Analysis of the expression and antioxidative property of a peroxiredoxin 6 from Scophthalmus maximus

Peroxiredoxins (Prxs) are a group of antioxidant proteins that protect cells from oxidative damage caused by various peroxides. To date, six different isoforms of peroxiredoxin (Prx1 to Prx6) have been identified, of which, Prx6 belongs to the 1-Cys Prx subfamily. Although Prx6 of several fish species have been reported at sequence level, there are very few documented studies on the potential function of fish Prx6. In this report, we describe the identification and analysis of a Prx6 homologue, SmPrx6, from turbot Scophthalmus maximus. The full length cDNA of SmPrx6 contains a 5'- untranslated region (UTR) of 60 bp, an open reading frame of 666 bp, and a 3'-UTR of 244 bp. The deduced amino acid sequence of SmPrx6 shares 81-87% overall identities with known fish Prx6. In silico analysis identified in SmPrx6 a conserved Prx6 catalytic motif, PVCTTE, and the catalytic triads putatively involved in peroxidase and phospholipase A2 activities. Expression of SmPrx6 was detected in most fish organs, with the highest expression levels found in blood and heart and the lowest level in spleen. Experimental challenges with bacterial pathogens and poly(I:C) upregulated SmPrx6 expression in liver and spleen in a manner that is dependent on the challenging agent and the tissue type. Treatment of cultured primary hepatocytes with H2O2 enhanced SmPrx6 expression in a dose-dependent manner. Recombinant SmPrx6 expressed in and purified from Escherichia coli exhibited thiol-dependent antioxidant activity and could protect cultured hepatocytes from H2O2-induced oxidative damage. Taken together, these results indicate that SmPrx6 is a Prx6 homologue with antioxidative property and is likely to be involved in both cellular maintenance and protective response during host immune defense against bacterial infection. (C) 2010 Elsevier Ltd. All rights reserved.

Modern changes of tidal troughs among the radial sand ridges in northern Jiangsu coastal zone

Using satellite images taken on different dates, GIS analysis of aerial photos, bathymetric maps and other field survey data, tidal troughs and major sand ridges in the northern Jiangsu coastal area were contrasted. The results show that there have been three types of movement or migration of tidal trough in this area: (1) Periodic and restricted, this type of trough usually developed along the beaches with immobile gully head as a result of the artificial dams and the swing range increased from gully head to the low reaches, so they have been obviously impacted by human activity and have longer swing periods; (2) Periodic and actively, this kind of trough, which swung with a fast rate and moved periodically on sand ridges, were mainly controlled by the swings of the host tidal troughs and hydrodynamic forces upon tidal sand ridge and influenced slightly by human constructions; (3) Steadily and slowly, they are the main tidal troughs with large scale and a steady orientation in this area and have slow lateral movement. The differences in migration mode of tidal trough shift result in different rates of migration and impact upon tidal sand ridges. Lateral accumulation on current tidal trough and deposition on abandoned tidal troughs are the two types of sedimentation of the tidal sand ridges formation. The whole radial sand ridge was generally prone to division and retreat although sand ridges fluctuated by the analysis of changes in talwegs of tidal troughs and shorelines of sand ridges.

北黄海表层沉积物粒度分布特征及其对沉积环境的指示

本文基于北黄海1140个表层沉积物样品的粒度分析结果，来探讨沉积物粒度组成、分布特征与物源和水动力环境的关系。结果表明，研究区底质类型主要有泥、粉砂、砂质粉砂、粉砂质砂、砂五种类型，少数站位含有砾石。砾石则主要分布在长山列岛附近海域、大连湾口及其东南近海；砂主要分布在123.3°E以东的海域和长山列岛附近海域；粉砂主要分布在研究区的西南部和大连湾外海；粘土的含量较低，含量大于30%的区域仅分布在研究区的西南部，大于16%的区域有向北和东北延伸的趋势，在大连湾至广鹿岛近海沉积物粘土含量也大于16%。 根据对沉积物粒度各粒级的因子分析结果,结合沉积物的Folk分类和Pejrup分类,将北黄海划分成五个主要沉积环境分区，分别受山东半岛沿岸流、黄海暖流、强潮流场、长山列岛和辽东沿岸流控制。北黄海中西部沉积物主要受山东半岛沿岸流影响，经过本区的黄海暖流限制了山东半岛沿岸流携带的细粒物质向东和向北的扩散和运移，研究区东部沉积作用的主控因素是潮流，长山列岛中部海域受附近岛屿剥蚀物影响，大连湾外海受辽东半岛沿岸流控制。研究区西南部细粒沉积物的粒度分布具有不均匀性和南北不对称性，其形成主要受控于山东半岛沿岸流和黄海暖流及其相互作用，潮流可能也起一定作用。

Feeding behaviour of Japanese flounder larvae under laboratory conditions

Tank-reared Japanese flounder larvae, Paralichthys olivaceus, had a major feeding peak in the morning and a secondary peak in the afternoon throughout the larval development, with light being the primary factor regulating their feeding activity. The larvae consumed rotifers in preference to Artemia for up to 10 days, after which the food preference shifted to Artemia. Feeding rates of the larvae prior to 10 days post-batch depended on prey density, but in the old larvae, feeding rates were independent of prey density. Maximum feeding rate occurred at 19 degrees C. The occurrence of the attack posture, after its onset at first feeding (2 days post-hatch), increased up to 25 days, began to decrease when the larvae prepared to settle down, then disappeared after settlement. The occurrence frequency of the attack posture was positively related to fish density, but inversely related to starvation duration, and occurred most frequently at 19 degrees C. This posture depended on prey density in larvae prior to 10 days post-hatch, but became independent of prey density as the larvae developed. It was obvious that, for flounder larvae, attack posture was a behavioural character closely related to feeding and subject to larval development and environmental factors. (C) 2000 The Fisheries Society of the British Isles.

陇西不同类型地区蒙古黄芪甲甙含量的变化研究

按照海拔、地形和地貌条件的不同，各选取666．67m~2试验样地，统一按照20 cm×20 cm(25．05万株／hm~2)株行距设计，栽种同一育苗基地同龄种苗，统一田间管理技术进行栽培试验，收获期统一测定黄芪甲甙含量。研究结果表明，不同地区黄芪甲甙含量变化较大，差异高达2．4倍；山地非灌溉地区黄芪甲甙含量最低，次为坡地，川地灌溉地区最高。因此，陇西地区黄芪人工栽培基地应当主要选择在川地及坡地地区种植(海拔2 100m以下地区)。

柴达木盆地唐古特白刺果实降血脂和抗氧化作用研究

为了研究柴达木盆地唐古特白刺果实的降血脂、抗氧化作用，本文采用高脂饲料诱导小鼠和大鼠 建立高脂动物模型，灌胃给药4周，测定各组实验动物的血清血脂水平，并测定大鼠红细胞SOD活性和血清脂质过氧化物（LPO）分解产物丙二醛（MDA）的含量变化。结果显示唐古特白刺果实1.8g/kg和3.6g/kg剂量对高脂饲料诱导的小鼠和大鼠血清TC、TG及大鼠的LDL具有显著的抑制作用；同时可显著升高高血脂大鼠HDL/TC和HDL/LDL的比值，提高高血脂大鼠SOD活力和降低高血脂大鼠MDA含量；对大鼠体重和正常小鼠血脂水平无明显影响。表明唐古特白刺果实具有降血脂、防治动脉粥样硬化和抗氧化作用。

陇西地区蒙古黄芪不同密度栽培试验研究

在陇西首阳黄芪人工栽培基地按照海拔、地形和地貌条件的不同,各选取666.67 m2试验样地,按照不同密度设计株行距,统一种苗和田间管理技术进行栽培试验,收获期统一测定黄芪产量和个体特征,利用HPLC方法对不同密度栽培黄芪甲甙含量进行测试.研究结果表明,从黄芪的外观等级、经济效益和黄芪甲甙含量等指标评价,最佳栽培密度为20 cm×20 cm.

Characterizing evapotranspiration over a meadow ecosystem on the Qinghai-Tibetan Plateau

To characterize evapotranspiration (ET) over grasslands on the Qinghai-Tibetan Plateau, we examined ET and its relevant environmental variables in a Kobresia meadow from 2002 to 2004 using the eddy covariance method. The annual precipitation changed greatly, with 554, 706, and 666 mm a(-1) for the three consecutive calendar years. The annual ET varied correspondingly to the annual precipitation with 341, 407, and 426 mm a(-1). The annual ET was, however, constant at about 60% of the annual precipitation. About 85% annual ET occurred during the growing season from May to September, and the averaged ET for this period was 1.90, 2.23, and 2.22 mm/d, respectively for the three consecutive years. The averaged ET was, however, very low (< 0.40 mm/d) during the nongrowing season from October to April. The annual canopy conductance (gc) and the Priestley-Taylor coefficient (a) showed the lowest values in the year with the lowest precipitation. This study first demonstrates that the alpine meadow ecosystem is characterized by a low ratio of annual ET to precipitation and that the interannual variation of ET is determined by annual precipitation.

基于随机路标法的超冗余度机械霄路径规划

本文对基于随机路标法的超冗余度机械臂路径规划问题进行了研究。首先，介绍了随机路标法的基本原理，然后结合随机路标法的具体实现，分析及研究了凸多边形的碰撞检测、局部路径的计算等路径规划的基本理论，从而实现了利用随机路标法对超冗余度机械臂进行无碰撞路径规划。仿真实验表明了随机路标法在解决超冗余度机械臂路径规划问题的有效性和可行性。

机器人控制器远程诊断系统的研究

机器人控制器是机器人控制系统的核心,它从一定程度上影响着机器人技术的发展,本文旨在跟踪国外机器人控制器技术的最新发展,同时针对国内的研究和应用现状,提出了一种在机器人控制器和上位PC机之间采用MODEM拨号方式实现的、具有开放式结构的机器人控制器远程诊断系统的研究方法。

退耕弃荒洼地土壤有机碳在生态系统转化过程中的动态变化

在贵州喀斯特区域一块典型的退耕弃荒洼地中央和周边坡面采集了4个土壤剖面,研究土壤有机碳（SOC）含量和δ^13Corg值的变化.结果表明,坡面不同土壤层次SOC的变化范围为6.0-92.3 mg·kg^-1,并沿着土壤层次的加深迅速降低,变化幅度远远大于洼地土壤剖面（6.3-26.7 mg·kg^-1）.坡面土壤δ^13Corg介于-25.103‰和-23.666‰之间,但各剖面土层内部δ^13Corg变化趋势不一致.洼地土壤δ^13Corg介于-23.495‰和-20.809‰之间,并随着土壤层次的加深δ^13Corg逐渐增加.洼地土壤剖面层次内C4-C占SOC的比例随土壤层次的加深逐渐增加,与林-农生态系统转变过程中的变化趋势相反;土壤δ^13Corg与C3-C之间呈显著相关性（R^2=0.7806,n=7）,对δ^13Corg起到主要影响作用的是退耕弃荒后新加入的C3-C.

云南会泽铅锌矿床脉石矿物方解石REE地球化学

方解石是云南会泽铅锌矿床最重要的脉石矿物，原生矿石中三种产状（即团块状状、团斑状和脉状）方解石的REE含量、有关参数和配分模式都有一定的差异，但不同产状方解石之间以及同种产状方解石的REE地球化学特征具有连续变化规律。分析结果表明：矿区原生矿石中三种产状方解石为同源不同阶段形成的产物；矿床成矿流体具有多来源特征，地幔流体在成矿流体形成过程中具有重要作用；成矿流体在演化过程REE含量逐渐降低；成矿环境由相对还原向相对氧化变化。

硅酸盐熔体-流体共存体系中Cu分配系数的实验研究

硅酸盐固相与液相共存体系中Cu分配系数研究近年来取得重大进展，但大部分工作主要集中在研究流体组分的变化对Cu分配系数的影响。而固相组成的变化对Cu分配系数的影响则少有涉及。本文作者在相同实验条件、实验流程下成功合成了数个硅酸盐组分初始凝胶。初始凝胶基于精确改变AIUAI，Na/K的相对摩尔比值及SiO_2，Na+K的摩尔含量分为四组，而且同一组内其它组分的相对摩尔含量控制不变。分配实验条件设定为温度800℃，压力Ikbar，时间5天，在此实验条件下讨论了不同成分的初始硅酸盐固相与共存流体相（0.1mol／l的HCI）中Cu的分配系数。通过上述研究，主要得出如下初步认识。在初始固相组成中，Alk＋Al所占的总相对摩尔含量不变，改变初始固相Alk/Al的摩尔比。实验结果表明：在本文实验条件下，铜的分配系数明显地受Alk/Al比值改变的制约。随着Alk/Al的比值从0.666增大到1.500，铜的分配系数由54.16线性下降到16.55。即Al／Alk比值增大有利于硅酸盐固相与液相共存体系中铜在流体相中富集。控制Na＋K在初始固相中的摩尔百分含量不变，改变Na/K的比值。实验结果表明：尽管Na/K的比值在一个较大的范围内变化，但Cu的分配系数值在10上下很小一个范围内摆动，基本上可以认为是不变的。即在本文实验条件下，初始固相组成中Na/K比值的变化不影响硅酸盐固相与液相共存体系中Cu的分配系数。故可初步认为：初始固相中Na、K对Cu分配作用的贡献可能是一致的。单独改变初始固相中Na＋K的总摩尔含量，实验表明：随着Na＋K．的总相对摩尔含量增大，铜的分配系数线性下降。我们还可以结合Al/Al的改变对铜分配系数的影响可得到相似的结果。又上一小段结论认为：在Na＋K含量不变的情况下，Na/K比值改变不影响铜的分配系数。综合上述几方面进一步认为：在可能制约Cu分配系数的因子中，Na＋K的总含量变化是影响铜分配系数的一个重要因素；而Na＋K的总含量不变的情况下，Na/K的相对改变并不会影响铜的分配系数。改变SiO_2的初始摩尔相对含量，实验结果的规律性不是很明显，但从整体上分析分配系数，仍可发现一些可能的趋势：SiO_2的相对摩尔含量越高，铜的分配系数有下降的趋势。该组实验结果的不确定性，可能与SiO_2初始含量的基数大有关。铜的分配系数受流体的pH值的的制约。实验结果认为，酸性流体有利于铜在分配过程中进入流体相。虽则所有实验初始流体浓度及量是一样的，但实验后流体组成中铜的浓度与氯的浓度却呈正相关线性关系。本文实验与前人通过改变初始流体氯的浓度来讨论铜的分配系数实验相比，虽然实验体系各异，但在流体相中却得到相同的铜与氯的浓度关系。从而更有力地说明了流体相中铜与氯之间的互相依存关系，很可能流体相中铜与氯结合成络合物的形式存在。

ELISA com MSP5 recombinante truncada para detecção de anticorpos contra Anaplasma marginale em bovinos.

Os objetivos buscados pelos autores neste estudo foram produzir e solubilizar a proteína MSP5 recombinante truncada de Anaplasma marginale e avaliar seu desempenho em um ensaio de imunoadsorção enzimática indireto para detecção de anticorpos contra a riquétsia. O gene msp5, exceto a região N-terminal hidrofóbica, foi amplificado por reação em cadeia da polimerase, clonado em plasmídeo pTrcHis-TOPO e expresso em Escherichia coli. A solubilização da proteína recombinante foi avaliada em diferentes pHs e concentrações de uréia. A sensibilidade e a especificidade do ensaio foram avaliados testando-se 66 soros de animais infectados experimentalmente com A. marginale e 96 soros negativos, com o estado de infecção desses animais confirmado por reação em cadeia da polimerase. Um total de 1.666 amostras de soros bovinos, provenientes do Brasil - Rio Grande do Sul (73), Mato Grosso do Sul (91), Pernambuco (86), Bahia (314) e Minas Gerais (267), assim como do Uruguai (32) e Costa Rica (803) foram testadas nos ELISAs com MSP5 truncada e com MSP1a recombinantes, e a concordância entre os dois testes foi avaliada. O ELISA indireto com MSP5 truncada foi capaz de detectar animais infectados com 96,97% de sensibilidade e 100% de especificidade. Nos animais infectados experimentalmente, o ELISA detectou anticorpos do 12o dia após a inoculação (DPI) até o último dia de observação (37o DPI). Os ELISAs para MSP5 e MSP1a apresentaram concordância de 95,67%, com índice kappa de 0,81. Os resultados discordantes apresentaram uma diferença significativa (P < 0,001). Anticorpos contra A. marginale foram detectados em animais de todas asregiões estudadas. O ELISA com MSP5 recombinante truncada apresentou bom desempenho na detecção de anticorpos contra A. marginale, com alta sensibilidade e especificidade, representando uma importante ferramenta para o diagnóstico da anaplasmose bovina em estudos epidemiológicos.