Semiactive backstepping control for vibration attenuation in structures equipped with magnetorheological actuatorscat

This paper deals with the problem of semiactive vibration control of civil engineering structures subject to unknown external disturbances (for example, earthquakes, winds, etc.). Two kinds of semiactive controllers are proposed based on the backstepping control technique. The experimental setup used is a 6-story test structure equipped with shear-mode semiactive magnetorheological dampers being installed in the Washington University Structural Control and Earthquake Engineering Laboratory (WUSCEEL). The experimental results obtained have verified the effectiveness of the proposed control algorithms

Attenuation of nicotine-induced antinociception, rewarding effects, and dependence in mu-opioid receptor knock-out mice

The involvement of μ-opioid receptors in different behavioral responses elicited by nicotine was explored by using μ-opioid receptor knock-out mice. The acute antinociceptive responses induced by nicotine in the tail-immersion and hot-plate tests were reduced in the mutant mice, whereas no difference between genotypes was observed in the locomotor responses. The rewarding effects induced by nicotine were then investigated using the conditioning place-preference paradigm. Nicotine produced rewarding responses in wild-type mice but failed to produce place preference in knock-out mice, indicating the inability of this drug to induce rewarding effects in the absence of μ-opioid receptors. Finally, the somatic expression of the nicotine withdrawal syndrome, precipitated in dependent mice by the injection of mecamylamine, was evaluated. Nicotine withdrawal was significantly attenuated in knock-out mutants when compared with wild-type mice. In summary, the present results show that μ-opioid receptors are involved in the rewarding responses induced by nicotine and participate in its antinociceptive responses and the expression of nicotine physical dependence.

Per què els castellanoparlants no miren TV3? Proposta de recerca sobre gust televisiu: anàlisi de textos i receptors

Amb l’objectiu d’orientar una futura tesi doctoral, aquest treball de recerca planteja una investigació sobre audiència televisiva a Catalunya. A partir de les aportacions fetes pels investigadors del camp, tant a nivell empíric com teòric, es dissenya una metodologia d’anàlisi del text i la recepció per tractar de donar resposta a un fenomen particular: la poca presència de públiccastellanoparlant en l’audiència de TV3, la televisió pública catalana. Sota elparaigües del construccionisme social moderat, la recerca dissenya unes hipòtesis relacionades amb la distància percebuda respecte de la cadena, el gust televisiu i les característiques enunciatives dels missatges televisius, i planteja donar-hi resposta a partir de l’anàlisi de l’enunciació de les principals cadenes generalistes que emeten a Catalunya, per una banda, i amb la realització d’entrevistes i grups de discussió amb una mostra d’espectadors, per l’altra.

Maximum-likelihood estimation of specific differential phase and attenuation in rain

Precise estimation of propagation parameters inprecipitation media is of interest to improve the performanceof communications systems and in remote sensing applications.In this paper, we present maximum-likelihood estimators ofspecific attenuation and specific differential phase in rain. Themodel used for obtaining the cited estimators assumes coherentpropagation, reflection symmetry of the medium, and Gaussianstatistics of the scattering matrix measurements. No assumptionsabout the microphysical properties of the medium are needed.The performance of the estimators is evaluated through simulateddata. Results show negligible estimators bias and variances closeto Cramer–Rao bounds.