Growth properties of Fourier transforms via moduli of continuity

We obtain new inequalities for the Fourier transform, both on Euclidean space, and on non-compact, rank one symmetric spaces. In both cases these are expressed as a gauge on the size of the transform in terms of a suitable integral modulus of continuity of the function. In all settings, the results present a natural corollary: a quantitative form of the Riemann-Lebesgue lemma. A prototype is given in one-dimensional Fourier analysis.     

Theory of phase-ordering kinetics

The theory of phase-ordering dynamics, that is the growth of order through domain coarsening when a system is quenched from the homogeneous phase into a broken-symmetry phase, is reviewed, with the emphasis on recent developments. Interest will focus on the scaling regime that develops at long times after the quench. How can one determine the growth laws that describe the time dependence of characteristic length scales, and what can be said about the form of the associated scaling functions? Particular attention will be paid to systems described by more complicated order parameters than the simple scalars usually considered, for example vector and tensor fields. The latter are needed, for example, to describe phase ordering in nematic liquid crystals, on which there have been a number of recent experiments. The study of topological defects (domain walls, vortices, strings and monopoles) provides a unifying framework for discussing coarsening in these different systems.     

Understanding fluxes as media for directed synthesis: in situ local structure of molten potassium polysulfides

Rational exploratory synthesis of new materials requires routes to discover novel phases and systematic methods to tailor their structures and properties. Synthetic reactions in molten fluxes have proven to be an excellent route to new inorganic materials because they promote diffusion and can serve as an additional reactant, but little is known about the mechanisms of compound formation, crystal precipitation, or behavior of fluxes themselves at conditions relevant to synthesis. In this study we examine the properties of a salt flux system that has proven extremely fertile for growth of new materials: the potassium polysulfides spanning K(2)S(3) and K(2)S(5), which melt between 302 and 206 °C. We present in situ Raman spectroscopy of melts between K(2)S(3) and K(2)S(5) and find strong coupling between n in K(2)S(n) and the molten local structure, implying that the S(n)(2-) chains in the crystalline state are mirrored in the melt. In any reactive flux system, K(2)S(n) included, a signature of changing species in the melt implies that their evolution during a reaction can be characterized and eventually controlled for selective formation of compounds. We use in situ X-ray total scattering to obtain the pair distribution function of molten K(2)S(5) and model the length of S(n)(2-) chains in the melt using reverse Monte Carlo simulations. Combining in situ Raman and total scattering provides a path to understanding the behavior of reactive media and should be broadly applied for more informed, targeted synthesis of compounds in a wide variety of inorganic fluxes.     

Ultrastructural study of spermiogenesis and the spermatozoon of Cavisoma magnum (Southwell, 1927) (Acanthocephala, Palaeacanthocephala, Cavisomidae), from Siganus lineatus (Pisces, Teleostei, Siganidae) (Valenciennes, 1835) in New Caledonia

This paper presents an ultrastructural study of Cavisoma magnum (Acanthocephala, Cavisomatidae) with a Transmission Electron Microscopy tool. This parasite of the fish Siganus lineatus is here reported for the first time from off New Caledonia, South Pacific. It is the first study describing the ultrastructure, spermiogenesis and spermatozoon of a species of the family Cavisomatidae. The young spermatid of C. magnum possesses a centriole constituted of doublets without a central element. After the elaboration of a flagellum of 9+2 pattern, the centriole migrates in a nuclear groove. Then the flagellum migration occurs and gives rise to a spermatozoon. The distribution and the size of the protein granules are reported and the posterior extremity appears like a chromatin lamina wave. Comparative ultrastructural data are presented on sperm and spermiogenesis of the Acanthocephala and Rotifers examined to date and the phylogenetic implications are discussed.     

Towards antihydrogen trapping and spectroscopy at ALPHA

Spectroscopy of antihydrogen has the potential to yield high-precision tests of the CPT theorem and shed light on the matter-antimatter imbalance in the Universe. The ALPHA antihydrogen trap at CERN??s Antiproton Decelerator aims to prepare a sample of antihydrogen atoms confined in an octupole-based Ioffe trap and to measure the frequency of several atomic transitions. We describe our techniques to directly measure the antiproton temperature and a new technique to cool them to below 10 K. We also show how our unique position-sensitive annihilation detector provides us with a highly sensitive method of identifying antiproton annihilations and effectively rejecting the cosmic-ray background.     

Experimental determination of the scattering length for positron scattering from krypton

We report the first experimentally supported determination of the scattering length for positron scattering from krypton. Our result of  ?10.3 ± 1.5 a.u. compares favourably with that from a convergent close coupling calculation performed as a part of this investigation (?9.5 a.u.), and also with an earlier many body theory calculation of  ?10.1 a.u. from Gribakin and Ludlow [Phys. Rev. A 70, 032720 (2004)] and a polarized-orbital result of  ?10.4 a.u. from McEachran et al. [J. Phys. B 13, 1281 (1980)]. The present experimental scattering length supports the existence of a low-lying positron-krypton virtual state (Surko et al. [J. Phys. B 38, R57 (2005)]) at an energy ε = 0.13 eV.     

“Function-First” Lead Discovery: Mode of Action Profiling of Natural Product Libraries Using Image-Based Screening

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Highlights? Application of high-content, image-based screening to natural product discovery ? Mode of action prediction for natural product libraries using cytological profiles ? Dereplication of natural products based on biological function ? Discovery of a unique family of iron siderophores and prediction of their mode of action     

Zur Beseitigung der Phosphate aus Wasserstoffsuperoxydl? sungen

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Arsen, Antimon, Zinn,

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Holz und Holzimpr?gnierung

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