Sistemazione idraulica del fosso Ombroncello sito nel comune di Pistoia

Sistemazione idraulica del fosso Ombroncell

Micro rayures et signes d’usure

Les traces laissées par les instruments anciens et modernes de travail ont, depuis plusieurs années, fait l’objet d’études avec succès. Aux différentes méthodes archéométriques utilisées pour l’identification de faux, ainsi que dans le domaine d’authentification d’orfèvrerie archéologique, nous proposons d’ajouter une technique basée sur l’observation de l’objet par microscopie optique ou électronique. Cette méthode repose sur l’étude de la surface de la tôle, pour identifier les stratifications des traces correspondant soit aux anciennes opérations du travail de l’orfèvre, soit au contact et au frottement au cours du temps de cette surface avec des matériaux extérieurs, qui viennent se superposer aux traces initiales. En reconnaissant la séquence chronologique des superpositions des marques, il est parfois possible de reconstruire l’histoire de l’objet et d’avancer une hypothèse sur son ancienneté. Les traces d’usure visibles sur la surface des objets d’orfèvrerie fournissent également des informations fondamentales sur la durée de vie de ces objets et sur leur utilisation.The traces left by ancient instruments and by modern ones have been successfully studied for many years. In the present paper, we propose to add to the different archaeometric methods employed for the identification of fakes a supplementary technique involving the observation of the object by optical or electron microscopy. This technique is based on the study of metallic surfaces in order to identify the stratifications of the marks related to the ancient stages of construction related to the work of the original goldsmiths and distinguish them from those which were added later to the initial marks. The latter are related to the contact and friction of the surface with external materials in the course of time. By recognising the chronological sequence of the marks’ superposition, it is at times possible to reconstruct the history of the object and to put forth hypotheses regarding its age. The visible wear marks on the surface of goldwork also provide fundamental information about the lifetime and use of the objects

La datazione tecnologica dei grandi bronzi antichi: il caso della Lupa Capitolina

A cominciare dagli anni settanta con le grandi mostre sui cavalli di San Marco ed i Bronzi di Riace, si sono sviluppate le ricerche scientifiche sulle tecniche di lavorazione dei grandi bronzi dell’antichità. I risultati che queste indagini hanno portato fino ad oggi hanno rivelato che parallelamente all’evoluzione stilistica dall’età arcaica greca fino al Rinascimento vi è stata anche una evoluzione delle tecniche di fusione e di rifinitura. Infatti, nonostante il persistente luogo comune diffuso tra archeologi e storici dell’arte, per il quale le tecniche di fusione a cera perduta sarebbero rimaste immutate dall’antichità in poi, questi recenti studi hanno messo in evidenza i cambiamenti delle tecniche delle varie età e le strette connessioni che le innovazioni tecnologiche avevano con i cambiamenti stilistici. Si è potuto così dimostrare che il mondo degli artigiani e degli esecutori materiali delle statue in bronzo era almeno strettamente collegato se non identico a quello degli artisti che creavano i modelli originali dei grandi bronzi. La possibilità di datare un grande bronzo attraverso le sue caratteristiche tecnologiche rappresenta una diretta conseguenza di questi studi, che recentemente si avvalgono anche di ricostruzioni sperimentali. Il caso della Lupa Capitolina fusa in età medioevale, ma considerata da molti studiosi di età etrusca, ha evidenziato e reso di pubblico dominio le indagini sulle tecnologie dei grandi bronzi che oggi dovrebbero ormai accompagnare ogni serio studio storico-artistico in questo campo.After the important exhibitions of the S.Marco horses and the Riace Bronzes in the 70’s, the scientific researches on the working techniques of large bronzes of the classical Antiquity became a great acceleration. The results of these studies have revealed that both style and casting/finishing techniques evolutes from the archaic time to the Renaissance. Despite the never-ending and widespread commonplace diffused by archaeologists and historians of art, that lost-wax casting techniques remained unchanged from the antiquity till today, these recent studies have also pointed out the close connection between technological and artistic innovations. It was possible to establish that the world of the artisans and material executors of the bronze statues was identical with that of the artists who created the original models. The possibility to date a big bronze on the basis of technological characteristics represents a direct effect of the development of these studies. The case of the Lupa Capitolina, considered by almost all archaeologists as an etruscan work, and recently unmasked as a medieval bronze, has revealed to the large public the researches on ancient techniques which should accompany today all historic artistic studies in this field

Same cycle shift from IVF with own oocytes to oocyte donation in no or poor response cycles

Our In-Vitro Fertilisation Centre is situated in a large developing country, Madagascar, with very bad roads and low income patients. Therefore we try to find ways to reduce as much as possible the number of attempts to obtain a pregnancy. Poor or no response to ovarian stimulation in In Vitro Fertilization (IVF) cycles is a great challenge. Here we describe a method whereby we shift from IVF to Oocyte Donation (OD) during the same cycle for patients whose ovaries do not respond properly to ovulation stimulation. Patients were superovulated with a long protocol agonist treatment and ultrasonically monitored for IVF/ICSI. When, at half way of the stimulation, it was clear that there was a no or poor response, gonadotropin administration was stopped and immediately replaced by estrogens; when the endometrium was considered to be sufficiently receptive, some donated oocytes from our concomitant oocyte donation (OD) program were fertilized with the patient‘s husband sperm and progesterone was added to the patients‘ treatment. After 48 hours the resulting embryos were transferred. Five poor responders patients underwent the described procedure. Three conceived, one of which aborted at 9 weeks, while the other two are ongoing. These patients signed the consent form accepting the possibility to shift from IVF to OD during the same cycle and three clinical pregnancies were obtained. OD through this technique seems more acceptable by poor responders than planned OD. This is a preliminary report and to our knowledge it is the first report of such a method.Keywords: IVF, Poor responders, Oocyte donation, Same cycle, Shift, Conversio

Redox Regulation of β-Actin during Integrin-mediated Cell Adhesion

Redox sensitivity of actin toward an exogenous oxidative stress has recently been reported. We report here the first evidence of in vivo actin redox regulation by a physiological source of reactive oxygen species, specifically those species generated by integrin receptors during cell adhesion. Actin oxidation takes place via the formation of a mixed disulfide between cysteine 374 and glutathione; this modification is essential for spreading and for cytoskeleton organization. Impairment of actin glutathionylation, either through GSH depletion or expression of the C374A redox-insensitive mutant, greatly affects cell spreading and the formation of stress fibers, leading to inhibition of the disassembly of the actinomyosin complex. These data suggest that actin glutathionylation is essential for cell spreading and cytoskeleton organization and that it plays a key role in disassembly of actinomyosin complex during cell adhesion