A dynamic, optimal disease control model for foot-and-mouth disease: I. Model description     

Kobayashi M  Carpenter TE  Dickey BF  Howitt RE 《Preventive veterinary medicine》2007,79(2-4):257-273

A dynamic optimization model was developed and used to evaluate alternative foot-and-mouth disease (FMD) control strategies. The model chose daily control strategies of depopulation and vaccination that minimized total regional cost for the entire epidemic duration, given disease dynamics and resource constraints. The disease dynamics and the impacts of control strategies on these dynamics were characterized in a set of difference equations; effects of movement restrictions on the disease dynamics were also considered. The model was applied to a three-county region in the Central Valley of California; the epidemic relationships were parameterized and validated using the information obtained from an FMD simulation model developed for the same region. The optimization model enables more efficient searches for desirable control strategies by considering all strategies simultaneously, providing the simulation model with optimization results to direct it in generating detailed predictions of potential FMD outbreaks.  相似文献   

Treatment of Pain in Rabbits     

《Veterinary Clinics of North America: Exotic Animal Practice》2023,26(1):201-227

  相似文献   

鸡新城疫油佐剂灭活疫苗的研究   总被引：3，自引：2，他引：3  

郑世兰  姜北宇 《华北农学报》1995,10(3):115-123

采用ＮＤ Ｌａｓｏｔａ株为种毒，福尔马林为灭活剂，７号白油为佐剂，吐温８０、司本８０为乳化剂，硫柳汞为防腐剂，高压匀浆泵为乳化工具，研制出ＮＤ油佐剂灭活疫苗。其剂型为双相型（Ｗ／Ｏ／Ｗ），呈稀薄乳状液，粒度为１ｕｍ左右，粘度≤１ｓ，通针性好。４￣８℃有效保存期１年。效力≥７０ＰＤ５０，最早产生免疫时间为１２天（１００％保护），生产中常用免疫剂量为２月龄内每只０．５ｍｌ，２月龄以上每只１．０ｍｌ皮下  相似文献   

Estrogen treatment enhances mesenteric lymphatic contractility in rats after hemorrhagic shock     

ZHANG Li-min  FENG Niu-niu  ZHAO Chen  ZHANG Yu-ping  NIU Chun-yu  ZHAO Zi-gang 《园艺学报》2021,37(1):66-71

AIM To investigate the effects of 17β-estradiol （E2） treatment on the mesenteric lymphatic microcirculation and isolated lymphatic contractility in rats after hemorrhagic shock, and to explore the relationship between contractility and the difference between intra- and extracellular calcium ion concentrations （［Ca²⁺］） of lymphatic smooth muscle cells （LSMCs）. METHODS Male Wistar rats were divided into sham group, shock group and shock+E2 group. The rats were subjected to hemorrhage ［（40±2） mmHg for 90 min］ and resuscitation with or without subcutaneous injection of E2 （2 mg/kg）. After resuscitation for 3 h, the mesenteric lymphatic microcirculation in vivo was observed. Moreover, the isolated mesenteric microlymphatic rings were prepared for the observations of lymphatic contractility evaluated by the indexes including end-systolic diameter, end-diastolic diameter, contraction frequency （CF） and passive diameter. Meanwhile, the difference between intra- and extracellular ［Ca²⁺］ of LSMCs was recorded during lymphatic contraction. RESULTS Treatment with E2 significantly enhanced the CF, total contractile fraction and lymphatic dynamics index in vivo in the rats after hemorrhagic shock, and increased the CF, the fractional pump flow and the difference between intra- and extracellular ［Ca²⁺］ of LSMCs in isolated lymphatics from the shocked rats （P<0.05）. CONCLUSION Estrogen treatment enhances lymphatic contractility in rats after hemorrhagic shock, which is related to enhancement of difference between intra- and extracellular ［Ca²⁺］ of LSMCs.  相似文献   

仔猪水肿病病原的分离、鉴定及生物学特性     

吴位珩  杨莉  任荣清  潘淑惠  伍春红 《贵州农业科学》2006,34(4):55-57

通过对引起贵州省仔猪水肿病病原的分离、鉴定和生物学特性的研究,分离到的菌株为致病性大肠杆菌,其因子血清型鉴定为O8∶K40∶K47;O25∶K19;O78∶K80;O29∶K?。药敏试验结果表明:该菌对菌必治、庆大霉素、链霉素、先锋V、头孢等抗生素敏感,对一些常见的抗生素如青霉素、四环素、氯霉素、苄拉霉素等产生了耐药性。因此,采用药物治疗该病时应根据药敏试验进行选择。  相似文献   

贵州火龙果溃疡病发生情况及发病因素调查     

柏自琴 《中国果业信息》2020,49(6)

溃疡病是火龙果种植上的重要病害。为掌握火龙果溃疡病在贵州火龙果主产区的发生情况和发病因素,为田间防控提供科学依据,特开展此调查研究。结果表明：罗甸、镇宁、关岭、望谟及贞丰5个主产县火龙果溃疡病均有不同程度发生,且主栽品种均可发病,各树龄果园均可发病。病害在冬季发生不明显,3月气温回升后病害开始陆续发生和扩展,4月上旬（清明前后）雨水较多病情迅速增长,是春季防控的关键时期。5~7月进入雨季,田间高温高湿,为病害大面积蔓延流行期,需及时做好田间防控,以保证火龙果安全生产。  相似文献   

观赏植物抗病育种现状     

刘光欣 《分子植物育种》2020,(2):514-519

观赏植物种类繁多,在这些植物的育种、销售及栽培过程中,与植物病害相关的各种病原物也被广泛传播。因此,培育抗病品种一直是园艺育种工作者的重要目标性状之一。在粮食作物中,抗病育种方面已经投入了很大的人力物力,新的生物技术不断被用于作物新品种的培育。但对于观赏植物而言,这些新技术应用范围还极为有限。本综述对园艺植物抗病育种现状进行了总结,并对育种前景进行了预测。  相似文献   

海带病害防治诊断专家系统的研究          下载免费PDF全文

张启宇  刘峰  贺强  陈英义  王承国  唐君玮 《农业工程》2024,14(4)

海带病害的诊断和防治是保障海带健康养殖的关键。为了提高海带养殖用户的病害诊断和防治水平,本文对海带病害诊断专家系统进行了研究。首先,研究了知识的获取,以学术期刊发表的文献为主,同时辅以专家的调研,收集整理28种海带病害;接着,选择产生式规则描述知识,并构造了规则库;最后,采用正向推理进行病害诊断。该系统采用JSP+Sevlet+JavaBean实现,可以满足海带养殖用户对病害防治诊断的需求,并指出了下一步的研究方向和内容。  相似文献   

禽病病理剖检诊断技术研究     

何玉珍 《广西农学报》2006,21(6):36-39

通过病理剖检,根据组织器官的病变特征来诊断禽病,已成为禽病诊断的重要手段.要搞好禽病剖检诊断,必须掌握禽类的解剖特点,识别禽类的正常组织器官,避免病理剖检时将正常组织器官误认作病变组织器官;必须熟悉各种禽病的特征病变并正确地辨认禽死亡后尸体的变化,避免把某些死后变化误认为是生前的病理变化;必须掌握正确的剖检诊断程序及方法,以确保剖检效率和发现有诊断价值的病变,并结合病禽发病情况和外部检查情况,认真而全面地分析剖检结果来做出初步诊断.另外,还应根据初步诊断,积极地实施防治实践来验证剖检初步诊断的正确性,不断地积累剖检诊断经验,提高剖检诊断水平.  相似文献   

白鲢出血病病原菌的鉴定   总被引：7，自引：0，他引：7  

何顺华  傅锦楠 《水产科技情报》1993,20(2):75-77

从患出血病的白鲢体内分离出两株细菌(编号为水_1、水_2),分别感染健康白鲢,人工复制白鲢出血病获得成功。对这两株细菌进行形态、营养需求、生长特性、以及生化反应等观察,作者认为,水_1菌为产碱假单胞菌(Pseudomonas alcaligenes);水_2菌为嗜水气单胞菌(Aeromonas hydrophila)。前者隶属于假单胞菌科(Pseudomonaceae),后者隶属于孤菌科(Vibrionaceae)。  相似文献