2,588 research outputs found

    Aquaculture induced erosion of tropical coastlines throws coastal communities back into poverty

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    Shallow tropical coastlines harbour unique mangrove ecosystems, which support livelihoods and provide a natural barrier against coastal flooding. Non-sustainable land-use practices, such as large-scale clear cutting of mangroves for aquaculture, ground water withdrawal and alteration of river flows, result in rapid subsidence. The collapse of aquaculture production, due to pollution and disease, is followed by coastal erosion, damage to infrastructure, intrusion of salt water and coastal flooding. Standard engineered interventions for protection often fail or are extremely expensive in these soft muddy environments. Subsidence and erosion render re-planting of mangroves in front of retreating coastlines impossible. Short-term solutions should focus on restoration of abiotic conditions, such as hydrology and sediment fluxes, to facilitate rapid establishment of protective mangrove belts. However, to ensure long-term sustainability, improved governance frameworks are required that put in place criteria for sustainable aquaculture, guide coastal infrastructure designs and limit ground water extraction

    Effectiveness and cost-effectiveness of a minimal psychological intervention to reduce non-severe depression in chronically ill elderly patients: the design of a randomised controlled trial [ISRCTN92331982]

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    BACKGROUND: Depression is a prevalent disorder in chronically ill elderly persons. It may decrease quality of life, and increase functional disability, medical costs, and healthcare utilisation. Because patients may slip into a downward spiral, early recognition and treatment of depression is important. Depression can be treated with antidepressants or psychological interventions; the latter can also be applied by trained paraprofessionals. In this paper, we describe the design of the DELTA study (Depression in Elderly with Long-Term Afflictions). The first objective of the DELTA study is to evaluate the effectiveness and cost-effectiveness of a minimal psychological intervention (MPI) to reduce depression in chronically ill elderly patients. The second objective is to evaluate whether a potential effect of the MPI may differ between types of chronic illnesses. The tailor-made intervention is administered by nurses, who are trained in the principles of cognitive behavioural therapy and self-management. METHODS/DESIGN: DELTA is a two-armed randomised controlled trial, comparing MPI to usual care. A total number of 180 patients with diabetes mellitus type II (DM) and 180 patients with chronic obstructive pulmonary disease (COPD), who in addition suffer from non-severe depression, will be included in the study. In our study, non-severe depression is defined as having minor depression, mild major depression or moderate major depression. The primary outcome measure is depression using the Beck Depression Inventory. Secondary outcome measures include quality of life, daily functioning, self-efficacy, autonomy, and participation. In the economic evaluation, cost-effectiveness and cost-utility ratios will be calculated. Furthermore, a process evaluation will be carried out. Analyses will include both univariate and multivariate techniques and according to the intention to treat principle. The economic evaluation will be done from a societal perspective and data of the process evaluation will be analysed using descriptive techniques. DISCUSSION: A total number of 361 patients has been included in the study. All interventions have been administered and follow-up data will be complete in September 2006. Preliminary results from the process evaluation indicate that patients' satisfaction with the intervention is high. If this intervention proves to be effective, implementation of the DELTA intervention is considered and anticipated

    A model of parity-dependent immunity to placental malaria

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    C1 - Journal Articles RefereedPlasmodium falciparum placental infection during pregnancy is harmful for both mother and child. Protection from placental infection is parity-dependent, that is, acquired over consecutive pregnancies. However, the infection status of the placenta can only be assessed at delivery. Here, to better understand the mechanism underlying this parity-dependence, we fitted a model linking malaria dynamics within the general population to observed placental histology. Our results suggest that immunity resulting in less prolonged infection is a greater determinant of the parity-specific patterns than immunity that prevents placental sequestration. Our results also suggest the time when maternal blood first flows into the placenta is a high-risk period. Therefore, preventative strategies implementable before or early in pregnancy, such as insecticide-treated net usage in women of child-bearing age or any future vaccine, could substantially reduce the number of women who experience placental infection

    Color-Octet Fragmentation and the psi' Surplus at the Tevatron

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    The production rate of prompt ψ\psi''s at large transverse momentum at the Tevatron is larger than theoretical expectations by about a factor of 30. As a solution to this puzzle, we suggest that the dominant ψ\psi' production mechanism is the fragmentation of a gluon into a ccˉc \bar c pair in a pointlike color-octet S-wave state, which subsequently evolves nonperturbatively into a ψ\psi' plus light hadrons. The contribution to the fragmentation function from this process is enhanced by a short-distance factor of 1/αs21/\alpha_s^2 relative to the conventional color-singlet contribution. This may compensate for the suppression by v4v^4, where vv is the relative momentum of the charm quark in the ψ\psi'. If this is indeed the dominant production mechanism at large pTp_T, then the prompt ψ\psi''s that are observed at the Tevatron should almost always be associated with a jet of light hadrons.Comment: 9 pages, LaTe

    J/psi Production via Fragmentation at the Tevatron

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    The production of \jpsi at large transverse momenta (\pt > M_\jpsi) in ppˉp\bar p collisions is considered by including the mechanism of fragmentation. Both contributions of fragmentation to \jpsi and of fragmentation to χ\chi states followed by radiative decay to \jpsi are taken into account. The latter is found to be dominant and larger than direct production. The overall theoretical estimate is shown to be nearly consistent with the experimental observation.Comment: LaTeX, 7 pages. Preprint FNT/T-94/13, LNF-94/024(P). Data taken from a reference were incorrect and have been changed. Complete postscript file available via anonymous ftp at cobra1.pv.infn.it, as pub/jpsi.ps(.Z)(.gz
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