Ottawa, Canada

Carleton University
Ottawa, Canada

Carleton University is a comprehensive university located in the capital of Canada, Ottawa, Ontario. The enabling legislation is The Carleton University Act, 1952, S.O. 1952. Originally founded on rented premises in 1942, Carleton would grow in size to meet the needs of returning World War II veterans and later became Ontario's first private, non-denominational college. It would expand further in the 1960s, consistent with government policy that saw increased access to higher education as a social good and means to economic growth, and is today a public university, offering more than 65 academic programs across a wide range of disciplines. Carleton is reputed for its strength in a variety of fields, such as engineering, humanities, international business and many of the disciplines housed in its Faculty of Public Affairs .It is named after the former Carleton County, Ontario, which included the city of Ottawa at the time Carleton was founded. Carleton County, in turn, was named in honour of Guy Carleton, 1st Baron Dorchester, an early Governor-General of British North America. Carleton currently houses more than 22,000 undergraduate and more than 3,000 postgraduate students. Its campus is located west of Old Ottawa South, within close proximity to The Glebe and Confederation Heights, and is bounded to the north by the Rideau Canal and Dow's Lake and to the south by the Rideau River. The university is represented in Canadian Interuniversity Sport by the Carleton Ravens. Wikipedia.

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Hayley S.,Carleton University
Frontiers in Behavioral Neuroscience | Year: 2011

It has become clear that the inflammatory immune system is altered during the course of clinical depression. In particular, studies on human patients have found depression to be associated with disturbances in the trafficking of cells of the adaptive immune system, coupled with elevations of innate immune messengers and pro-inflammatory cytokines. Paralleling these findings, stressor-based animal models of depression have implicated several cytokines, most notably interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α. Elevations of these cytokines and general inflammatory indicators, such as C-reactive protein, together with reductions of specific immune cells (e.g., T lymphocytes) might serve as useful biomarkers of depression or at least, certain subtypes of the disorder. Recent reports also suggest the possibility that antiinflammatory agents could have therapeutic value in acting as adjunct treatments with traditional anti-depressants. Along these lines, we presently discuss the evidence for pro-inflammatory cytokine involvement in depression, as well as the possibility that anti-inflammatory agents and trophic cytokines themselves might have important anti-depressant properties. © 2011 Hayley.

Morgan Y.L.,Carleton University
IEEE Communications Surveys and Tutorials | Year: 2010

The Dedicated Short-Range Communications (DSRC) standards suite is based on multiple cooperating standards mainly developed by the IEEE. In particular, we focus this paper on the core design aspects of DSRC which is called Wireless Access in Vehicular Networks (WAVE). WAVE is highlighted in IEEE 1609.1/.2/.3/.4. The DSRC and WAVE standards have been the center of major attention in both research and industrial communities. In 2008, WAVE standard was the third best seller standards in the history of the IEEE. This attention reflects the potential of WAVE to facilitate much of the vehicular safety applications. In this paper we present a fairly detailed tutorial of the WAVE standards. We extend the paper by describing some of the lessons learned from particular design approaches. We direct the reader to the landmark research papers in relevant topics. We alert the reader about major open research issues that might lead to future contribution to the WAVE design. © 2010 IEEE.

Barry S.T.,Carleton University
Coordination Chemistry Reviews | Year: 2013

The thermolysis of metal compounds incorporating amidinate-type ligands (RN(H)C(X)NR, where R is any alkyl and X is an alkyl or an amido) show a great complexity and diversity. Amidinates and guanidinates of copper(I), aluminium(III) and gallium(III) can undergo thermal decomposition by two main routes: elimination of carbodiimide (here called "deinsertion") and by abstraction of a β-hydrogen. In general terms carbodiimide deinsertion tends to be a low temperature and solution-based thermolysis route, and β-hydrogen elimination tends to be a high temperature and gas phase thermolysis path. There is little difference between amidinates and guanidiantes in this respect: both ligands show these decomposition pathways on a variety of metal centres. The iminopyrrolidinate (ip) ligand can be designed without β-hydrogens, and so the ligand tert-butyl-imino-2,2-dimethylpyrrolidinate (tBu-ip) was used on copper(I) to successfully show that this compound does not undergo these two thermolyses, but undergoes a much higher thermolysis through loss of the iminotertbutyl group and subsequent decomposition of the five-membered ring. This "redesigned" ligand boosts the thermal stability of the copper(I) dimer from 225°C for [CuI{(iPrN)2CNMe2}]2 to 350°C for [CuI(Me2-tBu-ip)]2. © 2013 Elsevier B.V.

Villeneuve P.J.,Carleton University
American Journal of Epidemiology | Year: 2014

Few studies have investigated associations between nonoccupational exposure to ambient volatile organic compounds and lung cancer. We conducted a case-control study of 445 incident lung cancers and 948 controls (523 hospital, 425 general population) in Toronto, Ontario, Canada, between 1997 and 2002. Participants provided information on several risk factors, including tobacco use, secondhand exposure to cigarette smoke, obesity, and family history of cancer. Exposure to benzene, hydrocarbons, and nitrogen dioxide was estimated using land-use regression models. Exposures were linked to residential addresses to estimate exposure at the time of interview, 10 years before interview, and across past residences (time-weighted average). Logistic regression was used to estimate adjusted odds ratios. Analyses involving the population-based controls found that an interquartile-range increase in the time-weighted average benzene concentration (0.15 g/m3) across previous residences was associated with lung cancer (odds ratio = 1.84, 95% confidence interval: 1.26, 2.68). Similarly, an interquartile-range increase in the time-weighted average nitrogen dioxide concentration (4.8 ppb) yielded an odds ratio of 1.59 (95% confidence interval: 1.19, 2.12). Our study suggests that long-term exposure to ambient volatile organic compounds and nitrogen dioxide at relatively low concentrations is associated with lung cancer. Further work is needed to evaluate joint relationships between these pollutants, smoking, and lung cancer. © The Author 2013.

Huang M.,Carleton University
IEEE Transactions on Automatic Control | Year: 2012

This paper considers both synchronous and asynchronous consensus algorithms with noisy measurements. For stochastic approximation based consensus algorithms, the existing convergence analysis with dynamic topologies heavily relies on quadratic Lyapunov functions, whose existence, however, may be difficult to ensure for switching directed graphs. Our main contribution is to introduce a new analytical approach. We first show a fundamental role of ergodic backward products for mean square consensus in algorithms with additive noise. Subsequently, we develop ergodicity results for backward products of degenerating stochastic matrices converging to a 0-1 matrix via a discrete time dynamical system approach. These results complement the existing ergodic theory of stochastic matrices and provide an effective tool for analyzing consensus problems. Under a joint connectivity assumption, our approach may deal with switching topologies, delayed measurements and correlated noises, and it does not require the double stochasticity condition typically assumed for the existence of quadratic Lyapunov functions. © 1963-2012 IEEE.

Simons A.M.,Carleton University
Proceedings of the Royal Society B: Biological Sciences | Year: 2011

Uncertainty is a problem not only in human decision-making, but is a prevalent quality of natural environments and thus requires evolutionary response. Unpredictable natural selection is expected to result in the evolution of bet-hedging strategies, which are adaptations to long-term fluctuating selection. Despite a recent surge of interest in bet hedging, its study remains mired in conceptual and practical difficulties, compounded by confusion over what constitutes evidence for its existence. Here, I attempt to resolve misunderstandings about bet hedging and its relationship with other modes of response to environmental change, identify the challenges inherent to its study and assess the state of existing empirical evidence. The variety and distribution of plausible bet-hedging traits found across 16 phyla in over 100 studies suggest their ubiquity. Thus, bet hedging should be considered a specific mode of response to environmental change. However, the distribution of bet-hedging studies across evidence categories- defined according to potential strength-is heavily skewed towards weaker categories, underscoring the need for direct appraisals of the adaptive significance of putative bet-hedging traits in nature. © 2011 The Royal Society.

Fahrig L.,Carleton University
Journal of Biogeography | Year: 2013

I challenge (1) the assumption that habitat patches are natural units of measurement for species richness, and (2) the assumption of distinct effects of habitat patch size and isolation on species richness. I propose a simpler view of the relationship between habitat distribution and species richness, the 'habitat amount hypothesis', and I suggest ways of testing it. The habitat amount hypothesis posits that, for habitat patches in a matrix of non-habitat, the patch size effect and the patch isolation effect are driven mainly by a single underlying process, the sample area effect. The hypothesis predicts that species richness in equal-sized sample sites should increase with the total amount of habitat in the 'local landscape' of the sample site, where the local landscape is the area within an appropriate distance of the sample site. It also predicts that species richness in a sample site is independent of the area of the particular patch in which the sample site is located (its 'local patch'), except insofar as the area of that patch contributes to the amount of habitat in the local landscape of the sample site. The habitat amount hypothesis replaces two predictor variables, patch size and isolation, with a single predictor variable, habitat amount, when species richness is analysed for equal-sized sample sites rather than for unequal-sized habitat patches. Studies to test the hypothesis should ensure that 'habitat' is correctly defined, and the spatial extent of the local landscape is appropriate, for the species group under consideration. If supported, the habitat amount hypothesis would mean that to predict the relationship between habitat distribution and species richness: (1) distinguishing between patch-scale and landscape-scale habitat effects is unnecessary; (2) distinguishing between patch size effects and patch isolation effects is unnecessary; (3) considering habitat configuration independent of habitat amount is unnecessary; and (4) delineating discrete habitat patches is unnecessary. © 2013 John Wiley & Sons Ltd.

Storey K.B.,Carleton University
Journal of Experimental Biology | Year: 2015

For many animals, survival of severe environmental stress (e.g. to extremes of heat or cold, drought, oxygen limitation, food deprivation) is aided by entry into a hypometabolic state. Strong depression of metabolic rate, often to only 1-20% of normal resting rate, is a core survival strategy of multiple forms of hypometabolism across the animal kingdom, including hibernation, anaerobiosis, aestivation and freeze tolerance. Global biochemical controls are needed to suppress and reprioritize energy use; one such well-studied control is reversible protein phosphorylation. Recently, we turned our attention to the idea that mechanisms previously associated mainly with epigenetic regulation can also contribute to reversible suppression of gene expression in hypometabolic states. Indeed, situations as diverse as mammalian hibernation and turtle anoxia tolerance show coordinated changes in histone post-translational modifications (acetylation, phosphorylation) and activities of histone deacetylases, consistent with their use as mechanisms for suppressing gene expression during hypometabolism. Other potential mechanisms of gene silencing in hypometabolic states include altered expression of miRNAs that can provide post-transcriptional suppression of mRNA translation and the formation of ribonuclear protein bodies in the nucleus and cytoplasm to allow storage of mRNA transcripts until animals rouse themselves again. Furthermore, mechanisms first identified in epigenetic regulation (e.g. protein acetylation) are now proving to apply to many central metabolic enzymes (e.g. lactate dehydrogenase), suggesting a new layer of regulatory control that can contribute to coordinating the depression of metabolic rate. © 2015. Published by The Company of Biologists Ltd | The Journal of Experimental Biology.

Scott J.L.,Carleton University
Nature communications | Year: 2010

Animal communication signals can be highly elaborate, and researchers have long sought explanations for their evolutionary origins. For example, how did signals such as the tail-fan display of a peacock, a firefly flash or a wolf howl evolve? Animal communication theory holds that many signals evolved from non-signalling behaviours through the process of ritualization. Empirical evidence for ritualization is limited, as it is necessary to examine living relatives with varying degrees of signal evolution within a phylogenetic framework. We examine the origins of vibratory territorial signals in caterpillars using comparative and molecular phylogenetic methods. We show that a highly ritualized vibratory signal--anal scraping--originated from a locomotory behaviour--walking. Furthermore, comparative behavioural analysis supports the hypothesis that ritualized vibratory signals derive from physical fighting behaviours. Thus, contestants signal their opponents to avoid the cost of fighting. Our study provides experimental evidence for the origins of a complex communication signal, through the process of ritualization.

Over the past decade research examining the human dimensions of climatic change in the Arctic has expanded significantly and has become the dominant framework through which the relations between northern peoples and climatic change are understood by scholars, policy makers, political leaders, and the media. This paper critically examines the assumptions, exclusions, and orientations that characterize this broad literature, and suggests revising and expanding the terms upon which it is carried out. It focuses in particular on the exclusion of colonialism from the study of human vulnerability and adaptation to climatic change, the framing of Indigenous peoples and communities in terms of the local and the traditional, and the ways in which efforts to improve the lives of northern Indigenous peoples risk perpetuating colonial relations. The paper argues that these exclusions and orientations lead scholars to systematically overlook the immense importance of resource extraction and shipping as human dimensions of climatic change in the Canadian Arctic, and it examines the implications of such oversights. © 2011 Elsevier Ltd.

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