The PAL-V ONE, which looks like a cross between a three-wheeler and a helicopter, uses a rear-mounted propeller to take off and a free-spinning rotor on top for lift. Made by PAL-V in the Netherlands, it needs about 200 meters to take off and costs nearly $300,000.
Category: Science
Towards a possible pill to let patients with celiac disease eat gluten
Scientists are reporting an advance toward development of a pill that could become celiac disease’s counterpart to the lactase pills that people with lactose intolerance can take to eat dairy products without risking digestive upsets.
They describe the approach, which involves an enzyme that breaks down the gluten that causes celiac symptoms, in the Journal of the American Chemical Society.
Justin Siegel, Ingrid Swanson Pultz and colleagues explain that celiac disease is an autoimmune disorder in which the gluten in wheat, rye or barley products causes inflammation in the digestive tract. Enzymes in the stomach break down gluten into smaller pieces, called peptides. For most people, these peptides are harmless. But for the 2 million-3 million Americans with celiac disease, the peptides trigger an autoimmune response and painful symptoms. Currently, the only treatment is a gluten-free diet. However, the scientists reasoned that if an enzyme could further break down the offending peptides in the stomach, celiac patients might be able to eat gluten-containing foods.
They describe discovery of a naturally occurring enzyme that has some of the ideal properties for doing so. The scientists modified the enzyme in the laboratory so that it would meet all the necessary criteria. The new enzyme (called KumaMax) broke down more than 95 percent of a gluten peptide implicated in celiac disease in acidic conditions like those in the stomach. “These combined properties make the engineered [enzyme] a promising candidate as an oral therapeutic for celiac disease,” say the researchers.
The authors acknowledge funding from the Howard Hughes Medical Institute and the Defense Advanced Research Projects Agency.
Journal Reference:
1.Sydney R. Gordon, Elizabeth J. Stanley, Sarah Wolf, Angus Toland, Sean J. Wu, Daniel Hadidi, Jeremy H. Mills, David Baker, Ingrid Swanson Pultz, Justin B. Siegel. Computational Design of an α-Gliadin Peptidase. Journal of the American Chemical Society, 2012; 134 (50): 20513 DOI: 10.1021/ja3094795
http://www.sciencedaily.com/releases/2012/12/121219133558.htm
In the Flesh: The Embedded Dangers of Untested Stem Cell Cosmetics
When cosmetic surgeon Allan Wu first heard the woman’s complaint, he wondered if she was imagining things or making it up. A resident of Los Angeles in her late sixties, she explained that she could not open her right eye without considerable pain and that every time she forced it open, she heard a strange click—a sharp sound, like a tiny castanet snapping shut. After examining her in person at The Morrow Institute in Rancho Mirage, Calif., Wu could see that something was wrong: Her eyelid drooped stubbornly, and the area around her eye was somewhat swollen. Six and a half hours of surgery later, he and his colleagues had dug out small chunks of bone from the woman’s eyelid and tissue surrounding her eye, which was scratched but largely intact. The clicks she heard were the bone fragments grinding against one another.
About three months earlier the woman had opted for a relatively new kind of cosmetic procedure at a different clinic in Beverly Hills—a face-lift that made use of her own adult stem cells. First, cosmetic surgeons had removed some the woman’s abdominal fat with liposuction and isolated the adult stem cells within—a family of cells that can make many copies of themselves in an immature state and can develop into several different kinds of mature tissue. In this case the doctors extracted mesenchymal stem cells—which can turn into bone, cartilage or fat, among other tissues—and injected those cells back into her face, especially around her eyes. The procedure cost her more than $20,000, Wu recollects. Such face-lifts supposedly rejuvenate the skin because stem cells turn into brand-new tissue and release chemicals that help heal aging cells and stimulate nearby cells to proliferate.
During the face-lift her clinicians had also injected some dermal filler, which plastic surgeons have safely used for more than 20 years to reduce the appearance of wrinkles. The principal component of such fillers is calcium hydroxylapatite, a mineral with which cell biologists encourage mesenchymal stem cells to turn into bone—a fact that escaped the woman’s clinicians. Wu thinks this unanticipated interaction explains her predicament. He successfully removed the pieces of bone from her eyelid in 2009 and says she is doing well today, but some living stem cells may linger in her face. These cells could turn into bone or other out-of-place tissues once again.
Dozens, perhaps hundreds, of clinics across the country offer a variety of similar, untested stem cell treatments for both cosmetic and medical purposes. Costing between $3,000 and $30,000, the treatments promise to alleviate everything from wrinkles to joint pain to autism. The U.S. Food and Drug Administration (FDA) has not approved any of these treatments and, with a limited budget, is struggling to keep track of all the unapproved therapies on the market. At the same time, pills, oils, creams and moisturizers that allegedly contain the right combination of ingredients to mobilize the body’s resident stem cells, or contain chemicals extracted from the stem cells in plants and animals, are popping up in pharmacies and online. There’s Stem Cell 100, for example, MEGA STEM and Apple Stem Cell Cloud Cream. Few of these cosmetics have been properly tested in published experiments, yet the companies that manufacture them say they may heal damaged organs, slow or reverse natural aging, restore youthful energy and revitalize the skin. Whether such cosmetics may also produce unintended and potentially harmful effects remains largely unexamined. The increasing number of untested and unauthorized stem cell treatments threaten both people who buy them and researchers hoping to conduct clinical trials for promising stem cell medicine.
So far, the FDA has only approved one stem cell treatment: a transplant of bone marrow stem cells for people with the blood cancer leukemia. Among the increasing number of unapproved stem cell treatments, some clearly violate the FDA’s regulations whereas others may technically be legal without its approval. In July 2012, for example, the U.S. District Court upheld an injunction brought by the FDA against Colorado-based Regenerative Sciences to regulate just one of the company’s several stem cell treatments for various joint injuries as an “unapproved biological drug product.” The decision hinged on what constitutes “minimal manipulation” of cells in the lab before they are injected into patients. In the treatment that the FDA won the right to regulate, stem cells are grown and modified in the lab for several weeks before they are returned to patients; in Regenerative Sciences’s other treatments, patients’ stem cells are extracted and injected within a day or two. Regenerative Sciences now offers the legally problematic treatment at a Cayman Island facility.
Many stem cell cosmetics reside in a legal gray area. Unlike drugs and “biologics” made from living cells and tissues, cosmetics do not require premarket approval from the FDA. But stem cell cosmetics often satisfy the FDA’s definitions for both cosmetics and drugs. In September 2012 the FDA posted a letter on its Web site warning Lancôme, a division of L’Oréal, that the way it describes its Genifique skin care products qualify the creams and serums as unapproved drugs: they are supposed to “boost the activity of genes,” for example, and “improve the condition of stem cells.” Other times the difference between needing or not needing FDA approval comes down to linguistic nuance—the difference between claiming that a product does something or appears to do something.
Personal Cell Sciences, in Eatontown, N.J., sells some of the more sophisticated stem cell–based cosmetics: an eye cream, moisturizer and serum infused with chemicals derived from a consumer’s own stem cells. According to its website and marketing materials, these products help “make skin more supple and radiant,” “reduce the appearance of fine lines and wrinkles around the eyes and lips,” “improve cellular renewal” and “stimulate cell turnover for renewed texture and tone.” In exchange for $3,000, Personal Cell Sciences will arrange for a participating physician to vacuum about 60 cubic centimeters (one quarter cup) of a customer’s fat from beneath his or her skin and ship it on ice to American CryoStem Corp. in Red Bank, N.J., where laboratory technicians isolate and grow the customer’s mesenchymal stem cells to around 30 million strong. Half these cells are frozen for storage; from the other half, technicians harvest hundreds of different kinds of exuded growth factors and cytokines—molecules that help heal damaged cells and encourage cells to divide, among other functions. These molecules are mixed with many other ingredients—including green tea extract, caffeine and vitamins—to create the company’s various “U Autologous” skin care products, which are then sold back to the consumer for between $400 and $800. When the customer wants a refill, technicians thaw some of the frozen cells, collect more cytokines and produce new bottles of cream.
In an unpublished safety trial sponsored by Personal Cell Sciences, Frederic Stern of the Stern Center for Aesthetic Surgery in Bellevue, Wash., and his colleagues monitored 19 patients for eight weeks as they used the U Autologous products on the left sides of their faces. A computer program meant to objectively analyze photos of the volunteers’ faces measured an average of 25.6 percent reduction in the volume of wrinkles on the treated side of the face. Analysis of tissue biopsies revealed increased levels of the protein elastin, which helps keep skin taut, and no signs of unusual or cancerous cell growth.
Supposedly, the primary active ingredients in the U Autologous skin care products are the hundreds of different kinds of cytokines they contain. Cytokines are a large and diverse family of proteins that cells release to communicate with and influence one another. Cytokines can stimulate cell division or halt it; they can suppress the immune system or provoke it; they can also change a cell’s shape, modulate its metabolism and force it to migrate from one location to another like a cowboy corralling cattle. Researchers have only named and characterized some of the many cytokines that stem cells secrete. Some of these molecules certainly help repair damaged cells and promote cell survival. Others seem to be involved in the development of tumors. In fact, some recent evidence suggests that the cytokines released by mesenchymal stem cells can trigger tumors by accelerating the growth of dormant cancer cells. Personal Cell Sciences does not pick and choose among the cytokines exuded by its customers’ stem cells—instead, it dumps them all into its skin care products.
Based on the available evidence so far, topical creams containing cytokines from stem cells pose far less risk of cancer than living stem cells injected beneath the skin. But scientists do not yet know enough about stem cell cytokines to reliably predict everything they will do when rubbed into the skin; they could interact with healthy skin cells in a completely unexpected way, just as the unintended interplay between calcium hydroxylapatite and stem cells produced bones in the Los Angeles woman’s eye. Stern acknowledges that unusual tissue growth is a concern for any treatment based on stem cells and the chemicals they release. “Down the line, we want to continue watching that,” he says. Unlike many other clinics, he and his colleagues have been keeping tabs on their patients through regular follow-ups. John Arnone, CEO of American CryoStem and founder of Personal Cell Sciences, says the fact that U Autologous skin care products contain such a diversity of cytokines does not bother him: “I’ve seen worse things out there. I’ve been putting this formulation for almost a year on myself prior to the study. I’m the best guinea pig here.”
Beyond the considerable risks to consumers, unapproved stem cell treatments also threaten the progress of basic research and clinical trials needed to establish safe stem cell therapies for serious illnesses. By harvesting stem cells, subsequently nourishing them in the lab and transplanting them back inside the human body, scientists hope to improve treatment for a variety of medical conditions, including heart failure, neurodegenerative disorders like Parkinson’s, and spinal cord injuries—essentially any condition in which the body needs new cells and tissues. Researchers are investigating many stem cell therapies in ongoing, carefully controlled clinical trials. Some of the principal questions entail which of the many kinds of stem cells to use; how to safely deliver stem cells to patients without stimulating tumors or the growth of unwanted tissues; and how to prevent the immune system from attacking stem cells provided by a donor. Securing funding for such research becomes all the more difficult if shortcuts taken by private clinics and cosmetic manufacturers—and the subsequent botched procedures and unanticipated consequences—imprint a stigma on stem cells.
“Many of us are super excited about stem cells, but at same time we have to be really careful,” says Paul Knoepfler, a cell biologist at the University of California, Davis, who regularly blogs about the regulation of stem cell treatments. “These aren’t your typical drugs. You can stop taking a pill and the chemicals go away. But if you get stem cells, most likely you will have some of those cells or their effects for the rest of your life. And we simply don’t know everything they are going to do.”
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https://www.scientificamerican.com/article.cfm?id=stem-cell-cosmetics&WT.mc_id=SA_emailfriend
Thanks to Dr. Nakamura for bringing this to the attention of the It’s Interesting community.
Closest Single Star Like Our Sun May Have Habitable Planet
An international team of astronomers led by the University of Hertfordshire has discovered that Tau Ceti, one of the closest and most Sun-like stars, may host five planets — with one in the star’s habitable zone.
At a distance of twelve light years and visible with the naked eye in the evening sky, Tau Ceti is the closest single star that has the same spectral classification as our Sun. Its five planets are estimated to have masses between two and six times the mass of Earth — making it the lowest-mass planetary system yet detected. One of the planets lies in the habitable zone of the star and has a mass around five times that of Earth, making it the smallest planet found to be orbiting in the habitable zone of any Sun-like star.
The international team of astronomers, from the UK, Chile, the USA, and Australia, combined more than six-thousand observations from three different instruments and intensively modelled the data. Using new techniques, the team has found a method to detect signals half the size previously thought possible. This greatly improves the sensitivity of searches for small planets and suggests that Tau Ceti is not a lone star but has a planetary system.
Mikko Tuomi, from the University of Hertfordshire and the first author of the paper, said: “We pioneered new data modelling techniques by adding artificial signals to the data and testing our recovery of the signals with a variety of different approaches. This significantly improved our noise modelling techniques and increased our ability to find low mass planets.”
“We chose Tau Ceti for this noise modelling study because we had thought it contained no signals. And as it is so bright and similar to our Sun it is an ideal benchmark system to test out our methods for the detection of small planets,” commented Hugh Jones from the University of Hertfordshire.
James Jenkins, Universidad de Chile and Visiting Fellow at the University of Hertfordshire, explained: “Tau Ceti is one of our nearest cosmic neighbours and so bright that we may be able to study the atmospheres of these planets in the not too distant future. Planetary systems found around nearby stars close to our Sun indicate that these systems are common in our Milky Way galaxy.”
Over 800 planets have been discovered orbiting other worlds, but planets in orbit around the nearest Sun-like stars are particularly valuable. Steve Vogt from University of California Santa Cruz said: “This discovery is in keeping with our emerging view that virtually every star has planets, and that the galaxy must have many such potentially habitable Earth-sized planets. They are everywhere, even right next door! We are now beginning to understand that Nature seems to overwhelmingly prefer systems that have a multiple planets with orbits of less than one hundred days. This is quite unlike our own solar system where there is nothing with an orbit inside that of Mercury. So our solar system is, in some sense, a bit of a freak and not the most typical kind of system that Nature cooks up.”
“As we stare the night sky, it is worth contemplating that there may well be more planets out there than there are stars … some fraction of which may well be habitable,” remarked Chris Tinney from the University of New South Wales.
Journal Reference:
1.M. Tuomi, H. R. A. Jones, J. S. Jenkins, C. G. Tinney, R. P. Butler, S. S. Vogt, J. R. Barnes, R. A. Wittenmyer, S. O’Toole, J. Horner, J. Bailey, B. D. Carter, D. J. Wright, G. S. Salter, D. Pinfield. Signals embedded in the radial velocity noise. Periodic variations in the tau Ceti velocities. Astronomy & Astrophysics, 2012; DOI: 10.1051/0004-6361/201220509
http://www.sciencedaily.com/releases/2012/12/121219084102.htm
Strengthened link between climate change and volcanic eruptions established
It has long been known that volcanic activity can cause short-term variations in climate. Now, researchers at the GEOMAR Helmholtz Centre for Ocean Research Kiel (Germany), together with colleagues from Harvard University have found evidence that the reverse process also occurs: Climate affects volcanic activity. “In times of global warming, the glaciers are melting on the continents relatively quickly. At the same time the sea level rises. The weight on the continents decreases, while the weight on the oceanic tectonic plates increases. The stress changes within in the earth to open more routes for ascending magma” says geophysicist Dr Marion Jegen from GEOMAR, who participated in the study. The rate of global cooling at the end of the warm phases is much slower, so there are less dramatic stress changes during these times.
“If you follow the natural climate cycles, we are currently at the end of a really warm phase. Therefore, things are volcanically quieter now. The impact from man-made warming is still unclear based on our current understanding” says GEOMAR volcanologist Dr Steffen Kutterolf, who has been with SFB 574 since its founding.
In 1991, it was a disaster for the villages nearby the erupting Philippine volcano Pinatubo. But the effects were felt even as far away as Europe. The volcano threw up many tons of ash and other particles into the atmosphere causing less sunlight than usual to reach the Earth’s surface. For the first few years after the eruption, global temperatures dropped by half a degree. In general, volcanic eruptions can have a strong short-term impact on climate. Conversely, the idea that climate may also affect volcanic eruptions on a global scale and over long periods of time is completely new.
Researchers at GEOMAR Helmholtz Centre for Ocean Research Kiel (Germany) and Harvard University in Massachusetts (USA) have now found strong evidence for this relationship from major volcanic eruptions around the Pacific Ocean over the past 1 million years. They have presented their results in the latest issue of the international journal Geology.
For more than ten years the project has been extensively exploring volcanoes of Central America. “Among others pieces of evidence, we have observations of ash layers in the seabed and have reconstructed the history of volcanic eruptions for the past 460,000 years,” says Kutterolf. Particular patterns started to appear. “There were periods when we found significantly more large eruptions than in others” says Kutterolf.
After comparing these patterns with the climate history, there was an amazing match. The periods of high volcanic activity followed fast, global temperature increases and associated rapid ice melting. To expand the scope of the discoveries, Dr Kutterolf and his colleagues studied other cores from the entire Pacific region. These cores had been collected as part of the International Integrated Ocean Drilling Program (IODP) and its predecessor programmes. They record more than a million years of the Earth’s history.
“In fact, we found the same pattern from these cores as in Central America” says Jegen. Together with colleagues at Harvard University, the geologists and geophysicists searched for a possible explanation. They found it with the help of geological computer models.
The next step is to investigate shorter-term historical variations to better understand implications for the present day.
For more information: Kutterolf, S., M. Jegen, J. X. Mitrovica, T. Kwasnitschka, A. Freundt, P. J. Huybers (2012): A detection of Milankovitch frequencies in global volcanic activity. Geology, G33419.1, dx.doi.org/10.1130/G33419.1 Journal reference: Geology
Mass squid suicides in California
Thousands of jumbo squid have recently beached themselves on central California shores, committing mass “suicide.” But despite decades of study into the phenomenon in which the squid essentially fling themselves onto shore, the cause of these mass beachings have been a mystery.
But a few intriguing clues suggest poisonous algae that form so-called red tides may be intoxicating the Humboldt squid and causing the disoriented animals to swim ashore in Monterey Bay, said William Gilly, a marine biologist at Stanford University’s Hopkins Marine Station in Pacific Grove, Calif.
Each of the strandings has corresponded to a red tide, in which algae bloom and release an extremely potent brain toxin, Gilly said. This fall, the red tides have occurred every three weeks, around the same time as the squid beachings, he said. (The squid have been stranding in large numbers for years, with no known cause.)
For decades, beach lovers have reported bizarre mass strandings where throngs of Humboldt squid (Dosidicus gigas), also called jumbo squid, fling themselves ashore, said Hannah Rosen, a marine biology doctoral candidate at the Hopkins Marine Station.
“For some reason they just start swimming for the beach,” Rosen told LiveScience. “They’ll asphyxiate because they’re out of the water too long. People have tried to throw them back in the water, and a lot of times the squid will just head right back for the beach.”
Before this, scientists in 2002 and 2006 noticed mass squid strandings from the Gulf of Mexico all the way to Alaska, Gilly said.
But the cause of the mass squid deaths was an enigma. The strandings seem to happen whenever schools of squid invade new territory, leading some to suggest the creatures simply get lost and don’t realize they are out of the water until it is too late. The squid washing ashore are juvenile size, about 1 foot (0.3 meters) long, and hadn’t been traveled to Monterey Bay before this fall. This season’s stranding, which started Oct. 9, happened around the time Humboldt squid entered the bay.
Other scientists have proposed that red tides that release a lethal toxin called domoic acid may be intoxicating the squid and disorienting them. But when researchers tested the stranded squid for domoic acid, they found only trace amounts of the chemical, Gilly said.
The poisonous chemical mimics a brain chemical called glutamate in mammals, though domoic acid is 10,000 times more potent than glutamate. The similar structure means domoic acid can bind to glutamate receptors on neurons. In turn, the receptor opens channels that let calcium into the cell. At high levels the poison causes brain cells to go haywire and fire like crazy, so much that they fill up with calcium, burst and die, Gilly said. [10 Weird Facts About the Brain]
Humans who eat shellfish contaminated with this red-tide toxin get amnesic shellfish poisoning, because the toxin destroys their brain’s memory center called the hippocampus. Sea lions that eat similarly poisoned anchovies or krill go into seizures or become disoriented and behave bizarrely.
However, no one has tested the effects of lower levels of the chemical on squid.
Potential cause?
But new evidence points to the red tide as at least one cause of the mass strandings. While most sea life follows daily tidal or lunar cycles, the mass deaths seem to be happening every three weeks. That led one of Gilly’s graduate students, R. Russell Williams, to see if something in the environment was leading them astray.
“He was fixated in finding some kind of environmental signal,” Gilly said.
Russell found that red tides occurred every three weeks, around the same time as the squid strandings, suggesting a link, Gilly said.
While past researchers have only found trace levels of the toxic red-tide chemical in stranded squid, low doses of domoic could essentially be making the squid drunk. Combined with navigating unfamiliar waters, that could cause the mass die-offs.
“They could be tipped over the edge by something like domoic acid that might cloud their judgment,” Gilly said.
This isn’t the first time Gilly and his colleagues have been led on a CSI-like hunt for Humboldt squid. In 2011, they figured out why the elusive jumbo squid left their usual feeding grounds off the Baja California coast in the winter of 2009 to 2010. Apparently, the squid had moved north, following their prey, small, bioluminescent fish called lantern fish, which had also moved north due to El Niño weather patterns.
Smoking Smothers Your Genes
Cigarettes leave you with more than a smoky scent on your clothes and fingernails. A new study has found strong evidence that tobacco use can chemically modify and affect the activity of genes known to increase the risk of developing cancer. The finding may give researchers a new tool to assess cancer risk among people who smoke.
DNA isn’t destiny. Chemical compounds that affect the functioning of genes can bind to our genetic material, turning certain genes on or off. These so-called epigenetic modifications can influence a variety of traits, such as obesity and sexual preference. Scientists have even identified specific epigenetic patterns on the genes of people who smoke. None of the modified genes has a direct link to cancer, however, making it unclear whether these chemical alterations increase the risk of developing the disease.
In the new study, published in Human Molecular Genetics, researchers analyzed epigenetic signatures in blood cells from 374 individuals enrolled in the European Prospective Investigation into Cancer and Nutrition. EPIC, as it’s known, is a massive study aimed at linking diet, lifestyle, and environmental factors to the incidence of cancer and other chronic diseases. Half of the group consisted of people who went on to develop colon or breast cancer 5 to 7 years after first joining the study, whereas the other half remained healthy.
The team, led by James Flanagan, a human geneticist at Imperial College London, discovered a distinct “epigenetic footprint” in study subjects who were smokers. Compared with people who had never smoked, these individuals had fewer chemical tags known as methyl groups—a common type of epigenetic change—on 20 different regions of their DNA. When the researchers extended the analysis to a separate group of patients and mice that had been exposed to tobacco smoke, they narrowed down the epigenetic modifications to several sites located in four genes that have been weakly linked to cancer before. All of these changes should increase the activity of these genes, Flanagan says. It’s unclear why increasing the activity of the genes would cause cancer, he says, but individuals who don’t have cancer tend not to have these modifications.
The study is the first to establish a close link between epigenetic modifications on a cancer gene and the risk of developing the disease, says Robert Philibert, a behavioral geneticist at the University of Iowa in Iowa City. “To the best of my knowledge, no previous genome-wide epigenetics study has taken such efforts from initial discovery to replication to experimental validation,” adds Lutz Breitling, an epidemiologist at the German Cancer Research Center in Heidelberg, Germany.
The work may lead to new ways to asses cancer risks from smoking. “Previous research into smoking has often asked people to fill out questionnaires, … which have their obvious drawbacks and inaccuracies,” Flanagan says. The new study, he says, may make it possible for doctors to quantify a person’s cancer risk simply through an epigenetic analysis of their DNA.
http://news.sciencemag.org/sciencenow/2012/12/smoking-smothers-your-genes.html
Thanks to Dr. Rajadhyaksha for bringing this to the attention of the It’s Interesting community.
Scientists Debunk the IQ Myth: Notion of Measuring One’s Intelligence Quotient by Singular, Standardized Test Is Highly Misleading
After conducting the largest online intelligence study on record, a Western University-led research team has concluded that the notion of measuring one’s intelligence quotient or IQ by a singular, standardized test is highly misleading.
The findings from the landmark study, which included more than 100,000 participants, were published Dec. 19 in the journal Neuron. The article, “Fractionating human intelligence,” was written by Adrian M. Owen and Adam Hampshire from Western’s Brain and Mind Institute (London, Canada) and Roger Highfield, Director of External Affairs, Science Museum Group (London, U.K).
Utilizing an online study open to anyone, anywhere in the world, the researchers asked respondents to complete 12 cognitive tests tapping memory, reasoning, attention and planning abilities, as well as a survey about their background and lifestyle habits.
“The uptake was astonishing,” says Owen, the Canada Excellence Research Chair in Cognitive Neuroscience and Imaging and senior investigator on the project. “We expected a few hundred responses, but thousands and thousands of people took part, including people of all ages, cultures and creeds from every corner of the world.”
The results showed that when a wide range of cognitive abilities are explored, the observed variations in performance can only be explained with at least three distinct components: short-term memory, reasoning and a verbal component.
No one component, or IQ, explained everything. Furthermore, the scientists used a brain scanning technique known as functional magnetic resonance imaging (fMRI), to show that these differences in cognitive ability map onto distinct circuits in the brain.
With so many respondents, the results also provided a wealth of new information about how factors such as age, gender and the tendency to play computer games influence our brain function.
“Regular brain training didn’t help people’s cognitive performance at all yet aging had a profound negative effect on both memory and reasoning abilities,” says Owen.
Hampshire adds, “Intriguingly, people who regularly played computer games did perform significantly better in terms of both reasoning and short-term memory. And smokers performed poorly on the short-term memory and the verbal factors, while people who frequently suffer from anxiety performed badly on the short-term memory factor in particular.”
1.Adam Hampshire, Roger R. Highfield, Beth L. Parkin, Adrian M. Owen. Fractionating Human Intelligence. Neuron, 2012; 76 (6): 1225 DOI: 10.1016/j.neuron.2012.06.022
http://www.sciencedaily.com/releases/2012/12/121219133334.htm
Are Bacteria Making You Hungry?
Over the last half decade, it has become increasingly clear that the normal gastrointestinal (GI) bacteria play a variety of very important roles in the biology of human and animals. Now Vic Norris of the University of Rouen, France, and coauthors propose yet another role for GI bacteria: that they exert some control over their hosts’ appetites. Their review was published online ahead of print in the Journal of Bacteriology.
This hypothesis is based in large part on observations of the number of roles bacteria are already known to play in host biology, as well as their relationship to the host system. “Bacteria both recognize and synthesize neuroendocrine hormones,” Norris et al. write. “This has led to the hypothesis that microbes within the gut comprise a community that forms a microbial organ interfacing with the mammalian nervous system that innervates the gastrointestinal tract.” (That nervous system innervating the GI tract is called the “enteric nervous system.” It contains roughly half a billion neurons, compared with 85 billion neurons in the central nervous system.)
“The gut microbiota respond both to both the nutrients consumed by their hosts and to the state of their hosts as signaled by various hormones,” write Norris et al. That communication presumably goes both ways: they also generate compounds that are used for signaling within the human system, “including neurotransmitters such as GABA, amino acids such as tyrosine and tryptophan — which can be converted into the mood-determining molecules, dopamine and serotonin” — and much else, says Norris.
Furthermore, it is becoming increasingly clear that gut bacteria may play a role in diseases such as cancer, metabolic syndrome, and thyroid disease, through their influence on host signaling pathways. They may even influence mood disorders, according to recent, pioneering studies, via actions on dopamine and peptides involved in appetite. The gut bacterium, Campilobacter jejuni, has been implicated in the induction of anxiety in mice, says Norris.
But do the gut flora in fact use their abilities to influence choice of food? The investigators propose a variety of experiments that could help answer this question, including epidemiological studies, and “experiments correlating the presence of particular bacterial metabolites with images of the activity of regions of the brain associated with appetite and pleasure.”
1.V. Norris, F. Molina, A. T. Gewirtz. Hypothesis: bacteria control host appetites. Journal of Bacteriology, 2012; DOI: 10.1128/JB.01384-12
http://www.sciencedaily.com/releases/2012/12/121219142301.htm
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