75 research outputs found
First Results from the LEIR Ionisation Profile Monitors
The role of the Low Energy Ion Ring, LEIR, is to transform long pulses of lead ions from the Linac 3 to short dense bunches for transfer to the LHC. This is accomplished by the accumulation of up to 4 Linac pulses by electron cooling. In order to non-destructively monitor the cooling performance and determine the accumulated beam characteristics, two prototype ionisation profile monitors have been built and were tested during the LEIR commissioning runs with O4+ and Pb54+ ions in 2006. In this paper we present the results obtained with the prototype monitors, the problems encountered and describe the modifications made for the final design. The modified monitors have been installed on the LEIR machine and are waiting for the next ion run planned in August
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
Cooled Beam Diagnostics on LEIR
Electron cooling is central in the preparation of dense bunches of lead beams for the LHC. Ion beam pulses from the LINAC3 are transformed into short highbrightness bunches using multi-turn injection, cooling and accumulation in the Low Energy Ion Ring, LEIR [1]. The cooling process must therefore be continuously monitored in order to guarantee that the lead ions have the required characteristics in terms of beam size and momentum spread. In LEIR a number of systems have been developed to perform these measurements. These include Schottky diagnostics, ionisation profile monitors and scrapers. Along with their associated acquisition and analysis software packages these instruments have proved to be invaluable for the optimisation of the electron cooler
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
L'appui à l'agriculture familiale au Brésil, le projet de coopération entre Embrapa et Cirad-tera.
Ce texte présente quelques éclairages de ces travaux conduits par différents chercheurs ou doctorants du Cirad-tera et par leurs colleges brésiliens, mettant en oeuvre diverses démarches, spécifiques et complémentaires, destinées à traiter du fait technique en agriculture familiale, du développement agricole et du développement rural. L'organisation des unités de production et le dispositif local de gestion de l'innovation dans les Cerrados. Les interactions entre changements techniques et institutionnels. Le cas du municipe de Silvânia. Organisation des producteurs et action collective dans Ia région du Nordeste. Valorisation des productions de I'agriculture familiale au Nordeste. Organisation des producteurs et action collective dans Ia région du Nordeste. De la diffusion technologique à Ia prise en compte de l'espace au Nordeste
A cadeia produtiva da uva de mesa do Nordeste do Brasil.
Caracterizacao da cadeia produtiva da uva; descricao da cadeia produtiva; analise de desempenho da cadeia produtiva; demandas prioritarias; proximos passos para a analise prognostica
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
Mutation of the palmitoylation site of estrogen receptor alpha in vivo reveals tissue-specific roles for membrane versus nuclear actions
Estrogen receptor alpha (ERalpha) activation functions AF-1 and AF-2 classically mediate gene transcription in response to estradiol (E2). A fraction of ERalpha is targeted to plasma membrane and elicits membrane-initiated steroid signaling (MISS), but the physiological roles of MISS in vivo are poorly understood. We therefore generated a mouse with a point mutation of the palmitoylation site of ERalpha (C451A-ERalpha) to obtain membrane-specific loss of function of ERalpha. The abrogation of membrane localization of ERalpha in vivo was confirmed in primary hepatocytes, and it resulted in female infertility with abnormal ovaries lacking corpora lutea and increase in luteinizing hormone levels. In contrast, E2 action in the uterus was preserved in C451A-ERalpha mice and endometrial epithelial proliferation was similar to wild type. However, E2 vascular actions such as rapid dilatation, acceleration of endothelial repair, and endothelial NO synthase phosphorylation were abrogated in C451A-ERalpha mice. A complementary mutant mouse lacking the transactivation function AF-2 of ERalpha (ERalpha-AF2(0)) provided selective loss of function of nuclear ERalpha actions. In ERalpha-AF2(0), the acceleration of endothelial repair in response to estrogen-dendrimer conjugate, which is a membrane-selective ER ligand, was unaltered, demonstrating integrity of MISS actions. In genome-wide analysis of uterine gene expression, the vast majority of E2-dependent gene regulation was abrogated in ERalpha-AF2(0), whereas in C451A-ERalpha it was nearly fully preserved, indicating that membrane-to-nuclear receptor cross-talk in vivo is modest in the uterus. Thus, this work genetically segregated membrane versus nuclear actions of a steroid hormone receptor and demonstrated their in vivo tissue-specific roles
Overturning established chemoselectivities : selective reduction of arenes over malonates and cyanoacetates by photoactivated organic electron donors
The prevalence of metal-based reducing reagents, including metals, metal complexes, and metal salts, has produced an empirical order of reactivity that governs our approach to chemical synthesis. However, this reactivity may be influenced by stabilization of transition states, intermediates, and products through substrate-metal bonding. This article reports that in the absence of such stabilizing interactions, established chemoselectivities can be overthrown. Thus, photoactivation of the recently developed neutral organic superelectron donor 5 selectively reduces alkyl-substituted benzene rings in the presence of activated esters and nitriles, in direct contrast to metal-based reductions, opening a new perspective on reactivity. The altered outcomes arising from the organic electron donors are attributed to selective interactions between the neutral organic donors and the arene rings of the substrates
Nutrition rehabilitation of undernourished children utilizing Spiruline and Misola
BACKGROUND: Malnutrition constitutes a public health problem throughout the world and particularly in developing countries. AIMS: The objective of the study is to assess the impact of an elementary integrator composed of Spiruline (Spirulina platensis) and Misola (millet, soja, peanut) produced at the Centre Medical St Camille (CMSC) of Ouagadougou, Burkina Faso, on the nutritional status of undernourished children. MATERIALS AND METHODS: 550 undernourished children of less than 5 years old were enrolled in this study, 455 showed severe marasma, 57 marasma of medium severity and 38 kwashiorkor plus marasma. We divided the children randomly into four groups: 170 were given Misola (731 ± 7 kcal/day), 170 were given Spiruline plus traditional meals (748 ± 6 kcal/day), 170 were given Spiruline plus Misola (767 ± 5 kcal/day). Forty children received only traditional meals (722 ± 8 kcal/day) and functioned as the control group. The duration of this study was eight weeks. RESULTS AND DISCUSSION: Anthropometrics and haematological parameters allowed us to appreciate both the nutritional and biological evolution of these children. The rehabilitation with Spiruline plus Misola (this association gave an energy intake of 767 ± 5 kcal/day with a protein assumption of 33.3 ± 1.2 g a day), both greater than Misola or Spiruline alone, seems to correct weight loss more quickly. CONCLUSION: Our results indicate that Misola, Spiruline plus traditional meals or Spiruline plus Misola are all a good food supplement for undernourished children, but the rehabilitation by Spiruline plus Misola seems synergically favour the nutrition rehabilitation better than the simple addition of protein and energy intake
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