583 research outputs found

    SEMICONDUCTOR DEVICE FOR DETECTION OF FRET SIGNALS

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    The transducer consists on a semiconductor device based on two stacked-i-n  heterostructures, that were designed to detect the emissions of the fluorescence resonance energy transfer between fluorophores in the cyan (470 nm) and yellow (588 nm) range of the spectrum. This research represents a preliminary study on the use of such wavelength sensitive devices as photodetectors for this kind of application. The device was characterized through optoelectronic measurements concerning spectral response measurements under different electrical and optical biasing conditions. To simulate the FRET pairs a chromatic time dependent combination of cyan and yellow wavelengths was applied to the device. The generated photocurrent was measured under reverse and forward bias to readout the output photocurrent signal. Different wavelength biasing light was also superimposed. Results show that under reverse bias the photocurrent signal presents four separate levels each one assigned to the different wavelength combinations of the FRET pairs. If a blue background is superimposed the yellow channel is enhanced and the cyan suppressed while under red irradiation the opposite behavior occurs. So under suitable biasing light the transducer is able to detect separately the cyan and yellow fluorescence pairs. An electrical model, supported by a numerical simulation supports the transduction mechanism of the device

    Atividade da reductase do nitrato em milho (Zea mays L.) var. Piranão em níveis crescentes de nitrogênio.

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    O objetivo deste trabalho foi estudar a atividade da reductase do nitrato em milho (Zea mays L. var. "Piranao") cultivado em solucao nutritiva e sob doses crescentes de nitrogenio, na forma de NO3. A atividade da enzima foi analisada aos 56 dias de idade, em rodelas de folhas do terco medio da folha +4, seguindo-se a metodologia proposta por MULDER et alii (15), adaptada por MALAVOLTA (13). Os resultados permitiram concluir que o aumento do teor de NO3 no meio favoreceu a atividade da reductase do nitrato ate o nivel maximo de 40,51 ug de N-NO-2/g de materia verde, correspondente a um nivel de 296,19 mg de N/litro de solucao nutritiva. Os resultados obtidos nas condicoes experimentais em que foi realizado o trabalho correspondem, provavelmente, ao maximo da capacidade genetica da variedade estudada. Os teores de N encontrados nas folhas inferiores foram mais baixos do que os das folhas superiores, em funcao da alta mobilizacao do elemento para as partes mais novas da planta. Houve tambem correlacao positiva entre a atividade da reductase do nitrato, o teor de N total da folha e a producao de materia seca

    School Feeding Programs in Middle Childhood and Adolescence

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    Almost every country in the world has a national school feeding program to provide daily snacks or meals to school-attending children and adolescents. The interven- tions reach an estimated 368 million children and ado- lescents globally. The total investment in the intervention is projected to be as much as US$75 billion annually (WFP 2013), largely from government budgets. School feeding may contribute to multiple objectives, including social safety nets, education, nutrition, health, and local agriculture. Its contribution to education objectives is well recognized and documented, while its role as a social safety net was underscored following the food and fuel crises of 2007 and 2008 (Bundy and others 2009). In terms of health and nutrition, school feeding contributes to the continuum of development by build- ing on investments made earlier in the life course, including maternal and infant health interventions and early child development interventions (see chapter 7 in this volume, Alderman and others 2017). School feeding may also help leverage global efforts to enhance the inclusiveness of education for out-of-school children, adolescent girls, and disabled persons, as called for in the Sustainable Development Goals (see chapter 17 in this volume, Graham and others 2017). Although the Disease Control Priorities series focuses on low- and middle-income countries (LMICs), evidence from high-income countries (HICs) is included because of the near universality of school feeding and the insights that inclusion can provide as economies develop. For example, the design of school feeding in countries under- going the nutrition transition 1 may provide some lessons on how to shift from providing access to sufficient calo- ries to promoting healthful diets and dietary behaviors for children and adolescents (WFP 2013). Agricultural development has increasingly gained attention. It is clear that to enable the transition to sus- tainable, scalable government-run programs, the inclu- sion of the agricultural sector is essential (Bundy and others 2009; Drake and others 2016). Accounting for the full benefits of school feeding through cost- effectiveness and benefit-cost analysis is challenging, similar to other complex interventions, but undertaking this accounting is critical for assessing the tradeoffs with competing investments. This chapter reviews the evidence about how school feeding meets these objectives and provides some indi- cation of costs in relation to benefits. The costs of the intervention are well established; estimates that encompass all the benefits of school feeding are more challenging. The benefits must be quantified and translated to the same unit to allow for aggregation. Moreover, how school feeding interventions are designed and implemented varies significantly across countries. Given that delivery of school feeding often involves multiple sectors, common policy frameworks and cross-sectoral coordination are required to achieve maximum benefit (Bundy and others 2009). Several other chapters in the volume highlight school feeding. These include chapter 11 (Lassi, Moin, and Bhutta 2017), chapter 20 (Bundy and others 2017), chapter 22 (Plaut and others 2017), and chapter 25 (Fernandes and Aurino 2017)

    Effects of exercise programs on phase angle in older adults: a systematic review and meta-analysis.

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    The purpose of this study was to calculate the effects of exercise programs on phase angle (PhA) in older people. A systematic review was undertaken in multiple electronic databases in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement guidelines for the purposes of selecting randomized controlled trials that measured the effects of the exercise programs on PhA in older adults on 31 March 2022. We carried out a random-effect meta-analysis for the effects of exercise programs on PhA. Additionally, we analysed the differences between subgroups in terms of weekly frequency, number of sets and repetitions, and duration of interventions. Studies were methodological assessed through the PEDro scale where one had excellent, ten had good, and three had poor methodological quality. For the purposes of the study, fourteen studies met the criteria for inclusion. However, four studies did not have enough information to be included in the quantitative analysis. The remaining ten articles revealed moderate effects on PhA in favour of intervention groups (p=0.009, SMD=0.72 [0.46–0.99], I2=54%). The meta-analysis also showed that interventions lasting twelve weeks are more successful in generating positive effects on PhA as opposed to eight weeks (SMD’s=0.79 vs. 0.64, respectively). These results indicate that resistance training (RT) is an effective and safe to improve PhA in the older people, especially through RT programs lasting from eight to twelve weeks. A novel finding of this study was that RT is the most used type of exercise by authors when assessing the PhA in older adults

    SEMICONDUCTOR DEVICE FOR DETECTION OF FRET SIGNALS

    Get PDF
    The transducer consists on a semiconductor device based on two stacked-i-n  heterostructures, that were designed to detect the emissions of the fluorescence resonance energy transfer between fluorophores in the cyan (470 nm) and yellow (588 nm) range of the spectrum. This research represents a preliminary study on the use of such wavelength sensitive devices as photodetectors for this kind of application. The device was characterized through optoelectronic measurements concerning spectral response measurements under different electrical and optical biasing conditions. To simulate the FRET pairs a chromatic time dependent combination of cyan and yellow wavelengths was applied to the device. The generated photocurrent was measured under reverse and forward bias to readout the output photocurrent signal. Different wavelength biasing light was also superimposed. Results show that under reverse bias the photocurrent signal presents four separate levels each one assigned to the different wavelength combinations of the FRET pairs. If a blue background is superimposed the yellow channel is enhanced and the cyan suppressed while under red irradiation the opposite behavior occurs. So under suitable biasing light the transducer is able to detect separately the cyan and yellow fluorescence pairs. An electrical model, supported by a numerical simulation supports the transduction mechanism of the device

    Características de fibra e fio do algodoeiro BRS 200 marrom sob condições de diferentes lâminas de irrigação e doses de regulador de crescimento.

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    O experimento foi conduzido na estação experimental da Embrapa Algodão em Barbalha ? Ceara, no período de agosto a novembro de 2003, objetivando estudar as características de fibra e fio do algodoeiro BRS 200 Marrom submetidas a condições de diferentes lâminas de irrigação e doses de regulador de crescimento. O delineamento foi em blocos ao acaso, num arranjo fatorial 5 x 4, com 4 repetições. Os fatores estudados foram quatro doses de regulador de crescimento (0,0 1,0 1,5 2,0, L/ha) e cinco lâminas de irrigação (125,30; 298,35; 353,89; 521,86 e 741,64 mm). O plantio foi conduzido em fileiras duplas (1,80 m x 0,45 m x 0,20 m). As avaliações realizadas consistiram nas características de fibra e fio: maturidade, uniformidade, resistência e comprimento. As características de fibra e fio foram influenciadas pelas lâminas de irrigação, enquanto o regulador de crescimento não influenciou. Apesar das diferenças significativas entre as variáveis da característica intrínsecas da fibra e fio, obteve-se resultados satisfatório onde todas as características avaliadas estão dentro dos padrões exigidos pela moderna industria têxtil
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