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Energy methods for local or nonlocal problems in sub-Riemannian setting
No full textLa tesi riguarda principalmente lo studio di regolarità e proprietà qualitative di soluzioni di equazioni locali o non locali, invarianti e omogenee rispetto a leggi non commutative, le quali rendono la struttura dello spazio ambiente sottostante quella di un gruppo di Lie omogeneo. In particolare, studiamo gli effetti della perdita di compattezza nell'immersione critica di Sobolev nel gruppo di Heisenberg, mostrando che, anche in questo ambiente, vale una congettura di Brezis e Peletier. Inoltre presentiamo risultati di regolarità alla De Giorgi-Nash-Moser per equazioni frazionarie non lineari nel gruppo di Heisenberg, dimostrando anche la risolubilità (nel senso di Perron) per i relativi problemi di Dirichlet, in domini possibilmente irregolari e per dati al bordo molto generali. Infine, dimostriamo che soluzioni deboli di equazioni cinetiche a diffusione frazionaria soddisfano una disuguaglianza di Harnack forte
Mean-field theory for consensus-based optimization and extensions to constrained and multi-objective problems
No full textStochastic particle methods in optimization constitute a popular class of heuristic
techniques where a set of possible solutions is iteratively updated according to deterministic and stochastic mechanisms. These algorithms are oftentimes inspired by natural
phenomena such as the collective motion of birds in a swarm or the reproduction of genes
in biology. Recent works apply kinetic tools developed for modeling such phenomena
to the analysis of particle-based optimization methods to develop a full mathematical
understanding of their convergence properties.
In this thesis, we follow this line of research and propose a semi-discrete mean-field
model for the analysis of Consensus-Based Optimization (CBO) methods. In the literature,
CBO methods are typically analyzed after a twofold approximation: first, the algorithm
dynamics are approximated by a system of time-continuous processes, then, the system is
approximated by a mono-particle process of McKean type. Here, we directly consider a
mean-field approximation of the algorithm’s update and derive a mono-particle difference
equation. We also adapt the convergence results for the time-continuous mean-field
model to these semi-discrete settings, claiming that this modeling procedure avoids the
introduction of an unnecessary additional approximation error.
The second part of the thesis extends the class of CBO methods to solve constrained
and multi-objective optimization problems. For constrained optimization, we couple the
CBO update rule with an exact penalization technique. By adding a penalty term, we
reformulate the constrained problem as an unconstrained one and further propose an
algorithmic technique to tune, during the computation, the penalization strength to its
optimal value. For multi-objective problems, we modify the CBO dynamics so that every
particle aims to optimize a different, parameterized scalar sub-problem. In this way, we
are able to compute an approximation of the entire Pareto front with a single run of the
algorithm. The parameters of the scalarized sub-problems are further adapted following
binary repulsive dynamics to improve the diversity of the computed front.
Via mean-field approximation, we show that the proposed algorithms are able to
converge into a neighborhood of the solutions under mild assumptions, both in the case
of constrained and multi-objective optimization problems. Numerical experiments over
benchmark problems illustrate the algorithms’ performance in different settings and for
different problem types
Food innovation for patients with dysphagia: experimentation with potential transformations of sensory and physical characteristics for a more pleasant andengaging meal experience
No full textIl presente progetto nasce con l’obiettivo di migliorare l’esperienza del pasto per i pazienti affetti da disfagia, una condizione che comporta difficoltà nella deglutizione e impatta significativamente sulla qualità della vita. In particolare, il progetto si concentra sulla sperimentazione per un approccio sensoriale e personalizzato, mirato a rendere il pasto non solo sicuro dal punto di vista medico, ma anche piacevole ed appagante. La ricerca è stata condotta in collaborazione con il Centro Diurno Socio-Riabilitativo di Torino, che accoglie pazienti con Sclerosi Multipla e patologie neurologiche similari, e ha visto l’utilizzo dei pasti forniti dalla Mensa CAMST. Attraverso l’introduzione di consistenze modificate, spezie, e una maggiore attenzione alla presentazione, il progetto ha mostrato un impatto positivo sulla soddisfazione dei pazienti e sulla loro disponibilità al consumo del cibo. Questo studio sperimentale ha fornito risultati incoraggianti, suggerendo la possibilità di continuare la ricerca per migliorare ulteriormente l'efficacia operativa e integrare nuove tecnologie. Il progetto ha gettato le basi per una visione inclusiva del momento del pasto, con l’obiettivo di promuovere la dignità e la qualità della vita dei pazienti affetti da disfagia, aprendo la strada a futuri sviluppi nel trattamento della condizione.This project was created with the goal of improving the mealtime experience for patients with dysphagia, a condition that involves difficulty swallowing and significantly impacts quality of life. Specifically, the project focuses on experimentation for a sensory and personalized approach aimed at making mealtime not only medically safe, but also enjoyable and satisfying. The research was conducted in collaboration with the Centro Diurno Socio-Riabilitativo di Torino, which accommodates patients with Multiple Sclerosis and similar neurological disorders, and involved the use of meals provided by the CAMST Canteen. Through the introduction of modified textures, spices, and increased attention to presentation, the project showed a positive impact on patient satisfaction and willingness to eat. This experimental study provided encouraging results, suggesting the possibility of continuing research to further improve operational effectiveness and integrate new technologies. The project laid the foundation for an inclusive view of mealtime, with the goal of promoting the dignity and quality of life of patients with dysphagia, paving the way for future developments in the treatment of the condition
Evaluation of the effect of an infusion of dexmedetomidine on femoral and sciatic nerve blocks in dogs
No full textScopo dello studio: valutazione dell’effetto di un’infusione continua di dexmedetomidina sulla durata del blocco del nervo sciatico e femorale in cani sottoposti a chirurgia di osteotomia di livellamento del piatto tibiale (TPLO) e avanzamento della tuberosità tibiale (TTA).
Materiali e metodi: sette cani di proprietà che dovevano essere sottoposti a chirurgia per rottura del legamento crociato craniale sono stati arruolati nello studio. Sono stati casualmente divisi in due gruppi, uno a cui è stata somministrata un’infusione di dexmedetomidina (DEX) a 1 μg /kg/h, l’altro a cui è stato somministrato un volume equivalente di Ringer Lattato (RL) in infusione. Tutti i cani sono stati premedicati con metadone (0,1 mg/kg) e prima dell’induzione è stato somministrato in 10 minuti un bolo di carico dello stesso volume di dexmedetomidina o Ringer Lattato. L’anestesia generale è stata indotta con propofol EV e mantenuta con isoflurano. Dopo l’induzione sono state iniziate le rispettive infusioni continue. Il blocco femorale attraverso il compartimento dello psoas e il blocco del nervo sciatico con approccio medio-prossimale sono stati effettuati in tutti i cani. Durante la chirurgia sono stati registrati frequenza cardiaca (FC), pressione arteriosa invasiva (PAS, PAM, PAD), diossido di carbonio a fine espirazione (EtCO2), percentuale di isoflurano a fine espirazione (EtISO). L’eventuale bisogno di analgesia intraoperatoria d’emergenza è stata registrata. Il dolore post-operatorio è stato valutato con la scala Glasgow del dolore, così come la valutazione del blocco sensoriale. La valutazione del blocco motorio è stata eseguita tramite due scale cliniche visive.
Risultati: non sono state evidenziate differenze significative tra i due gruppi per quanto riguarda FC, PAS, PAM, PAD, EtCO2 e EtISO. Durante la chirurgia, 1 caso su 3 ha avuto bisogno di analgesia di salvataggio nel gruppo DEX e 2 casi su 4 nel gruppo RL 1. La durata dei blocchi sensoriale e motorio è stata simile tra i due gruppi. Non è stata richiesta analgesia di salvataggio durante le prime 6 ore di monitoraggio postoperatorio.
Conclusioni: l'infusione continua di dexmedetomidina (DEX) a 1 μg/kg/h non sembra prolungare il blocco motorio e sensoriale dell'anestesia regionale.Aim of the study: evaluation of the effect of a constant rate infusion of dexmedetomidine on the duration of femoral and sciatic nerve blocks, performed in dogs undergoing tibial plateau leveling osteotomy (TPLO) and tibial tuberosity advancement (TTA).
Materials and methods: seven client-owned dogs who had to undergo surgery to treat the rupture of the cranial cruciate ligament were enrolled in the study. They were randomly divided into two groups, one that would receive a constant rate infusion of dexmedetomidine (DEX) at 1 μg/kg/h and the other that would receive an equivalent volume of Ringer Lactate infusion (RL). All dogs were premedicated with methadone (0.1 mg/kg IV) and they received an equal loading bolus of dexmedetomidine (group DEX) or Ringer Lactate (group RL) prior to induction, delivered in 10 minutes. General anesthesia was then obtained with propofol IV and maintained with isoflurane. After induction, the constant rate infusions were started. Femoral block through a psoas compartment approach and sciatic block middle proximal approach were performed in all dogs. Heart rate (HR), invasive blood pressure (SAP, MAP, DAP), end-tidal carbon dioxide (EtCO2) and end-tidal isoflurane percentage (EtISO) were recorded every 5 minutes throughout surgery. The need for intraoperative rescue analgesia was also noted. Post-operative pain was assessed with the Glasgow pain scale, as well as the evaluation of the sensory blockade. Motor block evaluation was obtained using two visual clinical scales.
Results: no significant differences in HR, SAP, MAP, DAP, EtCO2 and EtISO were observed between the two groups. During surgery, 1 in 3 cases in the DEX group and 2 in 4 cases in the RL group required rescue analgesia. Duration of sensory and motor blockade was similar between the groups. No rescue analgesia was required during the first 6 hours of postoperative monitoring in any case.
Conclusion: A continuous infusion of dexmedetomidine (DEX) at 1 μg/kg/h does not appear to prolong the motor and sensory blockade of regional anesthesia
A neurobehavioural assessment of adaptive responses to altered gravitational environments in ground-based hypergravity and microgravity models
No full textAltered gravitational environment represents a unique challenge for terrestrial biological systems. The investigation of the human and animal response to unphysiological gravity, such as the permanency in space or in conditions that in some way mimic weightlessness, represents an opportunity to understand the phenomena underlying tolerance and adaptation to environmental conditions. The initial and adaptive responses to these challenges are reflected in behavioural endpoints: a careful study of these responses enables to evaluate and understand coping strategies, mechanisms underlying neuroplasticity phenomena, and the individual vulnerability to stress. Furthermore, understanding the individual responses to stress and the identification of predictive indicators of susceptibility may effectively mitigate the negative effects of altered gravity and indeed they represent a relevant emerging topic for the future of human space exploration. Reproducing environments that recreate weightlessness on the Earth is practically impossible. Among the ground-based models that are extensively employed to simulate altered gravity, hypergravity induced by rotation, the hindlimb unloading model, and the bed rest paradigm are well-established methodologies. In this conceptual and methodological framework, the aim of the present work was to investigate the neurobehavioural profile of mice exposed to hypergravity or microgravity simulated conditions in order to define possible behavioural indicators of susceptibility to un-physiological gravity. Moreover, neuroinflammatory biomarkers of resilience or vulnerability were also evaluated in human volunteers subjected to bed rest. In animal studies, behavioural adaptive responses took place during the exposure to altered gravity and the behavioural repertoire resulted compromised when returned to normogravity. Interestingly, the behavioural items manifested during the first days in the centrifuge or upon suspension could predict susceptibility of the experimental subjects to these altered environments. Moreover, evaluation of individual profile on bed rest evidenced that active coping strategy in resilient individuals is characterized by an anticipatory role of biomarkers to counteract the environmental challenge. In line with the personalized medicine approach in space, data obtained from such studies could lead to new strategies to reduce health problems associated with spaceflight
Interazioni tra il suolo, l’atmosfera, l’idrosfera e la vite. Indagine geochimico-isotopica
No full textIn the wine world, isotopic analyses are carried out to verify the variation of these parameters depend on natural factors, i.e. soil-water-plant-atmosphere interactions. In water molecules of the grape berry the values of the isotope ratios 2H/1H and 18O/16O are linked to the characteristics of the water present in the soil and evaporation phenomena to which the leaves and the grape are subjected. The isotopic characteristics of the water assimilated by plants are, in turn, dependent on those of the precipitation waters, which are dependent on climatic factors. Therefore, the isotopic characteristics of the hydrogen and oxygen in the water of the grapes are the complex result of the water and the climate of the place where the plant grew (geological-geographical proxy). The isotopic composition of water in different parts of the vine is initially determined by the water absorbed from the soil since isotopic fractionation does not occur. Isotopic fractionation occurs gradually during the grapes ripen, as they are subject to climatic conditions. In turn, the isotope ratio of carbon in the organic part of the berry and, in general, in the different parts of the vine, is fundamentally linked to the biological fixation phenomenon that characterizes the plant, which is linked to climatic conditions.
Additional indications regional scale can be given by the report isotope of strontium (87Sr/86Sr), which is linked to the lithological characteristics of the area in which the plant grows up. The relevance of the use of these isotopes is due to the fact that they do not fractionate.
With regard to wine, the origin can be differentiated through the isotopic ratios measured on the water of the grape if the isotopic characteristics of the geological substrate on which the plant grows are known
Development of a method for sanising urban environments and contexts through the use of electrolysed water with low environmental impact: assessment of chemical sustainability aspects
No full textThe experimental campaign described and summarized in this PhD is an assessment of the chemical
and sustainability aspects of HOCl as a disinfectant, produced by GATE srl, Ferrara.
The work is twofold: a compatibility test on several reference materials, connected with the eventual
presence/deposition of NaCl over them and an LCA assessment, comparing HOCl with another
commercial disinfectant.
Analyzing the large amount of experimental data gathered during the PhD activities gave interesting
results. Where the exposure of non-metallic materials or steel did not lead to compatibility issues,
bare metals showed degradation due to salt deposition.
On the other hand, the experimental LCA analysis showed the clear ecological advantage of HOCl vs
other commercial products.
The experimental work was carried out at the ENEA DISPREV lab, in Bologna
Thought's "Happy Suicide". Genesis, Structure and Meaning of F. H. Bradley's Metaphysics (1873-1897)
No full textL’oggetto della presente ricerca è la metafisica di Francis Herbert Bradley (1846-1924), esponente di spicco del cosiddetto British idealism, considerato in vita come il massimo filosofo britannico della sua epoca. In particolare, ci proponiamo di ricostruire (i) la genesi della sua metafisica, per come viene esposta nella sua opera maggiore, 'Appearance and Reality. A Metaphysical Essay' (1893, 1897), e (ii) la sua struttura argomentativa generale, in modo da rendere infine possibile (iii) una valutazione preliminare del suo significato, che potrà costituire il punto di partenza per una ricerca futura, specificamente incentrata sul posto occupato da Bradley nella filosofia contemporanea. La ricerca si suddivide in tre parti. Nella prima parte, esaminiamo il contesto storico-filosofico nel quale il pensiero di Bradley si forma, comprendente non solo la filosofia britannica dell’Ottocento (1.3), ma anche quella tedesca da Kant a Lotze, passando per Hegel e Herbart (1.2). Il primo capitolo della prima parte, da leggersi come una sorta di introduzione storico-filosofica alle problematiche metafisiche affrontate da Bradley e dalle sue fonti più prossime, verte invece sulle immancabili origini greche di tali problematiche (1.1). Nella seconda parte, ricostruiamo da vicino la genesi della metafisica bradleyana attraverso lo studio di alcuni manoscritti giovanili, che prefigurano il saggio di metafisica (2.1), e della prima edizione dei 'Principles of Logic' (1883), analizzati selettivamente in funzione dei nostri obiettivi (2.2). I contenuti di questi testi vengono messi opportunamente in relazione con le fonti esaminate nella prima parte. Nella terza parte, infine, dopo aver presentato la concezione bradleyana della metafisica (3.1), proponiamo una ricostruzione della stessa per come viene esposta in 'Appearance and Reality', individuando e analizzando le tre tesi principali e gli argomenti a sostegno di ciascuna (3.2, 3.3, 3.4), per poi discutere alcune questioni meta-filosofiche relative alla coerenza del sistema bradleyano (3.5). Anche nella terza parte prestiamo attenzione a rilevare di volta in volta il rapporto fra la metafisica di Bradley e le sue fonti. In breve, si tratta di comprendere o quantomeno di chiarire il significato della metafisica di Bradley per come esso emerge dalla sua struttura generale, utilizzando come chiave di lettura la sua genesi a partire dalle sue fonti filosofiche e dagli scritti anteriori al saggio di metafisica. La nostra indagine mostra che, fra gli scritti teoretici degli anni ’70 e 'Appearance and Reality', è possibile rintracciare una certa continuità, dovuta non a una stasi ma, al contrario, a uno sviluppo costante della riflessione bradleyana, mediato dalla ricezione di altre filosofie. Dopo un’iniziale adesione all’idealismo hegeliano, interpretato alla maniera dei primi idealisti britannici (2.1.1), Bradley entra in contatto con Herbart e Lotze, assorbendo il loro (diverso) anti-idealismo in epistemologia (2.1.2) e in ontologia (2.1.3). Entrambi sono figure assolutamente centrali per Bradley, degne di stare almeno alla pari con Hegel: la sua metafisica è infatti il tentativo, tanto eclettico quanto originale, di far coesistere (i) il realismo razionalistico ed eleatizzante di Herbart, nel quale a farla da padrone è il principio di non contraddizione, (ii) il monismo normativo di Lotze, fondato su una concezione formalistica del pensiero, (iii) la critica hegeliana all’astratta logica intellettualistica e (iv) l’idea, altrettanto hegeliana (ma in parte anche platonica), dei gradi di verità (e realtà), a sua volta fondata su una concezione della contraddizione come incompletezza.The subject of this research is the metaphysics of Francis Herbert Bradley (1846-1924), a prominent exponent of the so-called British idealism, who in his lifetime was regarded as the leading British philosopher of his time. In particular, I aim to establish (i) the genesis of his metaphysics as displayed in his major work, 'Appearance and Reality. A Metaphysical Essay' (1893, 1897), and (ii) its general argumentative structure, in order to eventually enable (iii) a preliminary assessment of its significance, which may form the starting point for future investigation, specifically focused on Bradley's place in contemporary philosophy. The research is divided into three parts. In the first part, I will examine the historical-philosophical context in which Bradley's thought was shaped, including not only nineteenth-century British philosophy (1.3), but also German philosophy from Kant to Lotze, through Hegel and Herbart (1.2). The first chapter of the first part, which is to be read as a sort of historical-philosophical introduction to the metaphysical issues addressed by Bradley and his closest sources, will instead focus on the unavoidable Greek origins of these issues (1.1). In the second part, I will closely follow the genesis of Bradley's metaphysics by examining some early manuscripts, which prefigure the metaphysical essay (2.1), and the first edition of the 'Principles of Logic' (1883), which will be selectively surveyed for my purposes (2.2). The contents of these writings will be appropriately linked to the sources reviewed in the first part. Finally, in the third part, after having presented Bradley's conception of metaphysics (3.1), I will offer an account of it as expounded in 'Appearance and Reality', by identifying and analysing the three main theses and the arguments in support of each (3.2, 3.3, 3.4), and then I will discuss some meta-philosophical issues concerning the consistency of Bradley's system (3.5). In the third part, too, it will be my concern to point out the connection between Bradley's metaphysics and its sources. In short, my goal is to understand or at least clarify the meaning of Bradley's metaphysics as it emerges from its general structure, by using its genesis from philosophical sources and previous writings as a key to grasp it. My investigation shows that, between the theoretical writings of the 1970s and 'Appearance and Reality', a strong continuity can be traced, which is due not to a stasis but, on the contrary, to a continuous development of Bradley's thinking through the reception of other philosophical doctrines. After an early endorsement of Hegelian idealism, understood along the lines of the early British idealists (2.1.1), Bradley gets acquainted with Herbart and Lotze, assimilating their (different) anti-idealism in epistemology (2.1.2) and ontology (2.1.3). Both are central figures for Bradley, deserving to stand at least alongside Hegel: Bradley's metaphysics is in fact the attempt, as eclectic as it is original, to bring together (i) Herbart's rationalistic and 'Eleaticish' realism, in which the principle of non-contradiction rules, (ii) Lotze's normative monism, grounded upon a formalistic view of thought, (iii) the Hegelian criticism of abstract intellectualistic logic, and (iv) the likewise Hegelian (but also to some extent Platonic) idea of degrees of truth (and reality), itself grounded upon a conception of contradiction as incompleteness
Sintesi e studio di leganti calixarenici o piccole molecole per l'interazione con le biomacromolecole
No full textThe present thesis work handles the synthesis and studies of ligands for interactions with different biomolecules adapting the strategy of small molecules and supramolecules according to the goals. While the effectiveness of small molecules for this purpose has enabled the development of drugs, supramolecules have never been used as drugs but their use, in some cases, has been highly effective in interacting with biomolecules. In this regard, the calixarene scaffold was selected for the flexibility demonstrated in the selective and multiple functionalization.Il presente lavoro di tesi si occupa della sintesi e dello studio di ligandi per le interazioni con diverse biomolecole, adattando la strategia delle piccole molecole e delle supramolecole a seconda degli obiettivi. Mentre l'efficacia delle piccole molecole a questo scopo ha permesso lo sviluppo di farmaci, le supramolecole non sono mai state utilizzate come farmaci ma il loro impiego, in alcuni casi, si è rivelato altamente efficace nell'interazione con le biomolecole. A questo proposito, lo scaffold calixarenico è stato selezionato per la flessibilità dimostrata nella funzionalizzazione selettiva e multipla
Salification and cocrystallization to ameliorate physiochemical properties of drugs. Investigation of their interactions inside liposomal formulation with Small Angle X-ray Scattering.
No full textThe pharmaceutical industry is in a state of constant evolution, driven by the pursuit of innovative strategies to address persistent challenges in drug delivery. These challenges include, on one side, the burning need for more accessible and cost-effective methods to enhance solubility, dissolution rate, and permeability of drugs and, on the other side, the implementation of characterization methods of lipid nanoparticles that has never been so crucial.
In this work, salification of theophylline with squaric acid represents the first step in this direction, addressing the challenges posed by its infamous narrow therapeutic indices. Salification reduces API dissolution by a remarkable 54% within the critical first 10 minutes, simulating a controlled released formulation and therefore better controlling the therapeutic and adverse effects of theophylline.
Meanwhile, the cocrystallization technique is revolutionizing the delivery of caffeine, a psychoactive substance known for its adverse effects like nervousness and anxiety due to unstable blood concentration levels. By co-crystallizing caffeine with various small molecules, solubility, dissolution rate, and permeability can be meticulously modulated. The caffeine-xinafoic acid cocrystal, for instance, significantly lowers caffeine solubility, decreases dissolution rate, and increases permeability, promising a more controlled and efficient caffeine delivery system.
Similarly, we explored the potential of salts and cocrystals to enhance the pharmacokinetics of benzocaine, a widely used local anesthetic. Nine new salts and one cocrystal have been synthesized, each offering substantial improvements in dissolution rates and permeability. These findings not only open avenues for increased bioavailability but also the prospect of extended duration of action for benzocaine.
Diving even deeper into the ability of a counterion to affect the physiochemical properties of a drug, the encapsulation of benzocaine salts into a lipid-base formulation like liposomes has been investigated.
Therefore, liposomal formulations are meticulously characterized using noninvasive techniques like Small-Angle X-ray Scattering (SAXS). Unique drug localization between lipid tails and alterations in liposome arrangement are unveiled. Furthermore, to make these advanced methods more accessible, a simplified SAXS data analysis method, the beating wave approach, is introduced.
This new data analysis method is compared with two different techniques: Fluorescence lifetime imaging microscopy (FLIM) and NanoDSC, both utilized to study all-trans retinoic acid (ATRA) nanoencapsulated in liposomes, and both suggesting interactions between ATRA and the liposomal membrane in good agreement with SAXS data.
In conclusion, these multifaceted innovations in pharmaceutical research promise to revolutionize drug delivery, enhance drug performance, and streamline characterization methods. Our aim is to continuously push boundaries, ushering in a new era of pharmaceutical science that addresses the demands for precision, efficiency, and accessibility in drug development