233 research outputs found

    The vector-valued big q-Jacobi transform

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    Big qq-Jacobi functions are eigenfunctions of a second order qq-difference operator LL. We study LL as an unbounded self-adjoint operator on an L2L^2-space of functions on R\mathbb R with a discrete measure. We describe explicitly the spectral decomposition of LL using an integral transform F\mathcal F with two different big qq-Jacobi functions as a kernel, and we construct the inverse of F\mathcal F.Comment: 35 pages, corrected an error and typo

    PREPARATION OF NEW NITROGEN-BRIDGED HETEROCYCLES. 63. UNEXPECTED FORMATION OF THIENO[3 ',4 ':4,5]IMIDAZO[1,2-a]-PYRIDINES

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    The alkaline treatment and dehydrogenation of pyridinium salts, obtainable from the S-alkylation of 3,5-dimethylpyridinium 2-alkylthio-1-cyano2-thioxoethylides with some phenacyl bromides, afforded unexpected heterocycles, 3-alkylthio-1-arylcarbonyl-6,8-dimethylthieno[3',4':4,5]imidazo-[1,2-a]pyridines, together with the corresponding 2-alkylthio-1-arylcarbonylthio-6,8-dimethylindolizine-3-carbonitriles.ArticleHETEROCYCLES. 76(1): 391-399 (2008)journal articl

    A solution to the Al-Salam--Chihara moment problem

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    We study the qq-hypergeometric difference operator LL on a particular Hilbert space. In this setting LL can be considered as an extension of the Jacobi operator for q1q^{-1}-Al-Salam--Chihara polynomials. Spectral analysis leads to unitarity and an explicit inverse of a qq-analog of the Jacobi function transform. As a consequence a solution of the Al-Salam--Chihara indeterminate moment problem is obtained.Comment: 22 page

    Splines and Wavelets on Geophysically Relevant Manifolds

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    Analysis on the unit sphere S2\mathbb{S}^{2} found many applications in seismology, weather prediction, astrophysics, signal analysis, crystallography, computer vision, computerized tomography, neuroscience, and statistics. In the last two decades, the importance of these and other applications triggered the development of various tools such as splines and wavelet bases suitable for the unit spheres S2\mathbb{S}^{2}, S3\>\>\mathbb{S}^{3} and the rotation group SO(3)SO(3). Present paper is a summary of some of results of the author and his collaborators on generalized (average) variational splines and localized frames (wavelets) on compact Riemannian manifolds. The results are illustrated by applications to Radon-type transforms on Sd\mathbb{S}^{d} and SO(3)SO(3).Comment: The final publication is available at http://www.springerlink.co

    Expert consensus document: Semantics in active surveillance for men with localized prostate cancer — results of a modified Delphi consensus procedure

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    Active surveillance (AS) is broadly described as a management option for men with low-risk prostate cancer, but semantic heterogeneity exists in both the literature and in guidelines. To address this issue, a panel of leading prostate cancer specialists in the field of AS participated in a consensus-forming project using a modified Delphi method to reach international consensus on definitions of terms related to this management option. An iterative three-round sequence of online questionnaires designed to address 61 individual items was completed by each panel member. Consensus was considered to be reached if ≥70% of the experts agreed on a definition. To facilitate a common understanding among all experts involved and resolve potential ambiguities, a face-to-face consensus meeting was held between Delphi survey rounds two and three. Convenience sampling was used to construct the panel of experts. In total, 12 experts from Australia, France, Finland, Italy, the Netherlands, Japan, the UK, Canada and the USA participated. By the end of the Delphi process, formal consensus was achieved for 100% (n = 61) of the terms and a glossary was then developed. Agreement between international experts has been reached on relevant terms and subsequent definitions regarding AS for patients with localized prostate cancer. This standard terminology could support multidisciplinary communication, reduce the extent of variations in clinical practice and optimize clinical decision making
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