Some comments on re-estalishability

The present note consists of two separate but related parts. In the first, a new graphtheoretic proof is presented that an (ℳ,R)-system must always contain a nonreestablishable component. The second considers some questions concerning the relation between re-establishability and the time-lag structure in (ℳ,R)-systems. It is supposed that the reader is familiar with the terminology of the author's previous work on (ℳ,R)-systems, particularly R. Rosen,Bull. Math. Biophysics,20, 245–260, 1958.     

关于生态场的几点评述

依据植物生态场的系统研究资料,对生态场的概念、场和特征函数、生态场折图形以及生态场对植物相互作用的解释进行了评述。阐明了生态场的最基本属性是物质性,目前的研究水平尚不能确定生态场是还是有别于一稻物理场的特殊形式在场,对生态场的基本特征函数－生态热模型给予了形式与模型参数体测方面的评述,表明两种生态势模型各有一定的特点与优越性。作者强调,生态场更具生态学的方法论意义,应用生态场对植物相互作用形式与过     

关于生态场的几点评述

依据植物生态场的系统研究资料,对生态场的概念、场的特征函数、生态场的图形以及生态场对植物相互作用的解释进行了评述.阐明了生态场的最基本属性是物质性,目前的研究水平尚不能确定生态场是否是有别于一般物理场的特殊形式的场.对生态场的基本特征函数-生态势模型给予了形式与模型参数估测方面的评述,表明两种生态势模型各有一定的特点与优越性.作者强调,生态场更具生态学的方法论意义,应用生态场对植物相互作用形式与过程的分析描述,具有定量化、综合性与直观化特点.生态场的绘图为生态学研究开辟了新的途径,特别是应用生态场理论分析群体植物的动态变化过程(由互利共存到干涉竞争)会有合理的定量解释.     

Some comments on the classification of African vegetation

Abstract. Problems of naming African vegetation units are discussed, and related to the AETFAT vegetation scheme and other recent publications. Particularly, the distinction is emphasized between the terms forest and woodland, which are often considered synonyms. In other cases, no precise and ecologically meaningful definitions are presented, which leads to confusion and superfluous terms. More strict rules for the definition and application of vegetation terminology are proposed, and suggested as basic information to be given in vegetation literature.     

Some comments on the aerobiology of fungus spores

While exposure/symptom relationships are relatively well-defined for pollen allergens, such relationships have not been clearly established for airborne fungus spores due to a lack of clearly defined seasonal patterns, prevalence of world-wide cosmopolitan fungi, and serious problems with sampling and identification. Ascospores and basidiospores have been least studied with respect to aerobiology, although both are clearly allergenic. Preliminary data on allergenicity and diurnal and seasonal prevalence patterns for selected ascospore and basidiospore types are presented.     

Some comments on “Reduction”

Summary Something is wrong with current discussions about theory reduction. The question of whether higher level theories are reducible to lower level theories cannot be posed in a sensible way if methodological principles that are needed to evaluate scientific theories are disregarded. If this is recognized, the problem looses much of its alleged importance.     

Some comments on activation and inhibition

A system of rate equations gives rise to a corresponding pattern of activation and inhibition between the state variables. We consider the converse question: to what extent does the specification of a pattern of activation and inhibition between interacting quantities determine the rate equations? Among other things, it is shown that in order to determine a closed set of rate equations, a set of integrability conditions among the interactions must be satisfied; hence there is a sense in which an activation-inhibition pattern is more general than systems of rate equations. Questions of the structural stability of activation-inhibition patterns, and of the time-scales determined by dynamical interactions, are briefly discussed. A comparison is made between the properties of such activation-inhibition patterns and those of neural networks, or more general modular automata.     

Kinetics of the reaction between muscle glycogen phosphorylase B and glycogen

Kinetics of glycogen binding by glycogen phosphorylase b has been studied by stopped flow and temperature jump methods. This reaction is followed by increase in light scattering whose amplitude depends upon the enzyme binding sites concentration of glycogen particles occupied by the enzyme. It has been shown that the complex formation has the first order with respect to enzyme and glycogen concentrations. Relaxation kinetics is compatible with proposed bimolecular reaction scheme. Microscopic rate constants of the forward and reverse reactions of glycogen binding by glycogen phosphorylase b are determined in temperature range from 12,7 to 30 degrees C. The possibility of diffusional control of the binding rate is discussed.     

Some introductory comments on silver staining

Silver staining has become a versatile method for the visualization of specific cell structures and products. The similarity of the impregnation "nuclei" of reduced silver staining to the silver "specks" or "nuclei" of the latent image in photography is noted. "Physical" development (reduction of ionic silver in solution) in silver staining as compared to "chemical" development (reduction of ionic silver remaining in a silver halide crystal) in photographic procedures is briefly discussed.     

Some further comments on the DNA-protein coding problem

A notion of quasi-ergodicity is defined in free monoids, generalizing a notion introduced in a previous paper (Rosen, 1959,Bull. Math. Biophysics,21, 71–95). It is shown that under certain conditions the algebraic properties of quasi-ergodicity are very similar to those derived for the more specialized concept inloc. cit. If it is assumed that the DNA-protein coding processes in nature are of a quasi-ergodic nature, then a condition is specified under which only a finite number of different DNA-protein codes are possible, and an upper bound for the total number of different quasi-ergodic codes is obtained.