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POPSThe DNA Mystery: Scientists Stumped By "Telepathic" Abilities Even so, research published in ACS’ Journal of Physical Chemistry B, shows very clearly that homology recognition between sequences of several hundred nucleotides occurs without physical contact or presence of proteins. Double helixes of DNA can recognize matching molecules from a distance and then gather together, all seemingly without help from any other molecules or chemical signals. This recognition effect may help increase the accuracy and efficiency of the homologous recombination of genes, which is a process responsible for DNA repair, evolution, and genetic diversity. The new findings may also shed light on ways to avoid recombination errors, which are factors in cancer, aging, and other health issues.
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POPSNew theory of aging points the finger at misrepairs But sometimes these repair mechanisms go wrong, leaving small regions of misrepair. The new idea is that aging is the result of the accumulation of these misrepairs over time. This leads to a key prediction about aging. The team says: "Our theory suggests that for extending lifespan all efforts need to focus on the reduction of misrepair." So what should you do if you want to live longer? Avoid damage as far as possible, say Michelitsch and pals, emphasising that "it is especially important to prevent chronic inflammation, which is an important source of misrepair."
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POPSChemists edge closer to recreating early life Joyce's experiment was designed to test the 'RNA World' theory, which proposes that DNA-based life evolved from a stage whereby RNA acted as both an information-storage molecule, like DNA, and as a catalyst, like enzymes, and was also capable of self-replication. This work is the biggest injection of support for the RNA world hypothesis in a long time,' says Donna Blackmond, Chair in Catalysis at Imperial College London, UK. 'It's a demonstration of principle that indefinite replication, coupled with selection via mutation, is quite plausible for RNA. The fact that it goes on indefinitely is a big thing for showing that this really could have been how life started,' she adds.
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POPSYawning Is Caused by the Brain Overheating One of the main reasons why the team selected the parakeets for the study was the fact that these birds almost never engaged in group yawning, so they were deemed reliable test subjects. During the tests, they were subjected to three temperatures – one that increased constantly, one that was high, to begin with, and one for control. Examinations proved that the brain sought to cool itself by triggering the yawning reflex when the outside temperature was lower than that inside the body. “For instance, yawning should not occur when ambient temperatures exceed body temperature, as taking a deep inhalation of warm air would be counterproductive,” Gallup adds. “In addition, yawning when it is extremely cold may be maladaptive, as this may send unusually cold air to the brain, which may produce a thermal shock.”
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POPSScientists Identify Two Routes to Nerve Cell Regeneration In the long run, the optimal strategy for treating spinal injuries may involve a combination of therapies that restore neurons’ ability to grow axons and ones that counteract inhibitory signals near the injury. “You want to do each, and you may need to do both,”
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POPS'Junk' DNA proves functional Over evolutionary time, these repeats were dispersed within different species, creating new regulatory sites throughout these genomes. Thus, the set of genes controlled by these transcription factors is likely to significantly differ from species to species and may be a major driver for evolution. This research also shows that these repeats are anything but "junk DNA," since they provide a great source of evolutionary variability and might hold the key to some of the important physical differences that distinguish humans from all other species. The GIS study also highlighted the functional importance of portions of the genome that are rich in repetitive sequences.
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POPSStudy finds value in 'junk' DNA "Alu elements are a major source of new exons. Because Alu is a primate-specific retrotransposon, creation of new exons from Alu may contribute to unique traits of primates, so we want to better understand this process," said the study's senior author Yi Xing, Ph.D., assistant professor of internal medicine and biomedical engineering, who holds a joint appointment in the University of Iowa Carver College of Medicine and the UI College of Engineering. To study the impact of Alu-derived exons on human gene expression, the researchers used a high-density exon microarray. The technology has nearly six million probes for monitoring the expression patterns of all human exons. Using data generated by these microarrays, the scientists analyzed 330 Alu-derived exons in 11 human tissues. The team then identified a number of exons with interesting expression and functional characteristics.
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POPSComputing with RNA
That opens up the possibility of computing devices that can respond to specific conditions within the cell, he says. For example, it may be possible to develop drug delivery systems that target cancer cells from within by sensing genes used to regulate cell growth and death. "You can program it to release the drug when the conditions are just right, at the right time and in the right place," these biocomputers are built from three main components--sensors, actuators, and transmitters--all of which are made up of RNA. The input sensors are made from aptamers, RNA molecules that behave a bit like antibodies, binding tightly to specific targets. Similarly, the output components, or actuators, are made of ribozymes, complex RNA molecules that have catalytic properties similar to those of enzymes. These two components are joined by yet another RNA molecule that serves as a transmitter, which is activated when a sensor molecule recognizes input chemical and triggers an actuator molecule
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POPSVideo of the First 24 Hours of an Embryo's Cells The new technique, called Digital Scanned Laser Light-Sheet Fluorescence Microscopy, could be used on other animals such as mice, chicken and frogs, which would could help researchers better understand evolution at the cellular scale. Already, the research has shown that the initial stages of heart development do not happen as scientists thought.
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POPSBiologists on the Verge of Creating New Form of Life "We've made more progress on how the membrane of a protocell could grow and divide," Szostak said in a phone interview. "What we can do now is copy a limited set of simple sequences, but we need to be able to copy arbitrary sequences so that sequences could evolve that do something useful." By doing "something useful" for the cell, these genes would launch the new form of life down the Darwinian evolutionary path similar to the one that our oldest living ancestors must have traveled. Though where selective pressure will lead the new form of life is impossible to know.
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POPSScientists Develop New Computational Method To Investigate Origin Of Life "Retroelements are an ancient and highly diverse class of proteins; therefore, they provide a rigorous benchmark for us to test our approach. We are happy with the results we derived, even though our method is in an early stage," said Patterson. The team plans to make the algorithms that they used in their method available to others as open-source software that is freely available on the Web. Scientists map out the evolutionary histories of organisms by comparing their genetic and/or protein sequences. Those organisms that are closely related and share a recent common ancestor have greater degrees of similarity among their sequences.
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POPSPolygamy is the key to a long life Men, by contrast, can reproduce well into their 60s and even 70s and 80s, and most researchers assumed this explained their longevity. But Lummaa and colleague Andy Russell wondered whether other factors explained the long lifespan of men, such as a grandfather effect. If female survival is the main explanation for male longevity, then monogamous and polygamous men would live for about the same length of time. Instead, it seems that fathering more kids with more wives leads to increased male longevity. Men, then, live long because they're fertile well into their grey years. The explanation could be both social and genetic. Men who continue fathering kids into their 60s and 70s could take better care for their bodies because they have mouths to feed. But evolutionary forces acting over thousands of years could also select for longer-lived men in polygamous cultures.
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POPSFuture 'Top 10' Hot Careers in 2012 5) Simulation Engineering By 2012, an increase in processing power and rich data will make simulations more realistic, and user-friendly. Simulation engineers will be working on bringing us closer to “Star Trek’s” Holodecks—the ultimate total immersion simulation. Simulations will be in every industry and every engineering field, 6) Boomer Caregiving 7) Genetic Counseling 8) Brain Analysts 9) Space Tourism 10) Roboticists
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POPSThe Sound of Sight Both groups judged auditory patterns accurately about 85 percent of the time, the researchers report in the August 5 issue of Current Biology. On the visual trials, nonsynesthetes’ judgments fell to nearly chance levels, a result that corroborates other research showing that most people are better at judging auditory patterns than assessing visual patterns. In contrast, synesthetes—who reported hearing sounds such as beeps or taps in time with the visual signals—distinguished matching from nonmatching rhythms 75 percent of the time.
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POPSUnderstanding Hearing, Molecule By Molecule other sensory system in biology and the electrical engineering world is capable of this feat. “It’s one of the most beautifully deigned systems in the body,” says Manfred Auer of Berkeley Lab's Life Sciences Division. “But how it really works remains a mystery. Our goal is to determine what the system looks like, so we can determine how it functions.”
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