NCube/papyrus huggingface dataset:
Fondements métaphysiques des probabilités leibniziennes par le degré de perfection des mondes possibles

In this thesis, we attempt to prove the plausibility of Hacking's (1971) thesis saying that we can link the Leibniz’s metaphysics of possible worlds to the theory of probabilities. To show such a relationship between these two domains, we highlight Pascal's solution and Fermat's solution to the problem of points (or the problem of division of the stakes) for a game of chance, often considered as the foundation of mathematical probabilities. Furthermore, we also detail the nature of the Leibniz’s metaphysics of possible worlds: constrained by eternal truths, and from elementary possibilities that God can see by iteratively reflecting to himself, a construction of possible worlds can be done. Inclined by his goodness, by a moral necessity, God comes to choose the best of worlds and freely decides to create it. Pointing out that Leibniz indicates in De incerti aestimatione (dated September 1678), that probability is the degree of possibility, we show that a direct link emerges between Leibniz’s metaphysics and probabilities. For such a conception of the probable to emerge, we show that several conditions must be respected in Leibnizian metaphysics. Whereas Hacking (1971) attempted to compare it with Carnap's inductive logic, we show that the Leibnizian doctrine of probability can also be interpreted by considering the Leibniz's method of hypotheses. Finally, by introducing Bernoulli's law of large numbers and more particularly the inverse application of his theorem, we show that the Leibniz’s doctrine of probability brings to light a whole new interpretation of probabilities.

Keyphrases: Leibniz, Hacking, Metaphysics, Probability, Possible worlds, Degrees of perfection
La résistance du nom : Walter Benjamin et la liberté du langage

To start reading Benjamin constitutes a challenge in itself. It can be hard to grasp just what makes the variety of his topics part of the same philosophical quest. One often sees quotations from his work on well-known writers, such as Kafka or Brecht, or perhaps has heard the title of a very famous essay on the technological reproductibility of art. But these hardly make up for the depth of his work. This paper will try to answer for the demand his work imposed on philosophy: to find in the study of language (and the gesture of writing) the resources of its resistance against the invisible yet ubiquitous violence perpetrated by the myths of our culture, which we have to decipher in their endlessly mutating forms. By choosing as a starting point one of his well-known concern – the loss of experience – and by acknowledging different interpretations – whether it is seen from a theological or historical materialism stand point – it will be demonstrated that his concept of medium and the unusual role it takes within meditations of an ethical nature can be used as a lever for the transformation of the concept of freedom. Though this word might not appear very often in his work, when it does, it often has something to do with one’s own dealing with language, whether it is his or another langage. The first chapter will focus on his metacritic of Kant’s concept of the transcendental subject, carried out by the disclosure of the overlooked connection between reason and language. It will be followed by the introduction of the concept of medium that stems from his study on the first romantics. The second chapter will go deeper into the relationship between philosophy and art that ensues. His theory on literary criticism will be presented in relation to the importance of the theological stance that pertains to his theory on translation. By focusing on his work The Origin of German Tragic Drama, the third chapter will bear witness to his critical gesture. Through the presentation of the historical content of the work, this study discovers the very origin of the impoverishment of our experience and the difficulties of finding a concept worthy of its fullness, justifying in reverse the ethical stance his philosophical thinking engages in.

Keyphrases: langage, nature, histoire, Translation, Language, History, Theology
Neogenin function and modulation in spinal motor neuron development

The nervous system is the most exquisitely complex functional structure in the known universe. The nervous system is what enables multicellular organisms to experience life as individual entities. The functionality of the nervous system relies upon the precise assembly of neuronal circuits. To achieve this, during development, the extending axons of neurons are guided by cues in the extracellular environment that enable neurons to find their respective targets. To sense and respond to extracellular cues, growth cones at the tip of axons express guidance cue receptors. The interaction between guidance cues and their receptors induce downstream signaling cascades which lead to modulations in axon outgrowth and directionality. Although we have made great progress in understanding how individual cues guide axons, much less is known about how these cues act in concert. Motor neurons that reside within the lateral motor column (LMC) of the spinal cord extend axons that innervate the limbs, rely on a multitude of guidance cues. The evidence presented in this thesis shows that the transmembrane receptor Neogenin is implicated in several aspects of LMC neuron development including LMC subtype differentiation and segregation as well as the guidance of their axons. Our lab has previously shown that LMC axons are guided synergistically by Netrin-1 and ephrins. I will be presenting results exploring the mechanism underlying the synergistic activity of Netrin-1 and ephrin-A5 in LMC axon guidance. I provide evidence that ephrin-A5 sensitizes a subset of LMC axons to Netrin-1. I propose that this is a consequence of an ephrin-A5 induced increase in the abundance of iv Neogenin leading to enhanced Netrin-1 binding in LMC growth cones. Furthermore, I show that the ephrin-A5 modulation of Neogenin levels is dependent on the interaction between ephrin-A5 and its receptor EphA4. I also show that contrarily to the repulsion from ephrin-A5, sensitization to Netrin-1 occurs independently from the cytoplasmic tail of EphA4. These results suggest that the ephrin-A5 induced axon repulsion and sensitization to Netrin-1 occur in molecularly distinct pathways. Netrin-1, Neogenin and ephrins are vastly implicated during the development of the nervous system and beyond. Our demonstration that ephrin-A5/EphA4 interactions modulate the abundance of Neogenin and sensitivity to Netrin-1 brings forth the possibility that ephrins may have a profound impact on cellular processes implicating Netrin-1 and Neogenin.

Keyphrases: Neogenin, Axon guidance, Motor neuron, Guidage axonal, Netrin-1 ephrin
Structure de culture et minimalisme : l’enjeu politique du minimalisme sémantique

For most political philosophers, language is rarely a primary concern. Sometimes it is only seen as a tool of communication, while at other times, it is linked to a specific cultural group. Be that as it may, language doesn’t seem valuable enough to be considered as an independent object of study that plays a specific role in political theory. Yet, in the context of a liberal political philosophy, it seems legitimate to ask ourselves to what extent a liberal state can protect language without being accused to promote specific values within the community. In other words, is it possible for a liberal philosopher to promote linguistic laws and protect a specific language without violating the liberal principle of neutrality and the primacy of justice over good? With this question in mind, I try to explore a fundamental debate in philosophy of language that could shed some light on the contentious issue of liberal neutrality: the dispute between minimal semantics (E. Borg, E. Lepore et H. Cappellen) and those who promote contextual semantics (R. Carston, Sperber, Wilson, F. Recanati). By studying this debate, we will try to show that it is possible to distinguish between language and speech, meaning and belief system, literal meaning and occurrent meaning. We will try to answer the following question: is the cultural character of one community, understood as a set of background beliefs, values and ends, necessary for linguistic understanding or, is it possible to minimally understand these linguistics acts without the context of utterance? In other words, can language be understood as a fundamental part of the cultural structure as suggested by Will Kymlicka, as opposed to the character of culture? Our goal is to demonstrate that it is possible to promote language inside a liberal framework by showing that language is a relatively neutral and minimal institutional good.

Keyphrases: Political philosophy, Language philosophy, Liberalism, Conventionalism
The influence of cell size on cytokinesis in situ and genomic interrogation of human cell size regulation

Cells are the fundamental building blocks of life. The human body contains over twenty trillion cells that make up the different tissues and organs of our bodies. Cells within organs are of specific sizes to perform their specialized functions. In most cases, these cells must divide to proliferate and replenish the population of cells essential for proper organism function. The final stage of cellular division, termed cytokinesis, entails the assembly and constriction of a contractile ring that drives the dramatic cell shape changes required to physically partition the cell into two daughter cells. The first part of the work presented in this thesis addresses the characterization of cytokinesis in the epithelial vulval precursor cells (VPCs) of the nematode worm C. elegans. This study principally revealed that several aspects of cytokinesis scale with cell size. For instance, I observed that the breadth of the actomyosin ring scaled with VPC length. In addition, the speed of contractile ring constriction scaled with the circumference of VPCs. These scaling events raised the more general question as to how cells regulate their size. Proliferating cells attain cell size homeostasis by balancing cell growth and cell division. In order to define the molecular regulators of size in human cells a genome-wide approach was taken. Recently developed CRISPR/Cas9 technology was used to perform the first pooled knockout screens for human cell size regulators in the NALM-6 pre-B lymphocytic cell line. These screens revealed many genes that affect the size of NALM-6 cells, a number of which were previously known to be involved in growth regulation. In addition, these screens revealed the identity of many genes with no previously established functions associated with cell size regulation. Amongst the previously unknown regulators, I characterized the function of a co-repressor of transcription, TLE4, which I showed functions as a regulator of the B-cell lineage. This work contributes to the knowledge of the mechanics of cytokinesis in C. elegans epithelial cells and of the genes that coordinate cell size in humans. These results provide insights into cell growth and division in normal cells and how these processes may be perturbed in cancer and other diseases.

Keyphrases: C. elegans, VPCs, CRISPR/Cas9, criblage, mTORC1, TLE4, Cytokinesis, cell size, screen
Caractérisation du nouveau rôle de la phosphatase dOCRL durant la division cellulaire

Cytokinesis is a dynamic process that requires a precise coupling of actomyosin forces with the plasma membrane. In metaphase, a uniform distribution of actomyosin forces through the plasma membrane allows the characteristic cell rounding. During anaphase, the cytokinetic machinery becomes concentrated at the equatorial cortex to allow the cleavage furrow formation. The mechanisms underlying the localization of the cleavage furrow are not fully understood. Here we demonstrate that the phosphoinositide PI(4,5)P2 acts as a spatial cue for cytokinetic machinery recruitment. We have shown in Drosophila S2 cells that when the 5- phosphatase dOCRL is knocked down, ectopic accumulation of PI(4,5)P2 on endomembranes recruits the cytokinetic machinery. dOCRL is the ortholog of the human OCRL1 protein. Mutation in OCRL gene is responsible for Lowe syndrome, a rare, multisystemic X-linked disorder. Our further investigations demonstrated a new and unexpected function of the phosphatase PTEN that rescued the cellular manifestation of the Lowe syndrome. This work allowed us to find a small molecule capable of rescuing the cellular and in vivo manifestations of Lowe syndrome. Our results could represent a new therapeutic avenue to treat this disease.

Keyphrases: PTEN, OCRL1, PhosphoInositides, Cytokinesis, Lowe syndrome
Le dalaï-lama et la science moderne

The author presents and analyses the thoughts of Tenzin Gyatso, His Holiness the fourteenth Dalai Lama, about the possibility of a fruitful dialogue between Buddhism and modern science. To do so, he focuses on a specific book of His Holiness: The Universe in a Single Atom. The author thus presents the Dalai Lama’s book, its intention and the context in which it is written. He then divides His Holiness’s reflection in three axes. First, the author explores the converging views of modern science and Buddhism, as underlined by the Dalai Lama. He then takes an interest in their points of divergence and their possible complementarity, while discussing the criticisms that His Holiness addresses to scientists. The author concludes with the Dalai Lama’s ethical concerns about science, its technological productions and the world view that it tends to convey. In doing so, the author doesn’t intend to criticize His Holiness’s position, but rather aims at highlighting the philosophical relevance of Buddhism’s theoretical foundations, as well as the Dalai Lama’s approach.

Keyphrases: conscience, science, Dalai Lama, Buddhism, Ethics, Emptiness, consciousness, Quantum Physics, Consciousness, Biology, Cosmology, Philosophy
Biais écologique de la méta-analyse avec modificateur d'effet sous le paradigme de l'inférence causale

In the aggregate meta-analysis of randomized clinical trials, one may attempt to assess treatment effects in a general population using the aggregate information (means, variances, proportions, etc.) only provided in each study. If the parameter of interest is the average causal effect of a treatment on an outcome, analysis using aggregate data is sufficient. However, when the parameters of interest are those of a marginal structural model (MSM) describing the treatment effect modification caused by another covariate, the parameters of the aggregate level model may be different from those of the individual level model. If so, the estimates from the aggregate data are biased for the true effect modification in the MSM. This is called "ecological bias".   The natural solution to eliminate this bias would be to base the meta-analysis not on the aggregate data, but rather on the raw data from each study. Unfortunately, investigators conducting a meta-analysis rarely have access to raw data from all studies. Estimating the MSM using only studies with raw data available is feasible, but this approach is prone to selection bias. We therefore propose to circumvent the problem by adjusting the estimators obtained at the aggregate level. This is done using information describing the relationship between the outcome and the effect modifier that can be obtained from the individual patient data.   In this thesis, we describe the source of ecological bias in the estimation of a treatment-specific MSM for a continuous outcome using the counterfactual perspective of causal inference. We propose estimators for the marginal regression parameters that are adjusted for ecological bias using the individual level regression parameters of a subsample of studies. We prove the convergence of these adjusted estimators. The effectiveness of the bias correction as well as the extent of the ecological bias in several scenarios are evaluated numerically through a simulation study.

Keyphrases: Meta-analysis, Ecological bias, Effect modification, Marginal structural model, Causal inference
Rigidité du crochet de Poisson en topologie symplectique

This master’s thesis is an introduction to C0 rigidity phenomena in symplectic topology. More precisely, the main concern is the C0 rigidity of the Poisson bracket on a symplectic manifold. The elementary notions of symplectic geometry and Hamiltonian dynamics are recalled in the first chapter. The second chapter introduces the Hofer geometry of the group of Hamiltonian diffeomorphisms of a symplectic manifold. Chapter 3 concerns the application of Hofer geometry to the study of functionals defined in terms of the Poisson bracket. The main result, due to Buhovski, Entov and Polterovich, is the lower semi-continuity of the functional which assigns to every pair of functions the uniform norm of their Poisson bracket.

Keyphrases: Symplectic topology, Poisson bracket, Hamiltonian dynamics, Hofer geometry, Symplectic rigidity
Concentration des fonctions propres de Steklov sur les composantes connexes de la frontière

The Steklov operator on a Riemannian manifold with boundary is an elliptic pseudodifferential operator of order one. It is known that the asymptotics of the Steklov spectrum of a surface is determined, up to a very small error, by the lengths of the connected components of the boundary. In this thesis, we focus on the asymptotic properties of Steklov eigenfunctions on surfaces. In particular, we show that if all the ratios between the lengths of the connected components of the boundary are irrational numbers not admitting fast approximation by rationals, then each high energy eigenfunction concentrates along a single boundary component.

Keyphrases: Spectre, Steklov, Concentration, Pseudodifferential, Spectrum, Boundary
Distribution de la valeur escomptée de la réserve IBNR avec un modèle lognormal et un taux d'intérêt aléatoire

It is assumed that IBNR claims follow lognormal distribution and we also assume the force of interest follows a GNL law. The force of interest is incorporated into the incremental predictive claims to find the discounted value of the reserve.

Keyphrases: Disribution GNL, GNL distribution, Lognormal linear model, incremental predictive claims, IBNR reserves, Expected value
Solutions à courbure constante de modèles sigma supersymétriques

This master’s thesis is about constant curvature holomorphic solutions of the supersymmetric G(M,N) sigma models. We begin with a general presentation of the G(M,N) bosonic model. Then, after an introduction to supersymmetry, we construct a N = 2 supersymmetric extension of the model. We develop the gauge invariance of the SUSY model in details. Afterwards, we find a condition to obtain constant curvature solutions. We use this condition to obtain the existence of a supersymmetric constant curvature solution for all G(M,N) models. It is based on a result recently obtained in the litterature [15] for the CPN−1= G(1,N) model. We go back on the developments that lead to this last result and explain how to use the gauge invariance to show the uniqueness of the solution. Our main contribution to this work was to determine holomorphic constant curvature solutions of the SUSY G(2, 4) model from the corresponding bosonic solutions, using the gauge invariance.

Keyphrases: Sigma models, Gauge invariance, Supersymmetry, Gaussian curvature, Holomorphic functions
«Sur la figure des colonnes» de Lagrange revisité

The column's bucking load problem was formulated by Lagrange around 1770. There were many solutions proposed, but all contained some errors. Lagrange himself claimed the solution had a straight cylinder section, which was found to be suboptimal later. False solutions were mainly caused by the non-differentiability of the problem. In 1992, Cox and Overton revisited the problem using Auchmuty's dual principle and Clarke's generalized gradient. They established the existence of a solution by only considering columns whose  profile is bounded above and below by some positive constants.  According to Egorov, Cox and Overton's a priori hypothesis excluded  possibly degenerated column's profiles and, as a consequence, they cannot   justify and claim the existence of solutions.   In this Master's thesis, we will study the optimal shape/profile  problem and look for all the available information without assuming the existence of a priori bounds. Firstly, we will study the discrete form of the problem which will allow us to restrict the problem in finite dimension and guarantee the existence. Nonetheless, the problem will still be non-differentiable as it will keep his important characteristics.  Essentially, in both continuous and discrete versions, we want to maximize the first generalized eigenvalue under a constant volume constraint.  Since the problem is Hadamard semidifferentiable, a necessary optimality condition can be obtained.  But in this work we rather concentrated on including possibly degenerate profiles by enlarging the  Sobolev space of inflections for the minimization problem. Those new "custom-made" spaces are better suited for our purpose but, at the same time, they introduce new mathematical challenges.   The column's bucking load problem can be viewed as a generic problem of optimizing the least non-simple eigenvalue. Therefore, this work is relevant in a broader perspective for mathematical and numerical purposes.

Keyphrases: Lagrange, Clampled-clamped column, Eigenvalue problem, Multiplicity, Necessary optimality conditions, Degenerate operator
Estimation des modèles à volatilité stochastique par l’entremise du modèle à chaîne de Markov cachée

The problem of estimating the parameters of stochastic volatility models by direct maximisation of the likelihood is addressed. To this end, we present an algorithm that numerically approximates the optimal filter from the methodology proposed by Kitagawa (1987) for solving the filtering problem in non-linear and/or non-Gaussian systems.  We show that this algorithm corresponds to running the Hamilton filter (the Hamilton filter offers an optimal solution to the filtering problem for a hidden Markov model on a finite state space) on a discretization of the continuous latent variable. The proposed solution significantly improves the computation time and produces results at least as good as stateof-the-art approaches in the field.  Subsequently, we present and demonstrate a generalization of this algorithm in the case of stochastic volatility models incorporating leverage and jumps. Several Monte Carlo and empirical studies are conducted to evaluate the quality of the approach for approximating the log-likelihood and estimating the parameters. We also present a comparison of this approach to the continuous particle filter approach.

Keyphrases: Stochastic volatility, Hidden Markov model, Non-linear and non-Gaussian filtering, Numerical integration, Maximum likelihood, Particle filter, Leverage effect, Jumps