2,764 research outputs found

    Current trends of accelerometry to assess physical activity

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    Evaluar la actividad física de forma precisa y fiable sigue siendo un importante reto para los epidemiólogos, científicos, médicos, especialistas en ejercicio e investigadores del comportamiento. Para ello, actualmente, los acelerómetros son dispositivos ampliamente utilizados en investigación científica. En el presente artículo se pretende dar muestra de cuál es la situación actual del uso de la acelerometría para cuantificar niveles de actividad física. Así como sus limitaciones y perspectivas de futuro con el fin de contribuir a su mejor uso

    Estudio comparativo de la Salmonellosis y Pasteurellosis aviares en Colombia

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    Para estudiar la importancia de la avicultura hay que consultar lasestadísticas de los países que más se han interesado en su desarrollo, y enumerar los sistemas de explotación, junto con los rendimientos económicos que ella reporta: asuntos que serán tratados de paso, ya que el profundizar sería, por sí solo, tema suficiente para muchos capítulos.En los primeros lustros de este siglo España, Norteamérica, Inglaterra, Checoeslovaquia, Alemania, Francia, Italia Dinamarca, Holanda, etc., eran las naciones que mayores provechos reportaban de la avicultura

    Physical Exercise as an Effective Antiaging Intervention

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    Physical exercise has been well demonstrated as an effective antiaging intervention. Although exercise certainly cannot reverse the aging process, it does attenuate many of its deleterious systemic and cellular effects. This special issue contains a set of selected papers that represent the broad spectrum in which physical exercise can contribute to a healthy aging. As documented in this issue an active lifestyle represents a powerful tool that may be described as a polypill to prevent and/or treat many conditions and diseases. The topics discussed herein include muscle fiber and muscle functioning, protein intake and sarcopenia, cognitive analysis, study of the perception of the instructors, and association of different biomarkers with physical performance..

    Effects of eight months of whole body vibration training on hip bone mass in older women

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    Objective: The aim of this study was to examine the effect of 8 months of whole-body vibration training on bone mass in octogenarian women. Method: Thirty-seven women (aged 82.4 [SD=5.7] years) voluntarily participated in this study. The vibration group (n=19) trained on a vibration platform twice a week (20 Hz and 2 mm) whereas controls (n=18) did not participate in any training program. Bone mass was measured by dual-energy X-ray absorptiometry at the hip region. General linear repeated measures ANOVA (group by time) was used to examine the effect of whole body vibration on bone mass changes. Results: After the intervention, in all the hip regions (total hip, femoral neck, trochanter, intertrochanter, Ward’s area), no statistically significant changes in bone mass were found. Conclusion: Eight months of whole body vibration training (twice a week) in elderly women do not produce osteogenic effects

    Tendencias actuales de la acelerometría para la cuantificación de la actividad física

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    To assess precisely and reliability the Physical Activity is still a challenger to the epidemiologist, scientific, medicals, exercise specialists and behavioural researchers. Nowadays, the accelerometers are monitors activity broadly used in scientific research. The present work has as an aim to show the real situation of the accelerometry to quantify Physical Activity Levels, as well as, their limitations and future directions in order to promote a better use of this technology.Evaluar la actividad física de forma precisa y fiable sigue siendo un importante reto para los epidemiólogos, científicos, médicos, especialistas en ejercicio e investigadores del comportamiento. Para ello, actualmente, los acelerómetros son dispositivos ampliamente utilizados en investigación científica. En el presente artículo se pretende dar muestra de cuál es la situación actual del uso de la acelerometría para cuantificar niveles de actividad física. Así como sus limitaciones y perspectivas de futuro con el fin de contribuir a su mejor uso.

    Effect of the ionic liquid [bmim]Cl and high pressure on the activity of cellulase

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    The effect of the ionic liquid 1-butyl-3-methylimidazolium chloride ([bmim]Cl) and of high pressure on the activity of cellulase from Aspergillus niger were studied separately and in combination. The enzyme activity decreased with increasing concentrations of [bmim]Cl, reaching 50% the value in aqueous buffer with 20% [bmim]Cl. However, when the enzyme is held in 10% [bmim]Cl and is then assayed in 1% [bmim]Cl, it showed only 8% reduction of activity. These results can be explained by the fact that the activity of the enzyme in [bmim]Cl is linearly correlated with the decrease of the thermodynamic water activity (aw). Under pressure the enzyme activity varied from less 60% (at 200MPa) to equal (at 400 MPa), compared to atmospheric pressure. In 10% [bmim]Cl under pressure, cellulase activity is improved compared to atmospheric pressure, varying from equal (at 600 MPa) to 1.7-fold higher (at 100 MPa). This opens the possibility to improve cellulase activity in ionic liquids, and possibly of other enzymes, by carrying out the reaction under pressure

    Novel Bayesian Networks for Genomic Prediction of Developmental Traits in Biomass Sorghum.

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    The ability to connect genetic information between traits over time allow Bayesian networks to offer a powerful probabilistic framework to construct genomic prediction models. In this study, we phenotyped a diversity panel of 869 biomass sorghum (Sorghum bicolor (L.) Moench) lines, which had been genotyped with 100,435 SNP markers, for plant height (PH) with biweekly measurements from 30 to 120 days after planting (DAP) and for end-of-season dry biomass yield (DBY) in four environments. We evaluated five genomic prediction models: Bayesian network (BN), Pleiotropic Bayesian network (PBN), Dynamic Bayesian network (DBN), multi-trait GBLUP (MTr-GBLUP), and multi-time GBLUP (MTi-GBLUP) models. In fivefold cross-validation, prediction accuracies ranged from 0.46 (PBN) to 0.49 (MTr-GBLUP) for DBY and from 0.47 (DBN, DAP120) to 0.75 (MTi-GBLUP, DAP60) for PH. Forward-chaining cross-validation further improved prediction accuracies of the DBN, MTi-GBLUP and MTr-GBLUP models for PH (training slice: 30-45 DAP) by 36.4-52.4% relative to the BN and PBN models. Coincidence indices (target: biomass, secondary: PH) and a coincidence index based on lines (PH time series) showed that the ranking of lines by PH changed minimally after 45 DAP. These results suggest a two-level indirect selection method for PH at harvest (first-level target trait) and DBY (second-level target trait) could be conducted earlier in the season based on ranking of lines by PH at 45 DAP (secondary trait). With the advance of high-throughput phenotyping technologies, our proposed two-level indirect selection framework could be valuable for enhancing genetic gain per unit of time when selecting on developmental traits

    Effects of the type of exercise performed on the vibration delivered during whole-body vibration exercises

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    While the internal load factors of whole-body vibration training have been widely investigated, the study of external load magnitude has been overlooked. Thus, the aim of the present study was to evaluate differences in whole-body vibration stimulus magnitude between static/dynamic whole-body vibration training at various vibration conditions. Four Pro 5 Plate vibration platforms were exposed to twelve different vibration conditions and a triaxial USB Impact X250-2 accelerometer was used to measure platform acceleration during each condition. Paired samples t-test was calculated to evaluate differences among amplitude, frequency, time of acceleration and time of deceleration of each platform at each vibration condition and during static (squat of 90° knee flexion) or dynamic exercise (from stand to 90° knee flexion squat). Also, the intra-class correlation coefficients were examined in order to assess the inter-instrument reliability. Peak-to-peak amplitude, frequency, time of acceleration and deceleration of the vibration platform were not modified by the type of exercise performed. Moreover, the four platforms tested showed high repeatability values during the execution of free vibration, static or dynamic squat in all vibration conditions. This study confirms that the vibration delivered by the Pro 5 Plate vibration platform is not modified during the realization of static or dynamic exercises

    Strenuous exercise worse than sedentarism?

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    Schnohr et al. (1) reported a U-shaped association between all-cause mortality and exercise dose in a Danish cohort. Jogging 1 to 2.4 h/week was associated with the lowest mortality, whereas jogging >3 times/week was no better than being inactive and was worse than light jogging (adjusted hazard ratio [HR]: 9.08; 95% confidence interval [CI]: 1.87 to 44.01). Furthermore, older (61.3 16.2 years) sedentary nonjoggers with cardiovascular disease (CVD) risk factors...

    The Era of Smartphones: Back to Our Biological Makeup?

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    Physical inactivity is a major modifiable cardiovascular risk factor that has become a growing health problem in the 21st century: 83% of adolescents aged 13-15 years and approximately 1/3 of adults worldwide are inactive, that is, not meeting the minimum international physical activity (PA) recommendations (=150 minutes/week of moderate to vigorous PA) [1, 2]. Thus, the PA levels of the general population, especially of individuals at cardiovascular risk, should be routinely assessed by health care professionals, as it has been recently recommended by the American Heart Association [3]. To this end, accelerometers (usually attached to an elastic belt around the waist) allow objective quantification of PA by providing continuous recordings. At least 3 to 5 days of accelerometer monitoring (including weekend days) are required to determine habitual PA, and it is generally accepted that the device should be worn for =10 hours/day [4]. For this reason, the simple and inexpensive method of PA questionnaires is more widely used and generally better accepted. Unfortunately, the validity of self-reported PA is questionable..
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