Different origins of two corpora lutea recovered from a pregnant African elephant (Loxodonta africana)

Elephant ovaries contain multiple corpora lutea (CLs) throughout pregnancy. Two CLs (P‐1 and P‐2) collected from a pregnant African elephant were used to investigate their origin and physiological state in this study. The mRNA expressions of prolactin receptor, CYP11A and inhibin betaB subunit were higher in P‐2 than in P‐1, while LHCGR and inhibin betaA subunit mRNA were higher in P‐1 than in P‐2. Protein expression of cleaved caspase‐3 was detected in P‐1 but not in P‐2. These results suggest different origins for the two CLs in this one pregnant elephant, and we also demonstrated the production of bioactive prolactin by the elephant placenta.     

论茶的君子品德

新时代下，茶文化有了更大的发展和普及，茶德的提出使得茶文化上升为一种深层次、高品位的哲学思想范畴，旨在追求真善美的境界和道德风尚。历代古人将“仁”、“知”、“勇”等定义为君子的品德，本文从茶的平和里仁、睿智超然、坚贞清廉三个方面展开，初步论述了茶的君子品德。     

Genetic characterization of bovine viral diarrhea virus strains in Beijing,China and innate immune responses of peripheral blood mononuclear cells in persistently infected dairy cattle

To acquire epidemiological data on the bovine viral diarrhea virus (BVDV) and identify cattle persistently infected (PI) with this virus, 4,327 samples from Holstein dairy cows were screened over a four-year period in Beijing, China. Eighteen BVD viruses were isolated, 12 from PI cattle. Based on genetic analysis of their 5''-untranslated region (5''-UTR), the 18 isolates were assigned to subgenotype BVDV-1m, 1a, 1d, 1q, and 1b. To investigate the innate immune responses in the peripheral-blood mononuclear cells of PI cattle, the expression of Toll-like receptors (TLRs), RIG-I-like receptors, interferon-α (IFN-α), IFN-β, myxovirus (influenza virus) resistance 1 (MX1), and interferon stimulatory gene 15 (ISG15) was assessed by qPCR. When compared with healthy cattle, the expression of TLR-7, IFN-α, and IFN-β mRNA was downregulated, but the expression of MX1 and ISG-15 mRNA was upregulated in PI cattle. Immunoblotting analysis revealed that the expression of interferon regulatory factor 3 (IRF-3) and IRF-7 was lower in PI cattle than in healthy cattle. Thus, BVDV-1m and 1a are the predominant subgenotypes in the Beijing region, and the strains are highly divergent. Our findings also suggest that the TLR-7/IRF-7 signaling pathway plays a role in evasion of host restriction by BVDV.     

Accessory corpora lutea formation in pregnant Hokkaido sika deer (Cervus nippon yesoensis) investigated by examination of ovarian dynamics and steroid hormone concentrations

Generally, sika deer conceive a single fetus, but approximately 80% of pregnant females have two corpora lutea (CLs). The function of the accessory CL (ACL) is unknown; moreover, the process of ACL formation is unclear, and understanding this is necessary to know its role. To elucidate the process of ACL formation, the ovarian dynamics of six adult Hokkaido sika deer females were examined ultrasonographically together with peripheral estradiol-17β and progesterone concentrations. ACLs formed in three females that conceived at the first estrus of the breeding season, but not in those females that conceived at the second estrus. After copulation, postconception ovulation of the dominant follicle of the first wave is induced by an increase in estradiol-17β, which leads to formation of an ACL. A relatively low concentration of progesterone after the first estrus of the breeding season is considered to be responsible for the increase in estradiol-17β after copulation.     

没食子酸对水稻细菌性条斑病防治作用的持效期

利用高效液相色谱法(HPLC)检测没食子酸(gallic acid,简称GA)在水稻叶片上的残留时间,并在检测水稻叶片上残留量的同时接种病原菌,调查接种后水稻细菌性条斑病的发病情况,以确定GA在水稻叶片上对水稻细菌性条斑病防治作用的持效期。研究结果表明,GA不具有内渗作用,只残留在水稻叶片的表面。分别用100、200和400 mg/L的浓度处理叶片后,GA在叶片表面的残留时间分别为16、24和28 d。200 mg/L浓度处理叶片后,GA对水稻细菌性条斑病防治作用的持效期为16 d。研究结果可为有效使用GA防治水稻细菌性条斑病奠定基础。     

Effect of environmental C/N ratio on activities of lignin-degrading enzymes produced by Phanerochaete chrysosporium

Lignin-degrading enzymes secreted by white rot fungi play an important role in the degradation of lignin and persistent organic pollutants(POPs).In this study,effect of environmental C/N ratio on the activities of lignin-degrading enzymes,lignin peroxide(Li P)and manganese peroxidase(Mn P),produced by Phanerochaete chrysosporium,a white rot fungus,was investigated.Glucose was used as C source,and ammonium tartrate of different concentrations was used as N source to provide different C/N ratios.Relationships between Li P and Mn P activities and environmental C/N ratio were explored.The results showed that the higher the N source concentration,the faster the mycelium pellets aged.The faster the mycelium dry weight increased,the higher the Li P and Mn P activities.A high C/N ratio was a necessary condition for the secretion of Li P or Mn P.In addition,mycelium dry weight essentially affected enzyme activities.In the 122 C/N ratio and 50 C/N ratio treatments,mycelium dry weight essentially affected Mn P activity and both Li P and Mn P activities,respectively.     

基于VOA农业新闻英语语料库的主题词分析

研究基于VOA农业新闻英语语料库,旨在分析主题词与主题表达之间的关系,以及词汇的运用和搭配特点。研究结果发现,VOA农业新闻英语中主题词与主题表达之间有着紧密的联系,主题词可从7个方面表现主题,反映了VOA农业新闻英语的主要内容和关注焦点;主题词的搭配分析反映了VOA农业新闻英语词汇运用的丰富性,语言表达的准确性。研究结果对于深入了解VOA农业新闻英语词汇的语言特点,提高农业英语表达水平及翻译水平具有一定的指导作用和应用价值。     

语料库教学模式在汽车英语课堂上的应用与研究

语料库就是将在现实生活中出现的应用过语言加以收集、整理、分析、处理，利用计算机数据库技术并且结合现代网络平台，建立的资源共享体。目前美国当代英语语料库是世界上最大的英语语料库，该语料库可以通过网络平台为大众提供英语语料的检索和查询。将英语语料库引入汽车英语课堂，是汽车专业英语教学模式改革的重大尝试和探索，语料库教学模式在汽车英语课堂上的应用为提高专业英语教学水平，增强学生英语应用能力、培养高素质汽车专业人才提供一条行之有效的方法。     

Development of a novel diagnostic test for detection of bovine viral diarrhea persistently infected animals using hair

The purpose of this study was to determine whether manually plucked hairs might serve as an alternative sample for a quantitative real time polymerase chain reaction (qRT-PCR) testing. Twenty three, 1~3 week old, non-bovine viral diarrhea virus (BVDV) vaccinated calves, found to be positive for BVDV by immunohistochemical staining, were selected and hairs were manually plucked from the ear. qRT-PCR was performed on samples consisting of more than 30 hairs (30~100) and whole blood. All 23 animals were positive for the virus by qRT-PCR performed on the whole blood and when samples of more than 30 hairs were assayed. Additionally, qRT-PCR was performed on groups of 10 and 20 hairs harvested from 7 out of 23 immunohistochemical staining-positive calves. When groups of 20 and 10 hairs were tested, 6 and 4 animals, respectively, were positive for the virus.