935 resultados para myosin heavy chains
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AIMS: The aim of the study was to explore whether the concept of heavy substance use over time can be used as definition of substance use disorder. METHODS: Narrative review. RESULTS: Heavy use over time clearly underlies the neurobiological changes associated with current thinking of substance use disorders. In addition, there is evidence that heavy use over time can explain the majority of social problems and of burden of disease (morbidity and mortality). A definition of substance use disorders via heavy use over time would avoid some of the problems of current conceptualizations, for instance the cultural specificity of concepts such as loss of control. Finally, stressing the continuum of use may avoid the high level of stigmatization currently associated with substance use disorders. CONCLUSION: 'Heavy substance use over time' seems to be a definition of substance use disorders in line with results of basic research and epidemiology. Additionally, it reduces stigmatization. This approach should thus be further explored.
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The competitiveness of businesses is increasingly dependent on their electronic networks with customers, suppliers, and partners. While the strategic and operational impact of external integration and IOS adoption has been extensively studied, much less attention has been paid to the organizational and technical design of electronic relationships. The objective of our longitudinal research project is the development of a framework for understanding and explaining B2B integration. Drawing on existing literature and empirical cases we present a reference model (a classification scheme for B2B Integration). The reference model comprises technical, organizational, and institutional levels to reflect the multiple facets of B2B integration. In this paper we onvestigate the current state of electronic collaboration in global supply chains focussing on the technical view. Using an indepth case analysis we identify five integration scenarios. In the subsequent confirmatory phase of the research we analyse 112 real-world company cases to validate these five integration scenarios. Our research advances and deepens existing studies by developing a B2B reference model, which reflects the current state of practice and is independent of specific implementation technologies. In the next stage of the research the emerging reference model will be extended to create an assessment model for analysing the maturity level of a given company in a specific supply chain.
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The objective of the current study was to determine the predictive value of high normal gamma-glutamyltransferase (GGT) level as an indication of heavy drinking in young men. In a sample of 577 men attending a one-day army recruitment process mandatory for all Swiss men at age 19 years, GGT level was evaluated as the dependent variable for each of eight dichotomous classifications of individuals on the basis of meeting cut-off criteria for five indexes of alcohol use, two indexes of alcohol-related problems, and one index of body mass. The sensitivity, specificity, and predictive values of GGT level in identifying subjects as either heavy drinkers or being overweight were determined. Compared with findings for their counterparts, GGT level was higher in subjects reporting consumption of more than 14 drinks per week (20.5 +/- 7.81 vs. 18.9 +/- 7.60, P <.05), in those reporting being drunk at least once during the past 30 days (20.3 +/- 7.80 vs. 18.3 +/- 7.43, P <.001), and in individuals with body mass indexes >or=25 kg/m(2) (25.8 +/- 10.84 vs. 18.3 +/- 6.59, P <.001). At a GGT level cut-off of 20 U/l, the sensitivity, specificity, and positive and negative predictive values of either being a heavy drinker or overweight were 48.2%, 70.2%, 67.7%, and 51.2%, respectively. Exclusion of subjects with body mass indexes of >or=25 kg/m(2) revealed similar results. High normal GGT level in young men is indicative of heavy alcohol use or being overweight; when present, subjects should be screened further for potential concomitant drinking problems.
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During the period 1996-2000, forty-three heavy rainfall events have been detected in the Internal Basins of Catalonia (Northeastern of Spain). Most of these events caused floods and serious damage. This high number leads to the need for a methodology to classify them, on the basis of their surface rainfall distribution, their internal organization and their physical features. The aim of this paper is to show a methodology to analyze systematically the convective structures responsible of those heavy rainfall events on the basis of the information supplied by the meteorological radar. The proposed methodology is as follows. Firstly, the rainfall intensity and the surface rainfall pattern are analyzed on the basis of the raingauge data. Secondly, the convective structures at the lowest level are identified and characterized by using a 2-D algorithm, and the convective cells are identified by using a 3-D procedure that looks for the reflectivity cores in every radar volume. Thirdly, the convective cells (3-D) are associated with the 2-D structures (convective rainfall areas). This methodology has been applied to the 43 heavy rainfall events using the meteorological radar located near Barcelona and the SAIH automatic raingauge network.
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We have previously reported that actin filaments are involved in protein transport from the Golgi complex to the endoplasmic reticulum. Herein, we examined whether myosin motors or actin comets mediate this transport. To address this issue we have used, on one hand, a combination of specific inhibitors such as 2,3-butanedione monoxime (BDM) and 1-[5-isoquinoline sulfonyl]-2-methyl piperazine (ML7), which inhibit myosin and the phosphorylation of myosin II by the myosin light chain kinase, respectively; and a mutant of the nonmuscle myosin II regulatory light chain, which cannot be phosphorylated (MRLC2AA). On the other hand, actin comet tails were induced by the overexpression of phosphatidylinositol phosphate 5-kinase. Cells treated with BDM/ML7 or those that express the MRLC2AA mutant revealed a significant reduction in the brefeldin A (BFA)-induced fusion of Golgi enzymes with the endoplasmic reticulum (ER). This delay was not caused by an alteration in the formation of the BFA-induced tubules from the Golgi complex. In addition, the Shiga toxin fragment B transport from the Golgi complex to the ER was also altered. This impairment in the retrograde protein transport was not due to depletion of intracellular calcium stores or to the activation of Rho kinase. Neither the reassembly of the Golgi complex after BFA removal nor VSV-G transport from ER to the Golgi was altered in cells treated with BDM/ML7 or expressing MRLC2AA. Finally, transport carriers containing Shiga toxin did not move into the cytosol at the tips of comet tails of polymerizing actin. Collectively, the results indicate that 1) myosin motors move to transport carriers from the Golgi complex to the ER along actin filaments; 2) nonmuscle myosin II mediates in this process; and 3) actin comets are not involved in retrograde transport.
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Biofuels are considered as a promising substitute for fossil fuels when considering the possible reduction of greenhouse gases emissions. However limiting their impacts on potential benefits for reducing climate change is shortsighted. Global sustainability assessments are necessary to determine the sustainability of supply chains. We propose a new global criterion based framework enabling a comprehensive international comparison of bioethanol supply chains. The interest of this framework is that the selection of the sustainability indicators is qualified on three criterions: relevance, reliability and adaptability to the local context. Sustainability issues have been handled along environmental, social and economical issues. This new framework has been applied for a specific issue: from a Swiss perspective, is locally produced bioethanol in Switzerland more sustainable than imported from Brazil? Thanks to this framework integrating local context in its indicator definition, Brazilian production of bioethanol is shown as energy efficient and economically interesting for Brazil. From a strictly economic point of view, bioethanol production within Switzerland is not justified for Swiss consumption and questionable for the environmental issue. The social dimension is delicate to assess due to the lack of reliable data and is strongly linked to the agricultural policy in both countries. There is a need of establishing minimum sustainability criteria for imported bioethanol to avoid unwanted negative or leakage effects.
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Introduction: Prior repeated-sprints (6) has become an interesting method to resolve the debate surrounding the principal factors that limits the oxygen uptake (V'O2) kinetics at the onset of exercise [i.e., muscle O2 delivery (5) or metabolic inertia (3)]. The aim of this study was to compare the effects of two repeated-sprints sets of 6x6s separated by different recovery duration between the sprints on V'O2 and muscular de-oxygenation [HHb] kinetics during a subsequent heavy-intensity exercise. Methods: 10 male subjects performed a 6-min constant-load cycling test (T50) at intensity corresponding to half of the difference between V'O2max and the ventilatory threshold. Then, they performed two repeated-sprints sets of 6x6s all-out separated by different recovery duration between the sprints (S1:30s and S2:3min) followed, after 7-min-recovery, by the T50 (S1T50 and S2T50, respectively). V'O2, [HHb] of the vastus lateralis (VL) and surface electromyography activity [i.e., root-mean-square (RMS) and the median frequency of the power density spectrum (MDF)] from VL and vastus medialis (VM) were recorded throughout T50. Models using a bi-exponential function for the overall T50 and a mono-exponential for the first 90s of T50 were used to define V'O2 and [HHb] kinetics respectively. Results: V'O2 mean value was higher in S1 (2.9±0.3l.min-1) than in S2 (1.2±0.3l.min-1); (p<0.001). The peripheral blood flow was increased after sprints as attested by a higher basal heart rate (HRbaseline) (S1T50: +22%; S2T50: +17%; p≤0.008). Time delay [HHb] was shorter for S1T50 and S2T50 than for T50 (-22% for both; p≤0.007) whereas the mean response time of V'O2 was accelerated only after S1 (S1T50: 32.3±2.5s; S2T50: 34.4±2.6s; T50: 35.7±5.4s; p=0.031). There were no significant differences in RMS between the three conditions (p>0.05). MDF of VM was higher during the first 3-min in S1T50 than in T50 (+6%; p≤0.05). Conclusion: The study show that V'O2 kinetics was speeded by prior repeated-sprints with a short (30s) but not a long (3min) inter-sprints-recovery even though the [HHb] kinetics was accelerated and the peripheral blood flow was enhanced after both sprints. S1, inducing a greater PCr depletion (1) and change in the pattern of the fibres recruitment (increase in MDF) compared with S2, may decrease metabolic inertia (2), stimulate the oxidative phosphorylation activation (4) and accelerate V'O2 kinetics at the beginning of the subsequent high-intensity exercise.
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Phosphogysum (PG) or agricultural gypsum, a solid waste from the phosphate fertilizer industry, is used as soil amendment, especially on soils in the Cerrado region, in Brazil. This material may however contain natural radionuclides and metals which can be transferred to soils, plants and water sources. This paper presents and discusses the results of physical and chemical analyses that characterized samples of PG and compares them to the results found in two typical soils of the Cerrado, a clayey and sandy one. These analyses included: solid waste classification, evaluation of organic matter content and of P, K, Ca, Mg, and Al concentrations and of the mineralogical composition. Natural radionuclides and metal concentrations in PG and soil samples were also measured. Phosphogypsum was classified as Class II A - Not Dangerous, Not Inert, Not Corrosive and Not Reactive. The organic matter content in the soil samples was low and potential acidity high. In the mean, the specific 226Ra activity in the phosphogypsum samples (252 Bq kg-1) was below the maximum level recommended by USEPA, which is 370 Bq kg-1 for agricultural use. In addition, this study verified that natural radionuclides and metals concentrations in PG were lower than in the clayey Oxisol of Sete Lagoas, Minas Gerais, Brazil. These results indicated that the application of phosphogypsum as soil amendment in agriculture would not cause a significant impact on the environment.
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A two stage sampling strategy is necessary in order to optimize the study of distribution of pollution in soils and groundwater. First, detailed sampling from a limited area coupled with statistical analysis of the data are used to determine the microvariability of the parameter(s). The results from this detailed analysis are then used to calculate the optimal spacing between samples for the larger scale study. This two stage sampling strategy can result in significant financial savings during subsequent soil or groundwater remediation. This combined sampling and statistical analysis approach is illustrated with an example from a heavy metal contaminated site.
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A model for energy, pressure, and flow velocity distributions at the beginning of ultrarelativistic heavy ion collisions is presented, which can be used as an initial condition for hydrodynamic calculations. Our model takes into account baryon recoil for both target and projectile, arising from the acceleration of partons in an effective field F mu nu produced in the collision. The typical field strength (string tension) for RHIC energies is about 512 GeV/fm, which allows us to talk about string ropes. The results show that a quark-gluon plasma forms a tilted disk, such that the direction of the largest pressure gradient stays in the reaction plane, but deviates from both the beam and the usual transverse flow directions. Such initial conditions may lead to the creation of antiflow or third flow component [L. P. Csernai and D. Rhrich, Phys. Rev. Lett. B 458, 454 (1999)].
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Results for elastic electron scattering by nuclei, calculated with charge densities of Skyrme forces and covariant effective Lagrangians that accurately describe nuclear ground states, are compared against experiment in stable isotopes. Dirac partial-wave calculations are performed with an adapted version of the ELSEPA package. Motivated by the fact that studies of electron scattering off exotic nuclei are intended in future facilities in the commissioned GSI and RIKEN upgrades, we survey the theoretical predictions from neutron-deficient to neutron-rich isotopes in the tin and calcium isotopic chains. The charge densities of a covariant interaction that describes the low-energy electromagnetic structure of the nucleon within the Lagrangian of the theory are used to this end. The study is restricted to medium- and heavy-mass nuclei because the charge densities are computed in mean-field approach. Because the experimental analysis of scattering data commonly involves parameterized charge densities, as a surrogate exercise for the yet unexplored exotic nuclei, we fit our calculated mean-field densities with Helm model distributions. This procedure turns out to be helpful to study the neutron-number variation of the scattering observables and allows us to identify correlations of potential interest among some of these observables within the isotopic chains.