26 research outputs found

    UAN: underwater acoustic network

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    Acoustic networks are for underwater what wifi is for terrestrial networks. The ocean is a nearly perfect media for acoustic waves in which regards long range propagation but poses a number of challenges in terms of available bandwidth, Doppler spread and channel fading. These limitations originate in the physical properties of the ocean, namely its anisotropy and boundary interaction which are particularly relevant in coastal waters where acoustic propagation becomes predominantly de- pendent on seafloor and sea surface properties. The acoustic communication channel is therefore multipath dominated and time and Doppler spread variable. The problem is aggravated when involving moving receivers as for instance when attempting to establish communication with or between moving autonomous underwater vehicles. The EU-funded project UAN - Underwater Acoustic Network aims at conceiving, developing and testing at sea an innovative and operational concept for integrating in a unique communication system submerged, surface and aerial sensors with the objective of protecting off-shore and coastline critical infrastructures. UAN went through various phases, including the development of hardware and software specific components, its testing independently and then in an integrated fashion, both in the lab and at sea. This paper reports on the project concept and vision as well as on the progress of its various development phases and the results obtained herein. At the time of writing, a final project sea trial is being planned and will take place two weeks before the conference so, although here we will concentrate on the progress obtained so far, the presentation at the conference may include additional results depending on the outcome of the sea trial

    Flavouring Group Evaluation 76 Revision 2 (FGE.76Rev2): Consideration of sulfur-containing heterocyclic compounds, evaluated by JECFA, structurally related to thiazoles, thiophenes, thiazoline and thienyl derivatives from chemical group 29 and miscellaneous substances from chemical group 30 evaluated by EFSA in FGE.21Rev5

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    The Panel on Food Additives and Flavourings (FAF) was requested to consider the JECFA evaluations of 28 flavouring substances in the Flavouring Group Evaluation 76 (FGE.76Rev2). Twenty-one of these substances have been considered in FGE.76Rev1. Seven substances could not be evaluated, because of concerns with respect to genotoxicity. New genotoxicity data have been provided for 4-methyl-5-vinylthiazole [FL-no: 15.018] and 4,5-dimethyl-2-isobutyl-3-thiazoline [FL-no: 15.032], which are representative substances of [FL-no: 15.005] and [FL-no: 15.029, 15.030, 15.130 and 15.131], respectively. The Panel concluded that the concern for genotoxicity is ruled out for [FL-no: 15.018 and 15.005]. The concerns for gene mutations and clastogenicity are ruled out for [FL-no: 15.032, 15.029, 15.030, 15.130 and 15.131]. In vitro, [FL-no: 15.032] induced micronuclei through an aneugenic mode of action. The available in vivo micronucleus study was not adequate to rule out the concern for potential aneugenicity in vivo. The Panel compared the lowest concentration resulting in aneugenicity in vitro with the use levels reported for [FL-no: 15.032]. Based on this comparison, the Panel concluded that the use of [FL-no: 15.032] at the maximum reported use levels does not raise a concern for aneugenicity. Based on structural similarity, for the remaining four substances [FL-no: 15.029, 15.030, 15.130 and 15.131], an aneugenic potential may also be anticipated. Individual genotoxicity data are needed to establish whether they have aneugenic potential. The Panel agrees with JECFA conclusions for 24 flavouring substances 'No safety concern at estimated levels of intake as flavouring substances' when based on the MSDI approach. For six substances, more reliable information on uses and use levels are needed to refine the mTAMDI estimates. For 15 substances, use levels are needed to calculate the mTAMDIs. For [FL-no: 15.109 and 15.113], information on the actual stereochemical composition is inadequate and the conclusion reached for the named substances cannot be applied to the materials of commerce

    Connexin-43 upregulation in micrometastases and tumor vasculature and its role in tumor cell attachment to pulmonary endothelium

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    <p>Abstract</p> <p>Background</p> <p>The modulation of gap junctional communication between tumor cells and between tumor and vascular endothelial cells during tumorigenesis and metastasis is complex. The notion of a role for loss of gap junctional intercellular communication in tumorigenesis and metastasis has been controversial. While some of the stages of tumorigenesis and metastasis, such as uncontrolled cell division and cellular detachment, would necessitate the loss of intercellular junctions, other stages, such as intravasation, endothelial attachment, and vascularization, likely require increased cell-cell contact. We hypothesized that, in this multi-stage scheme, connexin-43 is centrally involved as a cell adhesion molecule mediating metastatic tumor attachment to the pulmonary endothelium.</p> <p>Methods</p> <p>Tumor cell attachment to pulmonary vasculature, tumor growth, and connexin-43 expression was studied in metastatic lung tumor sections obtained after tail-vein injection into nude mice of syngeneic breast cancer cell lines, overexpressing wild type connexin-43 or dominant-negatively mutated connexin-43 proteins. High-resolution immunofluorescence microscopy and Western blot analysis was performed using a connexin-43 monoclonal antibody. Calcein Orange Red AM dye transfer by fluorescence imaging was used to evaluate the gap junction function.</p> <p>Results</p> <p>Adhesion of breast cancer cells to the pulmonary endothelium increased with cancer cells overexpressing connexin-43 and markedly decreased with cells expressing dominant-negative connexin-43. Upregulation of connexin-43 was observed in tumor cell-endothelial cell contact areas <it>in vitro </it>and <it>in vivo</it>, and in areas of intratumor blood vessels and in micrometastatic foci.</p> <p>Conclusion</p> <p>Connexin-43 facilitates metastatic 'homing' by increasing adhesion of cancer cells to the lung endothelial cells. The marked upregulation of connexin-43 in tumor cell-endothelial cell contact areas, whether in preexisting 'homing' vessels or in newly formed tumor vessels, suggests that connexin-43 can serve as a potential marker of micrometastases and tumor vasculature and that it may play a role in the early incorporation of endothelial cells into small tumors as seeds for vasculogenesis.</p

    UAN-Underwater Acoustic Network

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    Underwater acoustic networks: the FP7 UAN project

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    The EU-funded project UAN - Underwater Acoustic Network aims at conceiving, developing and testing at sea an innovative and operational concept for integrating in a unique communication system submerged, surface and aerial sensors with the objective of protecting off-shore and coastline critical infrastructures. A crucial aspect of the project consisted in the use of autonomous underwater vehicles (AUVs) as mobile nodes in the underwater acoustic communication network. In particular, AUVs have the role of adapting the network geometry to the variation of the acoustic channel. This paper reports on the project concept and vision as well as on the progress of its various development phases. The recent at-sea successes that have been demonstrated within the UAN framework are detailed and results of the final UAN project demonstration, UAN11, held in the May of 2011, are reported. The UAN network was in operation for five continuous days with up to five nodes, of which three of them were mobile nodes. © IFAC

    Including non-dietary sources into an exposure assessment of the European Food Safety Authority: the challenge of multi-sector chemicals such as Bisphenol A

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    In the most recent risk assessment for Bisphenol A for the first time a multi-route aggregate exposure assessment was conducted by the European Food Safety Authority. This assessment includes exposure via dietary sources, and also contributions of the most important non-dietary sources. Both average and high aggregate exposure were calculated by source-to-dose modeling (forward calculation) for different age groups and compared with estimates based on urinary biomonitoring data (backward calculation). The aggregate exposure estimates obtained by forward and backward modeling are in the same order of magnitude, with forward modeling yielding higher estimates associated with larger uncertainty. Yet, only forward modeling can indicate the relative contribution of different sources. Dietary exposure, especially via canned food, appears to be the most important exposure source and, based on the central aggregate exposure estimates, contributes around 90% to internal exposure to total (conjugated plus unconjugated) BPA. Dermal exposure via thermal paper and to a lesser extent via cosmetic products may contribute around 10% for some age groups. The uncertainty around these estimates is considerable, but since after dermal absorption a first-pass metabolism of BPA by conjugation is lacking, dermal sources may be of equal or even higher toxicological relevance than dietary sources.info:eu-repo/semantics/publishedVersio
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