浅谈几种概率分布之间的相互关系

本文简述了几种常用的概率分布之间的相互关系     

Variations in parameters of liver function and plasma progesterone related to underfeeding and ketosis in a dairy herd

Twenty-eight Norwegian Red Cattle dairy cows were fed silage ad libitum and restricted amounts of concentrates. Blood samples were collected before morning feeding, once or twice weekly, from 2 weeks before to 12 weeks after calving. Parameters of liver function, carbohydrate status and fertility were recorded in order to assess their interrelationships. Eight cows were treated for clinical ketosis. Four of these had to be treated 2 or 3 times. Aspartate aminotransferase and bilirubin showed the highest within-animal coefficients of correlation with acetoacetate. Analysis of variance revealed a significant effect of carbohydrate status (indicated by plasma acetoacetate levels) on the levels of aspartate aminotransferase, glutamate dehydrogenase and sorbitol dehydrogenase, though only a small part of the total variation was explained by this factor. The estimated volume density of liver fat in the 4th week of lactation averaged 6.0 +/- 6.4% (+/- SD) ranging from 0.1-25.1%. Liver fat content at this stage of lactation was not significantly correlated with other indicators of liver function or carbohydrate status. Cows treated for clinical ketosis had significantly lower plasma progesterone values at the time of first ketosis treatment than untreated multiparous cows. The frequency of high progesterone values (greater than 3 ng/ml) being significantly lower in treated than in untreated cows during the period from 3-5 weeks post partum, though not at later stages. In conclusion, the results revealed a significant relationship between carbohydrate status and liver function, and also between clinical ketosis and luteal function.     

鸡空肠弯曲菌灭活苗的制备及其免疫保护试验研究

用分离到的空肠弯曲菌制备鸡空肠弯曲菌甲醛灭活疫苗 ,并进行了该病的免疫保护实验。制备 2× 10 9个 / m L浓度的细菌悬液 ,4m L / L浓度的甲醛溶液作用 12 h灭活后制成空肠弯曲菌灭活苗 ,免疫 2周龄的 SPF雏鸡 ,14 d后 ,进行攻击实验 ,观察其临床症状 ;并分别于感染后 7d和 14 d捕杀 ,观察病理学变化及进行细菌分离实验以揭示其保护率。结果表明 ,鸡空肠弯曲菌灭活苗的保护率可达 10 0 % ,说明该苗经口免疫后安全可靠 ,无毒副作用     

Changes in Endopeptidase Activity during Photosynthetic Declination in Rice Leaf

Two japonica rice varieties, Wuyujing 3 and 97-7, were used to study the changes in contents of soluble protein, free amino acids and endopeptidase activity during photosynthetic declination. The content of soluble protein in flag leaf of cv.Wuyujing 3 was higher than that of cv. 97-7, but decreased rapidly in Wuyujing 3. Free amino acids in flag leaf and the thirteenth leaf of Wuyujing 3 started to increase 10 days before the turning point of photosynthetic declination (TPPD), while it occurred just 1-2 days before TPPD in the flag leaf and the thirteenth leaf of 97-7. During reversible phase of photosynthetic declination,endopeptidase activity remained at a low level and increased slightly only in the later part of this phase. Then it rose up rapidly at irreversible decline phase and reached a very high level. For Wuyujing 3, the change in endopeptidase activity in the thirteenth leaf was parallel to that in flag leaf. However, for 97-7, the rapid increase of endopeptidase activity in the thirteenth leaf started later than that of flag leaf. The results implied that the rate of protein breakdown and conversion to transportable nitrogen in leaves of 97-7 was slower than that in leaves of Wuyujing 3 during photosynthetic declination and it led to relatively lower seed setting rate and fully filling grains rate in 97-7. This may be one of the important reasons why 97-7 could not bring the high yield potentiality into play and the findings may be taken into consideration while breeding for high potential varieties in future.     

锗─132对鸡马立克氏病肿瘤病变的抑制效果及其作用机理的研究Ⅰ．锗─132对健康及人工感染MDV雏鸡抗氧化功能的影响

选用１日龄肉用雏鸡３００只，随机分为４组：Ｉ组为健康对照；Ⅱ、Ⅲ组喂１００ｐｐｍ锗─１３２（Ｇｅ－１３２）；Ⅲ、Ⅳ组人工感染马立克氏病病毒（ＭＤＶ）。经６０ｄ临床观察并每隔１０ｄ用电子自旋共振波谱（ＥＳＲ）法测定胸腺、法氏囊及脾组织中自由基含量，同时检测全血ＧＳＨ－Ｐｘ、血清ＳＯＤ活性及血清丙二醛含量。结果，健康雏鸡全血ＧＳＨ－ｐｘ活性均值为７．９３８７±１．２３７８Ｕ／ｍＬ血清ＳＯＤ活性为８０．４６４３±１．０９８７ｎＵ／ｍＬ血清丙二醛含量为２．９９７８±０１７６０ｎｍｏｌ／ｍＬ；健康雏鸡胸腺、法氏囊及脾组织中自由基平均含量分别为：０．２７±０．０４、０．３４±０．０８、０．２８±０．０６相对浓度（×１０１０ｓｐｉｎｓ／ｇ湿重）。通过与健康对照组比较，人工感染ＭＤＶ雏鸡全血ＧＳＨ－ｐｘ和血清ＳＯＤ活性明显降低，而上述各组织中自由基和血清丙二醛含量则显著增多。Ⅲ、Ⅳ两组对比结果表明：Ⅲ组的全血ＧＳＨ－ｐｘ和血清ＳＯＤ活性高于Ⅳ组，组织中自由基和血清丙二醛含量却低于Ⅳ组，从而证实Ｇｅ－１３２能增强人工感染ＭＤＶ雏鸡的抗氧化功能。     

农户舍饲奶牛血清钙及游离羟脯氨酸水平测定

采用氯胺T比色法和EDTANa_2滴定法,对重庆市农户舍饲奶牛不同泌乳阶段血清中游离羟脯氨酸与血清钙的水平进行 测定,旨在调查试验条件下奶牛血钙代谢情况以及骨营养不良发生的可能性。结果显示: 在农户全舍饲条件下,血清钙含量Ⅱ组显著低于Ⅴ组、Ⅵ组,其它各组间差异不显著;Ⅰ～ Ⅵ组血清羟脯氨酸含量分别为2.32±0.37μg/ml、2.36±0.59μg/ml、2.02±0.54μg/ml、1.90±0.44μg/ml、1.98±0.45μg/ml、1.79±0.18μg/ml,Ⅰ、Ⅱ组与Ⅵ组差异极显著。采样后2-3个月内进行临床观察,血清游离羟脯氨酸水平与骨营养不良发生率呈现一致性变化。而钙磷摄入不足,比例不当是主要原因。     

三种幼虫外寄生蜂蛋白酶含量与离体培养饲料的关系

在离体培养幼虫外寄生蜂过程中，发现不同的蜂对饲料中的蛋白质及游离氨基酸的含量有不同的要求，本文对麦蛾茧蜂（Ｂ．ｈｅｂｅｔｏｒ），矛茧蜂（Ｏ．Ｐｌａｌｉａｔｕｓ），管氏肿腿蜂（Ｓ．ｇｕａｎｉ）的蛋白酶活性，饲料中蛋白质及游离氨基酸含量进行了测定．实验表明：蛋白酶含量低的蜂，饲料中含高游离氨基酸及低蛋白；蛋白酶含量高的蜂，饲料中含低游离氨基酸及高蛋白。     

干旱区20个紫花苜蓿品种抗旱性研究

该试验测定了20个苜蓿品种的水势、总含水量、自由水量、束缚水量、束/自比以及渗透调节物质.从植物水分生理与生化方面,测试各品种的抗旱性,并结合产草量、品质进行综合评价.从中选出5～6个抗旱性较强、产草量高、品质较好的苜蓿品种,为干旱区选择适宜的苜蓿品种提供具有实用价值的基础资料.     

Diurnal and individual variations in bile acids in the plasma of normal dairy cows

Blood samples were collected every 2 h during a 24 h period from 6 cows of one herd and 10 cows of another herd. In a third herd 9 cows were sampled every 2 h from 6 a.m. to 8 p.m. Concentrations of total bile acids, acetoacetate, glucose and free fatty acids were determined in blood plasma. A marked difference in individual bile acid concentrations and patterns of diurnal variation was found. For most cows the highest bile acid values were observed between 2 and 6 a.m. (overall mean (+/- SD) at 6 a.m.: 104 +/- 84 mumol/l, range: 20-307 mumol/l). Fourteen cows with a bile acid value greater than 90 mumol/l at 6 a.m. ("high BA") were characterized as a group by showing a pronounced decrease in the mean bile acid concentration after morning feeding. In the group of 11 cows with a 6 a.m. bile acid value less than 90 mumol/l ("low BA") the time of day did not contribute significantly to the bile acid variation. For the "high BA" group a nearly synchronous variation between the mean values of the 3 feeding dependent parameters (acetoacetate, glucose and free fatty acids) and the mean values of bile acids was found. The within animal coefficients of correlation between bile acids and the feeding dependent parameters were significantly higher in the "high BA" group than in the "low BA" group. No direct connection was found between bile acid levels and the quantity of concentrates fed or the individual milk yield.