栉孔扇贝(Chlamys farreri)Toll样受体及其信号传递相关基因的克隆与表达

扇贝是我国海水养殖的重要品种，但自1994年以来，养殖扇贝陆续爆发的大规模死亡，不但造成了巨大的经济损失，而且直接威胁到现有产业的生存和发展。引起扇贝大规模死亡原因是多方面的，其主要原因是养殖环境恶化、扇贝种质衰退和抗病力下降。因此，深入研究扇贝免疫防御机制，探讨提高机体抗病力的有效途径和方法，改良种质和培育抗病品系，无疑是解决目前困扰扇贝养殖业健康可持续发展的必经之路。 Toll样受体（TLRs）家族是新近发现的模式识别受体（PRRs），参与识别病原体相关的分子模式（PAMPs），在天然免疫系统中起着非常重要的作用。哺乳动物中Toll样受体信号通路还参与诱导树枝状细胞成熟、参与免疫耐受、参与凋亡发生发展、介导非感染性因素的识别等，被视为联系天然免疫和获得性免疫的桥梁。同时果蝇的Toll信号通路也是不具备获得性免疫的果蝇赖以抵御病毒、细菌和真菌感染，介导天然免疫反应的重要信号通路。 本研究采用大规模EST测序方法，结合Genome Walker库的构建和cDNA末端快速扩增技术，从栉孔扇贝克隆得到CfToll-1、CfMyd88、CfTRAF6和CfCactus这四个Toll样受体信号通路基因的全长cDNA，同时用荧光实时定量PCR技术检测了这些基因的组织分布及在脂多糖（LPS）和肽聚糖（PGN）刺激下的表达规律。 栉孔扇贝Toll样受体（CfToll-1）的cDNA序列全长4308 bp，包含5’非翻译区（UTR）211 bp，3597 bp的开放阅读框，500 bp的3’UTR，最后为18个腺嘌呤的ploy A 尾巴。开放阅读框编码1198个氨基酸的多肽，该多肽的估计分子量为137.41kd，估计的等电点为5.62，该多肽有信号肽，具有一个预测的跨膜区，因此是一种跨膜蛋白。经BLAST比对，CfToll-1基因与节肢动物多种Toll蛋白高度的相似性。SMART（Simple Modular Architecture Research Tool）软件分析，CfToll-1包含典型的Toll样受体的结构：富含亮氨酸的重复序列的胞外区（leucine-rich repeats, LRR），一段跨膜结构域，以及胞内区的TIR结构域（Toll/IL-1 receptor homologous region）。利用Real-time RT-PCR发现CfToll-1mRNA在扇贝体内普遍存在于血细胞、肌肉、外套膜、心、性腺和鳃组织中。利用体外培养的原代血细胞系研究不同浓度LPS刺激后CfToll-1的表达变化，结果显示低剂量（100ng.mL-1 ）LPS 使CfToll-1 mRNA表达量减小，该变化在1.5h、3h 和9h组差异显著，虽然在6h组表达量稍有恢复，但尚未达到对照水平；用1μg.mL-1LPS处理细胞时， 6h组CfToll-1表达量明显上调，约为对照水平的2倍。证实细菌结构脂多糖对CfToll-1基因的表达有影响，且这种影响有剂量依赖效应。 栉孔扇贝Myd88同源基因（CfMyd88）的cDNA序列全长1554bp，包含5’UTR 427 bp，1101bp的开放阅读框，最后为18个腺嘌呤的ploy A 尾。CfMyd88的开放阅读框可编码367个氨基酸的多肽，该多肽的估计分子量为42.37kD，估计的等电点为5.71。利用SMART程序分析发现CfMyd88编码了Death和TIR结构域, 这两个结构域是Myd88特征结构。BLAST程序发现扇贝的序列与数据库哺乳动物的Myd88基因高度同源。原代培养的扇贝血细胞在受到PGN刺激后，CfMyd88 mRNA表达在1.5小时开始下调，直到9小时下调至对照表达量的1/10，证实肽聚糖结构对CfMyd88基因的表达有影响。 栉孔扇贝TRAF6同源基因（CfTRAF6）的cDNA序列全长2510bp，包含5’UTR 337 bp，1965bp的开放阅读框，3’UTR 208bp，最后为21 个腺嘌呤的ploy A 尾巴。CfTRAF6开放阅读框编码655个氨基酸的多肽，该多肽的估计分子量为74.09kD，估计的等电点为6.01。InterPro Scan在线分析发现CfTRAF6有典型的TRAF蛋白家族的特征结构，包括的一个指环结构，两个锌指结构，一个MATH （the meprin and TRAF homology）结构域以及Coiled-coil区域。CfTRAF6的序列与数据库多物种的TRAF6高度同源，同源性最高的是乌贼序列（Identity＝68）和鼠类（Identity＝45%）。利用Real-time RT-PCR，发现CfTRAF6在各组织普遍存在，在性腺中的表达最高。原代培养的扇贝血细胞在受到不同浓度PGN刺激后，与CfMyd88的情况一样，CfTRAF6的表达量变化减少，且这种变化随剂量的增加更加明显。 栉孔扇贝Cactus同源基因（CfCactus）的cDNA序列全长2488bp，包含5’UTR 181 bp，840bp的开放阅读框， 3’UTR 1467bp，最后为19个腺嘌呤的ploy A 尾巴。CfCactus的开放阅读框编码279个氨基酸的多肽，该多肽的估计分子量为31.37 kD；估计的等电点为4.74，与果蝇的Cactus基因的等电点相近（4.5）。利用SMART程序分析发现CfCactus主要编码了ANK结构域（ankyrin repeats）。Cactus基因为哺乳动物NF-κB抑制蛋白IκB的同源分子，BLAST 程序发现扇贝的序列与数据库多物种的Cactus或IκB基因高度同源。同源性最高的是太平洋牡蛎（Identity=35%）和圆尾鲎（Identities = 44%）。对CfTCactus mRNA在扇贝的血细胞、性腺、 肠的组织表达进行分析，并同时与CfTRAF6和CfMyd88的表达量进行了对比，发现CfCactus的表达水平明显高于这两个基因，而且CfTRAF6的基因表达量也高于CfMyd88，表现出级联放大效应。正常情况下，三个基因在性腺的表达量最高，推测这条通路可能和发育等功能密切相关。 通过本研究我们首次在双壳类软体动物找得到与果蝇Toll蛋白家族高度同源的CfToll-1基因，同时发现其他三个在Toll样受体信号传递过程中起重要作用的基因，其中包括在软体动物中获得的第一个Toll样受体的接头分子－CfMyd88基因，该结果直接证明软体动物具有与哺乳动物和节肢动物高度类似Myd88依赖的Toll样受体信号通路。同时通过这些基因组织分布的研究以及细菌结构LPS和PGN对这条通路上基因表达的影响，证明扇贝Toll信号通路可能与在果蝇中一样，参与扇贝的发育和免疫防御等多种功能。

Cloning and expression analysis of a HSP70 gene from Pacific abalone (Haliotis discus hannai)

Heat shock protein 70 (HSP70), the primary member of HSPs that are responsive of thermal stress, is found in all multicellular organisms and functions mostly as molecular chaperon. The inducible HSP70 cDNA cloned from Pacific abalone (Haliotis discus hannai) using rapid amplification of cDNA ends (RACE), was highly homologous to other HSP70 genes. The full-length cDNA of the Pacific abalone HSP70 was 2631 bp, consisting of a 5'-terminal untranslated region (UTR) of 90 bp, a 3'-terminal UTR of 573 by with a canonical polyadenylation signal sequence AATAAA and a poly (A) tail, and an open reading frame of 1968 bp. The HSP70 cDNA encoded a polypeptide of 655 amino acids with an ATPase domain of 382 amino acids, the substrate peptide binding domain of 161 amino acids and a C-terminus domain of 112 amino acids. The temporal expression of HSP70 was measured by semi-quantitative RT-PCR after heat shock and bacterial challenge. Challenge of Pacific abalone with heat shock or the pathogenic bacteria Vibrio anguillarum resulted in a dramatic increase in the expression of HSP70 mRNA level in muscle, followed by a recovery to normal level after 96 h. Unlike the muscle, the levels of HSP70 expression in gills reached the top at 12 h and maintained a relatively high level compared with the control after thermal and bacterial challenge. The upregulated mRNA expression of HSP70 in the abalone following heat shock and infection response indicates that the HSP70 gene is inducible and involved in immune response. (c) 2006 Elsevier Ltd. All rights reserved.

江河源区人工草地及"黑土滩"退化草地群落演替与物种多样性动态

研究了"黑土滩"退化草地以及在"黑土滩"上建植的垂穗披碱草人工草地在第2～6年间植物群落演替及物种多样性动态.结果表明:随着演替的发生,两种不同类型草地群落的α多样性指数均呈现单峰变化趋势.人工草地群落的α多样性指数比"黑土滩"退化草地群落的低,建植第4年的人工草地群落和封育4年的"黑土滩"退化草地群落的各指数最高.两种不同类型草地草场质量指数也呈现先降后升的趋势,人工草地群落的草场质量和生物量比"黑土滩"退化草地群落高.从植物的生活型看,一年生植物被多年生植物替代.β多样性的时间动态反映出演替过程中,两种类型的草地群落2龄与5龄、6龄群落间的β多样性低,物种周转率高;2龄与3龄,5龄与6龄群落间的β多样性高,物种周转率低,4龄群落是过渡群落.在时间序列上可分为两个阶段,2～4龄主要是一年生草本的入侵,4～6龄主要是多年生草本的定居.

根据叶表皮特征试论国产三齿稃亚族的属间关系

根据植物叶片表皮结构,尤其下表皮特征,对国产三齿稃亚族6个属(包括1个引进属)进行了属间关系的分析.结果表明:国产三齿稃亚族中固沙草属最原始,草沙蚕属最高级,双稃草属、千金子属、三齿稃属和隐子草属演化居于其间;隐子草属可能直接起源于固沙草属,并在自身基础上派生了较为高级的三齿稃属;双稃草属与千金子属渊源关系直接,前者可能通过后者间接起生于固沙草属;草沙蚕属具有别于它属的性状级次,可能是起源于固沙草属、独树1支的顶级类群.这一结果不仅修正了前人演化理论的差误,而且为今后探讨该亚族的地理起源、散布路线提供了资料

六功能水下机械手的变结构控制方法和应用研究

随着各国对海洋资源开发利用的加剧，水下机械手作为作业型水下机器人首选配置的一种通用作业工具，应用范围不断扩展，而现有的水下机械手采用主从控制方式，在水下复杂的作业环境下精度及效率不高，限制了水下机械手的使用。引入监控模式的机械手系统是水下机械手发展的一个主流方向。本课题就是以实现机械手的监控模式为目标，针对在实现监控式机械手过程中遇到的两个鱼待解决的难题：机械手的实时运动学逆解和复杂条件下满足高精度轨迹跟踪要求的控制方法，以六功能水下机械手为对象展开并完成课题工作。本文的主要研究成果分为以下三个部分：针对此机械手运动学逆解不能简单由解析方式给出的特点，本文提出运用基于约束最优化的变尺度算法。运用惩罚函数和二次插值选取迭代步长，保证了搜索的有效性；没有直接求解二阶导数，不存在奇异解。该算法是超线性收敛。对实例的求解证明了该算法的快速性和在解决此水下机械手在线轨迹规划时的有效。针对现有的水下机械手关节位置控制中采用PID控制算法而存在的一些缺点，本文以电液位置伺服的肩转关节为例，进行了滑模控制方法的研究。设计了单关节的滑模控制器，并把简化后的滑模控制器运用到实际的控制系统中，仿真和实验结果表明在复杂条件下滑模控制与PID控制相比有高精度和快速的跟踪性能。针对滑模控制的“颤振”现象，引入模糊控制的思想，设计了单关节的模糊滑模控制器，仿真和最终的实验证明了运用模糊滑模控制能有效消弱“颤振”，系统有良好的跟踪性能。针对原有的控制系统不适合于监控方式的机械手控制的特点，重新设计了水下机械手的水下控制器，组建了基于RS－485通讯，以PC机为上位机系统和89C52为下位机系统的机械手两级控制系统，并在这个人机界面友好、工作稳定的系统上完成了本文所有的实验。

基于SRTM DEM数据的清水江流域地表水文模拟

为了检验航天飞机雷达地形测绘使命（SRTM）生产的数字高程数据在地表水文模拟分析中的应用效果，以贵州省内清水江流域为例，利用ArcHydroTools以CGIAR-CSI SRTM90m数据和国家基础地理信息系统1：400万数字水系图为数捌源，进行了流域地表水文模拟。分析结果表明：以CGIAR-CSI SRTM 90m数据为基础提取的数字河网的空间分布与实际情况十分接近，提取的数字流域界线与水文部门基本相符，说明CGIAR-CSI SRTM 90m数据在数字地形分析的诸多领域，特别是地表水文模拟分析方面必将有着十分广泛的应用前景.

Prediction of soil adsorption coefficients from retention parameters on three reversed-phase liquid chromatographic columns

Reversed-phase high-performance liquid chromatographic (RP-HPLC) retention parameters, which are determined by the intermolecular interactions in retention process, can be considered as the chemical molecular descriptors in linear free energy relationships (LFERs). On the basis of the characterization and comparison of octadecyl-bonded silica gel (ODS), cyano-bonded silica gel (CN), and phenyl-bonded silica gel (Ph) columns with linear solvation energy relationships (LSERs), a new multiple linear regression model using RP-HPLC retention parameters on ODS and CN columns as variables for estimation of soil adsorption coefficients was developed. It was tested on a set of reference substances from various chemical classes. The results showed that the multicolumn method was more promising than a single-column method was for the estimation of soil adsorption coefficients. The accuracy of the suggested model is identical with that of LSERs.

Development of process control methodology for tracking the quality and safety of pain, agitation and sedation management in critical care units

Objective: To develop sedation, pain, and agitation quality measures using process control methodology and evaluate their properties in clinical practice. Design: A Sedation Quality Assessment Tool was developed and validated to capture data for 12-hour periods of nursing care. Domains included pain/discomfort and sedation-agitation behaviors; sedative, analgesic, and neuromuscular blocking drug administration; ventilation status; and conditions potentially justifying deep sedation. Predefined sedation-related adverse events were recorded daily. Using an iterative process, algorithms were developed to describe the proportion of care periods with poor limb relaxation, poor ventilator synchronization, unnecessary deep sedation, agitation, and an overall optimum sedation metric. Proportion charts described processes over time (2 monthly intervals) for each ICU. The numbers of patients treated between sedation-related adverse events were described with G charts. Automated algorithms generated charts for 12 months of sequential data. Mean values for each process were calculated, and variation within and between ICUs explored qualitatively. Setting: Eight Scottish ICUs over a 12-month period. Patients: Mechanically ventilated patients. Interventions: None. Measurements and Main Results: The Sedation Quality Assessment Tool agitation-sedation domains correlated with the Richmond Sedation Agitation Scale score (Spearman [rho] = 0.75) and were reliable in clinician-clinician (weighted kappa; [kappa] = 0.66) and clinician-researcher ([kappa] = 0.82) comparisons. The limb movement domain had fair correlation with Behavioral Pain Scale ([rho] = 0.24) and was reliable in clinician-clinician ([kappa] = 0.58) and clinician-researcher ([kappa] = 0.45) comparisons. Ventilator synchronization correlated with Behavioral Pain Scale ([rho] = 0.54), and reliability in clinician-clinician ([kappa] = 0.29) and clinician-researcher ([kappa] = 0.42) comparisons was fair-moderate. Eight hundred twenty-five patients were enrolled (range, 59-235 across ICUs), providing 12,385 care periods for evaluation (range 655-3,481 across ICUs). The mean proportion of care periods with each quality metric varied between ICUs: excessive sedation 12-38%; agitation 4-17%; poor relaxation 13-21%; poor ventilator synchronization 8-17%; and overall optimum sedation 45-70%. Mean adverse event intervals ranged from 1.5 to 10.3 patients treated. The quality measures appeared relatively stable during the observation period. Conclusions: Process control methodology can be used to simultaneously monitor multiple aspects of pain-sedation-agitation management within ICUs. Variation within and between ICUs could be used as triggers to explore practice variation, improve quality, and monitor this over time

Checklists for grading object-oriented CS1 programs: concepts and misconceptions

Sanders, K. and Thomas, L. 2007. Checklists for grading object-oriented CS1 programs: concepts and misconceptions. In Proceedings of the 12th Annual SIGCSE Conference on innovation and Technology in Computer Science Education (Dundee, Scotland, June 25 - 27, 2007). ITiCSE '07. ACM, New York, NY, 166-170

The life and work of the Rev. E.J. Peck among the Eskimos / by Arthur Lewis.

http://www.archive.org/details/lifeandworkofrev00lewiiala

Comportamiento en el vivero de portainjertos micropropagados del género Prunus : 2 - crecimiento de los cvs. Fantasía y Forastero

p.165-170

Conocimiento del contenido sobre polígonos de estudiantes para profesor de matemáticas

En este trabajo analizamos el conocimiento geométrico sobre polígonos de estudiantes para profesor peruano. Este conocimiento se describe en función de las capacidades que evidencian. Hemos determinado dichas capacidades con base en el modelo de razonamiento de Van Hiele y en consideraciones sobre el aprendizaje geométrico. Mostramos los resultados generales del grupo de alumnos, así como el estudio de dos casos.

Educación a distancia: una experiencia para el ingreso en la FRBB

La sociedad plantea una variedad de demandas de educación dependiendo de su situación y circunstancias particulares. La educación a distancia representa una realidad mundial en constante crecimiento cuantitativo y cualitativo potenciada últimamente con nuevos medios de comunicación.

Scheduling parallel dedicated machines under a single non-shared resource

The scheduling problem of minimizing the makespan for m parallel dedicated machines under single resource constraints is considered. For different variants of the problem the complexity status is established. Heuristic algorithms employing the so-called group technology approach are presented and their worst-case behavior is examined. Finally, a polynomial time approximation scheme is presented for the problem with fixed number of machines.