1,226 research outputs found

    Technical and Economical Impacts on a Power System by Introducing an HTS FCL

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    Fault current limiters (FCLs) can be considered as key elements in power systems using high temperature superconductors. This analysis takes into account the system benefits provided by the introduction of FCLs in various network configurations. New meshing possibilities, alternative grounding method and increase of power transmission are highlighted. It is the desire of most power system utilities to maximise transferred power and to reduce system losses to a minimum in their systems. These goals could be achieved if the system impedance could be reduced. However, such measures would increase short-circuit currents enormously and endanger equipment and people's safety. This problem could be circumvented by the installation of an FCL. FCLs are often implemented in combination with transformers but the transformer itself could also be designed having an integrated current limiting functionality

    Parametrised Preisach Modelling of Hysteresis in High Temperature Superconductors

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    We present a parametrised Preisach-type model that describes the hysteresis exhibited by the high temperature superconductors (HTSC); hysteresis is the main cause for losses in the subcritical domain. The parametrised model, in combination with electrical measurements, is independent of geometry, number of filaments and other physical measures, and is identified by a novel method that uses electrical lock-in (loss) measurement technique, which greatly enhances the signal to noise ratio. Identification results from measurements on Bi-2223 multi-filamentary tapes are presented. We have further derived exact models for the hysteretic losses in strip and elliptic geometry strips, where the energy losses were calculated by Norris. The paper contains analysis of the Preisach Model, of its losses and of the suggested parametrisation

    Dissemination of Resistant Escherichia coli Among Wild Birds, Rodents, Flies, and Calves on Dairy Farms

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    Antimicrobial resistance (AMR) in bacteria in the livestock is a growing problem, partly due to inappropriate use of antimicrobial drugs. Antimicrobial use (AMU) occurs in Swedish dairy farming but is restricted to the treatment of sick animals based on prescription by a veterinary practitioner. Despite these strict rules, calves shedding antimicrobial resistant Enterobacteriaceae have been recorded both in dairy farms and in slaughterhouses. Yet, not much is known how these bacteria disseminate into the local environment around dairy farms. In this study, we collected samples from four animal sources (fecal samples from calves, birds and rodents, and whole flies) and two environmental sources (cow manure drains and manure pits). From the samples, Escherichia coli was isolated and antimicrobial susceptibility testing performed. A subset of isolates was whole genome sequenced to evaluate relatedness between sources and genomic determinants such as antimicrobial resistance genes (ARGs) and the presence of plasmids were assessed. We detected both ARGs, mobile genetic elements and low rates of AMR. In particular, we observed four potential instances of bacterial clonal sharing in two different animal sources. This demonstrates resistant E. coli dissemination potential within the dairy farm, between calves and scavenger animals (rodents and flies). AMR dissemination and the zoonotic AMR risk is generally low in countries with low and restricted AMU. However, we show that interspecies dissemination does occur, and in countries that have little to no AMU restrictions this risk could be under-estimated

    Light field image compression

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    Light field imaging based on a single-tier camera equipped with a micro-lens array has currently risen up as a practical and prospective approach for future visual applications and services. However, successfully deploying actual light field imaging applications and services will require identifying adequate coding solutions to efficiently handle the massive amount of data involved in these systems. In this context, this chapter presents some of the most recent light field image coding solutions that have been investigated. After a brief review of the current state of the art in image coding formats for light field photography, an experimental study of the rate-distortion performance for different coding formats and architectures is presented. Then, aiming at enabling faster deployment of light field applications and services in the consumer market, a scalable light field coding solution that provides backward compatibility with legacy display devices (e.g., 2D, 3D stereo, and 3D multiview) is also presented. Furthermore, a light field coding scheme based on a sparse set of microimages and the associated blockwise disparity is also presented. This coding scheme is scalable with three layers such that the rendering can be performed with the sparse micro-image set, the reconstructed light field image, and the decoded light field image.info:eu-repo/semantics/acceptedVersio

    Tumour microvessel density as predictor of chemotherapy response in breast cancer patients

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    The aim of this study was to evaluate the predictive value of intratumoural microvessel density in breast cancer. We studied immunohistochemically primary tumours of 104 patients with metastasised breast cancer who took part in a randomised multicentre trial comparing docetaxel to sequential methotrexate and 5-fluorouracil. Vessels were highlighted with factor VIII staining and counted microscopically. Microvessel density was compared with clinical response to chemotherapy and patient survival. The microvessel density of the primary tumour was not significantly associated with patient's response to chemotherapy, time to progression or overall survival in the whole patient population or in the docetaxel or methotrexate and 5-fluorouracil groups. However, disease-free survival was longer in patients with low microvessel density (P=0.01). These findings suggest that microvessel density of the primary tumour cannot be used as a predictive marker for chemotherapy response in advanced breast cancer

    Efficacy and safety of dapagliflozin in patients with type 2 diabetes and moderate renal impairment (chronic kidney disease stage 3A): The DERIVE Study

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    Aims: Dapagliflozin is a selective inhibitor of sodium glucose co-transporter 2 (SGLT2). This study assessed the efficacy and safety of dapagliflozin 10 mg vs placebo in patients with type 2 diabetes (T2D) and moderate renal impairment (estimated glomerular filtration rate [eGFR], 45-59mL/min/1.73m2; chronic kidney disease [CKD] stage 3A). Materials and methods: In this double-blind, parallel group, Phase 3 study (NCT02413398, clinicaltrials.gov) patients with inadequately controlled T2D (HbA1c 7.0%-11.0%) were randomized (1:1) to dapagliflozin 10 mg once daily (N=160) or matching placebo (N=161) for 24weeks. Randomization was stratified by pre-enrolment glucose-lowering therapy. The primary endpoint was change from baseline in HbA1c at Week 24. Results: At Week 24, compared with placebo, dapagliflozin significantly decreased HbA1c (difference [95% CI], -0.34% [-0.53, -0.15]; P < 0.001), body weight (difference [95% CI], -1.25kg [-1.90, -0.59]; P < 0.001), fasting plasma glucose (difference [95% CI], -0.9 mmol/L [-1.5, -0.4]; P = 0.001) and systolic blood pressure (difference [95% CI], -3.1 mmHg [-6.3, 0.0]; P < 0.05). Decreases from baseline in eGFR were greater with dapagliflozin than placebo at Week 24 (-2.49mL/min/1.73m2[-4.96, -0.02]), however, eGFR returned to baseline levels at Week 27 (3 weeks post-treatment) (0.61mL/min/1.73m2[-1.59, 2.81]). No increase in adverse events (AEs; 41.9% vs 47.8%) or serious AEs (5.6% vs 8.7%) were reported with dapagliflozin versus placebo. No AEs of bone fractures, amputations or DKA were reported. Conclusions: The findings of this study (NCT02413398, clinicaltrials.gov) support the positive benefit/risk profile of dapagliflozin for the treatment of patients with T2D and CKD 3A

    Association of objectively measured physical activity with body components in European adolescents

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    Background: Physical activity (PA) is suggested to contribute to fat loss not only through increasing energy expenditure “per se” but also increasing muscle mass; therefore, it would be interesting to better understand the specific associations of PA with the different body’s components such as fat mass and muscle mass. The aim of the present study was to examine the association between objectively measured PA and indices of fat mass and muscle components independently of each other giving, at the same time, gender-specific information in a wide cohort of European adolescents. Methods: A cross-sectional study in a school setting was conducted in 2200 (1016 males) adolescents (14.7 ±1.2 years). Weight, height, skinfold thickness, bioimpedance and PA (accelerometry) were measured. Indices of fat mass (body mass index, % fat mass, sum of skinfolds) and muscular component (assessed as fat-free mass) were calculated. Multiple regression analyses were performed adjusting for several confounders including fat-free mass and fat mass when possible. Results: Vigorous PA was positively associated with height (p?<?0.05) in males, whilst, vigorous PA, moderate-vigorous PA and average PA were negatively associated with all the indices of fat mass (all p?<?0.01) in both genders, except for average PA in relation with body mass index in females. Regarding muscular components, vigorous PA showed positive associations with fat-free mass and muscle mass (all p?<?0.05) in both genders. Average PA was positively associated with fat-free mass (both p?<?0.05) in males and females. Conclusion: The present study suggests that PA, especially vigorous PA, is negatively associated with indices of fat mass and positively associated with markers of muscle mass, after adjusting for several confounders (including indices of fat mass and muscle mass when possible). Future studies should focus not only on the classical relationship between PA and fat mass, but also on PA and muscular components, analyzing the independent role of both with the different PA intensities
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