2 resultados para 1235
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo
Resumo:
Wood production represents a large but variable fraction of gross primary production (GPP) in highly productive Eucalyptus plantations. Assessing patterns of carbon (C) partitioning (C flux as a fraction of GPP) between above- and belowground components is essential to understand mechanisms driving the C budget of these plantations. Better knowledge of fluxes and partitioning to woody and non-woody tissues in response to site characteristics and resource availability could provide opportunities to increase forest productivity. Our study aimed at investigating how C allocation varied within one apparently homogeneous 90 ha stand of Eucalyptus grandis (W. Hill ex Maiden) in Southeastern Brazil. We assessed annual above-ground net primary production (ANPP: stem, leaf, and branch production) and total belowground C flux (TBCF: the sum of root production and respiration and mycorrhizal production and respiration), GPP (computed as the sum of ANPP, TBCF and estimated aboveground respiration) on 12 plots representing the gradient of productivity found within the stand. The spatial heterogeneity of topography and associated soil attributes across the stand likely explained this fertility gradient. Component fluxes of GPP and C partitioning were found to vary among plots. Stem NPP ranged from 554 g C m(-2) year(-1) on the plot with lowest GPP to 923 g C m(-2) year(-1) on the plot with highest GPP. Total belowground carbon flux ranged from 497 to 1235 g C m(-2) year(-1) and showed no relationship with ANPP or GPP. Carbon partitioning to stem NPP increased from 0.19 to 0.23, showing a positive trend of increase with GPP (R-2 = 0.29, P = 0.07). Variations in stem wood production across the gradient of productivity observed at our experimental site were a result of the variability in C partitioning to different forest system components.
Resumo:
A systematic review of scientific production on Prison Health was conducted, seeking to verify how the subject matter has been dealt with, establishing which is the most exploited focus and identifying possible gaps. The search was carried out in the Virtual Health Library. 1160 articles were located: 1104 on MEDLINE, 19 on LILACS and 37 on SciELO, published from 1993 to 2010. As MEDLINE and LILACS do not show the entire articles, the places, dates and languages of the texts were charted. In-depth analysis was restricted to works which were shown in their entirety and free of charge hosted on SciELO. It revealed that scientific production is present all over the world with a predominantly quantitative approach. It focuses on identifying the socio-demographic profile and health conditions of prisoners, the incidence of tuberculosis, Human Immunodeficiency and Hepatitis C virus infections. There is a predominance of studies carried out with male prisoners, in comparison with the female sex. It is clear that prisoner health is a public health problem on the rise, which demands research that can orient health policies and strategies.