Efficient incorporation of channel cross-section geometry uncertainty into regional and global scale flood inundation models

This paper investigates the challenge of representing structural differences in river channel cross-section geometry for regional to global scale river hydraulic models and the effect this can have on simulations of wave dynamics. Classically, channel geometry is defined using data, yet at larger scales the necessary information and model structures do not exist to take this approach. We therefore propose a fundamentally different approach where the structural uncertainty in channel geometry is represented using a simple parameterization, which could then be estimated through calibration or data assimilation. This paper first outlines the development of a computationally efficient numerical scheme to represent generalised channel shapes using a single parameter, which is then validated using a simple straight channel test case and shown to predict wetted perimeter to within 2% for the channels tested. An application to the River Severn, UK is also presented, along with an analysis of model sensitivity to channel shape, depth and friction. The channel shape parameter was shown to improve model simulations of river level, particularly for more physically plausible channel roughness and depth parameter ranges. Calibrating channel Manning’s coefficient in a rectangular channel provided similar water level simulation accuracy in terms of Nash-Sutcliffe efficiency to a model where friction and shape or depth were calibrated. However, the calibrated Manning coefficient in the rectangular channel model was ~2/3 greater than the likely physically realistic value for this reach and this erroneously slowed wave propagation times through the reach by several hours. Therefore, for large scale models applied in data sparse areas, calibrating channel depth and/or shape may be preferable to assuming a rectangular geometry and calibrating friction alone

ATIVIDADE CITOTÓXICA DE Piper xylosteoides STEUD

Algumas espécies da família Piperaceae, tais como: Piper betle, Piper aborescens e Piper nigrumtêm sido relatadas na literatura por apresentarem substâncias com atividade citotóxica. A espécie Piperxylosteoides foi coletada no Estado do Rio Grande do Sul para investigação da atividade citotóxica.Inicialmente, extratos orgânicos e aquosos foram preparados a partir de folhas e galhos secos e adicionadosem cultivos de linhagens celulares provenientes de adenocarcinoma de células não pequenas de pulmão(NCI-H460) e carcinoma de cólon retal (HT29) derivadas de humanos. A atividade citotóxica foi avaliadaapós 72 horas de incubação pelo ensaio de Sulforodamina B (SRB), tendo sido encontrado resultadopositivo para o extrato orgânico de folhas e galhos. A partir do extrato ativo foi realizado fracionamentocom solventes de polaridade crescente (hexano e clorofórmio). Os experimentos evidenciaram a presençade compostos ativos tanto na fração hexânica como na clorofórmica desta espécie, sendo os menoresvalores de IC50 (concentração de extrato necessária para promover inibição de 50% do crescimento celular)encontrados para a segunda fração: 0,62 e 0,66 μg/ml nas linhagens HT29 e NCI-H460, respectivamente. Esta fração ativa encontra-se atualmente na fase de separação e purificação bioguiada de seuscompostos ativos

Judgment and imagination in Habermas' theory of law

Political Philosophy and Ethic

La correspondencia de Valencia : diario de noticias : eco imparcial de la opinión y de la prensa: Año XXXVI Número 15575 - 1913 Enero 10

Copia digital. Madrid : Ministerio de Cultura. Subdirección General de Coordinación Bibliotecaria, 200

Engineering high-level production of fatty alcohols by Saccharomyces cerevisiae from lignocellulosic feedstocks

Fatty alcohols in the C12-C18 range are used in personal care products, lubricants, and potentially biofuels. These compounds can be produced from the fatty acid pathway by a fatty acid reductase (FAR), yet yields from the preferred industrial host Saccharomyces cerevisiae remain under 2% of the theoretical maximum from glucose. Here we improved titer and yield of fatty alcohols using an approach involving quantitative analysis of protein levels and metabolic flux, engineering enzyme level and localization, pull-push-block engineering of carbon flux, and cofactor balancing. We compared four heterologous FARs, finding highest activity and endoplasmic reticulum localization from a Mus musculus FAR. After screening an additional twenty-one single-gene edits, we identified increasing FAR expression; deleting competing reactions encoded by DGA1, HFD1, and ADH6; overexpressing a mutant acetyl-CoA carboxylase; limiting NADPH and carbon usage by the glutamate dehydrogenase encoded by GDH1; and overexpressing the Δ9-desaturase encoded by OLE1 as successful strategies to improve titer. Our final strain produced 1.2\ua0g/L fatty alcohols in shake flasks, and 6.0\ua0g/L in fed-batch fermentation, corresponding to ~ 20% of the maximum theoretical yield from glucose, the highest titers and yields reported to date in S. cerevisiae. We further demonstrate high-level production from lignocellulosic feedstocks derived from ionic-liquid treated switchgrass and sorghum, reaching 0.7\ua0g/L in shake flasks. Altogether, our work represents progress towards efficient and renewable microbial production of fatty acid-derived products

Engineering high-level production of fatty alcohols by Saccharomyces cerevisiae from lignocellulosic feedstocks.

Fatty alcohols in the C12-C18 range are used in personal care products, lubricants, and potentially biofuels. These compounds can be produced from the fatty acid pathway by a fatty acid reductase (FAR), yet yields from the preferred industrial host Saccharomyces cerevisiae remain under 2% of the theoretical maximum from glucose. Here we improved titer and yield of fatty alcohols using an approach involving quantitative analysis of protein levels and metabolic flux, engineering enzyme level and localization, pull-push-block engineering of carbon flux, and cofactor balancing. We compared four heterologous FARs, finding highest activity and endoplasmic reticulum localization from a Mus musculus FAR. After screening an additional twenty-one single-gene edits, we identified increasing FAR expression; deleting competing reactions encoded by DGA1, HFD1, and ADH6; overexpressing a mutant acetyl-CoA carboxylase; limiting NADPH and carbon usage by the glutamate dehydrogenase encoded by GDH1; and overexpressing the Δ9-desaturase encoded by OLE1 as successful strategies to improve titer. Our final strain produced 1.2g/L fatty alcohols in shake flasks, and 6.0g/L in fed-batch fermentation, corresponding to ~ 20% of the maximum theoretical yield from glucose, the highest titers and yields reported to date in S. cerevisiae. We further demonstrate high-level production from lignocellulosic feedstocks derived from ionic-liquid treated switchgrass and sorghum, reaching 0.7g/L in shake flasks. Altogether, our work represents progress towards efficient and renewable microbial production of fatty acid-derived products