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30052. Positioned agents in eco-grammar systems with border markers and pure regulated grammars
- Creator:
- Langer, Miroslav and Kelemenová, Alica
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- positioned eco-grammar systems, bordered positioned eco-grammar systems, and pure regulated grammars with appearance checking
- Language:
- English
- Description:
- In this paper we follow our previous research in the field of positioned agents in the eco-grammar systems and pure grammars. We extend model of the positioned eco-grammar systems by boundary markers and we introduce bordered positioned eco-grammar systems (BPEG systems, for short) and that way we show one of the possible answers to the question stated in \cite{jou}. Namely we compare generative power of the BPEG systems with three types of pure regulated grammars with appearance checking.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
30053. Positioning ot the NOR-bearing chromosomes in relation to nucleoli in daughter cells after mitosis
- Creator:
- Markéta Kalmárová, Evgeny Smirnov, Lubomír Kováčik, Alexey Popov, and Ivan Raška
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Buněčná biologie. Cytologie, fyziologie, chromozomy, buněčná jádra, physiology, chromosomes, cell nuclei, chromosome positioning, Nucleolus Organizer Regions (NORs), daughter cells, 2, and 576
- Language:
- English
- Description:
- It is known that chromosomes occupy non-random positions in the cell nucleus. However, it is not clear to what extent their nuclear positions, together with their neighborhood, are conserved in daughter cells. To address specific aspects of this problem, we used the model of the chromosomes carrying ribosomal genes that are organized in clusters termed Nucleolus Organizer Regions (NORs). We compared the association of chosen NOR-bearing chromosomes (NOR-chromosomes) with nucleoli, as well as the numbers of nucleoli, in the pairs of daughter cells, and established how frequently the daughter cells had equal numbers of the homologs of certain NOR-chromosomes associated with individual nucleoli. The daughter cells typically had different numbers of nucleoli. At the same time, using immuno-FISH with probes for chromosomes 14 and 15 in HeLa cells, we found that the cell pairs with identical combinations appeared significantly more frequently than predicted by the random model. Thus, although the total number of chromosomes associated with nucleoli is variable, our data indicate that the position of the NOR-bearing chromosomes in relation to nucleoli is partly conserved through mitosis., M. Kalmárová, E. Smirnov, L. Kováčik, A. Popov, I. Raška., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
30054. Positive (?) Social Consequences of Gating
- Creator:
- Youssef, Karim W. F.
- Type:
- article, model:article, and TEXT
- Subject:
- gating, social capital, neighbourhood cohesion, and social sustainability
- Language:
- English
- Description:
- The social consequence of gating have been generally characterized as negative, particularly in regards to raising issues of social injustice such as the privatization of space, estrangement, and segregation. Some authors have found positive social consequences of gating particularly in regard to reducing the scale of segregation and promoting social interdependency as a form of social integration as well as encouraging neighbourhood cohesion and maintaining social capital. The following is a critical review of the positive consequences of gating within the overall trend of commodification of community in new residential developments.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
30055. Positive allosteric modulator of mGluR4 PHCCC exhibits proconvulsant action in three models of epileptic seizures in immature rats
- Creator:
- Szczurowska, E. and Pavel Mareš
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, metabotropic glutamate receptor 4, epileptic seizures, rat, ontogeny, 14, and 612
- Language:
- English
- Description:
- The activation of metabotropic glutamate receptors subtype 4 (mGluR4) potentiates models of absence seizures in adult rats. These seizures are age-dependent, but data concerning the role of mGluR4 in immature brain is insufficient. N-phenyl-7- (hydroxyimino)cyclopropa[b]chromen-1acarboxamide (PHCCC), which is a positive allosteric modulator of these receptors, was used in three different models of seizures in immature rats: 1) convulsions induced by high doses of pentetrazol (PTZ; a model of generalised tonic-clonic seizures); 2) rhythmic electroencephalographic (EEG) activity induced by low doses of PTZ (a model of absence seizures); and 3) electrically elicited cortical afterdischarges (ADs, a model of myoclonic seizures). We administered four doses of PHCCC (1, 3, 10 and 20 mg/kg) in PTZ-induced convulsions and two doses (3 and 10 mg/kg) in the two electrophysiological models of freely moving rats with implanted electrodes. Every dose and age group consisted from 8 to 10 rats. PTZ-elicited convulsions were not significantly influenced by PHCCC. In contrast, PHCCC potentiated the effect of a subconvulsant dose (60 mg/kg) of PTZ. The 10-mg/kg dose of PHCCC significantly prolonged the duration of PTZ-induced rhythmic activity episodes and shortened the intervals between individual episodes in 25-day-old rats (P25). In contrast, this potentiation was not seen in P18 rats. Cortical ADs were significantly prolonged with repeated stimulations by both doses of PHCCC in P12 and P18 animals. P25 rats exhibited only slightly longer AD durations. In conclusion, we did not find any anticonvulsant effect of PHCCC. On the contrary, proconvulsant action was demonstrated in all three models in immature rats., E. Szczurowska, P. Mareš., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
30056. Positive effect of oral supplementation with glycosaminoglycans and antioxidants on the regeneration of osteochondral defects in the knee joint
- Creator:
- Milan Handl, Evžen Amler, Bräun, K., Holzheu, J., Tomáš Trč, Imhoff, A. B., Lytvynets, A., Elena Filová, Hana Kolářová, Arnošt Kotyk, and Václav Martínek
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Patologie. Klinická medicína, experimentální medicína, chrupavka, experimental medicine, cartilage, glycosaminoglycans, oral supplementation, osteochondral lesion, 14, and 616
- Language:
- English
- Description:
- The effect of oral supplementation with glycosaminoglycans (GAG) and radical scavengers (vitamin E/selenium) on the regeneration of osteochondral defects was investigated in rabbits. After introduction of defined osteochondral defects in the knee joint, groups of ten animals were given a GAG/vitamin E/selenium mixture or a placebo (milk sugar) for 6 weeks. Following sacrifice, histological and histochemical analysis was performed. The amount of synovial fluid was increased in the placebo group, while the viscosity of the synovial fluid was significantly enhanced in the GAG group. The amount of sulfated GAG in the osteochondral regenerates (8.8±3.6 % vs. 6.0±5.6 %; p<0.03) was significantly higher in the GAG group. In both groups, the GAG amount in the cartilage of the operated knee was significantly higher than in the non-involved knee (p<0.05). Histological analysis of the regenerates in the GAG group was superior in comparison with the placebo group. For the first time, a biological effect following oral supplementation with GAG was demonstrated in healing of osteochondral defects in vivo. These findings support the known positive clinical results., M. Handl, E. Amler, K. Bräun, J. Holzheu, T. Trč, A. B. Imhoff, A. Lytvynets, E. Filová, H. Kolářová, A. Kotyk, V. Martínek., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
30057. Positive effects of different drug forms of silybin in the treatment of metabolic syndrome
- Creator:
- Poruba, M., Zuzana Matušková, Ludmila Kazdová, Olena Oliyarnyk, Hana Malínská, Igor Tozzi di Angelo, and Rostislav Večeřa
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, hyperglykémie, hyperlipidémie, hyperglycemia, hyperlipidemia, HHTg rats, metabolic syndrome, silybin, 14, and 612
- Language:
- English
- Description:
- Silymarin and silybin are widely used for their hepatoprotective properties. Our previous studies confirm positive effect of silymarin on lipoprotein profile and lipid homeostasis. Advanced drug forms may improve the bioavailability of these compounds. In this study, we investigate the effects of silybin in different drug forms (standardized silybin, micronized silybin, and silybin in form of phytosomes) on dyslipidemia and glucose metabolism in hereditary hypertriglyceridemic (HHTg) rats. Male HHTg rats were divided into four groups of seven animals and were fed by experimental diets. Silybin significantly decreased serum level of triglycerides in groups of rats fed by standardized silybin and silybin in form of phytosomes compared to control group. Results show that silybin did not affect the total cholesterol level, but significantly increased the levels of HDL cholesterol in all groups of animals. Silybin in a standardized form had the highest hypotriglyceridemic effect. On the other hand, the micronized form has caused the highest increase of protective HDL and most significantly decreased glucose and insulin levels. Our results suggest that silybin is probably responsible for some positive properties of silymarin. Subsequent dose-dependent studies of silybin action may reveal the intensity of its positive effects on lipid and glucose parameters., M. Poruba, Z. Matušková, L. Kazdová, O. Oliyarnyk, H. Malínská, I. Tozzi di Angelo, R. Večeřa., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
30058. Positive fixed point theorems arising from seeking steady states of neural networks
- Creator:
- Wang, Gen-Qiang and Cheng, Sui Sun
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- positive fixed point, neural network, periodic solution, difference equation, discrete boundary condition, and critical point theory
- Language:
- English
- Description:
- Biological systems are able to switch their neural systems into inhibitory states and it is therefore important to build mathematical models that can explain such phenomena. If we interpret such inhibitory modes as `positive' or `negative' steady states of neural networks, then we will need to find the corresponding fixed points. This paper shows positive fixed point theorems for a particular class of cellular neural networks whose neuron units are placed at the vertices of a regular polygon. The derivation is based on elementary analysis. However, it is hoped that our easy fixed point theorems have potential applications in exploring stationary states of similar biological network models.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
30059. Positive periodic solutions of $N$-species neutral delay systems
- Creator:
- Hui
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- positive periodic solutions, existence, and neutral delay system
- Language:
- English
- Description:
- In this paper, we employ some new techniques to study the existence of positive periodic solution of $n$-species neutral delay system \[ N^{\prime }_i(t)=N_i(t)\biggl [a_i(t)-\sum _{j=1}^n\beta _{ij}(t)N_j(t)- \sum _{j=1}^nb_{ij}(t)N_j(t-\tau _{ij}(t))-\sum _{j=1}^nc_{ij}(t) N^{\prime }_j(t-\tau _{ij}(t))\biggr ]. \] As a corollary, we answer an open problem proposed by Y. Kuang.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
30060. Positive periodic solutions of a neutral functional differential equation with multiple delays
- Creator:
- Li, Yongxiang and Liu, Ailan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- neutral delay differential equation, positive periodic solution, cone, and fixed point index
- Language:
- English
- Description:
- This paper deals with the existence of positive ω-periodic solutions for the neutral functional differential equation with multiple delays (u(t) − cu(t − δ))′ + a(t)u(t) = f(t, u(t − τ1), . . . , u(t − τn)). The essential inequality conditions on the existence of positive periodic solutions are obtained. These inequality conditions concern with the relations of c and the coefficient function a(t), and the nonlinearity f(t, x1, . . . , xn). Our discussion is based on the perturbation method of positive operator and fixed point index theory in cones.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public