不同毒力马立克氏病病毒毒株的vlL8表达水平分析

为研究马立克氏病毒(MDV)编码的vlL8与病毒毒力的相关性,本研究用等剂量的3个不同毒力的MDV毒株(CVI988/Rispens株、GA株和RBIB株)对1日龄SPF雏鸡进行接种,接种后第4 d、7 d和10 d分别采集雏鸡的脾脏组织,提取总RNA.以鸡β-actin作为内参基因,用半定量RT-PCR法测定MDV vIL8和MDV gB 基因在接种后不同时间的表达情况,进而分析vIL8的表达量与病毒毒力的关系.结果显示:不同病毒株感染后检测的不同时间均有vIL8和gB的表达,vIL8的相对表达量大于0.25,gB大于0.17;vIL8表达量与病毒毒力呈正相关,毒力越强,vlL8表达量越高,这种现象在病毒接种后的4 d和10 d较为明显;在各个不同时期,vIL8的mRNA表达量均要比gB表达量高.结果表明,vIL8与MDV毒力有一定相关性,参与MDV-1的致病过程.     

司家营铁矿降低露采穿爆成本的实践

穿孔、爆破是露天开采基础且重要的两个环节,且占开采成本的很大比例,针对司家营铁矿穿孔废孔率高,炸药消耗大问题,通过加强穿孔管理降低废孔率、使用强力膜降低炸药单耗、降低后排孔装药量三项措施,降低了矿山穿孔爆破成本。     

稳定转化家蚕BmN细胞表达人粒细胞-巨噬细胞集落刺激因子

为了建立稳定转化家蚕细胞持续表达外源基因的技术体系,构建了基于piggyBac转座子的带有人粒细胞-巨噬细胞集落刺激因子基因(hGM-CSF)和新霉素抗性基因(neo)表达元件的转基因载体pigA3GFP-IE-neo-FH-hGM-CSF-polyA-fib-L-intron1,以及带有hGM-CSF和吉欧霉素(zeocin)抗性基因的昆虫细胞转化载体pIZT-IE-hGM-CSF,分别转染家蚕卵巢BmN细胞,并以含相应抗生素G418或zeocin的培养液筛选,得到稳定的转化细胞系FH-hGM-CSF和IE-hGM-CSF。ELISA检测结果显示,hGM-CSF在FH-hGM-CSF和IE-hGM-CSF转化细胞系的表达水平分别为1.534 55 fg/个细胞和2.227 38 fg/个细胞。     

鳄鱼养殖场选址的主要因素分析

近年来,国内兴起建鳄鱼养殖场的热潮,而指导新养殖户们如何进行鳄鱼养殖场选址的相关研究尚未见报道。为此,笔者于2007年6月至2008年7月深入鳄鱼养殖场进行调查,探讨鳄鱼场选址时的主要考虑因素：温度、饲料、市场与交通、水质和安全等,并认为在实际操作过程中,其他的一些因素,如土地权属和水电供应等也不可忽略。     

初情期前母猪垂体细胞LH和FSH的释放及其对GnRH类似物的反应

利用垂体细胞单层培养模型研究了30，60，90，120和150日龄北京黑猪母猪垂体细胞LH和FSH的释放及其对LRH－A3反应能力。结果表明，猪垂体细胞LH和FSH释放对LRH－A3的反应呈S形剂量依赖型同线。LH基础释放量和LRH－A3刺激的最大释放量在不同日龄间没有显著差异，说明初情期前母猪垂体细胞已达最大LH释放和对GnRH反应的能力。FSH的基础释放量和LRH－A3刺激的最在释放量在30日龄与60日龄之间无差异，但90日龄以后垂体细胞FSH的释施量随日龄增大而降低，提出可能由于垂体在体内时受过抑制素的作用。     

Isolation and identification of a South China strain of Plasmodium inui from Macaca fascicularis

Southeast Asian macaques are hosts of a number of Plasmodium infections, some of which are transmittable to humans. During examination of blood films of five wild-caught long-tailed macaques Macaca fascicularis from South China, malaria infection was detected in one of the monkeys. In order to isolate this parasite for identification and characterization, we experimentally passed this parasite through both Assamese (M. assamensis) and rhesus (M. mulatta) monkeys by intravenous injection of infected blood. This parasite morphologically resembled Plasmodium inui, and had a typical 72 h quartan periodicity. This parasite was infective to Anopheles dirus mosquitoes, and salivary gland sporozoites appeared 13 days post feeding. Feeding by 20 infected An. dirus mosquitoes on another Assamese monkey produced infection with a prepatent period of 8 days. Molecular analysis of the small subunit rRNA genes and the mitochondrial genome confirmed this parasite as an isolate of P. inui. In spleen-intact macaques, the infection had a protracted duration with parasites being detected during the rearing of the infected monkeys for over two years. In summary, this study identified a P. inui isolate and successfully passed this parasite through Assamese monkeys by both intravenous inoculation and mosquito transmission.     

Isolation and Identification of Aeromonas hydrophila from the Case of Channel Catfish Bowel Disease

To ensure the cause of suspected bacteria disease for channel catfish, the bacteria from clinical cases were isolated and cultured, then the biochemical and molecular biology assay, and animal regression test were used to identify the species of the isolated bacteria, bacteria medicine sensitive test was used to detect the bacterial drug resistance. The results showed that the bacteria were gram negative bacilli. The colony morphology and biochemical characteristics of the isolated bacteria were same as Aeromonas hydrophila. The sequencing test of the 16S rDNA also confirmed the isolated bacteria were Aeromonas hydrophila. The isolated bacteria could infect the healthy channel catfish and cause the same symptoms as the clinical case. The isolated bacteria were sensitive to floroquinolones and resistant to penicillin and cephalosporin drugs. The results showed that the pathogen of case catfish bowel disease was Aeromonas hydrophila, and the floroquinolones could use to prevent and treat the disease.     

苜蓿产量性状的分析与表型选择研究

通过对单株种植条件下苜蓿产量与株高、枝条数和枝条直径等性状问的遗传相关分析与通径分析,结果表明,在穴播条件下,株高是构成苜蓿单株产量的重要因素,与单株产量密切相关.枝条数与枝条直径对产量的直接作用相对不大.     

城市化进程中失地农民的利益保障问题

城市化进程中，农村集体土地大量地被征用，大量农民成为失地农民。失地农民为我国城市化发展做出了巨大贡献，但他们的利益却没有得到根本的保障。为此，从当前失地农民的利益损失入手，对造成其利益损失的原因进行了探讨，最后提出了应该从短期和长期两方面出发，采取积极有效的措施，妥善解决失地农民的利益保障问题。