Digital Commons Network^™

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 …

Multiscale Mathematical Modelling Of Nonlinear Nanowire Resonators For Biological Applications, Rosa Fallahpourghadikolaei

Theses and Dissertations (Comprehensive)

Nanoscale systems fabricated with low-dimensional nanostructures such as carbon nanotubes, nanowires, quantum dots, and more recently graphene sheets, have fascinated researchers from different fields due to their extraordinary and unique physical properties. For example, the remarkable mechanical properties of nanoresonators empower them to have a very high resonant frequency up to the order of giga to terahertz. The ultra-high frequency of these systems attracted the attention of researchers in the area of bio-sensing with the idea to implement them for detection of tiny bio-objects. In this thesis, we originally propose and analyze a mathematical model for nonlinear vibrations of nanowire …

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 …

Long-Term Effects Of A Universal Program On Child Welfare Youth's Psychosocial Outcomes, Alexis Gilmer, Colleen Loomis

Theses and Dissertations (Comprehensive)

The present project conducted two studies to better understand the impacts of former involvement with the child welfare system on young adults’ psychosocial outcomes at ages 18 and 30. In the first study (N = 598, M_age = 18.47 years) participants who were involved with child welfare during youth had higher rates of depression than those not involved in care. Using a quasi-experimental design, we hypothesized that participation in a universal community program would moderate the relationship between child welfare system involvement and negative outcomes; the hypothesis was not supported. The second study explored trends ten years later …

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 …

Use Of Pre-Industrial Baselines To Assess Sources And Pathways Of Metals In Surface Sediment Of Floodplain Lakes In The Peace-Athabasca Delta (Alberta, Canada), Tanner Owca

Theses and Dissertations (Comprehensive)

The effects of natural resources exploitation in northern Canada on downstream aquatic ecosystems is a concern. Assessing these effects requires comprehensive monitoring practices to better inform stakeholders and environmental stewardship decisions. Here, a monitoring approach is developed and applied to assess metals concentrations in lake surface sediments of the Peace-Athabasca Delta (PAD), northern Alberta, Canada. Since the ecological integrity of the PAD is strongly tied to river floodwaters that are critical for replenishing the delta, and the PAD is located downstream of the Alberta oil sands, concerns have been raised over the potential transport of metal contaminants to the PAD …

Development And Application Of Hydrological And Limnological Monitoring In Lake-Rich Landscapes Of Canada’S Subarctic National Parks, Hilary Emma White

Theses and Dissertations (Comprehensive)

Arctic and subarctic environments are being adversely influenced by human-caused climate change across our entire planet. Canada’s northern freshwater ecosystems are influenced by a variety of environmental stressors and are particularly sensitive to climate change, since small shifts in climate have the potential to substantially alter their hydrological, limnological, and biogeochemical conditions. Some other indirect effects on northern freshwater landscapes are the expansion of vegetation as well as changes in wildlife and waterfowl populations and distribution. It is, therefore, critical to understand the observed and predicted influences of climate change and other environmental stressors on these northern freshwater environments dominant …

The Social Construction Of A Disaster Typology To Enhance Operational Emergency Planning For K-8 Public Schools In Southern Ontario, Patricia Martel

Theses and Dissertations (Comprehensive)

This dissertation outlines the development of a disaster typology that could be used as a tool for developing operational emergency plans for K-8 public schools with the potential to be applied more generally to other facilities that host vulnerable groups. The theoretical framework used to inform this study is the theory of the social construction of disasters. This theory conceptualizes disasters as being the result of the interaction between social factors, such as risk perception and vulnerability, and the hazards.The author of this dissertation is an emergency management practitioner and brought a perspective informed by both theory and practice of …

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 …

Diversity And Evolution Of Seeds In Cuscuta (Dodders, Convolvulaceae): Morphology And Structure, Magdalena Olszewski

Theses and Dissertations (Comprehensive)

Cuscuta is a genus of nearly 200 obligate stem parasites with a nearly cosmopolitan distribution and considerable agricultural and ecological significance. Dodder seeds are considered “unspecialized”, with no morphological adaptations towards particular dispersal vectors; however, the seed coat anatomy has recently suggested an adaptation to endozoochory. This is the first attempt to provide a genus-wide overview of the diversity in morphology and anatomy of Cuscuta seeds, together with an assessment of the water gap and exploration of various form-function relationships. I surveyed 104 species belonging to all four Cuscuta subgenera. Seeds of the species of the first infrageneric dodder …

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 …

Generative Adversarial Networks For Online Visual Object Tracking Systems, Ghsoun Zin

Theses and Dissertations (Comprehensive)

Object Tracking is one of the essential tasks in computer vision domain as it has numerous applications in various fields, such as human-computer interaction, video surveillance, augmented reality, and robotics. Object Tracking refers to the process of detecting and locating the target object in a series of frames in a video. The state-of-the-art for tracking-by-detection framework is typically made up of two steps to track the target object. The first step is drawing multiple samples near the target region of the previous frame. The second step is classifying each sample as either the target object or the background. Visual object …

Exploring The Female Autism Phenotype: Personal Identity Formation And Well-Being In Autistic Females, Erinn Nell Barry

Theses and Dissertations (Comprehensive)

A personal identity answers the questions: who am I and where do I fit in the world? While these are questions that all persons may encounter, I examine identity formation, as conceived by Marcia (1980), in a community sample of females diagnosed (or self-identified) as having an autism spectrum disorder (ASD), given that less is known regarding the identity process that autistic females undergo. More specifically, I examine the relationship between autism traits and the achieved and diffuse identity statuses. Research indicates the existence of a female autism phenotype (Lai et al., 2015), such that autistic females often present with …

The Influences Of Culture And The Self On Children’S Memory Encoding And Delayed Retrieval, Hongyuan Qi

Theses and Dissertations (Comprehensive)

Culture and the self form a dynamic system that shapes children’s memories. However, how these two constructs influence specific memory processes still requires further investigation. The present dissertation contains four studies that examined the influences of cultural backgrounds and self-views on children’s memory encoding and delayed retrieval. Participants across four studies were recruited in the year range of 2016 to 2018. A total of 243 Grade 1 and 2 (the younger group) and Grade 3 and 4 (the older group) children participated, with an age range of seven to ten years. Specifically, 121 Chinese children were from Mainland China and …

Blurred Lines: A Phenomenological Study Of Maternal-Child Interconnection., Laura Macgregor

Theses and Dissertations (Comprehensive)

This phenomenological study explored the lived experiences of maternal-child interconnection among 12 mothers raising children, of any age, with developmental disabilities as well communication challenges. During semistructured interviews, mothers told stories of maternal-child interconnection that described a sacred, mutual, and unique interpenetration of experiences between mother and child that was nurtured and sustained by ongoing togetherness. Mothers also shared that their unique mother-child interconnection was difficult to articulate, and often poorly understood beyond the mother-child dyad.

Maternal-child interconnection allowed mothers to understand their children’s unique, often non-verbal communication. As a result, mothers of children with significant communication challenges were able …

Rationality In Bargaining By Finite Automata, Jim Bell

Theses and Dissertations (Comprehensive)

Aspects of behavioral decision-making can be integrated into game-theoretic models of two-player bargaining using finite automata which can represent bargaining strategies in combination with various behavioral traits. The automata are used as bargaining agents who must jointly agree upon a fixed allocation of transferable utility in an infinite-horizon Rubinstein bargaining game. At each turn, the automata are given the opportunity to accept a proposed portion of the transferable utility, or to reject the proposal and make a counter-offer of their own. A round-robin tournament and ecological simulations were run to explore strategic dominance under different conditions. Principles of bargaining strategy …

Examining The Potential Involvement Of Sex Hormones On Appetite Regulation In Females Across The Menstrual Cycle, Sara Cabral Moniz

Theses and Dissertations (Comprehensive)

Appetite regulation has exclusively been examined during the follicular phase (FP) of the menstrual cycle, and it remains unclear whether the greater levels of estradiol (E₂) and progesterone (P₄) in the luteal phase (LP) affect this process. Thus, the purpose of this study was to utilize vigorous-intensity continuous training (VICT) as a method to modulate plasma concentrations of E₂ and P₄ and examine their associations with post-exercise alterations in acylated ghrelin, peptide tyrosine-tyrosine_3-36 (PYY_3-36), active glucagon like peptide-1 (GLP-1), subjective appetite perceptions, and energy intake across the menstrual cycle. Eleven women …

Expression, Purification, Functional Characterization And Crystallization Of Three Porphyromonas Gingivalis Gene Products, Katarina Mandic

Theses and Dissertations (Comprehensive)

Dental biofilms are coupled polymicrobial aggregates that have attached to solid surfaces in the oral cavity. These collections of microorganisms are known to cause periodontal diseases that commence as localized inflammation of the gingiva and if untreated, eventually lead to irreversible alveolar bone resorption and tooth loss. Porphyromonas gingivalis is one of three periodontal pathogens that make up the “Red Complex”; a bacterial consortium responsible for the production of polysaccharide-rich biofilms that are essential to the inception and progression of periodontal disease. The dysbiosis and destructive inflammation caused by these organisms propel a self-sustained feed-forward loop that perpetuates periodontal disease. …

Maple Syrup And Climate Change In Ontario: Assessing Transdisciplinary Research Across Multiple, Related Projects, Kendra Serbinski

Theses and Dissertations (Comprehensive)

The aim of this research was to critically evaluate the transdisciplinary process being utilized on the SSHRC and related research projects being led by Dr. Brenda Murphy. The approach was two-fold: first, a document analysis was performed using secondary data, and second, a questionnaire was conducted based on six themes that emerged from the literature. These themes were: Degree of Collaboration, The Value of Working Together over Time, Mutual Learning, Integration of Team Members, Complexity of the Problem Being Investigated and Bridging the Research-Societal Gap. Based on findings in the literature and responses to the questionnaire the themes were assessed …

The Surprising Reach Of Fda Regulation Of Cannabis, Even After Descheduling, Sean O'Connor

Faculty Scholarship

No abstract provided.

Signs Of Growth And Healing: Health Care And Science, Richard J. Fehring

College of Nursing Faculty Research and Publications

MY ESSAY ON THE HISTORY OF Catholic Natural Family Planning (NFP) scientists (chapter 8 in this volume) ended with discussing scientists who were active during the papacy of John Paul II (1979-2005). This present essay continues with the time period from approximately 2000 to 2018 and, indeed, into the future. My purpose here, however, is to delineate signs of growth and healing in health care and science related to NFP and not to focus on individual NFP scientists. Given that purpose, recent trends in NFP science and historical factors that influence NFP science can provide us with signs of growth …

Applications Of 3d Printing On Craniofacial Bone Repair: A Systematic Review, Michael Maroulakos, George Kamperos, Lobat Tayebi, Demetrios J. Halazonetis, Yijin Ren

School of Dentistry Faculty Research and Publications

Objectives

Three-dimensional (3D) bioprinting, a method derived from additive manufacturing technology, is a recent and ongoing trend for the construction of 3D volumetric structures. The purpose of this systematic review is to summarize evidence from existing human and animal studies assessing the application of 3D printing on bone repair and regeneration in the craniofacial region.

Data & sources

A rigorous search of all relevant clinical trials and case series was performed, based on specific inclusion and exclusion criteria. The search was conducted in all available electronic databases and sources, supplemented by a manual search, in December 2017.

Study selection

43 …

Predeath Grief, Resourcefulness, And Perceived Stress Among Caregivers Of Partners With Young-Onset Dementia, Karie Ruekert Kobiske, Abir K. Bekhet, Mauricio Garnier-Villarreal, Marilyn Frenn

College of Nursing Faculty Research and Publications

More than 200,000 Americans are currently diagnosed with young-onset dementia (YOD). YOD is dementia diagnosed prior to the age of 65. Most persons of YOD are cared for by their partners. Using the theoretical framework of Resilience Theory, this cross-sectional, correlational study examined the moderating effects of personal and social resourcefulness on the relationship between predeath grief and perceived stress among 104 YOD caregiving partners (life partners/spouses) using an online survey platform. Results indicated a large positive correlation between predeath grief and caregiver perceived stress (r = .65; p < .001). Together predeath grief, personal resourcefulness and social resourcefulness explained 51.5% of the variance in perceived stress. Personal resourcefulness did not moderate the relationship. Social resourcefulness did positively moderate this relationship between predeath grief and perceived stress. These findings allow for a better understanding of the caregiving experience for a partner with YOD and creates opportunities for future research studies.

Through The Microbial Looking Glass: Premature Labor, Preeclampsia, And Gestational Diabetes: A Scoping Review, Alexis B. Dunn, Lisa Hanson, Leona Vandevusse, Sharon Leslie

College of Nursing Faculty Research and Publications

The influence of microbial factors on adverse perinatal outcomes has become the focal point of recent investigations, with particular interest in the role of the microbiome and probiotic interventions. The purpose of this scoping review was to identify and critique the most recent evidence about these factors as they relate to pregnancies complicated by preeclampsia (PEC), preterm birth (PTB), and gestational diabetes mellitus (GDM). Four databases (PubMed, EMBASE, Web of Science, and Cochrane) were searched for articles published in English in the last 10 years with the concepts of the microbiome, probiotics, and PEC, PTB, or GDM. Forty-nine articles were …

Natural History Note: Anolis Sagrei Foraging On A Patch Of Obvious Prey, Stuart V. Nielsen, Aaron M. Bauer, Tony Gamble

Biological Sciences Faculty Research and Publications

No abstract provided.

A Multitrophic Perspective On Biodiversity–Ecosystem Functioning Research, Nico Eisenhauer, Holger Schielzeth, Andrew D. Barnes, Kathryn Barry, Aletta Bonn, Ulrich Brose, Helge Bruelheide, Nina Buchmann, Francois Buscott, Anne Ebeling, Olga Ferlian, Grégoire T. Freschet, Darren P. Giling, Stephan Hättenschwiler, Helmut Hillebrand, Jes Hines, Forest Isbell, Eva Koller-France, Birgitta König-Ries, Hans De Kroon, Sebastian T. Meyer, Alexandru Milcu, Jörg Müller, Charles A. Nock, Jana S. Petermann, Christiane Roscher, Christoph Scherber, Michael Scherer-Lorenzen, Bernhard Schmid, Andreas Schuldt, Teja Tscharntke, Manfred Türke, Nicole M. Van Dam, Fons Van Der Plas, Anja Vogel, Cameron Wagg, David A. Wardle, Alexandra Weigelt, Wolfgang W. Weisser, Christian Wirth, Malte Jochum

Biological Sciences Faculty Research and Publications

Concern about the functional consequences of unprecedented loss in biodiversity has prompted biodiversity–ecosystem functioning (BEF) research to become one of the most active fields of ecological research in the past 25 years. Hundreds of experiments have manipulated biodiversity as an independent variable and found compelling support that the functioning of ecosystems increases with the diversity of their ecological communities. This research has also identified some of the mechanisms underlying BEF relationships, some context-dependencies of the strength of relationships, as well as implications for various ecosystem services that mankind depends upon. In this paper, we argue that a multitrophic perspective of …

Assembling A Hispanic-Serving Institution: A Campus Landscape Analysis Of A Hispanic-Serving Institution, Brenda Lee Jimenez Sifuentez

Electronic Theses and Dissertations

Post-secondary educational spaces are often thought of as a backdrop to where education takes place. Architectural designs are seen as neutral sites; however, higher education institutions are sites of ideological production and therefore, fundamental exercises of power (Ford, 2017). The study of campus landscapes is relevant to uncovering and illuminating larger social issues of (in)equality in higher education. Literature regarding campus landscapes is scarce and this study seeks to demonstrate how the study of campus landscapes is both materially "real" and socially constructed. This study takes place at a four-year institution of higher education that has received the Hispanic Serving …

Chronic Stress And Ovarian Function In Female Childhood Cancer Survivors, Theresa Marie Hardy, Mauricio Garnier-Villarreal, Jennifer M. Ohlendorf, Donna O. Mccarthy

College of Nursing Faculty Research and Publications

Objectives: To explore the relationships among perceived stress, biomarkers of hypothalamic–pituitary–adrenal (HPA) activity, gonadotropin levels, and anti-Müllerian hormone (AMH) in female childhood cancer survivors (CCSs).

Sample & Setting: 24 female CCSs from the Royal Hospital for Sick Children in Edinburgh, Scotland, were included in the study.

Methods & Variables: Perceived stress was measured using the Perceived Stress Scale. HPA activity was measured using salivary cortisol and hair cortisol. Ovarian function was measured using serum gonadotropin levels and serum AMH levels. Latent growth curve modeling was used to determine diurnal cortisol slope and intercept. Bayesian structural equation modeling was used to …

The Relative Contribution Of Fixation Features, Activity, And Tibiofemoral Conformity On Initial Stability Of Cementless Tibial Trays, James Sullivan Deacy

Electronic Theses and Dissertations

Initial stability of cementless total knee replacements (TKR) is critical to implant success as excessive motion between the bone and implant prevents bony ingrowth that is critical to the long-term survivability of cementless implants. Prior studies have shown that excessive micromotion causes fibrous tissue growth instead of beneficial bony growth. There are many factors that influence initial stability including the design of the tibial tray and the tibiofemoral articulations. Understanding the impacts of these design features on micromotion between the bone and implants is crucial to improving the performance of cementless TKR. Prior studies only tested for the effect of …

Worldviews: Concepts Or Narratives? An Integrative Definition To Assess Their Controlling Effect In The Biblical And Atheistic Evolutionary Models, Flavio Prestes Iii

Andrews University Seminary Studies (AUSS)

What are worldviews? What are their characteristics? How do they work? This article offers tentative responses to these questions through the integration of concepts and narratives. Using the biblical and the atheistic evolutionary narratives as case studies, it also seeks to show how worldviews have a significant, though not absolute, controlling effect on one’s perception of reality.