Accelerated vaccination schedule provides protective levels of antibody and complete herd immunity to equine influenza

Reasons for performing study: During the 2007 Australian equine influenza (EI) outbreak, an accelerated primary course 14 day intervaccination schedule was proposed, but not widely implemented. Expert opinion was divided as to the efficacy of such a schedule given the lack of published data. This study determined the level and duration of humoral immunity following administration of a recombinant canarypox‐vectored vaccine (ALVAC‐EIV) with a primary intervaccination interval of 14 days and booster at 105 days. Objectives: To examine whether protective levels of immunity of adequate duration were achieved following a primary course reduced from a minimum interval of 28 to 14 days. Antibody responses to 2 H3N8 American lineage virus strains (including A/equine/Sydney/6085/2007) were assessed and compared to previous challenge studies using ALVAC‐EIV at conventional intervaccination intervals. Methods: Fourteen Thoroughbred horses and 2 ponies from a rural racehorse training property in Victoria, Australia, were vaccinated with ALVAC‐EIV on Days 0, 14 and 105. Serial blood samples were collected over the next 32 weeks and tested with haemagglutination inhibition and single radial haemolysis (SRH) in full assays to evaluate the serological response. Results: All horses and ponies responded to the accelerated ALVAC‐EIV vaccination schedule. Mean SRH antibodies remained above those consistent with clinical protection for the duration of the study period. All vaccinates demonstrated high SRH antibodies 14 days following V2, thereby achieving 100% herd immunity to homologous viral challenge. Conclusions: An accelerated vaccination schedule conferred long‐lasting protective antibody levels despite a >50% reduction in the recommended V1–V2 interval. Potential relevance: High levels of rapidly acquired herd immunity are critical in containing an outbreak of such a highly contagious pathogen as EIV. In a strategic vaccination programme, it is important that horses remain protected for sufficient time to allow control programmes to succeed. An accelerated 14 day primary course intervaccination interval and booster at 105 days achieves both of these objectives.     

我国家具行业的木材干燥问题

我国的实木家具产品主要以硬阔叶树材为材料,原料价格昂贵,所以提高干燥质量、减少干燥降等是关键的工艺环节.针对目前家具业木材干燥的主要问题,笔者建议必须进行良好的预干,合理地制定和实施干燥工艺,并严格控制生产过程中家具材料的含水率变化.     

抗旱节水剂对果树生长及灌溉制度的研究

通过对保水剂和旱地龙这两种抗旱节水剂在苹果生长上的试验研究,分析了抗旱节水剂集成应用对土壤含水率、苹果产量、苹果品质(主要指可溶性固形物)的影响。结果表明,施用抗旱节水剂可增加土壤含水率和果实品质,增产达13365 06～19036 58kg/hm2,增加纯经济效益20570～34750元/hm2;水分利用效率提高,每1hm2节水892m3,同时对抗旱节水剂应用条件下的果树灌溉制度进行了研究,提出了不同降雨年型的灌溉制度。     

枫香木材干燥基准的测定与研究

在分析了枫香木材材性的基础上对枫香木材进行生产性窑干试验。试验表明:采用合理的干燥基准,3.3cm厚的锯材从含水率100％干燥到10％以下只需121h,试验干燥的锯材质量超过国家二级标准。文章最后分析了枫香木材干燥时开裂的机理及规律,并提出了相应的工艺措施。     

大径级火力楠木材干燥特性和干燥工艺研究

采用百度试验法研究木材干燥特性,利用小型木材干燥试验机分别对25 mm和40 mm厚锯材进行常规干燥试验研究锯材干燥工艺基准。结果表明,火力楠木材的百度干燥缺陷程度较轻,初期开裂等级为2,扭曲变形等级为2,截面变形等级为1,内裂等级为1;木材的干燥速度中等,等级为3。木材含水率为15%时的密度为0.679 g·cm^-3,属中等。木材的差异干缩很小,干燥过程产生开裂的趋势较小。采用制定的干燥基准对锯材进行常规干燥,25 mm厚锯材从初含水率87.9%干至终含水率9.1%,干燥用时169.0 h (7.0 d),平均干燥速率0.47%·h^-1;40 mm厚锯材从87.5%干至8.5%,干燥用时341.0 h (14.2 d),平均干燥速率0.23%·h^-1。2种厚度干燥锯材的平均最终含水率、干燥均匀度、厚度上含水率偏差、残余应力以及可见干燥缺陷方面的指标,均达到了国家标准规定的锯材干燥质量二级及以上级别的要求。本研究编制的2种厚度火力楠锯材的干燥基准合理,可为实际木材的干燥生产提供科学依据。     

膜下滴灌制度与生物炭用量对玉米生长及水氮利用效率的影响

为探明干旱地区盐碱地膜下滴灌不同灌水下限施用生物炭对玉米产量和水肥利用效率的响应差异及相互影响关系,提出较优的灌溉制度和生物炭用量。连续2年在河套灌区盐渍化农田玉米生长阶段进行小区控制试验,设计3个灌水下限[土壤基质势为-15(W15),-25(W25),-35(W35)kPa,灌水定额为22.5 mm]和3个生物炭用量水平[0(B0),15(B15),30(B30)t/hm²],2因素完全随机试验设计,共9个处理。测定并分析玉米全生育期0—15 cm土壤理化性状、作物生长特征和水氮利用效率。结果表明：不同灌水下限施用生物炭整体提高玉米全生育期土壤含水率、有机质和碱解氮含量,同一灌溉水平下生物炭用量越高,各指标提升的幅度越大。施用生物炭提高玉米地上部干物质积累量和产量,灌溉水利用效率和氮肥偏生产力显著提高,且生物炭施用当年的效果普遍优于翌年。相较于不施用生物炭的对照,W15、W25、W35条件下,B15使玉米产量平均增加12.8%,10.3%,14.2%,灌溉水利用效率提高14.2%,10.4%,12.9%,氮肥偏生产力提升12.8%,10.4%,14.0%,其节...     

Calculation model for the turnover number of steel ladle based on casting schedule

In order to realize optimization of production organization and put forward a reasonable calculation model for the turnover number of steel ladle, the turnover process and time of steel ladle are analyzed with steel ladle of Q steelmaking plant. Gantt charts of steel ladle turnover for single casting schedule and double casting schedule are drawn. Calculation model for turnover number of steel ladle is put forward by analyzing the relationship between casting schedule and the turnover time of steel ladle, and the accuracy of the model is verified by simulation method. Researches show that the turnover number of steel ladle can be reduced 1-2 by adjusting cast starting time, and have significance for the optimization of steel ladle production organization.     

温度及烟草CMV病株对烟蚜生长发育的影响

研究了19℃、22℃、25℃、28℃和31℃恒温条件下,CMV烟草病株和健康烟草与烟蚜Myzuspersicae(Sulzer)生长发育和繁殖的关系。研究表明,随着温度的升高,在健康烟株(对照)和病株(处理)叶碟饲养条件下,烟蚜的成虫寿命和世代历期都显著缩短,繁殖力减弱。19℃时烟蚜的成虫寿命和世代历期最长,31℃时烟蚜最短。CMV烟草病株对烟蚜存活率和繁殖力有显著影响,与对照相比,烟草病株造成烟蚜成活率降低。烟蚜取食CMV烟草病株时,19℃烟蚜的繁殖力最强为36.9头,31℃最弱为2.17头。净增殖率R0在22℃时最大,在31℃时最小。周限增长率λ和内禀增长率rm在28℃和31℃时最大,在22℃时最小。世代平均周期T和种群加倍时间t在22℃时最大,在31℃时最小。研究结果说明,烟蚜的生长发育和繁殖与温度和感染CMV的烟草有关。     

滩羊多羔性能的RAPD标记研究

用RAPD技术和混合分离分析 (BSA)方法对双羔家系的 2 6只滩羊和对照系的 2 5只单羔滩羊进行了RAPD检测。发现 :OPB1 7-530、OPB1 9-92 6和OPB2 0 -1 4 2 6三条DNA片段仅出现在多羔家系的母本及多羔母本与单羔父本杂交产生的部分后代中 ,而在对单羔羊的逐个检测中未出现这三条片段。据此可以推断三个DNA分子标记与多羔性能主基因可能相关。作者系统优化组合出了能使滩羊基因组DNA稳定扩增的RAPD体系     

间歇光照对肉仔鸡生产性能和氮存留的影响

选用４００只７日龄艾维茵雏鸡（公母各半），随机分为２组（公母分饲，垫料平养），按２～４周龄，５～６周龄，７周龄３个生长阶段，分别比较间歇光照制度和连续光照制度对肉仔鸡生产性能、腹脂和先利用效率的影响。试验重复一次，结果表明，间歇光照（ＩＬ）能显著降低２８日龄前肉仔鸡体增重和来食量，但随后出现补偿生长，到４２日龄时，公鸡的生长速度能得到完全补偿，获得与连续光照（ＣＬ）相似的体重，而母鸡体重仍低于相应的ＣＬ组。母鸡受到的前期生长抑制要到４９日龄时才能得到完全补偿。ＩＬ虽然降低了全期采食量，但却改进了饲料报酬。ＩＬ极显著地降低了２８日龄腹胀率，显著降低了４２日龄和４９日龄腹胀率。氮平衡试验表明，ＩＬ可提高干物质消化率和氮利用效率。