Hydrogen-Atom Transfer Reactions of Transition-Metal Hydrides

Many reactions of transition-metal hydrides involve H* transfer. With olefins such transfer gives a radical cage, from which escape and collapse lead to product formation. Inverse isotope effects, second-order kinetics independent of ligand concentration, and CIDNP are diagnostic for this mechanism. Many other reactions of transition-metal hydrides occur by radical chain mechanisms, in which H* is abstracted by carbon-centered radicals or by metal radicals. Reasonably accurate values are now available for the M-H bond strengths of most of the common hydrides, and these values help rationalize the known H* transfer reactions of these hydrides. While the rates of certain H* transfer reactions have been measured by radical clock methods, the measurement of H* transfer rates to a substituted trityl radical has provided the first general comparison of the H* donor abilities of the various hydrides. These relative H* transfer rates are significantly affected by steric factors.     

MIL-STD-1679, weapon system software development

This article presents an overview and discussion of MIL-STD-1679 which is a Department of Defense tool to aid in contracting for the development of software. This Standard addresses the minimum set of contract requirements for the total software development process. Basically, it consolidates in one document many of the currently accepted software engineering practices and procedures. Although its use is required in the U.S. Navy, 1679 is approved for use by all other agencies within the DoD. MIL-STD-1679, which is becoming more and more an integral component of the solicitation/proposal/contract process, is appropriate for projects of most any size, including moderately small ones. Its fundamental concept of only specifying the minimum set of requirements for all projects enables this wide degree of applicability. By this same token, MIL-STD-1679 is equally applicable to all of DoD's different types of system developments, as well as for commercial and business applications. The computer program documentation scheme to be used in the project does not limit the applicability of either. Like most all of the other DoD standards, MIL-STD-1679 has its roots in and has as its primary goal improved software maintainability.     

Alcohol Expectancy Multiaxial Assessment: A Memory Network-Based Approach.

Despite several decades of activity, alcohol expectancy research has yet to merge measurement approaches with developing memory theory. This article offers an expectancy assessment approach built on a conceptualization of expectancy as an information processing network. The authors began with multidimensional scaling models of expectancy space, which served as heuristics to suggest confirmatory factor analytic dimensional models for entry into covariance structure predictive models. It is argued that this approach permits a relatively thorough assessment of the broad range of potential expectancy dimensions in a format that is very flexible in terms of instrument length and specificity versus breadth of focus. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning Game-Specific Spatially-Oriented Heuristics

This paper describes an architecture that begins with enough general knowledge to play any board game as a novice, and then shifts its decision-making emphasis to learned, game-specific, spatially-oriented heuristics. From its playing experience, it acquires game-specific knowledge about both patterns and spatial concepts. The latter are proceduralized as learned, spatially-oriented heuristics. These heuristics represent a new level of feature aggregation that effectively focuses the program's attention. While training against an external expert, the program integrates these heuristics robustly. After training it exhibits both a new emphasis on spatially-oriented play and the ability to respond to novel situations in a spatially-oriented manner. This significantly improves performance against a variety of opponents. In addition, we address the issue of context on pattern learning. The procedures described here move toward learning spatially-oriented heuristics for autonomous programs in other spatial domains.     

Recent Changes in U.S. Food and Drug Law: Implications for Drug Development

This paper examines in detail the Waxman/Hatch Act and the NDA Rewrite, from both an implementation point of view and from a world-wide research and development perspective. The central theme of these regulatory changes appears to be consistent with U.S. drug policy of the past two decades, i.e., cost containment, primarily, followed by uniformity and efficiency in the regulatory review process. These recent changes, just as the 1962 Drug Ammendments 22 years earlier, will continue to have profound effects upon the sites at which pharmaceutical research and development is carried out.     

A comparison of self-esteem lability and low trait self-esteem as vulnerability factors for depression.

Self-esteem lability (SEL), defined as daily event-related variability in state self-esteem, and low trait self-esteem (TSE) were assessed among 205 male and female undergraduates who were currently depressed, previously depressed (PD), and never depressed (ND). SEL scores were derived for the effect of positive, negative, and combined events on state self-esteem over 30 days. Consistent with psychodynamic and cognitive theories, SEL was found to be a better index of depression proneness than TSE. PD Ss showed higher lability on all SEL scores than ND controls but did not differ from controls on TSE. Ss were reassessed 5 mo later, and new cases showed higher premorbid SEL than ND controls but did not differ from controls on premorbid TSE. SEL at Time 1 was found to increase risk for depression at Time 2 among Ss reporting high life stress at Time 2. Theoretical and methodological implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use and appropriateness in cheese choice, and an evaluation of attributes influencing appropriateness

In recent years the variety of cheeses available on the UK market has increased dramatically, the range available widening to meet consumer demand. However, the relationships between intended use and appropriateness of cheeses and other factors determining choice have received little attention. Using the repertory grid method, appropriateness of a range of cheeses was examined. This methodology also facilitated study of attributes, related to intended use, providing insights into characteristics influencing perceptions of appropriateness. Eight significant Use Factors discriminated between cheeses in terms of appropriateness for different uses, with textural and melting properties being major determinants of appropriateness. A range of Cheddar cheeses, the most popular UK variety, also differed in appropriateness.