943 resultados para gruppi topologici rivestimenti SU(2) SO(3,R)
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We verify that SU(N)TC⊗ - SU(3) L⊗ - U(1)X models, where the gauge symmetry breaking is totally dynamical and promoted by the non-Abelian technicolor group and the strong Abelian interactions, are quite constrained by the LHC data. The theory contains a T quark self-energy involving the mixing between the neutral gauge bosons, which introduces the coupling between the light and heavy composite scalar bosons of the model. We determine the lightest scalar boson mass for these models from an effective action for composite operators, assuming details about the dynamics of the strong interaction theories. Comparing the value of this mass with the ATLAS and CMS observation of a new boson with a mass M∼125 GeV and considering the lower bound determined by the LHC Collaboration on the heavy neutral gauge boson (Z′) present in these models, we can establish constraints on the possible models. For example, if SU(N)TC≡SU(2)TC, with technifermions in the fundamental representation, the model barely survives the confrontation with the LHC data. © 2013 American Physical Society.
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Pós-graduação em Agronomia (Energia na Agricultura) - FCA
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Agronomia (Horticultura) - FCA
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The creation of the University of São Paulo in the early 1930’s brought about arguments in the projects about its organization. The idea was to establish the Polytechnic School of São Paulo as the core of the future institution. However, the option adopted in 1934 allocated this position to the newly created Faculty of Philosophy, Science and Letters. This caused a strong reaction by both former professional schools that were incorporated into the university, above all the Polytechnic School. This article sets out to describe the conflicts between the Polytechnic School and the Faculty of Philosophy, Science and Letters during the tumultuous beginnings of the University of São Paulo.
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Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE
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Background The e-Healthy Endothelial Accelerated Lining Inhibits Neointimal Growth (e-HEALING) registry was designed to capture clinical data on the use of the endothelial progenitor cell capture stent (ECS) in routine clinical practice. In this analysis, we investigated the 12-month clinical outcomes in patients treated with an ECS for a bifurcation lesion. Methods The worldwide, prospective, nonrandomized e-HEALING registry aimed to enrol 5000 patients treated for coronary artery disease with one or more ECS between October 2005 and October 2007. Clinical follow-up was obtained at 1, 6, and 12 months. The primary endpoint was target vessel failure (TVF), defined as the composite of cardiac death, myocardial infarction, and target vessel revascularization at 12 months. Results A total of 573 patients were treated for at least one bifurcation lesion and were assessed in the current analysis. Baseline characteristics showed a median age of 65 years; 21% were diabetic patients and 36% had unstable angina. A total of 63% of the bifurcation lesions were located in the left artery descending and the mean stent length was 20.7 +/- 12.6 mm. At 12 months, TVF was 12.7% and target lesion revascularization was 7.5%. Definite or probable stent thrombosis occurred in 1.7% of the patients. Moreover, one or more stents per lesion [hazard ratio (HR): 2.79, 95% confidence interval (CI): 1.60-4.86, P < 0.001], predilatation (HR: 0.39, 95% CI: 0.17-0.87, P = 0.023), and lesions located in the right coronary artery (HR: 4.56, 95% CI: 1.07-19.5, P = 0.041) were independent predictors of TVF. Conclusion In the e-HEALING registry, coronary bifurcation stenting with the ECS results in favorable clinical outcomes and low incidences of repeat revascularization and stent thrombosis. Coron Artery Dis 23:201-207 (C) 2012 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.
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In this work we compare the simple singularities of germs from R-2 to R-p with multiplicity 2 or 3 with the singularities appearing in the set of 2-ruled surfaces. We also study the topological type of all finitely determined singularities by studying generic projections of these singularities in R-3. (C) 2011 Elsevier B.V. All rights reserved.
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The National Institute for Clinical Excellence (NICE) guidelines recommend the use of bare-metal stents (BMS) in non-complex lesions with a low risk of restenosis (diameter a parts per thousand yen3 mm and lesion length a parts per thousand currency sign15 mm) and the use of drug-eluting stents (DES) in more complex lesions with a high risk of restenosis (diameter < 3.0 mm or lesion length > 15 mm). However, the guidelines were created based on studies evaluating BMS and DES only. We performed an analysis of patients undergoing non-urgent percutaneous coronary intervention with the novel endothelial cell capturing stent (ECS). The ECS is coated with CD34(+) antibodies that attract circulating endothelial progenitor cells to the stent surface, thereby accelerating the endothelialization of the stented area. We analyzed all patients enrolled in the worldwide e-HEALING registry that met the NICE criteria for either low-risk or high-risk lesions and were treated with a parts per thousand yen1 ECS. The main study outcome was target vessel failure (TVF) at 12-month follow-up, defined as the composite of cardiac death or MI and target vessel revascularization (TVR). A total of 4,241 patients were assessed in the current analysis. At 12-month follow-up, TVF occurred in 7.0% of the patients with low-risk lesions and in 8.8% of the patients with high-risk lesions (p = 0.045). When evaluating the diabetic patients versus the non-diabetic patients per risk group, no significant differences were found in TVF, MI or TVR in either risk group. The ECS shows good clinical outcomes in lesions carrying either a high or a low risk of restenosis according to the NICE guidelines with comparable rates of cardiac death, myocardial infarction, and stent thrombosis. The TVF rate with ECS was slightly higher in patients with high-risk lesions, driven by higher clinically driven TLR. The risk of restenosis with ECS in patients carrying high-risk lesions needs to be carefully considered relative to other risks associated with DES. Furthermore, the presence of diabetes mellitus did not influence the incidence of TVF in either risk group.
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Supersymmetric models with bilinear R-parity violation can account for the observed neutrino masses and mixing parameters indicated by neutrino oscillation data. We consider minimal supergravity versions of bilinear R-parity violation where the lightest supersymmetric particle is a neutralino. This is unstable, with a large enough decay length to be detected at the CERN Large Hadron Collider. We analyze the Large Hadron Collider potential to determine the lightest supersymmetric particle properties, such as mass, lifetime and branching ratios, and discuss their relation to neutrino properties.
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Abstract Background Phagocytosis of apoptotic cells by macrophages induces a suppressor phenotype. Previous data from our group suggested that this occurs via Platelet-activating factor receptor (PAF-R)-mediated pathways. In the present study, we investigated the impact of apoptotic cell inoculation or induction by a chemotherapeutic agent (dacarbazine, DTIC) on tumour growth, microenvironmental parameters and survival, and the effect of treatment with a PAF-R antagonist (WEB2170). These studies were performed in murine tumours: Ehrlich Ascitis Tumour (EAT) and B16F10 melanoma. Methods Tumour growth was assessed by direct counting of EAT cells in the ascitis or by measuring the volume of the solid tumour. Parameters of the tumour microenvironment, such as the frequency of cells expressing cyclo-oxygenase-2 (COX-2), caspase-3 and galectin-3, and microvascular density, were determined by immunohistochemistry. Levels of vascular endothelium growth factor (VEGF) and prostaglandin E2 (PGE2) were determined by ELISA, and levels of nitric oxide (NO) by Griess reaction. PAF-R expression was analysed by immunohistochemistry and flow cytometry. Results Inoculation of apoptotic cells before EAT implantation stimulated tumour growth. This effect was reversed by in vivo pre-treatment with WEB2170. This treatment also reduced tumour growth and modified the microenvironment by reducing PGE2, VEGF and NO production. In B16F10 melanoma, WEB2170 alone or in association with DTIC significantly reduced tumour volume. Survival of the tumour-bearing mice was not affected by WEB2170 treatment but was significantly improved by the combination of DTIC with WEB2170. Tumour microenvironment elements were among the targets of the combination therapy since the relative frequency of COX-2 and galectin-3 positive cells and the microvascular density within the tumour mass were significantly reduced by treatment with WEB2170 or DTIC alone or in combination. Antibodies to PAF-R stained the cells from inside the tumour, but not the tumour cells grown in vitro. At the tissue level, a few cells (probably macrophages) stained positively with antibodies to PAF-R. Conclusions We suggest that PAF-R-dependent pathways are activated during experimental tumour growth, modifying the microenvironment and the phenotype of the tumour macrophages in such a way as to favour tumour growth. Combination therapy with a PAF-R antagonist and a chemotherapeutic drug may represent a new and promising strategy for the treatment of some tumours.
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Lo scopo del clustering è quindi quello di individuare strutture nei dati significative, ed è proprio dalla seguente definizione che è iniziata questa attività di tesi , fornendo un approccio innovativo ed inesplorato al cluster, ovvero non ricercando la relazione ma ragionando su cosa non lo sia. Osservando un insieme di dati ,cosa rappresenta la non relazione? Una domanda difficile da porsi , che ha intrinsecamente la sua risposta, ovvero l’indipendenza di ogni singolo dato da tutti gli altri. La ricerca quindi dell’indipendenza tra i dati ha portato il nostro pensiero all’approccio statistico ai dati , in quanto essa è ben descritta e dimostrata in statistica. Ogni punto in un dataset, per essere considerato “privo di collegamenti/relazioni” , significa che la stessa probabilità di essere presente in ogni elemento spaziale dell’intero dataset. Matematicamente parlando , ogni punto P in uno spazio S ha la stessa probabilità di cadere in una regione R ; il che vuol dire che tale punto può CASUALMENTE essere all’interno di una qualsiasi regione del dataset. Da questa assunzione inizia il lavoro di tesi, diviso in più parti. Il secondo capitolo analizza lo stato dell’arte del clustering, raffrontato alla crescente problematica della mole di dati, che con l’avvento della diffusione della rete ha visto incrementare esponenzialmente la grandezza delle basi di conoscenza sia in termini di attributi (dimensioni) che in termini di quantità di dati (Big Data). Il terzo capitolo richiama i concetti teorico-statistici utilizzati dagli algoritimi statistici implementati. Nel quarto capitolo vi sono i dettagli relativi all’implementazione degli algoritmi , ove sono descritte le varie fasi di investigazione ,le motivazioni sulle scelte architetturali e le considerazioni che hanno portato all’esclusione di una delle 3 versioni implementate. Nel quinto capitolo gli algoritmi 2 e 3 sono confrontati con alcuni algoritmi presenti in letteratura, per dimostrare le potenzialità e le problematiche dell’algoritmo sviluppato , tali test sono a livello qualitativo , in quanto l’obbiettivo del lavoro di tesi è dimostrare come un approccio statistico può rivelarsi un’arma vincente e non quello di fornire un nuovo algoritmo utilizzabile nelle varie problematiche di clustering. Nel sesto capitolo saranno tratte le conclusioni sul lavoro svolto e saranno elencati i possibili interventi futuri dai quali la ricerca appena iniziata del clustering statistico potrebbe crescere.
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I modelli su reticolo con simmetrie SU(n) sono attualmente oggetto di studio sia dal punto di vista sperimentale, sia dal punto di vista teorico; particolare impulso alla ricerca in questo campo è stato dato dai recenti sviluppi in campo sperimentale per quanto riguarda la tecnica dell’intrappolamento di atomi ultrafreddi in un reticolo ottico. In questa tesi viene studiata, sia con tecniche analitiche sia con simulazioni numeriche, la generalizzazione del modello di Heisenberg su reticolo monodimensionale a simmetria SU(3). In particolare, viene proposto un mapping tra il modello di Heisenberg SU(3) e l’Hamiltoniana con simmetria SU(2) bilineare-biquadratica con spin 1. Vengono inoltre presentati nuovi risultati numerici ottenuti con l’algoritmo DMRG che confermano le previsioni teoriche in letteratura sul modello in esame. Infine è proposto un approccio per la formulazione della funzione di partizione dell’Hamiltoniana bilineare-biquadratica a spin-1 servendosi degli stati coerenti per SU(3).
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Questo studio prospettico valuta l’efficacia e i vantaggi del sistema LigasureTM rispetto alle tecniche chirurgiche tradizionali, in quattro differenti procedure eseguite su 77 cani. I soggetti sono stati suddivisi in 4 gruppi, a seconda della chirurgia eseguita: Gruppo 1, 25 pazienti sottoposti a Splenectomia “aperta” semplice; Gruppo 2, 15 pazienti sottoposti a Splenectomia “aperta” complessa; Gruppo 3, 22 pazienti sottoposti ad Ovariectomia “aperta”. Gruppo 4: 18 pazienti sottoposti a Linfoadenectomia. Ciascun gruppo è stato a sua volta suddiviso in due sottogruppi: a (LigasureTM) e b (Tradizionale), a seconda della metodica utilizzata. Sono stati analizzati: il segnalamento, i parametri ematologici, le condizioni cliniche, le informazioni riguardanti l’intervento chirurgico e l’outcome. In tutti i gruppi il ricorso all’utilizzo di garze nonché dei fili da sutura sono risultati statisticamente inferiori nei pazienti operati con il sistema a radiofrequenza (Gruppo 1, P < 0.0001; Gruppo 2, P < 0,0014; Gruppo 3, P = 0,0001; Gruppo 4, P = 0,0148). Anche i tempi per la rimozione dell’organo sono significativamente ridotti in tutti i gruppi in cui è stato utilizzato il sistema LigasureTM (Gruppo 1 P < 0.0001; Gruppo 2 P < 0,0014; Gruppo 3 P = 0,0009; Gruppo 4 P = 0,0008), come i tempi chirurgici nei gruppi 1, 2 e 3 (P = 0,0287; P = 0,0064; e P = 0,0124) ed anestesiologici nei gruppi 1a e 2a (P = 0,0176; P = 0,0043). Tra le variabili analizzate, l’utilizzo del sistema di sintesi vascolare a radiofrequenza, è l’unico ad influenzare i tempi necessari per l’esecuzione della procedura. Questo studio dimostra, quindi, come il sistema LigasureTM sia sicuro ed efficace per le procedure chirurgiche esaminate, riducendo i tempi della chirurgia e limitando, quindi, i rischi per il paziente, indipendentemente dall’operatore, dall’esecuzione di altre procedure contemporanee e dalla natura della patologia splenica o linfonodale.