氮硅添加对高寒草甸生物量和多样性的影响——以青藏高原为例

草地施肥多集中于添加氮肥与磷肥,很少涉及硅肥。硅作为对植物有益的一种元素,能提高植物对环境的抗性,促进植物的生长。本研究以青藏高原高寒草甸为研究对象,通过添加不同组合的氮肥和硅肥,研究群落地上生物量和生物多样性的变化。结果表明,氮肥和硅肥的添加均能提高群落的地上生物量,然而硅肥提高群落地上生物量的幅度远低于氮肥;在添加氮肥导致群落物种多样性下降的同时,添加硅肥可以缓解群落多样性下降的趋势;硅肥的生物学功能在群落水平上存在着最佳浓度效应。同时,我们推测硅肥在维持群落中杂草的存活率上发挥着积极的作用,并通过比较不同硅肥处理时,杂草生物量所占群落生物量比重的变化,支持了上述推测。     

牛腔前卵泡的简易机械分离方法

采用两种机械法分离牛腔前卵泡。方法一 (M -1) ,皮肤移植刀切割、剪碎、过滤镜下直接捡卵法。方法二 (M -2 ) ,皮质片剪碎、离心、悬浮、过滤镜下捡卵法。M -1平均每卵巢采卵数为 46 9个± 18 2个 ,M -2为 6 8 4个± 12 5个 ;处理时间M -1为 2 5 4min± 6 7min ,M -2为 46 3min± 16 8min ,两种方法采集腔前卵泡数量及处理时间均存在显著差异。平均每小时采集卵泡数分别为 99 5和 87 2个 ,M -1多于M -2。两种方法获得腔前卵泡大小分布规律也有明显差异 ,M -1采集腔前卵泡直径为 6 0～ 15 0 μm ,绝大部分是次级卵泡 ,而M -2获取腔前卵泡则偏小。总的看来 ,M -1处理时间短 ,回收效率高 ,方法简便 ,且分离卵泡直径较大 ,适于体外培养 ,是机械分离牛腔前卵泡的一种理想方法。     

Effects of Wnt10b on dermal papilla cells via the canonical Wnt/β‐catenin signalling pathway in the Angora rabbit

Wnt10b is a member of Wnt family that plays a variety of roles in biological functions, including those in the development of hair follicles. To investigate the effect of Wnt10b on hair growth in the Angora rabbit and to determine the underlying molecular mechanism, we cultured dermal papilla (DP) cells with exogenous Wnt10b in vitro. We observed the expressions of downstream critical gene β‐catenin and lymphoid enhancer‐binding factor 1 (LEF1) in Wnt/β‐catenin pathway. The levels of β‐catenin mRNA and protein were higher in the Wnt10b group of DP cells than in the Control group, and the mRNA level of LEF1 in the Wnt10b group was higher than in the Control group. Moreover, translocation of β‐catenin from cytoplasm to nucleus was activated in the Wnt10b group. Furthermore, the mRNA levels of the hair follicle‐regulatory genes, insulin‐like growth factor‐1 (IGF‐1) and alkaline phosphatase (ALP), and the protein activity of ALP was also upregulated in the Wnt10b group compared to their corresponding levels in the Control group. These data suggest that Wnt10b could activate the canonical Wnt/β‐catenin signalling pathway to induce DP cells in the Angora rabbit. In addition, the proliferation of DP cells was significantly promoted when cultured with Wnt10b for 48 and 72 hr, suggesting that Wnt10b plays a pivotal role in the proliferation and maintenance of DP cells in vitro. In conclusion, this study demonstrates that Wnt10b may promote hair follicle growth in Angora rabbit through the canonical Wnt/β‐catenin signalling pathway that promotes the proliferation of DP cells.     

Chemical composition and microstructure of uroliths and urinary sediment crystals associated with the feeding of high-level cottonseed meal diet to water buffalo calves

The chemical composition and microstructure of seven uroliths and four urinary sediment samples associated with the feeding of high-level cottonseed meal diet to buffalo calves were examined by chemical qualitative analyses, scanning electron microscopy ( ), X-ray diffraction, and X-ray energy dispersive spectrometry ( ). Struvite was a major component of kidney stones and of some bladder stones. The kidney stone sample appeared cracked under low power under , aggregated into tiny balls under high power, and as a bladelike structure under even higher power. The bladder stone samples appeared finely granular or granular with various forms of prismatic crystals. The urinary sediments were prismatic crystals, with granules. The newly found prismatic crystals, which were rich in potassium and similar to struvite in crystal structure, were identified as potassium magnesium phosphate (KMgPO₄ · 6H₂O) in some bladder stones and urinary sediments. However, crystals which contained Mg and P only, which had been used for struvite identification, were not found by examination in urinary sediments from fresh urine samples of buffalo calves fed the high-level cottonseed meal diet.     

草原综合顺序分类法的新改进：Ⅰ类的划分指标及其分类检索图

根据全国２３５２个气象站３０年以上的气候资料以及其他资料，对草原的综合顺序分类法第一级分类的热量级，湿润度级指标进行了修正，设计了新的分类检索图，将地带性和非地带性的天然草地，以及人工草地的类，纳入到统一的检索图的中，并可进行计算机检索。     

兽医病理学在现代兽医专业教学和动物疾病诊断中的重要作用

为了阐述兽医病理学在现代兽医专业教学和动物疾病诊断中的作用,本文从人才培养、科研和生产实践应用等方面进行了探讨。指出兽医病理学具有培养高素质兽医专业人才、为动物疾病诊断提供方向或确诊疾病、验证和评估诊断结果、为科研选题提供手段与方向和解决动物医疗纠纷的重要作用。期望广大兽医专业教学工作者重视该课程教学,使学生掌握兽医病理学基础及其诊断技术。     

辽西北暖性灌草丛类草原牧鸡治蝗效果试验

在辽西北暖性灌草丛类天然草原开展了牧鸡治蝗试验,通过对草原蝗虫防治效果、日捕食量、牧鸡日增重、牧草生产力水平及经济效益等指标进行测定分析,初步探索辽西北草原区牧鸡治蝗综合防治效果.     

泰王为爱犬两次著书

由泰国国王普密蓬亲自编写的再版新书《通丹的故事》在短短一周内就创下了50万本的销量，成为泰国8年来最畅销的书。就连佛教徒都认为，此书“可以扩大爱的范围，并且照亮人心”。     

Changes in VP2 gene during the attenuation of very virulent infectious bursal disease virus strain Gx isolated in China

Very virulent (vv) infectious bursal disease virus (IBDV) Gx strain with high pathogenicity was attenuated through replication in specific-pathogen-free (SPF) chicken embryos and in chicken embryo fibroblast (CEF) cell cultures. The changes in VP2 nucleotide and the deduced amino acid sequences were obtained during attenuation of vvIBDV in CEF culture. Sequence analysis of selected passages from numbers 0 to 20 in CEFs (designated here Gx to CEF-20) showed that no changes were detectable in the VP2 gene before CEF-7. There were a few changes in the nucleotide sequence of the VP2 gene but no amino acid substitutions at CEF-8. The virus of CEF-9 was an intermediate with some amino acid changes that possibly were related to virulence. CEF-10 virus had become similar to CU-1 strain. The VP2 gene sequence remained the same from CEF-10 to CEF-20. The results of pathogenicity tests showed that the mortalities of Gx, CEF-5, CEF-8, and CEF-9 in 4-wk-old SPF chickens were 64%, 60%, 60%, and 32%, respectively; whereas CEF-10, CEF-15, and CEF-20 were nonpathogenic. Virus neutralization tests with Gx strain showed that the antigenicities are similar from Gx to CEF-20.     

口服补液盐的临床应用与动物实验研究

作者于1983年开始将以葡萄糖—钠泵学说为理论的口服补液盐(ORS)技术引入我国畜牧兽医领域,经过几年的临床研究;先后在防治犊牛、猪、雏鸡和犬的腹泻脱水等获得86～98.7％的成功率。健康绵羊ORS液吸收实验和与静脉输液、口服蒸溜水吸收比较实验证明,ORS液的各种成分在服后2小时内,不仅能被胃肠粘膜吸收,极显著改善红细胞压积(P<0.01),而且初步观察到促水分吸收的葡萄糖—钠泵现象。