Circularity,evolution, systematics … and circularity

Many have argued strongly that incorporation of evolutionary theory into systematics is dangerously circular, while others have maintained that such an integrated approach increases the accuracy of phylogenetic inference. Here, it is demonstrated that such blanket statements regarding exclusion or inclusion of evolutionary principles in systematics fail to distinguish between two very different types of principles. ‘Phylogeny-neutral’ evolutionary principles are those inferred without any recourse to specific phylogenetic hypotheses (e.g. via developmental genetics, biomechanics). In contrast, ‘phylogeny-dependent’ principles are those which can only be inferred on the basis of specific phylogenetic hypotheses (e.g. character associations detected via ‘comparative methods’). Inclusion of phylogeny-neutral principles in systematic studies as a priori assumptions can be justified, since these principles have (often strong) external empirical support from other spheres of investigation. However, inclusion of phylogeny-dependent principles in systematic studies is circular, since such principles have no external empirical support but are themselves derived from systematic studies. Advocating inclusion or exclusion of all (or as many as possible) evolutionary principles from phylogenetic analysis is therefore misguided. Rather, phylogeny-neutral principles are independently supported and can be included, while phylogeny-dependent principles are unjustified assumptions and should be excluded to avoid circularity. However, integration of complex phylogeny-neutral principles in systematics can create operational problems, even though there are no methodological reasons against their inclusion.     

在生理学研究中如何严格遵循试验设计四原则

目的：为从事生理学研究的科研工作者严格遵循试验设计四原则（以下简称四原则）提供一些有效的技术方法。方法：通过简单介绍"四原则的概念"、举例阐述"生理学研究中在落实四原则方面出现的常见错误和案例"和简单介绍"生理学研究中如何遵循四原则"来阐述遵循四原则的具体做法。结果：需要根据实际情况,选择合适的随机化方法,分层随机化是常用的好方法;应力求设置合理的对照组,才能真正体现出对照原则的价值;有根据地给出每个小组合适的样本含量,是试验结果具有重现性的基本保证;严格遵循随机、对照和重复原则,最终才能实现对比组之间达到极好的均衡效果,这说明均衡原则是一个把关的原则。结论：在生理学科研中,严格遵循四原则对保证生理学研究结果准确可靠至关重要。     

Application of ecological engineering principles in agriculture

To what extent modern industrialized agriculture violates the principles of ecological engineering and which changes agriculture needs to make to be consistent with these principles are discussed. The 12 ecological principles presented are used as the starting point for this discussion. For each principle it is discussed how the agriculture of today violates these principles and how relatively small changes could make the agriculture more according to ecological engineering concepts.     

Thermodynamic extremization principles and their relevance to ecology

Theories based on simple principles have provided much insight into the common processes that underpin complex ecological systems. Although such theories (e.g. neutral theory, metabolic theories) often neglect specific ecological details, they compensate for this with their generality and broad applicability. We review several simple principles based on ‘thermodynamic extremization’ (the minimization or maximization of a thermodynamic quantity) and explore their application and relevance to ecology. Thermodynamic extremization principles predict that certain energetic quantities (e.g. entropy production) will tend towards maxima or minima within ecological systems, subject to local constraints (e.g. resource availability). These principles have a long history in ecology, but existing applications have had a theoretical focus and have made few quantitative predictions. We show that the majority of existing theories can be unified conceptually and mathematically, a result that should facilitate ecological applications of thermodynamic extremization principles. Recent developments in broader ecological research (e.g. metabolic theories) have allowed quantitative predictions of ecological patterns from thermodynamic extremization principles, and initial predictions have been supported by empirical data. We discuss how the application of extremization principles could be extended and demonstrate one possible extension, using an extremization principle to predict individual size distributions. A key focus in the application of thermodynamic extremization principles to mainstream ecological questions should be the generation of quantitative predictions and subsequent empirical validation.     

农业生态系统中新物种引进的初步探讨

在现有的农业生态系统中,引进某些新物种,往往可以使整个系统的功能发生变化。如果新物种引进得当,则可产生良好的效果,系统功能得以改善,效益提高;反之,则会造成人力、物力、财力的损失,削弱系统的功能,甚至可能遗患无穷。因此,对农业生态系统中     

生姜辛辣部位的高效液相色谱(HPLC)指纹图谱研究

采用HPLC法分析了4个居群生姜丙酮回流-乙醚萃取物中的多酚类化合物,建立了有较好专属性的HPLC指纹图谱,比较了姜辣素含量及其得率。     

化学学科背景下细胞生物学课程教学的改革和实践

细胞生物学在大学生物相关专业的课程设置中占有重要地位,为提高化学优势学科背景下细胞生物学的教学质量,研究从学生知识掌握能力、知识融合能力和创新能力等三个方面进行相关教学的改革与实践。围绕教学内容和教学课件的优化,学生课外调研和科研写作的开展,学生创新热情的产生,学生动手解决问题及发现新问题的精神面貌转变等方面,阐述教改的主要内容。     

Laws of biology: why so few?

Finding fundamental organizing principles is the current intellectual front end of systems biology. From a hydrogen atom to the whole cell level, organisms manage massively parallel and massively interactive processes over several orders of magnitude of size. To manage this scale of informational complexity it is natural to expect organizing principles that determine higher order behavior. Currently, there are only hints of such organizing principles but no absolute evidences. Here, we present an approach as old as Mendel that could help uncover fundamental organizing principles in biology. Our approach essentially consists of identifying constants at various levels and weaving them into a hierarchical chassis. As we identify and organize constants, from pair-wise interactions to networks, our understanding of the fundamental principles in biology will improve, leading to a theory in biology.     

框架描述对医疗资源分配公平感的影响

目的:初步探讨医疗资源分配方案设置及框架描述对人们感知公平的影响。方法:以120名大学生为研究对象,自编情境问题,分别依据Miller定义的平等、需求、责任及付出原则制定医疗资源分配分配方案,采用正、负及平衡框架进行描述。被试被随机分为三组,每组被试需要评估同一框架下,四种分配方案的公平性。结果:结果显示,分配方案主效应显著(F=7.27,P0.01),按照需求原则分配医疗资源,被试感到不公平(t=-2.04,P0.01),而以付出原则分配,被试感到公平(t=2.87,P0.01),以按责与平等原则分配,被试没有显著的公平或不公平感(P.05)。框架描述主效应显著(F=6.08,P.05),以正框架描述,公平感评估显著高于平衡框架与负框架。框架描述与分配原则交互作用显著(F=3.93,P0.01),在正框架下,分配方案效应不显著(F=1.29,P0.05),在负框架与平衡框架下,分配方案效应显著(F平衡=9.23,P0.01;F负=4.69,P0.01)。依据按需与按责原则制定的分配方案受到框架描述影响(F按需=12.88,P0.01;F按责=4.12,P0.05),而依据平等原则、付出原则制定的分配方案不会受到框架描述的影响。结论:分配原则及框架描述均能显著影响人们对医疗资源分配的公平感知。     

Priorities in plastic surgery

The study of historical priorities in plastic surgery must be based on established principles in the field instead of mere chronology. Examples of application of these principles to two landmarks in plastic surgery are given. The reader is commended to adhere to these principles in the study of other developments in plastic surgery.     

岛礁型海洋生物保护区（IMPA）的设计和管理：理论和实例研究

本文提出和论述了岛礁型海洋生物保护区（ＩＭＰＡ）设计和管理的７条原则;生物多样性和稀缺性,生境典型性和完整性,物种－面积关系,海－陆生态交错带,人工自然化,生态脆弱性和自养型经济。并且结合我国第一个国家级海洋生物保护区－南麂列岛自然保护区（ＮＩＮＲ）设计和规划的实践,说明如何实施这些原则。     

学术类科技期刊正文转接的原则与技巧

通过编辑实践经验,对学术类科技期刊正文转接的原则和技巧进行总结提炼。阐述了尽量避免跳页排印、以少接多、顺势接排、尽量避免逆向转接、分段或分句转接、不能出现背题的接排、含图表和公式部分不宜转接、应避免转接错误和字体混乱等8条原则以及具体实施的技巧,认为处理正文转接的最适宜时期是清样"定版"环节,其目的在于不断提高编辑工作的效率和期刊的编辑质量。     

Roots and promises of chemical-based computing.

General principles of information processing by chemical-based biomolecular systems (pseudobiological information processing paradigm) are discussed. These principles include very large scale parallelism of information processing, high behavioral complexity, complementarity of information features, self-organization, and multilevel architecture. Chemical-based information processing devices using these principles seem to be able to solve effectively problems of high computational complexity.     

The caudal neurosecretory system

Summary Recent information on the caudal neurosecretory system (urophysis) is collated, with special reference to cellular biology including neural relations, activity and chemistry of the biological principles associated with the urophysis, pharmacological analysis of the receptors for these principles, and their possible functions in a physiological sense. The existence of at least two principles, urotensins I and II, is well established. They differ pharmacologically and chemically and may arise from different cell types. At present, osmoregulation, cardiovascular regulation and reproduction are the most likely aspects of organismal physiology wherein these principles may be involved.Dedicated to Professor Doctor Berta Scharrer on the occasion of her seventieth birthday, with profound admiration and affection     

Some principles governing selection in self-reproducing macromolecular systems

Summary Starting with Eigen's model we discuss some principles pertaining to the selection of biological macromolecules. The principles have a certain analogy to Fisher's fundamental theorem for natural selection.     

鄂尔多斯高原植物群落季节生长格局模拟

影响大尺度空间生态模型模拟结果与资源管理整合的因素主要有两种:一是一些模型生态学意义不明确,二是一些模型所需要的生态输入信息过于复杂。建立一个基于基本的生态学公理且输入较为简单的生态学模型,便于更加有效地服务于资源环境管理。该模型用于模拟发生严重荒漠化的鄂尔多斯高原植物群落的季节及年生长、叶片投影盖度、蒸发系数。模型首先基于降雨、蒸散、渗漏及土壤水分特性与蒸发系数(k)的关系,采用迭代的计算方法,模拟植物群落蒸散与土壤可利用水分达到平衡状态时的k值,进而采用得到广泛验证的经验公式计算植物群落的其它参数。野外N PP观察数据对模型的验证表明:模拟结果与观察值相符较好。模拟结果表明:蒸发系数小于0 .35×10 - 2 ,显示鄂尔多斯高原气候较为干燥;叶片投影盖度低于5 0 % ;除东部的准格尔旗外,植物群落净第一性生产力均低于1t/(hm2·a) ,近90 %的N PP累积集中于5至8月份。根据该文的模拟结果,在进行植被恢复时,恢复植被密度必须低于5 0 % ,放牧密度以0 .8～2 .0个/hm2 羊单位为宜     

Methods for and results from the study of design principles in molecular systems

Most aspects of molecular biology can be understood in terms of biological design principles. These principles can be loosely defined as qualitative and quantitative features that emerge in evolution and recur more frequently than one would expect by chance alone in biological systems that perform a given type of process or function. Furthermore, such recurrence can be rationalized in terms of the functional advantage that the design provides to the system when compared with possible alternatives. This paper focuses on those design features that can be related to improved functional effectiveness of molecular and regulatory networks. We begin by reviewing assumptions and methods that underlie the study of such principles in molecular networks. We follow by discussing many of the design principles that have been found in genetic, metabolic, and signal transduction circuits. We concentrate mainly on results in the context of Biochemical Systems Theory, although we also briefly discuss other work. We conclude by discussing the importance of these principles for both, understanding the natural evolution of complex networks at the molecular level and for creating artificial biological systems with specific features.     

Privacy and Property Issues for a Familial Cancer Service

Approximately 1 in 30 people develop cancer due to an underlying familial predisposition. Genetic counselling and testing for people with (and at risk of) familial cancer are becoming more widely available, but service providers need to address challenging issues in relation to privacy and property. As in any counselling situation, a genetic counsellor seeks to ensure that the principles of autonomy, confidentiality, beneficence, and equity operate in favour of the client. But in dealing with a familial disorder, the application of these principles to the individual must be balanced with the potential for these principles to apply to other family members. This paper summarises the recent experience of a familial cancer service in seeking to avoid situations in which these principles, operating for both individual clients and their relatives, can come into conflict.