In public imagination, the sabre-toothed cat Smilodon ranks alongside Tyrannosaurus rex as the ultimate killing machine. Powerfully built, with upper canines like knives, Smilodon was a fearsome predator of Ice-Age America's lost giants. For more than 150 years, scientists have debated how this iconic predator used its ferocious fangs to kill its prey. Results will certainly put in dent in Smilodon's reputation. The innovative computer modeling shows it had a decidedly wimpy bite.
Individuals who are more conscientious -- in other words, those with a tendency to be self-disciplined, scrupulous and purposeful -- appear less likely to develop Alzheimer's disease, according to a new report. Conscientiousness refers to a person's tendency to control impulses and be goal-directed, and is also known as will, work and dependability, according to background information in the article. This characteristic has been associated with a wide range of mental and physical disorders, disability and death, suggesting it may be important for maintaining overall health.
Physicists have found that magnetic particles suspended in water and subjected to an alternating magnetic field will form snake-shaped structures that can control the flow of the surrounding fluid. Current incarnations of the magnetic snake are a few centimeters long, but the team envisions much smaller versions as pumps to manipulate liquids on microscopic scales or precursors for next-generation magnetic recording media in future computers.
A new study suggests current guidelines for weight gain during pregnancy should be revised. Severely obese women should lose weight during pregnancy, while obese women who are pregnant should gain less weight than currently recommended, according to new research. The findings run counter to current recommendations developed by the Institute of Medicine in 1990 that suggest women should gain at least 15 pounds during pregnancy and places no upper limit on pregnancy weight gain.
Arctic sea ice during the 2007 melt season plummeted to the lowest levels since satellite measurements began in 1979. If ship and aircraft records from before the satellite era are taken into account, sea ice may have fallen by as much as 50 percent from the 1950s. The September rate of sea ice decline since 1979 is now more than 10 percent per decade, according to scientists.
Hair samples from naturally preserved child mummiesdiscovered at the world's highest archaeological site in the Andes have provided a startling insight into the lives of the children chosen for sacrifice. Researchers used DNA and stable isotope analysis to show how children as young as 6-years old were "fattened up"and taken on a pilgrimage to their death.
Astronomers are pointing to three nearby stars they say may hold "embryonic planets"-- a missing link in planet-formation theories. As scientists try to piece together how our own planet came to be, they look to the forming planets of other star systems for clues. But astronomers have been unable to find evidence for one of the key stages of planet development, a period early in the planet's formation when it is only as large as tiny Pluto.
A popular prostate cancer treatment called androgen deprivation therapy may encourage prostate cancer cells to produce a protein that makes them more likely to spread throughout the body, a new study suggests. This is a preliminary finding.
Using enzymes from E. coli bacteria, chemists and engineers have introduced a hundred-fold improvement in the precision of features imprinted to create microdevices such as labs-on-a-chip. The inkless microcontact printing technique can imprint details measuring close to 1 nanometer, or billionths of a meter.
Leptin, a hormone known mainly for regulating appetite control and energy metabolism, has been found to play a major role in islet cell growth and insulin secretion. This finding opens up new avenues for studying leptin and its role in islet cell biology, which may lead to new treatments for diabetes.
Comets are made of the most primitive stuff in the solar system. As hunks of rock and ice that never coalesced into more planets, they give researchers clues to the evolution of solar systems. So a chance encounter between spacecraft Ulysses and Comet McNaught's ion tail has scientists in marveling at a stroke of luck and some surprising data.
Older women who experience at leastone full-blown panic attack may have an increased risk of having a heart attack or stroke and an increased risk of death in the next five years according to a new report. Panic attacks involve the sudden development of fear, anxiety or extreme discomfort accompanied by four or more additional symptoms, according to background information in the article. They may occur sporadically or as part of an anxiety disorder, such as panic disorder, social anxiety disorder or phobias.
A new study not only has important findings for the future of California tiger salamanders, but also contradicts prevailing scientific thought about what happens when animal species interbreed. They found that more of the hybrid young survived in the wild than did young of the native or the introduced species -- quite a surprise, since animal hybrids are usually less fit than their parents ("hybrid vigor"is largely limited to plant crosses).
The latest common wisdom on carbohydrates claims that eating so-called "bad"carbohydrates will make you fat, but University of Virginia professor Glenn Gaesser says, "that's just nonsense."Eating sandwiches with white bread, or an occasional doughnut, isn't going to kill you, or necessarily even lead to obesity, he said.
