Lymphoma as a model for chronic illness: effects on adrenocortical function testing

Many dogs with chronic illness have serum biochemical abnormalities consistent with hyperadrenocorticism (HAC). Lymphoma (LSA) is a chronic disease of dogs. The purpose of this study was to evaluate adrenocortical screening test results in dogs with LSA to evaluate their specificity. Criteria for inclusion in the study included a diagnosis of LSA, an expected survival time of 16-56 weeks, no glucocorticoid treatment beyond 4 weeks after the initiation of chemotherapy, no evidence of HAC, and owner consent. Post-ACTH stimulation plasma cortisol concentrations (PACs), urine cortisol : creatinine (UC : Cr) ratios, and maximal left adrenal width measurements were performed at the time of LSA diagnosis before the initiation of chemotherapy and at 16, 24, 32, 40, and 52 weeks or until the loss of remission or the development of another disease. Ten dogs met the criteria for inclusion. Forty-two PACs were performed; 1 abnormal, 2 borderline, and 39 normal values were detected. Thirty-five maximal left adrenal width measurements were obtained; 0 abnormal, 5 borderline, and 30 normal measurements were detected. Thirty-six UC : Cr ratios were obtained, with 26 abnormal, 4 borderline, and 6 normal values detected and 9 of 10 dogs having at least 1 abnormal value. These data suggest that in dogs with LSA, the UC : Cr ratio frequently is abnormal and may not be a specific test for HAC, or it may be the most sensitive test for increases in cortisol secretion due to chronic illness. Maximal left adrenal width measurements and PACs were almost always normal and may be more specific for HAC or less sensitive for demonstrating chronic increases in cortisol secretion.     

不同苜蓿品种在青岛地区的适应性

2007-2010年,在青岛地区对引进的23个国内外苜蓿品种进行了膜侧种植、无灌溉、无施肥模式的田间试验,观测分析了各品种产草量、株高、茎叶比等指标。结果表明,23个苜蓿品种在青岛普遍生长良好,国外品种生产性能优于国内品种;播种当年干草产量膜侧种植组明显高于直接播种组,干草产量增幅(除甘农4号、新疆大叶和牧歌401外)均在50%以上;干草产量与年均日照时数、年均温的灰色关联度分别达到0.795 5和0.878 9,而与年均降水量关联度仅为0.569 1;株高最高的是WL323为87.8 cm,最低的是敖汉苜蓿,仅74.7 cm;供试23个品种的干草产量与株高均存在显著性差异,株高与草产量相关系数达到0.65以上,具有很高的正相关性;茎叶比最低的是牧歌401,仅为1.22,绝大多数苜蓿品种的茎叶比有逐年增加的趋势。综合评价认为供试23个苜蓿品种中的WL323、牧歌401、驯鹿3个品种综合生产性能较好,适宜在青岛地区辅以膜侧种植模式进行大面积推广。     

东祁连山高寒草甸灌木和牧草营养成分含量季节变化动态

比较分析了高寒草甸和灌丛草甸中分布的几种优势牧草和灌木的营养成分，发现灌木蛋白质含量高，利用价值大，是一种重要的蛋白质饲草资源。     

Effects of diseases on reproductive performance in Swedish Red and White dairy cattle

The objectives of this study were to evaluate the effect of diseases on days open (DO), days to first breeding (DFB) and days from first breeding to conception (DFBC) using survival analysis models, and to assess the significance of the sire component and its possible confounding effect. The data consisted of a random sample of 20% of all herds enrolled in Swedish recording system and using 100% artificial insemination with at least 15 Swedish Red and White cows calving in 1991. The follow-up period was from 45 to 145 d after calving. After editing, the data sets had 23,927, 28,197, and 22,089 cows for days open, days to first breeding, and days from first breeding to conception, respectively. The Cox models included parity, calving season, cow milk production and age at first calving as fixed effects, and herd and sire as random effects. Ten disease groups were considered as possible risk factors for the reproductive traits. Disease groups were treated differently if they occurred before or after 45 d postpartum. Diseases occurring in the first 45 d after calving were treated as time-independent covariates and diseases occurring after day 45 were treated as time-dependent covariates for days open and days to first breeding. The percentages of censored cows were 35% for days open, 19% for days to first breeding, and 33% for days from first breeding to conception. Days open increased in cows with dystocia, stillbirth, retained placenta, metritis, or other diseases occurring in the first 45 d after calving, and in cows with metritis, mastitis, or other diseases occurring after 45 d. Days to first breeding increased in cows with stillbirth, retained placenta, milk fever, mastitis, foot and leg problems, or other diseases occurring before day 45, and in cows with metritis, mastitis, foot and leg problems, or other diseases occurring after 45 d. Days to first breeding decreased in cows treated for ovulatory dysfunctions either before or after 45 d. Days from first breeding to conception increased in cows with dystocia, stillbirth, retained placenta, metritis, or ovulatory dysfunctions occurring before first breeding, and in cows with mastitis occurring after first breeding. Although the additive genetic components were significant for all traits considered, the sires did not act as confounders because only a small amount of variability for the traits considered in this study was explained by the sires, with estimated heritabilities of 2% on the logarithmic scale and from 3 to 4% on the real scale.     

志贺氏菌的耐药性研究及防治对策

志贺氏菌能感染雏鸡，主要引起雏鸡拉脓血样粪便，该菌耐药性在兽医领域报道较少，本试验通过药敏试验，试管二倍稀释法测定三代头孢抗生素诱导志贺氏菌后可产生多重耐药性。     

禾草对禾顶囊壳玉米变种的抗病性研究

利用人工接菌方法测定了10种草坪禾草,包括多年生黑麦草、高羊茅、紫羊茅、中华结缕草、硬羊茅、草地早熟禾、加拿大早熟禾、匍匐剪股颖、细弱剪股颖、狗牙根;13种禾本科牧草,包括一年生黑麦草、鸭茅、碱茅、扁穗冰草、沙生冰草、披碱草、老芒麦、杂交小米草、猫尾草、弯叶画眉草、无芒雀麦、百喜草、苏丹草;以及4种禾本科作物,包括燕麦、甜高粱、小麦、玉米对禾顶囊壳玉米变种的抗病性。结果表明,多数供试禾草对其具有免疫能力,多年生黑麦草、一年生黑麦草、草地早熟禾、小麦高度抗侵染;无芒雀麦和玉米具有中等程度的抗侵染能力,但抗侵入能力较差;高粱属的苏丹草和甜高粱中度感病,属于中感作物。多年生黑麦草和草地早熟禾品种间存在着抗病性差异,有免疫品种和高抗品种。     

最佳逼近法求解定传动比连杆机构的精度预测

应用误差理论对最佳逼近法求解从动杆作近似等速运动的平面连杆机构的理论运动精度进行了分析,导出了误差传动比公式,利用计算机绘制了误差曲线,从而为仪器仪表中实现线性位移的平面连杆机构的尺度综合提供了精度预测手段和重要的评估参数。     

不同突扩比下空间淹没水跃的水力计算

突扩能够使局部范围内水流紊动剧烈,可以作为水利工程中消能工的一种重要方式．为了探讨突扩比对下游流体水力特性的影响规律,基于RNG k-ε紊流模型和PISO压力-速度耦合算法,采用非均匀结构网格技术,建立了三维紊流数学模型,对突扩比分别为1000,0833,0.667,0500,0333等5种空间水跃进行了多工况数值模拟,结合试验数据,计算结果量纲一化,讨论了不同突扩比大小对下游水力性能的影响,并分析了下游流速、紊动能及消能率等随突扩比的变化规律．数值计算结果表明:突扩比对下游流速、紊动能及消能率影响显著,突扩比越小,下游流速变化越显著,主流在空间内扩散愈迅速,流态转变越明显;随着突扩比的减小,紊动应力愈小,紊动能量愈小,而消能率越大;突扩水跃较典型水跃消能效果明显增强,当突扩比小于0500时,消能率增大不再显著．     

Sex determination of bovine embryos using H-Y antibodies

6 days old bovine embryos (n = 126) were obtained from 8 superovulated cows or heifers by flushing the uteri and oviducts either non-surgically or after slaughter. Part of the embryos (n = 72) (morula stages) were placed in Ham's F-10 or PBS supplemented with 10% fetal calf serum (FCS) diluted 1:1 with supernatant from the H-Y antibody producing clone and cultured at 38 degrees C, in 5% CO2/95% air and 100% humidity. Control embryos (n = 54) were cultured in H-Y antibody free medium. After culture the embryos could be separated into a blastocyst--and a morula group. A subsequent colchemid and hypotonic treatment and fixation and Giemsa staining allowed a precise karyotyping, and thus sex determination for 36 H-Y antibody treated embryos and 22 control embryos. The limiting factor for proper karyotyping was lack of metaphases, incomplete methaphases or poor preparation. Among the H-Y antibody treated embryos we found 7 males and 15 females in the blastocyst and 14 males and 0 females in the morula group. A statistical analysis of these proportions led to the conclusion that the H-Y antibody had a significant influence on the sex ratio.