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1592. Ageing of historical ceramics
- Creator:
- Vladimír Hanykýř, Koužková, Alexandra, Petr Bouška, and Miroslav Vokáč
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, historická keramika, historical ceramics, irreversible moisture expansion, fired roof tiles, dilatometric measurements, noncrystalline phase, 7, and 551
- Language:
- English
- Description:
- Irreversible moisture expansion of specimens made from porous ceramics of historical fired tiles is analysed here. Irreversible moisture expansion values, which reflect the rate of body ageing, were determined by heating at a temperature of 650 °C for 20 minutes and by repeated dilatometric measurement until a te mperature of 700 °C. To evaluate body ageing due to moisture expansion, it is necessary to specify the non-crystalline phase content. The causative factors influencing body ageing can be determined on bodies that have comparable non-crystalline phase content and are of similar chemical and mineralogical composition. Sufficient data set may facilitate a roughestimate of the age of historical ceramics., Vladimír Hanykýř, Alexandra Koužková, Petr Bouška and Miroslav Vokáč., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1593. Ageing related down-regulation of myocardial connexin-43 and up-regulation of MMP-2 may predict propensity to atrial fibrillation in experimental animals
- Creator:
- Nagibin, V., Egan Beňová, T., Viczenczová, C., Szeiffova Bacova, B., Ima Dovinová, Miroslav Barančík, and Narcisa Tribulová
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, aged heart, connexin-43, extracellular matrix, atrial fibrillation, 14, and 612
- Language:
- English
- Description:
- Mechanisms underlying atrial fibrillation (AF), the most common cardiac arrhythmia, particularly in aged population, are not fully elucidated. We have previously shown an increased propensity of old guinea pigs (GPs) heart to inducible AF when comparing to young animals. This study aimed to verify our hypothesis that susceptibility of aged heart to AF may be attributed to abnormalities in myocardial connexin-43 (Cx43) and extracellular matrix that affect cardiac electrical properties. Experiments were conducted on male and female 4-week-old and 24-week-old GPs. Atrial tissue was processed for analysis of Cx43 topology using immunohistochemistry, expression of Cx43 protein using immunobloting, and expression of mRNA of Cx43 and extracellular matrix metalloproteinase-2 (MMP-2) using real time PCR. Immunohistochemistry revealed uniform Cx43 distribution predominantly on lateral sides of the cardiomyocytes of young male and female GP atria. In contrast, non-uniform distribution, mislocalization and reduced immunolabeling of Cx43 were detected in atria of old GPs. In parallel, the atrial tissue levels of Cx43 mRNA were significantly decreased, while mRNA expression of MMP-2 was significantly increased in old versus young GPs. The changes were more pronounced in old GPs males comparing to females. Findings indicate that age-related down-regulation of atrial Cx43 and up-regulation of MMP-2 as well as disordered Cx43 distribution can facilitate development of AF in old guinea pig hearts., V. Nagibin, T. Egan Benova, C. Viczenczova, B. Szeiffova Bacova, I. Dovinova, M. Barancik, N. Tribulova., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1594. Ageing trajectory and longevity trade-off in an aphidophagous ladybird, Propylea dissecta (Coleoptera: Coccinellidae)
- Creator:
- Mishra, Geetanjali and Omkar
- Type:
- article, model:article, and TEXT
- Subject:
- Coccinellidae, age, ageing trajectory, fecundity, fertility, longevity, Propylea dissecta, and trade-off
- Language:
- English
- Description:
- The ageing trajectory (trend in ageing) and reproduction-longevity trade-off in both sexes of the ladybird Propylea dissecta were studied. The ageing trajectories of both sexes were investigated in terms of reproductive performance, using initial oviposition (egg laying within 24 h of mating) acting as an indicator of the effect of female age and initial viability (percentage of eggs laid within 24 h of mating that hatched) of the effect of male age. Ageing trends were sex dependent, with reproductive performance declining later in females than in males. Initial oviposition of females was largely age dependent and the initial viability of males was age dependent but less so than for females. There is a strong trade-off between number of matings and longevity. Statistical analyses reveal that this trade-off results from an early onset of mortality rather than an increase in mortality rate. A minimum lifespan was observed in this ladybird beyond which the longevity did not further decline.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1595. Agents of His Majesty :
- Creator:
- Král, Pavel,
- Type:
- text and studie
- Subject:
- Mezinárodní vztahy, světová politika, Jakub, povstání stavovská, vztahy anglicko-české, and diplomacie
- Language:
- English
- Rights:
- unknown
1596. Aggregation and survival of Neophilaenus albipennis (Hemiptera: Cercopidae) spittlebug nymphs
- Creator:
- Biedermann, Robert
- Type:
- article, model:article, and TEXT
- Subject:
- Aggregation, Neophilaenus albipennis, nymphs, spittlebug, survival, and vegetation structure
- Language:
- English
- Description:
- The nymphs of spittlebugs (Hemiptera, Cercopidae) are xylem-feeders and live on herbs, grasses or woody plants within their self-produced spittle masses. Nymphs of the spittlebug Neophilaenus albipennis live aggregated in these spittle masses on their host plant Brachypodium pinnatum, a common grass in dry grassland. The objective of this study was to estimate nymphal mortality rates and to examine what role aggregation and vegetation structure play in the mortality of the nymphs. The aggregation and mortality were measured using two different methods, direct monitoring and caging of nymphs. The nymphs passively aggregated with up to 4 nymphs per spittle and aggregation decreased with instar. The aggregation of the nymphs resulted in a reduced mortality in all instars. Although it has already been argued that aggregation may be an advantage, this study is the first direct evidence (i.e. direct measurement of single individuals) for the benefit of aggregation to individual spittlebug nymphs. Despite a clumped distribution of N. albipennis nymphs in tall vegetation, nymphal mortality was not correlated with vegetation height.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1597. Aggregation characteristics of three species of Coccinellidae (Coleoptera) at hibernation sites
- Creator:
- Honěk, Alois, Martinková, Zdeňka, and Pekár, Stano
- Type:
- article, model:article, and TEXT
- Subject:
- Coleoptera, Coccinellidae, Coccinella septempunctata, Ceratomegilla undecimnotata, Hippodamia variegata, overwintering, distribution, and hibernaculum
- Language:
- English
- Description:
- Adults of some coccinellid species overwinter in aggregations consisting of many individuals. They may clump because adults are attracted to particular environmental stimuli and/or of an innate tendency to join conspecific individuals. Aggregation behaviour was studied in Coccinella septempunctata L., which forms small clumps, and Ceratomegilla undecimnotata (Schneider) and Hippodamia variegata (Goeze), which form large clumps. Adults were recorded at five hilltop hibernacula (400-1500 m altitude) in central Europe (50-51°N, 14-16°E) for periods up to 27 years. The hibernacula occur in areas sparsely covered with isolated grass tussocks or completely with stones. Numbers of adults recorded under each of 300-900 stones or among the stems of the grass tussocks were counted every year at each hibernaculum. The degree of aggregation was determined using Taylor's power law. The coccinellid distributions became more aggregated and the size of the aggregations increased as their abundance increased, less in C. septempunctata than in the other two species. Aggregations formed even in the absence of prominent structures, which may attract immigrants, and even when unoccupied stones or tussocks suitable for overwintering were available. Aggregations may be established and their size limited by the strength of the intrinsic preference to join conspecifics. The supposed advantage of aggregated overwintering must be greater than the risk associated with the easy spread of diseases.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1598. Aggregation operators from the ancient NC and EM point of view
- Creator:
- Pradera, Ana and Trillas, Enric
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Non-Contradiction and Excluded-Middle principles, aggregation operators, and strong negations
- Language:
- English
- Description:
- This paper deals with the satisfaction of the well-known Non-Contradiction (NC) and Excluded-Middle (EM) principles within the framework of aggregation operators. Both principles are interpreted in a non-standard way, based on self-contradiction (as in Ancient Logic) instead of falsity (as in Modern Logic). The logical negation is represented by means of strong negation functions, and conditions are given both for those aggregation operators that satisfy NC/EM with respect to (w.r.t.) some given strong negation, as well as for those satisfying the laws w.r.t. any strong negation. The results obtained are applied to some of the most important known classes of aggregation operators.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1599. Aggregation operators on partially ordered sets and their categorical foundations
- Creator:
- Demirci, Mustafa
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- category theory, aggregation operator, associative aggregation operator, partially ordered groupoid, partially ordered semigroup, and partially ordered monoid
- Language:
- English
- Description:
- In spite of increasing studies and investigations in the field of aggregation operators, there are two fundamental problems remaining unsolved: aggregation of L-fuzzy set-theoretic notions and their justification. In order to solve these problems, we will formulate aggregation operators and their special types on partially ordered sets with universal bounds, and introduce their categories. Furthermore, we will show that there exists a strong connection between the category of aggregation operators on partially ordered sets with universal bounds (\textbf{Agop}) and the category of partially ordered groupoids with universal bounds (\textbf{Pogpu}). Moreover, the subcategories of \textbf{Agop} consisting of associative aggregation operators, symmetric and associative aggregation operators and associative aggregation operators with neutral elements are, respectively, isomorphic to the subcategories of \textbf{Pogpu} formed by partially ordered semigroups, commutative partially ordered semigroups and partially ordered monoids in the sense of Birkhoff. As a justification of the present notions and results, some relevant examples for aggregations operators on partially ordered sets are given. Particularly, aggregation process in probabilistic metric spaces is also considered.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1600. Aggression in reciprocal crosses of two subspecies of wild house mouse
- Creator:
- Volfová, Radka, Munclinger, Pavel, and Frynta, Daniel
- Type:
- article and TEXT
- Subject:
- wild mice, hybrid zone, social behaviour, hybrid advantage, and Y chromosome
- Language:
- English
- Description:
- We studied reciprocal hybrids of Mus musculus musculus and M. m. domesticus. These two subspecies of house mouse were found to differ in their social behaviour, the former being less aggressive than the latter. The paternal effect on aggression (observed repeatedly in laboratory mice) was not found. However, F2 generation mice were less aggressive than those from the F1 generation, and the maternal effect was also significant in a homogenous test set.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/