Metapopulation epidemic models with heterogeneous mixing and travel behaviour.

BACKGROUND: Determining the pandemic potential of an emerging infectious disease and how it depends on the various epidemic and population aspects is critical for the preparation of an adequate response aimed at its control. The complex interplay between population movements in space and non-homogeneous mixing patterns have so far hindered the fundamental understanding of the conditions for spatial invasion through a general theoretical framework. To address this issue, we present an analytical modelling approach taking into account such interplay under general conditions of mobility and interactions, in the simplifying assumption of two population classes. METHODS: We describe a spatially structured population with non-homogeneous mixing and travel behaviour through a multi-host stochastic epidemic metapopulation model. Different population partitions, mixing patterns and mobility structures are considered, along with a specific application for the study of the role of age partition in the early spread of the 2009 H1N1 pandemic influenza. RESULTS: We provide a complete mathematical formulation of the model and derive a semi-analytical expression of the threshold condition for global invasion of an emerging infectious disease in the metapopulation system. A rich solution space is found that depends on the social partition of the population, the pattern of contacts across groups and their relative social activity, the travel attitude of each class, and the topological and traffic features of the mobility network. Reducing the activity of the less social group and reducing the cross-group mixing are predicted to be the most efficient strategies for controlling the pandemic potential in the case the less active group constitutes the majority of travellers. If instead traveling is dominated by the more social class, our model predicts the existence of an optimal across-groups mixing that maximises the pandemic potential of the disease, whereas the impact of variations in the activity of each group is less important. CONCLUSIONS: The proposed modelling approach introduces a theoretical framework for the study of infectious diseases spread in a population with two layers of heterogeneity relevant for the local transmission and the spatial propagation of the disease. It can be used for pandemic preparedness studies to identify adequate interventions and quantitatively estimate the corresponding required effort, as well as in an emerging epidemic situation to assess the pandemic potential of the pathogen from population and early outbreak data

Au large de Villeneuve-lès-Maguelone – Épave de la Jeanne-Elisabeth (EA 649)

La fouille de la Jeanne-Élisabeth a pris en 2014 un nouveau tournant avec une autorisation trisannuelle accordée par la Cira Sud-Est et le Drassm. L’objectif annoncé est le dégagement de la partie arrière jusqu’au centre de la coque découverte en 2008 par l’équipe de Patrick Grandjean (Drassm). Il s’agit d’en assurer la fouille, le relevé et de réaliser la dépose du plancher de cale afin d’accéder à la liaison membrure-quille sur un maillage représentatif. L’agrandissement vers les ponts s’es..

Au large de Villeneuve-lès-Maguelone – L’épave de la Jeanne-Élisabeth (EA 6479)

L’opération de fouille 2015 s’est poursuivie dans le but de finir le dégagement de la zone arrière de la coque partiellement ouverte l’année précédente. Le secteur de la cale n’a pas apporté de donnée supplémentaire du point de vue de la culture matérielle contrairement à la zone de l’entrepont particulièrement riche cette année. En effet, l’entrepont arrière ne semble pas avoir été affecté par le pillage au-delà de la zone de lest résiduel encore en place. Cette zone traditionnellement réser..

Spectrometer for X-ray emission experiments at FERMI free-electron-laser

A portable and compact photon spectrometer to be used for photon in-photon out experiments, in particular x-ray emission spectroscopy, is presented. The instrument operates in the 25\u2013800 eV energy range to cover the full emissions of the FEL1 and FEL2 stages of FERMI. The optical design consists of two interchangeable spherical varied-lined-spaced gratings and a CCD detector. Different input sections can be accommodated, with/without an entrance slit and with/without an additional relay mirror, that allow to mount the spectrometer in different end-stations and at variable distances from the target area both at synchrotron and at free-electron-laser beamlines. The characterization on the Gas Phase beamline at ELETTRA Synchrotron (Italy) is presented

Knowledge of public health informatics among Italian medical residents: design and preliminary validation of a questionnaire

Background: public health requires strong information skills and competencies, as it is information-intensive and information-driven. Public health informatics has been defined as the “systematic application of information, computer science, and technology to public health practice, research, and learning”. New information and communication technologies offer unprecedented opportunities, such as linking smart-phones and mobiles devices to web based tools for data collection, enabling and enhancing participatory epidemiology. However, being an emerging discipline, despite its potential and importance, public health informatics is often neglected and overlooked, being rarely offered as course. The present study was designed as a pilot study, with the aim of designing and validating a questionnaire on the knowledge of public health informatics among medical residents in public health in Italy.  Methods and Results: thirty-two Italian residents in public health volunteered to take part into the study. Mean age of the sample was 31.44±2.23 years, most responders were males (68.8%), from northern Italy (53.1%), at the third year of residency (34.4%) and currently doing practical training at the clinical management staff/hospital directorate (34.4%). Other places of training were the Prevention Department (21.9%), the Institute of Hygiene (18.8%), the local health units and the territory (12.5%), the occupational health service (6.3%) and the Regional Health Agency (3.1%). Cronbach’s alpha coefficient yielded a value of 0.909, demonstrating excellent psychometric properties of the instrument.  Conclusion: in conclusion, the developed questionnaire seems to be an appropriate and useful tool to detect gaps concerning knowledge, education and practices of public health informatics among residents in public health.&nbsp

Thermodynamic Analysis for the Selection of low GWP Refrigerants in Ground Source Heat Pumps

One of the main objectives of the European Commission in the buildings sector, responsible for approximately 40% of total energy consumption and 36% of greenhouse gas emissions, is to identify technological solutions capable of reducing energy consumption and at the same time greenhouse gas emissions. For this purpose, ground source heat pump system (GSHPs) is a technology of particular interest that promises to considerably reduce greenhouse gas emissions of HVAC systems (up to 44% compared to air source heat pumps). In order to develop and test innovative GSHPs to be used for heating and cooling in the various European climatic zones, EU has funded the GEO4CIVHIC project, which will have a duration of 4 years and will end in 2022. As part of the project, the problem of identifying new generation low environmental impact refrigerants to be used in innovative GSHPs is tackled. In this article, we report the results of an energetic and exergetic analysis of the performance of heat pumps based on simulations carried out both on simple reverse cycles and on more complex cycles. Low pressure alternative fluids have been considered as an alternative to R134a and high pressure fluids as an alternative to R410A. The simulations were conducted at various heat sink and heat source temperature conditions, in order to evaluate the GSHPs performance in the whole range of real conditions that can be found in Europe. Particular attention was paid to the compression phase, with the aim to simulate the compressor performance in a more realistic way than simply assuming constant isentropic efficiency