189 research outputs found

    Current CONtrolled Transmit And Receive Coil Elements (C2ONTAR) for Parallel Acquisition and Parallel Excitation Techniques at High-Field MRI

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    A novel intrinsically decoupled transmit and receive radio-frequency coil element is presented for applications in parallel imaging and parallel excitation techniques in high-field magnetic resonance imaging. Decoupling is achieved by a twofold strategy: during transmission elements are driven by current sources, while during signal reception resonant elements are switched to a high input impedance preamplifier. To avoid B0 distortions by magnetic impurities or DC currents a resonant transmission line is used to relocate electronic components from the vicinity of the imaged object. The performance of a four-element array for 3 T magnetic resonance tomograph is analyzed by means of simulation, measurements of electromagnetic fields and bench experiments. The feasibility of parallel acquisition and parallel excitation is demonstrated and compared to that of a conventional power source-driven array of equivalent geometry. Due to their intrinsic decoupling the current-controlled elements are ideal basic building blocks for multi-element transmit and receive arrays of flexible geometry

    PROTÓTIPO MEDIDOR DE ENERGIA NÃO INVASIVO CONTROLADO POR ARDUINO

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    Este projeto possui como objetivo o desenvolvimento de um protótipo de medição de energia, o qual será de  grande importância na área de aprendizagem do curso. Tal equipamento poderá ser  ser aplicado tanto em circuitos monofásicos residenciais quanto industriais. Convém salientar, que o Arduino é uma plataforma universal utilizada por inúmeros programadores tanto profissionais quanto amadores devido seu baixo custo e facilidade de programação, tendo como foco a prototipagem eletrônica de código aberto. No desenvolvimento deste projeto foi utilizado como item principal, um Microcontrolador Arduino Uno, o qual é responsável por  processar os dados recebidos pelo Sensor de Energia (SCT-013), realizar cálculos das grandezas obtidas, exibir tais grandezas em uma tela LCD 16x2. Para a proteção do protótipo desenvolvido será utilizado um invólucro do tipo plástico

    Enhancing feedback and improving feedback: subjective perceptions, psychological consequences and behavioral outcomes

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    Three experiments examined subjective perceptions, psychological consequences, and behavioral outcomes of enhancing versus improving feedback. Across experiments, feedback delivery and assessment were sequential (i.e., at each testing juncture) or cumulative (i.e., at the end of the testing session). Although enhancing feedback was seen as more satisfying than useful, and improving feedback was not seen as more useful than satisfying, perceptions differed as a function of short-term versus long-term feedback delivery and assessment. Overall, however, enhancing feedback was more impactful psychologically and behaviorally. Enhancing feedback engendered greater success consistency, overall satisfaction and usefulness, optimism, state self-esteem, perceived ability, and test persistence intentions; improving feedback, on the other hand, engendered greater state improvement. The findings provide the fodder for theory development and applications

    The unruptured intracranial aneurysm treatment score A multidisciplinary consensus

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    Objective: We endeavored to develop an unruptured intracranial aneurysm (UIA) treatment score (UIATS) model that includes and quantifies key factors involved in clinical decision-making in the management of UIAs and to assess agreement for this model among specialists in UIA management and research. Methods: An international multidisciplinary (neurosurgery, neuroradiology, neurology, clinical epidemiology) group of 69 specialists was convened to develop and validate the UIATS model using a Delphi consensus. For internal (39 panel members involved in identification of relevant features) and external validation (30 independent external reviewers), 30 selected UIA cases were used to analyze agreement with UIATS management recommendations based on a 5-point Likert scale (5 indicating strong agreement). Interrater agreement (IRA) was assessed with standardized coefficients of dispersion (v(r)*) (v(r)* 5 0 indicating excellent agreement and v(r)* = 1 indicating poor agreement). Results: The UIATS accounts for 29 key factors in UIA management. Agreement with UIATS (mean Likert scores) was 4.2 (95% confidence interval [CI] 4.1-4.3) per reviewer for both reviewer cohorts; agreement per case was 4.3 (95% CI 4.1-4.4) for panel members and 4.5 (95% CI 4.3-4.6) for external reviewers (p = 0.017). Mean Likert scores were 4.2 (95% CI 4.1-4.3) for interventional reviewers (n = 56) and 4.1 (95% CI 3.9-4.4) for noninterventional reviewers (n = 12) (p = 0.290). Overall IRA (v(r)*) for both cohorts was 0.026 (95% CI 0.019-0.033). Conclusions: This novel UIA decision guidance study captures an excellent consensus among highly informed individuals on UIA management, irrespective of their underlying specialty. Clinicians can use the UIATS as a comprehensive mechanism for indicating how a large group of specialists might manage an individual patient with a UIA.Peer reviewe

    OxPhos Defects Cause Hypermetabolism and Reduce Lifespan in Cells and in Patients With Mitochondrial Diseases

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    Patients with primary mitochondrial oxidative phosphorylation (OxPhos) defects present with fatigue and multi-system disorders, are often lean, and die prematurely, but the mechanistic basis for this clinical picture remains unclear. By integrating data from 17 cohorts of patients with mitochondrial diseases (n = 690) we find evidence that these disorders increase resting energy expenditure, a state termed hypermetabolism. We examine this phenomenon longitudinally in patient-derived fibroblasts from multiple donors. Genetically or pharmacologically disrupting OxPhos approximately doubles cellular energy expenditure. This cell-autonomous state of hypermetabolism occurs despite near-normal OxPhos coupling efficiency, excluding uncoupling as a general mechanism. Instead, hypermetabolism is associated with mitochondrial DNA instability, activation of the integrated stress response (ISR), and increased extracellular secretion of age-related cytokines and metabokines including GDF15. In parallel, OxPhos defects accelerate telomere erosion and epigenetic aging per cell division, consistent with evidence that excess energy expenditure accelerates biological aging. To explore potential mechanisms for these effects, we generate a longitudinal RNASeq and DNA methylation resource dataset, which reveals conserved, energetically demanding, genome-wide recalibrations. Taken together, these findings highlight the need to understand how OxPhos defects influence the energetic cost of living, and the link between hypermetabolism and aging in cells and patients with mitochondrial diseases

    Jet energy measurement and its systematic uncertainty in proton–proton collisions at √s=7 TeV with the ATLAS detector

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    The jet energy scale (JES) and its systematic uncertainty are determined for jets measured with the ATLAS detector using proton–proton collision data with a centre-of-mass energy of √s=7 TeV corresponding to an integrated luminosity of 4.7 fb −1. Jets are reconstructed from energy deposits forming topological clusters of calorimeter cells using the anti-kt algorithm with distance parameters R=0.4 or R=0.6, and are calibrated using MC simulations. A residual JES correction is applied to account for differences between data and MC simulations. This correction and its systematic uncertainty are estimated using a combination of in situ techniques exploiting the transverse momentum balance between a jet and a reference object such as a photon or a Z boson, for 20≤pTjet1 TeV. The calibration of forward jets is derived from dijet pT balance measurements. The resulting uncertainty reaches its largest value of 6 % for low-pT jets at |η|=4.5. Additional JES uncertainties due to specific event topologies, such as close-by jets or selections of event samples with an enhanced content of jets originating from light quarks or gluons, are also discussed. The magnitude of these uncertainties depends on the event sample used in a given physics analysis, but typically amounts to 0.5–3 %

    Being Moved: Louis XIV’s Triumphant Tenderness and the Protestant Object

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    This essay examines the place of affect in Le Triomphe de la Religion, a text from 1687 that praises Louis XIV for the Revocation of the Edict of Nantes and the forced conversion of French Protestants. It explores the role of the material object in this text and contrasts it with seventeenth-century Protestant fears about the seductive power of Catholic objects. Drawing on the work of affect theory, it suggest how attention to the strange relation between emotion and the material object might better illuminate our sense of what it meant to be religiously different in absolutist France

    Air mass trajectories and land cover map reveal cereals and oilseed rape as major local sources of Alternaria spores in the Midlands, UK.

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    Transport of Alternaria spores from both local agricultural and remote areas has been implicated as a source of these spores in urban areas. The purpose of this study was to understand the relative contribution of local sources versus long distance transport on Alternaria spore concentrations, with applicability to Alternaria and other spore sampling sites worldwide. This was achieved by comparing two spore sampling sites in the cities of Worcester and Leicester in the UK, ~90 km apart, over a three year period (2016-2018) and focusing on a period of time when both sites experienced high spore counts. The study found 61 and 151 days of clinical significance (>100 spores/m³ air) at Worcester and Leicester, respectively. The spore concentrations were considerably higher in Leicester than in Worcester. Analysis of the crop map showed higher amounts of winter barley and oilseed rape near to Leicester compared to Worcester. HYSPLIT modelling during the episode revealed that the air masses arrived at both Leicester and Worcester from Ireland and the Atlantic Ocean. Long distance transport probably had a small but equal contribution to the observations at both sites. HYSPLIT particle dispersion simulations showed that the spores were dispersed and deposited from local sources. The results indicate that substantially higher concentrations of Alternaria spores occur in areas with high amounts of cereals and oilseed rape compared to those with lower amounts, or with different crops
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