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44262. Variants of learning algorithm based on Kolmogorov theorem
- Creator:
- Neruda, Roman, Arnošt, Štědrý, and Drkošová, Jitka
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Kolmogorov networks, approximation theory, and parallel algorithms
- Language:
- English
- Description:
- A thorough analysis of theoretical and computational properties of Kolmogorov learning algorithm for feedforward neural networks lead us to proposal of efficient sequential and parallel impleinentation. A novel approach to parallelization is presented which combines our previous rcsnlts in order to achieve higher parallel speed-up.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
44263. Variation in CDKAL1 gene is associated with therapeutic response to sulphonylureas
- Creator:
- Zbynek Schroner, Martin Javorský, Halušková, J., Klimčáková, L., Babjaková, E., Fabianová, M., Slabá, E., Kozárová, M., and Ivan Tkáč
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, pharmacogenetics, sulphonylureas, CDKAL1, glycemic control, type 2 diabetes, 14, and 612
- Language:
- English
- Description:
- The aim of the present pilot pharmacogenetic study was to analyse quantitative effects of sulphonylurea treatment in addition to metformin on parameters of glycemic control with respect to CDKAL1 genotypes in patients with type 2 diabetes. Effect of 6-month sulphonylurea therapy on glycemic control according to CDKAL1 genotypes was evaluated in 101 patients with type 2 diabetes who failed to achieve glycemic control on metformin monotherapy. CDKAL1 rs7756992 polymorphism was determined by melting curve analysis of small amplicon following real-time PCR. After sulphonylurea treatment fasting plasma glucose (FPG) levels were significantly different (p=0.045) among three CDKAL1 genotype groups (AA: n=49; AG: n=36; GG: n=16). In a dominant genetic model, carriers of the G-allele (AG+GG, n=52) achieved significantly lower FPG levels in comparison with patients with the AA genotype (6.90±1.08 vs. 7.48±1.12 mmol/l, p=0.013). Consequently, adjusted ΔFPG was significantly higher in the AG+GG compared to the AA group (1.48±1.51 vs. 1.02±1.33 mmol/l, p=0.022). Similar trend was observed for HbA1c levels, but the difference between the genotype groups did not reach the level of statistical significance. Relatively small number of included patients is a limitation of the present study. In conclusion, our results suggest that the magnitude of FPG reduction after 6-month sulphonylurea treatment in patients with type 2 diabetes is related to the variation in CDKAL1., Z. Schroner ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
44264. Variation in dung beetle (Coleoptera: Scarabaeoidea) assemblages with altitude in the Bulgarian Rhodopes Mountains: A comparison
- Creator:
- Lobo, Jorge M., Chehlarov, Evgeni, and Guéorguiev, Borislav
- Type:
- article, model:article, and TEXT
- Subject:
- Dung beetles, Scarabaeoidea, altitudinal variation, Rhodopes Mountains, European mountain assemblages, and species richness
- Language:
- English
- Description:
- Variation with altitude in the composition of dung beetle assemblages and species richness was measured by sampling in spring, summer and autumn, both manually and with pitfall traps at twelve localities in the western Rhodopes Mountains. Non-parametric estimates indicate that most of the regional species pool was collected, some 73% of all taxa previously recorded in the entire region. The rate of species richness decrease with altitude is around 11 species per km, with an evident altitudinal change in the incidence of two main dung beetle functional groups in which Aphodiinae species begin to dominate Rhodopes assemblages at around 1400-1500 m. Species richness of dung pats is dominated by Scarabaeinae in spite of the fact that the number of Aphodiinae species is highest at each locality. Thus, Aphodiinae species are the main contributors to both local and regional pool richness and to species turnover between localities. These characteristics are similar to those observed in the assemblages from another European mountain range, also located near the Mediterranean-Eurosiberian boundary, the Iberian Central System. These results suggest that eastern European dung beetle assemblages are similar in compositional turnover and species richness variation with altitude to that observed in western Europe and North America.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
44265. Variation in male and female mating behaviour among different populations of the two-spot ladybird, Adalia bipunctata (Coleoptera: Coccinellidae)
- Creator:
- Haddrill, Penelope R., M. E. N. Majerus, and Shuker, David M.
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, zoologie, entomologie, Coccinellidae, Adalia, mating behaviour, sexual selection, two-spot ladybird, UK population, Russian population, 2, and 59
- Language:
- English
- Description:
- nvestigating the function of both male and female mating behaviours is essential in our attempts to understand the evolution of mating systems. Variation in mating behaviours among different populations within a species provides a useful opportunity to explore how behaviours may co-vary, although comparative studies are still rather few in number. Population variation in mating behaviour may also have important implications in terms of the evolution of reproductive isolation, the distribution of genetic diversity within and between populations, and the associated ability of those populations to adapt. Here we consider male and female mating behaviour in two populations of the two-spot ladybird, Adalia bipunctata, from the UK and Russia. We find that male and female mating behaviours differ between the populations in terms of the length of female rejection behaviour and the duration of mating, and that this variation is independent of which population an individual's mating partner is from. Our data confirm that patterns of sexual selection and reproductive behaviour are likely to vary across populations in the two-spot ladybird. The extent to which this variation is due to current ecological factors or population history remains to be verified for this species, as for many others., Penelope R. Haddrill, Michael E.N. Majerus, David M. Shuker., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
44266. Variation in parameters affecting risk of human disease due to TBE virus
- Creator:
- Korenberg, E. I. and Kovalevskii, Yu V.
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- tick-borne encephalitis, Ixodes persulcatus, and risk of infection
- Language:
- English
- Description:
- To rank variables affecting risk of human disease due to tick-borne encephalitis (TBE) virus in the Russian Far East, we compared annual changes in ( 1 ) frequency of human contact with vector ticks, (2) prevalence of infection in the tick population and (3) quantity of virus present infected ticks. Sites were sampled uniformly over a 4-year period in a forested region where Ixodes persulcatus serves as the principle vector. The questing density of ticks on vegetation remained relatively constant during the course of this study. The frequency of contacts of the local human population with ticks carrying different doses of the TBE virus was changeable. The rate of TBE infection of humans in the study site corresponded to that of human contacts with highly infected ticks. The density of highly infected ticks represents the principal parameter for determining potential epidemiological significance of a natural TBE focus.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
44267. Variation in teeth number, teeth and skull disorders in Eurasian lynx, Lynx lynx from Croatia
- Creator:
- Gomerčić, Tomislav, Gužvica, Goran, Đuras Gomerčić, Martina, Frković, Aloizije, Pavlović, Dubravka, Kusak, Josip, Sindičić, Magda, and Huber, Đuro
- Type:
- article and TEXT
- Subject:
- skull, congenitally absent teeth, supernumerary teeth, and reintroduced lynx
- Language:
- English
- Description:
- The last specimens of indigenous Eurasian lynx (Lynx lynx) in Croatia were exterminated around year 1903. Lynx dispersed back to Croatia after six animals were reintroduced to Slovenia from Slovakia in 1973. Considering the consequences of founder effect, genetic drift and expected high level of homozygosity, the goal of this paper was to determine variation in teeth number, teeth and skull disorders in Croatian lynx. It should also determine whether there has been a change in frequency of occurrence of developmental anomalies in relation to the population it originates from and in relation to other lynx populations. We studied 58 lynx skulls originating from the reintroduced lynx population. Changes on teeth and skull were found on 23 skulls (39.7%): supernumerary maxillary second premolar P2 (9 skulls, 15.5%), supernumerary mandibular second molar M2 (3 skulls, 5.2%), congenitally absent maxillary incisor (3 skulls, 6.9%), extra tooth between maxillary third incisor I3 and canine (1 skull, 1.7%) and acquired disorders of teeth and skull (9, 15.5%).
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/
44268. Variation in the colour of the necrophagous fly, Prochyliza nigrimana (Diptera: Piophilidae): A case of seasonal polymorphism
- Creator:
- Martín-Vega, Daniel and Baz, Arturo
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, entomologie, melanism, seasonal polymorphism, Piophilidae, Prochyliza nigrimana, 2, and 59
- Language:
- English
- Description:
- The occurrence of colour polymorphism in wild populations of the necrophagous fly Prochyliza nigrimana (Diptera: Piophilidae) is recorded but never treated in detail. The present paper shows that there is a seasonal distribution in the morphotypes, with the dark morphs emerging in spring and pale morphs emerging later and most abundant in summer. Furthermore, different proportions of each morph occur along altitudinal gradients, with dark morphs significantly more abundant at low altitudes, where mean temperatures are warmer than at high altitudes where the pale coloured morphs were more abundant. Explanations based on the adaptive value of thermal melanism are discussed. and Daniel Martín-Vega, Arturo Baz.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
44269. Variation in the Melampyrum sylvaticum group in the Carpathian and Hercynian region
- Creator:
- Těšitel, Jakub, Malinová, Tamara, Štěch, Milan, and Herbstová, Miroslava
- Type:
- article and TEXT
- Subject:
- Carpathians, geometric morphometrics, haplotype lineage, Melampyrum, molecular variation, phylogeography, and refuge
- Language:
- English
- Description:
- We investigated variation in the Melampyrum sylvaticum group in the Carpathian and Hercynian regions using morphological and molecular tools. The aim of our study was to examine differences in the pattern of variation between the Eastern Carpathians and region of theWestern Carpathians and the Hercynian Massif. We also tested correlations between putatively taxonomically important variation in corolla colour present in the Melampyrum sylvaticum group in the Eastern Carpathian region and other morphological and molecular traits. Samples were collected from populations of the M. sylvaticum group in the Hercynian Massif and the Eastern and Western Carpathians. Morphometric analyses of the size and shape of the corolla (based on thin plate spline with sliding semilandmarks), length of the anthers and especially molecular analyses based on sequencing the nuclear ITS and trnL-trnT regions of chloroplast DNA, confirmed that the populations occurring on the opposite sides of the Eastern-Western Carpathian biogeographic boundary are very different. It is likely that the eastern and western lineages have been isolated for a long time and the extant pattern of variation with character disagreement within the border zone, originated from hybridization and introgression. The differences in corolla colour did not coincide with the variation in morphological traits or molecular markers within the North-Eastern Carpathian region. In addition, the geographical distribution of the populations with contrasting corolla colours lacked any pattern and there are populations with both corolla colours as well as plants with transitional pale-yellow flowers. Therefore, it is suggested that M. saxosum and M. herbichii, microspecies delimited on the basis of corolla colour, are conspecific. The high level of molecular variation and its pattern indicate that the M. sylvaticum group may have survived in or near the Eastern Carpathians during the Weichselian Ice Age. This hypothesis is supported by several recent phytogeographical and palaeoecological studies, which indicate the existence of a glacial refuge in the Eastern Carpathian region. Molecular uniformity of theWestern Carpathian and Hercynian populations might in contrast indicate recent (Holocene) migration from assumed perialpine refuges.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/
44270. Variation in the morphology of the wings of the endangered grass-feeding butterfly Coenonympha oedippus (Lepidoptera: Nymphalidae) in response to contrasting habitats
- Creator:
- Jugovic, Jure, Zupan, Sara, Bužan, Elena, and Čelik, Tatjana
- Format:
- print, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- motýli, babočkovití, křídla (zoologie), adaptace (biologie), butterflies, Nymphalidae, wings (zoology), adaptation (biology), Lepidoptera, Coenonympha oedippus, False Ringlet, classical morphometrics, geometric morphometrics, environmental heterogeneity, 2, and 59
- Language:
- English
- Description:
- At the southern limit of its range the endangered butterfly Coenonympha oedippus inhabits grasslands (wet, dry) that differ significantly in the abundance of its larval hostplants (wet > dry) and mean annual air temperature (wet < dry). We determined the difference in the wing morphology of individuals in the two contrasting habitats to test whether and how traits associated with wing size, shape and eye like spots vary in the sexes and two ecotypes. We show that sexual dimorphism follows the same (wing size and shape, number of eyespots on forewing) or different (relative area of eyespots on hindwings) patterns in the two contrasting habitats. Irrespective of ecotype, females had larger, longer and narrower wings, and more forewing eyespots than males. Sexual dimorphism in the relative area of eyespots on hindwing was female-biased in the wet, but male-biased in the dry ecotype. Ecotype dimorphism in wing size and the relative area of eyespots on the hindwing is best explained by mean annual air temperature and abundance of host-plants. While ecotype dimorphism in wing size did not differ between sexes, neither in direction (wet > dry) or in degree, in the two sexes the relative area of eyespots on hindwing had opposite patterns (males: dry > wet; females: wet > dry) and was more pronounced in males than in females. The differences in wing shape between ecotypes were detected only in the hindwings of males, with more rounded apex in the dry than in the wet ecotype. We discuss the life-history traits, behavioural strategies and selection mechanisms, which largely account for the sex- and ecotype-specific variation in wing morphology., Jure Jugovic, Sara Zupan, Elena Bužan, Tatjana Čelik., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public