amudu

Monday, August 29, 2011

Hand-held unit to detect cancer in poorer countries

An engineering researcher and a global health expert from Michigan State University are working on bringing a low-cost, hand-held device to nations with limited resources to help physicians detect and diagnose cancer.

Syed Hashsham explains his device. (Credit: Michigan State University).

Syed Hashsham, a professor of civil and environmental engineering at MSU, is developing the Gene-Z device, which is operated using an iPod Touch or Android-based tablet and performs genetic analysis on microRNAs and other genetic markers. MicroRNAs are single-stranded molecules that regulate genes; changes in certain microRNAs have been linked to cancer and other health-related issues.

He is working with Reza Nassiri, director of MSU’s Institute of International Health and an assistant dean in the College of Osteopathic Medicine, on the medical capabilities for the device and establishing connections with physicians worldwide.

Cancer is emerging as a leading cause of death in underdeveloped and developing countries where resources for cancer screening are almost non-existent, Nassiri said.

“Until now, little effort has been concentrated on moving cancer detection to global health settings in resource-poor countries,” he said. “Early cancer detection in these countries may lead to affordable management of cancers with the aid of new screening and diagnostic technologies that can overcome global health care disparities.”

Hashsham demonstrated the potential of the Gene-Z at the National Institutes of Health’s first Cancer Detection and Diagnostics Conference. The conference, held recently in Bethesda, Md., was sponsored by the Fogarty International Center and the National Cancer Institute.

“Gene-Z has the capability to screen for established markers of cancer at extremely low costs in the field,” Hashsham said. “Because it is a hand-held device operated by a battery and chargeable by solar energy, it is extremely useful in limited-resource settings.”

The NIH conference was attended by several U.S. research institutions, including MSU. One of the primary objectives of the meeting was to address the utility of new cancer detection technologies.

Since cancer diagnostics and rapid screening methods currently are not suitable for low-income and resource-limited countries, Nassiri said a concentrated effort should be made to develop more appropriate and cost-effective technologies such as the one developed by Hashsham for widespread global use.

Nassiri said the goal is to continue the partnership between Hashsham and MSU’s Institute of International Health to promote his Gene-Z device globally and validate it in the field with clinical care partners across the world.

In addition to cancer detection, the Gene-Z device also is being developed to diagnose routine tuberculosis and drug-resistant TB, determine HIV virus levels during treatment and monitor overall antibiotic resistance.

Working with Hashsham in the development of the Gene-Z device was a team of MSU students, led by Robert Stedtfeld and including Farhan Ahmad, Dieter Tourlousse and Greg Seyrig. The cancer marker approach was led by Maggie Kronlein, a civil and environmental engineering undergraduate researcher.

shridi Sai Baba Speciasl Photos with Song.divx

Sensor Chip for Monitoring Tumors

Posted by Biomechanism

A chip implant may soon be capable of monitoring tumors that are difficult to operate on or growing slowly. Medical engineers at Technische Universitaet Muenchen (TUM) have developed an electronic sensor chip that can determine the oxygen content in a patient’s tissue fluid. This data can then be wirelessly transmitted to the patient’s doctor to support the choice of therapy. A drop in oxygen content in tissue surrounding a tumor indicates that the tumor might be growing faster and becoming aggressive.

Sensor chip (held between two fingers) for measuring the concentration of dissolved oxygen in tissue; the biocompatible housing (open) also contains a transmitter, analysis unit and a battery. (Credit: Copyright: Sven Becker / Technische Universitaet Muenchen)

Surgery is usually one of the first therapy options in cancer treatment. However, some tumors, such as brain tumors, can be difficult to operate on if there is a risk of damaging surrounding nerve tissue. Other cancerous tumors, such as prostate carcinoma, grow at a very slow rate and primarily affect older patients. Operating in these cases often lowers patients’ quality of life without significantly extending their life expectancy.

A team of medical engineers headed by Prof. Bernhard Wolf at the TUM Heinz Nixdorf Chair of Medical Electronics have now developed a sensor chip that can be implanted close to a tumor. The sensor chip measures the concentration of dissolved oxygen in the tissue and wirelessly transmits this information to a receiver carried by the patient. The receiver forwards the data to the patient’s doctor, who can then monitor the tumor’s development and arrange for an operation or therapies such as chemotherapy.

The tumor is thus continually monitored and the patient does not have to visit the practice or hospital as frequently for check-ups.

The sensor chip has already passed laboratory tests with cell and tissue cultures. The main challenge for the researchers was developing a sensor that functions entirely autonomously for long periods of time. The sensor must continue to function and deliver correct values even in the presence of protein contamination or cell debris. It also has to be “invisible” to the body so that it is not identified as a foreign object, attacked and encapsulated in tissue.

“We designed the sensor chip to self-calibrate to a set dissolved oxygen concentration at measurement intervals,” explains engineer and project manager Sven Becker. “In addition, we enclosed the sensor chip, analysis electronics, transmitter and batteries in a biocompatible plastic housing.”

Not even twice the size of a thumbnail, the sensor chip and electronics have a compact footprint. However, the package must be made even smaller before it can be implanted in cancer patients using minimally invasive surgery. In addition, the designers want to add additional sensors for measuring acidity and temperature. Also at the development phase is a miniature medication pump to be implanted with the sensor chip. The pump will be able to release chemotherapeutic agents in direct proximity to the tumor if necessary. Before moving on to the next phase, the sensor has to pass trials in animals. The researchers hope that the new technology will make cancer therapies more targeted and less aggressive for patients.

The IntelliTuM (Intelligent Implant for Tumor Monitoring) project was supported by the Heinz Nixdorf Stiftung and received EUR 500,000 in funding from Germany’s Federal Ministry of Education and Research.

Saturday, August 27, 2011

First Glimpse Into Birth of the Milky Way

On the left, is an image of our simulated galaxy, with gas in red and stars in blue; on the right, a picture in false colors of the galaxy M74, again with gas shown in red and stars in blue. The spiral arms of the gas are evident in both images. (Credit: Image courtesy of University of Zurich)

Science Daily — For almost 20 years astrophysicists have been trying to recreate the formation of spiral galaxies such as our Milky Way realistically. Now astrophysicists from the University of Zurich present the world's first realistic simulation of the formation of our home galaxy together with astronomers from the University of California at Santa Cruz. The new results were partly calculated on the computer of the Swiss National Supercomputing Center (CSCS) and show, for instance, that there has to be stars on the outer edge of the Milky Way.

The aim of astrophysical simulations is to model reality in due consideration of the physical laws and processes. Astronomical sky observations and astrophysical simulations have to match up exactly. Being able to simulate a complex system like the formation of the Milky Way realistically is the ultimate proof that the underlying theories of astrophysics are correct. All previous attempts to recreate the formation of spiral galaxies like the Milky Way faltered on one of two points: Either the simulated spiral galaxies displayed too many stars at the center or the overall stellar mass was several times too big.

A research group jointly run by Lucio Mayer, an astrophysicist at the University of Zurich, and Piero Madau, an astronomer at University of California at Santa Cruz, is now publishing the first realistic simulation of the formation of the Milky Way in theAstrophysical Journal. Javiera Guedes and Simone Callegari, who are PhD students at Santa Cruz and the University of Zurich respectively, performed the simulation and analyzed the data. Guedes will be working on the formation of galaxies as a postdoc in Zurich from the fall.

Removing standard matter central to formation of spiral galaxies

For their study, the scientists developed a highly complex simulation in which a spiral galaxy similar to the Milky Way develops by itself without further intervention. Named after Eris, the Greek goddess of strife and discord, because of the decades of debate surrounding the formation of spiral galaxies, the simulation offers a glimpse in time lapse into almost the entire genesis of a spiral galaxy. Its origins date back to less than a million years after the Big Bang. "Our result shows that a realistic spiral galaxy can be formed based on the basic principles of the cold dark matter paradigm and the physical laws of gravity, fluid dynamics and radiophysics," explains Mayer.

The simulation also shows that in an entity that is supposed to develop into a spiral galaxy, the stars in the areas with giant cloud gas complexes have to form. In these cold molecular giant clouds, the gases exhibit extremely high densities. The star formation and distribution there does not occur uniformly, but rather in clumps and clusters. This in turn results in a considerably greater build-up of heat through local supernova explosions. Through this massive build-up of heat, visible standard matter is removed at high redshift. This prevents the formation of a concave disk in the center of the galaxy. The removal of baryonic matter, as the visible standard matter is also known, also reduces the overall mass of the gas present at the center. This results in the formation of the correct stellar mass, as can be observed in the Milky Way. At the end of the simulation, a thin, curved disk results that corresponds fully to the astronomical observations of the Milky Way in terms of the mass, angular momentum and rotation velocity ratios.

Astronomical computing power

For the calculations, the model Mayer and co. developed for the simulation of disk-shaped dwarf galaxies and published in the journal Nature in 2010 was refined. The high-resolution model simulates the formation of a galaxy with 790 billion solar masses and comprises 18.6 million particles, from which gases, dark matter and stars form. The high resolution of the numerical simulations is essential for the groundbreaking new results. For the calculations, the high-performance supercomputers Cray XT5 "Monte Rosa" at ETH Zurich's Swiss National Supercomputing Center (CSCS) and the NASA Advanced Supercomputer Division's Pleiades were used. A regular PC would have needed 570 years for the calculations.

Stars and gases at the outermost edge of the galaxy, hot gases at its center

The new simulation confirms the results for the formation of disk-shaped dwarf galaxies published by Mayer and demonstrates that the model -- unlike all previous approaches -- can recreate both small and extremely large galaxies realistically. Moreover, from the simulation it an also be deduced that protogalaxies with a large disk made of gases and stars at the center already formed a billion years after the Big Bang, and therefore long before our present galaxies.

Based on the simulation, the ratio of "cold dark matter" (CDM) and standard matter in spiral galaxies can also be adjusted. In order to obtain the correct overall stellar mass in the final stage of the galaxy -- until now, one of the main difficulties -- it is imperative that standard matter be removed from the center by supernova winds. On the strength of the simulation, it is highly probable that the ratio of standard matter to CDM on the outermost edge of the CDM rings of a spiral galaxy is 1:9, not 1:6 as previously assumed.

The simulation also predicts stars and gases for the outer halo of the Milky Way six hundred thousand light years away. Only the next generation of space probes and telescopes will be able to detect these extremely faint stars. Furthermore, the simulation makes predictions with regard to the radial distribution of hot gases around the galaxy's central disk. Future telescopes that can measure X-rays, as the IXO Mission of the European Space Agency (ESA) is planning, for example, will test these predictions

Mexico Bailout No Model for Asia / IMF's usual approach could be disaster, analysts say

By Robert Collier, Chronicle Staff Writer

As the East Asian financial crisis worsens, with one humiliated country after another pleading with the Clinton administration and the International Monetary Fund for billion-dollar bailouts, many politicians and experts are looking to Mexico for clues to economic recovery.

The $50 billion bailout of Mexico in 1995 has been lauded as a textbook example of an international rescue done right. As proof, U.S. and IMF officials cite Mexico's recent return to high economic growth and its rapid payment of its debts to the United States.

But analysts across the political spectrum are quietly warning that the Mexican solution is precisely the wrong answer for East Asia. Although IMF bailouts of some type are necessary to prevent global financial instability, they say, the IMF's repetition of its Mexican-style strategy will only cause more megacrises that in turn require larger and larger megabailouts.

These analysts say the standard IMF recipe has two key failings:

-- Forcing austerity on penny-wise governments. Unlike Mexico, where the 1995 crisis was caused by reckless govern

ment borrowing and spending, state finances in East Asia are generally healthy, domestic savings rates are high, and most debt is held by private banks and corporations. IMF austerity policies may simply worsen existing liquidity crises, needlessly curbing governments' ability to restimulate their economies.

-- Making governments pay for private-sector mistakes. Instead of obliging the U.S. and European banks that made unwise loans, and the South Korean banks that received them, to foot the bill for cleaning up the mess, the IMF has acquiesced to international creditors' demands that the Seoul government guarantee local banks' foreign debts. Thus the public, not the speculators, must pay for the cleanup with tax increases, reduced social services and layoffs of millions of workers.

As this debate grows in intensity, U.S. taxpayers are about to be asked to contribute billions of dollars to keep the IMF -- the 182-nation organization that has monitored its members' economies and provided emergency loans for a half century -- in the bailout business.

The 1995 Mexican bailout is cited by supporters and opponents alike as an IMF prototype: Quick pain with quick financial recovery, averting a wider meltdown. Big macroeconomic benefits, but big social and political costs.

Moral Hazard

What Does Moral Hazard Mean?
The risk that a party to a transaction has not entered into the contract in good faith, has provided misleading information about its assets, liabilities or credit capacity, or has an incentive to take unusual risks in a desperate attempt to earn a profit before the contract settles.

Investopedia explains Moral Hazard
Moral hazard can be present any time two parties come into agreement with one another. Each party in a contract may have the opportunity to gain from acting contrary to the principles laid out by the agreement. For example, when a salesperson is paid a flat salary with no commissions for his or her sales, there is a danger that the salesperson may not try very hard to sell the business owner's goods because the wage stays the same regardless of how much or how little the owner benefits from the salesperson's work.

Moral hazard can be somewhat reduced by the placing of responsibilities on both parties of a contract. In the example of the salesperson, the manager may decide to pay a wage comprised of both salary and commissions. With such a wage, the salesperson would have more incentive not only to produce more profits but also to prevent losses for the company.

New research increases understanding of learning, memory

Neuroscience

(Medical Xpress) -- New international research on how fruit flies learn to ignore a constant smell, which increases understanding of behavioural habituation, has been recently published in the leading international journal PNAS.

‘Habituation’ is a ubiquitous psychological phenomenon in which constant exposure to a stimulus results in a weakened response. Despite the ubiquity of habituation, and its importance for cognitive filtering required to efficiently identify new and important events, to date the neural mechanism of habituation has remained largely unexplained.

Professor of Neurogenetics, Mani Ramaswami’s research group at the Trinity College Institute of Neuroscience, the School of Genetics and Microbiology, and School of Natural Sciences at Trinity College Dublin, collaborated with Prof Veronica Rodrigues’ group in the National Center for Biological Sciences, Bangalore to understand how fruit flies (Drosophila melanogaster) habituate to a constant smell. The TCD research was funded by the Science Foundation Ireland.

Fruit flies show easily measured forms of olfactory habituation. Using fruit flies for their experiments, allowed these scientists to combine genetic and anatomical techniques with high-speed brain imaging to study how olfactory responses in the living brain change during olfactory habituation.

The research shows that continuous exposure to a smell causes the brain cells that receive signals from the antenna (the fly’s nose) to show a reduced response to odour. This reduction is not because sensory cells in antenna do not respond to the smell. Rather, it is because after habituation, brain cells that respond to this specific smell now begin to receive a strong inhibitory signal from another group of cells. These inhibitory cells release a negative neurotransmitter called GABA in response to smell. Several experiments reveal unexpected and interesting ways by which this inhibitory signal becomes stronger.

In a commentary in the same issue of PNAS, UCLA Neuroscientist, Professor David Glanzman observes that: “Ramaswami and colleagues’ important insights into the cellular and molecular mechanisms of olfactory habituation in Drosophila are likely to generalise to other forms of habituation in other species, including mammalian species.”

Professor Ramaswami explained: “In all brain regions, positive (excitatory) cells stimulate not only other excitatory cells but also turn on ‘negative’ (inhibitory) cells that dampen this excitation. If prolonged stimulation of any group of excitatory cells selectively strengthens its specific negative connections, then more complex and non-olfactory forms of habituation could also be explained.”

“It is also pleasing that this mechanism for habituation can theoretically explain the phenomenon of dishabituation, which psychologists have always felt is a defining property of habituation. There are times when it is important to ‘dishabituate’ or suddenly pay keen attention to what was previously a boring background. When you hear a tiger snarl in the forest for example, every blade of grass draws your attention.”

In this PNAS paper, the authors suggest that stimuli such as a tiger’s snarl, may work in part by causing inhibition of inhibitory neurons and thus restore the brain to its original (or even enhanced) behavioral state.

“Furthermore because defects in habituation are associated with human neuropsychiatric disorders, this work may also define an accessible neural circuit in which to identify neuronal functions of genes associated with human susceptibility to autism and psychosis,” concluded Professor Ramaswami.

More information: The full article, entitled ‘Plasticity of local GABAergic interneurons drives olfactory habituation’, is available online.

Provided by Trinity College Dublin

"New research increases understanding of learning, memory." August 26th, 2011. http://medicalxpress.com/news/2011-08-memory.html

Posted by
Robert Karl Stonjek

Helping neurons stay on track

Neuroscience

Compared to highly branched controls (left), axons of neurons treated with Sema3A tend to collapse (top right). However, this effect can be blocked by treatment with macropinocytosis inhibitor EIPA (bottom right), revealing the central importance of this mechanism in responses to repulsive signals (scale bar, 10 μm). Credit: 2011 the Society for Neuroscience

The complex inner wiring of the brain is coordinated in part by chemical guidance factors that help direct the interactions between individual neurons. As growing cells extend their axons outward, these tendrils are simultaneously drawn in the correct direction by attractive signals and steered away from ‘wrong turns’ by repulsive signals.

New work from a team led by Hiroyuki Kabayama and Katsuhiko Mikoshiba of the RIKEN Brain Science Institute in Wako has revealed insights into how one of these repulsive guidance cues, semaphorin 3A (Sema3A), gives axons their marching orders. In an earlier study, the researchers found evidence that Sema3A causes large-scale internalization of the cellular membrane at the growth cone, the tip of the growing axon, and determined that this internalization occurs via a process known as macropinocytosis. “These findings suggested an important role for massive, macropinocytosis-mediated membrane retrieval during Sema3A-induced growth cone collapse,” says Kabayama.

The neurotoxin C1, a protease enzyme, induces similar effects on growth cones, and Kabayama and Mikoshiba and their colleagues were able to uncover Sema3A’s mode of action via experiments using this enzyme. Based on a series of experiments with cultured neurons isolated from chick embryos, the researchers determined that the enzyme works by breaking down syntaxin 1B (Syx1B), a protein with a prominent role in membrane trafficking, thereby releasing an inhibitory mechanism that otherwise keeps macropinocytosis in check.

Accordingly, direct inhibition of Syx1B expression in neurons led to reduced axonal growth and increased growth cone collapse. On the other hand, treatment with the macropinocytosis-inhibiting compound EIPA countered the growth cone-collapsing effects of either neurotoxin C1 or inhibition of Syx1B. The researchers also found that this drug alone was sufficient to undermine Sema3A’s axon-repulsive effects (Fig. 1).

Kabayama, Mikoshiba and colleagues obtained additional confirmation of the central role of Syx1B in experiments that revealed that the treatment of neurons with Sema3A triggers rapid degradation of this protein as a prelude to the initiation of macropinocytosis. This effect could be countered by forcing these cells to overexpress Syx1B. Kabayama also notes that another repulsive signal, ephrin A2, appears to act via the same cellular mechanism. “It is likely that repulsive axon guidance is generally mediated by syntaxin 1B-regulated macropinocytosis,” he says.

In future studies, Kabayama and Mikoshiba intend to test this hypothesis by manipulating this pathway in transgenic animals. “We are going to generate Syx1B-overexpressing mice and investigate whether inhibition of macropinocytosis by Syx1B can prevent ephrin A2- or Sema3A-dependent growth cone collapse,” says Mikoshiba.

More information: Kabayama, H., et al. 1B suppresses macropinocytosis and semaphorin 3A-induced growth cone collapse. The Journal of Neuroscience 31, 7357–7364 (2011).

Kabayama, H., et al. Ca2+ induces macropinocytosis via F-actin depolymerization during growth cone collapse. Molecular and Cellular Neuroscience 40, 27–38 (2009).

Provided by RIKEN

"Helping neurons stay on track." August 26th, 2011. http://medicalxpress.com/news/2011-08-neurons-track.html

Posted by
Robert Karl Stonjek

Mapping the brain

Neuroscience
Mapping the brain

A pair of algorithms detect the cell boundaries in a 2D image (left) and color-code each neuron in a “stained glass” display (right). Taking advantage of a neuron’s continuity through space, the algorithm resolves ambiguities by comparing adjacent images from the same 3D stack. A neuron boundary that shows up in only one image, for example, is likely just an artifact. Image courtesy of Amelio Vasquez-Reina, a Ph.D. student in the Pfister Group at SEAS.

The brain of a mouse measures only 1 cubic centimeter in volume. But when neuroscientists at Harvard’s Center for Brain Science slice it thinly and take high-resolution micrographs of each slice, that tiny brain turns into an exabyte of image data. That’s 10¹⁸ bytes, equivalent to more than a billion CDs.

What can you do with such a gigantic, unwieldy data set? That’s the latest challenge for Hanspeter Pfister, the Gordon McKay Professor of the Practice of Computer Science at Harvard’s School of Engineering and Applied Sciences (SEAS).

Pfister, an expert in high-performance computing and visualization, is part of an interdisciplinary team collaborating on the Connectome Project at the Center for Brain Science. The ambitious Connectome Project aims to create a wiring diagram of all the neurons in the brain, and neuroscientists have developed innovative techniques for automatically imaging slices of mouse brain, yielding terabytes of data so far.

Pfister’s system for displaying and processing these images would be familiar to anyone who has used the Google MapsTM service. Because only a subsection of a very large image can be displayed on a screen, only that viewable subsection is loaded. Drag the image around, zoom in or out, and more of the image is displayed on the fly. (Watch a video demo below.)

This video is not supported by your browser at this time.

This “demand-driven distributed computation” is the central idea behind Pfister’s work, which recently won him a Google Faculty Research Award.

With new techniques producing ever-larger data sets in science, the problem is hardly unique to the Connectome Project. Pfister is certain that the tools his research group develops can be used by scientists working with large image data sets in any field—for example, astronomers processing radio telescope images or earth scientists analyzing atmospheric data.

Even for the Connectome, the ultimate tool will be much more than “Google Maps for the brain.” The project has two crucial new features, says Pfister. First, the mouse brain must be reconstructed in three dimensions, so one can quickly flip through the stack of images in addition to zooming and panning across it. The images, each representing a 30-nanometer-thick brain slice, can also be stacked together and viewed from the side, along the same axis they were sliced.

Additionally, the system developed by Pfister’s research team extends the demand-driven principle to image analysis and processing. If a neuroscientist wants to automatically align images, adjust the brightness of an image, or run an automatic cell boundary detector over a portion of the images, for example, these operations are also computed on the fly, so there is no need to wait for the entire stack of images to be processed before the relevant subsection is viewable. Pfister compares it to “a very specialized version of Adobe® Photoshop® software.”

Indeed, the existing tools are capable of far more advanced image processing. Since the collaboration began in 2007, computer scientists in Pfister’s group have created algorithms to automatically detect cell boundaries, a process known as segmentation, and to connect related cells in three dimensions, a process known as reconstruction. Previously, neuroscientists did this by hand.

With thousands of neurons in even a cubic millimeter of brain tissue, it would be impossible to scale the project up without automated segmentation, says Jeff Lichtman, the Jeremy R. Knowles Professor of Molecular and Cellular Biology at Harvard and leader of the Connectome Project.

Automated segmentation is done by a machine learning algorithm, which a neurobiologist trains by marking the cell boundaries in as few as five images. The algorithm then learns the features—edges, corners, textures, etc.—associated with cell boundaries. Occasional errors can be corrected on the go, and the algorithm learns from these errors. With all the cell boundaries in a stack of images identified, a second machine learning method combines information from the images to reconstruct the shape of a neuron in three-dimensional space.

Researchers in Pfister’s group are currently working on ways to automatically detect synapses, the sites where two neurons are connected.

“We spent four years developing algorithms to find cell boundaries and synapses as well as building up the infrastructure for viewing and displaying large image data sets,” says Pfister. The individual tools are in place, but “now we’re putting the two pieces together,” he adds, looking ahead to the next few years of research.

The Connectome Project is certainly an ambitious one. The sheer quantity of electron microscopy slices that need to be acquired and analyzed is a daunting but necessary challenge, says Lichtman: “We have made no progress on simple questions like how many neurons converge on a single neuron. A lot of brain functions are at that level.”

Lichtman believes that the Connectome will be able to answer those simple questions but also complex ones. The patterns that emerge about how different types of neurons connect to each other can give physical clues to how memories and personality traits are encoded. That is all far off, but it would certainly be impossible without the analysis tools developed by computer scientists.

The Connectome Project also draws together collaborators in neurobiology, molecular and cellular biology, medicine, and chemistry and chemical biology.

“This is a great example of a cross-disciplinary project,” adds Pfister, “At SEAS we are a bridge between different schools, which makes it easy for me to work with my collaborators. It’s very gratifying to see our tools used in real applications.”

More information: http://cbs.fas.har … tome-project

Provided by Harvard School of Engineering and Applied Sciences

"Mapping the brain." August 26th, 2011. http://medicalxpress.com/news/2011-08-brain_1.html

Posted by
Robert Karl Stonjek