Aggression by polyembryonic wasp soldiers correlates with kinship but not resource competition

Kin selection theory predicts that individuals will show less aggression and more altruism towards relatives. However, recent theoretical developments suggest that with limited dispersal, competition between relatives can override the effects of relatedness. The predicted and opposing influences of relatedness and competition are difficult to approach experimentally because conditions that increase average relatedness among individuals also tend to increase competition. Polyembryonic wasps in the family Encyrtidae are parasites whose eggs undergo clonal division to produce large broods. These insects have also evolved a caste system: some embryos in a clone develop into reproductive larvae that mature into adults, whereas others develop into sterile soldier larvae that defend siblings from competitors. In a brood from a single egg, reproductive altruism by soldiers reflects clone-level allocation to defence at the cost of reproduction, with no conflict between individuals. When multiple eggs are laid into a host, inter-clone conflicts of interest arise. Here we report that soldier aggression in Copidosoma floridanum is inversely related to the genetic relatedness of competitors but shows no correlation with the level of resource competition.     

模糊滑动控制的一般方法(英文)

陈述了一种新的模糊逻辑控制方法,它可消除滑动控制所固有的抖动问题。方法的推导是将多开关滑动控制问题简化成等效的单开关问题。控制规律显示它是一种模糊滑动控制的一般方法。文献中的其他方法可由此法导出。模糊推理规则由两个输入变量组成。第一个输入变量是系统状态到所预定的状态空间中的超平面之间的方向距离;第二个输入变量的选择可根据应用而定,例如方向距离的导数、控制设计者所感兴趣的特定变量,或者某些状态变量的加权之和。这个新方法易于在高阶系统中实现,并且可以直接而明确地控制系统的动态过程。它消除了滑动控制和经典模糊滑动控制中的抖动问题。此外。新方法比其他类似方法的控制要简单。稳定性和性能分析显示了此法的有效性。此法已用于一带有典型驱动和反馈传感器的工业直流电机的位置控制之中。     

Neonatal T-cell tolerance to minimal immunogenic peptides is caused by clonal inactivation

The mechanisms underlying T-lymphocyte tolerance induced in neonatal mice are still unknown. It is unclear whether the tolerant state is the result of inactivation of T cells on exposure to antigen during development or of active suppression by other T cells specific for the same antigen. To distinguish between these two hypotheses, we have analysed the specificity of tolerance to three cytochrome peptides which differ by only a single amino-acid substitution in the epitope recognized by proliferative T cells. The peptides stimulate proliferative responses which are highly specific with minimal cross-reactivity. As antigen-induced clonal inactivation would address the same cells normally activated by that antigen, the specificity of tolerance should exactly match that of the proliferative response to the antigen, and each cytochrome peptide should induce tolerance to itself alone. Conversely, as T-suppressor (Ts) and T-proliferative (Tp) cells almost invariably seem to recognize distinct, non-overlapping determinants on protein antigens, suppressor-mediated tolerance should not be affected by substitutions in the proliferative T-cell epitope. Tolerance would depend solely on the existence of a shared suppressor determinant, so each cytochrome peptide should induce cross-tolerance to the others. We found that the specificity of tolerance matched that of the proliferative response: each peptide induced tolerance for itself but the response to the variants was unaltered. This result strongly supports the hypothesis of clonal inactivation as an important mechanism in induction of neonatal tolerance.     

济阳坳陷岩性油气藏地震采集技术

济阳坳陷岩性油气藏存在砂体内部及层间地震反射弱，资料分辨率低的问题。通过较小炮检距、较小面元、较宽方位角、较大非纵距和较高的纵、横向覆盖次数等面元属性的优化组合，提高了该区地震资料的分辨率;建立了表层条件“特征网”，通过寻找表层变化“突变带”，可为最佳激发因素的选取提供可靠依据;总结了频谱分析的有效方法，提出要以砂体解释的需要为目标，避免陷入盲目追求高频率的误区。以上技术与方法在济阳坳陷官7地区岩性油气藏地震采集中取得了明显效果，显著地提高了资料的分辨率，解决了小砂体及内部的弱反射问题。     

呼肠孤病毒科斐济病毒属一新种: 南方水稻黑条矮缩病毒

近年在广东省和海南省部分地区新发生一种水稻病毒病, 其症状表现为植株矮缩、叶色深绿、叶背及茎秆出现条状乳白色或深褐色小突起、高位分蘖及茎节部倒生气生须根. 病株韧皮部细胞内可观察到具斐济病毒特征性晶格状排列直径为70~75 nm的球状病毒粒体以及病毒基质和管状结构. 从发病田块及其附近的玉米(Zea mays)、稗草(Echinochloa crusgalli)、水莎草(Juncellus serotinus)和白草(Pennisetum flaccidum)植株体内检测到病原病毒的存在. 田间调查及室内传毒实验表明, 白背飞虱(Sogatella furcifera)是该病毒的主要传毒介体. 该病毒的基因组由10条dsRNA组成, 其电泳图谱与水稻黑条矮缩病毒(Rice black-streaked dwarf virus)基本相同. 采用接头单引物扩增法获得了该病毒基因组两个片段(S9和S10)全长核苷酸序列, 两者在核苷酸组成、末端序列及基因排列上均具斐济病毒特征, 但与斐济病毒属已知种核苷酸同一率小于75% (S9)和80% (S10), 基于核苷酸及其推导编码产物氨基酸序列构建的系统进化树表明, 该病毒在斐济病毒属中处于相对独立的进化位置. 结果表明, 该病毒应为呼肠孤病毒科(Reoviridae)斐济病毒属(Fijivirus)第2组的一个新种, 建议将其命名为南方水稻黑条矮缩病毒(Southern rice black-streaked dwarf virus).     

谈原真性（Authenticity）

>authenticity是当前国际文化遗产领域中一个特别重要的术语,它出现在众多国际文化遗产文献当中,在文化遗产价值认证和文化遗产保护实践中起着不可替代的作用。国际遗产界的重要文件《奈良文献》即指出：“原真性……看来是评审遗产价值的本质因素。对原真性的认识,在所有的文化遗产研究中,在保护与修复规划中,在《世界遗产公约》和其他文化遗产目录所采用的申报程序中,发挥着基础性作用。”因此,准确理解和翻译这个术语,对于中国遗产界具有重要的理论和实践意义。然而,目前国内对于authenticity的翻译仍然处于混乱状态,多种译法并存。在各种译法中,尤以将其译为“真实性”最为常见。该译法散见于各类学术研究中,并见诸官方文件,如2004年2月15日国务院办公厅转发了九个部委联合发布的《关于加强我国世界文化遗产保护管理工作的意见》。这个文件中使用的就是“真实性”提法。那么将authenticity一词译为“真实性”是否合适呢？下面从该词本身的意义着手,进行细致分析。authenticity一词起源于中世纪的欧洲,在希腊语和拉丁语中有“权威的”(authoritative)和“原初的”(original)含义。它并非是文化遗产领域的专用术语,早在现代文化遗产理论出现之前,就已应用于伦理学、语言学、文学艺术等领域。在宗教占统治力量的中世纪,authenticity用来指宗教经本及宗教遗物的真实性^[1]。在英文词典Webster’s 9th New Collegiate Dictionary的释义中,authenticity有original(原初的)、real(真实的)、trustworthy(可信的)三层含义。英国文化遗产专家David Lowenthal认为,authenticity表示与“虚假”(false)相对应的“真正”(true),与“伪造”(fake)相对应的“真实”(real),与“复制”(copy)相对应的“原作”(original),与“欺骗”(corrupt)相对应的“诚实”(honest),与“世俗”(profane)相对应的“神圣”(sacred)。^[1]当“authenticity”一词应用于文化遗产领域时,是指文化遗产本身和所有相关信息的“原初”“真实”和“可信”。如果将authenticity译为“真实性”,此种翻译只表达了其中的real(真实的)、trustworthy(可信的)两层含义,而original(原初的)这层含义,却没有体现出来。但这层含义对于遗产理论和实践有着不可忽略的意义。original(原初的),包含着时间维度上的“真”,其中original可理解为第一手的,非复制的。这层意思表明,authenticity中的“真”,是一个与时间相关的概念,即时间起点和整个时间序列上各个点对于起始状态的“真”的反映。举个简单的例子,当面对一只在今天制造的金手镯时,人们讨论其是否是“真”,一般是指其是否用纯金制成;而面对一只古代的金手镯,当讨论其是否是“真”,不仅指其材料,更是指向时间维度,即这只金手镯是否是制造于古代而不是现代;如果这是一只古代著名人物用过的金手镯,那这个“真”还指代特定历史年代和特定历史人物,而这些信息都是不能复制的,都是“原”的。所以,“原”和“真”在指向的内容上有一定的交集,但并不是完全重合。在文化遗产领域翻译authenticity时,“原”的含义是不可以省略的。不恰当的翻译容易导致意思的缺损,会造成对术语的片面理解,影响人们对文化遗产领域中一些重要问题的判断,给文化遗产保护实践带来负面影响。一些学者提出了更为恰当的译法,其中“原真性”就是其中之一。张松提出：“原真性(authenticity),又译原生性、真实性、确实性、可靠性,主要有原始的、原创的、第一手的、非复制、非仿造等意思。”^[2]张成渝^[3],阮仪三^[4-5]等人都在文章中直接使用“原真性”作为“authenticity”一词的翻译。与其他译法相比,“原真性”一词中的“原”与“original”这层含义对应,“真”与“real”和“trustworthy”对应,完整得表达出了“authenticity”中所包含的三重含义,弥补了原译法的不足。这种译法能够与多样的文化遗产相适应,是对“authenticity”较为确切的中文翻译。     

Evolved structure of language shows lineage-specific trends in word-order universals

Languages vary widely but not without limit. The central goal of linguistics is to describe the diversity of human languages and explain the constraints on that diversity. Generative linguists following Chomsky have claimed that linguistic diversity must be constrained by innate parameters that are set as a child learns a language. In contrast, other linguists following Greenberg have claimed that there are statistical tendencies for co-occurrence of traits reflecting universal systems biases, rather than absolute constraints or parametric variation. Here we use computational phylogenetic methods to address the nature of constraints on linguistic diversity in an evolutionary framework. First, contrary to the generative account of parameter setting, we show that the evolution of only a few word-order features of languages are strongly correlated. Second, contrary to the Greenbergian generalizations, we show that most observed functional dependencies between traits are lineage-specific rather than universal tendencies. These findings support the view that-at least with respect to word order-cultural evolution is the primary factor that determines linguistic structure, with the current state of a linguistic system shaping and constraining future states.     

Purification, cloning, expression and biological characterization of an interleukin-1 receptor antagonist protein

A human myelomonocytic cell line, U937, produced an interleukin-1 (IL-1) receptor antagonist protein (IRAP) which was purified and partially sequenced. A complementary DNA coding for IRAP was cloned and sequenced. The mature translation product of the cDNA has been expressed in Escherichia coli and was an active competitive inhibitor of the binding of IL-1 to the T-cell/fibroblast form of the IL-1 receptor. Recombinant IRAP specifically inhibited IL-1 bioactivity on T cells and endothelial cells in vitro and was a potent inhibitor of IL-1 induced corticosterone production in vivo.