Thermodynamic characteristics of a biological organism: Information value of a gene and of a protein as a measure of the efficiency and as an index of selective pressure

1983 ◽  
Vol 2 (5) ◽  
pp. 1582-1601 ◽  
Author(s):  
V. Cuomo ◽  
M. Macchiato ◽  
A. Tramontano
2004 ◽  
Author(s):  
Joan E. Ricart-Costa ◽  
Brian Subirana ◽  
Josep Valor-Sabatier

Author(s):  
V. V. Goncharova

The increasing interest towards abstracting as a type of analytical and synthetical information processing due to science globalization trend, is emphasized. The professionals who study this primary information compression are bibliographers, linguists, and information specialists. The author argues that modern professors and students all have to and must learn abstracting in accordance with the international standards for scientific, research, reference and instructional works.The author points to the diversity of the national lexicographical studies and, based on the abstracts index obtained as a result of her study, characterizes the current trends in abstracting linguistic dictionaries. The key user groups are defined. Publishers’ abstracts of dictionaries are discussed and represented. The example of dictionary Internet-based abstract analysis is given (50 items). Based on the abstracts texts, main negative factors to impact information value of this secondary information source are revealed, that is: lacking data essential for users, incomplete description of targeted readership, etc.The author introduces a model plan for digital guides of Russian lexicographical works and complements the plan with the systematic aspect analysis. She concludes that abstracting is an intellectually intensive process. It is underexplored as far as lexicographical works are concerned, and offers many possibilities for further studies.


Author(s):  
I. Khidirov ◽  
V. V. Getmanskiy ◽  
A. S. Parpiev ◽  
Sh. A. Makhmudov

This work relates to the field of thermophysical parameters of refractory interstitial alloys. The isochoric heat capacity of cubic titanium carbide TiCx has been calculated within the Debye approximation in the carbon concentration  range x = 0.70–0.97 at room temperature (300 K) and at liquid nitrogen temperature (80 K) through the Debye temperature established on the basis of neutron diffraction analysis data. It has been found out that at room temperature with decrease of carbon concentration the heat capacity significantly increases from 29.40 J/mol·K to 34.20 J/mol·K, and at T = 80 K – from 3.08 J/mol·K to 8.20 J/mol·K. The work analyzes the literature data and gives the results of the evaluation of the high-temperature dependence of the heat capacity СV of the cubic titanium carbide TiC0.97 based on the data of neutron structural analysis. It has been proposed to amend in the Neumann–Kopp formula to describe the high-temperature dependence of the titanium carbide heat capacity. After the amendment, the Neumann–Kopp formula describes the results of well-known experiments on the high-temperature dependence of the heat capacity of the titanium carbide TiCx. The proposed formula takes into account the degree of thermal excitation (a quantized number) that increases in steps with increasing temperature.The results allow us to predict the thermodynamic characteristics of titanium carbide in the temperature range of 300–3000 K and can be useful for materials scientists.


2018 ◽  
Vol 22 (2) ◽  
pp. 263-266
Author(s):  
R.V. Kutsyk ◽  
O.I. Yurchyshyn

The emergence of microorganisms resistant strains is a natural biological response to the use of antimicrobial drugs that creates selective pressure, contributing to pathogens selection, survival and reproduction. The purpose of the investigation was to study the resistance development of staphylococci skin isolates to erythromycin and influence on it Alnus incana L. fruit extract subinhibitory concentrations. Development of resistance to erythromycin and influence on it Alnus incana L. fruit extract (extraction by 90% ethanol) subinhibitory concentrations were conducted with S epidermidis strains: sensitive and resistant to 14 and 15-membered macrolides. The study was carried out within 30 days by multiple consecutive passages of staphylococci test strains (concentration 1×107 CFU/ml) into test tubes containing broth and erythromycin ranging from 3 doubling dilutions above to doubling dilutions below the minimum inhibitory concentration. Statistical analysis of the results was carried out by one-and two-factor analysis of variance (ANOVA) and Microsoft Office Excel 2011. Rapid increase of resistance from 32 to 1024 μg/ml (F=34.2804; F> Fstand. max = 5.9874; p=0.0011) for S.epidermidis with a low level of resistance to 14 and 15-membered macrolides resistance to the erythromycine was observed. In the presence of Alnus incana L. fruit extract subinhibitory concentrations (¼ MIC), the initial MIC of erythromycin was decreased by 32 times to 1 μg/ml (F = 9.7497; F> Fstand. max = 5.9874; p = 0.0205). The sensitive strain after 30 passages did not develop resistance to erythromycin. Under the influence of erythromycin selective pressure, S.epidermidis strain with low initial level of MLS-resistance rapidly reaches a high-level resistance. Biologically active substances of the Alnus incana L. fruit extract significantly inhibit the resistance development in S. epidermidis to macrolides and eliminate it phenotypic features.


Author(s):  
Dean E. Biggins ◽  
David A. Eads

Black-footed ferrets were reduced to a remnant population of 10 in 1985 due to diseases (plague, canine distemper), but successful captive breeding and releases have improved the prospects for ferret recovery. Comparisons between black-footed ferrets and Siberian polecats, close relatives that can interbreed and produce fertile offspring, allow the following evolutionary speculation. Predation on ferrets and polecats tends to narrow their niches and promote specialization due to requirements for escape habitats. In Asia, that influence is countered by the larger and more diverse area of steppe and alpine meadow habitats for polecats, and by plague which causes large variation in prey abundance. In North America, the selective pressure favoring specialization in ferrets on prairie dog prey and burrows had no strong counter-force before plague invaded. Plague is an immense challenge to black-footed ferret recovery, and several management tools including vaccines and vector control may be necessary to conserve the species.


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