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Decisions Dynamics in ICT systems: the influence of a context-aware and social approach on the multiple criteria decision making processes
No full textIn an Information and Communication Technology (ICT) system, information and knowledge have a key role in the development as well as in the evolution of processes. Due to the continuous improvement of the ICT, there are no limits on when, where and how each process has to take place. This condition, if on one hand permits that all the processes can be easily performed, on the other hand it increases the complexity level of each process itself. Furthermore the development of each process is much more complicated considering the concepts of social networking. In fact, taking into consideration the mechanism of social influence and social contagion as well as the capability and knowledge of each individual, the network node is affected, in a positive or in a negative way, not only by the other nodes of the network connected to it but also by its position and importance within the network.
Considering an ICT system, there are a lot of processes that can take place within a network. The main focus of my Ph. D. research activity has been to analyse the decision making process taking place in a social network and, in particular, the main features that influence the development of the process itself. In fact, due to events and objectives that an individual, the decision maker (DM), had to face and deal, it becomes necessary to take decisions. In an ICT system, each decision making process is characterised by four main features: dynamism, context-dependence, multiple criteria and social influence.
Dynamism expresses the continuous change of the characteristics of both environment and of the decision maker who has to perform the process at each time step. Context-dependence, instead, means the importance of the context, defined as the information that is necessary to describe the situation where a decision maker performs its processes. As expressed before and as a confirmation of the importance of a multiple criteria decision analysis, the paradigm of the decision making process is the evaluation of each alternative on the basis of a set of criteria. In this way the advantages and the drawbacks of each alternative are highlighted. Social influence has to be taken into consideration in the development of the decision making process, because the decision maker performs its process not alone but it is surrounded by other individuals that have a minor or a greater, a positive or a negative, influence on it, leading its decisions near or far from its initial inclination, as a results of social interactions among individuals. These four aspects have to be considered together with the personal features of each decision maker, like, for example, its psychological and psycophysical state.
Thus, considering the aspects previously introduced, this Ph. D. dissertation proposes a multiple criteria and context-aware decision making model being able to represent the decision making process of an individual in a social network. This model is able to represent the dynamics of decision taken by an individual within a social network, considering the variation of the context and the influence that the individual perceives from its neighborhood. The behaviour of each individual is represented by a set of parameters, whose variation influences the dynamics of decision within the social network.
Successively, applying the same perspective to the process of knowledge transfer and learning, it is possible to consider these processes as individual decision making process where each individual has to decide if accept or not knowledge from its neighboring nodes.
In the Ph. D. dissertation the concepts and the analytical instruments provided by the multiple criteria decision analysis (MCDA) are applied to social networks in order to represent as much as possible realistic decision making processes involving individuals that are parts of social networks in different contexts
Surface engineered nanostructured oxides as multifunctional materials for environmental and biomedical applications
No full textDurante i tre anni del dottorato di ricerca in Scienze dei Materiali e Nanotecnologie presso il dipartimento di Scienze Chimiche dell Università degli studi di Catania mi sono occupato della ingegnerizzazione di superfici di ossidi nanostrutturati, con opportune molecole funzionali, al fine di ottenere dei materiali ibridi multifunzionali capaci di poter essere utilizzati in vari ambiti tecnologici. L approccio utilizzato per ottenere dei sistemi di questo tipo è stato quello già noto del bottom-up ovvero l utilizzo di mattoni molecolari che si auto-assemblano per via di un meccanismo intrinseco di riconoscimento chimico. Nello specifico le molecole funzionali utilizzate sono state: miscele di acidi fosfonici, che si legano covalentemente alla superficie di ossidi metallici, e diversi tipi di cavitandi (sintetizzati ad hoc presso l università di Parma dal gruppo del Prof. Enrico Dalcanale) nonché stabilizzatori, marker e dyes.
Questo approccio ha permesso la realizzazione di sistemi in grado di essere utilizzati nei seguenti ambiti:
1) Rilevazione di composti organici volatili (VOC) su nanostrutture di ZnO
2) Purificazione di acqua inquinata mediante nanoparticelle di Fe3O4
3) Incremento nel trasporto di farmaci all interno di cellul
Per l'edizione critica di "In portineria" di Giovanni Verga. I manoscritti conservati presso il Fondo Verga dea Biblioteca Regionale Universitaria di Catania
No full textIn merito al tema della valorizzazione del patrimonio culturale presente negli Archivi e nelle Fondazioni del territorio siciliano, questo progetto studia i manoscritti teatrali di Giovanni Verga inerenti al dramma In portineria, acquisiti dalla Regione Siciliana e conservati in originale presso la Biblioteca Regionale Universitaria di Catania e in copia presso la Fondazione G. Verga , istituita nel 1978. Considerato pertanto il Teatro quale bene culturale immateriale , il punto naturale di arrivo di una rivalutazione complessiva di questo materiale è l edizione critica delle opere per il teatro, edizione che ambisce a confluire nel più ampio progetto dell Edizione Nazionale delle opere di Verga, promossa dalla Fondazione G. Verga .
Il dramma In portineria è uno dei testi più ricco di testimoni manoscritti, sebbene pervenutici in uno stato di disordine. La Biblioteca Regionale Universitaria di Catania possiede sei manoscritti autografi ma non integrali e tre copie di altra mano con correzioni d autore; tutti testimoni attendibili . La ricerca si è concentrata sull archivio dei documenti presenti presso la Biblioteca Regionale Universitaria di Catania e, in copia, presso la Fondazione G. Verga . Condizione preliminare è stata la conoscenza della tradizione di ogni singolo testo oggetto della ricerca al fine di individuare nell immediato i termini concreti delle problematiche relative ai manoscritti da esaminare e di tracciare un piano specifico per poterle affrontare. Seguendo questa metodologia è possibile stabilire il numero e le caratteristiche dei differenti stati redazionali, la loro rappresentanza nella tradizione superstite, il loro valore di testimoni in direzione e della restituzione del testo e di una storia dell elaborazione testuale sub specie philologica
Contrôles distincts de la plasticité synaptique de l'hippocampe et de la mémoire par différentes populations de récepteurs CB1
No full textThe endocannabinoid system is a major brain modulatory system that controls memory and learning mainly via the cannabinoid receptor type 1 (CB1)-dependent regulation of neuronal and glial activity. In the hippocampus, bidirectional communication between neurons and astrocytes shapes synaptic plasticity and behavior. CB1 receptors have been shown to be present in the astrocytes and to mediate the disruptive effects of cannabinoids in synaptic plasticity and working memory. Yet, it is not currently known the role of this receptor in the physiological modulation of memory processes. Also, previous studies have shown that CB1 receptors expressed in dopamine D1 receptor-expressing cells are involved in the modulation of hippocampal-dependent aversive memories. However, their involvement in the modulation of non-aversive long-term memory formation and synaptic plasticity is presently unknown. In this thesis, I aimed at identifying the cellular and molecular mechanisms by which specific CB1 receptors in distinct brain neuronal and glial populations contribute to the physiological modulation of synaptic plasticity and learning and memory. For this aim we used conditional genetic mutant mice lacking CB1 receptors specifically in astrocytes or in D1-positive cells. By coupling these genetic mouse models with behavioral, pharmacological, and in vitro and in vivo electrophysiological approaches, we dissected the role of these CB1 receptors in the formation of memory. First, we show that astroglial CB1 receptors in the hippocampus control long-term potentiation (LTP) of CA3-CA1 synaptic transmission and long-term recognition memory. By allowing physiological availability of D-serine at NMDA receptors via gliotransmission, astrocytes are important elements controlling glia-neuron interactions that underlie synaptic plasticity and memory functions. The data show that astroglial CB1 receptors control plasticity and memory by regulating the synaptic availability of D-serine at NMDA receptors. Second, we show that CB1 receptors D1-positive cells control the consolidation, but not acquisition, of new memories and the enhancement of LTP induced by learning, showing that specific subpopulations CB1 receptor-expressing cells differentially modulate these processes.
Overall, by showing that the endocannabinoid system in astrocytes is an important modulator of learning and memory and by suggesting that CB1 receptors in D1-positive cells are important for specific components of memory formation, we provide functional evidence for the complex cell type-dependent regulation of long-term recognition memory by the CB1 receptors
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No full textIntroduction:One of the most common complications of the use of foreign material, both in reconstructive and cosmetic breast surgery, which often leads to re-intervention, is capsular contracture. It consists in pathological hardening of the fibrous shell developing around a breast prosthesis.The development of connective tissue around any foreign body is physiological, but progression into a thick and firm capsule, as around breast implants, is responsible for varying degrees of local inflammation, dislocation, and deformation of the prosthesis.
Infection, hematoma, and granulomatous response to free silicone, as well as many other conditions, have been considered possible causes of capsules formation and pathological progression around some breast implants.
the goal of the present thesis is to investigate the effects of omega-3 supplements on capsule contraction, evaluating the thickness, and tgfb expression on sample of capsule collected in a rat living model.
Materials and Methods:32 Wild-type C57BL/6 knockout mice were bred and maintained in a university vivarium.The animals were divided in two groups: Omega3/control. Mice were operated on at 8 weeks of age and following implant surgery.After 12 weeks, mice were euthanized using a carbon dioxide inhalation and implant and all tissues surrounding implants were harvested in one piece.Histology (Capsular Thickness) and PCR Analysis (tgfb2/COL1A2) were performed to evaluate the grade of fibrosis.
Results.:Capsular thickness and tgfb2/COL1A2 gene expression were significantly lower in treatment group.
Discussion:This study s results suggest that Omega 3 supplement seems to be effective in reducing capsular formation occurrence.
The main role in Omega 3 fatty acids in inflammation and fibrosis reduction around the implant is their inhibition of TGF-B pathway and thus impairment of collagen deposit.
We believe that omega 3 supplement is a simple and promising method that could be used to prevent capsular contracture after silicone implant surgery.
This therapy could have a high impact considering the number of patients who every year undergoes to breast reconstruction or to aesthetic mammoplasty.
Furthermore Omega fatty acids 3 are dietary supplement with minimal side effects, normally used worldwide for multiple purposes.
Nevertheless, further clinical studies are warranted to examine their therapeutic applicability and additional studies should be conducted to attempt a decrease in capsular contracture occurrence
Hybrid human-machine vision systems for automated object segmentation and categorization
No full textEmulating human perception is a foundational component in the research towards artificial intelligence (AI). Computer vision, in particular, is now one of the most active and fastest growing research topics in AI, and its field of practical applications range from video-survaillance to robotics to ecological monitoring. However, in spite of all the recent progress, humans still greatly outperform machines in most visual tasks, and even competitive artificial models require thousands of examples to learn concepts that children learn easily. Hence, given the objective difficulty in emulating the human visual system, the question that we intended to investigate in this thesis is in which ways humans can support the advancement of computer vision techniques. More precisely, we investigated how the synergy between human vision expertise and automated methods can be shifted from a top-down paradigm where direct user action or human perception principles explicitly guide the software component to a bottom-up paradigm, where instead of trying to copy the way our mind works, we exploit the by-product (i.e. some kind of measured feedback) of its workings to extract information on how visual tasks are performed. Starting from a purely top-down approach, where a fully-automated video object segmentation algorithm is extended to encode and include principles of human perceptual organization, we moved to interactive methods, where the same task is performed involving
humans in the loop by means of gamification and eye-gaze analysis strategies, in a progressively increasing bottom-up fashion. Lastly, we pushed this trend to the limit by investigating brain-driven image classification approaches, where brain signals were used to extract compact representation of image contents. Performance evaluation of the tested approaches shows that involving people in automated vision methods can enhance their accuracy. Our experiments, carried out at different degrees of awareness and control of the generated human feedback, show that top-down approaches may achieve a better accuracy than bottom-up ones, at the cost of higher user interaction time and effort. As for our most ambitious objective, the purely bottom-up image classification system from brain pattern analysis, we were able to outperform the current state of the art with a method trained to extract brain-inspired visual content descriptors, thus removing the need of undergoing EEG recording for unseen images
Localized Surface Plasmon Resonance: Nanoscale Sensing for Processes at Interfaces
No full textThis PhD thesis reports the use the emerging surface-sensitive optical technique of localized surface plasmon resonance (LSPR) to characterize the interaction of relevant classes of biomolecules, e.g. peptides, proteins, lipids and DNA strands, at solid-liquid interfaces, with an emphasis on deciphering kinetics and pathways of dynamic adsorption processes.
LSPR-based biosensor exploits the high sensitivity of the plasmon frequency to refractive index changes confined to 5-30 nanometers around the metal nanoparticles deposited on the sensor surface to monitor in situ and in real time the interaction of unlabeled biological molecules skipping the misleading contribution from the bulk of solution affecting conventional optical technique, e.g. SPR and OWLS.
In the present dissertation the advantages of applying this powerful technique are thoroughly demonstrated by investigating four case studies concerning relevant aspects for the biointerfaces science. The case of study 1 will involve the adsorption kinetics of single and binary solution of proteins onto model hydrophilic and hydrophobic surfaces. The analysis of the adsorption kinetics reveals that competitive adsorption occurs, at physiological pH 7.4 and relatively high ionic strength (NaCl 0.1 M), favoring the heavier protein (fibronectin, in our case), which is shown to adsorb faster and in larger amount than the lighter one (human serum albumin, in our case). The case of study 2 will discuss the DNA hybridization process for binary solutions of respectively perfectly matching (PM) and single base mismatching (MM) 93-mer ssDNA from KRAS codon 12, with a surface tethered probe complementary to the PM sequence. Sensitivity down to obtaining down to 10 nM and 13 nM, respectively for PM and MM were obtained, showing that the hybridization process occurs at a lower rate for MM with respect to PM target. The competitive hybridization was accounted for by an inhibition model, where the non-complementary sequences kinetically hinder the hybridization of the perfect matching sequences, owing to their above mentioned affinity constant differences for the same probe. The case of study 3 will cover the kinetics of phospholipid vesicle adsorption on silicon oxide surfaces as function of pH. Two different regimes have been observed for acidic and basic conditions. At low pH, vesicles adsorption showed one-step exponential kinetics. Moreover, no significantly variation of the adsorption rate was observed over the investigated pH range 3-6, suggesting the process is controlled by Van der Waals interactions and steric forces. At high pH, vesicles adsorb showing two-step kinetic. Furthermore, it was observed that the rate of the first step slows down linearly with the increasing of pH, suggesting that the process is primarily driven by vesicle-surface electrostatic repulsion. The case of study 4 will report preliminary results from the study of pH stimuli-responsive smart surfaces, formed by gold nanodisks array of an LSPR sensor chip decorated with Trichogin GA IV and two of its positively-charged analogs, i.e. Lipo-Lys and L20, in which four and eight Lysines positive charged residues have been introduced respectively. The surface-bound peptides exhibit reversible and rapid switching between conformations and can withstand several cycles of swelling and collapsing with no significant loss from the surfaces.
Overall, the results here reported demonstrated the great potential of LSPR technique as a unique tool to monitor specific and non-specific biomolecular interactions at interfaces in application fields ranging from biosensing to materials science
Giovanni Battista Quagliata (1603 ca.-1673). Un artista del barocco siciliano fra tardo caravaggismo e classicismo
No full textIl lavoro di ricerca ricostruisce l'itinerario biografico ed artistico di un pittore siciliano del Seicento, Giovanni Battista Quagliata, e parallellamente il contesto in cui egli ha operato attraverso svariati tipi di fonti
Film sottili organizzati in 3D su scala nanometrica per applicazioni in elettronica su plastica
No full textRiuscire a sviluppare processi che permettano di ottenere un elevato controllo sull organizzazione nanoscopica dei materiali, rappresenta una sfida di notevole interesse per la futura generazione di dispositivi elettronici. Le diverse possibili applicazioni, in cui le proprietà dei materiali e le prestazioni dei corrispondenti dispositivi migliorano in base all ordine interno del film attivo, richiedono un notevole controllo morfologico su scala nanometrica. Le prestazioni di dispositivi organici a eterogiunzione, per esempio, dipendono fortemente dalla morfologia dello strato fotoattivo, in termini di dimensione, densità dei domini e di interfacce tra i diversi componenti. Lo sviluppo di tali sistemi, quindi, non può prescindere dalla nano-ingegnerizzazione del film che li costituisce.
È stato mostrato come, sfruttando condizioni dinamiche fuori dall equilibrio, sia possibile ottenere strutture 3D con la morfologia desiderata. In particolare, partendo da sistemi con un elevato grado di ordine dei differenti componenti, in termini di spessore del film e di dimensioni dei domini, si riesce a modularne le proprietà optoelettroniche, controllando il processo di evoluzione del sistema verso una condizione di equilibrio termodinamico. Nel caso mostrato, tale approccio ha consentito di ottenere eterogiunzioni bulk a due componenti con un elevato controllo sia sulla morfologia nanoscopica, sia sulle proprietà optoelettroniche dello strato attivo.
È stato dimostrato, inoltre, come tale metodo risulti efficace anche in sistemi più complessi, costituiti da strutture di notevoli dimensioni, quali per esempio eterogiunzioni a base di CNTs. In tal caso, si è mostrata l importanza di riuscire a modulare l organizzazione delle strutture all interfaccia in una eterogiunzione P3HT-CNTs, al fine di ottimizzare i fenomeni che in essa avvengono. Si è dimostrato come tale scopo sia in egual misura perseguibile sfruttando sia l approccio covalente sia quello supramolecolare. In entrambi i casi, avere un controllo sul grado di funzionalizzazione della superficie dei CNTs consente di raggiungere il giusto compromesso tra proprietà optoelettroniche e solubilità.
Un elevato controllo sull organizzazione delle strutture all interfaccia e sui fenomeni che in essa avvengono permette, per esempio, di incrementare notevolmente le prestazioni dello strato attivo di dispositivi fotovoltaici ad eterogiunzione. Si è visto come, introducendo un terzo componente all interfaccia donatore/accettore, sia possibile ottimizzare quei parametri fotovoltaici che sono strettamente correlati alla morfologia dell eterogiunzione stessa. Anche in questo caso, un corretto design a livello molecolare è necessario per garantire un adeguata interazione tra i diversi componenti, indipendentemente dalla loro natura, sia essa organica o inorganica. È stato mostrato come migliorare l allineamento orbitalico consenta un notevole incremento del Voc e un ottimizzazione del trasferimento di carica, nonché della Jsc. Proprio la corrente può essere significativamente aumentata, sfruttando fenomeni di trasferimento di energia o di scattering di luce, rispettivamente per incrementare o localizzare la generazione di eccitoni. In quest ultimo caso, per esempio, ingegnerizzare l interfaccia mediante nanostrutture metalliche opportunamente funzionalizzate e aggregate, ha permesso di localizzare i fenomeni di scattering di luce nella regione di interesse, incrementando notevolmente l efficienza di dissociazione eccitonica. Così facendo è possibile ottimizzare significativamente la PCE anche di dispositivi su substrati plastici, che tipicamente presentano bassi valori di efficienza. Questi risultati rappresentano un grande potenziale per lo sviluppo delle OCSs, in quanto mostrano come la ricerca di nuovi materiali con migliori proprietà, debba necessariamente essere accompagnata da un adeguata ingegnerizzazione dello strato attivo che ottimizzi le prestazioni dei singoli componenti
Nella bottega della famiglia Napoli: codici e documenti dell Opera dei pupi di tradizione catanese
No full textQuesto lavoro si artivola in due parti. In una prima parte, partendo dallo stato dell arte del teatro di figura in Italia e all estero, ci si concentra sul teatro siciliano delle marionette per poi investigare la grammatica della messa in scena dell Opera dei pupi di area catanese, utile a mettere in rilievo le somiglianze e le differenze tra l Opera dei pupi tradizionale e quella che è nata dalle innovazioni dei giovani pupari. La seconda parte riguarda i codici figurativi relativi al mestiere dei Napoli: figurativo, performativo e sonoro. Il tutto è corredato da una ricca documentazione fotografica. Chiude questa parte un capitolo sull'archivio digitale. Lo studio delle tradizioni recitative, compositive e artistiche in cui si articola il magistero dei pupari Napoli ha come obiettivo il recupero di un frammento importante della cultura catanese, sul piano storico-antropologico, ma anche la proiezione internazionale di un mestiere riconosciuto già nel 2001 Patrimonio dell Umanità dall Unesco