Eating with Tension
The long, thin beaks of shorebirds called phalaropes are no good at sucking up water and any tasty crustaceans within. Instead they rely on the attractive force of liquid known as surface tension to ferry prey upward. The birds first swim in small, fast circles on the surface of the water, creating a vortex that pulls creatures up within their reach. They next peck at the water and then rapidly open and close their beaks. This scissoring motion both pulls and squeezes droplets, about two millimeters in size, and moves them from the tip of their beaks into their mouths. In experiments with mechanical beaks, scientists at the Massachusetts Institute of Technology and the French National Center for Scientific Research find that the droplets do not move well if the water contains oil, detergents and other pollutants that alter water’s surface tension. Draw in the findings from the May 16 Science.
The fusion of tumor cells with white blood cells may be the secret behind how cancer spreads around the body. Such hybrids can combine white blood cells’ natural ability to migrate with cancer’s proclivity for uncontrolled cell division. The fusion theory was first proposed in the early 1900s. In research spanning 15 years, Yale University scientists merged white blood cells with tumor cells, leading to remarkably metastatic hybrids that were lethal when implanted into mice. They later found that such hybrids occur naturally in mice. In recent studies of cancer patients who received a bone marrow transplant, genes from the marrow’s white blood cells were found in the patient’s tumor cells. Such fusion might occur after white blood cells engulf tumor cells. By viewing this fusion as another disease imposed onto tumor cells, scientists could devise new therapies against metastasis, the researchers say in the May Nature Reviews Cancer.
A Milk-Diabetes Connection?
Some research has suggested formula containing cow’s milk protein could raise an infant’s risk of later acquiring type 1 diabetes. A new study by Marcia F. Goldfarb of Anatek-EP, a protein research laboratory in Portland, Me., posits a mechanism that may be at play. She notes that a newborn’s immature immune system may destroy the human protein glycodelin in a mistaken effort to eliminate the similar cow’s milk protein. This error could result in the overproduction of T cells, which help to protect the body against infections. The overproduction could attack the insulin-producing cells of the pancreas and trigger diabetes, she wrote in the June 6 Journal of Proteome Research of the American Chemical Society. A large, international randomized trial called TIGR now under way should help settle the question of cow’s milk and diabetes risk.
GINA Becomes Genuine
By late May, President George W. Bush was expected to have signed into law the Genetic Information Nondiscrimination Act (GINA), which will prohibit health insurers from canceling or denying coverage or hiking premiums based on a genetic predisposition to a specific disease. The legislation, which sailed through the House and Senate, also bars employers from using genetic data to hire, fire, promote or make other employment-related decisions.
The measure caps more than a decade of political wrangling: Representative Louise Slaughter of New York introduced the first genetic antidiscrimination legislation 13 years ago. In the past, genetic discrimination has played a role in preventing many Americans from obtaining work or seeking health treatments. In the 1970s, for instance, many African-Americans were denied jobs and insurance coverage because they carried a gene for sickle-cell anemia. Physicians now have access to at least 1,000 genetic tests that diagnose or assess the risk of developing potentially life-threatening diseases, including breast cancer, diabetes, heart disease and Parkinson’s.
After nearly 40 years, scientists have constructed a new addition to the stable of circuit elements (inductors, capacitors and resistors). Called the memristor, or memory resistor, it is a nanometer-scale electric switch that “remembers” whether it is on or off after its power is turned off. It might become a useful tool for constructing nonvolatile computer memory or for packing transistors together more densely to make smaller chips. A Hewlett-Packard team crafted the device by inserting a layer of titanium dioxide as thin as three nanometers between a pair of platinum layers.
Concerte Math Learning
Abstract examples are more effective than practical problems for teaching math concepts. Researchers at the Ohio State University taught one group of students a new mathematical system using symbols, such as circles and diamonds, and another group using scenarios, such as combining liquids in measuring cups. Students who learned using symbols scored 80 percent on a test requiring them to apply their knowledge in a novel situation; the others scored between 40 and 50 percent.
Although climate change will likely raise temperatures more in temperate and polar regions than in equatorial zones, tropical insects may suffer more than their counterparts in cooler climes. Used to thriving in a narrow temperature range, tropical insects may be more sensitive to shifts—they already live in conditions that verge on being too hot for them, a recent study finds. Insects in temperate areas, however, will probably thrive with an extra bit of warming.
Note: This story was originally published with the title, "News Scan Briefs".