Insights into Hydration Dynamics and Cooperative Interactions in Glycerol-Water Mixtures by Terahertz Dielectric Spectroscopy.

We report relaxation dynamics of glycerol-water mixtures as probed by megahertz-to-terahertz dielectric spectroscopy in a frequency range from 50 MHz to 0.5 THz at room temperature. The dielectric relaxation spectra reveal several polarization processes at the molecular level with different time constants and dielectric strengths, providing an understanding of the hydrogen-bonding network in glycerol-water mixtures. We have determined the structure of hydration shells around glycerol molecules and the dynamics of bound water as a function of glycerol concentration in solutions using the Debye relaxation model. The experimental results show the existence of a critical glycerol concentration of ∼7.5 mol %, which is related to the number of water molecules in the hydration layer around a glycerol molecule. At higher glycerol concentrations, water molecules dispersed in a glycerol network become abundant and eventually dominate, and four distinct relaxation processes emerge in the mixtures. The relaxation dynamics and hydration structure in glycerol-water mixtures are further probed with molecular dynamics simulations, which confirm the physical picture revealed by the dielectric spectroscopy

International Lattice Data Grid

We propose the co-ordination of lattice QCD grid developments in different countries to allow transparent exchange of gauge configurations in future, should participants wish to do so. We describe briefly UKQCD's XML schema for labelling and cataloguing the data. A meeting to further develop these ideas will be held in Edinburgh on 19/20 December 2002, and will be available over AccessGrid.Comment: Lattice2002(plenary

Coherent states and related quantizations for unbounded motions

We build coherent states (CS) for unbounded motions along two different procedures. In the first one we adapt the Malkin-Manko construction for quadratic Hamiltonians to the motion of a particle in a linear potential. A generalization to arbitrary potentials is discussed. The second one extends to continuous spectrum previous constructions of action-angle coherent states in view of a consistent energy quantization

Autonomous Hybrid Ground/Aerial Mobility in Unknown Environments

Hybrid ground and aerial vehicles can possess distinct advantages over ground-only or flight-only designs in terms of energy savings and increased mobility. In this work we outline our unified framework for controls, planning, and autonomy of hybrid ground/air vehicles. Our contribution is three-fold: 1) We develop a control scheme for the control of passive two-wheeled hybrid ground/aerial vehicles. 2) We present a unified planner for both rolling and flying by leveraging differential flatness mappings. 3) We conduct experiments leveraging mapping and global planning for hybrid mobility in unknown environments, showing that hybrid mobility uses up to five times less energy than flying only

Sampling Theorem and Discrete Fourier Transform on the Riemann Sphere

Using coherent-state techniques, we prove a sampling theorem for Majorana's (holomorphic) functions on the Riemann sphere and we provide an exact reconstruction formula as a convolution product of $N$ samples and a given reconstruction kernel (a sinc-type function). We also discuss the effect of over- and under-sampling. Sample points are roots of unity, a fact which allows explicit inversion formulas for resolution and overlapping kernel operators through the theory of Circulant Matrices and Rectangular Fourier Matrices. The case of band-limited functions on the Riemann sphere, with spins up to $J$, is also considered. The connection with the standard Euler angle picture, in terms of spherical harmonics, is established through a discrete Bargmann transform.Comment: 26 latex pages. Final version published in J. Fourier Anal. App

Hemangiomes Larynges De L\'adulte A Propos De 9 Cas

L\'hémangiome laryngé de l\'adulte est extrêmement rare et présente des spécificités histologiques et évolutives. Il peut représenter un véritable défi thérapeutique. Les auteurs rapportent 9 cas d\'hémangiomes laryngés de l\'adulte colligés rétrospectivement sur une période de 20 ans (1984- 2004). Il s\'agissait de 6 hommes et 3 femmes, âgés en moyenne de 46 ans (17 à 75 ans). Les signes d\'appel étaient la dysphonie dans tous les cas, associée à des hémorragies de sang rouge extériorisées par voie buccale chez 3 patients. Le diagnostic reposait dans tous les cas sur la laryngoscopie directe qui retrouvait une tuméfaction glottique de couleur bleutée, à surface lisse. Une biopsie avec examen anatomo-pathologique a été systématique. Tous les patients ont bénéficié d\'une exérèse instrumentale de la masse par voie endoscopique, avec hémostase locale. Deux récidives ont été notées, pour lesquels une seconde exérèse instrumentale par voie endoscopique a été réalisée avec une évolution favorable. Le recul moyen était de 9 ans.The adult laryngeal hemangioma is extremely rare and presents histological and evolutionary particularities. It can represent a real therapeutic challenge. The authors report 9 cases of adult laryngeal hemangiomas over a period of 20 years (1984-2004). It was about 6 man and 3 women, old on average of 46 years ( 17 - 75 years). The signs of appeal were the dysphonia in every case, associated to bleedings of red blood exteriorized with oral way in 3 cases. Diagnosis based in every case on the direct laryngoscopy which found a glottic tumefaction of bluish colour, in smooth surface. A biopsy with anatomo-pathological exam was realized in every case. All the patients benefited from an instrumental excision of the mass by endoscopic way, with local haemostasis. Two recurrences were noted, which benefited from a second endoscopic instrumental excision, with a favorable evolution. Average follow up was of 9 years. Journal Tunisien d\'ORL et de chirurgie cervico-faciale Vol. 16 2006: pp. 5-

Multifractal scaling in the Bak-Tang-Wiesenfeld Sandpile and edge events

An analysis of moments and spectra shows that, while the distribution of avalanche areas obeys finite size scaling, that of toppling numbers is universally characterized by a full, nonlinear multifractal spectrum. Rare, large avalanches dissipating at the border influence the statistics very sensibly. Only once they are excluded from the sample, the conditional toppling distribution for given area simplifies enough to show also a well defined, multifractal scaling. The resulting picture brings to light unsuspected, novel physics in the model.Comment: 5 pages, 4 figure

Opiates Transdeactivate Chemokine Receptors: δ and μ Opiate Receptor- Mediated Heterologous Desensitization

An intact chemotactic response is vital for leukocyte trafficking and host defense. Opiates are known to exert a number of immunomodulating effects in vitro and in vivo, and we sought to determine whether they were capable of inhibiting chemokine-induced directional migration of human leukocytes, and if so, to ascertain the mechanism involved. The endogenous opioid met- enkephalin induced monocyte chemotaxis in a pertussis toxin-sensitive manner. Metenkephalin, as well as morphine, inhibited IL-8-induced chemotaxis of human neutrophils and macrophage inflammatory protein (MIP)-1α, regulated upon activation, normal T expressed and secreted (RANTES), and monocyte chemoattractant protein 1, but not MIP-1β-induced chemotaxis of human monocytes. This inhibition of chemotaxis was mediated by δ and μ but not κ G protein-coupled opiate receptors. Calcium flux induced by chemokines was unaffected by met-enkephalin pretreatment. Unlike other opiate-induced changes in leukocyte function, the inhibition of chemotaxis was not mediated by nitric oxide. Opiates induced phosphorylation of the chemokine receptors CXCR1 and CXCR2, but neither induced internalization of chemokine receptors nor perturbed chemokine binding. Thus, inhibition of chemokine-induced chemotaxis by opiates is due to heterologous desensitization through phosphorylation of chemokine receptors. This may contribute to the defects in host defense seen with opiate abuse and has important implications for immunomodulation induced by several endogenous neuropeptides which act through G protein-coupled receptors