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101.
102.
Histological and histochemical techniques have been employed to determine the structure and autonomic innervation of paraganglia located in the human pelvis. In foetal and early postnatal tissues, paraganglia formed rounded cellular masses which were frequently in company with the autonomic nerves and ganglia of the urinary bladder and other pelvic viscera. The constituent cells contained only small amounts of cholinesterase and were unrelated to enzyme positive autonomic nerves; acetylcholinesterase containing nerves were occasionally observed in the capsule and the fibrous septa of the pelvic paraganglia. In early postnatal specimens, pelvic paraganglia frequently contained single or multiple "pacinian-like" corpuscles, each possessing a central region which was rich in both acetyl and pseudocholinesterase. These structures were rarely observed within autonomic ganglia and were absent 4 1/2 years post partum. By means of a histochemical technique, pelvic paraganglia were found to contain catecholamine which was attributed to the presence of relatively large quantities of noradrenaline. These observations have been discussed with particular reference to the results of other studies on the autonomic innervation of paraganglia. 相似文献
103.
The right eye of a 9-year-old white boy with Best's vitelliform macular dystrophy had an intact egg-yolk lesion and a retinal pigment epithelial defect superiorly, suggesting an early pseudohypopyon stage. The disruptive phase of the left eye showed subretinal hemorrhages, a "signet ring," and a subretinal neovascular membrane. 相似文献
104.
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
105.
分层介质动态力学性能的实验研究 总被引:1,自引:0,他引:1
采用Φ75mm分离式霍普金森压杆实验装置,对由普通混凝土与泡沫混凝土组合的分层介质的动态力学性能进行了研究。结果表明,应力波通过普通混凝土时的衰减仅为其原来峰值的5%~10%,应力波通过泡沫混凝土时其峰值衰减为原来的1/5。由此说明在含泡沫混凝土与普通混凝土的分层介质中,泡沫混凝土提供削波与延缓应力波作用时间的作用,普通混凝土则为其提供较高强度。通过对分层介质应力衰减和动量变化的分析表明,分层介质在动态力学行为上表现为较大的塑性和应变率相关性,其应力衰减主要取决于泡沫混凝土材料。 相似文献
106.
We propose a new model of restricted branching programs specific to solving GEN problems, which we call incremental branching programs. We show that syntactic incremental branching programs capture previously studied models of computation for the problem GEN, namely marking machines
(Cook, S.A. in J. Comput. Syst. Sci. 9(3):308–316, 1974) and Poon’s extension (Proc. of the 34th IEEE Symp. on the Foundations of Computer Science, pp. 218–227, 1993) of jumping automata on graphs (Cook, S.A., Rackoff, C.W. in SIAM J. Comput. 9:636–652, 1980). We then prove exponential size lower bounds for our syntactic incremental model, and for some other variants of branching
program computation for GEN. We further show that nondeterministic syntactic incremental branching programs are provably stronger
than their deterministic counterpart when solving a natural NL-complete GEN sub-problem. It remains open if syntactic incremental
branching programs are as powerful as unrestricted branching programs for GEN problems.
A preliminary version of this paper appears as (Gál, A., Koucky, M., McKenzie, P., Incremental branching programs, in Proc.
of the 2006 Computer Science in Russia Conference CSR06. Lecture Notes in Computer Science, vol. 3967, pp. 178–190, 2006).
A. Gal supported in part by NSF Grant CCF-0430695 and an Alfred P. Sloan Research Fellowship. M. Koucky did part of this work
while being a postdoctoral fellow at McGill University, Canada and at CWI, Amsterdam, Netherlands. Supported in part by NWO
vici project 2004–2009, project No. 1M0021620808 of MŠMT ČR, grants 201/07/P276, 201/05/0124 of GA ČR, and Institutional Research
Plan No. AV0Z10190503.
P. McKenzie supported by the NSERC of Canada and the (Québec) FQRNT. 相似文献
107.
108.
Abstract In this paper, the problem of logical consistency in critical-tasks decision systems is addressed. It is shown how local search techniques can be used to check the (in)consistency of very large propositional knowledge bases (KBs). Using new heuristic findings. we can now implement efficient forms of diagnostic reasoning in the context of very large ICBs modeling deep models of complex devices and including patterns of default reasoning. 相似文献
109.
在重复率脉冲固体激光器中,由于储能电容需要频繁的充放电,通常采用谐振充电电路以适应其负载的大范围变化。为此研制了开关频率为20kHz,充电电流为2.1A,最高充电电压为1.86kV的半桥串联谐振充电电路。该电路工作于电流断续模式,开关管的开通和关断均为软开关。通过对周期电压、电流递推公式的分析,表明该工作模式中每个周期的平均充电电流均为恒定。应用递推公式计算稳态和暂态谐振电容电压和电流,结果显示暂态最大工作电压是稳态最大电压的2倍,暂态最大电流为稳态最大峰值电流的1.5倍,为谐振电容和开关管的选取提供了依据。 相似文献
110.
RD Howard RS Martens SA Innis JM Drnevich J Hale 《Canadian Metallurgical Quarterly》1998,55(5):1151-1163
A sexual size dimorphism usually occurs when size-dependent reproductive advantages exist in only one sex. Studies on Japanese medaka, Oryzias latipes, have demonstrated reproductive size advantages in females but not in males, even though males and females are similar in body size. We conducted mate-choice and mate-copying tests in which a female could first associate with, then mate with, either a large (>/=1 sd+X standard length) or a small male (=1 sd-X standard length). Large males obtained a mating advantage in both tests, and both mate choice and mate competition influenced their mating success. In the majority of trials, females associated with large males. Association preferences of females corresponded to their mating preferences when mate competition between males was weak; however, when mate competition was strong, large males obtained almost every mating regardless of female association preference. Preference for large males may provide females with a reproductive advantage if males mate multiply because small males become sperm-depleted sooner than large males. We found no indication that females copied the mating decisions of other females. Repeatability of female mating preference was low, not because females mated at random with respect to male size, but because most females consistently preferred large males. We also conducted mating tests at four density levels and found that large males maintained their mating advantage relative to small males at all densities. Thus, male and female medaka may be similar in body size because large size provides a fecundity advantage for females, as demonstrated in previous studies, and large size provides a mating advantage for males, as demonstrated in our study. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour. 相似文献