The isoperimetric problem for regular and crystalline norms in H1\mathbb H^1

We study the isoperimetric problem for anisotropic left-invariant perimeter measures on $\mathbb R^3$, endowed with the Heisenberg group structure. The perimeter is associated with a left-invariant norm $\phi$ on the horizontal distribution. We first prove a representation formula for the $\phi$-perimeter of regular sets and, assuming some regularity on $\phi$ and on its dual norm $\phi^*$, we deduce a foliation property by sub-Finsler geodesics of $\mathrm C^2$-smooth surfaces with constant $\phi$-curvature. We then prove that the characteristic set of $\mathrm C^2$-smooth surfaces that are locally extremal for the isoperimetric problem is made of isolated points and horizontal curves satisfying a suitable differential equation. Based on such a characterization, we characterize $\mathrm C^2$-smooth $\phi$-isoperimetric sets as the sub-Finsler analogue of Pansu's bubbles. We also show, under suitable regularity properties on $\phi$, that such sub-Finsler candidate isoperimetric sets are indeed $\mathrm C^2$-smooth. By an approximation procedure, we finally prove a conditional minimality property for the candidate solutions in the general case (including the case where $\phi$ is crystalline)

Optimal selection of contracts and work shifts in multi-skill call centers

This paper deals with the problem of finding the most suitable contracts to be used when hiring the operators of a call center and deciding their optimal working schedule, to optimize the trade-off between the service level provided to the customers and the cost of the personnel. In a previous paper (Cordone et al. 2011), we proposed a heuristic method to quickly build an integer solution from the solution of the continuous relaxation of an integer linear programming model. In this paper, we generalize that model to take into account a much wider class of working contracts, allowing heterogeneous shift patterns, as well as legal constraints related to continuously active working environments. Since our original rounding heuristic cannot be extended to the new model, due to its huge size and to the involved correlations between different sets of integer variables, we introduce a more sophisticated heuristic based on decomposition and on a multi-level iterative structure. We compare the results of this heuristic with those of a Greedy Randomized Adaptive Search Procedure, both on real-world instances and on realistic random instances

Prognostic stratification of acute pulmonary embolism: Focus on clinical aspects, imaging, and biomarkers

Pulmonary embolism (PE) represents a common disease in emergency medicine and guidelines for diagnosis and treatment have had wide diffusion. However, PE morbidity and mortality remain high, especially when associated to hemodynamic instability or right ventricular dysfunction. Prognostic stratification to identify high risk patients needing to receive more aggressive pharmacological and closer monitoring is of utmost importance. Modern guidelines for management of acute PE are based on risk stratification using either clinical, radiological, or laboratory findings. This article reviews the modern treatment of acute PE, which is customized upon patient prognosis. Accordingly the current risk stratification tools described in the literature such as clinical scores, echocardiography, helical computer tomography, and biomarkers will be reviewed

Pulmonary embolism in the elderly: a review on clinical, instrumental and laboratory presentation

OBJECTIVE: Diagnosis of pulmonary embolism (PE) remains difficult and is often missed in the elderly due to nonspecific and atypical presentation. Diagnostic algorithms able to rule out PE and validated in young adult patients may have reduced applicability in elderly patients, which increases the number of diagnostic tools use and costs. The aim of the present study was to analyze the reported clinical presentation of PE in patients aged 65 and more. MATERIALS AND METHODS: Prospective and retrospective English language studies dealing with the clinical, instrumental and laboratory aspects of PE in patients more than 65 and published after January 1987 and indexed in MEDLINE using keywords as pulmonary embolism, elderly, old, venous thromboembolism (VTE) in the title, abstract or text, were reviewed. RESULTS: Dyspnea (range 59%-91.5%), tachypnea (46%-74%), tachycardia (29%-76%), and chest pain (26%-57%) represented the most common clinical symptoms and signs. Bed rest was the most frequent risk factor for VTE (15%-67%); deep vein thrombosis was detected in 15%-50% of cases. Sinus tachycardia, right bundle branch block, and ST-T abnormalities were the most frequent ECG findings. Abnormalities of chest X-ray varied (less than 50% in one-half of the studies and more than 70% in the other one-half). Arterial blood gas analysis revealed severe hypoxemia and mild hypocapnia as the main findings. D-Dimer was higher than cut-off in 100% of patients in 75% of studies. Clinical usefulness of D-Dimer measurement decreases with age, although the strategies based on D-Dimer seem to be cost-effective at least until 80 years. CONCLUSION: Despite limitations due to pooling data of heterogeneous studies, our review could contribute to the knowledge of the presentation of PE in the elderly with its diagnostic difficulties. A diagnostic strategy based on reviewed data is proposed

Towards coordinated site monitoring and common strategies for mitigation of Radio Frequency Interference at the Italian radio telescopes

We present a project to implement a national common strategy for the mitigation of the steadily deteriorating Radio Frequency Interference (RFI) situation at the Italian radio telescopes. The project involves the Medicina, Noto, and Sardinia dish antennas and comprised the definition of a coordinated plan for site monitoring as well as the implementation of state-of-the-art hardware and software tools for RFI mitigation. Coordinated monitoring of frequency bands up to 40 GHz has been performed by means of continuous observations and dedicated measurement campaigns with fixed stations and mobile laboratories. Measurements were executed on the frequency bands allocated to the radio astronomy and space research service for shared or exclusive use and on the wider ones employed by the current and under-development receivers at the telescopes. Results of the monitoring campaigns provide a reference scenario useful to evaluate the evolution of the interference situation at the telescopes sites and a case series to test and improve the hardware and software tools we conceived to counteract radio frequency interference. We developed a multi-purpose digital backend for high spectral and time resolution observations over large bandwidths. Observational results demonstrate that the spectrometer robustness and sensitivity enable the efficient detection and analysis of interfering signals in radio astronomical data. A prototype off-line software tool for interference detection and flagging has been also implemented. This package is capable to handle the huge amount of data delivered by the most modern instrumentation on board of the Italian radio telecsopes, like dense focal plane arrays, and its modularity easen the integration of new algorithms and the re-usability in different contexts or telescopes.Comment: 39 pages, 10 Figures and 7 Tables. INAF Technical Report n. 149 (2022). http://hdl.handle.net/20.500.12386/3208

C-band observations of supernova remnants with SRT: 1 - Imaging performances

We report on observations of Supernova Remnants (SNR) with SRT in the frame of Astronomical Validation (AV) test activities. These tests are aimed to assess single-dish imaging performances of “SRT first light receivers” coupled with Total Power (TP) backend and related hw/sw subsystems/procedures (including innovative ad hoc imaging techniques based on OTF scans)