2,078 research outputs found

    Development of Measurement Methods for Testing of Hydrokinetic Devices to Evaluate the Environmental Effect on Local Substrate

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    Modifications and upgrades to the hydraulic flume facility in the Environmental Fluid Mechanics and Hydraulics Laboratory (EFM&H) at Bucknell University are described. These changes enable small-scale testing of model marine hydrokinetic(MHK) devices. The design of the experimental platform provides a controlled environment for testing of model MHK devices to determine their effect on localsubstrate. Specifically, the effects being studied are scour and erosion around a cylindrical support structure and deposition of sediment downstream from the device

    Closing Rikers Island: A Roadmap for Reducing Jail in New York City

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    New York City's promise to shutter its notorious Rikers Island jail complex hinges on reducing the number of people in city jails. This new report from the Independent Commission that called for Rikers' closure in 2017 and the Center for Court Innovation lays out a series of concrete, data-driven strategies to produce sizable jail reductions while prioritizing public safety.The annual cost of detaining someone on Rikers has soared to $447,000. As the report emphasizes, that is money that could be more productively used on a range of interventions to foster safer neighborhoods. Increasingly, research is finding stays in jail increase the likelihood of future criminal activity once someone is released, making us all less, not more, safe.The report recommends numerous policy changes, covering everything from improving case processing times—85 percent of the population on Rikers is presumed innocent and waiting, generally for months, for their day in court—to ensuring people's ability to pay bail is properly assessed, as is required by law. In combination, these changes can lastingly remake New York City's approach to incarceration

    Analysis and Mitigation of AC Losses in High Performance Propulsion Motors

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    In this paper, the AC copper losses in classical random windings are investigated and mitigated using several techniques across a range of permanent magnet synchronous motor designs. At high operating frequencies, AC copper losses can represent a substantial share of the total loss in electrical machines, thus, reducing the machine's overall performance, and increasing the thermal loading. Recently, different approaches for modelling AC copper losses have been proposed. This paper utilises simulation software to quantify the expected AC losses in six different propulsion motor designs. The motor designs are then modified to reduce the AC winding losses through the implementation of five different methods. Using two-dimensional finite element analysis, the magnetisation direction, magnet to airgap ratio, copper stranding, magnetic wedges and the motor slot openings are modified to reduce AC losses. The paper considers distributed, fractional, slot and concentrated windings, and the results show promising reductions across these different winding configurations

    Association of cardiovascular risk factors with microalbuminuria in hypertensive individuals: the i-SEARCH global study

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    OBJECTIVES: To define the prevalence of microalbuminuria (MAU) in hypertensive outpatients attending a cardiologist or internist (i-SEARCH A) and to compare hypertensive outpatients with or without coronary artery disease (CAD; i-SEARCH B). A secondary objective was to establish a correlation between MAU and known cardiovascular risk factors. METHODS: i-SEARCH was an international, observational study. which enrolled consecutive outpatients with hypertension. Patients with reasons for a false-positive MAU test were excluded. Main outcome measures were the prevalence of MAU as assessed using a dipstick test, hypertension co-morbidities, co-medication and presence of known cardiovascular risk factors. RESULTS: A total of 21,050 patients, from 26 countries, were included in the primary analysis. Overall prevalence of MAU was 58.4% (men > women), although there was considerable variation in prevalence across countries and continents (maximum 71% in Vietnam/Indonesia; minimum 53% in Germany/Switzerland). In multivariate analyses, predictors of MAU were identified to be male gender, high waist circumference, systolic blood pressure >or= 120 mmHg, diastolic blood pressure >or= 100 mmHg, creatinine clearance >or= 50 ml/min, and the presence of diabetes, congestive heart failure, CAD, history of cerebral pathology, peripheral arterial disease, dyspnoea or palpitations. MAU was present more often in patients with CAD than in patients without. CONCLUSIONS: MAU is extremely common in hypertensive outpatients worldwide, especially in patients with known cardiovascular risk factors. Given its importance as a strong, early and independent marker of increased cardiovascular risk in hypertension, the results of i-SEARCH mandate more rigorous MAU screening of hypertensive patients in clinical practice

    Abdominal obesity is associated with microalbuminuria and an elevated cardiovascular risk profile in patients with hypertension

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    BACKGROUND: Overweight and obesity are frequently associated with preventable death and have emerged as a major challenge to public health. There is an ongoing debate on the role of abdominal obesity and its value in predicting cardiovascular and renal outcomes. The present analysis evaluates the prevalence of microalbuminuria (MAU) and conventional cardiovascular risk factors in relation to measures of general and abdominal obesity. METHODS: In this multinational, observational study, 20828 hypertensive out-patients from 26 countries including Europe, North and Latin America, Middle East, and Asia were analyzed. Urinary dipstick screening for MAU was performed as well as data on patient demographics, anthropometric measures, cardiovascular risk factors, comorbid conditions, and cardiovascular drug therapy collected. MAU prevalence was determined by a stepwise logistic regression analysis with cardiovascular risk factors as univariate. RESULTS: In the univariate analysis, MAU prevalence systematically increased with body mass index (BMI) from 54.4% (1st tertial) to 62.1% (3rd tertial) (p < 0.0001), an increase which was also observed for waist circumference (WC). At any level of BMI, MAU increased with WC from 53.5%, 54.8%, and 55.0% (1st tertial of WC in all three BMI tertials) to 61.4%, 62.1%, and 64.0% (3rd tertial of WC in all BMI tertials) (p < 0.0001). In the multivariate analysis, WC, but not BMI was independently associated with MAU. Furthermore, overweight/obesity were associated with the presence of modifiable and nonmodifiable risk factors. CONCLUSION: An abnormal WC, but not BMI appears to be independently associated with MAU, an early marker of cardiovascular and renal risk. Increasing WC confers an incremental risk for MAU at any level of BMI, underlining the prognostic importance of abdominal fat accumulation beyond general obesity

    Luminal Ca2+ Regulation of Single Cardiac Ryanodine Receptors: Insights Provided by Calsequestrin and its Mutants

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    The luminal Ca2+ regulation of cardiac ryanodine receptor (RyR2) was explored at the single channel level. The luminal Ca2+ and Mg2+ sensitivity of single CSQ2-stripped and CSQ2-associated RyR2 channels was defined. Action of wild-type CSQ2 and of two mutant CSQ2s (R33Q and L167H) was also compared. Two luminal Ca2+ regulatory mechanism(s) were identified. One is a RyR2-resident mechanism that is CSQ2 independent and does not distinguish between luminal Ca2+ and Mg2+. This mechanism modulates the maximal efficacy of cytosolic Ca2+ activation. The second luminal Ca2+ regulatory mechanism is CSQ2 dependent and distinguishes between luminal Ca2+ and Mg2+. It does not depend on CSQ2 oligomerization or CSQ2 monomer Ca2+ binding affinity. The key Ca2+-sensitive step in this mechanism may be the Ca2+-dependent CSQ2 interaction with triadin. The CSQ2-dependent mechanism alters the cytosolic Ca2+ sensitivity of the channel. The R33Q CSQ2 mutant can participate in luminal RyR2 Ca2+ regulation but less effectively than wild-type (WT) CSQ2. CSQ2-L167H does not participate in luminal RyR2 Ca2+ regulation. The disparate actions of these two catecholaminergic polymorphic ventricular tachycardia (CPVT)–linked mutants implies that either alteration or elimination of CSQ2-dependent luminal RyR2 regulation can generate the CPVT phenotype. We propose that the RyR2-resident, CSQ2-independent luminal Ca2+ mechanism may assure that all channels respond robustly to large (>5 μM) local cytosolic Ca2+ stimuli, whereas the CSQ2-dependent mechanism may help close RyR2 channels after luminal Ca2+ falls below ∼0.5 mM

    Discrete Cylindrical Vector Beam Generation from an Array of Optical Fibers

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    A novel method is presented for the beam shaping of far field intensity distributions of coherently combined fiber arrays. The fibers are arranged uniformly on the perimeter of a circle, and the linearly polarized beams of equal shape are superimposed such that the far field pattern represents an effective radially polarized vector beam, or discrete cylindrical vector (DCV) beam. The DCV beam is produced by three or more beams that each individually have a varying polarization vector. The beams are appropriately distributed in the near field such that the far field intensity distribution has a central null. This result is in contrast to the situation of parallel linearly polarized beams, where the intensity peaks on axis

    Generating Realistic Synthetic Relational Data through Graph Variational Autoencoders

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    Synthetic data generation has recently gained widespread attention as a more reliable alternative to traditional data anonymization. The involved methods are originally developed for image synthesis. Hence, their application to the typically tabular and relational datasets from healthcare, finance and other industries is non-trivial. While substantial research has been devoted to the generation of realistic tabular datasets, the study of synthetic relational databases is still in its infancy. In this paper, we combine the variational autoencoder framework with graph neural networks to generate realistic synthetic relational databases. We then apply the obtained method to two publicly available databases in computational experiments. The results indicate that real databases' structures are accurately preserved in the resulting synthetic datasets, even for large datasets with advanced data types

    Comparison of Two-Dimensional- and Three-Dimensional-Based U-Net Architectures for Brain Tissue Classification in One-Dimensional Brain CT

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    Brain tissue segmentation plays a crucial role in feature extraction, volumetric quantification, and morphometric analysis of brain scans. For the assessment of brain structure and integrity, CT is a non-invasive, cheaper, faster, and more widely available modality than MRI. However, the clinical application of CT is mostly limited to the visual assessment of brain integrity and exclusion of copathologies. We have previously developed two-dimensional (2D) deep learning-based segmentation networks that successfully classified brain tissue in head CT. Recently, deep learning-based MRI segmentation models successfully use patch-based three-dimensional (3D) segmentation networks. In this study, we aimed to develop patch-based 3D segmentation networks for CT brain tissue classification. Furthermore, we aimed to compare the performance of 2D- and 3D-based segmentation networks to perform brain tissue classification in anisotropic CT scans. For this purpose, we developed 2D and 3D U-Net-based deep learning models that were trained and validated on MR-derived segmentations from scans of 744 participants of the Gothenburg H70 Cohort with both CT and T1-weighted MRI scans acquired timely close to each other. Segmentation performance of both 2D and 3D models was evaluated on 234 unseen datasets using measures of distance, spatial similarity, and tissue volume. Single-task slice-wise processed 2D U-Nets performed better than multitask patch-based 3D U-Nets in CT brain tissue classification. These findings provide support to the use of 2D U-Nets to segment brain tissue in one-dimensional (1D) CT. This could increase the application of CT to detect brain abnormalities in clinical settings
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