18,494 research outputs found
Geometrical interpretation of fluctuating hydrodynamics in diffusive systems
We discuss geometric formulations of hydrodynamic limits in diffusive
systems. Specifically, we describe a geometrical construction in the space of
density profiles --- the Wasserstein geometry --- which allows the
deterministic hydrodynamic evolution of the systems to be related to steepest
descent of the free energy, and show how this formulation can be related to
most probable paths of mesoscopic dissipative systems. The geometric viewpoint
is also linked to fluctuating hydrodynamics of these systems via a saddle point
argument.Comment: 19 page
Low-energy kink in the nodal dispersion of copper-oxide superconductors: Insights from Dynamical Mean Field Theory
Motivated by the observation in copper-oxide high-temperature
superconductors, we investigate the appearance of kinks in the electronic
dispersion due to coupling to phonons for a system with strong electronic
repulsion. We study a Hubbard model supplemented by an electron-phonon coupling
of Holstein type within Dynamical Mean Field Theory (DMFT) utilizing Numerical
Renormalization Group as impurity solver. Paramagnetic DMFT solutions in the
presence of large repulsion show a kink only for large values of the
electron-phonon coupling or large doping and, contrary to the
conventional electron-phonon theory, the position of such a kink can be shifted
to energies larger than the renormalized phonon frequency . When
including antiferromagnetic correlations we find a stronger effect of the
electron-phonon interaction on the electronic dispersion due to a cooperative
effect and a visible kink at , even for smaller . Our
results provide a scenario of a kink position increasing with doping, which
could be related to recent photoemission experiments on Bi-based cuprates.Comment: 10 pages, 10 figures; additional referene
Lewis acid catalyzed transfer hydromethallylation for the construction of quaternary carbon centers
The design and gramâscale synthesis of a cyclohexaâ1,4âdieneâbased surrogate of isobutene gas is reported. Using the highly electronâdeficient Lewis acid B(C6F5)3, application of this surrogate in the hydromethallylation of electronârich styrene derivatives provided sterically congested quaternary carbon centers. The reaction proceeds by C(sp3)âC(sp3) bond formation at a tertiary carbenium ion that is generated by alkene protonation. The possibility of two concurrent mechanisms is proposed on the basis of mechanistic experiments using a deuterated surrogate.TU Berlin, Open-Access-Mittel - 201
Semantic Visual Localization
Robust visual localization under a wide range of viewing conditions is a
fundamental problem in computer vision. Handling the difficult cases of this
problem is not only very challenging but also of high practical relevance,
e.g., in the context of life-long localization for augmented reality or
autonomous robots. In this paper, we propose a novel approach based on a joint
3D geometric and semantic understanding of the world, enabling it to succeed
under conditions where previous approaches failed. Our method leverages a novel
generative model for descriptor learning, trained on semantic scene completion
as an auxiliary task. The resulting 3D descriptors are robust to missing
observations by encoding high-level 3D geometric and semantic information.
Experiments on several challenging large-scale localization datasets
demonstrate reliable localization under extreme viewpoint, illumination, and
geometry changes
Public finance, trade, and development : what have we learned?
Interdependence of trade and public finance policy are important considerations in designing macroeconomic policy, public revenue policy, and public expenditure policy. A competitive real exchange rate, improved trade performance, and trade liberalization are all built on the base of sound fiscal management. Trade policies and trade liberalization may, however have a negative effect on fiscal balances, which must be considered and compensated for. Improving competitiveness and reducing protection is likely to involve reform of both trade tariffs and domestic taxation. Greater reliance on efficiently designed user charges will also help make a country more competitive internationally. Correct priorities should be set for public expenditures - whether they are rising or falling - to ensure that they are supportive of trade and of tradeable goods production.Public Sector Economics&Finance,TF054105-DONOR FUNDED OPERATION ADMINISTRATION FEE INCOME AND EXPENSE ACCOUNT,Banks&Banking Reform,Environmental Economics&Policies,Economic Theory&Research
Effect of Intraduodenal Bile and Taurodeoxycholate on Exocrine Pancreatic Secretion and on Plasma Levels of Vasoactive Intestinal Polypeptide and Somatostatin in Man
Intraduodenal (i.d.) application of bile or Na-taurodeoxycholate (TDC) dose dependently enhances basal exocrine pancreatic secretion. The hydrokinetic effect is mediated at least in part by secretin. This study should show, whether vasoactive intestinal polypeptide (VIP), a partial agonist of secretin, may also be involved in the mediation of the hydrokinetic effect. Furthermore, plasma concentrations of somatostatin-like immunoreactivity (SLI) were measured in order to check whether this counterregulating hormone is also released by bile and TDC. Twenty investigations were carried out on 10 fasting healthy volunteers provided with a double-lumen Dreiling tube. Bile and TDC were intraduodenally applied in doses of 2-6 g and 200-600 mg, respectively, at 65-min intervals. Plasma samples were withdrawn at defined intervals for radioimmunological determination of VIP and SLI. Duodenal juice was collected in 10-min fractions and analyzed for volume, pH, bicarbonate, lipase, trypsin, and amylase. I.d. application of bile or TDC dose dependently stimulated hydrokinetic and ecbolic pancreatic secretion. Bile exerted a slightly stronger effect than TDC. Pancreatic response was simultaneously accompanied by a significant increase of plasma VIP and SLI concentrations. The effect of bile on integrated plasma VIP and SLI concentrations seems to be dose dependent; the effect of TDC on integrated SLI, too. For the increase of integrated plasma VIP concentrations after TDC no dose-response relation could be established. We conclude that VIP may be a further mediator of bile-induced volume and bicarbonate secretion. The release of plasma SLI indicates that inhibitory mechanisms concomitantly are triggered by i.d. bile and TDC, as already shown during digestion for the intestinal phase of pancreatic secretion
Public Enterprises and Labor Market Performance
This paper shows that state control of some industries may have contributed to theincrease in European unemployment from the 1970s to the early 1990s. We develop asimple model with both publicly-run and privately-run enterprises and show that wheneconomic turbulence increases, higher unemployment rates may result in economies thathave a larger public sector.European Unemployment, Public Sector Employment
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