不同覆盖措施对盐碱地紫穗槐细根适应策略的影响

为分析不同覆盖措施对盐碱地以及紫穗槐(Amorpha fruticosa)细根垂直分布的影响,从而为宁夏引黄灌区盐碱荒地土壤改良与植被重建提供参考,本研究采用薄膜、沙子、稻草以及对照(无覆盖) 4种覆盖措施,并测定0–60 cm土壤环境因子(水分、温度、盐分、有机碳和有效氮);利用全株挖掘法,测量粗放型策略指标(细根生物量、细根长)和密集型策略指标(比根长、比根表面积)。结果表明:2016和2017年,3种覆盖措施中稻草覆盖保水效果最好,0–60 cm土层土壤水分增加了13.59%～14.38%;与对照相比,薄膜、沙子覆盖下土壤温度分别增加了8.48%～20.17%和5.07%～18.20%,稻草覆盖则出现降温效应。薄膜覆盖降盐抑盐效果最佳,土壤盐分降低了12.05%～45.10%,其次为稻草覆盖,土壤盐分下降了10.34%～34.73%,而沙子覆盖的土壤盐分则下降了4.42%～19.61%。2016和2017年稻草覆盖下土壤有机碳增加了6.61%～9.22%;2016年薄膜、沙子覆盖下土壤有机碳分别降低了13.95%、7.80%,而在2017年却分别增加了7.07%和5.77%。20...     

Bats adjust temporal parameters of echolocation pulses but not those of communication calls in response to traffic noise

Many studies based on acute short‐term noise exposure have demonstrated that animals can adjust their vocalizations in response to ambient noise. However, the effects of chronic noise over a relatively long time scale of multiple days remain largely unclear. Bats rely mainly on acoustic signals for perception of environmental and social communication. Nearly all previous studies on noise‐induced vocal adjustments have focused on echolocation pulse sounds. Relatively little is known regarding the effects of noise on social communication calls. Here, we examined the dynamic changes in the temporal parameters of echolocation and communication vocalizations of Vespertilio sinensis when exposed to traffic noise over multiple days. We found that the bats started to modify their echolocation vocalizations on the fourth day of noise exposure, with an increase of 42–91% in the total number of pulse sequences per day. Under noisy conditions, the number of pulses within a pulse sequence decreased by an average of 17.2%, resulting in a significantly slower number of pulses/sequence (P < 0.001). However, there was little change in the duration of a pulse sequence. These parameters were not significantly adjusted in most communication vocalizations under the noise condition (all P > 0.05), except that the duration decreased and the number of syllables/sequences increased in 1 type of communicative vocalization (P < 0.05). This study suggests that bats routinely adjust temporal parameters of echolocation but rarely of communication vocalizations in response to noise condition.     

3株猪胸膜肺炎放线杆菌山东株的分离及鉴定

从山东省几个猪场的疑似猪传染性胸膜肺炎病例中,采集病猪的肺脏、气管和扁桃体等病变组织,经细菌分离得到3个分离株BZ1株、BZ2株、BZ3株。经过革兰氏染色镜检、菌落形态观察、培养特性试验、生化试验、药敏试验、动物感染试验等一系列细菌学鉴定方法,可将3株分离菌鉴定为猪胸膜肺炎放线杆菌。     

Bio—G除臭剂对蛋鸡舍内氨气及产蛋性能的影响

在面积相等，饲养密度相近的2栋蛋鸡舍内连续15d喷洒Bio-G除臭剂，每天1次，每次5L，结果表明，喷洒Bio-G后，鸡舍氨气含量明显下降，但对蛋鸡产蛋性能无明显影响。     

用特殊方法"煮过的谷物"能给仔猪带来多种好处

饲料生产者根据猪的消化能力来细心地设计各个饲养阶段的日粮,以达到帮助改善猪的生长性能和健康的目的.有人建议可采用＂煮过＂的有特别形状的谷物,这种谷物是通过调控颗粒分裂和蒸汽膨化而加工出来的商用性的品牌产品,这种产品不仅可用于断奶前（教槽）日粮,而且可以用于断奶后和其他畜禽日粮中.     

A Preliminary Comparison of Lidocaine and Xylazine as Epidural Analgesics in Ponies

Xylazine (0.35 mg/kg) or lidocaine (0.35 mg/kg) was injected into the epidural space of six ponies to compare their effectiveness as epidural analgesics. Each pony received both treatments at 1 week intervals with the order of treatments randomized. Xylazine produced analgesia of significantly longer duration (247 +/- 58 minutes) than that produced by an equal dose of lidocaine (135 +/- 22 minutes). Mild transient ataxia of no clinical significance developed in all ponies with both treatments. Spinal cords were removed from two ponies and examined histologically. No discernible pathologic changes were noted.     

草地生态系统安全及其评价研究

探讨了草地生态安全及其评价的概念与内涵,认为草地生态系统安全判断与度量准则应该是草地生态系统健康、草地生态系统服务功能及生态风险与管理的科学统一。同时尝试提出了草地生态系统安全评价的"健康-服务功能-风险与管理(health-service-risk and management,HSRM)"模型,构建了HSRM评价模型的指标体系,提出草地生态安全评价中草地生态安全度计算公式和安全状态分级标准。     

鸭疫里默氏菌病的中西医结合诊治

根据福建省莆田市一起鸭疫里默氏菌病的发病情况,阐述了该病的临床症状、剖检病变与诊断,并结合临床经验提出了该病的防治措施。     

践踏和降水对环县典型草原土壤颗粒分维特征的影响

采用试验践踏与模拟降水控制试验,对16个不同试验组合样区表土(0~15 cm)质地的机械组成进行分析,结果表明,随着践踏强度增加,土壤颗粒表现出不同程度的粗化趋势,降水具有双向调节的作用。利用分形模型计算了土壤粒径分形维数,计算结果表明,分形维数指标与践踏强度呈负相关关系。但分形维数递减幅度与模拟降水处理水平相关,在模拟降水处理水平依次为干旱、自然降水、平水、丰水时,粒径分形维数递减幅度依次为4.33%,2.61%,1.34%和1.23%。降水与践踏的匹配关系,对形成确定的分形维数具有决定性作用。由于具有较高分形维数的土壤更易发生放牧侵蚀,若管理不善则会发展为荒漠化。因此,在此种意义上来说,土壤分形维数的测算对进一步研究放牧侵蚀机理和荒漠化形成过程可能具有推动作用。     

犬细小病毒病的病原学研究进展

犬细小病毒病是由犬细小病毒感染引起的一种急性传染病,以剧烈的呕吐、出血性肠炎和白细胞显著减少为主要特征,并可引起犬急性心肌炎。症状与猫泛白细胞减少症相似,是危害我国养犬业最为严重的传染病之一,可造成严重的经济损失。文章从病毒生物学特性、基因组结构、疫苗开发研制以及病原的检测方法等角度对犬细小病毒病的病原学研究进行了综述。