Research in the Xu laboratory focuses on plant and microalgal lipid metabolism. By applying state-of-the-art approaches in genetics, biochemistry, cellular biology, synthetic biology and biotechnology, we aim to address both fundamental and applied questions in the field. The major research objectives in our research group are to improve our understanding of the mechanisms underlying acyl lipid assembly (e.g. triacylglycerols/oils, galactolipids/photosynthetic membrane lipids, phospholipids/membrane lipids) in photosynthetic organisms and to design lipid biosynthetic pathways to improve agriculture production and produce value-added oils for food, feed, fuel, and materials applications.Learn More
Healthy gut microbiota can be disrupted due to antibiotic treatment, intestinal inflammation, or changes in diet. Targeted restoration of the microbiota will require an understanding of how genomic diversity between closely related microbes influences their ability to drive beneficial functions. To address this, our laboratory will use a large collection of whole-genome sequenced isolates to understand how variation between closely related gut isolates alters their ability to prevent pathogen expansion and maintain homeostatic interactions with the mucosal immune system.Learn More
My research is rooted in wildlife rehabilitation. Specifically, I am interested in the welfare of wild animals and helping restore health to sick and injured wildlife. I am also interested in looking at anthropogenic effects on wildlife that have been admitted to rehabilitation centres. There are so many ways that our actions have an impact on wildlife, and I am interested in helping wildlife rehabilitators care for wild animals for subsequent release back to the wild. I am also interested in wild animal welfare when working with free-ranging wildlife. In addition, we are investigating the extent of lead toxicosis in many (apparently) healthy Trumpeter Swans, as well as investigating other morbidities in individual wild animals admitted to rehabilitation centres.Learn More
I study the neurophysiology of cognitive processes. My research focuses on eye movements and how they interact with cognitive and executive functions. For example, I explore how features are integrated across multiple brain areas to form object representations, how attention and object representations drive eye movements, and how the visual system prioritizes peripersonal space. I am also interested in the networks in the brain that perform all these processes and how they can be impaired due to concussion and subconcussive impacts.Learn More
I conduct research in two areas:
1) Impact of teaching strategies on student learning and engagement in large classes: My goal is to modify and scale best teaching practices to suit large class sizes (100-600+ students). I evaluate the impact of these strategies on student learning and engagement. I am also interested in novel methods for teaching critical thinking and communication skills in health sciences education.
2) Health and performance of emerging adults in the early transition to university: I aim to better understand student experience to develop programs and strategies to optimize student performance. I study how lifestyle choices, social environments, and study strategies can influence student wellbeing and academic success.
In terms of teaching and learning, my primary areas of expertise are:
1) Curriculum design according to the new University of Guelph learning outcomes
2) Community-engaged, project-based learning
3) Creativity as a key learning outcome for student career development
In terms of knowledge transfer, my primary areas of expertise are:
1) Incorporating functional food and nutraceutical concepts into the design and practice of Lifestyle Medicine
2) Promoting studies of human anatomy as a foundation for the teaching and learning of Lifestyle Medicine in the general public
Our work spans three research themes:
1) DNA metasystematics: We gather biodiversity data through the analysis of marker genes from bulk samples (water, soil, and sediments). We pioneered this technique for benthic macroinvertebrates, used widely as bioindicators of aquatic ecosystems.
2) Biodiversity transcriptomics: We develop comparative transcritpome-based approaches for non-model organisms to gain insights on evolution of transcriptomes and understand molecular responses at ecological scale.
3) Bioinformatic approaches for biodiversity genomics data: We develop and test taxonomic assignment approaches for many taxonomic groups and marker genes, and develop tools to enhance analysis of metabarcoding and biodiversity genomic data through machine-learning methods and refined analysis.
My research program focuses on understanding the genetic basis of evolutionary change. In particular I am concentrating on two major components of the evolutionary process. Firstly, I study how genetic differences among individuals lead to variation in the numbers and survival of their offspring (fitness). Secondly, I determine how those genetic differences can become partitioned between populations when they begin to diverge genetically into different species. Salmonid fishes (Atlantic salmon, Arctic charr, rainbow trout, brook charr) continue to be the models for most of this work because their biology makes them interesting candidates for genetic analysis.Learn More
Dr. Spriet's basic research examines how skeletal muscle generates the large amounts of energy needed to exercise and compete in work and sport situations. The pathways that metabolize carbohydrate and lipid as fuel to produce energy are studied in human skeletal muscle. His practical research examines whether compounds that are purported to be "ergogenic" or work enhancing agents actually augment muscle metabolism and/or improve human performance (e.g. blood doping, creatine, carnitine, pyruvate, taurine, caffeine and omega-3 fatty acids). He also conducts hydration/sweat testing and research aimed at counteracting the effects of dehydration in athletes engaging in stop-and-go sports like ice hockey, basketball, and soccer.Learn More
My current research blends my research backgrounds in biomechanics and visuomotor control to examine how postural control is integrated and coordinated with voluntary movement (e.g. reaching, stepping, whole-body reaching). I am interested in developing an understanding of balance and movement both from a fundamental level, and in application to the immense problem of impaired mobility and falls in older adults and other clinical populations (e.g. stroke).Learn More
Research in my lab is focused on the behaviour, ecology, and conservation of animals living in seasonal environments. Much of our field work is conducted on songbirds and butterflies but also includes past and present studies on salamanders, fruit flies, nightjars, seabirds, and domestic cats. We use both observational and experimental approaches, often combining these with emerging tracking technologies, to understand factors influencing variation in fitness and population abundance. Our two primary long-term studies are on Canada jays in Algonquin Park, ON (50+ yrs) and Savannah sparrows on Kent Island, NB (30+ yrs).Learn More
Since changes in how the body metabolizes glucose are a hallmark of Type 2 diabetes, understanding how the function and metabolism of adipose tissue are regulated will be crucial for understanding diabetes itself. My students and I look at how exercise and nutritional interventions affect gene expression in adipose tissue, and, in turn, how these changes can affect both adipose tissue metabolism and whole-body glucose metabolism. One of the applications of my research is to potentially develop new, non-drug-based approaches that can be used to prevent and/or reverse Type 2 diabetes.Learn More
My main research focus centres around the issue of how contracting skeletal muscle can communicate with blood vessels in order to ensure adequate blood flow to the working skeletal muscle cells. There is a direct relationship between skeletal muscle metabolic rate and blood flow. This type of relationship requires that active skeletal muscle cells communicate their need for blood flow to the cells of the vasculature, endothelial cells and vascular smooth muscle cells, and that these cells alter their function in order to ensure the proper blood flow delivery. I am interested in this intercellular communication.Learn More
I am interested in understanding the physiological roles and regulation of adipose tissue and skeletal muscle-derived cytokines in mediating metabolic processes in the body. I am particularly interested in the mechanisms by which dietary factors and/or exercise modulate various cytokines and inflammatory mediators implicated in insulin resistance, a key characteristic of obesity and type 2 diabetes. My current research projects are:
1) Regulation of adipose tissue-derived cytokines in integrative metabolism.
2) Effect of n-3 and n-6 fatty acids in the presence and absence of LPS on adipocyte secretory factors and underlying mechanisms.
3) Effect of dietary fatty acids on pro-inflammatory markers in an in vitro murine adipocyte macrophage co-culture model.
To date, my research program has focused on strategies used to execute safe movement during adapted locomotor tasks (steering, obstacle circumvention, obstacle stepping) and the role of vision in these tasks. I am also interested in exploring the impact of cognitive or brain function on locomotor control. Given the commonness of dual tasking in our daily living, I hope to map patterns of cognitive-locomotor interference for multiple adapted locomotor (e.g. obstacle circumvention) and cognitive activities (e.g. visuo-spatial cognitive tasks) and ascertain optimal training strategies for dual-task performance.Learn More
My lab conducts research on several areas related to cardio-respiratory physiology and pathophysiology. For example, we are studying: 1) how the heart initially adapts to hypertension before the development of contractile dysfunction and heart failure; 2) skeletal and cardiomyocyte cell signalling during normal and hypoxic conditions; 3) proteomic alterations that occur in limb muscles during exercise; 4) key post-translational modifications of myofilament proteins that arise during the development of whole muscle dysfunction as a result of fatigue or ischemia; and, 5) dyastolic dysfunction in various physiological and pathological states, such as aging, sex differences, and models of heart failure.Learn More
The primary goals of our research program include: 1) to determine the fundamental role of methyl nutrients in health outcomes; 2) to determine molecular mechanisms underlying the development of obesity, metabolic syndrome and chronic diseases; and, 3) to contribute to evidence-based strategies that will improve the health of the population.Learn More
More than 4 million Canadians have arthritis and the number of people living with arthritis continues to increase year after year. Osteoarthritis involves multiple tissues and often includes cartilage damage, bone sclerosis and synovial inflammation. A pressing need remains for joint localized therapies and interventions that could slow or ideally stop this debilitating disease.
In our research, we use genetic and surgical models of spontaneous osteoarthritis (with old age) and post-traumatic osteoarthritis (following injury). We follow the progression of disease in a joint in order to better understand how proteins such as TRPV4, integrin alpha1beta1 and cilia influence chondrocyte signal transduction and thus the development of osteoarthritis.
My interests lie in the regulation of fat and carbohydrate metabolism in skeletal muscle, with a particular emphasis on the dysregulation that occurs in obesity and diabetes. Several cytokines released from skeletal muscle, including leptin and adiponectin, are known to significantly affect insulin response in peripheral tissues such as muscle. My research has focused on the effects of these adipokines on muscle lipid and carbohydrate metabolism, and particularly, how the muscle becomes resistant to their effects in obese models and with high fat feeding. The interaction of diet and exercise is also a point of interest in terms of the muscle's response to various hormones including insulin, leptin and adiponectin.Learn More
My background is in molecular and cell biology of lipid metabolism. Currently, my students and I work on the regulation of membrane phospholipids, fatty acids, and methyl-group donors. More specifically, we look at regulation of genes involved in choline transport and phospholipid metabolism; nutrient transporters and kinetics of membrane transport; molecular and cell biology of lipids; the effect of nutrients on protein synthesis and gene expression; and, nutritional genomics (nutrigenomics) of risk factors for cardiovascular disease and insulin resistance.Learn More
The primary goals of my research program are 1) to understand where posture is controlled 2) to understand what sensory information contributes to successful movement and equilibrium.
By investigating these two key questions I believe we will have a better understanding of how sensory decline contributes to a loss of mobility as we age. My research program involves two key areas of study:
1) To perform direct recordings from sensory afferents and motor efferents in awake human subjects to investigate sensory contributions to movement, balance control, and reflex responses.
2) To elicit balance perturbations to test the function of these reflex loops, and sensory contributions to the maintenance of equilibrium and postural control.
My students and I aim to understand the mechanistic role(s) of microbial-host intestinal communication. In particular, we focus on how microbial-derived metabolites (from dietary precursors) can influence the integrity of the colonic epithelial barrier (EB), as well as its capacity for defense and repair. The importance of this research lies on not only advancing basic knowledge on the effect of microbial metabolites on gastrointestinal functions, but also on informing the agri-food sector the ways in which the intake of nutrients, biomolecules, and dietary precursors can shape human health.Learn More
My research is primarily focused on understanding the regulation of mitochondrial bioenergetics, with a particular interest in studying fatty acid oxidation (breakdown of fat yielding energy) in skeletal and cardiac muscle. We also study human exercise performance as well as type 2 diabetes, heart failure, diabetic cardiomyopathy and various neuropathologies, all conditions that have been affiliated with alterations in mitochondria as a key event in the progression and/or development of the disease.Learn More
The ultimate goal of my research is to understand viruses and viral diseases for the betterment of agriculture. Our research involves a number of important viruses that infect plants, which include Grapevine rupestris stem pitting-associated virus (GRSPaV), a ubiquitous and important pathogen of grapes worldwide. Current research directions include: Processing and subcellular localization of polyproteins; structure and cellular localization of viral replication complexes; evolution and bio-informatics of grapevine viruses; development of virus-induced gene-silencing vectors ; and, development and application of technologies for the diagnosis of grapevine viruses.Learn More
Research in my laboratory is focused on the architecture and assembly of the cell surfaces of pathogenic bacteria. Current areas of emphasis are:
1) Structure and function of multi-enzyme complexes required for the export of capsular polysaccharides through the periplasm and across the outer membrane of Gram-negative bacteria.
2) Structural basis for substrate recognition by ABC transporters involved in the export of bacterial cell-surface polysaccharides.
3) Structure and function studies of prokaryotic glycosyltransferase enzymes.
4) Mechanisms that couple glycan biosynthesis and chain extension to transport pathways.