330 research outputs found

    The Foster-Hart Measure of Riskiness for General Gambles

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    Foster and Hart proposed an operational measure of riskiness for discrete random variables. We show that their defining equation has no solution for many common continuous distributions including many uniform distributions, e.g. We show how to extend consistently the definition of riskiness to continuous random variables. For many continuous random variables, the risk measure is equal to the worst--case risk measure, i.e. the maximal possible loss incurred by that gamble. We also extend the Foster--Hart risk measure to dynamic environments for general distributions and probability spaces, and we show that the extended measure avoids bankruptcy in infinitely repeated gambles

    Large and influential: firm size and governments' corporate tax rate choice?

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    Theory suggests that large firms are more likely to engage in lobbying behaviour and have better bargaining positions against their host governments than smaller entities. Conditional on jurisdiction size, public policy choices are thus predicted to depend on the shape of a jurisdiction's firm size distribution, with more business-friendly policies being enacted if economic activity is concentrated in a small number of entities. We empirically assess this prediction studying local business tax choices of German municipalities. Exploiting rich and quasi-experimental variation in localities' firm size structures, we find evidence for an inverse relationship between the concentration of economic activity and communities' business tax choices. The effect is statistically significant and quantitatively relevant, suggesting that the rising importance of large businesses may trigger shifts towards a more business-friendly design of (tax) policies

    A combined quantum-chemical and matrix-isolation study on molecular manganese fluorides

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    Molecular manganese fluorides were studied using quantum-chemical calculations at DFT and CCSD(T) levels and experimentally by matrix-isolation techniques. They were prepared by co-deposition of IR-laser ablated elemental manganese or manganese trifluoride with F2 in an excess of Ne, Ar, or N2 or with neat F2 at 5–12 K. New IR bands in the Mn–F stretching region are detected and assigned to matrix-isolated molecular MnFx (x = 1–3)

    A Dynamic Extension of the Foster-Hart Measure of Riskiness

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    Hellmann T, Riedel F. A Dynamic Extension of the Foster-Hart Measure of Riskiness. Center for Mathematical Economics Working Papers. Vol 528. Bielefeld: Center for Mathematical Economics; 2014.We analyze the Foster-Hart measure of riskiness for general dis- tributions in dynamic settings. The Foster-Hart measure avoids bankruptcy in the long run. It is not time-consistent

    Outcomes of stable and unstable patterns of subjective cognitive decline: results from the Leipzig Longitudinal Study of the Aged (LEILA75+)

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    Background: Subjective cognitive decline (SCD), i.e., the self-perceived feeling of worsening cognitive function, may be the first notable syndrome of preclinical Alzheimer’s disease and other dementias. However, not all individuals with SCD progress. Stability of SCD, i.e., repeated reports of SCD, could contribute to identify individuals at risk, as stable SCD may more likely reflect the continuous neurodegenerative process of Alzheimer’s and other dementias. Methods: Cox regression analyses were used to assess the association between stability of SCD and progression to MCI and dementia in data derived from the population-based Leipzig Longitudinal Study of the Aged (LEILA75+). Results: Of 453 cognitively unimpaired individuals with a mean age of 80.5 years (SD = 4.2), 139 (30.7 %) reported SCD at baseline. Over the study period (M = 4.8 years, SD = 2.2), 84 (18.5 %) individuals had stable SCD, 195 (43.1 %) unstable SCD and 174 (38.4 %) never reported SCD. Stable SCD was associated with increased risk of progression to MCI and dementia (unadjusted HR = 1.8, 95 % CI = 1.2–2.6; p < .01), whereas unstable SCD yielded a decreased progression risk (unadjusted HR = 0.5, 95 % CI = 0.4–0.7; p < .001) compared to no SCD. When adjusted for baseline cognitive functioning, progression risk in individuals with stable SCD was significantly increased in comparison to individuals with unstable SCD, but not compared to individuals without SCD. Conclusions: Our results, though preliminary, suggest that stable SCD, i.e., repeated reports of SCD, may yield an increased risk of progression to MCI and dementia compared to unstable SCD. Baseline cognitive scores, though within a normal range, seem to be a driver of progression in stable SCD. Future research is warranted to investigate whether stability could hold as a SCD research feature

    Open Energy Services -- Forecasting and Optimization as a Service for Energy Management Applications at Scale

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    Energy management, in sense of computing optimized operation schedules for devices, will likely play a vital role in future carbon neutral energy systems, as it allows unlocking energy efficiency and flexibility potentials. However, energy management systems need to be applied at large scales to realize the desired effect, which clearly requires minimization of costs for setup and operation of the individual applications. In order to push the latter forward, we promote an approach to split the complex optimization algorithms employed by energy management systems into standardized components, which can be provided as a service with marginal costs at scale. This work is centered around the systematic design of a framework supporting the efficient implementation and operation of such forecasting and optimization services. Furthermore, it describes the implementation of the design concept which we release under the name \emph{Energy Service Generics} as a free and open source repository. Finally, this paper marks the starting point of the \emph{Open Energy Services} community, our effort to continuously push the development and operation of services for energy management applications at scale, for which we invite researchers and practitioners to participate

    The Impact of the COVID-19 Pandemic on Avoidance of Health Care, Symptom Severity, and Mental Well-Being in Patients With Coronary Artery Disease

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    The COVID-19 pandemic affected regular health care for patients with chronic diseases. However, the impact of the pandemic on primary care for patients with coronary artery disease (CAD) who are enrolled in a structured disease management program (DMP) in Germany is not clear. We investigated whether the pandemic affected primary care and health outcomes of DMP-CAD patients (n = 750) by using a questionnaire assessing patients’ utilization of medical care, CAD symptoms, as well as health behavior and mental health since March 2020. We found that out of concern about getting infected with COVID-19, 9.1% of the patients did not consult a medical practitioner despite having CAD symptoms. Perceived own influence on infection risk was lower and anxiety was higher in these patients compared to symptomatic CAD patients who consulted a physician. Among the patients who reported chest pain lasting longer than 30 min, one third did not consult a medical practitioner subsequently. These patients were generally more worried about COVID-19. Patients with at least one worsening CAD symptom (chest pain, dyspnea, perspiration, or nausea without apparent reason) since the pandemic showed more depressive symptoms, higher anxiety scores, and were less likely to consult a doctor despite having CAD symptoms out of fear of infection. Our results provide evidence that the majority of patients received sufficient medical care during the COVID-19 pandemic in Germany. However, one in ten patients could be considered particularly at risk for medical undersupply and adverse health outcomes. The perceived infection risk with COVID-19 might have facilitated the decision not to consult a medical doctor

    Testing the differential adhesion hypothesis across the epithelial− mesenchymal transition

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    Weanalyze the mechanical properties of three epithelial/mesenchymal cell lines (MCF-10A, MDAMB- 231, MDA-MB-436) that exhibit a shift in E-, N- and P-cadherin levels characteristic of an epithelial−mesenchymal transition associated with processes such as metastasis, to quantify the role of cell cohesion in cell sorting and compartmentalization. Wedevelop a unique set of methods to measure cell–cell adhesiveness, cell stiffness and cell shapes, and compare the results to predictions from cell sorting in mixtures of cell populations.Wefind that the final sorted state is extremely robust among all three cell lines independent of epithelial or mesenchymal state, suggesting that cell sorting may play an important role in organization and boundary formation in tumours.Wefind that surface densities of adhesive molecules do not correlate with measured cell–cell adhesion, but do correlate with cell shapes, cell stiffness and the rate at which cells sort, in accordance with an extended version of the differential adhesion hypothesis (DAH). Surprisingly, theDAHdoes not correctly predict the final sorted state. This suggests that these tissues are not behaving as immiscible fluids, and that dynamical effects such as directional motility, friction and jamming may play an important role in tissue compartmentalization across the epithelial−mesenchymal transition

    The Candida albicans quorum-sensing molecule farnesol alters sphingolipid metabolism in human monocyte-derived dendritic cells

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    Candida albicans, an opportunistic fungal pathogen, produces the quorum-sensing molecule farnesol, which we have shown alters the transcriptional response and phenotype of human monocyte-derived dendritic cells (DCs), including their cytokine secretion and ability to prime T cells. This is partially dependent on the nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR-γ), which has numerous ligands, including the sphingolipid metabolite sphingosine 1-phosphate. Sphingolipids are a vital component of membranes that affect membrane protein arrangement and phagocytosis of C. albicans by DCs. Thus, we quantified sphingolipid metabolites in monocytes differentiating into DCs by High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Farnesol increased the activity of serine palmitoyltransferase, leading to increased levels of 3-keto-dihydrosphingosine, dihydrosphingosine, and dihydrosphingosine 1-phosphate and inhibited dihydroceramide desaturase by inducing oxidative stress, leading to increased levels of dihydroceramide and dihydrosphingomyelin species and reduced ceramide levels. Accumulation of dihydroceramides can inhibit mitochondrial function; accordingly, farnesol reduced mitochondrial respiration. Dihydroceramide desaturase inhibition increases lipid droplet formation, which we observed in farnesol-treated cells, coupled with an increase in intracellular triacylglycerol species. Furthermore, inhibition of dihydroceramide desaturase with either farnesol or specific inhibitors impaired the ability of DCs to prime interferon-γ-producing T cells. The effect of farnesol on sphingolipid metabolism, triacylglycerol synthesis, and mitochondrial respiration was not dependent on PPAR-γ. In summary, our data reveal novel effects of farnesol on sphingolipid metabolism, neutral lipid synthesis, and mitochondrial function in DCs that affect their instruction of T cell cytokine secretion, indicating that C. albicans can manipulate host cell metabolism via farnesol secretion
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