Partial articulated specimen of the Early Devonian putative chondrichthyan Polymerolepis whitei Karatajūtė-Talimaa, 1968, with an anal fin Spine [Un nouveau spécimen, partiellement articulé avec présence d'une épine anale, de Polymerolepis whitei Karatajūṫė-Talimaa, 1968, un supposé chondrichthyen du Dévonien inférieur]
Hanke G.F.,Royal British Columbia Museum |
Wilson M.V.H.,University of Alberta |
Saurette F.J.,University of Saint-Boniface
Geodiversitas | Year: 2013
Polymerolepis whitei Karatajute-Talimaa, 1968 was described based on isolated polyodontode scales recovered from the Ukraine, and originally was thought to be heterostracan (Agnatha). Additional scales with neck canals were described years later, and as a result, P. whitei was reclassified as a bradyodont holocephalan because it had scales similar to those of Listracanthus Newberry & Worthen, 1870. Until now, no articulated body fossils were known, and so the classification of this taxon has remained uncertain and based only on the original author's opinion. New specimens of P. whitei from the Mackenzie Mountains, Northwest Territories, Canada, show articulated scale patches from the head, with the best specimen showing part of an anal fin, caudal peduncle, and caudal fin. This new material confirms that the original account of scale variation was accurate, but also that P. whitei possesses an anal fin spine, a feature that, until recently, was thought to be a synapomorphy of acanthodian fishes among Palaeozoic fishes. Several primitive chondrichthyans (Obtusacanthus Hanke & Wilson, 2004; Lupopsyroides Hanke & Wilson, 2004; Kathemacanthus Gagnier & Wilson, 1996; Seretolepis Karatajute-Talimaa, 1968; Doliodus Traquair, 1893; Antarctilamna Young, 1982, and also problematic taxa such as Gyracanthides Woodward, 1902, and now Polymerolepis Karatajute-Talimaa, 1968), are known from articulated remains and show a fin-spine complement like that of acanthodian fishes. They also have placoid scales or polyodontode scales that grew by areal rather than superpositional accretion. These taxa blur the distinction that exists in historic literature between acanthodians and early chondrichthyans. © Publications Scientifiques du Muséum national d'Histoire naturelle, Paris.
Hawke L.D.,University of Western Ontario |
Hawke L.D.,University of Saint-Boniface |
Parikh S.V.,University of Western Ontario |
Parikh S.V.,King's College |
Michalak E.E.,University of British Columbia
Journal of Affective Disorders | Year: 2013
Background Psychiatric stigma is pervasive injustice that complicates the course of illness and reduces quality of life for people with mental illnesses. This article reviews the research examining stigma towards bipolar disorder (BD) with a view to guiding the development of stigma reduction initiatives and ongoing research. Methods PsychInfo, Medline, and Embase databases were searched for peer-reviewed studies addressing stigma in BD. Results Stigma is a serious concern for individuals with BD and their families. Stigma occurs within affected individuals, families, social environments, work and school environments, and the healthcare industry. With stigma often come a loss of social support and occupational success, reduced functioning, higher symptom levels and lower quality of life. BD stigma is comparable to that of other severe mental illnesses, such as schizophrenia. Few interventions are available to specifically target stigma against BD. Limitations Most studies have used explicit, attitude-based measures of stigma without controlling for social desirability, which may not translate into real-world stigmatizing behaviors. Furthermore, many studies have not clearly delineated results in a manner consistent with the conceptual framework of stigmatization. Conclusions Stigma toward BD is ubiquitous and has insidious consequences for affected individuals and their families. Stigma reduction initiatives should target individuals living with BD, their families, workplaces, and the healthcare industry, taking into account the experiences and impacts of BD stigma to improve social support, course of illness, and quality of life. © 2013 Elsevier B.V.
Oule K.M.,University of Saint-Boniface |
Dickman M.,University of Saint-Boniface |
Arul J.,Laval University
International Journal of Food Properties | Year: 2013
The effects of supercritical CO2 (SC-CO2) on the microbiological, sensory (taste, odour, and colour), nutritional (vitamin C content), and physical (cloud, total acidity, pH, and °Brix) qualities of orange juice were studied. The CO2 treatment was performed in a 1 litre capacity double-walled reactor equipped with a magnetic stirring system. Freshly extracted orange juice was treated with supercritical CO2, pasteurised at 90°C, or left untreated. There were no significant differences in the sensory attributes and physical qualities between the CO 2 treated juice and freshly extracted juice. The CO2 treated juice retained 88% of its vitamin C, while the pasteurised juice was notably different from the fresh juice and preserved only 57% of its vitamin C content. After 8 weeks of storage at 4°C, there was no microbial growth in the CO2 treated juice. © 2013 Copyright Taylor and Francis Group, LLC.
Balhara J.,University of Manitoba |
Koussih L.,University of Manitoba |
Koussih L.,University of Saint-Boniface |
Zhang J.,University of Manitoba |
And 2 more authors.
Frontiers in Immunology | Year: 2013
Pentraxin 3 (PTX3) is a soluble pattern recognition receptor that is a humoral component of the innate immune system. It interacts with pathogenic moieties, infected and dying host cells and facilitates their removal through activation of appropriate innate and adaptive mechanisms. PTX3 is secreted by a diverse variety of cells, ranging from immune cells to structural cells, in response to Toll like receptor (TLR) engagement, inflammatory stimuli, and physical and chemical stress. Further, PTX3 plays an essential role in female fertility as it facilitates the organization of extracellular matrix in the cumulus oophorus. Such activity is also implicated in post-inflammation tissue repair. PTX3 is a multifunctional protein and plays a non-redundant role in providing immunity against potential immunological dangers. Thus, we assessed its role in lung immunity, as lungs are at a constant risk of infections and tissue damage that is attributable to perpetual exposure to foreign agents. © 2013 Balhara, Koussih, Zhang and Gounni.
Gee J.H.,University of Manitoba |
Rondeau S.L.,University of Saint-Boniface
Herpetologica | Year: 2012
We measured gaseous lift and specific gravity of larval anurans at regular intervals during development to assess their importance in determining buoyancy in eight species. Specifically, we examined the hatchling, larval, and metamorphic stages of tadpoles from still waters (Limnodynastes dumerili, Limn. peronii, Lithobates septentrionalis, and Rhinella marina), intermittent streams (Litoria genimaculata and Lito. lesueuri), and torrent sections of rivers (Lito. nannotis and Nyctimystes dayi). Buoyancy levels and the strategies used to attain buoyancy varied at different phases of development and with the environment occupied. Buoyancy increased rapidly during development in hatchlings of Limn. peronii, Lith. septentrionalis, and R. marina due to a reduction in specific gravity. Lungs were inflated in early larval stages of all species except for Lito. nannotis, N. dayi, and R. marina, which inflated their lungs following metamorphosis. Limnodynastes dumerili and Limn. peronii used gaseous lift to maintain near-neutral buoyancy throughout larval and metamorphic stages. Lithobates septentrionalis, Stages 25-29 (first summer), possessed a high level of gaseous lift, but buoyancy declined as lung gas volume decreased in Stages 31-43 (second summer). Rhinella marina did not inflate lungs prior to transformation but achieved an intermediate buoyancy level due to a very low specific gravity. The intermittent-stream species Lito. genimaculata and Lito. lesueuri used gaseous lift to achieve buoyancy levels similar to those of Lith. septentrionalis (Stages 31-43) and R. marina. The torrent-dwelling species Lito. nannotis and N. dayi were the least buoyant; their lungs were not inflated prior to transformation and their specific gravity was elevated. Both gaseous lift and specific gravity are important factors in determining buoyancy in larval anurans. © 2012 by The Herpetologists' League, Inc.
Gagnon M.,University of Saint-Boniface
Physics Education | Year: 2011
The close relationship between charged particles and electromagnetic fields has been well known since the 19th century, thanks to James Clerk Maxwell's brilliant unified theory of electricity and magnetism. Today, electromagnetism is recognized as an essential aspect of human activity and has consequently become a major component of senior high-school and first-year university science curricula. However, while the action of electrical force on charged particles is generally well understood, that of the magnetic force still remains a mystery for some students, and thus the analysis of combined interactions quickly becomes a real puzzle. To improve the teaching of these phenomena, and also to facilitate comprehension by students, we have developed a computer-based simulator to replicate the motion of a real charged particle under the influence of any combination of electric and magnetic fields. Using this software, students are able to visualize the motion of charged particles and thus gain a better understanding of the effect of electric and magnetic fields. The software is available as a free download. © 2011 IOP Publishing Ltd.
Gagnon M.,University of Saint-Boniface
Physics Education | Year: 2011
Mainly used in the 1960s, bubble chambers played a major role in particle physics. Now replaced with modern electronic detectors, we believe they remain an important didactic tool to introduce particle physics as they provide visual, appealing and insightful pictures. Sadly, this rare type of detector is mostly accessible through open-door events only. To overcome this drawback, we have developed a realistic computer-based simulator to replicate the actual equipment. Using this software, students and instructors are able to obtain randomly created computer-simulated images comparable to real-life ones. We have successfully used this software in our mechanics, electromagnetism and modern physics courses to illustrate the effect of a magnetic field on charged particles, to exemplify relativistic mechanics and to discuss the conservation of energy, momentum and quantum numbers in particle collisions. It also provides original examples for students to practise their ability to identify the particles involved, thereby gaining a better understanding of the underlying physical laws. The software is available as a free download. © 2011 IOP Publishing Ltd.
Sims L.,University of Saint-Boniface
Impact Assessment and Project Appraisal | Year: 2012
This paper describes an innovative approach to environmental assessment that built local capacity enabling a more sustainable management of natural resources. It presents learning outcomes from a community-based strategic environmental assessment (CBSEA) involving communities from two Costa Rican watersheds who assessed the Instituto Costarricense de Electricidad's (ICE) proposed agro-conservation programme. Participants were engaged throughout the CBSEA process, from planning to the implementation of four highly interactive workshops representing steps in a strategic environmental assessment. Instrumental learning results included: learning about CBSEA and its role in programme planning; developing problem-solving skills related to assessing impacts and creating mitigation strategies; effective group-working strategies; and technical information. Communicative learning outcomes included becoming more self-aware, and appreciating environmental conservation and collaboration. ICE learnt a participatory methodology and reconsidered communities' role in programme planning. Findings contribute to understanding the process of adult learning in cross-cultural contexts and the link between individual learning and social action. © 2012 Copyright IAIA.
Issack B.B.,Concordia University at Montréal |
Issack B.B.,University of Saint-Boniface |
Peslherbe G.H.,Concordia University at Montréal
Journal of Physical Chemistry B | Year: 2015
While it has long been known that cholesterol reduces the permeability of biological membranes to water, the exact mechanism by which cholesterol influences transmembrane permeation is still unclear. The thermodynamic and kinetic contributions to the transport of water across mixed DPPC/cholesterol bilayers of different composition are thus examined by molecular dynamics simulations. Our analyses show that cholesterol decreases transmembrane permeability to water mainly by altering the thermodynamics of water transport. In particular, the free-energy barrier to permeation is magnified in the dense bilayer interior and the partitioning of water is significantly lowered. The changes are observed to correlate quantitatively well with the cholesterol-dependent density and thickness of the bilayers. In contrast, diffusion coefficients are relatively insensitive to cholesterol concentration, except in the sparsely populated center of the bilayer. Diffusion of water in cholesterol-containing bilayers appears to be related to changes in the free area in the middle of the bilayer and to the solute cross-sectional area in the denser hydrophobic regions. Overall, cholesterol is found to have an inhibitory effect on the permeation of water at all concentrations investigated, although bilayers containing cholesterol concentrations up to 20 mol % display a more dramatic dependence on cholesterol content than at higher concentrations. Our results show that it is possible to quantitatively reproduce the relative effects of cholesterol on lipid bilayer permeability from molecular dynamics simulations. (Graph Presented). © 2015 American Chemical Society.
Habeck J.C.,University of Saint-Boniface |
Diop L.,University of Saint-Boniface |
Dickman M.,University of Saint-Boniface
Journal of Chemical Education | Year: 2010
A dimethyl formamide-catalyzed synthesis of N,N-diethyl-3-methylbenzamide (DEET) from toluic acid and oxalyl chloride in an introductory organic chemistry laboratory course is presented. Students use this procedure and another procedure previously reported in this Journal. Thus, beginner chemists have the chance to compare complementary syntheticmethods. Copyright © 2010 The American Chemical Society and Division of Chemical Education, Inc.