ScienceDaily: Top Science News

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• Infertility is a warning: Poor semen quality linked to hypertension, other health problems
• Swarms of Pluto-size objects kick up dust around adolescent Sun-like star
• Scientists measure speedy electrons in silicon
• Cells can use dynamic patterns to pluck signals from noise
• Genes tell story of birdsong and human speech
• March of the penguin genomes
• Big Bang' of bird evolution mapped
• Biologists map crocodilian genomes
• Human DNA shows traces of 40 million-year battle for survival between primate and pathogen
• 3-d maps of folded genome: Catalog of 10,000 loops reveals new form of genetic regulation
• How birds get by without external ears
• Researchers detect possible signal from dark matter
• Story of bizarre deep-sea bone worm takes unexpected twist: Evolutionary reversal previously unseen in animal kingdom
• Relationship between personality, health: Study sheds new light on link
• Gut microbiota and Parkinson’s disease: Connection made
• Knees: Meniscus regenerated with 3-D-printed implant
• New drug proves effective against antibiotic-resistant 'superbugs'
• Blocking receptor in brain's immune cells counters Alzheimer's in mice

Infertility is a warning: Poor semen quality linked to hypertension, other health problems Posted: 11 Dec 2014 03:18 PM PST A study of men who were evaluated for the cause of their infertility finds previously unknown relationships between deficiencies in their semen and other, seemingly unrelated health problems.

Swarms of Pluto-size objects kick up dust around adolescent Sun-like star Posted: 11 Dec 2014 01:25 PM PST Astronomers may have detected the dusty hallmarks of an entire family of Pluto-size objects swarming around an adolescent version of our own Sun. By making detailed observations of the protoplanetary disk surrounding the star known as HD 107146, the astronomers detected an unexpected increase in the concentration of millimeter-size dust grains in the disk's outer reaches. This surprising increase, which begins remarkably far -- about 13 billion kilometers -- from the host star, may be the result of Pluto-size planetesimals stirring up the region, causing smaller objects to collide and blast themselves apart.

Scientists measure speedy electrons in silicon Posted: 11 Dec 2014 11:24 AM PST Attosecond lasers provide the shortest light pulses yet, allowing observation of nature's most short-lived events. Researchers have used these lasers for the first time to take snapshots of electrons jumping from silicon atoms into the conduction band of a semiconductor, the key event behind the transistor. They clocked the jump at 450 attoseconds and saw the rebound of the crystal lattice 60 femtoseconds later: a delay 120 times longer than the jump itself.

Cells can use dynamic patterns to pluck signals from noise Posted: 11 Dec 2014 11:24 AM PST Scientists have discovered a general principle for how cells could accurately transmit chemical signals despite high levels of noise in the system.

Genes tell story of birdsong and human speech Posted: 11 Dec 2014 11:24 AM PST A massive international effort to sequence and compare the entire genomes of 48 species of birds, representing every major order of the bird family tree, reveals that vocal learning evolved twice or maybe three times among songbirds, parrots and hummingbirds. Even more striking, the set of genes employed in each of those song innovations is remarkably similar to the genes involved in human speaking ability.

March of the penguin genomes Posted: 11 Dec 2014 11:24 AM PST Two penguin genomes have been sequenced and analyzed for the first time. The study reveals insights into how these birds have been able to adapt to the cold and hostile Antarctic environment.

Big Bang' of bird evolution mapped Posted: 11 Dec 2014 11:21 AM PST The first findings of the Avian Phylogenomics Consortium are being reported nearly simultaneously in 29 papers -- eight papers in a Dec. 12 special issue of Science and 21 more in Genome Biology, GigaScience and other journals. The analyses suggest some remarkable new ideas about bird evolution, including insights into vocal learning and the brain, colored plumage, sex chromosomes and the birds' relationship to dinosaurs and crocodiles.

Biologists map crocodilian genomes Posted: 11 Dec 2014 11:18 AM PST Understanding the crocodilian genome can help scientists better understand birds. The DNA in alligators, crocodiles and gharials is about 93 percent identical across the genome. By comparison, a human shares about 93 percent of his or her DNA with a macaque.

Human DNA shows traces of 40 million-year battle for survival between primate and pathogen Posted: 11 Dec 2014 11:18 AM PST Examination of DNA from 21 primate species – from squirrel monkeys to humans – exposes an evolutionary war against infectious bacteria over iron that circulates in the host's bloodstream. Supported by experimental evidence, these findings demonstrate the vital importance of an increasingly appreciated defensive strategy called nutritional immunity.

3-d maps of folded genome: Catalog of 10,000 loops reveals new form of genetic regulation Posted: 11 Dec 2014 09:44 AM PST  In a triumph for cell biology, researchers have assembled the first high-resolution, 3D maps of entire folded genomes and found a structural basis for gene regulation -- a kind of "genomic origami" that allows the same genome to produce different types of cells.

How birds get by without external ears Posted: 11 Dec 2014 08:57 AM PST Unlike mammals, birds have no external ears. The outer ears have an important function: they help the animal identify sounds coming from different elevations. But birds are also able to perceive whether the source of a sound is above them, below them, or at the same level. Now a research team has discovered that birds are able to localize these sounds by utilizing their entire head.

Researchers detect possible signal from dark matter Posted: 11 Dec 2014 08:55 AM PST Scientists have picked up an atypical photon emission in X-rays coming from space, and say it could be evidence for the existence of a particle of dark matter. If confirmed, it could open up new perspectives in cosmology.

Story of bizarre deep-sea bone worm takes unexpected twist: Evolutionary reversal previously unseen in animal kingdom Posted: 11 Dec 2014 07:18 AM PST The saga of the Osedax "bone-eating" worms began 12 years ago, with the first discovery of these deep-sea creatures that feast on the bones of dead animals. The Osedax story grew even stranger when researchers found that the large female worms contained harems of tiny dwarf males.

Relationship between personality, health: Study sheds new light on link Posted: 11 Dec 2014 06:06 AM PST New evidence has been found that explains how some aspects of our personality may affect our health and wellbeing, supporting long-observed associations between aspects of human character, physical health and longevity. But researchers ask: "Is this our biology determining our psychology or our psychology determining our biology?"

Gut microbiota and Parkinson’s disease: Connection made Posted: 11 Dec 2014 05:11 AM PST Parkinson's disease sufferers have a different microbiota in their intestines than their healthy counterparts, according to a study.  Researchers are now trying to determine what the connection between intestinal microbes and Parkinson's disease is.

Knees: Meniscus regenerated with 3-D-printed implant Posted: 10 Dec 2014 02:13 PM PST Researchers have devised a way to replace the knee's protective lining, called the meniscus, using a personalized 3D-printed implant, or scaffold, infused with human growth factors that prompt the body to regenerate the lining on its own. The therapy, successfully tested in sheep, could provide the first effective and long-lasting repair of damaged menisci, which occur in millions of Americans each year and can lead to debilitating arthritis.

New drug proves effective against antibiotic-resistant 'superbugs' Posted: 10 Dec 2014 05:07 AM PST A new treatment is far more effective than traditional antibiotics at inhibiting the growth of drug-resistant bacteria, including so-called 'superbugs' resistant to almost all existing antibiotics, which plague hospitals and nursing homes. The findings provide a needed boost to the field of antibiotic development, which has been limited in the last four decades and outpaced by the rise of drug-resistant bacterial strains.

Blocking receptor in brain's immune cells counters Alzheimer's in mice Posted: 09 Dec 2014 05:21 AM PST The mass die-off of nerve cells in the brains of people with Alzheimer's disease may largely occur because an entirely different class of brain cells, called microglia, begin to fall down on the job, according to a new study.

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