2,173 research outputs found

    Neutrinoless Double Beta Decay Search with 76^{76}Ge: Status and Prospect with LEGEND

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    The search for neutrinoless double beta (0νββ0\nu\beta\beta) decay is the best way to test lepton number violation and Majorana nature of neutrinos. One of the most promising techniques to discover 0νββ0\nu\beta\beta decay is by operating High-Purity Ge detectors enriched in 76^{76}Ge. The current generation of 76^{76}Ge experiments, GERDA and MAJORANA, lead the field in the achieved energy resolution and ultra-low background. These are two of the most important characteristics for sensitive searches of this undiscovered decay. The next generation of 0νββ0\nu\beta\beta decay experiments requires more mass and further reduction of backgrounds to maximize the discovery potential. Building on the successes of GERDA and MAJORANA, the LEGEND collaboration has been formed to pursue a tonne-scale 76^{76}Ge experiment, with a discovery potential projected to be a half-life beyond 10^{28} years. The collaboration aims to develop a phased experimental program, starting with a 200 kg measurement by repurposing the existing Gerda infrastructure.Comment: Contribution to the 2019 EW session of the 54th Rencontres de Moriond, 6 pages, 7 figure

    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

    Genomics knowledge and attitudes among European public health professionals. Results of a cross-sectional survey

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    Background The international public health (PH) community is debating the opportunity to incorporate genomic technologies into PH practice. A survey was conducted to assess attitudes of the European Public Health Association (EUPHA) members towards their role in the implementation of public health genomics (PHG), and their knowledge and attitudes towards genetic testing and the delivery of genetic services. Methods EUPHA members were invited via monthly newsletter and e-mail to take part in an online survey from February 2017 to January 2018. A descriptive analysis of knowledge and attitudes was conducted, along with a univariate and multivariate analysis of their determinants. Results Five hundred and two people completed the questionnaire, 17.9% were involved in PHG activities. Only 28.9% correctly identified all medical conditions for which there is (or not) evidence for implementing genetic testing; over 60% thought that investing in genomics may divert economic resources from social and environmental determinants of health. The majority agreed that PH professionals may play different roles in incorporating genomics into their activities. Better knowledge was associated with positive attitudes towards the use of genetic testing and the delivery of genetic services in PH (OR = 1.48; 95% CI 1.01–2.18). Conclusions Our study revealed quite positive attitudes, but also a need to increase awareness on genomics among European PH professionals. Those directly involved in PHG activities tend to have a more positive attitude and better knowledge; however, gaps are also evident in this group, suggesting the need to harmonize practice and encourage greater exchange of knowledge among professionals

    Education and training among Italian postgraduate medical schools in public health: a comparative analysis

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    Analisi comparativa dei percorsi formativi offerti dalle Scuole di specializzazione di Igiene e Medicina Preventiva in Italia Background: Il percorso formativo dello specialista in Igiene e Medicina Preventiva dovrebbe garantire adeguate conoscenze tecnico-scientifiche e professionali nei campi della medicina preventiva, della promozione della salute e della programmazione dei servizi sanitari secondo quanto indicato anche dal DM 285/2005. La Consulta degli Specializzandi, da sempre coinvolta in attività di monitoraggio della formazione a livello nazionale, si prefigge l’obiettivo di valutare l’omogeneità delle proposte formative tra le diverse sedi italiane, non solo per segnalare le criticità, ma anche per evidenziarne le opportunità. Metodi: Lo studio, di tipo cross-sectional, è stato condotto mediante la somministrazione di un questionario semi-strutturato inviato per la compilazione ai rappresentanti delle 32 le Scuole di Igiene e Medicina Preventiva italiane. Lo strumento di valutazione è costituito da quattro sezioni: informazioni generali, attività formativa universitaria, attività formativa extra-universitaria, attività formativa intersettoriale. L’indagine è stata svolta nel periodo tra marzo e maggio 2013 ed è stata prodotta un’analisi descrittiva dei dati ottenuti. Risultati: Il questionario è stato compilato da 28 Scuole su 32 (tasso di risposta 88%), distribuite su tutto il territorio nazionale. Il numero di medici in formazione varia tra 7 e 31 e il rapporto tra docenti del settore scientifico-disciplinare di interesse e i discenti è compreso tra 0,2 e 2. Per quanto riguarda la didattica, solo in 4 Scuole si effettuano tutti i corsi previsti dal DM. La maggior parte delle sedi svolge almeno il 75% dei corsi previsti, ma esistono sedi in cui il numero di corsi è inferiore al 50%. La maggior parte delle Scuole svolge più del 60% delle attività professionalizzanti essenziali secondo il decreto, ma 2 Scuole non arrivano al 50%. Tutte le Scuole prevedono un tirocinio di 6-12 mesi in ASL, affiancando principalmente attività del Dipartimento di Prevenzione. Ovunque è previsto un periodo in Direzione Medica Ospedaliera, mentre le Strutture Riabilitative rientrano raramente nella rete formativa. Nella maggioranza delle Scuole è possibile frequentare aziende con rischio biologico oppure seguire simili attività nei Servizi dedicati della ASL. Molte Scuole, infine, consentono di frequentare diverse strutture territoriali (Agenzia di Controllo delle Acque), regionali (Assessorati) o nazionali (Ministero, Istituto Superiore di Sanità); in alcuni casi si tratta di Università gemellate e Istituti di Ricerca. Conclusioni: Nonostante il DM 285/2005 indichi quali siano le fondamenta della sanità pubblica, la flessibilità nella scelta formativa è vista come requisito essenziale per ottimizzare le risorse e contestualizzare l’adeguata formazione del medico in formazione specialistica in Igiene e Medicina Preventiva. La maggior parte delle Scuole di Specializzazione italiane dovrebbe però prevedere lo svolgimento della quasi totalità delle attività formative previste, al fine di non creare disuguaglianze formative tra gli specializzandi. Infine, considerato che la sanità pubblica è una disciplina in continuo divenire, il DM del 2005 andrebbe rivisitato tenendo in considerazione la flessibilità della formazione ed i continui cambiamenti dei bisogni di salute essenziali della popolazione. Inoltre, nel processo di rivisitazione dei bisogni formativi dei medici in formazione specialistica, dovrebbero essere coinvolti anche i discenti al fine di rafforzare il potere e l’efficacia dell’insegnamento.Background The postgraduate medical Schools in Public Health (locally known as School of Hygiene and Preventive Medicine) should ensure adequate scientific and technical knowledge and professional skills in preventive medicine, health promotion and healthcare planning as provided by Ministerial Decree 285/2005. The Italian Committee of Medical Residents in Hygiene, Preventive Medicine and Public Health of the Italian Society of Hygiene, Public Health and Preventive Medicine - S.It.I. (Consulta Nazionale dei medici in formazione specialistica S.It.I.) has always been engaged in monitoring activities on public health teaching, guaranteeing the homogeneity of educational proposals among all national Schools in Public Health. The purpose of this study is to provide a 'snapshot' of public health education and training in Italy and to identify the improvement actions needed for implementing an innovative and homogeneous public health training. Methods: A cross-sectional study was carried out over a period of three months (March to May 2013). A self-administered questionnaire was e-mailed to local Committee’s delegates of all 32 postgraduate medical Schools in Public Health in Italy. The questionnaire was structured in four sections: general information, University education and training, extra-University training, interdisciplinary activities. The majority of local Committee’s delegates have agreed to be enrolled in the survey. Results: A total of 28 questionnaires were returned (88% response rate). The number of residents in each Italian School in Public Health ranged from 7 to 31. The distribution of professors in relation to residents is not similar for each University Schools. The ratio professors/residents spanning from 0.2 to 2. About teaching, only 4 University Schools offered all courses requested by Ministerial Decree 285/2005. Most of them offered at least 75% of the requested courses, but there were Schools in which the courses were less than 50%. The vast majority of schools held more than 60% of the qualifying activities considered essential according to the Decree, while 2 Schools were below 50%. All Schools required an internship of 6-12 months in local health authority offices (ASL), mainly concerning the Department of Prevention activities. In all Schools a period of stay in a Hospital Medical Direction was scheduled, while professional activities at Residential care homes were very rarely included in training programmes. Many Schools allowed residents to attend companies with biological hazard or to follow similar activities in dedicated services of ASL. Finally, in the majority of Schools, a training period in various local (Service for Water Control), regional (Departments) or national (Ministry, National Institute of Health) health facilities was contemplated and, in some cases, also in other Universities or Research Institutes. Conclusions: Although the Ministerial Decree indicates the essential milestones of the public health education, flexibility is seen as an important element in order to optimize resources and contextualize the adequate education of residents. In any case, at least regarding public health courses, the majority of University education and extra-University training activities should be carried out by all Schools. In order to obtain shared knowledge and skills, the Ministerial Decree should be revised taking into account flexibility and changing as intrinsic characteristics of public health profession and learners should be involved in the reform to strengthening the role of public health teachin

    Minimal length in quantum space and integrations of the line element in Noncommutative Geometry

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    We question the emergence of a minimal length in quantum spacetime, comparing two notions that appeared at various points in the literature: on the one side, the quantum length as the spectrum of an operator L in the Doplicher Fredenhagen Roberts (DFR) quantum spacetime, as well as in the canonical noncommutative spacetime; on the other side, Connes' spectral distance in noncommutative geometry. Although on the Euclidean space the two notions merge into the one of geodesic distance, they yield distinct results in the noncommutative framework. In particular on the Moyal plane, the quantum length is bounded above from zero while the spectral distance can take any real positive value, including infinity. We show how to solve this discrepancy by doubling the spectral triple. This leads us to introduce a modified quantum length d'_L, which coincides exactly with the spectral distance d_D on the set of states of optimal localization. On the set of eigenstates of the quantum harmonic oscillator - together with their translations - d'_L and d_D coincide asymptotically, both in the high energy and large translation limits. At small energy, we interpret the discrepancy between d'_L and d_D as two distinct ways of integrating the line element on a quantum space. This leads us to propose an equation for a geodesic on the Moyal plane.Comment: 29 pages, 2 figures. Minor corrections to match the published versio

    Is contrast-enhanced US alternative to spiral CT in the assessment of treatment outcome of radiofrequency ablation in hepatocellular carcinoma?

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    Purpose: The present study was conducted to assess the efficacy of contrast-enhanced ultrasound with low mechanical index in evaluating the response of percutaneous radiofrequency ablation treatment of hepatocellular carcinoma by comparing it with 4-row spiral computed tomography. Materials and Methods: 100 consecutive patients (65 men and 35 women; age range: 62 – 76 years) with solitary hepatocellular carcinomas (mean lesion diameter: 3.7cm± 1.1cm SD) underwent internally cooled radiofrequency ablation. Therapeutic response was evaluated at one month after the treatment with triple-phasic contrast-enhanced spiral CT and low-mechanical index contrast-enhanced ultrasound following bolus injection of 2.4 ml of Sonovue (Bracco, Milan). 60 out of 100 patients were followed up for another 3 months. Contrast-enhanced sonographic studies were reviewed by two blinded radiologists in consensus. Sensitivity, specificity, NPV and PPV of contrast-enhanced ultrasound examination were determined. Results: After treatment, contrast-enhanced ultrasound identified persistent signal enhancement in 24 patients (24%), whereas no intratumoral enhancement was detected in the remaining 76 patients (76%). Using CT imaging as gold standard, the sensitivity, specificity, NPV, and PPV of contrast enhanced ultrasound were 92.3% (95% CI = 75.9 – 97.9%), 100% (95% CI = 95.2 – 100%), 97.4% (95% CI = 91.1 – 99.3%), and 100% (95% CI = 86.2 – 100%). Conclusion: Contrast-enhanced ultrasound with low mechanical index using Sonovue is a feasible tool in evaluating the response of hepatocellular carcinoma to radiofrequency ablation. Accuracy is comparable to 4-row spiral CT

    Predictors of mortality in primary antiphospholipid syndrome. A single-centre cohort study.

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    The vascular mortality of antiphospholipid syndrome (APS) ranges from 1.4 % to 5.5 %, but its predictors are poorly known. It was the study objective to evaluate the impact of baseline lupus anticoagulant assays, IgG anticardiolipin (aCL), plasma fibrinogen (FNG) and von Willebrand factor (VWF), platelets (PLT) and of genetic polymorphisms of methylenetetrahydrofolate reductase C677T, of prothrombin G20210A and of paraoxonase-1 Q192R on mortality in primary APS (PAPS). Cohort study on 77 thrombotic PAPS and 33 asymptomatic carriers of aPL (PCaPL) seen from 1989 to 2015 and persistently positive for aPL as per annual review. At baseline all participants were tested twice for the ratios of kaolin clotting time (KCTr), activated partial thromboplastin time (aPTTr), dilute Russell viper venom time (DRVVTr), IgG aCL, FNG, VWF and once for PLT. All thrombotic PAPS were on warfarin with regular INR monitoring. During follow-up 11 PAPS deceased (D-PAPS) of recurrent thrombosis despite adequate anticoagulation yielding an overall vascular mortality of 10 %. D-PAPS had the strongest baseline aPTTr and DRVVTr and the highest mean baseline IgG aCL, FNG, VWF and PLT. Cox proportional hazards model identified baseline DRVVTr and FNG as main predictors of mortality with adjusted hazard ratios of 5.75 (95 % confidence interval [CI]: 1.5, 22.4) and of 1.03 (95 %CI: 1.01, 1.04), respectively. In conclusion, plasma DRVVTr and FNG are strong predictors of vascular mortality in PAPS; while FNG lowering agents exist further research should be directed at therapeutic strategies able to dampen aPL production

    Comparison of relativity theories with observer-independent scales of both velocity and length/mass

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    We consider the two most studied proposals of relativity theories with observer-independent scales of both velocity and length/mass: the one discussed by Amelino-Camelia as illustrative example for the original proposal (gr-qc/0012051) of theories with two relativistic invariants, and an alternative more recently proposed by Magueijo and Smolin (hep-th/0112090). We show that these two relativistic theories are much more closely connected than it would appear on the basis of a naive analysis of their original formulations. In particular, in spite of adopting a rather different formal description of the deformed boost generators, they end up assigning the same dependence of momentum on rapidity, which can be described as the core feature of these relativistic theories. We show that this observation can be used to clarify the concepts of particle mass, particle velocity, and energy-momentum-conservation rules in these theories with two relativistic invariants.Comment: 21 pages, LaTex. v2: Andrea Procaccini (contributing some results from hia Laurea thesis) is added to the list of authors and the paper provides further elements of comparison between DSR1 and DSR2, including the observation that both lead to the same formula for the dependence of momentum on rapidit
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