24,070 research outputs found
Microcystic adenoma of the pancreas (glycogen-rich cystadenoma) with stromal amyloid deposits
No full textWe report a case of a pancreatic glycogen-rich microcystic serous adenoma with stromal amyloid deposits, focusing on the significance of isolated amyloid deposits in tumours.
The architectural pattern was characterized by thin-walled cysts lined by a single layer of flat or cuboidal epithelial cells intensely stained by the PAS-reaction only before diastase digestion, suggesting the presence of glycogen. Tumour stroma was composed of broad fibrocollagenous tissue with lamellar hyalinized areas which were positively stained by Congo red and showed green birefringence and dichroism with polarized light. For amyloid protein characterization, immunohistochemical studies were performed with anti-beta amyloid protein and anti-amyloid precursor pre-A4695. The former antibody diffusely stained tumour stroma, while the latter stained only scattered stroma cells.
This is the first documented case of amyloid deposition in pancreatic serous adenoma. We indicate that the source of amyloid is an APP-like precursor secreted by stromal myofibroblasts
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
Ultrastructural features of bovine cumulus-corona cells surrounding oocytes, zygotes and early embryos
No full textIntegrated transmission and scanning electron microscopic (TEM and SEM)
techniques have provided the first detailed description of the ultrastructural
features of the bovine cumulus-corona (CC) cells surrounding oocytes at the time
of final maturation, zygotes and early cleaving embryos (2/4 to 6/8 blastomeres).
TEM revealed the presence of rough endoplasmic reticulum and Golgi complexes in
the cytoplasm of CC cells surrounding immature, mature and fertilized eggs, and
also revealed an increasing amount of smooth endoplasmic reticulation membranes,
lipid droplets and mitochondria with villiform and/or tubular cristae in the
cytoplasm of CC cells during maturation and fertilization of the oocyte. In
addition, a loss of cell-to-cell junctions between CC cells was evident. TEM also
demonstrated that a few residual CC cells were still associated with early
embryos and that these cells showed rather degenerative or apoptotic patterns,
the latter pattern also observed on cells associated with fertilized eggs. SEM
revealed that the complex of CC cells of immature oocytes was compact with narrow
intercellular spaces, which progressively enlarged in size around mature oocytes.
This phenomenon is mostly due to the production of abundant extracellular matrix.
Immature CC cell complexes possessed characteristic long and filiform microvilli
whereas the surface of CC cells surrounding mature oocytes showed numerous blebs
and occasional large cytoplasmic protrusions as well as microvilli. Zygotes and
early embryos were covered with a few polyhedral CC cells possessing scarce and
short microvilli and a large amount of pleomorphic blebs. This study demonstrated
a precocious luteinization occurring in bovine CC cells at ovulation until zygote
segmentation, and this process was associated with a progressive apoptotic
mechanism that ended in the complete denudation of the zona pellucida covering
the early embryo. The presence of CC cells around the maturing oocyte and
fertilized egg could have important functions related to the microenvironmental
requirements of ovum maturation as well as facilitating activities related to
fertilizatio
Language Change and SA-OT: The case of sentential negation
No full textSimulated Annealing for Optimality Theory (SA-OT) updates Optimality Theory by adding a model of performance to a theory of linguistic competence. Our aim is to show that SA-OT can contribute to language change simulations. Performance "errors" are considered to be one of the causes of variation and change. We have chosen to model the evolution of sentential negation (SN). The descriptive background adopts Jespersen's Cycle, according to which the evolution of sentential negation follows three main stages (1. pre-verbal, 2. discontinuous, and 3. post-verbal). Therefore, we advance a novel model for SN, based on SA-OT. It reproduces the three pure and the two observed mixed stages, whereas it correctly predicts the lack of an intermediate stage between 3 and 1. The success of the approach corroborates the computational, performance-based approach to the data. Finally, we employ the iterated learning paradigm to reproduce historical changes in a "simulated corpus study". This enterprise turns out to be more difficult than one would naively believe.Appeared open access as: Computational Linguistics in the Netherlands Journal (CLIN), vol. 1 (2011), pp. 21-40, and is available at http://www.clinjournal.org/sites/default/files/Lopopolo.pdfA. Lopopolo and Biró, T., “Language Change and SA-OT. The case of sentential negation”, Computational Linguistics in the Netherlands Journal, vol. 1, pp. 21-40, 2011.Peer Reviewe
Hepatoid gastric carcinoma. A case report
No full textAlpha-fetoprotein (AFP) is normally produced by primary hepatic neoplasms and germ cell tumors. There have, however, been reports of its production in cases of gastrointestinal tract adenocarcinoma. Gastric hepatoid carcinomas constitute a clinicopathological entity of recent acquisition and have certain common characteristics, which include the presence of hepatoid foci and frequent liver metastases, even in cases of early gastric cancer, and increasing serum AFP levels. In this study the case of one patient who underwent gastric resection and presented clinical, humoral, histological and immunohistochemical characteristics typical of hepatoid gastric carcinoma is reported. More biological studies, as well as precise criteria for pathological definition and therapy, are still necessary for a better understanding of this pathology
Cell reponse to oxidative stress induced apoptosis in patients with Leber’s hereditary optic neuropathy
No full textOBJECTIVES:
Leber's hereditary optic neuropathy (LHON) is a maternally inherited disease in which acute or subacute bilateral visual loss occurs preferentially in young men. Over 95% of LHON cases are associated with one of three mitochondrial DNA (mtDNA) point mutations, but only 50% of men and 10% of women who harbour a pathogenetic mtDNA mutation develop optic neuropathy. This incomplete penetrance and preference for men suggests that additional genetic (nuclear or mitochondrial) and/or environmental factors must modulate phenotype expression in LHON. A role for reactive oxygen species (ROS) in mitochondrial diseases, secondary to mtDNA mutations, or as a result of the direct effect of ROS cytotoxicity, has been implicated in many mitochondrial disorders, including LHON. The purpose of this study was to investigate the role of oxidative stress induced apoptosis in LHON.
METHODS:
The 2-deoxy-D-ribose induced apoptotic response of peripheral blood lymphocytes from six patients with LHON and six healthy subjects was investigated using light microscopy, flow cytometry, agarose gel electrophoresis, and the measurement of mitochondrial membrane potential.
RESULTS:
Cells of patients with LHON had a higher rate of apoptosis than those of controls and there was evidence of mitochondrial involvement in the activation of the apoptotic cascade.
CONCLUSIONS:
These differences in oxidative stress induced apoptosis are in line with the hypothesis that redox homeostasis could play a role in the expression of genetic mutations in different individuals and could represent a potential target in the development of new therapeutic strategie
Genetic Transformation and Genomic Resources for Next-Generation Precise Genome Engineering in Vegetable Crops
No full textEditio princeps delle Recollecte Georgicorum di Benvenuto da Imola e tradizione esegetica delle Georgiche nel basso Medioevo
No full textL’esito primario di questo progetto dottorale è l’editio princeps delle tre recollecte, ossia degli appunti di tre diversi discepoli, che trasmettono il ciclo di lezioni alle Georgiche virgiliane tenuto da Benvenuto da Imola a Ferrara fra il 1378 e il 1379. La tesi è suddivisa in tre capitoli: Premessa, Introduzione e Testo critico.
La Premessa vuole fornire una panoramica dell’esegesi georgica nel Medioevo, la cui tradizione non è ancora stata esaustivamente indagata. Quanto presentato è esito della ricognizione di prima mano della maggior parte dei manoscritti contenenti commenti continui alle Georgiche conservati nelle biblioteche europee. Si sono potute valutare in particolare l’esegesi francese del XII secolo e quella italiana del XIV secolo, per giungere infine al commentatore protagonista della ricerca, Benvenuto da Imola.
Dell’esegesi francese di XII secolo sono stati indagati due importanti centri: quello di Laon e quello di Orléans. Dal centro di Laon giunge il primo esempio di rinnovamento dell’esegesi serviana, in particolare nei manoscritti Paris, Bibliothèque nationale de France, Latin 3713 e London, British Library, Additional 16380. I commenti anepigrafi tramandati da questi testimoni provengono dal medesimo centro scolastico e, pur nelle loro specificità, sono caratterizzati dall’aderenza al dettato serviano e dalla presenza delle medesime fonti negli stessi luoghi. Elemento di grande novità è l’utilizzo di Macrobio quale auctoritas virgiliana al pari dell’esegeta tardoantico. Dal centro di Orléans giunge invece un altro commento anepigrafo, tramandato in due manoscritti: oggi Berlin, Staatsbibliothek, Lat. fol. 34 e London, British Library, Additional 33220. Il commento si rivela meno aderente al modello serviano e presenta probabilmente per la prima volta una suddivisione del testo georgico in capitula.
Dell’esegesi italiana del primo Trecento si è posta in luce la figura di Giovanni del Virgilio, corrispondente di Dante Alighieri e maestro bolognese che proprio per la sua fama di esegeta virgiliano ricevette tale soprannome. I suoi commenti virgiliani erano fino a poco tempo fa ritenuti perduti. Tuttavia, proprio nel tentativo di catalogare i commenti continui alle Georgiche, ho avuto la possibilità di ritrovarli. Questi commenti, oggi nei manoscritti Città del Vaticano, Biblioteca Apostolica Vaticana, Vat. lat. 5990 e Padova, Biblioteca Universitaria, 1084, assumono dei caratteri di assoluta novità rispetto all’esegesi precedente. In primo luogo, muta l’impianto esegetico: Giovanni rifiuta il discorso lemmatico simil-serviano, preferendo un discorso parafrastico molto più ampio e arricchito da numerosi excursus. In secondo luogo, l’auctoritas esegetica secolare di Servio, viene spesso criticata per errate interpretazioni e gli sono contrapposte fonti più antiche attentamente vagliate.
In ultimo, la Premessa presenta un medaglione bio-bibliografico di Benvenuto da Imola, definito historiarum receptor per le opere storiografiche e solemnissimus authorista per le fatiche esegetiche, e un’analisi della tipologia testuale in cui è tradito il testo delle sue lezioni, ossia quella della recollecta.
L’Introduzione si concentra sul lavoro di edizione critica del testo delle recollecte. È suddivisa in tre capitoli con un’appendice. Nel primo capitolo, Le tre recollecte di Benvenuto da Imola alle Georgiche, si descrive l’eccezionale e anomala tradizione in cui è giunto sino a noi tale commento. Sono infatti tre i diversi recollectores che hanno prodotto tre differenti recollecte dello stesso corso, tenuto da Benvenuto a Ferrara fra il 1378 e il 1379. Viene fornita la recensio dei nove testimoni che tramandano i testi, viene circoscritto l’ambiente di produzione, si dà conto del titolo dell’opera, della tipologia testuale, e ancora dell’autore-commentatore, della datazione e della localizzazione. In conclusione, si fornisce la dimostrazione che le tre recollecte dipendano tutte dal medesimo ciclo di lezioni.
Nel secondo capitolo, Nota critica, si illustra la tradizione delle tre recollecte dal punto di vista filologico. Ognuna delle tre recollecte è stata valutata singolarmente e ne è stato ricostruito lo stemma. Tuttavia, essendo le tre recollecte dipendenti dalle stesse parole di Benvenuto, si è ritenuto di poter considerare le lezioni di Benvenuto quale metaforico originale orale e le tre recollecte, ossia le tre belle copie degli appunti, tre differenti archetipi. Vengono dunque presentati nell’ordine gli errori d’autore, gli errori dei vari recollectores a livello di archetipo, gli errori separativi e congiuntivi fra i testimoni o le famiglie delle singole recollecte, le questioni relative alle omissioni e le interpolazioni. Si descrive quindi la tradizione di ognuna delle tre recollecte dai rami più alti a quelli più bassi e si dà conto dell’ortografia dei manoscritti. Nell’Appendice alla Nota critica che segue sono presentati tutti gli errori e le varianti per ognuna delle tre recollecte.
Nel terzo capitolo, Il commento, si passa alla descrizione del corso di Benvenuto da Imola, analizzandone quattro aspetti fondamentali in quattro corrispettivi sottocapitoli: Il ciclo di lezioni, L’esegesi, Le fonti e La fortuna. Per quanto riguarda Il ciclo di lezioni si è analizzato in primo luogo la struttura del corso, chiaramente visibile da alcune formule fisse di passaggio da una lezione alla successiva; in secondo luogo, l’articolazione della singola lezione; e in ultima istanza, gli stilemi formali di Benvenuto e dei recollectores, così da far emergere da un lato le dinamiche e la dimensione didattica fra il magister e i discipuli e dall’altro le divergenze fra le recollecte. Per quanto riguarda L’esegesi si è valutata la differenza di impostazione di lettura fra il precedente corso sulle Bucoliche, nel quale Benvenuto mira a svelare tutti e quattro i sensi (fabularis, historialis, allegoricus e tropologicus) e quello georgico concentrato solo sul dato reale. Proprio per sostenere questa lettura della realtà virgiliana che produce delectatio e utilitas, Benvenuto fa emergere il dato storico e culturale degli insegnamenti agresti, spesso fornendo attualizzazioni tramite realia vicini alla quotidianità dei suoi discepoli e lemmi in lingua volgare. Ancora in relazione all’esegesi si è descritto come Benvenuto proponga una suddivisione dell’opera virgiliana dal punto di vista tematico e come ne analizzi la dimensione più testuale, valutandone le peculiarità dal punto di vista filologico. Per quanto riguarda Le fonti si sono descritte: le ragioni che muovono Benvenuto a utilizzarle in maniera implicita o esplicita; le modalità di combinazione e unione di più materiali in uniche glosse; il riutilizzo di tali glosse nei differenti commenti; i rimandi e i rinvii esegetici fra le diverse opere commentate; infine, il peso della lettura dantesca su quella virgiliana. Si è poi passati a valutare il rapporto con l’esegesi virgiliana precedente, descrivendo in particolare: la dura critica che Benvenuto muove a Servio, il debito nei confronti di Giovanni del Virgilio e gli attacchi ai colleghi commentatori. Ancora, si è valutato il rapporto con due eccezionali contemporanei: Francesco Petrarca e Giovanni Boccaccio. Del primo, problematico interlocutore su questioni poetiche, Benvenuto dimostra di aver letto non solo il Bucolicum carmen, ma anche qualche passaggio dell’Africa. Del secondo, preceptor nel solco dantesco, Benvenuto si annovera analogamente fra i primi lettori e si rileva altresì debitore di molti materiali mitologici e geografici. In ultimo si fornisce l’elenco di tutte le fonti esplicite presenti nelle tre recollecte. Per quanto riguarda La fortuna, si dà conto di quei manoscritti contenenti commenti continui o glosse a margine del poema virgiliano dipendenti o derivate dai materiali delle recollecte. Chiudono l’Introduzione i Criteri di edizione.
L’ultimo capitolo offre il testo critico delle tre recollecte, suddiviso per libri e al suo interno per porzioni di testo virgiliano commentato, seguendo quanto presente sui manoscritti. All’inizio di ogni porzione testuale è presente il numero e l’incipit del verso virgiliano commentato: il primo inserito dall’editore, il secondo presente già sui testimoni. Il testo è inoltre corredato da un apparato di fonti e luoghi paralleli.The work of this thesis focuses on the first critical edition of the three recollecte, i.e., notes from three different disciples, which transmit the cycle of lectures held by Benvenuto da Imola on the Georgics in Ferrara between 1378 and 1379. The thesis is divided into three chapters: Premessa, Introduzione, and Testo Critico.
The Premessa aims to provide an overview of Georgic exegesis in the Middle Ages. What is presented is the result of a first-hand survey of most of the manuscripts containing continuous comments on the Georgics preserved in European libraries. More specifically, the French exegesis of the 12th century and the Italian one of the 14th century were evaluated, ultimately leading to Benvenuto da Imola, the exegete protagonist of the doctoral research.
Two important centres of the French exegesis of the 12th century were investigated: Laon and Orléans. From the centre of Laon comes the first example of the renewal of Servian exegesis, transmitted in the manuscripts Paris, Bibliothèque nationale de France, Latin 3713, and London, British Library, Additional 16380. The anepigraphic comments transmitted by these witnesses come from the same school centre and, despite their specificities, are characterised by adherence to the Servian dictation and the presence of the same sources in the same places. A great innovation is the use of Macrobius as a Virgilian auctoritas on par with the late antique exegete. On the other hand, from the centre of Orléans comes another anepigraphic comment, transmitted in two other manuscripts: Berlin, Staatsbibliothek, Lat. fol. 34, and London, British Library, Additional 33220. The comment reveals less adherence to the Servian model and presents, likely for the first time, a subdivision of the Georgic text into capitula.
Regarding the early 14th-century Italian exegesis, the figure of Giovanni del Virgilio stands out: Bolognese master and correspondent of Dante Alighieri, he received his nickname precisely because of his fame as a Virgilian exegete. The Virgilian comments of Giovanni del Virgilio have been considered lost until recently. However, in the attempt to catalogue the continuous comments on the Georgics, I had the opportunity to retrieve them. These comments, currently in the manuscripts Città del Vaticano, Biblioteca Apostolica Vaticana, Vat. lat. 5990, and Padova, Biblioteca Universitaria, 1084, assume characters of absolute novelty compared to the previous exegesis. First of all, the exegetical structure changes: Giovanni rejects the lemmatic discourse similar to Servius, preferring a much wider paraphrastic discourse enriched by numerous excursus. Giovanni further rejects the secular exegetical auctoritas of Servius, often criticising him for incorrect interpretations and opposing him to older sources carefully sifted.
Finally, the Premessa presents a bio-bibliographic medallion of Benvenuto da Imola, defined as historiarum receptor for the historiographical works and solemnissimus authorista for the exegetical ones, and an analysis of the textual typology in which the text of his lessons is handed down, i.e., the recollecta.
The Introduzione focuses on the critical edition work of the recollecte. It is divided into three chapters plus an appendix. In the first chapter, Le tre recollecte di Benvenuto da Imola alle Georgiche, it is described the exceptional tradition in which this comment has come down to us. In fact, there are three different recollectores who have produced three different recollecte of the same course, held by Benvenuto in Ferrara between 1378 and 1379. Furthermore, the chapter provides a recensio of the nine witnesses who transmit the texts, the circumscribed production environment, the title of the work, and the textual typology. In this chapter, there are also an analysis of the author-commentator, the dating, and the localization of the recollecte based on the explicit rubrics. In conclusion, it is demonstrated that all three recollecte depend on the same cycle of lessons.
In the second chapter, Nota critica, the tradition of the three recollecte is illustrated from a philological point of view. Each of the three recollecte has been evaluated individually, and each stemma has been reconstructed. However, because the three recollecte depend on the same words of Benvenuto, Benvenuto’s lessons were considered, at least metaphorically, an original, and the three recollecte, i.e., the three copies of the notes, are recognised as three different archetypes. Therefore, I present the author’s mistakes, the errors of the various recollectores at the archetype level, the separative and conjunctive errors between the witnesses or the families of the individual recollecte, and the issues related to omissions and interpolations. The tradition of each of the three recollecte is then described from the highest branches to the lowest ones, and an orthographic study of the manuscripts is provided. In the Appendice alla Nota critica, is it possible to find all errors and variants for each of the three recollecte.
In the third chapter, Il commento, we move on to the description of Benvenuto da Imola’s course, analysing four fundamental aspects in four sub-chapters, respectively: Il ciclo di lezioni, L’esegesi, Le fonti, and La fortuna. As for Il ciclo di lezioni, the following topics are analyzed: the structure of the course, clearly evident by a fixed formula of transition from one lesson to the next; the articulation of the single lesson; the formal styles of Benvenuto and the recollectores. This allows to bring out, on the one hand, the dynamics and didactic dimension between the magister and the discipuli and, on the other, the divergences between the recollecte. As for L’esegesi, I evaluated the differences in reading setting between the previous course on the Bucolics, in which Benvenuto aims to reveal all four senses (fabularis, historialis, allegoricus and tropologicus), and the Georgics one, focusing only on the real data. To support this reading of the reality described by Virgil, which produces delectatio and utilitas, Benvenuto brings out the historical and cultural data of the rural teachings, often providing realia close to the daily lives of his disciples and lemmas in the vernacular language. In relation to the exegesis, the sub-chapter also describes how Benvenuto proposes a subdivision of the Virgilian work from a thematic point of view and how he analyses the most textual dimension, evaluating its peculiarities from a philological perspective. As for Le fonti, I provide a description of the reasons that move Benvenuto to use the sources implicitly or explicitly, the methods of combination and union of several materials in unique glosses, the reuse of these glosses in different comments, and the references and exegetical referrals between the different commented works. Lastly, the chapter accounts for the weight of the Dantesque reading on the Virgilian one. Moreover, the relationship with the previous Virgilian exegesis is evaluated, describing in particular the harsh criticism that Benvenuto moves to Servius, the debt towards Giovanni del Virgilio, and the attacks on fellow commentators. Additionally, it was considered his relationship with Francesco Petrarca and Giovanni Boccaccio, two exceptional contemporaries. As far as the first, Benvenuto shows that he has read not only the Bucolicum carmen, but also some passages from Africa. Of the second, preceptor in the Dantean furrow, Benvenuto similarly counts himself among his first readers and also reveals himself to be a debtor of many mythological and geographical materials. Finally, I report the list of all explicit sources from the three recollecte. As for La fortuna of the Benvenutian Comment to the Georgics, I evaluate those manuscripts containing continuous comments or glosses on the margin of the Virgilian poem dependent on or derived from the materials of the recollecte. The Introduzione is concluded by the Criteri di edizione.
The last chapter provides the critical text of the three recollecte, divided by books and, within each book, by portions of the Virgilian text commented on, following what is present on the manuscripts. At the beginning of each portion there is also the verse number, inserted by the editor, and the incipit of the Virgilian text commented on, already present on the witnesses. The text is also accompanied by an apparatus of sources and parallel places.Nous avons procuré la première édition critique des trois recollecte, c’est-à-dire les notes de trois disciples différents, qui transmettent le cycle de leçons sur les Géorgiques dispensé par Benvenuto da Imola à Ferrare entre 1378 et 1379. La thèse est divisée en trois parties : un avant-propos, une introduction et le texte critique.
L’avant-propos propose un aperçu de l’exégèse sur les Géorgiques au Moyen Âge. Le travail présenté ici est le résultat d’une étude de première main de la plupart des témoins contenant des commentaires continus sur les Géorgiques conservés dans les bibliothèques européennes. On a, en particulier, analysé l’exégèse française du XIIe siècle et l’exégèse italienne du XIVe siècle, pour aboutir au commentateur Benvenuto da Imola qui constitue le cœur de notre recherche doctorale.
En ce qui concerne l’exégèse française du XIIe siècle, on a examiné deux centres renommés : Laon et Orléans. Du centre de Laon provient le premier exemple de renouvellement de l’exégèse servienne, conservé notamment dans les manuscrits Paris, Bibliothèque nationale de France, Latin 3713 et London, British Library, Additional 16380. Les commentaires anépigraphiques transmis par ces témoins sont produits dans le même centre scolastique et, s’ils présentent des spécificités, ils se caractérisent par leur fidélité au style servien et par la présence des mêmes sources aux mêmes endroits. Par ailleurs, une innovation importante de ces commentaires est l’utilisation de Macrobe comme auctoritas virgilienne au même titre que l’exégète de l’Antiquité tardive. Un autre commentaire anépigraphe provient du centre d’Orléans et il est transmis par deux autres manuscrits : Berlin, Staatsbibliothek, Lat. fol. 34 et London, British Library, Additional 33220. Le commentaire se révèle moins fidèle au modèle servien et présente probablement pour la première fois une subdivision du texte des Géorgiques en capitula.
S’agissant de l’exégèse italienne du début du XIVe siècle, on a mis en évidence la figure de Giovanni del Virgilio, correspondant de Dante Alighieri et maître bolognais qui reçut son surnom en raison de sa réputation d’exégète virgilie. Jusqu’à récemment, les commentaires virgiliens de Giovanni del Virgilio étaient considérés comme perdus. Toutefois, en essayant de cataloguer les commentaires continus des Géorgiques, j’ai réussi à les retrouver. Ces commentaires, conservés aujourd’hui dans les manuscrits Città del Vaticano, Biblioteca Apostolica Vaticana, Vat. lat. 5990 et Padova, Biblioteca Universitaria, 1084, présentent des caractéristiques absolument originales par rapport à l’exégèse précédente. Leur structure exégétique est remarquable : Giovanni rejette le discours lemmatique de type servien et préfère un discours paraphrastique beaucoup plus large, enrichi de nombreux excursus. Il refuse par ailleurs l’auctoritas exégétique séculaire de Servius, lui reprochant souvent des interprétations erronées et l’opposant à des sources plus anciennes soigneusement sélectionnées.
L’avant-propos s’achève par une présentation bio-bibliographique de Benvenuto da Imola, défini comme historiarum receptor pour ses ouvrages historiographiques et solemnissimus authorista pour ses ouvrages exégétiques ; elle s’accompagne d’une analyse de la typologie des textes qui transmettent ses leçons, c’est-à-dire la recollecta.
L’introduction porte sur l’édition critique du texte des recollecte. Elle est divisée en trois chapitres, suivis d’un appendice. Dans le premier chapitre, intitulé « Le tre recollecte di Benvenuto da Imola alle Georgiche », on décrit la tradition exceptionnelle grâce à laquelle ce commentaire nous est parvenu. On peut, en effet, identifier trois recollectores différents du même cours donné par Benvenuto à Ferrare entre 1378 et 1379. On fournit la recensio des neuf témoins qui ont transmis les textes, on circonscrit l’environnement de production, on analyse le titre de l’œuvre, la typologie textuelle et encore l’auteur-commentateur, la datation et la localisation sur la base des rubriques explicitaires. En conclusion, on démontre que les trois recollecte dépendent toutes du même cycle de cours.
Dans le deuxième chapitre, intitulé « Notes critiques », on analyse la tradition des trois recollecte d’un point de vue philologique. Chacune des trois recollecte a été évaluée individuellement et leur stemma a été reconstitué. Cependant, dans la mesure où les trois recollecte dépendent des propos prononcés par Benvenuto, ses leçons orales ont été considérées métaphoriquement comme un original et les trois recollecte, c’est-à-dire les trois belles copies des notes, comme trois archétypes différents. On présente donc les erreurs d’auteur ; les erreurs des différents recollectores au niveau de l’archétype ; les er
Redox state and carbonic anhydrase isozyme IX expression in human renal cell carcinoma: biochemical and morphological investigations
No full textClear renal cell carcinomas (RCC) frequently express carbonic anydrase IX (CA IX) because of non-functional mutation of von Hippel Lindau (VHL) tumor suppressor gene. CA IX is a tumor-associated transmembrane antigen, which catalyzes the extracellular, reversible hydration of carbon dioxide to bicarbonate and proton and thereby contributes to acidification of extracellular milieu. Extracellular acidic pH facilitates tumor growth and progression. CA IX expression is upregulated by Hypoxia Inducible Factor-1 (HIF-1), which is negatively controlled by oxygen via wild type VHL protein and is also regulated by the cell redox state. We investigated the immunohistochemical pattern of distribution of CA IX in a small series (14 cases) of RCCs. CA IX expression was matched with the redox state of RCC, stratifying our series in relation to clinical and histopathological parameters, such as Fuhrman grade, staging, proliferation markers expression, and particularly, the presence of necrosis. Our results show for the first time the existence of a perivascular pattern of CA IX distribution in RCC. We also found a significant relationship between CA IX expression and the presence of necrosis. Tumors with higher CA IX expression exhibited higher degree of necrosis (p < 0.05). Notably, an almost significant relationship between the redox state and CA IX expression was detected in RCC patients with 5 years disease-free survival, most of them showing organ-confined disease. Tumors with lower redox state showed an algebraically higher degree of CA IX expression. On the contrary, tumors with higher redox state exhibited an algebraically lower CA IX expression (p = 0.057). The observed relationship of CA IX expression and necrosis suggests a role for CA IX in RCC. Further investigations are necessary to further establish the role of the redox state in regulation of CA IX expression in RCC
Stress-induced diffusion of hydrogen in metallic membranes: cylindrical vs. planar formulation. I
No full textThe hydrogen chemical potential in metallic membranes is affected by the self-stresses generated by the interstitial transport within the lattice (stress-induced diffusion). This article provides analytical and numerical evidence that, in the presence of stress-induced diffusion, hydrogen transport in thin metallic cylindrical membranes can exhibit macroscopic features qualitatively different from those observed in planar structures. This is a consequence of the different ways diffusion-induced stresses propagate in planar and in the cylindrical structures. We focus on the investigation of the uphill diffusion effect (observed experimentally in Pd and I'd alloy membranes) originally explained as a consequence of the failure of the Fick law for solid-state diffusion. We show that the classical stress-induced diffusion (SID) model applied to a cylindrical structure leads to a Fickian-type transport equation, which indeed displays the uphill effect solely as a consequence of the non-linear, non-local time-dependent boundary conditions corresponding to permeation experiments. (C) 2003 Elsevier B.V. All rights reserved
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