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111.
Prendergast Michael L.; Urada Darren; Podus Deborah 《Canadian Metallurgical Quarterly》2001,69(3):389
A meta-analysis was conducted on studies using a treatment-comparison group design to evaluate HIV/AIDS risk-reduction interventions for clients enrolled in drug abuse treatment programs. Overall, the interventions studied were found to have a reliable positive (weighted) effect size (d?=?0.31), and this was unlikely to be due to publication bias. Effect sizes for specific categories of outcome variables were 0.31 for knowledge, attitudes, and beliefs; 0.26 for sexual behavior; 0.62 for risk-reduction skills; and 0.04 for injection practices. A number of potential moderators were examined. Effect sizes were negatively correlated with the presence of predominantly ethnic minority samples and positively correlated with the number of intervention techniques used, the intensity of the intervention, intervention delivery at a later stage of drug treatment or within methadone treatment, and the presence of a number of specific intervention techniques. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
112.
Huck U. William; Lisk Robert D.; Parente Eric J.; Principato Deborah E. 《Canadian Metallurgical Quarterly》1986,100(2):128
Four studies with golden hamsters investigated females' acceptance of multiple mating partners. Findings show that females that mated only with a single, recently mated male ran a high risk of pseudopregnancy or reduced litter size. Females paired with males that had mated to satiety 30 min, 8 hrs, or 24 hrs earlier showed a reduced willingness to engage in lordosis than did females paired with a sexually rested (2 wks) male. Females paired with recently mated males were also more likely to mate with additional (fresh) males than were females exposed to rested males. Females presented with 2 anesthetized stimulus males readily discriminated between sexually rested and recently mated individuals. Neither prior sexual experience nor recent copulatory activity was required for this discrimination. It is suggested that multiple-male mating (promiscuity) in female hamsters may be an adaptation against an infertile mating as a consequence of mating with a single, recently mated, sperm-depleted male. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
113.
This paper describes a flow-through toxicity testing system utilizing a new exposure chamber designed for microscopic organisms. Typically, flow-through testing is conducted with either a serial or proportional diluting system. While generally relying on gravity to drive water flow, as different amounts of toxicant and diluent are combined in glass or plexiglass mixing cells, they are almost always open to the surrounding atmosphere. In contrast, the system described here is based on a simple exposure design utilizing premixed stocks representing each exposure concentration. While the system is entirely closed to the surrounding atmosphere, for testing of volatile organic mixtures in addition to nonvolatile inorganic toxicants, the delivery manifold may be aerated for toxicants of low volatility and high BOD. The system incorporates flexible Teflon gas sampling bags for stock preparation and storage (thus avoiding need for a headspace), and digital unified-drive peristaltic pumps for controlled toxicant delivery. To reduce surface partitioning of toxicants, all system components are constructed of chemically inert materials (Teflon, glass and silicone). 相似文献
114.
Hamilton David L.; Grubb Paul D.; Acorn Deborah A.; Trolier Tina K.; Carpenter Sandra 《Canadian Metallurgical Quarterly》1990,59(5):891
Compared the processing and retrieval of attribution-relevant information when the attributional inference is easy or difficult to make. Ss attributed behavioral events to the person or to the situation, based on several items of context information. Each context sentence implied either the person or the entity as causal agent. When the attributional inference was difficult to make (an equal number of context sentences implied actor and entity as the causal agent), Ss recalled more of the behavioral events, recalled more context sentences, and were less confident in their attributions than when the attributional inference was easy to make (most context sentences implied the same causal agent). Ss also recalled context information that was implicationally incongruent with the majority of the other context sentences with a higher probability than when that same information was implicationally congruent. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
115.
The differences between urban and rural streams regarding hydrological process, channel morphodynamics and ecosystem functioning have been highlighted by a number of studies in recent decades. The need to understand lotic ecosystem functioning in these environments at scales relevant to individual organisms has led to research focusing on hydraulic composition and structure over small areas of channel bed. In this study we map and analyze the hydraulic biotope composition of two urban and two rural stream reaches in the North Carolina (USA) Piedmont to determine if urban flow regimes and attendant channel modification processes might translate into important differences in hydraulic environment, and if so, what those differences are. Hydraulic biotope assemblages were found to vary only moderately in diversity per unit stream length between sites, but were distinctly different in composition. One important control on the differences between rural and urban streams was found to be the localized incision of urban channels into bedrock and saprolite. Resistant rock outcrop in the beds of urban streams creates rapid and riffle biotopes and long stretches of upstream pool habitat by impoundment. Urban reaches were found to be more homogeneous than rural reaches in hydraulic composition and were dominated by pools. Rural reaches, characterized by copious sandy alluvium in the bed, were dominated by runs or glides. Quantitative differentiation of biotopes based on four hydraulic indices generally yields coherent associations, although these may vary in content. Comparisons between hydraulic and biotic diversities suggest relationships favoring biotic functional group aggregation over species richness‐based indices of diversity. Because the majority of published hydraulic diversity analyses are based on coarse‐bed streams, further study of hydraulic diversity in streams with finer substrate is likely to be beneficial. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
116.
A cell-free preparation has been obtained from Saccharomyces cerevisiae which will synthesize ethyl acetate from ethanol and acetyl-CoA. Ethyl acetate synthesizing activity is stimulated by magnesium ions, the optimal concentration being 8 mM. Subcellular fractionation indicates that the enzyme is associated with material sedimenting at 105 000g . 相似文献
117.
Pritchard Robert D.; Harrell Melissa M.; DiazGranados Deborah; Guzman Melissa J. 《Canadian Metallurgical Quarterly》2008,93(3):540
Meta-analytic procedures were used to examine data from 83 field studies of the Productivity Measurement and Enhancement System (ProMES). The article expands the evidence on effectiveness of the intervention, examines where it has been successful, and explores moderators related to its success. Four research questions were explored and results indicate that (a) ProMES results in large improvements in productivity; (b) these effects last over time, in some cases years; (c) the intervention results in productivity improvements in many different types of settings (i.e., type of organization, type of work, type of worker, country); and (d) moderator variables are related to the degree of productivity improvement. These moderator variables include how closely the study followed the original ProMES methodology, the quality of feedback given, whether changes were made in the feedback system, the degree of interdependence of the work group, and centralization of the organization. Implications based on these findings are discussed for future use of this intervention, and the system is discussed as an example for evidence-based management. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
118.
Deborah M. Vernon Janet Rankin Christine Caragianis-Broadbridge Bruce L. Laube 《Journal of the American Ceramic Society》1999,82(11):2969-2977
A novel processing procedure for significantly suppressing grain growth in submicrometer alumina compacts has been developed and implemented with the intent of ultimately using the same processing route to control grain size in nanophase alumina compacts. In this study, partially sintered alumina pellets made from 0.5 µm starting powders are altered by the chemical infiltration of Si3 N4 . The control and infiltrated pellets are then heated to 1650°C for 4 h. The fully sintered pellets are approximately 97% dense. Suppressed grain growth is observed in the infiltrated pellets. The average grain size in the control pellets after densification is 4.2 and 1.2 µm in the infiltrated pellets. Depth of infiltration is measured using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Depending on the specific infiltration conditions used, the outer 15-50% of the infiltrated pellets exhibit a graded microstructure consisting of a region of abnormal grain growth and a region of suppressed grain growth. Abnormal grain growth is visible on the outer surfaces of the infiltrated pellets where a relatively high ratio of Si to N is present. Further into the pellet, after some depletion of the Si source gas has occurred, regions of suppressed grain growth are apparent. Based on these results, an infiltration profile is determined. A mathematical model is developed to describe the infiltration process and to determine optimal infiltration conditions. High-resolution electron microscopy (HREM), energy dispersive spectroscopy (EDS), electron energy loss spectroscopy (EELS), and X-ray photoelectron spectroscopy (XPS) are used to study the infiltrated samples. 相似文献
119.
Ganster Daniel C.; Fox Marilyn L.; Dwyer Deborah J. 《Canadian Metallurgical Quarterly》2001,86(5):954
The authors tested the ability of stressful demands and personal control in the workplace to predict employees' subsequent health care costs in a sample of 105 full-time nurses. Both subjective and objective measures of workload demands interacted with personal control perceptions in predicting the cumulative health care costs over the ensuing 5-year period. Tonic elevations in salivary cortisol, moreover, mediated the effects of demands and control on health care costs. Neither the job demands variables nor physiological reactivity measures, however, explained subsequent mental health. The results support findings from the epidemiological literature that demonstrate an important role for employees' control in explaining occupational inequalities in coronary heart disease and mortality. The authors argue that the results also encourage control-enhancing job design interventions by suggesting that their outcomes can benefit both organizations and their members. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
120.
Kenny David A.; Mannetti Lucia; Pierro Antonio; Livi Stefano; Kashy Deborah A. 《Canadian Metallurgical Quarterly》2002,83(1):126
The authors elaborate the complications and the opportunities inherent in the statistical analysis of small-group data. They begin by discussing nonindependence of group members' scores and then consider standard methods for the analysis of small-group data and determine that these methods do not take into account this nonindependence. A new method is proposed that uses multilevel modeling and allows for negative nonindependence and mutual influence. Finally, the complications of interactions, different group sizes, and differential effects are considered. The authors strongly urge that the analysis model of data from small-group studies should mirror the psychological processes that generate those data. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献