Modellazione numerica di una porzione dell'acquifero della Piana orientale di Lucca: implementazione, calibrazione e determinazione dei parametri sensibili

La Pianura di Lucca è sede di un importante acquifero che, proprio per la sua conformazione idrogeologica, in seguito all’espansione sia civile che industriale è stato oggetto di un massiccio aumento dei prelievi in falda. Ciò ha portato, oltre ad una crisi idrica, a fenomeni di subsidenza generalizzata e alla formazione di cavità nei comuni di Porcari e Capannori. La modellazione numerica a differenze finite dei flussi in falda può risultare uno strumento efficace per la programmazione di opere di intervento atte a mitigare e a risolvere tali problematiche. Questo lavoro è stato eseguito in collaborazione con la Dott.ssa Angela Sartelli che, con la sua tesi “Modellazione numerica di una porzione dell’acquifero della Piana orientale di Lucca: oscillazioni piezometriche recenti e scenari previsionali”, ha acquisito i dati propedeutici alla modellazione, mentre lo scopo di questo studio è stato quello di implementare e calibrare il modello numerico a differenze finite, attraverso l’utilizzo del software Visual ModFlow 4.2®, e di definirne i parametri sensibili, ovvero quei dati che maggiormente influiscono sull’evolversi della superficie piezometrica. Per implementare il modello sono stati raccolti ed elaborati i seguenti dati: carte topografiche per ricostruire la geomorfologia dell’area; dati stratigrafici e geologici; dati delle caratteristiche idrogeologiche dell’acquifero; dati relativi alla situazione idrografica; dati climatici; dati relativi ai quantitativi di acqua emunti; dati del livello piezometrico mensile (Dicembre 2007 – Ottobre 2008) misurati in 97 pozzi censiti. I dati geologici e idraulici dell’acquifero sono stati elaborati al fine di determinare un modello geologico e idrogeologico concettuale dell’area in esame. Sono poi stati valutati i quantitativi di pioggia precipitata mensilmente durante il periodo di rilevamento e, in seguito all’elaborazione dei dati termometrici, sono stati valutati i quantitativi di evapotraspirazione mensile. Successivamente il modello è stato calibrato attraverso la variazione per tentativi di errore di alcuni parametri di input più incerti, in modo da ottenere un errore minimo fra i livelli piezometrici calcolati dal modello e quelli misurati durante il rilevamento. La calibrazione ha permesso di identificare i parametri sensibili: quantitativi di ricarica meteorica ed estrazioni idriche per mezzo di pozzi. Infine, è stato esaminato il bilancio idrogeologico del modello numerico, dal quale si sono potute identificare le zone di maggiore ricarica e prelievo. Da ciò si è potuto osservare che la risorsa idrica rinnovabile si sta esaurendo o addirittura viene intaccata la riserva permanente a causa dei quantitativi eccessivi di pompaggi effettuati nella zona del Padule di Porcari

All-sky Medium Energy Gamma-ray Observatory: Exploring the Extreme Multimessenger Universe

The All-sky Medium Energy Gamma-ray Observatory (AMEGO) is a probe class mission concept that will provide essential contributions to multimessenger astrophysics in the late 2020s and beyond. AMEGO combines high sensitivity in the 200 keV to 10 GeV energy range with a wide field of view, good spectral resolution, and polarization sensitivity. Therefore, AMEGO is key in the study of multimessenger astrophysical objects that have unique signatures in the gamma-ray regime, such as neutron star mergers, supernovae, and flaring active galactic nuclei. The order-of-magnitude improvement compared to previous MeV missions also enables discoveries of a wide range of phenomena whose energy output peaks in the relatively unexplored medium-energy gamma-ray band

Hydrogeological numerical modeling of the southeastern portion of the Lucca Plain (Tuscany, Italy), stressed by groundwater exploitation

In the hydrogeological field, the numerical modeling is well known as a powerful tool to set up a management strategy that can prevent groundwater mining. To overcome its somehow “exoteric fame”, it needs as many as possible of local field tests in order to become real world common practice in groundwater management. The Lucca Plain aquifer shows a severe piezometric drop associated to an unregulated competition between agriculture, industry, public and private drinking water wells. It was chosen to test a finite difference numerical model capability as a crisis analysis and forecasting tool and as a regulatory action technical support benchmark. The southern Lucca Plain geological and hydrogeological conceptual model was translated into a MODFLOW grid. Public and private pumping wells were monthly surveyed from January 2007 to October 2008. Calibration allowed the numerical model to achieve a good statistical correspondence with reality. The resulting virtual reality highlighted the heavy hydrogeological stress affecting the area, where pumping rate significantly exceeds the recharge in the studied period. The sensibility analysis highlighted rainfall recharge and pumping rate as the more sensitive values among the input data. Since the calibration process implied a remarkable increase of the officially declared pumping rate, numerical modeling, when a lot of calibration data are available, showed promising capability of back-analysis to estimate the real pumping rate for a given area

All-sky Medium Energy Gamma-ray Observatory: Exploring the Extreme Multimessenger Universe

Astro2020 APC White PaperThe All-sky Medium Energy Gamma-ray Observatory (AMEGO) is a probe class mission concept that will provide essential contributions to multimessenger astrophysics in the late 2020s and beyond. AMEGO combines high sensitivity in the 200 keV to 10 GeV energy range with a wide field of view, good spectral resolution, and polarization sensitivity. Therefore, AMEGO is key in the study of multimessenger astrophysical objects that have unique signatures in the gamma-ray regime, such as neutron star mergers, supernovae, and flaring active galactic nuclei. The order-of-magnitude improvement compared to previous MeV missions also enables discoveries of a wide range of phenomena whose energy output peaks in the relatively unexplored medium-energy gamma-ray band

Delayed colorectal cancer care during covid-19 pandemic (decor-19). Global perspective from an international survey

Background The widespread nature of coronavirus disease 2019 (COVID-19) has been unprecedented. We sought to analyze its global impact with a survey on colorectal cancer (CRC) care during the pandemic. Methods The impact of COVID-19 on preoperative assessment, elective surgery, and postoperative management of CRC patients was explored by a 35-item survey, which was distributed worldwide to members of surgical societies with an interest in CRC care. Respondents were divided into two comparator groups: 1) ‘delay’ group: CRC care affected by the pandemic; 2) ‘no delay’ group: unaltered CRC practice. Results A total of 1,051 respondents from 84 countries completed the survey. No substantial differences in demographics were found between the ‘delay’ (745, 70.9%) and ‘no delay’ (306, 29.1%) groups. Suspension of multidisciplinary team meetings, staff members quarantined or relocated to COVID-19 units, units fully dedicated to COVID-19 care, personal protective equipment not readily available were factors significantly associated to delays in endoscopy, radiology, surgery, histopathology and prolonged chemoradiation therapy-to-surgery intervals. In the ‘delay’ group, 48.9% of respondents reported a change in the initial surgical plan and 26.3% reported a shift from elective to urgent operations. Recovery of CRC care was associated with the status of the outbreak. Practicing in COVID-free units, no change in operative slots and staff members not relocated to COVID-19 units were statistically associated with unaltered CRC care in the ‘no delay’ group, while the geographical distribution was not. Conclusions Global changes in diagnostic and therapeutic CRC practices were evident. Changes were associated with differences in health-care delivery systems, hospital’s preparedness, resources availability, and local COVID-19 prevalence rather than geographical factors. Strategic planning is required to optimize CRC care

Risk of COVID-19 after natural infection or vaccinationResearch in context

Summary: Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health