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我,罗斯科,身为一只拥有优良血统的布鲁泰克猎犬,我本应该在森林中寻觅狐狸,追捕浣熊,帮猎人们完成捕猎任务。可惜,老天没有给我展示高超本领的机会。在来到南卡罗来纳州濒危和稀有动物研究所,也就是我现在的家之前,我一直过着风餐露宿的流浪生活。回想起过去那段不堪回首的日子,我只能用一个字来形容——惨!  相似文献   

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Cardiovascular physiology reflects the interrelations of flow, pressure, and resistance. Undergraduate students are often confused by the complexity of the system. This symposium presents a sequential presentation of the underlying concepts, building on analogies, past experience, and conceptual models to allow students to develop a physiologically appropriate understanding of cardiovascular physiology.  相似文献   

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训练两只猕猴进行延缓GO/NO-GO任务操作。猴坐在定制的猴椅中,正前方40cm处放着计算机显示器。显示器下方装有一压板。猴按压板0.5s后,显示器屏幕右下角或左下角出现一白色方块信号(1.5cm×1.5cm),持续0.5s。这一信号为暗示信号。暗示信号消失后,延缓0.0-4.0s,然后在显示器屏幕的下方正中处出现一红色方块信号(1.5cm×1.5cm)。这一信号为反应信号。如果暗示信号出现在右边,则要求猴在0.8s内放开一直按着的压板(GO反应);如果暗示信号出现在左边,则要求猴继续按住压板1.2s(NO-GO反应)。正确操作后,猴得到一滴水的奖励。在这一行为任务中,延缓期内的短时工作记忆是“非空间表象”(non-spatiallyrepresentatioal)短时工作记忆。前额叶皮层背外侧部(Walket46区、9区)内注射α2受体拮抗剂yohimbine(10μg/2μl)使猴的任务操作正确率下降。延缓期越长,下降的幅度越大。注射Yohimbine后,猴的操作错误率升高主要表现在“交叉”反应率升高,即应该作GO反应时作NO-GO反应,反之亦然。注射α1受体桔抗剂Prazosin(10μg/2μl)或  相似文献   

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Herrera C 《Bioethics》2008,22(3):137-146
Observers who note the increasing popularity of bioethics discussions often complain that the social sciences are poorly represented in discussions about things like abortion and stem-cell research. Critics say that bioethicists should be incorporating the methods and findings of social scientists, and should move towards making the discipline more empirically oriented. This way, critics argue, bioethics will remain relevant, and truly reflect the needs of actual people. Such recommendations ignore the diversity of viewpoints in bioethics, however. Bioethics can gain much from the methods and findings from ethnographies and similar research. But it is misleading to suggest that bioethicists are unaware of this potential benefit. Not only that, bioethicists are justified in having doubts about the utility of the social science approach in some cases. This is not because there is some inherent superiority in non-empirical approaches to moral argument. Rather, the doubts concern the nature of the facts that the sciences would provide. Perhaps the larger point is that disagreements about the relationship between facts and normative arguments should be seen as part of the normal inquiry in bioethics, not evidence that reform is needed.  相似文献   

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随着越来越多基因组测序的完成,人们可以获得大量的序列信息,如何利用这些信息对未知基因的功能进行预测是一个非常重要的问题.Blast是基本的预测新基因功能的工具,但是仅通过Blast的原始搜索结果,尚无法获得相关基因本体论(gene ontology,GO)注释信息.目前,用户为了获得新基因的GO注释信息,首先需要进行Blast搜索,然后用Blast搜索的结果到GO网站去查询相关的GO注释信息.这浪费了大量的时间,尤其是当Blast的结果数据量很大时.为此,基于GO分类系统,整合BLAST 的结果信息,结合bioperl模块,使用perl语言开发了GoBlast软件.通过GoBlast系统,对于新基因,研究人员只须1次分析运算,就可以同时获得Blast搜索结果和GO注释信息,从而有效地提高了基因功能注释的可信度,加速了功能基因组学的研究.GoBlast为B/S(Browser/Server)架构,用户客户端只要有浏览器程序,就可以通过国际互联网在http://bioq.org/goblast上使用GoBlast系统  相似文献   

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喻辉  郭政  李霞 《生物信息学》2003,1(1):15-19
我们研制了基于Gene Ontology与基因表达谱挖掘与实验条件相关的特征基因功能类的算法OntoFexed,它的特点是分别采用信息增益方法和Rand Index评价单个基因功能类与一组基因功能类鉴别差异表达基因与不差异表达基因的能力。算法的优点是充分利用了GO的结构信息来搜索特征功能类,并能给出各个抽象层次上的特征功能类。我们将OntoFexed应用于腺癌数据集和NCI60数据集,发现OntoFexed确能发掘与实验条件相关的功能类,且算法对主要的参数有较高的稳健性。  相似文献   

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螺旋藻乙醇酸氧化酶(GO)的研究   总被引:3,自引:0,他引:3  
采用比色法对鄂尔多斯高原碱湖的钝顶螺旋藻(S1)与国外引进的钝顶螺旋藻(S2)和极大螺旋藻(S3)的乙醇酸氧化酶(GO)进行了比较研究。结果表明:在25℃、pH 8.0条件下,S1、S2和S3的GO活性分别为70.9 U/gFW、59.6 U/gFW和80.9 U/gFW;最适温度均为30℃;在0℃~35℃(30℃)范围内比较稳定;最适pH值分别为8.6、8.2和8.4;pH值稳定范围,S1为7.6~10.0、S2为8.0~9.0;S3为8.0~8.6。S1的GO对温度和pH适应范围最宽,且在低温、高温、强酸和强碱下的活性均比引进种的高。  相似文献   

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Microvascular disease is a prominent feature of systemic sclerosis (SSc) and leads to Raynaud's phenomenon, pulmonary arterial hypertension, and scleroderma renal crisis. The presence of macrovascular disease is less well established, and, in particular, it is not known whether the prevalence of coronary heart disease in SSc is increased. Furthermore, in terms of cardiac involvement in SSc, there remains conjecture about the relative contributions of atherosclerotic macrovascular disease and myocardial microvascular disease. In this review, we summarize the literature describing cardiovascular disease in SSc, discuss the pathophysiological mechanisms common to SSc and atherosclerosis, and review the surrogate markers of cardiovascular disease which have been examined in SSc. Proposed mediators of the vasculopathy of SSc which have also been implicated in atherosclerosis include endothelial dysfunction, a reduced number of circulating endothelial progenitor cells, and an increased number of microparticles. Excess cardiovascular risk in SSc is suggested by increased arterial stiffness and carotid intima thickening and reduced flow-mediated dilatation. Cohort studies of adequate size are required to resolve whether this translates into an increased incidence of cardiovascular events in patients with SSc.  相似文献   

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E.T. Wei  A. Lee  J.K. Chang 《Life sciences》1980,26(18):1517-1522
In the urethane-anesthetized rat, intravenous injections of morphine produced a short-lasting fall in heart rate and blood pressure. The fall in heart rate (which is vagal in origin) was used here to bioassay peptides related to the enkephalins [-enk] and β-casomorphin [β-C, H-Tyr-Pro-Phe-Pro-Gly-Pro-Ile-OH]. A > 10% decrease in heart rate was used as a quantal index of response and the intravenous ED50 [μmol/kg] were estimated as: methionine-enk, 1.3 ± .24; leucine-enk, 1.5 ± .20; [D-Ala2, D-Leu5]-enk, 0.45 ± .05; [D-Ala2, NMePhe4, Met(0)5-ol]-enk, 0.0011 ± .0002; H-Tyr-Arg-OH, > 2.0; β-C (1–7), > 2.0; β-C(1–5), > 2.0; β-C(1–4), > 4.0; β-C(1–3), > 2.0; morphine sulfate, 0.11 ± .03; and human β-endorphin,, 0.07 ± .01. One β-C derivative, H-Tyr-Pro-Phe-Pro-NH2 [β-C(1–4)-NH2], was active at 0.32 ± .08. Naloxone pretreatment blocked the bradycardia produced by the enkephalins and β-C(1–4)-NH2. The bioassay described here, based on heart rate, may prove to be useful for the rapid detection and estimation of the in vivo pharmacological activities of new opioid peptides.  相似文献   

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To be Published in Aeta Siniea on Volume 59,Issues,Oetober 25,2007 Editors: YANG Huang·Tian(杨黄恬) Laboratory of Moleeular Cardiology(分子心脏学研究组) Institute of Health Seienees(健康科学研究所) Shanghai Institutes for Biologieal Seienees(上海生命科学研究院) Chinese Academy of Seienees(中国科学院)&Shanghai Jiaotong university sehool。f Medieine(l几海交通大赞l欠」’汁l坑) 225 Chongqing Nan Rd.#1 Building,Shanghai 200025,China(重庆南路225号I号楼,上海,200025) Phone:+86一2…  相似文献   

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