| The Effect of Our Surroundings on Body Weight Obesity is a “global epidemic,” according to the World Health Organization. Two thirds of American adults and one third of school-age children are either overweight or obese (defined as extremely overweight). These proportions have been rising steeply, report the latest surveys. From 1960 to 2002 the population of overweight and obese adults increased by roughly 50 percent, and the corresponding increase for children was 300 percent. Compounding the problem, obesity rates in other countries are rapidly approaching those in the U.S.What is causing this pandemic, and what can we do about it? Researchers have provided some tentative answers that fly in the face of commonly held beliefs. They suggest that the increase in obesity may be a result of environmental changes that tempt us into unhealthy habits and tend to overwhelm our psychological defenses against consuming too much and succumbing to fattening fare. In fact, environmental cues can exacerbate any innate tendency to use food as a balm for jittery nerves or sadness. Thus, many health experts advocate legislation--for instance, a tax on junk food--that promotes healthy eating. Others are trying to help individuals change their immediate eating milieu in ways that discourage overeating. [More] rss.sciam.com |
Newspapers Worldwide Call For Climate Change Action It’s like the publishing version of one of those scenes from a sci-fi movie where an alien invasion impels traditional adversaries to join together to face their larger, common threat. Today 56 newspapers, in Pakistan and India, in Israel and Lebanon, in Tawian and China, in Greece and Turkey, in Africa and in North, South and Central America are publishing an unprecedented joint editorial calling for meaningful action to face the threat posed by climate change. The editorial, published in 45 countries in 20 different languages, appears on this first day of the Copenhagen climate conference. The British paper the Guardian led the effort, which involved weeks of negotiations to reach a final version.The editorial notes that “the science is complex but the facts are clear. The world needs to take steps to limit temperature rises to 2 degrees C...a bigger rise of 3 to 4 degrees C would parch continents, turning farmland into desert. Half of all species could become extinct, untold millions of people would be displaced, whole nations drowned by the sea. The controversy over emails by British researchers that suggest they tried to suppress inconvenient data has muddied the waters but failed to dent the mass of evidence on which these predictions are based.” [More] rss.sciam.com |
Evolution of Minerals (preview) Once upon a time there were no minerals anywhere in the cosmos. No solids of any kind could have formed, much less survived, in the superheated maelstrom following the big bang. It took half a million years before the first atoms--hydrogen, helium and a bit of lithium--emerged from the cauldron of creation. Millions more years passed while gravity coaxed these primordial gases into the first nebulas and then collapsed the nebulas into the first hot, dense, incandescent stars.Only then, when some giant stars exploded to become the first supernovas, were all the other chemical elements synthesized and blasted into space. Only then, in the expanding, cooling gaseous stellar envelopes, could the first solid pieces of minerals have formed. But even then, most of the elements and their compounds were too rare and dispersed, or too volatile, to exist as anything but sporadic atoms and molecules among the newly minted gas and dust. By not forming crystals, with distinct chemical compositions and atoms organized in an orderly array of repeating units, such disordered material fails to qualify as minerals. [More] rss.sciam.com |
Bloomberg Weighs Smoking Ban in Parks Mayor Michael R. Bloomberg said the ban made sense because it would cut the health risks of secondhand smoke and reduce littering by smokers. nytimes.com |
What is stormwater runoff and why does it matter? Editor's Note: Expedition Blue Planet , led by Jacques Cousteau's granddaughter Alexandra Cousteau, is traveling 14,500 miles of road over 138 days to investigate and film some of North America's most pressing water-use and management stories. Expedition members will file dispatchs from the field for Scientific American until the expedition concludes on November 12 in Washington, D.C. This is their fourth blog post. Right from the start of our expedition, stormwater runoff has held center stage when it comes to water quality issues. It's a constant refrain: Tell us about the water quality issues that this watershed faces? Answer: Stormwater runoff. [More] rss.sciam.com |