281 research outputs found
Editorial: New Training Strategies and Evaluation Methods for Improving Health and Physical Performance
Physical activity is among the most effective methods for improving health, body composition, and physical function, and its practice is suitable for every population [...]
Stress-Free Two-Way Shape Memory Effect of Poly(ethylene glycol)/ Poly(epsilon-caprolactone) Semicrystalline Networks
In this work, poly(ethylene glycol) (PEG)/poly(epsilon- caprolactone) (PCL) semicrystalline networks were prepared by photo-cross-linking of methacrylated macromonomers with different molecular weights and in different proportions to obtain amphiphilic materials capable of displaying properly designed shape memory effects. Networks based on PCL 10 kDa and PEG 3 kDa showed suitable thermal and mechanical properties with well-separated crystallization and melting regions to achieve a self-standing two-way shape memory effect. Particularly, after the application of a specific thermomechanical history, these materials are capable of cyclically changing their shape between two configurations upon cooling-heating cycles in the absence of any external load applied. The effect of the composition of the networks and of the employed thermomechanical parameters, such as the applied strain and the actuation temperature, was investigated to shed light on the shape memory mechanism for this class of materials, which are considered promising for applications in the biomedical field and as reversible actuators for soft robotics
La relación fiscal Nación - Provincias: reformas realizadas en 2016 y temas pendientes para el futuro
En 2016 se han producido varias novedades con relación a los tributos nacionalesy su distribución entre Nación y Provincias, ya sea por cambios en tributos que se comparten con provincias (Ganancias, Derechos de Exportación e Impuesto al Valor Agregado "IVA"), como por el arreglo alcanzado para la devolución (gradual) a provincias de la detracción del 15% a la coparticipaciónque desde 1992 va a la Administración Nacional de Seguridad Social (ANSES). Además, se fijaron nuevos compromisos en materia de responsabilidadfiscal y se anunció el objetivo de discutir una nueva Ley de Coparticipación Federal de Impuestos en años venideros. Ante el nuevo contexto, los principales objetivos de este trabajo son, primero, exponer las principales características de las relaciones fiscales Nación - Provincias en el punto de partida del nuevo gobierno. Luego, estimar los efectos sobre los recursos de Nación y Provincias originados en los cambios tributarios y en la distribución de transferencias fiscales efectuados durante el año 2016. Finalmente, se plantean y en algunos casos se cuantifican algunos de los principales desafíos pendientes que quedan en materia de federalismo fiscal para los próximos años.http://www.depeco.econo.unlp.edu.ar/wp/?page_id=2454Fil: Capello, Marcelo Luis. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Toselli, Vanessa N. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Otras Economía y Negocio
Relación fiscal Nación-provincias: reformas realizadas en 2016 y temas pendientes para el futuro
En 2016 se han producido varias novedades con relación a los tributos nacionales y su distribución entre Nación y Provincias, ya sea por cambios en tributos que se comparten con provincias (Ganancias, Derechos de Exportación e Impuesto al Valor Agregado –IVA–), como por el arreglo alcanzado para la devolución (gradual) a provincias de la detracción del 15% a la coparticipación que desde 1992 va a la Administración Nacional de Seguridad Social (ANSES). Además, se fijaron nuevos compromisos en materia de responsabilidad fiscal y se anunció el objetivo de discutir una nueva Ley de Coparticipación Federal de Impuestos en años venideros.
Ante el nuevo contexto, los principales objetivos de este trabajo son, primero, exponer las principales características de las relaciones fiscales Nación – Provincias en el punto de partida del nuevo gobierno. Luego, estimar los efectos sobre los recursos de Nación y Provincias originados en los cambios tributarios y en la distribución de transferencias fiscales efectuados durante el año 2016. Finalmente, se plantean y en algunos casos se cuantifican algunos de los principales desafíos pendientes que quedan en materia de federalismo fiscal para los próximos años.
Con tales objetivos, el documento se organiza como sigue. En la primera sección, se plantea la situación anterior a 2016, con relación a la distribución primaria efectiva entre Nación y Provincias, la distribución secundaria efectiva entre provincias, la distribución de transferencias discrecionales a gobiernos intermedios, la situación existente en materia de resultado fiscal en Nación y Provincias y los resultados consolidados de los particulares mecanismos de nivelación fiscal entre provincias aplicados en Argentina. En la segunda sección se exponen los principales cambios ocurridos en 2016 en la relación Nación - Provincias, y se cuantifican sus efectos en la distribución primaria y secundaria efectiva. En la tercera sección, se enumeran e intentan cuantificar los principales desafíos pendientes en materia de federalismo fiscal en Argentina para los próximos años.Facultad de Ciencias Económica
Reversible Stress-Driven and Stress-Free Two-Way Shape Memory Effect in a Sol-Gel Crosslinked Polycaprolactone
The two-way shape memory effect is the ability of a material to change its shape between two configurations upon application and removal of a stimulus, and, among shape memory polymers, it is featured only by few systems, such as semicrystalline networks. When studied under tensile conditions, it consists of elongation-contraction cycles along cooling and heating across the crystallization and melting region, typically under the application of a constant load. However, recent studies on crosslinked semicrystalline co-polymers demonstrate that also a completely stress-free, or self-sustained, two-way effect may be achieved through specific thermomechanical cycles. This effect is currently regarded with interest for the development of intrinsically reversible sensors and actuators, and it may also be displayed by simpler materials, as homopolymer-based semicrystalline networks. Only seldom articles investigate this possibility, therefore in this work the two-way shape memory behavior is studied on a poly(e-caprolactone) system, crosslinked by means of a sol-gel approach. The effect is studied both under stress-driven and stress-free condition, by applying properly set-up thermo-mechanical histories. The results allow to describe the effect as a function of temperature, to reveal the dependence on specific testing parameters and to compare the extent of the reversible strain variation under these two conditions
Fertilizer Potential of Organic-Based Soil Amendments on cv. Sangiovese (V. vinifera L.) Vines: Preliminary Results
The intensification of highly specialized viticulture has led to a dramatic decrease of soil fertility that can be restored by increasing soil organic matter using organic fertilizers. The aim of the present experiment was to evaluate the effect of different organic amendments on vine vegetative growth and nutritional status, soil N availability and microbial biomass, as well as on yield and grape quality. The experiment was carried out in 2020 and 2021, on cv. Sangiovese (Vitis vinifera L.) vines grafted on 110 Richter (V. berlandieri × V. rupestris) planted in February 2019. Plants were fer-tilized yearly in spring with (1) mineral fertilization (MIN), (2) municipal organic waste compost (MOW), and (3) sewage sludge compost (SS). The application of SS increased nitrate availability in both years, while the supply of organic matter (no matter the source) enhanced soil microbial bio-mass content. Plant nutritional status was in the optimal range for all treatments, with an increase of N in SS and K in MOW. Fruit yield in 2020 was not influenced by treatments, while in 2021 it was enhanced by MIN and MOW, which also induced a higher berry quality. Plant vegetative growth was stimulated by the application of SS. In conclusion, from these preliminary results we observed a higher N availability as a consequence of SS supply that resulted in a higher plant biomass, but reduced yield and berry quality, supporting the theory that for vineyards, N should be carefully managed to reach an equilibrium between vegetative and reproductive activity
High-resolution stable isotope stratigraphy of the upper Cambrian and Ordovician in the Argentine Precordillera: Carbon isotope excursions and correlations
We report the occurrence of important carbon isotope excursions in early Paleozoic formations of the Eastern and Central Argentine Precordillera. The Steptoean positive isotope carbon excursion (SPICE) is known from North America, Kazakhstan, South China, Australia and South America, and the negative isotope carbon excursion (SNICE) has been described for the first time in South America. We report here the record of the SPICE and SNICE in a single section in the Eastern Precordillera. In the Central Precordillera, a minor middle Darriwilian positive carbon isotope excursion (MDICE) and a late Sandbian positive isotope carbon excursion, the GICE (~ + 3‰; C. bicornis biozone) are reported from two sections. One pre-GICE positive carbon-isotope excursion (Sandbian Sa1, N. gracilis biozone) in the Central Precordillera with a δ13C peak of ~ + 2‰ is, perhaps, equivalent to the positive Spechts Ferry δ13C excursion of North America. A positive δ13C excursion (~ 6‰; N. persculptus biozone) recorded at the base of the late Hirnantian La Chilca Formation probably corresponds to HICE. These carbon-isotope excursions resulted from more than one factor where paleoceanographic events probably played a major role: (a) sea-level fall and vigorous fluctuations in the Steptoean (SPICE), (b) sea-level rise in the Sunwaptan (SNICE), (c) important transgression in the Sandbian (pre-GICE and GICE), and (d) sea-level fall in the late Hirnantian (HICE). In the Darriwilian and Sandbian stages, organic burial has led to a large 12C sequestration in the deep anoxic ocean with saline bottom water, recorded by the graptoliferous black shales of the Gualcamayo and Los Azules formations in Central Precordillera, helped the building of the MDICE and GICE anomalies. δ18O values for the Upper Cambrian carbonates are likely near-primary isotope signals that point to progressive cooling from the SPICE to the SNICE, whereas for Sandbian carbonates they suggest strong temperature fluctuations. The δ13C peak of the GICE coincides with a cooler period with temperatures warming up towards the late Hirnantian to Rhuddanian. The Upper Cambrian to the Middle Ordovician of the Precordillera recorded a decrease of seawater 87Sr/86Sr ratios in accordance to the global picture. This decrease probably reflects the influence of widespread volcanic activity from arc terranes in low-latitude settings along eastern margins of Laurentia and in the Argentine Precordillera in the Early to Middle Ordovician. Five carbonate samples (from San Juan, Gualcamayo and Los Azules formations) yielded εNd values that along seven already published values seem to plot along the Nd isotopic evolution trend of the Iapetus Ocean. Together, the record of global Upper Cambrian and Ordovician carbon-isotope excursions in the Argentine Precordillera is a valuable proxy in refining Early Paleozoic stratigraphy, establishing of regional/global high-resolution correlations, and sea-level change history in South America.Fil: Sial, A. N.. Universidade Federal de Pernambuco; BrasilFil: Peralta, Silvio Heriberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Gaucher, C.. No especifíca;Fil: Toselli, Alejandro Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Correlación Geológica. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Departamento de Geología. Cátedra Geología Estructural. Instituto Superior de Correlación Geológica; ArgentinaFil: Ferreira, V. P.. Universidade Federal de Pernambuco; BrasilFil: Frei, R.. Universidad de Copenhagen; DinamarcaFil: Parada, M. A.. Universidad de Chile; ChileFil: Pimentel, M. M.. Universidade Federal do Rio Grande do Sul; BrasilFil: Silva Pereira, Natan. Universidade Federal de Pernambuco; Brasi
Understanding local ethnic inequalities in childhood BMI through cross-sectional analysis of routinely collected local data
Reference Percentiles for Bioelectrical Phase Angle in Athletes
The present study aimed to develop reference values for bioelectrical phase angle in male and female athletes from different sports. Overall, 2224 subjects participated in this study [1658 males (age 26.2±8.9 y) and 566 females (age 26.9±6.6 y)]. Participants were categorized by their sport discipline and sorted into three different sport modalities: Endurance, velocity/power, and team sports. Phase angle was directly measured using a foot-to-hand bioimpedance technology at a 50 kHz frequency during the in-season period. Reference percentiles (5th, 15th, 50th, 85th, and 95th) were calculated and stratified by sex, sport discipline and modality using an empirical Bayesian analysis. This method allows for the sharing of information between different groups, creating reference percentiles, even for sports disciplines with few observations. Phase angle differed (men: P<0.001; women: P=0.003) among the three sport modalities, where endurance athletes showed a lower value than the other groups (men: Vs. velocity/power: P=0.010, 95% CI=−0.43 to −0.04; vs. team sports: P < 0.001, 95% CI=−0.48 to −0.02; women: Vs. velocity/power: P=0.002, 95% CI=−0.59 to −0.10; vs. team sports: P=0.015, 95% CI=−0.52 to−0.04). Male athletes showed a higher phase angle than female athletes within each sport modality (endurance: p<0.01, 95% CI=0.63 to 1.14; velocity/power: P<0.01, 95% CI=0.68 to 1.07; team sports: P<0.01, 95% CI=0.98 to 1.23). We derived phase angle reference percentiles for endurance, velocity/power, and team sports athletes. Additionally, we calculated sex-specific references for a total of 22 and 19 sport disciplines for male and female athletes, respectively. This study provides sex and sport-specific percentiles for phase angle that can track body composition and performance-related parameters in athletes
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