2,755 research outputs found
Diagnóstico socioeconômico dos municípios da região noroeste do Estado do Rio de Janeiro.
O diagnóstico do noroeste fluminense tem por objetivo avaliar a situação atual de cada município da região, destacando os principais pontos socioeconômicos. Os resultados obtidos mostram a precariedade em diversos setores da sociedade, onde as estatísticas revelam números insatisfatórios. Na educação, foram registrados altos índices de analfabetismo, destacando ainda a presença significativa do trabalho infantil. O êxodo rural é uma realidade na região, onde todos os municípios vêm sofrendo sucessivas quedas nas populações de campo. Neste contexto, a produção agropecuária (lavoura e leite) é razoavelmente baixa no Noroeste, onde a produtividade nos diversos setores se encontra abaixo dos níveis estaduais. Melhorias nas condições de produção agropecuária, assim como projetos que visem atender às demandas sociais, tornam-se extremamente necessários para o desenvolvimento da região.bitstream/item/63326/1/bpd41-2003-socioeconomia-noroeste-rj.pd
Effects of experimental lightgaps and topography on enrichment plantings in a central Amazonian secondary forest
Enrichment plantings into secondary forest are an important option in restoring species diversity and ecosystem services. However, little attention has been given to environmental requirements for species performance. This study evaluated the effects of lightgaps and topographic position on the growth and survival of four native tree species (Pouteria caimito, Garcinia macrophylla, Dipteryx odorata and Cynometra bauhiniaefolia) planted into a 26-year old secondary forest originating from abandoned pastures in the central Amazon Basin. Artificial lightgaps and control plots under closed canopy were uniformly distributed on plateaus and bottomlands near water bodies. Seedlings were planted randomly into the plots and monitored for 28 months. Seedling survival rate was high (93%) and did not differ among species. Overall, lightgaps produced a 38% increase in seedling height relative to the controls. Although the four species naturally occur in mature forest, two of the four grew significantly more in lightgaps than in dosed canopy secondary forest. Overall, bottomlands facilitated greater seedling growth in height (38%) relative to plateaus, but only one species exhibited a significant increase. This study shows the importance of the environmental variability generated with canopy openings along the topographic gradient, suggesting that both the selection of species and microsite conditions of planting sites have to be considered important criteria in the recovery of degraded areas
Barragem subterrânea uma opção para exploração agrícola no semi-árido.
Desde 1982 a Embrapa Semi-Árido vem desenvolvendo estudos com Barragem Subterrânea (BS), objetivando aumentar a disponibilidade de água no meio rural para obtenção de condições favoráveis para a exploração agrícola. O modelo de barragens subterrâneas construídas pela Embrapa Semi-Árido utiliza septo impermeável de lona plástica de polietileno. O presente estudo teve como objetivo avaliar o manejo e a produtividade obtida em quatro barragens subterrâneas nos anos agrícolas 1982/1983, 1990/1991 e 2004/2005. Os resultados demonstram que a BS é uma alternativa que minimiza os riscos da agricultura dependente de chuva, proporcionando mais uma opção viável para exploração agrícola em regiões semi-áridas
Aplicação de métodos multicritério ordinais para avaliar o risco de subsidência de organossolos.
Foram usados os métodos multicritério ordinais de Borda, Condorcet e Copeland para ordenar, segundo o risco de subsidência, 19 perfis de organossolos de diferentes regiões do Brasil. Os resultados mostram correlação entre os métodos (exceto Condorcet) e o parâmetro usual para avaliar subsidência
Edaphic arthropods in different successional stages of Atlantic forest and abandoned.
The vegetation may modifies the structure and composition of the community of edaphic arthropods. This study aimed to compare the community of edaphic arthropods in four areas of abandoned pasture (AP1, AP2, AP3, AP4) and four secondary native forest fragments in a successional gradient (FF1, FF2, FF3, FF4), in Itaboraí, Rio de Janeiro, Brazil. The areas are positioned on the hillside and the sampling was conducted in transects outlined in a toposequence (upper, middle and lower sections), where pitfall traps were installed in the dry season. The organisms were identified in taxonomic groups (class, order and family). Comparing the averages for AP and FF, there was no defined pattern in terms of the response of structural attributes (total abundance, richness, uniformity and diversity). Among the areas of FF, higher values of all of the structural attributes occurred in the intermediate stages of forest succession (FF2, FF3), compared to the initial (FF1) and advanced stages (FF4). On average for the FF, the most favored groups were Archaeognatha, Coleoptera, Entomobryomorpha, Pseudoscorpionida, Psocoptera and Symphypleona. On average for the areas of AP, the most favored groups were Acari, Araneae, Formicidae, Diplopoda and Auchenorrhyncha. Among the areas of FF, Sternorryncha, Symphyla and Thysanura were favored in FF1, while Coleoptera, Psocoptera, Pseudoscorpionida, Entomobryomorpha and Archaeognatha were favored in the other successional stages (FF2, FF3, FF
Production asymmetry of D mesons in collisions
We study the production asymmetry of charm versus anticharm mesons in
photon-proton interactions. We consider photon gluon fusion plus higher order
corrections in which light quarks through vector meson-proton interactions
contribute to the cross section. Non perturbative effects are included in terms
of a recombination mechanism which gives rise to a production asymmetry.Comment: 15 pages, including 5 postscript figures. LaTeX. To appear in Phys.
Lett.
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