Aproveitamento das entrelinhas de cana-de-açúcar para produção de grãos de caupi (Vigna unguiculata L. Walp)

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Nitrogen and phosphorus additions negatively affect tree species diversity tropical forest regrowth trajectories.

Nutrient enrichment is increasingly affecting many tropical ecosystems, but there is no information on how this affects tree biodiversity. To examine dynamics in vegetation structure and tree species biomass and diversity, we annually remeasured tree species before and for six years after repeated additions of nitrogen (N) and phosphorus (P) in permanent plots of abandoned pasture in Amazonia. Nitrogen and, to a lesser extent, phosphorus addition shifted growth among woody species. Nitrogen stimulated growth of two common pioneer tree species and one common tree species adaptable to both high- and lowlight environments, while P stimulated growth only of the dominant pioneer tree Rollinia exsucca (Annonaceae). Overall, N or P addition reduced tree assemblage evenness and delayed tree species accrual over time, likely due to competitive monopolization of other resources by the few tree species responding to nutrient enrichment with enhanced establishment and/or growth rates. Absolute tree growth rates were elevated for two years after nutrient addition. However, nutrient-induced shifts in relative tree species growth and reduced assemblage evenness persisted for more than three years after nutrient addition, favoring two nutrientresponsive pioneers and one early-secondary tree species. Surprisingly, N þ P effects on tree biomass and species diversity were consistently weaker than N-only and P-only effects, because grass biomass increased dramatically in response to N þ P addition. The resulting intensi?ed competition probably prevented an expected positive N þ P synergy in the tree assemblage. Thus, N or P enrichment may favor unknown tree functional response types, reduce the diversity of coexisting species, and delay species accrual during structurally and functionally complex tropical rainforest secondary succession

Incidencia natural de parasitoides em ovos de percevejos (Hemiptera: Pentatomidae) encontrados na soja no Distrito Federal.

Um levantamento das especies de parasitoides de ovos de pentatomideos presentes na soja foi realizado em Planaltina, DF. Doze especies de parasitoides de ovos (Telenomus edessae Fabricius, Telenomus podisi Ashmead, Telenomus sp.; Trissolcus basalis (Wollaston), Trissolcus brochymenae Ashmead, Trissolcus sp., Trissolcus teretis Johnson, Trissolcus urichi Crawford; Anastatus auriceps Ashmead, Eupelmus sp., Ooencyrtus sp. e Neorileya sp.) foram encontradas em sete especies de percevejos em soja: Acrosternum aseadum Rolston, Edessa meditabunda (Fabricius), Euschistus heros (Fabricius), Nezara viridula Linnaeus, Piezodorus guildinii (Westwood), Podisus nigrispinus (Dallas) e Thyanta perditor (Fabricius). Registrando-se, pela primeira vez, a ocorrencia de novos hospedeiros de A.auriceps (A.aseadum); T. teretis (E.heros e T.perditor); T.urichi (A.aseadum, P.guildinii e P.nigrispinus)

Thin Domain Walls in Lyra Geometry

This paper studies thin domain walls within the frame work of Lyra Geometry. We have considered two models. First one is the thin domain wall with negligible pressures perpendicular and transverse direction to the wall and secondly, we take a particular type of thin domain wall where the pressure in the perpendicular direction is negligible but transverse pressures are existed. It is shown that the thin domain walls have no particle horizon and the gravitational force due to them is attractive.Comment: 8 pages, typos are corrected, published Astrophysics and Space Sciences 305, 337 (2006

Agricultural machinery adequacy for handling the mombaça grass biomass in agroforestry systems.

Abstract: The current scenario of Agroforestry Systems (AFS) worldwide lacks specific machinery, resulting in practically all operations being carried out manually. This leads to a significant physical effort for small-scale farmers and limits the implementation of AFS to small areas. The objective of the study was to evaluate the suitability of existing machines for performing agroforestry tasks. This research utilizes Descriptive Statistics and Exponentially Weighted Moving Average methods to evaluate the data and compare the treatments, where different machines are used to cut Mombaça grass (Megathyrsus maximus Jacq): (i) costal brushcutter (CBC); (ii) tractor-mounted rotary brushcutter (RBC); and (iii) mini grain reaper machine (GRM). The experiments were conducted in Jaguariúna, São Paulo, Brazil. GRM is recommended for achieving greater biomass production, reducing raking time, and minimizing operational costs. CBC is suitable for smaller areas due to its affordability and slow operation, which requires significant physical effort. RBC is recommended for reducing working time, physical effort, and personnel costs, making it suitable for larger-scale contexts

O PIBID/Química UEL - Um Relato de Experiência na Escola: Abordando o Tema Radioatividade

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Acute pulmonary histoplasmosis and first isolation of Histoplasma capsulatum from soil of Rio Grande do Sul, Brazil

A case of acute pulmonary histoplasmosis, where the clinical histoiy and epidemiological data led to the identification of H. capsulatum natural source, is described. Specimens of spleen and liver, obtained after intraperitonial inoculation in mice, grew H. capsulatum in culture from the soil of rural area of General Câmara, by the first time in Rio Grande do Sul