The Tao of traffic lights
When a traffic light goes green can seem to hinge on whimsy rather than the number of vehicles waiting. Scientists propose speeding up traffic by making signals go with the flow (SN: 10/23/10, p. 8). Inspired by the movement of crowds through narrow spaces such as doorways, Swiss and German researchers tried a responsive, flexible approach, rather than a top-down, centralized system. Their strategy puts two sensors at each intersection: One measures incoming flow and one measures outgoing flow. Lights are coordinated with every neighboring light, giving signals at ... (p. 23)
Credit: © Bettmann/Corbis
Gene therapy moves forward
Despite their promise, technologies to correct defective genes have been plagued by safety problems leading to unintended — and sometimes fatal — outcomes. But scientists are inching toward safer, more effective gene therapies that may one day treat a range of diseases, from psychiatric disorders to autoimmune diseases to cancers.
Studies in animals and isolated cells in the lab are showing promise. In mice, correcting gene function reverses depression-like behaviors (SN: 11/20/10, p. 14), blindness (SN: 7/17/10, p. 11) and ... (p. 24)
Credit: Michael Morgenstern
Lie detectors blend fact and fiction
Devices that can discern honest statements from lies are much sought after, especially since a 2003 National Research Council report concluded that traditional polygraphs flag stress, not deception. But newer gadgets increasingly used by police departments and other agencies don’t tell fact from fiction either, researchers now say (SN: 7/3/10, p. 28). Known collectively as voice stress analyzers, these next-gen lie detectors aim to tease out truth by reading consistent changes in speech that occur when someone is lyin... (p. 26)
Credit: Y. Haile-Selassie et al/PNAS 2010
Extreme makeover for Lucy’s kind
Recent fossil discoveries suggest that the early hominid species represented by the famous bones of Lucy, who lived 3.2 million years ago in Ethiopia, may have been more like modern humans than previously thought. The skeleton of a 3.6-million-year-old male of the same species, Australopithecus afarensis, shows that he had a nearly humanlike gait and ground-based lifestyle, says a team led by anthropologist Yohannes Haile-Selassie of the Cleveland Museum of Natural History. Dubbed Big Man, the male stood an ... (p. 27)
Credit: © Joe McNally/reconstruction by Kennis and Kennis
Gene sequencing for all, even Neandertals
An unprecedented picture of life’s diversity is emerging as researchers publish the full genetic instruction books of a growing list of species — including one that has been extinct for more than 30,000 years.
A project sequencing Neandertal DNA harvested from bones reveals evidence of prehistoric interbreeding between humans and Neandertals (SN: 6/5/10, p. 5). As for modern humans, scientists have compiled complete genetic profiles of Archbishop Desmond Tutu and a Bushman t... (p. 28)
Credit: Happy Little Nomad/Wikimedia Commons
Gimme an F
Chlorophyll, the pigment that makes the world go ’round, has come in four known flavors for more than 60 years: chlorophylls a, b, c and d. Now scientists have discovered another version of the pigment that allows plants and other photosynthesizing organisms to harness sunlight for making food and oxygen. Dubbed chlorophyll f, the new version is found in extracts of ground-up stromatolites — knobby chunks of rock and algae — collected in western Australia’s Shark Bay (SN: 9/11/10, p. 13).
Chlorophyll f absorbs light ... (p. 29)
Credit: Alvaro Ybarra Zavala/Getty Images
Inside the Haiti quake
Some 230,000 Haitians died when a magnitude-7 earthquake struck just outside Port-au-Prince on the afternoon of January 12. Scientists from around the world scrambled to the scene (SN Online: 1/16/10) to assess which fault had ruptured and whether more people were at risk. Early ideas held that the quake had broken along the well-known Enriquillo-Plantain Garden fault, which divides the Caribbean and North American tectonic plates. But U.S. Geological Survey scientists found no evidence of a large surface rupture there, ... (p. 30)
Fish oil packs a punch
Omega-3 fatty acids are turning up in plenty of promising reports, but some tests fail to show a benefit. Reported anti-inflammatory effects of the compound may help to shake out just how these nutrients boost health. High levels of omega-3s are found in fish oil from cold-water species and in walnut and flaxseed oils.Scientists report that people with sepsis, a lethal inflammatory overreaction triggered by a blood infection, fare better if they get fish oil rather than soybean oil (SN: 2/13/10, p. 14). Other researchers find that a... (p. 31)
Vaccine link to autism dismissed
In February, Lancet formally retracted a 1998 study that had kindled a storm of opposition to vaccines (SN Online: 2/3/10). The research suggested that autism arose in a handful of children after the kids received shots to prevent measles, mumps and rubella. The study's lead author committed several ethical breaches, and the selection of participants in the study may have been biased, the U.K. General Medical Council reported in January following an investigation. Following suit, Lancet retracted the paper, noting that "seve... (p. 32)
by An engaging history recounts how the Ball Brothers Co. went from making mason jars to building the Deep Impact spacecraft.
Earthview Media, 2010, 327 p., $24.95. (p. 34)