动物生理学实验教学单独设课之重要性

在高校的动物生理学教学中,实验教学是其中的一个重要组成部分。作为课堂教学的重要辅助和补充,动物生理实验教学效果对课堂教学具有极大的驱动作用。为突出动物生理实验教学的重要性,对动物生理学实验施行单独设课,这是考查理论教学效果、促进实验课教学质量的一种重要措施。     

昭通南方草山退化及人工改造对土壤种子库的影响

土壤种子库在退化生态系统的恢复中发挥着重要作用。本研究选取了昭通南方草山的4类草地,采集土样后通过萌发实验揭示其土壤种子库特征。结果表明：4类样地的土壤样品中共萌发出45种植物,隶属于20科39属,种子库储量为3 087～18 553粒·m^-2,种子库密度随土层加深均在逐渐降低。与轻度放牧草地相比,过度放牧草地的土壤种子库密度下降,但物种数量和多样性增加;严重退化的稀草裸斑土地种子库密度则显著降低(P<0.05),物种数量和多样性减少;而人工改造后的草地种子库密度显著增高(P<0.05)、物种数量和多样性也达到最高。昭通南方草山种子库与地上植被的总相似性系数为0.22～0.45,过度放牧草地、稀草裸斑土地和人工改造草地种子库与地上植被的相似系数均高于轻度放牧草地。总之,昭通南方草山退化和人工改造对土壤种子库产生巨大影响,上述结果可为后期退化草地治理提供理论依据。     

Heat stress-induced mucosal barrier dysfunction is potentially associated with gut microbiota dysbiosis in pigs

Heat stress(HS)can be detrimental to the gut health of swine.Many negative outcomes induced by HS are increasingly recognized as including modulation of intestinal microbiota.In turn,the intestinal microbiota is a unique ecosystem playing a critical role in mediating the host stress response.Therefore,we aimed to characterize gut microbiota of pigs’exposure to short-term HS,to explore a possible link between the intestinal microbiota and HS-related changes,including serum cytokines,oxidation status,and intestinal epithelial barrier function.Our findings showed that HS led to intestinal morphological and integrity changes(villus height,serum diamine oxidase[DAO],serum D-lactate and the relative expressions of tight junction proteins),reduction of serum cytokines(interleukin[IL]-8,IL-12,interferongamma[IFN-g]),and antioxidant activity(higher glutathione[GSH]and malondialdehyde[MDA]content,and lower superoxide dismutase[SOD]).Also,16S rRNA sequencing analysis revealed that although there was no difference in microbial a-diversity,some HS-associated composition differences were revealed in the ileum and cecum,which partly led to an imbalance in the production of short-chain fatty acids including propionate acid and valerate acid.Relevance networks revealed that HS-derived changes in bacterial genera and microbial metabolites,such as Chlamydia,Lactobacillus,Succinivibrio,Bifidobacterium,Lachnoclostridium,and propionic acid,were correlated with oxidative stress,intestinal barrier dysfunction,and inflammation in pigs.Collectively,our observations suggest that intestinal damage induced by HS is probably partly related to the gut microbiota dysbiosis,though the underlying mechanism remains to be fully elucidated.     

Foot use and hand preference during feeding in captive black‐and‐white snub‐nosed monkeys (Rhinopithecus bieti)

Postural origin theory predicts that body postures are related to hand preference in nonhuman primates due to hemispheric specialization. Foot preference, especially in manipulating objects, is also a good predictor of hemispheric specialization in humans. We studied limb (hand and foot) preferences in 11 captive adult black‐and‐white snub‐nosed monkeys (Rhinopithecus bieti) to see how limb preference is influenced by postures and foot manipulation. Hand preference was significantly different for this group between quadrupedal standing and clinging postures, and sitting and clinging postures, but not between bipedal standing and clinging postures. Individuals were significantly more likely to use the right hand in the clinging posture than in quadrupedal standing or sitting postures. In the sitting posture, individuals maintained their respective hand preference even when the food was on the other side of the body. There was a gender difference in the sitting posture, where females preferred their right hand but males preferred their left. Individuals who did not routinely use their feet to manipulate objects, compared to those who did, shifted to greater right hand use from the clinging posture to the bipedal posture. One male individual and his offspring were more likely to use their feet to manipulate objects than the rest of the monkeys. In the present study, we reveal the first evidence of a postural effect on hand preference in R. bieti as well as a foot preference in this species. Our results mostly agree with the postural origin theory and hemispheric specialization.     

不同缓控释氮肥对高羊茅草坪生长及氮素挥发的影响

 通过田间试验,研究了氮释放期为３０和６０ｄ的树脂包膜尿素（ＰＣＵ３０、ＰＣＵ６０）,硫包衣尿素（ＳＣＵ）,抑制剂型缓释尿素（ＵＩ）和普通尿素（Ｕ）对高羊茅草坪生长、氮素吸收及氮素挥发的影响。结果表明,在全年施氮量２６０ｋｇ／ｈｍ^２ 的情况下,ＰＣＵ３０、ＰＣＵ６０和ＳＣＵ 一年分春秋２次施用可以满足高羊茅草坪正常生长需要,其草屑累积量和氮素吸收量显著高于普通尿素一年４ 次施用处理;氮素气态损失方面,ＵＩ处理的氨挥发损失氮量高达４４．４２ｋｇ／ｈｍ^２,显著高于其他施氮处理,其Ｎ_２Ｏ 排放氮量为６．４６ｋｇ／ｈｍ^２,显著低于其他施氮处理;ＰＣＵ３０、ＰＣＵ６０、ＳＣＵ 处理的氨挥发量和Ｎ_２Ｏ 排放氮量分别为１７．６７,１３．５９,１８．５４ｋｇ／ｈｍ^２ 和８．１４,６．９２ ,９．９１ｋｇ／ｈｍ^２,显著低于Ｕ处 理。综合考虑各种因素,建议高羊茅草坪一年分春秋２次施用树脂包膜尿素ＰＣＵ６０较为适宜,可有效提高肥料利用率、降低氮素挥发损失,环境效益明显。     

实验性脾虚证与自由基代谢的相关性及四君子汤对其的调整作用

分别用小承气汤和利血平复制大鼠脾虚证模型，通过检测血清和心、肝、脾、肾等组织中抗氧化酶SOD和GSHP－Px的活性及脂质过氧化反应终产物MDA含量，研究脾虚证与自由基代谢的相关性及四君子汤对其影响。结果表明：两种方法复制脾虚证模型与对照组比较均表现为SOD活性显著升高（P＜0．05），GSH－Px活性显著降低（P＜0．05）；四君子汤反证治疗组与脾虚证组比较表现为SOD活性显著下降（P＜0．05），GSH－Px活性显著升高（P＜0．05），MDA含量显著降低（P＜0．05），与正常对照组接近。表明大鼠虚证动物模型与体内自由基代谢紊乱，脂质过氧化作用增强存在一定关系，健脾益气方药四君子汤能够提高体内抗氧化酶活性，拮抗自由基对生物膜的过氧化损伤，具有抗脂质过氧化损伤的作用。     

表达猪圆环病毒2型cap蛋白的重组罗伊氏乳酸杆菌在小鼠诱导的免疫应答分析

旨在构建表达猪圆环病毒2型（PCV2）cap蛋白的重组罗伊氏乳酸杆菌（Lactobacillus reuteri,L.reuteri）,并评价其在小鼠体内诱导的免疫应答效果。利用PCR扩增实验室分离保存的PCV2b型毒株的cap蛋白基因,以猪源L.reuteri为宿主菌,构建表达cap蛋白的重组菌株pPG-T7 g10-PPT-cap/L.reuteri,通过口服免疫BALB/c小鼠。采用间接ELISA方法测定免疫后小鼠血清中抗原特异性IgG抗体水平,粪便、鼻腔洗液、生殖道洗液、肠黏液中抗原特异性sIgA抗体水平,小鼠血清中各细胞因子水平;MTT法检测小鼠脾淋巴细胞增殖水平;流式细胞技术检测小鼠脾淋巴细胞中CD4⁺T细胞、CD8⁺T细胞的水平;荧光定量PCR检测免疫后攻毒的小鼠体内器官的病毒载量。结果显示,口服免疫重组乳酸菌组小鼠血清IgG抗体水平显著高于对照组（P<0.01）;小鼠粪便、鼻腔洗液、生殖道洗液、肠黏液中sIgA抗体水平显著高于对照组（P<0.01）;小鼠血清中细胞因子水平和对照组相比,IFN-γ、IL-2、IL-4、IL-12水平升高,IL-10水平降低,IFN-α无显著变化;体外孵育PCV2和小鼠脾淋巴细胞结果表明,重组乳酸菌组小鼠脾淋巴细胞增殖刺激指数显著高于对照组（P<0.01）;流式细胞技术检测结果显示,口服免疫重组乳酸菌组小鼠脾细胞中CD4⁺T细胞、CD8⁺T细胞含量高于对照组;荧光定量PCR结果显示,相比于对照组,口服免疫重组乳酸菌组小鼠体内的病毒载量明显低于对照组。综上所述,本研究成功构建了表达PCV2 cap蛋白的重组罗伊氏乳酸杆菌,经口服途径免疫动物,构建的重组乳酸杆菌能够刺激小鼠产生体液免疫和细胞免疫应答,且具有一定的免疫保护效果。     

透过期货价格看豆粕市场的潮起潮落

养殖行业和饲料行业在分析大豆、豆粕和玉米市场的现货供求状况和价格变动趋势的时候．透过期货市场可以得到许多在现货市场上无法得到的信息，而且方法非常简单．成本也更加低廉。因为期货市场充分竞争集中买卖的机制使价格涨跌更具预见性，而且其不同到期月份的合约和上下游产品期货价格间多层次价差结构更能充分反映当前市场的主要矛盾，从而为企业判断市场形势提供了更为全面可靠的依据。     

城市绿地土壤肥力评价的未确知属性测度分析法

基于未确知数学理论和属性数学理论,研究了土壤肥力综合评价方法,建立了城市绿地土壤肥力综合评价及分级的未确知属性测度分析法。该方法首先需要确定城市绿地土壤肥力状况的评价指标及分类标准,以及土壤肥力状况级别组数;然后构建单指标的未确知属性测度函数,以计算单指标的未确知属性测度函数值和样本的综合未确知属性测度值;最后应用置信度准则对城市绿地土壤样本进行识别,以确定土壤样本肥力状况的级别属性。基于两个城市绿地土壤样本的模糊综合评价结果,以及13个城市绿地土壤样本的全排列多边形图示指标法、物元可拓法以及改进的人工神经网络法的评价结果进行了验证,本研究方法的评价结果与模糊综合评价法、全排列多边形图示指标法、物元可拓法以及改进的人工神经网络法的一致性分别为100%、84.62%、92.31%和100%。实例评价表明,采用该方法对城市绿地土壤肥力状况进行评价是可行的,为城市绿地土壤肥力综合评价提供了新的途径和方法。     

透明颤菌血红蛋白基因(vgb)在大肠杆菌中的高效表达

利用PCR技术将透明颠菌血红蛋白基因（vgb）克隆到融合表达载体pET28a，在大肠杆菌BL21（DE3）表达。重组蛋白在30℃诱导获得可溶表达。利用Ni^2＋亲和层析对重组蛋白进行了纯化，得到重组的透明颠菌血红蛋白，蛋白呈红色。实验现象显示重组蛋白与血红索相结合。紫外光区和可见光区波长扫描分析显示：蛋白粗提物和纯化后的血红蛋白在230nm和413nm都有强吸收峰，初步表明，尽管重组蛋白比天然蛋白多36个氨基酸，重组蛋白仍然具有生理活性。诱导后4h和6h的培养液氨基乙酰丙酸含量分别达到17mg／L和21mg／L。说明重组蛋白的表达明显促进了体内heme合成途径。