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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]

Because the size of these metallic hotspots is far smaller than the wavelength of incident light, a new technique was needed to map the electromagnetic field within a hotspot. The Berkeley researchers developed the BEAST method to capitalize on the fact that individual fluorescent dye molecules can be localized with single nanometer accuracy. The fluorescence intensity of individual molecules adsorbed on the surface provides a direct measure of the electromagnetic field inside a single hotspot. BEAST utilizes the Brownian motion of single dye molecules in a solution to make the dyes scan the inside of single hotspot stochastically, one molecule at a time.

""Experiments with amoebae that usually live as individuals but must also join with others to form multicellular bodies to complete their life cycles showed that cooperation depends on kinship. If amoebae occur in well-mixed cosmopolitan groups, then cheaters will always be able to thrive by freeloading on their cooperative neighbors. But if groups derive from a single cell, cheaters will usually occur in all-cheater groups and will have no cooperators to exploit. A multicellular body like the human body is an incredibly cooperative thing," Queller says, "and sociobiologists have learned that really cooperative things are hard to evolve because of the potential for cheating. "It's the single-cell bottleneck that generates high relatedness among the cells that, in turn, allows them to cooperate, " he says."

Traditional methods of transmitting data, such as fibre optics or laser-based radar, require roughly 100 photons to transmit a single bit of data. Now a team led by Saikat Guha at Raytheon BBN Technologies in Cambridge, Massachusetts, say they can transmit 10 bits on a single photon - a 1000-fold improvement.

"A quest that began over a decade ago with a chance observation has reached a milestone: the identification of a gene that may regulate regeneration in mammals. The absence of this single gene, called p21, confers a healing potential in mice long thought to have been lost through evolution and reserved for creatures like flatworms, sponges, and some species of salamander. In a report published today in the Proceedings of the National Academy of Sciences, researchers from The Wistar Institute demonstrate that mice that lack the p21 gene gain the ability to regenerate lost or damaged tissue."

Just imagine, you are sitting on a sunny beach, contentedly letting the warm sand trickle through your fingers. Millions of sand grains. What you probably can't imagine: at the same time, billions upon billions of bacteria are also trickling through your fingers. Between 10,000 and 100,000 microorganisms live on each single grain of sand, as revealed in a new study. This means that an individual grain of sand can have twice as many residents as, say, the city of Fairbanks, Alaska!

Imagine a world in which every single human being can freely share in the sum of all knowledge. That's our commitment.

QuaLIS is an Enterprise scale Web based Laboratory Information Management Software (LIMS) that helps global organisations standardise on a single LIMS system.

Come work with us Interested in working with researchers from different disciplines within the Harvard, MIT and Broad community and an unique opportunity to participate in world-class research to make an impact on human health? Come work with us! We are looking for a computational biologists to handle data from a wide variety of experimental methods, focusing on next-gen sequencing technologies. Keep Reading...  SCDE is live The Stem Cell Discovery Engine (SCDE) is an integrated platform that allows users to consistently describe, share and compare cancer and tissue stem cell data. It is made up of an online database of curated experiments coupled to a customized instance of the Galaxy analysis engine with tools for gene list manipulation and molecular profile comparisons. The SCDE currently contains more than 50 stem cell-related experiments. Each has been manually curated and encoded using the ISA-Tab standard to ensure the quality of the data and its annotation. Keep Reading...  The Center for Health Bioinformatics at the Harvard School of Public Health provides consults to researchers for the management, integration and contextual analysis of biological high-throughput data. We are a member of the Center for Stem Cell Bioinformatics, the Environmental Statistics and Bioinformatics Core at the Harvard NIEHS Center for Environmental Health and the Genetics & Bioinformatics Consulting group for Harvard Catalyst and work closely with our colleagues in the Department of Biostatistics and the Program in Quantitative Genomics to act as a single point of contact for computational biology,

"The old phrase "united we stand, divided we fall" applies equally well to the mechanisms of attention as it does to a patriotic cause. When devoted to a single task, the brain excels; when several goals splinter its focus, errors become unavoidable... non-stop decision making "

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"Evolution likes to keep what works best. The rest falls by the wayside. In theory, this means that the most "fit" variations, say, a color that looks poisonous or one particularly attractive to the ladies, would become the most common. By this logic, the many colors of the guppy should have conformed to a single common pattern long ago. But they haven't. Instead, the male guppies continue to show not only bright colors but also a high diversity of colors. What keeps the variety going? The rare-male effect. Female guppies prefer the males that are rare, no matter what their color pattern actually is. This effect has been documented in the laboratory in guppies and in other species like fruit flies."

Scientists had thought that there was a single species of housecat-sized Brazilian tigrina. However, the molecular data now show that tigrina populations in northeastern versus southern Brazil are completely separate, with no evidence of interbreeding between them. As such, they are best described as two distinct species.

One of the most complete early human skulls yet found suggests that what scientists thought were three hominin species may in fact be one. This controversial claim comes from a comparison between the anatomical features of a 1.8-million-year-old fossil skull with those of four other skulls from the same excavation site at Dmanisi, Georgia. The wide variability in their features suggests that Homo habilis, Homo rudolfensis and Homo erectus, the species so far identified as existing worldwide in that era, might represent a single species.

Researchers have cracked the long-time mystery of how sex is determined in birds: A dose-dependent effect of a single gene on one of the sex chromosomes does the trick, according to a study published this week in Nature.

In a recent study, researchers show that a gene called DMRT1 found only on the Z chromosome partly explains bird "maleness". When a ZZ embryo gets less DMRT1, the embryos start to take on some female traits. These studies show us that bird gender can be partly explained by genetics. Not having enough of a single gene can keep a bird from becoming a bona fide male bird. But this doesn't rule out the possibility of a female gene being on the W chromosome. Scientists just haven't yet found one.

An illness that has been decimating US honeybees for more than three years probably isn't caused by a single virus, but by multiple viruses that wear down the bees' ability to produce proteins that can guard them against infection, according to a new study.

A single mega-colony of ants has colonised much of the world, scientists have discovered.

Researchers have regressed human stem cells to an embryonic state using just a single transcription factor, as opposed to the four factors previously needed to induce pluripotency in human cells, according to a study published online today (August 28) in Nature.