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Search Results: 1 - 10 of 139050 matches for " Horák "
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Solution to the Technical Infrastructure and Economic-Mathematical Methods
Radek Horák
Transactions of the V?B - Technical University of Ostrava. Construction Series , 2010, DOI: 10.2478/v10160-010-0004-5
Abstract: The application of economic-mathematical methods is used to propose a solution to the technical infrastructure because both solving the technical infrastructure and using economic-mathematical methods require economical conducting operations. The proposals can include a lot of solutions but only the most efficient one can be put into practice. That is why the optimal solution to the underground utilities is being looking for.
Slavomír Horák
Obrana a Strategie , 2011,
Abstract: The article focuses on the analysis of the internal politics of Afghanistan after 2001 and evaluates the results of state- and nation-building. The emphasis on internal politics is the only possible way to understand the processes in the country and work out the strategy for the country after the planned withdrawal (or limitation) of foreign troops from the country. In this context, the fragmentation and deepening cleavages among various social strata in the country (ethnic, sub-ethnic) is considered to be a crucial determinant of the development in the country. Several power groups define diverse attitudes towards the character of the future Afghan state. These circumstances could lead to the new round of the military conflict after the removal of foreign troops which are considered as a negative factor by a large part of the Afghan elite, albeit they serve as one of the stabilization factors in the country. However, the international community has (and will have) limited tools and influence to prevent any prospective conflict in the country.
Numerical investigation of the smallest eigenvalues of the p-Laplace operator on planar domains
Ji?í Horák
Mathematics , 2011,
Abstract: The eigenvalue problem for the p-Laplace operator with p>1 on planar domains with the zero Dirichlet boundary condition is considered. The Constrained Descent Method and the Constrained Mountain Pass Algorithm are used in the Sobolev space setting to numerically investigate the dependence of the two smallest eigenvalues on p. Computations are conducted for values of p between 1.1 and 10. Symmetry properties of the second eigenfunction are also examined numerically. While for the disk an odd symmetry about the nodal line dividing the disk in halves is maintained for all the considered values of p, for rectangles and triangles symmetry changes as p varies. Based on the numerical evidence the change of symmetry in this case occurs at a certain value p_0 which depends on the domain.
Pathogenicity of Trichobilharzia spp. for Vertebrates
Lichtenbergová Lucie,Horák Petr
Journal of Parasitology Research , 2012, DOI: 10.1155/2012/761968
Abstract: Bird schistosomes, besides being responsible for bird schistosomiasis, are known as causative agents of cercarial dermatitis. Cercarial dermatitis develops after repeated contact with cercariae, mainly of the genus Trichobilharzia, and was described as a type I, immediate hypersensitivity response, followed by a late phase reaction. The immune response is Th2 polarized. Primary infection leads to an inflammatory reaction that is insufficient to eliminate the schistosomes and schistosomula may continue its migration through the body of avian as well as mammalian hosts. However, reinfections of experimental mice revealed an immune reaction leading to destruction of the majority of schistosomula in the skin. Infection with the nasal schistosome Trichobilharzia regenti probably represents a higher health risk than infections with visceral schistosomes. After the skin penetration by the cercariae, parasites migrate via the peripheral nerves, spinal cord to the brain, and terminate their life cycle in the nasal mucosa of waterfowl where they lay eggs. T. regenti can also get over skin barrier and migrate to CNS of experimental mice. During heavy infections, neuroinfections of both birds and mammals lead to the development of a cellular immune response and axonal damage in the vicinity of the schistosomulum. Such infections are manifest by neuromotor disorders. 1. Introduction Despite their worldwide distribution, avian schistosomes were neglected by parasitologists who assumed that they have no or minor pathogenic impact on birds or mammals, including humans. Nowadays, many studies focus on these parasites since it has been recognized that they can be severe pathogens of birds. Moreover, their larval stages (cercariae) frequently infect humans and cause cercarial dermatitis. The most reported agents of swimmer’s itch are cercariae of the genus Trichobilharzia [1]. Human infections by bird schistosomes are associated mostly with the development of cercarial dermatitis (swimmer’s itch), an allergic skin response, which develops after repeated contact with cercariae penetrating into the skin. For a long time, it was assumed that the reaction eliminated the majority of the schistosomes that had penetrated into the skin. However, the studies on mice infected experimentally with bird schistosomes showed that soon after the penetration, the cercariae transform to schistosomula. Under certain circumstances, these schistosomula are able to resist host immune response, escape from the skin, and migrate further to target organs [2, 3]. In mammals, bird schistosomes can
Specific Emissions of Harmful Substances from Small Boilers
Ochodek Tadeá?,Horák Ji?í
Acta Montanistica Slovaca , 1998,
Abstract: Coal is on of the most important energy source and its significance will increase in a future. In Czech republic coal is except else widely used as a fuel for combustion in a small boilers (up to 50 kW). Low efficiency of the small boilers which is often below 50% together with high emissions of the harmful substances into near surroundings cause in average 40 70% of total local air pollution. The research was performed in a scope of the Grant no. 101/98/0820 of Grant Agency of Czech Republic was focused on quality of combustion process related to combustion efficiency and creation of harmful substances at combustion of domestic fuels. Experiments were performed to compare combustion of brown coal, clack coal, coke and black coal slurry. Extremely high creation of harmful substances (CO, NOX, solid particles and organic substances) was measured when the black coal slurry was used as a fuel, measured in kg of emissions per GJ of burned fuel. Combustion of brown coal produced significant emissions of solid particles which bond harmful substances as metals, polyaromatic hydrocarbons and others) together with high emissions of SO2 . Strong dependence between emissions of CO and low quality of combustion given by low combustion temperature, shortage of combustion air, not suitable design of after-combustion chamber and short duration of fuel presence in a combustion area was found out. Emissions of wide range of metals were investigated. The results of the research grant project describe and explain the combustion process and creation of harmful substances in small boilers plus give suggestions and recommendations leading to rational operation of the small boilers and lowering their negative impact to environment.
Every Coin Has a Back Side: Invasion by Limnohabitans planktonicus Promotes the Maintenance of Species Diversity in Bacterial Communities
Karel Horňák, Gianluca Corno
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0051576
Abstract: One of the earliest challenges for ecologists has been to study the impact of invasive species on microbial communities. Although bacteria are fundamental in biological processes, current knowledge on invasion effects by aquatic non-pathogenic bacteria is still limited. Using pure cultures of diverse planktonic bacteria as model organisms at two different carbon concentration levels, we tested the response of an assembled community to the invasion by Limnohabitans planktonicus, an opportunistic bacterium, successful in freshwaters. The invader, introduced at the early stationary growth phase of the resident community, caused a strong decrement of the abundance of the dominant species. This was due to competition for nutrients and a potential allelopathic interaction. Simultaneously, resident species formerly unable to successfully compete within the community, thus potentially exposed to competitive exclusion, increased their abundances. The overall result of the invasion was preservation of species diversity, the higher the lower was the substrate content available. Our study provides new insights into bacterial invasions, offering an alternative interpretation of invasions for community ecology.
Erratum to “Pathogenicity of Trichobilharzia spp. for Vertebrates”
Lucie Lichtenbergová,Petr Horák
Journal of Parasitology Research , 2013, DOI: 10.1155/2013/721061
Lorentz forces caused by rotating magnetic field
Horáková K.,Fraňa K.
EPJ Web of Conferences , 2013, DOI: 10.1051/epjconf/20134501039
Abstract: Leading topic of this article is description of Lorentz forces in the container with cuboid shape. Inside of the container is an electrically conductive melt. Lorentz forces are caused by rotating magnetic field. Lorentz forces were calculated by analytic formula. This formula was derived for cylindrical container. Using this formula for cuboid container was assumed. Results were compared with Lorentz forces from CFD computing program NS-FEM3D. Areas of differences were recognized and displayed.
Malakofauna údolí Tiché Orlice Mollusc fauna of the Tichá Orlice River valley
Jan My?ák,Jitka Horá?ková
Malacologica Bohemoslovaca , 2011,
Abstract: Altogether, 78 terrestrial mollusc species were recorded on 31 plots in a stretch of the Tichá Orlice River valley between the cities Choceň and Letohrad (East Bohemia, Czech Republic) in 2007 and 2009. This region harbours 46% of the total terrestrial mollusc fauna of the Czech Republic. The fairly high species richness corresponds to a high habitat diversity and species pool of the region that includes Alpine and Carpathian elements. Of prime conservation importance is a high share of rare and endangered species (EN-2, VU-9, NT-14 species) and species mostly having an isolated population there from the main distribution range. This region is a real hotspot of forest gastropods in Transalpine Europe.
Měkky i eského lesa – IV. Nové údaje pro ji ní ást eského lesa Molluscs of the esky Les Mts. – IV. New data for the southern partof the esky Les Mts.
Jitka Horá?ková,Libor Dvo?ák
Malacologica Bohemoslovaca , 2008,
Abstract: Data on recent molluscan fauna in the southern part of the esky Les Mts., with additional data from the phytogeographic district of the Plzeňská Pahorkatina hills, are presented. Altogether, 63 species (62 species of Gastropoda and 1 species of Bivalvia) were recorded at 22 selected sites. The author‘s collecting activity was focused on ruderal sites and abandoned villages along the state border. There is spruce plantation dominating in the woodlands with scarce malacofauna. The common forest species dominate there, with the presence of montane and submontane elements, such as Clausilia cruciata, Vertigo substriata, and Discus ruderatus, which occur in the rest of preserved deciduous forests. The record of Atlantic Oxychilus alliarius species is the fifth known in Czech Republic. The montane snail of Clausilia cruciata was found at one site at very low altitude of 550 m a.s.l. A slug species Arion alpinus, never found in this area before, was recorded at five sites. Its occurrence here is the westernmost one in the Czech Republic. The elements of open habitats presented by xerotherm sites and open wetlands were not recorded, except for the species Vallonia costata and Vallonia excentrica occurring only at the ruins of abandoned villages and their surroundings.
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