702 research outputs found
Sort by
L'autonomia della psichiatria universitaria in Italia. Analisi dell'archivio "Carlo Lorenzo Cazzullo".
Get PDFmissin
Document image classification combining textual and visual features.
Get PDFThis research contributes to the problem of classifying document images. The main addition of this thesis is the exploitation of textual and visual features through an approach that uses Convolutional Neural Networks.
The study uses a combination of Optical Character Recognition and Natural Language Processing algorithms to extract and manipulate relevant text concepts from document images.
Such content information are embedded within document images, with the aim of adding elements which help to improve the classification results of a Convolutional Neural Network.
The experimental phase proves that the overall document classification accuracy of a Convolutional Neural Network trained using these text-augmented document images, is considerably higher than the one achieved by a similar model trained solely on classic document images, especially when different classes of documents share similar visual characteristics. The comparison between our method and state-of-the-art approaches demonstrates the effectiveness of combining visual and textual features.
Although this thesis is about document image classification, the idea of using textual and visual features is not restricted to this context and comes from the observation that textual and visual information are complementary and synergetic in many aspects
Developpement et optimisation de détecteurs de lumière innovants et bolométres scintillants pour une expérience pilote sur la double désintégration bêta sans émission de neutrinos
No full textThe PhD work described in this manuscript was performed in the framework of the LUMINEU project, a pilot search for the neutrinoless double beta decay (0νββ) of the isotope in 100Mo with ZnMoO4 scintillating bolometers. The main PhD activity has consisted the development of a particle detection technology able to fulfill the requirement of a next generation experiment on 0νββ capable of exploring the inverted hierarchy region of the neutrino mass pattern. We report about an experimental physics work involving progress in detector prototype design and tests, and development of tools in view of a large experiment preparation.
The neutrinoless double beta decay is a hypothetical rare nuclear transition with a half life T1/2>1025 years, which is possible for some nuclei with an even number both of protons and neutrons. In the 0νββ transition two neutrons decay simultaneously in two protons with the emission of only two electrons. In a first approximation it can be seen as two simultaneous β-decays where the two neutrinos act as a single virtual particle joining the two decay vertices. It is demonstrated that any process which leads to 0νββ is possible only if ν≡ ν̄ˉ, i.e. the neutrino is a Majorana particle, which is in contrast with the Standard Model assumptions. Therefore, the observation of this phenomenon can determine the Majorana nature of massive neutrinos. This is of fundamental importance to make progress in our understanding of the origin of neutrino masses and mixing and of the symmetries governing the lepton sector of particle interactions. The measurement of the T1/2
of the process would give unvaluable information on the absolute scale of neutrino masses, the type of neutrino mass spectrum and the Majorana phases. The detection approach adopted in this thesis is the homogeneous bolometric technique, which fits well the detector characteristics needed to investigate rare events. The detector provides high efficiency and a very good energy resolution and, thanks to a scintillating absorber, it allows particle discrimination for background suppression. As can be easily understood, the control of the background is crucial to measure such rare decays.
The first part of this thesis focuses on the neutrino physics and on the 0νββ decay; moreover the experimental detection approaches are briey discussed and the sensitivity to the half life of a 0νββ experiment is discussed. To understand the progress achieved in the technology development, the following chapter is dedicated to the detector physics: the components of a bolometer, a simple thermal model, and the detector response are introduced.
The second part of this work is dedicated to the setup. The detectors used work at very low temperatures (~10 mK), thus sophisticated thermal machines are needed; the working principles of these cryogenic systems are presented focusing on the details of the ones used in this work. Since the experimental work discussed in this thesis concerns the detector assembly and measurement, the data acquisition and analysis are discussed in details too.
The final part of the thesis is devoted to the results, starting with the progress made on bolometric light detectors: a description and optimization of the light detector design, the effect of anti-reflective coating and the thermal response enhancement obtained with the Neganov-Luke effect are presented. The results on the development of the LUMINEU prototype detectors and the measurements are summarized, from the working tests to the radioactive contaminant measurements. The growth and purification process of the ZnMoO4 crystals are also presented. Based on these results, a final sensitivity of a future experiment based on this detector is computed.
Finally we present a spin-off of the LUMINEU project consisting in a scintillating bolometer prototype made with an alternative compound absorber, Li2MoO4. We examine the advantages and disadvantages with respect to the ZnMoO4.
This manuscript aims at being a guide to an experimental approach for the search for neutrinoless double beta decay, a manual for scintillating bolometer operations and a report about the successful LUMINEU project. Le travail de doctorat exposé dans ce manuscrit a été développé dans le cadre du projet LUMINEU, une expérience pilote pour la double désintégration bêta sans émission de neutrinos (0νββ) de l'isotope 100Mo avec des bolométres scintillants de ZnMoO4. L'activité principale du doctorat consistait en le développement d'une technologie de détection de particules capable de satisfaire les conditions nécessaire d'une experience de 0νββ de nouvelle génération qui soit capable d'examiner la région de la hiérarchie inversée du modèle de la masse du neutrino. Nous exposons un travail de physique expérimentale qui implique l'avancement du design et des tests des prototypes de détecteurs, et le développement des outils en vue de la préparation d'une expérience importante.
La double désintégration bêta sans émission de neutrinos est une hypothétique transition nucléaire rare avec une demi-vie de T1/2>1025 ans, qui est possible pour certains noyaux avec un nombre pair de protons et de neutrons. Dans la transition 0νββ deux neutrons se désintégrent simultanément en deux protons avec l'émission de deux électrons seulement. Dans une première approximation, ce peut être vu comme deux β désintégrations où les deux neutrinos agissent comme une seule particule virtuelle en joignant les deux sommets de désintégration. Il est prouvé que n'importe quel processus qui conduit au 0νββ est possible seulement si if ν≡ ν̄ˉ, v.g. le neutrino est une particule de Majorana, qui contraste avec les hypothéses du Modèle Standard. Par conséquence, l'observation de ce phénomène peut déterminer la nature Majorana des neutrinos massifs. C'est très important de faire progresser notre compréhension de l'origine de la masse et de la composition des neutrinos et de la symétrie qui régit le secteur des leptons des interactions de particules. La mesure du T1/2 du processus peut fournir des informations inestimables sur l'échelle absolue de la masse des neutrinos, sur le type de spectre de masse des neutrinos et sur les phases de Majorana. La méthode de détection adoptée dans cette thèse est la technique bolométrique, qui s'intègre bien avec les caractéristiques requises des détecteurs pour étudier les événements rares. Le détecteur fournit une grande efficacité et une très bonne résolution en énergie et, grâce à un absorbeur scintillant, il permet la discrimination des particules pour la suppression du fond. Comme on peut bien comprendre, le contrôle du background est crucial pour mesurer ces désintégrations rares. La première partie de cette thèse se concentre sur la physique du neutrino et sur la désintégration 0νββ; en outre, les méthodes de détection expérimentales et la sensibilité de la demi-vie d'une expérience 0νββ sont traitées. Pour comprendre les progrès réalisés dans le développement de la technologie, le chapitre suivant est dédié à la physique des détecteurs: les composants d'un bolomètre, un modèle thermique simple, et la réponse d'un détecteur sont présentés.
La deuxième partie de ce travail est dédiée au setup. Les détecteurs utilisés fonctionnent aux très basses températures (~10 mK), par conséquent, des machines thermique sophistiquées sont nécessaires; les principes de fonctionnement de ces systèmes cryogéniques sont présentés en se concentrant sur les détails de ceux qui ont été utilisés dans ce travail. Puisque l'activité expérimentale présentée dans cette thèse porte sur l'assemblage et sur les mesures du détecteur, aussi l'acquisition et l'analyse des données sont traités en détails.
La dernière partie de la thèse est consacrée aux résultats, à commencer par les progress réalisés dans le détecteurs bolométriques de lumière: une description et optimisation du design des détecteurs de lumiére, l'effet du traitement antireet et l'amélioration de la réponse thermique obtenue avec l'effet Neganov-Luke sont présentés. Les résultats sur le développement des prototypes des détecteurs LUMINEU et les mesures sont résumés. Les processus de croissance et purification des cristaux ZnMoO4 sont aussi présentés. Sur la base de ces résultats nous avons calculé une sensibilité finale sur une expérience à venir basée sur ces détecteurs.
Enfin, nous présentons un spin-off du projet LUMINEU qui consiste dans un prototype d'un bolomètre scintillant réalisé avec un absorbeur composé alternatif, Li2MoO4. Nous examinons les avantages et les désavantages par rapport au ZnMoO4. Ce manuscrit a comme but d'être un guide à une approche expérimentale pour la recherche de la double désintégration bêta sans émission de neutrinos, un manuel pour les opérations de bolomètres scintillants et un rapport sur l'expérience réussie du projet LUMINEU
La tutela dei minori in biomedicina: nuove sfide per l'etica clinica.
Get PDFClinical ethics in paediatrics may be considered as the clinical application of ethics in the field of paediatrics and its sub-specialties and there are many healthcare settings where the applications of clinical and experimental medicine in paediatrics pose ethical questions of paramount importance, and in which it is often difficult, for healthcare professionals, to make appropriate choices.
The purpose of the PhD project was to analyze the main clinical ethical issues in some areas of pediatrics that have been poorly addressed since nowadays in the literature and may therefore represent new challenges both for ethical reflection and for the contribution that clinical ethics counseling can provide for the analysis of conflicts in concrete cases. When dealing with individual situations it is important to ensure more adequate protection as possible for children involved, in order to respect the rights of children as embodied by the Convention on the rights of the child, which entered into force September 2, 1990.
Each topic has been dealt with starting from the medical ethics principles, in particular, the principle of autonomy and the characterization of the best interests of the child, both when children are placed in their familiar environment and thus are involved in definite relationships with parents, and when they are placed, more generally, in relation to society and to the needs of health promotion and protection of the common good that emerge from research.
The contribution given by clinical ethics consultation can be applied in everyday paediatric practice, facilitating conflict resolution in an atmosphere of respect and attention to the interests, rights and responsibilities of all persons involved
Comparison of multiple techniques for endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) specimen preparation in a single institution experience.
Get PDFmissin
Il sepolcreto dell’Ospedale Maggiore (Ca’ Granda) di Milano: indagini antropologiche di un singolare contesto di resti commisti
Get PDFRecently lots of human inhumations have been found in the burial chambers of Milan ancient hospital (Ospedale Maggiore commonly named Ca’ Granda). This institution was able to provide free medical assistance for the poorest of the city and to improve efficiency in healthcare starting from the 15th century. Actually, only people suffering from acute diseases could be admitted to this hospital. The Ca’ Granda connected the concept of charity with the therapeutic ideas, being a model for similar institutions in Italy and all over Europe.
The commingled human remains found into the burial chambers represent an extraordinary biological and historical archive remarkable for the large amount of bones (over 2.000.000 remains estimated) and the uniqueness of the context. In fact, according to the historical sources, the osteological findings refer to the deceased population from the 17th century onwards.
In order to outline the main features of this context, standard macroscopic and microscopic anthropological and paleopathological analyses have been carried out. In addition, toxicological, chemical and entomological studies have been conducted. Furthermore, taphonomic modifications have been observed.
Results allow to classify the context as a long-term usage commingled assemblage, indicative of long-term use of the same burial space through time, sometimes over hundreds years, as confirmed by the entomological study. The population seems to be heterogeneous both from sex and age, showing remains belonging to males and females of all age classes, even foetuses. Paleopathological studies reveal the presence of signs referring to lots of different diseases, such as osteoarthritis, erosive arthropathies, congenital anomalies, metabolic disorders, dental diseases. Particularly interesting are the infectious pathologies, especially the signs of syphilis, and the evidences of trauma. Results also show how important laboratory analyses may be in providing additional pieces of the complex puzzle of palaeopathological analysis.
This study represents a remarkable case of commingled human remains and highlights the importance of a multidisciplinary approach
Fistole rinoliquorali spontanee: verso un moderno algoritmo diagnostico-terapeutico.
Get PDFIntroduzione: Le fistole rinoliquorali spontanee sono un eterogeneo gruppo di fistole a cui afferiscono tutti i casi di fistola rinoliquorale per le quali non è stata possibile identificare un meccanismo eziopatogenetico. Permane tuttavia il dubbio da parte di molti autori che in tale gruppo confluiscano fistole rinoliquorali causate da patologie non correttamente diagnosticate. Sebbene siano state effettuate numerose ricerche per meglio identificare l’eziologia e la patogenesi delle fistole rinoliquorali spontanee non si è ancora giunti a formulare un algoritmo diagnostico-terapeutico condiviso. Tale tipologia di fistole, dai dati ricavati dalla analisi della letteratura, è gravata da un maggiore tasso di recidiva rispetto alle fistole a eziologia nota probabilmente proprio poiche' il fattore eziopatogenetico rimane spesso misconosciuto e conseguentemente non trattato.
Materiali e Metodi: Il presente studio, attraverso una valutazione retrospettiva della casistica (2002-2013) delle Cliniche Otorinolaringoiatrica e Neurochirurgica dell’Ospedale del Circolo e Fondazione Macchi-Università degli Studi dell’Insubria di Varese, analizza una popolazione di 103 pazienti sottoposti a intervento chirurgico di riparazione di fistola rinoliquorale spontanea. Scopo di questa tesi è arrivare alla stesura di un algoritmo diagnostico-terapeutico per le fistole rinoliquorali spontanee e in particolare identificare le indagini diagnostiche opportune per una diagnosi precoce delle fistole rinoliquorali spontanee e validare l’approccio endoscopico endonasale come tecnica chirurgica di scelta nel trattamento delle fistole rinoliquorali spontanee.
Discussione: L' algoritmo diagnostico da noi utilizzato ha permesso una rapida diagnosi ed una precisa localizzazione della fistola, e di conseguenza la pianificazione dell’intervento chirurgico più adeguato per il paziente. L’approccio endoscopico endonasale ha inoltre soppiantato nella maggior parte dei casi gli approcci intracranici ed extracranici non endoscopici, relegando quest’ultima tecnica al solo intervento combinato endoscopico-lembo osteoplastico frontale per il trattamento delle fistole rinoliquorali spontanee della parete posteriore del seno frontale. I vantaggi della chirurgia endoscopica consistono soprattutto in una minore invasività, che consente di evitare le principali complicanze dell’approccio intracranico come la lesione del bulbo olfattorio con conseguentemente anosmia, l’edema cerebrale.
Conclusioni: L’utilizzo di un valido algoritmo diagnostico-terapeutico ha infatti permesso una corretta e tempestiva diagnosi, una precisa localizzazione del difetto e un trattamento chirurgico ottimale. La possibilità di scegliere fra le varie tecniche d’approccio e di effettuare il tipo di chiusura ottimale, a seconda delle caratteristiche anatomopatologiche della fistola, risulta determinate per ottenere una bassa percentuale di recidive. Una maggiore comprensione della fisiopatologia delle fistole rinoliquorali spontanee potrebbe portare a un corretto inquadramento e a una adeguata classificazione di tale patologia poiché riconoscerne i meccanismi causali consentirebbe un miglioramento della loro gestione e permetterebbe di intraprendere, quando necessario, il trattamento più adeguato
Performaatività del linguaggio e risignificazione dei termini nella costruzione delle identità di genere.
Get PDFThis thesis aims to investigate the concept of performativity in the meaning given to it by the American philosopher Judith Butler. This means that this research refers to the Gender Studies' and Queer Theory's ambit of which the aforementioned scholar is one of the major representatives. In particular we chose to deepen the concept of performativity of language (beginning from the “speech act theory” analysis by philosopher John Austin) and its relation with gender. Thus we try to clarify in which sense gender is performative, to investigate which are its relations with the body and finally to evaluate if a resignification of the terms is possible, always referring to Butler's theories.
The structure of the thesis in its first half remains without doubt within the field of theoretic and critical treatment, in the second half instead it searches for confirmation of the theories in question by analysing some case studies.
What emerged is that the subjects always establish themselves in a double dynamic of subjection and subjectivity, they're vulnerable bodies but also capable of “agency” and these gendered bodies can be constructed by words in a performative manner, at the same time though the individuals themselves can speak and change the order of that discourse
Interfaces in implant dentistry.
Get PDFDental implants are a safe and effective solution for the prosthetic rehabilitation of partially and totally edentulous patients, as has been clearly demonstrated by several clinical articles with follow-up up > 20 years. The high percentage of long-term survival (> 95% at 10 years) that characterizes dental implants has made them an essential tool in modern dentistry, and today, implants are commonly used to support various types of prosthetic rehabilitation, such as fixed prostheses (single crowns, fixed partial dentures, fixed full arches) and removable dentures.
If we analyse an implant-fixed prosthetic restoration, it is possible to identify three critical levels or interfaces:
1. Bone/implant interface
2. Implant/abutment interface
3. Restoration/mucosa interface
The strengthening of each of these three interfaces is of fundamental importance in the ability to ensure the survival, biological integration, functional stability and aesthetic success of a prosthetic implant-supported restoration
