36 resultados para Maxwell-Chern-Simons
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BACKGROUND Since 2005, increasing numbers of children have started antiretroviral therapy (ART) in sub-Saharan Africa and, in recent years, WHO and country treatment guidelines have recommended ART initiation for all infants and very young children, and at higher CD4 thresholds for older children. We examined temporal changes in patient and regimen characteristics at ART start using data from 12 cohorts in 4 countries participating in the IeDEA-SA collaboration. METHODOLOGY/PRINCIPAL FINDINGS Data from 30,300 ART-naïve children aged <16 years at ART initiation who started therapy between 2005 and 2010 were analysed. We examined changes in median values for continuous variables using the Cuzick's test for trend over time. We also examined changes in the proportions of patients with particular disease severity characteristics (expressed as a binary variable e.g. WHO Stage III/IV vs I/II) using logistic regression. Between 2005 and 2010 the number of children starting ART each year increased and median age declined from 63 months (2006) to 56 months (2010). Both the proportion of children <1 year and ≥10 years of age increased from 12 to 19% and 18 to 22% respectively. Children had less severe disease at ART initiation in later years with significant declines in the percentage with severe immunosuppression (81 to 63%), WHO Stage III/IV disease (75 to 62%), severe anemia (12 to 7%) and weight-for-age z-score<-3 (31 to 28%). Similar results were seen when restricting to infants with significant declines in the proportion with severe immunodeficiency (98 to 82%) and Stage III/IV disease (81 to 63%). First-line regimen use followed country guidelines. CONCLUSIONS/SIGNIFICANCE Between 2005 and 2010 increasing numbers of children have initiated ART with a decline in disease severity at start of therapy. However, even in 2010, a substantial number of infants and children started ART with advanced disease. These results highlight the importance of efforts to improve access to HIV diagnostic testing and ART in children.
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We present the first-order corrected dynamics of fluid branes carrying higher-form charge by obtaining the general form of their equations of motion to pole-dipole order in the absence of external forces. Assuming linear response theory, we characterize the corresponding effective theory of stationary bent charged (an)isotropic fluid branes in terms of two sets of response coefficients, the Young modulus and the piezoelectric moduli. We subsequently find large classes of examples in gravity of this effective theory, by constructing stationary strained charged black brane solutions to first order in a derivative expansion. Using solution generating techniques and bent neutral black branes as a seed solution, we obtain a class of charged black brane geometries carrying smeared Maxwell charge in Einstein-Maxwell-dilaton gravity. In the specific case of ten-dimensional space-time we furthermore use T-duality to generate bent black branes with higher-form charge, including smeared D-branes of type II string theory. By subsequently measuring the bending moment and the electric dipole moment which these geometries acquire due to the strain, we uncover that their form is captured by classical electroelasticity theory. In particular, we find that the Young modulus and the piezoelectric moduli of our strained charged black brane solutions are parameterized by a total of 4 response coefficients, both for the isotropic as well as anisotropic cases.
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The Cochrane Musculoskeletal Group (CMSG), one of 53 groups of the not-for-profit, international Cochrane Collaboration, prepares, maintains, and disseminates systematic reviews of treatments for musculoskeletal diseases. It is important that authors conducting CMSG reviews and the readers of our reviews be aware of and use updated, state-of-the-art systematic review methodology. One hundred sixty reviews have been published. Previous method guidelines for systematic reviews of interventions in the musculoskeletal field published in 2006 have been substantially updated to incorporate methodological advances that are mandatory or highly desirable in Cochrane reviews and knowledge translation advances. The methodological advances include new guidance on searching, new risk-of-bias assessment, grading the quality of the evidence, the new Summary of Findings table, and comparative effectiveness using network metaanalysis. Method guidelines specific to musculoskeletal disorders are provided by CMSG editors for various aspects of undertaking a systematic review. These method guidelines will help improve the quality of reporting and ensure high standards of conduct as well as consistency across CMSG reviews.
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Public broadcasting has always been a regulatory field somewhat zealously guarded within the nation states' sphere and kept willingly untouched by regional or international rules. Values inherent to the role of public broadcasting, such as cultural and national identity, social cohesion, pluralism and a sustained public sphere, were thought too critical and too historically connected with the particular society to allow any "outside" influence. Different regulatory models have emerged to reflect these specificities within the national boundaries of European countries. Yet, as media evolved technologically and economically, the constraints of state borders were rendered obsolete and the inner tension between culture and commerce of the television medium became more pronounced. This tension was only intensified with the formulation of a European Community (EC) layer of regulation, which had as its primary objective the creation of a single market for audiovisual services (or as the EC Directive beautifully put it, a "Television without Frontiers"), while also including some provisions catering for cultural concerns, such as the infamous quota system for European and independent productions. Against this backdrop, public broadcasting makes a particularly intriguing subject for a study of regulatory dilemmas of national versus supranational, integration versus intergovernmentalism, culture versus commerce, intervention versus liberalisation, and all this in the dynamic setting of contemporary media. The present paper reviews Irini Katsirea's book PUBLIC BROADCASTING AND EUROPEAN LAW and seeks to identify whether all elements of the complex governance puzzle of European public service broadcasting rules are analytically well fitted together.
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Irrespective of the diverse stances taken on the effect of the UNESCO Convention on Cultural Diversity in the external relations context, since its wording is fairly open-ended, it is clear to all observers that the Convention’s impact will largely depend on how it is implemented domestically. The discussion on the national implementation of the Convention, both in the policy and in the academic discourses, is only just emerging, although six years the Convention’s entry into force have passed. The implementation model of the EU can set an important example for the international community and for the other State Parties that have ratified the UNESCO Convention, as both the EU and its Member States acting individually, have played a critical role in the adoption of the Convention, as well as in the longer process of promoting cultural concerns on the international scene. Against this backdrop, this article analyses the extent to which the EU internal law and policies, in particular in the key area of media, take into account the spirit and the letter of the UNESCO Convention on Cultural Diversity. Next to an assessment of the EU’s implementation of the Convention, the article also offers remarks of normative character – in the sense of what should be done to actually attain the objective of protecting and promoting cultural diversity. The article seeks to critically evaluate the present state of affairs and make some recommendations for calibration of future policies.
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This paper addresses the microscale heat transfer problem from heated lattice to the gas. A micro-device for enhanced heat transfer is presented and numerically investigated. Thermal creep induces 3-D vortex structures in the vicinity of the lattice. The gas flow is in the slip flow regime (Knudsen number Kn⩽0.1Kn⩽0.1). The simulations are performed using slip flow Navier–Stokes equations with boundary condition formulations proposed by Maxwell and Smoluchowski. In this study the wire thicknesses and distances of the heated lattice are varied. The surface geometrical properties alter significantly heat flux through the surface.
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We investigate numerically the excitation of nonlinear magnetic interactions in a ferrite material by an energetic pump pulse of terahertz (THz) radiation. The calculations are performed by solving the coupled Maxwell and Landau-Lifshitz-Gilbert differential equations. In a time-resolved THz pump/THz probe scheme, it is demonstrated that Faraday rotation of a delayed THz probe pulse can be used to map these interactions. Our study is motivated by the ability of soft x-ray free electron lasers to perform time-resolved imaging of the magnetization process at the submicrometer and subpicosecond length and time scales.
VEGF-B-induced vascular growth leads to metabolic reprogramming and ischemia resistance in the heart
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Angiogenic growth factors have recently been linked to tissue metabolism. We have used genetic gain- and loss-of function models to elucidate the effects and mechanisms of action of vascular endothelial growth factor-B (VEGF-B) in the heart. A cardiomyocyte-specific VEGF-B transgene induced an expanded coronary arterial tree and reprogramming of cardiomyocyte metabolism. This was associated with protection against myocardial infarction and preservation of mitochondrial complex I function upon ischemia-reperfusion. VEGF-B increased VEGF signals via VEGF receptor-2 to activate Erk1/2, which resulted in vascular growth. Akt and mTORC1 pathways were upregulated and AMPK downregulated, readjusting cardiomyocyte metabolic pathways to favor glucose oxidation and macromolecular biosynthesis. However, contrasting with a previous theory, there was no difference in fatty acid uptake by the heart between the VEGF-B transgenic, gene-targeted or wildtype rats. Importantly, we also show that VEGF-B expression is reduced in human heart disease. Our data indicate that VEGF-B could be used to increase the coronary vasculature and to reprogram myocardial metabolism to improve cardiac function in ischemic heart disease.
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Intensive land use is a driving force for biodiversity decline in many ecosystems. In semi-natural grasslands, land-use activities such as mowing, grazing and fertilization affect the diversity of plants and arthropods, but the combined effects of different drivers and the chain of effects are largely unknown. In this study we used structural equation modelling to analyse how the arthropod communities in managed grasslands respond to land use and whether these responses are mediated through changes in resource diversity or resource quantity (biomass). Plants were considered resources for herbivores which themselves were considered resources for predators. Plant and arthropod (herbivores and predators) communities were sampled on 141 meadows, pastures and mown pastures within three regions in Germany in 2008 and 2009. Increasing land-use intensity generally increased plant biomass and decreased plant diversity, mainly through increasing fertilization. Herbivore diversity decreased together with plant diversity but showed no response to changes in plant biomass. Hence, land-use effects on herbivore diversity were mediated through resource diversity rather than quantity. Land-use effects on predator diversity were mediated by both herbivore diversity (resource diversity) and herbivore quantity (herbivore biomass), but indirect effects through resource quantity were stronger. Our findings highlight the importance of assessing both direct and indirect effects of land-use intensity and mode on different trophic levels. In addition to the overall effects, there were subtle differences between the different regions, pointing to the importance of regional land-use specificities. Our study underlines the commonly observed strong effect of grassland land use on biodiversity. It also highlights that mechanistic approaches help us to understand how different land-use modes affect biodiversity.
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A split-ergative construction had developed during the late MIA period (Bubenik 1998; Peterson 1998) in which subjects of perfective transitive clauses were marked ergative by an oblique form, in contrast with the nominative form for non-ergative subjects. Later in the NIA period, most NIA languages (e.g. Urdu/Hindi) developed a postpositional clitic that was added to the oblique suffix, while others (e.g. Sindhi) continued to mark ergative subjects with a generic oblique suffix. This paper focuses on one exceptional case: the Dehwali language of Gujarat. Dehwali has an ergative marker that is a fusional suffix (i.e. layer I - Masica 1991: 231) and appears to inflect to agree in number and gender with the subject it marks. I will present two possible scenarios as to the origin of the Dehwali ergative marker: that it may be the remnant of an archaic MIA oblique form, or that it may be a more recent innovation as the result of increased contact with neighbouring varieties. Based on theories of grammaticisation, I argue that the former hypothesis is more likely. These theories show that it is not uncommon for oblique case forms (i.e. ablative; genitive) to carry agentive properties.
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OBJECTIVE Although protocol registration for systematic reviews is still not mandatory, reviewers should be strongly encouraged to register the protocol to identify the methodological approach, including all outcomes of interest. This will minimize the likelihood of biased decisions in reviews, such as selective outcome reporting. A group of international experts convened to address issues regarding the need to develop hierarchical lists of outcome measurement instruments for a particular outcome for metaanalyses. METHODS Multiple outcome measurement instruments exist to measure the same outcome. Metaanalysis of knee osteoarthritis (OA) trials, and the assessment of pain as an outcome, was used as an exemplar to assess how Outcome Measures in Rheumatology (OMERACT), the Cochrane Collaboration, and other international initiatives might contribute in this area. The meeting began with formal presentations of background topics, empirical evidence from the literature, and a brief introduction to 2 existing hierarchical lists of pain outcome measurement instruments recommended for metaanalyses of knee OA trials. RESULTS After discussions, most participants agreed that there is a need to develop a methodology for generation of hierarchical lists of outcome measurement instruments to guide metaanalyses. Tools that could be used to steer development of such a prioritized list are the COSMIN checklist (Consensus-based Standards for the selection of health status Measurement Instruments) and the OMERACT Filter 2.0. CONCLUSION We list meta-epidemiological research agenda items that address the frequency of reported outcomes in trials, as well as methodologies to assess the best measurement properties (i.e., truth, discrimination, and feasibility).
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INTRODUCTION Postoperative delirium is one of the most common complications of major surgery, affecting 10-70% of surgical patients 60 years and older. Delirium is an acute change in cognition that manifests as poor attention and illogical thinking and is associated with longer intensive care unit (ICU) and hospital stay, long-lasting cognitive deterioration and increased mortality. Ketamine has been used as an anaesthetic drug for over 50 years and has an established safety record. Recent research suggests that, in addition to preventing acute postoperative pain, a subanaesthetic dose of intraoperative ketamine could decrease the incidence of postoperative delirium as well as other neurological and psychiatric outcomes. However, these proposed benefits of ketamine have not been tested in a large clinical trial. METHODS The Prevention of Delirium and Complications Associated with Surgical Treatments (PODCAST) study is an international, multicentre, randomised controlled trial. 600 cardiac and major non-cardiac surgery patients will be randomised to receive ketamine (0.5 or 1 mg/kg) or placebo following anaesthetic induction and prior to surgical incision. For the primary outcome, blinded observers will assess delirium on the day of surgery (postoperative day 0) and twice daily from postoperative days 1-3 using the Confusion Assessment Method or the Confusion Assessment Method for the ICU. For the secondary outcomes, blinded observers will estimate pain using the Behavioral Pain Scale or the Behavioral Pain Scale for Non-Intubated Patients and patient self-report. ETHICS AND DISSEMINATION The PODCAST trial has been approved by the ethics boards of five participating institutions; approval is ongoing at other sites. Recruitment began in February 2014 and will continue until the end of 2016. Dissemination plans include presentations at scientific conferences, scientific publications, stakeholder engagement and popular media. REGISTRATION DETAILS The study is registered at clinicaltrials.gov, NCT01690988 (last updated March 2014). The PODCAST trial is being conducted under the auspices of the Neurological Outcomes Network for Surgery (NEURONS). TRIAL REGISTRATION NUMBER NCT01690988 (last updated December 2013).