can not only assess your vascular health but also partially monitor how well treatment is working. If a patient loses weight, lowers her blood pressure, or begins taking medication, positive changes in her endothelial function can be detected almost instantaneously. With other methods—calcium scoring, for instance—it would take years. Eventually, this finger test could be an invaluable aid for monitoring heart health.

Friday, February 5, 2010

Computers That Use Light Instead of Electricity? First Germanium Laser Created

MIT researchers have demonstrated the first laser built from germanium that can produce wavelengths of light useful for optical communication. It's also the first germanium laser to operate at room temperature. Unlike the materials typically used in lasers, germanium is easy to incorporate into existing processes for manufacturing silicon chips. So the result could prove an important step toward computers that move data -- and maybe even perform calculations -- using light instead of electricity. But more fundamentally, the researchers have shown that, contrary to prior belief, a class of materials called indirect-band-gap semiconductors can yield practical lasers.

As chips' computational capacity increases, they need higher-bandwidth connections to send data to memory. But conventional electrical connections will soon become impractical, because they'll require too much power to transport data at ever higher rates. Transmitting data with lasers -- devices that concentrate light into a narrow, powerful beam -- could be much more power-efficient, but it requires a cheap way to integrate optical and electronic components on silicon chips.

Chip assembly is a painstaking process in which layers of different materials are deposited on a wafer of silicon, and patterns are etched into them. Inserting a new material into this process is difficult: it has to be able to chemically bond to the layers above and below it, and depositing it must be possible at the temperatures and in the chemical environments suitable to the other materials.

The materials used in today's lasers, such as gallium arsenide, are "all tough fits," says Tremont Miao, a marketing director at Massachusetts-based Analog Devices Semiconductor. "They're all challenging integrations." As a consequence, the lasers have to be constructed separately and then grafted onto the chips, which is more expensive and time-consuming than building them directly on silicon would be. Moreover, gallium arsenide is much more expensive than silicon in the first place.

Integrating germanium into the manufacturing process, however, is something that almost all major chip manufacturers have already begun to do, since the addition of germanium increases the speed of silicon chips. "We and lots of other people know how to do that," Miao says.

Unchanneled energies

Gallium arsenide, silicon, and germanium are all examples of semiconductors, the type of material used in virtually all modern electronics. Lasers made from semiconductors convert the energy of electrons -- particles of charge -- into photons -- particles of light. Semiconductors come in two varieties: those with direct band gaps, like gallium arsenide, and those with indirect band gaps, like germanium and silicon. According to Jurgen Michel, principal research associate in the Electronic Materials Research Group and primary investigator on the germanium-laser project, "There was an opinion in the scientific area that indirect-band-gap semiconductors will never lase" -- that is, produce laser light. "That's just what you teach in classes," says Lionel Kimerling, the Thomas Lord Professor of Materials Science and Engineering, who leads the group.

In a semiconductor crystal, an excited electron -- one that's had energy added to it -- will break free and enter the so-called conduction band, where it can move freely around the crystal. But in fact, an electron in the conduction band can be in one of two states. If it's in the first state, and it falls out of the conduction band, it will release its extra energy as a photon. If it's in the second state, it will release its energy in other ways, such as heat.

In direct-band-gap materials, the first state -- the photon-emitting state -- is a lower-energy state than the second state; in indirect-band-gap materials, it's the other way around. An excited electron will naturally occupy the lowest-energy state it can find. So in direct-band-gap materials, excited electrons tend to go into the photon-emitting state, and in indirect-band-gap materials, they don't.

Bridging the gap

In a forthcoming paper in the journal Optics Letters, Kimerling, Michel and three other researchers in the group -- postdoc Jifeng Liu, the lead author on the paper, and grad students Xiaochen Sun and Rodolfo Camacho-Aguilera -- describe how they coaxed excited germanium electrons into the higher-energy, photon-emitting state.

Their first strategy is a technique, common in chip manufacturing, called "doping," in which atoms of some other element are added to a semiconductor crystal. The group doped its germanium with phosphorous, which has five outer electrons. Germanium has only four outer electrons, "so each phosphorous gives us an extra electron," Kimerling says. The extra electron fills up the lower-energy state in the conduction band, causing excited electrons to, effectively, spill over into the higher-energy, photon-emitting state.

According to the group's theoretical work, phosphorous doping "works best at 1020 atoms per cubic centimeter" of germanium, Kimerling explains. So far, the group has developed a technique that can add 1019 phosphorous atoms to each cubic centimeter of germanium, "and we already begin to see lasing," Kimerling says.

The second strategy was to lower the energy difference between the two conduction-band states so that excited electrons would be more likely to spill over into the photon-emitting state. The researchers did that by adapting another technique common in the chip industry: they "strained" the germanium -- or pried its atoms slightly farther apart than they would be naturally -- by growing it directly on top of a layer of silicon. Both the silicon and the germanium were deposited at high temperatures. But silicon doesn't contract as much as germanium when it cools. The atoms of the cooling germanium tried to maintain their alignment with the silicon atoms, so they ended up farther apart than they would ordinarily be. Changing the angle and length of the bonds between germanium atoms also changed the energies required to kick their electrons into the conduction band. "The ability to grow germanium on silicon is a discovery of this group," says Kimerling, "and the ability to control the strain of those germanium films on silicon is a discovery of this group."

"High-speed optical circuits like germanium in general," says Miao. "That's a good marriage and a good combination. So their laser research is very, very promising." Miao points out that the germanium lasers need to become more power-efficient before they're a practical source of light for optical communications systems. "But on the other hand," he says, "the promise is exciting, and the fact that they got germanium to lase at all is very exciting."