973 research outputs found
The quasi-bi-Hamiltonian formulation of the Lagrange top
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
We discuss the Boussinesq system with 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.
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
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
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
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.
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;
Detecting Recent Dynamics in Large-Scale Landslides via the Digital Image Correlation of Airborne Optic and LiDAR Datasets: Test Sites in South Tyrol (Italy)
Large-scale slow-moving deep-seated landslides are complex and potentially highly damaging phenomena. The detection of their dynamics in terms of displacement rate distribution is therefore a key point to achieve a better understanding of their behavior and support risk management. Due to their large dimensions, ranging from 1.5 to almost 4 km(2), in situ monitoring is generally integrated using satellite and airborne remote sensing techniques. In the framework of the EFRE-FESR SoLoMon project, three test-sites located in the Autonomous Province of Bolzano (Italy) were selected for testing the possibility of retrieving significant slope displacement data from the analysis of multi-temporal airborne optic and light detection and ranging (LiDAR) surveys with digital image correlation (DIC) algorithms such as normalized cross-correlation (NCC) and phase correlation (PC). The test-sites were selected for a number of reasons: they are relevant in terms of hazard and risk; they are representative of different type of slope movements (earth-slides, deep seated gravitational slope Deformation and rockslides), and different rates of displacement (from few cm/years to some m/years); and they have been mapped and monitored with ground-based systems for many years (DIC results can be validated both qualitatively and quantitatively). Specifically, NCC and PC algorithms were applied to high-resolution (5 to 25 cm/px) airborne optic and LiDAR-derived datasets (such as hillshade and slope maps computed from digital terrain models) acquired during the 2019-2021 period. Qualitative and quantitative validation was performed based on periodic GNSS surveys as well as on manual homologous point tracking. The displacement maps highlight that both DIC algorithms succeed in identifying and quantifying slope movements of multi-pixel magnitude in non-densely vegetated areas, while they struggle to quantify displacement patterns in areas characterized by movements of sub-pixel magnitude, especially if densely vegetated. Nonetheless, in all three landslides, they proved to be able to differentiate stable and active parts at the slope scale, thus representing a useful integration of punctual ground-based monitoring systems
Acute outcome after a single cryoballoon ablation: Comparison between Arctic Front Advance and Arctic Front Advance PRO
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
- …