46 research outputs found

    Properties of Recurrent Equations for the Full-Availability Group with BPP Traffic

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    The paper proposes a formal derivation of recurrent equations describing the occupancy distribution in the full-availability group with multirate Binomial-Poisson-Pascal (BPP) traffic. The paper presents an effective algorithm for determining the occupancy distribution on the basis of derived recurrent equations and for the determination of the blocking probability as well as the loss probability of calls of particular classes of traffic offered to the system. A proof of the convergence of the iterative process of estimating the average number of busy traffic sources of particular classes is also given in the paper

    Single Hysteresis Model for Limited-availability Group with BPP Traffic, Journal of Telecommunications and Information Technology, 2013, nr 3

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    This paper presents a single hysteresis model for limited-availability group that are offered Erlang, Engset and Pascal traffic streams. The occupancy distribution in the system is approximated by a weighted sum of occupancy distributions in multi-threshold systems. Distribution weights are obtained on the basis of a specially constructed Markovian switching process. The results of the calculations of radio interfaces in which the single hysteresis mechanism has been implemented are compared with the results of the simulation experiments. The study demonstrates high accuracy of the proposed model

    Traffic Modeling in Industrial Ethernet Networks

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    This article discusses the traffic types typically used in industrial networks. The authors propose a number of methods of generating traffic that can be used in modeling traffic sources in the networks under consideration. The proposed traffic models have been developed on the basis of the ON/OFF model. The proposed solutions can be applied to model typical traffic types that are used in industrial systems, such as Time-Triggered (TT) traffic, Audio-Video Bridging (AVB) traffic or Best Effort traffic. The article discusses four traffic models with modifications and shows how the proposed models can be used in modeling different traffic types used in industrial networks

    Plasma concentration of tryptophan and pregnancy-induced hypertension

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    Introduction. Pregnancy-induced hypertension (PIH) is one of the main clinical problems of unexplained etiopathogenesis. New factors involved in the pathogenesis of this disease are still being searched. The available literature lacks data regarding the differences in tryptophan concentrations in physiological and PIH-complicated pregnancy. Previous studies have shown that L-tryptophan treatment reduces blood pressure in hypertensive rats. The direct vascular effects of tryptophan have not been fully explored. In this study, the stimulating effect of tryptophan on the development of PIH was revealed. The aim of the present study was to assess the differences in plasma tryptophan concentrations in physiological pregnancies and pregnancies complicated with hypertension in the third trimester. Material and methods. The study was carried on 105 complicated by PIH and 105 pregnant women with blood pressure within normal limits between 25 and 41 weeks of gestation. Tryptophan concentration was determined by the automated ion-exchange chromatography using an Amino Acid Analyser (AAA 400) by Ingos, Czech Republic. Tryptophan concentration was expressed in μmol/cm3 plasma. Results. The mean concentration of tryptophan in the third trimester of physiological pregnancy was found to be 0.035 ± 0.009 μmol/cm3, whereas in PIH — 0.099 ± 0.007 μmol/cm3. Conclusions. The development of PIH in pregnant women is likely to be caused by increased concentrations of tryptophan, which is a substrate for production of serotonin and tryptamine. Further studies are needed to analyse the kinetics of tryptophan metabolism

    Analytical Modelingof the WCDMA Interfacewith Packet Scheduling, Journal of Telecommunications and Information Technology, 2009 nr 3

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    The article presents the application of a new analytical model of the full-availability group carrying a mixture of different multi-rate traffic classes with compression property for modeling the WCDMA radio interface with packet scheduling. The proposed model can be directly used for modeling of theWCDMA interface in the UMTS network servicing different traffic classes. The described model can be applied for a validation of the efficiency of the WCDMA interface measured by the blocking probability and the average carried traffic for particular traffic classes

    Study of the role of L-arginine in the diagnosis of pregnancy-induced hypertension

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    Background Pregnancy-induced hypertension (PIH) is a significant health issue in pregnancy, complicating 7–10% of pregnancies. L-arginine is an important mediator of vasodilation with a potential preventative role in pregnancy-related hypertensive diseases. Aim of the study The aim of the present study was to assess the differences in plasma L-arginine concentrations in physiological pregnancies and pregnancies complicated with hypertension in the third trimester. Material and methods Plasma concentration of L-arginine was determined by ion-exchange chromatography in 210 pregnant women (25–41 weeks of gestation). Plasma L-arginine concentration was expressed in μmol/cm3. Results The mean L-arginine concentration was significantly higher in physiological pregnancy (0.102) than in the PIH group (0.034). The analysis of plasma L-arginine concentration in the subgroups of third trimester showed that L-arginine concentration in the PIH group decreased with increasing stage of pregnancy (25–34 hbd — 0.051; 35–38 hbd — 0.03; 39–41 hbd — 0.02). L-arginine concentration in physiological pregnancies was the same in all subgroups (0.1). Conclusions L-arginine may have a role in the prevention and treatment of pregnancy-induced hypertension. Further well-designed and adequately powered research is warranted.Background Pregnancy-induced hypertension (PIH) is a significant health issue in pregnancy, complicating 7–10% of pregnancies. L-arginine is an important mediator of vasodilation with a potential preventative role in pregnancy-related hypertensive diseases. Aim of the study The aim of the present study was to assess the differences in plasma L-arginine concentrations in physiological pregnancies and pregnancies complicated with hypertension in the third trimester. Material and methods Plasma concentration of L-arginine was determined by ion-exchange chromatography in 210 pregnant women (25–41 weeks of gestation). Plasma L-arginine concentration was expressed in μmol/cm3. Results The mean L-arginine concentration was significantly higher in physiological pregnancy (0.102) than in the PIH group (0.034). The analysis of plasma L-arginine concentration in the subgroups of third trimester showed that L-arginine concentration in the PIH group decreased with increasing stage of pregnancy (25–34 hbd — 0.051; 35–38 hbd — 0.03; 39–41 hbd — 0.02). L-arginine concentration in physiological pregnancies was the same in all subgroups (0.1). Conclusions L-arginine may have a role in the prevention and treatment of pregnancy-induced hypertension. Further well-designed and adequately powered research is warranted

    Differential Quantitative Proteomics of Human Microvascular Endothelial Cells 1 by iTRAQ Reveals Palladin to be a New Biomarker During TGF-β1 Induced Endothelial Mesenchymal Transition

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    The study uses global quantitative proteomics to investigate the molecular mechanisms behind the induction of endothelial-mesenchymal transition (EndMT) by transforming growth factor–β (TGF-β). Orbitrap Velos mass spectrometers and iTRAQ – a labeling-based analysis were used to perform a global and quantitative comparison of two proteomes of Human Microvascular Endothelial Cells-1 (HMEC-1) treated or not treated by TGF-β1. iTRAQ analysis identified 43 differentially-expressed proteins in the early stages of EndMT induced by TGF-β1. From 5522 identified proteins, 26 were downregulated and 17 were upregulated, including proteins such as palladin, POTE I, torsin A and nucleoporin (NDC1). Further analysis of palladin revealed its increased mRNA and protein expression in response to TGF-β and Snail transcription factor. Our findings demonstrate that the newly- identified proteins may be involved in early stages of biological processes leading to EndM
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