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POPSResearchers Discover Remnant of an Ancient 'RNA World'
Breaker's lab solved a decades-old mystery by describing how tiny circular RNA molecules called cyclic di-GMP are able to turn genes on and off. This process determines whether the bacterium swims or stays stationary, and whether it remains solitary or joins with other bacteria to form organic masses called biofilms. Bacterial use of RNA to trigger major changes without the involvement of proteins resolves one of the questions about the origin of life: If proteins are needed to carry out life's functions and DNA is needed to make proteins, how did DNA arise? The answer is what Breaker and other researchers call the RNA World. They believe that billions of years ago, single strands of nucleotides that comprise RNA were the first forms of life and carried out some of the complicated cellular functions now done by proteins. The riboswitches are highly conserved in bacteria, illustrating their importance and ancient ancestry, Breaker said.
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POPSNewly described 'dragon' protein could be key to bird flu cure This unexpected relationship between the two subunits could inspire a number of different therapies or vaccines for H5N1 that rely on muzzling the "dragon's" jaws with another molecule or chemical compound that would block the PB1 subunit's access to the PA site, according to Joachimiak. "If we can put a bit in the dragon's mouth, we can slow or even potentially someday stop the spread of avian flu," he said. "Since we are talking about a relatively small protein surface area, finding a way to inhibit RNA replication in H5N1 seems very feasible."
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POPSHow Your Brain Controls Time Warren Meck of Duke University argues that the brain measures long stretches of time by producing pulses. But the brain does not then count the pulses in the way a clock does. Instead, Meck suspects, it does something more elegant. It listens to the pulses as if they were music. At Humboldt University of Berlin in Germany, scientists have been building a model of how memory may store time. When neurons produce a regular cycle of signals, some signals come a little sooner and some come a little later. The researchers propose that as neurons pass these signals along, they can add tiny advances, some bigger than others. With these tiny wobbles, the brain can compress memories of time from several seconds down to hundredths of a second—a small enough package to store for later retrieval. As it stores time in memories, the brain may alter it in another way that is even more radical. It may record time so that our brains recall events in backward order. Scientists at MIT discovered re
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POPSNew Mode Of Gene Regulation Discovered In Mammals As research advances, the more it becomes clear, that gene regulation networks are actually complex computing machines. DNA is not a mere repository of information. What's more, the newly discovered mechanism is self referential, which adds another later of complexity to gene regulation processes.
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POPS'Mind's eye' influences visual perception The new findings offer an objective tool to assess the often-slippery concept of imagination. This is an interesting and fascinating experiment. It is perhaps a far shot but this may point towards the roots of human's ability and inclination to envision a future reality and than change the world around to fit this reality.
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POPSRight and wrong lessons from biology The opposite view stresses that evolution is an extremely effective way of searching parameter space, and that in consequence is that we should assume that biological design solutions are likely to be close to optimal for the environment for which they’ve evolved. Where these design solutions seem odd from our point of view, their unfamiliarity is to be ascribed to the different ways in which physics works at the nanoscale. At its most extreme, this view regards biological nanotechnology, not just as the existence proof for nanotechnology, but as an upper limit on its capabilities.
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POPSGene silencer and quantum dots reduce protein production to a whisper Each quantum dot was surrounded by a proton sponge that carried a positive charge. Without any quantum dots attached, the siRNA's negative charge would prevent it from penetrating a cell's wall. With the quantum-dot chaperone, the more weakly charged siRNA complex crosses the cellular wall, escapes from the endosome (a fatty bubble that surrounds incoming material) and accumulates in the cellular fluid, where it can do its work disrupting protein manufacture. Key to the newly published approach is that researchers can adjust the chemical makeup of the quantum dot's proton-sponge coating, allowing the scientists to precisely control how tightly the dots attach to the siRNA. Quantum dots were dramatically better than existing techniques at stopping gene activity. In experiments, a cell's production of a test protein dropped to 2 percent when siRNA was delivered with quantum dots. By contrast, the test protein was produced at 13 percent to 51 percent of normal levels when the siRNA
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POPSVirtual Unreality (Part 2) Looking from the perspective of a futuristic, perfect virtual reality, we are forced to question the very essence of our existence. What is the point of living if a utopia is provided for us? Once the superficial shell of reality is peeled from us, what is left of the human soul? What are the common denominators of our existence? The virtual world paradigm opens up our eyes to the limitations of reality, and shows us the true essence of what it means to be human.
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POPSZebra's Stripes, Butterfly's Wings: How Do Biological Patterns Emerge? Previous work identified a specific signal necessary for getting these fly egg cells to move; the problem is that this signal is “graded.” Like drops of ink spreading out on wet paper, this signal travels in between surrounding cells, gradually fading away as it moves outwards. But clear lines are required for pattern formation — there is no grey area between a zebra’s black and white stripes, between heart and liver cells and, in this case, between migrating cells and those that stay put. How are graded signals converted to a clear move or stay signal? By examining flies containing mutations in different genes, the researchers discovered that one gene in particular, called apontic, is important for converting a graded signal.
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POPSGenetically engineered cells make their own nanomagnets, providing clear MRI images. If genetically engineering cells to produce their own magnetic nanoparticles proves successful, this provides a new window through which to view many biological processes as they unfold, from the formation of tumors to the migration of stem cells injected to treat disease. "It's just amazing that they can get a mammalian cell to actually make the material," says Lee Josephson, an associate professor at the Harvard Medical School's Center for Molecular Imaging Research. "I think it's a really meaningful piece of work."
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POPSBacteria make major evolutionary shift in the lab In the meantime, the experiment stands as proof that evolution does not always lead to the best possible outcome. Instead, a chance event can sometimes open evolutionary doors for one population that remain forever closed to other populations with different histories.
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POPSThinking ahead: Bacteria anticipate coming changes in their environment To test this idea, the researchers exposed a population of E. coli to different temperatures and oxygen changes, and measured the gene responses in each case. The results were striking: An increase in temperature had nearly the same effect on the bacterium's genes as a decrease in oxygen level. Indeed, upon transition to a higher temperature, many of the genes essential for aerobic respiration were practically turned off. To prove that this is not just genetic coincidence, the researchers then grew the bacteria in a biologically flipped environment where oxygen levels rose following an increase in temperature. Remarkably, within a few hundred generations the bugs partially adapted to this new regime, and no longer turned off the genes for aerobic respiration when the temperature rose.
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POPSBacterial Chemical Sensors on the Horizon? Bacteria is responsible for the vast majority of all fundamental life processes on this planet. Harnessing bacteria to the service of humanity will be a technological revolution allowing anything from supersensitive sensors to weather control.
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POPSSynthetic Biology: funders move to address social and ethical challenges It reviews what synthetic biology is, where it has come from, and where it is going, as well as making recommendations to research funders and the scientific community about how social and ethical issues should be addressed. These include: * The need for scientists to engage with the public early in the development of synthetic biology to ensure that research does not get ahead of public attitudes * Synthetic biology must not be over-hyped by its supporters and critics should not exaggerate the risks it poses * Reviewing current regulations and guidelines to ensure that an appropriate governance framework is in place before most synthetic biology applications are introduced
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POPSInvasion Strategy Of World's Largest Virus Revealed The scientists believe that the study of the mimivirus’s life cycle, from cellular infection to the production of new viruses, may yield valuable insights into the mechanisms of action of numerous other viruses, including those that cause human diseases.
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POPSThe More We Know About Genes, the Less We Understand About 95 percent of the rewired bacteria did just fine with their new networks. They went on with their lives, feeding, growing and dividing. Some even performed better than microbes with the original wiring, under some conditions. The tolerance these bacteria showed reveals something important about how evolution works. Humans can randomly rewire cells, and so can mutations. There's something about gene networks that allow them to thrive despite these mutations, and, in some cases, to even gain an edge in the evolutionary race.
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POPSThe 100$ Genome Five years away, thats impressive. It means individualy tailored medicine within 10-15 years.
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