939 research outputs found

    The quasi-bi-Hamiltonian formulation of the Lagrange top

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    Starting from the tri-Hamiltonian formulation of the Lagrange top in a six-dimensional phase space, we discuss the possible reductions of the Poisson tensors, the vector field and its Hamiltonian functions on a four-dimensional space. We show that the vector field of the Lagrange top possesses, on the reduced phase space, a quasi-bi-Hamiltonian formulation, which provides a set of separation variables for the corresponding Hamilton-Jacobi equation.Comment: 12 pages, no figures, LaTeX, to appear in J. Phys. A: Math. Gen. (March 2002

    Reduction of bihamiltonian systems and separation of variables: an example from the Boussinesq hierarchy

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    We discuss the Boussinesq system with t5t_5 stationary, within a general framework for the analysis of stationary flows of n-Gel'fand-Dickey hierarchies. We show how a careful use of its bihamiltonian structure can be used to provide a set of separation coordinates for the corresponding Hamilton--Jacobi equations.Comment: 20 pages, LaTeX2e, report to NEEDS in Leeds (1998), to be published in Theor. Math. Phy

    On the integrability of stationary and restricted flows of the KdV hierarchy.

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    A bi--Hamiltonian formulation for stationary flows of the KdV hierarchy is derived in an extended phase space. A map between stationary flows and restricted flows is constructed: in a case it connects an integrable Henon--Heiles system and the Garnier system. Moreover a new integrability scheme for Hamiltonian systems is proposed, holding in the standard phase space.Comment: 25 pages, AMS-LATEX 2.09, no figures, to be published in J. Phys. A: Math. Gen.

    A Left Atrial Appendage Closure Combined Procedure Review: past, present and future perspectives

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    Atrial fibrillation (AF) represents the most common cardiac arrhythmia worldwide; it poses a great burden in terms of quality of life reduction and yearly stroke risk. Left atrial appendage closure (LAAC) is a stroke prevention strategy that has been proven a viable alternative to anti-thrombotic regimens in non-valvular AF patients. LAAC can be performed as a stand-alone procedure or alongside a concomitant AF trans catheter ablation, in a procedure known as "Combined Procedure". Aim of this study is to summarize the scientific evidence backing this combined strategy

    Analisis Semiotika Komunikasi Pada Program Acara Talkshow Sarah Sechan

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    Penelitian ini berjudul “Analisis Semiotika Komunikasi Pada Program Acara Talkshow Sarah Sechan di Net. Tv”. Acara talkshow Sarah Sechan merupakan salah satu program acara televisi yang unik dan menarik untuk ditonton. Setiap program acara televisi termasuk tayangan talkshow Sarah Sechan di Net.tv pasti akan berusaha menyajikan tayangan yang unik, menarik, informatif dan menghibur agar diminati oleh pemirsa/penonton. Dalam program acara Talkshow Sarah Sechan terdapat tanda atau signal dalam konteks komunikasi yang melibatkan berbagai elemen komunikasi, baik dari panggung (stage), latar belakang panggung (stage background), theme song program (lagu tema program) dan ungkapan kata-kata dari Sarah Sechan (Host/Komunikator) bersama dengan bintang tamu (Komunikan) pasti mempunyai makna yang bisa diinterpretasikan berbeda-beda oleh pemirsa/penonton.Penelitian ini menggunakan metode penelitian Interpretatif. Dimana peneliti akan menjelaskan hasil observasi analisis semiotika komunikasi berdasarkan kesepuluh jenis tanda yang ada didalam teori Charles Sanders Pierce.Semiotika adalah suatu ilmu atau metode analisis untuk mengkaji tanda. Semiotika komunikasi mrngkaji tanda atau signal dalam konteks komunikasi yang lebih luas, yaitu yang melibatkan elemen komunikasi.Hasil penelitian ini menyimpulkan, bahwa tanda yang ada didalam program acara talkshow Sarah Sechan adalah tanda yang menginformasikan tentang sesuatu, informasi yang belum diketahui oleh khalayak umum. Informasi yang ada didalam acara talkshow Sarah Sechan disajikan secara unik dan menarik sehingga acara ini layak untuk ditonton karena memberikan makna yang positif kepada setiap penonton

    Crystal structure of the FAD-containing ferredoxin-NADP+ reductase from the plant pathogen Xanthomonas axonopodis pv. citri

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    We have solved the structure of ferredoxin-NADP(H) reductase, FPR, from the plant pathogen Xanthomonas axonopodis pv. citri, responsible for citrus canker, at a resolution of 1.5¿Å. This structure reveals differences in the mobility of specific loops when compared to other FPRs, probably unrelated to the hydride transfer process, which contributes to explaining the structural and functional divergence between the subclass I FPRs. Interactions of the C-terminus of the enzyme with the phosphoadenosine of the cofactor FAD limit its mobility, thus affecting the entrance of nicotinamide into the active site. This structure opens the possibility of rationally designing drugs against the X. axonopodis pv. citri phytopathogen

    Multisite international collaborative clinical trials in mania.

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    Multi-regional collaborative clinical trials include those conducted across heterogeneous areas of the world under common protocols. Such trials appear to be driven primarily to provide data required for regulatory approval or licensing of new drug products in a relatively rapid and presumably efficient and cost-effective manner. Commonly, they include underserved populations and areas where costs of trials are lower than in most developed countries. In addition, such studies can potentially make innovative treatments widely and rapidly available in vast, international markets. Other potential benefits to collaborating sites may include diffusion of knowledge and improvement of research skills, as well as improvement of treatment and a broader salutary impact on health services and perhaps on employment opportunities and economic growth (Demol +6; Weihrauch, 1997; Glickman et al. 2009; Gopal et al. 2005; Greco +6; Diniz, 2008; ICH Guideline, 2002; Smulevich et al. 2005; U.S. FDA, 1998). Successful conduct of international trials requires compliance with varying local and international laws, regulations and ethical requirements, and confronting a range of systems of review of ethical aspects of subject recruitment, compensation, consenting procedures, research protocols, and provision of aftercare – all which can add complexity. In addition, there is variance among regions, countries and cultures in levels of education, and in the nature of information, financial inducements, clinical care and aftercare provided to research subjects. Complexities arise also from culture-dependent conceptualizations of mental disorders, criteria for diagnosis, and efforts at validating, interpreting and scoring of symptom ratings designed to characterize changes during treatment, and methods for detecting adverse events. In the continuing quest to define core or universal features of psychiatric disorders, it is crucial to consider the anthropological and cultural context in which they develop and are modified (Karno +6; Jenkins, 1993; Lopez-Ibor, 2003;

    Acute outcome after a single cryoballoon ablation: Comparison between Arctic Front Advance and Arctic Front Advance PRO

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    BACKGROUND: The novel fourth-generation cryoballoon (CB4) potentially allows for enhanced catheter maneuverability and more frequent capture of pulmonary vein (PV) potentials which can be used to monitor real-time PV isolation (PVI). The aim of our study is to compare the acute procedural endpoints between the CB4 and second-generation cryoballoon (CB2). METHODS: A single-center retrospective chart review was used to examine 50 consecutive patients with drug-refractory atrial fibrillation undergoing CB4-based PVI. Procedural data and acute success of these patients were compared to 50 propensity-matched controls who underwent cryoballoon ablation procedure using CB2. RESULTS: Procedures performed with the CB4 showed significant shorter fluoroscopy time (14.8 \ub1 5.5 vs 18.0 \ub1 6.5 minutes, P = .04), shorter procedure time (58.3 \ub1 15.7 vs 65.3 \ub1 21 minutes, P = .13), and shorter total ablation time (10.8 \ub1 1.5 vs 13.8 \ub1 1.9 minutes, P = .42). The real-time PVI visualization rate was 33.3% in the CB2 group and 74.7% in the CB4 group (P < .001). CB4 was correlated to significant increase of acute real-time recordings with regard to all the single PV (left superior PV: 58% vs 84%, P = .02; left inferior PV: 26% vs 71%, P = .001; right superior PV 29% vs 61%, P = .01; and right inferior PV 19% vs 58%, P = .002). CONCLUSION: The CB4 was more often able to capture real-time recordings of PV potentials and the subsequent acute PV isolation

    Quantized W-algebra of sl(2,1) and quantum parafermions of U_q(sl(2))

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    In this paper, we establish the connection between the quantized W-algebra of sl(2,1){\frak sl}(2,1) and quantum parafermions of Uq(sl^(2))U_q(\hat {\frak sl}(2)) that a shifted product of the two quantum parafermions of Uq(sl^(2))U_q(\hat {\frak sl}(2)) generates the quantized W-algebra of sl(2,1){\frak sl}(2,1)
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