3,330 research outputs found

    Subalgebras of \gc_N and Jacobi polynomials

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    We classify the subalgebras of the general Lie conformal algebra \gc_N that act irreducibly on \C[\partial]^N and that are normalized by the sl2\operatorname{sl}_2--part of a Virasoro element. The problem turns out to be closely related to classical Jacobi polynomials Pn(σ,σ)P_n^{(-\sigma,\sigma)}, \sigma\in\C. The connection goes both ways -- we use in our classification some classical properties of Jacobi polynomials, and we derive from the theory of conformal algebras some apparently new properties of Jacobi polynomials.Comment: 35 pages, LaTe

    Usefulness of image guidance in the surgical treatment of petrous apex cholesterol granuloma

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    The petrous apex is a pyramid-shaped structure, located medial to the inner ear and the intrapetrous segment of the internal carotid artery. Lesions of the petrous apex can be surgically treated through different surgical routes. Because of the important neurovascular structures located inside the temporal bone, anatomical 3D knowledge is paramount. For this reason, image-guided surgery could represent a useful tool. We report the case of a young woman who came to our observation for a trigeminal neuralgia due to a petrous apex cholesterol granuloma. The lesion was treated through the placement of a drainage tube via an infracochlear approach, with the aid of neuronavigation and intraoperative MRI. Preoperative CT scan images and intraoperative MRI images were fused for surgical planning. The accuracy of the neuronavigation system has proved to be good, and the safety of the procedure was enhanced. Therefore, neuronavigation and intraoperative MRI, though not available in all neurootological centres, should be considered useful tools in these challenging procedures

    Sustaining the Medical Home: How PROMETHEUS Payment Can Revitalize Primary Care

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    Argues for reforming the current fee-for-service payment system on the PROMETHEUS model of budgeting for a comprehensive episode of care for a condition. Analyzes the implications for a sustainable patient-centered medical home model of care delivery

    Polariton-polariton scattering in microcavities: A microscopic theory

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    We apply the fermion commutation technique for composite bosons to polariton-polariton scattering in semiconductor planar microcavities. Derivations are presented in a simple and physically transparent fashion. A procedure of orthogonolization of the initial and final two-exciton state wavefunctions is used to calculate the effective scattering matrix elements and the scattering rates. We show how the bosonic stimulation of the scattering appears in this full fermionic approach whose equivalence to the bosonization method is thus demonstrated in the regime of low exciton density. We find an additional contribution to polariton-polariton scattering due to the exciton oscillator strength saturation, which we analyze as well. We present a theory of the polariton-polariton scattering with opposite spin orientations and show that this scattering process takes place mainly via dark excitonic states. Analytical estimations of the effective scattering amplitudes are given.Comment: Theoretical paper on polariton-polariton scattering in planar microcavities. The new version contains a slightly modified abstract and a revised introduction. Typos have been corrected wherever spotted. 16 page

    Abdominoplasty: Thromboembolic Risks for Both Sexes

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    During surgical procedures, coagulation complications may occur. Discriminating factors are multiple and may vary because of the anatomical regions involved and because of preexisting diseases. The aim of this study was to analyze changes in such hematological parameters of patients undergoing conventional abdominoplasty with standard surgical procedures under general anaesthesia. For the study, 40 patients (20 men and 20 women) 30 to 60 years with normal coagulation assessments, no previous or current history of hemorrhagic or thrombotic disease, and no primary family history of such problems were selected. All the patients underwent conventional abdominoplasty surgical procedures. Analysis of the results suggests that immediately after surgery, in the absence of any preexisting hypo- or hypercoagulability state, there was no circumstantial modification in coagulation factors considered predictive for thromboembolic risk. However, an interesting difference between male and female patients was noted. In the male group, there was an insignificant uniform downward trend of all values immediately after surgery. In conclusion, women are less hypercoagulative than men in the postoperative period, suggesting that women have limited protection from the development of thromboembolic complications immediately after surgical procedures.During surgical procedures, coagulation complications may occur. Discriminating factors are multiple and may vary because of the anatomical regions involved and because of preexisting diseases. The aim of this study was to analyze changes in such hematological parameters of patients undergoing conventional abdominoplasty with standard surgical procedures under general anaesthesia. For the study, 40 patients (20 men and 20 women) 30 to 60 years with normal coagulation assessments, no previous or current history of hemorrhagic or thrombotic disease, and no primary family history of such problems were selected. All the patients underwent conventional abdominoplasty surgical procedures. Analysis of the results suggests that immediately after surgery, in the absence of any preexisting hypo- or hypercoagulability state, there was no circumstantial modification in coagulation factors considered predictive for thromboembolic risk. However, an interesting difference between male and female patients was noted. In the male group, there was an insignificant uniform downward trend of all values immediately after surgery. In conclusion, women are less hypercoagulative than men in the postoperative period, suggesting that women have limited protection from the development of thromboembolic complications immediately after surgical procedures. © 2004 Springer Science+Business Media, Inc

    Correction of prominent ears with a new splinting technique

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    Correction of prominent ears represents one of the main applications in plastic surgery. Apart from its cosmetic nature, this operation is important because of the psychological distress that the deformity causes patients. In this study, 40 patients who underwent treatment for prominent ears in our department were evaluated. The classical surgical technique described by Chongchet followed by a new splinting procedure was performed. The advantages of this technique are described in comparison with traditional methods
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