The biological foundation of the Gompertz model

The paper examines the biological reasoning of the Gompertz model for tumor growth: the increase and loss rates of the tumor volume are both proportional to the volume itself. The statement is proved mathematically. The theoretical foundation is therefore established, this ensures the application of the Gompertz model as an effective aid for the understanding of the experimental and clinical tumor process.     

生物实验学习软环境的创设

以情境认知和学习理论为指导,结合生物实验学习实际运用的成效,阐述了生物实验学习软环境创设的操作要领。     

The data quality foundation in OMNIITOX information system

Extended Summary Goal and Scope  This paper describes the data quality foundation for the OMNIITOX information system, with regard to data quality requirements and maintenance. Main Features  The data quality concept applied in the OMNIITOX project is based on results that are successfully used in other contexts (Fig. 1). Specific data quality requirements have been developed, which are applied in data acquisition and data review. The data quality requirements and quality maintenance is supported by the OMNIITOX concept model, which supplies a common language for the users from the different disciplines. Results and Discussion  The quality requirements and the concept model have been tested during data acquisition for the information system, and have been found to be a successful framework. The results from practical work demonstrate that it is possible to have a common understanding of the concept model and quality requirements. The user's experience the initial phase of learning the concepts and quality requirements as tedious. Nevertheless, experiences show that the users will benefit from the education during the further work. A considerable amount of data has been acquired based on the data quality foundation. Conclusions  The data quality foundation has been a successful framework for managing data quality in the design and establishment of the OMNIITOX information system. The data quality concept, the concept model, and specific quality requirements are applied as quality management tools to find, acquire, document, and interpret the information. Several quality issues deriving from interdisciplinary differences between the different users have been resolved, which facilitates a common understanding and reduces the risk of misinterpretations and misuse of information. Recommendations and Outlook  An important task for the finalization of the OMNIITOX project is to secure the credibility and long-term stability of the information system. The OMNIITOX information system will somewhat have less potential to support the toxicology related assessments in Europe if any of the involved disciplines chooses to reject or not to apply the concept model and the quality requirements.     

The theory of organism and the culturalist foundation of biology

Summary After the disappearance of organism was diagnosed, the discussion about the role of a theory of organism in biology is characterised by a significant contradiction. On the one hand, the importance of a theory of organism is stated. Particularly developmental biology demands organism-centred approaches as a basis for conceptual integration. On the other hand, several modern biological disciplines such as genetics and molecular biology simply don’t need a theory of organism for their work. Consequently, the determination of the status of the organism and its relevance for biology at all is an unsolved problem. In order to clarify the methodological status of the organism in biology we start with the reconstruction of three important propositions. A life oriented approach and a hierarchy concept - which both are from a neo-Darwinian origin - are confronted with a structuralist approach of organism, that can be characterised as a non-Darwinist approach. Our own attempt for the solution of the organism problem applies the tools of culturalist methodology. In accordance to this pragmatic approach, the term organism is introduced as a concept of notion. A constructional morphological case study exemplifies the applicability of this concept. From the culturalist point of view a methodological foundation of biology can be achieved, that provides a consistent basis for a comprehensive integration of biological knowledge.     

The dialectic of glottogenesis--a contribution to the foundation of biolinguistics

Some analogies were demonstrated between the spontaneous acquisition of phonemes, especially gutturals and clicks, and their also spontaneous extinction during the early babble phase of infants on the one hand and the appearance and involution of some blastemata throughout the human ontogenesis on the other hand. Also analogues seem to be the producing of the so-called instinctives as mam(m)a and papa by somewhat older babies which are able to pass over from the babbling into permanent words of the adults' speech in which they persist if used without shifting of sounds since they are produced de novo generation by generation, but they are subordinate to shifting and possible extinction if used in the form of derivatives in the standard language, and some phenomena of the phylogenesis as the survival of less differentiated species contrary to the relatively quick extinction of the highly specialized ones. Thus the glottogenesis is a dialectic process consisting of interaction by formation, differentiation, and involution.     

The principle of optimality as the foundation of biotechnological modeling

There are many points of contact between optimization problems and modeling. On the one hand the model adjustment process itself as a process of estimation is closely connected with optimization, in that it is to produce what is in one sense the best possible model. The basic structure of the optimization problem as problem in decision making with the necessary input of an objective function is thus evident. On the other hand a model is never an end in itself but on the basis of its simulation capacity a means to an end, for example in biotechnological optimization. From this point of view the model is a product of scientific work and thus an economic value. Equally, through its intended purpose the model exhibits a utility value. A complete evaluation of the model as a condition of rational modeling must take into account both these aspects. That is possible in principle by adding the modeling expenditure to expenditure for the realization of biotechnological processes, expressing the economic consequences of model quality as an objective function, and minimizing the specific total expenditure for the product to be produced. Biotechnological practice requires that the “optimum” model is approached by means of iterative processes. Some practical examples will make the process clear, taking into account qualitative (semantic) and quantitative (accuracy) aspects of the utility value.     

The PhyloCode: a critical discussion of its theoretical foundation

The definition of taxon names as formalized by the PhyloCode is based on Kripke's thesis of "rigid designation" that applies to Millian proper names. Accepting the thesis of "rigid designation" into systematics in turn is based on the thesis that species, and taxa, are individuals. These largely semantic and metaphysical issues are here contrasted with an epistemological approach to taxonomy. It is shown that the thesis of "rigid designation" if deployed in taxonomy introduces a new essentialism into systematics, which is exactly what the PhyloCode was designed to avoid. Rigidly designating names are not supposed to change their meaning, but if the shifting constitution of a clade is thought to cause a shift of meaning of the taxon name, then the taxon name is not a "rigid designator". Phylogenetic nomenclature either fails to preserve the stability of meaning of taxon names that it propagates, or it is rendered inconsistent with its own philosophical background. The alternative explored here is to conceptualize taxa as natural kinds, and to replace the analytic definition of taxon names by their explanatory definition. Such conceptualization of taxa allows taxon names to better track the results of ongoing empirical research. The semantic as well as epistemic gain is that if taxon names are associated with natural kind terms instead of being proper names, the composition of the taxon will naturally determine the meaning of its name.
© The Willi Hennig Society 2006.     

The foundation of extranuclear inheritance: plastid and mitochondrial genetics

In 1909 two papers by Correns and by Baur published in volume 1 of Zeitschrift für induktive Abstammungs- und Vererbungslehre (now Molecular Genetics and Genomics) reported on the non-Mendelian inheritance of chlorophyll deficiencies. These papers, reporting the very first cases of extranuclear inheritance, laid the foundation for a new field: non-Mendelian or extranuclear genetics. Correns observed a purely maternal inheritance (in Mirabilis), whereas Baur found a biparental inheritance (in Pelargonium). Correns suspected the non-Mendelian factors in the cytoplasm, while Baur believed that the plastids carry these extranuclear factors. In the following years, Baur’s hypothesis was proved to be correct. Baur subsequently developed the theory of plastid inheritance. In many genera the plastids are transmitted only uniparentally by the mother, while in a few genera there is a biparental plastid inheritance. Commonly there is random sorting of plastids during ontogenetic development. Renner and Schwemmle as well as geneticists in other countries added additional details to this theory. Pioneering studies on mitochondrial inheritance in yeast started in 1949 in the group of Ephrussi and Slonimski; respiration-deficient cells (petites in yeast, poky in Neurospora) were demonstrated to be due to mitochondrial mutations. Electron microscopical and biochemical studies (1962–1964) showed that plastids and mitochondria contain organelle-specific DNA molecules. These findings laid the molecular basis for the two branches of extranuclear inheritance: plastid and mitochondrial genetics.     

奇静脉病变的影像表现及其病理解剖学基础

掌握奇静脉的病理解剖学基础,有助于提高奇静脉病变的影像诊断水平,为临床早期诊断有血流动力学变化却无明显临床症状的隐性病变提供依据,为奇静脉疾病的诊断及治疗提供帮助.本文就奇静脉病变的影像表现及其病理解剖学基础加以综述.     

Phylogenetic foundation of spirochetes

The spirochetes are free-living or host-associated, helical bacteria, some of which are pathogenic to man and animal. Comparisons of 16S rRNA sequences demonstrate that the spirochetes represent a monophyletic phylum within the bacteria. The spirochetes are presently classified in the Class Spirochaetes in the order Spirochetales and are divided into three major phylogenetic groupings, or families. The first family Spirochaetaceae contains species of the genera Borrelia, Brevinema, Cristispira, Spirochaeta, Spironema, and Treponema. The second family Brachyspiraceae contains the genus Brachyspira (Serpulina). The third family Leptospiraceae contains species of the genera Leptonema and Leptospira. Novel spirochetal species, or phylotypes, that can not be presently cultivated in vitro, have been identified from the human oral cavity, the termite gut, and other host-associated or free-living sources. There are now over 200 spirochetal species or phylotypes, of which more than half is presently not cultivable. It is likely that there is still a significant unrecognized spirochetal diversity that should be evaluated.