Scientists at the McEwen Centre for Regenerative Medicine and the Ontario Cancer Institute have isolated a human blood stem cell in its purest form: as a single stem cell capable of regenerating the entire blood system. "This discovery means we now have an increasingly detailed road map of the human blood development system, including the much sought after stem cell," says principal investigator John Dick, who holds a Canada Research Chair in Stem Cell Biology and is a Senior Scientist at the McEwen Centre for Regenerative Medicine and the Ontario Cancer Institute, University Health Network (UHN). "We have isolated a single cell that makes all arms of the blood system, which is key to maximizing the potential power of stem cells for use in more clinical applications. Stem cells are so rare that this is a little like finding a needle in a haystack," says Dr. Dick. Ref.: John E. Dick, Isolation of Single Human Hematopoietic Stem Cells Capable of Long-Term Multilineage Engraftment, Science, July 2011: Vol. 333 no. 6039 pp. 218-221 [DOI: 10.1126/science.1201219]

A new study of twins released online on Monday marked an important shift in thinking about the causes of autism.

ScienceDaily (June 28, 2011) - A recent study from scientists at the Salk Institute for Biological Studies suggests that a strawberry a day (or more accurately, 37 of them) could keep not just one doctor away, but an entire fleet of them, including the neurologist, the endocrinologist, and maybe even the oncologist.

ScienceDaily (June 27, 2011) - While the U.S. Food and Drug Administration notes "some concern" with the controversial chemical BPA, and many other countries, such as Japan and Canada, have considered BPA product bans, disagreement exists amongst scientists in this field on the effects of BPA in animals and humans. The latest research from the University of Missouri shows that BPA causes male deer mice to become demasculinized and behave more like females in their spatial navigational abilities, leading scientists to conclude that exposure to BPA during human development could be damaging to behavioral and cognitive traits that are unique to each sex and important in reproduction.

In 1967, Simon Kochen and Ernst Specker proved mathematically that even for a single quantum object, where entanglement is not possible, the values that you obtain when you measure its properties depend on the context. So the value of property A, say, depends on whether you chose to measure it with property B, or with property C. In other words, there is no reality independent of the choice of measurement. It wasn't until 2008, however, that Alexander Klyachko of Bilkent University in Ankara, Turkey, and colleagues devised a feasible test for this prediction. They calculated that if you repeatedly measured five different pairs of properties of a quantum particle that was in a superposition of three states, the results would differ for the quantum system compared with a classical system with hidden variables. That's because quantum properties are not fixed, but vary depending on the choice of measurements, which skews the statistics. "This was a very clever idea," says Anton Zeilinger of the Institute for Quantum Optics, Quantum Nanophysics and Quantum Information in Vienna, Austria. "The question was how to realise this in an experiment." Now he, Radek Lapkiewicz and colleagues have realised the idea experimentally. They used photons, each in a superposition in which they simultaneously took three paths. Then they repeated a sequence of five pairs of measurements on various properties of the photons, such as their polarisations, tens of thousands of times. A beautiful experiment They found that the resulting statistics could only be explained if the combination of properties that was tested was affecting the value of the property being measured. "There is no sense in assuming that what we do not measure about a system has [an independent] reality," Zeilinger concludes.

Playing sound effects both pleasant and awful, Julian Treasure shows how sound affects us in four significant ways. Listen carefully for a shocking fact about noisy open-plan offices. (Recorded at TEDGlobal University, July 2009, Oxford, UK. Duration: 5:47)

ScienceDaily (June 21, 2011) - An important milestone in the direct measurement of the magnetic moment of the proton and its anti-particle has been achieved.

Theodore Berger and his team at the USC Viterbi School of Engineering's Department of Biomedical Engineering have developed a neural prosthesis for rats that is able to restore their ability to form long-term memories after they had been pharmacologically blocked. In a dramatic demonstration, Berger blocked the ability to rats to form long-term memories by using pharmacological agents to disrupt the neural circuitry that communicates between two subregions of the hippocampus, CA1 and CA3, which interact to create long-term memory, prior research has shown. The rats were unable to remember which lever to pull to gain a reward, or could only remember for 5-10 seconds, when previously they could remember for a long period of time. The researchers then developed an artificial hippocampal system that could duplicate the pattern of interaction between CA3-CA1 interactions. Long-term memory capability returned to the pharmacologically blocked rats when the team activated the electronic device programmed to duplicate the memory-encoding function. The researchers went on to show that if a prosthetic device and its associated electrodes were implanted in animals with a normal, functioning hippocampus, the device could actually strengthen the memory being generated internally in the brain and enhance the memory capability of normal rats. "These integrated experimental modeling studies show for the first time that with sufficient information about the neural coding of memories, a neural prosthesis capable of real-time identification and manipulation of the encoding process can restore and even enhance cognitive mnemonic processes," says the paper. Next steps, according to Berger and Deadwyler, will be attempts to duplicate the rat results in primates (monkeys), with the aim of eventually creating prostheses that might help human victims of Alzheimer's disease, stroke, or injury recover function. Ref.: "A Cortical Neural Prosthesis for Restoring and Enhancing

It's not quite Cyclops, the sci-fi superhero from the X-Men franchise whose eyes produce destructive blasts of light, but for the first time a laser has been created using a biological cell. The human kidney cell that was used to make the laser survived the experience. In future such "living lasers" might be created inside live animals, which could potentially allow internal tissues to be imaged in unprecedented detail. It's not the first unconventional laser. Other attempts include lasers made of Jell-O and powered by nuclear reactors (see box below). But how do you go about giving a living cell this bizarre ability? Typically, a laser consists of two mirrors on either side of a gain medium - a material whose structural properties allow it to amplify light. A source of energy such as a flash tube or electrical discharge excites the atoms in the gain medium, releasing photons. Normally, these would shoot out in random directions, as in the broad beam of a flashlight, but a laser uses mirrors on either end of the gain medium to create a directed beam. As photons bounce back and forth between the mirrors, repeatedly passing through the gain medium, they stimulate other atoms to release photons of exactly the same wavelength, phase and direction. Eventually, a concentrated single-frequency beam of light erupts through one of the mirrors as laser light.

A new new brain imaging system that can identify a subject's simple thoughts may lead to clearer diagnoses for Alzheimer's disease or schizophrenia - as well as possibly paving the way for reading people's minds. Michael Greicius at Stanford University in California and colleagues used functional magnetic resonance imaging (fMRI) to identify patterns of brain activity associated with different mental states. He asked 14 volunteers to do one of four tasks: sing songs silently to themselves; recall the events of the day; count backwards in threes; or simply relax. Participants were given a 10-minute period during which they had to do this. For the rest of that time they were free to think about whatever they liked. The participants' brains were scanned for the entire 10 minutes, and the patterns of connectivity associated with each task were teased out by computer algorithms that compared scans from several volunteers doing the same task. This differs from previous experiments, in which the subjects were required to perform mental activities at specific times and the scans were then compared with brain activity when they were at rest. Greicius reasons his method encourages "natural" brain activity more like that which occurs in normal thought.

ScienceDaily (June 9, 2011) - Air and water meet over most of Earth's surface, but exactly where one ends and the other begins turns out to be a surprisingly subtle question.

ScienceDaily (June 9, 2011) - Observations from NASA's Voyager spacecraft, humanity's farthest deep space sentinels, suggest the edge of our solar system may not be smooth, but filled with a turbulent sea of magnetic bubbles.

A new study by MIT shows that babies can perform sophisticated analyses of how the physical world should behave. The scientists developed a computational model of infant cognition that accurately predicts infants' surprise at events that violate their conception of the physical world. The model, which simulates a type of intelligence known as pure reasoning, calculates the probability of a particular event, given what it knows about how objects behave. The close correlation between the model's predictions and the infants' actual responses to such events suggests that infants reason in a similar way, says Josh Tenenbaum, associate professor of cognitive science and computation at MIT.

Researchers at the University of Rochester have determined that when humans see the color red, their reactions become both faster and more forceful. The researchers measured the reactions of students in two experiments. In the first, 30 fourth-through-10th graders pinched and held open a metal clasp. Right before doing so, they read aloud their participant number written in either red or gray crayon. In the second experiment, 46 undergraduates squeezed a handgrip with their dominant hand as hard as possible when they read the word "squeeze" on a computer monitor. The word appeared on a red, blue, or gray background. In both scenarios, red significantly increased the force exerted, with participants in the red condition squeezing with greater maximum force than those in the gray or blue conditions, the researchers said. Ref.: Andrew J. Elliot, Henk Aarts, Perception of the color red enhances the force and velocity of motor output, Emotion, Vol 11(2), Apr 2011, 445-449

A new strain of MRSA has been identified in cows' milk and in people, but don't stop drinking milk - the bug is killed off in pasteurisation. However, the strain evades detection by standard tests used by some hospitals to screen for MRSA (methicillin-resistant Staphylococcus aureus), potentially putting people at risk. Laura Garcia Alvarez, then at the University of Cambridge, and colleagues were studying infections in British cows when they discovered antibiotic-resistant bacteria that they thought were MRSA. However, tests failed to identify the samples as any known strains of the superbug. Sequencing the mystery bacteria's genomes revealed a previously unknown strain of MRSA with a different version of a gene called MecA. The new strain was also identified in samples of human MRSA, and is now known to account for about 1 per cent of human MRSA cases.

The lushest patches of some jungles are rooted in enigmatic black soil - with unexpected origins

ScienceDaily (June 9, 2011) - New research just published in the journal Science by a team of chemists at the University of Georgia and colleagues in Germany shows for the first time that a mechanism called tunneling control may drive chemical reactions in directions unexpected from traditional theories.

ScienceDaily (June 9, 2011) - On rare occasion, the light-sensing photoreceptor cells in the eye misfire and signal to the brain as if they have captured photons, when in reality they haven't. For years this phenomenon remained a mystery. Reporting in the June 10 issue of Science, neuroscientists at the Johns Hopkins University School of Medicine have discovered that a light-capturing pigment molecule in photoreceptors can be triggered by heat, as well, giving rise to these false alarms.

ScienceDaily (June 4, 2011) - Do the principles of quantum mechanics apply to biological systems? Until now, says Prof. Ron Naaman of the Institute's Chemical Physics Department (Faculty of Chemistry), both biologists and physicists have considered quantum systems and biological molecules to be like apples and oranges. But research he conducted together with scientists in Germany, which appeared recently in Science, shows that a biological molecule -- DNA -- can discern between quantum states known as spin.