428 research outputs found

    Teaching and learning reflection in MPA programs: towards a strategy

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    __Abstract__ Reflection is an essential ingredient of academic education in PublicAdministration, both for an academic and a professional career. Making a distinction between reflectivity and reflexivity we identify 30 foci of reflection. The main question of the article is how these forms of reflection can be taught and learned in PA programs, especially in post-experience PAprograms. To answer this question,westudied de programand interviewed the teaching staff op the post-experienceMPA program at Erasmus University in Rotterdamto describe what is actually done in the to teach students reflection competences and to identify success and limitations of these efforts. We present our findings and describe how we, in consultation with the teaching staff, developed a number of feasible options for improvement. We discuss these options and present a strategy to actually get these implemented

    Bomb radiocarbon evidence for strong global carbon uptake and turnover in terrestrial vegetation

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    Vegetation and soils are taking up approximately 30% of anthropogenic CO2 emissions because of small imbalances in large gross carbon exchanges from productivity and turnover that are poorly constrained. We combine a new budget of radiocarbon (14C) produced by nuclear bomb testing in the 1960s with model simulations to evaluate carbon cycling in terrestrial vegetation. We find that most state-of-the-art vegetation models used in the Coupled Model Intercomparison Project underestimate the 14C accumulation in vegetation biomass. Our findings, combined with constraints on vegetation carbon stocks and productivity trends, imply that net primary productivity is likely at least 80 PgC/yr presently, compared to 43-76 PgC/yr predicted by current models. Storage of anthropogenic carbon in terrestrial vegetation is likely more short-lived and vulnerable than previously predicted

    Mapping biomass with remote sensing: a comparison of methods for the case study of Uganda

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    <p>Abstract</p> <p>Background</p> <p>Assessing biomass is gaining increasing interest mainly for bioenergy, climate change research and mitigation activities, such as reducing emissions from deforestation and forest degradation and the role of conservation, sustainable management of forests and enhancement of forest carbon stocks in developing countries (REDD+). In response to these needs, a number of biomass/carbon maps have been recently produced using different approaches but the lack of comparable reference data limits their proper validation. The objectives of this study are to compare the available maps for Uganda and to understand the sources of variability in the estimation. Uganda was chosen as a case-study because it presents a reliable national biomass reference dataset.</p> <p>Results</p> <p>The comparison of the biomass/carbon maps show strong disagreement between the products, with estimates of total aboveground biomass of Uganda ranging from 343 to 2201 Tg and different spatial distribution patterns. Compared to the reference map based on country-specific field data and a national Land Cover (LC) dataset (estimating 468 Tg), maps based on biome-average biomass values, such as the Intergovernmental Panel on Climate Change (IPCC) default values, and global LC datasets tend to strongly overestimate biomass availability of Uganda (ranging from 578 to 2201 Tg), while maps based on satellite data and regression models provide conservative estimates (ranging from 343 to 443 Tg). The comparison of the maps predictions with field data, upscaled to map resolution using LC data, is in accordance with the above findings. This study also demonstrates that the biomass estimates are primarily driven by the biomass reference data while the type of spatial maps used for their stratification has a smaller, but not negligible, impact. The differences in format, resolution and biomass definition used by the maps, as well as the fact that some datasets are not independent from the reference data to which they are compared, are considered in the interpretation of the results.</p> <p>Conclusions</p> <p>The strong disagreement between existing products and the large impact of biomass reference data on the estimates indicate that the first, critical step to improve the accuracy of the biomass maps consists of the collection of accurate biomass field data for all relevant vegetation types. However, detailed and accurate spatial datasets are crucial to obtain accurate estimates at specific locations.</p

    Biophysical suitability, economic pressure and land-cover change: a global probabilistic approach and insights for REDD+

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    There has been a concerted effort by the international scientific community to understand the multiple causes and patterns of land-cover change to support sustainable land management. Here, we examined biophysical suitability, and a novel integrated index of “Economic Pressure on Land” (EPL) to explain land cover in the year 2000, and estimated the likelihood of future land-cover change through 2050, including protected area effectiveness. Biophysical suitability and EPL explained almost half of the global pattern of land cover (R 2 = 0.45), increasing to almost two-thirds in areas where a long-term equilibrium is likely to have been reached (e.g. R 2 = 0.64 in Europe). We identify a high likelihood of future land-cover change in vast areas with relatively lower current and past deforestation (e.g. the Congo Basin). Further, we simulated emissions arising from a “business as usual” and two reducing emissions from deforestation and forest degradation (REDD) scenarios by incorporating data on biomass carbon. As our model incorporates all biome types, it highlights a crucial aspect of the ongoing REDD + debate: if restricted to forests, “cross-biome leakage” would severely reduce REDD + effectiveness for climate change mitigation. If forests were protected from deforestation yet without measures to tackle the drivers of land-cover change, REDD + would only reduce 30 % of total emissions from land-cover change. Fifty-five percent of emissions reductions from forests would be compensated by increased emissions in other biomes. These results suggest that, although REDD + remains a very promising mitigation tool, implementation of complementary measures to reduce land demand is necessary to prevent this leakage

    Identification of plasma lipid biomarkers for prostate cancer by lipidomics and bioinformatics

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    Background: Lipids have critical functions in cellular energy storage, structure and signaling. Many individual lipid molecules have been associated with the evolution of prostate cancer; however, none of them has been approved to be used as a biomarker. The aim of this study is to identify lipid molecules from hundreds plasma apparent lipid species as biomarkers for diagnosis of prostate cancer. Methodology/Principal Findings: Using lipidomics, lipid profiling of 390 individual apparent lipid species was performed on 141 plasma samples from 105 patients with prostate cancer and 36 male controls. High throughput data generated from lipidomics were analyzed using bioinformatic and statistical methods. From 390 apparent lipid species, 35 species were demonstrated to have potential in differentiation of prostate cancer. Within the 35 species, 12 were identified as individual plasma lipid biomarkers for diagnosis of prostate cancer with a sensitivity above 80%, specificity above 50% and accuracy above 80%. Using top 15 of 35 potential biomarkers together increased predictive power dramatically in diagnosis of prostate cancer with a sensitivity of 93.6%, specificity of 90.1% and accuracy of 97.3%. Principal component analysis (PCA) and hierarchical clustering analysis (HCA) demonstrated that patient and control populations were visually separated by identified lipid biomarkers. RandomForest and 10-fold cross validation analyses demonstrated that the identified lipid biomarkers were able to predict unknown populations accurately, and this was not influenced by patient's age and race. Three out of 13 lipid classes, phosphatidylethanolamine (PE), ether-linked phosphatidylethanolamine (ePE) and ether-linked phosphatidylcholine (ePC) could be considered as biomarkers in diagnosis of prostate cancer. Conclusions/Significance: Using lipidomics and bioinformatic and statistical methods, we have identified a few out of hundreds plasma apparent lipid molecular species as biomarkers for diagnosis of prostate cancer with a high sensitivity, specificity and accuracy

    The burden of co-existing dermatological disorders and their tendency of being overlooked among patients admitted to muhimbili national hospital in Dar es Salaam, Tanzania

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    \ud Skin diseases are underestimated and overlooked by most clinicians despite being common in clinical practice. Many patients are hospitalized with co-existing dermatological conditions which may not be detected and managed by the attending physicians. The objective of this study was to determine the burden of co-existing and overlooked dermatological disorders among patients admitted to medical wards of Muhimbili National hospital in Dar es Salaam. A hospital-based descriptive cross-sectional study conducted at Muhimbili National hospital in Dar es Salaam, Tanzania. Patients were consecutively recruited from the medical wards. Detailed interview to obtain clinico-demographic characteristics was followed by a complete physical examination. Dermatological diagnoses were made mainly clinically. Appropriate confirmatory laboratory investigations were performed where necessary. Data was analyzed using the 'Statistical Package for Social Sciences' (SPSS) program version 10.0. A p-value of < 0.5 was statistically significant. Three hundred and ninety patients admitted to medical wards were enrolled into the study of whom, 221(56.7%) were females. The mean age was 36.7 ± 17.9 (range 7-84 years). Overall, 232/390 patients (59.5%) had co-existing dermatological disorders with 49% (191/390) having one, 9% (36/390) two and 5 patients (1%) three. A wide range of co-existing skin diseases was encountered, the most diverse being non-infectious conditions which together accounted for 36.4% (142/390) while infectious dermatoses accounted for 31.5% (123/390). The leading infectious skin diseases were superficial fungal infections accounting for 18%. Pruritic papular eruption of HIV/AIDS (PPE) and seborrheic eczema were the most common non-infectious conditions, each accounting for 4.3%. Of the 232/390 patients with dermatological disorders, 191/232 (82.3%) and 154/232 (66.3%) had been overlooked by their referring and admitting doctors respectively. Dermatological disorders are common among patients admitted to medical wards and many are not detected by their referring or admitting physicians. Basic dermatological education should be emphasized to improve knowledge and awareness among clinicians.\u

    Markedly Divergent Tree Assemblage Responses to Tropical Forest Loss and Fragmentation across a Strong Seasonality Gradient

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    We examine the effects of forest fragmentation on the structure and composition of tree assemblages within three seasonal and aseasonal forest types of southern Brazil, including evergreen, Araucaria, and deciduous forests. We sampled three southernmost Atlantic Forest landscapes, including the largest continuous forest protected areas within each forest type. Tree assemblages in each forest type were sampled within 10 plots of 0.1 ha in both continuous forests and 10 adjacent forest fragments. All trees within each plot were assigned to trait categories describing their regeneration strategy, vertical stratification, seed-dispersal mode, seed size, and wood density. We detected differences among both forest types and landscape contexts in terms of overall tree species richness, and the density and species richness of different functional groups in terms of regeneration strategy, seed dispersal mode and woody density. Overall, evergreen forest fragments exhibited the largest deviations from continuous forest plots in assemblage structure. Evergreen, Araucaria and deciduous forests diverge in the functional composition of tree floras, particularly in relation to regeneration strategy and stress tolerance. By supporting a more diversified light-demanding and stress-tolerant flora with reduced richness and abundance of shade-tolerant, old-growth species, both deciduous and Araucaria forest tree assemblages are more intrinsically resilient to contemporary human-disturbances, including fragmentation-induced edge effects, in terms of species erosion and functional shifts. We suggest that these intrinsic differences in the direction and magnitude of responses to changes in landscape structure between forest types should guide a wide range of conservation strategies in restoring fragmented tropical forest landscapes worldwide

    Mapping and monitoring carbon stocks with satellite observations: a comparison of methods

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    Mapping and monitoring carbon stocks in forested regions of the world, particularly the tropics, has attracted a great deal of attention in recent years as deforestation and forest degradation account for up to 30% of anthropogenic carbon emissions, and are now included in climate change negotiations. We review the potential for satellites to measure carbon stocks, specifically aboveground biomass (AGB), and provide an overview of a range of approaches that have been developed and used to map AGB across a diverse set of conditions and geographic areas. We provide a summary of types of remote sensing measurements relevant to mapping AGB, and assess the relative merits and limitations of each. We then provide an overview of traditional techniques of mapping AGB based on ascribing field measurements to vegetation or land cover type classes, and describe the merits and limitations of those relative to recent data mining algorithms used in the context of an approach based on direct utilization of remote sensing measurements, whether optical or lidar reflectance, or radar backscatter. We conclude that while satellite remote sensing has often been discounted as inadequate for the task, attempts to map AGB without satellite imagery are insufficient. Moreover, the direct remote sensing approach provided more coherent maps of AGB relative to traditional approaches. We demonstrate this with a case study focused on continental Africa and discuss the work in the context of reducing uncertainty for carbon monitoring and markets
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