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Categories: Biology: General, Mathematics: Puzzles

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The bone density of astronauts -- of both the human and rodent variety -- decreases in space. Researchers report that changes to the gut microbiomes of space travelers might be associated with this bone loss. Rodents that spent a month or more on the International Space Station had altered and more diverse microbiomes, and the bacterial species that bloomed in space may have contributed to the increased production of molecules that are known to influence the bone remodeling process.

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Certain stem cells have a unique ability to move between growth compartments in hair follicles, but get stuck as people age and so lose their ability to mature and maintain hair color, a new study shows.

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Two protein complexes carry the major responsibility for the spatial organization of chromosomes in our cell nuclei. DNA tension plays a surprising role in this. Nanoscientists now publish how they have visualized this.

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A hitherto unknown mechanism for DNA folding is described in a new study. The findings provide new insights into chromosomal processes that are vital to both normal development and to prevent disease.

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Small interfering RNAs (siRNAs) are novel therapeutics that can be used to treat a wide range of diseases. This has led to a growing demand for selective, efficient, and safe ways of delivering siRNA in cells. Now, in a cooperation between the Universities of Amsterdam and Leiden, researchers have developed dedicated molecular nanocages for siRNA delivery. In a paper just out in the Journal Chem they present nanocages that are easy to prepare and display tuneable siRNA delivery characteristics.

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Millipede legs grow in an unexpected way, according to new research. Previously, it was thought that when a millipede molts (sheds its exoskeleton), it grows new segments on the end of its body without legs. Then after the next molt, the previously new segments re-emerge with fully formed legs attached. However, a team has found that new segments actually contain tiny bundles of legs, which appear as transparent protrusions before molting and then become fully formed afterwards. This discovery could help us understand how not only millipedes, but also other arthropods (invertebrates with jointed legs) grow.

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Plants that glow under ultraviolet (UV) light aren't only a figment of science fiction TV and movies. Roots of a traditional medicine plant called the orange climber, or Toddalia asiatica, can fluoresce an ethereal blue hue. And now, researchers have identified two coumarin molecules that could be responsible. These natural coumarins have unique fluorescent properties, and one of the compounds could someday be used for medical imaging.

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A new global survey of 1000 forest areas shows how climate change since the peak of the last ice age has had a major impact on the diversity and distribution of tree species we see today. The results can help us predict how ecosystems will react to future changes, thus having an impact on conservation management around the globe.

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Scientists can now use light to activate protein functions both inside and outside of living cells. The new method, called light-activated SpyLigation, can turn on proteins that are normally off to allow researchers to study and control them in more detail. This technology has potential uses in tissue engineering, regenerative medicine, and understanding how the body works. The scientists applied their new method to control the glow of a green fluorescent protein derived from Japanese eel muscle.

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The diverse swimming techniques of the ancient reptiles that ruled the Mesozoic seas have been revealed.

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Over the past 40 years, the financial losses caused by biological invasions have been equivalent to those caused by various types of natural disasters, such as earthquakes, floods or storms; however, according to scientists, they are now increasing at a faster pace.

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Scientists have recently made a surprising discovery, with the help of a wind tunnel and a flock of birds. Songbirds, many of which make twice-yearly, non-stop flights of more than 1,000 miles to get from breeding range to wintering range, fuel themselves by burning lots of fat and a surprising amount of the protein making up lean body mass, including muscle, early in the flight. This flips the conventional wisdom on its head, which had assumed that migrating birds only ramped up protein consumption at the very end of their journeys, because they would need to use every ounce of muscle for wing-flapping, not fuel.

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The high seas have been colonized by a surprising number of coastal marine invertebrate species, which can now survive and reproduce in the open ocean, contributing strongly to the floating community composition. Researchers found coastal species, representing diverse taxonomic groups and life history traits, in the eastern North Pacific Subtropical Gyre on over 70 percent of the plastic debris they examined. Further, the debris carried more coastal species than open ocean species.

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For more than half a century, the Tully monster (Tullimonstrum gregarium), an enigmatic animal that lived about 300 million years ago, has confounded paleontologists, with its strange anatomy making it difficult to classify. Recently, a group of researchers proposed a hypothesis that Tullimonstrum was a vertebrate similar to cyclostomes (jawless fish like lamprey and hagfish). If it was, then the Tully monster would potentially fill a gap in the evolutionary history of early vertebrates. Studies so far have both supported and rejected this hypothesis. Now, using 3D imaging technology, a team in Japan believes it has found the answer after uncovering detailed characteristics of the Tully monster which strongly suggest that it was not a vertebrate. However, its exact classification and what type of invertebrate it was is still to be decided.

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Many disease-causing bacteria like Streptococcus pneumoniae (S. pneumoniae) are encased in a sugar layer called the capsular polysaccharide (CPS). This layer is often essential for infections. In a ground-breaking discovery, features of the CPS that help the bacteria to colonize the human respiratory tract were identified. The research showed that the structures of the CPS capsule and its types of linkages and combinations matter greatly in allowing the bacteria to better attach and survive on the lining of the upper and lower human respiratory tracts.

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Discovery of a gene in multiple mammalian species could pave the way for a highly effective, reversible and non-hormonal male contraceptive for humans and animals. Researchers identified expression of the gene, Arrdc5, in the testicular tissue of mice, pigs, cattle and humans. When they knocked out the gene in mice, it created infertility only in the males, impacting their sperm count, movement and shape.

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For several years, a team of researchers used underwater microphones to listen for seals at the edge of the Antarctic. Their initial findings indicate that sea-ice retreat has had significant effects on the animals' behavior: when the ice disappears, areas normally full of vocalizations become very quiet.

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A species of ordinary gut bacteria that we all carry flourishes when the intestinal flora is knocked out by a course of antibiotics. Since the bacteria is naturally resistant to many antibiotics, it causes problems, particularly in healthcare settings. A study now shows how two molecular mechanisms can work together make the bacterium extra resistant.

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The dreaded tick-borne encephalitis (TBE) virus infects different types of brain cells in different parts of the brain, depending on whether the affected person's immune system is activated or not.

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Insect pollination is a decisive process for the survival and evolution of angiosperm (flowering) plants and, to a lesser extent, gymnosperms (without visible flower or fruit). There is a growing interest in studies on the origins of the relationship between insects and plants, especially in the current context of the progressive decline of pollinating insects on a global scale and its impact on food production. Pollinating insects can be recognized in the fossil record, although to date, there has been no protocol for their differentiation. Fossil pollinators have been found in both rock and amber deposits, and it is in rock deposits that the first evidence of plant pollination by insects is being studied across the globe. But how can we determine which was a true insect pollinator in the past?