Portraits of children in Québec art 1800-1860

Ce mémoire a pour objet l'étude d'un corpus de portraits d'enfants peints au Québec entre 1800 et 1860. Nous présentons d'abord un aperçu général du thème de 1'enfance tel qu'il s'est manifesté dans la peinture européenne et américaine dès le XVIe siècle. Cet aperçu est suivi d'une synthèse du contexte historique et artistique au sein duquel le portrait bourgeois s'est développé au Québec avec un examen de quelques-uns des premiers portraits d'enfants connus au Québec. Dans la deuxième partie, nous avons procédé à une étude stylistique et comparative du corpus à partir des différentes compositions que les artistes ont employées pour représenter l'enfant. Le corpus est divisé en deux catégories: les portraits de l'enfant en buste et ceux où l'enfant est représenté à 1'intérieur d'un groupe. Des comparaisons avec des portraits américains ont permis de dégager différentes similitudes mais aussi quelques éléments spécifiques propres au portrait d'enfant au Québec.The object of this thesis is the study of a corpus of portraits of children painted in Quebec between 1800 and 1860. After introducing the theme of childhood in European and American painting since the sixteenth century, we go on in the first part to examine the historical and artistic context in which the bourgeois portrait developed in Quebec as well as some of the earliest known portraits of children in Quebec. In the second part, we have undertaken a stylistic and comparative study of the corpus, using as our starting point the compositional arrangements employed by the artists to represent children. This led us to divide the corpus into two main categories : bust-length portraits of the child and group portraits. Comparison with American portraits has permitted us to identify compositional similarities as well as characteristic elements that constitute what is specific to portraits of children in Quebec.Montréal Trigonix inc. 201

Growth Media and Lipid Determination Comparison of High Rate Algae Ponds

Growth Media and Lipid Determination Comparison of High Rate Algae Ponds Eric Alexander Nicolai The feasibility of algal biofuel production relies on the use of a non-potable water source. Municipal wastewater is nutrient-rich and a cost effective option as a growth media in algae ponds. However, this resource may be too valuable for algal biomass production, as reclaimed wastewater is needed for surface irrigation and groundwater recharge. This thesis compares the performance of 4.2 m2 high rate algal raceway ponds (HRAPs) to 33 m2 HRAPs grown on primary settled wastewater during a media recycling study and a growth media comparison study using wastewater and reclaimed water. The comparative metrics of performance for this study included: pond productivity, settling efficiency, and nutrient removal. This thesis also discusses the variability of algal lipid content from wastewater ponds using three different lipid determination methods. Six 4.2-m2, 0.3 m deep HRAPs were compared to nine 33-m2 HRAPs located at the San Luis Obispo Water Resource Recovery Facility (SLOWRRF). During the media recycling study, the first round of growth (Round 1) included ponds operating at 2-day and 3-day hydraulic retention times (HRTs) for both pond sizes. The pond arrangements for the second round of growth (Round 2) were the same with the exception of no 2-day HRT for the 33-m2 pond set. Net biomass productivity in the 4.2-m2 ponds under predicted the productivity of the 33-m2 ponds. Settling efficiency was comparable between the different rounds of growth for both pond sizes. Total soluble nitrogen removal was predicted using 4.2-m2 ponds. Of the three lipid determination methods, the fatty acid methyl esters (FAMEs) quantification was the most precise between replicates. However, this method determined the lowest lipid content because it quantifies a better representative lipid content by excluding other constituents not relevant to biofuel production

A lattice path integral for supersymmetric quantum mechanics

We report on a study of the supersymmetric anharmonic oscillator computed using a euclidean lattice path integral. Our numerical work utilizes a Fourier accelerated hybrid Monte Carlo scheme to sample the path integral. Using this we are able to measure massgaps and check Ward identities to a precision of better than one percent. We work with a non-standard lattice action which we show has an {\it exact} supersymmetry for arbitrary lattice spacing in the limit of zero interaction coupling. For the interacting model we show that supersymmetry is restored in the continuum limit without fine tuning. This is contrasted with the situation in which a `standard' lattice action is employed. In this case supersymmetry is not restored even in the limit of zero lattice spacing. Finally, we show how a minor modification of our action leads to an {\it exact}, local lattice supersymmetry even in the presence of interaction.Comment: 18 pages, 7 figures, 1 reference added, 1 correcte

Estimation of Autoregressive Fading Channels Based on Two Cross-Coupled H∞ Filters

This paper deals with the on-line estimation of time-varying frequency-flat Rayleigh fading channels based on training sequences and using H∞ filtering. When the fading channel is approximated by an autoregressive (AR) process, the AR model parameters must be estimated. As their direct estimations from the available noisy observations at the receiver may yield biased values, the joint estimation of both the channel and its AR parameters must be addressed. Among the existing solutions to this joint estimation issue, Expectation Maximization (EM) algorithm or crosscoupled filter based approaches can be considered. They usually require Kalman filtering which is optimal in the H2 sense provided that the initial state, the driving process and measurement noise are independent, white and Gaussian. However, in real cases, these assumptions may not be satisfied. In addition, the state-space matrices and the noise variances are not necessarily accurately estimated. To take into account the above problem,we propose to use two crosscoupled H∞ filters. This method makes it possible to provide robust estimation of the fading channel and its AR parameters

Killer cell inhibitory receptors specific for HLA-C and HLA-B identified by direct binding and by functional transfer

AbstractAn inhibitory signal is delivered to natural killer (NK) cells and a subset of cytotoxic T cells upon recognition of HLA class 1 molecules on target cells. We demonstrate that soluble forms of killer cell inhibitory receptors (KIR) bind directly and specifically to HLA-C alleles on transfected cells. Furthermore, transfer of individual KIR Into NK clones reconstituted recognition of HLA-C on target cells, leading to inhibition of lysis. Using such functional reconstitution, a related KIR that confers specificity for some HLA-B alleles was also identified. These KIR share conserved tyrosine phosphorylation motifs in their cytoplasmic tails. Thus, a single receptor in NK cells provides both specificity for HLA class I on target cells and the Inhibitory signal that prevents lysis

A Note on E11 and Three-dimensional Gauged Supergravity

We determine the gauge symmetries of all p-forms in maximal three-dimensional gauged supergravity by requiring invariance of the Lagrangian. It is shown that in a particular ungauged limit these symmetries are in precise correspondence to those predicted by the very-extended Kac-Moody algebra E11. We demonstrate that whereas in the ungauged limit the bosonic gauge algebra closes off-shell, the closure is only on-shell in the full gauged theory. This underlines the importance of dynamics for understanding the Kac-Moody origin of the symmetries of gauged supergravity.Comment: Published versio

IIA Ten-forms and the Gauge Algebras of Maximal Supergravity Theories

We show that IIA supergravity can be extended with two independent 10-form potentials. These give rise to a single BPS IIA 9-brane. We investigate the bosonic gauge algebra of both IIA and IIB supergravity in the presence of 10-form potentials and point out an intriguing relation with the symmetry algebra $E_{11}$, which has been conjectured to be the underlying symmetry of string theory/M-theory.Comment: 18 pages, section on IIA 9-branes added, references added; version to be publishe

Recruitment of Tyrosine Phosphatase HCP by the Killer Cell Inhibitory Receptor

AbstractCytolysis of target cells by natural killer (NK) cells and by some cytotoxic T cells occurs unless prevented by inhibitory receptors that recognize MHC class I on target cells. Human NK cells express a p58 inhibitory receptor specific for HLA-C. We report association of the tyrosine phosphatase HCP with the p58 receptor in NK cells. HCP association was dependent on tyrosine phosphorylation of p58. Phosphotyrosyl peptides corresponding to the p58 tail bound and activated HCP in vitro. Furthermore, introduction of an inactive mutant HCP into an NK cell line prevented the p58-mediated inhibition of target cell lysis. These data imply that the inhibitory function of p58 is dependent on its tyrosine phosphorylation and on recruitment and activation of HCP

E10 and Gauged Maximal Supergravity

We compare the dynamics of maximal three-dimensional gauged supergravity in appropriate truncations with the equations of motion that follow from a one-dimensional E10/K(E10) coset model at the first few levels. The constant embedding tensor, which describes gauge deformations and also constitutes an M-theoretic degree of freedom beyond eleven-dimensional supergravity, arises naturally as an integration constant of the geodesic model. In a detailed analysis, we find complete agreement at the lowest levels. At higher levels there appear mismatches, as in previous studies. We discuss the origin of these mismatches.Comment: 34 pages. v2: added references and typos corrected. Published versio

Hydrodynamic Coupling of Two Brownian Spheres to a Planar Surface

We describe direct imaging measurements of the collective and relative diffusion of two colloidal spheres near a flat plate. The bounding surface modifies the spheres' dynamics, even at separations of tens of radii. This behavior is captured by a stokeslet analysis of fluid flow driven by the spheres' and wall's no-slip boundary conditions. In particular, this analysis reveals surprising asymmetry in the normal modes for pair diffusion near a flat surface.Comment: 4 pages, 4 figure