Ultrasonic determination of the superconducting energy gap in high-purity tantalum

Ultrasonic attenuation measurements as a function of temperature were made for sound propagating along the [100], [110], and [111] crystal directions of Ta single-crystal specimens. Sound frequencies from 180 to 500 MHz were used with single crystals having residual resistance ratios up to 3866. For the three propagation directions used, the superconducting energy gap had an average value of 1.77kT _c , which was within the experimental error for the three separate values of the gap parameter.     

Complement activation in vivo in cancer patients receiving C. parvum immunotherapy

Serum complement levels were assayed in 26 patients with disseminated cancer, who received immunotherapy with infusion of C. parvum. Complement activation, indicated by the consumption of C3 or C4 or both, was found in 46% of the patients. Serum samples showed direct correlation between decreased C3 and conversion of C3 proactivator, whereas such conversion did not occur when C4 alone was decreased. It is concluded that the bypass (properdin) pathway was activated in patients in whom C3 consumption was detected, while the classical (C1) pathway was activated in the patients with C4 consumption unaccompanied by C3 decrease. Direct correlation was observed between delayed cutaneous hypersensitivity reactions to recall antigens and the incidence of C. parvum-associated complement activation.     

Software accessibility standards and guidelines: progress, current status, and future developments

This article reviews progress in the development of standards and guidelines for software accessibility, including those developed within international and US standards bodies. Key factors driving efforts to identify and define effective design guidelines for software accessibility include demographic trends and the graying population, new legislation and the increasing pervasiveness of information technology and devices. An overview of the US Software Accessibility draft standard, including accessibility-focused design guidance for Interactive Voice Response (IVR) systems, is provided. A variety of resources providing design guidance for improved accessibility are identified, and expected developments in formal standards for software accessibility are discussed.     

Sex and ethnic differences in the use of power.

Hypothesized that women and Chicanos would make less internal and more external attributions for their own successful performance than would Anglo males. 40 Chicano male, 40 Chicano female, 40 Anglo male, and 40 Anglo female undergraduates participated as managers in an industrial simulation study. Ss were randomly assigned to 1 of 4 experimental conditions: designated powers vs unspecified powers, and supervision of male or female workers. Following the managerial task, Ss completed a questionnaire assessing their own performance and that of their workers. All Anglos devalued their workers as a function of controlling power and attributed workers' performance to external factors. All Ss tended to use their power to persuade workers. Males attempted to influence workers to a greater degree than did females. The predicted sex differences in terms of attribution were evident only among Anglos. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Robust strategies for diagnosing manufacturing defects

We describe several strategies used by expert troubleshooters performing a manufacturing screening task, the diagnosis of defects on a computer board. These strategies use "inexact models" of the components and connections on the board. A prototype expert system has been implemented that uses the strategies and models. The strategies and models are robust because they are applicable to a wide range of problems, including problems not previously encountered. The system saves useful data acquired during problem solving to assist in future problems. We also describe how the above strategies and models can be used in a sensorbased system that acquires information about the board through a vision camera and other sensing devices. This will further increase the productivity of human troubleshooters.