902 research outputs found

    The f-vector of the descent polytope

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    For a positive integer n and a subset S of [n-1], the descent polytope DP_S is the set of points x_1, ..., x_n in the n-dimensional unit cube [0,1]^n such that x_i >= x_{i+1} for i in S and x_i <= x_{i+1} otherwise. First, we express the f-vector of DP_S as a sum over all subsets of [n-1]. Second, we use certain factorizations of the associated word over a two-letter alphabet to describe the f-vector. We show that the f-vector is maximized when the set S is the alternating set {1,3,5, ...}. We derive a generating function for the f-polynomial F_S(t) of DP_S, written as a formal power series in two non-commuting variables with coefficients in Z[t]. We also obtain the generating function for the Ehrhart polynomials of the descent polytopes.Comment: 14 pages; to appear in Discrete & Computational Geometr

    Impact of a comprehensive prevention programme aimed at reducing incivility and verbal violence against healthcare workers in a French ophthalmic emergency department: an interrupted time-series study.

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    Primary prevention, comprising patient-oriented and environmental interventions, is considered to be one of the best ways to reduce violence in the emergency department (ED). We assessed the impact of a comprehensive prevention programme aimed at preventing incivility and verbal violence against healthcare professionals working in the ophthalmology ED (OED) of a university hospital. The programme was designed to address long waiting times and lack of information. It combined a computerised triage algorithm linked to a waiting room patient call system, signage to assist patients to navigate in the OED, educational messages broadcast in the waiting room, presence of a mediator and video surveillance. All patients admitted to the OED and those accompanying them. Single-centre prospective interrupted time-series study conducted over 18 months. Violent acts self-reported by healthcare workers committed by patients or those accompanying them against healthcare workers. Waiting time and length of stay. There were a total of 22 107 admissions, including 272 (1.4%) with at least one act of violence reported by the healthcare workers. Almost all acts of violence were incivility or verbal harassment. The rate of violence significantly decreased from the pre-intervention to the intervention period (24.8, 95% CI 20.0 to 29.5, to 9.5, 95% CI 8.0 to 10.9, acts per 1000 admissions, p&lt;0.001). An immediate 53% decrease in the violence rate (incidence rate ratio=0.47, 95% CI 0.27 to 0.82, p=0.0121) was observed in the first month of the intervention period, after implementation of the triage algorithm. A comprehensive prevention programme targeting patients and environment can reduce self-reported incivility and verbal violence against healthcare workers in an OED. NCT02015884

    Évolution des cancers de l’œsophage : impact de la stratégie thérapeutique

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    PURPOSE: To assess the outcome of esophageal cancer according to therapeutic strategy. PATIENTS AND METHODS: One-hundred and twenty patients with esophageal cancer treated by an association of radiotherapy and chemotherapy and possibly surgery, between 2004 and 2010, were retrospectively studied. The first site of relapse was classified as follows: local (tumour), locoregional (tumour and/or nodal: celiac, mediastinal, sus-clavicular) or metastatic. RESULTS: With a 15.7-months (1.4-62) median follow-up, there were 89 deaths and 79 recurrences. Three types of treatments were performed: 50Gy exclusive chemoradiotherapy (47 patients) or 50 to 65Gy exclusive chemoradiotherapy (44 patients) or chemoradiotherapy followed by surgery (27 patients). The local first relapse was as much frequent as distant relapse (50 patients). With a-5cm margin up and down to the tumour, there was only one nodal relapse. Two-year survival was 39.5% (95% confidence interval [IC]: 30.5-40.8) and relapse-free survival was 26.5% (CI: 18.6-35). Multivariate analysis revealed that treatment type and disease stage had a significant impact on survival, relapse-free survival and locoregional control. Compared to exclusive chemoradiotherapy, surgery improved locoregional control (40.2 versus 8.7 months, P=0.0004) but in a younger population. Despite postoperative mortality, the gain was maintained for distance relapse-free survival (40.2 versus 10 months, P=0.0147) and overall survival (29.3 versus 14.2 months, P=0.0088). Compared to 50Gy chemoradiotherapy, local control was improved if high dose chemoradiotherapy was performed (13.8 versus 7.5 months, P=0.05) but not overall survival (14.0 versus 15.4 months, P=0.24). CONCLUSION: More than one-third relapse is local. Locoregional control is better with high dose chemoradiotherapy. In this study, surgery performed in selected patients only, improved locoregional control, relapse-free disease and overall survival

    Traitement d'images scanographiques appliqué à l'étude tridimensionnelle de l'évolution de la forme du crâne humain

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    Extended proceedings of the workshop organized in May 1999.National audienceWe present an automatic method that allows one to visualize and analyze, in three dimensions, the evolution of the shape of the human skull from CT-Scan images. A first algorithm automatically extracts the crest lines from CT-Scan images of the skull of a modern Man and of a cast of a skull of a prehistoric Man. Those lines correspond to the salient lines of the skull surface. They will be used as landmarks to automatically find the homology points between the two skulls. Based on these couples of matched points, we compute a volumetric transformation that superposes the two skulls. This transformation can be interpolated to obtain intermediary transformations. We extract then a surface model of the skull of the modern Man and we apply successively the intermediary transformations to visualize the evolution of the sull between the prehistoric and the modern Man. We have applied this method to the skull of the Man of Tautavel, dated of about 450 000 years, and we present future applications in facial reconstruction and tridimensional morphometry.Nous présentons une méthode automatique qui permet de visualiser et d'analyser, en trois dimensions , l'évolution de la forme du crâne humain à partir d'images scanographiques. Un premier algorithme extrait automatiquement des lignes de crête à partir des scanographies d'un crâne d'un Homme moderne et du moulage du crâne d'un Homme préhistorique. Ces lignes correspondent aux lignes saillantes de la surface crânienne. Elles servent de repères à un algorithme de mise en correspondance pour trouver automatiquement les points homologues entre les deux crânes. A partir de ces points appariés, on calcule une transformation de l'espace qui superpose les deux crânes. Cette transformation peut ensuite être interpolée pour créer des transformations intermé-diaires. A partir de l'image scanographique, on extrait alors un modèle surfacique du crâne de l'Homme moderne auquel sont successivement appliquées les transformations intermédiaires pour visualiser l'évolution du crâne entre l'Homme préhistorique et moderne. Nous appliquons cette méthode au crâne de l'Homme de Tautavel, daté d'environ 450 000 ans, et nous présentons des applications futures en reconstruction faciale et en analyse morphométrique tridimensionnelle

    Noise Can Reduce Disorder in Chaotic Dynamics

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    We evoke the idea of representation of the chaotic attractor by the set of unstable periodic orbits and disclose a novel noise-induced ordering phenomenon. For long unstable periodic orbits forming the strange attractor the weights (or natural measure) is generally highly inhomogeneous over the set, either diminishing or enhancing the contribution of these orbits into system dynamics. We show analytically and numerically a weak noise to reduce this inhomogeneity and, additionally to obvious perturbing impact, make a regularizing influence on the chaotic dynamics. This universal effect is rooted into the nature of deterministic chaos.Comment: 11 pages, 5 figure

    New methods and equipment of decametric radio astronomy for continuum observation at the UTR-2 radio telescope

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    At present time the modernization of the giant decametric radio telescope UTR-2 is under way. New back-end facilities and methods which open up new possibilities for radio astronomical observations are developed. Some equipment was made in cooperation with Austrian and French radio astronomers. Current back-end facilities and methods used at the UTR-2 radio telescope are described and compared with former traditional methods, equipment and their characteristics. Some prospects regarding current progress in developing new generation of back-end facilities are also discussed. The main focus of the presentation is the observation methods and equipment applied at the UTR-2 radio telescope for the investigation of continuum radio sources: Galactic background, discrete sources (preparation for the catalogue of sources in the whole Northern Sky), SNR, HII regions. Some results of using the new back-end facilities (such as Digital Spectral Polarimeter) and processing methods are presented

    Regulation of extracellular ATP of human erythrocytes treated with α-hemolysin: Effects of cell volume, morphology, rheology and hemolysis

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    Alpha-hemolysin (HlyA) of uropathogenic strains of Escherichia coli irreversibly binds to human erythrocytes (RBCs) and triggers activation of ATP release and metabolic changes ultimately leading to hemolysis. We studied the regulation of extracellular ATP (ATPe) of RBCs exposed to HlyA. Luminometry was used to assess ATP release and ATPe hydrolysis, whereas changes in cell volume and morphology were determined by electrical impedance, ektacytometry and aggregometry. Exposure of RBCs to HlyA induced a strong increase of [ATPe] (3–36-fold) and hemolysis (1–44-fold), partially compensated by [ATPe] hydrolysis by ectoATPases and intracellular ATPases released by dead cells. Carbenoxolone, a pannexin 1 inhibitor, partially inhibited ATP release (43–67%). The un-acylated toxin ProHlyA and the deletion analog HlyA∆914-936 were unable to induce ATP release or hemolysis. For HlyA treated RBCs, a data driven mathematical model showed that simultaneous lytic and non-lytic release mainly governed ATPe kinetics, while ATPe hydrolysis became important after prolonged toxin exposure. HlyA induced a 1.5-fold swelling, while blocking this swelling reduced ATP release by 77%. Blocking ATPe activation of purinergic P2X receptors reduced swelling by 60–80%. HlyA-RBCs showed an acute 1.3–2.2-fold increase of Ca 2+ i, increased crenation and externalization of phosphatidylserine. Perfusion of HlyA-RBCs through adhesion platforms showed strong adhesion to activated HMEC cells, followed by rapid detachment. HlyA exposed RBCs exhibited increased sphericity under osmotic stress, reduced elongation under shear stress, and very low aggregation in viscous media. Overall results showed that HlyA-RBCs displayed activated ATP release, high but weak adhesivity, low deformability and aggregability and high sphericity.Fil: Leal Denis, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analítica y Fisicoquímica; ArgentinaFil: Lefevre, S.D.. Inserm; Francia. Université Paris Diderot - Paris 7; Francia. Université de la Réunion; Francia. Université des Antilles; Francia. Universite de Paris. Institut National de la Transfusion Sanguine.; FranciaFil: Alvarez, Cora Lilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Lauri, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Enrique, Nicolás Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas; ArgentinaFil: Rinaldi, Debora Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Gonzalez-Lebrero, Rodolfo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Vecchio Dezillio, Leandro Emmanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas; ArgentinaFil: Espelt, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Stringa, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Muñoz Garay, C.. Universidad Nacional Autónoma de México; MéxicoFil: Milesi, Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas; ArgentinaFil: Ostuni, M.A.. Inserm; Francia. Université Paris Diderot - Paris 7; Francia. Université de la Réunion; Francia. Université des Antilles; Francia. Universite de Paris. Institut National de la Transfusion Sanguine.; FranciaFil: Herlax, Vanesa Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner"; ArgentinaFil: Schwarzbaum, Pablo Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentin

    Global Search for New Physics with 2.0/fb at CDF

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    Data collected in Run II of the Fermilab Tevatron are searched for indications of new electroweak-scale physics. Rather than focusing on particular new physics scenarios, CDF data are analyzed for discrepancies with the standard model prediction. A model-independent approach (Vista) considers gross features of the data, and is sensitive to new large cross-section physics. Further sensitivity to new physics is provided by two additional algorithms: a Bump Hunter searches invariant mass distributions for "bumps" that could indicate resonant production of new particles; and the Sleuth procedure scans for data excesses at large summed transverse momentum. This combined global search for new physics in 2.0/fb of ppbar collisions at sqrt(s)=1.96 TeV reveals no indication of physics beyond the standard model.Comment: 8 pages, 7 figures. Final version which appeared in Physical Review D Rapid Communication
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