264 research outputs found

    Performances of a new directional optical module

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    Abstract The goal of the future KM3NeT neutrino telescope in the Mediterranean Sea is the investigation of the high energy component of the cosmic neutrino spectrum: a promising tool to better understand the mechanisms that generate extreme energy cosmic rays. Neutrino energy and direction will be reconstructed using the Cherenkov light produced in water by neutrino induced muons. In the framework of the EU funded KM3NeT Design Study, a new design for a large (10″) 4-anode photomultiplier has been developed. A prototype manufactured by Hamamatsu has been integrated into a spherical glass pressure-resistant optical module. It will be used for the first time to detect the direction of the detected Cherenkov light at one of the candidate site for KM3NeT, near Capo Passero in Sicily. The photocathode surface in these optical modules has been effectively divided into four quadrants by a pair of crescent shaped mirrors embedded in the optical gel linking the photomultiplier to the glass sphere. A series of measurements was performed at the testing facility of the NEMO group in Genova. The light collection and the angular response of the prototype have been studied, to have a complete characterisation and allow a comparison with previous models. The results of tests of the optical module are presented here

    Digital Dental Models: Is Photogrammetry an Alternative to Dental Extraoral and Intraoral Scanners?

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    Background: 3D models are nowadays part of daily clinical practice. Photogrammetry is a brand-new method for transforming small objects into 3D models while keeping their original shape and size. The aim of this study was to evaluate the accuracy, in terms of precision and trueness, of a digital dental model acquired with photogrammetry compared with those obtained using extraoral scanners and intraoral scanners, starting from the same plaster model. Methods: A plaster model was converted into a digital model using photogrammetry, an extraoral scanner and an intraoral scanner. Different references were measured twice at a distance of 30 min for each model, on the digital models using the software Blender and on the plaster model using a calibre. The Interclass Correlation Coefficient was calculated for each pair of measurements. A volumetric analysis was performed by superimposing the digital models. The coefficient of variation was calculated. A two-way ANOVA test was conducted. Results: For each reference, the coefficient of variation was less than 3%, and the two ANOVA tests resulted in a non-significant value in both cases (p > 0.05). The volumetric analysis demonstrated good agreement between the models derived from the different acquisition methods. Conclusions: Photogrammetry seems to be a good method for acquiring digital models starting from a plaster model, all the methods tested seem to be good for obtaining an accurate three-dimensional digital model. Other studies are needed to evaluate clinical efficacy

    Effetti di tipologie di suolo e colture foraggere sulle perdite per ruscellamento di azoto, fosforo e potassio in differenti areali italiani

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    Le colture foraggere svolgono un ruolo importante in molti areali italiani. Per una corretta pianificazione del territorio agricolo è necessario approfondire la conoscenza non solo delle caratteristiche produttive di queste colture, ma anche dei loro rapporti con l'ambiente. Questo lavoro prende in considerazione le perdite di azoto, fosforo e potassio dovute al ruscellamento in colture foraggere a diverso livello di intensificazione (dal pascolo alla coltura di erba medica, dal mais al doppio ciclo di mais e loiessa) in tre ambienti italiani: la Pianura Padana nord-occidentale, l'Appennino Toscano e la pianura sarda, con suoli varianti da franco-sabbioso a franco-argilloso. Il monitoraggio quanti-qualitativo del ruscellamento è stato fatto per periodi variabili da due a sei anni. La pendenza era dello 0,5% per gli appezzamenti in Piemonte e Sardegna e del 10% in Toscana. Per quanto riguarda l'azoto i rilasci sono risultati più bassi nei terreni più pianeggianti, anche per i ridotti volumi di ruscellamento registrati, non superando mai 15 kg di N ha -1 anno -1. Nei terreni in pendenza si sono invece registrati valori più elevati, con un massimo annuale di circa 30 kg ha -1 anno -1 di azoto, in relazione anche all'elevato ruscellamento ed erosione di un evento eccezionale. Per il fosforo solo in pochi casi si sono raggiunte perdite di 5 kg ha -1 anno -1, mentre nella maggior parte dei casi non sono stati superati 2 kg ha -1 anno -1. In Sardegna i rilasci di tale elemento sono da considerarsi pressoché trascurabili. Le perdite di potassio sono risultate minime in Sardegna e massime in Piemonte, dove si sono registrati valori dell' ordine di 10 kg ha -1 anno -1. Ove era possibile il confronto, si è verificato che le colture prative riducono il rilascio di elementi nutritivi rispetto alla coltura del mais e che la qualità delle acque di superficie appare legata piuttosto alle tecniche colturali che alla tipologia di suolo. Fodder crops play an important role in many Italian environments. The knowledge of the main productive characteristics of these crops is as important as their relationships with the environment, expecially for a proper territorial management. This paper compares nitrogen, phosphorous and potassium contents in runoff of some forage crops of different intensity (pasture, lucerne, silage maize, Italian ryegrass/maize double cropping) in different ltalian environments (north-western plain of Piemonte, Apennines hills of Tuscany and Mediterranean plain of Sardegna) on different typology of soils. Runoff data have been collected for periods ranging between two and six year, from plots of different extension and slope (0,5% in the plains, 10% in Apennine hills). Nitrogen losses, for the small amount of runoff, have been qui te low from ilat fields, being always less than 15 kg ha -1 year-1. Losses from slope fields have been higher, with a maximum of 30 kg ha -1 year-1, due to very high level of runoff and erosion in a conspicuous episode. Phosphorous losses only in a few cases were higher than 5 kg ha -I year -I, while mostly they have b>!en less than 2 kg ha -1 year-1. In the Mediterranean plain such losses have been quite insignificant. Minimum potassium 10sses were recorded in the Mediterranean plain, while in north-western plain they reached about 10 kg-1 year-1. Maize was, on average, the crop with highest nutrient losses, while quality of the runoff water was more related to agricultural practices than to soil types

    An Expanded Peripheral T Cell Population to a Cytotoxic T Lymphocyte (Ctl)-Defined, Melanocyte-Specific Antigen in Metastatic Melanoma Patients Impacts on Generation of Peptide-Specific Ctls but Does Not Overcome Tumor Escape from Immune Surveillance in Metastatic Lesions

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    It is not known if immune response to T cell–defined human histocompatibility leukocyte antigen (HLA) class I–restricted melanoma antigens leads to an expanded peripheral pool of T cells in all patients, affects cytotoxic T lymphocyte (CTL) generation, and correlates with anti-tumor response in metastatic lesions. To this end, a limiting dilution analysis technique was developed that allowed us to evaluate the same frequency of peptide-specific T cells as by staining T cells with HLA–peptide tetrameric complexes. In four out of nine patients, Melan-A/Mart-127–35–specific CTL precursors (CTLp) were ≥1/2,000 peripheral blood lymphocytes and found mostly or only in the CD45RO+ memory T cell subset. In the remaining five patients, a low (<1/40,000) peptide-specific CTLp frequency was measured, and the precursors were only in the CD45RA+ naive T cell subset. Evaluation of CTL effector frequency after bulk culture indicated that peptide-specific CTLs could be activated in all patients by using professional antigen-presenting cells as dendritic cells, but CTLp frequency determined the kinetics of generation of specificity and the final number of effectors as evaluated by both limiting dilution analysis and staining with HLA-A*0201–Melan-A/Mart-1 tetrameric complexes. Immunohistochemical analysis of 26 neoplastic lesions from the nine patients indicated absence of tumor regression in most instances, even in patients with an expanded peripheral T cell pool to Melan-A/Mart-1 and whose neoplastic lesions contained a high frequency of tetramer-positive Melan-A/Mart-1–specific T cells. Furthermore, frequent lack of a “brisk” or “nonbrisk” CD3+CD8+ T cell infiltrate or reduced/absent Melan-A/Mart-1 expression in several lesions and lack of HLA class I antigens were found in some instances. Thus, expansion of peripheral immune repertoire to Melan-A/Mart-1 takes place in some metastatic patients and leads to enhanced CTL induction after antigen-presenting cell–mediated selection, but, in most metastatic lesions, it does not overcome tumor escape from immune surveillance
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