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Enabling easy access to Grid storage services and digital repositories
No full textCurrently, storage services provided by Grid infrastructures have been mostly used by IT-experts scientists, managers, and researchers due to the their underlying complexities such as protocols, access mechanisms, and user unfriendly interfaces, often based on command line tools. In particular, one of the biggest obstacles that has until now prevented a large uptake of Grid infrastructures by large and diverse worldwide Virtual Research Communities is the Public Key Infrastructure (PKI) on which the Grid Security Infrastructure (GSI) is based. This knowledge is indeed needed for the authentication and the management of X.509 certificates, a mandatory requirement to get access to distributed storage services.
We propose a novel data management architecture, exploiting SAML based authentication, credential delegation, WebDAV and HTTP-standard redirections. This allows users to make use of their institutional credentials to authenticate and provide access to Grid data storage from Web applications, mobile, desktop and built-in clients of popular operating systems. On top of this service, we were able to design a digital asset management system, that promises to simplify the creation, management and access to large scale e- infrastructure based digital repositories aiming at permitting scientists, researchers, students to fully exploit them through tools they use everyday such as Web apps, portals and native mobile apps
Evidence of Nuclear Rainbow in the 16O + 27Al elastic scattering @ 280 MeV
No full textIn the present work the 16O + 27Al elastic scattering at 280 MeV incident energy is investigated. This study is inserted in the research line aiming at the investigation of the nuclear rainbow in the scattering process involving heavy nuclei. Nuclear rainbow is a peculiar phenomenon which reveals the nuclear interaction at small distances, where the projectile and target density overlaps can reach values up to twice the nuclear matter saturation value. The rainbow features were thought to be very unlikely for systems
heavier than 16O + 16O because of the strong absorption, always present in heavy-ion collisions, which tends to hide the refractive component of the scattering process, responsible for the rainbow phenomenon.
The experiment was performed at the Catania LNS-INFN laboratory using a 280 MeV energy 16O Cyclotron beam impinging on a 109 ug/cm2 thick 27Al target. The ejectiles were momentum analysed by the MAGNEX large acceptance magnetic spectrometer and detected by its Focal Plane Detector. In order to obtain wide elastic and inelastic angular distributions, five different angular settings were chosen, which covered a whole angular range from about 5° to about 40° in the laboratory reference frame. 27Al excitation energy spectra up to 85 MeV were extracted, showing the population of the ground state and low-lying excited states of the residual nucleus. In addition, the spectra measured at forward angles showed the
population of large structures in a narrow angular range at relatively-high excitation energy, corresponding to the excitation of collective modes of the target nucleus, i.e. Monopole and Quadrupole Giant Resonances. Then, elastic and inelastic cross section angular distributions were constructed for each angular setting.
A model independent data analysis was performed. The total elastic 16O + 27Al angular distribution was fitted using exponential functions in three different angular ranges. This procedure made it possible to better appreciate the systematic deviation of the data with respect to the rapid exponential decrease expected for a strong absorptive system. The rise of the cross section observed at the largest scattering angles is the evidence of a well developed nuclear rainbow structure for the investigated system. The elastic and inelastic angular distributions were then compared with a new generation of parameter-free calculations based on the Coupled Channel (CC) formalism, using the Sao Paulo potential (SPP). The calculations were performed with the computer code FRESCO. A good agreement with the data was obtained using a reduced real component of the nucleus-nucleus potential and adopting the weak coupling model. In such a model, the 27Al ground state and the first low lying excited states (1/2+ , 3/2+ , 5/2+ , 7/2+ , 9/2+) were described as a 1d5/2 proton hole coupled with the 28Si 0+ ground state and 2+ (1.779 MeV) excited state, respectively. The effect of the inclusion in the calculation of other 28Si excited states was also investigated in a preliminary way
Biological activity and regulation of cyclic lipopeptide production in Pseudomonas corrugata and Pseudomonas mediterranea
No full textPseudomonas corrugata and P. mediterranea, are two closely related bacteria both causal agents of tomato pith necrosis and recently evaluated as biocontrol agents and producers of industrially-promising biomolecules. The interest of our work focused on cyclic lipopeptides (CLPs) that are surface active molecules with antibacterial, antifungal and cytotoxic properties. P. corrugata is known to produce two kinds of cyclic lipopeptides, corpeptins and cormycin A. Investigations on P. corrugata strain CFBP5454 quorum sensing (QS) system helped to postulate its role on virulence mechanism mediated by CLPs during detrimental interaction with tomato plants. On the contrary no information was available on P. mediterranea/tomato molecular interaction. Both species are able to induce on tomato undistinguishable symptoms thus we thoughts that they likely share common virulence mechanisms. Starting from these premises we demonstrated that P. mediterranea CFBP 5447 harbours one system designated PmeI/R that is highly homologous to the PcoI/R system of P. corrugata and that virulence on tomatoes is affected by inactivation of QS genes in both species although with some differences. A LuxR regulator RfiA encoded by rfiA cotranscribed both with pcoI and pmeI was also demonstrated to be pivotal for virulence. The MALDI-TOF MS spectra of bacterial cell-free culture filtrates showed that P. corrugata CFBP5454 produces both corpeptins and cormycin and for the first time these CLPs were also found in a P. mediterranea strain which spectrum also showed a putatively unidentified bioactive compound. Mutational analysis revealed that P. mediterranea CFBP 5447 PmeI- and PmeR-, P. corrugata CFBP 5454 PcoR- and both RfiA-, were impaired in CLP production but also showed a drastic reduction of virulence when inoculated in tomato plants demonstrating their pivotal role. These results also evidence that the QS is involved in CLP production and all the correlated phenotypes (colony morphology, biosurfactant activity) via the RfiA transcriptional regulator.
In the P. corrugata CFBP 5454 cosmid insert sequence from which the AHL QS genes were identified we describes three genes crpC, crpD, crpE. Bioinformatics and mutational analysis of crpC and crpDE demonstrated they are involved in the production and secretion of corpeptins since the derivative mutant strain cell-free culture filtrates showed only the peaks of cormycin in their MALDI-TOF MS spectra. Moreover, pathogenicity tests revealed that these long chain CLPs are important for P. corrugata virulence. Using real-time PCR we also ascertained that the regulators PcoR and RfiA are involved in corpeptins production/secretion.
P. corrugata CFBP 5454 and P. mediterranea CFBP5447 produced in vitro diffusible compounds with antimicrobial properties which inhibited the growth of plant pathogenic fungi and bacteria, as well as antifungal volatile compounds. Antagonistic activity of QS mutants didn t different from that of their respective parent strains whereas antifungal activity was completely abolished in the rfiA- mutants. Since both the pcoR- (and pmeR-) and rfiA- mutants did not produce CLPs the production of one or more additional antimicrobial compound is suggested. In vivo experiment showed the good biocontrol activity of P. corrugata CFBP 5454 but also that the QS and rfiA mutants are still able to reduce the disease incidence in the in vivo investigated pathosystems. P. corrugata CFBP 5454 draft genome sequence helped in identifying a biosynthetic cluster hcnABC coding for the enzyme HCN synthase involved in this volatile compound biosynthesis. P. corrugata hcnA and hcnC knockout mutants failed to produce HCN and showed a reduced antimicrobial activity against Botrytis cinerea. Cyanogenesis seems to be not regulated either by AHL-QS or by RfiA because mutants still retained the ability to produce HCN
Graphene and related materials: from "scotch tape" to advanced production methods.
No full textThe main topic of this thesis is the synthesis and characterization of carbon-based nanomaterials. In particular, during the first year of my PhD, I focused my attention on the synthesis of graphene, a carbon-based nanomaterial arranged in a two-dimensional (2D) crystal structure. The main purpose of the study was to optimize the method of synthesis of graphene, using the Scotch-tape technique, to obtain greater amounts of graphene compared to samples consisting of several layers. Although this technique leads to high quality graphene sheets, it is not the suitable approach to obtain a gram-scale production of graphene for its employment in nanoelectronics. During the second year, my studies focused on the synthesis and characterization of graphene-based nanomaterials. In particular, I have dealt with graphene nanowalls (GNWs), which consist of few graphene layers vertically oriented on a suitable substrate. These materials have attracted the interest of many researchers due to their potential applications as cathode materials for field emission devices. The last year of my PhD, I studied the effects of ablation of a graphite target either with a nanosecond or a femtosecond laser, in liquids. It was found that the laser ablation of graphite can lead to the synthesis of large graphene domains employing the nanosecond laser, while the use of a femtosecond laser produces large amounts of porous graphene sheets, that are recovered at the water-air interface and the graphene quantum dots that are dispersed in the liquid
Imunohistochemical profile of the neuroblasts of the peripheral sympathetic nervous system and human neuroblastoma of childhood
No full textABSTRACT
I focused on the analysis of a protein involved in the development of the peripheral nervous system: the Wilms tumor1 (WT1).
My thesis is divided into two experimental phases: I) spatio-temporal distribution of WT1 during human embryonic development, II) expression and functional roles of WT1 during development of the peripheral sympathetic nervous system and gastrointestinal tract.
The Wilms tumor (WT1) gene and its protein product are known to exhibit a dynamic expression profile during development and in the adult organism. Apart from a nuclear expression observed in the urogenital system, its precise localization in other developing human tissues is still largely unknown. Accordingly, the aim of this study was to investigate immunohistochemically the temporal and spatial distribution of WT1 in epithelial and mesenchymal developing human tissues from gestational weeks 7 24. For this purpose we used antibodies against the N-terminal of WT1. As might be expected, WT1 nuclear expression was observed in mesonephric/metanephric glomeruli, metanephric blastema, celomderived membranes (pleura, peritoneum, serosal surfaces) and sex cords. With regard to mesenchymal tissues, a similar nuclear staining was also obtained in the mesenchyme surrounding Müllerian and Wolffian ducts, as well as in the submesothelial mesenchymal cells of all celomatic-derived membranes. The most striking finding was the detection of strong WT1 cytoplasmic immunostaining in developing skeletal and cardiac muscle cells and endothelial cells. The tissue-specific expression of WT1, together with its different nuclear/cytoplasmic localization, both suggest that WT1 protein may have shuttling properties, acting as a protein with complex regulator activity in transcriptional/translation processes during human ontogenesis. The reported cytoplasmic expression of WT1 in human rhabdomyosarcomas and in many vascular tumors strongly suggests an oncofetal expression of this protein. Although not specific, WT1 cytoplasmic expression can be used as a marker of skeletal muscle and endothelial differentiation in an appropriate morphological context. Developmental expression of Wilms tumor gene (WT1) and protein is crucial for cell proliferation, apoptosis, differentiation and cytoskeletal architecture regulation. More recently, it has been suggested a potential role of WT1 in the development of neural tissue and in neurodegenerative disorders. We have investigated immunohistochemically the developmentally regulated expression and distribution of WT1 in human fetal (from the 8th to the 28th week gestational age) peripheral sympathetic nervous system (PSNS) and gastro-enteric nervous system (GENS). Interestingly WT1 expression was restricted to the cytoplasm of sympathetic neuroblasts, while it progressively disappeared with advancing morphologic differentiation of these cells along both ganglionic and chromaffin cell lineages. In adult tissues, both ganglion and chromaffin cells lacked any WT1 expression. These findings show that WT1 is a reliable marker of human sympathetic neuroblasts, which can be used routinely in formalin-fixed, paraffin-embedded tissues. The progressive loss of WT1 in both ganglion and chromaffin cells, suggests its potential repressor role of differentiation in a precise temporal window during human PSNS and GENS development
La disciplina concorsuale dei finanziamenti dei soci
No full textCon la Riforma del 2003 e l introduzione dell art. 2467 c.c., il legislatore italiano ha disciplinato per la prima volta il fenomeno dei finanziamenti dei soci alla società sottocapitalizzata.
La norma non brilla per chiarezza e ha dato luogo a più di una questione interpretativa, come quella riguardante l esatto significato da attribuire alle nozioni di eccessivo indebitamento e di ragionevolezza del conferimento , che costituiscono il presupposto per l applicazione della disciplina dettata dal primo comma.
Pur collocato nell ambito della disciplina della s.r.l., l art. 2467 c.c. detta una regola destinata a trovare applicazione principalmente - se non esclusivamente - nelle procedure concorsuali, come reso evidente dallo stesso primo comma, che circoscrive espressamente l obbligo restitutorio del socio alla sola ipotesi di fallimento. Né può essere ignorato il suggerimento in tal senso proveniente dall osservazione degli ordinamenti stranieri, ove la corrispondente disciplina - assai più completa e dettagliata di quella italiana - è collocata nelle legislazioni concorsuali.
Ciò nondimeno, né l art. 2467 c.c., né le disposizioni fallimentari indicano in che modo la postergazione del credito del socio finanziatore debba concretamente operare, soprattutto nelle procedure di composizione negoziale della crisi d impresa. Lo statuto concorsuale dei soci finanziatori, pertanto, va ricostruito in via interpretativa, tenendo conto, da un lato, dello scopo e della funzione delle regole cristallizzate negli artt. 2467 e 2497-quinquies c.c., dall altro lato, delle soluzioni normative adottate nelle corrispondenti discipline straniere: ciò che costituirà oggetto specifico della presente trattazione.
L applicazione dell art. 2467 c.c. alla procedura di concordato preventivo ha sollevato numerose questioni interpretative in merito al trattamento riservabile alla peculiare categoria di creditori costituita dai soci finanziatori postergati. In particolare: se la società beneficiaria dei finanziamenti anomali possa proporre un concordato che includa anche i soci finanziatori; se il piano possa prevederne un (parziale) soddisfacimento, non potendo prescindere questa valutazione da una corretta interpretazione della c.d. absolute priority rule e del divieto di alterazione dell ordine delle cause legittime di prelazione. Ancora, se i soci finanziatori siano ammessi al voto e se la loro inclusione nel piano rappresenti un ipotesi di classamento obbligatorio.
Problemi analoghi a quelli dianzi illustrati sorgono anche con riferimento al concordato fallimentare, sicché le conclusioni eventualmente raggiunte per il concordato preventivo potrebbero essere estese anche a tale diversa fattispecie, sia pure con la dovuta cautela imposta dalle sostanziali differenze tra i due tipi di concordato.
Nel fallimento, la rigida graduazione dei crediti imposta dall art. 111 l. fall. consente di individuare più facilmente il trattamento dei creditori postergati ex art. 2467 c.c., cui è generalmente riconosciuto il rango di subchirografari, salvo che non si tratti di crediti che beneficiano della prededucibilità riconosciuta dagli artt. 182-quater e 182-quinquies l. fall. Ciò nondimeno, residua qualche incertezza sulla operatività della compensazione per i crediti postergati. Inoltre, spinosi problemi di coordinamento riguardano il rapporto tra la fattispecie restitutoria prevista dall art. 2467, comma 1°, c.c. e il sistema delle revocatorie
Il potere di autotutela delle Istituzioni europee e i riflessi sull ordinamento interno
No full textIl lavoro si propone di esaminare il potere di autotutela delle Istituzioni europee e i riflessi del diritto comunitario sulla configurazione di tale potere nell'ordinamento interno
Methods of fast Fourier transform in diffraction problems of elastic and acoustic waves
No full textThe activity is connected with a development of modern fast computational methods applied to problems in wave dynamics, acoustics, and boundary-value problems of mechanics with mixed boundary conditions. This includes:
1) Development of fast methods for integral equations with convolution kernels arising in these fields of application. Such integral equations, after discretization, may be reduced to linear algebraic systems with matrix of Toepliz or circulant form. For both the types there can be applied fast iteration methods founded on Conjugate Gradient method with a preconditioning. This leads to a quasi-linear numerical algorithm.
2) Applications are constructed in crack mechanics. Two problems are studied with their mechanical conclusions: (i) Diffraction of a planar acoustic wave by a planar crack in the classical linear elastic isotropic space; (ii) static problem for linear cracks in the non-classical porous material of a Cowin-Nunziato type.
3) In the case when the diffraction is happen by a general-form object whose shape is neither linear nor circular, the problem can be reduced to an integral equation with a general-form kernel. There is developed a new approach, which permits an iteration scheme with a convolution kernel at each iteration. This admits again a quasi-linear numerical algorithm.
4) The same idea is applicable to wave processes with obstacles which represent an arbitrary set of linear rigid screen of finite length. The iteration process is proposed, when at each iteration step one needs only solution of the problem for every isolated single screen. All equations in this case are of convolution type, and they are reduced again to Toepliz-like matrix equations in a discrete form
ES cells: Analysis of neural differentiation controlling pathways.
No full textSystematic, genome-wide interrogations have identified hundreds of genes, including several transcription factors, which have expression patterns tightly correlated with ES cell differentiation.
OCT4, SOX2 and NANOG constitute a triad of transcription factors, identified as crucial for the maintenance of ES cells self-renewal and pluripotent state.The principal aim of our project was to induce the differentiation process of embryo-derived stem cells into neural cells (neurons, glial cells), to follow during the differentiation process the changing in the expression of characteristic stemness markers (OCT4, SOX2 and NANOG) responsible for the regulatory networks involved in embryo-derived stem cells pluripotency, whose understanding is fundamental for any potential therapeutic application.
For this reason the use of advanced spectroscopic techniques, such as time-resolved fluorescence correlation spectroscopy (FCS), could allow to follow protein changes and to analyze different aspects such as the molecular dynamics and intracellular translocation of some selected transcription factors tightly bound to the activation of the ESCs differentiation processes into neural cells. Our Results show that the pluripotency circuit is known to act as a unit that strongly represses lineage specific gene expression in ESCs. However, rather than being a monolithic entity, the pluripotency circuit components have lineage specific roles, so that the same proteins can also be used for lineage selection
La tutela del superiore interesse del minore vittima di sottrazione internazionale
No full textLa tutela internazionale del fanciullo è un settore cruciale del diritto in quanto coinvolge il trattamento di un soggetto particolarmente vulnerabile e più esposto alla violazione dei diritti fondamentali. La sottrazione internazionale di minore ne è l esempio più significativo: la problematica dell affidamento della prole, soprattutto se caratterizzata da una connotazione di trans nazionalità, impone nuove sfide agli ordinamenti giuridici nazionali. Le frontiere diventano causa di violazione dei diritti fondamentali del bambino tutte le volte in cui un genitore decide di trasferire o trattenere il figlio lontano dal luogo di sua residenza abituale e dal genitore esercente il droit de garde. In questo caso, la reazione dell ordinamento giuridico nazionale appariva insufficiente, tanto che è intervenuta la normativa internazionale in chiave suppletiva regolando innanzitutto i problemi di diritto internazionale privato e processuale, con particolare riferimento alla vexata quaestio dei conflitti di giurisdizione e della legge applicabile per dirimere la controversia. Ma le soluzioni internazionalprivatistiche, se da una parte appaiono necessarie per incardinare legittimamente un procedimento che abbia ad oggetto l affidamento conteso della prole, dall altro sono insufficienti per tutelare la posizione del minore. Per questa ragione oggi non si può non parlare di normativa avente ad oggetto la protezione del fanciullo sottratto, senza riferirsi al principio del best interests of child e, più specificatamente, alla tutela dei diritti fondamentali della vittima del legal kidnappin