Statistical Modeling of Trivariate Static Systems: Isotonic Models

This paper presents an improved version of a statistical trivariate modeling algorithm introduced in a short Letter by the first author. This paper recalls the fundamental concepts behind the proposed algorithm, evidences its criticalities and illustrates a number of improvements which lead to a functioning modeling algorithm. The present paper also illustrates the features of the improved statistical modeling algorithm through a comprehensive set of numerical experiments performed on four synthetic and five natural datasets. The obtained results confirm that the proposed algorithm is able to model the considered synthetic and the natural datasets faithfully

Supervised learning of random quantum circuits via scalable neural networks

Predicting the output of quantum circuits is a hard computational task that plays a pivotal role in the development of universal quantum computers. Here we investigate the supervised learning of output expectation values of random quantum circuits. Deep convolutional neural networks (CNNs) are trained to predict single-qubit and two-qubit expectation values using databases of classically simulated circuits. These circuits are built using either a universal gate set or a continuous set of rotations plus an entangling gate, and they are represented via properly designed encodings of these gates. The prediction accuracy for previously unseen circuits is analyzed, also making comparisons with small-scale quantum computers available from the free IBM Quantum program. The CNNs often outperform these quantum devices, depending on the circuit depth, on the network depth, and on the training set size. Notably, our CNNs are designed to be scalable. This allows us exploiting transfer learning and performing extrapolations to circuits larger than those included in the training set. These CNNs also demonstrate remarkable resilience against noise, namely, they remain accurate even when trained on (simulated) expectation values averaged over very few measurements

Multi-scale analysis of the European airspace using network community detection

We show that the European airspace can be represented as a multi-scale traffic network whose nodes are airports, sectors, or navigation points and links are defined and weighted according to the traffic of flights between the nodes. By using a unique database of the air traffic in the European airspace, we investigate the architecture of these networks with a special emphasis on their community structure. We propose that unsupervised network community detection algorithms can be used to monitor the current use of the airspaces and improve it by guiding the design of new ones. Specifically, we compare the performance of three community detection algorithms, also by using a null model which takes into account the spatial distance between nodes, and we discuss their ability to find communities that could be used to define new control units of the airspace.Comment: 22 pages, 14 figure

How do elite female athletes cope with symptoms of their premenstrual period? A study on Rugby Union and Football players’ perceived physical ability and well-being

Women’s participation in sports has recently grown worldwide, including in sports typically associated with men (e.g., rugby and football). Similarly, literature on female athletes has increased, but how they cope with premenstrual (PM) physical and affective symptoms remains a poorly studied topic. Our study aimed to explain which coping strategies elite female rugby and football players use during their PM period to maintain perceived physical ability (PPA) and well-being. A mediation model analysis considering coping strategies (i.e., avoiding harm, awareness and acceptance, adjusting energy, self-care, and communicating) as independent variables, PPA and well-being as dependent variables, and PM physical and affective symptoms and PM cognitive resources as mediators was run on the data collected via an anonymous online survey. A dysfunctional impact of avoiding harm (indirect) and adjusting energy (both direct and indirect) and a functional indirect influence of awareness and acceptance, self-care, and communicating as coping strategies were found on PPA and well-being during the PM period. As predicted, PM physical and affective symptoms as mediators reduced PPA and well-being, while PM cognitive resources enhanced them. These results may inform practitioners on how to support elite female athletes’ PPA and well-being by knowing and reinforcing the most functional PM coping strategies for them

A conservative discontinuous target volatility strategy

The asset management sector is constantly looking for a reliable investment strategy, which is able to keep its promises. One of the most used approaches is the target volatility strategy that combines a risky asset with a risk-free trying to maintain the portfolio volatility constant over time. Several analyses highlight that such target is fulfilled on average, but in periods of crisis, the portfolio still suffers market’s turmoils. In this paper, the authors introduce an innovative target volatility strategy: the discontinuous target volatility. Such approach turns out to be more conservative in high volatility periods. Moreover, the authors compare the adoption of the VIX Index as a risk measure instead of the classical standard deviation and show whether the former is better than the latter. In the last section, the authors also extend the analysis to remove the risk-free assumption and to include the correlation structure between two risky assets. Empirical results on a wide time span show the capability of the new proposed strategy to enhance the portfolio performance in terms of standard measures and according to stochastic dominance theory

Characterization of a multifunctional caffeoyl-CoA O-methyltransferase activated in grape berries upon drought stress

Drought stress affects anthocyanin accumulation and modification in vegetative and reproductive plant tissues. Anthocyanins are the most abundant flavonoids in grape (Vitis vinifera L.) coloured berry genotypes and are essential markers of grape winemaking quality. They are mostly mono- and di-methylated, such modifications increase their stability and improve berry quality for winemaking. Anthocyanin methylation in grape berries is induced by drought stress. A few caffeoyl-CoA O-methyltransferases (CCoAOMTs) active on anthocyanins have been described in grape. However, no drought-activated O-methyltransferases have been described in grape berries yet. In this study, we characterized VvCCoAOMT, a grapevine gene known to induce methylation of CoA esters in cultured grape cells. Transcript accumulation of VvCCoAOMT was detected in berry skins, and increased during berry ripening on the plant, and in cultured berries treated with ABA, concomitantly with accumulation of methylated anthocyanins, suggesting that anthocyanins may be substrates of this enzyme. Contrary as previously observed in cell cultures, biotic stress (Botrytis cinerea inoculation) did not affect VvCCoAOMT gene expression in leaves or berries, while drought stress increased VvCCoAOMT transcript in berries. The recombinant VvCCoAOMT protein showed in vitro methylating activity on cyanidin 3-O-glucoside. We conclude that VvCCoAOMT is a multifunctional O-methyltransferase that may contribute to anthocyanin methylation activity in grape berries, in particular under drought stress conditions

Physical activity intervention for elderly patients with reduced physical performance after acute coronary syndrome (HULK study): Rationale and design of a randomized clinical trial

Background: Reduced physical performance and impaired mobility are common in elderly patients after acute coronary syndrome (ACS) and they represent independent risk factors for disability, morbidity, hospital readmission and mortality. Regular physical exercise represents a means for improving functional capacity. Nevertheless, its clinical benefit has been less investigated in elderly patients in the early phase after ACS. The HULK trial aims to investigate the clinical benefit of an early, tailored low-cost physical activity intervention in comparison to standard of care in elderly ACS patients with reduced physical performance. Design: HULK is an investigator-initiated, prospective multicenter randomized controlled trial (NCT03021044). After successful management of the ACS acute phase and uneventful first 1 month, elderly (≥70 years) patients showing reduced physical performance are randomized (1:1 ratio) to either standard of care or physical activity intervention. Reduced physical performance is defined as a short physical performance battery (SPPB) score of 4-9. The early, tailored, low-cost physical intervention includes 4 sessions of physical activity with a supervisor and an home-based program of physical exercise. The chosen primary endpoint is the 6-month SPPB value. Secondary endpoints briefly include quality of life, on-treatment platelet reactivity, some laboratory data and clinical adverse events. To demonstrate an increase of at least one SPPB point in the experimental arm, a sample size of 226 patients is needed. Conclusions: The HULK study will test the hypothesis that an early, tailored low-cost physical activity intervention improves physical performance, quality of life, frailty status and outcome in elderly ACS patients with reduced physical performance

Acute alcohol intoxication: a clinical overview

Alcohol is a legal and yet detrimental psychoactive substance, capable of establishing addiction and impacting the physical, mental, social, and economic health of people. Alcohol intake causes a large variety of tissue damages severely impacting the nervous system, digestive and cardiovascular systems and causing oral cavity, oropharyngeal, hypopharyngeal, esophageal, colon-rectal, laryngeal, liver and intrahepatic bile duct, and breast cancers. Alcohol can also play a role in the pathogenesis of diabetes mellitus, cardiomyopathy and hemorrhagic strokes. When drunk during pregnancy it is proved to be responsible for serious damage to fetuses causing a wide range of pathological conditions from miscarriage to Fetal Alcoholic Spectrum Disorder (FASD). Acute ethanol intoxication happens when the amount of alcohol consumed is greater than the disposal capacity of the liver, causing an accumulation of its metabolites displayed by initial dysphoria and disinhibition. Nausea, vomiting, memory loss could happen. Although, it can lead to more serious conditions like impaired speaking, impaired coordination, unstable gait, nystagmus, stupor, or coma. Respiratory depression and death could also happen in such cases. Unfortunately, diagnosis of acute alcohol intoxication is difficult because most of the drinkers deny or minimize their assumption. It is dramatically important to assess when the last intake happened to avoid withdrawal syndrome. Alcohol acute intoxication can be considered a serious harm to health and a relevant issue for healthcare provid-ers working in emergency rooms. Differential diagnosis is crucial to avoid serious outcomes. There is no consensus about therapies for acute intoxication, but supportive and symptomatic treatments were proved effective. The repercussions of alcohol misuse over drinkers' social, familiar, economical and working life enhance the importance of a multidisciplinary approach in such cases