L’évolution du nombre des habitants du Nord canadien de 1966 à 1971

À partir d'une régionalisation du Nord et à l'aide des documents du Recensement du Canada de 1971, les auteurs ont mis à jour leurs estimations de 1966 de la population du Canada par zone nordique et décrit le comportement démographique entre les deux derniers recensements. Ils ne font que présenter une masse statistique en fonction d'une conception du Nord. 253 559 personnes habitaient le Nord en 1971 soit 1,2% de la population totale du Canada. La nordicité explique la répartition de la population entre le Moyen Nord, le Grand Nord et l'Extrême Nord. De 1966 à 1971, la population du Nord s'est accrue à un rythme un peu plus rapide que celle du Canada de base tout en se densifiant légèrement. Selon la province ou le territoire retenu, l'on assiste à une nordification ou à une denordification assez accentuée. Les disparités de population sont aussi fortes en considérant un découpage vertical du Nord. Les développements miniers, administratifs, hydroélectriques et pétroliers demeurent les facteurs les plus importants de cette évolution.By dividing the North into regions, and with the aid of data from the 1971 Canadian Census, the authors have brought up to date the 1966 estimates of the population in each of the northern zones of Canada. They also describe the demographic patterns by zone between the last two censuses. They present a body of statistics in relation to a certain conception of the North. 253 559 persons or 1.2% of the population of Canada were living in the North in 1971 where the degree of northerness explains the distribution of the population amongst the Middle North, the Great North, and the Far North. From 1966 to 1971 the North grew at a slightly faster rate than the southern part of Canada or Canada de base, whilst at the same time it became slightly more densely populated. Depending on the province or territory, there is a fairly strong process of northernization or de-northemization. The disparities in populations are rather similar according to the vertical division of the North. The development of natural resources and of the territorial administration remain the most important factor in the growth and development of the North

Molecular Phylogenetics of Bromus (Poaceae: Pooideae) Based on Chloroplast and Nuclear DNA Sequence Data

We conducted a phylogenetic analysis to characterize relationships among Bromus and test the monophyly of five of the seven morphologically distinct groups within Bromus (Poaceae: Pooideae) that have been treated as sections, subgenera, or genera. We sequenced the chloroplast trnL (UAA) intron, the 3\u27-end of the chloroplast ndhF gene, and the internal transcribed spacers (ITS) of the nuclear ribosomal DNA region for 46 species that represent a large proportion of the morphological and geographical diversity in the genus. Independent analyses of plastid and nuclear ribosomal data identified several lineages in Bromus, but there is some evidence of incongruence between these linkage groups. Nuclear ribosomal trees indicate that two clades comprising some North and South American species of sect. Bromopsis are the successive sister groups of the rest of the genus, and that Old World species of sect. Bromopsis are more closely related to sects. Ceratochloa and Neobromus than they are to the remaining North American species of sect. Bromopsis. In contrast, plastid trees indicate a close relationship between Old World and some North American species of sect. Bromopsis. In the nuclear ribosomal trees, sects. Genea and Bromus (if sect. Triniusia is included within it, as treated by most authors) are monophyletic and not closely related. In the plastid trees, species of these two sections are intermixed, supporting a hybrid origin for B. pectinatus. The monophyly of sect. Ceratochloa is supported in the plastid and nuclear ribosomal trees, and the monophyly of sect. Neobromus is robustly supported in the nuclear ribosomal trees. Current classification schemes do not reflect phylogenetic relationships in Bromus. Tentative evidence of conflict among nuclear and plastid data partitions needs clarification with more robustly supported plastid and nuclear ribosomal gene trees

Recognition of Bromus Richardsonii and B. Ciliatus: Evidence from Morphology, Cytology, and DNA Fingerprinting (Poaceae: Bromeae)

Since our goal was to determine characteristic differences between Bromus richardsonii and B. ciliates, a discriminate analysis (DA), principal components analysis (PCA), multidimensional scaling (MDS), bivariate analysis, and an amplified fragment length polymorphisms (AFLP) analysis were undertaken on 93 herbarium specimens and 31 field-collected populations. A cytological survey of B. ciliates, B. richardsonii, and B. mucroglumis confirm previous reports that the first species is diploid (2n = 14) and the latter two are tetraploid (2n = 28). All taxa were correctly classified in the DA and important characters for each of the species were identified. Bromus richardsonii has lemmas with scattered hairs on the lower half between the mid nerve and margins [glabrous in B. ciliatus], anthers (1.2) 1.6-2.7 (3.4) mm long [(0.9) 1-1.4 (1.6) mm long in B. ciliatus], second glumes (7.8) 8.9 - 11.3 (13.2) mm long [(6.2) 7.1-8.5 (9.5) in B. ciliatus); and basal sheaths with dense, short to medium hairs [glabrous or with long hairs in B. ciliatus]. The PCA easily separated B. ciliatus and B. richardsonii into two well-defined groups and MDS mirrored the principal components analysis but displayed more overlap of individuals between the two groups. The AFLP-derived UPGMA dendrogram separated 154 individuals into two distinct clusters, one consisting entirely of B. ciliatus individuals and the other consisting of B. richardsonii individuals with six individuals of B. mucroglumis embedded within. Our study clearly indicates that there are distinctive morphological, cytological, and genetic differences to distinguish B. richardsonii and B. ciliatus as separate species

Computational prediction of neural progenitor cell fates

Understanding how stem and progenitor cells choose between alternative cell fates is a major challenge in developmental biology. Efforts to tackle this problem have been hampered by the scarcity of markers that can be used to predict cell division outcomes. Here we present a computational method, based on algorithmic information theory, to analyze dynamic features of living cells over time. Using this method, we asked whether rat retinal progenitor cells (RPCs) display characteristic phenotypes before undergoing mitosis that could foretell their fate. We predicted whether RPCs will undergo a self-renewing or terminal division with 99% accuracy, or whether they will produce two photoreceptors or another combination of offspring with 87% accuracy. Our implementation can segment, track and generate predictions for 40 cells simultaneously on a standard computer at 5 min per frame. This method could be used to isolate cell populations with specific developmental potential, enabling previously impossible investigations.The computational aspects of this work were supported by the Center for Subsurface Sensing and Imaging Systems (NSF Grant EEC-9986821), by the Rensselaer Polytechnic Institute and by the University of Wisconsin-Milwaukee. This work was supported by grants from the Canadian Institutes of Health Research and the Foundation Fighting Blindness – Canada (to M.C). M.C. is a CIHR New Investigator and a W.K. Stell Scholar of the Foundation Fighting Blindness – Canada

Mountains and rivers for a home : a study of the cultural and social repercussions of the return to nature in Leslie Marmon Silko's Ceremony and Thomas King's Green grass, running water

La présente recherche a pour but de procéder à une étude comparative du processus régénératif au cœur de deux romans phares de la fiction autochtone contemporaine, soit Ceremony de Leslie Marmon Silko et Green Grass, Running Water de Thomas King. Trois volets principaux sont examinés : le rôle de la nature en tant que référent culturel dans le processus de régénération des personnages principaux de chaque roman, l’évolution de la quête identitaire dans un environnement post-contact, ainsi que les répercussions de la réactualisation de l’identité de chaque protagoniste sur la communauté à laquelle il appartient. Cette comparaison entre les procédés employés par Silko et King permettront, en un premier temps, d’identifier des éléments de continuité entre les deux auteurs. Ces similarités incluent la centralité de la nature dans la reconnexion des protagonistes avec leur culture et leur identité ainsi que l’emphase sur la nécessité d’une identité hybride dans un environnement post-contact. De plus, la comparaison entre ces deux auteurs issus de deux contextes socio-historiques distincts permet d’isoler certains éléments du contexte propre à chaque roman afin de déterminer le rôle de la réalité autochtone sur la fiction produite à chaque époque. De façon plus spécifique, il sera entre autres question de l’influence de la montée du mouvement environnementaliste euro-américain sur la valeur symbolique du retour à la nature, ainsi que de l’importance grandissante de la classe moyenne autochtone éduquée et de la façon dont ce nouveau phénomène est exprimé dans l’œuvre de King.This thesis compares the regenerative processes at the heart of two milestone novels of contemporary Native American literature, Leslie Marmon Silko’s Ceremony and Thomas King’s Green Grass, Running Water. My comparative study will be divided into three main sections: the role of nature as a cultural referent in the main characters’ regenerative processes in each novel, the evolution of the identity quest in a post-contact environment, and finally, the repercussions of the protagonists’ re-actualization of identity on the rest of their community. Through the comparative study of the processes employed by Silko and King with respect to one’s relationship to nature, cultural identity and social relations, I will be able to identify several similarities shared by the two novels, which demonstrate that they belong to the same Native artistic continuum. These resemblances include the central role of nature in reconnecting the protagonists to their identity, as well as a predominant emphasis on the emergence of a hybridized identity in a post-contact environment. Moreover, the comparison of two novels emerging from two different eras of Native American Literature –that of the 1970s and of the 1990s- will allow me to isolate the influence of the cultural context to which each particular work belongs. In doing so, it becomes possible to determine the influence of some transformations in Native lifestyle on the fiction produced at a given time. More specifically, the modifications I chose to focus on include the rise of Euro-American environmentalism on the symbolic value of returning to nature for Natives as well as the increasing presence of middle-class, educated Natives and their representation, mostly present in King’s fiction

Orai and TRPC channel characterization in FcεRI-mediated calcium signaling and mediator secretion in human mast cells.

Inappropriate activation of mast cells via the FcεRI receptor leads to the release of inflammatory mediators and symptoms of allergic disease. Calcium influx is a critical regulator of mast cell signaling and is required for exocytosis of preformed mediators and for synthesis of eicosanoids, cytokines and chemokines. Studies in rodent and human mast cells have identified Orai calcium channels as key contributors to FcεRI-initiated mediator release. However, until now the role of TRPC calcium channels in FcεRI-mediated human mast cell signaling has not been published. Here, we show evidence for the expression of Orai 1,2, and 3 and TRPC1 and 6 in primary human lung mast cells and the LAD2 human mast cell line but, we only find evidence of functional contribution of Orai and not TRPC channels to FcεRI-mediated calcium entry. Calcium imaging experiments, utilizing an Orai selective antagonist (Synta66) showed the contribution of Orai to FcεRI-mediated signaling in human mast cells. Although, the use of a TRPC3/6 selective antagonist and agonist (GSK-3503A and GSK-2934A, respectively) did not reveal evidence for TRPC6 contribution to FcεRI-mediated calcium signaling in human mast cells. Similarly, inactivation of STIM1-regulated TRPC1 in human mast cells (as tested by transfecting cells with STIM1-KK(684-685)EE - TRPC1 gating mutant) failed to alter FcεRI-mediated calcium signaling in LAD2 human mast cells. Mediator release assays confirm that FcεRI-mediated calcium influx through Orai is necessary for histamine and TNFα release but is differentially involved in the generation of cytokines and eicosanoids

Nel positively regulates the genesis of retinal ganglion cells by promoting their differentiation and survival during development

Peer reviewedPublisher PD

Slender Moonwort, Botrychium lineare (Ophioglossaceae), Rediscovered in Quebec

Slender Moonwort (Botrychium lineare), described in 1994, is a very rare fern in eastern North America. It was known in Quebec, Canada, from only two sites in the Gaspé Peninsula but has not been relocated since its discovery at these sites in 1902 and 1942. An ongoing study of B. lineare and its recent discovery in northern Minnesota prompted a re-examination of a 1972 collection made in western Quebec, in Gatineau Park, previously identified under various names, including B. campestre. A recent visit (2008) to the Gatineau Park site disclosed continued presence of similar plants. Based on morphological characters, spore size, genotype (allozyme electrophoresis), and appropriate habitat features, we conclude that the newly discovered plants and those of the 1972 collection are B. lineare. B. lineare appears on the Quebec government list of plant species likely to be designated threatened or vulnerable