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Empirical analysis of the profitability of moderate grazing are presented based on sample dairy farms in Pennsylvania and New York. Net income per cow was higher for dairy farms that employed moderate intensive grazing than for dairy farms that employed extensive grazing. Income appeared to be adequate for family living expenses, but moderate intensive grazing could not be considered a high profit system. Detailed analyses of dairy farms that employed moderate and extensive grazing in northern Pennsylvania indicated that returns to management and owner equity were higher for pasture enterprises than for corn silage or hay enterprises. Positive dairy profits were related to lower feed costs. Milk production was lower on farms that employed moderate grazing than on farms that employed extensive grazing. Logit regression analysis characterized farms that employed moderate intensive grazing as oriented toward dairy rather than toward crop production; these farms had lower culling rates and a greater dependence on milk sales as a share of total sales. The reduced use of fertilizers and chemicals suggests that moderate grazing had environmentally sustainable features. 相似文献
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AN Degtiarev AIu Mikha?lovskaia LS Vasilevskaia VI Sergienko 《Canadian Metallurgical Quarterly》1998,61(3):35-37
The effect of cholisorb and its salt (Na and K) forms on the external secretion of the liver was studied. The cholagogic effect of the H-form of cholisorb and its salt forms was demonstrated in dog experiments. The effect of the H-form proved to be stronger. This effect was associated with decreased absorption of bile acids and cholesterol in the intestine and disturbed hepato-intestinal biliary cycle as a result of which adaptation mechanisms directed at restoration of this cycle are apparently switched on. 相似文献
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Research findings regarding general self-concept, academic self-concept, and self-awareness in students with learning disabilities have varied, and results are still inconclusive regarding the consistency between students' and teachers' judgments of academic performance. The current study focuses on students' and teachers perceptions of the students' strategy use and performance in nine different academic and organizational domains. Six hundred sixty-three students and their 57 teachers were involved in the study. Findings indicated that the students with learning disabilities considered themselves appropriately strategic and competent in the five domains of reading, writing, spelling, math, and organization. These students also rated their academic performance and organization as average to above-average in seven of nine domains, with the exception of checking and planning their work. Nevertheless, the self-ratings of the students with learning disabilities were still significantly lower than the self-ratings of average achievers in virtually all domains. The second major set of findings revealed a sharp discrepancy between the self-assessments of the students with learning disabilities and their teachers' judgments. Teachers rated the students with learning disabilities as weak in their strategy use and below-average in their performance in all nine academic and organizational domains. Finally, gender differences were not evident in eight of the nine domains. These results have added to the increasing body of literature indicating that students with learning disabilities frequently perceive themselves as capable and effective and often rate themselves as academically stronger than their teachers judge them to be. 相似文献
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Results of a study of nonstationary processes in the I. V. Kurchatov Beloyarsk Atomic-Power Station, using an electrical analog machine together with the actually-operating control apparatus, are presented. This enabled the dynamic characteristics of the power unit to be obtained and the optimum parameters for setting the main controls of the station to be selected.The theoretical characteristics of the reactor were also compared with experimental results measured directly.Translated from Atomnaya Énergiya, Vol. 19, No. 2, pp. 131–137, August, 1965 相似文献