Defining the immune response to Ehrlichia species using murine models

Pathogenic bacteria belonging to the family Anaplasmataceae include species of the genera Ehrlichia and Anaplasma. Ehrlichia chaffeensis, first known as the causative agent of human monocytic ehrlichiosis, also infects several vertebrate hosts including white-tailed deer, dogs, coyotes and goats. E. chaffeensis is transmitted from the bite of an infected hard tick, such as Amblyomma americanum. E. chaffeensis and other tick-transmitted pathogens have adapted to both the tick and vertebrate host cell environments. Although E. chaffeensis persists in both vertebrate and tick hosts for long periods of time, little is known about that process. Immunological studies will be valuable in assessing how the pathogen persists in nature in both vertebrate and invertebrate hosts. Understanding the host immune response to the pathogen originating from dual host backgrounds is also important to develop effective methods of diagnosis, control and treatment. In this paper, we provide our perspective of the current understanding of the immune response against E. chaffeensis in relation to other related Anaplasmataceae pathogens.     

海兰（褐）父母代种鸡引入青海高寒地区的饲养试验

对从山东引入青海高寒地区的海兰（褐）父母代鸡进行了饲养试验。结果表明,引入鸡32周龄最高产蛋率达78%,25周龄后种蛋受精率达88%,入孵蛋的孵化率达75%,母鸡1～18周龄成活率为94%,19～60周龄成活率为92%。引入鸡的各项指标基本达到山东标准。     

退牧还草工程对内蒙古鄂温克旗经济社会效益的影响

以内蒙古典型项目区鄂温克旗为例,通过实证分析与理论分析,了解退牧还草工程实施的经济社会效益及影响因素。工程的实施使地区生产总值、农林牧渔业生产总值和牧民人均纯收入比实施前分别增长22.9%、30.6%和6.9%;单位面积草地畜牧业净收益、项目牧户家庭畜牧业收入同比增加28.69%和5.82%,畜牧业支出减少11.70%。畜牧业生产收益不仅受到退牧还草工程的影响,还受到牧户家庭自身特征的影响与作用,其中,牧户拥有的草地资源和劳动力参加率对畜牧业生产收益影响均十分显著,草地资源占有量标准化系数达到0.461。畜牧业收益还与户主的教育水平和干部经历存在着显著的正相关。研究可为完善补偿体系、巩固退牧成果、实现退牧还草工程的预期目标提供科学依据。     

桂林抗战文化与中国现代文学

抗战时期,桂林的抗战文化运动蓬勃发展,被誉为“文化城”。荟萃桂林的现代作家在中国共产党领导和文协桂林分会的推动下,众志成城,使得桂林的抗战文学创作空前繁荣,创作了一大批思想和艺术较高、影响较大的优秀文学作品,大大地丰富了我国现代文学宝库,在中国新文学史上写下了光辉的一页。     

Duration of estrus induced after GnRH‐PGF2α protocol in dairy heifer

Estrous expressions in dairy cows have been shortened and weakened. Dairy heifers, on the other hand, may not have had such changes in estrous signs as observed in cows, since they have less stresses than cows. The aim of this study was to describe the duration of estrus in a herd of dairy heifers. A total of 56 Holstein Friesian heifers estrus was synchronized using two different hormonal protocols. They were checked for primary and secondary estrous signs with the help of heat detection devices for 48 h at an interval of 4 h starting at 16.00 hour, one day after PGF_2α treatment. Onset and end of standing estrus during 48 h observation period was recorded in 35 of the 44 heifers coming into estrus within 5 days after PGF_2α treatment during the observation period. The duration of standing estrus on the average (±SD) was 9.7 ± 5.3 h. Percentage of heifers with standing estrus longer than 12 h was 40%, and 53% showed standing estrus only for 4–8 h. It is indicated that duration of estrus in dairy heifers has been shortened recently.     

五味子萃取物有效成分含量测定及其对鸡肉中肌苷酸含量的影响

作者采用高效液相色谱测定五味子萃取物有效成分含量,并研究其对肉仔鸡胸肌、腿肌肌苷酸含量的影响。试验选择1日龄艾维茵肉仔鸡200羽,公母各半,随机分为5组,每组设4个重复,每个重复10羽。各组间鸡体重无统计学上的差异（P>0.05）,试验全期56 d。空白组饲喂基础日粮（不添加任何药物）,试验组分别在基础日粮中添加黄霉素5 mg/kg、五味子萃取物0.1%、0.2%、0.4%。56日龄屠宰试验鸡,取胸肌、腿肌肉,测定肌苷酸含量。研究结果表明,各试验组胸（腿）肌肌苷酸含量均高于空白组与黄霉素组,其中0.4%五味子萃取物组与空白组和黄霉素组相比差异显著（P<0.05）。     

以全产业链思维优化甘肃省“粮改饲”生产力布局

用全产业链思维优化“粮改饲”生产力布局具有重要的现实意义和理论价值。本文以甘肃省为例,总结甘肃省“粮改饲”工作已取得的工作成效和不足,论述了“粮改饲”构建全产业链的必要性,初步探讨了甘肃省“粮改饲”全产业链模式和布局优化,并提出完善相关支持政策、培育壮大龙头企业、高度重视品牌建设和创新科技带动引领4条对策建议。 [关键词]全产业链|粮改饲|生产力布局|甘肃省     

西施舌的食谱分析

为了提高西施舌（Coelomactra antiquata）种苗和人工养殖的生长率与成活率,以人工培育的西施舌稚贝和自然海区采捕的成贝为材料,采用人工投饵试验观察与镜检胃含物方法,对西施舌的食谱进行分析,结果表明：西施舌的稚贝除幼体发育阶段摄食超微型单细胞藻类外,还摄食个体大小为20～60μm的直链藻（Melosira spp．）、条纹小环藻（Cyclotella striam）、库氏园筛藻（Coscinodiscus kiitzngii）、小形园筛藻（C．minor）、小形舟形藻（Navicula Parva）、柔软舟形藻（N．mollis）、盾形舟形藻（N．scutiformis）、颗粒菱形藻（Nitzschia granulata）、碎片菱形藻（N．frustulum）、琴式菱形藻（N．panduriformis）、盾形卵形藻（Cocconeis scutellum）、双标胸隔藻（Mastogloia binotata）、施氏双壁藻（Diploneis schmidtii）等微型浮游硅藻及底栖硅藻。成体西施舌的食物以硅藻为主,计有35属114种。其中,直链藻、小环藻、园筛藻、舟形藻、菱形藻、辐裥藻（Actinoptychus sp．）、三角藻（Trlceretium sp．）、脆杆藻（Fragilaria sp．）、斑条藻（Grammatophora sp．）、褶盘藻（Frybioptychus sp．）、马鞍藻（Campylodiscussp．）、盒形藻（Biddulphia sp．）和双眉藻（Amphora sp．）等13属占优势。此外,还摄食单细胞绿藻、甲藻以及原生动物,小型甲壳动物和蔓足类的六肢幼虫及有机碎屑。     

应用MTT比色法评价不同牛血清促细胞生长作用

细胞培养过程中血清的选择对细胞的促生长增殖具有重要作用。本试验分别以商品新生牛血清、自制新生牛血清、自制成年牛血清培养成纤维细胞、骨髓瘤细胞、杂交瘤细胞,通过MTT比色法来判断细胞的增殖能力,进而对血清质量作出评价。结果表明,自制新生牛血清具有良好的促细胞生长作用(相对生长率＞0.96),并且3次试验结果比较差异不显著(P＞0.05),具有较好的重复性;而成年牛血清和无血清空白对照组促细胞作用不明显。因此应用MTT比色法能够评价血清质量。     

推进种养结合的制约因素及政策建议

随着粮食增产的迫切需求和化肥工业的快速发展,我国种植业与养殖业养分物质循环断裂,推进种养结合成为实现农业绿色发展重要途径。但目前,我国从农户层面以及区域层面都存在着种植与养殖之间的纽带断裂,造成了农业资源利用的错位,也产生了资源环境双重压力。推进种养结合的堵点主要表现在养殖场责任尚未压实、有机肥施用不便利、堆肥质量标准缺失、社会化服务体系不完善等多方面。本文结合对国内和国际上推进种养结合的典型做法的分析,在强化提升国家粮食安全保障能力的大背景下,从优化种养布局规划、压实养殖主体责任、强化科技支撑、培育社会化服务组织等方面提出了当前构建全新的种养循环体系的建议。