Anderson transition on the Bethe lattice: an approach with real energies

We study the Anderson model on the Bethe lattice by working directly with propagators at real energies $E$. We introduce a novel criterion for the localization-delocalization transition based on the stability of the population of the propagators, and show that it is consistent with the one obtained through the study of the imaginary part of the self-energy. We present an accurate numerical estimate of the transition point, as well as a concise proof of the asymptotic formula for the critical disorder on lattices of large connectivity, as given in [P.W. Anderson 1958]. We discuss how the forward approximation used in analytic treatments of localization problems fits into this scenario and how one can interpolate between it and the correct asymptotic analysis.Comment: Close to published versio

Maximally multipartite entangled states

We introduce the notion of maximally multipartite entangled states of n qubits as a generalization of the bipartite case. These pure states have a bipartite entanglement that does not depend on the bipartition and is maximal for all possible bipartitions. They are solutions of a minimization problem. Examples for small n are investigated, both analytically and numerically.Comment: 5 pages, 1 figure, final verso

Ostruzione polmonare ed aritmia respiratoria

Il monitoraggio di pazienti tramite segnali fotopletismografici (PhotoPlethysmoGram, PPG) acquisiti sul polso, arteria radiale, piuttosto che sulla punta dell’indice, permette di ottenere un segnale più stabile e con maggiori informazioni, come la gittata cardiaca, la durata della contrazione ventricolare e la chiusura dell’aorta. In questo lavoro è presentata un’attività preliminare per rilevare condizioni come l’ostruzione polmonare e le apnee notturne. Si è indagato l’andamento dell’aritmia respiratoria in relazione ad eventuali difficoltà respiratorie. Per il momento ci si è limitati ad osservare soggetti sani e l’ostruzione è stata simulata facendo respirare i soggetti attraverso una cannuccia

Legal scenarios in the coronavirus time: Medico legal implications in the aspects of governance

Along with rising levels of the infection around the world, the state of emergency prompted by the COVID-19 pandemic has also been having a heavy legal impact. The situation is posing important criminal challenges, as well as an ocean of social and public health issues around the world. It has not only directly affected constitutionally-guaranteed rights and individual freedoms, but also brought to the fore certain types of criminal offence that had previously been of little practical importance, such as the crime of ‘maliciously or unintentionally causing an epidemic’. Different countries and states have introduced policies to manage the emergency at different times and in different ways. The measures adopted have been the object of much criticism, also raising questions of constitutional legitimacy in countries like Italy. The present contribution begins with a brief outline of the different international scenarios. Then we examine some of the medicolegal aspects of criminal offences previously envisaged and newly introduced since the arrival of the pandemic. We suggest the need for a sort of ‘code of public health laws for the time of coronavirus’, that could also be applied to other public health emergencies, pandemic or otherwise. The idea is to give operators in the sector and the general population the opportunity to identify clear and simple rules to follow in the current complex global situation. We need a new, appropriate interpretation of the ‘boundaries’ of our individual rights in relation to the need to safeguard the wider community and its more vulnerable members

Relationship between tree-related microhabitats and the captures obtained using different trap methods for large threatened saproxylic beetles

Osmoderma eremita and Cerambyx cerdo are saproxylic beetle species, included in the IUCN Red List and in the EU/92 Habitats Directive. Their occurrence has been recorded, through appropriate traps, in several localities in Italy, including urban and peri-urban parks, mostly associated with veteran trees. In this study, traps were tested over 17 veteran oak trees in the Castelporziano Presidential Estate (Latium, Rome province, central Italy) and the abundance of sampled saproxylic beetles was related to the growing stock volume (GSV) and the abundance of microhabitats. Moreover, we compared three different trapping methods: a trap designed to monitor C. cerdo (CC), and two traps designed for monitoring O. eremita, i.e., the Black Cross Window Trap (BCWT) and the Black Bottle Traps (BBT). We found that larger trees hosted a great variety of microhabitats, in particular cavities, which abundance was correlated with the number of specimens sampled, especially O. eremita species. Both classic traps (i.e., CC traps and BCWT) and the herein-introduced BBT variants were effective for capturing large saproxylic beetles. In this work, we underline the importance of the preservation of veteran trees to the occurrence of threatened saproxylic beetles, and we contributed to (i) extending general knowledge of the habitat preferences of saproxylic beetles and (ii) improving new cost-effective trapping system variants

Prevalence, molecular epidemiology and intra-hospital acquisition of Klebsiella pneumoniae strains producing carbapenemases in an Italian teaching hospital from January 2015 to September 2016.

Objectives: We described Klebsiella pneumoniae producing carbapenemase (CPKP) spread from 01/01/2015 to 13/09/16 in a tertiary level hospital. Methods: The first positive surveillance rectal swab (SRS) or clinical sample (CS) collected in the medical department (MD), surgical department (SD) and intensive care department (ICD) were included in the study. A validated in-house Real-Time PCR method was used to detect carbapenemases; multilocus sequence typing (MLST) was used for further characterization of the strains. Results: 21535 patients were included: 213 CPKP strains from surveillance rectal swab (SRS) and 98 from clinical samples (CS) were collected. The percentage of CPKP detected in SRS with respect to CS increased in the medical MD from 2015 to 2016 (p = 0.01) and in ICD from 2012 to 2015 (p = 0.0001), while it decreased in SD from 2014 to 2016 (p = 0.003); 68.5% of the positive SRS had a previous negative SRS; CPKP was more frequently identified in CS than in SRS in MD. Twelve strains harboured more than one carbapenemase gene. Many other species harbouring a carbapenemase gene were collected. Conclusions: MDs need more inclusive surveillance criteria. The late detection of positive SRS underlined the risk of colonization during hospitalization

Intra-hospital acquisition of colonization and infection by Klebsiella pneumoniae strains producing carbapenemases and carriage evolution: A longitudinal analysis in an Italian teaching hospital from January 2017 to August 2019

Abstract Objectives We present an updated picture (1/1/2017–31/08/2019) of the frequency of carbapenemase producing Klebsiella pneumoniae (CPKP) in surveillance rectal swabs (SRS) and in clinical samples (CS) of patients admitted to a tertiary level hospital, focusing on longitudinal evolution of CPKP detected in SRS and on colistin resistant strains. Methods Retrospective longitudinal analysis. Only the first positive CPKP strain isolated from each patient was included. Results 638 CPKP strains were identified (471 in SRS and 167 in CS). SRS frequency increased over time in the medical department, remained high in the surgical department (SD) and decreased in the intensive care department. Most SRS–71.3%–and 49.1% of CS had nosocomial origin; about half of the SRS were identified in the SD. Regarding SRS evolution, carriage was confirmed in 39.5% of patients, no more testing in 25.5%, clinical involvement in 24.8 %, and negative result in 10.2%. Rates of colistin resistance were 20.1% in 2017, 31.2% in 2018 and 26.9% in 2019. Conclusions CPKP diffusion is still an important issue despite the surveillance program. It is vital to enhance medical staff's awareness on this because most CPKP first detections in SRS occurred during hospital stay due to a nosocomial acquisition with a comparable picture over time. Colistin resistance is increasing

Viral infections of the central nervous system in elderly patients: a retrospective study

Summary Objectives Very few data exist on viral meningitis and encephalitis in elderly patients (>65 years old). Methods This study investigated the detection of herpes simplex virus (HSV), varicella zoster virus (VZV), human herpes virus 6 (HHV-6), HHV-7, HHV-8, cytomegalovirus (CMV), Epstein–Barr virus (EBV), enterovirus (EV), human adenovirus (HAdV), human parechoviruses (HPeVs), and tick-borne encephalitis virus (TBEV) through real-time PCR (RT-PCR) in patients >65 years old who had cerebrospinal fluid (CSF) tested for a suspected central nervous system infection. Results A total of 2868 RT-PCRs were performed on 502 CSF samples. Overall, 65 positive RT-PCRs were found: 23 for HSV (35.4% of positives), 15 for EV (23.1% of positives), 14 for EBV (21.5% of positives), 12 for VZV (18.5% of positives), and one for CMV (1.5% of positives). A positive RT-PCR in CSF was detected in 24 (17.4%) patients aged ≥80 years and in 35 (9.6%) patients aged 65–79 years ( p =0.02). VZV was more frequently detected in the oldest subjects (5.9% vs. 1.6%, p =0.03). Conclusions HSV was the most common viral aetiology identified in the study, with VZV infection being recognized more frequently in those patients aged ≥80 years