I. P. Pavlov's theory on higher nervous activity: the landmarks and trends in its development

The theory of higher nervous activity created in Pavlovian time is compared with the present-day state of the theory developing due to appearance of new methods, techniques, facts, and concepts. Three principles of Pavlovian theory: determinism; analysis and synthesis; structural approach, as well s types of conditioned reflexes and techniques, types of higher nervous activity, and inhibition problems are discussed. The theory of higher nervous activity is schematically depicted as a tree, some branches of which are presented by facts and concepts obtained and introduced by I.P. Pavlov and his followers during his life, the others are formed by new facts and concepts advancing the theory. What is obsolete in the theory, what are the most prominent tendencies of its development and its new branches are discussed.     

Study of the Environment in the Pedological Works of L.S. Vygotsky: A Critical Study

Contemporary theoretical and empirical psychological research is often broken down into narrow areas, and develops within the very restricted framework of specific concepts. The accumulated empirical material requires the development of new concepts on a multidisciplinary basis.     

Evolution of microbiology as seen in the textbooks of Edwin O. Jordan and William H. Park

Historians of science account the appearance of textbooks as an important step in the formation and consolidation of a new discipline. The texts of Park and Jordan were both very important in this light; however; they also can be used as a gauge of changing concepts within microbiology in the first four decades after its consolidation as a discipline, 1900-1940. This paper tracks these important texts and through them changing attitudes toward several important concepts: bacterial variation, human/bovine tuberculosis, and the existence of a non-symptomatic carrier state in infectious disease. The two texts are also compared regarding their view of microbes as pathogens vs. microbes as important and ubiquitous ecological agents.     

Homophilic adhesion by cadherins.

Cadherins mediate cell-cell adhesion through homophilic interactions. High-resolution structures have greatly enhanced our understanding of this phenomenon over the past few years. Nonetheless, some of the original concepts about cadherin interactions need revision, with the new structural and additional mutagenesis data currently available. Furthermore, in vivo studies on cadherins have provided supplementary information.     

Hydrodynamic effects on animal cells grown in microcarrier cultures. Reprinted from Biotechnology and Bioengineering, Vol. 29, Issue 1, Pages 130-141 (1987)

Hydrodynamic phenomena in microcarrier cultures are investigated with regard to the development of improved reactor designs for large-scale operations. New concepts and theoretical models that describe new data as well as previously published data are presented.     

From metabolism to comparative biochemistry of toxic organophosphorus compounds. To the 100th anniversary from the birth of V. I. Rozengart

The main stages of the scientific biography of Professor Victor losifovich Rozengart are exposed: his works on muscle bioenergetics, discovery of the pathway of creatinine synthesis, his development of novel concepts of pathways of metabolism of organophosphorus xenobiotics, creation of biochemical grounds of selective toxicity as well as studies in the new field whose one of its founders he is--comparative biochemistry of toxic organophosphorus compounds.     

Automatic extension of Gene Ontology with flexible identification of candidate terms

MOTIVATION: Gene Ontology (GO) has been manually developed to provide a controlled vocabulary for gene product attributes. It continues to evolve with new concepts that are compiled mostly from existing concepts in a compositional way. If we consider the relatively slow growth rate of GO in the face of the fast accumulation of the biological data, it is much desirable to provide an automatic means for predicting new concepts from the existing ones. RESULTS: We present a novel method that predicts more detailed concepts by utilizing syntactic relations among the existing concepts. We propose a validation measure for the automatically predicted concepts by matching the concepts to biomedical articles. We also suggest how to find a suitable direction for the extension of a constantly growing ontology such as GO. AVAILABILITY: http://autogo.biopathway.org SUPPLEMENTARY INFORMATION: Supplementary materials are available at Bioinformatics online.     

Possible implications in the use of exogenous phospholipids.

The development of new techniques has shed more light on the physical state of phospholipids within the living cell. This has helped in the development of new concepts of the structural inter-relationship of phospholipids with proteins and other natural constituents and also of their functional role (e.g. enzyme modulators). On the other hand, understanding of phospholipid behaviour within the biological environment has encouraged research into the possibility of assigning to these molecules the role of carriers for exogenous or endogenous biologically active agents. Possible applications of this carrier potential in biology and medicine are discussed.     

CONTRIBUTION TOWARD A MONOGRAPH OF RAMARIA III. R. SANGUINEA,R. FORMOSA. AND TWO NEW SPECIES FROM EUROPE

A neotype specimen is designated for R. formosa and a representative specimen for R. sanguined, thus securing taxonomic concepts for these names. Two very similar taxa are proposed as new: R. eosanguinea, which differs from R. sanguinea chiefly in exhibiting clamp connections, and R. neoformosa which differs from R. formosa chiefly in the absence of clamps. The subject of mimic taxa is briefly discussed.     

Use of holomorph characters to delimit Microascus nidicola and M. soppii sp. nov., with notes on the genus Pithoascus

Several isolates of a perithecial microascaceous ascomycete having falcate ascospores and a Scopulariopsis anamorph were obtained from rotting wood in the boreal forest of Alberta, Canada. Additional isolates appeared conspecific based on anamorphic characters, but failed to produce a teleomorph. These isolates showed similarities to Microascus nidicola (type species of the genus Pithoascus) and Scopulariopsis flava. Sexual compatibility systems were investigated to establish holomorph concepts for these taxa. The teleomorph obtained in mating trials among anamorphic isolates was identical to that of self-fertile isolates. The new heterothallic species M. soppii is described. The anamorph is S. soppii. Single ascospore isolates derived from M. nidicola demonstrated homothallism and lacked an anamorph. Scopulariopsis flava (basionym Acaulium flavum) is considered a nomen dubium. Generic concepts of Pithoascus are evaluated and the genus is treated as a synonym of Microascus. Pithoascus stoveri is transferred as M. stoveri comb. nov.     

The Novartis-ILAR Rheumatology Prize 2001 Osteoarthritis: from molecule to man

During our careers, we have developed new and innovative concepts pertaining to the pathophysiology of osteoarthritis which have assisted in the development of new therapeutic approaches. Moreover, our laboratory has long sought to develop protective agents for osteoarthritic structural joint tissues. The most significant concepts that have originated from our lab are briefly outlined in this commentary.     

The Novartis-ILAR Rheumatology Prize 2001 Osteoarthritis: from molecule to man

During our careers, we have developed new and innovative concepts pertaining to the pathophysiology of osteoarthritis which have assisted in the development of new therapeutic approaches. Moreover, our laboratory has long sought to develop protective agents for osteoarthritic structural joint tissues. The most significant concepts that have originated from our lab are briefly outlined in this commentary.     

Predator-prey interactions in natural communities.

The familiar concepts of harvest and yield are developed for the purpose of describing predator-prey interactions in a community context. In this regard the functional response (appropriate for one predator-one prey systems) is replaced by a community harvest function. Conditions for the stability of an ecological community are obtained. Exploring the dynamics of predator-prey interactions within this framework leads to new interpretations of other dynamical models such as the Lotka-Volterra model. The concept of a community moving attractor point is introduced in order to describe the changes in all populations over time.     

Hammond memorial lecture. New concepts of the control of corpus luteum function

Five new concepts concerning the control of corpus luteum function in the cow have been developed in recent years. Prostacyclin (PGI-2) plays a luteotrophic role. Conversely, products of the lipoxygenase pathway of arachidonic acid metabolism, particularly 5 hydroxyeicosatetraenoic acid (5-HETE), play luteolytic roles. Luteal cells arise from two sources. The small luteal cells are all of theca cell origin; the large cells found early in the cycle (Days 2-6) are mainly of granulosa cell origin. However, a population of large cells found after Day 10 of the cycle are of theca cell origin. Oxytocin of luteal cell origin plays a role in development of the corpus luteum and possibly in its regression. The recently described Ca2+-polyphosphoinositol-protein kinase C second messenger system, as well as the LH-cAMP system, is involved in control of progesterone synthesis in the bovine corpus luteum. Progesterone synthesis in the small theca-derived luteal cells is primarily controlled by the cAMP system. However, elevated intracellular calcium diminishes cAMP-mediated progesterone synthesis in these cells. These findings modify our current concepts of the mechanisms of control of progesterone secretion by the corpus luteum and suggest several new lines of research.     

From physiological theory to psychological facts (on the centenary of I. P. Pavlov's speech in Madrid)

Pavlovian theory of conditioned reflexes and Ukhtomsky's theory of dominanta are considered as the most important biological concepts of the XX century. They have laid the foundation of the modern views of the adaptive and active character of the nervous activity underlying the integral behavior in the environment. Approach to a burning problem of neurophysiological mechanisms of goaldirected behavior is impossible without a comprehensive study of works of both these schools. They have formed not only the methodological basis of modern investigations but opened a new avenue of attack.     

Chance as an explanatory factor in evolutionary biology.

Darwinian evolutionary biology has often been criticized for appealing to the notion of 'chance' in its explanations. According to some critics, such appeals exhibit the explanatory poverty of evolutionary theory. In response, defenders of Darwinism sometimes downplay the importance of 'chance' in evolution. I believe that both of these approaches are mistaken. The main thesis of this paper is that the term 'chance' encompasses a number of distinct concepts, and that at least some of these concepts serve essential explanatory functions in evolutionary biology. This claim is defended by way of an historical survey of the major concepts of 'chance' in the history of evolutionary biology, especially the concepts used by Jean Baptiste Lamarck, Charles Darwin, and Sewall Wright. An examination of their biologies shows how the concepts of 'chance' used cohere with their major scientific objectives and methods. These concepts survive and continue to function as important explanatory factors in contemporary evolutionary biology. Examples of such usage are given, and the explanatory status of 'chance' assessed.     

Aspects of permian palaeobotany and palynology. III. A new reconstruction of Lilpopia raciborskii (Lilpop) conert et schaarschmidt (Sphenopsida)

The early Permian plant Lilpopia raciborskii (Sphenopsida) has been found for the first time outside its type region, the Karniowice area (Poland). On the basis of this new material, collected in the “Waderner Gruppe” of Sobernheim (Nahe area, German Federal Republic), L. raciborskii is described and discussed in the light of previous concepts of this species; a new and more complete reconstruction of the taxon is presented. For the first time epidermal features are described. The heterophyllous leaves of L. raciborskii are compared with Sphenophyllum thonii var. minor Sterzel.