95 research outputs found

    Exact Periodic Solutions of Shells Models of Turbulence

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    We derive exact analytical solutions of the GOY shell model of turbulence. In the absence of forcing and viscosity we obtain closed form solutions in terms of Jacobi elliptic functions. With three shells the model is integrable. In the case of many shells, we derive exact recursion relations for the amplitudes of the Jacobi functions relating the different shells and we obtain a Kolmogorov solution in the limit of infinitely many shells. For the special case of six and nine shells, these recursions relations are solved giving specific analytic solutions. Some of these solutions are stable whereas others are unstable. All our predictions are substantiated by numerical simulations of the GOY shell model. From these simulations we also identify cases where the models exhibits transitions to chaotic states lying on strange attractors or ergodic energy surfaces.Comment: 25 pages, 7 figure

    Pork quality related to the diet content of fermentable fibre-rich feedstuffs (chicory and lupine) with special emphasis on the effect on boar taint and meat quality

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    Boar taint is an off-flavour of pork caused primarily by skatole and, androstenone. Pig off-odour and flavour mostly caused by higher skatole concentrations in backfat. It is a problem in all types of pork production and is not restricted to entire male pigs. If uncastrated, 5-10% of Danish entire male pigs (100 kg liveweight) have > 0.25 ppm skatole in backfat and are then classified as boar tainted, having a markedly reduced value. Even backfat skatole values above 0.15 ppm enhance the off-odour for skatole sensitive consumers. An alternative way to reduce high skatole concentrations may be feeding with fibre-rich feedstuffs. This idea is based on previous studies which have demonstrated that 10% dried chicory or more in the feed reduces skatole in entire male pigs significantly after 7, 14 and 21 days of feeding, resulting in a significant reduction in perceived boar taint and thus an improvement in the flavour and taste of meat. Significantly decreased skatole concentrations and a tendency to increased eating quality have also been demonstrated by feeding 25% lupines to female and castrated male pigs during the whole fattening period. The question remains, however, whether the effects of lupines on skatole and other sensory characteristics of female and entire male pigs can be obtained when used only in the last 1 or 2 weeks before slaughter. Two experimental replicates each consisting of 24 pigs (12 entire male and 12 female) was divided into three treatments according to litter and initial weight and kept in pairs (pens) of either female or entire male pigs. The male and female pigs were kept in different stables. The pairs of pigs have been fed three organic diets for either 1 or 2 weeks prior to slaughter of which two diets contained different fermentable fibre-rich feedstuffs (10% dried chicory root plus 90% organic control feed and 25% blue lupine seed plus 75% other organic feed components). These two treatments were compared with a control; where the pairs of pigs were fed organic control concentrate (“conventional”) either 1 or 2 weeks prior to slaughter (at approx. 104 kg liveweight). Levels of skatole and indole in blood plasma from Vena jugularis were monitored at the start of the experiment and just before slaughter, and skatole in backfat was measured at slaughter. Production results were registered (daily weight gain, FUp per kg gain, slaughter weight, carcass meat percentage, warm and cold carcass weight), and after slaughter at Research Centre Foulum the following technological meat quality attributes were measured on M. Longissimus dorsi (LD): meat colour (L*, a*, and b* values), drip loss, pH measurements, temperatures and glycogen at 45 minutes and 24 hours post mortem. There was a significant reduction in skatole in blood and backfat for both sexes by feeding 25% blue lupine one or two weeks prior to slaughter (P<0.001). The 10% (and 13.3%) dried chicory roots showed no significant effect. This is possibly due to error in the heat treatment of the roots during the drying process. A majority of the meat quality parameters were not significantly affected by either of the two dietary treatments. However, glycogen contents tended to be higher 45 minutes and 24 hours post mortem (P<0.10) and the drip loss lower in the lupine-fed pigs. There were clear tendencies to significant differences in production results as the 25% lupines showed negative impact on growth rate, feed conversion ratio, slaughter weight and carcass weight. Newly mixed entire male pigs showed worse performance than newly mixed female pigs during the short time experiment

    Improved overall survival after implementation of targeted therapy for patients with metastatic renal cell carcinoma: Results from the Danish Renal Cancer Group (DARENCA) study-2

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    AbstractAimTo evaluate the implementation of targeted therapy on overall survival (OS) in a complete national cohort of patients with metastatic renal cell carcinoma (mRCC).MethodsAll Danish patients with mRCC referred for first line treatment with immunotherapy, TKIs or mTOR-inhibitors between 2006 and 2010 were included. Baseline and outcome data were collected retrospectively. Prognostics factors were identified using log-rank tests and Cox proportional hazard model. Differences in distributions were tested with the Chi-square test.Results1049 patients were referred; 744 patients received first line treatment. From 2006 to 2010 we observed a significant increase in the number of referred patients; a significant increase in treated patients (64% versus 75%, P=0.0188); a significant increase in first line targeted therapy (22% versus 75%, P<0.0001); a significant increase in second line treatment (20% versus 40%, P=0.0104), a significant increased median OS (11.5 versus 17.2 months, P=0.0435) whereas survival for untreated patients remained unchanged. Multivariate analysis validated known prognostic factors. Moreover, treatment start years 2008 (HR 0.74, 95% CI, 0.55–0.99; P=0.0415), 2009 (HR 0.72, 95% CI, 0.54–0.96; P=0.0277) and 2010 (HR 0.63, 95% CI, 0.47–0.86; P=0.0035) compared to 2006, and more than two treatment lines received for patients with performance status 0–1 (HR 0.76, 95% CI, 0.58–0.99; P=0.0397) and performance status 2–3 (HR 0.19, 95% CI, 0.06–0.60; P=0.0051) were significantly associated with longer OS.ConclusionThis retrospective study documents that the implementation of targeted therapy has resulted in significantly improved treatment rates and overall survival in a complete national cohort of treated mRCC patients

    A holistic multi-methodology for sustainable renovation

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    A review of the barriers for building renovation has revealed a lack of methodologies, which can promote sustainability objectives and assist various stakeholders during the design stage of building renovation/retrofitting projects. The purpose of this paper is to develop a Holistic Multi-methodology for Sustainable Renovation, which aims to deal with complexity of renovation projects. It provides a framework through which to involve the different stakeholders in the design process to improve group learning and group decision-making, and hence make the building renovation design process more robust and efficient. Therefore, the paper discusses the essence of multifaceted barriers in building renovation regarding cultural changes and technological/physical changes. The outcome is a proposal for a multi-methodology framework, which is developed by introducing, evaluating and mixing methods from Soft Systems Methodologies (SSM) with Multiple Criteria Decision Making (MCDM). The potential of applying the proposed methodology in renovation projects is demonstrated through a case study

    Human transformations of the Wadden Sea ecosystem through time: a synthesis

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    Todayrsquos Wadden Sea is a heavily human-altered ecosystem. Shaped by natural forces since its origin 7,500 years ago, humans gradually gained dominance in influencing ecosystem structure and functioning. Here, we reconstruct the timeline of human impacts and the history of ecological changes in the Wadden Sea. We then discuss the ecosystem and societal consequences of observed changes, and conclude with management implications. Human influences have intensified and multiplied over time. Large-scale habitat transformation over the last 1,000 years has eliminated diverse terrestrial, freshwater, brackish and marine habitats. Intensive exploitation of everything from oysters to whales has depleted most large predators and habitat-building species since medieval times. In the twentieth century, pollution, eutrophication, species invasions and, presumably, climate change have had marked impacts on the Wadden Sea flora and fauna. Yet habitat loss and overexploitation were the two main causes for the extinction or severe depletion of 144 species (~20% of total macrobiota). The loss of biodiversity, large predators, special habitats, filter and storage capacity, and degradation in water quality have led to a simplification and homogenisation of the food web structure and ecosystem functioning that has affected the Wadden Sea ecosystem and coastal societies alike. Recent conservation efforts have reversed some negative trends by enabling some birds and mammals to recover and by creating new economic options for society. The Wadden Sea history provides a unique long-term perspective on ecological change, new objectives for conservation, restoration and management, and an ecological baseline that allows us to envision a rich, productive and diverse Wadden Sea ecosystem and coastal society
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