Thompson Rivers University
Thompson Rivers University

Abstracts & Biographies

Winter 2017

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Presenter: Honors Research Presentations

Date:  Jan. 26, 2017

Title:  Short presentations by 4th year Honors students

Abstract:  Various

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 Presenter:  Dr. Sandra Jasinoski

Date:  Feb. 2, 2017

Title: Palaeobiology of basal cynodonts, the early ancestors of mammals

Abstract: The study of extinct non-mammaliaform cynodonts is important as this group gave rise to modern mammals. The basal cynodonts Thrinaxodon liorhinus and Galesaurus planiceps, both found in the Early Triassic of South Africa, are represented by dozens of well-preserved skulls that vary greatly in size. The abundance of specimens allowed a comprehensive investigation of the ontogenetic growth of the skull in these two basal cynodonts. Results of the survey revealed that many of the ontogenetic changes occurred in the temporal region, reflecting the greater development of the jaw musculature during growth. Other ontogenetic changes include differences in the morphology and fusion of some of the cranial sutures. From this survey, the samples of Thrinaxodon and Galesaurus were divided into at least three discrete ontogenetic stages: juvenile, subadult, and adult. In addition, a recent skeletal survey of these two taxa led to the discovery that individuals lived in intraspecific aggregations. This new research documents the structure and frequency of these intraspecific aggregations in Galesaurus and Thrinaxodon, and re-examines the possibility of parental care.


 Presenter:  Dr. Stanley Greenspoon, Capilano University (emeritus), Canadian Assoc. of Physics Speaker Series

Date:  Mar. 2nd, 2017

Title:  What's New in the Search for Exoplanets and Extraterrestrial Life

Abstract: The detection of the first planet outside our solar system in 1995 ushered in a period of intensive work directed at not only detecting more such exoplanets, of which well over 3000 have now been confirmed, but also aimed at determining the properties of exoplanets and their atmospheres, as well as exploring the variety of planetary systems. A principal goal of this research has been to make progress towards answering the question wondered about since antiquity, “are we alone?” I will survey some of the more interesting recent discoveries in exoplanet research, much of which is based on phenomena from areas familiar to physics students, ranging from classical mechanics to general relativity. The criteria for inferring the presence of extraterrestrial life will be discussed, as will the issues involved in our being able to gather data confirming its existence. In addition, I will survey some of the plans proposed for research in the near and distant future, including the launch of successors to the Hubble and Kepler space telescopes.



Presenter: Dr Saisamorn Lumyong

Date: Mar 8th, 2017

Title: Bioplastic Production

Abstract: Bioplastics are an increasing well-known alternative to petroleum based plastic. They are derived from biological resources such as starch, cellulose, natural oil or glycerol. Bioplastics were found to be superior to petroplastics in term of energy efficiency, petroleum consumption and C-emissions. Bioplastics in general were found to be safer. Some bioplastics are biodegradable while others are not. Starch based bioplastics (especially polylactic acid; PLA) are a majority of the bioplastic market. Other are cellulose, polybutylene succinate; PBS, biopolytrimethylene tethylene; PTT , polyhydroxyalkanoate; PHAs, poly-3-hydroxybutyrate; PHB and polyvinylalcohol;PVA. PHAs is the only polymer that all production process is biological meaning this PHA is produced by microorganisms using renewable feedstock. Efforts in making other bioplastics than that of starch based bioplastic into large scale production using microorganisms are ongoing.


 Presenter: Dr. Saisamorn Lumyong

Date:  Mar. 9th, 2017

Title:  Antioxidants in Mushrooms

Abstract:  Mushroom contains numerous secondary metabolites, including phenolic compounds, terpenes and steroids. Some common edible mushrooms have currently been found to possess antioxidant activity, which has shown a great correlation with their total phenolic content. An increasing interest in the consumption of mushrooms has occurred in many communities. Among the antioxidant compounds, phenolic compounds have gained importance because of their large biological actions, such as free radical scavenging, enzyme inhibitory activities, metal chelation. Four popular wild edible mushroom species (Rugiboletus extremiorientalis, Russula emetica, Russula sp. and Phleobopus portentosus) in Thailand were investigated for their total phenolic and flavonoid contents and phenolic profile. The phenolic profile of an effective water extract of R. extremiorientalis presented gallic acid, protocatechuic acid, catechin, vanillic acid, syringic acid, sinapic acid, ferulic acid, hydroxycinnamic acid, rutin and apigenin. This is the first report of phytochemical data for selected popular wild edible mushroom species in Thailand, and these findings could be applied to nutraceutical and cosmetic purposes.


Presenter: Dr. Jacob Omajali, Dept. of Biological Sciences, TRU

Date:  March 23, 2017

Title:  Bacterial-derived nanoparticles: Syntheses and applications

Abstract:  Bacteria are currently useful as renewable sources of bio-nanoparticles (bio-nanocatalysts) by serving as catalyst supports during production. Typical conventional commercial catalysts which are often very expensive, require the use of harmful chemicals as stabilizing and reducing agents, resulting in catalyst that sinter easily with ease for particle growth, deactivation and reduced life span. Bio-nanocatalysts made from biomass of either Gram-positive or Gram-negative bacteria are potential alternatives to commercial production and the biomass can be obtained as waste by-products from another biotechnology process. These bio-nanoparticles can be synthesized by reducing metal salts of palladium, ruthenium, gold, and platinum on bacterial surfaces (or intracellularly as observed recently via HAADF-STEM analysis), and are stabilized and prevented from particle growth and agglomeration by the various functional groups found on the bacterial surface. Interestingly, since these precious metals are quite expensive, they can be obtained from waste sources e.g. from road dust, electronic scraps, and catalytic converters and made useful through bio-patterning on bacteria. This seminar presentation will focus on the syntheses of mono and bimetallic bio-nanoparticles (bio-nanocatalysts) by Gram-positive and Gram-negative bacteria, their characterization and application in environmental and various industrial-type reactions.


Presenter: Dr. Gauld, University of Windsor

Date:  Mar. 30th, 2017

Title:  Computational Studies on Ancient Enzymes: Understanding How They Achieve High-Accuracy Catalysis

Abstract:  Due in part to their high specificity and efficiency, enzymes are often considered as exemplar models for catalysts and molecular recognition. Amongst enzymes, aminoacyl-tRNA synthetases (aaRS's) have been referred to as paradigms of specificity. This is due to the fact that on average they make only 1 error per 10,000 reactions.1 This is all the more remarkable as they are presumed to be ancient, functioning at a critical interface between RNA and protein biochemistry. Indeed, they are involved in a range of physiological processes including protein biosynthesis, viral assembly, and inflammation.2

AaRS's catalyse: (i) activation of their amino acid by forming an aminoacyl-adenylate, followed by (ii) transfer of the aminoacyl onto their cognate tRNA. Both are believed to proceed via substrate-assisted mechanisms in which the substrate itself assists its own reaction. Some aaRS's possess absolute fidelity while others are thought to exploit pre- and/or post-transfer editing. That is, they discriminate against non-cognate substrates either in the active site in which aminoacyl transfer occurs or, they have a second active site that removes the aminoacyl from misacylated-tRNA. In many cases, however, it is unclear whether these editing processes exploit chemical or physical discrimination, or whether they may exploit the direct intervention of active site residues.

Using multi-scale computational methods from Docking and molecular dynamics (MD), to quantum mechanical-chemical cluster and quantum mechanics/molecular mechanics (QM/MM)-MD approaches we have examined possible mechanisms by which these ancient enzymes catalyse aminoacylation of their cognate tRNA, and how they discriminate again non-cognate substrates. Such studies may have potential broader implications for other aaRS's and catalysts, as well as design of new, self-correcting or editing catalysts.


Presenter: Dr. Dustin Ritchie, Depart. of Physics & Nat'l Institute for Nanotechnology, University of Alberta

Date:  April 6th, 2017

Title:  What Effect Does RNA Mechanical Stability Have on Protein Synthesis?

Abstract:  A biochemical machine called the ribosome uses the message encoded in RNA to synthesize a functional protein. Specifically, the ribosome reads the RNA three nucleotides at a time such that each ‘triplet codon’ determines the next amino acid to be added to the growing protein. Complicating matters, RNA molecules fold into a rich variety of structures that can impede the ribosome’s travel along the RNA sequence. Unfolding of structured RNA by the ribosome is essential for continued protein synthesis. Maintenance of the ‘triplet codon’ reading frame is also required for production of functional protein. In rare cases structured RNA causes the ribosome to ‘hiccup’, resulting in a regulated change of reading frame before the structure is resolved and protein synthesis can continue. Changes to reading frame are a programmed feature of the RNA itself, but how the RNA structure regulates changes in reading frame is poorly understood. We have investigated the possible relationship between RNA mechanical stability and regulation of changes to reading frame by applying single-molecule optical tweezers pulling experiments to a panel of RNA structures associated with different levels of experimentally determined reading frame changes.

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Presenter: Dr. Soumya Ghosh, post doctural fellow, TRU

Date:  Apr. 13th, 2017

Title:  Save bats: biological control measures against white-nose syndrome

 

Abstract:  White nose syndrome (WNS) has devastated many eastern North American bat populations since 2007, killing more than 6 million bats. Since the first mortality was observed at a cave near Albany, New York in 2007, it has spread to 29 US states and 5 Eastern Canadian provinces, most recently appearing in 2016 in Washington State, USA. The etiological factor for WNS is Pseudogymnoascus destructans (Pd) which is a psychrophilic fungus that grows optimally on hibernating bats at temperatures between 12°C – 16°C. This fungus preferentially infects thinly haired regions on the skin of hibernating bats, and is able to degrade collagen and invade living tissue. Pd infection disrupts normal torpor and arousal cycles of hibernating bats. This causes a premature depletion of fat reserves, in addition to electrolyte imbalances and dehydration, resulting in mortality prior to the end of hibernation. Treatment of Pd infection is desired to reduce the likelihood of species extinctions, and increase the number of bats surviving WNS. Bats are worth billions of dollars to the US economy, justifying expenditure to mitigate WNS through treatment with control agent(s) against Pd. The study focusses to identify and investigate the in vitro antagonistic properties of natural biocontrol agents against Pd.

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