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Tandem running, whereby one worker recruits another is utilised by many ant species. Since first being recorded, it has provided a valuable experimental tool for testing hypotheses about collective decision making, communication and even teaching. In this review I explore the journey tandem running has taken, the twists and turns in the theories surrounding it and what tandem running has taught us. This review examines the empirical research conducted on tandem running, from when it was first described, considers the theories that have arisen from that research and ultimately what has been learnt and what is still yet to be explored.  相似文献   

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Pedigree reconstruction using genotypic markers has become an important tool for the study of natural populations. The nonstandard nature of the underlying statistical problems has led to the necessity of developing specialized statistical and computational methods. In this article, a new version of pedigree reconstruction tools (PRT 2.0) is presented. The software implements algorithms proposed in Almudevar & Field (Journal of Agricultural Biological and Environmental Statistics, 4, 1999, 136) and Almudevar (Biometrics, 57, 2001a, 757) for the reconstruction of single generation sibling groups (SG). A wider range of enumeration algorithms is included, permitting improved computational performance. In particular, an iterative version of the algorithm designed for larger samples is included in a fully automated form. The new version also includes expanded simulation utilities, as well as extensive reporting, including half-sibling compatibility, parental genotype estimates and flagging of potential genotype errors. A number of alternative algorithms are described and demonstrated. A comparative discussion of the underlying methodologies is presented. Although important aspects of this problem remain open, we argue that a number of methodologies including maximum likelihood estimation (COLONY 1.2 and 2.0) and the set cover formulation (KINALYZER) exhibit undesirable properties in the sibling reconstruction problem. There is considerable evidence that large sets of individuals not genetically excluded as siblings can be inferred to be a true sibling group, but it is also true that unrelated individuals may be genetically compatible with a true sibling group by chance. Such individuals may be identified on a statistical basis. PRT 2.0, based on these sound statistical principles, is able to efficiently match or exceed the highest reported accuracy rates, particularly for larger SG. The new version is available at http://www.urmc.rochester.edu/biostat/people/faculty/almudevar.cfm.  相似文献   

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Background and Aims

There has been little previous work on the toughness of the laminae of monocots in tropical lowland rain forest (TLRF) despite the potential importance of greater toughness in inhibiting herbivory by invertebrates. Of 15 monocot families with >100 species in TLRF, eight have notably high densities of fibres in the lamina so that high values for toughness are expected.

Methods

In north-eastern Australia punch strength was determined with a penetrometer for both immature leaves (approx. 30 % final area on average) and fully expanded, fully toughened leaves. In Singapore and Panama, fracture toughness was determined with an automated scissors apparatus using fully toughened leaves only.

Key Results

In Australia punch strength was, on average, 7× greater in shade-tolerant monocots than in neighbouring dicots at the immature stage, and 3× greater at the mature stage. In Singapore, shade-tolerant monocots had, on average, 1·3× higher values for fracture toughness than neighbouring dicots. In Panama, both shade-tolerant and gap-demanding monocots were tested; they did not differ in fracture toughness. The monocots had markedly higher values than the dicots whether shade-tolerant or gap-demanding species were considered.

Conclusions

It is predicted that monocots will be found to experience lower rates of herbivory by invertebrates than dicots. The tough monocot leaves include both stiff leaves containing relatively little water at saturation (e.g. palms), and leaves which lack stiffness, are rich in water at saturation and roll readily during dry weather or even in bright sun around midday (e.g. gingers, heliconias and marants). Monocot leaves also show that it is possible for leaves to be notably tough throughout the expansion phase of development, something never recorded for dicots. The need to broaden the botanist''s mental picture of a ‘tough leaf’ is emphasized.Key words: Dicots, fracture toughness, herbivory, leaves, monocots, punch strength, tropical rain forest  相似文献   

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The ascomcete Ceratocystis fimbriata, the causal agent of “canker stain disease,” secretes a protein of 12.4 kDa that elicits phytoalexin synthesis and plant cell death. This protein, named cerato-platanin (CP), is also located in the cell walls of ascospores, hyphae, and conidia; it contains four cysteines (S-S bridged) and is moderately hydrophobic. The cp gene consists of a single exon and has 42 bp codifying for a signal peptide of 14 residues. The recombinant protein was obtained by cloning the cp gene of the mature protein in Escherichia coli (BL21), and a refolding step was needed to achieve the native active form. In the European Molecular Biology data bank, CP is reported as the first member of the CP family; this is the first example of an set of secreted fungal proteins whose primary structure is very similar. Nonetheless, the data also revealed some structural and functional features that make CP simlar to proteins of the hydrophobin family.  相似文献   

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There are many great reports of polyamine stabilization of the Z-DNA by bridge conformation between neighboring, symmetry-related Z-DNA in the packing of crystals. However, polyamine binding to the minor groove of Z-DNA and stabilizing the Z-DNA structure has been rarely reported. We proved that the synthesized polyamines bind to the minor groove of Z-DNA and stabilize the conformation under various conditions, by X-ray crystallographic study. These polyamines consist of a polyamine nano wire structure. The modes of the polyamine interaction were changed under different conditions. It is the first example that the crystals consisted of metal free structure. This finding provides a basis for clarifying B-Z transition mechanics.  相似文献   

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《生物多样性公约》(以下简称《公约》)是三大环境国际公约之一。随着《公约》谈判的不断推进, 企业与生物多样性(Business and Biodiversity)逐渐由《公约》中的一个概念发展成为《公约》谈判中的一个重要议题。1996年召开的《公约》缔约方大会第三次会议(COP-3)首次提出企业(私营部门)参与生物多样性的概念后, COP-5将企业参与列入《公约》议题, COP-6正式将企业参与纳入《公约》全球战略, COP-8首次将企业参与生物多样性单独纳入《公约》决定, 并提出下一步开展推动企业参与生物多样性的做法, COP-9拟定了《企业优先行动框架(2008-2010年)》, COP-10决定开展企业参与生物多样性对话论坛。迄今为止, 《公约》秘书处共组织了4次全球企业界与生物多样性伙伴关系(Global Partnership for Business and Biodiversity, GPBB)论坛, 就这一议题进行专题交流和探讨。企业与生物多样性也是当前我国生物多样性管理工作中的一个新课题, 中国对此十分重视, 并派代表团参加了GPBB-3和GPBB-4两次会议。鉴于目前中国经济发展状况与生物多样性保护面临的形势, 作者提出以下建议: (1)积极参与国际合作, 利用GPBB国际平台适时宣传我国生物多样性和生态文明建设成果; (2)加强技术研究, 制定我国企业参与生物多样性的相关标准、规范或指南; (3)深化平台建设, 搭建企业参与的中国生物多样性伙伴关系; (4)建立跨部门的企业参与生物多样性协调机制。  相似文献   

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王钦宏  马延和 《生物工程学报》2022,38(11):3981-3990
工业生物技术是指以微生物或酶为催化剂进行物质转化,大规模地生产人类所需的化学品、医药、燃料、材料、食品等产品的生物技术。发展工业生物技术是人类由化石经济向生物经济过渡的关键路径,是解决人类目前面临的资源、能源及环境问题的重要手段。中国科学院天津工业生物技术研究所是我国工业生物技术和生物制造领域的主力代表。本文结合该研究所成立十年来的发展,简要回顾了我国工业生物技术发展战略规划布局、重要技术突破进展和行业影响,并对我国工业生物技术和生物制造的未来发展进行了展望分析。  相似文献   

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