1,721,225 research outputs found
Aspetti ultrastrutturali dei tumori uroteliali nei bovini: prime osservazioni preliminari sui carcinomi infiltranti.
No full textLa crescente incidenza dei tumori della vescica, osservata in patologia umana negli ultimi anni, motiva l’interesse dei ricercatori allo studio dei meccanismi eziopatogenetici responsabili della trasformazione neoplastica delle cellule uroteliali. Per questo motivo, molti studiosi stanno utilizzando modelli animali per lo studio della cancerogenesi vescicale. Si ha motivo di ritenere che il bovino possa rappresentare un utilissimo Animal model for human disease. Nel bovino, il tumore della vescica, rappresenta una forma di patologia spontanea comune in particolari aree geografiche (Galles, Turchia, Portogallo, Italia Meridionale) dove rigogliosa cresce la felce (Pteridium aquilinum) ed è associata con la cosiddetta ematuria enzootica bovina (EEB). I nostri risultati evidenziano la presenza di BPV-2 in oltre il 70% di neoplasie vescicali (Borzacchiello et. al, 2003). Durante gli ultimi tre anni, sono stati raccolti, presso macelli pubblici dell’Italia Meridionale, circa duecento neoplasie vescicali di bovini che clinicamente manifestavano una sintomatologia ascrivibile all’EEB. I prelievi sono stati processati per la microscopia ottica, per la microscopia laser confocale e, circa 200 casi, per la microscopia elettronica a trasmissione. E’ ben noto che la morfologia dei tumori della vescica dei bovini affetti da EEB è praticamente sconosciuta. Le caratteristiche ultrastrutturali osservate in questo studio contribuiscono a chiarire il ruolo del papillomavirus nella patogenesi dei tumori uroteliali nel bovino. L’obiettivo è stato quello ristudiare e meglio conoscere la patologia neoplastica associata ad infezioni virali che in medicina veterinaria provoca gravi danni economici all’ allevamento bovino. Ulteriori studi saranno necessari per una migliore conoscenza degli intimi meccanismi del sinergismo tra virus e principi tossici vegetali nel determinismo di neoplasie al fine di individuare modelli animali per lo studio di malattie neoplastiche in medicina umana
L'autonomia tributaria delle Regioni e degli enti locali alla luce della riforma del federalismo fiscale
Full text linkInquadramento generale della problematica federalista nell'ordinamento italiano. La Legge Delega 5 maggio 2009, n. 42. L'autonomia tributaria delle Regioni. L'autonomia tributaria degli Enti locali.Inquadramento generale della problematica federalista nell'ordinamento italiano. La Legge Delega 5 maggio 2009, n. 42. L'autonomia tributaria delle Regioni. L'autonomia tributaria degli Enti locali.LUISS PhD Thesi
OSSERVAZIONI ULTRASTRUTTURALI IN TUMORI UROTELIALI DELLA VESCICA DI BOVINI ASSOCIATI A PAPILLOMAVIRUS
No full textPetrographic and geochemical characterization of the Middle‒Upper Jurassic Fe–Mn crusts and mineralizations from Monte Inici (north-western Sicily): genetic implications
Full text linkFe–Mn concretions and mineralizations, associated with condensed horizons and hardground, are significant archives in ancient carbonate rocks. Their petro-chemical study allows an assessment of the palaeoenvironmental context in which they were formed also connected to their biotic or abiotic origin. At the western side of the Monte Inici (Fornazzo section, north-western Sicily) a well exposed outcrop of condensed pelagic limestones (Rosso Ammonitico facies: Middle‒Upper Jurassic) is well-known and thoroughly studied. In this section, the base of the Rosso Ammonitico facies consists of a very condensed level rich in fossils with a variable thickness deposited from the early Bathonian to the early/middle Callovian. It is characterized, at the top, by the noticeable presence of Fe–Mn concretions, typical of the Tethyan Jurassic and related to very low sedimentation rates. For this study, Fe–Mn crusts and mineralizations from the Fornazzo section were investigated using X-ray diffraction, scanning electron microscopy, X-ray fluorescence, ICP and stable-isotope mass spectrometry. The collected samples, deposited in submarine conditions (as testified by stable oxygen and carbon isotopes), have been subdivided in two typologies with different macroscopic and mineralogical features. The Fe–Mn crusts consist of hematite, todorokite and birnessite and are characterized by a relatively low Mn/Fe ratio. Their content in trace elements, rare earths and yttrium (REY) is compatible with a hydrogenetic origin involving the oxy-hydroxides colloids precipitation directly from seawater. Microbially mediated processes are here testified by the recognition of filamentous and coccoid-shaped microstructures referable to coexistence of chemosynthetic fungi and photosynthetic cyanobacteria and accounting for a deposition in the deep euphotic zone. An average growth rate of ~ 8.5 mm/Myr for the Fe–Mn crusts, estimated by cobalt concentrations, suggests a time elapsed for deposition of ~ 3.5 ± 1 Myr. This value is compatible with the stratigraphic gap embracing the time span from the early/middle Callovian to the middle Oxfordian. In the neighbouring pelagic limestones, Fe–Mn deposits are present in the form of micro-dendrites mainly consisting of pyrolusite, sometimes associated with carbonato-fluorapatite. The geochemical composition gives evidence of a prevalent early diagenetic origin with precipitation, at the sediment/water interface or in the first centimeters of sediments, of metals diffused from the crusts as consequence of fluctuating redox conditions. Although the well-preserved Frutexites texture is commonly related to a microbial activity, other bacterial microstructures have not been recognized, having probably been obliterated during the growth of the dendrites. Nevertheless, it is possible to suppose a deepening in the bathymetry consistent with the involvement of chemosynthetic microorganisms in
the formation of Frutexites structures
Archéologie du discours amoureux : prototypes et régimes de l'amour littéraire dans les traditions galloromanes médiévales
No full textL’histoire de l’amour courtois propose un récit complexe, dans les faits littéraires autant que dans les vicissitudes de son herméneutique.
De nombreux embarras et impasses dérivent d’emblée de l’histoire de sa désignation - et du patrimoine théorique qui l’accompagne. Utilisée régulièrement comme unité minimale d’identification de la représentation amoureuse, la notion d’amour courtois continue de délimiter l’érotique galloromane : mais si, d’une part, elle aide à en souligner les spécificités, elle en force, de l’autre, l’univocité. Depuis l’étude fondatrice de G. Paris (1883), l’amour dans la littérature médiévale a fini par correspondre, au sein des consciences critiques, aux critères fondamentaux de l’amour courtois.
Les conséquences de cet équilibre trompeur sont, dans la production critique, variées. Dans le domaine de l’étude synchronique mono et intertextuelle, les autres formes et sens que l’amour médiéval connaît en dehors de ce schéma ne font pas l’objet d’une attention interprétative aussi scrupuleuse que celle qu’on accorde à l’amour courtois proprement dit ; dans la perspective de l’histoire des origines, l’amour courtois est aisément placé dans un parcours idéologique et culturel indépendant par rapport à l’histoire littéraire générale ; les aspects chronologiques internes à ce phénomène sont généralement aplatis, dans un mécanisme de nivèlement des cycles temporels ; à l’immobilité des paradigmes exégétiques s’est associée, enfin, la constitution d’un “canon” de textes faisant fonction de garants de la définition.
L’état de l’art, qui compte à présent des progrès remarquables, bénéficie d’études éminentes sur ce sujet. L’ensemble de ces résultats n’a toutefois pas engendré un réseau critique compact, au vu de ce qui procède des pivots interprétatifs fondamentaux. Dans notre thèse, nous offrons des hypothèses herméneutiques et un modèle méthodologique visant à l’éclaircissement et à l’élargissement des perspectives.
à l’univocité des théories liées au canon et à la notion d’amour courtois, le présent travail substitue un plan d’analyse plus ample, celui du discours amoureux galloroman : les marges d’un tel objet sont ouvertes à toutes les expressions et représentations érotiques de matrice laïque. Les possibilités hétéroclites du discours amoureux (R. Schnell 1989), qu’il est fondamental de considérer comme un ensemble idéologique, culturel et littéraire, sont soumises à une analyse visant à offrir un cadre interprétatif à la fois particulier et général. Afin de réévaluer les fondements de cet objet (en renouvelant mais aussi en bornant les horizons de R. R. Bezzola, 1944-63), notre enquête fait collaborer les plans critiques et chronologiques: la phase exégétique de cette étude, supportée par l’analyse philologique des textes, s’accompagne de l’étude stylistique et rhétorique. Ce travail procède selon les étapes suivantes : l’identification des motifs et des thèmes génératifs (noyaux de fond) a été suivie par la construction d’un répertoire de prototypes du discours amoureux et par l’étude de leur diffusion selon les époques et les lieux. Cette opération a été supportée par la périodisation du discours amoureux en trois phases distinctes, au sein desquelles le code expressif s’est fixé : le Midi, d’abord, inaugure la phase de formation d’un langage lyrique primordial, qui vise à valoriser et sublimer l’amour humain, pour exalter la chasteté dans une morale interne et élitiste ; dans le Nord, ensuite, naît un discours amoureux qui concilie la pensée et la formation des clercs avec l’idéal conjugal séculier, construisant de ce fait un modèle d’ordre social ; enfin, les réalités urbaines septentrionales offrent, d’un côté, une réception néo-curiale des prototypes lyriques et, de l’autre, une réélaboration théologique et encyclopédique, mais aussi profane et pratique, de la tradition courtoise
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Ultra-low density carbon foams produced by pulsed laser deposition
No full textWe report on the manufacturing of ultra-lowdensity carbon foam produced by pulsed laser deposition. Mean mass density, morphology and structure were investigated within a broad range of process parameters.We have been able to obtain carbon foam layers having tun- able mean density and thickness in the range 1–1000 mg/cm^3 and 5–80 micron, respectively.
Surface uniformity has been achieved over 1 micron^2 areas with mean pore size around 10 nm. The morphological/structural properties have been investigated by means of quartz crystal microbalance, scanning electron microscopy and Raman spectroscopy. Based on these results, this work shows how pulsed laser deposition can be exploited as a versatile tool for the deposition of carbon foams with tunable and tailored density, thickness and uniformity
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