NASA seeks quiet supersonic flight
WASHINGTON, Jan. 26 (UPI) -- The U.S. space agency says it has conducted a series of flight tests that might help produce quieter supersonic aircraft.
The National Aeronautics and Space Administration said the tests measured shock waves generated by an F-15 jet to validate computer models that could be used in designing commercial aircraft that can fly faster than the speed of sound without generating loud sonic booms over land. Supersonic flights over land generally are prohibited because of such loud noises.
"A sonic boom is created by shock waves that form on the front and rear of an aircraft (with) the boom loudness related to the strength of the shock waves," NASA said. "The formation of the shock waves is dependent on the aircraft geometry and the way in which the wing generates lift."
During the flight tests one of two F-15s generally followed 100 feet to 500 feet below and behind the other, measuring the strength of the leading aircraft's shock waves at various distances using special instruments.
The tests were the latest in a series of NASA projects investigating effects of aircraft geometry and lift on the strength of shock waves.
New diabetic retinopathy therapy possible
BOSTON, Jan. 26 (UPI) -- U.S. scientists say they've developed a new therapy that may be effective in treating diabetic retinopathy -- a common eye-related complication of diabetes.
Researchers from the Joslin Diabetes Center in Boston and ActiveSite Pharmaceuticals Inc. in San Francisco say they've demonstrated a specific inhibitor of the protease plasma kallikrein -- ASP-440, developed by ActiveSite Pharmaceuticals -- might provide such a new therapeutic approach.
Led by Harvard University Associate Professor Edward Feener, the researchers discovered continuous systemic administration of ASP-440 proved effective in decreasing hypertension-induced increased retinal vascular permeability in rodents by as much as 70 percent. The scientists said increased retinal vascular permeability is a primary cause of diabetic macular edema, a leading cause of visual impairment associated with diabetes.
ASP-440 was also found to be effective in lowering the elevated blood pressure in the animals.
"These findings represent a pivotal step towards understanding the importance of plasma kallikrein as a target in diabetic eye disease and how its inhibition may support the development of a safe and effective therapy for diabetic retinopathy," said Barbara Araneo, director of complications research for the Juvenile Diabetes Research Foundation.
The research is reported in the February issue of the journal Hypertension.
Boat propels itself using water's energy
PITTSBURGH, Jan. 26 (UPI) -- U.S. scientists say they've designed a "mini boat" that propels itself by harnessing energy contained in the water's surface.
University of Pittsburgh researchers said the technique destabilizes the surface tension surrounding the boat with an electric pulse and causes the craft to move using the surface's natural pull.
Professor Sung Kwon Cho, who led the research, said the method offers an efficient and low-maintenance mechanism for small robots and boats that monitor water quality in oceans, reservoirs and other bodies of water. Such devices are currently propeller-driven, but the Pitt system has no moving parts and the low-energy electrode that emits the pulse could be powered by batteries, radio waves or solar power, Cho said.
Cho and doctoral students Sang Kug Chung and Kyungjoo Ryu presented their findings Monday in Sorrento, Italy, during the Institute of Electrical and Electronics Engineers' 2009 Micro Electro Mechanical Systems conference.
Scientists study developing chicken hearts
COLUMBIA, Mo., Jan. 26 (UPI) -- U.S. medical researchers are examining developing hearts in chickens in an effort to find solutions for human heart abnormalities
Since little is known about the complex processes that regulate the heartbeat, University of Missouri Assistant Professor Luis Polo-Parada and his team examined embryonic chickens' hearts, which develop morphologically and functionally similarly to humans' hearts, and tested the electrical activity present in the cardiac muscle cells during a 24-hour period. They found changes in local proteins have important effects on embryonic heart beat control.
"Electrical activity in the heart appears in very early stages of development," said Polo-Parada. "This study determined the role of the heart micro-environment in regulating electrical activity in cardiac cells that are required for normal cardiac function. Understanding exactly how a heart is made and how it begins to function will allow us to significantly improve therapies for a wide range of cardiac anomalies, injuries and diseases such as hypertension, cardiac fibrosis, cardiac hypertrophy and congestive heart failure."
The research has been accepted for publication in the journal Developmental Dynamics.
