Particle Fluxes and Transport Proceses Along the Continental Margins and in Deep Sea Environments.

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Influence of distributary channels on sediment and organic matter supply in event-dominated coastal margins: the Po prodelta as a study case

From November 2008 through May 2009, the Po river (Italy) experienced several floods exceeding 5000 m<sup>3</sup> s<sup>−1</sup>. This long series of events ended with a large flood in early May 2009 (~8000 m<sup>3</sup> s<sup>−1</sup>). An event-response sampling was carried out in the Po prodelta in April–May 2009 to characterize the preservation of this series of floods in the sediment record and to describe the event-supply and deposition of riverborne particulate material during the May 2009 flood. The water sampling was carried out early in the event under conditions of moderate river flow (~5000 m<sup>3</sup> s<sup>−1</sup>) and 24 h later during the peak discharge (~8000 m<sup>3</sup> s<sup>−1</sup>). Sediment cores were collected in the prodelta before and after the peak flood. At each station, profiles of conductivity, transmittance, and fluorescence were acquired. Surface and bottom waters were sampled to collect sediments in suspension. In addition, a few days before the May 2009 event, suspended sediments were collected at Pontelagoscuro gauging station, ~90 km upstream from the coast. Biogeochemical compositions and sedimentological characteristics of suspended and sediment samples were investigated using bulk and biomarker analyses. Furthermore, <sup>7</sup>Be and radiographs were used to analyze the internal stratigraphy of sediment cores. <br><br> During moderate flow, the water column did not show evidence of plume penetration. Stations re-occupied 24 h later exhibited marked physical and biogeochemical changes during the peak flood. However, the concentration of terrestrially-derived material in surface waters was still less than expected. These results suggested that, since material enters the Adriatic as buoyancy-driven flow with a reduced transport capacity, settling and flocculation processes result in trapping a significant fraction of land-derived material in shallow sediments and/or within distributary channels. <br><br> Although numerous discharge peaks occurred from November 2008 through April 2009 (4000–6000 m<sup>3</sup> s<sup>−1</sup>), sediment cores collected in late April 2009 showed lack of event-strata preservation and reduced <sup>7</sup>Be penetrations. This suggested that only a small fraction of the sediment supply during ordinary events reaches the deepest region of the prodelta (12–20 m water depth). As a result, these event-strata have a thickness not sufficient to be preserved in the sediment record because of post-depositional processes that destroy the flood signal. <br><br> Stations in the northern and central prodelta were re-occupied after the peak of the May 2009 flood. Based on <sup>7</sup>Be and radiographs, we estimated event layers of 17 and 6 cm thickness, respectively. Selective trapping of coarse material occurred in the central prodelta likely because of the geomorphologic setting of the central outlet characterized by an estuary-like mouth. Despite these settling processes, lignin-based parameters indicated that the composition of the terrigenous OC was fairly homogenous throughout the network of channels and between size-fractions

Characterization of Eucalyptus grandis' DOF gene family of transcription factors.

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A comparison of node vaccination strategies to halt SIR epidemic spreading in real-world complex networks

: We compared seven node vaccination strategies in twelve real-world complex networks. The node vaccination strategies are modeled as node removal on networks. We performed node vaccination strategies both removing nodes according to the initial network structure, i.e., non-adaptive approach, and performing partial node rank recalculation after node removal, i.e., semi-adaptive approach. To quantify the efficacy of each vaccination strategy, we used three epidemic spread indicators: the size of the largest connected component, the total number of infected at the end of the epidemic, and the maximum number of simultaneously infected individuals. We show that the best vaccination strategies in the non-adaptive and semi-adaptive approaches are different and that the best strategy also depends on the number of available vaccines. Furthermore, a partial recalculation of the node centrality increases the efficacy of the vaccination strategies by up to 80%

Network structure indexes to forecast epidemic spreading in real-world complex networks

Complex networks are the preferential framework to model spreading dynamics in several real-world complex systems. Complex networks can describe the contacts between infectious individuals, responsible for disease spreading in real-world systems. Understanding how the network structure affects an epidemic outbreak is therefore of great importance to evaluate the vulnerability of a network and optimize disease control. Here we argue that the best network structure indexes (NSIs) to predict the disease spreading extent in real-world networks are based on the notion of network node distance rather than on network connectivity as commonly believed. We numerically simulated, via a type-SIR model, epidemic outbreaks spreading on 50 real-world networks. We then tested which NSIs, among 40, could a priori better predict the disease fate. We found that the “average normalized node closeness” and the “average node distance” are the best predictors of the initial spreading pace, whereas indexes of “topological complexity” of the network, are the best predictors of both the value of the epidemic peak and the final extent of the spreading. Furthermore, most of the commonly used NSIs are not reliable predictors of the disease spreading extent in real-world networks