禁水条件下黄胸鼠存活耐受性的实验研究

目的　了解黄胸鼠在禁水条件下的存活耐受能力 ,为科学制定防制黄胸鼠的对策提供依据。方法　选取健康、非孕、无外伤的黄胸鼠 ,称量体重、鉴定性别。按性别分雌雄两组 ,分别为 8只和 7只 ;每日定时供给足量食饵 ,不供给水。每日定时称量并记录食饵的消耗量 ,直至黄胸鼠死亡 ,并称量其死亡后的体重 ,计算并分析其体重的变化和存活时间。结果　黄胸鼠在禁水条件下最长存活时间达 2 3d ,最短存活 5d ,平均存活 16 .7d ,其中雌性黄胸鼠、雄性黄胸鼠的平均存活时间分别为 18.4d和 14 .9d ,两者经统计学检验 ,差异不显著 (P >0 .0 5 )。黄胸鼠的亚成体组、成体Ⅰ组、成体Ⅱ组禁水耐受时间分别为 18.5、17.2、15 .2d ,雌性黄胸鼠和雄性黄胸鼠耐禁水存活时间 (d)和实验开始时的体重 (g)的直线回归方程分别为y =2 2 .4 2 2 - 0 .0 2 85x和y=16 .6 95 - 0 .0 16 6x。研究发现 ,随着体重的增加 ,黄胸鼠每千克体重的取食量呈下降趋势。结论　雌雄两组黄胸鼠对禁水有很强的存活耐受能力     

褐家鼠对大隆的实验室敏感性测定研究

目的实验室测定褐家鼠对第二代抗凝血灭鼠剂大隆的敏感性，为抗药性监测提供本底参数。方法参照全国鼠类抗药性监测协作组统一方法，在实验室作无选择性摄食试验。将试鼠雌雄分开，随机分组，按4个不同食毒期摄食0．00012％大隆毒饵。用Bliss计算机程序，计算不同食毒期与对应死亡率之间关系。结果褐家鼠性别之间对大隆的敏感性没有显著性差异（Pb〉0．05，PLFP50〉0．05），故雌雄数据合并计算，得毒力回归方程Y=3．62＋5．00z，LFP50、LFP99及其95％置信限分别是1．89（1．61—2．23）和5．52（3．65～8．34）。结论按WHO修订以致死99％敏感靶标鼠种的食毒期（LFR。）取整天数作为抗药性检验标准，湛江地区褐家鼠对0．00012％的大隆毒饵食毒期超过6d存活为产生抗药性。     

北京市昌平区肾综合征出血热监测分析

目的了解掌握肾综合征出血热 (HFRS)的流行规律 ,评价防治效果 ,制定合理的防治措施。方法HFRS病例诊断依据为“《中华人民共和国传染病防治法》规定管理的传染病诊断标准” ,经流行病学调查个案核实而确定。用夹夜法测定鼠密度 ,鉴定鼠种 ,采用直接免疫荧光法 (FAT)检测HV抗原抗体 :无菌采集疫区内完成基础免疫两周健康者 2毫升的静脉血 ,用间接免疫荧光法 (IFAT)检测荧光抗体。结果 1998- 2002年发病率波动在 0.49- 7.4010万 ,本地居民与流动人口HFRS发病差异显著 ( χ2 =31.69,P <0.0 1) ,出现春季高峰 ,15 - 50岁青壮年高峰 ,男女性别比为 1∶0.26,轻中型病例占 87.10 % ,预防接种抗体阳转率 96.61% ,褐家鼠占捕获总数的87.06% ,鼠密度为 5.07% ,2001年的病毒携带率最高为 6.98%。结论昌平区HFRS发病率呈迅速增长趋势 ,褐家鼠为优势鼠种 ,应开展以流动人口为主要对象的预防接种工作。     

黄胸鼠体表寄生革螨的种多度分布

目的 研究黄胸鼠体表寄生革螨的种多度分布，阐明革螨群落内物种数与个体数之间的关系。方法 原始资料来自对云南22个县（市）14年的零星调查。现场调查中所采集的革螨用霍氏液封制成玻片标本后于显微镜下鉴定至种。革螨种多度分布用对数正态分布模型拟合。结果 所采集到的18249份革螨标本鉴定为8科17属40种。毒厉螨、纳氏厉螨和柏氏禽刺螨占全部采集革螨的93．58％，其染螨率（7．46％～27．43％）和螨指数（0．3415～2．8324）较高，被确定为黄胸鼠的优势螨种。其中有19种革螨占全部采集革螨的6．25％，系一般种；另外18种革螨仅占0．17％，属于稀有种。在半对数直角坐标系中，黄胸鼠体表革螨种多度理论曲线拟合成功，曲线最高点（0对数区间）的11种革螨仅具有1个个体。从0对数区间到第9对数区间，革螨种类数显示逐渐下降的趋势。结论 黄胸鼠体表革螨种多度分布呈对数正态分布模式，大多数革螨属于一般种和稀有种，而优势种仅为少数种类。     

Introduced rats indirectly change marine rocky intertidal communities from algae- to invertebrate-dominated

It is widely recognized that trophic interactions structure ecological communities, but their effects are usually only demonstrated on a small scale. As a result, landscape-level documentations of trophic cascades that alter entire communities are scarce. Islands invaded by animals provide natural experiment opportunities both to measure general trophic effects across large spatial scales and to determine the trophic roles of invasive species within native ecosystems. Studies addressing the trophic interactions of invasive species most often focus on their direct effects. To investigate both the presence of a landscape-level trophic cascade and the direct and indirect effects of an invasive species, we examined the impacts of Norway rats (Rattus norvegicus) introduced to the Aleutian Islands on marine bird densities and marine rocky intertidal community structures through surveys conducted on invaded and rat-free islands throughout the entire 1,900-km archipelago. Densities of birds that forage in the intertidal were higher on islands without rats. Marine intertidal invertebrates were more abundant on islands with rats, whereas fleshy algal cover was reduced. Our results demonstrate that invasive rats directly reduce bird densities through predation and significantly affect invertebrate and marine algal abundance in the rocky intertidal indirectly via a cross-community trophic cascade, unexpectedly changing the intertidal community structure from an algae- to an invertebrate-dominated system.     

新型处方灭鼠诱饵的初步研究

目的研究适合广东省农田害鼠用的处方饵料。方法采用室内有选择条件下适口性检验法,配制饵料并对广东省农区主要农业害鼠黄毛鼠、板齿鼠、褐家鼠进行效果检测。结果初步筛选出适合不同害鼠种类的＂基本配方C＋引诱配方Ⅱ＂和＂基本配方G＋引诱配方Ⅰ＂2种处方饵料配方,当以稻谷为对照时,新型处方饵料对黄毛鼠、板齿鼠的摄食系数分别为2.97和2.89,对褐家鼠的摄食系数为1.76;适口性均为优。结论本研究为领域内的同类研究提供了借鉴与参考,研究成果为下一步处方诱饵应用技术研究奠定了基础。     

Litter size is negatively correlated with corticosterone levels in weanling and juvenile laboratory rats

An animal's environment during early life can strongly affect its physiological development. For example, litter size, i.e. the number of litter siblings, has been previously shown to strongly affect early growth in many small mammal species including laboratory rats. In the present study we tested whether natural, unmanipulated litter size is also associated with differences in stress hormone levels in young Long-Evans laboratory rats. We found a negative correlation between serum corticosterone (CORT) concentrations and litter size during two different stages of juvenile life. On postnatal day 17, shortly before weaning, this relationship was apparent with respect to basal CORT values. On day 33, however, two weeks after weaning, we found this relationship only when animals were challenged by a 10-min test on an elevated plus maze, but not in control animals (basal values). Although the physiological basis of these differences is not clear, we discuss two main, not mutually exclusive possibilities: (a) delayed maturation of the HPA axis in typically lower body mass pups of large litters, and (b) that such pups, encountering greater competition for maternal resources, adjust to this presumably more stressful developmental environment by down-regulating responsiveness of the HPA axis. In conclusion, our study provides evidence that a naturally varying feature of the developmental environment of many altricial mammals — number of littermates — may contribute to individual differences in stress-related physiology. Furthermore, it suggests the need to consider litter-size effects when investigating differences in animals' stress responses.     

云南省保山市啮齿类动物组成及生物学调查

目的调查和了解保山地区啮齿动物的组成、分布和生物学特征。方法对多年调查结果和监测资料的数据进行整理和分析。结果发现保山地区啮齿动物有6科21属46种。以黄胸鼠为优势种,占捕获总数的58.73%,该鼠是鼠疫菌的重要贮存宿主。密度高峰在室内出现于4、8、10月,在农田出现于5月和9月。该鼠全年均能繁殖,怀孕率年平均为5.48%,以4-5月最高（8.60%和9.01%）,其次为8-10月（6.31%～7.38%）,最低为1月（2.81%）;怀孕率消长呈双峰型,春末夏初峰期显著高于秋峰期（t=7.345,P〈0.01）。黄胸鼠两性之比雌性多于雄性。结论大面积灭鼠工作不仅大幅度控制了黄胸鼠的数量,也破坏了鼠类季节性变化的一般规律,这对鼠疫菌的长期保存可能起到抑制作用。