643 resultados para Padé approximants


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La evidencia de estudios alrededor del mundo relaciona altas concentraciones de contaminantes del aire con efectos agudos y crónicos en la salud. “Muertes por causas cardiovasculares, cáncer de pulmón e infecciones respiratorias en los niños se asoció a niveles de contaminantes que exceden las normas de calidad del aire exterior” (Cohen 2004). Marco teórico: la contaminación del aire se puede definir como “cualquier condición atmosférica en la que las sustancias presentes producen un efecto adverso medible, en la salud del humano, los animales y vegetales, o bien un daño físico en los materiales". Debido al tamaño fino de estas partículas (30 veces más pequeñas que el grosor de un cabello), estas pueden ingresar en las partes más profundas de los pulmones, como son los alvéolos, lo cual relaciona éstas partículas finas y varios problemas de salud incluyendo asma, bronquitis y síntomas respiratorios agudos y crónicos. Metodología: compuesta por 90 pacientes que provienen de dos centros asistenciales, residentes dentro de un radio de 4 km. alrededor de las torres de monitoreo. Método: análisis descriptivo basado en medidas de frecuencias medias y tendencias para caracterizar la población y la exposición a material particulado. Análisis de los datos mediante GRAPH PAD PRISM 6.0 usando las tablas de contingencia para la estimación de diferencia entre proporciones y el riesgo relativo. Se utilizó test de normalidad de D´Agostino Pearson para definir trato estadístico. Se utilizó test de KolmorogovSmirnov y Test de Fisher para encontrar la relación entre calidad de aire y aparecimiento de síntomas. Se aplicó regresión lineal de Deming para establecer relación en cuanto a los síntomas. Resultados: no hay relación estadísticamente significativa entre la calidad del aire y los síntomas respiratorios. La regresión lineal de Deming si encontró cambios estadísticos significativos para los síntomas: sibilancias, taquipnea y estornudos. Conclusiones: no se consideraron otros factores importantes como contaminación intradomiciliar y exposición a tabaco que pudo haber modificado el resultado del estudio. Se demostró que existe una tendencia a relacionar síntomas como la taquipnea, rinorrea, estornudos y sibilancias con niveles no satisfactorios de calidad del aire.

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Introdução: A Depressão é um problema de saúde pública, presente em 7,9% da população Portuguesa, sobretudo nas mulheres. A sua prevalência está a aumentar exponencialmente, assim como o consumo de ADTs, os quais podem causar alterações eletrocardiográficas. Objetivo: Estudar as alterações eletrofisiológicas induzidas pelo tratamento psicofarmacológico com Clomipramina endovenosa, em contexto psiquiátrico. Métodos: Realizou-se um estudo do tipo observacional, longitudinal e prospetivo, tendo como base a população referenciada para o CHEDV- Hospital de São João da Madeira. Os dados são relativos ao período entre o dia 11 de Março e 9 de Setembro de 2013. A amostra é constituída por dois grupos de indivíduos do sexo feminino, agrupados em função da mediana de idade (47 anos), com o grupo 1 (≤mediana idade) e o grupo 2 (>mediana idade), cada um com 15 indivíduos. Foram recolhidos por inquérito os dados sociodemográficos, os FRCVs, as medidas antropométricas e efetuada a avaliação pressão arterial no início, pico máximo e final do tratamento. Assim como, a análise comparativa no início e no pico máximo, da FC e dos diferentes intervalos (PQ, QRS, QT, QTc, QTpeak, jT, jTpeak e Tpeak-end) e da dispersão (QT e QTc). Resultados: Foram encontrados aumentos quase estatisticamente significativos no intervalo QTpeak (p=0,06) e jTpeak (p=0,05), assim como diminuição do Tpeak-end (p=0,05) nas mulheres do grupo 1 (39,27±6,22 anos), bem como aumento da PAD (p=0,09). Relativamente aos outros parâmetros eletrocardiográficos não se verificam alterações estatisticamente significativas, em nenhum dos grupos, nem na amostra total. Conclusão: A medicação causa prolongação e dispersão espacial da repolarização, sobretudo nas mulheres do grupo 1, apesar de não ser estatisticamente significativa, podendo contribuir para maior instabilidade elétrica ventricular, da qual as arritmias ventriculares malignas poderão ser a expressão clínica expectável.

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Dissertação de Mestrado para obtenção do grau de Mestre em Design de Comunicação, apresentada na Universidade de Lisboa - Faculdade de Arquitectura.

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In the multi-core CPU world, transactional memory (TM)has emerged as an alternative to lock-based programming for thread synchronization. Recent research proposes the use of TM in GPU architectures, where a high number of computing threads, organized in SIMT fashion, requires an effective synchronization method. In contrast to CPUs, GPUs offer two memory spaces: global memory and local memory. The local memory space serves as a shared scratch-pad for a subset of the computing threads, and it is used by programmers to speed-up their applications thanks to its low latency. Prior work from the authors proposed a lightweight hardware TM (HTM) support based in the local memory, modifying the SIMT execution model and adding a conflict detection mechanism. An efficient implementation of these features is key in order to provide an effective synchronization mechanism at the local memory level. After a quick description of the main features of our HTM design for GPU local memory, in this work we gather together a number of proposals designed with the aim of improving those mechanisms with high impact on performance. Firstly, the SIMT execution model is modified to increase the parallelism of the application when transactions must be serialized in order to make forward progress. Secondly, the conflict detection mechanism is optimized depending on application characteristics, such us the read/write sets, the probability of conflict between transactions and the existence of read-only transactions. As these features can be present in hardware simultaneously, it is a task of the compiler and runtime to determine which ones are more important for a given application. This work includes a discussion on the analysis to be done in order to choose the best configuration solution.

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El desarrollo acelerado de la ciencia y 1a técnica en los últimos cincuenta años, la incorporación de la computadora a la enseñanza de la matemática y su uso creciente en esta dirección, nos exige revisar los programas de las diferentes asignaturas que comprende la matemática con el objetivo de perfeccionarlos y actualizarlos, pues muchos de los contenidos que aparecen en dichos programas se convierten en obsoletos. El propósito de este trabajo es mostrar las bondades de la aproximación racional o más precisamente la aproximación según Padé, que con ayuda de algún asistente matemático nos sugiere su tratamiento en los cursos de pregrado y así complementar la aproximación según Taylor.

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In order to identify the impact of teaching menstrual health and hygiene with reusable menstrual pads on knowledge retention and school attendance, qualitative and quantitative data was collected from three rural schools in three districts of eastern Uganda: Amuria, Bukedea, and Ngora. Research techniques employed were preliminary and post surveys of 85 young women; average age 16.9 years. Findings include positive and negative results. Participants’ feelings of normalcy and comfort increased and participants had improved understanding of sexual climax and appropriate menstrual management strategies. There was no statistically significant impact of teaching on topics of sexual intercourse or pregnancy. The impact of reusable menstrual pad sanitary technology on school attendance was negative as more young women reported missing up to a full day of school during their menstrual period (χ2 (3, 73) = 7.81, p = 0.05). Study limitations are discussed and future work is suggested.

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Background and Purpose. This descriptive cohort study investigated a physical therapy program of pelvic-floor neuromuscular electrostimulation (NMES) combined with exercises, with the aim of developing a simple, inexpensive, and conservative treatment for postpartum genuine stress incontinence (GSI). Subjects. Eight female subjects with urodynamically established GSI persisting more than 3 months after delivery participated in the study. The subjects ranged in age from 24 to 37 years (X̅=32, SD=4.2). Methods. This was a descriptive multiple-subject cohort study. Each subject received a total of nine treatment sessions during 3 consecutive weeks, consisting of two 15-minute sessions of NMES followed by a 15-minute pelvic-floor muscle exercise program. Patients also practiced daily pelvic-floor exercises during the 3-week treatment period. The treatment intervention was measured using three separate variables. Maximum muscle contractions (pretraining, during training, and posttraining) were measured indirectly as pressure, using perineometry. Urine loss pretraining and posttraining was measured by means of a Pad test. Self-reported frequency of incontinence was recorded daily throughout the period of the study, using a diary. Data were analyzed using a one-way repeated measures analysis of variance (ANOVA), a Wilcoxon signed-ranks test, and a Friedman two-way ANOVA by ranks. Results. The results indicated that maximum pressure generated by pelvic-floor contractions was greater and both the quantity of urine loss and the frequency of incontinence were lower following the implementation of the physical therapy program. Five subjects became continent, and three others improved. A follow-up survey 1 year later confirmed the consistency of these results. Conclusion and Discussion. The results suggest that the proposed physical therapy program may influence postpartum GSI. Further studies are needed to validate this simple, inexpensive, and conservative physical therapy protocol.

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Objective: To assess the effectiveness of 12 weekly physical therapy sessions for urinary incontinence (UI) compared with a control intervention, for reducing the number of UI episodes measured with the 7-day bladder diary, at 3 months and 1 year postrandomization. Methods: A single parallel-group randomized controlled trial was conducted at one outpatient public health center, in postmenopausal women aged 55 years and over with osteoporosis or low bone density and UI. Women were randomized to physical therapy (PT) for UI or osteoporosis education. The primary outcome measure was number of leakage episodes on the 7-day bladder diary, assessed at baseline, after treatment and at 1 year. The secondary outcome measures included the pad test and disease-specific quality of life and self-efficacy questionnaires assessed at the same timepoints. Results: Forty-eight women participated (24 per group). Two participants dropped out of each group and one participant was deceased before 3-month follow-up. Intention-to-treat analysis was undertaken. At 3 months and 1 year, there was a statistically significant difference in the number of leakage episodes on the 7-day bladder diary (3 mo: P = 0.04; 1 y: P = 0.01) in favor of the PT group. The effect size was 0.34 at 1 year. There were no harms reported. Conclusions: After a 12-week course of PT once per week for UI, PT group participants had a 75% reduction in weekly median number of leakage episodes, whereas the control group's condition had no improvement. At 1 year, the PT group participants maintained this improvement, whereas the control group's incontinence worsened.

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Trabalho de Projeto apresentado à Escola Superior de Educação do Instituto Politécnico de Castelo Branco para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Atividade Física.

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Sweet potato is an important strategic agricultural crop grown in many countries around the world. The roots and aerial vine components of the crop are used for both human consumption and, to some extent as a cheap source of animal feed. In spite of its economic value and growing contribution to health and nutrition, harvested sweet potato roots and aerial vine components has limited shelf-life and is easily susceptible to post-harvest losses. Although post-harvest losses of both sweet potato roots and aerial vine components is significant, there is no information available that will support the design and development of appropriate storage and preservation systems. In this context, the present study was initiated to improve scientific knowledge about sweet potato post-harvest handling. Additionally, the study also seeks to develop a PV ventilated mud storehouse for storage of sweet potato roots under tropical conditions. In study one, airflow resistance of sweet potato aerial vine components was investigated. The influence of different operating parameters such as airflow rate, moisture content and bulk depth at different levels on airflow resistance was analyzed. All the operating parameters were observed to have significant (P < 0.01) effect on airflow resistance. Prediction models were developed and were found to adequately describe the experimental pressure drop data. In study two, the resistance of airflow through unwashed and clean sweet potato roots was investigated. The effect of sweet potato roots shape factor, surface roughness, orientation to airflow, and presence of soil fraction on airflow resistance was also assessed. The pressure drop through unwashed and clean sweet potato roots was observed to increase with higher airflow, bed depth, root grade composition, and presence of soil fraction. The physical properties of the roots were incorporated into a modified Ergun model and compared with a modified Shedd’s model. The modified Ergun model provided the best fit to the experimental data when compared with the modified Shedd’s model. In study three, the effect of sweet potato root size (medium and large), different air velocity and temperature on the cooling/or heating rate and time of individual sweet potato roots were investigated. Also, a simulation model which is based on the fundamental solution of the transient equations was proposed for estimating the cooling and heating time at the centre of sweet potato roots. The results showed that increasing air velocity during cooling and heating significantly (P < 0.05) affects the cooling and heating times. Furthermore, the cooling and heating times were significantly different (P < 0.05) among medium and large size sweet potato roots. Comparison of the simulation results with experimental data confirmed that the transient simulation model can be used to accurately estimate the cooling and heating times of whole sweet potato roots under forced convection conditions. In study four, the performance of charcoal evaporative cooling pad configurations for integration into sweet potato roots storage systems was investigated. The experiments were carried out at different levels of air velocity, water flow rates, and three pad configurations: single layer pad (SLP), double layers pad (DLP) and triple layers pad (TLP) made out of small and large size charcoal particles. The results showed that higher air velocity has tremendous effect on pressure drop. Increasing the water flow rate above the range tested had no practical benefits in terms of cooling. It was observed that DLP and TLD configurations with larger wet surface area for both types of pads provided high cooling efficiencies. In study five, CFD technique in the ANSYS Fluent software was used to simulate airflow distribution in a low-cost mud storehouse. By theoretically investigating different geometries of air inlet, plenum chamber, and outlet as well as its placement using ANSYS Fluent software, an acceptable geometry with uniform air distribution was selected and constructed. Experimental measurements validated the selected design. In study six, the performance of the developed PV ventilated system was investigated. Field measurements showed satisfactory results of the directly coupled PV ventilated system. Furthermore, the option of integrating a low-cost evaporative cooling system into the mud storage structure was also investigated. The results showed a reduction of ambient temperature inside the mud storehouse while relative humidity was enhanced. The ability of the developed storage system to provide and maintain airflow, temperature and relative humidity which are the key parameters for shelf-life extension of sweet potato roots highlight its ability to reduce post-harvest losses at the farmer level, particularly under tropical climate conditions.

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Background and Purpose. This descriptive cohort study investigated a physical therapy program of pelvic-floor neuromuscular electrostimulation (NMES) combined with exercises, with the aim of developing a simple, inexpensive, and conservative treatment for postpartum genuine stress incontinence (GSI). Subjects. Eight female subjects with urodynamically established GSI persisting more than 3 months after delivery participated in the study. The subjects ranged in age from 24 to 37 years (X̅=32, SD=4.2). Methods. This was a descriptive multiple-subject cohort study. Each subject received a total of nine treatment sessions during 3 consecutive weeks, consisting of two 15-minute sessions of NMES followed by a 15-minute pelvic-floor muscle exercise program. Patients also practiced daily pelvic-floor exercises during the 3-week treatment period. The treatment intervention was measured using three separate variables. Maximum muscle contractions (pretraining, during training, and posttraining) were measured indirectly as pressure, using perineometry. Urine loss pretraining and posttraining was measured by means of a Pad test. Self-reported frequency of incontinence was recorded daily throughout the period of the study, using a diary. Data were analyzed using a one-way repeated measures analysis of variance (ANOVA), a Wilcoxon signed-ranks test, and a Friedman two-way ANOVA by ranks. Results. The results indicated that maximum pressure generated by pelvic-floor contractions was greater and both the quantity of urine loss and the frequency of incontinence were lower following the implementation of the physical therapy program. Five subjects became continent, and three others improved. A follow-up survey 1 year later confirmed the consistency of these results. Conclusion and Discussion. The results suggest that the proposed physical therapy program may influence postpartum GSI. Further studies are needed to validate this simple, inexpensive, and conservative physical therapy protocol.

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Objective: To assess the effectiveness of 12 weekly physical therapy sessions for urinary incontinence (UI) compared with a control intervention, for reducing the number of UI episodes measured with the 7-day bladder diary, at 3 months and 1 year postrandomization. Methods: A single parallel-group randomized controlled trial was conducted at one outpatient public health center, in postmenopausal women aged 55 years and over with osteoporosis or low bone density and UI. Women were randomized to physical therapy (PT) for UI or osteoporosis education. The primary outcome measure was number of leakage episodes on the 7-day bladder diary, assessed at baseline, after treatment and at 1 year. The secondary outcome measures included the pad test and disease-specific quality of life and self-efficacy questionnaires assessed at the same timepoints. Results: Forty-eight women participated (24 per group). Two participants dropped out of each group and one participant was deceased before 3-month follow-up. Intention-to-treat analysis was undertaken. At 3 months and 1 year, there was a statistically significant difference in the number of leakage episodes on the 7-day bladder diary (3 mo: P = 0.04; 1 y: P = 0.01) in favor of the PT group. The effect size was 0.34 at 1 year. There were no harms reported. Conclusions: After a 12-week course of PT once per week for UI, PT group participants had a 75% reduction in weekly median number of leakage episodes, whereas the control group's condition had no improvement. At 1 year, the PT group participants maintained this improvement, whereas the control group's incontinence worsened.

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Introducción: La percepción puede ser considerada principalmente como un grupo de procesos internos en las personas que genera en los observadores una representación mental del entorno. Percibir es adelantarse al suceso, a lo que puede llegar a suceder, determinando lo que puede ser un peligro a nuestra seguridad y salud. Objetivo: El presente estudio tiene como objetivo determinar la percepción de los trabajadores acerca de la seguridad en el trabajo en áreas de procesos automatizados y mecánicas en una empresa del sector de gas natural en el departamento de Casanare, Colombia 2016. Metodología: Se llevó a cabo un estudio de corte transversal en 50 trabajadores de una empresa del sector de gas natural en Casanare. Se uttilizó el Cuestionario nórdico NOSACQ-50-Spanish, instrumento validado para evaluar la percepción acerca de la seguridad y salud en el lugar de trabajo. Se incluyeron variables sociodemográficas, laborales y las relacionadas con la percepción de la seguridad en el lugar del trabajo. Para el análsiis estadistico se calcularon medidas de tendencia central y de dispersión. El estudio de la percepción de seguridad tuvo como puntos de corte: < 2,5 mala percepción y > 2,5 buena percepción. Se emplearon pruebas de asociación X2 o test exacto de Fisher (valores esperados <5) y medidas de asociación OR con sus intervalos de confianza del 95% y se usaron modelos de regresión lineal. Resultados: El total de trabajadores fue de 50 personas, el 76% correspondió al sexo masculino y la mayor distribución se presentó en áreas mecánicas con 52% frente al 48% que se encontró en áreas automatizadas. Se halló asociación estadísticamente significativa entre las variables sociodemográficas área/sexo (Pr = 0,016), indicando que a los trabajadores de sexo femenino se les ubican en el área mecánica mientras que los de sexo masculino, laboran en todas las áreas sin darle relevancia al género. También se encontró asociación con las variables área/año de nacimiento (Pr =0.022), indicando que en el área automatizada se dejan profesionales con promedio de edad de 32 años, por el tipo de requisitos en competencias que exigen para ejecutar las labores. Para las demás variables ocupacionales que evaluaron la percepción de seguridad frente al trabajo, no se encontró asociación significativa. Conclusión: Los resultados permiten realizar acciones en pro de mejorar la percepción de los trabajadores dentro de la organización. Se podrán desarrollar programas de seguridad y salud en el trabajo, que respondan de manera efectiva a los peligros laborales detectados.