4,556 research outputs found

    On the Defect Group of a 6D SCFT

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    We use the F-theory realization of 6D superconformal field theories (SCFTs) to study the corresponding spectrum of stringlike, i.e. surface defects. On the tensor branch, all of the stringlike excitations pick up a finite tension, and there is a corresponding lattice of string charges, as well as a dual lattice of charges for the surface defects. The defect group is data intrinsic to the SCFT and measures the surface defect charges which are not screened by dynamical strings. When non-trivial, it indicates that the associated theory has a partition vector rather than a partition function. We compute the defect group for all known 6D SCFTs, and find that it is just the abelianization of the discrete subgroup of U(2) which appears in the classification of 6D SCFTs realized in F-theory. We also explain how the defect group specifies defining data in the compactification of a (1,0) SCFT.Comment: 24 page

    Higher form symmetries of Argyres-Douglas theories

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    We determine the structure of 1-form symmetries for all 4d N = 2 theories that have a geometric engineering in terms of type IIB string theory on isolated hypersurface singularities. This is a large class of models, that includes Argyres-Douglas theories and many others. Despite the lack of known gauge theory descriptions for most such theories, we find that the spectrum of 1-form symmetries can be obtained via a careful analysis of the non-commutative behaviour of RR fluxes at infinity in the IIB setup. The final result admits a very compact field theoretical reformulation in terms of the BPS quiver. We illustrate our methods in detail in the case of the (g,g′) Argyres-Douglas theories found by Cecotti-Neitzke-Vafa. In those cases where N = 1 gauge theory descriptions have been proposed for theories within this class, we find agreement between the 1-form symmetries of such N = 1 Lagrangian flows and those of the actual Argyres-Douglas fixed points, thus giving a consistency check for these proposals

    Higher form symmetries and M-theory

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    We discuss the geometric origin of discrete higher form symmetries of quantum field theories in terms of defect groups from geometric engineering in M-theory. The flux non-commutativity in M-theory gives rise to (mixed) ’t Hooft anomalies for the defect group which constrains the corresponding global structures of the associated quantum fields. We analyze the example of 4d N = 1 SYM gauge theory in four dimensions, and we reproduce the well-known classification of global structures from reading between its lines. We extend this analysis to the case of 7d N = 1 SYM theory, where we recover it from a mixed ’t Hooft anomaly among the electric 1-form center symmetry and the magnetic 4-form center symmetry in the defect group. The case of five-dimensional SCFTs from M-theory on toric singularities is discussed in detail. In that context we determine the corresponding 1-form and 2-form defect groups and we explain how to determine the corresponding mixed ’t Hooft anomalies from flux non-commutativity. Several predictions for non-conventional 5d SCFTs are obtained. The matching of discrete higher-form symmetries and their anomalies provides an interesting consistency check for 5d dualities

    Impact of pneumococcal conjugate vaccination: a retrospective study of hospitalization for pneumonia in North-East Italy

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    Introduction. Pneumonia remains a common reason for hospitalizing infants and the elderly worldwide, and streptococcal infection is often responsible. The aim of this study was to assess the burden of pneumonia in a large general population. Methods. All pneumonia-related hospitalizations from 2004 to 2013 in north-east Italy were identified from the hospital records with a first-listed diagnosis on discharge of bacterial pneumonia, or a first-listed diagnosis on discharge of meningitis, septicemia or empyema associated with a secondary diagnosis of bacterial pneumonia. We identified major comorbidities, calculated agespecific case-fatality rates (CFR), and estimated the related cost to the health care system. Results. Of the 125,722 hospitalizations identified, 96.9% were cases of pneumonia, 2.4% of septicemia, 0.4% of meningitis, and 0.3% of empyema; 75.3% of hospitalizations involved 65 65-yearolds. The overall CFR was 12.4%, and it increased with age, peaking in people over 80 (19.6%). The mean annual pneumonia-associated hospitalization rate was 204.6 per 100,000 population, and it peaked in 0- to 4-year-old children (325.6 per 100,000 in males, 288.9 per 100,000 in females), and adults over 65 (844.9 per 100,000 in males, 605.7 per 100,000 in females). Hospitalization rates dropped over the years for the 0-4 year-olds, and rose for people over 80. The estimated overall annual cost of these pneumonia-related hospitalizations was approximately \u20ac 41 million. Conclusions. This study shows that the burden on resources for pneumonia-related hospitalization is an important public health issue. Prevention remains the most valuable tool for containing pneumonia, and vaccination strategies can help in the primary prevention of infection, possibly reducing the number of cases in all age groups

    The Higgs branch of heterotic ALE instantons

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    We begin a study of the Higgs branch of six-dimensional (1, 0) little string theories governing the worldvolumes of heterotic ALE instantons. We give a description of this space by constructing the corresponding magnetic quiver. The latter is a three-dimensional N = 4 quiver gauge theory that fows in the infrared to a fxed point whose quantum corrected Coulomb branches is the Higgs branch of the six-dimensional theory of interest. We present results for both types of heterotic strings, and mostly for C 2/Zk ALE spaces. Our analysis is valid both in the absence and in the presence of small instantons. Along the way, we also describe small SO(32) instanton transitions in terms of the corresponding magnetic quiver, which parallels a similar treatment of the small E8 instanton transitions in the context of the E8 Ă— E8 heterotic string

    A new vista on the heterotic moduli space from six and three dimensions

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    We settle a longstanding question about the hypermultiplet moduli spaces of the heterotic strings on asymptotically locally Euclidean singularities. These heterotic backgrounds are specified by the singularity type, an instanton number, and a (nontrivial) flat connection at infinity. Building on their interpretation as six-dimensional theories, we determine a class of three-dimensional N=4 quiver gauge theories whose quantum corrected Coulomb branch coincides with the exact heterotic hypermultiplet moduli space

    Infinitely many N=2 SCFT with ADE flavor symmetry

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    We present evidence that for each ADE Lie group G there is an infinite tower of 4D N = 2 SCFTs, which we label as D(G, s) with s 08 \u2115, having (at least) flavor symmetry G. For G = SU(2), D(SU(2),s) coincides with the Argyres-Douglas model of type D8+1, while for larger flavor groups the models are new (but for a few previously known examples). When its flavor symmetry G is gauged, D(G,s) contributes to the Yang-Mills beta-function as 8/2(+1) adjoint hypermultiplets. The argument is based on a combination of Type IIB geometric engineering and the categorical deconstruction of arXiv: 1203.6743. One first engineers a class of N = 2 models which, trough the analysis of their category of quiver representations, are identified as asymptotically-free gauge theories with gauge group G coupled to some conformal matter system. Taking the limit gYM \u2192 0 one isolates the matter SCFT which is our D(G, s). \ua9 SISSA 2013

    Mechanisms involved in the β-cell mass increase induced by chronic sucrose feeding to normal rats

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    The aim of the present study was to clarify the mechanisms by which a sucrose-rich diet (SRD) produces an increase in the pancreatic β-cell mass in the rat. Normal Wistar rats were fed for 30 weeks either an SRD (SRD rats; 63% wt/wt), or the same diet but with starch instead of sucrose in the same proportion (CD rats). We studied body weight, serum glucose and triacylglycerol levels, endocrine tissue and β-cell mass, β-cell replication rate (proliferating cell nuclear antigen; PCNA), islet neogenesis (cytokeratin immunostaining) and β-cell apoptosis (propidium iodide). Body weight (g) recorded in the SRD rats was significantly (P<0.05) larger than that of the CD group (556.0 ± 8.3 vs 470.0 ± 13.1). Both serum glucose and triacylglycerol levels (mmol/l) were also significantly higher (P<0.05) in SRD than in CD rats (serum glucose, 8.11 ± 0.14 vs 6.62 ± 0.17; triacyglycerol, 1.57 ± 0.18 vs 0.47 ± 0.04). The number of pancreatic islets per unit area increased significantly (P<0.05) in SRD rats (3.29 ± 0.1 vs 2.01 ± 0.2). A significant increment (2.6 times) in the mass of endocrine tissue was detected in SRD animals, mainly due to an increase in the β-cell mass (P=0.0025). The islet cell replication rate, measured as the percentage of PCNA-labelled β cells increased 6.8 times in SRD rats (P<0.03). The number of apoptotic cells in the endocrine pancreas decreased significantly (three times) in the SRD animals (P=0.03). The cytokeratin-positive area did not show significant differences between CD and SRD rats. The increase of β-cell mass induced by SRD was accomplished by an enhanced replication of β cells together with a decrease in the rate of β-cell apoptosis, without any evident participation of islet neogenesis. This pancreatic reaction was unable to maintain serum glucose levels of these rats at the level measured in CD animals.Centro de Endocrinología Experimental y AplicadaFacultad de Ciencias Médica

    Increased cancer risk in patients undergoing dialysis: a population-based cohort study in North-Eastern Italy

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    open116noBACKGROUND: In southern Europe, the risk of cancer in patients with end-stage kidney disease receiving dialysis has not been well quantified. The aim of this study was to assess the overall pattern of risk for de novo malignancies (DNMs) among dialysis patients in the Friuli Venezia Giulia region, north-eastern Italy. METHODS: A population-based cohort study among 3407 dialysis patients was conducted through a record linkage between local healthcare databases and the cancer registry (1998-2013). Person-years (PYs) were calculated from 30 days after the date of first dialysis to the date of DNM diagnosis, kidney transplant, death, last follow-up or December 31, 2013, whichever came first. The risk of DNM, as compared to the general population, was estimated using standardized incidence ratios (SIRs) and 95% confidence intervals (CIs). RESULTS: During 10,798 PYs, 357 DNMs were diagnosed in 330 dialysis patients. A higher than expected risk of 1.3-fold was found for all DNMs combined (95% CI: 1.15-1.43). The risk was particularly high in younger dialysis patients (SIR = 1.88, 95% CI: 1.42-2.45 for age 40-59 years), and it decreased with age. Moreover, significantly increased DNM risks emerged during the first 3 years since dialysis initiation, especially within the first year (SIR = 8.52, 95% CI: 6.89-10.41). Elevated excess risks were observed for kidney (SIR = 3.18; 95% CI: 2.06-4.69), skin non-melanoma (SIR = 1.81, 95% CI: 1.46-2.22), oral cavity (SIR = 2.42, 95% CI: 1.36-4.00), and Kaposi's sarcoma (SIR = 10.29, 95% CI: 1.25-37.16). CONCLUSIONS: The elevated risk for DNM herein documented suggest the need to implement a targeted approach to cancer prevention and control in dialysis patients.openTaborelli, Martina; Toffolutti, Federica; Del Zotto, Stefania; Clagnan, Elena; Furian, Lucrezia; Piselli, Pierluca; Citterio, Franco; Zanier, Loris; Boscutti, Giuliano; Serraino, Diego for the Italian Transplant & Cancer Cohort Study; Sarah Shalaby, Raffaella Petrara, Patrizia Burra, Giacomo Zanus, Stefano Zanini,Paolo Rigotti; Maria Rendina, AlfredoDi Leo, Francesco Paolo Schena, Giuseppe Grandaliano, Marco Fiorentino, Augusto Lauro, Antonio Daniele Pinna, PaoloDi Gioia, Sara Pellegrini, Chiara Zanfi, Maria Piera Scolari, Sergio Stefoni, PaolaTodeschini, Laura Panicali, Chiara Valentini, Umberto Baccarani, Andrea Risaliti, Gian Luigi Adani, Dario Lorenzin, Giuseppe Maria Ettorre, Giovanni Vennarecci,Marco Colasanti, Manuela Coco, Fabrizio Ettorre, Roberto Santoro, LuciaMiglioresi, Francesco Nudo, Massimo Rossi,Gianluca Mennini, Luca Toti, GiuseppeTisone, Annachiara Casella, Laura Fazzolari, Daniele Sforza, Giuseppe Iaria,Carlo Gazia, Chiara Belardi, ClaudiaCimaglia, Alessandro Agresta, Gianpiero D’Offizi, Ubaldo Visco Comandini,Raffaella Lionetti, Marzia Montalbano, Chiara Taibi, Giovanni Fantola, Fausto Zamboni, Gian Benedetto Piredda,Maria Benigna Michittu, Maria Gavina Murgia, Bruno Onano, Lucia Fratino, Luigino Dal Maso, Paolo De Paoli, Diana Verdirosi,Emanuela Vaccher, Francesco Pisani, Antonio Famulari, Federica Delreno, Samuele Iesari, LindaDe Luca, Maurizio Iaria, Enzo Capocasale,Elena Cremaschi, Silvio Sandrini, Francesca Valerio,Valentina Mazzucotelli, Nicola Bossini, Gisella Setti, Massimiliano Veroux, Pierfrancesco Veroux, Giuseppe Giuffrida,Alessia Giaquinta, Domenico Zerbo, GhilBusnach, Laura Di Leo, Maria Luisa Perrino, Marialuisa Querques, ValerianaColombo, Maria Chiara Sghirlanzoni , Piergiorgio Messa, Antonio Leoni , Laura Galatioto, Salvatore Gruttadauria, Vito Sparacino, FlaviaCaputo, Barbara Buscemi ,Franco Cit-terio, Gionata Spagnoletti, Maria Paola Salerno, Evaldo Favi Giuseppe Paolo Segoloni, Luigi Biancone, AntonioLavacca, Maria Cristina Maresca, CarmeloCascone, Bice Virgilio, Donato Donati, Fiorella Dossi, Andrea Fontanella, Andrea Ambrosini, Marco Di CiccoTaborelli, Martina; Toffolutti, Federica; Del Zotto, Stefania; Clagnan, Elena; Furian, Lucrezia; Piselli, Pierluca; Citterio, Franco; Zanier, Loris; Boscutti, Giuliano; Serraino, Diego for the Italian Transplant & Cancer Cohort Study; Shalaby, Sarah; Petrara, MARIA RAFFAELLA; Burra, Patrizia; Zanus, Giacomo; Zanini, Stefano; Rigotti, Paolo; Maria, Rendina; Alfredodi, Leo; Francesco Paolo Schena, ; Giuseppe, Grandaliano; Marco, Fiorentino; Augusto, Lauro; Antonio Daniele Pinna, ; Paolodi, Gioia; Sara, Pellegrini; Chiara, Zanfi; Maria Piera Scolari, ; Sergio, Stefoni; Paolatodeschini, ; Laura, Panicali; Chiara, Valentini; Umberto, Baccarani; Andrea, Risaliti; Gian Luigi Adani, ; Dario, Lorenzin; Giuseppe Maria Ettorre, ; Giovanni, Vennarecci; Marco, Colasanti; Manuela, Coco; Fabrizio, Ettorre; Roberto, Santoro; Luciamiglioresi, ; Francesco, Nudo; Massimo, Rossi; Gianluca, Mennini; Luca, Toti; Giuseppetisone, ; Annachiara, Casella; Laura, Fazzolari; Daniele, Sforza; Giuseppe, Iaria; Carlo, Gazia; Chiara, Belardi; Claudiacimaglia, ; Alessandro, Agresta; Gianpiero, D’Offizi; Ubaldo Visco Comandini, ; Raffaella, Lionetti; Marzia, Montalbano; Chiara, Taibi; Giovanni, Fantola; Fausto, Zamboni; Gian Benedetto Piredda, ; Maria Benigna Michittu, ; Maria Gavina Murgia, ; Bruno, Onano; Lucia, Fratino; Luigino Dal Maso, ; Paolo De Paoli, ; Diana, Verdirosi; Emanuela, Vaccher; Francesco, Pisani; Antonio, Famulari; Federica, Delreno; Samuele, Iesari; Lindade, Luca; Maurizio, Iaria; Enzo, Capocasale; Elena, Cremaschi; Silvio, Sandrini; Francesca, Valerio; Valentina, Mazzucotelli; Nicola, Bossini; Gisella, Setti; Massimiliano, Veroux; Pierfrancesco, Veroux; Giuseppe, Giuffrida; Alessia, Giaquinta; Domenico, Zerbo; Ghilbusnach, ; Laura Di Leo, ; Maria Luisa Perrino, ; Marialuisa, Querques; Valerianacolombo, ; Maria Chiara Sghirlanzoni, ; Piergiorgio, Messa; Antonio, Leoni; Laura, Galatioto; Salvatore, Gruttadauria; Vito, Sparacino; Flaviacaputo, ; Barbara, Buscemi; Franco, Cit-terio; Gionata, Spagnoletti; Maria Paola Salerno, ; Evaldo Favi Giuseppe Paolo Segoloni, ; Luigi, Biancone; Antoniolavacca, ; Maria Cristina Maresca, ; Carmelocascone, ; Bice, Virgilio; Donato, Donati; Fiorella, Dossi; Andrea, Fontanella; Andrea, Ambrosini; Marco Di Cicco

    6D SCFTs and gravity

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    We study how to couple a 6D superconformal field theory (SCFT) to gravity. In F-theory, the models in question are obtained working on the supersymmetric background R \mathbb{R} 5,1 × B where B is the base of a compact elliptically fibered Calabi-Yau threefold in which two-cycles have contracted to zero size. When the base has orbifold singularities, we find that the anomaly polynomial of the 6D SCFTs can be understood purely in terms of the intersection theory of fractional divisors: the anomaly coefficient vectors are identified with elements of the orbifold homology. This also explains why in certain cases, the SCFT can appear to contribute a “fraction of a hypermultiplet” to the anomaly polynomial. Quantization of the lattice of string charges also predicts the existence of additional light states beyond those captured by such fractional divisors. This amounts to a refinement to the lattice of divisors in the resolved geometry. We illustrate these general considerations with explicit examples, focusing on the case of F-theory on an elliptic Calabi-Yau threefold with base P2/Z3 {\mathrm{\mathbb{P}}}^2/{\mathbb{Z}}_3
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