10081 research outputs found
Sort by
From aldabra giant tortoises to humans: how diet and age influence gut microbiota structure and function across vertebrates
No full textThe gut microbiota plays a crucial role in host physiology by metabolizing dietary carbohydrates via carbohydrate-active enzymes (CAZymes) and producing short-chain fatty acids (SCFAs). This research explores microbiome dynamics across vertebrates, integrating studies on tortoises and humans. First, in Aldabra giant tortoises, wild populations harbor greater microbial diversity than captive individuals. Infant tortoises exhibit higher CAZyme gene diversity, particularly from Bacteroides cellulosilyticus, suggesting enhanced carbohydrate metabolism early in life. Second, a human dietary fiber intervention shows rapid increases in SCFA levels, particularly acetate and propionate, alongside delayed enrichment of Parabacteroides, a CAZyme-rich genus. Third, a comparative analysis of 35 vertebrate species reveals widespread conservation of CAZyme families and SCFA-producing taxa across reptiles, birds, and mammals, despite differences in host diet and phylogeny. These findings highlight the interplay between diet, age, and microbial function, demonstrating that while microbiome composition varies, core metabolic pathways remain evolutionarily conserved
Donor-acceptor thermally activated delayed fluorescence (TADF) chromophores: photocatalysis and photochemical mechanism
No full textThis thesis explores donor-acceptor-based TADF (Thermally Activated Delayed Fluorescence) compounds for their potential as photocatalysts (PCs), with a focus on chromophore design, photophysical and electrochemical properties, and photoreaction mechanisms. Chapter 1 outlines the fundamental characteristics of TADF, the key concepts essential for understanding TADF photocatalysis, and its fields of application. Chapter 2 investigates the photophysical properties of a TADF emitter, pDTCz-DPmS, developed by the Zysman-Colman group at the University of St. Andrews, UK. The study examines its photocatalytic role in a C-C bond-forming reaction, specifically the decarboxylative addition of protected proline to diethyl maleate. This research underscores the importance of comprehending reaction mechanisms to enhance and optimize efficiencies in diverse photocatalytic systems. Chapter 3 focuses on a carbazole-1,3-dicarbonitrile derivative obtained from the photoconversion of 3DPAFIPN. This compound, proven to be a TADF emitter, exhibits distinct photophysical properties and catalytic potential. It was applied in photoredox-mediated catalysis with a Co(II) species by the Cozzi group at the University of Bologna, Italy. The reaction mechanism is thoroughly analyzed in this thesis.
Chapter 4 examines the formation and consumption of radical anions of 4CzIPN under photoredox conditions. Misconceptions regarding the absorption and emission profiles of 4CzIPN˙⁻ are addressed, along with its assumed role in strong photoreduction reactions. Chapter 5 explores the applicability of donor-acceptor TADF emitters, initially developed for OLEDs, as photocatalysts in various reactions. Their unique redox and photophysical properties are discussed, with solvent choice playing a significant role in optimizing reaction yields. Chapter 6 introduces a new series of dicyanoarene-cored persulfurated chromophores. Their synthesis, photophysical and electrochemical characterization, and application in photocatalysis are examined. Structural modifications enhanced charge transfer properties, red-shifted emissions, and visible light absorption, showcasing the versatility of these chromophores. This comprehensive study provides valuable insights into the design and optimization of TADF emitters for advanced photocatalytic applications
The role of small and large extracellular vesicles in lymphoproliferative disorders: the “off the beaten truck” liquid biopsy
No full textExtracellular vesicles (EVs) are particles delimited by a lipid bilayer secreted by all cell types that play a critical role in intercellular communication. EVs are generally classified as small (S-; 50–200 nm) and large (L-; 0.2–10 µm) EVs based on size and biogenesis mechanisms. Distinctions between S- and L-EVs in terms of molecular cargo and functional effect on target cells has been described in various cancers including solid tumors and selected hematologic malignancies, highlighting EV heterogeneity as potential target to develop precision oncology tools. This thesis focuses on the characterization of S- and L-EVs in lymphoproliferative disorders such as Diffuse Large B-cell Lymphoma (DLBCL) and classic Hairy Cell Leukemia (HCL). A special focus on tumor-derived L-EVs is also addressed. In DLBCL, the most common non-Hodgkin lymphoma, RNA sequencing of EV RNA profiles revealed both similarities and differences in mRNA and miRNA content across EV subpopulations, suggesting a selective RNA enrichment within S- and L-EVs. Further deconvolution analysis identified diverse cellular origins for EV RNAs, linking EV mRNA content to the cell of origin, sometimes different according to EV subtype. In HCL, a rare lymphoproliferative B-cell disorder, EV analysis highlighted a distinct vesicle-type and tumor-associated phenotype in both S- and L-EVs. This unique signature was detected at the level of surface proteins (flow cytometry), lipid composition (liquid chromatography-mass spectrometry), and RNA cargo (RNA sequencing), suggesting EVs as potential minimally invasive tool for liquid biopsy biomarkers in rare malignancies. Together, these studies demonstrate EV diagnostic and prognostic potential within lymphoproliferative disorders in order to deepen our knowledge of the pathogenesis of these tumors. The unique profile of S- and L-EVs in cancer offers a significant promise for future liquid biopsy applications, supporting their role in precision oncology
Design, modelling and integration of renewable sources to foster wave energy exploitation and the Blue Growth.
No full textL’energia da onda potrebbe assumere un ruolo fondamentale per la transizione energetica durante i prossimi decenni, grazie alla sua continuità nel tempo molto superiore rispetto ad altre risorse rinnovabili e alla sua vasta distribuzione nello spazio. Tuttavia, l’energia da onda è ancora lontana dall’essere economicamente sostenibile, a causa di diverse problematiche tecnologiche e alle difficoltà finanziarie associate. In questa ricerca, si è innanzitutto affrontata una delle maggiori sfide tecniche, nello specifico la progettazione e modellazione di sistemi di ancoraggio per i dispositivi galleggianti, proponendo possibili soluzioni per la modellazione numerica di sistemi di ancoraggio complessi e per l’ottimizzazione dei dispositivi stessi. Successivamente sono state analizzate le possibili sinergie strategiche di installazioni per lo sfruttamento della energia da onda con altre risorse rinnovabili e la loro applicazione nel contesto di aree marine multiuso. In particolare, una metodologia per la valutazione della combinazione ottimale delle risorse rinnovabili è stata sviluppata e verificata in due diversi casi studio: un’isola e una piattaforma offshore. Si è così potuto evidenziare l’importante contributo della risorsa ondosa per la continuità energetica e per la riduzione della necessità di accumulo. Inoltre, è stato concepito un metodo di supporto decisionale multicriteriale per la valutazione delle opzioni di riuso delle piattaforme offshore alla fine della loro vita operativa, come alternativa al decommissionamento, nell’ottica di una gestione sostenibile e della ottimizzazione dell’uso dello spazio marino. Sulla base dei criteri selezionati, l’inclusione di attività innovative come la produzione di energia da onda si è dimostrata essere rilevante per rendere vantaggioso il riuso rispetto al decommissionamento. Numerosi studi recenti hanno infatti sottolineato che, nell’ambito della “crescita blu”, i mercati come l’oil&gas, le attività offshore e le isole stimoleranno lo sviluppo di tecnologie innovative come lo sfruttamento dell’energia da onda, promuovendo la sperimentazione e fornendo un importante contributo all’avanzamento tecnico e alla commercializzazione.The wave resource could play a fundamental role in the energy transition during the next decades, thanks to its greater continuity over time with respect to other renewable sources and to its wide spatial distribution. However, wave energy is still far from being economically feasible, due to several technical issues and to associated financial difficulties. In this work, one of the main technological challenges is firstly addressed, specifically the design and modelling of moorings for floating devices, proposing possible solutions for the numerical simulation of complex mooring systems and for the optimisation of the devices themselves. The possible strategic synergies of wave energy installations with other renewable energy sources and their application in the context of multiuse offshore areas are then analysed. In particular, a tool for the assessment of the optimal mixing of renewable energy sources is developed and tested in two different case studies: an island and an offshore platform. The important contribution of wave resource for the continuity of the energy supply and for the reduction of the storage needs is highlighted. Also, a decision-support multicriterial method is conceived for the evaluation of the reuse options of oil&gas platforms after the end of their operational phase, as an alternative to decommissioning, in the perspective of a sustainable management and optimisation of the marine space use. Based on the chosen criteria, the inclusion of innovative activities, as wave energy production, prove to be relevant to make reuse beneficial compared to decommissioning. After numerous recent studies, it is expected in fact that, in the framework of the Blue Growth, smaller markets like oil&gas, offshore activities and islands will boost the development of breakthrough technologies as the wave energy harvesting, promoting the testing and giving an important contribution towards the improvement of the technology and the commercialisation
Unveiling the molecular mechanism of BRCA2-RAD51 interaction to tackle cancer onset
No full textDifferent kinds of lesions can occur to DNA, and among them, one of the most dangerous is the double strand breaks (DSBs). Actually, DSBs can result in mutations, chromosome translocation or deletion. For this kind of lesions, depending on cell cycle phase as well as DNA-end resection, cells have developed specific repair pathways. Among these the error-free homologous recombination (HR) plays a crucial role. HR takes place during S/G2 phases, since the sister chromatids can be used as homologous templates. In this process, hRAD51 and BRCA2 are key players. hRAD51 is a recombinase of 339 amino-acids highly conserved through evolution which displays an intrinsic tendency to form oligomeric structures. BRCA2 is a very large protein of 3418 amino-acids, essential for the recruitment and accumulation of hRAD51 in the nucleus repairing-foci. BRCA2 interacts with hRAD51 through eight, so-called, BRC repeats, composed of 35-40 amino-acids. Mutations within this region have been linked to an increased risk of ovarian cancer development. In particular, several reports highlighted that missense mutations within one BRC repeat can hamper BRCA2 activity. Considering the close homology between the BRC repeats, it is striking how these mutations cannot be counterbalanced by the other non-mutated repeats preserving the function and the interactions of BRCA2 with hRAD51. To date the only interaction that has been structurally elucidated, is the one taking place amid the fourth BRC repeat and hRAD51. Only very little biophysical information is available on the interaction of the other BRC repeats with hRAD51. This thesis aims at elucidating the mechanism of hRAD51-BRCA2 interaction, by means of biophysical and structural approaches.Il nostro DNA è continuamente danneggiato da fattori endogeni ed esogeni. Ciò può determinare differenti tipologie di danno, tra le quali le rotture a doppio filamento sono considerabili come le più pericolose. Fortunatamente, le nostre cellule hanno sviluppato differenti strategie per riparare questi danni a seconda della fase del ciclo cellulare in cui si trovano. Tra questi meccanismi di riparazione del DNA un ruolo fondamentale è certamente giocato dalla cosiddetta ricombinazione omologa. Tale processo avviene nelle fasi S e G2 del ciclo cellulare e consente una riparazione del DNA molto accurata. In questo meccanismo di riparazione hRAD51 e BRCA2 sono due proteine fondamentali. hRAD51 è una recombinasi di 339 aminoacidi altamente conservata in diversi organismi, che possiede una tendenza intrinseca a formare strutture oligomeriche. BRCA2 è invece una proteina di notevoli dimensioni, 3418 aminoacidi, che è essenziale per il reclutamento e l’accumulo di hRAD51 nel nucleo. In particolare, si è dimostrato che BRCA2 interagisca con hRAD51 attraverso otto sequenze ripetute composte da 35-40 aminoacidi denominate “BRC-repeats”. Studi epidemiologici hanno evidenziato come le mutazioni all’interno di questa regione siano correlate ad un incremento del rischio di sviluppare cancro ovarico. Inoltre, è stato dimostrato come mutazioni che avvengono all’interno di una sola ripetizione BRC possano essere sufficienti a bloccare il reclutamento di hRAD51 e conseguentemente la ricombinazione omologa. Considerata l’alta omologia tra queste sequenze è sorprendente come tali mutazioni all’interno di una sola ripetizione BRC non possano essere controbilanciate dalle altre sette. Ad oggi, l’unica interazione che è stata caratterizzata dal punto di vista strutturale è quella che sussiste tra la quarta ripetizione BRC e hRAD51. Lo scopo di questa tesi è quello di studiare il meccanismo di interazione tra i “BRC repeats” e hRAD51 attraverso metodiche biofisiche e di biologia strutturale
Solid state micro and nanopore sensors for single entity detection
No full textA general description of the work presented in this thesis can be divided into three areas of interest: micropore fabrication, nanopore modification, and their applications. The first part of the thesis is related to the novel, reliable, cost-effective, potable, mass-productive, robust, and ease of use micropore flowcell that works based on the RPS technique. Based on our first goal, which was finding an alternate materials and processes that would shorten production times while lowering costs and improving signal quality, the polyimide film was used as a substrate to create precise pores by femtosecond laser, and the resulting current blockades of different sizes of the nanoparticles were recorded. Based on the results, the device can detecting nano-sized particles by changing the current level. The experimental and theoretical investigation, scanning electron microscopy, and focus ion beam were performed to explain the micropore's performance. The second goal was design and fabrication of a leak-free, easy-to-assemble, and portable polymethyl methacrylate flowcell for nanopore experiments. Here, ion current rectification was studied in our nanodevice. We showed a self-assembly-based, controllable, and monitorable in situ Poly(l-lysine)- g-poly(ethylene glycol) coating method under voltage-driven electrolyte flow and electrostatic interaction between nanopore walls and PLL backbones. Using designed nanopore flowcell and in situ monolayer PLL-g-PEG functionalized 20±4 nm SiN nanopores, we observed non-sticky α-1 anti-trypsin protein translocation. additionally, we could show the enhancement of translocation events through this non-sticky nanopore, and also, estimate the volume of the translocated protein. In this study, by comparing the AAT protein translocation results from functionalized and non-functionalized nanopore we demonstrated the 105 times dwell time reduction (31-0.59ms), 25% amplitude enhancement (0.24-0.3 nA), and 15 times event’s number increase (1-15events/s) after functionalization in 1×PBS at physiological pH. Also, the AAT protein volume was measured, close to the calculated AAT protein hydrodynamic volume and previous reports
Xenophanes' elegiac fragments: critical text and commentary
No full textLa tesi consiste in un saggio di edizione critica commentata dei frammenti pervenutici sotto il nome di Senofane di Colofone. Se la ricerca, negli ultimi anni, ha beneficiato di una raccolta aggiornata delle testimonianze su questo autore, per quanto concerne la sua produzione poetica un’acquisizione di tal sorta rimane tuttora un desideratum. A fronte dell’impossibilità di editare e commentare in maniera esaustiva tutte le testimonianze e i lacerti del corpus senofaneo (che, pur non molto numerosi, si caratterizzano per una vasta eterogeneità di problemi esegetici e critico-testuali), si sono privilegiati i frammenti elegiaci, forse il campo maggiormente bisognoso di indagini. L’elaborato si compone di tre sezioni principali. Nell’introduzione, dopo un inquadramento della dibattuta cronologia di Senofane e della sua variegata produzione poetica, si rivolge specifica attenzione a testimoni, forma, struttura, lingua e stile, metrica e prosodia dei frammenti elegiaci, allargando, ove possibile, l’indagine agli esametri stichici superstiti. Il testo critico dei lacerti sicuramente elegiaci, fondato su una rinnovata collazione dei testimoni (autoptica o su riproduzione digitale) e su un censimento il più possibile esaustivo dell’attività filologica dalle prime edizioni a stampa fino ai giorni nostri, è accompagnato da una traduzione di servizio e da un commento di carattere linguistico-filologico. Quattro appendici finali sono riservate ai frr. 21 G.-P. = 21 W., 13 G.-P. e 45 G.-P. = 41 W., che, pur non rubricabili con sicurezza fra i lacerti elegiaci, esibiscono con questi ultimi alcuni significativi punti di contatto.My thesis aims at providing a specimen of critical edition and commentary on the fragments attributed to Xenophanes of Colophon. While research has recently benefited from an up-to-date collection of the testimonies on this author, as far as his poetic production is concerned, such an acquisition still remains a desideratum. Faced with the impossibility of comprehensively editing and commenting on all Xenophanes’ testimonies and fragments (which, although not very numerous, present many exegetical and critical-textual challenges), in this study the elegiac fragments, perhaps the subject most in need of investigation, have been chosen for. This thesis consists of three parts. The introduction provides an outline of Xenophanes’ much debated chronology and his varied poetic production, with particular focus on the witnesses, form, structure, language and style, metrics and prosody of the elegiac fragments, extending the investigation to the surviving stichic hexameters where possible. The critical text is based on a renewed collation of the main witnesses and on a census of the philological activity from the earliest printed editions to the present day; it will be accompanied by an Italian translation and a linguistic-philological commentary. Four final appendices will be dedicated to frr. 21 G.-P. = 21 W., 13 G.-P. and 45 G.-P.2 = 41 W., which, though not strictly classifiable as elegiac fragments, share some key features with the latter
Data surveillance for infectious diseases: models, complex networks and machine learning
No full textIn this thesis, we investigate the role of applied physics in epidemiological surveillance through the application of mathematical models, network science and machine learning. The spread of a communicable disease depends on many biological, social, and health factors. The large
masses of data available make it possible, on the one hand, to monitor the evolution and spread of pathogenic organisms; on the other hand, to study the behavior of people, their opinions and habits. Presented here are three lines of research in which an attempt
was made to solve real epidemiological problems through data analysis and the use of statistical and mathematical models. In Chapter 1, we applied language-inspired Deep Learning models to transform influenza protein sequences into vectors encoding their information content. We then attempted to reconstruct the antigenic properties of different viral
strains using regression models and to identify the mutations responsible for vaccine escape. In Chapter 2, we constructed a compartmental model to describe the spread of a bacterium within a hospital ward. The model was informed and validated on time series of clinical measurements, and
a sensitivity analysis was used to assess the impact of different control measures. Finally (Chapter 3) we reconstructed the network of retweets among COVID-19 themed Twitter users in the early months of the SARS-CoV-2 pandemic. By means of community detection algorithms and centrality measures, we characterized users’ attention shifts in the network, showing that scientific communities, initially the most retweeted, lost influence over time to national political communities. In the Conclusion, we highlighted the importance of the work done in light
of the main contemporary challenges for epidemiological surveillance. In particular, we present reflections on the importance of nowcasting and forecasting, the relationship between data and scientific research, and the need to unite the different scales of epidemiological surveillance
The legal status of shareholders within banking corporations in the age of financial stability
No full textLa tesi si propone di attualizzare il dibattito degli anni Settanta tra Ferri e Visentini sulla posizione giuridica dell’azionista bancario alla luce della recente evoluzione del framework regolamentare e delle prassi di supervisione, nonché delle teorie della dottrina giuridica ed economica in materia di impresa bancaria. Il lavoro si concentra principalmente sulla disciplina relativa all’accesso al mercato bancario (tanto da parte delle imprese, quanto da parte dei partecipanti qualificati) e allo svolgimento fisiologico dell’attività bancaria, nonché sulle possibili intersezioni tra la disciplina prudenziale e altre normative speciali - altrettanto vincolistiche - che disciplinano le operazioni straordinarie che possono riguardare la banca. Si svolge quindi un’indagine sulla portata dell’attuale regolamentazione di settore per vagliarne la tenuta nell’ottica dell’azionista bancario, anche al fine di comprendere sino a che punto la tutela del risparmio e il perseguimento dell’interesse pubblico alla stabilità finanziaria possano giustificare una compressione o un indebolimento della tutela accordata agli azionisti in nome della specialità dell’impresa bancaria. Nella seconda parte del lavoro il richiamo ai principali approdi della letteratura economica sulle relazioni economiche esistenti tra la struttura degli assetti proprietari, la regolamentazione, la performance della banca e la stabilità del sistema finanziario è funzionale al tentativo di rintracciare ed evidenziare i tratti caratterizzanti del modello di azionista bancario in un’ottica attuale e prospettica.The thesis aims to modernise the 1970s Italian debate on the role and legal status of shareholders of banking corporations, in light of the evolution of the regulatory framework and the supervisory approach, as well as of the recent academic debate on the nature and the function of banking corporation. The paper focuses on the regulation regarding banking corporation in its viable phase of life, as well as on the potential jamming between the prudential regulation and other special regulations (equally constraining) regarding specific transactions that may involve a bank and its major shareholders. The analysis on the scope and the main features of the current banking regulation aims also to scrutinize its sustainability in the perspective of banking shareholder. In doing so, the thesis seeks to identify the boundaries up to which the protection of savings and the pursuit of the public interest in financial stability may justify a restriction of the protection accorded to banking shareholders in the name of the special regime applicable to banking corporations. In the second part of the thesis, the reference to the main landmarks of the economic literature on the relationships existing between bank’s ownership structures, regulation, level of performance and the stability of the financial system lies in the attempt to shed light, both in a current and a forward-looking perspective, on the key features of a theoretical model for banking shareholders
Digital technologies and human-machine interaction in air traffic control operations
No full textAs global air travel demand rises, airports must manage increasing traffic while maintaining safety standards. Current air traffic management (ATM) systems, particularly within control towers, have limitations that reduce situational awareness by diverting controllers' attention from critical out-of-window views. This research explores the potential of extended reality (XR) technologies to enhance air traffic control (ATC) by delivering spatially relevant information to controllers in real time. The integration of unmanned aerial systems (UAS) into shared airspace further complicates ATM, particularly in low-altitude operations around busy airports. Traditional ATM frameworks and UAS management systems often operate separately, creating risks in congested airspaces where manned and unmanned vehicles coexist. Addressing these challenges, this thesis investigates XR technologies to improve human-machine interfaces (HMI) in ATC, focusing on both tower operations and drone monitoring tasks. Two XR-based systems were developed. The first enhances situational awareness in traditional ATC by enabling controllers to maintain a head-up position through adaptive Augmented Reality (AR) overlays. It integrates multimodal interactions and attention guidance to improve efficiency and reaction times, especially in hazardous conditions. This system was validated through simulated scenarios at Bologna Guglielmo Marconi Airport. The second system facilitates the supervision of both manned and unmanned traffic by overlaying drone-related information and alert cues, allowing seamless monitoring without distracting from primary ATC tasks. This solution, experimentally validated at Toulouse-Blagnac Airport, demonstrated improved operational efficiency, reduced workload, and enhanced situational awareness, though some ergonomic challenges with XR hardware were noted. This thesis highlights the transformative potential of XR in ATC by optimizing controller efficiency and enhancing safety. Future research will focus on overcoming hardware limitations and conducting real-world trials to refine these solutions for practical implementation