F06RS SGB No. 3 (Amend Budget)

A Bill To amend the Student Government General Operating Budget for FY 2006-2007 (Act No. 1 of the 2006-2007 First Extraordinary Session) to provide for legislative salaries; to provide for related matter

CIV Absorption From Galaxies in the Process of Formation

We investigate the heavy element QSO absorption systems caused by gas condensations at high redshift which evolve into galaxies with circular velocity of 100 to 200 km/s at the present epoch. Artificial QSO spectra were generated for a variety of lines-of-sight through regions of the universe simulated with a hydrodynamics code. The CIV and HI absorption features in these spectra closely resemble observed CIV and HI absorption systems over a wide range in column density. CIV absorption complexes with multiple-component structure and velocity spreads up to about 600 km/s are found. The broadest systems are caused by lines-of-sight passing through groups of protogalactic clumps with individual velocity dispersions of less than 150 km/s aligned along filamentary structures. The temperature of most of the gas does not take the photoionization equilibrium value. This invalidates density and size estimates derived from thermal equilibrium models. Consequences for metal abundance determinations are briefly discussed. We predict occasional exceptionally large ratios of CIV to HI column density (up to a third) for lines-of-sight passing through compact halos of hot gas with temperature close to 3 10^5 K. Our model may be able to explain both high-ionization multi-component heavy-element absorbers and damped Lyman alpha systems as groups of small protogalactic clumps.Comment: 13 pages, uuencoded postscript file, 4 figures included submitted to ApJ (Letters); complete version also available at http://www.mpa-garching.mpg.de/Galaxien/prep.htm

Le développement durable (DD) au service des pourvoiries du Saguenay-Lac-Saint-Jean

Affiche présentée dans le cadre du Colloque de l'ARC, «La culture de la recherche au collégial», dans le cadre du 82e Congrès de l'Acfas, Université Concordia, Montréal, le 14 mai 2014.Au Québec, un vaste réseau hydroélectrique a été développé afin de satisfaire les besoins énergétiques de la population. Toutefois, certains territoires isolés n’ont pas d’accès à ce réseau. La demande d’électricité, de chauffage et de transport y est comblée par l’usage des combustibles fossiles, qui émettent d’importantes quantités de gaz à effet de serre. Au cégep de Jonquière, la Chaire de recherche industrielle en technologies des énergies renouvelables et du rendement énergétique (TERRE) travaille depuis 2013 au développement d’un outil d’analyse pour l’approvisionnement en énergies vertes des sites isolés. Une étude préliminaire a déjà été effectuée dans quatre pourvoiries du Saguenay– Lac-Saint-Jean afin de valider l’outil. Ce dernier, sous forme de tableur Excel, permet d’évaluer les thèmes issus des dimensions sociale, écologique, économique et de gouvernance qui sous-tendent le développement durable. L’outil permet de dresser une liste de priorités afin d'entamer un virage de développement plus vert. Les résultats préliminaires mettent l’accent sur la dépendance des sites isolés aux combustibles fossiles, mais également sur la volonté de diversifier leurs ressources en énergie. Au cours de la présente année, l’outil sera testé dans un plus grand nombre de pourvoiries et les résultats seront couplés à une analyse technico-économique qui mesurera le potentiel d’intégration des filières énergétiques renouvelables dans chacun des sites étudiés

Le lien entre l'induction et la définition dans les dialogues socratiques de Platon

La présente recherche a pour but de retracer les débuts de l'histoire de la logique et de faire ressortir l'importante contribution de Socrate à ce chapitre. Pour y arriver, nous nous pencherons sur le lien entre les deux instruments logiques découverts par Socrate : le raisonnement inductif et la définition universelle. Dans un premier temps, une attention particulière sera accordée à la nature de ces deux instruments, ainsi qu'au contexte dans lequel ils prennent place. Ensuite, l'étude de quelques Dialogues de Platon (l'Hippias majeur, le Charmide , le Lysis, l'Euthyphron, le Lâchés, le Protagoras et le Ménon) montrera que ces deux instruments sont reliés de multiples façons. Nous verrons d'abord comment le raisonnement inductif peut contribuer à la recherche de la définition et, ensuite, comment l'induction et la définition sont au principe du syllogisme démonstratif

The MgII Cross-section of Luminous Red Galaxies

We describe a search for MgII(2796,2803) absorption lines in Sloan Digital Sky Survey (SDSS) spectra of QSOs whose lines of sight pass within impact parameters of 200 kpc of galaxies with photometric redshifts of z=0.46-0.6 and redshift errors Delta z~0.05. The galaxies selected have the same colors and luminosities as the Luminous Red Galaxy (LRG) population previously selected from the SDSS. A search for Mg II lines within a redshift interval of +/-0.1 of a galaxy's photometric redshift shows that absorption by these galaxies is rare: the covering fraction is ~ 10-15% between 20 and 100 kpc, for Mg II lines with rest equivalent widths of Wr >= 0.6{\AA}, falling to zero at larger separations. There is no evidence that Wr correlates with impact parameter or galaxy luminosity. Our results are consistent with existing scenarios in which cool Mg II-absorbing clouds may be absent near LRGs because of the environment of the galaxies: if LRGs reside in high-mass groups and clusters, either their halos are too hot to retain or accrete cool gas, or the galaxies themselves - which have passively-evolving old stellar populations - do not produce the rates of star formation and outflows of gas necessary to fill their halos with Mg II absorbing clouds. In the rarer cases where Mg II is detected, however, the origin of the absorption is less clear. Absorption may arise from the little cool gas able to reach into cluster halos from the intergalactic medium, or from the few star-forming and/or AGN-like LRGs that are known to exist.Comment: Accepted by ApJ; minor correction

Positive pleiotropic effects of HMG-CoA reductase inhibitor on vitiligo

BACKGROUND: HMG-CoA reductase inhibitors (statins) are commonly used in medicine to control blood lipid disorder. Large clinical trials have demonstrated that statins greatly reduces cardiovascular-related morbidity and mortality in patients with and without coronary artery disease. Also, the use of HMG-CoA reductase inhibitors has been reported to have immunosuppressive effects. CASE PRESENTATION: We describe an unusual case of regression of vitiligo in a patient treated with high dose simvastatin. The relation between simvastatin and regression of vitiligo in this case report may be related to the autoimmune pathophysiology of the disease. CONCLUSION: This unexpected beneficial impact provides another scientific credence to the hypothesis that immune mechanisms play a role in the development of vitiligo and that the use of statins as immuno-modulator could be of use not only for treatment relative to organ transplant but in other pathologies such as vitiligo

Mid-Infrared Selected Quasars I: Virial Black Hole Mass and Eddington Ratios

We provide a catalog of 391 mid-infrared-selected (MIR, 24$\mu$m) broad-emission-line (BEL, type 1) quasars in the 22 deg$^2$ SWIRE Lockman Hole field. This quasar sample is selected in the MIR from Spitzer MIPS with $S_{\rm 24} > 400\mu$Jy, jointly with an optical magnitude limit of r (AB) $<$ 22.5 for broad line identification. The catalog is based on MMT and SDSS spectroscopy to select BEL quasars, extends the SDSS coverage to fainter magnitudes and lower redshifts, and recovers a more complete quasar population. The MIR-selected quasar sample peaks at $z\sim$1.4, and recovers a significant and constant (20\%) fraction of extended objects with SDSS photometry across magnitudes, which was not included in the SDSS quasar survey dominated by point sources. This sample also recovers a significant population of $z 19.1$. We then investigate the continuum luminosity and line profiles of these MIR quasars, and estimate their virial black hole masses and the Eddington ratios. The SMBH mass shows evidence of downsizing, though the Eddington ratios remain constant at $1 < z < 4$. Compared to point sources in the same redshift range, extended sources at $z < 1$ show systematically lower Eddington ratios. The catalog and spectra are publicly available online.Comment: 72 pages, 27 figures, 16 tables; ApJ accepte

Can a quantum mixmaster universe undergo a spontaneous inflationary phase?

We study a semi-classical model of the mixmaster universe. We first derive the quantum model and then introduce its semi-classical approximation. We employ a general integral quantization method that respects the symmetries of the model given by the affine and the Weyl-Heisenberg groups, and can produce a wide class of quantum models. The semi-classical approximation is based on the coherent states. The semi-classical dynamics is complex and can not be solved by analytical methods. We focus on a key qualitative feature of the dynamics, namely, we investigate whether the primordial anisotropic universe can undergo a spontaneous inflationary phase driven by the anisotropic energy combined with semi-classical corrections. The answer to this question provides a useful perspective on the inflationary paradigm as well as on alternative bouncing models.Comment: 15 pages, 6 figure

Potential changes in forest composition could reduce impacts of climate change on boreal wildfires

There is general consensus that wildfires in boreal forests will increase throughout this century in response to more severe and frequent drought conditions induced by climate change. However, prediction models generally assume that the vegetation component will remain static over the next few decades. As deciduous species are less flammable than conifer species, it is reasonable to believe that a potential expansion of deciduous species in boreal forests, either occurring naturally or through landscape management, could offset some of the impacts of climate change on the occurrence of boreal wildfires. The objective of this study was to determine the potential of this offsetting effect through a simulation experiment conducted in eastern boreal North America. Predictions of future fire activity were made using multivariate adaptive regression splines (MARS) with fire behavior indices and ecological niche models as predictor variables so as to take into account the effects of changing climate and tree distribution on fire activity. A regional climate model (RCM) was used for predictions of future fire risk conditions. The experiment was conducted under two tree dispersal scenarios: the status quo scenario, in which the distribution of forest types does not differ from the present one, and the unlimited dispersal scenario, which allows forest types to expand their range to fully occupy their climatic niche. Our results show that future warming will create climate conditions that are more prone to fire occurrence. However, unlimited dispersal of southern restricted deciduous species could reduce the impact of climate change on future fire occurrence. Hence, the use of deciduous species could be a good option for an efficient strategic fire mitigation strategy aimed at reducing fire propagation in coniferous landscapes and increasing public safety in remote populated areas of eastern boreal Canada under climate change

Forest productivity decline caused by successional paludification of boreal soils

Long-term forest productivity decline in boreal forests has been extensively studied in the last decades, yet its causes are still unclear. Soil conditions associated with soil organic matter accumulation are thought to be responsible for site productivity decline. The objectives of this study were to determine if paludification of boreal soils resulted in reduced forest productivity, and to identify changes in the physical and chemical properties of soils associated with reduction in productivity. We used a chronosequence of 23 black spruce stands ranging in postfire age from 50 to 2350 years and calculated three different stand productivity indices, including site index. We assessed changes in forest productivity with time using two complementary approaches: (1) by comparing productivity among the chronosequence stands and (2) by comparing the productivity of successive cohorts of trees within the same stands to determine the influence of time independently of other site factors. Charcoal stratigraphy indicates that the forest stands differ in their fire history and originated either from high- or low-severity soil burns. Both chronosequence and cohort approaches demonstrate declines in black spruce productivity of 50-80% with increased paludification, particularly during the first centuries after fire. Paludification alters bryophyte abundance and succession, increases soil moisture, reduces soil temperature and nutrient availability, and alters the vertical distribution of roots. Low-severity soil burns significantly accelerate rates of paludification and productivity decline compared with high-severity fires and ultimately reduce nutrient content in black spruce needles. The two combined approaches indicate that paludification can be driven by forest succession only, independently of site factors such as position on slope. This successional paludification contrasts with edaphic paludification, where topography and drainage primarily control the extent and rate of paludification. At the landscape scale, the fire regime (frequency and severity) controls paludification and forest productivity through its effect on soil organic layers. Implications for global carbon budgets and sustainable forestry are discussed