The Physics of Double-Dutch
Mirella Bucci | Jun 20, 2004
If you were twirling double-dutch ropes and someone shook the ropes back and forth from the middle, you and your partner would be pulled together. These are the kinds of large-scale behaviors of cellular polymers that David Weitz studies at Harvard University.To measure the flexibility of actin, Weitz and his colleagues exploited the stiffness of scruin, a glue-like protein that holds the actin fibers together.1 In this scenario, "the joints are stiffer than the fibers, so the properties of the
Recycling the Energy of Waste
Sam Jaffe | Jun 20, 2004
Every resource carried onto a manned spaceship is precious, because it costs hundreds of dollars to lift each pound of material past Earth's surly bonds. Now that NASA is in the process of planning a trip to Mars that might take up to two years, no type of recycling can be overlooked. One thing that can provide three basic raw materials (water, energy, and fertilizer) needed for a long space journey: human waste.Most methods of recycling organic waste involve the production of methane, a flammab
Blocking Bitterness
Ricki Lewis | Jun 6, 2004
Drowning bitter-tasting pharmaceuticals in sweeteners or dispersing them into liposomes, microcapsules, or gums are standard ways to get people to swallow medications such as antibiotics, cold remedies, and ulcer medications. Cranbury, NJ-based Linguagen is developing a new approach using the signal transduction pathways that underlie taste: The company is screening libraries of small, natural molecules to be used as additives that would block the binding of bitter-tasting compounds before the b
Humor and Handedness
Mike May | Jun 6, 2004
When Seana Coulson, assistant professor of cognitive science, and her graduate student, Christopher Lovett, looked for a high-level language task to study brain responses in right- and left-handers, the investigators turned to humor. The University of California, San Diego, researchers recorded brainwaves in 16 righties and 16 lefties while they read jokes, such as "I still miss my ex-wife, but I am improving my aim"; or nonsequiturs, such as "I still miss my ex-wife, but I am improving my ego."
Seaweed's Role in Bioremediation
Silvia Sanides | May 23, 2004
It was during a walk along the coast that Ravi Naidu found the answer to his problem: "Seaweed! The idea just popped up." The ubiquitous and cheap plant material held the solution to his biore-mediation experiments DDT-contaminated soils. He and colleague Mallavarapu Megharaj of the University of South Australia found that sodium enhances bacteria's ability to degrade DDT in anaerobic environments. Throwing in some organic matter as fertilizer further accelerated the process. "Seaweed contains s
Marshalling Bio-IT in the Name of Preparedness
Myrna Watanabe | May 23, 2004
Discerning whether a biological threat comes from terrorism or an emerging infectious disease is one problem that researchers at the Courant Bioinformatics Group at New York University (NYU) want to solve. Bhubaneswar Mishra's multidisciplinary team has created a series of complex software programs that allow researchers who deal with intricate, real-world bioinformatics problems to develop their own algorithms. This allows them to use mathematics to solve real issues in biology.With one interac
A Tick-Slimming Secret
Karen Heyman | May 9, 2004
Reuben Kaufman and graduate student Brian Weiss have found that for females, the secret to staying slim is staying virginal. Fortunately for males, human and otherwise, this works only if you're a special type of tick. Kaufman and Weiss have isolated the engorgement factor protein (EF) in the semen of the tick family ixodidae; this protein inspires gluttony in inseminated females. They have dubbed it "voraxin," from the Latin vorare, to devour.Tick blood lust is ghastly: Some can consume up to 4
Economic Progress, Medical Regress
Maria Anderson | May 9, 2004
ACTIONS AND REACTIONS:©Wiley-Liss, IncBlood pressure of Samoan males, by age, in the 1979 and 1991–93 samples.Modernization has changed the Samoans' lifestyle, and their cardiovascular health as well. A study by Stephen McGarvey, director of Brown University's International Health Institute, and colleagues found that youngsters between the ages of 10 and 18 in American Samoa and independent Samoa had higher blood pressures in 1991–1993 than did the same age group in 1979; they a
Reading Eukaryotic Barcodes
Myrna Watanabe | Apr 25, 2004
If cereal can be barcoded, so can Daphnia or a butterfly, or a hummingbird, or any eukaryotes. A worldwide consortium of research organizations, led by the Smithsonian's National Museum of Natural History (NMNH), has begun a 2 1/2-year project with $669,000 in seed money from the Sloan Foundation, which they hope will lead to a relatively simple, fast, and cheap way of identifying eukaryotic organisms in the field.The point of the Barcode of Life Initiative, to be based at NMNH, is to sequence o
The Physics of Footwear
Caryn Evilia | Apr 25, 2004
Erica P. JohnsonTo bring scientific concepts into the mainstream, sometimes explaining popular culture helps. Inspired by TV's Sex and the City and its heroine, Carrie, who often wobbles around in designer shoes, Paul Stevenson at the UK-based Institute of Physics developed a formula to determine the maximum "safe" height for such footwear. Stevenson, of the University of Surrey, wanted to see just how high Carrie could go. "As you get up in a high heel," Stevenson says, "your base of support is
Mother Love and the Brain
Harvey Black | Apr 11, 2004
If you're looking for the source of mother love, you might consider the orbitofrontal cortex. A new study1 finds that this part of the brain, just above the eyes, is active when new mothers view pictures of infants; the activity increases, as measured by functional magnetic resonance imaging, when the women see pictures of their newborns. "This is evidence that positive emotional aspects of maternal attachment are reliably associated with this region of the brain," says lead author Jack Nitschke
Bone Loss Still a Problem for Astronauts
Harvey Black | Apr 11, 2004
While President George W. Bush waxes enthusiastically about astronauts further exploring space, the reality is that a major obstacle to an astronaut's health remains: bone loss in zero gravity.Despite an exercise program designed to counter bone loss, astronauts on the International Space Station showed as much degradation as did their counterparts one decade ago on the Soviet space station Mir,1 says a NASA-funded study.2 "Despite the passage of [time], this problem has not really been ameliora
Radical Findings in the Mountains
Silvia Sanides | Mar 28, 2004
When physicians examined members of a Swiss expedition to Mount Everest in the 1980s, they discovered widespread damage to the climbers' muscles. Mito-chondrial volume had decreased by 20% and there was evidence of cell deterioration in tissue samples. However, their guides, the indigenous Tibetan Sherpas, were not affected.Now a Swiss-Italian team has found that several antioxidant enzymes seem to shield the Tibetans from the insults of oxygen deficiency at high altitudes.1 "Hypoxia leads to th
Getting Water to the Desert, the Old-Fashioned Way
Elizabeth Bryant | Mar 28, 2004
Courtesy of William JamesThey may be the world's first example of technology transfer: ancient Persian irrigation systems known as qanats, whose use later spread as far east as Japan and as far west as Chile. Now, a new international qanat center based in Yazd, Iran, aims to revive the cultural heritage and use of these underground water channels. Still in limited existence in Oman and Syria, these systems are better known in Iran, where the center aims to repair and preserve approximately 2,500
Seeing the Whole Picture, and Then Some
Mirella Bucci | Mar 14, 2004
Courtesy of Jason KuslerA quarterback decides where to throw the football based on the field's layout and the players' positions on it. Scanning the field, he sees loads of images that help him make his split-second decisions. He actually views even more that he may not recall.René Marois of Vanderbilt University, Nashville, Tenn., and colleagues study the delicate balance between seeing, registering, and recalling images in the visual field. If images come faster than two per second, subje
Deducing the Brain's Evolution, Scale by Scale
Harvey Black | Mar 14, 2004
Courtesy of Allen ChartierDavid Crews' lab resembles an exotic pet store; there's not a mouse or rat in sight. This professor of integrative biology at the University of Texas, Austin, studies animals such as the inches-long whiptail lizard."I'm interested in the evolution of brain mechanisms involved in social and sexual behaviors," Crews says. "You have to have ancestral species." The lizard, Cnemidophorus uniparens, reproduces parthenogenetically, though it evolved from the still extant C. in
Nails and Hooves: Designed for Wear and Tears
Silvia Sanides | Mar 1, 2004
At first glance, it seems like a paper worthy of an Ig Nobel Prize. Roland Ennos, University of Manchester, has examined why fingernails, when nibbled or torn, tend to rip in a transverse direction, not longitudinally toward the nail bed.1 Using 3 mm-long snippets of undergraduates' nails, he found that it took twice the energy (6kJm-2) to cut them lengthwise as crosswise (3kJm-2). "And that's a good thing," he says. "Otherwise, we would be in agony throughout our lives, because every tear would
More Predators, Healthier Prey
Maria Anderson | Mar 1, 2004
Courtesy of Jon Eisenback, NemaPixA new mathematical model is turning the conventional notion of predator-prey relationships on its head. David Brown and colleagues at the University of California, Davis, have shown that prey populations can benefit from a high predator density.1Ecologists previously have shown that predators can have indirect positive effects on their prey through nutrient cycling and mineralization. Brown's group, however, modeled predators' direct positive effects on the prey
Sparkling Spirals: A Romantic Twist on DNA
Karen Heyman | Feb 15, 2004
Courtesy of CSHLWere you late getting that Valentine's Day gift? Not to fret: Buy double helix jewelry for your molecular biologist sweetheart. Cathy Cyphers Soref, a fundraiser for Cold Spring Harbor Laboratory (CSHL), says the double helix is "as universal a symbol as the heart." And it looks just as lovely in diamonds.Soref has opened a store to benefit CSHL, called DNA Stuff It sells DNA-themed items including jewelry and denim clothing that puns on "gene/jean." The
Among the Giants, Tiny Footprints
Silvia Sanides | Feb 15, 2004
Courtesy of Martin Lockey, University of ColoradoIt's a slab of rock, two-by-two feet square, which tells a 75-million-year-old story. Imprinted in one part is a footprint indentation (below the coin) of a tiny mammal and the impressions of a leaf; on another part are marks typically left by raindrops."It looks like the animal took cover underneath some type of leaf that protected the surface from raindrops," says Martin Lockley, University of Colorado, Denver, who discovered the fossilized trac