Complex singularities and PDEs

In this paper we give a review on the computational methods used to characterize the complex singularities developed by some relevant PDEs. We begin by reviewing the singularity tracking method based on the analysis of the Fourier spectrum. We then introduce other methods generally used to detect the hidden singularities. In particular we show some applications of the Pad\'e approximation, of the Kida method, and of Borel-Polya method. We apply these techniques to the study of the singularity formation of some nonlinear dispersive and dissipative one dimensional PDE of the 2D Prandtl equation, of the 2D KP equation, and to Navier-Stokes equation for high Reynolds number incompressible flows in the case of interaction with rigid boundaries

Reliability as a tool for hydraulic networks planning

This paper presents a methodology to evaluate the reliability of water distribution systems that can be used in the design phase and for identifying repair works to be carried out on existing systems. The methodology is based on the statistical analysis of dimensionless performance indices (hydraulic performance indices) derived from a large number of simulations of various water system demand scenarios and/or operating conditions. The hydraulic reliability index is assumed as the probability that, under a given operating condition, the hydraulic performance index will be above a certain threshold. Finally, the system’s overall reliability (mechanical 1 hydraulic) is estimated using the overall reliability index, which is defined by the weighted mean of the hydraulic performance indices obtained for the various operating conditions. A case study using this methodology shows the concrete possibilities of applying this approach to a wide spectrum of cases, and the small influence on overall system reliability normally exerted by such events as the failure of links, pipes, and valves

Study of neutron-rich calcium isotopes with a realistic shell-model interaction

We have studied neutron-rich calcium isotopes in terms of the shell model employing a realistic effective interaction derived from the CD-Bonn nucleon-nucleon potential. The short-range repulsion of the potential is renormalized by way of the V-low-k approach. The calculated results are in very good agreement with the available experimental data, thus supporting our predictions for the hitherto unknown spectra of 53-56Ca nuclei. In this context, the possible existence of an N=34 shell closure is discussed.Comment: 11 pages, 3 figures, to be published in Physical Review

Closure to Reliability as Tool for Hydraulic Network Planning

Closure to the discussion carried by prof. Kansal on the paper "Reliability as Tool for Hydraulic Network Planning

NICU Infants & SNHL: Experience of a western Sicily tertiary care centre

Introduction: The variability of symptoms and signs caused by central nervous system (CNS) lesions make multiple sclerosis difficult to recognize,Introduction: This study adds the evaluation of the independent etiologic factors that may play a role in the development of SNHL in a NICU population. We compared neonatal intensive care unit NICU infants with sensorineural hearing loss SNHL to age and gender matched normal hearing NICU controls. Materials and methods: 284 consecutive NICU infants positive to the presence of risk indicators associated with permanent congenital, delayed-onset, or progressive hearing loss underwent to global audiological assessment. The following risk factors were researched, making a distinction between prenatal and perinatal risk factors: in the first group, family history of permanent childhood hearing impairment, consanguinity, pregnant maternal infection and drugs exposition during pregnancy; in the second group, premature birth, respiratory distress, hyperbilirubinemia requiring exchange tranfusion, very low birth weight, cranio-facial abnormality, perinatal infections, ototoxic drugs administration, acidosis, hyponatremia, head trauma. Results: The analysis of the auditory deficit for infants according to numbers of risk factors showed mean values of: 78 + 28.08 dB nHL for infants positive to two risk factors; 75.71 + 30.30 dB nHL in cases positive to three risk factors; 96.66 + 34.46 dB nHL for four risk factors and 85 + 35 dB nHL in case of >5 risk factors. Conclusion: NICU infants have greater chances of developing SNHL, because of the presence of multiple risk factors; in fact, as the number of coexisting risk factors increases, the prevalence rate of SNHL also increases (r=0.81)

The immunohistochemical expression of leptin in lymph node metastasis from laryngeal squamous cell carcinoma (SCC)

Introduction: Leptin is a proteohormone produced predominantly by white adipocytes and primarily known for its key role in the control of food intake and sense of satiety. From its discover leptin has been found in different body districts, involved in always new functions and processes. In the last years numerous relationships between leptin and cancer has been found. The aim of this study is to test the leptin positivity in human primitive laryngeal squamous cell carcinoma (SCC) and in its lymph node metastasis. Materials and methods: Leptin positivity was detected by immunohistochemical analysis on pathological samples from 18 patients subjected to laryngectomy and neck dissection for SCC. Results: During the study we pointed out a statistically significant relationship (p < 0.05) between leptin positivity levels and tumor differentiation grade, in particular we observed that a decrease in tumor leptin production correlates with higher level of cancer histological dedifferentiation. Conclusion: Our research on leptin expression in laryngeal squamous neoplastic pathology is aimed to the attempt of establishing a more precise patient risk stratification thanks to a new marker able to give a contribution to the identification of patient with poor prognosis and at risk of failure of actual standard therapy

Chiral nucleon-nucleon forces in nuclear structure calculations

Realistic nuclear potentials, derived within chiral perturbation theory, are a major breakthrough in modern nuclear structure theory, since they provide a direct link between nuclear physics and its underlying theory, namely the QCD. As a matter of fact, chiral potentials are tailored on the low-energy regime of nuclear structure physics, and chiral perturbation theory provides on the same footing two-nucleon forces as well as many-body ones. This feature fits well with modern advances in ab-initio methods and realistic shell-model. Here, we will review recent nuclear structure calculations, based on realistic chiral potentials, for both finite nuclei and infinite nuclear matter.Comment: 10 pages, 8 figures, plenary talk presented at "Nucleus-Nucleus 2015" Conference, 21-26 June 2015, Catania, to be published in the "Conference Proceedings" Series of the Italian Physical Societ

the overall pulse model for water demand of aggregated residential users

Abstract The models for the end-user demand give a detailed description of the water request, which takes into account the consumes of each dwelling. Therefore, these approaches can model the water demand at WDS nodes by aggregating the single request of each user. The effectiveness of a novel approach the Overall Pulse model (OP)- to describe the aggregated water demand has been tested. In fact, the OP model, unlike the commonly used rectangular pulse models (e.g. PRP, NSRP), does not aim to reconstruct single demand pulses as they occur when home faucets and hydro-sanitary appliances are operated, but allows the generation of the water demand as it is observed at the house water meter. This feature makes the model very versatile, allowing the direct modeling of either a single user or of a group of n users. The possibility of 'pre-aggregation' of the water demand makes it easier to take into account the spatial variability of the model parameters. In the paper, the performance of the OP model is investigated, and to this aim the generated time series are compared with the observed ones of real users. In addition, the comparison of series obtained by means of the classical PRP approach and of the OP model show the effectiveness of the latter

Early detection of biochemically occult autonomous thyroid nodules

Objective: Autonomously functioning thyroid areas may be associated with subclinical or overt hyperthyroidism, but may exist even in the presence of normal TSH. This study was aimed at comparing the rate of autonomously functioning areas and their cardiac sequelae in patients with nodular goitre studied with the usual and a novel approach. Design and methods: In total 490 adult outpatients with thyroid nodular goitre, living in a mild iodine-deficient area, were selected in our referral centre for thyroid diseases from 2009 to 2014 on the basis of a suspicion of thyroid functional autonomy. They were divided in three groups according to a non-conventional approach (excessive response to thyroxine treatment: group 1) or conventional approach (low/normal TSH with clinical suspicion or low TSH: groups 2 and 3). All patients of the study with the suspicion of thyroid functional autonomy underwent thyroid scan with radioactive iodine (I131) uptake (RAIU). Results: The percentage of confirmed thyroid functional autonomy was 319/490, being significantly higher in group 3 than in groups 1 and 2 (81.5 vs 64.7 vs 52.6%; chi-square P < 0.0001). However, the diagnosis with non-conventional approach was made at a significant earlier age (P < 0.0001). Cardiac arrhythmias as well as atrial fibrillation were similarly detected by conventional and non-conventional approaches (chi-square test: P = 0.2537; P = 0.8425). Conclusions: The hyper-responsiveness to thyroxine treatment should induce the suspicion of thyroid functional autonomy at an early stage, allowing to detect autonomous functioning areas in apparently euthyroid patients