Use of ANTARES and IceCube data to constrain a single power-law neutrino flux

We perform the first statistical combined analysis of the diffuse neutrino flux observed by ANTARES (nine-year) and IceCube (six-year) by assuming a single astrophysical power-law flux. The combined analysis reduces by a few percent the best-fit values for the flux normalization and the spectral index. Both data samples show an excess in the same energy range (40--200 TeV), suggesting the presence of a second component. We perform a goodness-of-fit test to scrutinize the null assumption of a single power-law, scanning different values for the spectral index. The addition of the ANTARES data reduces the $p$-value by a factor 2$\div$3. In particular, a single power-law component in the neutrino flux with the spectral index deduced by the six-year up-going muon neutrinos of IceCube is disfavored with a $p$-value smaller than $10^{-2}$.Comment: 6 pages, 4 figures. Version published in AP

A Pedagogical Intrinsic Approach to Relative Entropies as Potential Functions of Quantum Metrics: the qq-zz Family

The so-called $q$-z-\textit{R\'enyi Relative Entropies} provide a huge two-parameter family of relative entropies which includes almost all well-known examples of quantum relative entropies for suitable values of the parameters. In this paper we consider a log-regularized version of this family and use it as a family of potential functions to generate covariant $(0,2)$ symmetric tensors on the space of invertible quantum states in finite dimensions. The geometric formalism developed here allows us to obtain the explicit expressions of such tensor fields in terms of a basis of globally defined differential forms on a suitable unfolding space without the need to introduce a specific set of coordinates. To make the reader acquainted with the intrinsic formalism introduced, we first perform the computation for the qubit case, and then, we extend the computation of the metric-like tensors to a generic $n$-level system. By suitably varying the parameters $q$ and $z$, we are able to recover well-known examples of quantum metric tensors that, in our treatment, appear written in terms of globally defined geometrical objects that do not depend on the coordinates system used. In particular, we obtain a coordinate-free expression for the von Neumann-Umegaki metric, for the Bures metric and for the Wigner-Yanase metric in the arbitrary $n$-level case.Comment: 50 pages, 1 figur

Association and diffusion of Li+ in carboxymethylcellulose solutions with application to environmentally friendly Li-ion batteries: a combined Molecular Dynamics and NMR study

Carboxymethylcellulose (CMC) has been proposed as a polymeric binder for the electrodes in environmentally friendly Li-ion batteries. Its physical properties and interaction with Li+ ions in water are interesting from the point of view of electrode preparationprocessability in water is one of the main reasons for its environmental friendlinessbut also for its possible application in aqueous Li-ion batteries. We combine MD simulations and variable-time PFGSE-NMR spectroscopy to investigate Li+ transport in CMC-based solutions. Both simulation and experiment show that, at concentrations such that Li-CMC has a gel like consistency, the Li+ diffusion coefficient is still very close to that in water. These ions interact preferentially with CMC’s carboxylate groups, giving rise to a rich variety of coordination patterns. However, the diffusion of Li+ in these systems is essentially unrestricted, with a fast, nanosecond-scale exchange of the ions between CMC and the aqueous environment

Digital interaction: where are we going?

In the framework of the AVI 2018 Conference, the interuniversity center ECONA has organized a thematic workshop on "Digital Interaction: where are we going?". Six contributions from the ECONA members investigate different perspectives around this thematic

Sistemi silvoarabili mediterranei: nuove esperienze in campo al Centro di Ricerche Agro-ambientali“Enrico Avanzi” di Pisa

L’agroselvicoltura, ovvero la deliberata associazione di colture arboree, erbacee e/o animali nel medesimo appez- zamento, è stata proposta come “nuovo sistema colturale” in grado di coniugare l’aumento di produtività dell’agricoltura in un’otica di maggiore eco-suficienza. Tra i diversi modelli colturali ascrivibili ai sistemi agro- silvopastorali o agrosilvicoli, i sistemi silvoarabili, che prevedono la coltivazione di colture erbacee di pieno cam- po in consociazione con colture arboree, garantiscono una serie di benefici direti: (i) la diversificazione delle col - ture, (ii) la riduzione del rischio di erosione del suolo dall’acqua e dal vento, (iii) l’aumento della percentuale di sostanza organica nel suolo, e (iv) la riduzione del rischio di lisciviazione dei nitrati. D’altro canto, la consociazio - ne di colture erbacee e alberi fuori-foresta determina la riduzione della superficie arabile complessiva e la compe- tizione per le risorse (nutrienti, luce ed acqua) tra alberi e strato erbaceo. Al fine di approfondire le conoscenze su questi particolari sistemi colturali, presso il Centro di Ricerche Agro-ambientali “Enrico Avanzi” dell’Universi - tà di Pisa sono in corso di implementazione due sperimentazioni di pineo campo. La prima prova è un sistema agro-silvo-pastorale che prevede la coltivazione di specie erbacee da granella (cereali autunno-vernini e legumi- nose) e prati-pascolo in rotazione, nel tempo e nello spazio, in consociazione con filari policiclici di pioppi ( Popu- lus spp.) e farnie (Qercus robur L.). I sistemi verranno implementati con due diverse densità di impianto: i) 60 piante per etaro, in cui i filari verranno posti in prossimità dell’afossatura di ogni appezzamento, e ii) 100 piante per etaro, in cui i filari di soli pioppi verranno ripetuti anche lungo la bisetrice del campo. La prova prevede il confronto dei servizi ecosistemici generati dai due sistemi silvoarabili con: i) un sistema arabile privo di alberatu- re, e ii) un sistema di arboricoltura ad alta densità. Nella seconda prova un campo parcellare silvoarabile, compo - sto da: erba mazzolina (Dactylis glomerata L.), erba medica (Medicago sativa L.), panico (Panicum virgatum L.) e sulla (Hedysarum coronarium L.) in consociazione con filari di pioppo a taglio ravvicinato, short-rotation coppice (SRC), a bassa densità (0.5 m di distanza tra gli alberi e 13.5 metri tra le file), verrà messo a confronto con: (i) una prova parcellare di SRC con impianto 0.5 m × 2.7 m, e (ii) un campo parcellare con le medesime colture erbacee prive di copertura arborea. L’obietivo della prova è valutare il grado di produtività e sostenibilità dei diversi si- stemi con particolare atenzione al ciclo del carbonio e al ciclo dei nutrienti

PRISTUP «VREMENSKE SERIJE» REŽIMU KINESKOG VALUTNOG TEČAJA

This paper deals with the issue of the exchange rate regime that China has established since 2005, when it announced a move away from the US dollar peg. In fact, from that date, the RMB was managed with reference to a basket of currencies rather than being pegged to the dollar; the exchange rate, therefore, became more flexible. But, though in the presence of basket peg, early econometric analysis (Shan-2005, Frankel & Wei- 2006, Ogawa-2006, Yamazaky-2006) found that the assigned basket gave overwhelming weight to the dollar, and that the degree of flexibility had hardly increased at all. Almost all those studies used a technique introduced by Frankel in 1994 to estimate the weights in a currency basket: on one side regressed changes in the value of the local currency, in this case the RMB, while on the other one changes in the values of the dollar, the euro, the yen and other currencies that may be in the basket. Though there are numerous econometric techniques for estimating the exchange rate system, the technique proposed by Frankel is still the most widely used. However, in our opinion, this model has an error of autocorrelation among the variables, a factor that could lead the analysis to different results. Therefore, this work proposes a study on the Chinese exchange rate regime through an alternative econometric technique.Ovaj se rad bavi pitanjem režima valutnog tečaja kojeg je Kina uvela 2005. kad je najavila odmak od veze s američkim dolarom. Doista, otada se RMB (CNY) veže za košaricu valuta osim za dolar te je tako tečaj postao fleksibilniji. No usprkos tome, prve ekonometrijske analize (Shan-2005, Frankel & Wei-2006, Ogawa-2006, Yamazaky-2006) pokazale su da je odlučujuća valuta u košarici još uvijek dolar i da je stupanj fleksibilnosti jedva povećan. Gotovo su sve te analize koristile tehniku koju je uveo Frankel 1994. kako bi procijenio važnost pojedinih valuta u košarici: s jedne strane RMB a s druge promjene u vrijednosti dolara, eura, jena i ostalih valuta koje se mogu naći u košarici valuta. Iako postoje brojne ekonometrijske tehnike za procjenu sustava valutnog tečaja, još uvijek je najraširenija Frankelova tehnika. Ipak, po našem mišljenju taj model ima grešku u autokorelaciji varijabli što je faktor koji bi analizu mogao odvesti do drugačijih rezultata. Stoga ovaj rad predlaže proučavanje režima kineskog valutnog tečaja pomoću alternativne ekonometrijske tehnike

STUDY OF THE PATHOGENESIS AND TREATMENT OF HEART FAILURE THROUGH THE HARMONIZATION OF EVIDENCE-BASED CLINICAL DATA, ARTIFICIAL INTELLIGENCE AND ANIMAL MODELS

Background: Heart failure (HF) is a major cause of death and hospitalization, especially in diabetic patients. The cornerstone of medical treatment for HF is represented by Sodium-glucose cotransporter type 2 inhibitors (SGLT2i), gliflozins, especially in heart failure with reduced left ventricular ejection fraction (HFrEF). Nevertheless, the effects of SGLT2i on ventricular remodeling and function have not been completely understood yet. Explainable artificial intelligence represents an unprecedented explorative option to clinical research in this field. Based on echocardiographic evaluations, our first aim was to identify some key clinical responses to gliflozins by employing a machine learning approach. In the setting of HF, atrial fibrillation (AF) represents an extremely frequent arrhythmia. Oral anticoagulant therapy (OAT) for managing AF encompasses vitamin K antagonists (VKAs) and direct-acting oral anticoagulants. Due to the lower risk of major bleeding associated with DOACs, anticoagulant switching is a common practice in AF patients. Nevertheless, there are issues related to OAT switching that still need to be fully understood, especially for patients in whom AF and heart failure (HF) coexist. As second aim, we therefore sought to assess the real positive and pleiotropic effects mediated by DOACs in addition to their anticoagulant activity. In particular, we aimed at the effective impact of the therapeutic switching from warfarin to DOACs in HF patients with AF by a machine learning (ML) analysis of a clinical database. Methods: for the first aim, we assessed 78 consecutive diabetic outpatients followed for HFrEF, using a random forest classification. A single subject analysis was performed to define the profile of patients treated with gliflozins. Moreover, an explainability analysis using Shapley values was used to outline clinical parameters that mostly improved after gliflozin therapy and machine learning runs highlighted specific variables predictive of gliflozin response. For the second aim, 42 consecutive outpatients with HFrEF and AF in OAT for at least one year were enrolled. The k-means clustering method and the Random Forest learning algorithm were adopted in order to evaluate how switching from warfarin to DOACs may affect the clinical progression of the patients. Results: The five-fold cross-validation analyses showed that gliflozins patients can be identified with a 0.70 ± 0.03% accuracy. The most relevant parameters distinguishing gliflozins patients were Right Ventricular S'-Velocity, Left Ventricular End Systolic Diameter and E/e' ratio. In addition, low Tricuspid Annular Plane Systolic Excursion values along with high Left Ventricular End Systolic Diameter and End Diastolic Volume values were associated with lower gliflozin efficacy in terms of anti-remodeling effects. In patients with AF and HFrEF, at the baseline, 75% of patients were correctly separated. At the follow-up, after the switch to DOACs, this accuracy decreased to 64%. The baseline model is more accurate, achieving an average accuracy of 78%. At follow-up, the accuracy decreases to 58%. The accuracy loss of about 20% is statistically significant and suggests a fundamental loss of the features’ discriminative power. N-terminal pro-brain natriuretic peptide (NTproBNP)brought a fundamental contribution in discriminating the clinical cohorts. Discussion and Conclusions: A ML analysis on a population of diabetic patients with HFrEF showed that SGLT2i treatment improved left ventricular remodeling. This cardiovascular response may be predicted with an explainable artificial intelligence approach, suggesting a lower efficacy in case of advanced stages of cardiac remodeling. Our ML analysis in patients with AF and HFrEF demonstrated that, when warfarin-treated patients switched to DOACs, they were no longer differentiable. This means that DOACs somehow modify the considered features which have specific clinical significanc

A Neural Network Evidence of the Nexus Among Air Pollution, Economic Growth, and COVID-19 Deaths in the Hubei Area

In this study, we used an image neural network model to assess the relationship between economic growth, pollution (PM2.5, PM10, and CO2), and deaths from COVID-19 in the Hubei area (China). Data analysis, neural network analysis, and deep learning experiments were carried out to assess the relationship among COVID-19 deaths, air pollution, and economic growth in China (Hubei province, the epicenter of the COVID-19 pandemic). We collected daily data at a city level from January 20 to July 31, 2020. We used main cities in the Hubei province, with data on confirmed COVID-19 deaths, air pollution (expressed in µg/m3 as PM2.5, PM10, and CO2), and per capita economic growth. Following the most recent contributions on the relationship among air pollution, GDP, and diffusion of COVID-19, we generated an algorithm capable of identifying a neural connection among these variables. The results confirmed a strong predictive relationship for the Hubei area between changes in the economic growth, fine particles, and deaths from COVID-19. These results would recommend adequate environmental reforms to policymakers to contain the spread and adverse effects of the virus. Therefore, there is a requirement to reconsider the system of transport and return to production by combining it with economic growth to protect the planet