5,077 research outputs found

    Well-posedness and stationary solutions

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    In this paper we prove existence and uniqueness of variational inequality solutions for a bistable quasilinear parabolic equation arising in the theory of solid-solid phase transitions and discuss its stationary solutions, which can be discontinuous

    A General Method for Model-Independent Measurements of Particle Spins, Couplings and Mixing Angles in Cascade Decays with Missing Energy at Hadron Colliders

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    We outline a general strategy for measuring spins, couplings and mixing angles in the case of a heavy partner decay chain terminating in an invisible particle. We consider the common example of a new scalar or fermion D decaying sequentially to other new particles C, B and A by emitting a quark jet j and two leptons ln and lf. We derive analytic formulas for the dilepton {ln,lf} and the two jet-lepton ({j,ln} and {j,lf}) invariant mass distributions for most general couplings and mixing angles of the new partners. We then consider various spin assignments for the particles A, B, C and D, and derive the relevant functional basis for the invariant mass distributions which contains the intrinsic spin information and does not depend on the couplings and mixing angles. We propose a new method for determining the spins of the new partners, using the three experimentally observable distributions {l+,l-}, {j,l+}+{j,l-} and {j,l+}-{j,l-}. We show that the former two only depend on a single model-dependent parameter alpha, while the latter may depend on two other parameters beta and gamma. By fitting these distributions to our set of basis functions, we are able to do a pure measurement of the spins per se. Our method is also applicable at a pp-bar collider such as the Tevatron, for which the previously proposed lepton charge asymmetry is identically zero and does not contain any spin information. In the process of determining the spins, we also obtain an independent measurement of the parameters alpha, beta and gamma, which represent certain combinations of the couplings and the mixing angles of the heavy partners A, B, C and D.Comment: 67 pages, 29 figures, typeset in JHEP styl

    Aspects carbohydrate metabolism in the plerocercoid of Schistocephalus solidus.

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    PhDThree spined sticklebacks infected with Schistocephalus solidus plerocercoids were used for in-vivo experiments to determine the relative distribution of 14C-labelled sugars (D-glucose and 3-0-M D-glucose) in fish and worm tissues. A maximum of 23.6% labelled material from D-glucose was found in plerocercoids after 4.5 hours and a maximum of 2.8% labelled material from 3-0-M glucose after 24 hours. Comparison of distribution levels between the two sugars and between infected and uninfected fish tissues did not show significant differences except in a few cases. In-vitro studies with plerocercoids demonstrate D-glucose uptake to be sodium dependent, saturable with an apparent Kt of O.66mM, inversely related to dry weight and absorbed against a concentration gradient. Uptake is also affected by temperature with high rates at 200 and 400C and lower rates at 100 and 30°C. Uptake is inhibited (non-competitively) by phlorizin and to a lesser extent by ouabain and DNP. The nature of inhibition caused by the latter two compounds was not determined. THe effect of 3-O-M glucose on D-glucose uptake was inconclusive. Similarly the effect of D-galactose was inconclusive and also inconsistent,causing both stimulation and inhibition of D-glucose uptake. A gradient of glucose absorption is present along the length of the plerocercoid; the lowest rate being found at the anterior section and the highest at the posterior end. Plerocercoids incubated under aerobic conditions in 14C-D-glucose produced insignificant amounts of labelled CO2. Under aerobic conditions lactate is produced by plerocercoids at the rate of O.13mg/ml/hour but no detectable amounts of pyruvate were found under similar conditions. Glycogen extracts from plerocercoids incubated in-vivo contain increasing levels of 14C-labelled material with increased incubation periods. Host metabolism is significantly affected by the presence of plerocercoids. Lower levels of glycogen are found in the liver tissue of infected fish compared to uninfected fish. Also the rate of D-glucose uptake by fish stomach and intestinal tissues is considerably reduced in infected fish

    Are small businesses an appropriate vehicle through which to tackle unemployment?

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    Jobs created by small businesses represent the majority of employment opportunities created in the UK. Efforts to reduce long term unemployment might focus on the benefits of working closely with these businesses. The UK Government’s New Deal employment initiative, introduced in 1998, used wage subsidies to encourage the integration of the long term unemployed to the labour market. This might have naturally complemented the recruitment needs of small business, however, such businesses generally seek skills lacking in the long term unemployed. As such, the employment opportunities they create tend not to be accessed by this group. Small business use of employment interventions are undermined by the complex social and economic issues presented by the target group and the deeply rooted causal factors of unemployment that wage subsidies, alone, struggle to influence. Recognising the New Deal as the main labour market intervention of the last 10 years, its relationship with small businesses relied on a series of hopeful and naive assumptions in terms of candidate suitability and employer participation. Only by developing intensive, multidimensional, complementary and long term interventions can long term unemployment be tackled successfully as a partnership effort with small business

    Nitrate pollution from horticultural production systems : tools for policy and advice from field to catchment scales

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    The implementation of the Nitrates Directive has imposed a requirement to restrict N fertiliser and manuring practices on farms across the EU in order to reduce nitrate losses to water. These requirements have since been extended by the more demanding Water Framework Directive, which broadens the focus from the control of farm practices to a consideration of the impacts of pollutants from all sources on water quality at a catchment or larger scale. Together, these Directives set limits for water quality, and identify general strategies for how these might be achieved. However, it is the responsibility of policy makers in each Nation State to design the details of the management practices and environmental protection measures required to meet the objectives of the legislation, to ensure they are appropriate for their specific types of land use and climate. This paper describes various modelling tools for comparing different cropping and land use strategies, and illustrates with examples how they can inform policy makers about the environmental benefits of changing management practices and how to prioritise them. The results can help to provide the specific advice on N fertiliser and land use management required by farmers and growers at a field scale, and by environmental managers at a catchment or larger scale. A further example of how results from multiple catchments can be up-scaled and compared using Geographic Information Systems is also outlined

    Douglas, William 0., The Court Years, 1939-1975: The Autobiography of William O. Douglas. New York: Random House, 1980. 434 pp., $16.95

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    Since embarking on a career in the law, I have regarded William 0. Douglas as one of a handful of outright heroes
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