| EPA Draft Greenhouse Gas Rule Focuses on Large Emitters U.S. EPA has sent a draft rule to the White House that could limit regulations on greenhouse gas emissions to cover only very large industrial sources.The agency yesterday submitted a rule to the White House Office of Management and Budget that experts say will likely limit strict permitting requirements to industrial sources of more than 25,000 tons a year of carbon dioxide equivalent. [More] rss.sciam.com |
Pollution's Toll on the Brain In these days of hybrid cars and carbon credits, it is common knowledge that substances exhaled by autos and coal plants are harmful to our respiratory system. What may be surprising is the degree to which they may harm the brain--in some instances, as much as exposure to lead. A recent string of studies from all over the world suggests that common air pollutants such as black carbon, particulate matter and ozone can negatively affect vocabulary, reaction times and even overall intelligence.The most recent of these studies found that New York City five-year-olds who were exposed to higher levels of urban air pollutants known as polycyclic aromatic hydrocarbons (PAH) while in the womb exhibited an IQ four points lower than those subjected to less PAH. Alarmingly, “the drop was similar to that seen in exposure to low levels of lead,” says epidemiologist Frederica Perera, director of the Columbia Center for Children’s Environ­mental Health and head author of the study, in which mothers wore personal air monitors during their pregnancy. The IQ change was enough of a dip to affect school per­formance and scores on standardized tests. [More] rss.sciam.com |
Bacteria Transformed into Biofuel Refineries The bacteria responsible for most cases of food poisoning in the U.S. has been turned into an efficient biological factory to make chemicals , medicines and, now, fuels. Chemical engineer Jay Keasling of the University of California, Berkeley, and his colleagues have manipulated the genetic code of Escherichia coli , a common gut bacteria, so that it can chew up plant-derived sugar to produce diesel and other hydrocarbons, according to results published in the January 28 issue of Nature . ( Scientific American is part of Nature Publishing Group.) [More] rss.sciam.com |
Human Uniqueness and the Future What is human uniqueness, and how did it contribute to what we could now call behavioral modernity? How did it develop? And what implications does it have for understanding our present and future? This past February the Origins Project that I direct at Arizona State University helped to convene an interesting meeting of paleontologists, anthropologists, primatologists, evolutionary biologists, geneticists, archaeologists and psychologists to attempt to address such questions, among others.I began the meeting by pointing out that when some people heard about its subject, they had asked me what was so unique about humans? Surely all animals are unique in their own way, and although we have special traits, so do bees and giraffes. But as my A.S.U. colleague Kim Hill has put it, “Even before the invention of agriculture, human communities may have eventually numbered around 70 million individuals ... as Homo sapiens spread over the planet more broadly than any other large vertebrate. No creature on earth lives in cohesive social units that rival this complexity or biomass.” [More] rss.sciam.com |
The World at Our Fingertips: The Connection Between Touch and Learning (preview) One evening while one of us (Colosi) was making dinner, her six-year-old daughter, Gianna, appeared with 10 little pieces of paper in her hand. She had been doing her homework, she said, and each of the scraps contained one of the words she was supposed to learn. When her mother asked why Gianna had torn apart her spelling list, she shrugged: “So I can do stuff with it.” For Gianna, abstract concepts became easier to understand after she had transformed them into physical objects--in this case, pieces of paper she could hold, feel and manipulate.The connection between touch and understanding is deeply instinc­tual, beginning in infancy and continuing, in varying forms, throughout our lives. Experiments have found that touch is as important as vision for learning and retaining information. Studies also show that tactile activities such as playing with blocks help children improve everything from their math abilities to their thinking skills. We are knowledge architects, building intellectual edifices through physical experiences. [More] Abstraction - Education - Learning - Physical body - Math rss.sciam.com |