Citing national security interests, the U.S. Supreme Court ruled on November 12 that the Navy can once again conduct sonar training exercises, even if the tests harm marine life. The 5–4 decision overturns restrictions that require the Navy to stop using sonar when marine mammals are spotted within 2,200 yards of its vessels. The Navy uses sonar technology to send underwater sound waves at frequencies between 1 kHz and 10 kHz. Gauging the time it takes the acoustic waves to echo off an object — enemy submarines in a combat situation — provides a way to determine the distance to the ...

Some harmful strains of E. coli might rely on something sweet to do harm. (p. 15)

WASHINGTON — Treating HIV earlier can increase a patient’s survival chances, a new study of more than 8,000 HIV patients shows. The findings suggest doctors should rethink the standard practice of HIV treatment, a team reports at a meeting of microbiologists and infectious disease researchers. HIV depletes key immune cells called CD4 T cells. A patient’s T cell count, the concentration of CD4 cells still in circulation, is used to gauge how far the virus that causes AIDS has progressed and to determine when to treat a patient with the frontline drug cocktail for HIV. The standard benchm...

New findings suggest that nanotechnology paints for walls, ceilings and surfaces could one day be used to kill antibiotic-resistant bacteria in hospitals.