338 research outputs found
A Simple Theory of Optimal Redistributive Taxation with Equilibrium Unemployment
We propose a canonical model of optimal nonlinear redistributive taxation with matching unemployment. In our model, agents are endowed with different skill levels and labor markets are perfectly segmented by skill. The government only observes negotiated wages. More progressive taxation leads to wage moderation that boosts labor demand. We design the optimal nonlinear redistributive tax schedule in the absence of welfare benefits and extensive labor supply margin. Compared to theire efficient values, at the optimum gross wages and unemployment are lower. Average tax rates are moreover increasing in wages. The robustness of these properties is also discussed.
A Simple Theory of Optimal Redistributive Taxation with Equilibrium Unemployment
We propose a canonical model of optimal nonlinear redistributive taxation with matching unemployment. In our model, agents are endowed with different skill levels and labor markets are perfectly segmented by skill. The government only observes negotiated wages. More progressive taxation leads to wage moderation that boosts labor demand. We design the optimal nonlinear redistributive tax schedule in the absence of welfare benefits and extensive labor supply margin. Compared to their efficient values, at the optimum gross wages and unemployment are lower. Average tax rates are moreover increasing in wages. The robustness of these properties is also discussed.optimal income taxation, unemployment, matching
A new method for the spectroscopic identification of stellar non-radial pulsation modes. II. Mode identification of the Delta Scuti star FG Virginis
We present a mode identification based on new high-resolution time-series
spectra of the non-radially pulsating Delta Scuti star FG~Vir (HD 106384, V =
6.57, A5V). From 2002 February to June a global Delta Scuti Network (DSN)
campaign, utilizing high-resolution spectroscopy and simultaneous photometry
has been conducted for FG~Vir in order to provide a theoretical pulsation
model. In this campaign we have acquired 969 Echelle spectra covering 147 hours
at six observatories. The mode identification was carried out by analyzing line
profile variations by means of the Fourier parameter fit method, where the
observational Fourier parameters across the line are fitted with theoretical
values. This method is especially well suited for determining the azimuthal
order m of non-radial pulsation modes and thus complementary with the method of
Daszynska-Daszkiewicz (2002) which does best at identifying the degree l. 15
frequencies between 9.2 and 33.5 c/d were detected spectroscopically. We
determined the azimuthal order m of 12 modes and constrained their harmonic
degree l. Only modes of low degree (l <= 4) were detected, most of them having
axisymmetric character mainly due to the relatively low projected rotational
velocity of FG Vir. The detected non-axisymmetric modes have azimuthal orders
between -2 and 1. We derived an inclination of 19 degrees, which implies an
equatorial rotational rate of 66 km/s.Comment: 14 pages, 26 figure
Darstellung und Charakterisierung neuer niedrig koordinierter, binärer Stickstoffverbindungen der Elemente Antimon und Bismut
Es wurden Schutzgruppen bezüglich ihrer sterischen und elektronischen Eigenschaften quantenchemisch untersucht. Eine Reihe von silylierten Aminostibanen wurde dargestellt und hinsichtlich einer Eliminierung untersucht. So konnte eine neue Synthese für Distibadiazane durch Silyltriflateliminierung gefunden werden. Eine Isomerisierung eines Diazidodistibadiazans führte zu einem Tetrazastibol. Des Weiteren wurde ein neuer Syntheseweg für Dibismadiazane über eine Transmetallierung entwickelt, und die bisher unbekannten Distibadiazenium und Dibismadiazeniumkationen konnten dargestellt werden
Optimal Income Taxation in an Equilibrium Unemployment Model : Mirrlees meets Pissarides
This paper characterizes optimal non-linear income taxation in an economy with a continuum of unobservable productivity levels and endogenous involuntary unemployment due to frictions in the labor markets. Redistributive taxation distorts labor demand and wages. Compared to the laissez-faire, gross wages, unemployment and participation are lower. Average tax rates are increasing. Marginal tax rates are positive, even the top. Finally, numerical simulations suggest that redistribution is much more important in our setting than in a comparable Mirrlees (1971) setting.Optimal Income Taxation; Unemployment; Wage Bargaining; Matching
Accuracy and performance of the lattice Boltzmann method with 64-bit, 32-bit, and customized 16-bit number formats
Fluid dynamics simulations with the lattice Boltzmann method (LBM) are very
memory-intensive. Alongside reduction in memory footprint, significant
performance benefits can be achieved by using FP32 (single) precision compared
to FP64 (double) precision, especially on GPUs. Here, we evaluate the
possibility to use even FP16 and Posit16 (half) precision for storing fluid
populations, while still carrying arithmetic operations in FP32. For this, we
first show that the commonly occurring number range in the LBM is a lot smaller
than the FP16 number range. Based on this observation, we develop novel 16-bit
formats - based on a modified IEEE-754 and on a modified Posit standard - that
are specifically tailored to the needs of the LBM. We then carry out an
in-depth characterization of LBM accuracy for six different test systems with
increasing complexity: Poiseuille flow, Taylor-Green vortices, Karman vortex
streets, lid-driven cavity, a microcapsule in shear flow (utilizing the
immersed-boundary method) and finally the impact of a raindrop (based on a
Volume-of-Fluid approach). We find that the difference in accuracy between FP64
and FP32 is negligible in almost all cases, and that for a large number of
cases even 16-bit is sufficient. Finally, we provide a detailed performance
analysis of all precision levels on a large number of hardware
microarchitectures and show that significant speedup is achieved with mixed
FP32/16-bit.Comment: 30 pages, 20 figures, 4 tables, 2 code listing
Dibenzazecine compounds with a novel dopamine/5HT(2A )receptor profile and 3D-QSAR analysis
BACKGROUND: Antipsychotics are divided into typical and atypical compounds based on clinical efficacy and side effects. The purpose of this study was to characterize in vitro a series of novel azecine-type compounds at human dopamine D(1)-D(5 )and 5HT(2A )receptors and to assign them to different classes according to their dopamine/5HT(2A )receptor profile. RESULTS: Regardless of using affinity data (pK(i )values at D(1)-D(5 )and 5HT(2A)) or selectivity data (15 log (K(i )ratios)), principal component analysis with azecine-type compounds, haloperidol, and clozapine revealed three groups of dopamine/5HT(2A )ligands: 1) haloperidol; 2) clozapine plus four azecine-type compounds; 3) two hydroxylated dibenzazecines. Reducing the number of K(i )ratios used for principal component analysis from 15 to two (the D(1)/D(2 )and D(2)/5HT(2A )K(i )ratios) obtained the same three groups of compounds. The most potent dibenzazecine clustering in the same group as clozapine was the non-hydroxylated LE410 which shows a slightly different D(2)-like receptor profile (D(2L )> D(3 )> D(4.4)) than clozapine (D(4.4 )> D(2L )> D(3)). The monohydroxylated dibenzacezine LE404 clusters in a separate group from clozapine/LE410 and from haloperidol and shows increased D(1 )selectivity. CONCLUSION: In conclusion, two compounds with a novel dopamine/5HT(2A )receptor profile, LE404 and LE410, with some differences in their respective D(1)/D(2 )receptor affinities including a validated pharmacophore-based 3D-QSAR model for D(1 )antagonists are presented
Microplastic fibers affect dynamics and intensity of CO2 and N2O fluxes from soil differently
Microplastics may affect soil ecosystem functioning in critical ways, with previously documented effects including changes in soil structure and water dynamics; this suggests that microbial populations and the processes they mediate could also be affected. Given the importance for global carbon and nitrogen cycle and greenhouse warming potential, we here experimentally examined potential effects of plastic microfiber additions on CO2 and N2O greenhouse gas fluxes. We carried out a fully factorial laboratory experiment with the factors presence of microplastic fibers (0.4% w/w) and addition of urea fertilizer (100 mg N kg− 1) using one target soil. The conditions in an intensively N-fertilized arable soil were simulated by adding biogas digestate at the beginning of the incubation to all samples. We continuously monitored CO2 and N2O emissions from soil before and after urea application using a custom-built flow-through steady-state system, and we assessed soil properties, including soil structure. Microplastics affected soil properties, notably increasing soil aggregate water-stability and pneumatic conductivity, and caused changes in the dynamics and overall level of emission of both gases, but in opposite directions: overall fluxes of CO2 were increased by microplastic presence, whereas N2O emission were decreased, a pattern that was intensified following urea addition. This divergent response is explained by effects of microplastic on soil structure, with the increased air permeability likely improving O2 supply: this will have stimulated CO2 production, since mineralization benefits from better aeration. Increased O2 would at the same time have inhibited denitrification, a process contributing to N2O emissions, thus likely explaining the decrease in the latter. Our results clearly suggest that microplastic consequences for greenhouse gas emissions should become an integral part of future impact assessments, and that to understand such responses, soil structure should be assessed
Patterns among Patients with Chronic Pruritus: A Retrospective Analysis of 170 Patients.
Chronic pruritus profoundly affects patients' quality of life. The objective of this retrospective cross-sectional study was to characterize patients with chronic pruritus and identify patterns, in order to delineate a better diagnostic approach. Both semantic connectivity map and classical analysis were applied, linking demographic, clinical, laboratory and histopathological data with clinical and aetiological categories of 170 patients with chronic pruritus (median age 72 years, 58.2% women). The semantic map showed clinical categories separated in different hubs associated with distinct patterns concerning sex, aetiology, laboratory findings, and pharmacological treatment. Diabetes, diagnosis of cancer and psychiatric comorbidities were linked with certain clinical categories. Skin eosinophilia was a common finding of chronic pruritus, on both diseased and non-diseased skin. High frequencies of patients with chronic pruritus taking anti-arrhythmics, beta-blockers and AT-II receptor antagonists were noticed among those with underlying systemic, neurological and psychiatric diseases. This study provides a complex analysis of chronic pruritus and thus basic principles for a clinical work-up
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