The benefits and challenges of conducting an overview of systematic reviews in public health: a focus on physical activity

Introduction The ultimate aim of Cochrane systematic reviews is to inform policy and practice decisions for better health outcomes. However, due to the increasing numbers of scientific publications, wading through the available evidence of both individual studies and systematic reviews can be challenging and overwhelming even for avid authors and readers. This paper briefly describes the first overview (a systematic review of reviews) of the Cochrane Public Health Group (CPHG) in development and proposes a way forward for the methodologies under consideration.

Uso del lenguaje publicitario en la campaña electoral del 28 de octubre de 1982.

Se presenta un análisis del uso del lenguaje en la campaña electoral de octubre de 1982. Se demuestra que los políticos utilizan un lenguaje político-publicitario en el que adquieren fórmulas similares al usado por mensajes publicitarios en los medios de comunicación social. El objetivo es utilizar dichos procedimientos para el estudio de los temas de COU, programados en la disciplina de lengua para la enseñanza media.

Population dynamics of the seabob shrimp Xiphopenaeus kroyeri (Dendrobranchiata, Penaeidae) in south-eastern Brazil

The population dynamics, including the sex ratio, reproductive period, individual growth and longevity, and population structure of the shrimp Xiphopenaeus kroyeri, are described. The shrimps were collected monthly from July 2005 to June 2007 at four sites in Ubatuba Bay, Brazil. The salinity, temperature, depth, organic matter content and sediment grain size were measured at each site. Specimens were quantified and sexed, their carapace length measured and their gonads were classified according to the stage of maturation. A von Bertalanffy model was used to estimate the individual growth, and longevity was calculated using its inverted formula. In total, 6 470 individuals were examined and the number of males and females differed significantly in favour of females. During some periods, the segregation could be related to the reproductive period. Reproductive females were captured throughout the sampled period, and there were biannual peaks that were followed by peaks of juveniles. Carapace growth was less for males than for females, which is likely related to oocyte production and the higher fecundity of the females. The higher probability of female capture can be related to their longer foraging to sustain the enhanced food requirement during the ovarian maturation period. © 2013 Copyright NISC (Pty) Ltd.

Auxin dynamics after decapitation are not correlated with the initial growth of axillary buds

One of the first and most enduring roles identified for the plant hormone auxin is the mediation of apical dominance. Many reports have claimed that reduced stem indole-3-acetic acid (IAA) levels and/ or reduced basipetal IAA transport directly or indirectly initiate bud growth in decapitated plants. We have tested whether auxin inhibits the initial stage of bud release, or subsequent stages, in garden pea (Pisum sativum) by providing a rigorous examination of the dynamics of auxin level, auxin transport, and axillary bud growth. We demonstrate that after decapitation, initial bud growth occurs prior to changes in IAA level or transport in surrounding stem tissue and is not prevented by an acropetal supply of exogenous auxin. We also show that auxin transport inhibitors cause a similar auxin depletion as decapitation, but do not stimulate bud growth within our experimental time- frame. These results indicate that decapitation may trigger initial bud growth via an auxin-independent mechanism. We propose that auxin operates after this initial stage, mediating apical dominance via autoregulation of buds that are already in transition toward sustained growth.