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28262. Vector invariant ideals of abelian group algebras under the actions of the unitary groups and orthogonal groups

Creator:
Zeng, Lingli and Nan, Jizhu
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
matematika, vektorová algebra, mathematics, vector algebra, vector invariant ideal, group algebra, unitary group, orthogonal group, 13, and 51
Language:
English
Description:
Let F be a finite field of characteristic p and K a field which contains a primitive pth root of unity and char K ≠ p. Suppose that a classical group G acts on the F-vector space V. Then it can induce the actions on the vector space \left [ V\bigoplus V \right ] and on the group algebra K\left [ V\bigoplus V \right ], respectively. In this paper we determine the structure of G-invariant ideals of the group algebra K\left [ V\bigoplus V \right ], and establish the relationship between the invariant ideals of K[V] and the vector invariant ideals of K\left [ V\bigoplus V \right ], and establish the relationship between the invariant ideals of K[V] and the vector invariant ideals of K\left [ V\bigoplus V \right ], if G is a unitary group or orthogonal group. Combining the results obtained by Nan and Zeng (2013), we solve the problem of vector invariant ideals for all classical groups over finite fields., Lingli Zeng, Jizhu Nan., and Obsahuje seznam literatury
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

28263. Věda - národ - dějiny /

Type:
text, katalogy výstav, and publikace jubilejní
Subject:
Věda. Všeobecnosti. Základy vědy a kultury. Vědecká práce, instituce vědecké, Akademie věd ČR, věda, umění, dějiny vědeckých institucí, vysokých škol, Československo 1918-1992, české země od r. 1993 do současnosti, and dějiny vědy, umění, kultury a techniky, kulturní vztahy
Language:
Czech and English
Description:
Název z obálky and Podnázev v tiráži: doprovodná publikace k výstavě
Rights:
unknown

28265. Vegetable oils used as vitamin E vehicle affect the electrical activity of rat heart

Creator:
Ozdemir, S., Ayaz, M., Tuncer, T., Ugur, M., and Turan, B.
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, vitamin E, fyziologie, physiology, action potential, corn oil, penaut oil, hazelnut oil, papillary muscle, atrial muscle, repolarization, 14, and 612
Language:
English
Description:
The aim of this study is to define the possible effects of vegetable oils used as vitamin E vehicle on the electrical activity of the rat heart. To test the possible effects of vitamin E vehicles we studied the effect of i.p. injected corn oil, hazelnut oil or peanut oil on the action potential parameters recorded in both papillary and left atrial muscle strips. Four experimental groups were used. The control group was injected (i.p.) with distilled water, while the three remaining groups received injections of corn oil, hazelnut oil, or peanut oil for five weeks (in a dose of 0.4 ml/kg/day - minimum amount of oil in which vitamin E could be dissolved). We used borosilicated (15-20 MΩ) capillary electrodes and intracellular action potentials (AP) were recorded in isolated papillary and left atrium muscle strips. While administration of three different types of vegetable oil had no significant effect on AP parameters of papillary muscle, they significantly prolonged the repolarization phase of AP in atrial strips. These results show that vegetable oils used as vitamin E vehicles may alter the electrical activity of the heart in a tissue-dependent manner. The present data indicate that the possible effect of vegetable oil vehicles should be kept in mind while evaluating the possible effects of in vivo vitamin E administration., S. Ozdemir, M. Ayaz, T. Tuncer, M. Ugur, B. Turan., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

28267. Vegetace Vltavského luhu na Šumavě a problém reliktních praluk

Creator:
Sádlo, Jiří and Bufková, Iva
Type:
article and TEXT
Subject:
phytosociology, historical botany, palynology, Early Holocene, refuges, grassland, woodland, secular succession, Vltava (Moldau) river, Šumava Mts, and Czech Republic
Language:
English
Description:
Nutrient-rich terrestric habitats form small areas in the peaty alluvial plain of upper stream of the Vltava river. Their vegetation consists of birch and grey alder alluvial woodland, willow and bridewort scrub and tall grassland of sedges, grasses and forbs. A hypothesis that this vegetation is an Early Holocene relic is presented. The relict origin is supported by recent dynamics of habitats and vegetation, findings of palynology, palaeoecology and history of land use, and by the analogical composition and history of relict vegetation of northernmost Europe. The refugial effect of the habitat is suggested by stable conditions on high temporal and spatial scales, and by permanent reclaiming of open gaps along the stream.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/

28268. Vegetation diversity of mesic meadows and pastures in the West Carpathians

Creator:
Rozbrojová, Zuzana, Hájek, Michal, and Hájek, Ondřej
Type:
article and TEXT
Subject:
hay meadow, mesic pasture, vegetation classification, vegetation diversity, and West Carpathians
Language:
English
Description:
A phytosociological study of the West Carpathian mesic hay meadows and pastures (order Arrhenatheretalia elatioris) was performed and is the first unified investigation into the vegetation diversity in the area, which is situated in three countries (Slovakia, Czech Republic and Poland). Because of the differences in the current classification systems used in different countries it was not possible to make a single selection of the Arrhenatheretalia relevés from the databases, so a data set containing relevés originally assigned to three orders encompassing this vegetation in hay meadows and pastures in the area (Arrhenatheretalia elatioris, Molinietalia and Nardetalia strictae) was established. This data set was classified using cluster analysis. Only the cluster corresponding to the order Arrhenatheretalia elatioris at the level of three clusters was further classified in the same way as the whole data set. The ecological interpretation of the classification was based on altitude, Ellenberg indicator values and geological bedrock. The clusters were also compared with the syntaxonomical assignment of the relevés by their authors. The classification at the level of 12 clusters reflected the most widespread vegetation types of mesicmeadows and pastures recorded in the area. The vegetation of extensive pastures, corresponding to the association Anthoxantho odorati-Agrostietum tenuis, seemed to be more similar in floristic composition to the mesic meadows of Arrhenatherion elatioris than to the intensive pastures of Cynosurion cristati, where it was traditionally classified, which has important conservation consequences because of the different position of these units in conservation systems such as Natura 2000. Higher altitude meadows were divided into four vegetation types including meadows corresponding to the association Gladiolo imbricati-Agrostietum capillaris, which is a frequent community in the Polish Carpathians that does not occur in the other regions. Montane meadows currently classified in Polygono bistortae-Trisetion flavescentis were less clearly distinguished, probably because of their patchy distribution in theWest Carpathians. The differences in vegetation diversity of meadows and pastures between particular countries were confirmed, with Gladiolo imbricati-Agrostietum capillaris occurring predominantly in the northern part of the West Carpathians and Anthoxantho odorati-Agrostietum tenuis virtually absent here. The ecological determinants of variation in montane meadows are discussed.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/

28269. Vegetation gradients in fishpond mires in relation to seasonal fluctuations in environmental factors

Creator:
Navrátilová, Jana and Navrátil, Josef
Type:
article and TEXT
Subject:
Central Europe, electrical conductivity, fen, fluctuation, mire veegtation, water pH, and water table
Language:
English
Description:
The composition of the vegetation of fishpond mires in the Třeboň Basin (Czech Republic) was studied in relation to temporal fluctuations in certain environmental factors. The water-table depth, water pH and electrical conductivity at 49 permanent plots were measured at approximately threeweek intervals from March to October 2003. Minimum, maximum, mean, median and variation in the above-mentioned environmental factors were correlated with vegetation composition. The most important environmental factors explaining the variation in vegetation were mean pH and maximum water-table level. Median conductivity increased with increase in waterlogging and eutrophication. Some seasonal trends in the dynamics of these parameters were observed. The lowest conductivity was in spring, increased continuously throughout summer and peaked in autumn. In contrast, water level decreased in summer, when evapotranspiration was greatest, and rose in autumn after heavy rainfall. The pH increased from March to June, then was stable and decreased at the end of summer. Seasonal trends were generally identical in all vegetation types. The fluctuations in the environmental factors were so considerable that they may influence the reliability of vegetation environmental analyses.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/

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