Adaptive estimation of the hazard rate with multiplicative censoring

We propose an adaptive estimation procedure of the hazard rate of a random variable X in the multiplicative censoring model, Y = XU , with U ∼ U([0, 1]) independent of X. The variable X is not directly observed: an estimator is built from a sample {Y1, ..., Yn} of copies of Y. It is obtained by minimisation of a contrast function over a class of general nested function spaces which can be generated e.g. by splines functions. The dimension of the space is selected by a penalised contrast criterion. The final estimator is proved to achieve the best bias-variance compromise and to reach the same convergence rate as the oracle estimator under conditions on the maximal dimension. The good behavior of the resulting estimator is illustrated over a simulation study

Salsolinol Facilitates Glutamatergic Transmission to Dopamine Neurons in the Posterior Ventral Tegmental Area of Rats

Although in vivo evidence indicates that salsolinol, the condensation product of acetaldehyde and dopamine, has properties that may contribute to alcohol abuse, the underlying mechanisms have not been fully elucidated. We have reported previously that salsolinol stimulates dopamine neurons in the posterior ventral tegmental area (p-VTA) partly by reducing inhibitory GABAergic transmission, and that ethanol increases glutamatergic transmission to VTA-dopamine neurons via the activation of dopamine D1 receptors (D1Rs). In this study, we tested the hypothesis that salsolinol stimulates dopamine neurons involving activation of D1Rs. By using whole-cell recordings on p-VTA-dopamine neurons in acute brain slices of rats, we found that salsolinol-induced increase in spike frequency of dopamine neurons was substantially attenuated by DL-2-amino-5-phosphono-valeric acid and 6, 7-dinitroquinoxaline-2, 3-dione, the antagonists of glutamatergic N-Methyl-D-aspartic acid and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors. Moreover, salsolinol increased the amplitude of evoked excitatory postsynaptic currents (EPSCs) and the frequency but not the amplitude of spontaneous EPSCs. Additionally, SKF83566, a D1R antagonist attenuated the salsolinol-induced facilitation of EPSCs and of spontaneous firing of dopamine neurons. Our data reveal that salsolinol enhances glutamatergic transmission onto dopamine neurons via activation of D1Rs at the glutamatergic afferents in dopamine neurons, which contributes to salsolinol's stimulating effect on p-VTA dopamine neurons. This appears to be a novel mechanism which contributes toward rewarding properties of salsolinol

Projecting the Medium-Term: Outcomes and Errors for GDP Growth

The focus of this paper is the evaluation of a very popular method for potential output estimation and medium-term forecasting - the production function approach - in terms of predictive performance. For this purpose, a forecast evaluation for the three to five years ahead predictions of GDP growth for the individual G7 countries is conducted. To carry out the forecast performance check a particular testing framework is derived that allows the computation of robust test statistics given the specific nature of the generated out-of sample forecasts. In addition, medium-term GDP projections from national and international institutions are examined and it is assessed whether these projections convey a reliable view about future economic developments and whether there is scope for improving their predictive content

Adaptive estimation of the hazard rate with multiplicative censoring

We propose an adaptive estimation procedure of the hazard rate of a random variable X in the multiplicative censoring model, Y = XU , with U ∼ U([0, 1]) independent of X. The variable X is not directly observed: an estimator is built from a sample {Y1, ..., Yn} of copies of Y. It is obtained by minimisation of a contrast function over a class of general nested function spaces which can be generated e.g. by splines functions. The dimension of the space is selected by a penalised contrast criterion. The final estimator is proved to achieve the best bias-variance compromise and to reach the same convergence rate as the oracle estimator under conditions on the maximal dimension. The good behavior of the resulting estimator is illustrated over a simulation study

La codification en Belgique :le droit de la consommation dans le nouveau Code de droit économique: in n L. Arcelin Lécuyer (éd.), Quels moyens pour un droit de la consommation effectif et efficace à l’ère numérique ?

Cet article, rédigé suite à un colloque international tenu à l’Université de La Rochelle le 10 octobre 2014 ( intervention consultable ici :http://portail-video.univ-lr.fr/La-pertinence-d-un-code-de-la), a pour objet de montrer et analyser l’approche suivie en droit belge dans le domaine de la codification du droit de la consommation. Cette approche a plusieurs particularités :au contraire de pays comme l’Allemagne, les Pays-Bas ou l’Autriche, la Belgique a d’emblée régi le droit de la consommation en-dehors Code civil ;mais, par ailleurs, au contraire d’autres Etats membres de l’Union européenne, comme la France, elle n’a pas non plus fait le choix de l’adoption d’un Code propre au droit de la consommation. Depuis l’origine (récente) de ce droit en Belgique, le législateur régit en un seul corps de texte le droit de la concurrence déloyale (les normes de loyauté dans les rapports entre professionnels), d’une part, et le droit de la consommation (normes d’information et de protection des consommateurs), de l’autre, ce qui présente des avantages mais pose aussi des problèmes aigus lors de la transposition des directives européennes lorsque celles-ci ne concernent que le droit de la consommation.info:eu-repo/semantics/publishe

Dopaminergic transmission in STOP null mice.

International audienceNeuroleptics are thought to exert their anti-psychotic effects by counteracting a hyper-dopaminergic transmission. Here, we have examined the dopaminergic status of STOP (stable tubule only polypeptide) null mice, which lack a microtubule-stabilizing protein and which display neuroleptic-sensitive behavioural disorders. Dopamine transmission was investigated using both behavioural analysis and measurements of dopamine efflux in different conditions. Compared to wild-type mice in basal conditions or following mild stress, STOP null mice showed a hyper-locomotor activity, which was erased by neuroleptic treatment, and an increased locomotor reactivity to amphetamine. Such a behavioural profile is indicative of an increased dopaminergic transmission. In STOP null mice, the basal dopamine concentrations, measured by quantitative microdialysis, were normal in both the nucleus accumbens and the striatum. When measured by electrochemical techniques, the dopamine efflux evoked by electrical stimulations mimicking physiological stimuli was dramatically increased in the nucleus accumbens of STOP null mice, apparently due to an increased dopamine release, whereas dopaminergic uptake and auto-inhibition mechanisms were normal. In contrast, dopamine effluxes were slightly diminished in the striatum. Together with previous results, the present study indicates the association in STOP null mice of hippocampal hypo-glutamatergy and of limbic hyper-dopaminergy. Such neurotransmission defects are thought to be central to mental diseases such as schizophrenia