La femme, le chien et le clerc

This article explores the symbolical nexus between woman and animal in the Middle English fabliau of Dame Sirith and the Weeping Bitch. It offers a new interpretation of the character of Margery in the light of the Liber vaccae, a pseudo-scientific treatise that circulated widely in university circles from the early thirteenth century onwards. This work attests to the reality of the belief, even among the educated, of the possibility of turning a human being into an animal. The young wife’s credulity is not just an idiosyncratic weakness, therefore, as has generally been assumed by previous critics. Caxton’s version of the tale shows his uneasiness with this aspect of the fabliau, explaining his setting of the story in a distant, pagan land rather than Christian England, and his substituting a cat (with its attendant demonic association) to the dog of the earlier narrative. Cette étude explore le réseau symbolique entre femme et animal dans le fabliau moyen-anglais Dame Sirith and the Weeping Bitch, et offre une réinterprétation du personnage de Margery à la lumière du Liber vaccae. Cet ouvrage (pseudo-)scientifique bien connu dans les milieux universitaires dès le début du XIIIe siècle atteste une croyance en la possibilité de transformer un être humain en animal: la crédulité de la jeune femme relèverait ainsi d’un trait de société, tout autant que d’une faiblesse personnelle. Les changements apportés par Caxton à sa version du fabliau – en particulier, sa substitution d’une chienne par une chatte dans son récit de la ruse de l’entremetteuse, et un retour au context païen de l’histoire telle que la relate Petrus Alfonsi – sont révélateurs d’un désir de distanciation par rapport à une thématique plus dérangeante que ne l’aurait soupçonné le lecteur du XXIe siècle

Understanding mixing processes in stars using hydrodynamic simulations

Waves that propagate in stellar interiors are essential to stellar physics for two reasons. First, the interiors of stars are studied by detection of global modes of oscillations resulting from wave interference. Secondly, waves are involved in various transport phenomena. In stars, there are two main types of waves: acoustic and gravity. This duality of waves as observational tools and physical processes impacting stellar structure makes them a crucial field of study in astrophysics. In this thesis, we focus on internal gravity waves (IGWs), which are well known for transporting angular momentum, energy and chemical elements in stably stratified media. Despite observations of very high precision, detection of IGWs is still challenging and their properties in stellar interiors remain poorly understood and/or constrained. This is mostly because IGWs are inherently 3D, non-linear and anisotropic phenomena. Consequently, multidimensional modelling is a great tool to study these waves. However, stellar hydrodynamics faces important challenges such as numerical stability and thermal relaxation. To face them, an artificial increase of the stellar luminosity and of the thermal diffusivity by several orders of magnitudes is a commonly used tactic. Using two-dimensional simulations of a solar-like model, we quantify the impact of such a technique on IGWs. Our results suggest that this technique affect the excitation of IGWs, because of an impact on convective motions and overshooting, but also their damping. Main-sequence intermediate-mass stars, with M ≳ 2M⊙, possess a convective core and a radiative envelope. It remains unclear if waves generated at the edge of the convective core should be able to propagate up to the stellar surface. In this context, we have carried out an analysis of IGWs in simulations of 5 M⊙ star model. Our results show that low frequency waves excited by core convection are strongly impacted by radiative effects as they propagate. In the upper layers of the simulation domain, we observe an increase of the temperature, likely due to heat added in these layers by IGWs damped by radiative diffusion. We show that nonlinear effects linked to large amplitude IGWs may be relevant just above the convective core. Both these effects are intensified by the artificial enhancement of the luminosity and radiative diffusivity. Our results also highlight that direct comparison between numerical simulations with enhanced luminosity and observations must be made with caution

A Visibility and Spatial Constraint-Based Approach for Geopositioning

Over the past decade, automated systems dedicated to geopositioning have been the object of considerable development. Despite the success of these systems for many applications, they cannot be directly applied to qualitative descriptions of space. The research presented in this paper introduces a visibility and constraintbased approach whose objective is to locate an observer from the verbal description of his/her surroundings. The geopositioning process is formally supported by a constraint-satisfaction algorithm. Preliminary experiments are applied to the description of environmental scenes

A semantic and language-based representation of an environmental scene

The modeling of a landscape environment is a cognitive activity that requires appropriate spatial representations. The research presented in this paper introduces a structural and semantic categorization of a landscape view based on panoramic photographs that act as a substitute of a given natural environment. Verbal descriptions of a landscape scene provide themodeling input of our approach. This structure-based model identifies the spatial, relational, and semantic constructs that emerge from these descriptions. Concepts in the environment are qualified according to a semantic classification, their proximity and direction to the observer, and the spatial relations that qualify them. The resulting model is represented in a way that constitutes a modeling support for the study of environmental scenes, and a contribution for further research oriented to the mapping of a verbal description onto a geographical information system-based representation

A Visibility and Spatial Constraint-Based Approach for Geopositioning

Over the past decade, automated systems dedicated to geopositioning have been the object of considerable development. Despite the success of these systems for many applications, they cannot be directly applied to qualitative descriptions of space. The research presented in this paper introduces a visibility and constraintbased approach whose objective is to locate an observer from the verbal description of his/her surroundings. The geopositioning process is formally supported by a constraint-satisfaction algorithm. Preliminary experiments are applied to the description of environmental scenes

A multilocus sequence analysis of Xanthomonas campestris reveals a complex structure within crucifer-attacking pathovars of this species

Previous classification of Xanthomonas campestris has defined six pathovars (aberrans, armoraciae, barbareae, campestris, incanae, and raphani) that cause diseases on cruciferous plants. However, pathogenicity assays with a range of strains and different hosts identifies only three types of symptom: black rot, leaf spot and bacterial blight. These findings raise the question of the genetic relatedness between strains assigned to different pathovars or symptom phenotypes. Here we have addressed this issue by multilocus sequence analysis of 42 strains. The X. campestris species was polymorphic at the 8 loci analysed and had a high genetic diversity; 23 sequence types were identified of which 16 were unique. All strains that induce black rot (pathovars aberrans and campestris) were genetically close but split in two groups. Only three clonal complexes were found, all within pathovar campestris. The assignment of the genome-sequenced strain 756C to pathovar raphani suggested from disease symptoms was confirmed, although this group of strains was particularly polymorphic. Strains belonging to pathovars barbareae and incanae were closely related, but distinct from pathovar campestris. There is evidence of genetic exchanges of housekeeping genes within this species as deduced from a clear incongruence between individual gene phylogenies and from network structures from SplitsTree analysis. Overall this study showed that the high genetic diversity derived equally from recombination and point mutation accumulation. However, X. campestris remains a species with a clonal evolution driven by a differential adaptation to cruciferous hosts