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We present an innovative approach for solving time dependent Four Dimensional Variational Data Assimilation (4D VAR DA) problems. The proposed approach performs a decomposition of the whole physical domain, i.e. both along spatial and temporal directions; a reduction in space and time of both the Partial Differential Equations-based model and the Data Assimilation functional; finally it uses a modified regularization functional describing restricted 4D VAR DA problems on the domain decomposition. Innovation mainly lies in the introduction ab initio, i.e. on the numerical model – of a domain decomposition approach in space and time joining the idea of Schwarz's method and Parallel in Time (PinT)–based approaches. We provide the numerical framework of this method including convergence analysis and error propagation. A validation analysis is performed discussing computational results on a case study relying on Shallow Water Equations. © 2020 IMACS

Evidence supports a sex disparity in clinical outcomes of COVID-19 patients, with men exhibiting higher mortality rates compared to women. We aimed to test the correlation between serum levels of sex hormones [total testosterone, estradiol (E2), estradiol to testosterone (E2/T) ratio, progesterone), prolactin and 25-hydroxyvitamin D [25(OH)D] and markers of inflammation, coagulation and sepsis at admission in hospitalized men with COVID-19.We conducted an exploratory retrospective study including symptomatic men with confirmed SARS-CoV-2 infection who were consecutively admitted to our Institution between April 1 and May 31, 2020.Patients were divided into survivors (n=20) and non-survivors (n=39). As compared to survivors, non-survivors showed significantly higher median neutrophil-to-lymphocyte ratio (NLR) values, D-dimer and procalcitonin (PCT) levels, along with significantly lower median 25(OH)D levels and total testosterone levels. Non-survivors exhibited significantly higher median values of E2/T ratio (a marker of aromatase activity). Spearman's correlation analysis revealed that total testosterone levels were significantly and inversely correlated with NLR, high-sensitivity C-reactive protein (hsCRP), interleukin-6, D-dimer and PCT. Conversely, E2/T ratio values were significantly and positively correlated with the aforementioned markers and with white blood cell (WBC) count. In a multivariate analysis performed by a logistic regression model after adjusting for major confounders (age, body mass index, hypertension and cardiovascular disease, diabetes mellitus and malignancy), total testosterone levels were significantly and inversely associated with risk of COVID-19-related in-hospital mortality.Low total testosterone levels and elevated E2/T ratio values at admission are associated with hyperinflammatory state in hospitalized men with COVID-19. Low total testosterone levels at admission represent an independent risk factor for in-hospital mortality in such patients. Therefore, total testosterone and E2/T ratio may serve as prognostic markers of disease severity in this population.

We address the design and development of innovative mathematical models for Predictive Science simulations described by Variational Data Assimilation (DA) methods tightly coupled with time-dependent Partial Differential Equations (PDEs). The result is a PDE-based variational problem that is extremely large scale. The innovation refers to the simultaneous introduction of space-andtime decomposition approaches, consisting of Parallel in Time (PinT)-based approaches for solving the PDEs and functional decomposition for solving the Variational DA model; finally, domain is decomposed both along the space and the time dimension. The core of our approach is that the DA model acts as coarse-propagator/predictor for local PDEs, by providing the background values for the local initial conditions. The main outcome of this approach is that, in contrast to other PinT-based approaches, local solvers run concurrently, so that the resulting algorithm only requires exchange of boundary conditions between adjacent sub-domains. This work is carried on in collaboration with E. Constantinescu (ANL) and L. Carracciuolo (CNR-IT).

Assessing and reducing the uncertainty of large-scale simulations in the geosciences have become fundamental to increase the reliability of model forecasts. One of the major challenges arises when the description of model uncertainty and the availability of field observations are not straightforward. Especially in these cases, it is necessary to develop robust assimilation approaches combined with computationally efficient procedures. For instance, the use of appropriate surrogate models and the implementation on emerging computing architectures can help reduce the computational burden, provided that the most significant non-linearities of the physical system are preserved. This mini-symposium aims to discuss recent advances in geoscience applications where parameter and state estimation problems are tackled. Contributions dealing with novel algorithmic approaches and efficient computational procedures used in challenging applications are welcome

Aim of the present study is to propose a clinic-therapeutic course for the treatment of hemorrhoidal disease able to combine radical anatomic surgery with a painless postoperative path.The present study is based on the evaluation of 20 selected patients who underwent radical hemorrhoidectomy for very high grade hemorrhoidal disease. The clinical course was characterized by careful bowel cleansing, hemorrhoidectomy according to Milligan-Morgan using LigaSure, intraoperative perianal infiltration of Ropivacaine and postoperative use of analgesic drugs.A low postoperative pain may descend from a scheduled timing of clinical procedures. Preoperative bowel cleansing delays the first postoperative evacuation, thus avoiding the perianal nerve stimulation. The use of LigaSure allows to perform surgical excision in a perfect way: lack of hemostatic stitches, less tissue trauma, very low early morbidity. A rational and scheduled intra and postoperative drug administration offers a highly significant contribution to the pain control. The intra and postoperative use of drugs makes it possible to perform the so-called "preventive anesthesia with activation of the pain memory" and postoperative evacuations with low pain perception. All patients, in fact, reported low and well tolerated pain, satisfaction and return to normal activities in a short period.Radical hemorrhoidectomy with LigaSure and attention to pre, intra and postoperative protocol makes the procedure painless, safe and with low morbidity.Hemorrhoidectomy, LigaSure, Painless procedure.Gli autori propongono una procedura clinica, che consente di praticare un intervento anatomico di emorroidectomia radicale ben sopportato dal paziente, in funzione del dolore molto contenuto nel periodo post operatorio. Come è noto, negli interventi di emorroidectomia, in tutte le tecniche chirurgiche praticate, il dolore è legato alla complessità dell’intervento e, quindi, allo stadio di malattia. Per tale motivo abbiamo valutato nel nostro studio, i risultati relativi ad un gruppo selezionato di 20 pazienti con malattia emorroidaria avanzata ed sintomatica. Il protocollo clinico è stato caratterizzato da: accurata pulizia dell’intestino, emorroidectomia sec. Milligan- Morgan eseguita con LigaSure, infiltrazione intraoperatoria di Ropivacaina, uso postoperatorio di farmaci analgesici. La pulizia preoperatoria del colon, con assenza di evacuazione postoperatoria nelle successive 24-30 ore, evita in tale periodo una stimolazione nervosa perianale. L’uso del LigaSure consente di eseguire l’intervento in maniera ottimale: assenza di punti aggiuntivi per l’emostasi, minore trauma dei tessuti, morbilità immediata praticamente assente. Una programmata e razionale utilizzazione di farmaci in sede intra e postoperatoria permette un efficace controllo del dolore. L’uso di farmaci intraoperatori consente, inoltre, di attuare la “analgesia preventiva con attivazione della memoria del dolore” (paziente asintomatico sino alla prima evacuazione), mentre la somministrazione post operatoria permette di avere evacuazioni intestinali con bassa percezione del dolore. Applicando il protocollo descritto, abbiamo ottenuto, nei 20 casi selezionati, i seguenti risultati: tempo operatorio contenuto, assenza di sanguinamento intra e postoperatorio, assenza di ano fibroso o stenosi nei controlli a distanza, ritenzione urinaria, nel 35% dei soggetti, transitoria e reversibile (una singola cateterizzazione), dolore postoperatorio contenuto e ben tollerato in tutti i pazienti, rapido ritorno alla normale attività e vita di relazione, con buona soddisfazione dei pazienti.