1,137 research outputs found

    Decision-support tools for cost-effective bioprocess design in the cell therapy sector

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    Towards a marine biorefinery through the hydrothermal liquefaction of macroalgae native to the United Kingdom

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    Hydrothermal liquefaction (HTL) is a promising biomass conversion method that can be incorporated into a biorefinery paradigm for simultaneous production of fuels, aqueous fertilisers and potential remediation of municipal or mariculture effluents. HTL of aquatic crops, such as marine macro- or microalgae, has significant potential for the UK owing to its extensive coastline. As such, macroalgae present a particularly promising feedstock for future UK biofuel production. This study aimed to bridge the gaps between previous accounts of macroalgal HTL by carrying out a more comprehensive screen of a number of species from all three major macroalgae classes, and examining the correlations between biomass biochemical composition and HTL reactivity. HTL was used to process thirteen South West UK macroalgae species from all three major classes (Chlorophyceae, Heterokontophyceae and Rhodophyceae) to produce bio-crude oil, a bio-char, gas and aqueous phase products. Chlorophyceae of the genus Ulva generated the highest bio-crude yields (up to 29.9% for U. lactuca). Aqueous phase phosphate concentrations of up to 236 mg L−1 were observed, obtained from the Rhodophyta, S. chordalis. Across the 13 samples, a correlation between increasing biomass lipids and increasing bio-crude yield was observed, as well as an increase in biomass nitrogen generally contributing to bio-crude nitrogen content. A broader range of macroalgae species has been examined than in any study previously and, by processing using identical conditions across all feedstocks, has enabled a more cohesive assessment of the effects of biochemical composition

    Fandom and Coercive Empowerment: The commissioned production of Chinese online literature

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    This article examines how the relationship between consumers and producers of cultural products is shaped by the proprietary nature of digital platforms. Drawing on 4 years of online observation and analysis, we examine the relationship between the producers of online Chinese fiction, amateur writers, and their consumers, that is, the fan communities of readers who respond to their work. Enabled by Chinese literary websites, readers act like sponsors who provide emotional and financial incentives for writers to produce online fictions by commenting, voting, and sending money. Readers become actively involved not just because of the content of the stories but because they form strong commitments to stories and their writers, and gain reciprocity and a sense of self-determination during the interactional process. We argue that although writers are freer from state control online, they are still beholden to the whims of their fans because of what we call the commissioned production of fictions. We contribute to fan community studies by analyzing how commercialized website settings structure the strategies available to participants, how these settings affect the content of the cultural products, and how the Chinese historical and cultural contexts impact the dynamics of the online community.postprin

    Two Earth-sized planets orbiting Kepler-20

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    Since the discovery of the first extrasolar giant planets around Sun-like stars, evolving observational capabilities have brought us closer to the detection of true Earth analogues. The size of an exoplanet can be determined when it periodically passes in front of (transits) its parent star, causing a decrease in starlight proportional to its radius. The smallest exoplanet hitherto discovered has a radius 1.42 times that of the Earth's radius (R Earth), and hence has 2.9 times its volume. Here we report the discovery of two planets, one Earth-sized (1.03R Earth) and the other smaller than the Earth (0.87R Earth), orbiting the star Kepler-20, which is already known to host three other, larger, transiting planets. The gravitational pull of the new planets on the parent star is too small to measure with current instrumentation. We apply a statistical method to show that the likelihood of the planetary interpretation of the transit signals is more than three orders of magnitude larger than that of the alternative hypothesis that the signals result from an eclipsing binary star. Theoretical considerations imply that these planets are rocky, with a composition of iron and silicate. The outer planet could have developed a thick water vapour atmosphere.Comment: Letter to Nature; Received 8 November; accepted 13 December 2011; Published online 20 December 201

    Emergent global patterns of ecosystem structure and function from a mechanistic general ecosystem model

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    Anthropogenic activities are causing widespread degradation of ecosystems worldwide, threatening the ecosystem services upon which all human life depends. Improved understanding of this degradation is urgently needed to improve avoidance and mitigation measures. One tool to assist these efforts is predictive models of ecosystem structure and function that are mechanistic: based on fundamental ecological principles. Here we present the first mechanistic General Ecosystem Model (GEM) of ecosystem structure and function that is both global and applies in all terrestrial and marine environments. Functional forms and parameter values were derived from the theoretical and empirical literature where possible. Simulations of the fate of all organisms with body masses between 10 µg and 150,000 kg (a range of 14 orders of magnitude) across the globe led to emergent properties at individual (e.g., growth rate), community (e.g., biomass turnover rates), ecosystem (e.g., trophic pyramids), and macroecological scales (e.g., global patterns of trophic structure) that are in general agreement with current data and theory. These properties emerged from our encoding of the biology of, and interactions among, individual organisms without any direct constraints on the properties themselves. Our results indicate that ecologists have gathered sufficient information to begin to build realistic, global, and mechanistic models of ecosystems, capable of predicting a diverse range of ecosystem properties and their response to human pressures

    Effects of Curcuma longa (turmeric) on postprandial plasma glucose and insulin in healthy subjects

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    <p>Abstract</p> <p>Background</p> <p>Previous animal studies have shown that <it>Curcuma (C.) longa </it>lowers plasma glucose. <it>C. longa </it>may thus be a promising ingredient in functional foods aimed at preventing type 2 diabetes. The purpose of the study is to study the effect of <it>C. longa </it>on postprandial plasma glucose, insulin levels and glycemic index (GI) in healthy subjects.</p> <p>Methods</p> <p>Fourteen healthy subjects were assessed in a crossover trial. A standard 75 g oral glucose tolerance test (OGTT) was administered together with capsules containing a placebo or <it>C. longa</it>. Finger-prick capillary and venous blood samples were collected before, and 15, 30, 45, 60, 90, and 120 min after the start of the OGTT to measure the glucose and insulin levels, respectively.</p> <p>Results</p> <p>The ingestion of 6 g <it>C. longa </it>had no significant effect on the glucose response. The change in insulin was significantly higher 30 min (<it>P </it>= 0.03) and 60 min (<it>P </it>= 0.041) after the OGTT including <it>C. longa</it>. The insulin AUCs were also significantly higher after the ingestion of <it>C. longa</it>, 15 (<it>P </it>= 0.048), 30 (<it>P </it>= 0.035), 90 (<it>P </it>= 0.03), and 120 (<it>P </it>= 0.02) minutes after the OGTT.</p> <p>Conclusions</p> <p>The ingestion of 6 g <it>C. longa </it>increased postprandial serum insulin levels, but did not seem to affect plasma glucose levels or GI, in healthy subjects. The results indicate that <it>C. longa </it>may have an effect on insulin secretion.</p> <p>Trial registration number</p> <p>NCT01029327</p
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