39 research outputs found
Reporting of eligibility criteria of randomised trials: cohort study comparing trial protocols with subsequent articles
Objective To determine whether and how eligibility criteria of participants prespecified in protocols of randomised trials are reported in subsequent articles
Treatment of depressive disorders in primary care - protocol of a multiple treatment systematic review of randomized controlled trials
Background: Several systematic reviews have summarized the evidence for specific treatments of primary care patients suffering from depression. However, it is not possible to answer the question how the available treatment options compare with each other as review methods differ. We aim to systematically review and compare the available evidence for the effectiveness of pharmacological, psychological, and combined treatments for patients with depressive disorders in primary care. Methods/Design: To be included, studies have to be randomized trials comparing antidepressant medication (tricyclic antidepressants, selective serotonin reuptake inhibitors (SSRIs), hypericum extracts, other agents) and/or psychological therapies (e.g. interpersonal psychotherapy, cognitive therapy, behavioural therapy, short dynamically-oriented psychotherapy) with another active therapy, placebo or sham intervention, routine care or no treatment in primary care patients in the acute phase of a depressive episode. Main outcome measure is response after completion of acute phase treatment. Eligible studies will be identified from available systematic reviews, from searches in electronic databases (Medline, Embase and Central), trial registers, and citation tracking. Two reviewers will independently extract study data and assess the risk of bias using the Cochrane Collaboration's corresponding tool. Meta-analyses (random effects model, inverse variance weighting) will be performed for direct comparisons of single interventions and for groups of similar interventions (e.g. SSRIs vs. tricyclics) and defined time-windows (up to 3 months and above). If possible, a global analysis of the relative effectiveness of treatments will be estimated from all available direct and indirect evidence that is present in a network of treatments and comparisons. Discussion: Practitioners do not only want to know whether there is evidence that a specific treatment is more effective than placebo, but also how the treatment options compare to each other. Therefore, we believe that a multiple treatment systematic review of primary-care based randomized controlled trials on the most important therapies against depression is timely
Beiträge der Fernerkundung zu einem nachhaltigen Ressourcenmanagement in der Aralseeregion
Per-Field Irrigated Crop Classification in Arid Central Asia Using SPOT and ASTER Data
Abstract: The overarching goal of this research was to explore accurate methods of mapping irrigated crops, where digital cadastre information is unavailable: (a) Boundary separation by object-oriented image segmentation using very high spatial resolution (2.5âÂÂ5 m) data was followed by (b) identification of crops and crop rotations by means of phenology, tasselled cap, and rule-based classification using high resolution (15âÂÂ30 m) bi-temporal data. The extensive irrigated cotton production system of the Khorezm province in Uzbekistan, Central Asia, was selected as a study region. Image segmentation was carried out on pan-sharpened SPOT data. Varying combinations of segmentation parameters (shape, compactness, and color) were tested for optimized boundary separation. The resulting geometry was validated against polygons digitized from the data and cadastre maps, analysing similarity (size, shape) and congruence. The parameters shape and compactness were decisive for segmentation accuracy. Differences between crop phenologies were analyzed at field level using bi-temporal ASTER data. A rule set based on the tasselled cap indices greenness and brightness allowed for classifying crop rotations of cotton, winter-wheat and rice, resulting in an overall accuracy of 80 %. The proposed field-based crop classification method can be an important tool for use in water demand estimations, crop yield simulations, or economic models in agricultural systems similar to Khorezm
Objektbasierte Klassifikation der agrarischen Landnutzung im Gebiet Khorezm (Usbekistan)
Catenary soil development influencing erosion susceptibility along a hillslope in Uganda
Systematic variations of soil properties occur along the hillslope due to differences in water and
energy conditions. Such catenary soil variations are often assumed, in turn, to influence erosion
processes, but quantitative investigations dealing with the reciprocal relationship between catenary
soil development and erosion processes are limited. This study models the influence of catenary soil
development on erosion processes on a hillslope in Uganda. The Water Erosion Prediction Project
(WEPP)- model was selected to determine the impact of spatial distribution of soil types on hillslope
soil loss. A detailed soil survey confirmed a well-developed catenary sequence at the study site. Soils
at the summit position had a thick solum due to the stable soil formation on the flat surface, whereas
soils at the shoulder position had shallow A-horizons due to active erosion processes. Valley and
footslope soils showed hydromorphic features and accumulation of soil material from upslope. The
performance of the WEPP- model was evaluated by a sensitivity analysis, which proved that the
model was sensitive to vertical changes in soil properties to a depth of 40 cm. High sensitivity to soil
texture indicated that the catenary sequence at the study site may have a strong influence on model
simulations. When the hillslope was modelled as a uniform soil-landscape unit using each individual
soil profile separately, simulated outputs showed high variations with annual soil loss ranging
between 2.5 and 9 t/ha. This variation was reduced by including an increasing number of distinct
soil-landscape units representative for the individual slope sections. Simulations considering a
catenary soil sequence showed a clear spatial demarcation between erosion and sedimentation zones,
which was verified by soil investigations. This implies that simulations including a higher number of
soil-landscape units generate a more realistic spatial distribution of erosion–sedimentation processes
at a hillslope