On the positivity of MSbar parton distributions

We revisit our argument that shows that parton distribution Functions (PDFs) in the MSbar{ scheme are non-negative in the perturbative region, with the main goals of elucidating its domain of validity and clarifying its theoretical underpinnings. We specifically discuss recent results proving that PDFs can turn negative at sufficiently low scale, we clarify quantitatively various aspects of our derivation of positivity in the perturbative region, and we provide an estimate for the scale above which PDF positivity holds

Bayesian Inference with Gaussian Processes for the Determination of Parton Distribution Functions

We discuss a Bayesian methodology for the solution of the inverse problem underlying the determination of parton distribution functions (PDFs). In our approach, Gaussian Processes (GPs) are used to model the PDF prior, while Bayes theorem is used in order to determine the posterior distribution of the PDFs given a set of data. We discuss the general formalism, the Bayesian inference at the level of both parameters and hyperparameters, and the simplifications which occur when the observable entering the analysis is linear in the PDF. We benchmark the new methodology in two simple examples for the determination of a single PDF flavor from a set of Deep Inelastic Scattering (DIS) data and from a set of equal-time correlators computed using lattice QCD. We discuss our results, showing how the proposed methodology allows for a well-defined statistical interpretation of the different sources of errors entering the PDF uncertainty, and how results can be validated a posteriori

Moderata Durant. Connessione tra frammento e città nel progetto d’inserimento del Conservatorio G. Briccialdi nell’ex mercato coperto di Terni

LAUREA MAGISTRALE"MODERATA DURANT”. Questa è l’iscrizione che si trova sopra l’architrave dell’ingresso del Conservatorio G. Briccialdi di Terni. La frase latina attesta il destino duraturo delle opere create nel giusto modo e che trovano la giusta misura. Dunque, la scelta del titolo è intesa a manifestare l’intenzione di identificare quella che è la matrice che permane in una città la cui struttura urbana è stata fortemente alterata nell’ultimo secolo, prima dai bombardamenti della Seconda guerra mondiale e poi dalla sperimentazione di piano di Mario Ridolfi che ha delineato l’impianto della città presente. Ci si propone quindi di definire il modo e la misura che restituiscano la piazza del Mercato alla città di Terni, tramite un progetto per la nuova sede del conservatorio G. Briccialdi. La piazza attualmente è un tassello scollegato all’interno del centro cittadino: ricostruita dopo la distruzione della guerra senza tenere conto della morfologia del tessuto medievale circostante e sottostante, si impone come una cesura significativa nella continuità dell’edificato e dello spazio pubblico cittadino. Manifesto della modernità veloce degli anni del dopoguerra, con la chiusura del mercato coperto ha perso anche la sua vocazione di luogo pubblico aperto alla cittadinanza. La struttura dell’ex-mercato è ora un oggetto alieno in una piazza estranea al tessuto circostante e dunque l’insieme presenta uno stato di degrado e di abbandono inusuale per una parte così significativa del centro storico di una città di medie dimensioni. Contrariamente alle varie proposte che intendono privatizzare la struttura dell’ex mercato coperto, rendendolo un centro commerciale, la tesi vuole proporre l’intervento pubblico come motore per la riattivazione del tessuto architettonico e sociale. Si è individuato così il conservatorio G. Briccialdi, attualmente collocato in una struttura carente di spazi e servizi, come nuovo uso in grado di riattivare tutto il contesto. Il progetto della scuola è integrato dalla creazione di un auditorium in grado di diventare polo attrattore di una città in cerca di una nuova vocazione rispetto a quella industriale, così forte in passato ma ora in decisa discussione. L’edificio pubblico risponde a queste esigenze, manifesta la volontà di riappropriarsi dello spazio circostante rendendolo effettivamente una piazza urbana e scavando si riallaccia alla memoria della città storica dimenticata e a lungo trascurata. Il progetto diventa quindi uno strumento di reinterpretazione del luogo che si pone come fine il reinserimento di un frammento all'interno del sistema della città analizzata come processo di stratificazione, tramite un'operaione che trova il suo fondamento nell'interferenza di tracce appartenenti ad epoche diverse. . Lo scavo ha il ruolo di rendere manifesta questa interferenza, creando una cerniera tra il sistema dell’auditorium, del conservatorio e dello spazio pubblico: la memoria storica diventa così capace di assumere un ruolo decisivo tanto per il progetto quanto per la città, proponendo una maniera più consapevole e attenta al luogo di interpretare il progetto e le trasformazioni urbane."MODERATA DURANT". This is the inscription found above the architrave of the entrance to the G. Briccialdi Conservatory in Terni. The Latin phrase attests to the enduring destiny of the works created in the right way and that find the right measure. Therefore, the choice of the title is aimed to show what is the matrix that remains in a city whose urban structure has been strongly altered in the last century, first by the World War II bombings and then by the experimentation of the urban city plan by Mario Ridolfi, who outlined the present city structure. We therefore want to define the way and the extent by which the Piazza del Mercato goes back to the city of Terni, through a project for the new Headquarters of the G. Briccialdi conservatory. The square appears currently an unconnected block inside the city center: rebuilt after the war without taking into account the morphology of the surrounding and underlying medieval fabric, it imposes itself as a significant caesura in the continuity of the buildings and public space. Manifesto of the fast modernity of the post-war years, with the closure of the covered market it has also lost its vocation as a public place open to citizens. The structure of the previous market is now an alien object in a square unrelated to the surrounding fabric and therefore the whole presents a state of degradation and unusual abandon for such a significant part of the historical center of a medium-sized city. Unlike the various proposals that intend to privatize the structure of the former covered market making it a mall, this study aims to propose public intervention as an engine for the reactivation of the architectural and social fabric. Thus the G. Briccialdi conservatory, currently located in a structure lacking both space and services, is identified as a new function capable of reactivating the whole context. The school project is complemented by the creation of an auditorium capable of becoming a centre of attraction for a city in search of a new vocation other than the industrial one, so marked in the past but now strongly questioned. The public building responds to these needs; it expresses the desire to reclaim the surrounding space, actually making it a urban square and in its depth it finds again the memory of the ancient city ,so long neglected. This project thus becomes a tool for reinterpretation of the place, aimed to re-inserting a fragment within the city system considered as a stratification process, with traces belonging to different ages. The excavation has the goal of making this interference manifest, creating a link between the auditorium, the conservatory and the public space: the historical memory thus becomes capable of assuming a decisive role both for the project and for the city, proposing a more conscious and attentive approach to the project and the urban transformations

Benchmarking of robotic and laparoscopic spleen-preserving distal pancreatectomy by using two different methods

Benchmarking; PancreatectomyBenchmarking; PancreatectomiaBenchmarking; PancreatectomíaBackground Benchmarking is an important tool for quality comparison and improvement. However, no benchmark values are available for minimally invasive spleen-preserving distal pancreatectomy, either laparoscopically or robotically assisted. The aim of this study was to establish benchmarks for these techniques using two different methods. Methods Data from patients undergoing laparoscopically or robotically assisted spleen-preserving distal pancreatectomy were extracted from a multicentre database (2006–2019). Benchmarks for 10 outcomes were calculated using the Achievable Benchmark of Care (ABC) and best-patient-in-best-centre methods. Results Overall, 951 laparoscopically assisted (77.3 per cent) and 279 robotically assisted (22.7 per cent) procedures were included. Using the ABC method, the benchmarks for laparoscopically assisted and robotically assisted spleen-preserving distal pancreatectomy respectively were: 150 and 207 min for duration of operation, 55 and 100 ml for blood loss, 3.5 and 1.7 per cent for conversion, 0 and 1.7 per cent for failure to preserve the spleen, 27.3 and 34.0 per cent for overall morbidity, 5.1 and 3.3 per cent for major morbidity, 3.6 and 7.1 per cent for pancreatic fistula grade B/C, 5 and 6 days for duration of hospital stay, 2.9 and 5.4 per cent for readmissions, and 0 and 0 per cent for 90-day mortality. Best-patient-in-best-centre methodology revealed milder benchmark cut-offs for laparoscopically and robotically assisted procedures, with operating times of 254 and 262.5 min, blood loss of 150 and 195 ml, conversion rates of 5.8 and 8.2 per cent, rates of failure to salvage spleen of 29.9 and 27.3 per cent, overall morbidity rates of 62.7 and 55.7 per cent, major morbidity rates of 20.4 and 14 per cent, POPF B/C rates of 23.8 and 24.2 per cent, duration of hospital stay of 8 and 8 days, readmission rates of 20 and 15.1 per cent, and 90-day mortality rates of 0 and 0 per cent respectively. Conclusion Two benchmark methods for minimally invasive distal pancreatectomy produced different values, and should be interpreted and applied differently

Observation of J/ψpJ/\psi p resonances consistent with pentaquark states in Λb0→J/ψK−p{\Lambda_b^0\to J/\psi K^-p} decays

Observations of exotic structures in the $J/\psi p$ channel, that we refer to as pentaquark-charmonium states, in $\Lambda_b^0\to J/\psi K^- p$ decays are presented. The data sample corresponds to an integrated luminosity of 3/fb acquired with the LHCb detector from 7 and 8 TeV pp collisions. An amplitude analysis is performed on the three-body final-state that reproduces the two-body mass and angular distributions. To obtain a satisfactory fit of the structures seen in the $J/\psi p$ mass spectrum, it is necessary to include two Breit-Wigner amplitudes that each describe a resonant state. The significance of each of these resonances is more than 9 standard deviations. One has a mass of $4380\pm 8\pm 29$ MeV and a width of $205\pm 18\pm 86$ MeV, while the second is narrower, with a mass of $4449.8\pm 1.7\pm 2.5$ MeV and a width of $39\pm 5\pm 19$ MeV. The preferred $J^P$ assignments are of opposite parity, with one state having spin 3/2 and the other 5/2.Comment: 48 pages, 18 figures including the supplementary material, v2 after referee's comments, now 19 figure

Low-grade fibromyxoid sarcoma and sclerosing epithelioid fibrosarcoma, outcome of advanced disease: retrospective study from the Ultra-Rare Sarcoma Working Group

Low-grade fibromyxoid sarcoma; Sclerosing epithelioid fibrosarcoma; Systemic therapiesSarcoma fibromixoide de bajo grado; Fibrosarcoma epitelioide esclerosante; Terapias sistémicasSarcoma fibromixoide de baix grau; Fibrosarcoma epitelioide esclerosant; Teràpies sistèmiquesBackground To present findings from a retrospective study conducted by the Ultra-Rare Sarcoma Working Group on metastatic low-grade fibromyxoid sarcoma (LGFMS), sclerosing epithelioid fibrosarcoma (SEF), and hybrid (H)-LGFMS/SEF across 28 global centres. Methods Patients treated at participating institutions from January 2000 to September 2022 were retrospectively selected. Diagnosis was confirmed by expert pathologists. Primary endpoint was progression-free survival (PFS-1) from metastasis detection to first progression or death. PFS-2 was calculated from therapy initiation. Results A total of 101 patients were identified (32 LGFMS, 50 SEF, 19 H-LGFMS/SEF). Median (m) follow-up was 62.1 months. mPFS-1 was 28.7, 11.8, and 20.3 months for LGFMS, SEF, and H-LGFMS/SEF, respectively. mOS was 145.8, 41.9, and 113.5 months, respectively. Treatments included anthracycline-based chemotherapy, gemcitabine-based chemotherapy (G), pazopanib, trabectedin, others. mPFS-2 was: 20.1, 5.5, and 3.5 months in H-LGFMS/SEF, SEF, and LGFMS, respectively, with anthracyclines; 19.5, 7.7, and 6.9 months in LGFMS, SEF, and H-LGFMS/SEF, respectively, with pazopanib; 12.0, 9.7, and 3.1 months in H-LGFMS/SEF, LGFMS, and SEF, respectively. Occasional responses occurred with ifosfamide/oral cyclophosphamide, and prolonged stable disease with immune checkpoint inhibitors. Conclusions In this series, the largest available, metastatic LGFMS, SEF, and H-LGFMS/SEF showed different courses. Systemic agents have modest efficacy, informing future trials of novel agents for these tumours.This work was supported by the Italian Ministry of Health, Ricerca Corrente (no grant number)

Cefiderocol use for the treatment of infections by carbapenem-resistant Gram-negative bacteria: an Italian multicentre real-life experience

Background: Cefiderocol is a novel siderophore cephalosporin with promising activity against most carbapenem-resistant Gram-negative bacteria (CRGNB). However, extensive postmarketing experiences are lacking. This study aimed to analyse the early experience on cefiderocol postmarketing use at three tertiary care hospitals in Italy. Methods: We retrospectively included patients with infections caused by CRGNB treated with cefiderocol at three Italian tertiary care hospitals from 1 March 2021 to 30 June 2022. A multivariate Cox model was used to identify predictors of 30 day mortality. A propensity score (PS) analysis with inverse probability weighting (IPW) was also performed to compare the treatment effect of cefiderocol monotherapy (CM) versus combination regimens (CCRs). Results: The cohort included 142 patients (72% male, median age 67 years, with 89 cases of Acinetobacter baumannii infection, 22 cases of Klebsiella pneumoniae, 27 cases of Pseudomonas aeruginosa and 4 of other pathogens). The 30 day all-cause mortality was 37% (52/142). We found no association between bacterial species and mortality. In multivariate analysis, a Charlson Comorbidity Index >3 was an independent predictor of mortality (HR 5.02, 95% CI 2.37-10.66, P < 0.001). In contrast, polymicrobial infection (HR 0.41, 95% CI 0.21-0.82, P < 0.05) was associated with lower mortality. There was no significant difference in mortality between patients receiving CM (n = 70) and those receiving a CCR (n = 72) (33% versus 40%, respectively), even when adjusted for IPW-PS (HR 1.11, 95% CI 0.63-1.96, P = 0.71). Conclusions: Real-life data confirm that cefiderocol is a promising option against carbapenem-resistant Gram-negative infections, even as monotherapy

Study of production and cold nuclear matter effects in pPb collisions at=5 TeV

Production of mesons in proton-lead collisions at a nucleon-nucleon centre-of-mass energy = 5 TeV is studied with the LHCb detector. The analysis is based on a data sample corresponding to an integrated luminosity of 1.6 nb(-1). The mesons of transverse momenta up to 15 GeV/c are reconstructed in the dimuon decay mode. The rapidity coverage in the centre-of-mass system is 1.5 < y < 4.0 (forward region) and -5.0 < y < -2.5 (backward region). The forward-backward production ratio and the nuclear modification factor for (1S) mesons are determined. The data are compatible with the predictions for a suppression of (1S) production with respect to proton-proton collisions in the forward region, and an enhancement in the backward region. The suppression is found to be smaller than in the case of prompt J/psi mesons

A MSFD complementary approach for the assessment of pressures, knowledge and data gaps in Southern European Seas : the PERSEUS experience

PERSEUS project aims to identify the most relevant pressures exerted on the ecosystems of the Southern European Seas (SES), highlighting knowledge and data gaps that endanger the achievement of SES Good Environmental Status (GES) as mandated by the Marine Strategy Framework Directive (MSFD). A complementary approach has been adopted, by a meta-analysis of existing literature on pressure/impact/knowledge gaps summarized in tables related to the MSFD descriptors, discriminating open waters from coastal areas. A comparative assessment of the Initial Assessments (IAs) for five SES countries has been also independently performed. The comparison between meta-analysis results and IAs shows similarities for coastal areas only. Major knowledge gaps have been detected for the biodiversity, marine food web, marine litter and underwater noise descriptors. The meta-analysis also allowed the identification of additional research themes targeting research topics that are requested to the achievement of GES. 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license.peer-reviewe

The Role of Uric Acid in Acute and Chronic Coronary Syndromes.

Uric acid (UA) is the final product of the catabolism of endogenous and exogenous purine nucleotides. While its association with articular gout and kidney disease has been known for a long time, new data have demonstrated that UA is also related to cardiovascular (CV) diseases. UA has been identified as a significant determinant of many different outcomes, such as all-cause and CV mortality, and also of CV events (mainly Acute Coronary Syndromes (ACS) and even strokes). Furthermore, UA has been related to the development of Heart Failure, and to a higher mortality in decompensated patients, as well as to the onset of atrial fibrillation. After a brief introduction on the general role of UA in CV disorders, this review will be focused on UA's relationship with CV outcomes, as well as on the specific features of patients with ACS and Chronic Coronary Syndrome. Finally, two issues which remain open will be discussed: the first is about the identification of a CV UA cut-off value, while the second concerns the possibility that the pharmacological reduction of UA is able to lower the incidence of CV events