458 resultados para drain


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In many bacteria, accumulation of K+ at high external osmolalities is accompanied by accumulation of glutamate. To determine whether there is an obligatory relationship between glutamate and K+ pools, we studied mutant strains of Salmonella typhimurium with defects in glutamate synthesis. Enteric bacteria synthesize glutamate by the combined action of glutamine synthetase and glutamate synthase (GS/GOGAT cycle) or the action of biosynthetic glutamate dehydrogenase (GDH). Activity of the GS/GOGAT cycle is required under nitrogen-limiting conditions and is decreased at high external ammonium/ammonia ((NH4)+) concentrations by lowered synthesis of GS and a decrease in its catalytic activity due to covalent modification (adenylylation by GS adenylyltransferase). By contrast, GDH functions efficiently only at high external (NH4)+ concentrations, because it has a low affinity for (NH4)+. When grown at low concentrations of (NH4)+ (< or = 2 mM), mutant strains of S. typhimurium that lack GOGAT and therefore are dependent on GDH have a low glutamate pool and grow slowly; we now demonstrate that they have a low K+ pool. When subjected to a sudden (NH4)+ upshift, strains lacking GS adenylyltransferase drain their glutamate pool into glutamine and grow very slowly; we now find that they also drain their K+ pool. Restoration of the glutamate pool in these strains at late times after shift was accompanied by restoration of the K+ pool and a normal growth rate. Taken together, the results indicate that glutamate is required to maintain the steady-state K+ pool -- apparently no other anion can substitute as a counter-ion for free K+ -- and that K+ glutamate is required for optimal growth.

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A irrigação quando bem manejada, pode minimizar os riscos econômicos da atividade sucroalcooleira, particularmente em safras com presença de instabilidade climática onde a restrição hídrica, promovida pela diminuição no volume de chuvas, pode reduzir a produtividade dos canaviais. Dentre as ferramentas disponíveis para a gestão eficiente da água na agricultura irrigada, a técnica de irrigação sob déficit pode se tornar uma escolha acertada para a cana-de-açúcar, desde que sejam identificadas as fases fenológicas e épocas de cultivo onde a limitação da oferta de água não implique em reduções antieconômicas no rendimento da cultura. Diante disso, a hipótese que norteia essa pesquisa, é a de que existe uma estratégia de irrigação sob déficit, que associada a uma variedade com características específicas, possibilite a expressão de indicadores de produtividade tão satisfatórios quanto os obtidos em condições de irrigação plena. Nessa linha, os objetivos da pesquisa envolveram o estudo da dinâmica foliar, acúmulo e particionamento de biomassa e ainda, índices de produtividade da água para biomassa, açúcar e etanol de 1ª e 2ª geração de oito variedade de cana-de-açúcar, submetidas a diferentes condições de disponibilidade hídrica no solo em dois ciclos de cultivo (cana-planta e cana-soca). A pesquisa foi realizada na Escola Superior de Agricultura \"Luiz de Queiroz\", em Piracicaba/SP, onde foram estudados os dois primeiros ciclos de cultivo da cana-de-açúcar, sendo estes abordados nesta tese como Experimento 1 (cana-planta) e Experimento 2 (cana-soca). O delineamento experimental adotado para ambos os ciclos foi o de blocos casualizados, com três blocos completos. Os tratamentos foram compostos por três fatores em esquema de parcelas sub-subdivididas. Estas parcelas foram formadas por duas plantas (touceiras) alocadas em um vaso com aproximadamente 330 litros de solo. No Experimento 1, foram estudados três fatores, sendo o primeiro e segundo com quatro níveis e o terceiro com oito (4x4x8), totalizando assim 128 tratamentos, sendo eles: quatro níveis de irrigação ao longo do ciclo (125, 100, 75 e 50% da ETc); oito variedades comerciais de cana-de-açúcar e quatro procedimentos de maturação, impostos por meio de variações na intensidade do déficit hídrico aplicado. Para o Experimento 2, substitui-se o fator Maturação por Épocas de Corte, o qual consistiu em colheitas de um quarto do experimento a cada 90 dias. Os resultados encontrados apontaram que a área foliar responde positivamente a maior disponibilidade hídrica no solo, tendo sido verificado uma relação proporcional entre estes. Quanto ao acúmulo de biomassa, verificou-se que para as oito variedades estudadas houve incremento de biomassa a medida em que se aumentou o volume de água disponibilizado às variedades. No tocante ao particionamento, as folhas foram os drenos principais de fotoassimilados da planta até os 100 dias de cultivo, sendo que após este período, os colmos ocuparam o lugar de dreno preferencial. Os indicadores de produtividade da água apresentaram diferenças significativas para o fator lâmina, o que indica a existência de cultivares de cana-de-açúcar mais eficientes no uso da água. Por fim, observou-se que a produtividade da água para etanol total apresentou valores expressivos, com média para essa variável igual a 1,81 L m-3, o que denota o potencial de rendimento de etanol (1G + 2G) a partir da cana-de-açúcar quando é adotado o aproveitamento integral das plantas.

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The impending mass retirement of the Baby Boom generation in the United States may cause a drastic talent drain. Companies should pay attention to this upcoming problem now to alleviate an exodus by encouraging Baby Boomers to continue working past their normal retirement age. One solution is to offer them effective incentives. The most compelling incentives for Baby Boomers are the ability to choose their own hours (how many hours they wish to work, and when they wish to work them), the ability to telecommute from wherever they choose, and the offer of extra health care benefits.

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We study the spin polarization of tunneling holes injected from ferromagnetic GaMnAs into a p-doped semiconductor through a tunneling barrier. We find that spin-orbit interaction in the barrier and in the drain limits severely spin injection. Spin depolarization is stronger when the magnetization is parallel to the current than when it is perpendicular to it.

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Tese de doutoramento, Geologia (Hidrogeologia), Universidade de Lisboa, Faculdade de Ciências, 2016

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On 28 June 2016, just a few days after the historic Brexit vote, High Representative of the Union for Foreign Affairs and Security Policy Federica Mogherini presented the paper on the new European Union Global Strategy (EUGS) at the European Council, outlining the strategic coordinates for the EU’s foreign and security policy. In this Discussion Paper, Giovanni Grevi takes a closer look at the EUGS and assesses its main rationale, features, added value and prospects against the backdrop of an ever more complex world. Not only is the EU dealing with increasingly contested and polarised politics at home, but the global theatre itself has become hugely disorienting, more integrated and yet more fragmented at the same time. The paper recalibrates the overall foreign policy posture of the EU and sketches out a more modest and concrete approach compared to earlier aspirations, and a more joined-up one compared to current practice. By doing so, the strategy seeks to square the circle between the need for Europe to be cohesive and purposeful in a harder strategic environment and the fact that domestic politics within the Union constrain its external action and drain its attractiveness. The EUGS calls on the EU and member states to fully take on their responsibility to underpin unity, prosperity and security at home by taking more effective and joined-up action abroad. The question is, of course, whether this call will be heeded.

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"Das Prinzip der Freizügigkeit. Eine Idee für alle". Presentation (in German) by Charlotte Sieber-Gasser at the 2d Doctoral Seminar of the Center for Migration Law held in Oberdorf (Switzerland) on 30 November and 1 December 2012. In the presentation (in German), Charlotte Sieber-Gasser argues that there is a direct link between regional labour market integration, economic development and migration pressure. The link consists of the impact of labour market integration on added-value production: Through more added-value production in the global South, economic development in the region is more sustainable, jobs are created and brain drain is to a certain extent reversed. As this is acknowledged also by developing countries, more and more regional labour market integration measures emerge in the global South. These newer forms of regulation of the movement of labour is in some cases relatively unique and innovative. Charlotte Sieber-Gasser presents five examples of such newer regulation. The different models range from liberalisation restricted to high skilled labour and indirect liberalisation through the recognition of certificates to relatively far reaching liberalisation for particular groups of professionals and their families, also covering low skilled labour.

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Caption title.

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"Colombia has experienced conflict for decades. In the 1990s it was a paradigm of the failing state, beset with all manner of troubles: terrorism, kidnapping, murder, drug trafficking, corruption, an economic downturn of major scope, general lawlessness, and brain drain. Today the country is much safer, and the agents of violence are clearly on the defensive. Nonetheless, much work lies ahead to secure the democratic system. Security and the rule of law are fundamental to the task. As the monopoly over the legitimate use of force is established, democratic governance also needs the architecture of law: ministry of justice, courts, legislative scrutiny, law enforcement agencies, regulatory bodies, public defenders, police, correctional system, legal statutes, contracts, university level academic education to train lawyers, judges, and investigators, along with engagement with civil society to promote a culture of lawfulness. Security without the rule of law puts a society at risk of falling into a Hobbesian hell."--P. v.

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The Chicago River/Lake Shore area assessment, part of a series of statewide regional assessments, examines approximately 348 square miles in northeastern Illinois that falls within portions of two counties-- Cook and Lake. The area is defined by the watershed of the Chicago River and the areas of Cook and Lake counties that drain to Lake Michigan, excluding the area in southern Cook County that drains to the Calumet River. The report provides information on the natural and human resources of the area as a basis for managing and improving its ecosystems. The development of ecosystem-based information and management programs in Illinois are the result of three processes-- the Critical Trends Assessment Program, Conservation Congress, and Water Resources and Land Use Priorities Task Force.

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Yellow, blue, black ink on linen. Drain pipes, topo. lines, walkways, pool. Residence by John S. Van Burgen. Signed. 95 cm. x 67 cm. Scale: 1"=10' [from photographic copy by Lance Burgharrdt]

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Red ink, green, orange, black pencil on tracing papers; location of drain tiles, gardens, pools, footpaths; signed (with initials MJ below name). 70 x 66 cm. Scale: 1"=20' [from photographic copy by Lance Burgharrdt]

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Ink on linen; water, drain, gas, sewer, electric light and telephone lines; residence by Marshall and Fox; signed; 117 x 43 cm.; Scale: 1"=50' [from photographic copy by Lance Burgharrdt]

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Red, black ink on linen; plan, sections of pool, detail of drain; signed; 99 x 54 cm. [from photographic copy by Lance Burgharrdt]