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1.
2003年6月至2004年5月,通过底拖网作业收集鱼类标本对广西合浦儒艮国家级自然保护区及其邻近水域鱼类种数进行了调查,并走访当地鱼市进行实地调查.共记录到保护区及其邻近水域的鱼类14目41科57种,其中55种为硬骨鱼类,占总数的96.49%,另有2种软骨鱼类,占总数的3.51%.有41种为暖水性鱼类,占总数的71.93%.生态类型中底层鱼类共37种,占总数64.91%.区系特征以北太平洋和印度太平洋区系为主.掠夺性获取和开发以及环境污染是目前这一水域鱼类资源面临的最大威胁,针对以上威胁提出了相应的保护对策.  相似文献   

2.
Laboratory-reared Lymnaea catascopium snails (1–269 days old) were exposed individually to different numbers of Schistosomatium douthitti miracidia. Increasing the exposure dosage from 3 to 10 miracidia generally increased infection rates, in some age classes up to 100%. Successful re-exposure of snails not infected after a primary exposure was possible. Neonatal snails were least likely to become infected, primarily because miracidia were not attracted to them. Snails 12–55 days old were most susceptible to infection. Miracidia were readily attracted to these snails, and many were ingested and subsequently penetrated the host esophageal wall. Miracidial penetration of external snail surfaces was rare. Susceptibility of older snails (65–269 days) progressively declined with age. Many miracidia were entangled and immobilized in mucus produced by these snails, and fewer were ingested. No conspicuous host cellular responses to mother sporocysts were observed in any of the snails sectioned. A comparison of susceptibility of deliberately stunted snails and comparably aged controls of normal size indicated that the former were more susceptible.  相似文献   

3.
To catalog polypeptides that were specific to developing hearts, we separated 35S-methionine-labeled 9.5 day mouse embryos into cardiac and noncardiac (carcass) components. Two-dimensional gels were then used to analyze the polypeptides synthesized in these two fractions. As a result, we were able to distinguish polypeptides that were specific to or increased in the heart as well as those polypeptides that were specific to or increased in the embryo minus the dissected heart. Using this analysis, there were two polypeptides that were cardiac-specific and 17 that were expressed at increased levels by at least twofold in the heart. The cardiac-specific polypeptides may be used in further studies to identify early cardiac tissue. Conversely, there were 26 polypeptides unique to noncardiac structures and an additional 15 that were increased in the carcass more than twofold relative to the heart. The noncardiac-specific polypeptides may be used to define contamination of putative cardiac tissue with noncardiac material. Two of the polypeptides expressed more abundantly in the carcass appeared to correspond to known proteins in the mouse fibroblast database, cyclin and tropomyosin 4. Thus the heart at 9.5 days of murine development can be distinguished readily from the remainder of the embryonic mouse both macroscopically and on two-dimensional gels.  相似文献   

4.
Proteins fromFusarium sporotrichioides M-1-1, a T2-toxin-producing strain, were separated by two-dimensional polyacrylamide gel electrophoresis. One thousand two hundred and forty-four protein spots were resolved and 103 protein spots were subjected to N-terminal sequencing. Fifty-eight protein spots were sequenced and 48 proteins were observed to have blocked N termini. Forty out of 58 sequenced proteins were identified by homology search against the PIR protein sequence data base and protein superfamily data base, while the residual 18 sequences were not identified. Twenty-seven of the N-terminal-blocked proteins were subjected to mild anhydrous hydrazine vapor deblocking. Twenty-four spots were not deblocked indicating the presence of acyl groups at the N termini, while 3 proteins were deblocked showing the blocked group to be pyrroglutamyl carboxylic acid residues. The results can provide a more global view of cellular genetic expression than any other technique. The created data may offer a unique opportunity to link information with DNA sequence data.  相似文献   

5.
Honey bee foragers were tested for their proboscis extension response (PER) to water and varying solutions of sucrose. Returning pollen and nectar foragers were collected at the entrance of a colony and were assayed in the laboratory. Pollen foragers had a significantly higher probability of responding to water and to lower concentrations of sucrose. Bees derived from artificially selected high- and low-pollen-hoarding strains were also tested using the proboscis extension assay. Returning foragers were captured and tested for PERs to 30% sucrose. Results demonstrated a genotypic effect on PERs of returning foragers. The PERs of departing high- and low-strain foragers were consistent with those of returning foragers. The PERs were related to nectar and water reward perception of foragers. High strain bees were more likely to return with loads of water and lower concentrations of sucrose than foragers from the low pollen strain. Low-strain bees were more likely to return empty. We identified a previously mapped genomic region that contains a variable quantitative trait locus that appears to influence sucrose response thresholds. These studies demonstrate a gene-brain-behavior pathway that can be altered as a consequence of colony-level selection for quantities of stored food. Accepted: 3 September 1997  相似文献   

6.
目的 探讨感染性心内膜炎(IE)患者致病菌分布、致病菌耐药性及患者死亡因素。方法 回顾性分析我院2014年11月至2018年3月收治的80例感染性心内膜炎患者的临床资料。根据是否发生死亡将患者分成存活组(75例)与病死组(5例)。采集两组患者血液标本进行细菌培养、鉴定及药敏试验,并对患者死亡因素进行统计。结果 80例IE患者共检测出96株病原菌,其中革兰阳性菌63株,占65.63%;革兰阴性菌27株,占28.13%;真菌6株,占6.25%。药敏试验显示链球菌属及金黄色葡萄球菌对青霉素耐药率最高,分别为90.32%和93.33%;其次为红霉素,分别为70.97%和73.33%。单因素分析结果显示,肝脏肿大、血红蛋白(<90 g/L)及抗生素的使用与IE患者的死亡有关(均P<0.05)。结论 IE患者病原菌以革兰阳性菌为主,其主要菌属对青霉素耐药率最高,要加强对肝脏肿大、血红蛋白及抗生素相关因素的防治,降低IE患者的病死率。  相似文献   

7.
Albino mouse embryonic cells (Gpi-la/a) at 3.5–8.5 and 11.5 days were aggregated with zona cut 8–16 cell stage embryos from F1 females (Gpi-1 b/b), respectively. The aggregated embryos were transferred to pseudopregnant female mice. The recipients were allowed to go to term or were dissected at mid-gestation to assess the donor contribution in the conceptuses using glucose phosphate isomerase (GPI) analysis. The donor cells, which were previously labeled with fluorescent latex microparticles, were aggregated with embryos, and the allocation of the donor cells at the compacted morula and blastocyst stages were observed under a fluorescence microscope. When 3.5 and 45 day old inner-cell-mass (ICM) cells were used, fertile chimeric mice were obtained (50 and 19%, respectively), and when 5.5 days old primitive ectoderm cells were aggregated, they did not form chimeras but contributed to the fetuses, placenta and membrane after 13.5 days of pregnancy. However, cells from further stages never contributed to the conceptuses even though they were analyzed after 10.5 days of pregnancy. The labeled donor cells at these stages were not positively incorporated in the interior part of the compacted morula and the ICM of the blastocyst stage unlike the ICM at 3.5 days post-coitum after overnight culture.  相似文献   

8.
目的了解人工饲养树[鼠句]肠道菌群感染情况及其各种细菌对药物的敏感性。方法通过肠道细菌采样、培养、分离和菌落生长特性观察,并经革兰氏染色、氧化酶试验、触酶试验、生化编码鉴定管试验和9种药敏试验分析,初步鉴定了107例人工饲养树[鼠句]肠道感染细菌的种类和这些细菌对药物的敏感程度。结果本次细菌培养共从树[鼠句]肠道中培养分离出5株细菌,其中革兰氏阳性菌2株,革兰氏阴性菌3株,以大肠杆菌和葡萄球菌最为多见。同时确定了菌株的药敏情况为:(1)大肠杆菌对头孢类药头孢哌酮最为敏感,对药物磺胺甲嚼唑/甲氧苄定、氧氟沙星、左氧氟沙星、呋喃妥因、诺氟沙星、氨苄西林高敏;(2)沙门氏菌对阿米卡星最为敏感,对药物头孢哌酮青霉素G高敏;(3)链球菌对试验药物氨苄西林、头孢哌酮、呋喃妥因显示为中敏;(4)葡萄球菌对头孢类药头孢哌酮、磺胺类磺胺甲晤唑/甲氧苄定、沙星类诺氟沙星、左氧氟沙星、氧氟沙星、呋喃妥因和氨苄西林最为敏感,对其它药物均为中敏;(5)假单胞菌对药物左氧氟沙星最为敏感,对大多数药物都显示高敏。结论大肠杆菌和葡萄球菌可能是树鼢肠道中正常寄生的主要菌群,同时其它菌群也有寄生。用药敏实验筛选出的药物可为临床用药和动物的生物净化提供指导依据。  相似文献   

9.
Truss and length measurements were made on 463 tilapia Oreochromis niloticus of known mass. These measurements were then used to build mathematical models to estimate tilapia biomass. Two different approaches were used to build the models. The first was to take some simple mathematical models, and to optimize them using least squares regression. The second approach was to build models using artificial neural network software. Models were built for two different but overlapping size ranges and both approaches were successful in creating models that estimated the total biomass to within ±1%. The truss measurements were also used to assess the principal shape components of different sized tilapia.  相似文献   

10.
为了探明小峰熊蜂Bombus hypocrita蜂王蛹期发育蛋白质表达调控方面的特点,揭示其发育的分子机理。采用双向电泳法对小峰熊蜂蜂王蛹期发育进行蛋白质组研究,结果在小峰熊蜂蜂王蛹期的白眼期(A期)、褐眼期(B期)和黑眼期(C期)分别检测到81、80和75个蛋白点,特有蛋白质分别为8个、7个和2个,共有蛋白质为61个,A期到B期有4个蛋白质显著上调,5个显著下调,B期到C期有7个蛋白质显著上调,1个显著下调,A期到C期有10个蛋白质显著上调,有4个显著下调。此外,3个蛋白质是在A、B期表达C期关闭,6个蛋白质A、C期表达,B期关闭,5个蛋白质A期关闭,而B、C期表达。初步表明小峰熊蜂蜂王从蛹期发育到成蜂过程中,不仅需要一些保守蛋白质来调控,而且还需要一些特异蛋白质。  相似文献   

11.
Large herbivores, including livestock and ostrich, were counted along a 200-km long track in south-western Kalahari, Botswana. Altogether, 37 counts were made during different seasons. The number of animals seen and group size were recorded. These variables were compared with monthly and accumulated rainfall (number of animals and group size) and distance to pans (number of animals). Observations of game and livestock were also related to distance to villages. In four of the seven studied species, most animals were seen during the wet season. Group size also varied between seasons apart from the non-gregarious steenbok and duiker. Number of animals and group size were in some cases correlated with rainfall during the month of observation or with accumulated rainfall during the preceding months. The various species were more often observed close to pans than further away from the pans. Compared to livestock, game was on average observed >10 km further away from the villages. Few observations of game were made between village centres and the livestock observations most distant from the village.  相似文献   

12.
Lin QX  Que HP  Lu SH  Liu SJ 《生理学报》2004,56(2):130-136
为探讨神经干细胞分化成熟的神经元是否能够分裂。实验取材于成年哺乳动物,将神经干细胞体外培养8d后,诱导分化为神经元,然后进一步诱导其分裂。采用连续摄影与NF-160免疫细胞化学方法检测神经元的分裂过程,同时运用PCNA NF-160(或Chat、GABA、GAD)的免疫双标记证明分裂神经元是否为成熟神经元。将神经干细胞体外诱导分化培养8d,直至分化神经元外形成熟,进而加入EGF与bFGF诱导分裂。诱导分裂2d后,观察到有神经元样细胞分裂;同一区域内神经元样细胞的数量不断增加,表现为NF-160阳性。连续拍摄了神经元样细胞的分裂过程,分裂完成后的细胞同样表现为NF-160抗体反应阳性。PCNA NF-160(或Chat、GABA、GAD)的免疫双标记结果显示,一些细胞的胞浆显示为棕色的同时细胞核显示为黑色。结果提示,在一定的条件下,先前所认为的终末分化神经元可以重新进入细胞周期,成熟神经元仍然可以进行分裂增殖和自我更新。  相似文献   

13.
大豆种质对SMV成株和种粒斑驳抗性的SSR标记辅助鉴定   总被引:1,自引:0,他引:1  
对186份大豆种质资源进行了成株和种粒斑驳抗性鉴定,并利用与成株抗性及种粒斑驳抗性分别相关的SSR标记验证抗病毒分子辅助选择的可行性。结果表明:接种SMV1,选出成株和种粒双抗种质38份,成株抗病种质149份,种粒抗病种质45份,成株和种粒双感种质26份。利用与成株抗性相关的SSR标记Sat_229、Sat_317、Satt335、Satt160、Satt516、Sat_309进行检测,抗病毒资源筛选的准确率分别达到68.9%、74.3%、71.1%、69.8%、77.4%和68.2%。利用与种粒斑驳抗性相关的SSR标记Sat_297、Sat_229、Sat_317、Satt335、Set_188、Satt160、Satt516、Sat_133进行检测,Sat_317标记准确率达79.1%,标记Sat_229、Satt335、Satt516和Sat_133抗病毒资源筛选的准确率均达70%以上,可以用作抗病毒分子辅助育种的选择标记。  相似文献   

14.
This study investigated traditional cement-based and non-conventional (using accelerated carbonation) solidification/stabilization to treat 2 dredged sediments contaminated with mercury from two different locations in UK. Canal and estuarine-derived sediments were mixed with blended binders and powdered activated carbon. Fresh mixtures of sediment and cement were exposed to gaseous carbon dioxide and were allowed to carbonate for fixed time periods, after which they were cured for 28 days. Following curing, samples were leach tested to evaluate the fixation of mercury in the treated products. The results obtained indicated that both conventional and accelerated carbonated treatments were capable of reducing the concentration of mercury in the eluates to acceptable limits.  相似文献   

15.
用3种方法使紫云英根瘤菌(Rhizobium astragali Huikui)、田菁根瘤菌(R.sesbania sp.)分别入侵大麦(hordeum vulgare L.)和水稻(Oryza sativa L.),形成拟瘤状组织。一是用一定磁场强度处理根瘤菌和植物,并接种培养。二是用含有水稻幼苗根提取物的培养基培养根瘤菌,接种水稻。三是重复别人用2,4-D外源激素处理植物,接种根瘤菌。镜检观察,用紫云英根瘤菌接种形成的大麦根拟瘤细胞结构非常精细,保持各种细胞器。有侵入线结构和根瘤菌从侵入线释放。根瘤菌被宿主细胞来源的膜包围,成为拟菌体。这些形态结构与豆科根瘤细胞相似,有共生状态特征,但拟菌体有泡状化现象。田菁根瘤菌入侵水稻根形成的拟瘤,在细胞间隙和细胞内都有细菌分布。受侵染的细胞结构粗糙,根瘤菌裸露,无胞膜包围。用2,4-D处理接种根瘤菌的拟瘤细胞结构也如此,但在维管系统内有大量密集的细菌存在。这种结构完全不同于豆科根瘤细胞结构,细菌与植物细胞的形态学相互关系是一种非共生联合作用。  相似文献   

16.
长白山大型真菌物种多样性调查名录Ⅳ针阔混交林带   总被引:1,自引:1,他引:0  
根据2000-2009年间在长白山自然保护区针阔混交林及露水河、松江河、长白县等地相同林带所采的1700余份标本,报道了长白山针阔混交林带分布的大型真菌68科209属498种.其中,中国新记录种8种,待定种3种,吉林省新记录种12种,所有标本保存于吉林农业大学菌物标本馆(HMJAU).  相似文献   

17.
The aims of this study were to investigate machine beam parameters using the TomoTherapy quality assurance (TQA) tool, establish a correlation to patient delivery quality assurance results and to evaluate the relationship between energy variations detected using different TQA modules. TQA daily measurement results from two treatment machines for periods of up to 4 years were acquired. Analyses of beam quality, helical and static output variations were made. Variations from planned dose were also analysed using Statistical Process Control (SPC) technique and their relationship to output trends were studied. Energy variations appeared to be one of the contributing factors to delivery output dose seen in the analysis. Ion chamber measurements were reliable indicators of energy and output variations and were linear with patient dose verifications.  相似文献   

18.
Water quality and mollusc communities have been declining in Lake Winnipeg., the tenth largest freshwater lake in the world. Ninety sites were surveyed in the southern half of the lake. Nitrate and total dissolved solids were found to be significantly higher on the west side, while cadmium, copper and lead were higher on the east side. Agriculture, urban effluent, and recreational development were major factors directly affecting nearshore water quality. Human impacts were sporadically aggravated by Red River floodwaters entering the lake. A total of 26 gastropod were currently found in the lake, but 16 of them were found at 5 or fewer sites. Only 6 unionid species were found, compared to at least 11 historical species records. Species richness of both gastropods and unionids was positively correlated with total dissolved solids, and inversely with lead. Gastropod and unionid species richness were also mutually positively correlated. Catchment basin and shoreline management policies affecting Lake Winnipeg need to be reexamined to reduce further habitat decline.  相似文献   

19.
江苏紫金山的多孔菌   总被引:9,自引:1,他引:8  
2003年7月、10月,2004年10月和2005年6月在中国江苏省南京紫金山采集木腐菌标本157号,此外,还研究了其它标本馆保存的采于同地的木腐菌标本,经鉴定发现多孔菌67种,本文报道了这些多孔菌名录,并根据采样列出了每种的寄主,其中绝大多数种类为该地区首次报道,47种为江苏新记录种,Ceriporialacerata为中国新记录种,根据中国的标本材料对其进行了详细描述。紫金山的多孔菌主要是温带广布种,也有一些热带或亚热带种类分布。  相似文献   

20.
采用常规石蜡切片法.对鱼腥草的药用部位地上茎、根状茎和叶进行了解剖学观察。鱼腥草茎和叶的表皮下有特殊的皮下层细胞.茎的皮层和髓中有分泌细胞存在。地上茎和根状茎之间在皮层细胞层数、周维纤维柱的有无、维管柱和髓所占比例、维管束束数、次生生长等办面存在差异,这些差异与它们各自担负的生理功能相关联。叶的皮下层细胞显著,它们是复表皮的一部分。叶表皮上有胶质化表皮细胞和水钵的结构。对鱼腥草茎和叶中的皮下层细胞的来源和功能、与其他古草本类群相关的结构特征以及水钵的结构与分铂等问题进行了探讨。  相似文献   

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