基于16S rRNA序列的角蟾科部分属间系统关系

采用最大似然法(ML法)、最大简约法(MP法)、邻接法(NJ法)对来自角蟾科Megophryidae(Anura)8属17种及外群2种共25条400bp左右的线粒体16S rRNA序列进行系统发育关系分析。结果表明,用于分析的所有角蟾科物种形成两大支,第一支包括Megophrys,Brachytarsophrys和Atympanophrys,第二支包括Leptobrachium,Leptolalax,Scutiger,Oreolalax和Vibrissaphora。支持将角蟾科划分为两大类群,即第一支属于Megophryini族．第二支属于Leptobrachiini族。根据分子钟模型初步推测两类群问的分歧时间大致为14．2～18．7百万年前。在Megophryini族中,基因树的拓扑结构不支持Atympanophrys建立后的Megophrys为单系;而在Leptobrachiini族中,Leptolalax为一有效属,其系统发生较早。     

鼎湖山森林土壤渗透水酸度和无机氮含量对模拟氮沉降增加的早期响应

在林地分别喷加0、50、100和150kg N hm^-1a^-1,研究鼎湖山马尾松林、马尾松针阔混交林和季风常绿阔叶林中土壤20cm深渗透水酸度和无机氮含量在开始9个月的变化。结果表明,3种森林对照样方土壤渗透水pH值为3．82—4．24,外加氮处理使其平均降低了0．08—0．18。3个森林对照样方土壤渗透水无机氮平均含量分别为6．14、6．66和11．64mg L^-1,铵态氮占15．0％、11．9％和3．0％。外加氮处理使3种森林土壤渗透水铵态氮和硝态氮含量均有不同程度的提高,这表明外加氮处理不但增加了无机氮从森林土壤流失的潜力,而且使土壤进一步酸化。     

炎症及炎症耐受模型筛选广谱趋化因子抑制肽

通过减少炎性组织或细胞趋化因子及炎性因子的表达量能将炎症性病理过程抑制在起始阶段．我们通过体外构建人外周血单个核细胞LPS激活的急性炎症模型及内毒素耐受模型,进行噬菌体肽库亲和筛选,ELISA检测与炎性PBMC的结合能力,分泌抑制实验筛选抑制性噬菌体克隆,经趋化抑制、竞争结合及生成抑制实验检测体外活性,大鼠足肿胀及关节炎模型检验多肽体内作用,SqRT-PCR检测趋化因子及TTP的mRNA水平,探讨其作用机制．筛选到的目标多肽CI-S5趋化抑制率达到48.72%,明显抑制噬菌体阳性克隆P15与LPS激活PBMC的结合,动物试验能明显降低大鼠足肿胀及关节炎症．机制研究显示,CI-S5多肽能降低3种趋化因子的表达量,并调节TTP使其表达增加,提示CI-S5能够靶向炎症前期PBMC,为炎症治疗提供了针对早期急性炎症反应的广谱小分子抑制肽．     

湖北省维管植物分布新记录

报道了湖北省神农架大九湖国家湿地公园内发现的湖北省维管植物分布的新记录类群,包括1个新记录属大爪草属（Spergula Linnaeus）,含1个新记录种大爪草(Spergula arvensis Linnaeus);1种新记录的蕨类植物宪需耳蕨(Polystichum kungianum H. He & Li Bing Zhang);1个新记录变种,倒钩琉璃草[Cynoglossum wallichii var. glochidiatum (Wallich ex Bentham) Kazmi]。这些新分布类群丰富了湖北省的植物多样性,为本地区的植物区系研究提供了新资料。     

珍贵固氮树种降香黄檀与二代巨尾桉混交种植对土壤微生物群落结构和功能的影响

该研究以二代巨尾桉/降香黄檀混交林(MP)作为研究对象,并以邻接的二代巨尾桉纯林(PP)作为对照(CK),采用磷脂脂肪酸(PLFAs)和土壤酶活性分别表征土壤微生物群落结构和功能,重点探究南亚热带PP引入降香黄檀混交种植对土壤微生物群落结构和功能的影响.结果表明:(1)与PP相比,MP的土壤有机碳(SOC)、总氮(TN...     

中国瘿蚊一新种记述(双翅目,瘿蚊科)

记述采自浙江省的端突瘿蚊属Epidiplosis 1新种:指状端突瘿蚊Epidiplosis dactylina sp.nov,.模式标本存放于山东农业大学昆虫标本室.     

Comparison of Endocrine Response to Stress Between Captive-Raised and Wild-Caught Bighorn Sheep

ABSTRACT Stress hormones in Rocky Mountain bighorn sheep (Ovis canadensis canadensis), produced in response to environmental changes, road development, or high population density, may impact their immune systems to a threshold level that predisposes them to periodic, large-scale mortality. We compared the stress response to a novel environmental situation and repeated handling between bighorn sheep born and raised in captivity (CR) and bighorn sheep born in the wild (WC) and brought into captivity. We measured plasma epinephrine, norepinephrine, cortisol, and fecal glucocorticoid metabolites (FGM). Three weeks after each group's arrival we used a one-time drop-net event to elicit an acute stress response, and we collected blood samples from each sheep over 35 minutes, as well as one fecal sample. We collected blood and fecal samples from both groups on 7 other occasions over the subsequent 6 months. We also collected fecal samples from the pen at approximately 24-hour intervals for 3 days following every handling event to monitor the stress response to handling. We found that CR sheep had a stronger autonomic nervous system response than WC sheep, as measured by epinephrine and norepinephrine levels, but we found a very similar hypothalamic-pituitary–adrenal axis (HPA) response, measured by cortisol levels, to the acute stress event of a drop-net restraint. We also found that once the WC sheep had acclimated, as indicated by the return to the initial baseline FGM levels within 12 weeks, the CR and WC groups' HPA responses to sampling events were not significantly different from one another. Fecal samples can provide a noninvasive mechanism for managers to monitor baseline FGM for a given herd. Using long-term monitoring of FGM rather than values from a single point in time may allow managers to correlate these levels to outside influences on the herd and better understand the impacts of management changes, population density, or increased human developments on the health of the sheep population.     

尖孢镰刀菌M1耐热蛋白酶纯化及酶学性质

[背景]前期工作中,从北大仓白酒大曲分离到一株真菌,经形态学和分子生物学方法,将其鉴定为尖孢镰刀菌(Fusarium oxysporim) M1,研究发现该菌能产中性蛋白酶.中性蛋白酶是应用于工业化生产的重要酶制剂.由于其作用条件温和、催化速率较高,被广泛应用于食品、医药、皮革、饲料、化工和废弃物处理行业.[目的]为了...     

Fluorescent vital staining of plant sexual cell nuclei with DNA—specific fluorochromes and its application in gametoplast fusion

DNA－binding fluorochromes are often used for vital staining of plant cell nuclei.However,it is not always sure whether the cells after staining still remain in living state.We chose several criteria to estimate the validity of real vital staining for sexual cell nuclei.These were:the cytoplasmic streaming in pollen tubes whose nuclei were stined,the simultaneous visualization of fluorochromatic reaction and nucleus staining in isolated generative cells,and the capability of isolated.prestained generative or sperm cells to fuse with other protoplasts.The results confirmed that 4,6-diamidino-2-phenylindole(DAPI),Hoechst 33258 and mithramycin could be used as real vital stains,though their efficiency varied from case to case;among them DAPI showed best effect.The fluo rescent vital staining technique offered a useful means foridentification and selection of heterokaryons in gametoplast manipulation studies.