Changes in Resistance to Salinity and Temperature in Some Species of Polychaetes from the White Sea in Early Ontogenesis

We studied the effects of different salinities on plankton larvae of some polychaetes in the White Sea. It has been found that the salinity resistance of Alitta virens (Nereidae) increases during ontogenesis. Successful fertilization and further larval development in this species occur at the salinity of 22 to 34; embryos taken into the experiment at the stage of 32 blastomeres, trochophores, and early nektochaetes could survive and normally develop at the salinity of 16–32, 14–45, and 12–45 respectively. The rate of settling and metamorphosis in late nektochaetes of A. virens at normal or lowered (down to 14) salinity is dependent on temperature in the range of 5 to 23°C. It is found that the larvae of Harmothoe imbricata (Polynoidae) show the greatest salinity resistance at the stage of nektochaeta, whose lower limit of salinity is 14. Later larval stages of these species can survive in a wide range of salinity due to the development of a provisory nephridial system. The eurybionty of larvae of Spirorbis spirorbis ready for metamorphosis was higher than that in the larvae of Circeus spirillum (Spirorbidae). Under salinity reduced down to 10 the larvae of S. spirorbis die in 8–14 days, whereas more stenohaline larvae of C. spirillum die by the 3-rd day of the experiment. At water temperatures under 5°C the survival of S. spirorbis was the highest at three examined values of salinity, whereas C. spirillum showed the highest survival only under normal salinity.     

芽胞气溶胶表面滞留抗力预测模型研究

针对生物威胁的现场处置工作,建立气溶胶芽胞表面滞留抗力的智能预测模型,以准确预测环境表面芽胞污染状况,为大规模的现场洗消任务提供重要依据,有利于实现及时反应、恰当反应和准确防护的目标。以枯草杆菌芽胞为试验菌,在气溶胶实验室进行芽胞的环境因素暴露及活力测定,以模拟环境中芽胞抗力变化规律数据为依据,采用Matlab6.1软件包中的神经网络工具箱进行抗力预测模型研究。根据研究目的、模拟环境条件和数据训练的平滑曲线等特征,设定了5个输入神经元,8个隐层节点和1个输出神经元。‘tansig’、‘purelin’为传递函数,trainlm为训练函数,网络迭代100次。模型回顾预测效率达到100%,前瞻预测效率达到91%。以实验室数据为依据,利用Matlab平台中的BP神经网络建立的芽胞气溶胶表面滞留抗力预测模型能利用环境因素信息有效预测芽胞抗力。     

Beyond the Post-Structural Impasse in the Anthropology of Development

In recent years anthropologists have produced innovative and critical scholarship that refuses to simplify or essentialise the development process. However, for the most part the anthropology of development remains closely tied to the post-structuralist paradigm. Why, after more than two decades, does the post-structuralist critique continue to hold its dominant grip on the anthropology of development? Why haven’t anthropologists been able to move the anthropology of development, or development itself, further ahead? These are the main questions addressed in this article. More specifically, it is argued that the anthropology of development has reached an impasse; it remains bound to an overly structural interpretation of the development process, a construction that privileges not only structure over agency, but also hegemony over dialectics. Using the ethnography of a high-profile case of development in northwest Namibia, the article suggests a possible path forward by outlining a proposal for a simultaneous theoretical re-orientation and methodological reclamation in the anthropology of development.     

柑桔抗寒研究的现状与展望

柑桔是一种经济价值极高但又常受冻害影响的亚热带果树,本文总结了柑桔抗寒研究取得的成果,介绍了对于柑桔抗寒研究还是空白但是在其他植物抗寒研究上取得的新进展,并由此提出了柑桔抗寒可在冷诱导蛋白、冷诱导基因和抗寒基因工程等方面进行探讨以及作者粗浅的研究设想。     

细菌生物膜与耐药性相关性研究进展

细菌生物膜是一种包裹于细胞外多聚物基质中不可逆的黏附于非生物或生物表面的微生物细胞菌落.生物膜状态下的细菌相对其浮游状态具有显著增强的耐药性,对人及动物细菌性感染具有重要研究价值.然而尽管动物细菌耐药性被广泛报道,却很少涉及细菌生物膜与其之间的相关性,本文综述了细菌生物膜的耐药机制并探讨了细菌生物膜与动物源性细菌耐药性的关系,可作为研究细菌耐药性及控制动物产品安全的参考.     

TRAIL耐药产生的机制及逆转耐药的最新策略

肿瘤坏死因子相关凋亡诱导配体（tumor necrosis factor-related apoptosis inducing li-gand,TRAIL）是唯一能诱导癌细胞凋亡而对机体正常组织无明显损伤的内源性细胞因子,因而被认为是一种极具前景的抗癌药物。然而目前研究发现,许多恶性肿瘤细胞对TRAIL具有耐药性,使TRAIL在临床应用中遭遇瓶颈。越来越多的证据表明,一些关键信号通路可能与TRAIL耐药有关,且利用靶向基因治疗策略以及借助某些天然药物或小分子抑制剂能够部分恢复癌细胞对TRAIL的敏感性。该文主要描述了肿瘤细胞对TRAIL的耐药机制,并对如何有效克服和逆转TRAIL耐药的策略作了简要概括。     

高粱抗病虫资源创新与利用研究

利用"八五"、"九五"期间,发掘和鉴定出的一些具有单一抗病虫特性和优良农艺性状的资源,通过有性杂交和人工接种鉴定,有目的进行抗性基因转移和优良基因聚合,从而获得了具有多抗、农艺性状优良的LR625、LR622、2381等3个恢复系和L405A、L407A 2个不育系等新种质资源,并用新创资源组配了一批高产、多抗、综合农艺性状好的杂交组合.     

细菌生物被膜对抗生素耐药机制的研究进展

细菌生物被膜引发的感染已成为医院感染的主要原因之一,具有耐药性和难治性的特点,引起了基础和临床研究的极大关注。但是细菌生物被膜对抗生素的耐药机制目前还不十分明确,对近年来生物被膜怎样和为什么会对抗生素如此耐药形成了几种可能机制进行综述。     

转Bt基因抗虫棉对亚洲玉米螟抗性的研究

对转Bt抗虫棉苏抗103与GK—22对玉米螟抗性的研究结果显示：(1)用苏抗103嫩叶、簧,花、蕾饲曩第三代玉米螟幼虫,最终幼虫校正死亡率分别达100％、95．83％、83．33％与100％。校正化蛹下降率分别达100％、92．31％、50．07％与100％,校正幼虫成蛾减退率分别达100％、90．92％、0％与100％。(2)人工饲料中加入5个不同浓度苏抗103嫩叶饲喂第二代幼虫,除0．4％浓度,幼虫校正死亡率与成蛹下降率均为100％,0．4％浓度的幼虫期延长20．68％,蛹重下降18．24％,蛹期延长19．79％。(3)人工饲料中加入5个浓度的苏抗103或GK22嫩叶分别饲喂第三代幼虫,苏抗103上幼虫校正死亡率较第二代有所下降,分别为3．04％、-16．68％、28．2％、33．33和75％。GK22上幼虫校正死亡率分别为3．13％、26．89％、45．69％、70．816％和68．09％。其幼虫校正死亡率及幼虫期、蛹期、成虫校正减退率均有随浓度增加而上升的趋势。较亲本棚,对蛹重、雌成虫寿命、单雌产卵量、卵孵化率也有一定程度的影响。上述研究结果表明,苏抗103与GK22影响棉田玉米螟幼虫与蛹的存活与生命力,进而影响其成虫繁殖力而表现出良好抗性。     

Don C. Ohadike: The Man, his Intellectual Legacy and African Historiography

It is difficult to completely understand the life history of an intellectual excluding an understanding of his family upbringing and formative years. Family upbringing and childhood environment, often the less known part of a life history, play crucial roles in shaping the ideas and values individuals espouse in their adult life. Notwithstanding, this paper is not concerned with Don C. Ohadike’s childhood. It rather focuses on the professional career of our able historian – that is the part of his life as revealed by his most outstanding published writings. Ohadike’s published works contain a wellspring of idioms that tell much about his values, quality of mind, and his mission as an African historian. Ohadike was a humanist, an African patriot, and a nationalist crusader. His entire philosophy centered on safeguarding his African identity in an emergent world of cultural imperialism. The funds for this research were provided by a NEH-funded fellowship at the Schomburg Center, New York in the Spring of 2007. I owe a lot of gratitude to Professor John McLeod and Dean Blaine Hudson for granting me the extra incentives to pursue my research in New York. While all errors and misinterpretations are mine, I wish to thank the editors and anonymous reviewers for Journal of Dialectical Anthropology for their perspective comments and suggestions on earlier drafts of this paper.     

玉米种质资源抗灰斑病鉴定与评价

2001-2004年,于田间应用人工注射接种的方法对413份玉米自交系和59份玉米杂交种进行抗灰斑病(Gray leaf spot)鉴定,筛选出病级1级高抗(HR)自交系6份、3级抗病(R)自交系28份和杂交种7份.鉴定结果表明,在供试的不同玉米自交系及杂交种间的抗病性存在明显差异,而表现高抗的玉米自交系较少,没有发现高抗杂交种.加强玉米抗灰斑病种质资源的收集和评价,对玉米抗病育种非常必要.     

内生真菌对植物生长发育及抗逆性的影响

本文从内生真菌的涵义和基本生物学特征出发,以国内外近二十年来关于内生真菌与植物关系的研究情况作了综述。主要包括内生真菌的检测、鉴定和转染,内生真菌对植物生长发育与抗逆性的影响,以及内生真菌在农业及其他相关领域的应用前景。文中提及作者近期开展的关于内生真菌对黑麦草抗旱性影响的研究课题及其初步进展。     

Resistance of larvae of common species of White Sea invertebrates to extreme changes in salinity

This study examines the effect of sharp changes in salinity on pelagic larvae of ten common species of invertebrates from the brackish White Sea (Mollusca, Polychaeta, Echinodermata, Cnidaria, Ascidia). For five species, the low salinity resistance limit was in the range of 8–12‰: for the gastropod Littorina littorea, it was below 8‰; for Dyaphana sp. and the bivalves Hiatella arctica and Heteranomia ovata, it was more than 12‰; and for the ascidian Styela rustica, it was 16‰. About 50% of larvae of four investigated species were able to withstand high salinity and survived at 36–40 and even 50‰ (Littorina). Larvae of littoral-sublittoral species proved to be more euryhaline than larvae of sublittoral species.     

An Induced Resistance Effect of Hydroxyurea on Plants Infected by Meloidogyne javanica

Aqueous solutions of hydroxyurea (HU) in various concentrations were applied as soil drenches to Meloidogyne javanica-infected plants. At a concentration of 15 ppm, the chemical hampered giant cell formation and the number of females on the roots was 20% of that of the control but the growth of the host plants was not affected. Additional HU applications after the one at infection did not add to the inhibitory effect. HU exerted its effect on M. javanica-infected tomato in five soil types. Soil temperature of 32 C neutralized the HU-induced resistance in much the same way that high temperature breaks the natural resistance in M. incognita-resistant tomato. This study provides further evidence of the role of HU as an induced resistance agent.     

果蔬采后诱导抗病性

诱导抗病性是生物防治的途径之一 ,本文综述了诱导抗病性在果蔬采后病害防治中的研究进展 ,包括多种物理性、化学性和生物性激发子对许多采后果蔬抗病性的诱导以及诱导抗病性产生的机制 ,并分析它在果蔬防腐保鲜上的应用前景。     

水稻细菌性条斑病和白叶枯病抗性遗传研究

分析了Ｈａｓｈｉｋａｌｍｉ,Ｄｕｌａｒ和９０ＩＲＢＢＮ４４三个抗源品种对水稻细菌性条斑病Ｓ－１０３菌株和白叶枯病Ｐ１菌系的抗性遗传。结果表明,Ｈａｓｈｉｋａｌｍｉ和Ｄｕｌａｒ对Ｓ－１０３的抗性均由２对隐性基因所控制,９０ＩＲＢＢＮ４４则带有１对隐性抗性基因。经等位性测定表明,Ｈａｓｈｉｋａｌｍｉ和Ｄｕｌａｒ的２对基因中至少有１对是等位的,但它们与９０ＩＲＢＢＮ４４的１对基因均不等位。３个抗源品种对Ｐ１的抗性都受１对隐性基因控制,该基因与ｘａ－５等位。连锁遗传分析表明,Ｈａｓｈｉｋａｌｍｉ和Ｄｕｌａｒ对Ｓ－１０３的２对抗细条病基因中的１对与ｘａ－５相连锁,而９０ＩＲＢＢＮ４４的１对抗性基因与ｘａ－５呈独立遗传。本文还就开展水稻抗细菌性条斑病育种进行了讨论。     

Resistance of dogs to Echinococcus granulosus

Further studies on the immunization of dogs against E. granulosus indicated that certain dogs have a natural resistance, which is not mediated by specific antibodies or sensitized lymphocytes to tapeworm secretory antigens. In a pilot experiment with two pups, E. granulosus recovered from an immunized pup were arrested in their development and exhibited 100% inhibition of egg production compared to 100% egg production in mature worms recovered from a control pup. When the experiment was repeated with 10 pups, three of five control pups given Freud's adjuvant and Bordetella pertussis carried E. granulosus which were arrested in their development and showed 100% inhibition of egg production. Two of five immunized pups also exhibited signs of resistance. Arrested worms recovered 40 days after infection appeared to be at a stage equivalent to about 18 days of optimal development. Although immunized pups exhibiting resistance showed strong positive in vitro and in vivo immune responses, all control pups gave negative reactions to tapeworm secretory antigens.     

Some Methods for the Measurements of Tonoplast Resistance of Nitellopsis obtusa

Measurements of tonoplast resistance for unit area, T were carriedout by four methods. The T values obtained by two of these methods,when taking into account a correction for leakage current, were0.024 and 0.010 k cm². The other two methods, which made itpossible to neglect leakage current, gave the T values of 0.036and 0.021 k cm². Thus, the mean value of tonoplast resistancein the investigated cells of Nitellopsis obtusa was 0.023 kcm², while the measurements in which leakage current was nottaken into account gave the value 10.6 k cm². The results obtainedin this study indicate the fact that leakage current significantlyaffects measurements of tonoplast resistance and that the truevalue of that resistance is smaller by two or three orders ofmagnitude than that usually reported.     

茶树种质资源抗病性鉴定

１９８７～１９９５年开展了茶树种质资源抗病性鉴定研究．经田间和室内鉴定试验,从３４份资源材料中筛选出对茶轮斑病高抗材料１份,抗性材料１１份;从３０份资源材料中筛选出对茶苗根结线虫病高抗材料５份,抗性材料１３份．从而为抗病育种或推广生产提供了抗源材料,同时也为抗性机制及遗传规律研究提供了基础．