824 research outputs found

    Milošević, Marko and Rekawek, Kacper, eds.: Perservance of Terrorism: Focus on Leaders, IOS Press, Amsterdam, 2014

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    An exploratory study of heavy domain wall fermions on the lattice

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    We report on an exploratory study of domain wall fermions (DWF) as a lattice regularisation for heavy quarks. Within the framework of quenched QCD with the tree-level improved Symanzik gauge action we identify the DWF parameters which minimise discretisation effects. We find the corresponding effective 4dd overlap operator to be exponentially local, independent of the quark mass. We determine a maximum bare heavy quark mass of amh0.4am_h\approx 0.4, below which the approximate chiral symmetry and O(a)-improvement of DWF are sustained. This threshold appears to be largely independent of the lattice spacing. Based on these findings, we carried out a detailed scaling study for the heavy-strange meson dispersion relation and decay constant on four ensembles with lattice spacings in the range 2.05.7GeV2.0-5.7\,\mathrm{GeV}. We observe very mild a2a^2 scaling towards the continuum limit. Our findings establish a sound basis for heavy DWF in dynamical simulations of lattice QCD with relevance to Standard Model phenomenology.Comment: 23 pages, 8 figure

    Crown structure of Picea omorika trees in the plantation

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    The study was carried out in Serbian spruce (Picea omorika Panč/Purkynĕ) plantations in the western Serbia. The paper presents results of the analysis of crown development. The following elements were analyzed: total tree height, height of the crown base, absolute and relative crown length, maximal crown diameter, coefficient of crown spreading and degree of crown girth. We discuss approaches to the modeling of tree crown growth and development, growing under favorable environmental and stand conditions, without anomalies in development. In order to establish the relationship between analyzed factors, regression analyses were applied. Data fitting was by the analytic method, by the implementation of Prodan’s functions of growth, linear and parabolic function. Received models can be used for the simulation of various growth and developing processes in forest

    Toxicological analysis of the risk of lead exposure in metal processing

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    Purpose: To evaluate toxicological risks for workers who are exposed to lead in their work environment. Methods: Since it is an important indicator of toxicological risk, a statistical analysis of lead concentration and biological lead toxicity markers in blood and urine were performed for both exposed and control groups. Both experimental groups consisted of employees from "NISSAL" JSC factory. Analytical epidemiological method in the form of a retrospective cohort study was applied, and covered the period from 2001 to 2010. The concentration of lead, δ-aminolevulinic acid, and coproporphyrin in biological samples were determined by spectrophotometric methods. Results: The results showed a high positive correlation between lead concentrations in blood and urine and the length of exposure of the participants (p < 0.01). Also, increase of lead concentration in the biological material significantly increased δ-aminolevulinic acid (p < 0.01) and slightly increased the concentration of coproporphyrin, both of which are important indicators of toxicological risk. Conclusion: The control group of employees belonged to the normal risk category, while the exposed group belonged to a moderate risk category. Correlation between the monitored parameters is statistically significant at p < 0.01 and p < 0.05. Keywords: Lead, δ-Aminolevulinic acid, Coproporphyrin, Chronic exposure, Toxicity, Correlatio

    GALS for Bursty Data Transfer based on Clock Coupling

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    In this paper we introduce a novel burst-mode GALS technique. The goal of this technique is improving the performance of the GALS approach for systems with predominantly bursty data transfer. This new technique has been used to implement a GALS-based version of a hardware accelerator of a 60 GHz OFDM baseband processor. The simulation results show a significant performance improvement in comparison with a classical implementation of GALS using pausible clocking. © 2009 Elsevier B.V. All rights reserved

    Vibrational level population of H2_2 and H2+_2^+ in the early Universe

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    We formulate a vibrationally resolved kinetics for molecular hydrogen and its cation in the primordial Universe chemistry. Formation, destruction and relaxation processes for each vibrational level are studied and included as chemical pathways of the present model. The fractional abundance of each vibrational level as a function of the redshift is given: a strong deviation from the Boltzmann distribution is found at low zz. A discussion of the results is provided, also evaluating the effects of relaxation processes on the level populations. Analytical fits for some LTE rate coefficients are given in the Appendix.Comment: 12 pages, 14 figures, 3 tables; published on ApJS 2011, 193,

    A stochastic model of Min oscillations in Escherichia coli and Min protein segregation during cell division

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    The Min system in Escherichia coli directs division to the centre of the cell through pole-to-pole oscillations of the MinCDE proteins. We present a one dimensional stochastic model of these oscillations which incorporates membrane polymerisation of MinD into linear chains. This model reproduces much of the observed phenomenology of the Min system, including pole-to-pole oscillations of the Min proteins. We then apply this model to investigate the Min system during cell division. Oscillations continue initially unaffected by the closing septum, before cutting off rapidly. The fractions of Min proteins in the daughter cells vary widely, from 50%-50% up to 85%-15% of the total from the parent cell, suggesting that there may be another mechanism for regulating these levels in vivo.Comment: 19 pages, 12 figures (25 figure files); published at http://www.iop.org/EJ/journal/physbi

    The influence of diazinon and its metabolites on acetylcholinesterase, NA+/K+-ATPase and antioxidant enzymes in rat brain synaptosomes

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    The aim of this study was to investigate neurotoxic potential and oxidative stress responses of diazinon and its metabolites, diazoxon and 2-isopropyl-6-methyl-4-pyrimidinol using synaptosomes as a model system. Synaptosomes were isolated from the brain of Wistar albino rats and incubated at 37oC for 1 hour in the presence of selected concentrations of the investigated compounds. Acetylcholinesterase, Na+/K+-ATPase and antioxidant enzymes activities were determined by standard spectrophotometric methods. Diazinon induced concentration-dependent acetylcholinesterase and Na+/K+-ATPase inhibition, while the activity of catalase, superoxide dismutase and glutathione peroxidase was not significantly affected. Increasing concentrations of diazoxon, oxo analog of diazinon, caused almost complete acetylcholinesterase and Na+/K+-ATPase inhibition, and activated antioxidant enzymes: catalase (up to 25%), superoxide dismutase (up to 55%) and glutathione peroxidase (up to 30%). Unlike diazoxon, diazinon hydrolysis product, 2-isopropyl-6-methyl-4-pyrimidinol did not remarkably change the activities of the investigated enzymes, except superoxide dismutase that was stimulated up to 25%. The obtained results suggest that neurotoxic and prooxidative potential of diazinon, thioorganophoshate used as a commercial insecticide preparation, significantly reinforces mostly due to its transformation to diazoxon in the metabolic pathways.Third International Conferenceon Radiation and Applications in Various Fields of Research, RAD 2015, June8-12, 2015, Budva, Montenegr
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