A generic key to the known larval Elmidae (Insecta: Coleoptera) of French Guiana

An identification key is provided for 21 larval types of Elmidae (riffle beetles) known to occur in French Guiana. Not all elmid genera known to occur in French Guiana are known in the larval stage. Nor are all the known larval types assigned to known elmid genera

Sistemas de intermediação e valorização econômica dos produtos.

Este capítulo aborda a valorização de produtos da agricultura familiar. Trata da diversidade e da especialidade das formas de inserção do mercado da agricultura familiar e da multiplicidade dos circuitos de comercialização e de transformação que ela mobiliza. Os exemplos citados referem-se à cadeia do leite e seus derivados nas zonas semiáridas e às cadeias regionais de uva de mesa e do melão, duas culturas irrigadas importantes no Nordeste.bitstream/item/196562/1/Camponeses-do-Sertao-pag-179-200.pd

Assessing ecosystem services from multifunctional trees in pastures using Bayesian belief networks

A Bayesian belief network (BBN) was developed to assess preferred combinations of trees in live fences and on pastures in silvopastoral systems. The BBN was created with information from Rivas, Nicaragua, using local farmer knowledge on tree species, trees' costs and benefits, farmers' expressed needs and aspirations, and scientific knowledge regarding tree functional traits and their contribution to ecosystem services and benefits. The model identifies combinations of trees, which provide multiple ecosystem services from pastures, improving their productivity and contribution to farmer livelihoods. We demonstrate how the identification of portfolios of multifunctional trees can satisfy a profile of desired ecosystem services prioritized by the farmer. Diagnostics using Bayesian inference starts with an identification of farmer needs and ‘works backwards’ to identify a silvopastoral system structure. We conclude that Bayesian belief networks are a promising modeling technique for multi-criteria decisions in farm adaptation processes, where interventions must be adapted to specific contexts and farmer preferences

Abrindo a porteira: a relação dos sistemas de produção com a comercialização e a transformação, num enfoque de pesquisa-desenvolvimento.

Busca-se apresentar o interesse cientifico para aprofundar a relacao entre sistemas de producao e sistemas de comercializacao e transformacao, com vista a planejar e realizar acoes mais eficientes de pesquisa apra o desenvolvimento rural. A primeira parte do trablaho trata da evolucao dos enfoques ta pesquisa em sistemas de producao, como fundamento para a inclusao das nacoes de sistema de comercializacao e de trasformacao na implementacao da P.D. Na segunda parte, frisam-se os motivos da aplicacao deste enfoque ao caso da agricultura familiar nordestina. Finalmente, na terceira parte, descreve-se em grandes linhas uma metodologia de estudo sobre circuitos de comercializacao e oportunidades de agregacao devalor para os produtos da agricultura familiar, atualmente desenvolvida pela EMBRAPA-CPATSA

Cadeia produtiva de melão do Nordeste.

O estudo da cadeia produtiva do melao na regiao Nordeste se baseou na metodologia do diagnostico rapito dos circuitos de comercializacao, na metodologia "Dephi", no levantamento de dados estatisticos, em entrevistas com os principais agentes envolvidos, do produtor ate o consumidor, em vistas de campo e as feiras. No Brasil, a producao de melao se concentra na regiao Nordeste, de modo especial nos Estados do RN, BA, CE, PE e PB, os quais, conjuntamente, tem respondido, nos ultimos anos, por mais de 89% da oferta de melao, e em 1996, totalizaram uma area plantada de 9.800 hectares. Dentro da estrutura produtiva, ocorre uma diferenciacao do perfil dos produtores de melao em grandes e medias empresas, pequenas empresas e pequenos e medios produtores. Observou-se que o polo RN/CE se caracteriza pela existencia de grandes e medias empresas com modernas tecnologias, equipamentos importados para irrigacao, fertirrigacao, processamento de embalagem, classificacao de frutos, alta produtividade apresenta alta competitividade, jnto aos mercados interno e externo. As grandes e medias empresas sao responsaveis por mais de 90% da producao do polo RN/CE. Cerca de 80% das pequenas empresas tambem estao situadas neste polo com o custo de producao menor, pois nao apresentam os custos administrativos das grandes e medias empresas. Os pequenos e medios produtores representam a maioria dos envolvidos com a producao do melao no Vale do Sao Francisco. Estes frequentemente plantam em parceria com comerciantes de insumos ou com atravessadores e possuem baixo nivel tecnologico. A producao de melao do Nordeste, basicamente esta voltada, em mais de 50%, para o mercado interno, mesmo nas grandes empresas. Como atributo de mercado, e grande a preferencia por "frutos doces"(alto teor de solidos soluveis, brix). As organizacoes de comercializacao tem acumulado a maior fracao do capital circulante no agronegocio do melao (85%). Ha como excecao o caso das grandes empresas, que dispoem de infra-estrutura de comercializacao. Os principais pontos de estrangulamento no processo produtivo sao: o uso inadequado de tecnologias; a falta de cultivares com boa resistencia as pragas e as doencas e de boa qualidade comercial; a ausencia do manejo integrado de pragas; a ausencia de manejo adequado na pos-colheita; a ausencia de organizacao dos pequenos e medios produtores, principalmente para comercializacao e aquisicao de financiamentos para custeios e investimentos; a instabilidade do mercado; as pessimas condicoes do sistema rodoviario e a falta de padronizacao da producao para o mercado interno. Estes aspectos permitiram a definicao das demandas tecnologias e nao tecnologicas, a serem implementadas a outro, medio e longo prazos

The short-chain fatty acid acetate reduces appetite via a central homeostatic mechanism

Increased intake of dietary carbohydrate that is fermented in the colon by the microbiota has been reported to decrease body weight, although the mechanism remains unclear. Here we use in vivo11C-acetate and PET-CT scanning to show that colonic acetate crosses the blood–brain barrier and is taken up by the brain. Intraperitoneal acetate results in appetite suppression and hypothalamic neuronal activation patterning. We also show that acetate administration is associated with activation of acetyl-CoA carboxylase and changes in the expression profiles of regulatory neuropeptides that favour appetite suppression. Furthermore, we demonstrate through 13C high-resolution magic-angle-spinning that 13C acetate from fermentation of 13C-labelled carbohydrate in the colon increases hypothalamic 13C acetate above baseline levels. Hypothalamic 13C acetate regionally increases the 13C labelling of the glutamate–glutamine and GABA neuroglial cycles, with hypothalamic 13C lactate reaching higher levels than the ‘remaining brain’. These observations suggest that acetate has a direct role in central appetite regulation

Nut production in Bertholletia excelsa across a logged forest mosaic: implications for multiple forest use

Although many examples of multiple-use forest management may be found in tropical smallholder systems, few studies provide empirical support for the integration of selective timber harvesting with non-timber forest product (NTFP) extraction. Brazil nut (Bertholletia excelsa, Lecythidaceae) is one of the world’s most economically-important NTFP species extracted almost entirely from natural forests across the Amazon Basin. An obligate out-crosser, Brazil nut flowers are pollinated by large-bodied bees, a process resulting in a hard round fruit that takes up to 14 months to mature. As many smallholders turn to the financial security provided by timber, Brazil nut fruits are increasingly being harvested in logged forests. We tested the influence of tree and stand-level covariates (distance to nearest cut stump and local logging intensity) on total nut production at the individual tree level in five recently logged Brazil nut concessions covering about 4000 ha of forest in Madre de Dios, Peru. Our field team accompanied Brazil nut harvesters during the traditional harvest period (January-April 2012 and January-April 2013) in order to collect data on fruit production. Three hundred and ninety-nine (approximately 80%) of the 499 trees included in this study were at least 100 m from the nearest cut stump, suggesting that concessionaires avoid logging near adult Brazil nut trees. Yet even for those trees on the edge of logging gaps, distance to nearest cut stump and local logging intensity did not have a statistically significant influence on Brazil nut production at the applied logging intensities (typically 1–2 timber trees removed per ha). In one concession where at least 4 trees ha-1 were removed, however, the logging intensity covariate resulted in a marginally significant (0.09) P value, highlighting a potential risk for a drop in nut production at higher intensities. While we do not suggest that logging activities should be completely avoided in Brazil nut rich forests, when a buffer zone cannot be observed, low logging intensities should be implemented. The sustainability of this integrated management system will ultimately depend on a complex series of socioeconomic and ecological interactions. Yet we submit that our study provides an important initial step in understanding the compatibility of timber harvesting with a high value NTFP, potentially allowing for diversification of forest use strategies in Amazonian Perù

Mitochondrial Substrate-Level Phosphorylation as Energy Source for Glioblastoma: Review and Hypothesis

Glioblastoma multiforme (GBM) is the most common and malignant of the primary adult brain cancers. Ultrastructural and biochemical evidence shows that GBM cells exhibit mitochondrial abnormalities incompatible with energy production through oxidative phosphorylation (OxPhos). Under such conditions, the mitochondrial F0-F1 ATP synthase operates in reverse at the expense of ATP hydrolysis to maintain a moderate membrane potential. Moreover, expression of the dimeric M2 isoform of pyruvate kinase in GBM results in diminished ATP output, precluding a significant ATP production from glycolysis. If ATP synthesis through both glycolysis and OxPhos was impeded, then where would GBM cells obtain high-energy phosphates for growth and invasion? Literature is reviewed suggesting that the succinate-CoA ligase reaction in the tricarboxylic acid cycle can substantiate sufficient ATP through mitochondrial substrate-level phosphorylation (mSLP) to maintain GBM growth when OxPhos is impaired. Production of high-energy phosphates would be supported by glutaminolysis-a hallmark of GBM metabolism-through the sequential conversion of glutamine -> glutamate -> alpha-ketoglutarate -> succinyl CoA -> succinate. Equally important, provision of ATP through mSLP would maintain the adenine nucleotide translocase in forward mode, thus preventing the reverse-operating F0-F1 ATP synthase from depleting cytosolic ATP reserves. Because glucose and glutamine are the primary fuels driving the rapid growth of GBM and most tumors for that matter, simultaneous restriction of these two substrates or inhibition of mSLP should diminish cancer viability, growth, and invasion

Cadeia produtiva da uva de mesa no Nordeste.

O estudo da cadeia de uva de mesa na regiao Nordeste, visando a identificacao das demandas tecnologias, se baseou na metodologia do diagnostico rapido dos circuitos de comercializacao, no levantamento de dados estatisticos, em entrevistas com os principais agentes envolvidos, do produtor ate o consumidor e em visitas de campo e as feiras. Dentre as tres principais regioes brasileiras de destaque no cultivo de parreiras (Sudeste, Sul e Nordeste), o sertao nordestino se sobressai pela expansao da area cultivada de uva de mesa fina, concentrando-se no submedio do Sao Francisco. Em 1996, 113.013 toneladas foram produzidas nessa regiao, representando 27% da producao nacionial e um volume de negocios acima de 90 milhoes de reais. Observou-se uma diversidade de produtores de uva de mesa representada em cinco categorias: pequenos agricultores nao especializados; pequenas e medias empresas. Essa tipologia permite identificar logicas distintas de manejo, assim como problemas e potencialidades especificas de cada categoria, no tocante a producao e comercializacao. Dos produtores de uva, 70% sao pequenos agricultores, embora detenham apenas 17% da area cultivada. O mercado brasileiro de uva de mesa, marcado nos ultimos anos por um forte crescimento, constitui atualmente o terceiro maior mercado mundial, superando o Japao e paises da Europa. 95% da producao de uva da regiao Nordeste e destinada para o mercado interno. A cadeia de comercializacao de uva envolve atacadistas, cooperativas e outras organizacoes da intermediacao como os supermercados, que estao ganhando importancia na regiao. Os principais pontos de estrangulamento na cadeis produtiva de uva sao: a predominancia de uva Italia, quando a demanda do mercado e por uva sem sementes ou por "compra casada", envolvendo tres variedades de diferentes coloracoes; as pessimas condicoes de conservacao da malha rodoviaria que implicam negativamente sobre os custos de comercializacao e na qualidade da uva; o elevado custo de producao da regiao (em torno de R$ 400,00/ t); a ausencia de barreiras fitossanitarias; a falta de padronizacao da producao; e a ausencia de organizacao dos pequenos e medios produtores, principalmente para comercializacao e aquisicao de financiamentos para custeios e investimentos. Estes aspectos permitiram a definicao das demandas tecnologicas e nao tecnologicas, a serem implementadas a curto, medio e longo prazos

Transcriptional responses of Trichodesmium to natural inverse gradients of Fe and P availability

The filamentous diazotrophic cyanobacterium Trichodesmium is responsible for a significant fraction of marine di-nitrogen (N2) fixation. Growth and distribution of Trichodesmium and other diazotrophs in the vast oligotrophic subtropical gyres is influenced by iron (Fe) and phosphorus (P) availability, while reciprocally influencing the biogeochemistry of these nutrients. Here we use observations across natural inverse gradients in Fe and P in the North Atlantic subtropical gyre (NASG) to demonstrate how Trichodesmium acclimates in situ to resource availability. Transcriptomic analysis identified progressive upregulation of known iron-stress biomarker genes with decreasing Fe availability, and progressive upregulation of genes involved in the acquisition of diverse P sources with decreasing P availability, while genes involved in N2 fixation were upregulated at the intersection under moderate Fe and P availability. Enhanced N2 fixation within the Fe and P co-stressed transition region was also associated with a distinct, consistent metabolic profile, including the expression of alternative photosynthetic pathways that potentially facilitate ATP generation required for N2 fixation with reduced net oxygen production. The observed response of Trichodesmium to availability of both Fe and P supports suggestions that these biogeochemically significant organisms employ unique molecular, and thus physiological responses as adaptations to specifically exploit the Fe and P co-limited niche they construct