946 research outputs found

    The ZEW combined microsimulation-CGE model: innovative tool for applied policy analysis

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    This contribution describes the linkage of microsimulation models and computable general equilibrium (CGE) models using two already established models called “STSM” and “PACE-L” used by the Centre for European Economic Research. This state of the art research method for applied policy analysis combines the advantages of both model types: On the one hand, microsimulation models allow for detailed labor supply and distributional effects due to policy measures, as individual household data is used. On the other hand, by using a general equilibrium framework, labour market responses, such as wage and labour demand reactions are taken into account. --microsimulation,applied CGE analysis,linked micro-macro models

    Land Use Changes and Their Perception in the Hinterland of Barranquilla, Colombian Caribbean

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    The coastal strip of the western peri-urban area of Barranquilla in the Atlántico Department (Colombia) is experiencing changes in human-environment interactions through infrastructure, residential, and tourism projects in a vulnerable landscape. In the hilly area, fragments of biodiverse tropical dry forest still exist in various states of conservation and degradation. To understand the interrelated social, economic, and ecological transformations in the area, we analyzed land use change on the local scale including the local community’s perception, because the local community is a key actor for sustainable land use. For the analysis of the interrelated social, economic, and ecological processes, we combined visual interpretation of high-resolution satellite imagery, on-site field land use mapping, and a spatial statistical analysis of the distribution of land use classes with in-depth interviews and a participatory GIS workshop, thus benefitting from the complementary methodological strengths of these approaches. The case study is the rural community of El Morro, which exhibits the typical social, economic, and ecological changes of the coastal strip of the western peri-urban area of Barranquilla. The local community perceives a continuous loss of forest area, but observations from on-site field mapping cannot confirm this linear trend. We observed a gradual replacement of traditional land uses such as smallholder agriculture, charcoal production, and cattle breeding by services for tourism, gated community projects for urban dwellers, and infrastructure projects; these spatial developments have several characteristics of rural gentrification. We conclude that the drivers of environmental degradation have changed and the degradation increased. The development projects of external companies have been rejected by the local community and have induced environmental consciousness among community members. Thus, the local community has become an advocate for sustainable land use in the study area

    The ZEW combined microsimulation-CGE model : innovative tool for applied policy analysis

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    This contribution describes the linkage of microsimulation models and computable general equilibrium (CGE) models using two already established models called “STSM” and “PACE-L” used by the Centre for European Economic Research. This state of the art research method for applied policy analysis combines the advantages of both model types: On the one hand, microsimulation models allow for detailed labor supply and distributional effects due to policy measures, as individual household data is used. On the other hand, by using a general equilibrium framework, labour market responses, such as wage and labour demand reactions are taken into account

    The Role of Insulin and Insulin-Like Growth Factor-1/FoxO-Mediated Transcription for the Pathogenesis of Obesity-Associated Dementia

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    Epidemiological studies suggest that being obese in midlife is a risk factor for cognitive decline and dementia in later life. Hyperinsulinemia is one of the most frequent endocrine features in overweight people which results in insulin desensitization. Thus, chronically high insulin levels have been identified as risk factor for dementia. Accordingly, chronically high insulin levels might be harmful for brain function. Furthermore, insulin and IGF-1-induced signaling is reduced in the brains of patients suffering from Alzheimer's disease (AD). Interestingly, studies in rodents suggest that reduced insulin receptor (IR) and insulin-like growth factor-1 receptor (IGF-1R) signaling decrease AD pathology, that is, β-amyloid toxicity. Data obtained in C. elegans indicate that the beneficial effect mediated via reduced IR/IGF-1R signaling might partially be induced via the forkhead-box O transcription factors (FoxO). In the mammalian brain, there are FoxO1, FoxO3a, and FoxO6 expressed. Surprisingly, high-fat diet specifically reduces the expression of FoxO3a and FoxO6 suggesting that IR/IGF-1 → FoxO-mediated transcription is involved in the pathogenesis of obesity-associated cognitive impairment. Therefore, the function of FoxO1 and FoxO3a has been investigated in animal models of Alzheimer's disease in detail. The current paper focuses on the role of IR/IGF-1 signaling and IR/IGF-1 → FoxO-mediated transcription for the pathogenesis of obesity-associated dementia

    Airway responses and inflammation in subjects with asthma after four days of repeated high-single-dose allergen challenge

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    Background: Both standard and low-dose allergen provocations are an established tool in asthma research to improve our understanding of the pathophysiological mechanism of allergic asthma. However, clinical symptoms are less likely to be induced. Therefore, we designed a protocol for repetitive high-dose bronchial allergen challenges to generate clinical symptoms and airway inflammation. Methods: A total of 27 patients aged 18 to 40 years with positive skin-prick tests and mild asthma underwent repetitive high-dose allergen challenges with household dust mites for four consecutive days. Pulmonary function and exhaled NO were measured at every visit. Induced sputum was analysed before and after the allergen challenges for cell counts, ECP, IL-5, INF-γ, IL-8, and the transcription factor Foxp3. Results: We found a significant decrease in pulmonary function, an increased use of salbutamol and the development of a late asthmatic response and bronchial hyperresponsiveness, as well as a significant induction of eNO, eosinophils, and Th-2 cytokines. Repeated provocation was feasible in the majority of patients. Two subjects had severe adverse events requiring prednisolone to cope with nocturnal asthma symptoms. Conclusions: Repeated high-dose bronchial allergen challenges resulted in severe asthma symptoms and marked Th-2-mediated allergic airway inflammation. The high-dose challenge model is suitable only in an attenuated form in diseased volunteers for proof-of-concept studies and in clinical settings to reduce the risk of severe asthma exacerbations. Trial registration: ClinicalTrials.govNCT0067720

    Investigation of the radial effect on the transition velocities in a bubble column based on the modified Shannon entropy

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    AbstractA new parameter for flow regime identification in a bubble column based on the calculation of the Shannon entropy (SE) from different parts of the signal was developed. The bubble column (0.15m in ID) was equipped with a perforated plate distributor (14 holes, Ø 4×10−3m) and operated with an air-deionized water system at ambient conditions. The newly introduced dimensionless ratio of minimum SE to maximum SE was capable of identifying the main transition velocities Utrans at three different dimensionless radial positions (r/R): 0.0 (core), 0.63 (inversion point of axial liquid velocity) and 0.88 (annulus).In the column’s core the new dimensionless SE ratio identified successfully three Utrans values at 0.034, 0.089 and 0.134m/s. They marked the end of the gas maldistribution regime, the onset and the end of the churn-turbulent flow regime, respectively. Three Utrans values (at 0.045, 0.089 and 0.124m/s) were also identified in the annulus. However, the second Utrans value identified the boundary between the first and second transition sub-regimes. The third Utrans value distinguished the onset of the churn-turbulent flow regime. It was found that in the core both the transition and churn-turbulent flow regimes started earlier.At r/R=0.63 the end of the gas maldistribution regime was shifted to a somewhat higher Utrans value (0.067m/s). The second transition sub-regime began at 0.101m/s, whereas the onset of the churn-turbulent regime occurred at 0.124m/s

    Effects of Disorder on the Pressure-Induced Mott Transition in κ\kappa-BEDT-TTF)2_2Cu[N(CN)2_2]Cl

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    We present a study of the influence of disorder on the Mott metal-insulator transition for the organic charge-transfer salt κ\kappa-(BEDT-TTF)2_2Cu[N(CN)2_2]Cl. To this end, disorder was introduced into the system in a controlled way by exposing the single crystals to x-ray irradiation. The crystals were then fine-tuned across the Mott transition by the application of continuously controllable He-gas pressure at low temperatures. Measurements of the thermal expansion and resistance show that the first-order character of the Mott transition prevails for low irradiation doses achieved by irradiation times up to 100 h. For these crystals with a moderate degree of disorder, we find a first-order transition line which ends in a second-order critical endpoint, akin to the pristine crystals. Compared to the latter, however, we observe a significant reduction of both, the critical pressure pcp_c and the critical temperature TcT_c. This result is consistent with the theoretically-predicted formation of a soft Coulomb gap in the presence of strong correlations and small disorder. Furthermore, we demonstrate, similar to the observation for the pristine sample, that the Mott transition after 50 h of irradiation is accompanied by sizable lattice effects, the critical behavior of which can be well described by mean-field theory. Our results demonstrate that the character of the Mott transition remains essentially unchanged at a low disorder level. However, after an irradiation time of 150 h, no clear signatures of a discontinuous metal-insulator transition could be revealed anymore. These results suggest that, above a certain disorder level, the metal-insulator transition becomes a smeared first-order transition with some residual hysteresis.Comment: 20 pages, 7 figures, appeared in the Special Issue "Advances in Organic Conductors and Superconductors" of Crystal
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