380 research outputs found

    model checking for data anomaly detection

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    Abstract Data tipically evolve according to specific processes, with the consequent possibility to identify a profile of evolution: the values it may assume, the frequencies at which it changes, the temporal variation in relation to other data, or other constraints that are directly connected to the reference domain. A violation of these conditions could be the signal of different menaces that threat the system, as well as: attempts of a tampering or a cyber attack, a failure in the system operation, a bug in the applications which manage the life cycle of data. To detect such violations is not straightforward as processes could be unknown or hard to extract. In this paper we propose an approach to detect data anomalies. We represent data user behaviours in terms of labelled transition systems and through the model checking techniques we demonstrate the proposed modeling can be exploited to successfully detect data anomalies

    Measurements and optimization of the light yield of a TeO2_2 crystal

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    Bolometers have proven to be good instruments to search for rare processes because of their excellent energy resolution and their extremely low intrinsic background. In this kind of detectors, the capability of discriminating alpha particles from electrons represents an important aspect for the background reduction. One possibility for obtaining such a discrimination is provided by the detection of the Cherenkov light which, at the low energies of the natural radioactivity, is only emitted by electrons. This paper describes the method developed to evaluate the amount of light produced by a crystal of TeO2_2 when hit by a 511 keV photon. The experimental measurements and the results of a detailed simulation of the crystal and the readout system are shown and compared. A light yield of about 52 Cherenkov photons per deposited MeV was measured. The effect of wrapping the crystal with a PTFE layer, with the aim of maximizing the light collection, is also presented

    Use of psychiatric inpatient services by heavy users: Findings from a national survey in Italy

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    Indagine epidemiologica nazionale sull'uso dei SPDC da parte dei pazienti piĂą gravi sul versante dell'uso dei Serviz

    Ukrainian refugee crisis management in the Local Health Authority Roma 1: the challenges of implementing public health policies and lessons learned

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    Background: The conflict between Russia and Ukraine has strained the health systems of countries that welcome war refugees on all levels, from national to local. Despite the Public Health guidelines regarding assistance being published on the topic, the scientific literature currently lacks evidence on the experience of applying theory in practice. This study aims to describe evidence-based practices that were implemented and to provide a detailed description of emerging problems and solutions pertaining Ukrainian refugee assistance in the context of one of the biggest Local Health Authorities in Italy (LHA Roma 1). Methods: LHA Roma 1 developed a strategic plan based on local expertise, national and international guidelines to ensure infectious disease prevention and control, as well as continuity of care for non-communicable diseases and mental health. Results: The insertion of Ukrainian refugees in the National Health System through an identification code assignment and other services such as COVID-19 swab and vaccination were provided either in one of the three major assistance hubs or in local district level ambulatories spread throughout the LHA. Many challenges were faced during the implementation phase of the outlined practice guidelines, which required sensible and timely solutions. These challenges include the necessity of rapid resource provision, overcoming linguistic and cultural barriers, guaranteeing a standard of care across multiple sites and coordination of interventions. Public Private Partnerships, the creation of a centralized multicultural and multidisciplinary team and the mutually beneficial collaboration with the local Ukrainian community were essential to guarantee the success of all operations. Conclusions: The experience of LHA Roma 1 helps shed light on the importance of leadership in emergency settings and how a dynamic relationship between policy and practice would allow each intervention to be modulated according to the local environment, to better realize the potential of local realities to provide appropriate health interventions to all those in need

    Model Checking to Improve Precision of Design Pattern Instances Identification in OO Systems

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    In the last two decades some methods and tools have been proposed to identify the Design Pattern (DP) instances implemented in an existing Object Oriented (OO) software system. This allows to know which OO components are involved in each DP instance. Such a knowledge is useful to better understand the system thus reducing the effort to modify and evolve it. The results obtained by the existing methods and tools can suffer a lack of completeness or precision due to the presence of false positive/negative. Model Checking (MC) algorithms can be used to improve the precision of DP's instances detected by a tool by automatically refining the results it produces. In this paper a MC based technique is defined and applied to the results of an existing DPs mining tool, called Design Pattern Finder (DPF), to improve the precision by verifying automatically the DPs instances it detects. To verify and assess the feasibility and the effectiveness of the proposed technique, we carried out a case study where it was applied on some open source OO systems. The results showed that the proposed technique allowed to improve the precision of the DPs instances detected by the DPF tool

    The CUORE cryostat: an infrastructure for rare event searches at millikelvin temperatures

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    The CUORE experiment is the world's largest bolometric experiment. The detector consists of an array of 988 TeO2 crystals, for a total mass of 742 kg. CUORE is presently taking data at the Laboratori Nazionali del Gran Sasso, Italy, searching for the neutrinoless double beta decay of 130Te. A large custom cryogen-free cryostat allows reaching and maintaining a base temperature of about 10 mK, required for the optimal operation of the detector. This apparatus has been designed in order to achieve a low noise environment, with minimal contribution to the radioactive background for the experiment. In this paper, we present an overview of the CUORE cryostat, together with a description of all its sub-systems, focusing on the solutions identified to satisfy the stringent requirements. We briefly illustrate the various phases of the cryostat commissioning and highlight the relevant steps and milestones achieved each time. Finally, we describe the successful cooldown of CUORE

    Search for Neutrinoless Double-Beta Decay of 130^{130}Te with CUORE-0

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    We report the results of a search for neutrinoless double-beta decay in a 9.8~kg⋅\cdotyr exposure of 130^{130}Te using a bolometric detector array, CUORE-0. The characteristic detector energy resolution and background level in the region of interest are 5.1±0.3 keV5.1\pm 0.3{\rm~keV} FWHM and 0.058±0.004 (stat.)±0.002 (syst.)0.058 \pm 0.004\,(\mathrm{stat.})\pm 0.002\,(\mathrm{syst.})~counts/(keV⋅\cdotkg⋅\cdotyr), respectively. The median 90%~C.L. lower-limit sensitivity of the experiment is 2.9×1024 yr2.9\times 10^{24}~{\rm yr} and surpasses the sensitivity of previous searches. We find no evidence for neutrinoless double-beta decay of 130^{130}Te and place a Bayesian lower bound on the decay half-life, T1/20ν>T^{0\nu}_{1/2}>~2.7×1024 yr 2.7\times 10^{24}~{\rm yr} at 90%~C.L. Combining CUORE-0 data with the 19.75~kg⋅\cdotyr exposure of 130^{130}Te from the Cuoricino experiment we obtain T1/20ν>4.0×1024 yrT^{0\nu}_{1/2} > 4.0\times 10^{24}~\mathrm{yr} at 90%~C.L.~(Bayesian), the most stringent limit to date on this half-life. Using a range of nuclear matrix element estimates we interpret this as a limit on the effective Majorana neutrino mass, mββ<270m_{\beta\beta}< 270 -- 760 meV760~\mathrm{meV}.Comment: 6 pages, 5 figures, updated version as published in PR

    Analysis Techniques for the Evaluation of the Neutrinoless Double-Beta Decay Lifetime in 130^{130}Te with CUORE-0

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    We describe in detail the methods used to obtain the lower bound on the lifetime of neutrinoless double-beta (0νββ0\nu\beta\beta) decay in 130^{130}Te and the associated limit on the effective Majorana mass of the neutrino using the CUORE-0 detector. CUORE-0 is a bolometric detector array located at the Laboratori Nazionali del Gran Sasso that was designed to validate the background reduction techniques developed for CUORE, a next-generation experiment scheduled to come online in 2016. CUORE-0 is also a competitive 0νββ0\nu\beta\beta decay search in its own right and functions as a platform to further develop the analysis tools and procedures to be used in CUORE. These include data collection, event selection and processing, as well as an evaluation of signal efficiency. In particular, we describe the amplitude evaluation, thermal gain stabilization, energy calibration methods, and the analysis event selection used to create our final 0νββ0\nu\beta\beta decay search spectrum. We define our high level analysis procedures, with emphasis on the new insights gained and challenges encountered. We outline in detail our fitting methods near the hypothesized 0νββ0\nu\beta\beta decay peak and catalog the main sources of systematic uncertainty. Finally, we derive the 0νββ0\nu\beta\beta decay half-life limits previously reported for CUORE-0, T1/20ν>2.7×1024T^{0\nu}_{1/2}>2.7\times10^{24} yr, and in combination with the Cuoricino limit, T1/20ν>4.0×1024T^{0\nu}_{1/2}>4.0\times10^{24} yr.Comment: 18 pages, 18 figures. (Version 3 reflects only minor changes to the text. Few additional details, no major content changes.

    Measurement of the Two-Neutrino Double Beta Decay Half-life of 130^{130}Te with the CUORE-0 Experiment

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    We report on the measurement of the two-neutrino double beta decay half-life of 130^{130}Te with the CUORE-0 detector. From an exposure of 33.4 kg⋅\cdoty of TeO2_2, the half-life is determined to be T1/22νT_{1/2}^{2\nu} = [8.2 ±\pm 0.2 (stat.) ±\pm 0.6 (syst.)] ×\times 1020^{20}y. This result is obtained after a detailed reconstruction of the sources responsible for the CUORE-0 counting rate, with a specific study of those contributing to the 130^{130}Te neutrinoless double beta decay region of interest.Comment: Corrected typo in section 9: 3.43E5 Bq/kg should have read 3.43E-5 Bq/k

    Antipsychotic prescribing for vulnerable populations: a clinical audit at an acute Australian mental health unit at two-time points

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    Background: Antipsychotics are recognised as a critical intervention for schizophrenia and bipolar disorder. Guidelines globally endorse the routine practice of antipsychotic monotherapy, at the minimum effective dose. Even in treatmentresistant schizophrenia, clozapine use is endorsed before combining antipsychotics. This aim of this study was to review antipsychotic polytherapy alone, high-dose therapy alone, polytherapy and highdose prescribing patterns in adults discharged from an inpatient mental health unit at two time-points, and the alignment of this prescribing with clinical guideline recommendations. Additionally, associations with polytherapy and high-dose antipsychotic prescribing, including patient and clinical characteristics, were explored. Methods: A retrospective clinical audit of 400 adults (200 patients at two different time-points) discharged with at least one antipsychotic. Preliminary findings and education sessions were provided to physicians between Cohorts. Outcomes (polytherapy alone, high-dose therapy alone, polytherapy and high-dose therapy) were compared between study Cohorts using chi-squared and rank-sum tests. Associations between outcomes and covariates were assessed using multivariable logistic regression. Results: Most patients (62.5%) were discharged on a single antipsychotic within the recommended dose range. There was a clear preference for prescribing second generation antipsychotics, and in this respect, prescribing is aligned with current evidence-based guidelines. However, sub-optimal prescribing practices were identified for both Cohorts in relation to polytherapy and high-dose antipsychotic rates. Involuntary treatment, frequent hospitalisations and previous clozapine use significantly increased the risk of all three prescribing outcomes at discharge. Conclusions: In a significant minority, antipsychotic prescribing did not align with clinical guidelines despite increased training, indicating that the education program alone was ineffective at positively influencing antipsychotic prescribing practices. Further consideration should be given when prescribing antipsychotics for involuntary patients, people with frequent hospitalisations, and those who have previously trialled clozapine
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