Laws, constraints, and the modeling relation--history and interpretations

The modeling relation and models of complex systems expressed by non-integrable constraints were developed during ca. 1970-1987, when I worked most closely with Robert Rosen. I contrast the modeling relation within the organism itself as a necessary condition for life and evolution, as Rosen developed it in his fundamental work 'Anticipatory Systems', with the modeling relation within our brain as a necessary condition for understanding life, as Rosen developed it in 'Life Itself'. Our approaches to the modeling relation were complementary. Rosen focused on the formal relational conditions necessary for life, and on the limitations that formal mathematical-symbol systems impose on our models. I focused on the physical conditions necessary for these abstract relations to be realized, and on the symbolic control in organisms that allows open-ended evolution. I contrast Rosen's views on physics and evolution in 'Anticipatory Systems' and later papers with his views in 'Life Itself', and I speculate on why they differ so greatly.     

Identification of the domains required for the localization of Prp19p to lipid droplets or the nucleus

Prp19p is a protein found in the nucleus, cytosol or lipid droplets depending on the cell type. Prp19p participates in pre-mRNA splicing, in neuronal/astroglial cell fate decisions or in adipocyte lipid droplet biogenesis. In this study, the motifs of Prp19p that are necessary for its localization to lipid droplets or the nucleus in 3T3-L1 adipocytes are investigated using a series of truncated mutants of Prp19p that were fused to EGFP and transiently introduced into differentiated 3T3-L1 adipocytes. Immunofluorescence microscopy revealed that a domain of amino acids 167–250 is necessary for the recruitment of Prp19p to lipid droplets and that a domain of amino acids 1–166 is necessary for the recruitment of Prp19p to a nucleus.     

Determinants of GPI-PLC Localisation to the Flagellum and Access to GPI-Anchored Substrates in Trypanosomes

In Trypanosoma brucei, glycosylphosphatidylinositol phospholipase C (GPI-PLC) is a virulence factor that releases variant surface glycoprotein (VSG) from dying cells. In live cells, GPI-PLC is localised to the plasma membrane where it is concentrated on the flagellar membrane, so activity or access must be tightly regulated as very little VSG is shed. Little is known about regulation except that acylation within a short internal motif containing three cysteines is necessary for GPI-PLC to access VSG in dying cells. Here, GPI-PLC mutants have been analysed both for subcellular localisation and for the ability to release VSG from dying cells. Two sequence determinants necessary for concentration on the flagellar membrane were identified. First, all three cysteines are required for full concentration on the flagellar membrane. Mutants with two cysteines localise predominantly to the plasma membrane but lose some of their flagellar concentration, while mutants with one cysteine are mainly localised to membranes between the nucleus and flagellar pocket. Second, a proline residue close to the C-terminus, and distant from the acylated cysteines, is necessary for concentration on the flagellar membrane. The localisation of GPI-PLC to the plasma but not flagellar membrane is necessary for access to the VSG in dying cells. Cellular structures necessary for concentration on the flagellar membrane were identified by depletion of components. Disruption of the flagellar pocket collar caused loss of concentration whereas detachment of the flagellum from the cell body after disruption of the flagellar attachment zone did not. Thus, targeting to the flagellar membrane requires: a titratable level of acylation, a motif including a proline, and a functional flagellar pocket. These results provide an insight into how the segregation of flagellar membrane proteins from those present in the flagellar pocket and cell body membranes is achieved.     

The necessity for low temperature treatment on the eggs of Emma Cricket,Teleogryllus emma and the method of increasing the hatching rate after low temperature treatment

The necessity for low temperature treatment of Emma Cricket Eggs, Teleogryllus emma, to dormancy breaking and the method of increasing hatching rate after low temperature treatment were investigated. Emma Cricket Eggs were treated by constant temperature, room temperature, low temperature, step‐down low temperature. As a result, constant temperature treatment was the lowest on hatching rate. The hatching rates of the rest of other temperature treatments were not different statistically (one‐way ANOVA). In other word, low temperature treatment was not necessary to dormancy breaking. But low temperature treatment was necessary to control individual number of Emma Cricket, Teleogryllus emma, on the mass indoor‐rearing system. And the step‐up temperature treatment was necessary to increase hatching rate after low temperature treatment.     

生防菌对土壤微生态影响的风险评估

土壤微生物在地理生物化学循环过程中起着极其重要的作用。在农业生态系统中,土壤微生物通过降解植物残体为植物提供营养,同时维持植物生产所需的土壤性质。生防菌的引入可能会破坏土壤原有微生物的群落结构和功能,从而对整个生态系统造成有害的影响,因此不论生防菌有无经过基因修饰,在商业化应用前必须对其在农业生态环境中的行为和对土壤生态系统的潜在影响进行风险评估。     

Factors interacting with promoter region of immunoglobulin genes. Determination of the binding site boundaries

The nuclear extracts of plasmacytomas producing antibodies were found to contain factors which formed complexes with the promoter fragment of the gene for immunoglobulin kappa-chains. The corresponding complexes found in the extracts of nonlymphoid cells had a different mobility. Two approaches were proposed for determining the boundaries of the region necessary for protein factors to be bound to DNA using nuclease Ba131. A 5'-ATTTGCAT-3' octanucleotide sequence was shown to be necessary for interaction with the protein nuclear factor in the studied plasmacytoma lines. The protein completely lost its affinity if at least one nucleotide was removed or substituted at the 5'- or 3'-end of this sequence. The procedures proposed for determining the precise boundaries of the sequence necessary for protein binding to DNA do not require a preliminary protein purification. The principles on which the procedures are based, set no limitations to their application to other systems used for studying the interaction of proteins with DNA.     

Prognosis of the dynamics and intensity of the epidemic process in viral hepatitis A

The article deals with approaches to the calculation of the annual morbidity rate in virus hepatitis A at the period preceding the season of maximum morbidity, necessary for planning the relevant prophylactic and antiepidemic measures in due time. The method for calculating the monthly levels of sporadic morbidity in virus hepatitis A is proposed. This method permits the detection of complications on the epidemic situation, which is necessary for the timely organization of antiepidemic measures. The proposed method for predicting annual and monthly morbidity levels can be used in the practical work of specialists at sanitary and epidemic stations.     

Positively charged residues, the helical conformation and the structural flexibility of the leader sequence of pALDH are important for recognition by hTom20

Tom20, a mitochondrial outer membrane receptor necessary for protein translocation, was found to interact specifically with mitochondrial preproteins. The interaction of proteins containing an N-terminal matrix targeting signal was enhanced in an hydrophobic environment and the dependence of this interaction on the alpha helical conformation of the presequence was postulated. In order to test this hypothesis and to gain insights about the features of a matrix targeting signal necessary to be recognized by the receptor machinery including Tom20, the interaction of pALDH and signal sequence mutants to Tom20 in the absence and presence of a hydrophobic environment was investigated. Here we present evidence to show that in a hydrophobic environment the interaction between Tom20 and the leader sequence is strongly dependent on the positive charges within the signal sequence as well as on the flexibility of this signal.     

Reexamination of the 'regulative development' of amphibian embryos

In this article, we have reviewed a series of our recent results of isolation, defect and transplantation experiments on early embryos of Xenopus laevis. The results show that as early as the 8-cell stage an embryo consists of several kinds of cells which differ distinctly in developmental capacities and that their capacities are much more restricted than previously thought. Thus, for the formation of complete embryos a certain set of cells is necessary; and no regulation occurs whenever any one of the necessary cells is lacking.     

Developmental Analysis of the Achaete-Scute System of DROSOPHILA MELANOGASTER

The interpretation of the wild-type function of a gene depends on our knowledge of the phenotype caused by its absence. We have first defined the genetic extent of the achaete-scute system by studying the phenotype of different terminal and intercalary deficiencies including these genes. When these deficiencies were lethal, we have defined the phenoeffective phase of lethality and studied their phenotype in genetic mosaics (gynandromorphs and mitotic recombination clones). The achaete-scute system affects two functions, one necessary for the differentiation of the embryonic (central?) nervous system and the other necessary for the differentiation of peripheral nervous elements of the chaetes and sensillae of the adult cuticle. The possibility that these functions correspond to differential expression of a single mechanism is discussed.     

Determination of the minimal length DNA homologous region required for plasmid integration into the Bacillus subtilis chromosome via homologous recombination]

With a view to determine a minimal sequence length of homology necessary for RecE-dependent homologous recombination in Bacillus subtilis cells, we developed a system, based on interaction between plasmid replicon and bacterial chromosome. Recombination frequencies were measured between ts plasmid pE194 derivatives carrying chromosomal beta-glucuronidase gene (bglS) fragments of various length, and a bacterial chromosome. The homologous recombination events resulted in bglS gene disruption. Approx. 70 bp of homology were found to be necessary for detectable homologous recombination. Homologous recombination was not detected when homology was equal 25 bp. These data indicate that homology requirement for recombination in B. subtilis differs from that in Escherichia coli.     

Eggs, egg formation and the timing of breeding

The eggs of birds contain all the nutrients necessary for the developing embryo. The female has to obtain these nutrients, and while in some species these may be gathered and stored over a period of time, in many species they seem to be obtained on a daily basis. Obtaining the calcium necessary for the eggshell may pose special problems for some species, which may have to give up valuable feeding time in order to search for calcium.
Egg size varies considerably, even within species, and the reasons for this are not clear. In the Great Tit Parus major , large eggs produce nestlings which have a higher chance of hatching, surviving to fledging and surviving after fledging. However, large eggs require the female to acquire more nutrients to form them, and large chicks may sometimes be at a disadvantage. The amount of energy required to form a larger egg often seems small unless the metabolic costs of egg formation are taken into account.     

Water: the bloodstream of the biosphere

Water, the bloodstream of the biosphere, determines the sustainability of living systems. The essential role of water is expanded in a conceptual model of energy dissipation, based on the water balance of whole landscapes. In this model, the underlying role of water phase changes--and their energy-dissipative properties--in the function and the self-organized development of natural systems is explicitly recognized. The energy-dissipating processes regulate the ecological dynamics within the Earth's biosphere, in such a way that the development of natural systems is never allowed to proceed in an undirected or random way. A fundamental characteristic of self-organized development in natural systems is the increasing role of cyclic processes while loss processes are correspondingly reduced. This gives a coincidental increase in system efficiency, which is the basis of growing stability and sustainability. Growing sustainability can be seen as an increase of ecological efficiency, which is applicable at all levels up to whole landscapes. Criteria for necessary changes in society and for the design of the measures that are necessary to restore sustainable landscapes and waters are derived.     

Eggs, egg formation and the timing of breeding

The eggs of birds contain all the nutrients necessary for the developing embryo. The female has to obtain these nutrients, and while in some species these may be gathered and stored over a period of time, in many species they seem to be obtained on a daily basis. Obtaining the calcium necessary for the eggshell may pose special problems for some species, which may have to give up valuable feeding time in order to search for calcium.
Egg size varies considerably, even within species, and the reasons for this are not clear. In the Great Tit Pants major, large eggs produce nestlings which have a higher chance of hatching, surviving to fledging and surviving after fledging. However, large eggs require the female to acquire more nutrients to form them, and large chicks may sometimes be at a disadvantage. The amount of energy required to form a larger egg often seems small unless the metabolic costs of egg formation are taken into account.     

Pathogenetic significance of the psychrophilia of Yersinia pseudotuberculosis

The work presents the data indicating that the temperature of Y. pseudotuberculosis cultivation is very important in regulating the activity of pathogenicity factors, necessary for the initiation of the pathogenic process in the cells of the macroorganism. Low temperature (8-10 degrees C), necessary for the growth of Y. pseudotuberculosis, facilitates the activation of invasive and toxic pathogenicity factors. At a growth temperature of 37 degrees C the inhibition of such necessary attributes of virulence as adhesion and invasion into epithelial cells occurs in Y. pseudotuberculosis, which decreases the capacity of these bacteria for inducing the infectious process. The virulence of Y. pseudotuberculosis population, lost as the result of its cultivation in synthetic culture media at a temperature of 37 degrees C, has been found to be restored at low temperature.     

Use of different oxidation substrates in the energy metabolism of mammalian germ cells and embryos

Mammalian oocytes and embryos on the early stages of development are in need of pyruvate as source of energy. The pyruvate or pyruvate and lactate combination are necessary for the processes of the maturation and fertilisation. The 8-cell stage embryos tend to change their energetical metabolism. The mouse embryos at this stage of development begin to utilise the glucose. alpha-Ketoglutarate without pyruvate, lactate or glucose is necessary for the development of cow and pig embryos after 8-cell stage.     

Role of heparin in the realization of the hypoglycemic action of insulin

The presence of reactive heparin in blood circulation is necessary for realization of the hypoglycemic action of insulin. This is confirmed by the fact that after heparin binding by protamin sulfate both endogenous and exogenous insulin do not exhibit any hypoglycemic activity. In animals with different basal concentration of heparin in the blood, the blockade of insulin action is attained by application of different doses of protamin sulfate, respectively. Based on the data obtained one can determine an approximate blood heparin concentration necessary for realization of the hypoglycemic action of insulin.     

Calculation of the number of samples needed to estimate the species richness of a taxocene

A formula to calculate the area of samples that would provide the necessary level of completeness for a species richness survey of a cenosis has been deduced. The model is based on a stochastic differential equation that describes random fluctuations in species abundance and on the assumption that a Poisson distribution of individuals in space occurs. The calculations are illustrated based on the example of the littoral polychaete taxocene in Vityaz Bay of Possiet Bay of the Sea of Japan.