广西：“粉蕉—果蔗轮作”技术研究与应用项目成效显著

正本刊讯(特约通讯员钱开胜)据广西农业农村厅网站有关消息,近日,专家组对广西区农业科学院生物技术研究所等单位承担的位于玉林市兴业县的粉蕉—果蔗轮作技术研究与应用示范基地进行过程查定。经测产,示范基地粉蕉单株重30.23 kg,平均种植密度为每667 m~2栽植120株,平均产量达3.60 t,产值达1.44万元。据悉,"粉蕉—果蔗轮作技术"破解了粉蕉与果蔗的连作障碍,解决了传统种植模式中,无论是果蔗还是粉蕉都存在土壤板结、病虫害严重,产品质量与品质下降等问题,创造了"3年粉蕉+2     

果蔗病害及其防治

果蔗 (Ｓａｃｃｈａｒｕｍｏｆｆｉｃｉｎａｒｕｍ)是一种营养丰富、价格低廉的消暑果品 ,其种植效益好。果蔗在栽培过程中 ,会受到多种病害的为害 ,严重影响其产量和品质。我省紫皮蔗等 9个地方品种病害发生的共同特点是 :甘蔗花叶病 (亦称嵌纹病 )和宿根矮化病发生普遍严重 ;根结线虫、矮化线虫等 10多种线虫病的为害造成严重的产量损失。由于线虫分布于土壤中 ,为害不易被觉察 ,防治难度大。因而 ,我国对甘蔗线虫病的研究尚处于空白。1　果蔗病害的发生与为害1 1　甘蔗花叶病 :该病是由甘蔗花叶病毒 (Ｓｕｇａｒ ｃａｎｅｃａｎｅｍｏｓ…     

无公害粉蕉高产栽培技术

为进一步推进特色农业产业化工程 ,汕头市绿园农业科技发展有限公司自 2 0 0 0年以来致力于优质台湾粉蕉无公害栽培技术的试验与研究 ,并取得显著效益。至 2 0 0 3年 8月 ,累计示范推广无公害粉蕉栽培面积 4 83 3hm2 。现将近年来无公害粉蕉栽培管理的技术经验整理如下。1　园地选择产地区域内及上风口、灌溉水源上游没有工业“三废”及其他污染源。要求土壤肥沃、土层深厚。平地蕉园要选用沙质壤土或轻粘壤土 ,土层深 1m以上 ,底土层不宜选重粘土、全沙或石砾未风化土。土壤要有团粒结构 ,含有机质 2 0 % ,速效磷0 0 0 2 5 %以上 ,速效钾 0 0 1 %以上 ,全氮 0 1 5 %以上 ,全磷 0 1 7%以上 ,全钾 0 0 5 %以上。地下水位低于 70cm ,土壤可溶性盐总量少于 0 0 5 % ,pH值5 5～ 8 0 ,空气含氟浓度低于 0 0 2mg/m3 。园地要连片 ,最好与水稻或其他作物轮作。2　肥水管理及吸芽留取2 1　施肥方法　粉蕉植株高大 ,根系发达 ,养分需求较多。经多年实践 ,采用“二轻、二重、二巧”的施肥方法较经济高效。“二轻” ,一是在定...     

设施栽培青椒疫病的综合防治

青椒疫病是一种由大水漫灌造成的土传病害。当田间温度达28～30℃、土壤湿度90%以上时，持续6小时左右，病菌即可完成侵染，2~3天就可发生1代，因此，青椒疫病是发病周期短、流行速度快的毁灭性病害。由于温室轮作较困难，年年重茬，土壤中病菌越积越多，危害越来越严重。据调查，病地连作1年，发病率为19.6%；连作2年发病率为21.76%；连作3年发病率可达30.16%。可见，疫病发生早晚及流行程度与初始菌量有密切关系，因而病地重茬发病早、病情重、蔓延快。病菌主要靠水传播，因此，疫病发生和流行与水分管理也有密切的关系。如果浇水早，次数多，水量大，就会发病早，危害重。一般发病高峰往往是浇水后或雨量高峰之后2~3天。此疫病比较难防治，根据疫病发生的特点，必须早防、早治，主要采取以下综合防治技术。1．病地实行轮作病地实行与其他蔬菜（如豆科、十字花科、百合科等蔬菜）轮作3年或与大田作物轮作2年，即可收到良好的效果。如果不能轮作，可在三夏期间利用太阳能高温消毒土壤病菌（即物理防治，也叫无公害防治），其防病效果显著，方法简便易行。具体措施：①病田拉秧后清洁田园；②每667m2施石灰100kg和碎稻草500kg，再翻耕土壤60cm...     

北疆平原荒漠区粮草轮作模式经济效益分析

为分析北疆平原荒漠区苜蓿（Medicago sativa）（1年）+小麦（Triticum aestivum）（3年）+苜蓿（1年）和小麦（1年）+苜蓿（4年）2种粮草轮作模式的经济效益,本研究在呼图壁核心试验区开展连续5年的实地调查,比较了两种模式下粮草产量、投入成本、利润和产投比。结果表明：小麦（1年）+苜蓿（4年）种植模式下年均总利润较苜蓿（1年）+小麦（3年）+苜蓿（1年）模式提高18.71%;老苜蓿地倒茬种植小麦的前两年籽粒产量较小麦连作增产25%;小麦倒茬轮作苜蓿后,苜蓿的干草产量呈逐年下降趋势,种植3~4年苜蓿的年均粮草利润为9 050 元·hm^-2,是小麦的3.26倍。综上所述,在粮食耕作系统中引入低成本苜蓿,可提高作物产量,增加轮作的利润,解决蛋白质饲料短缺的问题。     

西北灌区薯/豆连续套作对系统产量及土壤肥力的影响

探求马铃薯/大豆连续套作下复合群体产量优势,为实现持续高产的生产目标提供理论和技术依据。2011-2014年,在西北沿黄灌区会宁县郭城镇,选用马铃薯品种克新4号和大豆品种冀豆17作为试验材料,设置马铃薯连作(PM)、大豆连作(SM)、薯-豆轮作(P-S)、薯/豆套作连作(IC)和薯/豆套作轮作(IR)5种种植方式开展大田定位试验,研究不同种植模式连续种植4年对系统产量及产量构成的影响,分析系统生产力及土壤肥力的变化特点,进而揭示薯/豆套作系统的生产价值。结果表明, 1)薯/豆套作具有明显的产量优势,4年间,IC和IR系统产量与连作相比,分别提高了28.54%~254.07%和39.39%~283.98%,与轮作相比,分别提高了57.51%和70.81%。2011和2012年,IC与IR系统产量间差异不显著,但IC和IR与PM、SM、P-S处理间系统产量差异达到显著水平(P<0.05),2013和2014年IR系统产量均最高,分别达到9912.79和9589.90 kg/hm²,较IC处理分别提高了15.38%和8.45%,且与其他处理间均差异达到显著水平(P<0.05)。2)不同种植模式在年际间变化显著,对于PM,2012年(连作1年)与2011年(正茬)产量差异不显著,而2013年(连作2年)和2014年(连作3年)产量较2011年分别下降了22.07%和42.11%;SM和IC变化趋势与PM表现一致,连作2年后,降幅分别为31.15%~53.60%和13.91%~24.17%;对于P-S和IR而言,年际间系统产量无显著变化。3)不同种植模式对耕层土壤肥力性质指标的影响程度是:有效磷>碱解氮>全氮>全磷>速效钾>有机质>全钾>pH。较PM、SM和P-M,IC和IR连续套作4年,耕层土壤全氮、全磷、全钾、碱解氮、有效磷和速效钾呈下降趋势,尤其是有效磷和速效钾,下降幅度分别达到26.24%~42.87%和18.48%~30.22%。马铃薯和大豆连作2年后产量显著下降,薯/豆连续套作4年(IC或IR),相对于连作或轮作具有明显的生产力优势,尤其是薯/豆套作轮作模式,基于养分吸收量的增加和养分利用效率的提高,连续4年系统产量相对稳定。     

紫花苜蓿与草地早熟禾轮作模式对其农艺性状和营养品质的影响

为研究紫花苜蓿（Medicago sativa,本试验中记为A）与草地早熟禾（Poa pratensis,本试验中记为K）轮作对其农艺性状和营养品质的影响,本试验以种植5年的紫花苜蓿（A）和草地早熟禾（K）为前茬,在2块草地上分别种植紫花苜蓿（A）和草地早熟禾（K）,即形成AA,AK,KA,KK 4种种植模式,以AK和KA为轮作处理,AA和KK为连作对照。研究了轮作对紫花苜蓿和草地早熟禾各刈割茬次的株高、干草产量、干鲜比、茎叶比、粗蛋白（Crude protein,CP）、中性洗涤纤维（Neutral detergent fiber,NDF）和酸性洗涤纤维（Acid detergent fiber,ADF）等指标变化的影响。结果表明：第1~3茬,AK轮作草地早熟禾的株高较KK连作提高6.31%~9.47%,且在第2茬差异显著（P<0.05）。KA轮作紫花苜蓿的株高较AA连作提高6.72%~9.02%,且在第2茬差异显著（P<0.05）。AK轮作的草地早熟禾年干草产量较KK连作提高8.54%,KA轮作的紫花苜蓿年干草产量较AA连作提高11.57%。AK轮作草地早熟禾的干鲜比较KK连作在3茬间差异显著（P<0.05）,且增加幅度大于KA比AA的增加幅度。不同轮作模式对茎叶比的提高在后2茬差异明显。AK轮作下,草地早熟禾的粗蛋白含量比KK提高14.16%~15.95%,增长幅度优于KA比AA的增加幅度。AK轮作和KA轮作的中性洗涤纤维含量和酸性洗涤纤维在不同茬次较KK连作和AA连作模式差异显著（P<0.05）。紫花苜蓿与草地早熟禾轮作可以提高后茬牧草的株高、干草产量、茎叶比和干鲜比以及粗蛋白含量;并且降低后茬的酸性洗涤纤维和中性洗涤纤维。本试验旨在通过探究紫花苜蓿与草地早熟禾轮作下牧草农艺性状和营养成分的变化情况,为今后豆-禾牧草轮作、草种搭配以及模式排布提供借鉴依据。     

基于APSIM模型的黄土旱塬区苜蓿——小麦轮作系统深层土壤水分及水分利用效率研究

黄土高原地区降水较少且季节性分配不均,苜蓿连续种植所导致的深层土壤干燥化问题已经引起普遍关注,苜蓿与粮食作物轮作是恢复苜蓿草地土壤水分、提高粮草种植系统可持续性的有效方式。但是长期轮作对土壤水分环境和水分利用效率的影响仍然缺乏研究,农业生产系统模拟模型（APSIM）具有广泛的适应性,可准确模拟耕作管理对作物系统资源利用的影响。首先根据黄土旱塬区庆阳、长武、镇原3个试验区试验数据验证APSIM模型模拟苜蓿长期连作和苜蓿-小麦轮作系统深层土壤水分和苜蓿产量的可行性,然后设置历时38年的81组轮作情景,评估不同轮作模式对农田深层土壤水分、系统干物质产量、氮素吸收和水分利用效率的影响。结果表明：APSIM模型模拟苜蓿产量的精度较高,模拟结果的决定系数（R²）为0.65,均方误差（RMSE）和平均绝对误差（MAE）分别为0.23 t·hm^-2和0.17 t·hm^-2,归一化均方误差（NRMSE）为29.2%;模型能够精确模拟长期苜蓿连作和苜蓿轮作小麦农田0~1000 cm的土壤含水量,长期连作模拟结果的R²为0.73,RMSE、MAE及NRMSE分别为0.021 t·hm^-2、0.017 t·hm^-2和11.7%,轮作系统模拟结果的决定系数为0.83,RMSE、MAE及NRMSE分别为0.024 t·hm^-2、0.018 t·hm^-2和11.8%。情景模拟结果表明,随着苜蓿在系统中轮作年限的增加,0~1000 cm土壤剖面水分极度缺乏（含水量在0.10~0.15）的区域以400~600 cm土层为起点不断扩大,当苜蓿轮作年限大于12年时,所有轮作周期的处理土壤都出现了大范围水分缺乏。81个情景中12年苜蓿轮作14年小麦（L12W14）、L12W16和L8W16这3个处理的总产量最大;系统吸氮量随着苜蓿加入年限的增加而增加,小麦轮作年限大于10年以后系统吸氮量急剧下降;苜蓿轮作大于8年以后系统水分利用效率随着苜蓿年限的增加而降低。综合考虑土壤水分环境和水分利用效率,建议研究区苜蓿-小麦轮作系统中苜蓿轮作年限为4~6年,小麦轮作年限大于4年。研究结果可为黄土旱塬区苜蓿草地管理及草田轮作实践提供一定的参考。     

祁连山区轮作对燕麦土壤酶活性及微生物数量的影响

【目的】通过燕麦与油菜、箭筈豌豆、青稞、大麦等作物轮作，研究该种植模式对土壤酶活性和土壤微生物数量的影响。【方法】在山丹马场连续 3 年种植燕麦的地块上，设 6 个处理，分别种植箭筈豌豆、燕麦+箭筈豌豆、油菜、青稞、大麦、燕麦，研究不同处理下土壤酶活性及微生物数量的变化情况。 【结果】土壤酶活性随土层加深而逐渐下降，轮作较连作显著提高了土壤过氧化氢酶、蔗糖酶和碱性磷酸酶活性；燕麦与豆科轮作的土壤酶活性明显高于它与禾本科轮作，其中以燕麦-箭筈豌豆轮作效果最显著，开花期 0~20 cm 土层土壤过氧化氢酶、蔗糖酶和碱性磷酸酶活性较连作分别增加了 55. 92%、 20. 36% 和 51. 47%。轮作也显著增加了土壤微生物数量，其中燕麦→箭筈豌豆处理下增幅最大，0~ 10、10~20 和 20~30cm 土层土壤细菌数量较连作分别增加了 23. 34%、16. 51% 和 38. 92%（P＜0. 05）； 真菌数量分别增加了 110%、135. 29% 和 150%；放线菌数量分别增加 112. 65%、107. 41% 和 175. 38%。【结论】燕麦与豆科轮作对土壤酶活性和微生物数量的提高幅度显著大于它与禾本科轮作。 在祁连山区燕麦生产中，燕麦与箭筈豌豆轮作有望修复连作障碍，改善土壤环境。     

土壤熏蒸-微生物有机肥联用对连作马铃薯生长和土壤生化性质的影响

甘肃省中部沿黄灌区是全国重要的加工型马铃薯生产基地,但因集约化种植带来的连作障碍问题已严重影响到产业的健康发展,因而寻求能够缓解或克服马铃薯连作障碍的有效措施。本研究评估了土壤熏蒸和微生物有机肥联用的方法对马铃薯连作障碍的防控效果,特别是对植株生长发育、土传病害抑制以及微生物区系和酶活性等土壤生化性质的影响。田间试验共设置5个处理:对照(CK)、氨水熏蒸(SFA)、石灰+碳铵熏蒸(SFB)、氨水熏蒸与微生物有机肥联用(SFA+BOF)、石灰+碳铵熏蒸与微生物有机肥联用(SFB+BOF)。结果表明,SFA+BOF和SFB+BOF处理较CK均显著增加连作马铃薯的块茎产量,增幅分别达到13.62%和20.36%,也显著降低植株的发病率(54.92%和72.82%)和收获后的病薯率(66.15%和64.76%),并且提高叶绿素含量和改善根系形态结构。SFA+BOF和SFB+BOF处理显著影响土壤可培养微生物的数量,表现为增加马铃薯生育后期土壤细菌和放线菌的数量,降低真菌的数量,在土壤中维持一个更高的细菌/真菌。与CK、SFA和SFB处理相比,SFA+BOF和SFB+BOF处理大幅度降低了连作马铃薯生育期内主要土传致病菌——镰刀菌的数量,使植株发病率降低且块茎产量显著增加。SFA+BOF和SFB+BOF处理对连作土壤脲酶、蔗糖酶、脱氢酶和过氧化氢酶的活性无显著影响,但显著提高磷酸酶的活性。因此,土壤熏蒸和微生物有机肥联用的方法在克服甘肃省中部沿黄灌区的马铃薯连作障碍上具有较大的应用潜力,且石灰+碳铵熏蒸与微生物有机肥联用的效果优于氨水熏蒸与微生物有机肥联用。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Changes in proportion of canine urinary calculi composed of calcium oxalate or struvite in specimens analyzed from 1981 through 2001

The objective of this report was to characterize 20-year changes in proportion of calcium oxalate (CaOx) calculi and struvite calculi in dogs, and associations with breed, age, and sex. In this retrospective study, results of analysis of urinary calculi from dogs were reviewed for specimens received between July 1, 1981, and December 31, 2001. Breed, sex, age, year of submission of the specimen, and mineral type(s) were analyzed statistically. CaOx or Struvite or both were contained in 18,966 of 20,884 (91%) specimens. For both sexes, a 20-year statistically significant increase was observed in the proportion of calculus specimens that contained CaOx. The increase in this proportion was greater in females (1% to 31%) than in males (18% to 82%). From 1998 to 2001, when proportions may have plateaued, the odds of specimens containing CaOx were markedly higher in 18 breeds, markedly lower in 5 breeds, and not significantly different in 13 breeds compared with crossbreds. For both sexes, a 20-year statistically significant decrease was observed in the proportion of calculus specimens that contained struvite. This decrease in proportion was greater for males (79-16%) than for females (97-68%). From 1998 to 2001, when proportions plateaued, the odds of calculi containing struvite were markedly lower in 20 breeds, markedly higher in 1 breed, and not significantly different in 15 breeds when compared with crossbreds. Breed, age, and sex were associated statistically with CaOx or struvite urolithiasis. In conclusion, there appears to have been a long-term increase in the proportion of specimens of canine urinary calculi that contain CaOx as well as a long-term decrease in the proportion of specimens of calculi that contain struvite for both male and female dogs. The rate of change appeared to begin leveling off in the period 1998 to 2001. The recent proportion of dogs with either CaOx- or struvite-associated urolithiasis may depend on breed, age, and sex, and on interactions among these 3 factors.     

Smart Phone Assisted City-scale Wireless Sensor Network Deployment for Transportation System Monitoring

<正>1.INTRODUCTION Ensuring transportation network security is one Of the most daunting challenges confronting homeland security agencies today.Significant research has been dedicated.To model and analyze the vulnerability of transportation systems,while notably fewer studies propose specific strategies for deploying defensive technologies to safeguard these systems.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.