scholarly journals THE DIVERSITY OF THE PARASITIC SYSTEM IS THE BASE OF THE STABILITY OF THE FUNCTIONING OF NATURAL FOCUS OF THE INFECTION

2017 ◽  
Vol 22 (4) ◽  
pp. 208-213
Author(s):  
Yuriy I. Arutyunov ◽  
B. N Mishan’kin ◽  
I. V Orekhov ◽  
N. L Pichurina
Keyword(s):  
Causative Agent ◽  
Vector Species ◽  
Natural Focus ◽  
Two Component ◽  
High Virulence ◽  
Abundance Peak ◽  
Focus Of Infection ◽  
Parasitic System ◽  
The Stability

This paper presents the authors’ opinion concerning such understudied issue of epizootology as the cause of the stability of the functioning of the natural focus of infection. The diversity of the biocenotic complex including main, secondary and casual carriers; numerous, small in number and rare vectors; strains with high virulence, low virulence and altered strains of the causative agent of infection, as well as population nonuniformity of biocenosis constituents contribute to the stability of the functioning of the natural focus in certain landscape-geographic conditions. The heterogeneity during the achievement of the abundance peak by various carrier and vector species also promotes to the stability. Universality of the principle of the proposition offered here for three- and two-component constituents of a natural focus of infection, as well as for infections caused by sapronotic pathogens, allows consider it as a biological law of the stable functioning of a natural focus of infection.

Risk of infestation of population by opisthorchiasis causative agent in the middle and lower current of the Iset river. influence of loimopotential of the focus of infestation on the risk values

2017 ◽  
pp. 52-56
Author(s):  
A.V. Ushakov ◽  
R.G. Fattakhov ◽  
T.F. Stepanova
Keyword(s):  
Causative Agent ◽  
Water Bodies ◽  
Risk Of Infection ◽  
Natural Focus ◽  
Opisthorchis Felineus ◽  
Large Water

The risk of infestation of the population by the opisthorchiasis causative agent in the middle and lower reaches of the Iset River was estimated. Areas with the highest risk of peoples infection by Opisthorchis felineus’ metacercaria are identified. These territories are confined to the zones of removal of the opisthorchiasis causative agent, which are river beds and large water bodies that constantly connect with rivers. Steady risk of infection of the population is determined by the loimopotential of the opisthorchiasis natural focus. The general infestation of juveniles fishes in the middle and lower current of the Iset River made 9,9 %, annuals – 21,5 %, two-year-olds – 19,5 %.

scholarly journals EPIDEMIC AND EPIZOOTIC SITUATION OF NATURAL-FOCAL ZOONOTIC INFECTIONS IN VLADIMIR REGION

2018 ◽  
pp. 20-26
Author(s):  
A. A. Martsev ◽  
V. M. Rudakova ◽  
A. V. Ilina
Keyword(s):  
Biological Material ◽  
Statistical Data ◽  
Preventive Measures ◽  
Natural Focus ◽  
Zoonotic Infections ◽  
Vladimir Region ◽  
Laboratory Results ◽  
Natural Foci ◽  
Focus Of Infection ◽  
Epidemiological Significance

Aim. Assessment of the epidemiological and epizootic situation and the degree of danger of the territory of Vladimir region in terms of a complex of natural focal zoonotic infections. Materials and methods. In the work, a retrospective analysis of statistical data on the incidence of zooanthroponosis in the population, obtained from Reporting Form No. 2 «Information on Infectious and Parasitic Diseases» of Center for Hygiene and Epidemiology in the Vladimir Region for the period 1958 - 2016 was conducted. Studies of biological material for the presence of pathogens of natural focal infections were conducted in the laboratory of natural focal and especially dangerous infections of Center of Hygiene and Epidemiology in the Vladimir Region. Results. It is established that the following natural focal diseases are registered in the territory of the Vladimir region: rabies, heemorrhagic fever with renal syndrome (HFRS), tick-borne borreliosis (ТВВ), leptospirosis, pseudotuberculosis and tularemia. The largest share in the structure of morbidity falls on HFRS and ТВВ. Annual laboratory studies of biological material for the presence of pathogens of natural focal infections indicate the presence of epizootics among rodent mice, the dominant species among which is the red vole. The ratio of men to women with HFRS is about 3 to 1, the main risk factors for transmission are harvesting in summer cottages and visiting forest areas. As for the ТВВ, in the region there are persistent natural foci of this infection. It was established that there is no territorial dependence between the incidence and «riches» of the territory, and the main epidemiological significance is the iksodid mites I.ricinus and I.persulcatus. Conclusion. The cartographic mapping of the registered incidence allowed to show the territories with different degree of epidemic manifestation for individual natural-focal diseases and for a complex of morbidity in general. Positive laboratory results indicate epizootic activity and a constant risk of exacerbation of the epidemic situation of zooanthroponous infections, and the absence of human morbidity over a number of years is not evidence of the attenuation of the natural focus of infection and the basis for the curtailment of preventive measures.

scholarly journals Analysis of stability problems via matrix Lyapunov functions

1990 ◽  
Vol 3 (4) ◽  
pp. 209-226 ◽  
Author(s):  
Anatoly A. Martynyuk
Keyword(s):  
Lyapunov Functions ◽  
Systems Of Nonlinear Equations ◽  
Matrix Functions ◽  
Singularly Perturbed Systems ◽  
Two Component System ◽  
Two Component ◽  
Lyapunov Matrix ◽  
Analysis Of Stability ◽  
The Stability ◽  
The Given

The stability of nonlinear systems is analyzed by the direct Lyapunov's method in terms of Lyapunov matrix functions. The given paper surveys the main theorems on stability, asymptotic stability and nonstability. They are applied to systems of nonlinear equations, singularly-perturbed systems and hybrid systems. The results are demonstrated by an example of a two-component system.

scholarly journals Are Pressure-Confined Clouds in Galactic Halos Possible Models of Lyman Alpha Clouds?

1999 ◽  
Vol 186 ◽  
pp. 481-481
Author(s):  
Keiko Miyahata ◽  
Satoru Ikeuchi
Keyword(s):  
Galactic Halo ◽  
Observational Constraints ◽  
Galactic Halos ◽  
Tidal Disruption ◽  
Lyman Alpha ◽  
Hot Gas ◽  
General Stability ◽  
Luminous Galaxies ◽  
Two Component ◽  
The Stability

Our understanding of the Lyα forest has changed considerably following observations by HST and Keck. Lyα clouds at low redshifts (z < 1.7) observed by HST showed two unexpected features: Lanzetta et al. (1995) found that most luminous galaxies at such redshifts produce Lyα absorptions at mean impact parameter ~160h−1kpc, and established the association between Lyα clouds and galaxies. Ulmer (1996) pointed out the strong clustering of Lyα clouds in this redshift range. Motivated by the above, we propose a two-component protogalaxy model for the Lyα clouds based upon our previous work (Miyahata & Ikeuchi 1995). In our model, the Lyα clouds are stable cold clouds confined by the pressure of ambient hot gas in a galactic halo. We determine the properties of these cold clouds and hot gas on the basis of theoretical and observational constraints. We take into account the stability of a cold cloud in the galactic halo in addition to the general stability conditions in a two-component medium (e.g. Ikeuchi & Ostriker 1986), and compare the derived quantities of Lyα clouds in the galactic halo and in the intergalactic medium at both high and low redshifts. We conclude that the ciondition that a cloud is stable against both evaporation and tidal disruption by a hot galactic halo is very restrictive. In the most noteworthy example at z ~ 0.5, a pressure-confined, stable spherical Lyα cloud with NHI = 1014cm−2 cannot survive in the galactic halo, although much higher column density clouds of NHI = 1017cm−2 can. Miyahata & Ikeuchi (1997) discuss how these results constrain an alternative model for Lyα clouds associated with the galaxies observed by Lanzetta et al. (1995).

Study on Vinyl Ester Based Structural Anchor Adhesive for Fast, Low Temperature Cures

2014 ◽  
Vol 919-921 ◽  
pp. 2099-2104 ◽  
Author(s):  
Ben Wei Zhu ◽  
An Lin ◽  
Fu Xin Gan
Keyword(s):  
Low Temperature ◽  
Oxalic Acid ◽  
Heat Source ◽  
Vinyl Ester ◽  
High Performance ◽  
Vinyl Ester Resin ◽  
Chemical Heat ◽  
Two Component ◽  
Early Strength ◽  
The Stability

An high performance two-component structural anchor adhesive based on vinyl ester resin is synthesized by adding the toughener to improve the material brittleness and bringing in chemical heat source to reduce the affection of the environment on chemical reaction and it can be cured in the damp or in the environment with water by adding the water-absorbable filler.Compound stabilizer consisted of inhibitor and oxalic acid improve the stability of the pro-accelerated vinyl ester resin.The adhesive exhibites high-early-strength developing, excellent bong strength with “can’t dry”substrate and can cure rapid in lower temperature.it allows construction crews to install threaded rod or rebar in concrete that is too damp or soaked to bond with other adhesives.

scholarly journals Solitonic Solutions for Homogeneous KdV Systems by Homotopy Analysis Method

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Mohammed Ali ◽  
Marwan Alquran ◽  
Mahmoud Mohammad
Keyword(s):  
Homotopy Analysis Method ◽  
Stability Region ◽  
Analysis Method ◽  
Auxiliary Parameter ◽  
Analytical Treatment ◽  
Third Order ◽  
Kdv Equations ◽  
Two Component ◽  
Homotopy Analysis ◽  
The Stability

We study two-component evolutionary systems of a homogeneous KdV equations of second and third order. The homotopy analysis method (HAM) is used for analytical treatment of these systems. The auxiliary parameterhof HAM is freely chosen from the stability region of theh-curve obtained for each proposed system.

On the Equilibrium of Cavitation Nuclei in Liquid-Gas Solutions

1981 ◽  
Vol 103 (3) ◽  
pp. 425-430 ◽  
Author(s):  
Y. S. Cha
Keyword(s):  
Stable Equilibrium ◽  
Thermodynamic Theory ◽  
Phase System ◽  
Saturated Liquid ◽  
Theoretical Justification ◽  
Two Phase ◽  
System Pressure ◽  
Two Component ◽  
Cavitation Nuclei ◽  
The Stability

The stability of a spherical bubble in a two-component two-phase system is examined by employing the thermodynamic theory of dilute solutions. It is shown that a bubble can remain in a state of stable equilibrium provided that the ratio of the total number of moles of the solute to the total number of moles of the solvent in the system is not extremely small and that the system pressure falls between an upper bound (dissolution limit) and a lower bound (cavitation limit). The results of the analysis provide a theoretical basis for the persistence of microbubbles in a saturated liquid-gas solution. Thus to a certain extent, the results also help to resolve the dilemma that exists in the field of cavitation due to (1) the necessity of postulating the existence of microbubbles; and (2) the lack of theoretical justification for the persistence of such bubbles in a liquid.

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