2,106 research outputs found
Keywords given by authors of scientific articles in database descriptors
This paper analyses the keywords given by authors of scientific articles and the descriptors assigned to the articles in order to ascertain the presence of the keywords in the descriptors. 640 INSPEC, CAB abstracts, ISTA and LISA database records were consulted. After detailed comparisons it was found that keywords provided by authors have an important presence in the database descriptors studied, since nearly 25% of all the keywords appeared in exactly the same form as descriptors, with another 21% while normalized, are still detected in the descriptors. This means that almost 46% of keywords appear in the descriptors, either as such or after normalization. Elsewhere, three distinct indexing policies appear, one represented by INSPEC and LISA (indexers seem to have freedom to assign the descriptors they deem necessary); another is represented by CAB (no record has fewer than four descriptors and, in general, a large number of descriptors is employed; in contrast, in ISTA, a certain institutional code towards economy in indexing, since 84% of records contain only four descriptors
1001-28 Chronotropic incompetence in children with late postoperative atrial flutter: A case-control study
Inclusive , , ... reactions in nuclei
We study the inclusive , , , reactions in nuclei using a Monte Carlo simulation
method to treat the multichannel problem of the final state. The input consists
of reaction probabilities for the different steps evaluated using microscopical
many body methods. We obtain a good agreement with experiment in some channels
where there is data and make predictions for other channels which are presently
under investigation in several electron laboratories. The comparison of the
theoretical results with experiment for several kinematical conditions and
diverse channels can serve to learn about different physical processes ocurring
in the reaction. The potential of this theoretical tool to make prospections
for possible experiments, aiming at pinning down certain reaction
probabilities, is also emphasized.Comment: 21 pages (LaTeX + figure files
Biomarkers of physical activity and exercise
Tradicionalmente, los biomarcadores han sido de interés
en las ciencias del deporte para medir el rendimiento,
el progreso en el entrenamiento y para identificar el
sobreentrenamiento. Durante los últimos años, cada vez
hay mayor interés en evaluar los efectos relacionados con
la salud que se producen en el organismo debidos a una
actividad física regular y al deporte. El valor o la concentración de un biomarcador depende de muchos factores, como el grado de entrenamiento, el grado de fatiga y del tipo, la intensidad y la duración del ejercicio, aparte de la edad y del sexo. La mayor parte de los biomarcadores se miden en sangre, orina y saliva. Una de las principales limitaciones que presentan los biomarcadores bioquímicos es la falta de valores de referencia adaptados específicamente para deportistas y personas físicamente activas.
Las concentraciones pueden variar considerablemente
de los valores de referencia normales. Por lo tanto, es
importante adaptar los valores de referencia siempre y
cuando sea posible y controlar a cada sujeto regularmente,
con el fin de establecer su propia escala de referencia.
Otros biomarcadores útiles son la composición corporal
(específicamente masa muscular, masa grasa, peso),
la condición física (capacidad cardiorrespiratoria, fuerza,
agilidad, flexibilidad), frecuencia cardíaca y presión
arterial. Dependiendo de la finalidad, será conveniente
analizar uno o varios biomarcadores. Para esta revisión,
profundizaremos en los biomarcadores que se emplean
para evaluar condición física, fatiga crónica, sobreentrenamiento, riesgo cardiovascular, estrés oxidativo e inflamación
Evaluation of nutritional status and energy expenditure in athletes
El ejercicio físico continuo conduce al atleta a mantener
un equilibrio inestable entre la ingesta dietética, el gasto
de energía y las exigencias adicionales de un alto grado de
actividad física. Por lo tanto, una evaluación precisa del
estado nutricional es esencial para optimizar el rendimiento, ya que afecta a la salud, la composición corporal, y la recuperación del atleta. Aspectos específicos como tipo de deporte, especialidad o posición de juego, programa de entrenamiento y calendario de competiciones, la categoría, objetivos específicos, que difieran de la población en general, deben ser tenidos en cuenta. La evaluación bioquímica nos puede dar una idea general del estado nutricional, del perfil lipídico, del funcionamiento de hígado o riñón, de si la dieta
es demasiado alta en proteínas o grasas, así como las posibles deficiencias nutricionales y la necesidad de suplementación.
La cineantropometría deportiva tiene gran utilidad
ya que permite la evaluación de la masa corporal, altura,
longitud, diámetro, perímetro y pliegues cutáneos, donde la
información se procesa mediante la aplicación de diferentes ecuaciones, obteniendo información sobre el somatotipo, la composición corporal y la proporcionalidad de las distintas partes del cuerpo. Para poder dar una orientación nutricional adecuada, las necesidades de energía de los atletas deben ser conocidas. Si la medición objetiva no es posible, existen tablas que incluyen los requerimientos de energía teóricamente establecidos para diferentes deportes. La evaluación dietética debe incluir información sobre el consumo de alimentos y nutrientes para establecer la relación entre la dieta, el estado de salud y el rendimiento del atleta. Por otro lado, un estado adecuado de hidratación en los atletas es esencial para mantener un rendimiento óptimo. Se debe valorar específicamente la ingesta de líquidos por parte del
deportista. La deshidratación puede causar efectos nocivos
en la salud de los atletas. Como no existe un método “gold
standard”, la gravidez y el color de la orina son los métodos
más extendidos para analizar el estado de hidratación.
Hay consenso en que la combinación de diferentes métodos asegura una captura efectiva de datos para la valoración nutricional del deportista que permitirá proceder a la intervención dietética y nutricional
Reported Dietary Intake, Disparity between the Reported Consumption and the Level Needed for Adequacy and Food Sources of Calcium, Phosphorus, Magnesium and Vitamin D in the Spanish Population: Findings from the ANIBES Study
Calcium, phosphorus, magnesium and vitamin D have important biological roles in the body, especially in bone metabolism. We aimed to study the reported intake, the disparity between the reported consumption and the level needed for adequacy and food sources of these four nutrients in the Spanish population. We assessed the reported intake for both, general population and plausible reporters. Results were extracted from the ANIBES survey, n = 2009. Three-day dietary reported intake data were obtained and misreporting was assessed according to the European Food Safety Authority (EFSA). Mean ± SEM (range) total reported consumption of calcium, phosphorus, magnesium, and vitamin D for the whole population were 698 ± 7 mg/day (71–2551 mg/day), 1176 ± 8 mg/day, (331–4429 mg/day), 222 ± 2 mg/day (73–782 mg/day), and 4.4 ± 0.1 µg/day (0.0–74.2 µg/day), respectively. In the whole group, 76% and 66%; 79% and 72%; and 94% and 93% of the population had reported intakes below 80% of the national and European recommended daily intakes for calcium, magnesium and vitamin D, respectively; these percentages were over 40% when the plausible reporters were analysed separately. The main food sources were milk and dairy products for calcium and phosphorus, cereals and grains for magnesium and fish for vitamin D. In conclusion, there is an important percentage of the Spanish ANIBES population not meeting the recommended intakes for calcium, magnesium and vitamin D.The ANIBES study was financially supported by a grant from Coca-Cola Iberia through an agreement with the Spanish Nutrition Foundation (FEN)
Clustering of Dietary Patterns, Lifestyles, and Overweight among Spanish Children and Adolescents in the ANIBES Study
Weight gain has been associated with behaviors related to diet, sedentary lifestyle, and physical activity. We investigated dietary patterns and possible meaningful clustering of physical activity, sedentary behavior, and sleep time in Spanish children and adolescents and whether the identified clusters could be associated with overweight. Analysis was based on a subsample (n = 415) of the cross-sectional ANIBES study in Spain. We performed exploratory factor analysis and subsequent cluster analysis of dietary patterns, physical activity, sedentary behaviors, and sleep time. Logistic regression analysis was used to explore the association between the cluster solutions and overweight. Factor analysis identified four dietary patterns, one reflecting a profile closer to the traditional Mediterranean diet. Dietary patterns, physical activity behaviors, sedentary behaviors and sleep time on weekdays in Spanish children and adolescents clustered into two different groups. A low physical activity-poorer diet lifestyle pattern, which included a higher proportion of girls, and a high physical activity, low sedentary behavior, longer sleep duration, healthier diet lifestyle pattern. Although increased risk of being overweight was not significant, the Prevalence Ratios (PRs) for the low physical activity-poorer diet lifestyle pattern were >1 in children and in adolescents. The healthier lifestyle pattern included lower proportions of children and adolescents from low socioeconomic status backgrounds.The authors would like to thank Coca-Cola Iberia for its support and technical advice, particularly Rafael Urrialde and Isabel de Julián.The ANIBES study was financially supported by a grant from Coca-Cola Iberia through an agreement with the Spanish Nutrition Foundation (FEN)
Predicting enhanced absorption of light gases in polyethylene using simplified PC-SAFT and SAFT-VR
International audienceAbsorption of light gases in polyethylene (PE) is studied using two versions of the Statistical Associating Fluid Theory (SAFT): SAFT for chain molecules with attractive potentials of variable range (VR) and simplified perturbed-chain (PC) SAFT. Emphasis is placed on the light gases typically present during ethylene polymerisation in the gas-phase reactor (GPR) process. The two approaches are validated using experimental binary-mixture data for gas absorbed in PE, and predictions are made for mixtures of more components. For most cases studied both SAFT versions perform equally well. For the case of ternary mixtures of two gases with PE, it is predicted that the less-volatile of the two gases acts to enhance the absorption of the more-volatile gas, while the more-volatile gas inhibits the absorption of the less-volatile gas. This general behaviour is also predicted in mixtures containing more gases, such as typical reactor mixtures. The magnitude of the effect may vary considerably, depending on the relative proximity of the gas-mixture saturation pressure to the reactor pressure; for example it is predicted that the absorption of ethylene may be approximately doubled if diluent gases, propane or nitrogen, are partially or completely replaced by less-volatile butane or pentane for a reactor pressure similar to 2 MPa. In the case of a co-polymerisation reaction, it is predicted that increases in absorption of both co-monomers may be obtained in roughly equal proportion. Our findings cast light on the so-called co-monomer effect, in which substantial increases in the rate of ethylene polymerisation are observed in the presence of hexene co-monomer, while suggesting that the effect is more general and not restricted to co-monomer. For example, similar rate increases may be expected in the presence of, e.g., pentane instead of hexene, but without the change in the branch structure of the produced polymer that is inevitable when the amount of co-monomer is increased
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