Exchanging screen for non-screen sitting time or physical activity might attenuate depression and anxiety: A cross-sectional isotemporal analysis during early pandemics in South America.

OBJECTIVES: To examine the theoretical substitutions of screen exposure, non-screen sitting time, moderate and vigorous physical activity with depressive and anxiety symptoms in South American adults during the COVID-19 pandemic. DESIGN: A cross-sectional study during the first months of the COVID-19 pandemic with data from 1981 adults from Chile, Argentina, and Brazil. METHODS: Depressive and anxiety symptoms were assessed using the Beck Depression and Anxiety Inventories. Participants also reported physical activity, sitting time, screen exposure, sociodemographic, and tobacco use data. Isotemporal substitution models were created using multivariable linear regression methods. RESULTS: Vigorous physical activity, moderate physical activity, and screen exposure were independently associated with depression and anxiety symptoms. In adjusted isotemporal substitution models, replacing 10 min/day of either screen exposure or non-screen sitting time with any intensity of physical activity was associated with lower levels of depressive symptoms. Improvements in anxiety symptoms were found when reallocating either screen exposure or non-screen sitting time to moderate physical activity. Furthermore, replacing 10 min/day of screen exposure with non-screen sitting time was beneficially associated with anxiety (B = -0.033; 95 % CI = -0.059, -0.006) and depression (B = -0.026; 95 % CI = -0.050, -0.002). CONCLUSIONS: Replacement of screen exposure with any intensity of physical activity or non-screen sitting time could improve mental health symptoms. Strategies aiming to reduce depressive and anxiety symptoms highlight physical activity promotion. However, future interventions should explore specific sedentary behaviors as some will relate positively while others negatively.

Global Matrix 4.0 Physical Activity Report Card Grades for Children and Adolescents: Results and Analyses From 57 Countries.

BACKGROUND: The Global Matrix 4.0 on physical activity (PA) for children and adolescents was developed to achieve a comprehensive understanding of the global variation in children's and adolescents' (5-17 y) PA, related measures, and key sources of influence. The objectives of this article were (1) to summarize the findings from the Global Matrix 4.0 Report Cards, (2) to compare indicators across countries, and (3) to explore trends related to the Human Development Index and geo-cultural regions. METHODS: A total of 57 Report Card teams followed a harmonized process to grade the 10 common PA indicators. An online survey was conducted to collect Report Card Leaders' top 3 priorities for each PA indicator and their opinions on how the COVID-19 pandemic impacted child and adolescent PA indicators in their country. RESULTS: Overall Physical Activity was the indicator with the lowest global average grade (D), while School and Community and Environment were the indicators with the highest global average grade (C+). An overview of the global situation in terms of surveillance and prevalence is provided for all 10 common PA indicators, followed by priorities and examples to support the development of strategies and policies internationally. CONCLUSIONS: The Global Matrix 4.0 represents the largest compilation of children's and adolescents' PA indicators to date. While variation in data sources informing the grades across countries was observed, this initiative highlighted low PA levels in children and adolescents globally. Measures to contain the COVID-19 pandemic, local/international conflicts, climate change, and economic change threaten to worsen this situation.

Mechanical Behavior of Plaster Composites Based on Rubber Particles from End-of-Life Tires Reinforced with Carbon Fibers.

The principal objective of this research project is the disposal of end-of-life tire rubber waste and its incorporation in gypsum composites. As a continuation of previous projects, which established a reduction in the mechanical properties of the resulting products, the behavior of these composites is analyzed with the incorporation of carbon fibers. The density, Shore C hardness, flexural strength, compressive strength, dynamic modulus of elasticity, strength-strain curves, toughness and resistance values and microstructure of the material are studied and compared. The results obtained show a significant increase in the mechanical tensile strength of all of the samples containing fibers. The moduli of elasticity results show a decrease in rigidity and increase in toughness and resistance of the material produced by incorporating the fibers. An optimum dosage of a water/gypsum ratio of 0.6 and incorporation of 1.5% carbon fibers is proposed. This lightweight material, which offers a high mechanical performance, features characteristics which are suitable for large prefabricated building elements in the form of panels or boards.

Changes in Sitting Time, Screen Exposure and Physical Activity during COVID-19 Lockdown in South American Adults: A Cross-Sectional Study.

The worldwide prevalence of insufficient physical activity (PA) and prolonged sedentary behavior (SB) were high before the coronavirus (COVID-19) pandemic. Measures that were taken by governments (such as home confinement) to control the spread of COVID-19 may have affected levels of PA and SB. This cross-sectional study among South American adults during the first months of COVID-19 aims to (i) compare sitting time (ST), screen exposure, moderate PA (MPA), vigorous PA (VPA), and moderate-to-vigorous PA (MVPA) before and during lockdown to sociodemographic correlates and (ii) to assess the impact of lockdown on combinations of groups reporting meeting/not-meeting PA recommendations and engaging/not-engaging excessive ST (≥7 h/day). Bivariate associations, effect sizes, and multivariable linear regressions were used. Adults from Argentina (n = 575) and Chile (n = 730) completed an online survey with questions regarding demographics, lifestyle factors, and chronic diseases. Mean reductions of 42.7 and 22.0 min./day were shown in MPA and VPA, respectively; while increases of 212.4 and 164.3 min./day were observed in screen and ST, respectively. Those who met PA recommendations and spent <7 h/day of ST experienced greatest changes, reporting greater than 3 h/day higher ST and more than 1.5 h/day lower MVPA. Findings from the present study suggest that efforts to promote PA to South American adults during and after COVID-19 restrictions are needed.

[Vitamin A deficiency and the anthropometric nutritional status of urban and rural marginalized children in the state of Zulia, Venezuela]. / Deficiencia de vitamina A y estado nutricional antropométrico en niños marginales urbanos y rurales en el Estado Zulia, Venezuela.

The present transversal study was carried out to estimate the prevalence of both vitamin A deficiency (VAD) and protein-energy malnutrition among children (24 to 85 months) from three urban slums (n = 173) in Maracaibo city, Zulia State, Venezuela and a rural slum area (n = 34), vieinal to Maracaibo, by measuring serum retinol and z score of anthropometric indices Height//Age (H//AZ); Weight//Age (W//AZ) and Weight//Height (W//HZ), compared to NCHS-WHO reference values. The Graffar's methodology adapted to Venezuela by Méndez Castellano (1986) confirmed the underprivileged socio-economic condition of the children population. For serum retinol analysis, peripheral venous blood was drawn and serum was treated according to the Bieri et al. (1979) technique and HPLC procedure. Values were recorded in microgram/dL. Statistical analysis was done by using Epi Info 2000, release 1.0 and SAS release 6.0 (1996) computer programs. The prevalence of VAD (serum retinol < 20 micrograms/dL) in the total children population (n = 207) was 22.2%, being higher in urban children than in rural children (22.5% vs 20.5%). No clinical signs of VAD were detected in the children. The nutritional status analysed by Z score of anthropometric indices revealed that 27.4% of children suffered from undernutrition (Z score = -2 to > -3 SD), being 15.4% stunted, 9.6% wasted and 2.6% with acute protein-energy malnutrition. Neither severe malnutrition nor overweight were detected. According with the H//AZ index, 54.6% of children had adequate nutrition. However 23% of them suffered from VAD. In children at risk of developing undernutrition (Z score = -1 to > -2 SD), 20.9% had VAD and of the stunted children, 21.9% presented VAD. With W//AZ, 60.3%, 29.9% and 9.1% of children were with adequate nutrition, at risk, or wasted respectively; of each group, 25.6%, 17.7% and 15%, respectively had serum retinol values below 20 micrograms/dL. The Z score of W//HZ indicator revealed that 87.4%, 10.4% and 2.4% of children were in good nutrition, at risk, or with acute protein-energy malnutrition, respectively. In the three groups 22.1%, 23.8% and 20%, respectively were affected by VAD. These results indicate that VAD coexists indistinctly in healthy, adequately nourished children, as in those malnourished ones. Our VAD prevalence results and others from Venezuela, are higher than the criteria laid down by WHO and PAHO which warrant wide community intervention. This public health problem becomes more significant because children are apparently healthy and, if timely vitamin A supplementation is not given, any intercurrent infection is likely to worsen the vitamin A status, increasing the widely known consequences.

Técnicas de medición de la actividad física en investigaciones argentinas: necesidad de incorporar técnicas objetivas / Measurement techniques used in physical activity argentinean research: necessity of incorporating objetive techniques

Introducción: actualmente ninguna técnica por sí sola puede medir todas las dimensiones de la actividad física simultáneamente. Por este motivo se sugiere utilizar múltiples monitores objetivos a la vez o una combinación de monitores objetivos y técnicas subjetivas.Objetivos: revisar las técnicas de medición de actividad física utilizadas en las investigaciones argentinas y presentar los resultados de un estudio piloto en el que se utilizó la técnica objetiva de frecuencia cardíaca con calibración individual para la estimación del gasto energético total diario y de las actividades físicas cotidianas. Materiales y métodos: para revisar las técnicas utilizadas se realizó una búsqueda general en PubMed, LILACS, SciELO y Google Académico utilizando los términos "actividad física", "sedentarismo" y "Argentina"; además se consultaron expertos locales. Luego se aplicó la técnica de frecuencia cardíaca con calibración individual en laboratorio y se efectuó un monitoreo de cuatro días de la semana a una muestra piloto de seis sujetos de ambos sexos profesores de Educación Física. Resultados: se identificaron 70 publicaciones donde se midió la actividad física habitual en Argentina. En el 94% se utilizaron cuestionarios. Un sólo estudio empleó cuestionario validado en la población local. El 92% fue de corte transversal. Ningún estudio utilizó la técnica de frecuencia cardíaca. Los sujetos de nuestra muestra tuvieron un gasto energético total promedio±desvío estándar de 2.670±1.062 kcal y un gasto energético por actividades físicas de 1.351±957 kcal siendo estos valores comparables a los de estudios previos. Cuatro sujetos alcanzaron las recomendaciones diarias de actividad física para la salud. Conclusiones: resulta relevante y necesario comenzar a validar técnicas subjetivas en la población argentina y/o utilizar técnicas objetivas para medir la actividad física en futuras investigaciones locales. La técnica de frecuencia cardíaca con calibración individual, aunque con limitaciones, puede resultar eficaz para cumplir con ambas finalidades.

Introduction: currently no single technique can measure all dimensions of physical activity simultaneously. For this rea-son it is suggested to use multiple objective monitors or a combination of objective monitors with subjective techniques simultaneously. Objectives: review the measurement techniques used in physical activity Argentinean research and present the results of a pilot study in which the heart rate objective technique with individual calibration was used for estimating the total daily energy expenditure and daily physical activities.Materials and methods: to review the techniques used, it was conducted a general search in PubMed, LILACS, SciELO and Google Scholar using the terms "physical activity", "se-dentarism" and "Argentina", in addition local experts were consulted. After that, heart rate technique with individual calibration was applied in the laboratory and monitoring four days a week was performed to a pilot sample of six physical education teachers subjects of both sexes.Results: it was identified 70 publications where regular phy-sical activity was measured in Argentina. In 94% of them were used questionnaires. Only one study used a question-naire validated with local population. 92% used a cross-sectional design. No study used the technique of heart rate. The subjects of our sample had a mean±standard deviation total energy expenditure of 2.670±1.062 kcal and a physical activity energy expenditure of 1.351±957 kcal being these values comparable to those of previous studies. Four subjects reached daily physical activity recommendations for health.Conclusions: it is relevant and necessary to begin to vali-date subjective techniques in Argentinean population and/or to use objective techniques for measuring physical activity in future local research. The technique of heart rate with indi-vidual calibration, albeit with limitations, can be an effective way to meet both purposes.

Deficiencia de vitamina A y estado nutricional antropométrico en niños marginales urbanos y rurales en el Estado Zulia, Venezuela / Vitamin A deficiency and the anthropometric nutritional status of urban and rural marginalized children in the state of Zulia, Venezuela

The present transversal study was carried out to estimate the prevalence of both vitamin A deficiency (VAD) and protein-energy malnutrition among children (24 to 85 months) from three urban slums (n = 173) in Maracaibo city, Zulia State, Venezuela and a rural slum area (n = 34), vieinal to Maracaibo, by measuring serum retinol and z score of anthropometric indices Height//Age (H//AZ); Weight//Age (W//AZ) and Weight//Height (W//HZ), compared to NCHS-WHO reference values. The Graffar's methodology adapted to Venezuela by MÚndez Castellano (1986) confirmed the underprivileged socio-economic condition of the children population. For serum retinol analysis, peripheral venous blood was drawn and serum was treated according to the Bieri et al. (1979) technique and HPLC procedure. Values were recorded in microgram/dL. Statistical analysis was done by using Epi Info 2000, release 1.0 and SAS release 6.0 (1996) computer programs. The prevalence of VAD (serum retinol < 20 micrograms/dL) in the total children population (n = 207) was 22.2, being higher in urban children than in rural children (22.5 vs 20.5). No clinical signs of VAD were detected in the children. The nutritional status analysed by Z score of anthropometric indices revealed that 27.4 of children suffered from undernutrition (Z score = -2 to > -3 SD), being 15.4 stunted, 9.6 wasted and 2.6 with acute protein-energy malnutrition. Neither severe malnutrition nor overweight were detected. According with the H//AZ index, 54.6 of children had adequate nutrition. However 23 of them suffered from VAD. In children at risk of developing undernutrition (Z score = -1 to > -2 SD), 20.9 had VAD and of the stunted children, 21.9 presented VAD. With W//AZ, 60.3, 29.9 and 9.1 of children were with adequate nutrition, at risk, or wasted respectively; of each group, 25.6, 17.7 and 15, respectively had serum retinol values below 20 micrograms/dL. The Z score of W//HZ indicator revealed that 87.4, 10.4 and 2.4 of children were in good nutrition, at risk, or with acute protein-energy malnutrition, respectively. In the three groups 22.1, 23.8 and 20, respectively were affected by VAD. These results indicate that VAD coexists indistinctly in healthy, adequately nourished children, as in those malnourished ones. Our VAD prevalence results and others from Venezuela, are higher than the criteria laid down by WHO and PAHO which warrant wide community intervention. This public health problem becomes mor