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1.
2.
It is shown that a wide variety of structural alterations in both the “metabolic” and “genetic” apparatus of ( , ℜ)-systems can result from specific changes in the environment of such systems. A number of specific examples are investigated in order to demonstrate the scope of these alterations. Certain biological applications of this discussion are suggested, including a suggestion for a possible interpretation of the mitotic cycle. This research was supported by the United States Air Force through the Air Force Office of Scientific Research of the Air Research and Development Command, under Contract #AF 49 (638)-917.  相似文献   

3.
A theory for environmental systems is defined on the basis of two elements, termed ‘environmental unity’ and ‘behavior’. Environmental systems are regarded as non-living systems, each one related with only one biological system. We construct a material-energetic environmental diagram, which is introduced in terms of the theory of categories, thereby giving rise to a new categoryE. By means of two biological conditions, and the definition of static property of the biological system (related to its own environment), a set of theorems is obtained, exhibiting mathematical consequences for the represented theory.  相似文献   

4.
The relational phenomena exhibited by metabolizing systems may be considered as special cases of those exhibited by a more general class of systems. This class is specified, and some of tis properties developed. An attempt is then made to apply these properties to a theory of metabolism by suitable specialization. A number of biologically significant theorems are obtained which apply directly to the theory of the free-living single cell. Among the results obtained are the following: On the basis of our model, there must always exist a component of the system which cannot be replaced or repaired by the system in the event of its inhibition or destruction. Under certain conditions, a metabolizing system possesses a component the inhibition of which will completely terminate the metabolic activity of the system. Furthermore a number of other diverse phenomena, such as the effects of a deficient environment, encystment phenomena, and even an indication of why a metabolizing system which represents a cell should possess a nucleus, follow in a straightforward fashion from our model.  相似文献   

5.
A complex systems theory of teleology   总被引:2,自引:0,他引:2  
Part I [sections 2–4] draws out the conceptual links between modern conceptions of teleology and their Aristotelian predecessor, briefly outlines the mode of functional analysis employed to explicate teleology, and develops the notion of cybernetic organisation in order to distinguish teleonomic and teleomatic systems. Part II is concerned with arriving at a coherent notion of intentional control. Section 5 argues that intentionality is to be understood in terms of the representational properties of cybernetic systems. Following from this, section 6 argues that intentional control needs to be seen as a particular type of relationship between the system and its environment.I would like to gratefully acknowledge the large guiding input of Professor C. A. Hooker, who supervised the development of this paper from its inception. Bill herfel also provided valuable criticism of late drafts.  相似文献   

6.
The general Theory of Categories is applied to the study of the (M, R)-systems previously defined. A set of axioms is provided which characterize “abstract (M, R)-systems”, defined in terms of the Theory of Categories. It is shown that the replication of the repair components of these systems may be accounted for in a natural way within this framework, thereby obviating the need for anad hoc postulation of a replication mechanism. A time-lag structure is introduced into these abstract (M, R)-systems. In order to apply this structure to a discussion of the “morphology” of these systems, it is necessary to make certain assumptions which relate the morphology to the time lags. By so doing, a system of abstract biology is in effect constructed. In particular, a formulation of a general Principle of Optimal Design is proposed for these systems. It is shown under what conditions the repair mechanism of the system will be localized into a spherical region, suggestive of the nuclear arrangements in cells. The possibility of placing an abstract (M, R)-system into optimal form in more than one way is then investigated, and a necessary and sufficient condition for this occurrence is obtained. Some further implications of the above assumptions are then discussed.  相似文献   

7.
A dynamical systems perspective is employed to develop a simple conceptual model of vegetation and environment as coupled dynamical systems. The conceptual model characterizes the influence of environment on vegetation, the effect of vegetation on the environment, and the subsequent response of vegetation to the modified environment. Vegetation and environmental dynamics are modeled as trajectories in complementary state spaces, with the trajectories jointly determined by the position of a given site in both spaces. The vegetation and environment state spaces are coupled by the physiological requirements of the component species and the modification of environment by vegetation. From a dynamical systems perspective, current vegetation theory and analyses overemphasize environmental determination of vegetation composition and neglect the effects of vegetation on environment. A dynamical systems perspective is capable of synthesizing previous concepts of vegetation; the continuum and community type concepts are possible consequences of site specific differences in vegetation metabolism and environmental plasticity.I would like to acknowledge the helpful comments and criticisms of Drs G. Cottam, J. D. Aber, T. F. H. Allen, R. P. McIntosh, C. G. Lorimer, and anonymous reviewers.I would like to thank the University of Wisconsin, Madison for a fellowship which supported this research. This paper is dedicated with great respect and gratitude to Professor G. Cottam on the occasion of his retirement from the University of Wisconsin.  相似文献   

8.

1. 1. The writers present the general theory of evaluation that is being developed by their group.

2. 2. The evaluation of a human environment is a complex mental process.

3. 3. In an effort to express numerically the quality of an environment, one tends to oversimplify the complex aspects of it and the entailing problems in relation to its inhabitants.

4. 4. In this paper, some examples are taken in the evaluation of thermal environments, wherein much has been said and done in setting up numerical scales to express human comfort, and yet neither clear-cut explanations nor convincing logic seem to exist to terminate the argument over the widely scattered and sometimes seemingly contradicting experimental data.

5. 5. The writers suggest that many of the reasons for this confusion may be traced back to the oversimplified notion of evaluation.

6. 6. It is shown that there are various possibilities when looking at the scales of evaluation.

7. 7.|The nominal scale, least studied of all the four traditional scales, may be given a prominent place in evaluating a thermal environment. The pseudo-interval order scale is another example.

Author Keywords: evaluation; scales; thermal environment; classification; pseudo-interval order  相似文献   


9.
Patient autonomy, as exercised in the informed consent process, is a central concern in bioethics. The typical bioethicist's analysis of autonomy centers on decisional capacity--finding the line between autonomy and its absence. This approach leaves unexplored the structure of reasoning behind patient treatment decisions. To counter that approach, we present a microeconomic theory of patient decision-making regarding the acceptable level of medical treatment from the patient's perspective. We show that a rational patient's desired treatment level typically departs from the level yielding an absence of symptoms, the level we call ideal. This microeconomic theory demonstrates why patients have good reason not to pursue treatment to the point of absence of physical symptoms. We defend our view against possible objections that it is unrealistic and that it fails to adequately consider harm a patient may suffer by curtailing treatment. Our analysis is fruitful in various ways. It shows why decisions often considered unreasonable might be fully reasonable. It offers a theoretical account of how physician misinformation may adversely affect a patient's decision. It shows how billing costs influence patient decision-making. It indicates that health care professionals' beliefs about the 'unreasonable' attitudes of patients might often be wrong. It provides a better understanding of patient rationality that should help to ensure fuller information as well as increased respect for patient decision-making.  相似文献   

10.
Gordon (1953,J. Fish. Res. Bd Can.10, 442–457) used economic theory to predict how catch rates, price and fishing costs should balance in a multi-area, open-access fishery. We use the data from the Tasmanian rock lobster fishery to test this theory. We find that, as prediced by theory, areas with higher monetary and non-monetary costs have consistently higher catch rates than areas with lower costs. We show that this theory also predicts that an increase in price would result in an overall increase in catch rate, and suggest that in fisheries with spatial variation in costs, catch rates may be determined as much by economic factors as biological ones.  相似文献   

11.
Aggregation phenomena in immunological systems have been profitably treated in the past by applying theories developed to describe polymerization reactions. An interesting result of these theories is the prediction that critical ratios exist for the reactants. These are ratios at which the composition of the system changes abruptly from one characterized primarily by small aggregates to one characterized primarily by large aggregates. In this paper, these ratios are studied as a function of physical and molecular parameters. In particular, the valence of the antibody is allowed to be greater than two and certain types of intramolecular reactions are considered. The effect of antigen and antibody heterogeneity on the results is discussed by developing the theory for a particular heterogeneous system.  相似文献   

12.
13.
Murariu M  Drochioiu G 《Bio Systems》2012,109(2):126-132
Eugen Macovschi is among the few scientists who tried, and partly succeeded, to explain the differences between "dead" and "living" in biological sciences. He discovered and characterized the so-called biostructure of the living bodies and worked out a biostructural theory, which is the first supramolecular conception in biology. Nevertheless, complex biological systems are currently considered only from the molecular point of view, although they may be regarded as specific phenomena on highly structured bodies within the four-dimensional Universe. According to Macovschi, the biostructure provides organisms with life properties and controls their life processes and chemical changes. Nevertheless, plant cells or bacterial ones differ much from the animal or human cells. In fact, there are various biostructures which are related with cell properties. Hence, this theory creates confusions and cannot be easily used to explain all the properties of the biosystems. Consequently, it is our goal to highlight the principles, advantages, limitations, and applications of the biostructural theory, which might support new ideas and theories in modern life sciences.  相似文献   

14.
15.
The development of a molecular theory of the diffusion drag forces in liquids is attempted by considering the liquids as limiting cases of very dense gases. An expression is derived for the force on a small particle suspended in a nonuniform mixture of such gases on the basis of kinetic theory. Another expression for the order of magnitude of the force on a larger particle is obtained by introducing certain hydrodynamical considerations. These results are compared with an expression previously derived by N. Rashevsky, and estimates are made of the order of magnitude of the volume force on the granules and particles within a typical cell due to the diffusion of metabolites. It is found that the drag forces, exerted by a diffusing solute, depend to a very large extent on the physical properties of the solvent.  相似文献   

16.
The concept of energy intensity (the energy needed, directly and indirectly, to effect the production of a “modity” an be applied to both economic and ecological systems. Hannon (1979) and Constanza (1980) have remarked on the lack of variation of energy intensity between different commodities for an ecosystem and an economic system, respectively. T This is particularly surprising for the ecosystem, since it seems to violate the traditional pyramid view of trophic systems. I show rigorously that Hannon's result is a mathematical consequence of his assumptions which are physically unjustified. I present a similar intuitive argument for Costanza's result, which is based on controversial but not physically unacceptable assumptions. The discussion brings out common threads of input-output economics and ecosystem analysis.  相似文献   

17.
18.
Fuzzy systems vegetation theory is a comprehensive framework for the expression of vegetation theory and conceptual models, as well as the development of vegetation analyses. It is applicable to vegetation/environment relations, vegetation dynamics, and the effects of environmental dynamics on vegetation composition. Fuzzy systems vegetation theory is a fuzzy set generalization of dynamical systems theory and incorporates a formal logic and mathematics. This paper presents the elements of fuzzy systems vegetation theory and discusses the relationship of the fuzzy systems theory to the geometric concepts generally employed in vegetation theory.  相似文献   

19.
史亚琪  朱晓东  孙翔  李扬帆  魏婷 《生态学报》2010,30(15):4119-4128
经济与环境协调发展评价是发展中国家可持续发展领域研究的热点问题。目前协调评价的模型取得了新的进展,但在应用方面多集中在现状评价,预测的案例较少;另外现有的研究多以经济子系统的发展水平与环境子系统的发展水平进行协调性评价,忽略了发展潜力这一重要变量。以连云港为分析案例,把发展潜力作为重要变量与发展水平变量相结合计算得到的综合发展指数纳入经济与环境协调评价模型中,并尝试根据系统历史与现状协调发展的演变规律运用GM(1,1)灰色模型预测系统未来的协调发展状态。现状评价与未来的预测结果表明:(1)1996—1999年连云港经济与环境系统从低级共生向环境资源的粗放利用转变;(2)2000—2006年,经济与环境的关系进入快速调整期,经济-环境复合生态系统综合发展指数不断增强,协调程度较上一阶段变化稳定;(3)到2007—2009年,环境对经济的限制作用将又逐渐显现;(4)2010—2015年,经济-环境复合生态系统整体协调度和综合发展指数都相应处于快速上升阶段。综合来看,1999年以后连云港经济-环境复合生态系统的协调度均处于0°以下,说明连云港在经济快速发展的初期往往是以环境破坏为代价的,因此在以后的发展中应主要处理好经济发展与环境保护的速度和公平问题。  相似文献   

20.
李敏  张小洪  李远伟  肖鸿  漆辉  邓仕槐 《生态学报》2012,32(22):6936-6945
运用改进的能值评价指标和经济指标对构建的两个污水处理综合系统("污水处理厂处理+脱水污泥填埋"及"污水处理厂处理+脱水污泥填埋+中水回用")进行了环境可持续性和经济竞争力的综合分析。改进的能值指标(能值产出率SEYR、环境负载率SELR、环境可持续发展指数SESI和能值受益率SEBR)是在考虑研究对象废物及产物能值对环境影响的基础上提出的,更好地反映了系统的特征。结果表明,中水回用系统的增加有利于提升系统的环境可持续发展能力;"污水处理厂处理+脱水污泥填埋+中水回用"系统较"污水厂处理+脱水污泥填埋"系统的经济竞争力差,但却拥有更强的可持续发展能力,有利的经济政策能够刺激其更好的推广运用。  相似文献   

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