对称蛋白质序列与结构关系研究

进化的观点认为,蛋白质结构的对称性是基因复制和融合的结果,但是由于在长期进化过程中的氨基酸突变,绝大多数现有的蛋白质序列都失去了这种直观的重复性特征。该文简要地回顾了国际上发展的寻找蛋白质序列中重复片段的方法,重点介绍了作者自己提出的分析蛋白质序列和结构对称性的方法以及在蛋白质对称结构形成机理方面的初步工作,并系统分析了各类对称折叠子的序列与结构关系,发现它们的序列都具有隐含的与结构相同的对称性,或者说序列的对称性决定结构的对称性。     

我国生态产品价值实现政策的配置与优化——基于政策文本分析

为促进城乡区域协调发展,推动地区生态产业化和产业生态化,完善生态产品价值实现的多元化路径和政策制度体系,对当前中央和地方政府发布的生态产品价值实现相关政策文本展开分析,并提出优化建议,为后续相关政策配置与优化提供参考。通过选取2019年-2022年8月间36份生态产品价值实现政策文本作为研究对象,构建政策工具-政策目标二维分析框架,借助质性分析工具Nvivo12对其进行量化分析和综合评价。研究发现,政策文件以通知和实施方案为主;政策工具覆盖较为全面,但内部存在分配不太协调的现象。政策目标维度中生态环境优美化受关注度较高,而生态产业高效化较少。工具-目标配置上,存在多对多的关系,不同政策目标对应的政策工具也存在差异。为进一步优化生态产品价值实现的政策供给,从政策工具上应以战略、具体规划为重点,平衡政策工具内部结构比例;从政策目标上应强调从金融和技术方面助推生态产品价值实现的同时,也需要加强法规管制力度,推出更专业化和可操作性的具体举措,因地制宜凸显区域化特色和差异,真正将生态产品价值实现政策落到实处,确保成果看得见摸得着。     

Evolution of Defence Portfolios in Exploiter–Victim Systems

Some organisms maintain a battery of defensive strategies against their exploiters (predators, parasites or parasitoids), while others fail to employ a defence that seems obvious. In this paper, we shall investigate the circumstances under which defence strategies might be expected to evolve. Brood parasites and their hosts provide our main motivation, and we shall discuss why the reed warbler Acrocephalus scirpaceus has evolved an egg-rejection but not a chick-rejection strategy as a defence against the common (Eurasian) cuckoo Cuculus canorus, while the superb fairy-wren Malurus cyaneus has evolved a chick-rejection but not an egg-rejection strategy as a defence against Horsfield's bronze-cuckoo Chrysococcyx basalis. We suggest that the answers lie in strategy-blocking, where one strategy (the blocking strategy) prevents the appearance of another (the blocked strategy) that would be adaptive in its absence. This may be common in exploiter–victim systems.     

湖南省生态-经济系统耦合发展探析

从系统论视角出发,剖析了湖南省生态-经济系统内部诸要素及其结构特征,构建评价指标体系;运用定量评价模型,对区域系统的耦合状态进行了分析.结果表明:1996-2006年湖南省综合支撑能力呈对数型上升,而综合消耗水平呈指数型上升,二者演化速度具有非同步性,耦合度呈快速上升趋势,年均增长4.89度;从2008年起将进入过度开发时期,虽然湖南省资源较丰富,但远未具备过度开发型的物质条件;湖南省进入过度开发时期的原因是,在经济增长方式仍然非常落后和产业结构未得到有效调整的情况下,一味突出出口导向型经济,从而导致综合消耗水平发展快速增长.     

The granuloma in cryptococcal disease

Although we have recognized cryptococcosis as a disease entity for well over 100 years, there are many details about its pathogenesis which remain unknown. A major barrier to better understanding is the very broad range of clinical and pathological forms cryptococcal infections can take. One such form has been historically called the cryptococcal granuloma, or the cryptococcoma. These words have been used to describe essentially any mass lesion associated with infection, due to their presumed similarity to the quintessential granuloma, the tubercle in tuberculosis. Although clear distinctions between tuberculosis and cryptococcal disease have been discovered, cellular and molecular studies still confirm some important parallels between these 2 diseases and what we now call granulomatous inflammation. In this review, we shall sketch out some of the history behind the term “granuloma” as it pertains to cryptococcal disease, explore our current understanding of the biology of granuloma formation, and try to place that understanding in the context of the myriad pathological presentations of this infection. Finally, we shall summarize the role of the granuloma in cryptococcal latency and present opportunities for future investigations.     

Negative regulation of immunoreceptor signaling by protein adapters: Shc proteins join the club

Protein adapters couple surface receptors to multiple intracellular signaling modules by acting as scaffolds for the assembly of multimolecular complexes responsible for the coordination and amplification of signals. Through the spatiotemporally controlled recruitment of mediators with opposite activities (e.g. protein tyrosine kinases and phosphatases), adapters are implicated not only in signal initiation and propagation, but also in feedback loops for signal extinction. Moreover, adaptors specialized in preventing or dampening signaling have been more recently discovered. Here we shall present of brief overview of the principal adaptors which act as negative regulators of TCR and BCR signaling, with a focus of the mechanisms underlying this function. We shall then discuss our recent findings implicating p66Shc and Rai, two members of the Shc family of cytosolic protein adapters, in the negative control of antigen receptor signaling, and their role as gatekeepers of autoimmunity and leukemia.     

三级综合性医院压力蒸汽灭菌设备配置的探讨

从量化研究和定性分析的角度,分析探讨了三级综合性医院压力蒸汽灭菌设备的配置数量的计算,安装位置的确定与设备的选型等方法。以期为医院合理配置高压灭菌设备提供一个通用的、标准的解决方案。     

Early childhood development project in Uganda as a strategy for reducing children's poor growth indicators: an explanatory study

This study shall explore the activities of the Uganda nutrition and early childhood development project using explanatory program effects, qualitative research methods to determine the role/interplay of project factors and community dynamics in relation to poor growth and social indicators in Ugandan children. This project aimed to improve the quality of life for children age less than 6 years by improving their nutrition, health, cognitive and psychosocial development. The key concern remains how successful and sustainable are the outcomes? Data shall be collected using interviews, focus groups and document reviews. Data analysis shall employ the thematic networks analytical tool, which is aided by the ATLAS.ti software. The key hypotheses and recommendations from the analysis shall then be tested in a suitable community location and period in line with the research questions.     

Steroid interactions with structure and function of avian song control regions

Following the pioneering work of Nottebohm, the brain regions involved in song production in songbirds have become a focus of extensive research in several laboratories. As both singing behavior and the neuroanatomy of song control regions are strongly affected by sex steroids in many songbird species, this system has become regarded as an ideal model system in which one can potentially determine how steroids affect neuronal anatomy, how altered anatomy leads to altered physiology, and how the altered physiology causes changes in singing. In the initial part of this review, I shall focus on canaries and zebra finches as most of our knowledge of the song system has been obtained from these two species. I shall describe singing behavior, the constituents of the song system, what is known of how these nuclei contribute to song, and how each is affected by steroid fluctuations. I shall then speculate on new ways of posing questions on hormone—anatomy interaction in this system (which I will illustrate with preliminary data from my own lab). This review will be brief as several reviews of aspects of the song system have recently been published (Arnold, 1982; Nottebohm, 1984; Arnold and Gorski, 1984; DeVoogd, 1984; Konishi, 1985).     

Network mechanisms of grid cells

One of the major breakthroughs in neuroscience is the emerging understanding of how signals from the external environment are extracted and represented in the primary sensory cortices of the mammalian brain. The operational principles of the rest of the cortex, however, have essentially remained in the dark. The discovery of grid cells, and their functional organization, opens the door to some of the first insights into the workings of the association cortices, at a stage of neural processing where firing properties are shaped not primarily by the nature of incoming sensory signals but rather by internal self-organizing principles. Grid cells are place-modulated neurons whose firing locations define a periodic triangular array overlaid on the entire space available to a moving animal. The unclouded firing pattern of these cells is rare within the association cortices. In this paper, we shall review recent advances in our understanding of the mechanisms of grid-cell formation which suggest that the pattern originates by competitive network interactions, and we shall relate these ideas to new insights regarding the organization of grid cells into functionally segregated modules.     

Protected areas — protected from a greater ‘what’?

Natural environments are assailed on every side through the unprecedentedly rapid expansion of human activities. In the absence of conservation responses of a scope and scale to match the challenge, we shall shortly witness the widespread degradation and destruction of many wildlands and their biotas. Fortunately we still have time, though only just time, to slow and stem the biotic holocaust overtaking the biosphere. But the traditional measures, notably in the form of protected areas, are becoming ever-more limited in their capacity to resist. While we need many more protected areas — better protected too — we shall find there is a much more positive payoff in tackling the tide of environmentally impoverishing human activities, principally through initiatives directed at sustainable development of all environments and all their communities, both human and non-human.     

Orthology relations, symbolic ultrametrics, and cographs

Orthology detection is an important problem in comparative and evolutionary genomics and, consequently, a variety of orthology detection methods have been devised in recent years. Although many of these methods are dependent on generating gene and/or species trees, it has been shown that orthology can be estimated at acceptable levels of accuracy without having to infer gene trees and/or reconciling gene trees with species trees. Thus, it is of interest to understand how much information about the gene tree, the species tree, and their reconciliation is already contained in the orthology relation on the underlying set of genes. Here we shall show that a result by Böcker and Dress concerning symbolic ultrametrics, and subsequent algorithmic results by Semple and Steel for processing these structures can throw a considerable amount of light on this problem. More specifically, building upon these authors’ results, we present some new characterizations for symbolic ultrametrics and new algorithms for recovering the associated trees, with an emphasis on how these algorithms could be potentially extended to deal with arbitrary orthology relations. In so doing we shall also show that, somewhat surprisingly, symbolic ultrametrics are very closely related to cographs, graphs that do not contain an induced path on any subset of four vertices. We conclude with a discussion on how our results might be applied in practice to orthology detection.     

You Can't Do Nothing

Unless we can think right down to the reaches of mankind's long past and into the future in which the earth is only one part of a known and explored solar system, and in which mankind's problems will become extraordinarily different, we shall not be what we want to be: anthropologists, whatever our area, whatever our specialty, whatever our subdivision.     

《应用生态学报》论文参考文献著录要求

为提高参考文献编排质量,有效配合期刊检索与评价, 推动国际学术交流,《应用生态学报》依据GB/T7714-2005对论文参考文献著录格式加以调整,自2008年始文献采用顺序编码制著录. 本文给出了具体实例, 并提出了作者在引用文献过程中应注意的问题.     

Characterization and preparation of chymosin from calf rennet samples by means of isoelectric focusing

Chymosin has been identified in rennet samples from stomaches of living calfs by means of it's isoelectric points (IP), molecular weight (Mol. Wt.) and enzymatic activity. The values obtained by isoelectric focusing (IEF) and a two-dimensional electrophoretic technique, amount 4,5…4,7 (IP) and 36 300 (Mol. Wt.) respectively. Furthermore the fractionation of calf rennet by IEF has been performed in a preparative scale. From one gramme of calf rennet we obtained 53 mg of purified chymosin, which shall be used for preparing antisera against chymosin.     

Analysis of gene expression for studying tumor progression: the case of glucocorticoid administration

Background

Glucocorticoids are commonly used as adjuvant treatment for side-effects and have anti-proliferative activity in several tumors but, on the other hand, their proliferative effect has been reported in several studies, some of them involving the spread of cancer. We shall attempt to reconcile these incongruities from the genomic and tissue-physiology perspectives with our findings.

Methods

An accurate phenotype analysis of microarray data can help to solve multiple paradoxes derived from tumor-progression models. We have developed a new strategy to facilitate the study of interdependences among the phenotypes defined by the sample clusters obtained by common clustering methods (HC, SOTA, SOM, PAM). These interdependences are obtained by the detection of non-linear expression-relationships where each fluctuation in the relationship implies a phenotype change and each relationship typology implies a specific phenotype interdependence. As a result, multiple phenotypic changes are identified together with the genes involved in the phenotype transitions. In this way, we study the phenotypic changes from microarray data that describe common phenotypes in cancer from different tissues, and we cross our results with biomedical databases to relate the glucocorticoid activity to the phenotypic changes.

Results

11,244 significant non-linear expression relationships, classified into 11 different typologies, have been detected from the data matrix analyzed. From them, 415 non-linear expression relationships were related to glucocorticoid activity. Studying them, we have found the possible reason for opposite effects of some stressor agents like dexamethasone on tumor progression and it has been confirmed by literature. This hidden reason has resulted in being linked with the type of tumor progression of the tissues. In the first type of tumor progression found, new cells can be stressed during proliferation and stressor agents increase tumor proliferation. In the second type, cell stress and tumor proliferation are antagonists so, therefore, stressor agents stop tumor proliferation in order to stress the cells. The non-linear expression relationships among DUSP6, FERMT2, FKBP5, EGFR, NEDD4L and CITED2 genes are used to synthesize these findings.     

Slips,leaks and channels in glutamate transporters

Glutamate transporters are unusual proteins in that they can function as both a transporter and a chloride channel. With the recent determination of the crystal structure of an archaeal aspartate transporter it is now possible to begin to put together a physical picture of how these proteins are able to carry out their dual functions. In this review we shall discuss our current understanding of the functional states of glutamate transporters and how they may arise. We will also discuss some of the alternate conducting states of glutamate transporters and provide definitions of the various states.     

Slips, leaks and channels in glutamate transporters

Glutamate transporters are unusual proteins in that they can function as both a transporter and a chloride channel. With the recent determination of the crystal structure of an archaeal aspartate transporter it is now possible to begin to put together a physical picture of how these proteins are able to carry out their dual functions. In this review we shall discuss our current understanding of the functional states of glutamate transporters and how they may arise. We will also discuss some of the alternate conducting states of glutamate transporters and provide definitions of the various states.     

Lineus as a model for studying developmental processes in animals reconstructed from adult pieces

The difficulties that prevent reconstruction of animals by piecing together body fragments from several adults are overcome by using nemerteans of the genus Lineus. For 25 years I have managed to make viable composite worms by grafting body parts cut out of Lineus specimens either from the same clonal strain (syngeneically reconstructed worms) or from the same species (allogeneically reconstructed worms) or else from different species (xenogeneically reconstructed worms). Body reconstruction has usually been carried out orthotopically, i.e., the components of composite animals have been selected so as to be anatomically complementary. However, reconstruction has been made heterotopically when it was essential to obtain morphogenetic events in the adults. Here, I shall review some of the developmental processes that took place in such reconstructed animals. First, I shall report immune responses in composite worms derived from various combinations of body pieces grafted together. Second, I shall study sex differentiation during gonad development in growing or regenerating chimeric worms made by the grafting of male and female components. I shall refer also to gonadogenesis in the asexual progeny of bipartite chimeras derived from lateral body halves of both sexes fused together (clones of bilaterally allophenic worms). Third, I shall analyze regulative processes (regeneration, transgeneration) during localized morphogenesis occurring in heterotopically reconstructed worms. The data show how reconstructed Lineus may be exploited to increase our knowledge of developmental mechanisms, especially in the misunderstood field of organismal pattern homeostasis.