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693. A Study of Mechanisms Involved in Vasodilatation Induced by Resveratrol in Isolated Porcine Coronary Artery

Creator:
Li, H. -F., Tian, Z.-F., Qiu, X. -Q., Wu, J. -X, Zhang, P., and Jia, Z.-J.
Type:
article, model:article, and TEXT
Subject:
Resveratrol, Coronary artery, Calcium channel, Vascular endothelium, and Nitric oxide
Language:
English
Description:
The present study was designed to investigate the acute relaxing effect of phytoestrogen resveratrol on isolated porcine coronary arteries and to determine the mechanisms underlying its vasodilatation. Rings of porcine coronary arteries were suspended in organ baths containing Krebs-Henseleit solution, and then isometric tension was measured. Resveratrol concentration-dependently relaxed arterial rings precontracted with 30 mM KCl. The IC50 value of resveratrol was 38.67±3.21 μM. Incubation with Nω-L-nitro-arginine (L-NNA), endothelium removal or the presence of a potent inhibitor of protein tyrosine phosphatase sodium orthovanadate partly decreased the relaxation induced by resveratrol. However, the relaxation induced by resveratrol was unaffected by the estrogen receptor antagonist tamoxifen, the inhibitor of prostanoid synthesis indomethacin, the antagonist of β-adrenoceptors propranolol or the protein synthesis inhibitor, cycloheximide. In addition, resveratrol significantly decreased the contractile responses of 5-HT, KCl and CaCl2, and shifted their cumulative concentration-response curves to the right. These results suggest that the mechanisms of vasorelaxation induced by resveratrol are heterogeneous, two mechanisms participating partially in the relaxation of porcine coronary artery were detected in the study, one being the nitric oxide released from the endothelium, the other causing inhibition of Ca2+ influx, but estrogen receptors were not involved in resveratrol-induced relaxation.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

694. A study of meiosis and spermiogenesis in the testicular lobes of Antiteuchus tripterus (Heteroptera: Pentatomidae)

Creator:
Souza, Hederson Vinícius de, Campos Bicudo, Hermione Elly Melara De, Costa, Luiz Antônio Alves, and Itoyama, Mary Massumi
Type:
article, model:article, and TEXT
Subject:
Heteroptera, Pentatomidae, meiosis, spermatozoa, testicular lobes, and harlequin lobe
Language:
English
Description:
An analysis of testicular morphology and spermatogenesis in the Heteroptera species Antiteuchus tripterus (Pentatomidae) revealed that these traits differ from that recorded for other species of the same family. The testes of A. tripterus have only six lobes, while other species of the same family typically have seven lobes, including a compound lobe, i.e., a lobe containing another in its lumen. A study of meiosis and sperm structure in the different lobes of A. tripterus revealed a conventional meiosis in the lobes numbered one to three. In lobe four, however, prophase I spermatocytes exhibit the morphological characteristics of the so called "diffuse" stage and are larger than those in lobes 1-3 in this and the remaining phases of meiosis. Thus, the resulting spermatids are not only larger but also their head is morphologically different. Lobe 5 exhibits characteristics known from other Pentatomidae species such as an uneven distribution of chromatin to the daughter cells, which give rise to cells of different sizes. This lobe forms spermatozoa of different sizes. Lobe 6, contained within lobe 5, differs from it by having larger cells at a stage similar to the so called "diffuse" and spermatid tails with cross divisions, which are not found in other lobes and unreported in the literature.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

695. A study of various results for a class of entire Dirichlet series with complex frequencies

Creator:
Kumar, Niraj and Manocha, Garima
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Dirichlet series, Banach algebra, topological zero divisor, division algebra, continuous linear functional, and total set
Language:
English
Description:
Let F be a class of entire functions represented by Dirichlet series with complex frequencies ∑ ake hλ k ,zi for which (|λ k |/e)|λ k | k!|ak| is bounded. Then F is proved to be a commutative Banach algebra with identity and it fails to become a division algebra. F is also proved to be a total set. Conditions for the existence of inverse, topological zero divisor and continuous linear functional for any element belonging to F have also been established.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

696. A study on African animal trypanosomosis in four areas of Senegal

Creator:
Ravel, Sophie, Mediannikov, Oleg, Bossard, Géraldine, Desquesnes, Marc, Cuny, Gérard, and Davoust, Bernard
Format:
electronic, počítač, and online zdroj
Type:
model:article and TEXT
Subject:
psi, osli, skot, epidemiologie, dogs, donkeys, cattle, epidemiology, Trypanosoma congolense, 2, and 59
Language:
English
Description:
In Senegal, several areas provide great potential for agriculture and animal production, but African animal trypanosomosis (AAT) is one of the major constraints to the development of more effective livestock production systems. A study was conducted to assess the current situation of AAT in this country. Surveys were carried out between June 2011 and September 2012 in four different areas: Dakar, Sine Saloum, Kedougou region and Basse Casamance in several animal species: dogs (152), donkeys (23), horses (63), sheep (43), goats (52) and cattle (104), distributed in the four sites. Molecular tools (PCR) indicated 3.4% positive animals including dogs, donkeys, a goat and cattle. The savannah type of Trypanosoma congolense Broden, 1904 (53% of positive cases) and the forest type of T. congolense (subgenus Nannomonas Hoare, 1964) were predominant. Trypanosoma vivax Ziemann, 1905 (subgenus Duttonella Chalmers, 1918) was only present in one animal and no trypanosome of the subgenus Trypanozoon Lühe, 1906 was found. Half of the positive cases were detected in Sine Saloum, where T. congolense savannah-type was predominant, and the other half in Basse Casamance, where T. congolense forest-type was predominant; no cases were found in Dakar or in the Kedougou region. A high risk of infection in dogs with T. congolense savannah-type was shown in Sine Saloum, requiring prevention and control of dogs in this area. The involvement of tsetse flies in the transmission of T. congolense in Sine Saloum and Basse Casamance is discussed., Sophie Ravel, Oleg Mediannikov, Géraldine Bossard, Marc Desquesnes, Gérard Cuny, Bernard Davoust., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

697. A study on decentralized H∞ feedback control systems with local quantizers

Creator:
Zhai, Guisheng, Chen, Ning, and Gui, Weihua
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
decentralized H∞ feedback control system, quantizer, quantization, matrix inequality, and output feedback
Language:
English
Description:
In this paper, we study decentralized H∞ feedback control systems with quantized signals in local input-output (control) channels. We first assume that a decentralized output feedback controller has been designed for a multi-channel continuous-time system so that the closed-loop system is Hurwitz stable and a desired H∞ disturbance attenuation level is achieved. However, since the local measurement outputs are quantized by a general quantizer before they are passed to the controller, the system's performance is not guaranteed. For this reason, we propose a local-output-dependent strategy for updating the quantizers' parameters, so that the closed-loop system is asymptotically stable and achieves the same H∞ disturbance attenuation level. We also extend the discussion and the result to the case of multi-channel discrete-time H∞ feedback control systems.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

698. A study on global stabilization of periodic orbits in discrete-time chaotic systems by using symbolic dynamics

Creator:
Suzuki, Masayasu and Sakamoto, Noboru
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
symbolic dynamics, chaos control, and global stability
Language:
English
Description:
In this report, a control method for the stabilization of periodic orbits for a class of one- and two-dimensional discrete-time systems that are topologically conjugate to symbolic dynamical systems is proposed and applied to a population model in an ecosystem and the Smale horseshoe map. A periodic orbit is assigned as a target by giving a sequence in which symbols have periodicity. As a consequence, it is shown that any periodic orbits can be globally stabilized by using arbitrarily small control inputs. This work is a new attempt to systematically design a control system based on symbolic dynamics in the sense that one estimates the magnitude of control inputs and analyzes the Lyapunov stability.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

699. A study on molecular mechanisms of adiposis induced by long-term treatment of high-fat and high-sucrose in C57BL/6J mice

Creator:
Li, X., Tu, P. , Umar, M., Liu, Q. , Luo, W. , Yang, X., Zhu, J. , Kong, D., and Li, M.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
obesity, dietary, epigenetic, DNA methylation, and DNMT1
Language:
English
Description:
Adiposis is reputed as a twin disease of type 2 diabetes and greatly harmful to human health. In order to understand the molecular mechanisms of adiposis, the changes of physiological, pathological, epigenetic and correlative gene expression were investigated during the adiposis development of C57BL/6J mice induced by long time (9 months) high-fat and high-sucrose diet (HFSD) sustainably. The results showed that mRNA transcription level of the Leptin, Glut4 and Glut2 genes have been obviously changed, which exhibit a negative correlation with methylation on their promoter DNA. The results also revealed that HFSD induced higher level of DNA methyltransferase 1 (DNMT1) in fat tissue might play important role in regulating the changes of methylation pattern on Glut4 and Leptin genes, and which might be one of the molecular mechanisms for the adiposis development.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

700. A subcopula based dependence measure

Creator:
Erdely, Arturo
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
subcopula, dependence, and concordance
Language:
English
Description:
A dependence measure for arbitrary type pairs of random variables is proposed and analyzed, which in the particular case where both random variables are continuous turns out to be a concordance measure. Also, a sample version of the proposed dependence measure based on the empirical subcopula is provided, along with an R package to perform the corresponding calculations.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

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