Posted: 8/2/2015
- At Tiny Scales, a Giant Burst on Tree of Life A new technique for finding and characterizing microbes has boosted the number of known bacteria by almost 50 percent, revealing a hidden world all around us. (“By reconstructing complete or nearly complete genomes, Brown and his collaborators were able to locate 16S rRNA genes and identify organisms without relying on primers. The group published their results in the July 9 issue of Nature. Some of the newly discovered bacteria have hairlike structures on their surface. The fuller genomic picture they created also allowed them to tease out traits of the life forms they’d discovered. All the organisms they found have very short genomes, about one million base pairs (compare that to E. coli, which has about five million), and they all have minimal metabolic function, requiring them to use fermentation to generate energy. They are also missing many basic biosynthetic pathways and need help making nucleotides and amino acids. The researchers divided the 789 organisms into 35 phyla — 28 of which were newly discovered — within the domain bacteria. They based the sorting on the organisms’ evolutionary history and on similarities in the code on the organisms’ 16S rRNA genes — those with at least 75 percent of their code in common went into the same phylum. With these new additions, there are now roughly 90 identified bacterial phyla.”)
- http://news.sciencemag.org/physics/2015/07/exploding-star-solves-cosmic-mystery (“Astronomers have seen for the first time an exploding star—a nova—that seems to churn out lithium, solving a nagging cosmic mystery. The very oldest stars in the universe seem to have much less lithium than they should, and young stars have too much.”)
- Researchers demonstrate the world's first white lasers (“The technological advance puts lasers one step closer to being a mainstream light source and potential replacement or alternative to light emitting diodes (LEDs). Lasers are brighter, more energy efficient, and can potentially provide more accurate and vivid colors for displays like computer screens and televisions. Ning's group has already shown that their structures could cover as much as 70 percent more colors than the current display industry standard.”)
- Making the new silicon: Gallium nitride electronics could drastically cut energy usage (“Now MIT spinout Cambridge Electronics Inc. (CEI) has announced a line of GaN transistors and power electronic circuits that promise to cut energy usage in data centers, electric cars, and consumer devices by 10 to 20 percent worldwide by 2025.”)
- How Do Fireflies Glow? Mystery Solved After 60 Years Scientists have sussed out the chemical secret of these bright summertime beetles—and it may someday improve human health, a new study says. (“Branchini's experiments showed the oxygen involved in the firefly's glow comes in a special form called a superoxide anion. "Superoxide anion is a form of molecular oxygen that contains an extra electron," ... This extra electron gives the oxygen properties ... in fact, be able to cause a chemical reaction with the luciferin like scientists have suspected.”)
- A DNA Search for the First Americans Links Amazon Groups to Indigenous Australians The new genetic analysis takes aim at the theory that just one founding group settled the Americas (“The latest genetic analyses backup skeletal studies suggesting that some groups in the Amazon share a common ancestor with indigenous Australians and New Guineans.”)
- Important Link between the Brain and Immune System Found The new line of communication prompts rethinking of neurologic disease (“... Kipnis and colleagues had previously shown that a type of white blood cell called T-cells in the meninges are associated with significant influences on cognition and hence were curious about the role of meningeal immunity on brain function. By mounting whole mouse meninges and using neuroimaging the team noticed that T-cells were present in vessels separate from arteries and veins, confirming that the brain does in fact have a lymphatic system linking it directly the peripheral immune system. … Other recent work by Kipnis and colleagues found that an injury to the central nervous system results in a strong activation of T-cells in the deep cervical lymph nodes.”)
- TSRI-Designed Drug Candidate Significantly Reduces HIV Reactivation Rate (“But now, scientists from the Florida campus of The Scripps Research Institute (TSRI) have shown that, unlike other antiretroviral therapies, a natural compound called Cortistatin A reduces residual levels of virus from these infected dormant cells, establishing a near-permanent state of latency and greatly diminishing the virus’ capacity for reactivation.”)
- Small RNAs Found to Play Important Roles in Memory Formation (“Unlike some types of RNA, microRNAs (miRNAs) do not code for proteins but instead regulate various biological processes by modulating the level of gene expression. A number of studies have shown that miRNAs are critical for normal development and cellular growth and may contribute to the complexity of neurodegenerative diseases.
In the new study, 134 different miRNAs were tested for roles in learning and memory in the central nervous system of Drosophila melanogaster, the common fruit fly, which is a recognized animal model for memory studies.
The researchers tested the potential involvement of miRNAs in intermediate-term memory by silencing them individually and identified at least five different miRNAs involved in memory formation or retention.
“Among the five miRNAs identified in this study, we found one that is necessary for memory formation,” said Research Associate Germain U. Busto, a first author of the study with Research Associate Tugba Guven-Ozkan. “Interestingly, its human counterpart is altered in several neurodegenerative diseases, including Alzheimer’s and Huntington’s.”)
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