Shedding and Seroprevalence of Pathogenic Leptospira spp. in Sheep and Cattle at a New Zealand Abattoir          下载免费PDF全文

F. Fang  J. M. Collins‐Emerson  A. Cullum  C. Heuer  P. R. Wilson  J. Benschop 《Zoonoses and public health》2015,62(4):258-268

A cross‐sectional study was carried out on sheep and cattle slaughtered at a New Zealand abattoir from September to November 2010 to investigate the supplier‐specific shedding rate, renal carriage rate and seroprevalence of leptospires. In the 2008/2009 season, this abattoir experienced three human leptospirosis cases from 20 staff, of which two were hospitalized. Urine, kidney and blood samples were collected from carcasses of 399 sheep (six suppliers, 17 slaughter lines) and 146 cattle (three suppliers, 22 slaughter lines). The urine and kidney samples were tested by quantitative real‐time PCR (qPCR), while serum samples (from coagulated blood samples) were tested by microscopic agglutination test (MAT). In total, 27% (73/274; 95% CI: 18–37) of urine samples tested positive by qPCR. Species‐specific shedding rates (prevalence of positive urine qPCR) were 31% (95% CI: 17–48) for sheep and 21% (95% CI: 14–30) for cattle. For 545 kidney samples tested, 145 were qPCR positive (27%; 95% CI: 17–39). The average prevalence of kidney qPCR positivity was 29% (95% CI: 17–45) for sheep and 21% (95% CI: 15–28) for cattle. Three hundred and thirty of 542 sampled sheep and cattle had antibodies against Leptospira borgpetersenii serovar Hardjobovis (Hardjobovis) and/or Leptospira interrogans serovar Pomona (Pomona), based on reciprocal MAT titre ≥1 : 48 (overall seroprevalence of 61%; 95% CI: 48–73). Seroprevalence was 57% (95% CI: 40–72) for sheep and 73% (95% CI: 59–83) for cattle. Among the seropositive animals, 41% (70/170; 95% CI: 30–54) were shedding (tested positive by urine qPCR) and 42% (137/330; 95% CI: 30–54) had renal carriage (tested positive by kidney qPCR). Some risk management options for abattoirs or farms to prevent human leptospirosis infections include vaccination of maintenance hosts, the use of personal protective equipment, and the application of urine qPCR to detect shedding status of stock as surveillance and as an alert.  相似文献   

并列双箱梁桥面风致涡激振动试验研究     

陈政清  牛华伟  李春光 《湖南农业大学学报(自然科学版)》2007,34(9)

基于两座具有并列双箱梁的缆索承重桥梁,做了一系列的弹性悬挂节段模型风洞试验.结果表明,双桥面之间存在不可忽略的气动干扰效应,它对双桥面桥梁的涡激振动会产生不利影响.以平胜桥主梁节段模型为基础的风洞试验研究表明,并列双桥面之间的气动干扰效应随着桥面间距的增加而减弱,从而使主梁的涡激振动特性随两桥面之间的距离而变化,而增加阻尼是抑制双桥面涡激振动的有效手段.  相似文献   

基于窗口与运算的数据流降载方法     

马瑞民  吴亚娟 《东北林业大学学报》2009,37(10)

提出了一种新颖的局部降载方法,该方法通过滑动窗口与运算对数据流上相邻的滑动窗口中输出速率较大的基本窗口进行合并处理,解决CPU过载问题,达到了降载的目的.理论分析与运算结果表明所提出的降载方法是有效的.  相似文献   

蕾铃脱落对棉花果枝叶光合产物积累及“源”潜力的影响     

阚家强  刘玉  周治国  陈兵林  赵文青  胡伟  胡少鸿  陈阳  王友华 《中国农业科学》2023,56(9):1658-1669

【目的】棉花蕾铃脱落率常超过60%,蕾铃脱落后的果枝叶常作为“辅助源”对其邻位铃的发育起重要作用。探明棉花果枝叶在其对位蕾铃脱落后作为“辅助源”的潜力及其变化趋势,丰富棉花产量形成的“源-库”调控理论,为棉花补偿性生长的栽培管理提供理论依据。【方法】以中棉425为材料于2021年分2个播期（5月10日、6月1日）在江苏南京（118°50′E,32°02′N）南京农业大学牌楼试验站开展田间试验,研究果枝韧皮部阻断条件下,去库（化学法阻断第四、五、六果枝第一果节“蕾-对位叶”系统与主茎连接的韧皮部,同时去除该系统蕾/花,模拟蕾铃脱落条件）后棉花果枝叶形态特征、气体交换参数、碳氮物质及内源激素含量等叶片源能力相关指标的变化。【结果】（1）去库处理显著增加了果枝叶中果糖、蔗糖、淀粉、纤维素含量,却显著降低了其葡萄糖含量。随着时间的推延,去库后1 d,淀粉的增幅最大,纤维素增幅则主要在去库后3 d明显变大;去库后5 d,蔗糖、纤维素、淀粉的增幅较大。（2）去库后,糖分更多地以非还原性糖形式积累;光合产物更多地向淀粉形式分配;多聚糖/低聚糖呈先降低后升高的趋势,而果枝叶C/N则呈现先升高后下降的趋...  相似文献   

A Method for Digitization of Information for Cotton Plant Mapping   总被引：2，自引：1，他引：1  

《棉花学报》2018,30(1):92-101

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Length of winter coat in horses depending on husbandry conditions          下载免费PDF全文

Krzysztof Bocian  Katarzyna Strzelec  Iwona Janczarek  Zygmunt Jabłecki  Ryszard Kolstrung 《Animal Science Journal》2017,88(2):339-346

This paper analyzes changes in the length of coat on selected body areas in horses and ponies kept under different husbandry (stable) conditions during the winter‐spring period. The study included 12 Ma?polski geldings and 12 geldings of Felin ponies aged 10–15 years. Horses were kept in two stables (six horses and six ponies in each stable). The type of performance, husbandry conditions and feeding of the studied animals were comparable. As of December 1, samples of hair coat from the scapula, sternum, back and abdomen areas of both body sides were collected seven times. The lengths of 20 randomly selected hair fibers were measured. Daily measurements of air temperature in the stables were also taken. An analysis of variance (ANOVA) was performed using the following factors: the body part from where the coat was sampled, the subsequent examination and the stable as well as the interaction between these factors. The significance of differences between means was determined with a t‐Tukey test. The relations between air temperature in the stable and hair length were calculated using Pearson's correlation. It was found that air temperature in the stable impacts the length of winter coat in horses and ponies. The effect of this factor is more pronounced in ponies; as in the stables with lower temperatures it produces a longer hair coat which is more evenly distributed over the body in comparison with horses. Keeping horses and ponies in stables with a low air temperature accelerates coat shedding by approximately 25 days. Coat shedding begins from the scapula area.  相似文献   

鸭源新城疫病毒强毒株对鸭的致病性     

刘梅  程旭  沈欣悦  周生  韦玉勇  刘加圣  戴亚斌 《兽医大学学报》2014,(2):214-218,226

对鸭源新城疫病毒（NDV）强毒株JSD0812对鸭的致病性进行了研究。结果显示,对于15日龄雏鸭,JSD0812株病毒尿囊液的半数致死剂量（LD50）为101mL。15,30,45,60。110日龄鸭肌肉注射感染试验结果表明,所有日龄鸭感染JSD0812株后均可发病,但死亡率随日龄的增长而下降,110日龄鸭感染后未见死亡。鸭感染后可经咽喉和/或泄殖腔短期排毒,感染鸭组织器官中病毒分离率较低。  相似文献   

人工辅助授粉的理论与技术研究Ⅰ父本开花与散粉     

周宗岳  曹孟飞 《杂交水稻》1996,(4)

桂９９在试验条件下开花与散粉在时间上接近正态分布，跟开花相比，散粉比较分散，高峰出现较晚。花粉的空间分布很不均匀，随着对父本距离增加而急剧减少，５０％以上的花粉散落在父本行内。花粉有效率仅３．３％。  相似文献   

海南南繁生态区玉米自交系雄穗发育动态研究     

许海涛  彭舜磊  王文文  冯晓曦  郭海斌  张军刚  许波  王成业 《陕西农业科学》2023,69(8):11-18

为探明海南南繁生态区玉米自交系雄穗发育动态,以6个不同类型玉米自交系KWS2-4321、13H6、10H9、KWS2-2220、11H37、PHHJC为试验材料,研究了玉米自交系雄穗鲜重、雄穗体积发育动态,雄穗逐日开花与逐时开花规律及雄穗逐日散粉特点。结果表明：雄穗鲜重发育呈现先上升后下降趋势,雄穗发育第1～4 d鲜重变化不大,第7～10天鲜重迅速增加,第13～16天稍有下降,玉米自交系雄穗鲜重与发育日数间经拟合附合二次多项式数量关系;雄穗体积与雄穗鲜重变化趋势不同,随雄穗发育进程的推进呈先升高后下降,最后又升高的变化趋势;雄穗开花可持续6～8 d,第2～4 d为盛花期,超过开花总量50%,第1 d开花较少,第2～4天开花数急剧增加,第7～8天开花数显著降低;07∶00、08∶00雄穗开花数量较少,09∶00、10∶00雄穗开花数量迅速增加,其开花数超过当日总开花数40%,11∶00开花数有所下降,12∶00之后开花数显著减少;逐日散粉量随散粉日数的推进呈现先升高后下降趋势,散粉后2～4 d达最大峰值,散粉持续5～8 d,与逐日开花规律基本一致。雄穗鲜重第7～10天增加快,雄穗体积与雄...  相似文献   

Protective efficacy of commercial inactivated Newcastle disease virus vaccines in chickens against a recent Korean epizootic strain     

Woo-Jin Jeon  Eun-Kyoung Lee  Young-Jeong Lee  Ok-Mi Jeong  Yong-Joo Kim  Jun-Hun Kwon  Kang-Seuk Choi 《Journal of veterinary science (Suw?n-si, Korea)》2008,9(3):295-300

Despite the intensive vaccination policy that has been put in place to control Newcastle disease virus (NDV), the recent emergence of NDV genotype VII strains in Korea has led to significant economic losses in the poultry industry. We assessed the ability of inactivated, oil-emulsion vaccines derived from La Sota or Ulster 2C NDV strains to protect chickens from challenge with Kr-005/00, which is a recently isolated Korean epizootic genotype VII strain. Six-week-old SPF chickens were vaccinated once and challenged three weeks later via the eye drop/intranasal route. All vaccinated birds were fully protected from disease, regardless of the vaccine strains used. All vaccinated and challenged groups showed significant sero-conversion 14 days after challenge. However, some vaccinated birds, despite being protected from disease, shed the challenge virus from their oro-pharynx and cloaca, albeit at significantly lower titers than the unvaccinated challenged control birds. The virological, serological, and epidemiological significance of our observations with regard to NDV disease eradication is discussed.  相似文献