Science News
clock | April 4, 2007Sleep Quantity Affects Morning Testosterone Levels In Older Men
The testosterone levels of healthy men decline as they get older. As sleep quality and quantity typically decrease with age, objectively measured differences in the amount of sleep a healthy older man gets can affect his level of testosterone in the morning, according to a study published in the April 1st issue of the journal SLEEP.
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"The results of the study raise the possibility that older men who obtain less actual sleep during the night have lower blood testosterone levels in the morning," said Penev. "Although…
clock | April 3, 2007The Eyes Have It! How Box Jellyfish Avoid Banging Into Things:
Box jellyfish are much more active swimmers than other jellyfish -- they exhibit strong directional swimming, are able to perform rapid 180 degree turns, and can deftly move in between objects. So how do they manage to manoeuvre the obstacle course that is in the sea bed?
Bats Get The Munchies Too!:
Many of us will be familiar with cravings for sweet food, after having overindulged in alcohol the night before. It appears that Egyptian fruit bats also crave particular types of sugar to reduce the effects of ethanol toxicity.…
clock | March 30, 2007In today's issue of Science, there is a study showing that hunting of sharks, by eliminating the main predator of rays, leads to a decline in the ray's - and ours - food: the scallops:
A team of Canadian and American ecologists, led by world-renowned fisheries biologist Ransom Myers at Dalhousie University, has found that overfishing the largest predatory sharks, such as the bull, great white, dusky, and hammerhead sharks, along the Atlantic Coast of the United States has led to an explosion of their ray, skate, and small shark prey species.
"With fewer sharks around, the species they prey…
clock | March 30, 2007Overfishing Large Sharks Impacts Entire Marine Ecosystem, Shrinks Shellfish Supply:
Fewer big sharks in the oceans mean that bay scallops and other shellfish may be harder to find at the market, according to an article in the March 30 issue of the journal Science, tying two unlikely links in the food web to the same fate.
Dinosaur Extinction Didn't Cause The Rise Of Present-day Mammals, Claim Researchers:
A new, complete 'tree of life' tracing the history of all 4,500 mammals on Earth shows that they did not diversify as a result of the death of the dinosaurs, says new research published in…
clock | March 29, 2007Ewwwww! UCLA Anthropologist Studies Evolution's Disgusting Side:
Behind every wave of disgust that comes your way may be a biological imperative much greater than the urge to lose your lunch, according to a growing body of research by a UCLA anthropologist.
The Delayed Rise Of Present-day Mammals:
It took 10 to 15 million years after the dinosaurs were wiped out before modern mammals - including our ancient human ancestors - were able to diversify and rise to their present-day prominence across the globe, a landmark new study has found. The surprise finding overturns the widely held belief…
clock | March 28, 2007Migratory Birds: Innocent Scapegoats For The Dispersal Of The H5N1 Virus:
A review to be published shortly in the British Ornithologists' Union's journal, Ibis, critically examines the arguments concerning the role of migratory birds in the global dispersal of the highly pathogenic avian influenza virus H5N1. Ecologists of the Station Biologique de la Tour du Valat and of the GEMI-CNRS in the Camargue (France), Michel Gauthier-Clerc, Camille Lebarbenchon and Frédéric Thomas conclude that human commercial activities, particularly those associated with poultry, are the major factors that have…
clock | March 27, 2007Chimpanzee Facial Expressions Are Helping Researchers Understand Human Communication:
Behavioral researchers led by Lisa Parr, PhD, director of the Yerkes National Primate Research Center Cognitive Testing Facility and Chimpanzee Core, have found understanding chimpanzee facial expressions requires more attention to detail than researchers initially thought. Correctly interpreting the subtleties within chimpanzees' facial expressions may be key to understanding the evolution of human emotional communication.
Ladybugs May Be Cute, But Watch Out When They Get Near Wine:
Ladybugs may look pretty…
clock | March 26, 2007Salamanders Suffer Delayed Effects Of Common Herbicide:
Pollution from a common herbicide might be causing die-offs in stream salamanders, according to biologists who say findings from their long-term study raise concerns over the role of atrazine in global amphibian declines.
Experience Affects New Neuron Survival In Adult Brain; Study Sheds Light On Learning, Memory:
Experience in the early development of new neurons in specific brain regions affects their survival and activity in the adult brain, new research shows. How these new neurons store information about these experiences may…
clock | March 25, 2007Studying Snail Slime Substitutes:
A team of engineers have set a small robot climbing walls in order to compare how natural and artificial snail slimes work. A snail's slime acts as both a glue and a lubricant, allowing the snail to crawl up walls and across ceilings without falling off. The snail pushes until the structure of the glue breaks, at which point it glides forward. When the snail stops, the glue structure reforms - sticking the snail safely to the ceiling.
Changing Ocean Conditions Led To Decline In Alaska's Sea Lion Population:
A new study out of Alaska points out the impacts of…
clock | March 23, 2007Bird Sex Is Something Else:
We've all heard about the birds and the bees. But apparently when it comes to birds, they have an unusual take on his and hers -- and the difference is genetic. Species with differentiated sex chromosomes (X and Y in humans, for example) get around the fact that males and females get different-sized portions of sex chromosome genes with a balancing act geneticists call dosage compensation. But research published today in the Journal of Biology shows that birds are extraordinary, because some bird genomes can live with an apparent overdose of sex-related genes.
Why…
clock | March 22, 2007Is Bigger Better? Breast Surgery Linked To Boost In Self-esteem And Sexuality:
Women who undergo breast enlargement often see a sizable boost in self-esteem and positive feelings about their sexuality, a University of Florida nurse researcher reports.
Study Focuses On Wandering Minds:
Do your thoughts stray from your work or studies? Do you catch yourself making to-do lists when your attention should be elsewhere? Welcome to the club. College students reported mind-wandering almost one-third of the time in their daily lives, according to a new study led by faculty and graduate students at The…
clock | March 21, 2007Threatened Vulture Wanders Far From Mongolia:
Dr. Rich Reading (Denver Zoo) reports that a young cinereous vulture tagged in Mongolia as part of his Earthwatch-supported research was spotted 1200 miles away, near Pusan, South Korea. The vulture was tagged last August. Two other vultures were subsequently sighted in other parts of South Korea and one was seen in Heibei Province, China. Scientists have suspected that birds from Mongolia sometimes winter in Korea, but believe that their research provides the first documented confirmation.
Termites Get The Vibe On What Tastes Good:
Researchers…
clock | March 21, 2007Researchers Uncover Protection Mechanism Of Radiation-resistant Bacterium:
Results of a recent study titled "Protein Oxidation Implicated as the Primary Determinant of Bacterial Radioresistance," will be published in the March 20 edition of PLoS Biology. The study, headed by Michael J. Daly, Ph.D., associate professor at the Uniformed Services University of the Health Sciences (USU), Department of Pathology, shows that the ability of the bacterium Deinococcus radiodurans to endure and survive enormous levels of ionizing radiation (X-rays and gamma-rays) relies on a powerful mechanism that…
clock | March 20, 2007No Sex For 40 Million Years? No Problem:
A group of organisms that has never had sex in over 40 million years of existence has nevertheless managed to evolve into distinct species, says new research published today. The study challenges the assumption that sex is necessary for organisms to diversify and provides scientists with new insight into why species evolve in the first place.
The research, published in PLoS Biology, focuses on the study of bdelloid rotifers, microscopic aquatic animals that live in watery or occasionally wet habitats including ponds, rivers, soils, and on mosses and…
j7uy5 | March 20, 2007Not
only that, but the genetically modified "organism" is an engineered
HIV. At least, that is what researchers at Emory College in
London are contemplating.
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clock | March 20, 2007Crows Can Recognize The Calls Of Relatives:
Most of us would know our mother's voice on the phone from the first syllable uttered. A recent Cornell study suggests that crows also can recognize the voices of their relatives. By recording and analyzing the alarm caws of American crows, Jessica Yorzinski '05 found seven subtle acoustic differences in features that differed among individuals -- differences that the crows could potentially use to recognize one another's calls. She also found that female crows had higher-pitched calls than males. Yorzinski is now a graduate student at the…
clock | March 20, 2007Actually, no, he knows exactly where they went - and for a good reason:
Shooting Marbles At 16,000 Miles Per Hour:
NASA scientist Bill Cooke is shooting marbles and he's playing "keepsies." The prize won't be another player's marbles, but knowledge that will help keep astronauts safe when America returns to the Moon in the next decade. Cooke is firing quarter-inch diameter clear shooters - Pyrex glass, to be exact - at soil rather than at other marbles. And he has to use a new one on each round because every 16,000 mph (7 km/s) shot destroys his shooter.
evolgen | March 19, 2007Both Carl Zimmer and Larry Moran have posts on the gene content in the human genome. Carl points out that the estimate of the total number of genes in the human genome is decreasing, but we still don't know what a whole bunch of those genes do (according to the one database he searched). Larry's post deals with what he considers a misconception regarding the historical estimates of gene content in humans. He argues that, while the estimates of the number of protein coding genes have decreased over the years, they haven't really decreased as much as some people seem to think (from about 40,000…
clock | March 19, 2007New Bird Species Found In Idaho, Demonstrates Co-evolutionary Arms Race
One does not expect to discover a bird species new to science while wandering around the continental United States. Nor does one expect that such a species would provide much insight into how coevolutionary arms races promote speciation. On both fronts a paper to appear in The American Naturalist proves otherwise.
Julie Smith, now at Pacific Lutheran University, and her former graduate advisor, Craig Benkman at the University of Wyoming, have uncovered strong evidence that coevolution has led to the formation of a species…
clock | March 19, 2007Jurassic Crocodile Is Unearthed From Blue Mountains In Eastern Oregon:
An ancient sea-going crocodile has surfaced from the rocks of Crook County in eastern Oregon. Really. It's discovery by the North American Research Group (NARG), whose members were digging for Jurassic-age mollusks known as ammonites, is another confirmation that the Blue Mountains consist of rocks that traveled from somewhere in the Far East, says retired University of Oregon geologist William Orr, who was called in to examine the find for the state.