PERCEPÇÕES E PRÁTICAS DE MÃES DE PRÉ-ESCOLARES BRASILEIROS ACERCA DA ALIMENTAÇÃO DOS FILHOS

Introduction: In March, 2006, there were 5,.588,.153 children aged 4 to 6 years enrolled in Brazilian pre-schools. Unfortunately only 3.8% of these institutions have a health professional, in addition to which, the relationship between the pre-schools and the Health System is poor. The first 5 years of life are crucial in the development of good eating habits, and consequently, for preventing degenerative illnesses in later life, such as obesity. Objective: The aim of this study is to identify and analyze maternal perceptions and practices concerning the eating behaviors of children aged 3 to 6 years attending a Brazilian pre-school. Material and methods: A qualitative survey was carried out using individual, non-directive interviews. 21 mothers were interviewed: 10 with children enrolled in full-time classes and 11 with children in part-time classes. In terms of height and weight, the children were between the 10 and 90 percentile (NCHS standard). For data analysis we used the method of Thematic Content Analysis, as proposed by Bardin. Results: Diet is an issue of major concern for these mothers. The main difficulty is child development: they do not know how to deal with it. Therefore, they use harmful strategies, such as bargaining, coercion, disguising food, and punishment. Also, they do not know how food is served in the pre-school. However, 15 of the 21 children improved their eating behavior after attending the institution (autonomy, regular meal times, and better meal choices), particularly twhose attending the pre-school on a full-time basis. Conclusion: Brazilian pre-schools ought to implement health programs in partnership with the SUS (Unified Health System) - the Brazilian national health system.En marzo de 2006, existían 5.588.153 de niños entre 4 y 6 años de edad matriculados en escuelas de preescolar en Brasil. Lamentablemente, sólo el 3.8% de esas instituciones tiene un profesional de salud y, además, no existe una relación efectiva entre esas instituciones y el Sistema de Salud en el país. Los primeros cinco años de vida son cruciales en el desarrollo de hábitos alimentares sanos y, consecuentemente, en la prevención de enfermedades degenerativas en la fase adulta, y también de la obesidad. Objetivo: Identificar y analizar las percepciones y prácticas maternas sobre la alimentación de niños de 3 a 6 años que frecuentaban una preescuela brasileña. Material y Método: Estudio cualitativo con entrevistas a fondo, individuales y no directivas, involucrando a madres de preescolares, donde los criterios para inclusión fueron: edad del niño entre 3 y 6 años; mínimo de 1 año de preescuela y peso del niños entre los percentiles 10 y 90 (gráficos NCHS). 21 madres fueron entrevistadas: 10 cuyos hijos estaban matriculados en el período integral y 11 en el período parcial. Para el análisis de los datos, fueron utilizados los métodos del Análisis Temático de Contenido, propuesto por Bardin. Resultados: La alimentación es tema de gran preocupación para las madres. La principal dificultad se refiere a los cambios propios del desarrollo infantil: No saben lidiar con esos cambios y, así, usan varias estrategias perjudiciales, tales como cambalache, insistencia, castigo y coerción, además de camuflar o mezclar los alimentos recusados con los aceptados. Las madres en este estudio tampoco sabían cómo eran los momentos de alimentación en la preescuela, aunque 15 de los 21 niños mejoraron la conducta alimentaria después de frecuentar la institución (autonomía, mejora en elhábito alimentario y estandarización en los horarios de las comidas), especialmente los niños de período integral. Conclusión: Las preescuelas brasileñas deberían implementar programas de salud en colaboración con el Sistema Único de Salud.Introdução: Em Março de 2006, existiam 5.588.153 crianças de 4 a 6 anos matriculadas em pré-escolas no Brasil. Infelizmente, apenas 3.8% dessas instituições têm um profissional da saúde e, adicionalmente, não existe relação efetiva entre essas instituições e o Sistema de Saúde no país. Os primeiros cinco anos de vida são cruciais no desenvolvimento de hábitos alimentares saudáveis e, consequentemente, na prevenção de doenças degenerativas na fase adulta, assim como a obesidade. Objetivo: identificar e analisar as percepções e práticas maternas sobre a alimentação de crianças de 3 a 6 anos que frequentavam uma pré-escola brasileira. Material e Método: estudo qualitativo com entrevistas aprofundadas, individuais e não-diretivas, realizado com mães de pré-escolares, onde os critérios para inclusão foram: idade da criança entre 3 e 6 anos;  tempo de frequência à pré-escola de, no mínimo 1 ano e peso da criança entre os percentis 10 e 90 (gráficos NCHS). Vinte e uma mães foram entrevistadas: 10 cujos filhos estavam matriculados no período integral e 11 no período parcial. Para a análise dos dados, foram utilizados os métodos da Análise Temática de Conteúdo, proposta por Bardin. Resultados: a alimentação é assunto que causa preocupação e dificuldades para as mães, devido as mudanças peculiares ao desenvolvimento infantil. Devido a isto usam diversas estratégias negativas para tentar modificar o comportamento alimentar dos filhos, sendo elas: barganha, insistência, castigo e coação, além de misturar ou camuflar os alimentos recusados com os aceitos. Além disto, as mães não tinham informações sobre a alimentação na pré-escola. No entanto, 15 das 21 crianças melhoraram o comportamento alimentar depois de começarem a frequentar a instituição. Ficaram mais autônomas, passaram a aceitar novos alimentos e padronizaram os horários das refeições. As mudanças foram mais evidentes nas crianças que frequentam a pré-escola período integral (de 8 a 9.5 horas por dia). Conclusão: as mães não sabem lidar, no domicílio, com as peculiaridades de desenvolvimento dos filhos na área de alimentação. Além disto, desconhecem seus comportamentos alimentares na pré-escola, onde há melhoras em comparação com o domicílio. Sugere-se melhorar a comunicação entre famílias e pré-escola, além de parceria entre estas e o sistema público de saúde

Effects of curing modes on depth of cure and microtensile bond strength of bulk fill composites to dentin

Objectives: To compare the microtensile bond strength (µTBS) and depth of cure (DOC) of bulk-fill composites cured by monowave (MW) and polywave (PW) LED units using different curing times. Methodology: Three composites were tested: Tetric EvoCeram Bulk Fill (TBF), Filtek Bulk Fill (FBF), and Tetric EvoCeram (T; control). Flat dentin surfaces treated with adhesive (AdheSE Universal®, Ivoclar Vivadent) were bonded with 4 mm cylindrical samples of each bulk-fill composite material (n=6) and cured with monowave (Satelec) or polywave (Bluephase Style) curing units for 10 or 20 seconds. After 24 hours, teeth were sectioned into individual 0.9 mm2 beams and tested for µTBS. Failure modes were analysed. Moreover, the DOC scrape test (IOS 4090) was completed (n=5) following the same curing protocols. Two-way ANOVA (a=0.05) was performed, isolating light-curing units. Results: For samples cured with the MW light-curing unit, no significant effects were observed in the µTBS results between any of the resin composite brands and the curing times. Conversely, when resins were cured with a PW light unit, a significant effect was observed for TBF resin. In general, bulk-fill composites presented greater DOC and longer curing time resulted in higher DOC for all composites. Conclusion: The µTBS of the composites to dentin was not affected by the curing mode of the resins, except for TBF cured with PW light unit. Bulk-fill composites exhibit greater DOC than conventional resin-based composites

High-rate deposition of nano-crystalline silicon thin films on plastics

Nanocrystalline silicon (nc-Si:H) is commonly used in the bottom cell of tandem solar cells. With an indirect bandgap, nc-Si:H requires thicker (∼1 µm) films for efficient light harvesting than amorphous Si (a-Si:H) does. Therefore, thin-film high deposition rates are crucial for further cost reduction of highly efficient a–Si:H based photovoltaic technology. Plastic substrates allow for further cost reduction by enabling roll-to-roll inline deposition. In this work, high nc-Si:H deposition rates on plastic were achieved at low substrate temperature (150 °C) by standard Radio-frequency (13.56 MHz) Plasma Enhanced Chemical Vapor Deposition. Focus was on the influence of deposition pressure, inter-electrode distance (1.2 cm) and high power coupled to the plasma, on the hydrogen-to-silane dilution ratios (HD) necessary to achieve the amorphous-to-nanocrystalline phase transition and on the resulting film deposition rate. For each pressure and rf-power, there is a value of HD for which the films start to exhibit a certain amount of crystalline fraction. For constant rf-power, this value increases with pressure. Within the parameter range studied the deposition rate was highest (0.38 nm/s) for nc-Si:H films deposited at 6 Torr, 700 mW/cm2 using HD of 98.5 %. Decreasing the pressure to 3 Torr (1.5 Torr) and rf-power to 350 mW/cm2 using HD – 98.5 % deposition rate is 0.12 nm/s (0.076 nm/s). Raman crystalline fraction of these films is 72, 62 and 53 % for the 6, 3 and 1.5 Torr films, respectively.Fundação para a Ciência e a Tecnologia (FCT)DREBM/PICS_CNRS/201

Modulating spin transfer torque switching dynamics with two orthogonal spin-polarizers by varying the cell aspect ratio

We study in-plane magnetic tunnel junctions with additional perpendicular polarizer for subnanosecond-current-induced switching memories. The spin-transfer-torque switching dynamics was studied as a function of the cell aspect ratio both experimentally and by numerical simulations using the macrospin model. We show that the anisotropy field plays a significant role in the dynamics, along with the relative amplitude of the two spin-torque contributions. This was confirmed by micromagnetic simulations. Real-time measurements of the reversal were performed with samples of low and high aspect ratio. For low aspect ratios, a precessional motion of the magnetization was observed and the effect of temperature on the precession coherence was studied. For high aspect ratios, we observed magnetization reversals in less than 1 ns for high enough current densities, the final state being controlled by the current direction in the magnetic tunnel junction cell.Comment: 6 pages, 7 figure

Deposition of silicon nitride thin films by hot-wire CVD at 100ºC and 250ºC

Silicon nitride thin films for use as passivation layers in solar cells and organic electronics or as gate dielectrics in thin-film transistors were deposited by the Hot-wire chemical vapor deposition technique at a high deposition rate (1-3 Ǻ/s) and at low substrate temperature. Films were deposited using NH3/SiH4 flow rate ratios between 1 and 70 and substrate temperatures of 100º C and 250ºC. For NH3/SiH4 ratios between 40 and 70, highly transparent (T ~ 90%), dense films (2.56 - 2.74 g/cm3) with good dielectric properties and refractive index between 1.93 and 2.08 were deposited on glass substrates. Etch rates in BHF of 2.7 Ǻ/s and 10 MV cm−1.Fundação para a Ciência e Tecnologia (FCT) - FCT/CNRS programa com o contracto no. 20798, bolsa de investigaçao e projecto PTDC-CTM-66558-200

Flexible n-i-p thin film silicon solar cells on polyimide foils with textured ZnO:Ga back reflector

In thin film silicon solar cells on opaque substrates in n-i-p deposition sequence where the textured transparent conductive oxide (TCO) layer serves as a back reflector, one can independently optimize the morphology of the TCO layer without compromise on transparency and conductivity of this layer and further adjust the electro-optical properties of the back contact by using additional layers on top of the textured TCO. In the present work, we use this strategy to obtain textured back reflectors for solar cells in n-i-p deposition sequence on non-transparent flexible plastic foils. Gallium doped ZnO (ZnO:Ga) films were deposited on polyimide substrates by DC magnetron sputtering at a temperature of 200 °C. A wet-chemical etching step was performed by dipping the ZnO:Ga covered foil into a diluted HCl solution. The textured ZnO:Ga is then coated with a highly reflective Ag/ZnO double layer. On this back reflector, we develop thin film silicon solar cells with a microcrystalline silicon absorber layer. The current density for the cell with the textured ZnO:Ga layer is ~ 23 mA/cm2, 4 mA/cm2 higher than the one without such layer, and a maximum efficiency of 7.5% is obtained for a 1 cm2 cell.Fundação para a Ciência e a Tecnologia (FCT

Montagens de circuitos elétricos em sala de aula: uma contribuição significativa no processo ensino-aprendizagem

Pesquisas apontam que o ensino experimental durante as aulas de física no ensino médio tem sido uma ferramenta muito útil para desenvolvimento conceitual dos fenômenos físicos. O entendimento dos fenômenos elétricos não é um assunto tão trivial e requer a superação das concepções alternativas dos alunos. Em virtude dessa realidade foi criado um estudo experimental, paralelo com as aulas teóricas, com 55 alunos do terceiro ano do ensino médio de uma escola no município de Pinheiral - RJ. Com a proposta de verificar as concepções alternativas, foi elaborado um questionário inicial com perguntas abertas, de cunho qualitativo sobre alguns conceitos envolvendo corrente elétrica e circuitos elétricos. Os alunos tiveram aulas teóricas sobre os fenômenos com a proposta de tentar confrontar as suas concepções prévias sobre o assunto. Em seguida, ocorreu o primeiro contato com o circuito elétrico. Durante a aula experimental, a atividade proposta consistiu em dividir a turma em grupos. Foram desenhados esquemas envolvendo a associação de lâmpadas em série. Um grupo se apresentava para interpretar o desenho e montar o circuito na bancada enquanto que os demais, sentados em seus lugares, estavam encarregados de responder a um questionário (perguntas abertas de cunho quali-quantitativo). Durante o momento em que os grupos realizavam os cálculos, aqueles que estavam encarregados de montar o circuito na bancada com o mediador confrontavam alguns conceitos relacionados aos circuitos elétricos. Ao final dos cálculos os grupos conferiam os valores calculados com os encontrados nos aparelhos de medição e identificavam que a lâmpada com o maior brilho era a que apresentava a maior potência. O processo foi repetido de modo que todos os alunos participaram das duas etapas. Os resultados qualitativos foram comparados com um questionário prévio e apresentaram uma grande evolução no processo ensino-aprendizagem em função dos dados obtidos

Structure of rhodolith beds from 4 to 55 meters deep along the southern coast of Espírito Santo State, Brazil

Rhodoliths are one of the most extensive benthic communities of the Brazilian continental shelf, but their structure is poorly known. The richest marine flora of Brazil’s coastal zone is found in Espírito Santo State and its diversity has been partly associated with the presence of extensive areas of rhodoliths, extending from the intertidal zone to 120 m across the continental shelf. One species of kelp, Laminaria abyssalis, is endemic to this area and occurs between 45 and 120 m depth. Our objective was to determine the density and physical dimensions of the superficial rhodoliths between 4 and 55 m depth in the southern region of Espírito Santo State. The study area was 3 to 45 km offshore. Samples were obtained in 2004 and 2005 by Scuba diving in three depth zones: 4–18 m, 25–30 m and 50–55 m. Transect lines and video images were used to determine rhodolith density. The diameter and sphericity of at least 60 individuals from each zone were measured. Rhodolith size increased and density decreased from the shallow to the deeper zones. Spheroidal was the typical shape throughout the depth zones. Five rhodolith-forming genera were identified: Lithothamnion, Lithophyllum, Hydrolithon, Neogoniolithon and Sporolithon. Epibenthic biomass and species richness over the rhodolith bed in the shallow zone was lowest in winter, likely the result of disturbance caused by typical winter storms. Changes in light and temperature are probably the most important factors in the changes observed in the rhodolith beds from the deepest zones.Web of Scienc

Applications of infrared thermography in sports. A review

La termografía infrarroja (TI) registra el calor irradiado de un cuerpo, que es emitido en un rango del espectro electromagnético que la visión humana no es capaz de identificar. La respuesta térmica depende de una serie de ajustes fisiológicos específicos como la homeostasis corporal y salud del deportista, lo cual permite establecer interesantes aplicaciones en el deporte. El objetivo de este trabajo ha sido revisar la literatura en torno a las aplicaciones de la TI en el ámbito del deporte, y proponer las características óptimas del registro en relación al evaluado, las condiciones ambientales y la cámara utilizada. Concluimos que la principal contribución de la TI en el ámbito del deporte es ayudar a identificar signos de lesión antes de que la lesión se produzca, permitiéndonos actuar de manera preventiva durante el proceso de entrenamientoInfrared thermography (IRT) records the radiant heat of a body, which is emitted in the range of the electromagnetic spectrum that human vision is not able to identify. The thermal response depends on a number of specific physiological adjustments as body homeostasis and athlete’s health, which allow us to establishing interesting applications in sport. The aim of this study was to review the literature on IRT applications in sports, and to propose the optimal characteristics of the register in terms of the subject, the environmental conditions and the camera used. We conclude that the main contribution of IRT in the field of sport is to help identify signs of injury before it occurs, allowing us to act proactively along the training proces

Supplements of carbohydrates long during exercise: Effects on the electrolytes and glucose

Objetivo: Identificar si la forma de presentación de los suplementos de carbohidratos (SC) influye en la respuesta de la concentración plasmática de electrólitos y glucosa durante un ejercicio de larga duración. Doce hombres realizaron cuatro pruebas de 90 min en cicloergometro (55-60%VO2máx), seguidas por 6 km a máxima velocidad, consumiendo SC en diferentes presentaciones (líquido, gel o sólido) y un día únicamente consumían agua. Se analizaron las concentraciones de sodio, potasio y glucosa en sangre antes del ejercicio, cada 30 minutos de prueba, y tras los 6 km. No hubo diferencia significativa en la respuesta de los electrolitos durante todo estudio. Hubo diferencias significativas (p<0,05) en la glucosa cuando se consumieron SC independientemente de su presentación frente al consumo exclusivo de agua. Se concluye que la forma de presentación de los SC no influye en la concentración de glucosa en sangre durante el ejercicio de larga duraciónObjective: To identify if the format of carbohydrate supplements (CS) influence the response of the plasmatic concentration of electrolytes and glucose during long duration exercise. Twelve men performed four tests of 90 min on a cycle ergometer (55-60% VO2max), followed by 6 km at maximum speed, consuming CS in different forms (liquid, gel or solid) and one day just consuming water. It was analyzed the concentrations of sodium, potassium and blood glucose before exercise, every 30 minutes of test, and after 6 km. There was no significant difference in the response of electrolytes during the study. However, the glucose showed significant differences (p <0.05) when it was consumed CS regardless of their form, whenever just water was consumed. In this way is possible to conclude, that the format of the SC does not affect the blood glucose concentration during long duration exercis