Antecedent search processes and the structure of text.

Kintsch and van Dijk (1978) assumed that when a reader encounters a reference to a concept no longer available in short-term memory, a search through long-term memory for the original concept is necessary. In the present study, subjects read passages that contained two possible antecedents: one appearing early in the passages and the other appearing relatively late. Reading time differences demonstrated that late antecedents are reinstated more quickly than early antecedents, which is in disagreement with predictions from several search models within the Kintsch and van Dijk framework. The best account of the reinstatement time differences assumes that text is represented as an integrated network accessed by a backward parallel search. Experiment 3 demonstrated that naming time, as used in the current studies, measures only current activation and is not sensitive to differences in long-term memory strength. Experiment 4 provided further support for the assumptions of a backward parallel-search model by showing that concepts appearing between an antecedent and the end of a passage are often accessed during the search for the antecedent. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Formal schooling for four-year-olds? No.

Examines the recent movement toward enrolling 4-yr-olds in academic programs. The research base and political forces that guided the direction of the movement are considered: remedial intervention programs for economically disadvantaged children, the need for change in decaying school programs, and the urgent need for increased day-care services. It is determined that the research base does not demonstrate that early schooling will be beneficial to middle-class children who constitute the majority of 4-yr-olds. It is suggested that early schooling may be an inappropriate solution to the current crisis in child care for working parents and that children's development may suffer if limited educational funds are expended on nonfunctional programs. Developmentally appropriate care programs carried out in school buildings by specialists in early childhood development are suggested as an alternative. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Design considerations for an automotive magnetorheological brake

In this paper, design considerations for building an automotive magnetorheological (MR) brake are discussed. The proposed brake consists of multiple rotating disks immersed in a MR fluid and an enclosed electromagnet. When current is applied to the electromagnet, the MR fluid solidifies as its yield stress varies as a function of the magnetic field applied. This controllable yield stress produces shear friction on the rotating disks, generating the braking torque. In this work, practical design criteria such as material selection, sealing, working surface area, viscous torque generation, applied current density, and MR fluid selection are considered to select a basic automotive MR brake configuration. Then, a finite element analysis is performed to analyze the resulting magnetic circuit and heat distribution within the MR brake configuration. This is followed by a multidisciplinary design optimization (MDO) procedure to obtain optimal design parameters that can generate the maximum braking torque in the brake. A prototype MR brake is then built and tested and the experimental results show a good correlation with the finite element simulation predictions. However, the braking torque generated is still far less than that of a conventional hydraulic brake, which indicates that a radical change in the basic brake configuration is required to build a feasible automotive MR brake.     

Phytochemical evaluation of essential oils, medicinal plants and their preparations

The central objectives of GLAS are (a) to study the associations between pathology--and related impairments and disability--on the one hand, and well-being and utilization of care among older people on the other, and (b) how these associations are affected by person-bound and environmental factors. The present paper describes the main research questions, the design and some preliminary results of GLAS. In addition, an explanatory model for well-being, derived from the theory of social-production functions (spf) is elaborated. Two major conclusions can be drawn from these results. (1) The hypotheses derived from spf are mainly supported by the results of several substudies of GLAS. (2) The cross-sectional analyses showed main effects of psychological attributes--independent of pathology and impairments--on disability and well-being; we hardly found any empirical support for the hypothesized moderating effects of psychological attributes on the associations between these concepts. We conclude with some suggestions for future research.     

Dispositional optimism and primary and secondary appraisal of a stressor: Controlling for confounding influences and relations to coping and psychological and physical adjustment.

Previous research has shown that dispositional optimism (M. E Scheier & C. S. Carver, 1985) is linked to both coping and adjustment but has failed to consider the potential influence of appraisals in the stress and coping process (R. S. Lazarus & S. Folkman, 1984). The present study examined the influence of optimism and appraisals on coping and psychological and physical adjustment in 726 college students. Results from correlational analyses indicated that stress-related appraisals were associated with optimism, coping, and adjustment. Comparative analyses further indicated that optimists (n?=?109) and pessimists (n?=?110) differed significantly in secondary (but not primary) appraisal, coping, and adjustment. In addition, optimism was found to add significant incremental validity in predicting adjustment, beyond what was accounted for by appraisals and coping. The implications of these findings for understanding the influence of dispositional optimism are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis of Vanadium Oxide Powders by Evaporative Decomposition of Solutions

Powders of the vanadium oxides V₂O₄, V₆O₁₃, and V₂O₅were produced by thermal decomposition of aqueous solutions of vanadyl sulfate hydrate in atmospheres of N₂, H₂mixed with N₂, or air. The composition of the oxide powder was determined by the reactor temperature and gas composition. Residual sulfur concentrations in powders produced by decomposition at 740°C were less than 1 at.%, and these powders consisted of hollow, roughly spherical aggregates of particles less than 1 μm in diameter.