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排序方式: 共有822条查询结果,搜索用时 15 毫秒
41.
Turrisi Rob; Mastroleo Nadine R.; Mallett Kimberly A.; Larimer Mary E.; Kilmer Jason R. 《Canadian Metallurgical Quarterly》2007,21(4):453
The present study used perspectives from the general literature on college alcohol consumption to examine mediational influences of peer, environmental, and parental variables on heavy drinking for student athlete and nonathlete samples. Eight hundred thirty-five freshmen who differed in organized sports involvement were compared on heavy drinking outcomes, peer norms, environmental influences, and parental communication. College athletes reported significantly more heavy drinking experiences than nonathletes. Peer norms, environmental influences, and parental communication were all significant mediators of the athlete-heavy drinking relationship. Athletes reported a higher perception of peer drinking, peer approval of drinking, higher alcohol availability, and direct drink offers, which, in turn, were related to higher rates of heavy drinking. Parental communication mediated the athlete-heavy drinking relationship differently, depending on the specific topic of conversation. Discussion surrounding the importance of incorporating a variety of interventions aimed at reducing collegiate athlete drinking on the basis of the peer, environmental, and parental influences observed in the present analyses are presented. Limitations and directions for future research are also noted. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
42.
Chi-Won In Jin-Yeon Kim Kimberly E. Kurtis Laurence J. Jacobs 《NDT & E International》2009,42(7):610-617
This research examines the application of ultrasonic Rayleigh surface waves to the non-destructive evaluation (NDE) of asphaltic concrete in the frequency range 40–100 kHz. Two ultrasonic parameters, the phase velocity and amplitude attenuation, are considered to be sensitive to local compositional and structural variations and are measured. A wedge technique is used to generate Rayleigh surface waves in an asphaltic concrete beam with uniformly distributed aggregate, and this technique is shown to be effective in launching Rayleigh waves in this highly viscoelastic (absorptive) and heterogeneous medium. Three different ultrasonic detection setups using contact and non-contact transducers as receivers are examined and their results are compared. The experimental results show that the wedge generation technique along with an air-coupled receiving transducer with a finite-size aperture is the most reliable for characterizing Rayleigh waves in asphaltic concrete. It is also experimentally demonstrated that the proposed setup may be used to detect aggregate segregation in asphaltic concrete. 相似文献
43.
44.
Cokley Kevin O.; Tran Kimberly; Hall-Clark Brittany; Chapman Collette; Bessa Luana; Finley Angela; Martinez Michael 《Canadian Metallurgical Quarterly》2010,3(3):187
[Correction Notice: An erratum for this article was reported in Vol 4(3) of Journal of Diversity in Higher Education (see record 2011-16523-001). There are two errors in Table 2 under the RWA heading and the Cog-gender heading. The necessary changes are provided in the erratum.] [Correction Notice: An erratum for this article was reported in Journal of Diversity in Higher Education on August 1 2011 (see record 2011-16523-001). There are two errors in Table 2. Under the RWA heading, the SDO row should have indicated a positive correlation of .266**, not -.266**. Under the Cog-gender heading, the SDO row should have indicated a negative correlation of -.438**, not .438**.] Factors related to attitudes about racial diversity and gender equity were examined in an ethnically diverse sample of 432 college students (167 European Americans, 83 African Americans, 81 Asian Americans, and 82 Hispanic Americans). In addition to variables of self-interest (i.e., ethnicity, gender, and political views), social ideology (i.e., social dominance orientation, right-wing authoritarianism) and personality traits (openness to experience) were uniquely predictive of attitudes about racial diversity and gender equity. Hierarchical regressions revealed that social dominance orientation most strongly predicted racial attitudes, while right-wing authoritarianism most strongly predicted gender attitudes. Implications for diversity education efforts related to prejudice reduction are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
45.
Laura M. Russell Kimberly Y. Donaldson D. P. H. Hasselman Robert Ruh † Jane W. Adams ‡ 《Journal of the American Ceramic Society》1996,79(10):2767-2770
The thermal diffusivity of mullite-ZrO2 -SiCw materials was determined from 25° to 1000°C for composites in which the ZrO2 had different amounts of monoclinic and tetragonal phase, and varying SiC w content. At 25°C the thermal diffusivity of the matrix materials increased with increasing amounts of monoclinic phase, and little or no anisotropy was seen. Composites with SiC w additions showed significant increases in thermal diffusivity and anisotropy as compared with the matrix materials. With increasing temperature, thermal diffusivities of the matrices and their respective composites decreased, and at 1000°C differences were small. Specific heat was determined from 25° to 700°C and thermal conductivity values calculated. Specific heat increased with temperature and was not composition dependent, except for one sample. Thermal conductivity values as a function of temperature followed the same trends as the thermal diffusivity values. 相似文献
46.
Zifan Gong Mary T. Doolin Sayanee Adhikari Kimberly M. Stroka Amy J. Karlsson 《American Institute of Chemical Engineers》2019,65(12):e16768
Although the interactions of cell-penetrating peptides (CPPs) with mammalian cells have been widely studied, much less is known about their interactions with fungal cells. To study how the properties of CPPs affect translocation into fungal cells, we designed variants of the peptides pVEC and SynB with altered levels of charge and hydrophobicity and evaluated the translocation of the variants into the important human fungal pathogen Candida albicans. Charge played a greater role in translocation efficacy of the peptides than hydrophobicity, with a higher net positive charge leading to higher level of translocation into C. albicans and a higher level of cytosolic localization. Hydrophobicity had little effect on translocation efficacy, but a low level of hydrophobicity did lead to increased vacuolar localization and an energy-dependent translocation mechanism. Our results suggest that CPPs can be designed for desired levels of cargo delivery into fungal cells and for desired translocation mechanisms. 相似文献
47.
Joel L. Ramirez Greg J. Zahner Kimberly A. Spaulding Sukaynah A. Khetani Nancy K. Hills Warren J. Gasper William S. Harris Beth E. Cohen S. Marlene Grenon 《Lipids》2019,54(4):211-219
Population-based data suggest that individuals who consume large dietary amounts of n-3 polyunsaturated fatty acids (PUFA) have lower odds of peripheral artery disease (PAD); however, clinical studies examining n-3 PUFA levels in patients with PAD are sparse. The objective of this study is to compare erythrocyte membrane fatty acid (FA) content between patients with PAD and controls. We conducted a cross-sectional study of 179 vascular surgery outpatients (controls, 34; PAD, 145). A blood sample was drawn and the erythrocyte FA content was assayed using capillary gas chromatography. We calculated the ratio of the n-3 PUFA eicosapentaenoic acid (EPA) to the n-6 PUFA arachidonic acid (ARA) as well as the omega-3 index (O3I), a measure of erythrocyte content of the n-3 PUFA, EPA, and docosahexaenoic acid (DHA), expressed as a percentage of total erythrocyte FA. Compared with controls, patients with PAD smoked more and were more likely to have hypertension and hyperlipidemia (p < 0.05). Patients with PAD had a lower mean O3I (5.0 ± 1.7% vs 6.0 ± 1.6%, p < 0.001) and EPA:ARA ratio (0.04 ± 0.02 vs 0.05 ± 0.05, p < 0.001), but greater mean total saturated fats (39.5 ± 2.5% vs 38.5 ± 2.6%, p = 0.01). After adjusting for several patient characteristics, comorbidities, and medications, an absolute decrease of 1% in the O3I was associated with 39% greater odds of PAD (odds ratio [OR] 1.39, 95% confidence interval [CI] 1.03–1.86, and p = 0.03). PAD was associated with a deficiency of erythrocyte n-3 PUFA, a lower EPA:ARA ratio, and greater mean total saturated fats. These alterations in FA content may be involved in the pathogenesis or development of poor outcomes in PAD. 相似文献
48.
Substrate age and precipitation effects on Hawaiian forest canopies from spaceborne imaging spectroscopy 总被引:1,自引:0,他引:1
Gregory P. Asner Kimberly M. Carlson Roberta E. Martin 《Remote sensing of environment》2005,98(4):457-467
We used spaceborne imaging spectroscopy provided by the Earth Observing-1 Hyperion sensor to quantify the relative importance of precipitation and substrate age that control ecosystem development and functioning in Metrosideros polymorpha rainforests of Hawaii. Four hyperspectral vegetation indices provided metrics of forest canopy structure, biochemistry and physiology to compare along gradients of annual rainfall (750 to > 6000 mm year− 1) and substrate age (0 to 250,000 years). The canopy greenness index NDVI increased with annual precipitation and substrate age, but saturated in forests with rainfall of 3000 mm year− 1. Precipitation and substrate age were roughly equal contributors to the observed greenness of the forests. A canopy water content index (NDWI) also increased with precipitation and substrate age, but did not reach a maximum until very wet (> 5000 mm year− 1) forest conditions were encountered on the oldest substrates. The water index appears superior to the NDVI in capturing spatial and climate-substrate driven variations in canopy structure. The photochemical reflectance index (PRI) indicated highest light-use efficiency levels in canopies on the most developed substrates and at annual precipitation levels of 3-4500 mm year− 1. A leaf carotenoid index (CRI) suggested a maximum canopy photosynthetic capacity at ∼ 4000 mm rainfall year− 1 on the oldest substrates. These results quantify the sensitivity of rainforest canopies to changing precipitation and soil conditions, and they corroborate plot-scale analyses in native Hawaiian forests ecosystems. Structural and functional studies of remote rainforest regions are possible with spaceborne imaging spectroscopy, and could be used to understand the dynamics of rainforests with climate change. 相似文献
49.
In 2 experiments, separate groups of rats were given stimulus conditioning, temporal conditioning, untreated control and (in Experiment 2) learned irrelevance control procedures followed by a compound with both stimulus and temporal cues. Stimulus conditioning consisted of a random 15-s duration conditioned stimulus (CS) followed by food; temporal conditioning consisted of food–food intervals of fixed 90 s (Experiment 1) or fixed 75?+?random 15 s (Experiment 2). The stimulus group abruptly increased responding after CS onset, and the temporal group gradually increased responding over the food–food interval. When the food–food interval was fixed 90 s, the temporal cue exerted stronger control in the compound, whereas when the food–food interval was fixed 75?+?random 15 s, the stimulus cue exerted stronger control. The strength of conditioning, temporal gradients of responding, and cue competition effects appear to reflect simultaneous timing of multiple intervals. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
50.
Rudman Laurie A.; Dohn Matthew C.; Fairchild Kimberly 《Canadian Metallurgical Quarterly》2007,93(5):798
Four experiments demonstrated implicit self-esteem compensation (ISEC) in response to threats involving gender identity (Experiment 1), implicit racism (Experiment 2), and social rejection (Experiments 3-4). Under conditions in which people might be expected to suffer a blow to self-worth, they instead showed high scores on 2 implicit self-esteem measures. There was no comparable effect on explicit self-esteem. However, ISEC was eliminated following self-affirmation (Experiment 3). Furthermore, threat manipulations increased automatic intergroup bias, but ISEC mediated these relationships (Experiments 2-3). Thus, a process that serves as damage control for the self may have negative social consequences. Finally, pretest anxiety mediated the relationship between threat and ISEC (Experiment 3), whereas ISEC negatively predicted anxiety among high-threat participants (Experiment 4), suggesting that ISEC may function to regulate anxiety. The implications of these findings for automatic emotion regulation, intergroup bias, and implicit self-esteem measures are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献