Liouville theory and uniformization of four-punctured sphere

Few years ago Zamolodchikov and Zamolodchikov proposed an expression for the 4-point classical Liouville action in terms of the 3-point actions and the classical conformal block. In this paper we develop a method of calculating the uniformizing map and the uniformizing group from the classical Liouville action on n-punctured sphere and discuss the consequences of Zamolodchikovs conjecture for an explicit construction of the uniformizing map and the uniformizing group for the sphere with four punctures.Comment: 17 pages, no figure

A simple model for heterogeneous flows of yield stress fluids

Various experiments evidence spatial heterogeneities in sheared yield stress fluids. To account for heterogeneities in the velocity gradient direction, we use a simple model corresponding to a non-monotonous local constitutive curve and study a simple shear geometry. Different types of boundary conditions are considered. Under controlled macroscopic shear stress $\Sigma$, we find homogeneous flow in the bulk and a hysteretic macroscopic stress - shear rate curve. Under controlled macroscopic shear rate $\dot{\Gamma}$, shear banding is predicted within a range of values of $\dot{\Gamma}$. For small shear rates, stick slip can also be observed. These qualitative behaviours are robust when changing the boundary conditions.Comment: 13 pages, 13 figure

Reduction for constrained variational problems on 3D null curves

We consider the optimal control problem for null curves in de Sitter 3-space defined by a functional which is linear in the curvature of the trajectory. We show how techniques based on the method of moving frames and exterior differential systems, coupled with the reduction procedure for systems with a Lie group of symmetries lead to the integration by quadratures of the extremals. Explicit solutions are found in terms of elliptic functions and integrals.Comment: 16 page

Northern Flint, Southern Roots: A Diachronic Analysis of Paleoethnobotanical Remains and Maize Race at the Aztalan Site (47-JE-0001)

Located in Southeast Wisconsin on the west bank of the Crawfish River, the Aztalan site was first settled by horticultural Late Woodland peoples. By the mid-eleventh century A.D., Middle Mississippian migrants arrived from the south. The site was eventually transformed into a fortified village with three platform mounds. During the later component, Middle Mississippian and Late Woodland peoples appear to have coexisted. This thesis consists of a diachronic comparison of floral subsistence remains and maize race at the site. The results of the analysis indicate that while the Late Woodland inhabitants grew maize, food production involving maize and native cultigens was intensified following the appearance of Mississippian traits. The transformation of the site into a fortified agricultural village may have related to intergroup hostility within the region and territorial circumscription. The analysis also identified a possible early Mississippian feasting context. Maize race data indicate both an Eastern Great Lakes connection tied to collared Late Woodland pottery, and a southern, likely American Bottom, connection. This thesis also explores environmental and social explanations for differences between the Aztalan floral assemblage and Late Woodland and Oneota subsistence within the region

Developing independent listening skills for English as an additional language students

This paper describes an action research project to develop online, self-access listening resources mirroring the authentic academic contexts experienced by graduate university students. Current listening materials for English as an Additional Language (EAL) students mainly use Standard American English or Standard British pronunciation, and far fewer materialsuse Australian or regional accents. Materials are also simplified or spoken at a slower speed, emphasizing comprehension-type questions, despite the fact that literature reveals effective listening development involves practice in real-life listening contexts. Academic listening materials conversely emphasize the formal lecture and development of note-taking skills. We developed a range of activities where listening input was accompanied by materials reflecting top-down and bottom-up strategies as well as other cognitive and meta-cognitive skills. Materials were developed over two action research cycles involving EAL research student participants. Paper-based exercises were trialed and then developed into online materials where students could create their own listening materials and build portfolios. Results from the participants in the workshops/focus groups indicate they were able to develop their listening skills independently because of the explicit and focused approach of the materials. However, even more explicit and simple instructional design was needed when translated into the online environment

Slow flows of yield stress fluids: complex spatio-temporal behaviour within a simple elasto-plastic model

A minimal athermal model for the flow of dense disordered materials is proposed, based on two generic ingredients: local plastic events occuring above a microscopic yield stress, and the non-local elastic release of the stress these events induce in the material. A complex spatio-temporal rheological behaviour results, with features in line with recent experimental observations. At low shear rates, macroscopic flow actually originates from collective correlated bursts of plastic events, taking place in dynamically generated fragile zones. The related correlation length diverges algebraically at small shear rates. In confined geometries bursts occur preferentially close to the walls yielding an intermittent form of flow localization.Comment: 4 pages, 4 figure

High Dimensional Classification with combined Adaptive Sparse PLS and Logistic Regression

Motivation: The high dimensionality of genomic data calls for the development of specific classification methodologies, especially to prevent over-optimistic predictions. This challenge can be tackled by compression and variable selection, which combined constitute a powerful framework for classification, as well as data visualization and interpretation. However, current proposed combinations lead to instable and non convergent methods due to inappropriate computational frameworks. We hereby propose a stable and convergent approach for classification in high dimensional based on sparse Partial Least Squares (sparse PLS). Results: We start by proposing a new solution for the sparse PLS problem that is based on proximal operators for the case of univariate responses. Then we develop an adaptive version of the sparse PLS for classification, which combines iterative optimization of logistic regression and sparse PLS to ensure convergence and stability. Our results are confirmed on synthetic and experimental data. In particular we show how crucial convergence and stability can be when cross-validation is involved for calibration purposes. Using gene expression data we explore the prediction of breast cancer relapse. We also propose a multicategorial version of our method on the prediction of cell-types based on single-cell expression data. Availability: Our approach is implemented in the plsgenomics R-package.Comment: 9 pages, 3 figures, 4 tables + Supplementary Materials 8 pages, 3 figures, 10 table

Sur le Regina Cœli: Paraphrase de l\u27antienne liturgique

A French arrangement for solo voice of the Regina Cœli, one of the Marian antiphons sung during night prayers (Compline). The music was composed by Charles Bordes and the lyrics are based on a poem by l\u27abbé Picard. Included as part of a supplement in the May 1911 issue of Mois Littéraire et Pittoresque, a monthly Catholic magazine published by the Maison de la Bonne Presse, which was run by the Augustine Fathers of the Assumption.https://ecommons.udayton.edu/imri_sheetmusic/1041/thumbnail.jp