NCube/papyrus huggingface dataset:
Performance d'une technique de tomodensitométrie synthétique par IRM pour le calcul de dose en radiothérapie

Magnetic resonance imaging (MRI)-guided radiotherapy has become a topic of great interest in the last decade, especially with MRI-linac prototypes being currently commissioned for clinical use. MRI has the benefit of providing high contrast in soft tissues while assuring zero imaging dose to the patient. However, the nuclear information contained in MRI data can have little link to electronic data, which is required by treatment planning systems and is obtained with computed tomography (CT). A lot of groups have developed several methods to produce simulated HU maps, called synthetic CT, from MRI images. The purpose of this work is to present and evaluate a new bayesian approach to produce synthetic CT using a gaussian mixture regression model (GMR). The method is also compared to an existing GMR method. The data consist of MRI images of three pig heads acquired following T1, T2, PD and PETRA sequences, resulting in 13 contrasts. CT images of each heads were also acquired at 120 kVp. The synthetic CT are then compared to the CT images and the errors on HU are analyzed. Finally, to evaluate the impact on the dosimetry, three simulated treatment plans were calculated, using the treatment planning system Eclipse. The plans were done on real CT and transferred to the synthetic CT. The errors on dose are evaluated using the dose-volume histogram (DVH) curves and several dose statistics as well as with analyses based on gamma index. The results show that Bayes-GMR yields a mean error of -7 ± 20 HU and GMR -4 ± 29 HU on synthetic CT. The mean errors are large for bone only (up to 150 HU). However, these bias lead to mean dose errors of less than 0.5 % for most of the treatment plans. Although the Bayes-GMR method performs better than the GMR method on 7 out of 9 treatment plans, a clinical improvement by the Bayes-GMR method is still to be demonstrated.

Keyphrases: Synthetic CT, MRI in radiotherapy, GMR model
Calculs ab initio de la fonctionnalisation du graphène par l’azote

Our project is conduced in collaboration with a plasma physics group. Our goal is to study and caracterize a new nitrogen doping process involving the late afterglow regime of a nitrogen plasma, by using calculations based on the density functional theory. We begin this text with a presentation of the current context in graphene doping and some motivations for the project. We also present theoretical considerations regarding our calculations. In the second chapter, we study the principal doping structures and present the formation energy results we obtained. The third chapter is about adsorbed nitrogens on the surface of graphene sheets. We calculated energy barriers for their migration and incorporation and found that the incorporation inside a monovacancy should be an easy process. Likewise, we study the interaction between two defects, namely a monovacancy and an adsorbed nitrogen and a pair of adsorbed nitrogens. It already seems clear that a vacancy attracts a nitrogen. As for the pair of nitrogens, more work is needed for a conclusion, but we have some leads. In the fourth chapter, we present the impact of including the K point of the first Brillouin Zone on the calculations. We note it induces a lowering of formation energies when included in the momentum space discretisation, and that this effect can be overestimated if the discretisation is too sparse. The last chapter presents the possible next steps to pursue this project.

Keyphrases: Nitrogen doping, Plasma doping, Adsorbed nitrogen, Density Functional Theory, Computer simulation, Formation energy, Defect interaction
Application radio-oncologique d'un plasma jet, l’APGD-t, pour le traitement de cancer du sein

This study takes place in the context of research and development of new cancer treatments using plasma technology: a recently discovered new application of plasma discharges. The latest scientific studies show that cancer cells (also including breast cancer cells) treatment with plasma has a promising future. Main characteristics that made non-thermal plasma a good candidate to eradicate cancer cells are (a) the production of a variety of reactive oxygen species (ROS), (b) the weak temperature operating conditions which respect biological tissues integrity, and (c) the possibility of a precise local treatment preserving adjacent area... Very good results in in-vitro and in-vivo treatments and, also, the possibility to have selectivity between healthy and tumoral cells let us see a promising future for clinical applications in oncological therapy. The plasma source used in this study is the APGD-t (Atmospheric plasma glow discharge-torch) which generates a He+O2 atmospheric non-thermal plasma discharge. This plasma was firstly characterized electrically; after that, this non-thermal plasma was used to treat cancer cells like STS117 (sarcoma) and MCF7, MDA-MB-231 (breast cells). After optimizing experimental parameters to avoid cells detachment and, ideally, inducing permeability in treated cells, we noticed that if no furrow (or track) was observed, treatment efficacy was reduced since mortality rate never exceed 20%. Nevertheless, if furrows (or tracks) are observed during plasma treatment, mortality rate can reach more than 90% as Dapi/Calcein AM staining shows. If damages induced by plasma treatment involve severe morphological changes of cells, FACS analysis become inappropriate since results are under-estimated (because of, amongst others, the weak number of cells detected). These furrows generated by application of the plasma jet on the media (which covered cells) allow the plasma to treat cells effectively. As we were able to identify lethal experimental conditions, the existence of selectivity using APGD-t treatment was explored. Result seems very hopeful. Indeed, we found some experimental settings providing us to have selectivity by killing cancer cells (MCF7 and MDA-MB-231) and preserving healthy cells (Arpe). However, during these latest tests, the reproductibility of the results was more complex: the observed changes of the He gas temperature may have been due to changes in the operating conditions (replacing the He bottle, variation in atmospheric conditions...). The in-vitro results presented in this thesis clearly confirm that the jet of a cold plasma, namely APGD-t, can selectively treated tumoral breast cells, which really give real hope for future clinical applications in the breast cancer treatment.

Keyphrases: APGD-t, cancer, FACS, plasma, cold plasma jet, cancer cells, breast cancer, oncology, physics, biomedical, apoptosis
Influence du trou noir supermassif central dans l’amas de galaxies MACS J1447.4+0827

X-rays observations have shown that the distribution of gas in galaxy clusters is far from uniform. Many clusters contain X-rays cavities, gigantic bubbles lacking X-ray bright gas. These bubbles are inflated by relativistic jets that originate from the active galactic nucleus of the central galaxy in the cluster. These jets heat the gas and offset the cooling of the intracluster medium. In this dissertation, I will present results obtained from the analysis of new radio observations from the Karl G. Jansky Very Large Array (JVLA, 9 hours) and new observations from the Chandra X-ray Observatory (70 ks or 19 hours) of MACS J1447.4+0827, a cluster at a redshift of z = 0.3755 especially luminous which harbours a central galaxy with extreme properties. Those observations have revealed new structures never seen before in this object such as a system of X-ray cavities (Pcav ≈ 8 × 1044 erg/s), relativistic jets (R ≈ 16 kpc) and a diffuse radio structure surrounding the central galaxy (R ≈ 155 kpc) associated with a mini-halo (P1.4GHz = 2.6 ± 0.9 × 1024 W/Hz). Furthermore, the Chandra data revealed an X-ray plume that matches the position of Hα filaments in the central galaxy. They also confirmed the presence of an active galactic nucleus at the core of the cluster that is visible at X-ray and radio wavelengths. Whether it is from the power of its mini-halo, from the energy in its cavities or from its high X-ray luminosity, MACS J1447.4+0827 has extreme properties and is among the most massive and X-ray bright clusters of galaxies known.

Keyphrases: Galaxies, Radio, Jets, Mini-halos, Galaxy clusters, Intracluster Medium, Active galactic nuclei, Black Holes, X-ray, Cavities
Étude ab initio de courbes de décharge de piles organiques ayant pour cathode des composés carbonylés

Organic batteries are believed to be an interesting alternative to the actual inorganic batteries because of their low-cost and environmental-friendly fabrication processes. Many recent studies have been successful in elaborating fast and easy numerical methods to scan a wide range of organic compounds relevant in battery applications, but most of them focuses only on the reproduction of the first plateau voltage. The aim of this master’s thesis is to reproduce the entire discharge curve of organic batteries with carbonyl-based cathode using ab initio methods. Different methods were compared to determine which one is the most suitable for this purpose including different exact-exchange functionals such as PBE and B3LYP and implicit solvation methods such as without solvent, PCM and SMD. The method yielding the best results was the SMD solvation method along with PBE functional which had a mean-squared deviation of 0,25 V compared to experimental results. However, this method wasn’t systematically the most accurate for each and every carbonyl compound studied. In most cases, B3LYP functional reproduced the experimental results with less accuracy than PBE functional. Also, overall, the differences between the voltage plateaus of the discharge curves were better reproduced than the plateaus themselves. In addition, by studying some compound’s energy levels, the degeneracy of the lowest unoccupied energy levels were related to the discharge curve constant shape. Finally, some tests were performed on novel materials to predict their discharge curve and some of them showed interesting properties for organic batteries using sodium as active element.

Keyphrases: Cathode, Energy, Simulation, Organic batteries, Carbonyl compounds
q-oscillateurs et q-polynômes de Meixner

An algebraic interpretation of the q-Meixner polynomials is obtained in this master's thesis. It is based on representations of U_q(su(1,1)) on q-oscillator states with the polynomials appearing as matrix elements of unitary q-pseudorotation operators. These operators are built from q-exponentials of the U_q(su(1,1)) generators. The orthogonality, recurrence relation, difference equation, and other properties of the q-Meixner polynomials are systematically obtained in this framework. Two introductory chapters on orthogonal polynomials, algebraic structures (encoding symmetry properties) and their connections to the associated physical systems precede the article.

Keyphrases: q-Meixner polynomials, q-oscillator, Algebraic interpretation, U_q(su(1,1)) algebra, Deformations of physical theories, Spectrum generating algebra, Runge-Lenz vector
Étude spectroscopique de décharge à barrière diélectrique à la pression atmosphérique dans des mélanges Ar/NH3 et Ar/Lactate d'éthyle

This thesis consists of an emission spectroscopy study of dielectric barrier discharges at atmospheric pressure in Ar/NH3 and Ar/Ethyl lactate mixtures. We were able to extract, by combining optical emission spectroscopy with a collisional-radiative model, the behaviour of active species inside the plasma like electrons and excited species. A time resolved study of the development of the discharge enabled us to determine that the electron temperature was at its maximum at the beginning of the discharge, then the electron number density rose to its maximum to the detriment of the electron temperature, followed by a fall of the electron density combined with a rise of the argon metastable number density associated with most of the light emission of the plasma. Moreover, a correlation between the electron temperature and the argon metastable number density permitted us to establish that the step-wise excitation and ionization processes were dominant in this type of plasma. We then showed that the ratio of argon and NH emission lines was not a good indicator of the behaviour of the electron energy distribution function. Finally, these types of Penning mixture discharges were use in thin-film deposition processes of biodegradable films on a thermal substrate for biomedical applications, as shown in the annexes through articles wrote in collaboration with l’Université Laval in Québec (Canada) and l’Université Paul Sabbatier in Toulouse (France).

Keyphrases: Argon, NH3, Dielectric barrier discharges, Atmospheric pressure, Ethyl lactate, Electron temperature, Metastable number density, Spectroscopy, Collisionnal radiative model
Recherche d’un boson de Higgs doublement chargé par diffusion de bosons vectoriels à désintégration leptonique dans le modèle de Georgi-Machacek avec le détecteur ATLAS au LHC

We seek to establish limits on the exclusion of a doubly-charged scalar resonance in the Georgi-Machacek model based on data gathered by the ATLAS experiment located on the LHC ring, at CERN. Key models that extend the scalar sector of the standard model by addition of weak isospin scalar triplets are listed, and their relationship with the custodial symmetry is studied. The phenomenology of the VBS process generating the doubly-charged resonance of the Georgi-Machacek model is presented, particularly regarding the VBS jets and charge misidentification. Mass reconstruction techniques in the presence of neutrinos and signal isolation techniques via cuts are explored, as well as their optimisation process. Expected limits are produced, and true limits will be obtainable once the standard model study on same-sign W bosons has been completed. A machine learning tool aiming to identify charge misidentification cases is suggested as a future asset for the analysis.

Keyphrases: ATLAS, VBS, Particle physics, Hadronic colliders, Higgs boson, Georgi-Machacek model, Same-sign leptons, Custodial symmetry, Multivariate analysis
Transfert d'information quantique et intrication sur réseaux photoniques

The analytic specifications of photonic lattices with fractional revival (FR) and perfect state transfer (PST) are reviewed in this master's thesis. The approach to their design which is based on orthogonal polynomials is highlighted. A compendium of analytic models with PST is offered. New results on their FR properties are included. The nearest-neighbour approximation is adopted in most of the review ; two analytic examples with next-to-nearest neighbour interactions are also presented. An introductory chapter on the description of the model for the spin chain point of view and the derivation of the model in photonic lattices precedes the article. The second system with next-to-nearest neighbour interactions will be presented in the appendix.

Keyphrases: Intrication, Information quantique, Perfect State Transfer, Fractional Revival, Quantum information, Quantum computer, Quantum wire, XX spin chains, Photonic lattices, Inverse spectrum problem, Orthogonal polynomials
Two principles of justice in the philosophy of John Rawls and libertarian critique of Robert Nozick

This work consists of an attempt to ground the rationality that is inherent to the theories of justice espoused by John Rawls and Robert Nozick; it does so by treating the foundational arguments for their principles of justice. The aim here is to contrast both of these foundations by first mapping the logic of Rawls' core arguments, which will then lead us to his basic political concepts: social justice, the principle of equality, rights and the distribution shares within a wider social contract. We will then contrast these concepts with those that Nozick introduces in his counter-argument.  By presenting and developing such a contrast, we will show that there exists fundamental ambiguities that underpin both liberal and libertarian theories; as a result, many of the concepts presented earlier will be called back into question.

Keyphrases: Justice as fairness, Distribution of justice, Theory of justice, Utilitarianism, Libertarianism, Liberalism, Liberal political theory, Principles of justice, Two principles of justice, Principle of the average utility, Lexical order, Least advantaged, Dichotomy rule, Original position, Veil of ignorance, Principles for institutions, Distribution of goods, State, Idea of good, Morality, Negative and positive arguments, Sustainability of the principles of justice, Nozick’s critique of the theory of justice
Constructivisme moral : la question de l’objectivité des faits moraux

This thesis will focus on the following question: can moral constructivism, particularly the one defended by Sharon Street, be considered a convincing metaethical view, able to answer in a distinctive way to the most important problems raised by the question of moral realism and the objectivity of normative facts? Accordingly, the first chapter will be dedicated to the understanding of what implies the question of realism. After having identified the principal alternatives between realism and antirealism, we will explore the main problems that the question raises from four different perspectives: metaphysics, moral disagreement, epistemology and moral psychology. The chapter will then be concluded on an analysis of the general position of moral constructivism regarding the realism/antirealism axis. Once the implications of the moral realism question understood, we will move in a second chapter to the details of Sharon Street’s philosophy. Will be discussed the antirealist arguments at the foundation of her position, the answers given to her 2006 article and the Darwinian Dilemma argument and the general conception of normative facts she defends in her Humean constructivism. The chapter will end on an analysis of possible normative implications that her constructivism could have. In conclusion, we should be able to determine if moral constructivism meets the conditions we have established at the beginning of our work.

Keyphrases: Sharon Street, Metaethics, Moral constructivism, Moral realism, Antirealism, Normativity
L’impact critique de l’éthique communicationnelle habermassienne dans la théorie démocratique d’Iris Marion Young

This master's thesis aims to critically examine the theory of deliberative democracy developed by Iris Marion Young in Inclusion and Democracy (2000). In this book, Young proposes a complex theory of democracy that is largely inspired by the theses developed by Jürgen Habermas, notably in Théorie de l’agir communicationnel (1981), Morale et communication (1983) and Droit et démocratie (1992). Many of Young's theses are developed from a critical look at habermassian theory: thus, it is important to clarify what Young really learns from these texts. We will therefore show that Young, while inspired to a great extent by habermassian theories, retains only a very small part of them, drawing instead on feminist theories. To do this, we will first analyze, in Chapter 1, the origins and development of Young’s theory in Inclusion and Democracy. This exercise will allow us to see that Young is inspired by Habermas, on the one hand to conceptualize the public sphere, and on the other hand to formulate rules of discussion. In chapters 2 and 3, we will therefore take a critical look at these two themes. These critical assessments of the youngian theory will lead us to conclude that a shift from the theoretical basis of habermassian theory to feminist epistemologies would be beneficial for Young's theory.

Keyphrases: Iris Marion Young, Jürgen Habermas, Démocratie, Philosophy, Democracy, Deliberation, Feminism, Ethic, Politic
Les visées de l'enseignement de la philosophie au collégial d'hier à aujourd'hui

Firstly, this master's thesis focuses on the historical justifications that established a place for philosophy within the compulsory education, starting in France, and then in Quebec. Secondly, it proposes to expose a tension that is inherent to the current redefinition of this teaching, namely the interlacing of its perfectionist and social intent with the valorization of the intellectual autonomy of each. For that purpose, we reinterpret a theoretical means that is defended by many in order to support this autonomy : axiological neutrality. These thoughts culminate towards a central question : is it desirable that the professor conceals her or his opinion on various topics in a classroom context ? Lastly, we defend that it is not necessarily the case, but that several means shall be mobilized to promote students intellectual autonomy.

Keyphrases: Transparence, Philosophy, Teaching, Compulsory education, Perfectionism, Intellectual autonomy, Neutrality, Academic freedom, Transparency
L'aperception pure ou la distance de l'objet : une étude sur la subjectivité dans la Critique de la raison pure

The present MA Thesis is a study of the notion of Apperception in Emmanuel Kant's Critique of pure reason, in so far as a dimension of reflexivity is therein implied. The first part will situate Apperception within the argument of the Deduction, which aims to legitimate the objective validity of the pure concepts of understanding. Apperception will be defined as the principle of intelligibility of experience. The second part will consist in an effort to explicate the characteristic of reflexivity attributed by Kant to Apperception. Divergent interpretations will be examined here, leading us finally to a conception of reflexivity which necessarily entails alterity.

Keyphrases: Philosophy, Kant, Pure Apperception, Subjectivity, Alterity
Le rôle du langage dans l'ouverture de l'être-au-monde : interprétation du chapitre V de la première partie d'Être et temps de Martin Heidegger

The present study puts forward an interpretation of the Chapter V of the first division of Martin Heidegger’s (1889-1976) Being and Time (1927), on the opening of Being-in-the-world and its constitutive moments – attunement, understanding and discourse – while highlighting its last moment, that is, language. Through our interpretation of this chapter, we want to clarify what is a world according to Heidegger and how it always relates to the three moments we just evoked: there can only be a world through attunement, understanding and discourse and it is through these three that Dasein exists daily. Only, in the daily existence of Dasein, the world appears within a daily attunement, understanding and discourse, in which things of the world are expressed in a humdrum and tedious way. Within discourse two possibilities stand out: hearing and keeping-silent. If keeping-silent has the possibility to “break the idle talk”, hearing has the possibility to let things say themselves in a new way. In hearing and keeping-silent, as possibilities of discourse, arise the possibility to redefine and see the world in a more accurate and new way. The aim of this study is to see how Heidegger’s thought in 1927 already articulates the problem of the relation between language and the world. We will argue that in doing so, Being and Time is already on the way towards the thought of poetry and language, as it will be elaborated in the 30s.

Keyphrases: Heidegger, Philosophy, Ontology, Hermeneutic, Phenomenology, Heidegger, Being and Time, Understanding, Language