Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic

Search for Eccentric Black Hole Coalescences during the Third Observing Run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass $M>70$ $M_\odot$) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities $0 < e \leq 0.3$ at $0.33$ Gpc$^{-3}$ yr$^{-1}$ at 90\% confidence level.Comment: 24 pages, 5 figure

Toward a fully automated and digitally controlled squeezed vacuum source

The PHD work deals of the developement of a vacuum squeezed optical source for the Virgo gravitational wave detector. The main result achieved is the production and the measurement of 6 dB of squeezing and 15 dB of antisqueezing at high frequencies. The activities was mainly focused on the developement of the electronic and control system for the optical bench. It is completely based on digital systems controlled with microcontrollers, microprocessors and DSP. The system has been developed to be integrated in the Virgo Data Acquisition framework.L'attività svolta durante il dottorato tratta lo sviluppo di una sorgente ottica di stati di vuoto squeezato per l'interferometro per onde gravitazionali Virgo. Il principale risultato conseguito è la generazione e la relativa misura di 6 dB di squeezing e 15 dB di antisqueezing ad alta frequenza. Le attività svolte erano principalmente focalizzate allo sviluppo di un sistema elettronico e di controllo del banco ottico. Questo sistema è completamente basato su sistemi digitali ed è controllato tramite microcontrollori, microprocessori e DSP. Il sistema elettronico/informatico è stato progettato per essere integrato nel sistema di acquisizione dati dell'esperimento Virgo

Design for interaction: Factorized Nyquist based control design applied to a Gravitational Wave detector

Gravitational Wave detectors require feedback control to control the length between the sensitive components of the detector. The degrees of freedom in the control system are inherently coupled and the level of interaction furthermore varies over time. A systematic control design approach for the feedback controllers is presented which provides a guide on how to cope with the varying levels of interaction. A new controller for one of the loops has been designed and experimental results measured on the Gravitational Wave detector Advanced Virgo show a significant reduction in the root mean square error of the loop with the new controller

Finite state machine controls for a source of optical squeezed vacuum

In this paper we present a software, developed in the distributed control system environment of the Virgo gravitational-wave detector, for the management of a highly automated optical bench. The bench is extensively used for the research and development of squeezed states of light generation in order to mitigate the quantum noise in the next generations of interferometric gravitational-wave detectors. The software is developed using Finite-State Machines, recently implemented as a new feature of damping-adv Software Development Kit. It has been studied for its ease of use and stability of operation and thus offers a high duty-cycle of operation. Much attention has been drawn to ensure the software scalability and integration with the existing Data AcQuisition and control infrastructure of the Virgo detector

Commento all'art. 2097 c.c. Durata del contratto di lavoro

Il commento esamina la disciplina del contratto a tempo determinato alla luce delle recenti novelle legislative e delle modiche introdotte, da ultimo, con il d.l. n. 87/2018 (cd. decreto dignità)

Electronic hardware and software development for the Advanced Virgo EPR squeezer

In this paper, we introduce the work on hardware and software built to manage the optical bench which hosts the optical squeezer source at the Virgo site in Cascina. In the past, the ex-perimental setup implemented frequency-independent squeezing and it will be soon recon gured in order to implement frequency-dependent squeezing via EPR entanglement for Virgo gravitational-wave detector. Furthermore we introduce an idea of automation for this prototypic subsystem in order to deliver a compact and robust apparatus which does not require surveillance of an operator

Del lavoro subordinato

il testo curato dal Prof. Ioele, che ha anche redatto personalmente il commento di larga parte delle norme , raccoglie una serie di commenti relativi alle note del codice civile dedicate al rapporto di lavoro subordinato e redatti da autori che hanno inteso rendere omaggio alla Prof.ssa Vaccaro per il suo pensionamento . Sono affrontate tutte le principali tematiche della disciplina del rapporto di lavoro subordinato: la contrattazione collettiva, la disciplina del rapporto individuale di lavoro (dalla costituzione all'estinzione), i particolari rapporti di lavoro subordinato