Life Sciences Commons^™

Does A Carbonatite Deposit Influence Its Surrounding Ecosystem?, James M.C. Jones, Elizabeth A. Webb, Michael D.J. Lynch, Trevor C. Charles, Pedro M. Antunes, Frédérique C. Guinel

Biology Faculty Publications

Carbonatites are unusual alkaline rocks with diverse compositions. Although previous work has characterized the effects these rocks have on soils and plants, little is known about their impacts on local ecosystems. Using a deposit within the Great Lakes–St. Lawrence forest in northern Ontario, Canada, we investigated the effect of a carbonatite on soil chemistry and on the structure of plant and soil microbial communities. This was done using a vegetation survey conducted above and around the deposit, with corresponding soil samples collected for determining soil nutrient composition and for assessing microbial community structure using 16S/ITS Illumina Mi-Seq sequencing. In some …

Arts Of Living On A Damaged Planet: Ghosts And Monsters Of The Anthropocene By Anna Lowenhaupt Tsing, Heather Anne Swanson, Elaine Gan, And Nils Bubandt, Randy Lee Cutler

The Goose

Review of Anna Lowenhaupt Tsing, Heather Anne Swanson, Elaine Gan, and Nils Bubandt's Arts of Living on a Damaged Planet: Ghosts and Monsters of the Anthropocene.

Hawk On Wire: Ecopoems By Scott T. Starbuck, Vivian M. Hansen

The Goose

Review of Scott T. Starbuck’s Hawk on Wire: Ecopoems

Ecological Art: Art With A Purpose, Aaron M. Ellison, David Buckley Borden

The Goose

Ecological art is purposeful and often prescriptive: the actions and directions intended by the artists for activists to undertake often are clearly represented. Yet, ecological art has been no more successful than, for example, targeted scientific research, deposits on returnable bottles, or land-protection campaigns at slowing global warming, reducing the amount of waste we generate every day, or halting the ongoing sixth mass extinction in the history of the Earth. Here, we consider the idea that prescriptive ecological art provides insufficient mental space for creative reflection about future scenarios of, and responses to, environmental change. We ask whether, by presenting …

Spirituality And The Infant Brain: Implications For Attachment Theory And Therapeutic Process Across The Life Span, Caitlin Eliasson

Consensus

No abstract provided.

A Stimulatory Role For Cytokinin In The Arbuscular Mycorrhizal Symbiosis Of Pea, Dane M. Goh, Marco Cosme, Anna B. Kislala, Samantha Mulholland, Zakaria M.F. Said, Lukáš Spíchal, R.J. Neil Emery, Stéphane Declerck, Frédérique C. Guinel

Biology Faculty Publications

The arbuscular mycorrhizal (AM) symbiosis between terrestrial plants and AM fungi is regulated by plant hormones. For most of these, a role has been clearly assigned in this mutualistic interaction; however, there are still contradictory reports for cytokinin (CK). Here, pea plants, the wild type (WT) cv. Sparkle and its mutant E151 (Pssym15), were inoculated with the AM fungus Rhizophagus irregularis. E151 has previously been characterized as possessing high CK levels in non-mycorrhizal (myc^-) roots and exhibiting high number of fungal structures in mycorrhizal (myc⁺) roots. Myc^- and myc⁺ plants were …

Alternative Nad(P)H Dehydrogenase And Alternative Oxidase: Proposed Physiological Roles In Animals, Allison Mcdonald, Dmytro V. Gospodaryov

Biology Faculty Publications

The electron transport systems in mitochondria of many organisms contain alternative respiratory enzymes distinct from those of the canonical respiratory system depicted in textbooks. Two of these enzymes, the alternative NADH dehydrogenase and the alternative oxidase, were of interest to a limited circle of researchers until they were envisioned as gene therapy tools for mitochondrial disease treatment. Recently, these enzymes were discovered in several animals. Here, we analyse the functioning of alternative NADH dehydrogenases and oxidases in different organisms. We propose that both enzymes ensure bioenergetic and metabolic flexibility during environmental transitions or other conditions which may compromise the operation …

Identification Of The Alternative Oxidase Gene And Its Expression In The Copepod Tigriopus Californicus, Allison Mcdonald, Carly E. Tward, Willie Cygelfarb, Jaspreet Singh

Biology Faculty Publications

In addition to the typical electron transport system (ETS) in animal mitochondria responsible for oxidative phosphorylation, in some species there exists an alternative oxidase (AOX) pathway capable of catalyzing the oxidation of ubiquinol and the reduction of oxygen to water. The discovery of AOX in animals is recent and further investigations into its expression, regulation, and physiological role have been hampered by the lack of a tractable experimental model organism. Our recent DNA database searches using bioinformatics revealed an AOX sequence in several marine copepods including Tigriopus californicus. This species lives in tidepools along the west coast of North …

The Effect Of Loading Rate On Annulus Fibrosus Strength Following Endplate Fracture, John Mcmorran

Theses and Dissertations (Comprehensive)

Low back pain is the most prevalent cause of chronic pain for North Americans, and its correlation with endplate damage, and deficient mechanical properties in the annulus fibrosus (AF) makes this injury particularly concerning. To date, biomechanical alterations in the AF following endplate fracture have not been well described. Owing to the AF’s collagenous composition, and the intrinsic biomechanics of intervertebral discs (IVDs) during compression, it was hypothesized that the mechanical properties of AF specimens would show rate-dependent alterations in their tensile and adhesive strengths following endplate fracture. The purpose of the present study was to quantify the mechanical properties …

The Task At Hand: Fatigue-Associated Changes To Corticospinal Excitability During Writing, Kezia Cinelli

Theses and Dissertations (Comprehensive)

Corticospinal excitability as measured via transcranial magnetic stimulation (TMS) is highly dependent on the task being performed at the time of stimulation. As such, this study sought out to measure corticospinal excitability during the relevant, daily task of writing and compare it to the conventional abduction task often utilized. We used single-pulse motor evoked potentials (MEPs) to provide a measure of corticospinal excitability and cortical silent period (CSP) duration, and paired-pulse conditioned MEPs to assess short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) recorded from the right first dorsal interosseous (FDI) of 19 participants on two randomized and counter-balanced days. …

Functional Characterization Of O-Acetyltransferase Wssi: Role In Bacterial Cellulose Acetylation Of Achromobacter Insuavis And Pseudomonas Fluorescens, Alysha Burnett

Theses and Dissertations (Comprehensive)

Cellulose biofilms consist of a community of bacterial cells encased in a self-produced matrix of polymers (e.g. exopolysaccharides, such as cellulose) that facilitate a firm adherence to surfaces. The acetylation (addition of an acetyl group on carbohydrates) is crucial in virulence; thereby in some cases allowing opportunistic bacteria to cause harmful diseases. Pertaining to this research, the wrinkly spreader (WS) genotype of Pseudomonas fluorescens colonizes the air-liquid interface on food, water sources and human tissue to form a robust biofilm with the ability to spread across surfaces. The composition of this biofilm largely consists of bacterial cellulose polymers …

Competition Or Facilitation: Examination Of Interactions Between Endangered Sida Hermaphrodita And Invasive Phragmites Australis, Samantha N. Mulholland

Theses and Dissertations (Comprehensive)

Virginia Mallow (Sida hermaphrodita) is a perennial herb of the Malvaceae family that is native to riparian habitats in northeastern North America. Throughout most of its geographical distribution however, it is considered threatened and only two populations are known from Canada. The biology and ecology of S. hermaphrodita are still poorly understood and although few studies have been performed to determine the factors that contribute to the species rarity, it is considered threatened potentially due to the loss of habitat caused by exotic European Common reed (Phragmites australis subsp. australis) invasion. Allelopathic and phytotoxic conditioning of …

Riparian Zone Soil Microbial Community Dynamics: Interactions With Nutrient Loadings, James Bannister

Theses and Dissertations (Comprehensive)

Riparian zones are a type of wetland described as the interface between land and a body of water such as a river or stream. Riparian zones are effective buffers against anthropogenic pollutants and nutrient loads from non-point sources that can greatly diminish water quality. Riparian zones can host a variety of plant species and associated microbial communities. The combined biological processes of plants, bacteria, and arbuscular mycorrhizal fungi (AMF) are key to nutrient cycling and nutrient removal in riparian zones. As such, understanding the factors that influence them is critical for watershed management. This research is targeted at obtaining a …

Characterization Of The Red Complex Bacterial Biofilm, Alena Pratasouskaya

Theses and Dissertations (Comprehensive)

Commonly associated with severe inflammation and destruction of the tooth-supporting tissue is bacterial consortia Treponema denticola, Tannerella forsythia, and Porphyromonas gingivalis, collectively referred to as the red complex. The red complex uses the common bacterial strategy of producing and embedding itself in extracellular polymeric substance, which contributes to the recalcitrance of periodontitis and was therefore of interest in this study. The red complex static cultures were grown in combination with different chemicals in order to establish what changes accompany these chemical challenges. This research established that extracellular polymeric substance carbohydrate yields increased with time. Interestingly, carbohydrate composition …

Influence Of Ligand Complexation On Nickel Toxicity, Speciation And Bioavailability In Marine Waters, Samantha Sherman

Theses and Dissertations (Comprehensive)

Currently there are no site-specific bioavailability-based prediction models for assessing the impacts of nickel (Ni) in marine environments although there are indications that these may be warranted. The aim of this research was to characterize the complexation of Ni in relation to toxicity and speciation. Various complexing ligands were used, and it was predicted that the binding affinity (logKf) of ligands would be inversely correlated to toxicity based on dissolved Ni concentrations ([NiD]) but that on a free ion concentration ([Ni2+]) basis, toxicity would not vary. A two-phased approach was used; the first was a proof of principle where synthetic …

Structural Investigation Of Bcsc: Insight Into Periplasmic Transport During Cellulose Export, William Scott, Joel T. Weadge

Theses and Dissertations (Comprehensive)

A biofilm can be defined by a community of microbes coexisting within a self-produced protective polymeric matrix. Exopolysaccharide (EPS) is a key component in biofilms and a contributor to their virulence and pathogenicity. The cellulose bacterial synthesis complex is one such EPS system that is found in many Enterobacteriaceae,including Escherichia coli and Salmonella spp., and is responsible for the production and secretion of the EPS cellulose. BcsC is the periplasmic protein responsible for the export of the exopolysaccharide cellulose and was the focus of this research. Sequence homology comparisons and structural predictions between BcsC, and the previously characterized alginate …

Potential Quality Indicators For Seriously Ill Home Care Clients: A Cross-Sectional Analysis Using Resident Assessment Instrument For Home Care (Rai-Hc) Data For Ontario, Lisa E. Harman, Dawn M. Guthrie, Joachim Cohen, Anja Declercq, Kathryn Fisher, Donna Goodridge, John P. Hirdes, Hsien Seow

Health Sciences Faculty Publications

Background

Currently, there are no formalized measures for the quality of home based palliative care in Ontario. This study developed a set of potential quality indicators for seriously ill home care clients using a standardized assessment.

Methods

Secondary analysis of Resident Assessment Instrument for Home Care data for Ontario completed between 2006 and 2013 was used to develop quality indicators (QIs) thought to be relevant to the needs of older (65+) seriously ill clients. QIs were developed through a review of the literature and consultation with subject matter experts in palliative care. Serious illness was defined as a prognosis of …

Physical Fatigue Negatively Affects Decision-Making During A Closing-Gap Aperture Crossing Task When Using Joystick-Controlled Locomotion, Natalie Snyder

Theses and Dissertations (Comprehensive)

Goal-direct locomotion is made possible through the integration of sensory input from the visual, vestibular, and somatosensory system. However, changes in collision avoidance behaviours and action capabilities (i.e., affordances) may occur when a sensory conflict is introduced (i.e., via incongruent input from a sensory system). Further, changes to the person (such as physical fatigue) may have negative implications on the cognitive abilities of an individual following physically fatiguing exercise. This in turn could affect an individual’s ability to avoid collisions with objects or other individuals in their environment. Thus, the objective of this thesis was to explore how physical fatigue …

The Impacts Of Gold Mining On Vegetation And Mycorrhizal Colonization In Northern Canada, Sarah Mediouni

Theses and Dissertations (Comprehensive)

Gold mining is an important part of economic development in Northern Canada. A large portion of the gold that is found in the North is contained within arsenopyrite ores, therefore, arsenic contamination is of special concern. Little is known regarding the impacts of arsenic on plants and mycorrhizae in Northern Ecosystems. Arsenic has been shown to negatively impact plant growth and seed germination in some temperate species, while others are tolerant and can accumulate arsenic concentrations over 1000 mg/kg. In temperate regions, arbuscular mycorrhiza can accelerate the remediation process in gold mines by supporting plant growth in poor soil conditions …

Expression Of Alternative Oxidase In The Copepod T. Californicus When Exposed To Environmental Stressors, Carly Tward

Theses and Dissertations (Comprehensive)

In addition to the typical electron transport system in animal mitochondria responsible for oxidative phosphorylation, some species possess an alternative oxidase (AOX) pathway, which causes electrons to bypass proton pumping complexes. Although AOX appears to be energetically wasteful, studies have revealed its wide taxonomic distribution, and indicate it plays a role in environmental stress tolerance. AOX discovery in animals is recent, and further research into its expression, regulation, and physiological role has been impeded by the lack of an experimental model organism. DNA database searches using bioinformatics revealed an AOX sequence present in the arthropod Tigriopus californicus. Multiple sequence …

Investigating The Antiviral Effects Of Vig-3 From Rainbow Trout, Shanee Herrington-Krause

Theses and Dissertations (Comprehensive)

Rainbow trout is the most farmed fish in Ontario, and thus is economically important to the province. Despite this, there is a lack of understanding regarding fish innate immunity, specifically with regards to interferon-stimulated genes (ISGs) and their antiviral effector functions. ISGs are the workhorses of the innate antiviral response, operating together to limit each step of virus replication. The Viral Hemorrhagic Septicemia Virus (VHSV) induced gene (Vig)-3 is a newly identified ISG within many fish species and is homologous to ISG-15 in mammals. It is a small ubiquitin-like protein inducible by type I interferon (IFN-I), and is suggested to …

Adventures In Time And Space: What Shapes Behavioural Decisions In Drosophila Melanogaster?, Heather Malek, Tristan Af Long Dr.

Theses and Dissertations (Comprehensive)

Variation in behaviour can be observed both between individuals, based on their condition and experience as well as between populations due to sources of heterogeneity in the environment. These behavioural differences have evolved as a result of natural and sexual selection where different strategies may be favoured depending on the costs and benefits associated with those behaviours. In this thesis I examine two sources of heterogeneity within the environment and their behavioural consequences: how spatial complexity mediates sexual selection over time, and how inter and intraspecific signals and individual condition influence social oviposition behaviour. By increasing spatial complexity, we were …

Spinal Motor Neuron Excitability During Fatigue, Nathalie Cecire

Theses and Dissertations (Comprehensive)

Fatigue during sustained or repeated muscular contractions can be from contractile failure within the muscle or reduced excitability in the supraspinal and spinal motor neurons. However, spinal motor neurons can also compensate for fatigue. We speculate that one way the spinal motor neuron compensates for fatigue is through an increase in excitability via the activation of persistent inward currents (PIC). In other conditions where there is a reduction in descending drive, such as during spinal cord injury and aging, there are adaptions of the spinal motor neurons to have elevated PIC amplitudes or towards a greater prevalence of PIC, respectively. …

Characterization Of Wssf; A Putative Acetyltransferase From Achromobacter Insuavis And Pseudomonas Fluorescens, Cody Reese

Theses and Dissertations (Comprehensive)

Biofilms are a survival mechanism commonly employed by communities of bacteria for adherence and protection. Bacteria produce a matrix of polymers (e.g. exopolysaccharides, such as cellulose) that allow them to exert control on their local environment. In the case of cellulose biofilms, acetylation (addition of acetate on carbohydrates) is paramount for polymer integrity and in some cases virulence. For this research, the wrinkly spreader (WS) genotype of the emergent human pathogen Achromobacter insuavis facilitates infections of the eyes of contact lens wearers and the lungs of Cystic Fibrosis patients (CF). Chronic infections have created a growing concern for the protective …

Structural And Functional Analysis Of Three Upregulated Gene Products, Tde0626, Tde1701, And Tde2714 From Treponema Denticola During Biofilm Formation, Jonah Nechacov

Theses and Dissertations (Comprehensive)

The progression of human chronic periodontitis within periodontal disease has been often linked to the presence of key pathogens, such as the presence of Treponema denticola, a late colonizer found in the deepening pockets of the gingival sulcus. This pathogen, as well as its associates Porphyromonas gingivalis and Tannerella forsythia, are classified as the ‘red complex’ and exist in a mixed biofilm during infection. It is within this biofilm state that previous transcriptomic analysis revealed a total of 126 genes that had an increase in their expression by 1.5-fold or greater in T. denticola. Three of these …

Dispersal As A Buffer Against Zooplankton Community Change In Response To Fluctuating Salinity Levels On The Great Plains, Mercedes Huynh

Theses and Dissertations (Comprehensive)

The North American Great Plains is home to thousands of closed-basin lakes that are sensitive to changes in hydrology. Climate change models predict increased aridity in this region over the coming century, which is expected to lead to higher salinity levels in many freshwater lakes. Increases in salinity levels may impact zooplankton communities, as laboratory experiments show that many freshwater species have a low tolerance for elevated salinity levels, and field data demonstrate that salinity is the primary factor structuring aquatic communities on the Great Plains. Changes to zooplankton communities could lead to a trophic cascade based on their important …

Going Back To The Soil: An Integrated Approach To Farming., Renée V. Christie

Theses and Dissertations (Comprehensive)

Agricultural productivity is often constrained by nutrient availability; as such, copious amounts of synthetic fertilizers are applied to maintain productivity. However, the intensive use of synthetic fertilizers has reduced the capacity of the soil to carry out crucial roles such as nutrient cycling because of shifts in the microbial community composition and structure. In addition, much of the applied synthetic fertilizers become lost to the environment through run-off, which contributes to soil degradation. With the increasing demand on agricultural systems to provide food and fibre and the adverse impacts of agricultural production on the soil resource, amendments that support soil …

Characterization Of The Microbial Phosphonate-Activating Pntc Enzymes, Kyle Rice

Theses and Dissertations (Comprehensive)

New strategies are urgently needed to combat infectious diseases in an era of rising antibiotic resistance. Furthermore, an emerging appreciation for the human microbiome’s role in maintaining health motivates discovery of species-specific antibiotics that minimally disrupt our native bacterial communities. Small molecule modifications to bacterial cell surfaces represent a potentially rich source of new targets for next generation antibiotics, as these molecules mediate virulence and evasion of the host immune response. Phosphocholine (PCho) is a rare cell surface modification that contributes to virulence, and modifications with phosphonates like 2-aminoethylphosphonate (AEP) are even more unusual and therefore provide opportunities for species- …

Potential Impact Of Northern Resource Development On Aquatic Biota: Toxicity Of Chromium And Rare Earth Element Processing Reagent, So Yeon Choi

Theses and Dissertations (Comprehensive)

Chromite and rare earth element development was identified in the 2015 Canadian Federal budget as a significant opportunity, however, key data gaps exist regarding the environmental concerns related to these resource developments. Chromium is essential in the production of stainless steel, and no suitable substitute is known. Rare earth elements (REEs) are a series of metals that are composed of 15 lanthanides, as well as scandium and yttrium. Uses for REEs range from electronic devices (i.e. cell phones, computers, televisions) to magnets and controlling nuclear reactors. While commercial production of REEs signify a great economic opportunity for Canada, key data …

Happy Or Hangry Families: Does Kinship Mediate Cooperation And Cannibalism In Drosophila Melanogaster Larvae?, Lucas Khodaei

Theses and Dissertations (Comprehensive)

The fruit fly Drosophila melanogaster has a long history as a research model for studies on behaviour and group dynamics. When individuals are grouped in an environment and resources decrease, then they may behave co-operatively with one another or antagonistically compete. Hamilton’s Law states that if the benefit of helping a related individual out-weighs the cost to its direct fitness, then the individual’s indirect fitness will increase when they help their kin compared to helping an unrelated stranger. Yet it is unknown whether kinship mediates larval behaviour to encourage co-operation and/or lessen antagonistic behaviours between consanguineous individuals. In this thesis …