Efecto de las condiciones de almacenamiento refrigerado sobre el estrés oxidativo en raquis de uva de mesa, cv. Red Globe

Indexación: Web of Science; ScieloTable grape (Vitis vinifera L.) quality includes the condition of both the berries and the rachis. In the present report, physiological parameters of Red Globe rachises from fully elongated inflorescences (RFEI) and from mature clusters were studied after storage at 0 or 20 °C for different durations. To understand changes in rachis physiology as a result of changes in temperature conditions and storage time, the activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) were measured. In addition, hydrogen peroxide content, membrane lipoperoxidation (TBARS), total phenolic compounds and antioxidant capacity (FRAP) were assayed. TBARS was higher in mature rachises than in RFEI. This parameter remained constant throughout storage, indicating a change presumably associated with ontogeny or senescence processes. Short-term storage (096 h) increased SOD, CAT and APX activities in RFEI, while in mature rachises, no changes were observed in enzyme activities or in hydrogen peroxide content. Longer cold storage (25 or 53 days at 0 °C) of mature rachises reduced CAT activity, but SOD and APX activities did not change under these conditions. At 0 h, the FRAP and total phenolic contents of mature rachises were three and 20 times higher than in immature rachises, respectively.La calidad de uva de mesa (Vitis vinifera L.) involucra tanto la condición de bayas y el raquis. En el presente trabajo, los parámetros fisiológicos de raquis de 'Red Globe' de inflorescencias completamente elongadas (RFEI) y de racimos maduros fueron estudiados después de almacenamientos por diferentes tiempos a 0 ó 20 °C. Para entender los cambios en la fisiología del raquis debido a variaciones de temperatura y condiciones de almacenamiento, se midieron las actividades de superoxido dismutasa (SOD), catalasa (CAT), ascorbato peroxidasa (APX). Además fueron analizados el contenido de peróxido de hidrógeno, lipoperoxidación de membranas (TBARS), compuestos fenólicos totales y capacidad antioxidante (FRAP). TBARS de los raquis maduros a la cosecha fue mayor que el de inflorescencias completamente elongadas (RFEI). Este parámetro permaneció constante a través del almacenamiento, indicando cambios presuntamente asociados a ontogenia o procesos de senescencia. Almacenamiento cortos (0-96h) incrementaron la actividad de SOD, CAT y APX en RFEI, sin embargo no se observaron cambios en la actividad de estas enzimas o contenido de peróxido de hidrogeno en raquis maduros. Almacenamiento refrigerado prolongado (25 ó 30 días 0 °C) de raquis maduros redujo la actividad de CAT, pero SOD y APX no mostraron cambios bajo estas condiciones. A 0 h el contenido de FRAP y fenólicos totales de raquis maduros fueron tres y 20 veces mayores que en raquis inmaduro respectivamente.http://ref.scielo.org/m3mg4

Effects of Nitrogen Supply and Nitrogen Form on Intrinsic Water-Use Efficiency in Temperate, Semi-Natural Grasslands under Rising Atmospheric CO\u3csub\u3e2\u3c/sub\u3e

Carbon uptake and water loss of plants are controlled by the regulation of carbon assimilation rate (A) and stomatal conductance (gs). Any changes in these parameters under rising atmospheric CO2 concentration (ca) influence plant water-use efficiency and can affect carbon and water relations in grassland ecosystems. Time-series analyses of intrinsic water-use efficiency (Wi) of C3 grassland vegetation during the 20th century have shown that carbon uptake relative to water loss generally increased (Köhler et al. 2010, 2012; Barbosa et al. 2010). Short-term experiments suggest that nitrogen (N) supply (Stitt and Krapp 1999) and N form (Bloom et al. 2011) also play a role. We hypothesize that any increase in Wi should be stronger in swards with high N availability and with ammonium (NH4)-N instead of nitrate (NO3)-N fertilization

THE ROLE OF THE INTERNAL ROTATION OF THE UPPER ARM IN JAVELIN THROWING

We performed a kinematic and inverse dynamic study with javelin throwers in order to assess the role of the internal rotation of the upper arm in javelin throwing and then compare the findings to baseball throwing. On the one hand, the results show an equal behaviour of the angular velocity, torque and power curves compared to baseball pitching. The evaluated peak values differ on the other hand. Hence, the different release velocities in baseball pitching and this study could serve as an explanation for the different values, which can vary enormously

Arbeitsmarkt und Beschäftigung

The Labor Market and Employment (Handbook article). The labor market differs from typical markets in important ways. We find job competition and collective mechanisms that set wages and working conditions. Changes in employment bring about changes in wages and prices and entail political and monetary responses. The goals of price stability and full employment cannot, usually, be attained simultaneously under the present conditions.Der Arbeitsmarkt unterscheidet sich grundlegend von anderen Märkten. Wir finden hier einen ausgeprägten Qualifikationswettbewerb und kollektive Mechanismen der Festlegung von Entlohnungs- und Arbeitsbedingungen. Beschäftigungsänderungen müssen im Zusammenhang mit Lohn- und Preisbewegungen gesehen werden. Die wirtschaftspolitischen Ziele von Vollbeschäftigung und Preisstabilität stehen bei den gegebenen Lohnsetzungsmechanismen typischerweise im Widerspruch zueinander