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排序方式: 共有1298条查询结果,搜索用时 31 毫秒
71.
McAuley Edward; Morris Katherine S.; Motl Robert W.; Hu Liang; Konopack James F.; Elavsky Steriani 《Canadian Metallurgical Quarterly》2007,26(3):375
Objective: To examine the contribution of social-cognitive factors (self-efficacy and affect) in predicting long-term physical activity in a sample of older adults (N = 174). Design: A prospective design assessed physical activity and psychosocial variables at 2 and 5 years following a 6-month randomized, controlled exercise trial. Main Outcome Measures: The primary outcome variable was self-reported physical activity, with previous behavior, self-efficacy, and affect assessed as determinants of physical activity. Results: Covariance modeling analyses indicated that physical activity at Year 2 was the strongest predictor of physical activity at 5-year follow-up. Both self-efficacy and affect at Year 2 were also associated with physical activity at Year 5, as was original treatment condition. Variables accounted for 35% of the variance in Year 5 activity. Conclusion: Older adults with higher levels of physical activity, more positive affect, and higher self-efficacy at Year 2 were more likely to continue to be active at Year 5. This study is one of the longest follow-ups of exercise behavior in older adults and has implications for structuring environments to maximize the maintenance of physical activity. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
72.
Jaleh Mansouri Chris A. Wood Katherine Roberts Yi-Bing Cheng Robert P. Burford 《Journal of Materials Science》2007,42(15):6046-6055
Glass frits were added into silicone-based composites with the aim to improve low temperature ceramification at elevated temperatures.
The effect of glass frits on the properties of ceramic residue is investigated. Field emission scanning electron microscopy
(FESEM), electron probe microchemical analysis (EPMA) and X-ray diffraction analysis (XRD) showed that glass frits reacted
via a eutectic reaction with mica and silica. Electrical conductivity measurements at elevated temperatures showed a decline
in volume resistivity with glass frit addition. It was concluded that increased conductivity is a result of ionic conduction
of the glass phase produced by eutectic reactions between frits, silica and mica at high temperatures. Thermal mechanical
analysis (TMA) was used to explore the dimensional changes of these composites during programmed heat treatment. 相似文献
73.
Philip J. Murray Bart Cornelissen Katherine A. Vallis S. Jon Chapman 《Journal of the Royal Society Interface》2016,13(114)
DNA double-strand breaks (DSBs) are formed as a result of genotoxic insults, such as exogenous ionizing radiation, and are among the most serious types of DNA damage. One of the earliest molecular responses following DSB formation is the phosphorylation of the histone H2AX, giving rise to γH2AX. Many copies of γH2AX are generated at DSBs and can be detected in vitro as foci using well-established immuno-histochemical methods. It has previously been shown that anti-γH2AX antibodies, modified by the addition of the cell-penetrating peptide TAT and a fluorescent or radionuclide label, can be used to visualize and quantify DSBs in vivo. Moreover, when labelled with a high amount of the short-range, Auger electron-emitting radioisotope, 111In, the amount of DNA damage within a cell can be increased, leading to cell death. In this report, we develop a mathematical model that describes how molecular processes at individual sites of DNA damage give rise to quantifiable foci. Equations that describe stochastic mean behaviours at individual DSB sites are derived and parametrized using population-scale, time-series measurements from two different cancer cell lines. The model is used to examine two case studies in which the introduction of an antibody (anti-γH2AX-TAT) that targets a key component in the DSB repair pathway influences system behaviour. We investigate: (i) how the interaction between anti-γH2AX-TAT and γH2AX effects the kinetics of H2AX phosphorylation and DSB repair and (ii) model behaviour when the anti-γH2AX antibody is labelled with Auger electron-emitting 111In and can thus instigate additional DNA damage. This work supports the conclusion that DSB kinetics are largely unaffected by the introduction of the anti-γH2AX antibody, a result that has been validated experimentally, and hence the hypothesis that the use of anti-γH2AX antibody to quantify DSBs does not violate the image tracer principle. Moreover, it provides a novel model of DNA damage accumulation in the presence of Auger electron-emitting 111In that is supported qualitatively by the available experimental data. 相似文献
74.
A series of quaternized-chitosan derivatives (QCDs) with various degrees of quaternization was synthesized using glycidyltrimethylammonium chloride as a main quaternized reagent. These QCDs were then processed into hydroxide—form quaternary ammonium salts with aqueous potassium hydroxide solutions. The resultant hydroxide—form QCD gels were further crosslinked into anion-exchange membranes using ethylene glycol diglycidyl ether. The crosslinking density, crystallinity, swelling index, ion exchange capacity, ionic conductivity and thermal stability of the crosslinked membranes were subsequently investigated. It was found that properties of crosslinked membranes were modulated mainly by the degree of quaternization and crosslinking density of membranes. Some membranes exhibited promising characteristics and had the potential for applications in alkaline polymer electrolyte fuel cells in considering their integrative properties. 相似文献
75.
As a media genre, advertising offers a unique opportunity to study how the beauty ideal is constructed across cultures. This research analyzes the content of advertisements from women's fashion and beauty magazines in Singapore, Taiwan, and the U.S. to compare how beauty is encoded and found a noticeable difference between the portrayals of women from the U.S. and from the two East Asian societies in terms of sexual portrayal. In addition, Asian ads contained a large proportion of cosmetics and facial beauty products whereas the U.S. ads were dominated by clothing. These findings suggest that beauty in the U.S. may be constructed more in terms of "the body," whereas in Singapore and Taiwan the defining factor is more related to a pretty face. The article also discusses how feminist critiques of the sexual objectification of women in advertising may need to be considered within their historical, Western context of origin. 相似文献
76.
This study examined marital conflict's indirect effects on children through disruptions in family alliances and parenting. Forty married couples were observed interacting with their 6–8-year-old sons after pleasant and conflictual discussions. After conflictual discussion, fathers showed lower support/engagement toward sons, and coparenting styles were less democratic. Couple negativity was correlated with family negativity, regardless of the topic of discussion, which suggests continuity in the affective quality of the two family subsystems. Mothers' marital satisfaction moderated families' responses to the experimental manipulation. The results provide stronger evidence than previously available of a causal link between conflict and disrupted parenting. Further research is needed to identify which conflict-related disruptions in parenting influence the development of children's problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
77.
ABET Engineering Criteria 2000 require a selection of outcomes and outcome indicators for each educational objective adopted by an engineering program. This paper describes a database created using Microsoft Access 97 © linking choices of program outcomes and choices of program outcome indicators for all of the accredited engineering programs in an academic institution. With this database, benchmarking searches can be conducted by type of engineering program, by choice of outcome, or by choice of outcome indicator. Several example searches are presented using data describing the engineering programs at Clemson University. A web-site address is given where copies of the Clemson database can be downloaded. 相似文献
78.
We examine employees’ perceptions of communication problems in the workplace and their active communication behavioral responses when multiple information communication technologies (ICTs) are available for use. Through the lens of the situational theory of publics, we shed light on how employees adapt to increasing communication demands. We uncovered active technology-mediated behavior such as information gaining, action, and social interaction seeking, and their association with perceived risk (i.e., message, information and action). Findings suggest that technology-mediated communication behaviors are not only enabled by the use of ICTs but behavior also involves appropriate structuring of single and multiple ICTs to manage problems encountered during communication. 相似文献
79.
Asymmetric switch cost, observed when switching between tasks varying in difficulty, shows that the difference between repeat and switch trials is greater when switching to the easier task. Early explanations of this effect attributed this pattern to both positive priming of the difficult task and negative priming of the easier task, but more recent models have focused only on activation processes. The role of inhibition in asymmetric switch cost was examined using backward inhibition, a more direct measure of task-set inhibition. The results indicated asymmetric backward inhibition, with greater sequential inhibition of the easier task (i.e., easy-difficult-easy sequences). Switch costs, however, showed both typical and reversed asymmetry (greater cost when switching from the easy to the difficult task), depending on the relative difficulty of task pairs. This pattern of results indicates that switch costs are attributable to both activation and inhibition processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
80.
Trahan Donald E.; Goethe Katherine E.; Larrabee Glenn J. 《Canadian Metallurgical Quarterly》1989,3(2):81
Provided a normative data base for a measure of verbal supraspan based on 301 neurologically intact adults (aged 18–91 yrs) and examined the test's clinical sensitivity in 3 patient groups. Data from 55 patients with severe head trauma, 38 with right hemisphere and cerebrovascular accident (CVA), and 15 with left hemisphere CVA reveal significant age-related differences, with older Ss performing below levels obtained by younger ones. Group data reveal that Ss in all 3 groups performed significantly below levels obtained by age-matched controls. Supraspan scores did not correlate appreciably with years of education. However, scores on the supraspan test correlated modestly with Wechsler Adult Intelligence Scale—Revised (WAIS—R) Information and Block Design scores, suggesting that task performance may be dependent in part on the S's general level of cognitive functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献