743 research outputs found

    A trace formula for the quantization of coadjoint orbits

    Full text link
    The main goal of this paper is to compute the characteristic class of the Alekseev-Lachowska *-product on coadjoint orbits. We deduce an analogue of the Weyl dimension formula in the context of deformation quantization

    On the 1/c Expansion of f(R) Gravity

    Full text link
    We derive for applications to isolated systems - on the scale of the Solar System - the first relativistic terms in the 1/c1/c expansion of the space time metric gμνg_{\mu\nu} for metric f(R)f(R) gravity theories, where ff is assumed to be analytic at R=0R=0. For our purpose it suffices to take into account up to quadratic terms in the expansion of f(R)f(R), thus we can approximate f(R)=R+aR2f(R) = R + aR^2 with a positive dimensional parameter aa. In the non-relativistic limit, we get an additional Yukawa correction with coupling strength G/3G/3 and Compton wave length 6a\sqrt{6a} to the Newtonian potential, which is a known result in the literature. As an application, we derive to the same order the correction to the geodetic precession of a gyroscope in a gravitational field and the precession of binary pulsars. The result of the Gravity Probe B experiment yields the limit a5×1011m2a \lesssim 5 \times 10^{11} \, \mathrm{m}^2, whereas for the pulsar B in the PSR J0737-3039 system we get a bound which is about 10410^4 times larger. On the other hand the E\"ot-Wash experiment provides the best laboratory bound a1010m2a \lesssim 10^{-10} \, \mathrm{m}^2. Although the former bounds from geodesic precession are much larger than the laboratory ones, they are still meaningful in the case some type of chameleon effect is present and thus the effective values could be different at different length scales.Comment: 11 pages, accepted for publication in Physical Review

    The Role of Equality and Equity in Social Preferences

    Get PDF
    Engelmann and Strobel (AER 2004) question the relevance of inequity aversion in simple dictator game experiments claiming that a combination of a preference for efficiency and a Rawlsian motive for helping the least well-off is more important than inequity aversion. We show that these results are partly based on a strong subject pool effect. The participants of the E&S experiments were undergraduate students of economics and business administration who self-selected into their field of study (economics) and learned in the first semester that efficiency is desirable. We show that for non-economists the preference for efficiency is much less pronounced. We also find a non-negligible gender effect indicating that women are more egalitarian than men. However, perhaps surprisingly, the dominance of equality over efficiency is unrelated to political attitudes

    Julien du Bouchet

    Get PDF

    Satzarten unterscheiden - Kann das der Computer? Syntaktische Explorationen anhand von COSMAS II

    Get PDF
    Is the computer capable of recognizing different sentence types in a linguistic corpus such as COSMAS II (Mannheim), which has not been previously treated by a tagger or a parser? The answer is in fact no. However, in the present article it is shown that under certain circumstances an automatic distinction is nevertheless possible. Making use of a procedure that we have called Anfragezuspitzung (literally: making a query pointed; encirclement of a grammatical phenomenon by a combination of several specific queries), and taking as a starting point philological prior knowledge that has been gathered "by hand", it proves to be perfectly possible to arrive at a satisfactory result. With the example of sentence types in German, in particular the distinction between interrogative and exclamatory sentences, we demonstrate in this article that such a distinction can be carried out automatically with a high degree of accuracy, e.g. the distinction between War das eine gute Idee? (Was this a good idea?) and War das eine gute Idee! (What a good idea this was!)

    Pharmacokinetics and analgesic potency of [Delta]9-tetrahydrocannabinol (THC)

    Get PDF
    It is known from the folk medicine that Cannabis may reduce pain. The aim of the pain study was to compare analgesic effects of oral delta-9-tetrahydrocannabinol (THC, dronabinol, Marinol‚, main psychoactive component of the Cannabis plant) and a THC-morphine combination to morphine and placebo. This pain study was performed with 12 healthy volunteers in four different experimental models of acute pain. Additionally, side effects and vital functions were monitored and blood samples collected for the pharmacokinetic profiling of oral THC. In none of the pain models THC showed a significant analgesic effect. The THC-morphine combination showed a slight tendency to an additive effect compared to morphine alone, but this was not statistically significant. The side effects observed with THC were mainly sleepiness and mild to intermediate psychotropic side effects. The plasma concentrations of THC, analysed with gas chromatography mass-spectrometry, were very low, showed a plasma peak time of 60 to 120 min with high inter-individual variation. In addition, an extensive liver first pass metabolism could be observed leading to high metabolite-THC ratios. In the second part of the present work the aim was to develop an application form as alternative to the Marinol‚ capsules. The very lipophilic THC was solubilised with Cremophor‚ RH 40 leading to a water-soluble THC formulation, which could be used as inhalation solution for the pulmonal administration of THC. This formulation underwent an in vitro quality assurance focussing on stability and physiological tolerability. Additionally, the particle size of the droplets in the aerosol and the output rate of the evaluated nebuliser system for the clinical application were determined. In the third part of this work, the developed application form (inhalation solution) was used for a second clinical study with eight healthy volunteers. The pharmacokinetic properties of pulmonal THC were compared to intravenous THC and the analgesic effects were determined comparing with pulmonal placebo. With the pulmonal application form the very low bioavailability of oral THC could be increased up to 6-fold. Comparing the elimination half-lives, a 5-fold decrease of the half-life after pulmonal and intravenous THC compared to oral THC was observed, indicating that absorption is the time-determining step in the pharmacokinetic behaviour of orally administered THC. This was also reflected by the peak plasma concentration time, which occurred right at the end of the inhalation procedure of about 20 min (3 to 6-times earlier than with oral THC). Peak plasma concentrations were much higher after pulmonal than oral administration causing much less side effects, indicating that not only THC itself is responsible for the psychotropic side effects but also the known strongly psychoactive 11-hydroxy-THC. Metabolite-THC ratios were found to be much lower after pulmonal and intravenous THC than after oral THC. The most prominent side effect of pulmonal THC was the irritation of the throat and coughing during the inhalation, which were reversible within short time after finishing the inhalation procedure. Despite the increased bioavailability of pulmonal THC no analgesic effect resulted, suggesting that the bioavailability does not affect the efficacy in the pain reducing properties of THC. We assume that the used experimental pain models, which were all models of acute pain, were not appropriate to study the analgesic properties of THC. Further experiments are needed to evaluate the appropriate pain tests for THC and healthy subjects. In addition, it would be very interesting to investigate the analgesic effect of the pulmonal THC in patients suffering from chronic and neuropathic pain

    The Compatibility of the Swedish Alcohol Monopoly with EC Law

    Get PDF
    Sweden has traditionally pursued a restrictive policy on alcohol. One of the fundamental and outstanding features of this policy is the monopolization of the retail sales of alcoholic beverages. Spirits, wine and beer with an alcohol content of more than 3.5 per cent by volume may only be sold by the State-owned Systembolaget AB. The products available in Systembolaget's shops are selected and purchased centrally, based on their price-quality ratio and a 'blind test' carried out by Systembolaget's tasters. The products that are eventually purchased must then reach a certain sales volume during an introductory period, failing which they will not be included in Systembolaget's basic assortment. Similarly, products that are included in this assortment will be dropped if their sales fail to reach a certain volume. In 1997 the European Court of Justice had the opportunity to pronounce on the compatibility of Systembolaget's monopoly in the so-called Franzén case. The owner of a food shop had unlawfully sold wine in his shop and maintained that the statutory monopoly was contrary to the Community rules on the free movement of goods. To the surprise of most lawyers, the monopoly was upheld by the Court. What was particularly surprising was the Court's approach regarding the applicability of Art. 28 EC. It held that Art. 31 EC was «specifically applicable to the exercise, by a domestic monopoly, of its exclusive rights Case C-189/95, para. 35.» and refused to examine the monopoly under Art. 28 EC. This approach was totally at odds not only with the opinion of the Advocate General, but also with the Court's previous cas-law and even with the judgements in the energy monopoly cases, which were handed down on the very same day. The Court's judgement was far from convincing on a number of points. First of all, the Court did not state whether Franzén marked a general change of direction in its case-law concerning Art. 28 EC or whether that Article would continue to be applicable to State monopolies of a commercial character. To deny the applicability of Art. 28 EC to State monopolies, however, would lead to the paradox result that such monopolies are privileged over less harmful obstacles to the free movement of goods. While Art. 28 EC prohibits all kinds of quantitative restrictions, Art. 31 EC only forbids discriminative measures. If, however, it was not the Court's intention to exclude the applicability of Art. 28 EC in general, the question remains why it did not apply that Article to Systembolaget's monopoly. Had an examination under Art. 28 EC taken place, the Court would in all likelyhood have come to the conclusion that the monopoly constituted a measure having equivalent effect to quantitative restrictions and was therefore prohibited under Community law. Moreover, the Court only examined whether the rules governing Systembolaget's monopoly were applied in a discriminatory manner. If, what should have happened, it had examined whether these rules excluded any possibility of discrimination, the outcome of the case might well have been a different one. Some commentators have therefore seen Franzén as a mainly politically motivated judgement. The judges, they argue, may have been deeply split in their opinions and did not want to take a decision against a Member State in such a sensitive political field without having a clear majority. Franzén should therefore be interpreted as a judgement based solely on its particular facts and circumstances and does not prejudice the outcome of further legal actions against the Swedish alcohol monopoly. While the Court in Franzén focused its assessment on the free movement rules, it is clear that other provisions of the Treaty may be equally applicable to the monopoly. From a competition law perspective, Art. 82 and 86 EC are of a particular relevance. As a monopoly undertaking, Systembolaget clearly holds a dominant position on the retail market for alcoholic beverages, which it may not abuse. Moreover, the State may not create a situation in which Systembolaget cannot avoid abusing this position. The main purpose behind the Swedish alcohol monopoly is the limitation of the sales of alcoholic beverages. This is to be achieved, inter alia, by the limitation of the accessibility of such beverages. It is therefore not Systembolaget's purpose to satisfy the actual demand for alcoholic beverages. On the contrary, the rules governing Systembolaget's activities are designed to render the access to such products more difficult. In practice, this is achieved by limiting Systembolaget's sales network to 417 shops and 570 agents, through which alcoholic beverages can be ordered. Several factors indicate that this sales network is not apt to satisfy the actual demand for such products. By reserving the retail sale of alcoholic beverages to Systembolaget and by imposing restrictive rules on that company, th Swedish State has therefore left Systembolaget in a position where it cannot avoid abusing its dominant position. In summary, it must be held that the Swedish statutory rules on the retail sale of alcoholic beverages are contrary to both Art. 28 and 31 EC as well as Art. 86 in connection with Art. 82 EC

    Distributional Random Forests: Heterogeneity Adjustment and Multivariate Distributional Regression

    Full text link
    Random Forests (Breiman, 2001) is a successful and widely used regression and classification algorithm. Part of its appeal and reason for its versatility is its (implicit) construction of a kernel-type weighting function on training data, which can also be used for targets other than the original mean estimation. We propose a novel forest construction for multivariate responses based on their joint conditional distribution, independent of the estimation target and the data model. It uses a new splitting criterion based on the MMD distributional metric, which is suitable for detecting heterogeneity in multivariate distributions. The induced weights define an estimate of the full conditional distribution, which in turn can be used for arbitrary and potentially complicated targets of interest. The method is very versatile and convenient to use, as we illustrate on a wide range of examples. The code is available as Python and R packages drf
    corecore