A WZW model based on a non-semi-simple group

We present a conformal field theory which desribes a homogeneous four dimensional Lorentz-signature space-time. The model is an ungauged WZW model based on a central extension of the Poincar\'e algebra. The central charge of this theory is exactly four, just like four dimensional Minkowski space. The model can be interpreted as a four dimensional monochromatic plane wave. As there are three commuting isometries, other interesting geometries are expected to emerge via $O(3,3)$ duality.Comment: 8 pages, phyzzx, IASSNS-HEP-93/61 Texable versio

Vulnerabilità del territorio vesuviano a fenomeni meteorologici attraverso l’analisi quantitativa di fattori geologici ed antropici.

In questo lavoro viene descritta l’applicazione al territorio vesuviano di una metodologia di analisi geomorfologico-quantitativa multiparametrica da DTM (Digital Terrain Model) di dettaglio (5x5m) in ambiente GIS, utilizzando procedure di analisi e tecniche di valutazione della vulnerabilità a fenomeni meteorologici che tengano conto della complessità dell’assetto geologico, geomorfologico, urbanistico ed economico dell’area. Il risultato del lavoro è stato la realizzazione di mappe di vulnerabilità idrogeologica prodotte tenendo conto delle mutue relazioni tra fattori territoriali ed antropici. L’obiettivo di questo studio è stato sviluppare un sistema di analisi utile alla valutazione del rischio idrogeologico ed al suo controllo e prevenzione, considerato che negli ultimi anni si e’ assistito ad incrementi rilevanti e disordinati dell’urbanizzazione nell’area vesuviana, per la maggior parte abusiva e con forti carenze strutturali, che, unitamente ad eventi piovosi particolarmente intensi nonché alle caratteristiche geologico-geomorfologiche del territorio, hanno causato eventi franosi parossistici come quelli dei comuni di Sarno, Episcopia e Bracigliano. L’area di indagine, rappresentata dal complesso vulcanico del Somma–Vesuvio in Campania, è densamente abitata (2500 abitanti per km2) ed oltre ad essere ad alto rischio vulcanico è anche esposta ad alto rischio idrogeologico come dimostrato dalle ripetute esondazioni disastrose fin dall’epoca storica (Accardo et al., 1981; Catenacci et al., 1992). La conoscenza dell’assetto geologico e geomorfologico del complesso Somma-Vesuvio è necessaria per una corretta individuazione dei parametri utili per questo studio. Un esempio è quello della caratterizzazione dei versanti del vulcano, fattore di notevole importanza per la valutazione del rischio idrogeologico, sia per la pendenza che per le loro caratteristiche morfologiche superficiali. Il primo parametro geomorfologico adottato per l’applicazione della metodologia (Tagil and Jenness, 2008) è stato l’indice di posizione topografica (TPI, Topographic Position Index) che ha consentito una classificazione del paesaggio sia in base alla distribuzione areale delle pendenze (slope position) che in classi uniformi di paesaggio (landform classes). La classificazione finale è stata adeguata al particolare paesaggio oggetto di studio, che è di tipo vulcanico. L’analisi della vulnerabilità è stata condotta tenendo conto della permeabilità del suolo e dei dati pluviometrici in quanto possibili fattori predisponenti al dissesto idrogeologico. Il GIS ha rappresentato lo strumento necessario per gestire dati di tipo diverso ed effettuarne l’analisi e la rappresentazione congiunta. Il software utilizzato è stato ArcGis (9.3) e attraverso l’applicazione Spatial Analyst è stato possibile estrarre dati ed informazioni nuove che non sarebbe stato possibile ottenere con l’analisi geomorfologica classica da cartografia su supporto cartaceo. La realizzazione di mappe di vulnerabilità idrogeologica dell’area del Somma-Vesuvio, ottenute stabilendo le relazioni tra i vari fattori incidenti con l’ausilio di metodologie note (Cherubini et al., 2006), ha rappresentato uno dei risultati del lavoro. Le interrelazioni tra i vari fattori (geologico, geomorfologico, idrogeologico, urbanistico) mostrate dalle mappe prodotte costituiscono uno strumento indispensabile per monitorare il rischio territoriale e per poter intervenire laddove venga superata una soglia di rischio ritenuta accettabile

The current progress of the ALICE Ring Imaging Cherenkov Detector

Recently, the last two modules (out of seven) of the ALICE High Momentum Particle Identification detector (HMPID) were assembled and tested. The full detector, after a pre-commissioning phase, has been installed in the experimental area, inside the ALICE solenoid, at the end of September 2006. In this paper we review the status of the ALICE/HMPID project and we present a summary of the series production of the CsI photo-cathodes. We describe the key features of the production procedure which ensures high quality photo-cathodes as well as the results of the quality assessment performed by means of a specially developed 2D scanner system able to produce a detailed map of the CsI photo-current over the entire photo-cathode surface. Finally we present our recent R&D efforts toward the development of a novel generation of imaging Cherenkov detectors with the aim to identify, in heavy ions collisions, hadrons up to 30 GeV/c.Comment: Presented at the Imaging-2006 Conference, Stockholm, Sweden, June 200

Heterogeneous response to immunotherapy in a patient with tonsillar squamous cell carcinoma assessed by18f-fdg pet/ct

Tonsillar carcinoma is the second most common malignancy of the head and neck region, with Squamous Cell Carcinoma (TSCC) as the most common histological type (>90%). For the advanced stage of TSCC, radiotherapy with or without platinum-based chemotherapy is the only therapeutic option. Immuno-checkpoint inhibitors (ICIs), in particular Nivolumab, considerably improves clinical management of these patients, but the response can be unpredictable. Difficulties can be encountered in evaluating response to immunotherapy, especially with morphological imaging, which can show an atypical response, such as pseudo-progression, leading to a premature discontinuation. Conversely, metabolic imaging can guide a more properly therapeutic decision. We present a case of a 71-year-old man affected by TSCC, treated with chemotherapy, radiotherapy, and Nivolumab as the last line of treatment. Pre-and post-immunotherapy18F-FDG PET/CT showed an impressive response, avoiding early drug discontinuation and ensuring better management of this patient

R&D results on a CsI-TTGEM based photodetector

The very high momentum particle identification detector proposed for the ALICE upgrade is a focusing RICH using a C4F10 gaseous radiator. For the detection of Cherenkov photons, one of the options currently under investigation is to use a CsI coated Triple-Thick-GEM (CsI-TTGEM) with metallic or resistive electrodes. We will present results from the laboratory studies as well as preliminary results of beam tests of a RICH detector prototype consisting of a CaF2 radiator coupled to a 10x10 cm2 CsI-TTGEM equipped with a pad readout and GASSIPLEX-based front-end electronics. With such a prototype the detection of Cherenkov photons simultaneously with minimum ionizing particles has been achieved for the first time in a stable operation mode

Signals of Warped Extra Dimensions at the LHC

We discuss the signatures of the spin-2 graviton excitations predicted by the Randall-Sundrum model with one warped extra dimension, in dilepton and diphoton production at LHC. By using a specific angular analysis, we assess the ranges in mass and coupling constant where such gravitons can be discriminated against competitor spin-1 and spin-0 objects, that potentially could manifest themselves in these processes with the same mass and rate of events. Depending on the value of the coupling constant to quarks and leptons, the numerical results indicate graviton identification mass ranges up to 1.1-2.4 TeV and 1.6-3.2 TeV for LHC nominal energy of 14 TeV and time-integrated luminosity of 10 and 100~${\rm fb}^{-1}$, respectively.Comment: 8 pages, Talk given at QCD@Work - International Workshop on QCD - Theory and Experiment, 20 - 23 June, 2010, Martina Franca Ital

Progress in the development of a S RETGEM-based detector for an early forest fire warning system

In this paper we present a prototype of a Strip Resistive Thick GEM photosensitive gaseous detector filled with Ne and ethylferrocene vapours at a total pressure of 1 atm for an early forest fire detection system. Tests show that it is one hundred times more sensitive than the best commercial ultraviolet flame detectors and therefore, it is able to reliably detect a flame of 1.5x1.5x1.5 m3 at a distance of about 1km. An additional and unique feature of this detector is its imaging capability, which in combination with other techniques, may significantly reduce false fire alarms when operating in an automatic mode. Preliminary results conducted with air filled photosensitive gaseous detectors are also presented. The approach main advantages include both the simplicity of manufacturing and affordability of construction materials such as plastics and glues specifically reducing detector production cost. The sensitivity of these air filled detectors at certain conditions may be as high as those filled with Ne and EF. Long term test results of such sealed detectors indicate a significant progress in this direction. We believe that our detectors utilized in addition to other flame and smoke sensors will exceptionally increase the sensitivity of forest fire detection systems. Our future efforts will be focused on attempts to commercialize such detectors utilizing our aforementioned findings.Comment: Presented at the International Conference on Micropattern gaseous detectors, Crete, Greece, June 200

Bibliometric Evaluation vs. Informed Peer Review: Evidence from Italy

A relevant question for the organization of large scale research assessments is whether bibliometric evaluation and informed peer review where reviewers know where the work was published, yield similar results. It would suggest, for instance, that less costly bibliometric evaluation might - at least partly - replace informed peer review, or that bibliometric evaluation could reliably monitor research in between assessment exercises. We draw on our experience of evaluating Italian research in Economics, Business and Statistics, where almost 12,000 publications dated 2004-2010 were assessed. A random sample from the available population of journal articles shows that informed peer review and bibliometric analysis produce similar evaluations of the same set of papers. Whether because of independent convergence in assessment, or the influence of bibliometric information on the community of reviewers, the implication for the organization of these exercises is that these two approaches are substitutes

Bibliometric Evaluation vs. Informed Peer Review:Evidence from Italy

A relevant question for the organization of large scale research assessments is whether bibliometric evaluation and informed peer review where reviewers know where the work was published, yield similar results. It would suggest, for instance, that less costly bibliometric evaluation might - at least partly - replace informed peer review, or that bibliometric evaluation could reliably monitor research in between assessment exercises. We draw on our experience of evaluating Italian research in Economics, Business and Statistics, where almost 12,000 publications dated 2004-2010 were assessed. A random sample from the available population of journal articles shows that informed peer review and bibliometric analysis produce similar evaluations of the same set of papers. Whether because of independent convergence in assessment, or the influence of bibliometric information on the community of reviewers, the implication for the organization of these exercises is that these two approaches are substitutes