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Highlights • Long term time series returns fundamental information on climate studies. • Short term time series returns information on temperature dynamics. • Comparison of heterogeneous series should account local dynamics and uncertainty. • RMN data represent an additional source of information in coastal areas. Abstract The aim of this paper is to give an overview of the various measurement collections that contribute to the observation of Sea Surface Temperature in Italian Seas. Long term time series are collected since the 19th century but are affected by a large systematic errors. Despite the lack of accuracy, their contribution to the analysis of trends is fundamental into the climate change context. On the other hand, recent systematic observations are more accurate and continuous in space and time. Short term time series better define the status of the temperature during the last years in term of variability and dynamics. [ABSTRACT FROM AUTHOR]

A fully three-dimensional (3D) model of a CdZnTe semiconductor gamma-ray detector is presented. It takes into account the physical phenomena involved in the detection process and models the readout electronic response and noise. The model successively involves the finite element transient computation of the adjoint transport equation, the Monte Carlo simulation of the photon transport and the electronic signal processing including an accurate noise model. The simulation is fast and accurate because the solution of the adjoint equation allows us to obtain a continuous mapping of the induced charge collection (at any time and any interaction point) with a single 3D transient finite element computation. The simulation outputs are pulse height spectra and biparametric (rise time versus pulse height) spectra. [Copyright &y& Elsevier]

Abstract: In this paper, we propose a novel decentralized resource maintenance strategy for peer-to-peer (P2P) distributed storage networks. Our strategy relies on the Wuala overlay network architecture, (The WUALA Project). While the latter is based, for the resource distribution among peers, on the use of erasure codes, e.g., Reed–Solomon codes, here we investigate the system behavior when a simple randomized network coding strategy is applied. We propose to replace the Wuala regular and centralized strategy for resource maintenance with a decentralized strategy, where users regenerate new fragments sporadically, namely every time a resource is retrieved. Both strategies are analyzed, analytically and through simulations, in the presence of either erasure and network coding. It will be shown that the novel sporadic maintenance strategy, when used with randomized network coding, leads to a fully decentralized solution with management complexity much lower than common centralized solutions. [Copyright &y& Elsevier]

Toxic hazard in sites with varying types and levels of contamination in the Lagoon of Venice was estimated by means of toxicity bioassays based on the early life-stages of the autochthonous sea urchin Paracentrotus lividus. Elutriate was chosen as the test matrix, due to its ability to highlight potential toxic effects towards sensitive biological components of the water column caused by sediment resuspension phenomena affecting the Lagoon. Surficial sediments (core–top 5 cm deep), directly influenced by resuspension/redeposition processes, and core sediments (core 20 cm deep), recording time-mediated contamination, were sampled in some sites located in the lagoonal area most greatly influenced by anthropogenic activities. Particle size, organic matter and water content were also analysed. In two sites, the results of physical parameters showed that the core–top sediments were coarser than the 20-cm core sediments. Sperm cell toxicity test results showed the negligible acute toxicity of elutriates from all investigated sites. The embryo toxicity test demonstrated a short-term chronic toxicity gradient for elutriates from the 20-cm core sediments, in general agreement both with the expected contamination gradient and with results of the Microtox® solid-phase test. Elutriates of the core–top 5-cm sediments revealed a totally inverted gradient, in comparison with that for the 20-cm core sediments, and the presence of a “hot spot” of contamination in the site chosen as a possible reference. Investigations on ammonia and sulphides as possible confounding factors excluded their contribution to this “hot spot”. Integrated physico-chemical and toxicity results on sediments at various depths demonstrated the presence of disturbed sediments in the central basin of the Lagoon of Venice. [Copyright &y& Elsevier]

A Monte Carlo radiation transport simulation program, EGS4 Nova, and a Computer Aided Design software, BRL-CAD, have been coupled within the framework of Sindbad, a X-ray Nondestructive Evaluation (NDE) simulation system, in order to simulate the images of the uncollided and scattered photon fluxes in a single NDE software environment. We present an experimental validation performed in a 40–140 keV energy range, comparing simulation and experimental data acquired on a setup designed for 2D Dual Energy X-ray absorptiometry, and equipped with a 2D digital flat panel. The agreement between experimental and simulated data is good if we correct the signal from scattering effects inside the detector. [Copyright &y& Elsevier]

Graphical abstract Unlabelled Image Highlights • Presence and impact of derelict fishing gear were studied in North Adriatic outcrops. • The occurrence of derelict fishing gear was evidenced in half of the monitored areas. • A total of 362 items were removed by scuba divers. • The complexity of macro-benthic community gradually improved in the cleared areas. • Cryptic fish species occupied cracks previously obstructed by derelict fishing gear. [ABSTRACT FROM AUTHOR]

The identification of sea regimes from environmental multivariate times series is complicated by the mixed linear-circular support of the data, by the occurrence of missing values, by the skewness of some variables, and by the temporal autocorrelation of the measurements. We address these issues simultaneously by a hidden Markov approach, and segment the data into pairs of toroidal and skew-elliptical clusters by means of the inferred sequence of latent states. Toroidal clusters are defined by a class of bivariate von Mises densities, while skew-elliptical clusters are defined by mixed linear models with positive random effects. The core of the classification procedure is an EM algorithm accounting for missing measurements, unknown cluster membership, and random effects as different sources of incomplete information. Moreover, standard simulation routines allow for the efficient computation of bootstrap standard errors. The proposed procedure is illustrated for a multivariate marine time series, and identifies a number of wintertime regimes in the Adriatic Sea. [ABSTRACT FROM AUTHOR]

A new cadmium zinc telluride (CZT) portable spectrometric system called OMEGA has been developed at CEA/LETI for high-energy applications like spent fuel assay in response to needs in the nuclear industry. The unit has been designed to operate at room temperature under water. The CZT OMEGA system is based on a single 10 × 10 × 10 mm³ CZT detector associated with a single electronics channel. To improve performance, the system incorporates several technologies including: an electrode design named the "Mixed" electrode which combines a noncontacting Frisch grid and the pixel field effect to obtain maximum sensitivity from the 10 × 10 × 10 mm³ CZT detector, a single hybrid preamplifier designed to reduce noise, an electronics board configured to enhance count rate capabilities and finally, electron bi-parametric (BP) correction (pulse height corrected via measurement of rise time) to improve both energy resolution and detection efficiency. [ABSTRACT FROM AUTHOR]