Trends of influenza B during the 2010–2016 seasons in 2 regions of north and south Italy: The impact of the vaccine mismatch on influenza immunisation strategy

Influenza A and B viruses are responsible for respiratory infections, representing globally seasonal threats to human health. The 2 viral types often co-circulate and influenza B plays an important role in the spread of infection. A 6-year retrospective surveillance study was conducted between 2010 and 2016 in 2 large administrative regions of Italy, located in the north (Liguria) and in the south (Sicily) of the country, to describe the burden and epidemiology of both B/Victoria and B/Yamagata lineages in different healthcare settings. Influenza B viruses were detected in 5 of 6 seasonal outbreaks, exceeding influenza A during the season 2012–2013. Most of influenza B infections were found in children aged ≤ 14 y and significant differences were observed in the age-groups infected by the different lineages. B/Victoria strains prevailed in younger population than B/Yamagata, but also were more frequently found in the community setting. Conversely, B/Yamagata viruses were prevalent among hospitalized cases suggesting their potential role in the development of more severe disease. The relative proportions of viral lineages varied from year to year, resulting in different lineage-level mismatch for the B component of trivalent influenza vaccine. Our findings confirmed the need for continuous virological surveillance of seasonal epidemics and bring attention to the adoption of universal influenza immunization program in the childhood. The use of tetravalent vaccine formulations may be useful to improve the prevention and control of the influenza burden in general population

Study of the isotropic contribution to the analysis of photoelectron diffraction experiments at the ALOISA beamline

The angular distribution of the intensity in photoemission experiments is affected by electron diffraction patterns and by a smoothly varying ISO contribution originated by both intrumental details and physical properties of the samples. The origin of the various contributions to the ISO component has been identified since many years. Nonetheless in this work we present original developement of the ED analysis, which arises from the evolution of instrumental performance, in terms of analyzers positioning and angular resolution, as well as collimation and size of X-ray beams in third generation synchrotron sources. The analytical treatement of the instrumental factors is presented in detail for the end station of the ALOISA beamline (Trieste Synchrotron), where a wide variety of scattering geometries is available for ED experiments. We present here the basic formulae and their application to experimental data taken on the Fe/Cu3Au(001) system in order to highlight the role of the various parameters included in the distribution function. A specific model for the surface illumination has been developed as well as the overlayer thickness and surface roughness have been considered.Comment: RevTex, nine pages with five eps figures; to be published in J. Electron Spectrosc. Relat. Pheno

Advancements in the Investigation of Vertical Profiles of Thunderstorm Outflows

The dynamic complexity and unpredictability of the occurrence of thunderstorms make it difficult to collect reliable and systematic measurements of this atmospheric phenomenon, which are definitely needed to evaluate its action on structures. The area of the Northern Tyrrhenian Sea is a \u201chot-spot\u201d for the genesis of severe potentially damaging wind phenomena, such as downbursts, whose occurrence in this geographical region is not well documented. In the context of the two European projects \u201cWind and Ports\u201d and \u201cWind, Ports and Sea\u201d, a large and complex wind monitoring network has been installed in this area. Since the years 2014-2015, this network is equipped with three LiDAR profilers which provide vertical scanning of the atmosphere up to 250 m above the ground level. All the wind profiles have been systematically analysed in order to detect the ones that can be referred to thunderstorm events. The aim of this study is to extend a first set of analyses up to mid-2018 to provide a preliminary investigation of the main parameters describing the non-synoptic events and a first classification of thunderstorm events into different subsets

Leakage flow noise and related flow pattern in a low-speed axial fan with rotating shroud

The effect of rotational speed and pressure rise on the leakage flow noise radiated by a low-speed axial fan, provided with rotating shroud, has been systematically investigated. The leakage flow noise generally increases with the blade loading, with a trend which is qualitatively independent from the rotational speed but non-monotonic, as its growth is interrupted by local minima. As the loading increases, the SPL spectrum shows important modifications, since the characteristic frequency of the subharmonic narrowband humps related to the leakage noise decreases. The flow in the gap region has been studied by means of PIV measurements taken in the meridional plane. At low blade loading, the leakage flow is restrained close to the rotor ring and, at higher loading, it forms a wide recirculation zone. In the latter conditions, an unsteady flow separation likely takes place in the blade tip region which may be observed in the instantaneous flow field only. Possibly, it is responsible for the observed frequency shift of the humps

Surfactant-like Effect and Dissolution of Ultrathin Fe Films on Ag(001)

The phase immiscibility and the excellent matching between Ag(001) and Fe(001) unit cells (mismatch 0.8 %) make Fe/Ag growth attractive in the field of low dimensionality magnetic systems. Intermixing could be drastically limited at deposition temperatures as low as 140-150 K. The film structural evolution induced by post-growth annealing presents many interesting aspects involving activated atomic exchange processes and affecting magnetic properties. Previous experiments, of He and low energy ion scattering on films deposited at 150 K, indicated the formation of a segregated Ag layer upon annealing at 550 K. Higher temperatures led to the embedding of Fe into the Ag matrix. In those experiments, information on sub-surface layers was attained by techniques mainly sensitive to the topmost layer. Here, systematic PED measurements, providing chemical selectivity and structural information for a depth of several layers, have been accompanied with a few XRD rod scans, yielding a better sensitivity to the buried interface and to the film long range order. The results of this paper allow a comparison with recent models enlightening the dissolution paths of an ultra thin metal film into a different metal, when both subsurface migration of the deposit and phase separation between substrate and deposit are favoured. The occurrence of a surfactant-like stage, in which a single layer of Ag covers the Fe film is demonstrated for films of 4-6 ML heated at 500-550 K. Evidence of a stage characterized by the formation of two Ag capping layers is also reported. As the annealing temperature was increased beyond 700 K, the surface layers closely resembled the structure of bare Ag(001) with the residual presence of subsurface Fe aggregates.Comment: 4 pages, 3 figure

Monitoring the solid-state dewetting of densely packed arrays of Au nanoparticles

We report a real time, in-situ spectroscopic ellipsometry study of the temperature-induced solid-state dewetting of Au nanowires into nanoparticles. Very large spectral variations are observed at different temperatures. Analysis of the key features in the acquired spectra reveals two different regimes: up to 300 \ub0C the variation in the optical response is dominated by solid-state dewetting, while above that temperature, smaller variations not compatible with such mechanism are visible. Therefore our ellipsometry measurements allow us to determine in real time at which temperature the solid-state dewetting ceases and the morphology of our sample becomes stable. We point out that this observation is possible thanks to the higher sensitiviy of ellipsometry with respect to reflectance/transmittance measurements

Comparison between the results of a new version of the AVACTA II atmospheric diffusion model and tracer experiments

A new version of the AVACTA II code (a code recommended by EPA) has been implemented and evaluated. AVACTA II is a code based on a mixed segmentpuff approach, which allows numerical simulations of both non-stationary and nonhomogeneous conditions. In our version, the wind field is calculated through the 3D mass-consistent code WINDS developed at the Department of Physics of the University of Genoa, Italy. The model evaluation of this new version of the AVACTA II code has been performed using field experiment data on flat, but rough, terrain (Karlsruhe Nuclear Research Center (KNRC) tracer experiments) and wind tunnel measurements(EPA Rushil experiments) both in flat and complex terrain. A comparison is made between simulated and measured concentration distributions. The results of these evaluations are very encouraging

Instantaneous PIV data related to the leakage flow of a low-speed axial-flow fan with rotating shroud

The present paper is companion to Large-scale unsteady flow structures in the leakage flow of a low-speed axial fan with rotating shroud, Canepa et al., 2019. Two-dimensional PIV has been used in order to investigate the leakage flow in a low-speed fan with rotating shroud at three operating conditions. The reported data are constituted by about 3000 instantaneous meridional velocity fields, which are statistically independent. Each velocity field contains 41 7 55 velocity values deployed on a rectangular grid. In order to allow taking ensemble averages of the data, each velocity field has been assigned to a 4-deg bin in the rotor reference. The data are particularly valuable, since no data of this kind and detail have been made available to the scientific community yet