Flood propagation modelling with the Local Inertia Approximation: theoretical and numerical analysis of its physical limitations

Attention of the researchers has increased towards a simplification of the complete Shallow water Equations called the Local Inertia Approximation (LInA), which is obtained by neglecting the advection term in the momentum conservation equation. In the present paper it is demonstrated that a shock is always developed at moving wetting-drying frontiers, and this justifies the study of the Riemann problem on even and uneven beds. In particular, the general exact solution for the Riemann problem on horizontal frictionless bed is given, together with the exact solution of the non-breaking wave propagating on horizontal bed with friction, while some example solution is given for the Riemann problem on discontinuous bed. From this analysis, it follows that drying of the wet bed is forbidden in the LInA model, and that there are initial conditions for which the Riemann problem has no solution on smoothly varying bed. In addition, propagation of the flood on discontinuous sloping bed is impossible if the bed drops height have the same order of magnitude of the moving-frontier shock height. Finally, it is found that the conservation of the mechanical energy is violated. It is evident that all these findings pose a severe limit to the application of the model. The numerical analysis has proven that LInA numerical models may produce numerical solutions, which are unreliable because of mere algorithmic nature, also in the case that the LInA mathematical solutions do not exist. The applicability limits of the LInA model are discouragingly severe, even if the bed elevation varies continuously. More important, the non-existence of the LInA solution in the case of discontinuous topography and the non-existence of receding fronts radically question the viability of the LInA model in realistic cases. It is evident that classic SWE models should be preferred in the majority of the practical applications

Resistivity probability tomography imaging at the castle of Zena, Italy

We present the results of an electrical resistivity investigation performed at Castle of Zena (Castello di Zena), a 13th-century fortress located between the towns of Fiorenzuola and Piacenza in the Emilia Romagna Region (Northern Italy), in the frame of a project of restoration. Dipole-dipole resistivity tomographies were planned in three areas suspected of containing buried archaeo-architectural remnants. Data analysis has been made using a 3D tomography imaging approach based on the concept of occurrence probability of anomaly sources in the electrical resistivity distribution. The 3D tomography has allowed three interesting anomaly source areas to be identified in the 1-2 m depth range below ground level. Subsequent excavations have brought to light a giacciara, that is, a brickwork room for food maintenance, a furnace, and the basement of a wing of the castle destroyed in the 18th century, exactly in correspondence with the anomaly sources detected by the resistivity tomography

Management of Severe Asthma in Eosinophilic Granulomatosis with Polyangiitis with Interleukin-5-Targeted Therapies: Current Status and Report of Two Cases

Eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic disorder characterized by peripheral eosinophilia, severe eosinophilic asthma, sinusitis, transient pulmonary infiltrates, and features of medium/small-vessel vasculitis. EGPA belongs to the group of anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitides, although only 30 to 40% of patients display ANCA positivity, which is mainly of myeloperoxidase (MPO) specificity. Particularly, ANCA-positive patients typically show vasculitic features. Interleukin (IL)-5 has been demonstrated to play a crucial role in determining eosinophilic airway inflammation in EGPA patients. Specifically, maturation, activation, and survival of eosinophils especially depend on IL-5 availability. Therefore, blocking IL-5 biological activity may be a rewarding strategy for control of eosinophilic inflammation. Several monoclonal antibodies with the ability to interfere with the biological activity of IL-5 have been developed, namely, mepolizumab, reslizumab, and benralizumab. Here, we discuss the role of these drugs in the management of severe eosinophilic asthma in the context of EGPA and report the outcome of two EGPA patients with severe eosinophilic asthma treated at our outpatient clinic

The effects of beta (2)-adrenergic receptors activation on the cardiovascular system and on the skeletal muscle: A narrative review

Beta(2)-adrenergic receptors (adrenoceptors) are activated by the catecholamines norepinephrine and epinephrine. Adrenoceptors are found in different tissues, such as smooth muscle, skeletal muscle and myocardium. Stimulation of adrenoceptors is implicated in several physiological functions in the body, such as bronchodilation, increased perfusion and vasodilation. The latters, together with increased muscular mass and contraction speed, facilitate muscle’s motility and contraction. In the cardiovascular system, the activation of adrenoceptors increases heart muscle contraction, cardiac output and heart rate. Some studies also suggested a cardioprotective role of the stimulation of adrenoceptors. Beta(2)-adrenergic receptors agonists, principally divided in long-acting beta(2) agonists (LABAs) and short-acting beta(2) agonists (SABAs), are primarily used to treat asthma and other pulmonary disorders. Beta(2)-adrenergic receptors activation has been correlated with anabolic properties and muscular hypertrophy with the use of oral clenbuterol, as well as intravenous albuterol. Given these anabolic, lipolytic and performance-enhancing effects, LABAs are frequently abused by athletes. For this reason, most of these drugs are banned by the World Anti-Doping Agency, or admissible only with limitations. The aim of this narrative review is to report the results of some recent studies about the effects of beta(2)-adrenergic receptors activation on the cardiovascular system and on the skeletal muscle

Heterochromatin distribution in selected taxa of the 42-chromosomes Orchis s. l. (Orchidaceae)

In six 42-chromosomes taxa belonging to genus Orchis s. l. heterochromatin location and distribution and staining properties were analysed by means of C-banding and of the fluorochromes 4'-6-diamino-2-phenylindole-2HCl (DAPI) and Hoechst 33258. Most species could be distinguished on the basis of heterochromatin amounts and distribution. In the species O. mascula and O. provincialis most DAPI-positive sites did not co-localize with C-bands. DAPI revealed bright fluorescence at telomeric or subtelomeric regions of numerous chromosomes of O. mascula and particularly large/bright blocks at the telomeres of O. provincialis. In O. x penzigiana (Orchis mascula ssp. ichnusae x O. provincialis) overall heterochromatin distribution followed that of the parental species. In Neotinea group all DAPI positive bands co-localize with C-bands, but have different distribution in the taxa analysed. Present and literature data indicate a high level of plasticity of heterochromatin organization in Orchis s. l., and suggest evolutionary pathways in agreement with recent molecular data

A Derivative Recovery Spectral Volume model for the analysis of constituents transport in one-dimensional flows

The treatment of advective fluxes in high-order finite volume models is well established, but this is not the case for diffusive fluxes, due to the conflict between the discontinuous representation of the solution and the continuous structure of analytic solutions. In this paper, a derivative reconstruction approach is proposed in the context of spectral volume methods, for the approximation of diffusive fluxes, aiming at the reconciliation of this conflict. Two different reconstructions are used for advective and diffusive fluxes: the advective reconstruction makes use of the information contained in a spectral cell, and allows the formation of discontinuities at the spectral cells boundaries; the diffusive reconstruction makes use of the information contained in contiguous spectral cells, imposing the continuity of the reconstruction at the spectral cells boundaries. The method is demonstrated by a number of numerical experiments, including the solution of shallow-water equations, complemented with the advective-diffusive transport equation of a conservative substance, showing the promising abilities of the numerical scheme proposed

Friction decoupling and loss of rotational invariance in flooding models

Friction decoupling, i.e. the computation of friction vector components making separate use of the corresponding velocity components, is common in staggered grid models of the SWE simplifications (Zero-Inertia and Local Inertia Approximation), due to the programming simplicity and to the consequent calculations speed-up. In the present paper, the effect of friction decoupling has been studied from the theoretical and numerical point of view. First, it has been found that friction vector decoupling causes the reduction of the computed friction force and the rotation of the friction force vector. Second, it has been demonstrated that decoupled-friction models lack of rotational invariance, i.e. model results depend on the alignment of the reference framework. These theoretical results have been confirmed by means of numerical experiments. On this basis, it is evident that the decoupling of the friction vector causes a major loss of credibility of the corresponding mathematical and numerical models. Despite the modest speed-up of decoupled-friction computations, classic coupled-friction models should be preferred in every case

Spinal Fusion Surgery: Epidemiologic and Economic Burden Attributable to First Intervention

IntroductionLow back pain (LBP) is the single most common cause for disability in individuals aged 50 years or younger with a high socioeconomic impact. In USA, LBP costs are estimated to exceed $1..

COVID-19 and arrhythmia: The factors associated and the role of myocardial electrical impulse propagation. An observational study based on cardiac telemetric monitoring

BACKGROUND: The heart is commonly involved in COVID-19, and rhythm disorders have been largely reported. OBJECTIVE: To evaluate the association of some non-cardiac and cardiac comorbidities and QT dispersion with arrhythmias and their impact on outcomes in hospitalized patients with COVID-19. METHODS: Each patient underwent cardiac telemetry monitoring through the entire hospitalization period, laboratory analyses, 12-lead ECG, and lung imaging examination. Patients with arrhythmia were divided into three groups (bradyarrhythmias, tachyarrhythmias, and tachy- and bradyarrhythmias). RESULTS: Two-hundred patients completed the study (males, 123; mean age, 70.1 years); of these, 80 patients (40%) exhibited rhythm disorders on telemetry. Patients with arrhythmia were older (p < 0.0001), had a greater number of comorbidities (p < 0.0001), higher values of creatinine (p = 0.007), B-type natriuretic peptide (p < 0.0001), troponin (p < 0.0001), C-reactive protein (p = 0.01), ferritin (p = 0.001), D-dimer (p < 0.0001), procalcitonin (p = 0.0008), QT interval (p = 0.002), QTc interval (p = 0.04), and QTc dispersion (p = 0.01), and lower values of sodium (p = 0.03), magnesium (p = 0.04), glomerular filtration rate (p < 0.0001), and hemoglobin (p = 0.008) as compared to patients without arrhythmia. By comparing the three subgroups of patients, no significant differences were found. At multivariate analysis, age [odds ratio (OR) = 1.14 (95% CI: 1.07–1.22); p = 0.0004], coronary artery disease [OR = 12.7 (95% CI: 2.38–68.01); p = 0.005], and circulating troponin [OR = 1.05 (95% CI: 1.003–1.10); p = 0.04] represented risk factors independently associated with arrhythmia. All-cause in-hospital mortality was ∼40-fold higher among patients with arrhythmia [OR = 39.66 (95% CI: 5.20–302.51); p = 0.0004]. CONCLUSION: Arrhythmias are associated with aging, coronary artery disease, subtle myocardial injury, hyperinflammatory status, coagulative unbalance, and prolonged QTc dispersion in patients with COVID-19, and confer a worse in-hospital prognosis. Given its usefulness, routinary use of cardiac telemetry should be encouraged in COVID wards

CXCL4 in undifferentiated connective tissue disease at risk for systemic sclerosis (SSc) (previously referred to as very early SSc)

The aim of the study was to evaluate CXCL4 levels in undifferentiated connective tissue disease at risk for SSc (UCTD-SSc-risk) and confirm its increase and investigate its prognostic value. Serum CXCL4 levels were measured in 45 patients and 24 controls. CXCL4 was significantly higher in UCTD-SSc-risk patients than in controls. It resulted higher in patients with a shorter disease duration and in those lacking capillaroscopic alterations. We confirm that CXCL4 levels are increased in UCTD-risk-SSc patients. Further studies are needed to investigate the role of CXCL4 assessment in UCTD-risk-SSc