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21.
Shackelford Todd K.; Goetz Aaron T.; McKibbin William F.; Starratt Valerie G. 《Canadian Metallurgical Quarterly》2007,121(2):214
Sperm competition occurs when the sperm of multiple males concurrently occupy the reproductive tract of a female and compete to fertilize an egg. We used a questionnaire to investigate psychological responses to the risk of sperm competition for 237 men in committed, sexual relationships. As predicted, a man who spends a greater (relative to a man who spends a lesser) proportion of time apart from his partner since the couple's last copulation reported (a) greater sexual interest in his partner, (b) greater distress in response to his partner's sexual rejection, and (c) greater sexual persistence in response to his partner's sexual rejection. All effects were independent of total time since the couple's last copulation and the man's relationship satisfaction. Discussion addresses limitations of the current research and situates the current results within the broader comparative literature on adaptation to sperm competition. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Safron Adam; Barch Bennett; Bailey J. Michael; Gitelman Darren R.; Parrish Todd B.; Reber Paul J. 《Canadian Metallurgical Quarterly》2007,121(2):237
Men exhibit much higher levels of genital and subjective arousal to sexual stimuli containing their preferred sex than they do to stimuli containing only the nonpreferred sex. This study used event-related functional magnetic resonance imaging to investigate how this category-specific pattern would be reflected in the brains of homosexual (n = 11) and heterosexual (n = 11) men. Comparisons of activation to preferred sexual stimuli, nonpreferred sexual stimuli, and sports stimuli revealed large networks correlated with sexual arousal, spanning multiple cortical and subcortical areas. Both homosexual and heterosexual men exhibited category-specific arousal in brain activity. Within the amygdala, greater preference-related activity was observed in homosexual men, but it is unclear whether this is a cause or a consequence of their sexuality. In a subsequent analysis of regions hypothesized to support arousal, both participant groups demonstrated widespread increases in evoked activity for preferred stimuli. Aggregate data from these regions produced significant differences between stimulus types in 16 out of 22 participants. Significant activational differences matched reported sexual orientation in 15 of these 16 participants, representing an advance in psychophysiological measures of arousal. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
24.
The hedonic properties of delta-9-tetrahydrocannabinol (THC) were assessed in place and taste conditioning paradigms in both Lewis and Sprague-Dawley rat strains. THC produced place avoidance, taste avoidance, and aversive taste reactivity responses in both strains. The Lewis strain displayed more aversive taste reactions and a stronger taste avoidance when conditioned with lower doses of THC than did the Sprague-Dawley strain of rats. THC is an anomalous drug of abuse that appears to be aversive to rats when assessed by these measures. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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S Whitman L Lacey D Ansell EH Chen J Dell CW Phillips 《Canadian Metallurgical Quarterly》1993,22(3):393-397
Magnetic resonance imaging allows a noninvasive assessment of myelination during normal brain maturation as well as the detection of genetically determined and acquired diseases that affect the synthesis and maintenance of myelin. If this high sensitivity of magnetic resonance imaging for white matter changes is completed by adequate clinical and biochemical information, a unique diagnostic tool is available to gain new insights in the formation of myelin and pathogenesis of myelin disorders. 相似文献
27.
It is sometimes forgotten that industry is an important customer of engineering education. Ignoring this relationship has produced graduates that often fail to meet the changing needs of industry in today's competitive environment. On the basis of feedback from our industrial customers, faculty from Mechanical Engineering and Manufacturing Engineering at Brigham Young University have jointly developed a new senior capstone design course entitled “Integrated Product and Process Design.” This new capstone course is centered on industrial design and manufacturing projects. These projects involve both product and process design activities. Multidisciplinary teams of students are taught a structured development approach to produce typical industrial deliverables. These deliverables include a functional specification, product and process design, prototype, and first production sample. This paper identifies changing industrial needs, describes how the course was designed to meet these needs, and presents results from the initial offerings of the course. 相似文献
28.
Continuous old-new recognition was studied in relation to 3 factors that have been relatively neglected in previous research-stimulus attributes, old-new base rates, and informative feedback following responses. Under all conditions, both hits and false alarms increased over trials and all measures of recognition depended strongly on stimulus properties, notably interitem similarity. In contrast to expectations based on earlier results, both hit and false-alarm levels proved independent of old-new base rate when tests were given without feedback; with feedback added, false-alarm rates tended to approach true old-stimulus base rates with some types of stimuli, though not with words. The findings are compatible, in general, with current composite-memory models and were predicted in detail by an array-similarity model deriving from categorization theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
29.
Cagnon Christine; Valverde Viviane; Masson Jean-Michel 《Protein engineering, design & selection : PEDS》1991,4(7):843-847
A set of 11 expression vectors was constructed, each of themharbouring a cloning cassette under the control of the promoter.Some of these vectors enable expression of foreign proteinsin the cytoplasm, while others include a synthetic sequencecoding for a very efficient secretion signal sequence. Otherfeatures are an fl origin of replication (in plus or minus orientation)and a promoterup mutation that enhances the already very highlevel of expression from these vectors. With such a versatilevector family, cloning, sequencing and sitedirected mutagenesiscan be performed on the same vector, and the level of expressioncan be defined according to the specific constraints of a givenprotein. 相似文献
30.
KE McLaughlin IN Jacobs NW Todd GS Gussack G Carlson 《Canadian Metallurgical Quarterly》1997,107(10):1322-1331
Nasopharyngeal stenosis and oropharyngeal stenosis are rare and challenging problems in the pediatric population. The most common etiology is currently the surgical trauma associated with adenotonsillectomy. Stenosis can vary from a thin band to a complete obstructing cicatrix. Presenting symptoms range from mild hyponasal speech to severe airway obstruction. We present a series of eight children with varying degrees of stenosis and associated symptoms. Choice of treatment varied with the severity of disease. In our series, successful interventions included triamcinolone acetonide injection, lysis of adhesions, rotational and advancement mucosal flaps, and jejunal free flap. Preoperative evaluation and individualized surgical repair are essential for successful treatment. 相似文献