Neurosensory Alterations in Retinopathy of Prematurity: A Window to Neurological Impairments Associated to Preterm Birth

Retinopathy of prematurity (ROP) is one of the main blinding diseases affecting preterm newborns and is classically considered a vascular disorder. The premature exposure to the extrauterine environment, which is hyperoxic in respect to the intrauterine environment, triggers a cascade of events leading to retinal ischemia which, in turn, makes the retina hypoxic thus setting off angiogenic processes. However, many children with a history of ROP show persistent vision impairment, and there is evidence of an association between ROP and neurosensory disabilities. This is not surprising given the strict relationship between neuronal function and an adequate blood supply. In the present work, we revised literature data evidencing to what extent ROP can be considered a neurodegenerative disease, also taking advantage from data obtained in preclinical models of ROP. The involvement of different retinal cell populations in triggering the neuronal damage in ROP was described along with the neurological outcomes associated to ROP. The situation of ROP in Italy was assessed as well

Books in Arabic Script

The chapter approaches the book in Arabic script as the indispensable means for the transmission of knowledge across Eurasia and Africa, within cultures and across cultural boundaries, since the seventh century ad. The state of research can be divided into manuscript and print studies, but there is not yet a history of the book in Arabic script that captures its plurilinear development for over fourteen hundred years. The chapter explores the conceptual and practical challenges that impede the integration of the book in Arabic script into book history at large and includes an extensive reference list that reflects its diversity. The final published version was slightly updated, and includes seven illustrations of six Qurans from the holdings of Columbia University Libraries, four manuscripts and two printed versions. Moreover, the illustrations are images of historical artifacts which are in the public domain - despite Wiley's copyright claim

Hysteresis Losses of Minor Loops vs. Temperature in MnZn Ferrite

This paper analyzes hysteresis losses of minor loops versus temperature in MnZn ferrite core. The study is carried out through an experimental analysis in the temperature range-32°C to +110° C. The most interesting result is a nonmonotonic behavior of losses versus temperature for minor loops defined between magnetic field relatively close around the zero value. Such a result is qualitatively explained on the basis of a competition between exchange energy and magnetic anisotropy. In more detail, the relationships between permeability and exchange energy as well as coercivity and magnetic anisotropy are discussed via recognized models

The hybridogenetic Rana (Pelophylax) esculenta complex studied in a molecular context

The study of hybridogenesis is expected to shed light on the role played by the so-called ‘asexual reproduction’ in vertebrate evolution, since hybridogenesis, gynogenesis and parthenogenesis are restricted to lower vertebrates. Hence, it seemed interesting to define the stage and time of germline differentiation in reproductively unstable organisms which, to accomplish functional gamete maturation, can change the normal approach to meiosis by means of unusual cytological steps, such as genome elimination and endoreduplication. The cytogenetic aspects of ‘asexual’ meiosis have already been thoroughly studied. At present, molecular investigations are in progress to characterise the single steps of germline differentiation in a hybridogenetic green frog system, and the results obtained so far can be considered promising, as shown in this work. Vasa, PL10 and Y-box homolog genes, first isolated in Rana (Pelophylax), are expressed during early phases of gametogenesis in R. (P.) ridibunda and R. (P.) lessonae (parental species), and R. (P.) esculenta (their natural hybrid), suggesting that gametogenesis, during the adult life, follows a unique genetic sequence in the two parental species as well as in hybridogenetic hybrids. Similar molecular investigations need to be carried out on larval stages prior to metamorphosis, when the genetic plasticity of gemline cells allows their commitment versus either the standard and/or hybridogenetic reproduction mode

Experimental Analysis of Shielding Performance in Rail-Launcher Environment

In this paper we develop an experimental analysis aimed at characterizing the shielding performance of shields operating in electromagnetic rail launchers. The experimental analysis is carried out for various shield configurations and different materials. In particular, cylindrical shell cylinders are adopted. The experiments are performed on a rail launcher prototype supplied by a high pulsed power device. Finally, we make some remarks on the measurement of the shielding effectiveness in such critical environments

Simple or complex bids in the day-ahead electricity market

The liberalization of the electricity market, already affirmed or in progress in many European and worldwide countries, has originated many technical debates over the definition of the market model that can be considered as optimal for electricity. In this context, one of the most discussed issues is the mechanism for bid selection in the day-ahead energy market. On the one hand, the method used to define electricity price and accepted quantities must aim to simplicity and transparency, essential requirements to allow an adequate development and a constant monitoring of the market; on the other hand, it must consider the physical and security requirements of the electric system, translated into specific technical-economical constraints. The selection mechanism based on the so-called "simple bids”, used at present for example in the Italian Market, enables the producers to submit sale proposals containing only the indication of offered amount and requested price. In this case, the target of obtaining a production profile consistent with the technical performances of his own power plants, and economically profitable as well, is left to the bidding skill of each single generating company. Precise critics have been addressed to this methodology, because this mechanism does not take into account some technical aspects about generation units (max load gradient, technical minimum, etc.) or economical issues not directly expressed by the price-quantity curves (no-load costs, start-up costs, etc.). On the basis of these consideration (ref.[1]), some electricity markets, like the Spanish one, are providing for the possibility of producers to submit so-called “complex bids”, containing technical-economical specifications in addition to the indications provided by the simple price/quantity pairs. This paper proposes a quantitative approach to compare the economical and technical effects of simple and complex bids. By means of a market simulation tool, the possible impact of complex bids in the Italian electricity market has been estimated

High Power Lithium Batteries Usage in Hybrid Vehicles

Hybrid vehicles require an energy storage device capable of delivering or absorbing high specific powers (powers per unit of the device size), and still, in some cases, adequate levels of specific energy. The paper shows that high power Lithium Batteries already on the market are able to fulfil this task satisfactorily, by means of experimental tests, whose results are shown and discussed. The results show that very high power lithium batteries can be used in hybrid vehicles as the sole energy storage device, thus avoiding the complexity of composite (e.g. battery plus supercapacitor) storage systems

CARATTERIZZAZIONE DI ALTE CORRENTI IMPULSIVE E LORO DISTRIBUZIONE IN ARMATURE MULTISPAZZOLA

In questo articolo viene descritto un metodo per la misura della corrente in un lanciatore elettromagnetico (railgun) e della sua distribuzione tra le spazzole di un'armatura solida. Dalla misura del flusso concatenato è possibile ricavare le correnti nelle spazzole. Per la misura della corrente totale viene descritto un prototip di shunt realizzato presso i laboratori dell'Unità di Pisa. Le tecniche di misura descritte sono state sviluppate sulla base del metodo delle induttanze parziali