A distributed suction i1igh-lift boundary layer control system fitted to a standard liaison L-19 aircraft incre~sed the aircraft c 1 max to 5.74 and decreased the take-off and landing distance over a 50-foot obstacle by 38 percent and 29 percent, respectively, with no increase in available power. The modified aircraft demonstrated acceptable stability, control, and handling characteristics in a...

The difference between the disease rates of two groups, one exposed and one not exposed to a suspected aetiological factor, is a useful measure of the risk associated with the factor. This measure is of most interest when the association is considered causal, and has been termed the attributable risk (MacMahon and Pugh, 1970). Expressed as a percentage of the total disease rate in a group (the ...

A "thrifty gene" may put some groups at risk for type 2 diabetes. More than 20.8 million Americans—7 percent of the population—have diabetes. The number continues to grow, driven mostly by an upsurge in obesity. From 1994 to 2004, diagnosed diabetes rose at least 50 percent in 23 states. In addition, an estimated 54 million U.S. adults have prediabetes—an elevated blood sugar level that is not ...

Insurers and policymakers encourage the use of generic drugs to reduce costs, but generics remain underused. We conducted a national survey of commercially insured adults to evaluate their perceptions about generic drugs. Patients agreed that generics are less expensive and a better value than brand-name drugs, and are just as safe. However, although 56 percent reported that Americans should us...

Karp and Lipton introduced advice-taking Turing machines to capture nonuniform complexity classes. We study this concept for automata-like models and compare it to other nonuniform models studied in connection with formal languages in the literature. Based on this we obtain complete separations of the classes of the Chomsky hierarchy relative to advices.