On homogeneous CR manifolds and their CR algebras

In this paper we show some results on homogeneous CR manifolds, proved by introducing their associated CR algebras. In particular, we give different notions of nondegeneracy (generalizing the usual notion for the Levi form) which correspond to geometrical properties for the corresponding manifolds. We also give distinguished equivariant CR fibrations for homogeneous CR manifolds. In the second part of the paper we apply these results to minimal orbits for the action of a real form of a semisimple Lie group \^G on a flag manifold \^G/Q.Comment: 14 pages. AMS-LaTeX v2: minor revisio

Flexible investment planning for water distribution networks

Abstract The present work focuses on the planning of water distribution networks (WDNs). The research proposes an innovative strategy which aims at helping water managers formulate flexible investment plans while allowing for adaptive management under the increasing unawareness of medium–long term planning. This innovative strategy differs from existing strategies accounting for flexibility in WDN design. It allows for developing flexible investment plans without assuming that statistic or deterministic assumptions can account for all unawareness. The strategy introduces the key idea of technical contiguity of actions/solutions by post-processing a Pareto front obtained by a classic optimization technique in order to obtain sequential actions. This means retrieval of a set of 'technically contiguous' actions from the Paretian solutions, namely, by increasing the investment each action needs to contain the previous one. The application to the Apulian network allows discussion of the need for post-processing the Pareto front of solutions returned by the classic multi-objective design optimization and presenting the general strategy to obtain adaptive and flexible investment plans. We discuss further perspectives of the proposed strategy based on the integration of different flexible plans, each obtained with different assumptions, which could be statistic or deterministic, for the system boundary conditions

Non semi-simple sl(2) quantum invariants, spin case

Invariants of 3-manifolds from a non semi-simple category of modules over a version of quantum sl(2) were obtained by the last three authors in [arXiv:1404.7289]. In their construction the quantum parameter $q$ is a root of unity of order $2r$ where $r>1$ is odd or congruent to $2$ modulo $4$. In this paper we consider the remaining cases where $r$ is congruent to zero modulo $4$ and produce invariants of $3$-manifolds with colored links, equipped with generalized spin structure. For a given $3$-manifold $M$, the relevant generalized spin structures are (non canonically) parametrized by $H^1(M;\mathbb C/2\mathbb Z)$.Comment: 13 pages, 16 figure

Nonlinear anisotropic dielectric metasurfaces for ultrafast nanophotonics

We report on the broadband transient optical response from anisotropic nanobrick amorphous silicon particles, exhibiting Mie-type resonances. A quantitative model is developed to identify and disentangle the three physical processes that govern the ultrafast changes of the nanobrick optical properties, namely two-photon absorption, free-carrier relaxation, and lattice heating. We reveal a set of operating windows where ultrafast all-optical modulation of transmission is achieved with full return to zero in 20 ps. This is made possible due to the interplay between the competing nonlinear processes and despite the slow (nanosecond) internal lattice dynamics. The observed ultrafast switching behavior can be independently engineered for both or- thogonal polarizations using the large anisotropy of nanobricks thus allowing ultrafast anisotropy control. Our results categorically ascertain the potential of all-dielectric resonant nanophotonics as a platform for ultrafast optical devices, and reveal the pos- sibility for ultrafast polarization-multiplexed displays and polarization rotators

Erratum: "Ultraviolet poling of pure fused silica by high-intensity femtosecond radiation" [Appl. Phys. Lett. 86, 071106 (2005)]

Erratu

Analog image processing with nonlinear nonlocal flat optics

Digital signal processing has revolutionized many fields of science and engineering, but it still shows critical limits, mainly related to the complexity, power consumption, and limited speed of analogue-to-digital converters. A long-sought solution to overcome these hurdles is optical analog computing. In this regard, flat optics has been recently unveiled as a powerful platform to perform data processing in real-time, with low power consumption and a small footprint. So far, these explorations have been mainly limited to linear optics. Arguably, significantly more impact may be garnered from pushing this operation towards nonlinear processing of the incoming signals. In this context, we demonstrate here that nonlinear phenomena combined with engineered nonlocality in flat optics devices can be leveraged to synthesize Volterra kernels able to outperform linear optical analog image processing

Perceived need for an International Elective Experience among Italian Medical Residents.

In the contemporary society an International Health Elective (IHE) represents a strategic tool in order to implement future medical doctor\u2019s education. In Italy, in the last decade, an increasing interest of trainees and residents to IHE and opportunities was documented and supported by the reorganization of the Italian residency programs, provided by the Ministry for Education, University and Research (MIUR). Aim of the present study was to collect data on perceived need of medical residents for an IHE. A structured questionnaire was developed and administered to medical residents of Palermo\u2019s University who underwent their annual visit to the Occupational Health Physician Ambulatory (OHPA) of Palermo\u2019s University Hospital, in the period between March and October 2011. Medical residents more prone to undergo an IHE were, younger than 29 years old (p <0.01), attending the new educational system (p 0.02) and surgical residents (p= 0.0001). A negative opinion about the formative quality performances of the residency program was significantly associated with surgical residencies (p= 0.002). Future Italian surgeons are more prone to undergo an IHE and this statement is probably related to the not satisfying residency program. Residents attending the old educational system consider the IHE as a way to implement their professional perspectives possibly for their more realistic professional perspective facing an approaching future full of work uncertainties. Considering the future competition between medical professionals working in different EU contexts, the Italian Government should implement future medical education policy in order to provide for a Healthcare \u201cwithout Border\u201d in the EU

Studio trasversale sulle variabili di stress lavoro-correlato nei medici in formazione specialistica del maggiore Policlinico Universitario della Sicilia

Introduzione: Il rischio stress lavoro-correlato è uno degli obiettivi della valutazione e prevenzione dei rischi occupazionali negli operatori sanitari (O.S.). I medici in formazione specialistica (MIFS) rappresentano una tipologia di OS sovrapponibile ai dirigenti medici in termini di esposizione lavorativa e quindi di insorgenza di sindromi da stress lavoro-correlato. Obiettivi: Obiettivo dello studio è valutare un set di fattori di rischio stress lavoro-correlato nei MIFS del principale Policlinico Universitario della Sicilia, sottoposti a sorveglianza sanitaria. Materiali e Metodi: Studio trasversale condotto mediante questionario anonimo ed autosomministrato. Risultati: Il 45% dei MIFS di area clinica ed il 37% di area chirurgica usufruiscono del giorno di riposo compensativo a fronte del 92% dell’area dei servizi (p<0,001). Il sistema di rendicontazione delle presenze/monte orario è presente nell’80% delle scuole dell’area dei servizi, nel 60% di quelle di area medica e nel 50% di quelle di area chirurgica (p<0,001). I MIFS delle scuole dell’area chirurgica dichiarano di usufruire delle pause lavorative (41%) con frequenza minore rispetto ai MIFS dell’area medica (60%) e dell’area dei servizi (74%) (p<0,001). I MIFS sia di area medica (47%) che di area chirurgica (47%) risultano essere più esposti a stress lavoro-correlato (p<0,001) rispetto ai MIFS dell’area dei servizi (29%). Conclusioni: Il lavoro documenta un maggiore rischio di stress lavoro-correlato nei MIFS di area chirurgica rispetto alle altre aree professionali indagate. Appare necessario strutturare degli specifici programmi formativi finalizzati alla gestione dell’esposizione al rischio di stress lavoro-correlato per i MIFS, incentrandoli sia sulla persona che sull’ambiente di lavoro.Background: Among health care workers (HCWs), assessment and prevention of work-related stress in the workplace is one of the main goal. Post-graduate medical residents (MRs) are a group of HCWs comparable to medical doctors in terms of occupational exposure and of work-related stress syndromes occurrence. Objectives: To assess the risk of the exposition to work-related stress among MRs attending the major University Hospital of Sicily. Methods: Cross-sectional survey through an anonymous and self-administered questionnaire. Results: 45% of clinical MRs and 37% of surgical MRs have access to compensatory rest days against 92% of MRs of the services area (p <0.001). A work attendance detection system for MRs is available in 80% of the postgraduate medical schools of the services area, in 60% of the clinical postgraduate schools and in 50% of the surgical postgraduate schools (p <0.001). MRs of postgraduate surgical schools declare to have access to work breaks (41%) with less frequency compared to clinical (60%) and services MRs (74%) (p <0.001). Both clinical (47%) and surgical MRs (47%) result to be more exposed to work-related stress than MRs of the services area (27%) (p <0.001). Conclusions: The survey documents an exposure excess of work-related stress for all the considered variables in MRs of surgical area. It is strongly suggested to provide for specific training programs aimed to manage the MRs risk exposure to work-related stress, focusing both on the workers and the work environment

Precise reply and clarifications on behalf of Sicilian Public Health Authorities to the case report published by La Rosa and collegues

As a results of the case report “Post-rotavirus vaccine intussusception in identical twins: a case report” recently published on Human Vaccines & Immunotherapy by La Rosa et al., the principal Sicilian Public Health Authorities decided to specify several points and underline some important details omitted by the authors. In particular, aims to underline the remarkable benefit for Sicilian Regional Health service after the introduction of the rotavirus vaccination. Universal mass vaccination against rotavirus is properly managed by the Regional Health Authorities and is contributing to a consistent increase of public health in the Sicilian pediatric population; any modification of such a program should be based on robust scientific evidences. Finally, a single case report should not be considered as a basis to recommend a change in the clinical practice but instead a possible point of start for discussion and research