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Measurement of -meson pair production in pp collisions at = 5.02 TeV and 7 TeV with the ALICE experiment
Get PDFThe Quark-Gluon Plasma (QGP) has been studied extensively by many experiments in the last decades. One of the first proposed signatures for its existence was the enhancement of strange and multistrange hadrons, called Strangeness Enhancement (SE). SE is the enhancement of strange and multistrange production in heavy-ion collisions with respect to pp collisions, where no hot plasma is expected to be formed. This effect is responsible for the production of an enhancement of the yield of strange and multistrange hadrons relative to pions and is more pronounced in hadrons carrying more strangeness. SE is now measured in pp collision events with a high multiplicity of charged particles in the final state. These new measurements hinting at high-density QCD phenomena happening in a class of pp collisions paved the way to a new vision where these systems were seen as a new frontier where precision measurements could be conducted to understand non-perturbative QCD phenomenology. The φ meson is then a probe of choice to study the strangeness hadronisation mechanisms and to help deepening our knowledge on the nature behind the SE phenomenon. Its hidden strangeness makes its yield only dependent on strangeness production and its phenomenological description differs significantly between models, which makes it an invaluable tool in discriminating underlying physics phenomena. The measurement of the φ-meson pairs is not only interesting in its own right, but also for its possibility to be combined with the inclusive φ-meson yield. This allows one to directly asses the second moment (variance) of the statistical distribution of φ-meson production, opening the way to new observables to compare to Monte Carlo predictions such as PYTHIA8 phenomenological model. In the last chapter an R&D work on SiPMs detectors for the ePIC experiment at the EIC collider is presented
Studi su virus emergenti a livello di interfaccia uccelli domestici-fauna selvatica
Get PDFThis thesis delves into the dynamics of pathogen transmission at the poultry-wildlife interface. Employing a multidisciplinary approach involving fieldwork, molecular biology techniques, sequence and phylogenetic analyses, and statistical analysis and modeling, these studies focus on significant poultry pathogens, namely avian influenza virus (AIV), avian metapneumovirus (aMPV), and infectious bursal disease virus (IBDV), within the context of their circulation in wild birds. A camera-trap survey conducted in Northern Italy enabled the identification of wild and domestic animal species frequenting the vicinity of poultry houses. The spatiotemporal patterns of these visits were thoroughly characterized, providing groundwork for the implementation of biosecurity measures to prevent pathogen spillover to poultry. In the same study area, a combination of sampling strategies and genomic analyses revealed 11 low pathogenic (LP) AIVs circulating in wild birds during the 2021-2022 AI epidemic in Italian poultry.
While the role of wild birds in the AIV epidemiology has long been recognized, the involvement of free-ranging avifauna in the aMPV and IBDV transmission to poultry has been questioned. A systematic review and meta-analysis of aMPV in wild species identified the potential virus reservoirs or vectors, such as wild ducks, geese, gulls, and pheasants. Notably, the first detection of an aMPV subtype C virus in a novel migratory duck species, the Eurasian wigeon, further emphasized the likely wild duck’s role in aMPV-C virus circulation. Additionally, a systematic review and meta-analysis of IBDV prevalence in wild birds provided valuable insights into the virus’s epidemiology, although conclusive evidence on specific species' roles remains elusive. Overall, this thesis has offered novel insights for evidence-based epidemiological studies and targeted viral surveillance in wild hosts concerning AIV, aMPV and IBDV, avian viruses of great economic importance for the global poultry industry.Questo lavoro di tesi è stato concentrato sulle dinamiche di trasmissione di virus emergenti a livello di interfaccia tra uccelli domestici e fauna selvatica. Utilizzando un approccio multidisciplinare che ha incluso attività di campo, tecniche di biologia molecolare, analisi di sequenza e filogenetiche ed analisi statistiche avanzate, le attività di ricerca si sono focalizzate su tre fra i principali patogeni dei volatili domestici - il virus dell'influenza aviaria (AIV), il metapneumovirus aviare (aMPV) e il virus della bursite infettiva aviare (IBDV)-, considerandoli nel contesto della loro circolazione negli uccelli selvatici. Uno studio di video-trappolaggio condotto in tre allevamenti di galline ovaiole del Nord Italia ha permesso di identificare le specie di animali selvatici e domestici presenti in prossimità dei ricoveri. Nella stessa area di studio, 11 ceppi di AIV a bassa patogenicità sono stati rilevati in volatili acquatici selvatici, e caratterizzati mediante whole genome sequencing.
Se il ruolo dei volatili selvatici nell'epidemiologia dell’influenza aviaria è ben noto, il coinvolgimento dell'avifauna nella trasmissione di aMPV e IBDV è tutt'ora oggetto di studio. Mediante revisione sistematica e meta-analisi della letteratura sulla prevalenza di aMPV in volatili selvatici, sono state identificate specie con un ruolo di potenziale serbatoio o vettore del virus, tra cui anatre selvatiche, oche, gabbiani e fagiani. Successivamente, mediante un'indagine epidemiologica su uccelli acquatici selvatici, per la prima volta è stato anche identificato e caratterizzato un aMPV sottotipo C in un fischione eurasiatico. Inoltre, una revisione sistematica e meta-analisi della letteratura sulla prevalenza di IBDV negli uccelli selvatici, ha riassunto le conoscenze sino ad ora acquisite sull'epidemiologia virale in questi ospiti. Per concludere, i risultati ottenuti nella presente tesi pongono le basi per lo svolgimento di nuovi studi epidemiologici e la eventuale messa a punto di programmi di sorveglianza in specie selvatiche target per AIV, aMPV e IBDV
Forest responses to global change drivers: insights from temperate and tropical ecosystems
No full textForests, often likened to the lungs of our planet, are at the forefront of climate mitigation strategies. Understanding how major changes affecting the atmosphere (i.e., climate and pollutants) affect ecological and ecophysiological processes underpinning forest functioning is paramount to the preservation of essential ecosystem services they provide. In the era of global change, this thesis encompasses three scientific studies that together contribute to advancing our understanding of the intricate ecophysiological responses of both temperate and tropical forest ecosystems to diverse global change drivers.
The initial two papers, focus on the impact of atmospheric nitrogen (N) deposition on two temperate forest ecosystems. These studies employ a long-term manipulative experiment, where the application of N fertilizer simulates the increase in N deposition. The first study investigates forest health under elevated N deposition by employing foliar nutrient and photosynthetic pigment concentrations as stress indicators. The second paper integrates measurements of N concentration and its isotopic composition across various forest compartments, coupled with molecular analyses of soil nitrogen functional genes, to characterize processes underpinning the N cycle.
The third paper, delves into water and nutrient balances in a tropical montane cloud forest (TMCF). It underscores the imperative to address the knowledge gap on tropical forest ecosystems, which may be compromised by climate change, such as alterations in precipitation water regimes and rising temperatures. This study utilizes carbon (C) and N stable isotopes in soil and plant tissues to evaluate water-use efficiency and nutrient dynamics, highlighting the potential vulnerability of TMCFs to evolving climatic conditions.
These studies articulate the challenges faced by forests. From the effects of N deposition on nutrient concentrations and N dynamics in temperate forests to the ecohydrological balance in the TMCFs, these insights deepen our comprehension of the complex interplay between human-induced changes and the resilience of forest ecosystems
Regional glacial isostatic adjustment modeling: integration of geodetic, geophysical and geological data
Get PDFThe Earth is always on the move, constantly. In the last millions of years the Earth's climate has followed a cycle of alternating glacial and interglacial conditions, with a periodicity of the order of 100 kyr. The most recent cycle began approximately 110 kyr ago and reached the Last Glacial Maximum at approximately 20-26 kyr before present . As a result, the average sea-level was about 125-130 m lower than at present and large regions, now covered by shallow seas, were dry land in places forming bridges between islands. Though the ice melted long ago, the land once under and around the ice is still rising and falling in reaction to ice burden. This ongoing movement of land is called Glacial Isostatic Adjustment (GIA) and represents the response of the solid Earth to mass redistribution during a glacial cycle, that is describes the viscoelastic response of the solid Earth to time-dependent changes in ice and ocean loading over the course of a glacial-interglacial cycle. In the first part of this work the impact of the GIA process in the Mediterranean basin will be analyzed, with particular attention to the Venice Lagoon, where the sea-level variations could be catastrophic if we consider the current effect of climate changes. The second piece of work is on the study of the strength of the lithosphere beneath Graham Land region (Antarctic Peninsula) using numerical modeling which simulate lithospheric deformation as a function of geological and geophysical parameters. Although these two works might seem disconnected, the study of the rheology and strength of the lithosphere play an important role in GIA modeling. Indeed, increasingly advanced knowledge of the crustal and upper mantle rheological structure will lead to better understanding the geological processes but also to better constrain geophysical processes such as GIA
Healthcare services re-organization based on lessons learned during COVID-19 pandemic. Conceptual frameworks and measurement and assessment tools for public health emergency preparedness.
Get PDFPublic health emergency preparedness (PHEP) is a core element for health systems, which involves a coordinated and continuous process of planning and implementation based on measuring performance and taking corrective actions.
The COVID-19 pandemic highlighted critical areas within health systems, with the need of a revision of previous logic models and the implementation of new assessment tools for PHEP.
On this basis, the European Union (EU) promoted an evolution of the legislative context on PHEP and the mandate of its main institutions, mainly the European Centre for Disease Prevention and Control (ECDC).
Building on collaborative efforts between international organizations and research centers, the aim of the current PhD thesis is to study and upgrade conceptual frameworks of PHEP in response to pandemic emergencies and identify assessment models relating to the organization of care pathways, with a specific focus on the hospital setting and on the integration with primary care systems related to the rearrangements induced by the COVID-19 pandemic.
The findings of the thesis provided elements for the revision of the current ECDC Logic Model for PHEP and evidence for improvements in the area of healthcare coordination; additionally, they suggested methodological approaches for standardized assessment and evaluation tools for PHEP systems within the EU
Development and pre-clinical validation of a computer-assisted predictor of the risk of vertebral fracture
Get PDFPathologies such as metastasis and osteoporosis affect the mechanical properties of the vertebrae, increasing fragility fractures incidence. Patient-specific models, generated from diagnostic images, could predict fracture risk, helping clinicians in the correct therapy choice. However, validation is required to use them in clinical practice. Many proposed finite element (FE) models consider single vertebrae only, neglecting the role of intervertebral discs in load transmission. Multi-vertebrae models would include more physiological boundary conditions, but computed tomography (CT) imaging does not provide information about discs' mechanical properties.
Consequently, in the first part of the thesis CT-based multi-vertebrae FE model was generated assigning to the discs a linear isotropic material with Young’s modulus values in the literature range. Boundary conditions were assigned experimentally-matched and computational displacements and strains on vertebral surface compared to experimental ones coming from Digital Image Correlation measurements. Good agreement was obtained for displacements (R2>0.9 and RMSE%<8%), but strains local distribution differed substantially.
Hence, in the second part the focus was shifted on individual vertebrae. Specifically, µCT scans were acquired before and after compressive tests and used as input to Digital Volume Correlation algorithm, allowing to extract deformation field within bone structure. FE models were generated from unloaded scans and subjected to experimentally-matched boundary conditions. Predicted displacements were compared pointwise against experimental data, showing good agreement, both for healthy (R2=0.69÷0.83, RMSE%=3÷22%) and metastatic (R2=0.64÷0.93, RMSE%=5÷18%) vertebrae. Additionally, qualitative comparison between computational and experimental strains was performed, correctly identifying regions with highest strains concentration.
In conclusion, when the boundary conditions are accurately modelled, subject-specific CT-based FE can predict displacements and strains with accuracies comparable to that of experimental method used for validation. But in multi-segment models, predictions are highly sensitive to biomechanical properties of intervertebral discs; thus, accurate models can be built only if disc's properties are personalised
Covalent modification of graphene oxide: water remediation and carbocatalysis
Get PDFThe objective of this thesis is the application of new materials derived from the functionalization of graphene oxide in the fields of water remediation and CO2 utilization.
Chapter 4.1 reports the synthesis and characterization of the graphene oxide (GO) modified with branched polyethyleneimine (GOPEI) material. This polymer was then functionalized with a fluorescent dye to monitor its purification through UV-vis spectroscopy. This process also allowed for a better understanding of the mechanisms underlying purification by microfiltration. By studying adsorption isotherms and formulating theoretical models, the kinetics, efficiency, and adsorption mechanism of GOPEI towards two pollutants, arsenic and lead, were discussed.
Chapter 4.2 presents the study of the adsorption properties of a family of GO-based composites, covalently modified with three amino acids: L-Lysine, L-glutamic acid, and L-methionine (GO-Lys, GO-Glu, and GO-Met). Along with synthesis, the purification protocol was also improved to be faster and more efficient than previously reported, and their complete characterization was performed through XPS analysis. Finally, these materials were used as adsorbents towards a mixture of selected contaminants including pharmaceuticals, polymer additives, and dyes.
Finally, in Chapter 4.3, a new synthesis of a GO-arginine composite (GO-Arg) and its utilization in carbon capture and utilization processes was reported. In the first part, the efficacy of CO2 fixation through the selective opening of epoxides to cyclic carbonates was demonstrated. The reported protocol was found to be applicable to a wide range of substrates, and its reusability was tested for up to 5 cycles. Furthermore, the application of this material in an ICCC process was discussed. It was shown that the material can capture CO2 from both high-purity atmospheres and low-concentration mixtures (such as the atmosphere) and converting it into cyclic carbonates when exposed to reaction conditions. The entire process was thoroughly studied and rationalized through computational and spectroscopic analyses
The protection of personal data of netizens in international, EU, and chinese legal frameworks
Get PDFIn contemporary society, the Internet is as vital as the air we breathe, with each online interaction leaving traces of data stored within the system. Scholars equate this data, encompassing personal and non-personal information, to the 21st century's new "oil."
This thesis investigates how international, EU, and Chinese legal frameworks regulate the right to personal data protection for "Netizens" in the era where the Internet is the primary domain for data collection and processing, as well as a fertile ground for illicit activities. The virtual environment's lack of physical borders complicates legislators' task of formulating effective rules for personal data protection.
Through a comprehensive comparative analysis of regulations, including legal sources, doctrine, jurisprudence, and existing principles, the thesis aims to identify mutual influences among the examined regulatory tools. This analysis is motivated by the imperative to ensure uniform and effective international guarantees for the right to personal data protection. The study also explores a comparative analysis between the EU and Chinese legal systems, acknowledging the influential role of European legislation, particularly the General Data Protection Regulation (GDPR). Despite China's nascent legislative system, its status as the world's largest digital market adds significance to this comparison. The thesis additionally considers the interplay between personal data protection and the contemporary challenge posed by artificial intelligence.
Structured into five parts, the thesis addresses specific aspects of personal data protection, including examining legal sources related to Netizens' data protection, analyzing the concepts of personal data in international and EU law, as well as personal information in Chinese legislation. It also focuses on rules related to the data subject's consent, explores the rights of the data subject in the three legal systems, and outlines rules for cross-border data transfer along with corresponding sanctions for breaches of data processing regulations.La tesi in esame si concentra sull'importanza cruciale di Internet nella società contemporanea, paragonandola all'essenzialità dell'aria che respiriamo. La rete, spesso considerata un luogo privato, è in realtà permeata di tracce di ogni interazione, tradotte in dati archiviati. Questi dati, personali e non, sono ora considerati il "nuovo petrolio" del secolo.
L'obiettivo principale della tesi è esplorare come gli strumenti giuridici internazionali, europei e cinesi regolamentino il diritto alla protezione dei dati personali dei "Netizens". L'Internet è oggi la principale fonte di raccolta e trattamento dei dati personali, ma anche un terreno fertile per attività illecite, e la mancanza di confini fisici nel mondo virtuale complica la formulazione di norme efficaci per la loro protezione.
Attraverso una comparazione approfondita delle normative, il lavoro analizza se vi sia una reciproca influenza tra gli strumenti normativi esaminati. Questa analisi è motivata dalla necessità di garantire che il diritto alla protezione dei dati personali sia efficacemente garantito a livello internazionale. Inoltre, viene eseguita un'analisi comparativa tra gli ordinamenti dell'Unione Europea e cinese, considerando il ruolo preminente del Regolamento Generale sulla Protezione dei Dati (GDPR) nell'ordinamento internazionale e la posizione di leadership della Cina nel mercato digitale mondiale.
La struttura della tesi si articola in cinque parti. La prima esamina le fonti giuridiche relative alla protezione dei dati personali dei Netizens, la seconda analizza il concetto di dati personali nell'ordinamento internazionale, dell'UE e nella legislazione cinese. La terza parte si focalizza sulle regole del consenso dell'interessato per il trattamento dei dati personali, mentre la quarta esplora i diritti riservati all'interessato nei tre ordinamenti. Infine, l'ultima parte delinea le regole per il trasferimento transfrontaliero dei dati e le sanzioni previste in caso di violazione delle norme sul trattamento dei dati
Deep learning for massive multiple access in 6G
Get PDFIn recent years, the number of massive Internet of Things (mIoT) has grown tremendously, giving rise to the term massive machine-type communications (mMTC). Cellular Internet of Things (IoT) is an economical solution for connecting devices wirelessly because it reuses existing cellular infrastructure. 3rd Generation Partnership Project (3GPP) has recognized mMTC as one of the use cases of 6G. However, providing massive access to the IoT devices within the constraints of limited system resources has been an ongoing challenge in cellular networks. On the other hand, Deep learning (DL) has emerged as a powerful method for various applications, such as image processing and natural language processing. More recently, DL has been successfully applied to a wide range of wireless communication tasks. Given that, this thesis aims to design massive multiple-access protocols using DL algorithms for both cell-based and cell-free networks
Organic mixed ionic-electronic conductors for bioelectronic interfaces
Get PDFUsing electrical signals to interact with biological systems has shed light on different signaling principles of living organisms, leading to the development of various healthcare devices. However, conventional (inorganic) electronic materials significantly differ from living matter in critical aspects including mechanical rigidity, three-dimensional structure, and predominant electronic conductivity. Due to their “soft” nature, biocompatibility, and ability to conduct ions in addition to electrons, organic materials with mixed ionic and electronic conductivity (OMIECs) have recently emerged as a promising material platform for highly efficient interfaces with biology. Faster and significative progresses in organic bioelectronics are predicated on a comprehension of fundamental material processes and their relation to device functionality, but the mixed conductivity renders the experimental characterization of ionic or electronic carrier transport difficult as both are intrinsically entangled. The objective of this thesis is investigating these phenomena and exploiting the resulting knowledge to develop optimized bioelectronic applications. We introduced the electrolyte-gated van der Pauw’s method for the characterization of electronic transport in OMIEC materials, allowing the determination of the electronic mobility independent from contact resistance effects. We developed the modulated electrochemical atomic force microscopy (mEC-AFM) to monitor fast local ion exchange processes causing electroactuation in OMIECs, combining multidimensional spectroscopies of electroswelling with multichannel imaging. We extended mEC-AFM to a depth-sensitive technique to acquire subsurface profiles of ion migration and swelling in OMIEC thin films, revealing the spatiotemporal dynamics of electroactuation in the polymer bulk. We finally studied OMIEC applications in bioelectronic devices, including the microfabrication of flexible microelectrode arrays for in-vivo neural recording and stimulation, and the realization of impedance sensors for in-vitro cell adhesion experiments reaching the single cell resolution limit. The quantitative findings obtained in his work are expected to contribute to the rational optimization of enhanced organic bioelectronics interfaces for future healthcare, biomedicine, and biosensing devices