1,117 research outputs found

    Attentive monitoring of multiple video streams driven by a Bayesian foraging strategy

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    In this paper we shall consider the problem of deploying attention to subsets of the video streams for collating the most relevant data and information of interest related to a given task. We formalize this monitoring problem as a foraging problem. We propose a probabilistic framework to model observer's attentive behavior as the behavior of a forager. The forager, moment to moment, focuses its attention on the most informative stream/camera, detects interesting objects or activities, or switches to a more profitable stream. The approach proposed here is suitable to be exploited for multi-stream video summarization. Meanwhile, it can serve as a preliminary step for more sophisticated video surveillance, e.g. activity and behavior analysis. Experimental results achieved on the UCR Videoweb Activities Dataset, a publicly available dataset, are presented to illustrate the utility of the proposed technique.Comment: Accepted to IEEE Transactions on Image Processin

    Impact of a Cost Minimisation User Cost Model on Public Transport Subsidy

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    We show that optimal public transport subsidy is sensitive to the use of alternative user cost models, and that a model based on cost minimisation principles may lead to an improvement in subsidy estimates. For the case of homogeneous consumers and non-peaked demand, the cost minimisation user cost model yields optimal subsidy estimates which differ by up to 55% from those generated by existing'models. Multiple optimal subsidy equilibria may also exist arising from a kink in the user cost schedule at a critical frequency and a resulting discontinuity in the marginal benefit of frequency enhancement scheduleefficiency; economic models; costs; economic equilibrium

    Measurements of seismic attenuation and transient fluid pressure in partially saturated Berea sandstone: evidence of fluid flow on the mesoscopic scale

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    A novel laboratory technique is proposed to investigate wave-induced fluid flow on the mesoscopic scale as a mechanism for seismic attenuation in partially saturated rocks. This technique combines measurements of seismic attenuation in the frequency range from 1 to 100 Hz with measurements of transient fluid pressure as a response of a step stress applied on top of the sample. We used a Berea sandstone sample partially saturated with water. The laboratory results suggest that wave-induced fluid flow on the mesoscopic scale is dominant in partially saturated samples. A 3-D numerical model representing the sample was used to verify the experimental results. Biot's equations of consolidation were solved with the finite-element method. Wave-induced fluid flow on the mesoscopic scale was the only attenuation mechanism accounted for in the numerical solution. The numerically calculated transient fluid pressure reproduced the laboratory data. Moreover, the numerically calculated attenuation, superposed to the frequency-independent matrix anelasticity, reproduced the attenuation measured in the laboratory in the partially saturated sample. This experimental—numerical fit demonstrates that wave-induced fluid flow on the mesoscopic scale and matrix anelasticity are the dominant mechanisms for seismic attenuation in partially saturated Berea sandston

    Source and dynamics of a volcanic caldera unrest : Campi Flegrei, 1983–84

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    Acknowledgements We thank Tiziana Vanorio, Antonella Amoruso, Luca Crescentini, Nicholas Rawlinson, Yasuko Takei, and David Cornwell for the valuable suggestions regarding the methodology and interpretation. Reviews from Tim Greenfield and two anonymous reviewers helped improving both clarity of the manuscript and interpretation. The Royal Society of Edinburgh - Accademia dei Lincei Bilateral Agreement, the Santander Mobility Award of the College of Physical Sciences, University of Aberdeen, and the TIDES EU COST action granted L.D.S. travel grants for the realisation of this study. E.D.P. has been supported by the EPHESTO and KNOWAVES projects, funded by the Spanish Ministry of Education and Science.Peer reviewedPublisher PD

    Therapeutic potential of the phosphino Cu(I) complex (HydroCuP) in the treatment of solid tumors

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    [Cu(thp)4][PF6] (HydroCuP) is a phosphino copper(I) complex highly soluble and stable in physiological media that has been developed as a possible viable alternative to platinum-based drugs for anticancer therapy. HydroCuP potently inhibited the growth of human cancer cells derived from solid tumors by inducing endoplasmatic reticulum (ER) stress thus leading to cell death through paraptosis with a preferential efficacy against cancer rather than non-cancer cells. Aim of the present study was to assess the therapeutic potential of HydroCuP in vivo, in syngenic and xenograft murine models of solid tumors by triggering the Unfolded Protein Response (UPR) pathway. With respect to platinum drugs, HydroCuP induced a markedly higher reduction of tumor growth associated with minimal animal toxicity. In human colorectal cancer xenografts, chemotherapy with HydroCuP was extremely effective in both oxaliplatin-sensitive and resistant models. The favorable in vivo tolerability of HydroCuP was also correlated to an encouraging biodistribution profile. Additionally, no signs of drug-related neurotoxicity and nephrotoxicity were observed. Altogether, these results demonstrate that HydroCuP appears worth of further investigation to evaluate its therapeutic activity towards a broad spectrum of solid malignancies

    Study on Modern and Contemporary works of Art through non invasive integrated physical techniques

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    During my PhD I developed two parallel and complementary topics, concerning both works of art and materials. The first one, focused on non-invasive investigations on works of art (ancient and contemporary), was aimed to deepen conservative state, material composition, painting techniques and the early detection of any deterioration. This latter goal also guided the study of pictorial and restoration materials, mainly aimed at their characterization from the optical point of view. Diagnostic activities made use of different methods of investigation. Among image techniques, photography and macrophotography in diffuse, specular and raking light, ultraviolet fluorescent, image spectroscopy, wide band infrared reflectography, digital and differential K-edge radiography. To get as much information as possible, to be properly integrated with other data, punctual diagnostic techniques, such as reflectance spectrophotometry, colorimetry and X Ray fluorescence, were also used

    Inflammation and Cardiovascular Cross Talk in Ischemic Vascular Diseases

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    Ischemic vascular diseases include different pathological events characterized by distinctive features but share the common hallmark of inflammation. In this light, myocardial infarction can be a good paradigm to summarize the different connections linking inflammation and the cardiovascular system during an ischemic event. The immune system and inflammation, through several cellular and soluble inflammatory mediators, play a crucial role in the local tissue structural changes of ischemic heart disease, with a different impact and outcome during acute myocardial infarction compared to the more chronic long-term inflammation. In response to acute damage and hemodynamic stress, there is expansion of resident immune cells and recruitment of extra cells involved in a critical cross talk with parenchymal cells. In other words, postischemic tissue repair is crucial to survival. Recruited inflammatory cells can remove debris and facilitate the repair process; conversely, unrestrained inflammation inhibits optimal healing leading to adverse events. Moreover, other mediators such as some key coagulation factors might influence innate immunity as well as cell-mediated reactions like healing, response to tissue injury, or inflammatory processes. Overall, as recently suggested, the different immune/inflammatory cell subsets act as messengers implicated in novel inflammatory networks that link different organ systems enlarging the continuum beyond the myocardium and blood vessels in a more integrative pathophysiology standpoint. This special issue aims to collect insights about this cross talk with a dual purpose: on the one hand to expand the comprehension on the mechanisms of action and impact of “old” inflammatory mediators and on the other to bring out “new” potential pathways and intermediates. The overall aim is to increase knowledge on the pathophysiological processes of ischemic vascular disease to improve diagnosis and treatment
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