Sunday, January 17, 2016

Hot Recent Science & Technology Articles (23)

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  1. Nanosubmarines Promise a Fast Drug Delivery Device (“Tour and his team have designed and fabricated a molecule consisting of 244 atoms that can move within a liquid environment using a tail-like propeller powered by ultraviolet light. What is really impressive about the nanoscale submarines is their speed. One wag of its tail can move it 18 nanometers. … The operation of the motor resembles the movement of a bacterium’s flagellum. The process involves four steps. In the first, when light hits the double bond that holds the rotor to the main body, it becomes a single bond. This removal of a single bond allows the rotor to turn a quarter rotation. This motor is seeking to get to a lower energy state, which leads it to jump to the next adjacent atom. This causes the rotor to turn another quarter step, and so goes the process while the light shines on it.”)
  2. Laser-Induced Graphene Looks to Displace Batteries With Supercapacitors (“The researchers claim that the microsupercapacitors they have fabricated using LIG have demonstrated an energy density that is on par with thin-film lithium-ion batteries. The microsupercapitors’ capacitance was measured at 934 microfarads per square centimeter; they boast an energy density of 3.2 milliwatt-hours per cubic centimeter. As these are supercapacitors, their power density far exceeds that of batteries. Perhaps most importantly, the devices did not exhibit any degradation over time, maintaining mechanical stability even after being bent 10,000 times.”)
  3. People's Brain Chemistry May Reveal the Hour of Their Death  The tiny biological clocks ticking away inside the body stop when life ends, leaving a timestamp of sorts (“People who died in the morning have a different mix of active genes and proteins in their brain cells than people who died in the evening or at night, reports Carl Zimmer for The New York Times. The discovery is more than just a morbid oddity. Researchers are trying to understand exactly how internal clocks dictate brain biology and chemistry.”)
  4. New research shows Earth’s tilt influences climate change (“DeLong analyzed data from the past 282,000 years that shows, for the first time, a connection between the Earth’s tilt called obliquity that shifts every 41,000 years, and the movement of a low pressure band of clouds that is the Earth’s largest source of heat and moisture — the Intertropical Convergence Zone, or ITCZ.”)
  5. Why too much evidence can be a bad thing (“In a new paper to be published in The Proceedings of The Royal Society A, a team of researchers, Lachlan J. Gunn, et al., from Australia and France has further investigated this idea, which they call the "paradox of unanimity." "If many independent witnesses unanimously testify to the identity of a suspect of a crime, we assume they cannot all be wrong," coauthor Derek Abbott, a physicist and electronic engineer at The University of Adelaide, Australia, told Phys.org. "Unanimity is often assumed to be reliable. However, it turns out that the probability of a large number of people all agreeing is small, so our confidence in unanimity is ill-founded. This 'paradox of unanimity' shows that often we are far less certain than we think."”)
  6. Strong magnetic fields discovered in majority of stars (“An international group of astronomers led by the University of Sydney has discovered strong magnetic fields are common in stars, not rare as previously thought, which will dramatically impact our understanding of how stars evolve. Using data from NASA's Kepler mission, the team found that stars only slightly more massive than the Sun have internal magnetic fields up to 10 million times that of the Earth, with important implications for evolution and the ultimate fate of stars.”)
  7. Biomedical Science Studies Are Shockingly Hard to Reproduce  Limited access to research details and a culture that emphasizes breakthroughs are undermining the credibility of science (“To kick things off, Ioannidis and his colleagues evaluated a random sample of 441 biomedical articles published between 2000 and 2014. They checked whether these papers provided public access to raw data and experimental protocols, were replicated in subsequent studies, had their results integrated into systematic reviews of a subject area and included documentation of funding sources and other potential conflicts of interest. Their results were troubling to say the least. For instance, only one study provided full experimental protocols, and zero studies provided directly available raw data.”)
  8. MILK-PRODUCING PROTEIN ‘GOES ROGUE’ TO DRIVE BREAST CANCER SPREAD (“Their work shows that the rogue protein, called Elf5, summons immune cells to gather in breast tumours. In a model of breast cancer, this caused inflammation and encouraged new blood vessels to form around the tumour. These blood vessels became ‘leaky’, opening a gateway for cancer cells to escape into the blood and, ultimately, to spread to lung.”)
  9. Scientists teach bacterium a new trick for artificial photosynthesis (“We've demonstrated the first self-photosensitization of a non-photosynthetic bacterium, M. thermoacetica, with cadmium sulfide nanoparticles to produce acetic acid from carbon dioxide at efficiencies and yield that are comparable to or may even exceed the capabilities of natural photosynthesis”)
  10. Team reports that black hole activity can be observed via visible rays (“An international research team reports that the activity of such phenomena can be observed by visible light during outbursts, and that flickering light emerging from gases surrounding black holes is a direct indicator of this. The team's results, published in Nature, indicate that optical rays and not just X-rays provide reliable observational data for black hole activity.”)
  11. This Ancient Grain May Have Helped Humans Become Farmers  Millet's short growing season and low water needs might also benefit a modern world stressed by climate change (This could be huge. Agriculture started perhaps 10,000 years ago in northern China. “Researchers based in the U.S., U.K. and China pieced together the history of millet by dating the charred remains of the grain found at archaeological sites in China and Inner Mongolia. … The crop was first domesticated about 10,000 years ago in northern China, around the same time as rice was domesticated in southern China and barley and wheat in western China. Shepherds and herders probably carried the grain across Eurasia between 2,500 and 1,600 B.C. It has previously been assumed that early agriculture was focused in river valleys where there is plentiful access to water … The team’s analysis shows that millet was farmed along with other grains, such as barley, all in the same fields,  … This multi-cropping system helped early farmers weather rough seasons—if one grain didn’t do well, perhaps another could cope with the conditions. ”)
  12. Defective control of pre–messenger RNA splicing in human disease (Nice review article, but complex. “Examples of associations between human disease and defects in pre–messenger RNA splicing/alternative splicing are accumulating. ... This review highlights recent progress in our understanding of how the altered splicing function of RNA-binding proteins contributes to myelodysplastic syndromes, cancer, and neuropathologies.”)
  13. The Iceman's Stomach Bugs Offer Clues to Ancient Human Migration DNA analysis of the mummy's pathogens may reveal when and how Ötzi's people came to the Italian Alps (“These bacteria, Helicobacter pylori, are providing fresh evidence about Ötzi's diet and poor health in the days leading up to his murder. ... “When we looked at the genome of the Iceman's H. pylori bacteria, we found that it's quite a virulent strain, and we know that in modern patients it can cause stomach ulcers, gastric carcinoma and some pretty severe stomach diseases,” ... “We also found proteins that are very specific and only released if you have an inflammatory response, so we can say that he most probably had a quite severe H. pylori infection in his stomach ... What they found was a surprisingly pure strain of the stomach bug that's closely related to the version found in modern Asian populations. By contrast, the modern European strain of H. pylori seems to be a mix of Asian and African ancestral strains. This provides evidence that pure African populations of the bacteria arrived in Europe only within the past few thousand years. ... it was believed that the mixture of the ancestral African and Asian strains had already occurred maybe 10,000 years ago or even earlier,” Zink says. “But the very small part of African ancestry in the bacteria genome from the Iceman tells us that the migrations into Europe aren't such an easy story.” ... The iceman's unmixed stomach bacteria are “in line with recent archaeological and ancient DNA studies that suggest dramatic demographic changes shortly after the Iceman’s time, including massive migration waves and significant demographic growth,”)
  14. Researchers' metallic glue may stick it to soldering and welding (“... made possible by unique properties of metallic nanorods—infinitesimally small rods with metal cores that we have coated with the element indium on one side and galium on the other. These coated rods are arranged along a substrate like angled teeth on a comb: There is a bottom 'comb' and a top 'comb.' We then interlace the 'teeth.' When indium and galium touch each other, they form a liquid. The metal core of the rods acts to turn that liquid into a solid. The resulting glue provides the strength and thermal/electrical conductance of a metal bond.”)
  15. 4.5 Billion-Year-Old Meteorite Found in the Australian Desert/This 3.7 pound rock could help scientists learn about Earth's origins (I find it even more important how this meteorite was discovered and this technique promises to discover many more in the future. “The meteorite is the first detected by the Desert Fireball Network, a system of 32 automated observation cameras spread out over remote and rural regions in the outback. Of these cameras, five detected the meteorite’s entry into Earth’s atmosphere on November 25, 2015, giving planetary scientists plenty of data to calculate its trajectory. ”)
  16. Antibiotics pave way for C. diff infections by killing bile acid-altering bacteria (“New research from North Carolina State University and the University of Michigan finds that bile acids which are altered by bacteria normally living in the large intestine inhibit the growth of Clostridium difficile, or C. diff. C. diff is a harmful bacterium that can cause painful and sometimes fatal infections.”)
  17. Genetic Flip Helped Organisms Go From One Cell to Many (“The authors of the new study focused on a single molecule called GK-PID, which animals depend on for growing different kinds of tissues. Without GK-PID, cells don’t develop into coherent structures, instead growing into a disorganized mess and sometimes even turning cancerous. All animals ... carry a gene sequence that’s very similar to the one producing GK-PID. But that gene encodes ...  an enzyme that helps build DNA. The enzyme can be found even in other organisms, from fungi to bacteria. That analysis allowed the scientists to figure out the DNA sequence for GK-PID in the single-celled ancestors of animals — a gene that hasn’t been seen in hundreds of millions of years. ... They recreated those ancient molecules to see how they once functioned. ... Instead, it behaved like a DNA-building enzyme. ... The scientists altered the gene for the ancestral enzyme with the earliest mutations that evolved in it. They found it took a single mutation to flip GK-PID ...”)
  18. A Journey to the Oldest Cave Paintings in the World The discovery in a remote part of Indonesia has scholars rethinking the origins of art—and of humanity (This is an unusually long article for Smithsonian. “He found that it is staggeringly ancient: at least 35,400 years old. That likely makes it the oldest-known example of figurative art anywhere in the world—the world’s very first picture. It’s among more than a dozen other dated cave paintings on Sulawesi that now rival the earliest cave art in Spain and France, long believed to be the oldest on earth.”)
  19. Got It Down Cold: Cryo-Electron Microscopy Named Method of the Year (“... cryo-electron microscopy (cryo-EM). The technique, which involves flash-freezing molecules in liquid nitrogen and bombarding them with electrons to capture their images with a special camera, has advanced dramatically since its inception … . In fact, cryo-EM has improved so much that its mapping performance now rivals that of X-ray crystallography ...”)
  20. 1,500-year-old skeleton with prosthetic foot found in Austria (“This represents one of the oldest examples of prosthetic limb replacement associated with the skeleton of its wearer in Europe to date … The middle-aged man's left foot was missing, and in its place was an iron ring and pieces of wood, according to the researchers. They used radiography and CT-scanning to determine that the man had a lesion that had healed.”)

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