890 resultados para Total Body Potassium
Resumo:
La condición física, o como mejor se la conoce hoy en día el “fitness”, es una variable que está cobrando gran protagonismo, especialmente desde la perspectiva de la salud. La mejora de la calidad de vida que se ha experimentado en los últimos años en las sociedades desarrolladas, conlleva un aumento de la esperanza de vida, lo que hace que cada vez más personas vivan más años. Este rápido crecimiento de la población mayor de 60 años hace que, un grupo poblacional prácticamente olvidado desde el punto de vista de la investigación científica en el campo de la actividad física y del deporte, cobre gran relevancia, con el fin de poder ayudar a alcanzar el dicho “no se trata de aportar años a la vida sino vida a lo años”. La presente memoria de Tesis Doctoral tiene como principal objetivo valorar los niveles de fitness en población mayor española, además de analizar la relación existente entre el fitness, sus condicionantes y otros aspectos de la salud, tales como la composición corporal y el estado cognitivo. Entendemos que para poder establecer futuras políticas de salud pública en relación a la actividad física y el envejecimiento activo es necesario conocer cuáles son los niveles de partida de la población mayor en España y sus condicionantes. El trabajo está basado en los datos del estudio multicéntrico EXERNET (Estudio Multi-céntrico para la Evaluación de los Niveles de Condición Física y su relación con Estilos de Vida Saludables en población mayor española no institucionalizada), así como en los datos de dos estudios, llevados a cabo en población mayor institucionalizada. Se han analizado un total de 3136 mayores de vida independiente, procedentes de 6 comunidades autónomas, y 153 mayores institucionalizados en residencias de la Comunidad de Madrid. Los principales resultados de esta tesis son los siguientes: a) Fueron establecidos los valores de referencia, así como las curvas de percentiles, para cada uno de los test de fitness, de acuerdo a la edad y al sexo, en población mayor española de vida independiente y no institucionalizada. b) Los varones obtuvieron mejores niveles de fitness que las mujeres, excepto en los test de flexibilidad; existe una tendencia a disminuir la condición física en ambos sexos a medida que la edad aumenta. c) Niveles bajos de fitness funcional fueron asociados con un aumento en la percepción de problemas. d) El nivel mínimo de fitness funcional a partir del cual los mayores perciben problemas en sus actividades de la vida diaria (AVD) es similar en ambos sexos. e) Niveles elevados de fitness fueron asociados con un menor riesgo de sufrir obesidad sarcopénica y con una mejor salud percibida en los mayores. f) Las personas mayores con obesidad sarcopénica tienen menor capacidad funcional que las personas mayores sanas. g) Niveles elevados de fuerza fueron asociados con un mejor estado cognitivo siendo el estado cognitivo la variable que más influye en el deterioro de la fuerza, incluso más que el sexo y la edad. ABSTRACT Fitness is a variable that is gaining in prominence, especially from the health perspective. Improvement of life quality that has been experienced in the last few years in developed countries, leads to an expanded life expectancy, increasing the numbers of people living longer. This population consisting of people of over 60 years, an almost forgotten population group from the point of view of scientific research in the field of physical activity and sport, is becoming increasingly important, with the main aim of helping to achieve the saying “do not only add years to life, but also add life to years”. The principal aim of the current thesis was to assess physical fitness levels in Spanish elderly people, of over 65 years, analyzing relationship between physical fitness, its determinants, and other aspects of health such as body composition and cognitive status. In order to establish further public health policies in relation to physical activity and active ageing it is necessary to identify the starting physical fitness levels of the Spanish population and their determinants. The work is based on data from the EXERNET multi-center study ("Multi-center Study for the Evaluation of Fitness levels and their relationship to Healthy Lifestyles in noninstitutionalized Spanish elderly"), and on data from two studies conducted in institutionalized elderly people: a total of 3136 non-institutionalized elderly, from 6 Regions of Spain, and 153 institutionalized elderly in nursing homes of Madrid. The main outcomes of this thesis are: a) sex- and age-specific physical fitness normative values and percentile curves for independent and non-institutionalized Spanish elderly were established. b) Greater physical fitness was present in the elderly men than in women, except for the flexibility test, and a trend toward decreased physical fitness in both sexes as their age increased. c) Lower levels of functional fitness were associated with increased perceived problems. d) The minimum functional fitness level at which older adults perceive problems in their ADLs, is similar for both sexes e) Higher levels of physical fitness were associated with a reduced risk of suffering sarcopenic obesity and better perceived health among the elderly. f) The elderly with sarcopenic obesity have lower physical functioning than healthy counterparts. g) Higher strength values were associated with better cognitive status with cognitive status being the most influencing variable in strength deterioration even more than sex and age.
Resumo:
El equilibrio es una habilidad compleja esencial para la realización de cualquier tarea motriz y para la prevención de lesiones y caídas. La aparición de las pulseras holográficas, con supuestos beneficios entre los cuales se incluye la mejora del equilibrio, recibió la atención del público y los medios de comunicación por igual. Sin embargo, no hay evidencia científica de que los hologramas mejoren cualquier atributo físico. El objetivo de este estudio fue evaluar el efecto de las pulseras holográficas Power Balance® en el equilibrio. Siguiendo un método triple ciego, 25 estudiantes sanos y físicamente activos universitarios (14 mujeres, 11 hombres) fueron sometidos a la prueba de organización sensorial (SOT) en dos días separados mientras llevaban una pulsera con o sin hologramas (los ensayos se realizaron al azar en un orden contrabalanceado). El SOT proporciona detalles sobre el equilibrio total y la contribución relativa de los tres sistemas sensoriales principales (somatosensoriales, visuales y vestibulares) que intervienen en el equilibrio. Los resultados para el grupo como un todo revelaron que el uso de una pulsera holográfica no tiene ningún efecto significativo en cualquiera de estas variables. Sin embargo, cuando se analizaron los resultados de las mujeres de forma aislada, el uso de las pulseras holográficas se asoció con diferencias significativas en las puntuaciones de dos variables SOT: Equilibrio compuesto (86.5±3.7 con la pulsera holográfica en comparación con 85.5±4.5 sin ella; p?0.05) y la media general (93.5±2.0 en comparación con 92.8±2.4; p?0.05). Sin embargo, aunque a nivel estadístico estas diferencias fueron encontradas, la magnitud era tan pequeña que el equilibrio no se podría haber mejorado en ningún sentido práctico. En conclusión, las pulseras holográficas Power Balance® no ejercen ningún efecto significativo en el equilibrio en adultos jóvenes sanos.
Resumo:
The present study aimed to investigate the relationships between macronutrient intake and serum lipid profile in adolescents from eight European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) cross-sectional study (2006–7), and to assess the role of body fat-related variables in these associations. Weight, height, waist circumference, skinfold thicknesses, total choles- terol, HDL-cholesterol (HDL-C), LDL-cholesterol, TAG, apoB and apoA1 were measured in 454 adolescents (44 % boys) aged 12·5–17·5 years. Macronutrient intake (g/4180 kJ per d (1000 kcal per d)) was assessed using two non-consecutive 24 h dietary recalls. Associations were evaluated by multi-level analysis and adjusted for sex, age, maternal education, centre, sum of four skinfolds, moderate-to-vigorous.
Resumo:
Los objetivos de esta tesis fueron 1) obtener y validar ecuaciones de predicción para determinar in vivo la composición corporal y de la canal de conejos en crecimiento de 25 a 77 días de vida utilizando la técnica de la Impedancia Bioeléctrica (BIA), y 2) evaluar su aplicación para determinar diferencias en la composición corporal y de la canal, así como la retención de nutrientes de animales alimentados con diferentes fuentes y niveles de grasa. El primer estudio se realizó para determinar y después validar, usando datos independientes, las ecuaciones de predicción obtenidas para determinar in vivo la composición corporal de los conejos en crecimiento. Se utilizaron 150 conejos a 5 edades distintas (25, 35, 49, 63 y 77 días de vida), con un rango de pesos entre 231 y 3138 g. Para determinar los valores de resistencia (Rs,) and reactancia (Xc,) se usó un terminal (Model BIA-101, RJL Systems, Detroit, MI USA) con cuatro electrodos. Igualmente se registró la distancia entre electrodos internos (D), la longitud corporal (L) y el peso vivo (PV) de cada animal. En cada edad, los animales fueron molidos y congelados (-20 ºC) para su posterior análisis químico (MS, grasa, proteína, cenizas y EB). El contenido en grasa y energía de los animales se incrementó, mientras que los contenidos en proteína, cenizas y agua de los animales disminuyeron con la edad. Los valores medios de Rs, Xc, impedancia (Z), L y D fueron 83.5 ± 23.1 , 18.2 ± 3.8 , 85.6 ± 22.9 , 30.6 ± 6.9 cm y 10.8 ± 3.1 cm. Se realizó un análisis de regresión lineal múltiple para determinar las ecuaciones de predicción, utilizando los valores de PV, L and Z como variables independientes. Las ecuaciones obtenidas para estimar los contenidos en agua (g), PB (g), grasa (g), cenizas (g) and EB (MJ) tuvieron un coeficiente de determinación de (R2) de 0.99, 0.99, 0.97, 0.98 y 0.99, y los errores medios de predicción relativos (EMPR) fueron: 2.79, 6.15, 24.3, 15.2 y 10.6%, respectivamente. Cuando el contenido en agua se expresó como porcentaje, los valores de R2 y EMPR fueron 0.85 and 2.30%, respectivamente. Al predecir los contenidos en proteína (%MS), grasa (%MS), cenizas (%MS) y energía (kJ/100 g MS), se obtuvieron valores de 0.79, 0.83, 0.71 y 0.86 para R2, y 5.04, 18.9, 12.0 y 3.19% para EMPR. La reactancia estuvo negativamente correlacionada con el contenido en agua, cenizas y PB (r = -0.32, P < 0.0001; r = -0.20, P < 0.05; r = -0.26, P < 0.01) y positivamente correlacionada con la grasa y la energía (r = 0.23 y r = 0.24; P < 0.01). Sin embargo, Rs estuvo positivamente correlacionada con el agua, las cenizas y la PB (r = 0.31, P < 0.001; r = 0.28, P < 0.001; r = 0.37, P < 0.0001) y negativamente con la grasa y la energía (r = -0.36 y r = -0.35; P < 0.0001). Igualmente la edad estuvo negativamente correlacionada con el contenido en agua, cenizas y proteína (r = -0.79; r = -0.68 y r = -0.80; P < 0.0001) y positivamente con la grasa y la energía (r = 0.78 y r = 0.81; P < 0.0001). Se puede concluir que el método BIA es una técnica buena y no invasiva para estimar in vivo la composición corporal de conejos en crecimiento de 25 a 77 días de vida. El objetivo del segundo estudio fue determinar y validar con datos independientes las ecuaciones de predicción obtenidas para estimar in vivo la composición de la canal eviscerada mediante el uso de BIA en un grupo de conejos de 25 a 77 días, así como testar su aplicación para predecir la retención de nutrientes y calcular las eficacias de retención de la energía y del nitrógeno. Se utilizaron 75 conejos agrupados en 5 edades (25, 35, 49, 63 y 77 días de vida) con unos pesos que variaron entre 196 y 3260 g. Para determinar los valores de resistencia (Rs, ) y reactancia (Xc, ) se usó un terminal (Model BIA-101, RJL Systems, Detroit, MI USA) con cuatro electrodos. Igualmente se registró la distancia entre electrodos internos (D), la longitud corporal (L) y el peso vivo (PV) del cada animal. En cada edad, los animales fueron aturdidos y desangrados. Su piel, vísceras y contenido digestivo fueron retirados, y la canal oreada fue pesada y molida para posteriores análisis (MS, grasa, PB, cenizas y EB). Los contenidos en energía y grasa aumentaron mientras que los de agua, cenizas y proteína disminuyeron con la edad. Los valores medios de Rs, Xc, impedancia (Z), L y D fueron 95.9±23.9 , 19.5±4.7 , 98.0±23.8 , 20.6±6.3 cm y 13.7±3.1 cm. Se realizó un análisis de regresión linear múltiple para determinar las ecuaciones de predicción, utilizando los valores de PV, L and Z como variables independientes. Los coeficientes de determinación (R2) de las ecuaciones obtenidas para estimar los contenidos en agua (g), PB (g), grasa (g), cenizas (g) and EB (MJ) fueron: 0.99, 0.99, 0.95, 0.96 y 0.98, mientras que los errores medios de predicción relativos (EMPR) fueron: 4.20, 5.48, 21.9, 9.10 y 6.77%, respectivamente. Cuando el contenido en agua se expresó como porcentaje, los valores de R2 y EMPR fueron 0.79 y 1.62%, respectivamente. Cuando se realizó la predicción de los contenidos en proteína (%MS), grasa (%MS), cenizas (%MS) y energía (kJ/100 g MS), los valores de R2 fueron 0.68, 0.76, 0.66 and 0.82, y los de RMPE: 3.22, 10.5, 5.82 and 2.54%, respectivamente. La reactancia estuvo directamente correlacionada con el contenido en grasa (r = 0.24, P < 0.05), mientras que la resistencia guardó una correlación positiva con los contenidos en agua, cenizas y proteína (r = 0.55, P < 0.001; r = 0.54, P < 0.001; r = 0.40, P < 0.005) y negativa con la grasa y la energía (r = -0.44 y r = -0.55; P < 0.001). Igualmente la edad estuvo negativamente correlacionada con los contenidos en agua, cenizas y PB (r = -0.94; r = -0.85 y r = -0.75; P < 0.0001) y positivamente con la grasa y la energía (r = 0.89 y r = 0.90; P < 0.0001). Se estudió la eficacia global de retención de la energía (ERE) y del nitrógeno (ERN) durante todo el periodo de cebo (35-63 d), Los valores de ERE fueron 20.4±7.29%, 21.0±4.18% and 20.8±2.79% en los periodos 35 a 49, 49 a 63 y 35 a 63 d, respectivamente. ERN fue 46.9±11.7%, 34.5±7.32% y 39.1±3.23% para los mismos periodos. La energía fue retenida en los tejidos para crecimiento con una eficiencia del 52.5% y la eficiencia de retención de la energía como proteína y grasa fue de 33.3 y 69.9% respectivamente. La eficiencia de utilización del nitrógeno para crecimiento fue cercana al 77%. Este trabajo muestra como el método BIA es técnica buena y no invasiva para determinar in vivo la composición de la canal y la retención de nutrientes en conejos en crecimiento de 25 a 77 días de vida. En el tercer estudio, se llevaron a cabo dos experimentos con el fin de investigar los efectos del nivel de inclusión y de la fuente de grasa, sobre los rendimientos productivos, la mortalidad, la retención de nutrientes y la composición corporal total y de la canal eviscerada de conejos en crecimiento de 34 a 63 d de vida. En el Exp. 1 se formularon 3 dietas con un diseño experimental factorial 3 x 2 con el tipo de grasa utilizada: Aceite de Soja (SBO), Lecitinas de Soja (SLO) y Manteca (L) y el nivel de inclusión (1.5 y 4%) como factores principales. El Exp. 2 también fue diseñado con una estructura factorial 3 x 2, pero usando SBO, Aceite de Pescado (FO) y Aceite de Palmiste como fuentes de grasa, incluidas a los mismos niveles que en el Exp. 1. En ambos experimentos 180 animales fueron alojados en jaulas individuales (n=30) y 600 en jaulas colectivas en grupos de 5 animales (n=20). Los animales alimentados con un 4% de grasa añadida tuvieron unos consumos diarios y unos índices de conversión más bajos que aquellos alimentados con las dietas con un 1.5% de grasa. En los animales alojados en colectivo del Exp. 1, el consumo fue un 4.8% más alto en los que consumieron las dietas que contenían manteca que en los animales alimentados con las dietas SBO (P = 0.036). La inclusión de manteca tendió a reducir la mortalidad (P = 0.067) en torno al 60% y al 25% con respecto a las dietas con SBO y SLO, respectivamente. La mortalidad aumentó con el nivel máximo de inclusión de SLO (14% vs. 1%, P < 0.01), sin observarse un efecto negativo sobre la mortalidad con el nivel más alto de inclusión de las demás fuentes de grasa utilizadas. En los animales alojados colectivo del Exp. 2 se encontró una disminución del consumo (11%), peso vivo a 63 d (4.8%) y de la ganancia diaria de peso (7.8%) con la inclusión de aceite de pescado con respecto a otras dietas (P < 0.01). Los dos últimos parámetros se vieron especialmente más reducidos cuando en las dietas se incluyó el nivel más alto de FO (5.6 y 9.5%, respectivamente, (P < 0.01)). Los animales alojados individualmente mostraron unos resultados productivos muy similares. La inclusión de aceite pescado tendió (P = 0.078) a aumentar la mortalidad (13.2%) con respecto al aceite de palmiste (6.45%), siendo intermedia para las dietas que contenían SBO (8.10%). La fuente o el nivel de grasa no afectaron la composición corporal total o de la canal eviscerada de los animales. Un incremento en el nivel de grasa dio lugar a una disminución de la ingesta de nitrógeno digestible (DNi) (1.83 vs. 1.92 g/d; P = 0.068 en Exp. 1 y 1.79 vs. 1.95 g/d; P = 0.014 en Exp. 2). Debido a que el nitrógeno retenido (NR) en la canal fue similar para ambos niveles (0.68 g/d (Exp. 1) y 0.71 g/d (Exp. 2)), la eficacia total de retención del nitrógeno (ERN) aumentó con el nivel máximo de inclusión de grasa, pero de forma significativa únicamente en el Exp. 1 (34.9 vs. 37.8%; P < 0.0001), mientras que en el Exp. 2 se encontró una tendencia (36.2 vs. 38.0% en Exp. 2; P < 0.064). Como consecuencia, la excreción de nitrógeno en heces fue menor en los animales alimentados con el nivel más alto de grasa (0.782 vs. 0.868 g/d; P = 0.0001 en Exp. 1, y 0.745 vs. 0.865 g/d; P < 0.0001 en Exp.2) al igual que el nitrógeno excretado en orina (0.702 vs. 0.822 g/d; P < 0.0001 en Exp. 1 y 0.694 vs. 0.7999 g/d; P = 0.014 en Exp.2). Aunque no hubo diferencias en la eficacia total de retención de la energía (ERE), la energía excretada en heces disminuyó al aumentar el nivel de inclusión de grasa (142 vs. 156 Kcal/d; P = 0.0004 en Exp. 1 y 144 vs. 154 g/d; P = 0.050 en Exp. 2). Sin embargo, la energía excretada como orina y en forma de calor fue mayor en el los animales del Exp. 1 alimentados con el nivel más alto de grasa (216 vs. 204 Kcal/d; P < 0.017). Se puede concluir que la manteca y el aceite de palmiste pueden ser considerados como fuentes alternativas al aceite de soja debido a la reducción de la mortalidad, sin efectos negativos sobre los rendimientos productivos o la retención de nutrientes. La inclusión de aceite de pescado empeoró los rendimientos productivos y la mortalidad durante el periodo de crecimiento. Un aumento en el nivel de grasa mejoró el índice de conversión y la eficacia total de retención de nitrógeno. ABSTRACT The aim of this Thesis is: 1) to obtain and validate prediction equations to determine in vivo whole body and carcass composition using the Bioelectrical Impedance (BIA) method in growing rabbits from 25 to 77 days of age, and 2) to study its application to determine differences on whole body and carcass chemical composition, and nutrient retention of animals fed different fat levels and sources. The first study was conducted to determine and later validate, by using independent data, the prediction equations obtained to assess in vivo the whole body composition of growing rabbits. One hundred and fifty rabbits grouped at 5 different ages (25, 35, 49, 63 and 77 days) and weighing from 231 to 3138 g were used. A four terminal body composition analyser was used to obtain resistance (Rs, ) and reactance (Xc, ) values (Model BIA-101, RJL Systems, Detroit, MI USA). The distance between internal electrodes (D, cm), body length (L, cm) and live BW of each animal were also registered. At each selected age, animals were slaughtered, ground and frozen (-20 ºC) for later chemical analyses (DM, fat, CP, ash and GE). Fat and energy body content increased with the age, while protein, ash, and water decreased. Mean values of Rs, Xc, impedance (Z), L and D were 83.5 ± 23.1 , 18.2 ± 3.8 , 85.6 ± 22.9 , 30.6 ± 6.9 cm and 10.8 ± 3.1 cm. A multiple linear regression analysis was used to determine the prediction equations, using BW, L and Z data as independent variables. Equations obtained to estimate water (g), CP (g), fat (g), ash (g) and GE (MJ) content had, respectively, coefficient of determination (R2) values of 0.99, 0.99, 0.97, 0.98 and 0.99, and the relative mean prediction error (RMPE) was: 2.79, 6.15, 24.3, 15.2 and 10.6%, respectively. When water was expressed as percentage, the R2 and RMPE were 0.85 and 2.30%, respectively. When prediction of the content of protein (%DM), fat (%DM), ash (%DM) and energy (kJ/100 g DM) was done, values of 0.79, 0.83, 0.71 and 0.86 for R2, and 5.04, 18.9, 12.0 and 3.19% for RMPE, respectively, were obtained. Reactance was negatively correlated with water, ash and CP content (r = -0.32, P < 0.0001; r = -0.20, P < 0.05; r = -0.26, P < 0.01) and positively correlated with fat and GE (r = 0.23 and r = 0.24; P < 0.01). Otherwise, resistance was positively correlated with water, ash and CP (r = 0.31, P < 0.001; r = 0.28, P < 0.001; r = 0.37, P < 0.0001) and negatively correlated with fat and energy (r = -0.36 and r = -0.35; P < 0.0001). Moreover, age was negatively correlated with water, ash and CP content (r = -0.79; r = -0.68 and r = -0.80; P < 0.0001) and positively correlated with fat and energy (r = 0.78 and r = 0.81; P < 0.0001). It could be concluded that BIA is a non-invasive good method to estimate in vivo whole body composition of growing rabbits from 25 to 77 days of age. The aim of the second study was to determine and validate with independent data, the prediction equations obtained to estimate in vivo carcass composition of growing rabbits by using the results of carcass chemical composition and BIA values in a group of rabbits from 25 to 77 days. Also its potential application to predict nutrient retention and overall energy and nitrogen retention efficiencies was analysed. Seventy five rabbits grouped at 5 different ages (25, 35, 49, 63 and 77 days) with weights ranging from 196 to 3260 g were used. A four terminal body composition analyser (Model BIA-101, RJL Systems, Detroit, MI USA) was used to obtain resistance (Rs, ) and reactance (Xc, ) values. The distance between internal electrodes (D, cm), body length (L, cm) and live weight (BW, g) were also registered. At each selected age, all the animals were stunned and bled. The skin, organs and digestive content were removed, and the chilled carcass were weighed and processed for chemical analyses (DM, fat, CP, ash and GE). Energy and fat increased with the age, while CP, ash, and water decreased. Mean values of Rs, Xc, impedance (Z), L and D were 95.9±23.9 , 19.5±4.7 , 98.0±23.8 , 20.6±6.3 cm y 13.7±3.1 cm. A multiple linear regression analysis was done to determine the equations, using BW, L and Z data as parameters. Coefficient of determination (R2) of the equations obtained to estimate water (g), CP (g), fat (g), ash (g) and GE (MJ) content were: 0.99, 0.99, 0.95, 0.96 and 0.98, and relative mean prediction error (RMPE) were: 4.20, 5.48, 21.9, 9.10 and 6.77%, respectively. When water content was expressed as percentage, the R2 and RMPE were 0.79 and 1.62%, respectively. When prediction of protein (%DM), fat (%DM), ash (%DM) and energy (kJ/100 g DM) content was done, R2 values were 0.68, 0.76, 0.66 and 0.82, and RMPE: 3.22, 10.5, 5.82 and 2.54%, respectively. Reactance was positively correlated with fat content (r = 0.24, P < 0.05) while resistance was positively correlated with water, ash and protein carcass content (r = 0.55, P < 0.001; r = 0.54, P < 0.001; r = 0.40, P < 0.005) and negatively correlated with fat and energy (r = -0.44 and r = -0.55; P < 0.001). Moreover, age was negatively correlated with water, ash and CP content (r = -0.97, r = -0.95 and r = -0.89, P < 0.0001) and positively correlated with fat and GE (r = 0.95 and r = 0.97; P < 0.0001). In the whole growing period (35-63 d), overall energy retention efficiency (ERE) and nitrogen retention efficiency (NRE) were studied. The ERE values were 20.4±7.29%, 21.0±4.18% and 20.8±2.79%, from 35 to 49, 49 to 63 and from 35 to 63 d, respectively. NRE was 46.9±11.7%, 34.5±7.32% and 39.1±3.23% for the same periods. Energy was retained in body tissues for growth with an efficiency of approximately 52.5% and efficiency of the energy for protein and fat retention was 33.3 and 69.9%, respectively. Efficiency of utilization of nitrogen for growth was near to 77%. This work shows that BIA it’s a non-invasive and good method to estimate in vivo carcass composition and nutrient retention of growing rabbits from 25 to 77 days of age. In the third study, two experiments were conducted to investigate the effect of the fat addition and source, on performance, mortality, nutrient retention, and the whole body and carcass chemical composition of growing rabbits from 34 to 63 d. In Exp. 1 three diets were arranged in a 3 x 2 factorial structure with the source of fat: Soybean oil (SBO), Soya Lecithin Oil (SLO) and Lard (L) and the dietary fat inclusion level (1.5 and 4%) as the main factors. Exp. 2 had also arranged as a 3 x 2 factorial design, but using SBO, Fish Oil (FO) and Palmkernel Oil (PKO) as fat sources, and included at the same levels than in Exp. 1. In both experiments 180 animals were allocated in individual cages (n=30) and 600 in collectives cages, in groups of 5 animals (n=20). Animals fed with 4% dietary fat level showed lower DFI and FCR than those fed diets with 1.5%. In collective housing of Exp. 1, DFI was a 4.8% higher in animals fed with diets containing lard than SBO (P = 0.036), being intermediate for diet with SLO. Inclusion of lard also tended to reduce mortality (P = 0.067) around 60% and 25% with respect SBO and SLO diets, respectively. Mortality increased with the greatest level of soya lecithin (14% vs. 1%, P < 0.01). In Exp. 2 a decrease of DFI (11%), BW at 63 d (4.8%) and DWG (7.8%) were observed with the inclusion of fish oil with respect the other two diets (P < 0.01). These last two traits impaired with the highest level of fish oil (5.6 and 9.5%, respectively, (P < 0.01)). Animals housed individually showed similar performance results. The inclusion of fish oil also tended to increase (P = 0.078) mortality (13.2%) with respect palmkernel oil (6.45%), being mortality of SBO intermediate (8.10%). Fat source and level did not affect the whole body or carcass chemical composition. An increase of the fat sources addition led to a decrease of the digestible nitrogen intake (DNi) (1.83 vs. 1.92 g/d; P = 0.068 in Exp. 1 and 1.79 vs. 1.95 g/d; P = 0.014 in Exp. 2). As the nitrogen retained (NR) in the carcass was similar for both fat levels (0.68 g/d (Exp. 1) and 0.71 g/d (Exp. 2)), the overall efficiency of N retention (NRE) increased with the highest level of fat, but only reached significant level in Exp. 1 (34.9 vs. 37.8%; P < 0.0001), while in Exp. 2 a tendency was found (36.2 vs. 38.0% in Exp. 2; P < 0.064). Consequently, nitrogen excretion in faeces was lower in animals fed with the highest level of fat (0.782 vs. 0.868 g/d; P = 0.0001 in Exp. 1, and 0.745 vs. 0.865 g/d; P < 0.0001 in Exp.2). The same effect was observed with the nitrogen excreted as urine (0.702 vs. 0.822 g/d; P < 0.0001 in Exp. 1 and 0.694 vs. 0.7999 g/d; P = 0.014 in Exp.2). Although there were not differences in ERE, the energy excreted in faeces decreased as fat level increased (142 vs. 156 Kcal/d; P = 0.0004 in Exp. 1 and 144 vs. 154 g/d; P = 0.050 in Exp. 2). In Exp. 1 the energy excreted as urine and heat production was significantly higher when animals were fed with the highest level of dietary fat (216 vs. 204 Kcal/d; P < 0.017). It can be concluded that lard and palmkernel oil can be considered as alternative sources to soybean oil due to the reduction of the mortality, without negative effects on performances or nutrient retention. Inclusion of fish impaired animals´ productivity and mortality. An increase of the dietary fat level improved FCR and overall protein efficiency retention.
Resumo:
Pregnancy leads to several changes in body composition and morphology of women. It is not clear whether the biomechanical changes occurring in this period are due exclusively to body composition and size or to other physiological factors. The purpose was to quantify the morphology and body composition of women throughout pregnancy and in the postpartum period and identify the contribution of these parameters on the lower limb joints kinetic during gait. Eleven women were assessed longitudinally, regarding anthropometric, body composition, and kinetic parameters of gait. Body composition and body dimensions showed a significant increase during pregnancy and a decrease in the postpartum period. In the postpartum period, body composition was similar to the 1st trimester, except for triceps skinfold, total calf area, and body mass index, with higher results than at the beginning of pregnancy. Regression models were developed to predict women’s internal loading through anthropometric variables. Four models include variables associated with the amount of fat; four models include variables related to overall body weight; three models include fat-free mass; one model includes the shape of the trunk as a predictor variable. Changes in maternal body composition and morphology largely determine kinetic dynamics of the joints in pregnant women.
Resumo:
A fundamental shift to a total system approach for crop protection is urgently needed to resolve escalating economic and environmental consequences of combating agricultural pests. Pest management strategies have long been dominated by quests for “silver bullet” products to control pest outbreaks. However, managing undesired variables in ecosystems is similar to that for other systems, including the human body and social orders. Experience in these fields substantiates the fact that therapeutic interventions into any system are effective only for short term relief because these externalities are soon “neutralized” by countermoves within the system. Long term resolutions can be achieved only by restructuring and managing these systems in ways that maximize the array of “built-in” preventive strengths, with therapeutic tactics serving strictly as backups to these natural regulators. To date, we have failed to incorporate this basic principle into the mainstream of pest management science and continue to regress into a foot race with nature. In this report, we establish why a total system approach is essential as the guiding premise of pest management and provide arguments as to how earlier attempts for change and current mainstream initiatives generally fail to follow this principle. We then draw on emerging knowledge about multitrophic level interactions and other specific findings about management of ecosystems to propose a pivotal redirection of pest management strategies that would honor this principle and, thus, be sustainable. Finally, we discuss the potential immense benefits of such a central shift in pest management philosophy.
Resumo:
High-affinity K+ uptake in plant roots is rapidly up-regulated when K+ is withheld and down-regulated when K+ is resupplied. These processes make important contributions to plant K+ homeostasis. A cDNA coding for a high-affinity K+ transporter, HKT1, was earlier cloned from wheat (Triticum aestivum L.) roots and functionally characterized. We demonstrate here that in both barley (Hordeum vulgare L.) and wheat roots, a rapid and large up-regulation of HKT1 mRNA levels resulted when K+ was withdrawn from growth media. This effect was specific for K+; withholding N caused a modest reduction of HKT1 mRNA levels. Up-regulation of HKT1 transcript levels in barley roots occurred within 4 h of removing K+, which corresponds to the documented increase of high-affinity K+ uptake in roots following removal of K+. Increased expression of HKT1 mRNA was evident before a decline in total root K+ concentration could be detected. Resupply of 1 mm K+ was sufficient to strongly reduce HKT1 transcript levels. In wheat root cortical cells, both membrane depolarizations in response to 100 μm K+, Cs+, and Rb+, and high-affinity K+ uptake were enhanced by K+ deprivation. Thus, in both plant systems the observed physiological changes associated with manipulating external K+ supply were correlated with levels of HKT1 mRNA expression. Implications of these findings for K+ sensing and regulation of the HKT1 mRNA levels in plant roots are discussed.
Resumo:
The rates of whole body nitric oxide (NO) synthesis, plasma arginine flux, and de novo arginine synthesis and their relationships to urea production, were examined in a total of seven healthy adults receiving an L-amino acid diet for 6 days. NO synthesis was estimated by the rate of conversion of the [15N] guanidino nitrogen of arginine to plasma [15N] ureido citrulline and compared with that based on urinary nitrite (NO2-)/nitrate (NO3-) excretion. Six subjects received on dietary day 7, a 24-hr (12-hr fed/12-hr fasted) primed, constant, intravenous infusion of L-[guanidino-15N2]arginine and [13C]urea. A similar investigation was repeated with three of these subjects, plus an additional subject, in which they received L-[ureido-13C]citrulline, to determine plasma citrulline fluxes. The estimated rates (mean +/- SD) of NO synthesis over a period of 24 hr averaged 0.96 +/- 0.1 mumol .kg-1.hr-1 and 0.95 +/- 0.1 mumol.kg-1.hr-1, for the [15N]citrulline and the nitrite/nitrate methods, respectively. About 15% of the plasma arginine turnover was associated with urea formation and 1.2% with NO formation. De novo arginine synthesis averaged 9.2 +/- 1.4 mumol. kg-1.hr-1, indicating that approximately 11% of the plasma arginine flux originates via conversion of plasma citrulline to arginine. Thus, the fraction of the plasma arginine flux associated with NO and also urea synthesis in healthy humans is small, although the plasma arginine compartment serves as a significant precursor pool (54%) for whole body NO formation. This tracer model should be useful for exploring these metabolic relationships in vivo, under specific pathophysiologic states where the L-arginine-NO pathway might be altered.
Resumo:
At birth, pulmonary vasodilation occurs as air-breathing life begins. The mechanism of O2-induced pulmonary vasodilation is unknown. We proposed that O2 causes fetal pulmonary vasodilation through activation of a calcium-dependent potassium channel (KCa) via a cyclic nucleotide-dependent kinase. We tested this hypothesis in hemodynamic studies in acutely prepared fetal lambs and in patch-clamp studies on resistance fetal pulmonary artery smooth muscle cells. Fetal O2 tension (PaO2) was increased by ventilating the ewe with 100% O2, causing fetal total pulmonary resistance to decrease from 1.18 +/- 0.14 to 0.41 +/- 0.03 mmHg per ml per min. Tetraethylammonium and iberiotoxin, preferential KCa-channel inhibitors, attenuated O2-induced fetal pulmonary vasodilation, while glibenclamide, an ATP-sensitive K+-channel antagonist, had no effect. Treatment with either a guanylate cyclase antagonist (LY83583) or cyclic nucleotide-dependent kinase inhibitors (H-89 and KT 5823) significantly attenuated O2-induced fetal pulmonary vasodilation. Under hypoxic conditions (PaO2 = 25 mmHg), whole-cell K+-channel currents (Ik) were small and were inhibited by 1 mM tetraethylammonium or 100 nM charybdotoxin (CTX; a specific KCa-channel blocker). Normoxia (PaO2 = 120 mmHg) increased Ik by more than 300%, and this was reversed by 100 nM CTX. Nitric oxide also increased Ik. Resting membrane potential was -37.2 +/- 1.9 mV and cells depolarized on exposure to CTX, while hyperpolarizing in normoxia. We conclude that O2 causes fetal pulmonary vasodilation by stimulating a cyclic nucleotide-dependent kinase, resulting in KCa-channel activation, membrane hyperpolarization, and vasodilation.
Resumo:
Detailed electronic structure calculations of picene clusters doped by potassium modeling the crystalline K3picene structure show that while two electrons are completely transferred from potassium atoms to the lowest-energy unoccupied molecular orbital of pristine picene, the third one remains closely attached to both material components. Multiconfigurational analysis is necessary to show that many structures of almost degenerate total energies compete to define the cluster ground state. Our results prove that the 4s orbital of potassium should be included in any interaction model describing the material. We propose a quarter-filled two-orbital model as the most simple model capable of describing the electronic structure of K-intercalated picene. Precise solutions obtained by a development of the Lanczos method show low-energy electronic excitations involving orbitals located at different positions. Consequently, metallic transport is possible in spite of the clear dominance of interaction over hopping.
Resumo:
The aim of this study was to develop an anthropometric profile on highly skilled male water polo players by specific playing positions. Also, to identify significant relationships between these features an overhead throwing speed in highly skilled male Water Polo players by specific playing positions. Methods: A total of 94 male water polo players (24.5±5.3 yrs) who were playing in the Spanish King´s cup were studied. Subjects were grouped according to their specific playing positions: 15 goalkeepers, 45 offensive wings, 20 center backs and 14 center forwards. Anthropometric assessment was made following ISAK protocols. Hand grip and throwing speed in several situations were also assessed. A one-way analysis of variance (ANOVA) was used to determine if significant differences existed among the four playing positions. Pearson product-moment correlation coefficients (r) were used to determine the relationships of all anthropometric measures with throwing speed and hand grip. The total player’s somatotype was endomorphic-mesomorphic (2.9–5.8–2.3). Center forwards exhibit important anthropometric differences compared with the other specific playing positions in elite male water polo players, but no differences were found in throwing speed by specific playing positions in each throwing conditions. Moreover, a higher number of relationships between anthropometric and throwing speed were found in wings and also in center backs but no relationships were found in center forwards. The data reflects the importance of muscle mass and upper body in the throwing skill. Coaches can use this information in order to select players for the different specific positions.
Resumo:
Pregnancy leads to several changes in body composition and morphology of women. It is not clear whether the biomechanical changes occurring in this period are due exclusively to body composition and size or to other physiological factors. The purpose was to quantify the morphology and body composition of women throughout pregnancy and in the postpartum period and identify the contribution of these parameters on the lower limb joints kinetic during gait. Eleven women were assessed longitudinally, regarding anthropometric, body composition, and kinetic parameters of gait. Body composition and body dimensions showed a significant increase during pregnancy and a decrease in the postpartum period. In the postpartum period, body composition was similar to the 1st trimester, except for triceps skinfold, total calf area, and body mass index, with higher results than at the beginning of pregnancy. Regression models were developed to predict women’s internal loading through anthropometric variables. Four models include variables associated with the amount of fat; four models include variables related to overall body weight; three models include fat-free mass; one model includes the shape of the trunk as a predictor variable. Changes in maternal body composition and morphology largely determine kinetic dynamics of the joints in pregnant women.
Resumo:
Voluminous, subaerial magmatism resulted in the formation of extensive seaward-dipping reflector sequences (SDRS) along the Paleogene Southeast Greenland rifted margin. Drilling during Leg 163 recovered basalts from the SDRS at 66ºN (Site 988) and 63ºN (Sites 989 and 990). The basalt from Site 988 is light rare-earth-element (REE) enriched (La(n)/Yb(n) = 3.4), with epsilon-Nd(t=60) = 5.3, 87Sr/86Sr = 0.7034, and 206Pb/204Pb = 17.98. It is similar to tholeiites recovered from the Irminger Basin during Leg 49 and to light-REE-enriched tholeiites from Iceland. Drilling at Site 989, the innermost of the sites on the 63ºN transect, was proposed to extend recovery of the earliest part of the SDRS initiated during Leg 152. These basalts are, however, younger than those from Site 917 and are compositionally similar to basalts from the more seaward Sites 990 and 915. Many of the basalts from Sites 989 and 990 show evidence of contamination by continental crust (e.g., epsilon-Nd(t=60) extends down to -3.7, 206Pb/204Pb extends down to 15.1). We suggest that the contaminant is a mixture of Archean granulite and amphibolite and that the most contaminated basalts have assimilated ~5% of crust. Uncontaminated basalts are isotopically similar to basalts from Site 918, on the main body of the SDRS, and are light-REE depleted. Consistent with previous models of the development of this margin, we show that at the time of formation of the basalts from Sites 989 and 990 (1) melting was at relatively shallow levels in a fully-fledged rift zone; (2) fragments of continental crust were present in the lithosphere above the zones of melt generation; and (3) the sublithospheric mantle was dominated by a depleted Icelandic plume component.
Resumo:
The influence of salinity, temperature and prey availability on the marine migration of anadromous fishes was determined by describing the movements, habitat use and feeding behaviours of Arctic char (Salvelinus alpinus). The objectives were to determine whether char are restricted to the upper water column of the inter-/subtidal zones due to warmer temperatures. Twenty-seven char were tracked with acoustic temperature/pressure (depth) transmitters from June to September, 2008/2009, in inner Frobisher Bay, Canada. Most detections were in surface waters (0-3 m). Inter-/subtidal movements and consecutive repetitive dives (maximum 52.8 m) resulted in extreme body temperature shifts (-0.2-18.1 °C). Approximately half of intertidal and subtidal detections were between 9-13 °C and 1-3 °C, respectively. Stomach contents and deep diving suggested feeding in both inter-/subtidal zones. We suggest that char tolerate cold water at depth to capture prey in the subtidal zone, then seek warmer water to enhance feeding/digestion physiology.
Resumo:
Serpentinized abyssal peridotites sampled by the Ocean Drilling Program Leg 209 along the mid-Atlantic Ridge near the 15°20'N Fracture Zone have been analyzed for oxygen, hydrogen, and chlorine isotope compositions in order to determine isotopic behavior under a wide range of serpentinization conditions and place constraints on fluid history. Oxygen and hydrogen thermometry suggests peak serpentinization temperatures of 300-500°C. Serpentine separates have low deltaD values possibly due to a magmatic fluid component or low-temperature exchange during seafloor weathering. Chlorine geochemistry focused on three holes: 1274A and 1272A (serpentinized peridotites) and 1268A (serpentinite locally altered to talc). Concentrations of both, water-soluble chloride (WSC) and structurally bound chloride (SBC) are significantly lower at Hole 1268A compared to Holes 1274A and 1272A. The delta37Cl values for WSC and SBC of serpentinites in Holes 1274A and 1272A are slightly positive (avg. WSC = 0.20 per mil, n = 22 and avg. SBC = 0.35 per mil, n = 22), representing typical seawater-hydration conditions commonly determined for abyssal peridotite. The SBC of serpentinites from Hole 1268A are also positive (avg. = 0.63 per mil); whereas, the SBC in talc-dominated samples is negative (avg. = -1.22 per mil). The WSC of both talc- and serpentine-dominated samples are also negative (avg. = -0.15 per mil). We interpret the chlorine isotope data to preserve a record of multiple fluid events. As seawater hydrated the peridotite, 37Cl was preferentially incorporated into the forming serpentine and water-soluble salts, yielding similar delta37Cl values on a regional scale as sampled by Holes 1268A, 1274A and 1272A. The resultant pore fluid was left depleted in 37Cl. Locally (Hole 1268A), this evolved fluid was remobilized possibly due to the initiation of hydrothermal circulation in response to emplacement of a mafic magma body. The low delta37Cl pore fluids attained elevated SiO2 and sulfur concentrations due to interaction with the gabbroic intrusion and, when ascending through the surrounding serpentinite, caused formation of isotopically negative talc. This secondary fluid also flushed the preserved serpentinite of its previously formed salts, resulting in negative delta37Cl WSC values. The delta37Cl SBC values of the serpentinite samples remained unmodified by reaction with the secondary fluid.
