180 research outputs found

    Создание испытательного стенда для проверки шумов операционного усилителя

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    Объектом исследования является стенд для определения шумовых параметров операционного усилителя. Цель работы – создание испытательного стенда для определения действительных шумовых параметров операционного усилителя, которые необходимы при конструировании прецизионных средств измерений, а также, знания значений которых, позволяют определить целесообразность использования конкретного операционного усилителя в любом устройстве. В результате работы был создан испытательный стенд для определения шумовых параметров операционного усилителя, управление которым осуществляется с помощью персонального компьютера, а также проведены испытания и определены некоторые шумовые параметры операционного усилителя К544УД2А.The object of the research is bench to determine the noise parameters of operational amplifier. The work purpose – creation of a test stand to determine actual noise levels of the operational amplifier, which are necessary in the design of precision measuring instruments, as well as, knowledge of the values of which determine the appropriateness of a particular operational amplifier to any device. The resulting works were created a test stand for determining the noise parameters of an operational amplifier that is controlled using a personal computer and also tested and identified some of the noise parameters of the operational amplifier К544УД2А

    Responsible innovation and political accountability: genetically modified mosquitoes in Brazil

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    This is the author accepted manuscript. The final version is available from Taylor & Francis via the DOI in this record.In this paper, we analyse the introduction of genetically modified (GM) mosquitoes in Brazil and use this case to probe the notion of Responsible Innovation and its applicability to the development of new public health biotechnologies in the global South. OX513A, a strain of GM Aedes aegypti mosquitoes developed by the British firm Oxitec, has been used experimentally in Brazil since 2009, when it was imported into the country as a promising new tool in the fight against dengue. We discuss the regulatory history of OX513A in Brazil, as well as the forms of ‘community engagement’ that have accompanied the release of transgenic mosquitoes. We argue that the conduct of a scientific research project is only part of a broader effort to localise insect biotechnology in Brazil, an effort that has enjoyed very visible support from political authorities across the country. We conclude by arguing that if the framework of Responsible Innovation is to have purchase on this sort of transnational and multifaceted innovation trajectory, it has to include at its centre a strong notion of political accountability.Research by Javier Lezaun was supported by the European Research Council (ERC) under the European Community’s Seventh Framework Programme [grant number 263447: BioProperty]. Research by Sarah Hartley was supported by the Leverhulme Trust ‘Making Science Public’ programme [grant number RP2011-SP-013]

    Clinical and anatomopathological features of eosinophilic oesophagitis in children and adults

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    Introduction: Eosinophilic oesophagitis (EoE) is a chronic clinical-pathological disorder with an immunological basis characterised by symptoms of oesophageal dysfunction and, histologically, eosinophilic inflammation. Objective: To evaluate the clinical characteristics and differences in children and adults diagnosed with EoE in a tertiary level hospital. Method: Descriptive, retrospective and cross-sectional study. We randomly selected 40 children and 40 adults diagnosed with EoE between 2009 and 2016. The patient characteristics were analysed by means of epidemiological, clinical, diagnostic and therapeutic variables. Results: The average age at diagnosis was 10 years (children) and 34 years (adults), with a higher frequency in males. The majority were sensitised to aeroallergens (77.5% children vs. 82.5% adults) and foods (75% children vs. 82.5% adults). Statistically significant differences were detected in sensitisation to fruits (p = 0.007) and grains (p < 0.001). Differences were observed in impaction (22.5% children vs. 82.5% adults), dysphagia (42.5% children vs. 77.5% adults) and abdominal pain (25% children vs. 7.5% adults). Endoscopy showed that children had a higher frequency of exudates (92.5%) and adults, trachealisation (50% vs. 5%) and stenosis (17.5% vs. 2.5%). Statistically significant differences were found in treatment with topical corticosteroids (30% children vs. 77.5% adults), with a variable positive response. 77.5% of the patients received elimination diets. Conclusions: Statistically significant differences were observed between the paediatric and adult populations in the food sensitisation profiles, clinical manifestations, endoscopic findings and treatments received. This is a complex pathology that calls for a multidisciplinary team and would require new non-invasive techniques to facilitate its management

    Optimization of the management of platelet concentrate stocks in the Basque Country using mathematical simulation

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    Background and Objectives: The management of platelet concentrate (PC) stocks is not simple given their short shelf life and variable demand. In general, managers decide on PC production based on personal experience. The objective of this study was to provide a tool to help decide how many PC units to produce each day in a more rational and objective way. Materials and Methods: From the historical data on PCs produced, transfused and discarded in the Basque Country in 2012, a mathematical model was built, based on the normality of the time series of the transfusions performed on each day of the week throughout the year. This model was implemented in an easy-to-use Excel spreadsheet and validated using real production data from 2013. Results: Comparing with real 2013 data, in the best scenario, the number of PC units that expired was 87·7% lower, PC production, 14·3% lower and the age of the PCs transfused nearly 1-day younger in the simulation. If we want to ensure a minimum stock at the end of each day, the outdating rate and average age of the transfused PCs progressively increase. Conclusion: The practical application of the designed tool can facilitate decision-making about how many PC units to produce each day, resulting in very significant reductions in PC production and wastage and corresponding cost savings, together with an almost 1 day decrease in the mean age of PCs transfused

    Suppressed-scattering spectral windows for radiative cooling applications

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    The scattering of light by resonant nanoparticles is a key process for enhancing the solar reflectance in daylight radiative cooling. Here, we investigate the impact of material dispersion on the scattering performance of popular nanoparticles for radiative cooling applications. We show that, due to material dispersion, nanoparticles with a qualitatively similar response at visible frequencies exhibit fundamentally different scattering properties at infrared frequencies. It is found that dispersive nanoparticles exhibit suppressed-scattering windows, allowing for selective thermal emission within a highly reflective sample. The existence of suppressed-scattering windows solely depends on material dispersion, and they appear pinned to the same wavelength even in random composite materials and periodic metasurfaces. Finally, we investigate calcium-silicate-hydrate (CSH), the main phase of concrete, as an example of a dispersive host, illustrating that the co-design of nanoparticles and host allows for tuning of the suppressed-scattering windows. Our results indicate that controlled nanoporosities would enable concrete with daylight passive radiative cooling capabilities

    Big data and machine learning to improve european grapevine moth (Lobesia botrana) predictions

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    Machine Learning (ML) techniques can be used to convert Big Data into valuable information for agri-environmental applications, such as predictive pest modeling. Lobesia botrana (Denis &amp; Schiffermüller) 1775 (Lepidoptera: Tortricidae) is one of the main pests of grapevine, causing high productivity losses in some vineyards worldwide. This work focuses on the optimization of the Touzeau model, a classical correlation model between temperature and L. botrana development using data-driven models. Data collected from field observations were combined with 30 GB of registered weather data updated every 30 min to train the ML models and make predictions on this pest’s flights, as well as to assess the accuracy of both Touzeau and ML models. The results obtained highlight a much higher F1 score of the ML models in comparison with the Touzeau model. The best-performing model was an artificial neural network of four layers, which considered several variables together and not only the temperature, taking advantage of the ability of ML models to find relationships in nonlinear systems. Despite the room for improvement of artificial intelligence-based models, the process and results presented herein highlight the benefits of ML applied to agricultural pest management strategies

    Effects of a massage protocol in tensiomyographic and myotonometric proprieties

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    Background: Pre-competition massage is usually used to improve athletic performance and reduce risk of injury. Despite its usual use, the effects of pre-competition massage on neuromuscular function have barely been studied. The aim of this study is to evaluate the effects of the pre-competition massage over the gastrocnemius neuromuscular function. Method: The study is a quasi-experimental clinical trial thirty healthy athletes were enrolled in the study. Subjects received an intervention in one leg (experimental), consisting of a massage, and no intervention in the opposite leg (control). From all values of neuromuscular function, the following were analyzed: contraction time (Tc) and maximal displacement (Dm) by tensiomyography, and stiffness and tone by myotonometry. Results: Main effects of pre-competition massage on neuromuscular function include a significant (p < 0.05) increase in Tc and Dm variables, as well as a reduction in stiffness and tone. Conclusion: Data shows an increase in Tc and maximal radial displacement (Dm) variables, as well as a reduction in stiffness and tone. More quality studies are needed to draw clear conclusions about the effects of pre-competition massage. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    Effectiveness of Protein Supplementation Combined with Resistance Training on Muscle Strength and Physical Performance in Elderly: A Systematic Review and Meta-Analysis

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    The aim of this study was to evaluate the effectiveness of the combination of resistance training (RT) and protein supplementation (PS), compared to RT alone or combined with a placebo (plS), in the improvement of muscle strength and physical performance. The search strategy in PubMed, Cochrane Library, and Web of Sciences databases found a total of 294 studies. Once inclusion and exclusion criteria were applied, 16 studies were included for the qualitative analysis. A total of 657 healthy elderly (>60 years) participants were analysed. Finally, 15 articles were included in the quantitative analysis with one being excluded due to issues with data availability. Upper-limb, lower-limb, and handgrip strength were the primary outcomes of the meta-analysis. The secondary outcomes, related to physical performance, were Short Physical Performance Battery (SPPB), gait speed, and the five-chair-rise test (5CRT). The main results of the meta-analysis show no statistical differences for upper-limb (SMD: 0.56, 95% CI: -0.09, 1.21, p = 0.09, I2 = 68%), lower-limb (SMD: 0.00, 95% CI: -0.18, 0.18, p = 1.0, I2 = 11%), and handgrip strength (SMD: 0.03, 95% CI: -0.26, 0.32, p = 0.84, I2 = 0%) between the RT + PS and the RT alone (or combined with plS). Moreover, no statistical differences were found relating to physical performance. In view of these results, protein supplementation combined with RT does not provide additional benefits compared to RT alone or with plS in healthy elderly adults

    Deliberating stratospheric aerosols for climate geoengineering and the SPICE project

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    Increasing concerns about the narrowing window for averting dangerous climate change have prompted calls for research into geoengineering, alongside dialogue with the public regarding this as a possible response. We report results of the first public engagement study to explore the ethics and acceptability of stratospheric aerosol technology and a proposed field trial (the Stratospheric Particle Injection for Climate Engineering (SPICE) ‘pipe and balloon’ test bed) of components for an aerosol deployment mechanism. Although almost all of our participants were willing to allow the field trial to proceed, very few were comfortable with using stratospheric aerosols. This Perspective also discusses how these findings were used in a responsible innovation process for the SPICE project initiated by the UK’s research councils
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