3,366 research outputs found

    Smallholder dairy farming in Uganda with special reference to an intensive dairy smallholding at the Veterinary Training Institute, Entebbe

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    A Class of Free Boundary Problems with Onset of a new Phase

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    A class of diffusion driven Free Boundary Problems is considered which is characterized by the initial onset of a phase and by an explicit kinematic condition for the evolution of the free boundary. By a domain fixing change of variables it naturally leads to coupled systems comprised of a singular parabolic initial boundary value problem and a Hamilton-Jacobi equation. Even though the one dimensional case has been thoroughly investigated, results as basic as well-posedness and regularity have so far not been obtained for its higher dimensional counterpart. In this paper a recently developed regularity theory for abstract singular parabolic Cauchy problems is utilized to obtain the first well-posedness results for the Free Boundary Problems under consideration. The derivation of elliptic regularity results for the underlying static singular problems will play an important role

    Adding low-dose antidepressants to interferon alpha treatment for chronic hepatitis C improved psychiatric tolerability in a patient with schizoaffective psychosis

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    Treatment of chronic hepatitis C with interferon alpha (IFN-alpha) is relatively contraindicated in patients with psychiatric disorders because of possible severe psychiatric side effects. We report on a case of a female patient with a chronic schizoaffective psychosis, who was treated for 3 months with 3 x 3 mio IE IFN-alpha s.c./week because of a chronic hepatitis C (genotype Ib). Psychosis was stable with flupentixol monotherapy. After 2 months, she developed a severe depressive syndrome which lead to suicidal ideation. Until this time, she was without any antidepressive medication. Depressive symptoms disappeared after interferon therapy was stopped. Under prophylactic treatment with low-dose trimipramine (50 mg) or nefazodone (200 mg/day) therapy with IFN-alpha 3 x 3 mio IE/week was re-established after several months and again 2 years later adding ribavirin 1200 mg/day, a virustaticum. In contrast to the symptoms during monotherapy with IFN-alpha, during the time of both combination treatments, no psychiatric side effects occurred. While for ribavirin antidepressant effects are not known, we suppose that antidepressants may in serotonergic or noradrenergic caused by IFN-alpha. prevent changes neurotransmission caused by IFN-alpha. Copyright (C) 2000 S. Karger AG, Basel

    The impact of air pollutant and methane emission controls on tropospheric ozone and radiative forcing: CTM calculations for the period 1990-2030

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    To explore the relationship between tropospheric ozone and radiative forcing with changing emissions, we compiled two sets of global scenarios for the emissions of the ozone precursors methane (CH<sub>4</sub>), carbon monoxide (CO), non-methane volatile organic compounds (NMVOC) and nitrogen oxides (NO<sub>x</sub>) up to the year 2030 and implemented them in two global Chemistry Transport Models. The 'Current Legislation' (CLE) scenario reflects the current perspectives of individual countries on future economic development and takes the anticipated effects of presently decided emission control legislation in the individual countries into account. In addition, we developed a 'Maximum technically Feasible Reduction' (MFR) scenario that outlines the scope for emission reductions offered by full implementation of the presently available emission control technologies, while maintaining the projected levels of anthropogenic activities. Whereas the resulting projections of methane emissions lie within the range suggested by other greenhouse gas projections, the recent pollution control legislation of many Asian countries, requiring introduction of catalytic converters for vehicles, leads to significantly lower growth in emissions of the air pollutants NO<sub>x</sub>, NMVOC and CO than was suggested by the widely used and more pessimistic IPCC (Intergovernmental Panel on Climate Change) SRES (Special Report on Emission Scenarios) scenarios (Nakicenovic et al., 2000), which made Business-as-Usual assumptions regarding emission control technology. With the TM3 and STOCHEM models we performed several long-term integrations (1990-2030) to assess global, hemispheric and regional changes in CH<sub>4</sub>, CO, hydroxyl radicals, ozone and the radiative climate forcings resulting from these two emission scenarios. Both models reproduce broadly the observed trends in CO, and CH<sub>4</sub> concentrations from 1990 to 2002. <P style='line-height: 20px;'> For the 'current legislation' case, both models indicate an increase of the annual average ozone levels in the Northern Hemisphere by 5ppbv, and up to 15ppbv over the Indian sub-continent, comparing the 2020s (2020-2030) with the 1990s (1990-2000). The corresponding higher ozone and methane burdens in the atmosphere increase radiative forcing by approximately 0.2 Wm<sup>-2</sup>. Full application of today's emissions control technologies, however, would bring down ozone below the levels experienced in the 1990s and would reduce the radiative forcing of ozone and methane to approximately -0.1 Wm<sup>-2</sup>. This can be compared to the 0.14-0.47 Wm<sup>-2</sup> increase of methane and ozone radiative forcings associated with the SRES scenarios. While methane reductions lead to lower ozone burdens and to less radiative forcing, further reductions of the air pollutants NO<sub>x</sub> and NMVOC result in lower ozone, but at the same time increase the lifetime of methane. Control of methane emissions appears an efficient option to reduce tropospheric ozone as well as radiative forcing

    Gap solitons in spatiotemporal photonic crystals

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    We generalize the concept of nonlinear periodic structures to systems that show arbitrary spacetime variations of the refractive index. Nonlinear pulse propagation through these spatiotemporal photonic crystals can be described, for shallow nonstationary gratings, by coupled mode equations which are a generalization of the traditional equations used for stationary photonic crystals. Novel gap soliton solutions are found by solving a modified massive Thirring model. They represent the missing link between the gap solitons in static photonic crystals and resonance solitons found in dynamic gratings.Comment: 3 figures, submitte

    The GAINS Optimization Module as of 1 February 2007

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    This document describes the optimization framework of the GAINS model for Europe. The approach is compared to the approach used in the RAINS model and a detailed description of the objective function, the constraints and the impact functions is given. Finally a comparison of individual single pollutant cost curves generated from the RAINS model and with the optimization module of GAINS is given to illustrate the consistency of the two approaches for single pollutant measures

    Scenarios of cost-effective emission controls after 2020

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    Although emissions of most air pollutants are expected to significantly decline in the coming decades, the magnitude of the remaining impacts of poor air quality on human health and ecosystems will still be substantial. Technical and non-technical measures will be still available to reduce emissions and resulting impacts below the "current legislation" baseline levels. However, these additional measures come at certain costs. It is estimated that full implementation of all available technical emission control measures would require up to 0.32% of GDP in 2030, and thereby increase total costs of air pollution control by more than 50%. The GAINS optimization offers a tool for a systematic analysis of the cost-effectiveness of further measures. This report presents a series of illustrative optimization calculations addressing the health and ecosystems impact indicators that have been employed for earlier cost-effectiveness analyses for the 2005 Thematic Strategy on Air Pollution and the 2012 revision of the Gothenburg protocol. As a first step, a series of calculations determined for each of these endpoints the increase in emission control costs for gradually tightened "gap closure" targets between the current legislation and the full application of all available technical measures. Costs increase most rapidly for improvements of health impacts (for ozone and PM), while significant progress at comparably low costs is possible for eutrophication and acidification. In a second step, illustrative joint optimizations for multiple targets have been conducted, aiming at arbitrarily chosen gap closure targets of 25/50/75% for all impact indicators in 2030. The costs of the portfolios of measures that meet these targets range from Euros 0.3 bn/yr to Euros 9.9 bn/yr for the most ambitious case. In a further step, the temporal interactions between emission reductions that have been optimized for a more distant year (e.g., 2030) and potential interim targets for earlier years are discussed. While there are several alternatives for securing temporal consistency of targets over time to avoid regret investments, the choice of the temporal path of environmental ambitions remains a political decision, depending on the weight given to environmental improvements in the near term versus the long-term target. All calculations presented in this report must be considered as illustrative, since they do not yet include the forthcoming final TSAP baseline scenario that will build on the latest expectations of economic development and energy use

    Late recurrent ischaemia in infarct patients with a normal predischarge exercise test after thrombolysis

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    We investigated the prognostic value of normal predischarge exercise test in 109 patients after myocardial infarction treated with i. v. thrombolysis within 4 h. In 29 of these 109 patients, elective PTCA or bypass surgery was performed for prognostic reasons after coronary angiography; 80 patients were treated conservatively with drug therapy. Recurrent postinfarct angina early after hospital discharge was the reason in 4 of 80 for PTCA or bypass surgery. Twenty-three of the remaining 76 conservatively treated patients developed recurrent ischaemia during long-term follow-up of 12.0 ± 6.2 months, including one patient with reinfarction. Late recurrent ischaemia during long-term follow-up was observed in one third of the conservatively treated patients with a normal predischarge exercise test, although a high percentage (30%) of patients in this subgroup had been treated with PTCA or bypass surgery mainly for prognostic reasons. Predischarge exercise test is therefore of limited value for detection of still viable myocardium at risk of further ischaemic events after acute myocardial infarction and thrombolysi

    GAINS: The impact of economic crisis on GHG mitigation potentials and costs in Annex I Countries

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    This report analyzes how GHG mitigation potentials and costs in the Annex I countries of the UNFCCC are influenced by the current economic crisis
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