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81.
Response to selection for milk yield in Holsteins was examined by a controlled selection experiment initiated in 1964. Foundation cows were paired by sire and divided randomly into two breeding groups, selection and control. Selection group was mated to four sires each year highest for Predicted Difference milk. Twenty bulls selected in 1964 as near breed average for milk sired all control cows. Milk yield was recorded for each lactation, and height of udder from ground, distances between teats, and perimeter and area bound by the four teats were measured at 30 to 75 days postpartum on 153 selection and 202 control cows over 14 yr. Most estimates of repeatability and heritability of udder dimensions before and after milking were .45 or larger. Correlations with milk yield were negative for udder height and positive for other udder measurements. Selection cows exceeded controls for lactational milk yield. Daughters of high milk bulls had greater distances between teats, greater perimeters, and larger areas of udder floor. Selection cows did not differ from controls in udder height for first parity but were below controls in udder height and had udders that collapsed more for all parities. 相似文献
82.
This paper describes how SWoRD (scaffolded writing and rewriting in the discipline), a web-based reciprocal peer review system, supports writing practice, particularly for large content courses in which writing is considered critical but not feasibly included. To help students gain content knowledge as well as writing and reviewing skills, SWoRD supports the whole cycle of writing, reviews, back-reviews, and rewriting by scaffolding the journal publication process as its authentic practice model. In addition, SWoRD includes algorithms that compute individual reviewer’s review accuracy, which is in turn used to support the various drawbacks of reciprocal peer reviews (e.g., variation in motivation or ability of reviewers). Finally, this paper describes an empirical evaluation showing that the SWoRD approach is effective in improving writing quality in content classes. 相似文献
83.
In a series of experiments over 3 yr, relatively low doses of selenium and vitamin E were injected intramuscularly 3 wk prepartum to pregnant Israeli-Holstein dairy cows in a high-producing herd (9000 kg milk/yr) with a history of retained placenta in 17% of the primiparous and 28% of the multiparous animals, as recorded for the 12 mo preceding the study. Selenium ranged from .035 to .109 ppm in the prepartum diet and from .160 to .200 ppm in the postpartum diet. Doses of selenium ranging from 2.3 to 23.0 mg reduced the incidence of retained placenta in 186 primiparous and in 428 multiparous to 7 and 15%, which was half of that of controls. Low doses of selenium (2.3 to 4.6 mg) tended to be more effective than higher ones. Selenium alone was at least as effective as a combination of selenium and vitamin E. Dosage, timing, mechanism, and interactions of selenium with other factors in reducing the incidence of retained placenta need clarification. 相似文献
84.
85.
Self-disclosure plays a central role in the development and maintenance of relationships. One way that researchers have explored these processes is by studying the links between self-disclosure and liking. Using meta-analytic procedures, the present work sought to clarify and review this literature by evaluating the evidence for 3 distinct disclosure-liking effects. Significant disclosure-liking relations were found for each effect: (1) People who engage in intimate disclosures tend to be liked more than people who disclose at lower levels, (2) people disclose more to those whom they initially like, and (3) people like others as a result of having disclosed to them. In addition, the relation between disclosure and liking was moderated by a number of variables, including study paradigm, type of disclosure, and gender of the discloser. Taken together, these results suggest that various disclosure-liking effects can be integrated and viewed as operating together within a dynamic interpersonal system. Implications for theory development are discussed, and avenues for future research are suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
86.
LA Miller 《Canadian Metallurgical Quarterly》1998,13(4):717-25, iv
Medical networks offer discounted fees, control of the workers' compensation case, quality monitoring, and managed care services. As channeling of workers' compensation cases to networks increases, credentialed physicians will benefit. 相似文献
87.
It was proposed that individuals' responses to information regarding their relative position in a performance distribution would depend on how they frame the information. To the degree that they focus selectively on the positive features of the feedback (i.e., the number of others who performed worse than them) rather than the negative features (i.e., the number of others who performed better than them) they should report higher ability levels and more positive affective reactions. In Study I, Ss received feedback indicating that they occupied a particular percentile standing in either a large or small distribution. Individuals with negative orientations (depressives and pessimists) reported lower ability levels as a function of increases in comparison group size, whereas individuals with positive orientations (nondepressives and optimists) reported higher ability levels. Presumably, these effects occurred because negatively oriented persons focused on the negative features of the feedback and positively oriented persons focused on the positive features of the feedback. The results of Study 2 support this explanation. Implications for the social comparison literature are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
88.
89.
Miller Ralph R.; Barnet Robert C.; Grahame Nicholas J. 《Canadian Metallurgical Quarterly》1995,117(3):363
The Rescorla-Wagner model has been the most influential theory of associative learning to emerge from the study of animal behavior over the last 25 years. Recently, equivalence to this model has become a benchmark in assessing connectionist models, with such equivalence often achieved by incorporating the Widrow-Hoff delta rule. This article presents the Rescorla-Wagner model's basic assumptions, reviews some of the model's predictive successes and failures, relates the failures to the model's assumptions, and discusses the model's heuristic value. It is concluded that the model has had a positive influence on the study of simple associative learning by stimulating research and contributing to new model development. However, this benefit should neither lead to the model being regarded as inherently "correct" nor imply that its predictions can be profitably used to assess other models. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
90.
'Borderline' methicillin-resistant Staphylococcus aureus (MRSA) strains are inhibited by drug concentrations of 2 to 8 micrograms/mL. This type of resistance is usually mediated by 'hyper beta-lactamase' production which is detectable in vitro by susceptibility to combinations of a beta-lactam and a beta-lactamase inhibitor (ie, amoxicillin and clavulanic acid). A survey of Canadian infection control experts was performed to assess the knowledge, attitudes and beliefs regarding the containment requirements for borderline MRSA strains in acute health care facilities. Twenty-three of 38 Canadian infection control experts (61%) (members of the Canadian Hospital Epidemiology Committee [CHEC] or the Society for Healthcare Epidemiology of American [SHEA]) returned a questionnaire about a fictional patient with a postoperative wound infection with such a strain. Eleven respondents (48%) considered the isolate as an MRSA, 11 did not and one was unsure. All who did not believe the strain to be MRSA would not have isolated or cohorted the patient. Four in the latter group would have isolated the patient if he or she were on a neurosurgery or cardiovascular surgery unit, indicating a desire to restrict spread of this isolate on those units. Seven of the 12 individuals who had managed at least one patient with a borderline MRSA did not advocate patient isolation or cohorting, and five did. This survey has supported the belief that there are discrepancies among infection control decision-makers in Canada regarding the approach, precautions and therapy of patients infected with borderline strains of MRSA. Further data on virulence of and effective therapy for these isolates are needed to assess whether the additional cost is warranted in controlling the nosocomial spread of these isolates. 相似文献