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51.
EJ Topol 《Canadian Metallurgical Quarterly》1998,352(9131):897-898
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BW Hess EJ Scholljegerdes SA Coleman JE Williams 《Canadian Metallurgical Quarterly》1998,76(7):1767-1777
Primiparous beef cows (n = 35 Bos taurus, average initial BW of 498 kg) were allotted to treatments in a split-plot designed experiment to determine the effects of supplemental ruminally protected amino acids on cow and calf productivity and metabolic changes in the cows. Cows were fed chopped annual rye hay at 1.5% of BW. The following treatments were used: 1) .8 kg soybean hulls, 1.4 kg ground corn, .6 kg soybean meal (CON); 2) 1.4 kg ground corn, 1.4 kg soybean meal (PRO); 3) PRO plus ruminally protected methionine and lysine (supplied 5 and 10 g, respectively; PRO1); and 4) PRO with twice the level of ruminally protected amino acids in PRO1 (PRO2). Cow weight gain was not different (P > .26) among treatments and averaged 1.2 kg/d for the 45 + 6 d before parturition. After parturition, cow weight gain did not differ (P > .47) between CON and PRO treatments, but it decreased quadratically (P < .01) with increasing level of ruminally protected amino acids. Total milk yield, protein, and fat (4 h) were greater (P < .05) for cows consuming PRO supplements than for CON, whereas CON cattle tended (P = .11) to lose less body condition. Total milk protein showed a quadratic increase (P < .05) in response to level of ruminally protected amino acids that was the inverse of the quadratic response noted for cow weight gain. Serum urea N concentration was greater (P = .07) for cattle consuming additional protein. Metabolic hormones were not affected (P > .18) by dietary treatment, but they responded (P < .05) to changes in physiological state. Supplements with additional protein supported greater (P = .0001) milk urea N concentration and output. Milk urea N concentration increased (P < .05) and milk IGF-I decreased (P < .05) as the lactation period progressed. The measurement of CON and PRO diets revealed that supplements with additional soybean meal had greater (P < .05) DM and N degradation; the extent of forage DM and NDF degradation was similar (P > .05) among treatments. Production shifted away from body weight gain to increased milk protein production when daily supplementation of ruminally protected methionine and lysine increased from 5 and 10 to 10 and 20 g, respectively. This shift in production was not reflective of changes in the metabolic regulators measured. 相似文献
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A new aerospace application of structural reliability techniques is presented, where the applied forces depend on many probabilistic variables. This application is the plume impingement loading of the Space Station Freedom Photovoltaic Arrays. When the space shuttle berths with Space Station Freedom it must brake and maneuver towards the berthing point using its primary jets. The jet exhaust, or plume, may cause high loads on the photovoltaic arrays. The many parameters governing this problem are highly uncertain and random. An approach, using techniques from structural reliability, as opposed to the accepted deterministic methods, is presented which assesses the probability of failure of the array mast due to plume impingement loading. A Monte Carlo simulation of the berthing approach is used to determine the probability distribution of the loading. A probability distribution is also determined for the strength of the array. Structural reliability techniques are then used to assess the array mast design. These techniques are found to be superior to the standard deterministic dynamic transient analysis, for this class of problem. The results show that the probability of failure of the current array mast design due to the examined failure modes is minute. Significantly, this paper details a structural reliability analysis of a complex aerospace structure for which little statistical information is available. 相似文献
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D Robinette S Wada T Arroll MG Levy WL Miller EJ Noga 《Canadian Metallurgical Quarterly》1998,54(5):467-475
BACKGROUND: A major reduction in the energy demand of the myocardium results from the electromechanical arrest, and cooling contributes to a lesser degree to this reduction. It is from this assumption that strategies of myocardial protection, utilizing warm blood cardioplegic induction, followed by cold cardioplegia with terminal warm reperfusion before removal of the aortic cross clamp, became established as optimal myocardial protection. Continuous normothermic perfusion 'closed the loop' by avoiding myocardial ischemia and linking warm induction and terminal reperfusion. A series of laboratory and clinical data confirmed the benefits of warm heart surgery on myocardial function and metabolism. The disadvantages of continuous warm blood cardioplegia including disturbance of the operative field, led surgeons to administer warm hyperkalaemic blood intermittently as a new cardioplegic strategy. METHODS: This review examines the laboratory and clinical data with reference to the intermittent warm blood cardioplegia, to establish its experimental basis and place in clinical practice. CONCLUSIONS: Experimental observation and clinical application have established intermittent warm blood cardioplegia as a practical, effective and cheap myocardial protection technique, particularly with reference to coronary artery surgery. 相似文献
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SE Santos AK Ribeiro-Dos-Santos JF Guerreiro EJ Santos TA Weimer SM Callegari-Jacques MA Mestriner MH Franco MH Hutz FM Salzano 《Canadian Metallurgical Quarterly》1998,25(6):505-522
A total of 732 individuals affiliated with six Amazonian Indian populations were variously studied in relation to 26 protein genetic systems. Eleven of them were found to be monomorphic in these groups, in accordance with previous investigations. Similarities and dissimilarities (the latter involving the Rh, Duffy, haptoglobin and transferrin systems) were observed in relation to earlier investigations in four of these populations (Galibi, Palikour, Mundurucu and Tenharim). A dimeric, cathodal variant of albumin was found among two Galibi subjects, and the fairly common occurrence of CP* ACAY among some South American Indian populations was confirmed. The results in the six populations were compared with those from 29 others. When relationships are searched for among tribes of the same linguistic group, the factor that seems to be most influential is geographical localization, an exception being the pattern observed among the Cayapo subgroups. The latter shows genetic differences of the same level of magnitude as those observed among Ge-speaking tribes. 相似文献
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