Abstract Objective: To investigate the effects of different physical exercise programs and polymorphisms of the FTO (fat mass and obesity-associated gene) on body composition and cardiovascular risk factors in adolescents with overweight and obesity. Methods: A randomized, parallel, double-blind clinical trial consisting of the adolescent overweight from the state public network, in a simple representative random sample, who participated in an aerobic exercise or weight training intervention for 10 weeks. Anthropometry, body composition, biochemical markers, sexual maturation, and rs9939609 polymorphism in the FTO gene were assessed. 347 adolescents had their characterization of nutritional status. 72 individuals with overweight and obesity were invited to participate. 39 remained for the start of the program and were randomly allocated to both types of intervention. In the end, 26 subjects participated in the intervention programs, with 12 and 14 in the aerobic and weight training programs, respectively. Results: Heterozygous and homozygous bearers of risk allele A participating in the aerobic program showed improvements in glycemia (p = 0.002) and total cholesterol (p = 0.023) and a reduction in body fat mass (p = 0.041). The weight training program reduced glycemia in patients with the risk allele A (p = 0.027). Cameron’s stage four sexual maturation participants were 2.1 times more likely to improve their body fat (CI = 1.31–3.39). Conclusion: Aerobic exercises produced exclusively a significant decrease in fat mass and total cholesterol in patients with risk allele A. Distinct physical exercise programs may cause diverse changes in risk variables related to the health of adolescents.

Resumen Debido a la disminución de las reservas de gas natural y al elevado número de fallecidos por explosiones en minas de carbón, Colombia ha venido adelantando exploraciones preliminares del gas metano asociado al carbón (CBM). Hasta ahora, la exploración de CBM se ha centrado en el contenido de gas por tonelada de carbón a partir de sistemas de desorción utilizando canister, pero se han hecho pocos ensayos adicionales para determinar la saturación de gas en el carbón, el origen del gas, el porcentaje de metano y la permeabilidad de los carbones. El propósito de esta investigación es analizar la información reciente en el país sobre el uso de isotermas de adsorción, ensayos en isótopos de C13 y deuterio, cromatografía de gases y modelación de la permeabilidad. Los ensayos de isotermas de adsorción indican que el carbón está subsaturado, los resultados isotópicos muestran que el origen del gas sería biogénico principalmente, que los contenidos de metano estarían por debajo de 77 %, y que los valores de permeabilidad podrían ser altos. Los resultados también indican que se requieren más ensayos de isotermas, isótopos, cromatografía y permeabilidad, para aclarar con mayor precisión la saturación del metano, el origen del gas, el porcentaje de metano y la capacidad de flujo que tendrían los depósitos de CBM en Colombia, y de esta manera asegurar que haya gas suficiente para lograr la factibilidad económica en futuros proyectos. La exploración de CBM en el país ha sido superficial, se requiere investigar a profundidades superiores a 500 m, a prudente distancia de los trabajos mineros y lejos de áreas muy fracturadas, preferiblemente en estructuras como sinclinales con bajos buzamientos, y que se incluyan estudios de fracturas, diagénesis y modelado del yacimiento.

Abstract Due to the decrease of natural gas reserves and the high death toll from explosions in coal mines, Colombia has been carrying out preliminary explorations of coalbed methane (CBM). Until now, CBM exploration has focused on the gas content per ton of coal from canister desorption systems, but few additional tests have been done to determine coal gas saturation, gas origin, methane percentage and coalbeds permeability. The purpose of this research is to analyze recent information in the country on the use of adsorption isotherms, C13 and deuterium isotopes analyses, gas chromatography and permeability modeling. Adsorption isothermal test indicates that coalbeds are sub saturated, isotopic results show that gas origin is mainly biogenic, that methane content would be below 77%, and that permeability values could be high. These results also indicate that more isotherms, isotopes, chromatography and permeability tests are required to clarify with greater precision methane saturation, gas origin, methane percentage and flow capacity that CBM deposits would have in Colombia, and in this way ensure that there is enough gas to achieve economic feasibility in future projects. It is also concluded that the exploration has been superficial and that it is necessary to investigate the CBM at depths greater than 500 m, at a prudent distance from mining works and away from highly fractured areas; preferably in structures such as synclines with low deep structures, which should include studies of fractures, diagenesis, and reservoir modeling.

Abstract The deuteration of organic compounds has contributed to several fields of scientific knowledge, such as analytical, medicinal, organic chemistry, and polymer science. In this manuscript the concepts of kinetic isotopic effects, synthesis of deuterated compounds, and principal applications of deuteration are summarized to obtain a brief article that serves to teach multidisciplinary sciences to undergraduate chemists.

Resumen La deuteración de compuestos orgánicos ha contribuido a varios campos del conocimiento científico, como la química analítica, médica, orgánica y de polímeros. En este manuscrito se resumen los conceptos de efectos isotópicos cinéticos, síntesis de compuestos deuterados y principales aplicaciones de la deuteración para obtener un breve artículo que sirva para enseñar ciencias multidisciplinarias a estudiantes de química.

RESUMO Objetivo: Verificar mudanças no estado nutricional de crianças com câncer antes e após o tratamento quimioterápico e avaliar a correlação entre diluição de óxido de deutério, análise de impedância bioelétrica (BIA) e dados antropométricos. Métodos: Quatorze crianças (entre 5,6 e 13,6 anos de idade) foram incluídas e classificadas como tendo tumores hematológicos ou sólidos. A composição corporal foi medida pelo óxido de deutério, impedância bioelétrica e medidas antropométricas antes da primeira quimioterapia e após três e seis meses de terapia. Resultados: Os pacientes do grupo de tumores hematológicos aumentaram o peso, a estatura, o índice de massa corporal, a circunferência da cintura, quadril e braço, dobra cutânea subescapular e a massa gorda com a técnica de diluição isotópica durante o tratamento quimioterápico. No grupo de tumores sólidos, as crianças mostraram uma redução na massa magra quando avaliadas por análise de impedância. Houve uma correlação positiva entre a dobra cutânea tricipital e a massa gorda determinadas pela análise de impedância e pelo óxido de deutério. A circunferência muscular do braço correlacionou-se com a massa magra estimada pela análise de impedância e pelo óxido de deutério. Conclusões: Pacientes com tumores hematológicos tiveram aumento no peso corporal, estatura e massa gorda, o que não foi observado naqueles com tumores sólidos. A boa correlação entre a antropometria (dobra cutânea tricipital e circunferência muscular do braço), a diluição do óxido de deutério e a análise da impedância bioelétrica mostra a aplicabilidade da antropometria na prática clínica.

ABSTRACT Objective: To explore changes in the nutritional status of pediatric cancer patients before and after chemotherapy and evaluate the correlation between deuterium oxide dilution, bioelectric impedance analysis, and anthropometry for assessment of body composition. Methods: This study included 14 children (aged 5.6 to 13.6 years) and classified them as having hematologic or solid tumors. They had their body composition analyzed according to deuterium oxide, bioelectric impedance, and anthropometric measurements before the first chemotherapy cycle and after three and six months of therapy. Results: The patients in the hematologic tumor group had an increase in weight, height, body mass index, waist, hip, and arm circumference, subscapular skinfold thickness, and fat mass with the isotope dilution technique during chemotherapy. In the solid tumor group, the children showed a reduction in fat-free mass when assessed by bioimpedance analysis. We found a positive correlation between the triceps skinfold thickness and fat mass determined by bioimpedance analysis and deuterium oxide. The arm muscle circumference correlated with the fat-free mass estimated by bioimpedance analysis and deuterium oxide. Conclusions: Patients with hematologic tumors had an increase in body weight, height, and fat mass, which was not identified in the solid tumor group. The positive correlation between anthropometry (triceps skinfold thickness and arm muscle circumference), deuterium oxide dilution, and bioelectric impedance analysis shows the applicability of anthropometry in clinical practice.

Abstract Introduction: in patients with severe and morbid obesity it has been observed that bioimpedance (BIA) assessment generates an underestimation of fat mass (FM) and weight loss as FM after bariatric surgery, overestimating the loss of fat-free mass (FFM) and muscle mass. Objective: to evaluate the reliability of bioelectrical impedance analysis (BIA) to estimate total body water (TBW), fat-free mass (FFM), fat mass (FM), and its changes after 6 months of a Roux-en-Y gastric bypass (RYGBP), in patients with severe and morbid obesity. Methods: thirty-six patients approved for RYGBP were prospectively studied. TBW was measured by deuterium (D), and FM and FFM were calculated. A dual-frequency BIA device (5 and 200 kHz) (Bodystat Dualscan®) was used to estimate FM, FFM, TBW, extracellular water (ECW), intracellular water (ICW), and ECW/ICW ratio. Results: before RYGBP, BIA overestimated TBW by 2.6 ± 4.3 L (p = 0.002) and FFM by 3.5 ± 5.7 kg (p = 0.002), and underestimated FM% by 2.98 ± 4.7% (p = 0.002). The ECW/ICW ratio showed a significant and positive correlation with the difference BIA-D for FFM (r = 0.49; p = 0.002). After surgery, the differences between BIA and D were not significant, and the estimation error of FFM did not correlate with the ECW/ICW ratio. Conclusions: BIA generates an underestimation of FM as reported in patients with severe and morbid obesity, which is attenuated after weight reduction, underestimating weight loss as FM and overestimating FFM loss. Future research may assess whether these errors are reproduced by other BIA devices.

Resumen Introducción: en pacientes con obesidad severa y mórbida se ha observado que la evaluación por bioimpedanciometría (BIA) genera una subestimación de la masa grasa (MG) y del peso perdido como MG después de la cirugía bariátrica, sobreestimándose la pérdida de masa libre de grasa (MLG) y la masa muscular. Objetivo: evaluar la confiabilidad de la BIA para estimar el agua corporal total (ACT), la MLG, la MG y sus cambios después de 6 meses de un baipás gástrico en Y de Roux (BPGYR) en pacientes con obesidad severa y mórbida. Métodos: 36 adultos con indicación de BPGYR se estudiaron prospectivamente. Se midió el ACT por deuterio (D) y se calcularon la MLG y MG. Con BIA de doble frecuencia (5 y 200 kHz) (Bodystat Dualscan®) se estimaron la MG, la MLG, el ACT, el agua extracelular (AEC), el agua intracelular (AIC) y la relación AEC/AIC. Resultados: antes del BPGYR, la BIA sobreestimó el ACT en 2,6 ± 4,3 L (p = 0,002) y la MLG en 3,5 ± 5,7 kg (p = 0,002), y subestimó el %MG en 2,98 ± 4,7% (p = 0,002). La relación AEC/AIC mostró una correlación positiva con la sobreestimación de la MLG por BIA (r = 0,49; p = 0,002). Después de la cirugía, las diferencias entre BIA y D no fueron significativas y el error de estimación de la MLG no se correlacionó con la relación AEC/AIC. Conclusiones: la BIA genera una subestimación de la MG como la reportada, la cual se atenúa después de la reducción de peso, subestimando el peso perdido como MG y sobreestimando la pérdida de MLG. Futuras investigaciones podrán evaluar si estos errores se reproducen con otros equipos de BIA.

Resumen Pregunta de investigación: ¿Cuál será la composición corporal, el agua corporal total, y el agua extra e intracelular relacionados a los cambios después del ejercicio submaximo de 30 minutos y post rehidratacion con agua pura en adultos residentes permanentes de gran altitud, La Paz, Bolivia, gestión 2019? Objetivo: Determinar la composición corporal, el agua corporal total, y el agua extra e intracelular relacionados a los cambios después del ejercicio submaximo de 30 minutos y post rehidratacion con agua pura en adultos residentes permanentes de gran altitud, La Paz, Bolivia, gestión 2019. Material y métodos: El trabajo de investigación fue tipo experimental, antes y después, sobre Fisiología de Altitud, en 29 jóvenes residentes de gran altitud (3600 m.s.n.m.). Se evaluó variables antes y después de realizar una prueba de ejercicio submaxima, de 30 minutos, y la rehidratacion post ejercicio, tras el consumo de agua pura. Variables dependientes fueron: 1. Composición corporal, medida a través del análisis de impedancia bioeléctrica (AIB), 2. Volumen de agua corporal total, determinado por AIB. 3. Agua extra e intracelular evaluada por AIB y 4. Estado de rehidratacion, evaluado por el cambio de peso post ejercicio, y mediante el AIB. Las variables independientes fueron el ejercicio a través de la prueba submaxima de 30 minutos y la rehidratacion con agua pura. Resultados: En jóvenes residentes de gran altitud, se estima que el porcentaje de agua corporal total en las mujeres está disminuida en relación a la referencia de poblaciones del nivel del mar. La masa grasa corporal está muy incrementada en las mujeres. La diferencia de agua basal versus el agua post ejercicio entre varones y mujeres no es significativa. La diferencia de agua del líquido extra e intracelular basal versus el agua post ejercicio entre varones y mujeres no es significativa. La diferencia en la distancia recorrida en 30 minutos de ejercicio de trote submáximo es estadísticamente significativa a favor de los varones (4424 vs. 3619 metros). La correlación del IMC y el porcentaje de masa grasa es muy baja (r=0.109). El IMC entre varones y mujeres no presenta diferencia estadísticamente significativa (26±3 vs 24±3 respectivamente). La frecuencia de exceso de grasa corporal evaluada por AIB, es del 55% en las mujeres y de 0% en varones. La presión arterial sistémica en varones (PS:107±6 y PD:73± 4mmHg) y en mujeres (PS:104±8 y PD:70± 7mmHg), está disminuida en relación a referencia del nivel del mar. La frecuencia respiratoria esta incrementada tanto en varones (21 ±2) y mujeres (23±3). Conclusiones: El método de AIB permite evaluar la composición corporal y el agua corporal total y por tanto la masa grasa, mismo que fue validado en altitud por el método estándar de referencia de dilución isotópica en estudios previos en altitud. El ejercicio de trote submáximo ejecutado, ha exigido más a los universitarios estudiados. Se verifica que en el mismo tiempo los varones han recorrido una mayor distancia que las mujeres. Se estima que en mujeres la masa grasa corporal (MGC) esta incrementada y que el exceso de grasa (obesidad) es del 55%. La diferencia del agua al momento basal y post ejercicio y el LEC y LIC entre varones y mujeres no es significativa. El IMC subestima en este grupo la frecuencia de obesidad, principalmente en mujeres. El uso de técnicas nucleares, ha permitido a través del análisis del deuterio estudiar el agua, la composición corporal, y se asocia fuertemente con determinaciones similares mediante el uso de la bioimpedancia eléctrica.

Abstract Research question: What will be the body composition, the total body water, and the extra and intracellular water related to the changes aftersubmaximal exercise of30 minutes and post rehydration with puré water in permanent resident adults ofhigh altitude, La Paz, Bolivia, management 2019? Objective: To determine the body composition, the total body water, and the extra and intracellular water related to the changes after submaximal exercise of 30 minutes and post rehydration with puré water in permanent residents ofhigh altitude adults, La Paz, Bolivia, management 2019. Material and methods: The research workwas experimental, before and after, on Altitude Physiology, in 29young residents ofhigh altitude (3600 m.a.s.l.). Variables were evaluated before and after performing a 30-minute submaximal exercise test and post-exercise rehydration after consuming puré water. Dependent variables were: 1. Body composition, measured through bioelectrical impedance analysis (AIB), 2. Total body water volume, determined by AIB. 3. Extra and intracellular water evaluated by AIB and 4. Rehydration status, evaluated by post-exercise weight change, and by AIB. The independent variables were exercise through the 30-minute submaximal test and rehydration with puré water. Results: In young residents of high altitude, it is estimated that the percentage of total body water in women is decreased in relation to the reference of sea level populations. Body fat mass is greatly increased in women. The difference in basal water versus post-exercise water between men and women is not significant. The difference in water from basal extra and intracellular fluid versus post-exercise water between men and women is not significant. The difference in distance covered in 30 minutes of submaximal jogging exercise is statistically significant in favor ofmen (4424 vs. 3619 meters). The correlation of BMI and the percentage of fat mass is very low (r = 0.109). The BMI between men and women did not present a statistically significant difference (26 ± 3 vs 24 ± 3 respectively). The frequency of excess body fat evaluated byAIB is 55% in women and 0% in men. The systemic blood pressure in men (PS: 107 ±6 and PD: 73 ± 4mmHg) and in women (PS: 104 ±8 and PD: 70 ± 7mmHg), is decreased in relation to the sea level reference. Respiratory rate is increased in both men (21 ±2) and women (23 ± 3). Conclusions: The AIB method allows evaluating body composition and total body water and therefore fat mass, which was validated at altitude by the isotopic dilution reference standard method in previous studies at altitude. The submaximal trot exercise performed has demanded more from the university students studied. It is verified that in the same time the men have traveled a greater distance than the women. It is estimated that in women the body fat mass (FGM) is increased and that the excess fat (obesity) is 55%. The difference in water at baseline and post-exercise and the LEC and LIC between men and women is not significant. The BMI underestimates the frequency of obesity in this group, mainly in women. The use of nuclear techniques has allowed the analysis of deuterium to study water, body composition, and is strongly associated with similar determinations through the use of eléctrica! bioimpedance.

This study investigated the isotopic composition of daily rainfall in Johannesburg from November 2016 to October 2018. The moisture sources and trajectories for rainfall events of extreme isotopic signatures were deduced using the Hybrid Single Particle Lagrangian Integrated Trajectory model (HYSPLIT). The results from time series and regression analysis show temperature and amount effects, with low coefficient of determination (R²) values of 0.21 and 0.12, respectively. The rainfall with amounts of <20 mm yielded a meteoric water line (MWL) with a slope of +6.9 and deuterium excess (d-excess) of +11.9‰. Rainfall with amounts of ≥20 mm had slope and d-excess values of +8.2 and +18.6‰, respectively. The lower slope in rainfall of <20 mm indicated the preferential occurrence of sub-cloud re-evaporation on light rainfall. Considering the lack of re-evaporation in heavy rainfall (≥20 mm), its slope and d-excess were approximated to those of incoming or in-cloud moisture prior to condensation. Therefore, a high d-excess of +18.6‰ in incoming moisture indicates evaporation that mainly occurs under warm sea surface temperature and low relative humidity. HYSPLIT shows that the moisture for the most depleted and the most enriched rainfall originates in the higher latitudes but differs in trajectory. The moisture for the most depleted rainfall had long residence in the higher latitudes following a semi-direct trajectory to Johannesburg, over the Atlantic and Indian Oceans. The most enriched rainfall followed a curved anticlockwise trajectory with long residence in the lower latitudes over the Indian Ocean. Circulation of saturated moisture over the warm Indian Ocean leads to a loss of light isotopes, thereby enhancing enrichment in the moisture that moves further inland. HYSPLIT indicated the importance of atmospheric conditions along the moisture trajectory on the signature of Johannesburg rainfall.

RESUMO A avaliação da composição corporal ao nível molecular é relevante para a população esportiva e sua associação com o alto rendimento é bem reconhecida. O modelo molecular a quatro compartimentos (4C) é o método de referência para as estimativas de massa gorda (MG) e massa livre de gordura (MLG). No entanto, sua implementação no contexto real não é viável. Técnicos e atletas precisam de métodos práticos de composição corporal para a avaliação da composição corporal e o método de análise de impedância bioelétrica (BIA) é geralmente visto como uma alternativa útil. O objetivo deste estudo foi testar a validade da BIA (Tanita, TBF-310) na determinação de MG e MLG em atletas de elite de judô. Um total de 29 atletas masculinos foi avaliado em um período de estabilidade de peso usando o método de referência (4C) e o método alternativo (Tanita, TBF-310). Em relação ao método a 4C, a água corporal total foi avaliada pela diluição de deutério, mineral ósseo por DXA e volume corporal por pletismografia por deslocamento de ar. Os declives e interceções diferiram de 1 (0,39 e 1,11) e 0 (4,24 e –6,41) para MG e MLG, respectivamente. A MG da Tanita TBF-310 superestimou o método 4C em 0,2 kg, embora não tenham sido encontradas diferenças para MLG. A Tanita TBF-310 explicou 21% e 72%, respectivamente, na estimativa dos valores absolutos de MG e MLG do método a 4C. Os limites de concordância foram grandes, variando de –6,7 kg a 7,0 kg para MG e de –8,9 kg a 7,5 kg para MLG. Em conclusão, a TBF-310 Tanita não é um método alternativo válido para estimar a composição corporal em judocas altamente treinados.

SUMMARY Body composition assessment at the molecular level is relevant for the athletic population and its association with high performance is well recognized. The four-compartment molecular model (4C) is the reference method for fat mass (FM) and fat-free mass (FFM) estimation. However, its implementation in a real context is not feasible. Coaches and athletes need practical body composition methods for body composition assessment, and the bioelectrical impedance analysis method (BIA) is usually seen as a useful alternative. The aim of this study was to test the validity of BIA (Tanita, TBF-310) to determine the FM and FFM of elite judo athletes. A total of 29 males were evaluated in a period of weight stability using the reference method (4C) and the alternative method (Tanita, TBF-310). Regarding the 4C method, total-body water was assessed by deuterium dilution, bone mineral by DXA, and body volume by air displacement plethysmography. The slops and intercepts differed from 1 (0.39 and 1.11) and 0 (4.24 and -6.41) for FM and FFM, respectively. FM from Tanita TBF-310 overestimated the 4C method by 0.2 kg although no differences were found for FFM. Tanita TBF-310 explained 21% and 72% respectively in the estimation of absolute values of FM and FFM from the 4C method. Limits of agreement were significant, varying from -6.7 kg to 7.0 kg for FM and from -8.9 kg to 7.5 kg for FFM. In conclusion, TBF-310 Tanita is not a valid alternative method for estimating body composition in highly trained judo athletes.

O objetivo deste estudo foi identificar a relação entre a massa gordurosa (MG), expressa como percentagem de gordura corporal (%GC) medida pelo método de deutério (D2O) e indicadores antropométricos em escolas da Costa Rica. Trata-se de um estudo descritivo transversal, no qual participaram 54 meninos e 49 meninas com idade entre seis e nove anos. Foram realizadas medidas antropométricas: peso, tamanho, índice de massa corporal (IMC), circunferência do braço (CB), circunferência da cintura (CC), circunferência abdominal (CA), prega cutânea subescapular (PCS) e prega cutânea tricipital (PCT). A análise da %GC foi realizada pelo método de referência D2O, realizou-se uma estatística descritiva e foi aplicada análise coeficiente de correlação de Pearson para identificar a relação entre as medições antropométricas e a %GC obtida por meio do D2O. No grupo de escolares, as meninas apresentaram maiores valores de estatura e PCT (p<0,05) e %GC obtida por D2O (p<0,001). Observou-se uma importante correlação entre %GC medida por D2O e IMC, CC e CA tanto nos meninos quanto nas meninas. Conclui-se que a CC e a CA poderiam ser utilizadas conjuntamente com o IMC como ferramenta para o diagnóstico de sobrepeso e obesidade em população escolar, quando não se conte com metodologias mais precisas que determinem o %GC.

The purpose of this study was to identify the relationship between fat mass (FM) expressed as body fat percentage (%BF) measured by the deuterium method (D2O) and anthropometric indicators in Costa Rican schoolchildren. A cross-sectional descriptive study was performed and the participants were 54 boys and 49 girls of ages between six and nine years old. The anthropometric measurements recorded were weight, height, body mass index (BMI), arm circumference (AC), waist circumference (WC), abdominal circumference (AC), subscapular skinfold (SSF), and tricipital skinfold (TSF). The analysis of %BF was performed by means of D2O reference method. Descriptive statistics and the application of Pearson correlation coefficient analysis identified the relationship between anthropometric measurements and %BF obtained by D2O. From the group of schoolchildren, the girls showed greater values for height and tricipital skinfold (p<0.05) and %BF obtained by D2O (p<0.001). This study evidences a strong correlation between %BF measured by D2O and BMI, WC and AC in both girls and boys. It is concluded that WC and AC could be used together with the IMC as tools for the diagnosis of overweight and obesity in schoolchildren, when there are no more precise methodologies that determine the %BF.

El propósito de este estudio fue identificar la relación entre la masa grasa expresada como porcentaje de grasa corporal (%GC) medida por el método de deuterio (D2O) e indicadores antropométricos en escolares costarricenses. Se trata de un estudio descriptivo transversal en el que participaron 54 niños y 49 niñas de 6 a 9 años. Se realizaron medidas antropométricas: peso, talla, índice de masa corporal, circunferencia de brazo, circunferencia de cintura, circunferencia abdominal, pliegue cutáneo subescapular y pliegue cutáneo tricipital. El análisis del %GC se realizó por medio del método de referencia del D2O. Se realizó una estadística descriptiva y se aplicó un análisis de coeficiente de correlación de Pearson para identificar la relación entre las mediciones antropométricas y el %GC obtenido por D2O. En el grupo de escolares, las niñas presentaron valores mayores de talla y pliegue cutáneo tricipital (p<0,05) y %GC obtenida por D2O (p<0,001). Se observó una fuerte correlación entre el %GC medido por D2O y el índice de masa corporal, la circunferencia de cintura y la circunferencia abdominal tanto en los niños como en las niñas. Se concluye que la circunferencia de cintura y la circunferencia abdominal podrían ser utilizadas conjuntamente con el IMC como herramientas para el diagnóstico de sobrepeso y obesidad en población escolar, cuando no se cuente con metodologías más precisas que determinen el %GC.

Resumen Se presentaron resultados de estudios de investigación científica sobre fisiología de altura a través de la utilización de técnicas nucleares en la primera Jornada Científica de Ciencia Nuclear. Se ha tenido como objetivo el poderdifundir resultados de proyectos de investigación basados en los principios fisiológicos realizados a través del uso de trazadores isotópicos estables, como el óxido de deuterio, para determinar el agua corporal total y la composición corporal, constituida por la masa grasa y la masa libre de grasa; así mismo establecer el consumo de leche materna en condiciones de actividad diaria libre junto a la composición corporal de las madres en etapa de lactancia, en residentes permanentes de gran altitud. La meta de las jornadas fue incentivar, promover y favorecer que los resultados y/o productos de la investigación científica provenientes del uso de la ciencia nuclear asociada al conocimiento científico alcanzado proveniente de la Fisiología de Altura, permitan orientar y consolidar Políticas de Salud para residentes permanentes de gran altitud; así mismo favorecer la formación de recurso humano del pregrado de nuestra universidad y que la sociedad en general de nuestro medio sea informada y beneficiada en la mejora de su estado fisiológico y de salud en un medio de gran altitud. Se obtuvo como resultados una plena participación en investigación de los universitarios del pregrado de Medicina, quienes fueron activos en el trabajo de investigación y se involucraron en actividades de investigación en nuestros laboratorios de isótopos estables. Los resultados alcanzados favorecerán un mejor conocimiento del agua corporal total, la masa grasa y la masa libre de grasa, junto al ejercicio físico estudiado a gran altitud.

Abstract Results of scientific research studies on height physiology were presented through the use of nuclear techniques in the first Scientific Conference on Nuclear Science. It has been aimed at disseminating results of research projects based on physiological principles carried out through the use of stable isotopic tracers, such as deuterium oxide, to determine total body water and body composition, consisting of fat mass and fat free dough; likewise, establish the consumption of breast milk in conditions of free daily activity together with the body composition of the nursing mothers, as permanent residents of high altitude. The goal of the conference was to encourage, promote and encourage the results and / or products of scientific research from the use of nuclear science associated with the scientific knowledge obtained from Height Physiology, to guide and consolidate Health Policies for residents high altitude permanent; likewise, to favor the formation of human resources of the undergraduate of our university and that the society in general of our environment be informed and benefited in the improvement of its physiological and health status in a high altitude environment. The results were full participation in research of undergraduate students of Medicine, who were active in the research work and engaged in research activities in our stable isotope laboratories. The results achieved will favor a better knowledge of total body water, fat mass and fat free mass, together with the physical exercise studied at high altitude.

Abstract: Stable isotopes have been widely used in the literature both to discuss current ocean circulation processes, as well as to reconstitute paleoceanographic parameters. The distribution of oxygen and deuterium stable isotopes in seawater (δ18Osw and δDsw) at the Western Tropical South Atlantic border was investigated to better understand the main fractionation processes of these isotopes and establish a regional salinity and δ18Osw relation to improve the paleoceanographic knowledge in the region. This study was conducted during a quasi-synoptic oceanographic cruise in which 98 discrete seawater samples were collected in the core of the main water masses for stable isotope analysis. A strong correlation between δ18Osw and δD was found, which made it possible to extrapolate the results for δ18Osw to δD. Although it was not possible to distinguish the water masses based only on their isotopic signatures, the water masses had a strong salinity and δ18Osw relation, and compared with previous studies, a seasonal pattern was observed. Paleosalinity differences of up to 0.2 psu between Summer and Winter are reported. Considering the limitations of the current techniques to seasonally separate the samples for the paleoceanographic studies, an intermediate Mixing Line for the Tropical South Atlantic (SSS = 1.942* δ18Osw + 34.56) was proposed to reduce the estimated errors associated with these seasonal variations.

Resumen Las concentraciones de metales pesados en aves están influenciadas por factores como dieta, migración y tiempo de residencia. En el presente estudio se midieron las concentraciones (en μg(g-1 de peso seco) de los metales pesados cadmio (Cd), níquel (Ni), cobre (Cu), plomo (Pb), cromo (Cr) y zinc (Zn) en sangre de gallo (Gallus gallus domesticus). Para ello se le extrajeron 2 ml de sangre a ocho adultos y siete juveniles, y luego se procesaron con técnicas rutinarias de digestión, vertiendo 0,5 g de sangre en tubos de digestión con 5 ml de una mezcla ácida (180 ml de ácido nítrico y 100 ml de ácido clorhídrico), para lo cual se usó un bloque de calentamiento. Se analizaron en un espectrofotómetro de absorción atómica con flujo de aire-acetileno y corrector de fondo de deuterio. Las concentraciones promedio de metales pesados determinados en la sangre de los gallos adultos y juveniles no mostraron diferencias estadísticamente significativas, pero se pudo evidenciar que el patrón de las concentraciones se distribuyó de distinta manera en cada grupo. En orden descendente: Zn ˃ Ni ˃ Pb ˃ Cu ˃ Cr ˃ Cd, en adultos; mientras que para los juveniles fue: Zn ˃ Pb ˃ Ni ˃ Cu ˃ Cr ˃ Cd. Las concentraciones promedio para cada uno de los metales pesados analizados obtenidos en sangre de gallo fueron similares o estuvieron por debajo de los límites permisibles a los señalados en estudios realizados en otros países. En general, las concentraciones de los metales pesados obtenidos en los gallos no se consideran alarmantes.

Abstract The concentrations of heavy metals in birds are influenced by factors such as diet, migration, and residence time. The present study measured the concentrations (in μg(g-1 of dry weight) of the following heavy metals in the blood of cocks (Gallus gallus domesticus): cadmium (Cd), nickel (Ni), copper (Cu), lead (Pb), chromium (Cr), and zinc (Zn). For the effect, 2 ml of blood was extracted from eight adult and seven juvenile cocks, and then they were processed with routine digestion techniques, pouring 0.5 g of blood into digestion tubes with 5 ml of an acid mixture (180 ml of nitric acid and 100 ml of hydrochloric acid), using a heating block, to analyze them in an atomic absorption spectrophotometer with air-acetylene flow and a deuterium corrector. The average concentrations of heavy metals found in the blood of adult and juvenile cocks did not show statistically significant differences, but it evidenced that the pattern of concentrations was different in each group. In descending order: Zn ˃ Ni ˃ Pb ˃ Cu ˃ Cr ˃ Cd, in adults; and Zn ˃ Pb ˃ Ni ˃ Cu ˃ Cr ˃ Cd, in juveniles. Average concentrations for each one of the analyzed heavy metals obtained in rooster blood were below the permissible limits or were similar to those indicated in studies carried out in other countries. In general, the concentrations of heavy metals found in cocks are not considered alarming.

Resumo As concentrações de metais pesados em aves estão influenciadas por fatores como dieta, migração e tempo de residência. No presente estudo foram medidas as concentrações (em μg(g-1 de peso seco) dos metais pesados cadmio (Cd), níquel (Ni), cobre (Cu), chumbo (Pb), cromo (Cr) e zinco (Zn) em sangue de galo (Gallus gallus domesticus). Para isso, foram extraídos 2 ml de sangue a oito adultos e sete jovens, e logo foram processados com técnicas rotineiras de digestão, vertendo 0,5 g de sangue em tubos de digestão com 5 ml de uma mescla ácida (180 ml de ácido nítrico e 100 ml de ácido clorídrico), utilizando um bloco de aquecimento, para depois analisá-las em um espectrofotômetro de absorção atômica com fluxo de ar-acetileno e corretor de fundo de deutério. As concentrações médias de metais pesados determinados no sangue dos galos adultos e jovens não mostraram diferenças estatisticamente significativas, mas se pôde evidenciar que o padrão das concentrações se distribuiu de forma distinta em cada grupo. Em ordem descendente: Zn ˃ Ni ˃ Pb ˃ Cu ˃ Cr ˃ Cd, em adultos; enquanto que para os jovens foi: Zn ˃ Pb ˃ Ni ˃ Cu ˃ Cr ˃ Cd. As concentrações médias para cada um dos metais pesados analisados obtidos em sangue de galo foram similares ou estiveram abaixo dos limites permitidos aos apontados em estudos realizados em outros países. De modo geral, as concentrações dos metais pesados obtidos nos galos não se consideram alarmantes.

Resumen Reconocer la conexión hidráulica entre la zona de recarga y la zona de descarga en acuíferos solo es posible mediante el uso de trazadores, y los isótopos de 18O y 2H han probado ser buenos trazadores. En Ibagué y el lago de Tota se supone que la recarga de los acuíferos en la parte baja se da no solamente por infiltración vertical directa, sino también por precipitación e infiltración en las montañas altas, para luego infiltrarse regionalmente hasta alimentar los acuíferos en la parte baja. En Tota, los valores delta (δ) para el 18O son más ligeros en la parte alta que en la parte baja; en la parte alta los valores están cerca de -10 9%, mientras que los de la parte baja están en torno a -3 %%. En Ibagué, los valores 5 para el 18O son, igualmente, más bajos en la parte alta que en la parte baja; en la parte alta están entre -8 y -11 %, mientras que en la parte baja están entre -7 y -9 %. En ambos casos, la diferencia isotópica entre los valores de la parte alta y los de la parte baja podría indicar que no toda la infiltración de los acuíferos en la parte baja proviene de la recarga por la precipitación en la parte montañosa alta, y, por lo tanto, esa recarga adicional sería producto de la precipitación y la infiltración en la parte baja.

Abstract Identifying the hydraulic connection between the area of recharge and the area of discharge in aquifers is only possible by using tracers; the 18O and 2H isotopes have proven to be good tracers to determine such hydraulic connection. It is assumed that in Ibagué and Lake Tota the recharge of the aquifers is given by two processes: vertical infiltration and precipitation, and infiltration in the high mountains followed by regional permeation that reaches the aquifers in the lower part. In Tota, the delta (δ) values of 18O are lower in the higher part than in the lower part: in the higher area, the values are close to -10 %%, while in the lower area they are close to -3%o. In Ibagué, the delta values (δ) of 18O are also higher in the lower part: in the upper area the values are between -8 and -11 %%, while in the lower area are between -7 and -9 %%. In both cases, the isotopic difference between the upper and the lower areas could indicate that not all the water recharge in the lower area comes from precipitation in the high mountains, but that additional recharge can be the product of precipitation and infiltration in the lower part.

Resumo Reconhecer a conexão hidráulica entre a área de recarga e a área de descarga em aquíferos só é possível mediante o uso de traçadores, e os isótopos de 18O e 2H têm provado serem bons traçadores. Em Ibagué e no lago de Tota supõe-se que a recarga dos aquíferos na parte baixa se dá não somente por infiltração vertical direta, mas também por precipitação e infiltração nas montanhas altas, para depois infiltrar-se regionalmente até alimentar os aquíferos na parte baixa. Em Tota, os valores delta (δ) para o 18O são mais leves na parte alta do que na parte baixa; na parte alta os valores estão perto de -10 %, enquanto que os da parte baixa estão próximos a -3 %. Em Ibagué, os valores 5 para o 18O são, igualmente, mais baixos na parte alta do que na parte baixa; na parte alta estão entre -8 e -11 %, enquanto que na parte baixa estão entre -7 e -9 %. Em ambos os casos, a diferença isotópica entre os valores da parte alta e os da parte baixa poderia indicar que não toda a infiltração dos aquíferos na parte baixa provem da recarga pela precipitação na parte montanhosa alta, e, portanto, essa recarga adicional seria produto da precipitação e a infiltração na parte baixa.

Abstract: A promissory low-to-medium temperature geothermal system located in Sonora (Mexico) has been studied. In the present work, a detailed geochemical survey was carried out to understand the hydrogeochemical signatures of hot spring waters. A field work campaign was conducted for collecting water samples from twelve hot springs placed in four major zones (NW, NE, C, and S). The collected samples were analysed by chemical and isotopic methods for determining their chemical (major and trace elements) and isotopic (18O/16O and D/H) compositions. Using geochemometric analyses of the fluid composition and fractionation, depletion and enrichment processes exhibited by major and trace elements were analysed. Hydrogeochemical classification was used to indicate the presence of sodium-sulphate (Na-SO4) waters in the North (NW and NE) and South hydrothermal zones; whereas calcium-magnesium-bicarbonate (Ca-Mg-HCO3) waters were identified for the Central zone. Some hot spring waters located in the NE zone were also typified as sodium-bicarbonate (Na-HCO3). In relation to the isotopic signatures of 18O/16O and D/H, four water samples from NE and C zones lie near to the global meteoric water line; whereas the remaining eight samples showed a shift for both oxygen and deuterium isotopes. A mixing line with a small shift of δ18O was identified and used as a proxy to discriminate waters with different isotopic signatures. After applying a geochemometric outliers detection/rejection and an iterative ANOVA statistical test, the mean temperature inferred from the most reliable solute geothermometers was 149±40 °C, which suggests to be considered as the minimum value of the reservoir temperature. As most of the hot spring waters fall outside of the full equilibrium curve, the original reservoir conditions were corrected by using a mixing conductive model, which predicted a deep equilibrium temperature of 210±11 °C. As this temperature is considerably higher than the mean temperature inferred from the geothermometers, it was suggested as an optimistic maximum reservoir temperature of the Sonora geothermal system. Using 150 °C and 200 °C as rounded-off reservoir temperatures (or min-max estimates), geochemical equilibria modelling based on fluid-mineral stability diagrams was carried out. An equilibrium process among local hydrothermal waters and albite-potassium feldespar and muscovite-prehnite-laumontite mineral assemblages was found. These minerals were proposed as representative mineral assemblages of low-grade metamorphism, which seems to indicate that the geothermal fluid equilibria were probably reached within the intermediate to acidic volcanic rocks from the Tarahumara Formation.

Resumen: Se estudió geoquímicamente un sistema geotérmico promisorio de baja-media temperatura localizado en el Estado de Sonora (México). En el presente trabajo, se llevó a cabo un estudio geoquímico para entender las firmas hidrogeoquímicas de los manantiales termales. Con estos propósitos, se llevó a cabo una campaña de trabajo de campo para recolectar muestras de agua de doce manantiales termales localizados en cuatro zonas principales (NW, NE, C y S). Las muestras recolectadas se analizaron mediante métodos químicos e isotópicos para determinar sus principales rasgos químicos (elementos mayores y traza) e isotópicos (18O/16O y D/H). Usando las firmas químicas y un análisis geoquimiométrico de la composición del fluido y de los procesos de fraccionamiento se examinaron los procesos de empobrecimiento y enriquecimiento exhibidos por los elementos mayores y traza. La clasificación hidrogeoquímica indicó la presencia de aguas de tipo sulfatadas-sódicas (Na-SO4) en las zonas hidrotermales del Norte (NW y NE) y Sur; mientras que aguas bicarbonatadas-cálcico-magnésicas (Ca-Mg-HCO3) se identificaron en la zona Central. Algunas aguas termales ubicadas en la zona NE se caracterizaron como bicarbonatadas sódicas (Na-HCO3). Con relación a las firmas isotópicas de 18O/16O y D/H, cuatro muestras de agua de las zonas hidrotermales NE y C se ubicaron cerca de la Línea Meteórica Mundial; mientras que las ocho muestras restantes mostraron un desplazamiento tanto para los isótopos de oxígeno como para deuterio. Se identificó una línea de mezclado con un pequeño desplazamiento de δ18O, el cual se utilizó como una guía para discriminar aguas con una firma isotópica diferente. A partir de un análisis geoquimiométrico basado en un algoritmo de detección/eliminación de valores discordantes y una prueba iterativa de ANOVA, la temperatura media del yacimiento predicha por los geotermómetros de solutos fue de 149±40 °C, la cual se consideró como la temperatura mínima del yacimiento. Como la mayoría de las aguas termales están fuera del equilibrio, las condiciones originales del yacimiento se corrigieron utilizando un modelo de mezcla, que estima una temperatura de equilibrio profundo de 210±11 °C. Como esta temperatura resultó considerablemente más alta que el valor promedio calculado por los geotermómetros, se refirió a ésta como una estimación optimista o como la temperatura máxima del reservorio geotérmico. Utilizando 150 °C y 200 °C como los valores mínimos y máximos de la temperatura del yacimiento, se desarrolló un modelo de equilibrio basado en diagramas de estabilidad fluido-mineral. Se encontró un proceso de equilibrio entre las aguas termales locales y los sistemas minerales de albita-feldespato potásico y muscovita-prehnita-laumontita. Estos minerales se proponen como un conjunto mineral representativo del metamorfismo de bajo grado, que parecen indicar que se alcanzó el equilibrio de los fluidos geotérmicos con las rocas volcánicas intermedias a ácidas de la Formación Tarahumara.

Resumen: Mediante la utilización de la Ciencia Nuclear es posible hacer uso de los isótopos estables, identificados como trazadores, que permiten la aplicación del principio fisiológico de "dilución isotópica" en el organismo y con él se puede medir el agua corporal total. En los estudios de fisiología de altura, también se aplica el fundamento que aporta la ley de conservación de masas en un organismo. La práctica de este método permite generar conocimiento en altitud, haciendo bien las cosas correctas, por lo que se logra ser efectivo en los estudios realizados en diferentes grupos poblacionales habitantes permanentes de gran altitud. La técnica nuclear, ha permitido mediante el análisis del deuterio en sujetos estudiados, establecer la composición corporal, determinando el porcentaje del agua corporal total y la masa grasa corporal. Se estima que los habitantes permanentes de gran altitud presentarían una composición corporal con menor porcentaje de agua corporal que los habitantes de nivel del mar.

Abstract Using the Nuclear Science it is possible to make use of stable isotopes, identified as tracers, which allow the application of the physiological principle of "isotopic dilution" in the organism and with it the total body water can be measured. In the studies of physiology at high altitude, the foundation that the law of conservation of masses in an organism is also applied. The practice of this method allows to generate knowledge at altitude doing the right things well, so it is effective in studies conducted in different population groups permanent inhabitants of high altitude. The nuclear technique, has allowed by means of the analysis of the deuterium in studied subjects, to establish the corporal composition, determining the percentage of the total corporal water and the body fat mass. It is estimated that permanent inhabitants of high altitude would have a body composition with a lower percentage of body water than sea level inhabitants.