398 research outputs found

    Three-dimensional fluorescent microscopy via simultaneous illumination and detection at multiple planes.

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    The conventional optical microscope is an inherently two-dimensional (2D) imaging tool. The objective lens, eyepiece and image sensor are all designed to capture light emitted from a 2D 'object plane'. Existing technologies, such as confocal or light sheet fluorescence microscopy have to utilize mechanical scanning, a time-multiplexing process, to capture a 3D image. In this paper, we present a 3D optical microscopy method based upon simultaneously illuminating and detecting multiple focal planes. This is implemented by adding two diffractive optical elements to modify the illumination and detection optics. We demonstrate that the image quality of this technique is comparable to conventional light sheet fluorescent microscopy with the advantage of the simultaneous imaging of multiple axial planes and reduced number of scans required to image the whole sample volume

    Twinning superlattices in indium phosphide nanowires

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    Here, we show that we control the crystal structure of indium phosphide (InP) nanowires by impurity dopants. We have found that zinc decreases the activation barrier for 2D nucleation growth of zinc-blende InP and therefore promotes the InP nanowires to crystallise in the zinc blende, instead of the commonly found wurtzite crystal structure. More importantly, we demonstrate that we can, by controlling the crystal structure, induce twinning superlattices with long-range order in InP nanowires. We can tune the spacing of the superlattices by the wire diameter and the zinc concentration and present a model based on the cross-sectional shape of the zinc-blende InP nanowires to quantitatively explain the formation of the periodic twinning.Comment: 18 pages, 4 figure

    Quantification of the energy gap in young overweight children. The PIAMA birth cohort study

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    Background: Overweight develops gradually as a result of a long term surplus on the balance between energy intake and energy expenditure. Aim of this study was to quantify the positive energy balance responsible for excess body weight gain (energy gap) in young overweight children. Methods. Reported data on weight and height were used of 2190 Dutch children participating in the PIAMA birth cohort study. Accumulated body energy was estimated from the weight gain observed between age 2 and age 5-7. Energy gap was calculated as the difference in positive energy balance between children with and without overweight assuming an energy efficiency of 50%. Results: Ten percent of the children were overweight at the age of 5-7 years. For these children, median weight gain during 4-years follow-up was 13.3 kg, as compared to 8.5 kg in the group of children who had a normal weight at the end of the study. A daily energy gap of 289-320 kJ (69-77 kcal) was responsible for the excess weight gain or weight maintenance in the majority of the children who were overweight at the age of 5-7 years. The increase in daily energy requirement to maintain the 4.8 kilograms excess weight gain among overweight children at the end of the study was approximately 1371 kJ. Conclusions: An energy gap of about 289-320 kJ per day over a number of years can make the difference between normal weight and overweight in young children. Closing the energy gap in overweight children can be achieved by r

    Satisfação corporal associada à gordura corporal e estado nutricional em jovens basquetebolistas

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    O objetivo deste estudo foi comparar e verificar a possibilidade de associação entre a satisfação corporal (SC), classificaçÔes de estado nutricional (EN) e gordura corporal (GC) em jovens basquetebolistas masculinos. Participaram da pesquisa 93 adolescentes com idades de 10 a 16 anos. A SC foi avaliada pelo Body Shape Questionnaire. Foram coletadas massa corporal, estatura e dobras cutĂąneas para classificar o EN (kg/mÂČ) e medir a GC, respectivamente. Realizaram-se os testes Ancova e Qui-quadrado no "software" SPSS 17.0. Identificaram-se diferenças estatisticamente significativas (p < 0,05) de SC entre classificaçÔes de EN e GC. Encontrou-se associação significativa (p < 0,05) entre SC e EN, assim como entre SC e GC (p < 0,05). Os resultados confirmaram diferenças e associação da SC com o EN e GC em jovens basquetebolistas

    Project FIT: Rationale, design and baseline characteristics of a school- and community-based intervention to address physical activity and healthy eating among low-income elementary school children

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    <p>Abstract</p> <p>Background</p> <p>This paper describes Project FIT, a collaboration between the public school system, local health systems, physicians, neighborhood associations, businesses, faith-based leaders, community agencies and university researchers to develop a multi-faceted approach to promote physical activity and healthy eating toward the general goal of preventing and reducing childhood obesity among children in Grand Rapids, MI, USA.</p> <p>Methods/design</p> <p>There are four overall components to Project FIT: school, community, social marketing, and school staff wellness - all that focus on: 1) increasing access to safe and affordable physical activity and nutrition education opportunities in the schools and surrounding neighborhoods; 2) improving the affordability and availability of nutritious food in the neighborhoods surrounding the schools; 3) improving the knowledge, self-efficacy, attitudes and behaviors regarding nutrition and physical activity among school staff, parents and students; 4) impacting the 'culture' of the schools and neighborhoods to incorporate healthful values; and 5) encouraging dialogue among all community partners to leverage existing programs and introduce new ones.</p> <p>Discussion</p> <p>At baseline, there was generally low physical activity (70% do not meet recommendation of 60 minutes per day), excessive screen time (75% do not meet recommendation of < 2 hours per day), and low intake of vegetables and whole grains and high intake of sugar-sweetened beverages, French fries and chips and desserts as well as a high prevalence of overweight and obesity (48.5% including 6% with severe obesity) among low income, primarily Hispanic and African American 3<sup>rd</sup>-5<sup>th </sup>grade children (n = 403).</p> <p>Trial registration</p> <p><b>ClinicalTrials.gov <a href="http://www.clinicaltrials.gov/ct2/show/NCT01385046">NCT01385046</a></b></p

    The relationship between a child's postural stability and manual dexterity

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    The neural systems responsible for postural control are separate from the neural substrates that underpin control of the hand. Nonetheless, postural control and eye-hand coordination are linked functionally. For example, a stable platform is required for precise manual control tasks (e.g. handwriting) and thus such skills often cannot develop until the child is able to sit or stand upright. This raises the question of the strength of the empirical relationship between measures of postural stability and manual motor control. We recorded objective computerised measures of postural stability in stance and manual control in sitting in a sample of school children (n = 278) aged 3–11 years in order to explore the extent to which measures of manual skill could be predicted by measures of postural stability. A strong correlation was found across the whole sample between separate measures of postural stability and manual control taken on different days. Following correction for age, a significant but modest correlation was found. Regression analysis with age correction revealed that postural stability accounted for between 1 and 10 % of the variance in manual performance, dependent on the specific manual task. These data reflect an interdependent functional relationship between manual control and postural stability development. Nevertheless, the relatively small proportion of the explained variance is consistent with the anatomically distinct neural architecture that exists for ‘gross’ and ‘fine’ motor control. These data justify the approach of motor batteries that provide separate assessments of postural stability and manual dexterity and have implications for therapeutic intervention in developmental disorders

    Anthropometry and body composition in ethnic Japanese and Caucasian adolescent girls: Considerations on ethnicity and menarche

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    Objective: This study aimed to compare the various anthropometric and body composition parameters based on the ethnicity and the absence or presence of menarche.Design: A cross-sectional study with incomplete sampling, using the subject as the evaluation unit.Subjects: the final sample of 550 subjects was composed of 122 Japanese and 179 Caucasian premenarcheal adolescents, and 72 Japanese and 177 Caucasian postmenarcheal adolescents.Methods: the variables of body composition were measured through the following methods: bioelectrical impedance analysis, near-infrared interactance (NIR), Slaughter cutaneous skinfold equations and body mass index. Weight, height and sitting height were also evaluated.Results: the Japanese pre- and postmenarcheal girls presented lower weight and height values when compared with the Caucasian girls. in general, the Japanese premenarcheal girls presented less fat and fat-free mass than the premenarcheal Caucasian girls. This fact was demonstrated through NIR results. Conversely, the Japanese postmenarcheal adolescents accumulated more fat than their Caucasian counterparts. However, significant differences were solely encountered in the values of cutaneous skinfold percent body fat. With regard to menarche, it was verified that, regardless of ethnicity, all the anthropometric and body composition variables reached higher values among postmenarcheal adolescents when compared with premenarcheal adolescents.Conclusion: Different results of weight and height between the ethnic groups may bring back the discussion concerning separate growth curves for different ethnic groups. the results of the body composition analysis indicated high adiposity levels among postmenarcheal adolescents.Universidade Federal de SĂŁo Paulo, Escola Paulista Med, Dept Postgrad Nutr, BR-04020060 SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo, Escola Paulista Med, Dept Prevent Med, SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo, Escola Paulista Med, Dept Postgrad Nutr, BR-04020060 SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo, Escola Paulista Med, Dept Prevent Med, SĂŁo Paulo, BrazilWeb of Scienc

    Relationship of aerobic fitness and motor skills with memory and attention in preschoolers (Ballabeina): A cross-sectional and longitudinal study

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    BACKGROUND: The debate about a possible relationship between aerobic fitness and motor skills with cognitive development in children has recently re-emerged, because of the decrease in children's aerobic fitness and the concomitant pressure of schools to enhance cognitive performance. As the literature in young children is scarce, we examined the cross-sectional and longitudinal relationship of aerobic fitness and motor skills with spatial working memory and attention in preschool children. METHODS: Data from 245 ethnically diverse preschool children (mean age: 5.2 (0.6) years, girls: 49.4%) analyzed at baseline and 9 months later. Assessments included aerobic fitness (20 m shuttle run) and motor skills with agility (obstacle course) and dynamic balance (balance beam). Cognitive parameters included spatial working memory (IDS) and attention (KHV-VK). All analyses were adjusted for age, sex, BMI, migration status, parental education, native language and linguistic region. Longitudinal analyses were additionally adjusted for the respective baseline value. RESULTS: In the cross-sectional analysis, aerobic fitness was associated with better attention (r=0.16, p=0.03). A shorter time in the agility test was independently associated with a better performance both in working memory (r=-0.17, p=0.01) and in attention (r=-0.20, p=0.01). In the longitudinal analyses, baseline aerobic fitness was independently related to improvements in attention (r=0.16, p=0.03), while baseline dynamic balance was associated with improvements in working memory (r=0.15, p=0.04). CONCLUSIONS: In young children, higher baseline aerobic fitness and motor skills were related to a better spatial working memory and/or attention at baseline, and to some extent also to their future improvements over the following 9 months. TRIAL REGISTRATION: clinicaltrials.gov NCT0067454

    Intervenção multiprofissional melhora a aptidĂŁo fĂ­sica relacionada Ă  saĂșde de adolescentes com maior efeito sobre as meninas em comparação aos meninos

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    Resumo Este estudo teve como objetivo verificar as diferenças entre as respostas de meninos e meninas a um programa multiprofissional de tratamento da obesidade sobre a aptidĂŁo fĂ­sica relacionada Ă  saĂșde. Fizeram parte do estudo 163 adolescentes com excesso de massa corporal e idade entre 10 e 18 anos. Foram avaliados parĂąmetros antropomĂ©tricos, composição corporal, flexibilidade, força e resistĂȘncia abdominal e aptidĂŁo cardiorrespiratĂłria antes e apĂłs 16 semanas de intervenção multiprofissional. A intervenção multiprofissional contou com a participação de profissionais de educação fĂ­sica, nutrição, psicologia e pediatria e teve como foco principal o incentivo a mudanças nos hĂĄbitos alimentares e de atividade fĂ­sica que pudessem promover alteraçÔes positivas nos parĂąmetros analisados. A intervenção teve frequĂȘncia semanal de trĂȘs sessĂ”es, sendo uma hora de intervençÔes teĂłricas com os profissionais de educação fĂ­sica, nutrição e psicologia e a outra hora destinada Ă  prĂĄtica regular de exercĂ­cios fĂ­sicos, com predominĂąncia de exercĂ­cios fĂ­sicos resistidos, aerĂłbios e prĂĄtica de basquetebol. ApĂłs a intervenção tanto as meninas quanto os meninos apresentaram melhoras significativas nas variĂĄveis IMC, circunferĂȘncia de cintura e quadril, massa gorda relativa e absoluta, massa magra, flexibilidade, força/resistĂȘncia abdominal e aptidĂŁo cardiorrespiratĂłria, porĂ©m com resultados mais expressivos para as meninas sobre a circunferĂȘncia de cintura, gordura corporal (kg), VO2max e força/resistĂȘncia abdominal

    Ethnic differences in body fat distribution among Asian pre-pubertal children: A cross-sectional multicenter study

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    Background Ethnic differences in body fat distribution contribute to ethnic differences in cardiovascular morbidities and diabetes. However few data are available on differences in fat distribution in Asian children from various backgrounds. Therefore, the current study aimed to explore ethnic differences in body fat distribution among Asian children from four countries. Methods A total of 758 children aged 8-10 y from China, Lebanon, Malaysia and Thailand were recruited using a non-random purposive sampling approach to enrol children encompassing a wide BMI range. Height, weight, waist circumference (WC), fat mass (FM, derived from total body water [TBW] estimation using the deuterium dilution technique) and skinfold thickness (SFT) at biceps, triceps, subscapular, supraspinale and medial calf were collected. Results After controlling for height and weight, Chinese and Thai children had a significantly higher WC than their Lebanese and Malay counterparts. Chinese and Thais tended to have higher trunk fat deposits than Lebanese and Malays reflected in trunk SFT, trunk/upper extremity ratio or supraspinale/upper extremity ratio after adjustment for age and total body fat. The subscapular/supraspinale skinfold ratio was lower in Chinese and Thais compared with Lebanese and Malays after correcting for trunk SFT. Conclusions Asian pre-pubertal children from different origins vary in body fat distribution. These results indicate the importance of population-specific WC cut-off points or other fat distribution indices to identify the population at risk of obesity-related health problems
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