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4362. Compact elements in the lattice of varieties
- Creator:
- Ježek, J. and Slavík, V.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- variety, lattice, and compact element
- Language:
- English
- Description:
- We prove that the lattice of varieties contains almost no compact elements.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
4363. Compact embeddings of Besov spaces involving only slowly varying smoothness
- Creator:
- Caetano, Antonio, Gogatishvili, Amiran, and Opic, Bohumír
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Besov spaces with generalized smoothness, Lorentz-Karamata spaces, and compact embeddings
- Language:
- English
- Description:
- We characterize compact embeddings of Besov spaces $B^{0,b}_{p,r}(\mathbb {R}^n)$ involving the zero classical smoothness and a slowly varying smoothness $b$ into Lorentz-Karamata spaces $L_{p, q; \bar {b}}(\Omega )$, where $\Omega $ is a bounded domain in $\mathbb {R}^n$ and $\bar {b}$ is another slowly varying function.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
4364. Compact images of spaces with a weaker metric topology
- Creator:
- Yan, Peng-Fei and Lü, Cheng
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- sequence-covering mappings, sequentially-quotient mappings, compact mappings, and weaker metric topology
- Language:
- English
- Description:
- If $X$ is a space that can be mapped onto a metric space by a one-to-one mapping, then $X$ is said to have a weaker metric topology. \endgraf In this paper, we give characterizations of sequence-covering compact images and sequentially-quotient compact images of spaces with a weaker metric topology. The main results are that \endgraf (1) $Y$ is a sequence-covering compact image of a space with a weaker metric topology if and only if $Y$ has a sequence $\{\mathcal F_i\}_{i\in \mathbb N}$ of point-finite $cs$-covers such that $ {\bigcap _{i\in \mathbb N}}\mathop{\rm st} (y,\mathcal F_i)=\{y\}$ for each $y\in Y$. \endgraf (2) $Y$ is a sequentially-quotient compact image of a space with a weaker metric topology if and only if $Y$ has a sequence $\{\mathcal F_i\}_{i\in \mathbb N}$ of point-finite $cs^*$-covers such that ${\bigcap _{i\in \mathbb N}}\mathop{\rm st} (y,\mathcal F_i)=\{y\}$ for each $y\in Y$.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
4365. Companion to Central and Eastern European Humanism, Volume 2 Czech Lands, Part 1. Storchová, Lucie (ed.)
- Creator:
- Sladká, Veronika
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4366. Comparaison mondiale des pendules: fractionnaire
- Creator:
- Nušl, František
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- astronomy and pendulum
- Language:
- Czech
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
4367. Comparative analysis of drought stress effects on photosynthesis of Eurasian and North African genotypes of wild barley
- Creator:
- Jedmowski, C., Brüggemann, W., and Bayramov, S.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, ječmen, photosynthesis, barley, Hordeum, Calvin cycle, chlorophyll fluorescence, JIP-test, performance index, photosynthetic CO2 assimilation, drought stress, Hordeum spontaneum, 2, and 581
- Language:
- Multiple languages
- Description:
- The impact of drought stress (DS) on eight Eurasian and North African genotypes of wild barley (Hordeum spontaneum) was evaluated by analysis of chlorophyll (Chl) a fluorescence fast induction curves using the JIP-test. Three-week-old, pot-grown plants were exposed to a DS treatment by withholding water for nine days. The genotype-specific impairment of the functionality of the photosynthetic electron transport chain was quantified using the relative decline of the performance indices (PIabs and PItot), two key parameters of the JIP-test. The genotypes showing the highest (HOR10164) and lowest (HOR10710) relative PIs under DS were subjected to additional experiments, including measurements of leaf gas exchange, water status, pigment content, key enzyme activity, and protein abundance. The genotypes showed a specific profile of DS-mediated inhibition of photosynthesis, associated with higher relative leaf water contents in HOR10164 at the end of the treatment. Whereas decreased photosynthetic rate in HOR10164 was mainly caused by stomatal closure, nonstomatal limitations (decreased Rubisco content and activity) were detected in HOR10710. Additional genotype specific features were the upregulation of the NADP-malate dehydrogenase in HOR10164 and a decreased fraction of QA-reducing reaction centers in HOR10710., C. Jedmowski, S. Bayramov, W. Brüggemann., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4368. Comparative analysis of quality metrics for community detection in social networks using genetic algorithm
- Creator:
- Kaur, S., Singh, S., Kaushal, S., and Sangaiah, A. K.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- community detection, social network, optimization, objective function, genetic algorithm, and Néormalized mutual information
- Language:
- English
- Description:
- Web 2.0 has led to the expansion and evolution of web-based communities that enable people to share information and communicate on shared platforms. The inclination of individuals towards other individuals of similar choices, decisions and preferences to get related in a social network prompts the development of groups or communities. The identification of community structure is one of the most challenging task that has received a lot of attention from the researchers. Network community structure detection can be expressed as an optimisation problem. The objective function selected captures the instinct of a community as a group of nodes in which intra-group connections are much denser than inter-group connections. However, this problem often cannot be well solved by traditional optimisation methods due to the inherent complexity of network structure. Therefore, evolutionary algorithms have been embraced to deal with community detection problem. Many objective functions have been proposed to capture the notion of quality of a network community. In this paper, we assessed the performance of four important objective functions namely Modularity, Modularity Density, Community Score and Community Fitness on real-world benchmark networks, using Genetic Algorithm (GA). The performance measure taken to assess the quality of partitions is NMI (Normalized mutual information). From the experimental results, we found that the communities' identified by these objectives have different characteristics and modularity density outperformed the other three objective functions by uncovering the true community structure of the networks. The experimental results provide a direction to researchers on choosing an objective function to measure the quality of community structure in various domains like social networks, biological networks, information and technological networks.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
4369. Comparative analysis of tryptophan oxygenase activity and glucocorticoid receptor under the influence of insulin
- Creator:
- Isenović, Esma R., Zakula, Z., Koricanac, G., and Ribarac-Stepić, N.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Biochemie. Molekulární biologie. Biofyzika, molekulární genetika, glukokortikoidy, inzulín, tryptofan, molecular genetics, glucocorticoids, insulin, tryptophan, stability of glucocorticoid-receptor complex, tryptophan oxygenase, 2, and 577
- Language:
- English
- Description:
- This investigation addresses the interaction of insulin (INS) and glucocorticoid (GC) signaling in the hepatic regulation of tryptophan oxygenase (TO) enzyme activity in the rat. Male Wistar rats (200-250 g b.w) received an injection of the different doses of INS (10, 25, 50, 70 and 100 μg/200 g b.w., i.p.) and were used for experiments 3 h and 18 h after INS administration. This study shows that maximum of TO activity was found at dose of 50 μg of INS with peak increases observed at 3 h and 18 h after injection of INS, while INS had no effect on TO activity in adrenalectomized rats. The analysis of INS effects on glucocorticoid receptor-complex (GC/GR complex) stability shows that complexes from INS-treated rats are less stable than those from control animals. In addition, INS-stimulated stability of glucocorticoid receptor (GR) protein was significantly increased from the controls. Furthermore, the results show that GC/GR complexes from INS-treated rats could be activated and accumulated at higher rate in cell nuclei of control animals. These data support the involvement of INS in modulation of GC signaling pathway which mediates, in part, the activity of TO., E. R. Isenović, Z. Zakula, G. Koricanac, N. Ribarac-Stepić., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4370. Comparative analysis of ultrastructure, antioxidant enzyme activities, and photosynthetic performance in rice mutant 812HS prone to photooxidation
- Creator:
- Ma, J., Lv, C. F., Zhang, B. B., Wang, F., Shen, W. J., Chen, G. X., Gao, Z. P., and Lv, C. G.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- obecná botanika, bílkoviny, general botany, proteins, malondialdehyde, photophosphorylation, reactive oxygen species, 2, and 581
- Language:
- Multiple languages
- Description:
- Under optimal conditions, most of the light energy is used to drive electron transport. However, when the light energy exceeds the capacity of photosynthesis, the overall photosynthetic efficiency drops down. The present study investigated the effects of high light on rice photooxidation-prone mutant 812HS, characterized by a mutation of leaf photooxidation 1 gene, and its wild type 812S under field conditions. Our results showed no significant difference between 812HS and 812S before exposure to high sunlight. However, during exposure to high light, shoot tips of 812HS turned yellow and their chlorophyll (Chl) content decreased. Transmission electron microscopy showed that photooxidation resulted in significant damage of chloroplast ultrastructure. It was confirmed also by inhibited photophosphorylation and reduced ATP content. The decreased coupling factor of ATP, Ca2+-ATPase and Mg2+-ATPase activities also verified these results. Further, significantly enhanced activities of antioxidative enzymes were observed during photooxidation. Malondialdehyde, hydrogen peroxide, and the superoxide generation rates also increased. Chl a fluorescence analysis found that the performance index and maximum quantum yield of PSII declined on August 4, 20 days after high-light treatment. Net photosynthetic rate also decreased and substomatal CO2 concentration increased in 812HS at the same time. In conclusion, our findings indicated that excessive energy triggered the production of toxic reactive oxygen species and promoted lipid peroxidation in 812HS plants, causing severe damage to cell membranes, degradation of photosynthetic pigments and proteins, and ultimately inhibition of photosynthesis., J. Ma, C. F. Lv, B. B. Zhang, F. Wang, W. J. Shen, G. X. Chen, Z. P. Gao, C. G. Lv., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public