117 research outputs found
Environmental taxation and structural change in an open economy: a CGE analysis with imperfect competition and free entry
The economic effects of environmental taxes depend on the market structure. Under imperfect competition with free entry and exit, environmental taxes have an impact on economies of scale by changing the number and size of firms. Whether economies of scale rise or fall in a particular industry depends on induced changes in the price elasticity of demand. Because export demand is more price elastic than domestic demand, the overall price elasticity rises (falls) as the industry gains (loses) in comparative advantage. We use a computable general equilibrium model for Germany to examine the effects of a unilaterally introduced carbon tax under both perfect and imperfect competition. Our key finding is that induced structural change in favor of the less energy intensive, more labor intensive industries is more pronounced under imperfect competition than under perfect competition. At the macroeconomic level, the total costs of environmental regulation under imperfect competition can be higher or lower than those under perfect competition depending on whether aggregate gains or losses in economies of scale across imperfectly competitive sectors prevail. --environmental taxation,imperfect competition,structural change
Environmental Taxation and Structural Change in an Open Economy : A CGE Analysis with Imperfect Competition and Free Entry
The economic effects of environmental taxes depend on the market structure. Under imperfect competition with free entry and exit, environmental taxes have an impact on economies of scale by changing the number and size of firms. Whether economies of scale rise or fall in a particular industry depends on induced changes in the price elasticity of demand. Because export demand is more price elastic than domestic demand, the overall price elasticity rises (falls) as the industry gains (loses) in comparative advantage. We use a computable general equilibrium model for Germany to examine the effects of a unilaterally introduced carbon tax under both perfect and imperfect competition. Our key finding is that induced structural change in favor of the less energy intensive, more labor intensive industries is more pronounced under imperfect competition than under perfect competition. At the macroeconomic level, the total costs of environmental regulation under imperfect competition can be higher or lower than those under perfect competition depending on whether aggregate gains or losses in economies of scale across imperfectly competitive sectors prevail
Distribution patterns of the early life stages of pelagic cephalopods in three geographically different regions of the Arabian Sea
The present study describes the distribution patterns of the early life stages of pelagic cephalopods in three different areas of the Arabian Sea, Indian Ocean. Specimens were collected during the Meteor-expedition to the Indian Ocean in 1987 by means of multiple opening/closing nets in the top 150m of the water column. A total of 3836 specimens were caught at 67 stations. The following taxa were prevailing: Sthenoteuthis oualaniensis (Ommastrephidae), Abralia marisarabica and Abraliopsis lineata (Enoploteuthidae), Onychoteuthis banksi (Onychoteuthidae), and Liocranchia reinhardti (Cranchiidae). While the enoploteuthid species dominated the two neritic regions (the stations grids off Oman and Pakistan), the ommastrephid and cranchiid species were most abundant in the oceanic waters of the central Arabian Sea. The geographical and vertical distribution patterns of the taxa were analyzed and are discussed along with hydro graphic features which characterized the different areas. The data provide new and important information on the spawning areas of pelagic tropical cephalopod
Molecular basis of telaprevir resistance due to V36 and T54 mutations in the NS3-4A protease of the hepatitis C virus
Structural analysis of the inhibitor Telaprevir (VX-950) of the hepatitis C virus (HCV) protease NS3-4A shows that mutations at V36 and/or T54 result in impaired interaction with VX-950, explaining the development of viral breakthrough variants
Development of a shape memory based air conditioning system
The following contribution presents a new concept of an air conditioning device based on the elastocaloric cooling effect of shape memory alloys (SMA’s). This technology provides an energy efficient and environment friendly alternative to conventional vapor compression based cooling principles. Starting from the thermodynamic investigation of the elastocaloric cooling process, a continuous operating elastocaloric air cooling device is developed. The device enables an optimized thermodynamic process control under various operating conditions as well as large temperature spans. This work presents the design process of such a system starting from SMA based heat engines to a thermodynamically optimized design of an elastocaloric air conditioning device
AI-assisted ethics? considerations of AI simulation for the ethical assessment and design of assistive technologies
Current ethical debates on the use of artificial intelligence (AI) in healthcare treat AI as a product of technology in three ways. First, by assessing risks and potential benefits of currently developed AI-enabled products with ethical checklists; second, by proposing ex ante lists of ethical values seen as relevant for the design and development of assistive technology, and third, by promoting AI technology to use moral reasoning as part of the automation process. The dominance of these three perspectives in the discourse is demonstrated by a brief summary of the literature. Subsequently, we propose a fourth approach to AI, namely, as a methodological tool to assist ethical reflection. We provide a concept of an AI-simulation informed by three separate elements: 1) stochastic human behavior models based on behavioral data for simulating realistic settings, 2) qualitative empirical data on value statements regarding internal policy, and 3) visualization components that aid in understanding the impact of changes in these variables. The potential of this approach is to inform an interdisciplinary field about anticipated ethical challenges or ethical trade-offs in concrete settings and, hence, to spark a re-evaluation of design and implementation plans. This may be particularly useful for applications that deal with extremely complex values and behavior or with limitations on the communication resources of affected persons (e.g., persons with dementia care or for care of persons with cognitive impairment). Simulation does not replace ethical reflection but does allow for detailed, context-sensitive analysis during the design process and prior to implementation. Finally, we discuss the inherently quantitative methods of analysis afforded by stochastic simulations as well as the potential for ethical discussions and how simulations with AI can improve traditional forms of thought experiments and future-oriented technology assessment
Quantitative T2 Mapping Shows Increased Degeneration in Adjacent Intervertebral Discs Following Kyphoplasty
Objective
A minimally invasive treatment of osteoporotic and nonosteoporotic thoracic and lumbar spine fractures is cement augmentation (kyphoplasty). Little is known about the impact on adjacent intervertebral discs. A quantitative magnetic resonance imaging (MRI) approach in addition to morphological MRI is desirable to evaluate changes in the intervertebral disc. Our study aims to evaluate the feasibility of T2 mapping for the detection of subtle changes in the intervertebral discs in spines after kyphoplasty.
Design
Intervertebral discs were assessed by quantitative MRI (3.0 T) using T2 relaxation time mapping. Region of interest (ROI; 6 per disc) analyses were performed. The ROIs at the anterior and posterior edges were interpreted as annulus fibrosus (AF). The 2 very inner zones were regarded as nucleus pulposus (NP) and the regions in between as intermediate transition zone. We compared T2 relaxation time values of intervertebral discs adjacent to the vertebrae after kyphoplasty with those nonadjacent to vertebrae after kyphoplasty, especially in the NP.
Results
The analysis of the ROIs showed that the intervertebral discs of the adjacent vertebral segments are associated with reduced T2 values compared to those that are nonadjacent to the affected vertebrae.
Conclusion
This study is to our knowledge the first investigation of intervertebral discs after kyphoplasty by quantitative MRI. Quantitative T2 mapping shows increased degeneration in adjacent intervertebral discs following kyphoplasty. Besides its contribution to a broader knowledge of postoperative changes after kyphoplasty, our findings may help to improve differentiation between healthy and degenerated intervertebral discs using these techniques
The role of macrophage-inducible C-type lectin in different stages of chronic liver disease
The macrophage-inducible C-type lectin (mincle) is part of the innate immune system and acts as a pattern recognition receptor for pathogen-associated molecular patterns (PAMPS) and damage-associated molecular patterns (DAMPs). Ligand binding induces mincle activation which consequently interacts with the signaling adapter Fc receptor, SYK, and NF-kappa-B. There is also evidence that mincle expressed on macrophages promotes intestinal barrier integrity. However, little is known about the role of mincle in hepatic fibrosis, especially in more advanced disease stages. Mincle expression was measured in human liver samples from cirrhotic patients and donors collected at liver transplantation and in patients undergoing bariatric surgery. Human results were confirmed in rodent models of cirrhosis and acute-on-chronic liver failure (ACLF). In these models, the role of mincle was investigated in liver samples as well as in peripheral blood monocytes (PBMC), tissues from the kidney, spleen, small intestine, and heart. Additionally, mincle activation was stimulated in experimental non-alcoholic steatohepatitis (NASH) by treatment with mincle agonist trehalose-6,6-dibehenate (TDB). In human NASH, mincle is upregulated with increased collagen production. In ApoE deficient mice fed high-fat western diet (NASH model), mincle activation significantly increases hepatic collagen production. In human cirrhosis, mincle expression is also significantly upregulated. Furthermore, mincle expression is associated with the stage of chronic liver disease. This could be confirmed in rat models of cirrhosis and ACLF. ACLF was induced by LPS injection in cirrhotic rats. While mincle expression and downstream signaling via FC receptor gamma, SYK, and NF-kappa-B are upregulated in the liver, they are downregulated in PBMCs of these rats. Although mincle expressed on macrophages might be beneficial for intestinal barrier integrity, it seems to contribute to inflammation and fibrosis once the intestinal barrier becomes leaky in advanced stages of chronic liver disease
Osteitis and synovitis, but not bone erosion, is associated with proteoglycan loss and microstructure damage in the cartilage of patients with rheumatoid arthritis
Objectives: To investigate the relation between anatomic changes of the synovium, the bone, the bone marrow and the cartilage to biochemical properties of the cartilage in patients with rheumatoid arthritis (RA).
Methods: 33 patients with RA received 3-T MRI scans of the metacarpophalangeal joints. Two independent methods, (A) the delayed gadolinium enhanced MRI of the cartilage (dGEMRIC, T2-mapping), which was used to assess the biochemical properties of the cartilage; (B) synovitis, osteitis and bone erosions were quantified according to the RA MRI scoring (RAMRIS) method and cartilage thickness (CT), interbone joint space (IBJS, distance between proximal and distal bone surface) and intercartilage joint space (ICJS, distance between proximal and distal cartilage surface) were measured.
Results: Biochemical changes of the cartilage, corresponding to low dGEMRIC and high T2 values, were more likely to be seen in joints with decreased IBJS and ICJS as well as decreased CT. For instance, dGEMRIC was directly correlated to the IBJS (p=0.001) and ICJS (p=0.001), whereas T2 mapping was inversely correlated to IBJS and ICJS (both p=0.017). Moreover, the degree of osteitis, and to some extent synovitis, was correlated to biochemical cartilage changes as measured by dGEMRIC (p=0.003) or the T2 mapping (p=0.013). By contrast, bone erosions did not correlate to the degree of biochemical cartilage changes.
Discussion: These data support the concept that synovitis and osteitis may be two main triggers for cartilage damage. Thus, the actual inflammatory state of a joint, but not so much the degree of bone erosion, appears to influence cartilage properties in RA
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