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The aim of this work is to investigate possible relationships between air quality and the spread of the pandemic. We evaluate the performance of machine learning techniques in predicting new cases. Specifically, we describe a cross-correlation analysis on daily COVID-19 cases and environmental factors, such as temperature, relative humidity, and atmospheric pollutants. Our analysis confirms a significant association of some environmental parameters with the spread of the virus. This suggests that machine learning models trained using environmental parameters might provide accurate predictions about the number of infected cases. Our empirical evaluation shows that temperature and ozone are negatively correlated with confirmed cases (therefore, the higher the values of these parameters, the lower the number of infected cases), whereas atmospheric particulate matter and nitrogen dioxide are positively correlated. We developed and compared three different predictive models to test whether these technologies can be useful to estimate the evolution of the pandemic.

Currently, turbomachinery design optimization methodologies are mainly restricted to steady state approaches, due to the high computational cost associated with time-accurate shape optimization algorithms. However, the possibility to include unsteady effects in turbomachinery optimization can significantly increase the level of accuracy of the design predictions, leading to a more realistic representation of the actual performance and ultimately to a substantial increase in operating efficiency. Unsteady effects are particularly relevant in Organic Rankine Cycle turbines. A trade-off between high-fidelity time-accurate unsteady simulations of the flow solution and computational cost is therefore needed at design level. In this paper, a first application of the harmonic balance method to non-ideal compressible flows is presented. The methodology allows to solve the unsteady flow equations for a set of specified frequencies only, with significant computational time savings. An algorithm is proposed for non uniform time sampling in order to resolve frequencies that do not need to be integral multiple of one fundamental harmonic. This enables the solution of quasi-periodically forced non-linear flow problems, in combination with complex fluid models based on accurate equations of state. The method is applied to the unsteady analysis of a supersonic Organic Rankine Cycle stator with quasi-periodic inlet operating conditions, showing about one order magnitude lower computational cost compared to time-accurate simulations.

A non myeloablative conditioning with total lymphoid irradiation (TLI) and antithymocyte globulin (ATG) was shown to protect against graft-versus-host disease (GVHD). To evaluate the effects of TLI-ATG in a multicenter study, 45 heavily pretreated patients, median age 51, with lymphoid (n = 38) and myeloid (n = 7) malignancies were enrolled at 9 centers. Twenty-eight patients (62%) received at least 3 lines of treatment before allografting, and 13 (29%) had refractory/relapsed disease at the time of transplantation. Peripheral blood hematopoietic cells were from HLA identical sibling (n = 30), HLA-matched (n = 9), or 1 antigen HLA-mismatched (n = 6) unrelated donors. A cumulative TLI dose of 8 Gy was administered from day −11 through −1 with ATG at the dose of 1.5 mg/kg/day (from day −11 through −7). GVHD prophylaxis consisted of cyclosporine and mycophenolate mofetil. Donor engraftment was reached in 95% of patients. Grade II to IV acute GVHD (aGVHD) developed in 6 patients (13.3%), and in 2 of these patients, it developed beyond day 100. Incidence of chronic GVHD (cGVHD) was 35.8%. One-year nonrelapse mortality was 9.1%. After a median follow-up of 28 months (range, 3-57 months) from transplantation, median overall survival was not reached, whereas median event-free survival was 20 months. This multicenter experience confirms that TLI-ATG protects against GVHD and maintains graft-vs-tumor effects.

The stable marriage (SM) problem has a wide variety of practical applications, ranging from matching resident doctors to hospitals, to matching students to schools, or more generally to any two-sided market. In the classical formulation, n men and n women express their preferences (via a strict total order) over the members of the other sex. Solving a SM problem means finding a stable marriage where stability is an envy-free notion: no man and woman who are not married to each other would both prefer each other to their partners or to being single. We consider both the classical stable marriage problem and one of its useful variations (denoted SMTI) where the men and women express their preferences in the form of an incomplete preference list with ties over a subset of the members of the other sex. Matchings are permitted only with people who appear in these lists, an we try to find a stable matching that marries as many people as possible. Whilst the SM problem is polynomial to solve, the SMTI problem is NP-hard. We propose to tackle both problems via a local search approach, which exploits properties of the problems to reduce the size of the neighborhood and to make local moves efficiently. We evaluate empirically our algorithm for SM problems by measuring its runtime behaviour and its ability to sample the lattice of all possible stable marriages. We evaluate our algorithm for SMTI problems in terms of both its runtime behaviour and its ability to find a maximum cardinality stable marriage.For SM problems, the number of steps of our algorithm grows only as O(nlog(n)), and that it samples very well the set of all stable marriages. It is thus a fair and efficient approach to generate stable marriages.Furthermore, our approach for SMTI problems is able to solve large problems, quickly returning stable matchings of large and often optimal size despite the NP-hardness of this problem., Comment: 12 pages, Proc. COMSOC 2010 (Third International Workshop on Computational Social Choice)

The study examined the role of alexythimia and emotional distress in patients with diagnosis of chronic headaches (tension-type and medication overuse headache).The Toronto Alexithymia Scale (TAS-20)and the Rapid Stress Assessment (RSA) were administered to a sample of 104 patients (day hospital and outpatients) composed by 70 with CTTH and 34 with MOH.In total sample, 16.3% of patients were classified as alexithymics, 20.2% as intermediates and 63.5% as non-alexithymics, according to the TAS-20 criteria. Anxiety and Lack of social support (RSA) showed the higher values, yet the RSA mean profile didn't exceed the normative range. Alexithymics scored higher on all the RSA scales; significant positive correlations were also obtained among RSA and TAS-20 values. MOH patients were more frequently classifi ed as alexithymics and reported higher values on Aggressiveness scale (RSA) compared to CCTH patients.Findings supported a link between alexithymia and emotional distress, as an index of psychological maladjustment in chronic headache patients.

Risk analysis has recently emerged as a structured and precise methodology to help modern companies understand their risks and plan the relative countermeasures well in advance. It is based on a number of indicators: parameters that quantify the key concepts on which an enterprise designs its security and safety investments. A modificator is a function that further modifies an existing indicator, and is itself an indicator. It is argued here that Risk Analysis can dramatically benefit from three novel modificators. One, the Exposure Factor during Critical Time (EFCT), expresses the percentage of loss or damage that an attack can infer to a time-critical asset. Another one, the Exposure Factor under Retaliation (EFR), formalises the mitigation to the loss or damage that an attack can infer to an asset when that loss or damage can be retaliated back onto the attacker. The third one, the Mitigated Risk against Collusion (MRC), formalises how a security measure can be effective against a single attacker but not necessarily against a large team of attackers working collaboratively for the same target. Our simulated results firmly support the benefits of such augmented Risk Analysis confirming the novel insights it can provide.

Real-life problems present several kinds of preferences. We focus on problems with both positive and negative preferences, that we call bipolar preference problems. Although seemingly specular notions, these two kinds of preferences should be dealt with differently to obtain the desired natural behaviour. We technically address this by generalizing the soft constraint formalism, which is able to model problems with one kind of preferences. We show that soft constraints model only negative preferences, and we define a new mathematical structure which allows to handle positive preferences as well. We also address the issue of the compensation between positive and negative preferences, studying the properties of this operation. Finally, we extend the notion of arc consistency to bipolar problems, and we show how branch and bound (with or without constraint propagation) can be easily adapted to solve such problems.

Low temperature specific heat $C(T)$ and zero-field muon spin resonance ($\mu^+$SR) measurements were performed in Gd(hfac)$_3$NITiPr, a quasi one-dimensional molecular magnet with competing nearest neighbor and next-nearest neighbor intrachain exchange interactions. The specific heat data exhibit a $\lambda$-peak at $T_0$=2.08$\pm$0.01K that disappears upon the application of a 5 Tesla magnetic field. Conversely, the $\mu^+$SR data do not present any anomaly at $T\approx 2$ K, proving the lack of divergence of the two-spin correlation function as required for usual three-dimensional (3D) long range helical order. Moreover, no muon spin precession can be evinced from the $\mu^+$SR asimmetry curves, thus excluding the presence of a long range ordered magnetic lattice. These results provide indications for a low $T$ phase where chiral order is established in absence of long range helical order., Comment: 5 pages, 3 figures

In 1982 a programme of multi-disciplinary follow-up on 12 patients that underwent a gastric tube oesophagoplasty for long-gap oesophageal atresia was started. Radiological examination, performed on all gastric tubes but one (died a few days after surgery), assessed the morphology and dynamics of gastric tube, either distally or proximally based, and stomach 2 to 8 years after surgery. Endoscopic backward exploration was performed on 7 cases, to allow a closer analysis of stomach, gastric tube mucosa and upper oesophageal stump, demonstrating that the gastric transplant is viable and almost undamaged. No evidence of oesophagitis of the proximal stump was found. Histological stainings on biopsy specimens and on sections from one post-mortem examination, showed a mild degree of dystrophy in gastric tube mucosa, progressively shading into proper gastric mucosa. No evidence of a progressive change for the worse was found in any of the 7 tubes controlled.

We describe the case of a patient 4 months old transferred to our hospital for evaluation of occasionally detected cardiac alterations: ecg showed abnormal Q and negative T waves in D1 - aVL leads and chest x-ray was consistent with enlargement of the left ventricular cavity. After admission, 2D echocardiographic examination disclosed, in the left ventricular cavity, a large mass extending from the papillary muscles to the outflow tract. The mass was of uniform density and easily recognizable as a tumor. Although asymptomatic, the patient underwent operation 10 months later because of the risk of occurrence of severe conduction disturbances or arrhythmias. Histological examination demonstrated that the mass was a fibroma. At post-op echocardiographic and angiographic evaluation the left ventricle appeared abnormally dilated with a large aneurysm of the lateral wall and very poor pump function. Nevertheless the patient did well in the following months until a ventricular fibrillation occurred at home. He was immediately brought to hospital and resuscitation was attempted unsuccessfully. We discuss the role of 2D echocardiography in the diagnosis of cardiac tumors, the indication of the early surgical removal and the possible limitations of the technique we used in this case.

Metastable condensation is the phase transition from vapor to liquid that occurs in a fluid subjected to rapid temperature variations. Under these conditions, the nucleation process is triggered when the fluid is in a supersaturated thermodynamic state. The dispersed phase forming during the process of condensation is not in stable thermodynamic equilibrium with the surrounding vapor. As a consequence, models suitable for condensing flows under large temperature gradients, which are relevant to many scientific studies and industrial applications, are rather complex as they must correctly treat metastable thermodynamic states. Applications of metastable condensation flowmodels include improved climate models [1], biomedical treatments [2], heat transfer enhancement for industrial purposes [3], natural gas separation [4], power conversion [5] and many others. The scope of the research documented in this dissertation is the numerical investigation of metastable condensing flows in turbomachinery for propulsion and power applications. The flow inside turbomachinery components is highly compressible, with absolute temperature gradients that can reach values of the order of 1e6 K/s[6], in the case of supersonic expansions. In such extreme conditions, metastable phenomena impact severely on the component performance in terms of both thermodynamic and fluid dynamic losses and lifetime. The number of technologies for propulsion and power characterised by the presence of condensing mixtures in turbomachinery is increasing. Considerable research and development efforts are currently concerned with components of next-generation thermal power and refrigeration systems, in which the flow undergoes metastable condensation. The characterization of metastable condensing flows and the development of advanced fluid dynamic design tools capable of treating these complex flow phenomena are fundamental steps towards the commercial application fo such promising technologies.

The constant progress of humanity is inherently linked to an ever-increasing demand for energy. Coping with this demand by means of fossil-fuel power plants has lead to extensive environmental damage like global warming, destruction of natural habitats, and air pollution. In order to ensure the well-being of future generations, civilization must transition to a new energy mix, where clean energy technologies play a major role.

Neurological disorders are often associated with immobilization, thus placing patients at increased risk for venous thromboembolism (VTE). This risk is very high in patients with acute ischemic stroke and spinal cord injuries, and it remains poorly defined in patients with peripheral nervous disorders or degenerative disorders of the central nervous system. The benefit of prophylactic strategies remains often unclear. The Italian Society for Studies on Haemostasis and Thrombosis promoted the development of evidence- and consensus-based guidelines to help physicians involved in the management of neurological patients. After a comprehensive and systematic review of the literature, a panel of experts formulated recommendations for the prevention of VTE in adolescent or adult patients presenting with different neurological disorders. Patients with acute ischemic stroke should routinely receive pharmacological prophylaxis to be started within 48 hours and continued for approximately 14 days; patients with acute hemorrhagic stroke should routinely receive mechanical prophylaxis, pharmacological prophylaxis should be considered once the patient is stable; patients with neuro-muscular degenerative diseases and with other major risk factors for venous thrombosis should be considered for the administration of pharmacological or mechanical prophylaxis; patients with peripheral nerve diseases should receive mechanical prophylaxis while immobilized and in the presence of additional risk factors for VTE, patients with Guillain Barrè should be considered for pharmacological prophylaxis with low molecular weight heparin; patients with spinal cord injury should receive combined mechanical and pharmacological prophylaxis; patients with non traumatic spinal cord diseases should be considered for pharmacological prophylaxis.

Summary. Background: Little information is available on the long-term clinical outcome of cerebral vein thrombosis (CVT). Objectives and methods: In an international, retrospective cohort study, we assessed the long-term rates of mortality, residual disability and recurrent venous thromboembolism (VTE) in a cohort of patients with a first CVT episode. Results: Seven hundred and six patients (73.7% females) with CVT were included. Patients were followed for a total of 3171 patient-years. Median follow-up was 40 months (range 6, 297 months). At the end of follow-up, 20 patients had died (2.8%). The outcome was generally good: 89.1% of patients had a complete recovery (modified Rankin Score [mRS] 0–1) and 3.8% had a partial recovery and were independent (mRS 2). Eighty-four per cent of patients were treated with oral anticoagulants and the mean treatment duration was 12 months. CVT recurred in 31 patients (4.4%), and 46 patients (6.5%) had a VTE in a different site, for an overall incidence of recurrence of 23.6 events per 1000 patient-years (95% confidence Interval [CI] 17.8, 28.7) and of 35.1 events/1000 patient-years (95% CI, 27.7, 44.4) after anticoagulant therapy withdrawal. A previous VTE was the only significant predictor of recurrence at multivariate analysis (hazard ratio [HR] 2.70; 95% CI 1.25, 5.83). Conclusions: The long-term risk of mortality and recurrent VTE appears to be low in patients who survived the acute phase of CVT. A previous VTE history independently predicts recurrent events.