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1.
The aim of the study was to determine the effect of exogenous melatonin treatment on circulating prolactin levels in red deer. Melatonin was administered from 12 June 1984 (day 1) to lactating and non-lactating hinds in the feed daily at 1600 h, and to non-lactating hinds by a subcutaneous implant. Average concentrations (ng/ml) of prolactin in plasma taken serially over 15-h periods were significantly higher for untreated hinds than for melatonin-treated animals on day 15 whether lactating (66-133 v. 23-28, P less than 0.05) or non-lactating (28-174 v. 8-13, P less than 0.01), remained higher on day 36 (lactating: 41-152 v. 15-21, P less than 0.05; non-lactating: 21-50 v. 1-7, P less than 0.001) but had decreased to similar levels on day 72 (lactating: 5-24 v. 7-17; non-lactating: 2-9 v. 0-4). The advanced reduction in plasma prolactin for all melatonin-treated hinds was associated with an advanced onset of seasonal breeding activity.  相似文献   
2.
Occupational airborne allergic contact dermatitis from tylosin   总被引:2,自引:1,他引:1  
  相似文献   
3.
阿弗菌素产生菌SIPI-AV-99081的选育   总被引:1,自引:0,他引:1  
阿弗菌素链霉菌SIPI-AV-99081采用UV和NTG进行诱变处理。选育得到一高产菌株和几个典型的突变株。高产菌株AV-h-360的阿弗菌素B1的生产能力较出发菌株提高了3倍,AV-m-486和AV-m-796为阿弗菌素合成阻断突变株,它们都不能产生天然的阿弗菌素。  相似文献   
4.
作者于1999年5月在新疆哈巴河铁热克提林牧区调查莱姆病时,采用布旗法和宿主检蜱法,对当地莱姆病媒介蜱类作了调查研究,捕获蜱类标本3090只,经整理鉴定,共系8种,其中森林革蜱D.silvarum1543,占捕获总数49.94%,银盾革蜱D.niveus1099只,占35.57%,草原草蜱D.nuttalli383只,占12.49%,边缘革蜱D.marginatus58只,占1.88%,嗜群血蜱H.concin-ma、铃头血蜱H.campanulata、全沟硬蜱I.persulcatus和残缘璃眼蜱Hy.detrtum共7只,占0.22%。当地蜱类在不同生境、不同寄主和不同时间内,其种类组成、活动及数量动态各不相同。  相似文献   
5.
Rats selectively bred for disparate degrees of ethanol-induced depression of spontaneous locomotor activity (most affected = MA; least affected = LA) were trained on a swim task. Undrugged rats of the MA line swam significantly faster than rats of the LA line. Ethanol, 0.0–2.25 g/kg i.p., produced dose-dependent increases in swim time in rats of the 13th generation (F13). Averaged over trials, these increases were greater in LA than in MA rats and greater in males than in females, but there was no sex difference in peak impairment. Increases in swim time were uncorrelated with predrug performance. These findings were confirmed in younger F17 rats receiving 1.75 g EtOH/kg i.p. Although the lines differed in ethanol-induced impairment, F17 males of the two lines were not differentially impaired by pentobarbital (12.5–22.5 mg/kg, i.p.). The existence of task-dependent line differences in ethanol sensitivity emphasizes the nonunitary nature of ethanol-induced behavioral depression.  相似文献   
6.
This review summarizes the history and current state of the known genetic basis for soybean resistance to Soybean mosaic virus (SMV), and examines how the integration of molecular markers has been utilized in breeding for crop improvement. SVM causes yield loss and seed quality reduction in soybean based on the SMV strain and the host genotype. Understanding the molecular underpinnings of SMV–soybean interactions and the genes conferring resistance to SMV has been a focus of intense research interest for decades. Soybean reactions are classified into three main responses: resistant, necrotic, or susceptible. Significant progress has been achieved that has greatly increased the understanding of soybean germplasm diversity, differential reactions to SMV strains, genotype–strain interactions, genes/alleles conferring specific reactions, and interactions among resistance genes and alleles. Many studies that aimed to uncover the physical position of resistance genes have been published in recent decades, collectively proposing different candidate genes. The studies on SMV resistance loci revealed that the resistance genes are mainly distributed on three chromosomes. Resistance has been pyramided in various combinations for durable resistance to SMV strains. The causative genes are still elusive despite early successes in identifying resistance alleles in soybean; however, a gene at the Rsv4 locus has been well validated.  相似文献   
7.
Gregor Mendel was an Augustinian priest in the Monastery of St. Thomas in Brünn (Brno, Czech Republic) as well as a civilian employee who taught natural history and physics in the Brünn Modern School. The monastery’s secular function was to provide teachers for the public schools across Moravia. It was a cultural, educational, and artistic center with an elite core of friar-teachers with a well-stocked library and other amenities including a gourmet kitchen. It was wealthy, with far-flung holdings yielding income from agricultural productions. Mendel had failed his tryout as a parish priest and did not complete his examination for teaching certification despite 2 y of study at the University of Vienna. In addition to his teaching and religious obligations, Mendel carried out daily meteorological and astronomical observations, cared for the monastery''s fruit orchard and beehives, and tended plants in the greenhouse and small outdoor gardens. In the years 1856 to 1863, he carried out experiments on heredity of traits in garden peas regarded as revolutionary today but not widely recognized during his lifetime and until 16 y after his death. In 1868 he was elected abbot of the monastery, a significantly elevated position in the ecclesiastical and civil hierarchy. While he had hoped to be elected, and was honored to accept, he severely underestimated its administrative responsibilities and gradually had to abandon his scientific interests. The last decade of his life was marred by an ugly dispute with civil authorities over monastery taxation.  相似文献   
8.
从自然界中分离聚乙烯醇(PVA)的降解细菌,经紫外线诱变,得到两株具有单重抗药性的突变菌株S7(Str^s,Kan^r)和K15(Str^r,Kan^s),两者对PVA的去除率分别达到52%和58%.将S7和K15作为亲本菌株进行原生质体融合,并对融合条件进行优化,融合子F4菌株对PVA去除率达到79.9%,将其培养成活性污泥后,PVA去除率可达87%,是普通活性污泥的三四倍.  相似文献   
9.
为探讨德国肉用美利奴杂交F1代肉羊在舍饲、放牧补饲和全放牧条件下的肥育效果,进行了不同饲养方式的肥育试验。试验结果表明:舍饲组育肥体重平均为47.25kg,比放牧补饲和放牧对照组分别提高了22.60%和28.13%,差异极显著(P<0.01)。经屠宰测定和胴体分割测定:舍饲组屠宰率、净肉率为51.29%和43.19%,比补饲组和对照组分别提高4.57、8.21和4.65、7.58个百分点。舍饲组每只羊平均多盈利30~50元。  相似文献   
10.
从桑椹成熟果实、桑叶以及桑果园的土壤采样,进行桑椹果酒专用酵母的筛选,得到一株在性能上优于对照菌葡萄酒干酵母的酵母菌Y11。该菌起酵快,从第2天开始糖度大幅度下降,酒精度快速上升,发酵第4天酒精体积分数即可达到10%以上。发酵过程pH值变化趋势比较平缓,发酵结束后高级醇量符合要求。综合发酵性能及感官评定,表明该菌能代替葡萄酒干酵母用于桑椹果酒的生产。  相似文献   
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