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Integral operators and partial differential equations in Morrey type spaces
No full textLo scopo di questa tesi è lo studio della limitatezza di alcuni operatori integrali in spazi funzionali di tipo Morrey. Inoltre si studia la regolarità di soluzioni di equazioni differenziali alle derivate parziali
All'ombra del Vulcano. Il Futurismo in Sicilia & la Sicilia del Futurismo
No full textQuesto lavoro è nella sua prima parte, uno studio sul Futurismo in Sicilia che si focalizza in particolar modo su due riviste futuriste siciliane: «La Balza Futurista», la «prima rivista veramente futurista» a detta di Marinetti, stampata sorprendentemente a Ragusa nel 1915; «Haschisch», la rivista del futurfiumanesimo siciliano, fondata a Catania nel 1921, all indomani del Natale di Sangue, quel Natale che pone fine all esperienza fiumana. Nella sua seconda parte, questo studio sposta il proprio fuoco sulla Sicilia del Futurismo, vale a dire sulla Sicilia di Marinetti. Una Sicilia, che per Marinetti è fatta essenzialmente di un elemento, il più congeniale al suo temperamento, vale a dire il Vulcano: l Etna
Applications of CW and pulsed EPR spectroscopy for the characterization of copper(II) complex stereochemistry and of Beta-peptide secondary structure
No full textElectron Paramagnetic Resonance (EPR) is a spectroscopic technique, based on the magnetic resonance principles, that allows the characterization of systems containing unpaired electrons to achieve information on their chemical environment with high resolution. Considering the peculiar class of samples that can be investigated, nowadays, EPR spectroscopy finds applications in several areas of science. Thanks to the modern Site-Directed Spin Labelling (SDSL) approaches, it is possible to introduce spin labels into defined positions of a natural diamagnetic system making it detectable by EPR. This method has further extended the applications towards samples which are naturally EPR silent. The first part of the thesis offers an overview of the main theoretical key concepts required to understand the set-up and the outcomes of an EPR experiment. In the second part of the thesis CW-EPR spectroscopy is employing to characterize the geometries adopted in aqueous solution by some copper(II) complexes with important biological ligands. The study of biochemical processes, in fact, cannot be performed neglecting the inorganic biometals dissolved in biological fluids. These metal ions are involved in the cell biochemistry coordinated by several biomolecules forming metal complexes which are the real players with specific biological activities. The functions of these systems are strictly related with the arrangement of the ligands around the metal centre and with the overall geometry of the complex. The experimental results presented in this part of the thesis enable to develop a more detailed picture of these copper(II) species in solution in order to better clarify their structure-function relationships for further biochemical considerations about their role. Additionally, voltammetric measurements are performed on the same systems to support the spectroscopic data. In the third part of the thesis, the results of a project developed in the Electron Spin Resonance research group at the Max Planck Institute for Biophysical Chemistry (Göttingen Germany), under the supervision of Professor Marina Bennati, is presented. It is well-known that the structural characterization of membrane proteins in their natural environment is a challenging task. EPR spectroscopy in combination with SDSL approaches is emerging as a powerful biophysical tool to reveal biomolecular structural information at atomic resolution. In particular, Pulsed Electron Double Resonance (PELDOR) spectroscopy, called also Double Electron Electron Resonance (DEER), is a pulsed EPR method which enables to detect distances between two paramagnetic centres in a biological system in order to characterize its structure. Measuring the dipolar coupling between two unpaired electrons, PELDOR allows to probe their intramolecular distances with high resolution and reliability. In this project, CW-EPR and PELDOR/DEER spectroscopy are employed for the structural characterization of a transmembrane peptide in solution and in a lipid environment. The samples are prepared introducing two semi-rigid TOPP nitroxide spin labels into the peptide s backbone in order to make it detectable by EPR. The experimental results of this part of the thesis demonstrate the great potential of EPR spectroscopy in structural biology to characterize biomolecular structures and encourage the employment of TOPP spin label as useful tool for the EPR investigation of peptides foldamers in solution and in lipid bilayer
Phenotypic and transcriptional analysis of secondary metabolites production in Pseudomonas corrugata CFBP5454
No full textNatural products have received a great deal of attention as sustainable alternative for management of plant diseases. In this study the potential and actual arsenal of secondary antimicrobial metabolites of the bacterium Pseudomonas corrugata, an ubiquitous bacterium, was dissected by phenotypic assays, genome mining and transcriptional studies. Pseudomonas corrugata strain CFBP 5454 was shown to produce diffusible compounds that inhibit the growth of plant pathogenic fungi and bacteria and antifungal volatile compounds and to produce cyanide. Mutant derivatives in LuxR transcriptional regulators, i.e. P. corrugata GL2 (pcoR mutant) and GLRFIA (rfiA mutant) impaired in cyclic lipopeptide (CLP) production, showed a diffusible compound-mediated reduced activity, depending on the biocontrol strain, challenge microorganism and culture medium but clearly indicate the production of additional antimicrobial substances.
PcoR is the cognate receptor of the N-acyl-homoserine lactones, synthetised by PcoI in P. corrugata quorum sensing (QS) system. The QS system also directly activates the transcriptional regulator gene rfiA. In order to define the complete regulon of PcoR and RfiA, deep sequencing of cDNA library (RNA-seq) was used to analyse the whole transcriptomes of GL2 (pcoR-) and GLRFIA (rfiA-) mutants at early stationary phase of growth on a minimal medium. Differential expression analysis between the Wt and the mutants showed that the CLP cormycin and corpeptins biosynthetic clusters as well as that of an additional putative bioactive peptide and the exopolisaccharide alginate are under the control of the PcoR-RfiA regulon. Quantitative Real-time PCR assays demonstrated that CLP genes are upregulated in minimal medium and plant growth conditions as compared to reach medium cultures, whereas alginate production and biosynthesis gene expression were upregulated in rich growth conditions. In addition this study shows that citronellol is able to inhibit the growth of plant pathogenic bacteria but also could interfere with Quorum sensing system mediated by medium chain AHL in the biosensor strain Chromobacterium violaceum and in P. corrugata with QS system and the expression of genes contributing to the production of CLPs
A spread plasticity flexure-schera inelastic finite element for the study of rc structures
No full textcapable to model the flexure-shear interaction both in terms of stiffness, strength and residual ductility. The objective is not the definition of an itemized model, rather an accurate model with a sustainable computational cost for the seismic vulnerability analysis of existing buildings. Especially for non slender structures, the contribution to the nonlinear behaviour due to flexure may be not sufficient and flexure-shear interaction changes deeply the structural response.
This new finite element is based on the adoption of Heaviside s distributions functions to model abrupt, both flexural and shear, stiffness discontinuities of the beam, by which it is possible to lead to the exact closed-form solution of the Timoshenko beam differential equations. The new frame element is composed by two sectional constitutive models, one for flexure and one for shear, that can interact by means of an empirical relation that relates curvature demand and shear strength degradation.
The flexure shear model is verified against experimental tests on RC rectangular columns, walls and frames. Comparisons with experimental results on these shear-sensitive elements shows relatively good agreement
Innovative technologies of phytoremediation for contaminated soils
No full textHeavy metals pollution has become a global problem in all industrialized countries. Since the industrial revolution, a continuous release of heavy metals has led to a severe contamination of the soil. There are many techniques available for the remediation of contaminated soils, that to date represent a constantly evolving field, absorbing a lot of resources for research and development. Phytoremediation is a technique that uses plants to clean up metals and other contaminants from the soil or to make them harmless or less dangerous. Cynara cardunculus L. (cardoon), a perennial species from Asteraceae family, native to Mediterranean countries, is a crop studied as a metal accumulator in several researches. In this work, two experiments were performed to evaluate the effects of Cadmium (Cd) and Arsenic (As) on growth of different cardoon subspecies and to determine if this crop can be used for the remediation of polluted soils, combining this application with energy production. Different As and Cd concentrations were tested in Cynara cardunculus L. var. altilis in Experiment 1, with the aim to study the biological response of cardoon to heavy metals stress. In cardoon, the biomass production and Cd and As concentrations were determined in 4 different stages of the biological cycle in different parts of plant. The results showed that the cardoon was a plant that could tolerate the presence of Cd and As, even in high doses. Under Cd treatment, the Cd concentration decreased in the roots while increased in the leaves over time. Under As treatment, the As concentration in cardoon tissues increased with increasing As concentration; in particular the plants showed a several reduction in the production of biomass and the highest dose of As caused the death of the plants. In the combined Cd and As treatments, the plants improved resistance to As and Cd and the presence of Cd increased the ability of cardoon to tolerate As up to 45 days after artificial contamination. In the second study (Experiment 2), three accessions belonging to var. altilis (Gen 1) and var. sylvestris (Gen 2 and Gen 3) were compared and different concentrations of As, Cd and As+Cd were used. The aim of this work was to assess the concentration and bioaccumulation of As and Cd in the soil and in different parts of the plant, to understand the effects of Cd and As comparing different varieties and genotypes of cardoon plants and to study the specific speciation of As and Cd into plants. The results showed that plants were considerable tolerant to Cd and As, suggesting that this species was able to tolerate low doses of these toxic elements.
Moreover, as shown in the values of bioaccumulation factor, cardoon plants had the ability to accumulate large quantities of metal contaminants in its tissue. The results regarding the speciation of As and Cd suggested that exposure of plants to toxic metals appeared to induce the synthesis of sulfur-rich ligands such as phytochelatins, a cysteine-rich oligopeptide, that strongly bound metals. The presence of As upregulated the production of these specific proteins/ligands that bound and traslocated Cd into the plant tissue suggesting that the two metals interacted to magnify phytochelatin production, leading to sequestration of both metals and consequently increasing the tolerance to both.
In conclusion cardoon was a plant that could tolerate the presence of heavy metals including Cd and As. The combination of As+Cd treatment, however, increased the resistance of plants allowing them to survive. Furthurmore, Cynara Cardunculus var. sylvestris was the best subspecies that could tolerate high levels of As and Cd in its tissues and bioaccumulate greater concentrations of both metals than var. altilis. It would be useful to continue the trials with the selected Genotype 3 in future works, with the aim to test for more years, its remediation efficiency in polluted soils and exploit its biomass for energy purposes
Development and characterization of nanocarbon-based devices for sensing applications
No full textThe subject of this PhD thesis has been the development and characterization of nanocarbon-based sensors, with particular attention to the use of easy and cheap methodologies and processes that are required for future large scale production (dielectrophoresis, lift-off, etc..). In the first part of the thesis the development of Carbon nanotubes (CNTs)-based devices for biosensing applications is reported and the tests on protein detection are shown. In the second part the development of Graphene oxide (GO)-based devices is shown and the electrical behavior of the devices is investigated in different ambient conditions and for different oxygen functionalization (GO and reduced GO).
The thesis work is divided as follows:
In the first chapter the Carbon-like materials basics are recalled. In particular the types, the properties, and the main synthesis methods are described;
The second chapter introduces the FET/Resistor devices and then describes the most common CNTs/GO structures in literature;
In the third chapter, the methods for devices preparation are described with a focus on the dielectrophoretic process, used for the deposition of the carbon-based sensitive layers. Therefore, the characterization of the devices and the sensing properties achieved as immunosensors, or humidity/temperature and volatile organic compounds (VOC) sensors are shown and discussed;
Finally, in the conclusions the main results, work in progress, developments and future applications are discussed
A mobile xrf scanner for a real-time elemental imaging of painted artworks
No full textPainted artworks are complex multi-layered materials studied over the time with several sophisticated imaging techniques. Scanning MA-XRF technique provides information on pigment materials and their distribution over the painted surface in non-invasive manner. Further, it provides information on conservation state of artworks and also their authenticity can be approached. The penetrating nature of X-rays allows visualizing overpainted hidden pictorial compositions, not visible to naked eye. In the present PhD activity an advanced XRF scanning system for a real time imaging of painted artworks has been developed at the LANDIS laboratory of LNS-INFN and IBAM-CNR in Catania (Italy).The MA-XRF scanner presents a modular set-up to be assembled/disassembled in a short time (30-60 min) and easily moved in museums for analyses in situ. Spectrometric head is moved by three linear stages covering an area up to 110 × 70 × 20 cm3 (XYZ) . All motion sensors and their synchronization with the acquisition system are fully controlled by a custom developed and programmed Control Unit (CU) and all instrument operations can be in real-time monitored by a graphical user interface (GUI). The CU controls also the Z-axis movement, along the focal distance, via the communication with a laser triangulation sensor maintaining dynamically constant the painting-spectrometer distance in case of non-flat sample surface. Further, the CU interrupts immediately the scan if the safety distance is overcame. SDD detector coupled to a Digital X-ray Processors (DXP) that works in a time-list event mode (TLIST) allows to perform scans in real time (or in continuous mode). Ultra-fast scans can be performed up to 100 mm/sec covering the total area in 4.2 hours. The MA-XRF device is aimed to the macroscopic analysis of large size paintings. However, the use of a polycapillary lens equipping the X-ray source, allows to combine imaging at both the macro and micro scale of length with a simple adjustment of the sample position along the focal distance obtaining a lateral resolution up to 35 µm. A long range optical microscope is used for the accurate positioning of the painting. To date, performances of this device in terms of lateral resolution, scanning speed and dimensions of the scanning area, makes it as one of the most (or even the most) efficient portable MA-XRF systems available in the scientific community for studying paintings. X-ray spectra are processed in real-time during the scanning by the non-linear least-squares fitting procedure developed in PyMCa and integrated in the in-house programmed analysis software with a maximum processing speed of 5000 fitted spectra per second. Further a number of editing and mathematical tools for processing the images in live-mode are available. During the present research activity, the scanner was validated by studying three painted artworks on different support (canvas, wood and paper) and different size, for which the instrument has been moved in situ. MA-XRF provided valuable information through the determination of the pigment palette on painting techniques and artist connections with other workshops, the degradation state of the paintings, the reconstruction of the creative process by revealing overpainted figure and hidden inscriptions as well by the identification of changes introduced during the creation of the work. Analytical results obtained by MA-XRF analysis of the Paston Treasure , a mid-1670s oil on canvas painting at the Norwich Castle Museum (UK); painted wooden coffers belonging to the funerary collection of the tomb of Kha and Merit (1549-1292 BC) at the Museo Egizio in Torino (Italy); and an Italian illuminated manuscripts manufactured in the 14th century at the Fitzwilliam Museums (Cambridge) are presented and discussed
New perspectives in criminal network analysis: multilayer networks, time evolution, and visualization
No full textThe work presented in this Dissertation reflects a long-term human, professional and cultural path started some years ago when I first developed LogAnalysis, a tool for the analysis and visualization of criminal and social networks. Since then, I devoted myself to the development of frameworks, algorithms and techniques for supporting intelligence and law enforcement agencies in the task of unveiling the CN structure hidden in communication data, identifying the target offenders for their removal or selecting effective strategies to disrupt a criminal organization. In a natural way, I successively focused on the evaluation of the resilience of criminal networks and on the multiplex formalism, which takes into account the various relationships existing within a criminal organization.
In this context I introduce criminal network analysis tools: LogAnalysis, LogViewer, Semantic viewer and Failure simulator. I have been involved in the design, modeling, and writing of all of the works presented. In particular, I have also developed and tested all the visual tools included therein.
Finally, I introduce Multiplex PBFS (Mx-PBFS) a novel multi-threaded parallel Breadth-First Search algorithm for categorical and inter-layer couplings multiplex networks, and the framework CriMuxnet (still under development) for multilayer criminal networks analysis based on high-quality 3D visualizations of network data. CriMuxnet was designed to work in conjunction with a 3D computer graphics (CG) packages: Autodesk Maya or Blender. CriMuxnet exploits 3D engine features to significantly improve both exploratory search and visualization strategy
Diabete mellito: "una nuova causa di infertilità"
No full textIntroduzione: Il diabete mellito (DM) può determinare infertilità maschile agendo a livello pre-testicolare, testicolare e post-testicolare.
Scopo della tesi: valutare la presenza di infertilità maschile e i meccanismi di danno spermatico nei pazienti con DM in età fertile.
Materiali e Metodi: Sono stati arruolati 34 pazienti con DM1, 55 pazienti con DM2, e 100 soggetti fertili sani controllo normale . I pazienti diabetici sono stati ulteriormente suddivisi in 3 gruppi sulla base del compenso glicometabolico e della durata di malattia. Sono stati eseguiti: esame standard del liquido seminale e valutazione citofluorimetrica dei parametri spermatici non convenzionali (frammentazione del DNA nemaspermico, valutazione del grado di vitalità, apoptosi precoce e apoptosi tardiva e del grado di condensazione cromatinica; studio del potenziale di membrana mitocondriale, MMP), formula leucocitaria nell eiaculato mediante analisi citofluorimetrica, valutazione del grado di perossidazione lipidica (PL), e dei livelli spermatici di superossido mitocondriale, ecografia didimo-epididimaria e determinazione sierica in chemiluminescenza di testosterone totale, LH.
Risultati: i pazienti diabetici presentano concentrazione nemaspermica, motilità progressiva e morfologia ridotte rispetto al gruppo di controllo (p<0.05). Il volume dell eiaculato è significativamente inferiore nei pazienti con DM1 (p<0.05), ma sembra non subire variazioni significative nei pazienti con DM2 rispetto al gruppo di controllo. Le concentrazioni di leucociti risultano più elevate solo nei pazienti con DM2 (p<0.05), registrando una riduzione statisticamente significativa della percentuale di linfociti T helper nel liquido seminale e un aumento di quella dei linfociti T suppressor rispetto ai soggetti di controllo (p<0.05)
L analisi dei parametri spermatici non convenzionali ha mostrato un peggioramento dell MMP nei pazienti diabetici (p10 anni) durata di malattia rispetto agli altri due gruppi, accompagnata da basso MMP dopo 5 anni di malattia (p<0.05).
Il grado di PL è maggiore nel gruppo con DM2 rispetto agli altri due gruppi (p<0.05), mentre le concentrazioni di superossido mitocondriale risultano maggiori nei diabetici rispetto al gruppo di controllo, e maggiori nel DM2 maggiori rispetto al DM1 (p<0.05). I dati ecografici mostrano che il diametro del caput e della coda dell epididimo dopo eiaculazione sono maggiori rispetto al controllo nei pazienti con DM1 di lunga durata rispetto a quelli di breve durata (p<0.05). I livelli di TT risultano più bassi nei DM2 rispetto al gruppo di controllo (p<0.05). Conclusione: i pazienti con DM1 presentano bassi volumi dell eiaculato per mancato svuotamento epididimario, associato ad un danno mitocondriale che anticipa il successivo declino della motilità nemaspermica. A questi dati si associa comunque, un aumento dello stress ossidativo in grado di alterare anche gli altri parametri convenzionali del liquido seminale, anche se in misura minore rispetto al DM2. Il DM2 si caratterizza invece per una condizione infiammatoria con incremento leucocitaria, anche in assenza di infezione causata da specifico agente microbico, in grado di innalzare gli indici di stress ossidativo determinando un danno non solo dei parametri convenzionali del liquido seminale ma anche a carico del DNA spermatico riducendone inoltre anche la vitalità