3,639 research outputs found

    A percolation transition in Yang-Mills matter at finite number of colours

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    We examine baryonic matter at quark chemical potential of the order of the confinement scale, \mu_q\sim \lqcd. In this regime, quarks are supposed to be confined but baryons are close to the ``tightly packed limit'' where they nearly overlap in configuration space. We show that this system will exhibit a percolation phase transition {\em when varied in the number of colours} NcN_c: at high NcN_c, large distance correlations at quark level are possible even if the quarks are essentially confined. At low NcN_c, this does not happen. We discuss the relevance of this for dense nuclear matter, and argue that our results suggest a new ``phase transition'', varying NcN_c at constant μq\mu_q.Comment: Accepted for publication, Physical Review Letters. Title changed from original, "Quarkyonic percolation at finite number of colors", at the request of the edito

    Riflessioni con Vincenzo Cabianca sulle Isole Eolie

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    With Vincenzo Cabianca, planner of Aeolian Islands landscape, we talk about scientific knowledge and landscape planning in small islands. In particular, when natural system is so strongly giving shape from the viewpoint of geophysics and vulcanology. During the discussion we carry out deep reflections upon significant of cultural heritage and insularity in this geographical contest, so unique like an insular Vulcan arc can be. Before partially lived in, then place of permanent and productive life, today archipelago’s landscape plan challenges the strong tourist pressure and business to protect his cultural scientific heritage, subject of specific international research.

    Il limite del territorio costiero nel piano paesaggistico della sardegna

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    The costal area is considered as a border, between see and earth, with its own dimension and physical space, with its history and inhabitants, in a little big word, with its identity. The landscape regions are an instruments to identify territory where it’s possible to recognize similar geographic, historical, social characteristics. Inside these regions it has been identified the costal zone. It has been considered like a public heritage, of all inhabitants. Its identification is based about scientific criterions that consider natural elements, ecosystems and habitats as single units in relationship among them, with environmental, formal and functional dynamics.

    Mini invasive hemodynamic monitoring: from arterial pressure to cardiac output

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    To evaluate the Cardiac Output (CO) the standard invasive pulmonary artery catheter (PAC) is considered today the gold standard. The major criticism to the PAC is that its level of invasiveness is not supported by an improvement in patient\u27s outcome. The interest to lesser and lesser invasive techniques is high. Therefore, the alternative techniques have been recently developed.Cardiac Output can be monitored continuously by different devices that analyze the arterial waveform to track changes in stroke volume (SV) and CO. The analysis of the arterial pressure wave to determine cardiac output is classified as Pulse Contour analysis or Pulse Pressure Analysis. Starting from a similar principle three main devices are now available on the market, with different algorithms and features:• PiCCO System (Pulsion Medical System, Munich, Germany)• LiDCOTM plus System (LidCO, Cambridge, UK)• Flotrac technology and Vigileo Monitor (Edwards Lifesciences, Irvine, CA, USA).The algorithm used by all these devices has been also implemented even with the analysis of the variation of stroke volume (SVV) and of the pulse pressure (PPV). SVV and PPV represent the variation of stroke volume and of the pulse pressure during the respiratory cycle. In sedated ventilated patients these indexes have proven to predict the response to a fluid challenge. A high variation (>10-12%) identifies with good sensitivity and specificity responders and not responders

    Silicone-coated non-woven polyester dressing enhances reepithelialisation in a sheep model of dermal wounds

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    Negative-pressure wound therapy (NPWT) also known as V.A.C. (Vacuum-assisted closure), is widely used to manage various type of wounds and accelerate healing. NPWT has so far been delivered mainly via opencell polyurethane (PU) foam or medical gauze. In this study an experimental setup of sheep wound model was used to evaluate, under NPWT conditions, the performance of a silicone-coated non-woven polyester (N-WPE) compared with PU foam and cotton hydrophilic gauze, used as reference materials. Animals were anesthetized with spontaneous breathing to create three 3 9 3 cm skin defects bilaterally; each animal received three different samples on each side (n = 6 in each experimental group) and was subjected to negative and continuous 125 mmHg pressure up to 16 days. Wound conditions after 1, 8 and 16 days of treatment with the wound dressings were evaluated based on gross and histological appearances. Skin defects treated with the silicone-coated N-WPE showed a significant decrease in wound size, an increase of re-epithelialization, collagen deposition and wound neovascularisation, and a minimal stickiness to the wound tissue, in comparison with gauze and PU foam. Taken all together these findings indicate that the silicone-coated N-WPE dressing enhances wound healing since stimulates higher granulation tissue formation and causes minor tissue trauma during dressing changes

    Communication Structure of Cortical Networks

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    Large-scale cortical networks exhibit characteristic topological properties that shape communication between brain regions and global cortical dynamics. Analysis of complex networks allows the description of connectedness, distance, clustering, and centrality that reveal different aspects of how the network's nodes communicate. Here, we focus on a novel analysis of complex walks in a series of mammalian cortical networks that model potential dynamics of information flow between individual brain regions. We introduce two new measures called absorption and driftness. Absorption is the average length of random walks between any two nodes, and takes into account all paths that may diffuse activity throughout the network. Driftness is the ratio between absorption and the corresponding shortest path length. For a given node of the network, we also define four related measurements, namely in- and out-absorption as well as in- and out-driftness, as the averages of the corresponding measures from all nodes to that node, and from that node to all nodes, respectively. We find that the cat thalamo-cortical system incorporates features of two classic network topologies, Erdös–Rényi graphs with respect to in-absorption and in-driftness, and configuration models with respect to out-absorption and out-driftness. Moreover, taken together these four measures separate the network nodes based on broad functional roles (visual, auditory, somatomotor, and frontolimbic)
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