A Possible Association Between Insulin Regulation and Alzheimer’s Disease Alzheimer’s disease (AD) is a neurodegenerative disease which affects millions of people worldwide. This disease of ageing has been associated with amyloid-beta (Aβ) plaques and tauneurofibrillary tangles in the brain, causing symptoms such as confusion, memory loss, and
impaired cognitive abilities. It is well known that insulin is a key regulator in the ageing process, as well as many other bodily processes such as metabolism and fat storage. An association between insulin regulation and amyloid-beta plaque accumulation has been noted in C. elegans. This study uses C. elegans to investigate how decreased inulin signaling affects the deposition of human amyloid-beta in a transgenic worm strain, and phenotypes associated with Aβ expression. The findings from this study indicate the interaction between insulin and Aβ is complex, and research in this area is critical to determine possible therapeutic strategies for AD in the future. Meghan Hamp, MSc Candidate, Terrestrial Ecosystem Ecology Lab Atmospheric deposition of nitrogen (N) derived from fossil fuel burning is likely to impact the long-term stability of many ecosystems as it can have critical impacts on soil health, plant species diversity, and nutrient cycling. Grassland ecosystems are one of the most important terrestrial carbon sinks that could be utilized to mitigate climate change because of their high productivity, and their significant potential for enhanced soil carbon sequestration due to their rapid turnover of fine roots. Eastern Ontario is currently experiencing atmospheric N deposition levels of ~10 kg N ha-1 yr-1 , and meadow hayfields in the region occur on a wide range of soiltypes. The long-term consequences of enhanced atmospheric N deposition on such grasslands are difficult to predict because their responses to increased low-level N availability may be strongly influenced by factors such as soil texture that have not previously been investigated. A simulated enhanced atmospheric N deposition experiment was set up within a meadow hayfield in Eastern Ontario in 2005 and consists of six replicate treatment and control plots on both clay-based soils and sand-based soils. The objective of this research is to determine the relative impacts of experimentally increased low-level N additions (simulating 2050 atmospheric N input rates) and soil texture on species diversity, above- and belowground biomass and ecosystem carbon dioxide fluxes. The chronic low-level nitrogen additions had no significant impacts on growth of any plant species or on carbon dioxide fluxes. Instead, ecosystem carbon dioxide fluxes were primarily controlled by soil texture, soil temperature, and sampling date over the growing season. Aboveground biomass and species diversity were principally controlled by variation in soil moisture, while belowground biomass did not vary in response to any measured environmental parameters. The consistent lack of responses to the nitrogen addition treatment indicates that future increases in atmospheric nitrogen deposition are unlikely to have major impacts on Ontario’s meadow hayfields. By contrast, the strong interconnected influences of soil texture and soil moisture on multiple community and ecosystem-level properties suggest that effects of anticipated future declines in summer precipitation on subsequent water availability to vegetation will differ among soil-types. Therefore, future climate changes in this region are likely to have very substantial, but highly spatially variable, impacts on plant community structure and carbon cycling in its meadow hayfield ecosystems.
Dr. Anthony Ricciardi McGill University Incorporating time-since-invasion into invasion science and risk assessment Although considerable management attention is given to non-native species, invasions are essentially population-level events. Owing to the influence of the environment and other context dependencies on introduced populations, the impacts of non-native species vary across space and time. Climate warming of inland waters have imposed a universal stressor that is expected to alter species interactions and the impacts of invaders on food webs; the magnitude and direction of these alterations has both fundamental and applied importance to ecology. Time-since-invasion is also recognized as a mediator of impact but has not yet been well integrated into invasion theory and is virtually absent from consideration in risk assessment. Here I review evidence from aquatic case studies that evaluates the role of time-since-invasion in invasion dynamics, especially the phenomena of i) higher impacts at the leading edge of spreading populations, and ii) time lags, especially the ‘sleeper populations’—i.e., apparently innocuous non-native populations that are subsequently triggered to become invasive by an external factor or stressor that alters the physical or biological environment. Theory needs to be further developed to explain and predict spatiotemporal variation in population outbreaks and their impacts, especially in the context of climate change.
Peiwen Li, PhD Candidate Lougheed Lab Towards a sustainable Arctic fishery: Using genomics to quantify population structure and genetic diversity of the Arctic char (Salvelinus alpinus) Climate change is having profound impacts on ecosystems worldwide, and is especially pronounced at high-latitudes that have witnessed proportionately greater regional warming. In the Arctic, climate change is considered to be one of the major threats to traditional diets and this has resulted in changing distributions of game and fish species, food insecurity, and human health issues. However, decline in sea ice extent brought about by rising air and water temperature has also opened the Lower Northwest Passage (LNWP) to shipping, and has increased opportunities to establish a sustainable, commercial fishery. Our research, as part of the Genome Canada-funded Towards a Sustainable Fishery for Nunavummiut (TSFN) project, uses genomic tools to understand population structure and genetic diversity of the Arctic char (Salvelinus alpinus) in the LNWP, with the goal of contributing to the development of management plans for a local fishery. Using both DNA sequencing- and RNA sequencing-derived genome-wide panels of markers, I found multiple lines of evidence supporting the existence of two char genetic clusters, one corresponding to King William Island (KWI), and the other corresponding to the adjacent mainland sites. I found little to no genetic sub-structure within these two regions. I also developed a reduced panel of 182 informative markers using Genotyping-in-Thousands as a tool for monitoring the local fishery, allowing fast and accurate assignment of individuals of unknown natal origin to the two genetic clusters. Overall, my results suggest the possibility for a regionally-based management approach, rather than a river-based scheme. Taken together, my research provides insights on population structure of this most northern fish species, and some guidance and tools for the development of a sustainable char fishery in the KWI region of the LNWP.
Dr. Edan Foley University of Alberta Invasion of the fruitfly snatchers: What Drosophila can teach us about Vibrio cholerae pathogenesis The aquatic pathogen Vibrio cholerae infects roughly three million people and claims 100,000 lives each year. Pathogen-encoded virulence factors activate host innate immune defenses, disrupt the gut barrier, and cause a diarrheal disease characterized by expulsion of up to 15 liters of pathogen-laden fluid daily. To infect the host, V. cholerae uses a type-six secretion system (T6SS) to attack Gram-negative members of the gut microbiota. The T6SS in induced in the small intestine, where it injects a payload of deadly effectors into commensals that compete for access to the host. Eradication of competitors allows V. cholerae to build clonal microcolonies that concentrate cholera toxin in the small intestine, activating a cAMP-dependent signal that results in severe rice-water diarrheal purges. Using the fly model of Vibrio infection, my group studies how interbacterial-warfare impacts Vibrio pathogenesis. In this seminar, I will present recent data from my group that implicates T6SS-mediated commensal killing in the inhibition of host epithelial repair during an infection.
Bio from Dr. Edan Foley : ''I did my BSc in Galway, Ireland, followed by a PhD in Cologne, a postdoctoral fellowship in San Francisco, and finally settled in Edmonton. My work primarily uses the genetically accessible model organism Drosophila melanogaster to understand how pathogenic and commensal bacteria affect stem cell development and function in the gut. More recently, we have started to extend our work to include the zebrafish Danio rerio.'' Dr. Kathryn Turner Idaho State University Ecological genomics of invasive and introduced plants Humans have introduced species both intentionally and unintentionally to novel environments. Introduced and invasive species represent excellent opportunities to study the evolutionary potential of traits and biotic interactions important to success in their new environments. While evolutionary studies often describe adaptation to novel environments over millions of years, rapid evolution can occur over decades, in species under strong selective pressure, such as introduced and invasive species. Typically, our knowledge of rapid evolution in contemporary populations is based on current and static patterns of genetic variation in those populations. Since static patterns may be the result of multiple and opposing processes, such patterns reveal little about the initial stages or key transitions of rapid adaptation to environmental change. Another key gap in our understanding of the process of adaptation to novel environments in plants is the interaction between available genetic diversity in the adapting species and that species’ microbiome. Temporally referenced data may help us understand how the interaction between host and microbiome enables species to adapt to rapid environmental change. I will present work on the current patterns of genomic diversity in an heavily human dispersed ornamental wildflower, Texas Bluebonnet (Lupinus texensis, Fabaceae), and ongoing work investigating historical patterns of genomic and metagenomic diversity using herbarium specimens in an invasive crop weed, Blue Mustard (Chorispora tenella, Brassicaceae).
Bio: I’m an evolutionary ecologist interested in introductions, range expansions, biological invasions, and rapid evolution. I went to undergrad at the University of Texas at Austin where I got a BS in Plant Biology and a BA in Asian Studies. I then worked as a field and lab technician in Texas, Arizona, and Indiana for 3 years. I completed my PhD at the University of British Columbia with Dr. Loren Rieseberg in 2015. After graduating, I held an NSF Postdoctoral Fellowship at Colorado State University with Dr. Ruth Hufbauer and Dr. John McKay. I was then an Eberly Postdoctoral Fellow at Pennsylvania State University with Dr. Jesse Lasky. I joined the Department of Biological Sciences at Idaho State University as an Assistant Professor in 2019. Rachel Fanelli MSc Candidate, Bonier Lab Quantifying responses of North American birds to urbanization Species vary in their responses to urbanization – most species avoid urban habitats, some tolerate these environments, and very few thrive in them. To better characterize the extent to which species vary in their responses to urbanization (hereafter urban responses), we developed several methods to quantify these responses at a continental scale across all birds. Using open access community science-derived data from the eBird Status and Trends Products and two different types of high-resolution geospatial data that quantify urbanization of landscapes, we calculated urban response indices for 476 species with breeding ranges that overlap large cities in Canada or the United States. We used six different calculations to characterize species-level urban response indices, allowing us to assess how each species’ relative abundance during the breeding season varied with estimates of urbanization. We assessed correlations among these six indices, then compressed them into a single principal component (multivariate urban response index) that captured variation in urban responses among species. We demonstrated the accuracy of our multivariate urban response index using 24 species that are well characterized in their tolerance or avoidance of urban habitat, as well as with previously published, independent urban response estimates for 99 species. We found a significant phylogenetic signal in the multivariate urban response index for younger lineages but not among deeper lineages, suggesting that traits associated with urban responses are not highly conserved. Our study provides some of the most precise estimates of species' responses to urbanization to date.
Dynamic aquatic ecosystems in a changing world: leveraging seasonal variation to advance global change ecology Temperate aquatic ecosystems are inherently dynamic. Temperature varies drastically from location to location and with the changing seasons. For example, in temperate lakes, temperatures can surpass 25C in summer, but plummet to 0C during ice-covered winters. However, the consequences of seasonal temperature variation for aquatic communities and food webs remains poorly studied. This is a problem because climate change is shifting seasonal conditions and shortening the duration of ice covered winters across Canada’s freshwater lakes. The goal of my research program is to quantify how aquatic organisms, communities and food webs respond to seasonal temperature variation, now, so that we may better predict the consequences of shorter, warmer winters in the future. I will discuss ongoing research that explores how aquatic organisms respond to seasonal temperature variation via internal physiological adjustments and behavioral shifts. I will argue that seasonally dynamic responses, and diverse responses among coexisting species, have underappreciated consequences for the structure and sustained function of aquatic communities and food webs. New information on the dynamic nature of aquatic ecosystems, in both space and time, can be applied to better monitor and manage these systems in the face of a changing global climate. Bio from Dr. Bailey McMeans: I am originally from Nashville, TN and completed my undergrad at Middle Tennessee State University, where I spent 3 years as a pre-med major before changing course in 4th year after finishing a field course in freshwater ecology that got me hooked on research. I decided to pursue graduate studies and moved to Canada to complete both my MSc and PhD at the Great Lakes Institute of Environmental Research at the University of Windsor with Aaron Fisk, where I worked on dynamic Arctic food webs. I then completed 2 post docs, one studying fatty acids in freshwater zooplankton with Martin Kainz in Austria and one studying tropical freshwater food webs with Kevin McCann at the University of Guelph. I started as an Assistant Professor at the University of Toronto Mississauga in 2017.
Bioremediating Cyanobacteria Using the Aquatic Snails Viviparus georgianus In a rapidly warming world, Cyanobacteria Harmful Algal Blooms (CyanoHABs) have the potential to become a more pressing issue on a global scale. CyanoHABs’ effects on the well-being of ecosystems and detrimental impact on animal and human health demand economical, environmentally friendly solutions. It is critical that if CyanoHABs are to be reduced or eliminated, we must consider the long-term implications of potential solutions. Algaecides, artificial mixing, flushing and flocculation are techniques used to mitigate CyanoHABs; however, these strategies are temporary, small scale, costly and impact ecosystems. To be effective, they would need to be combined with the reduction of nutrients in the water, which is not a plausible option given nutrient load reduction costs and current demands of agriculture and industry. Our research has shown that the benthic snail Viviparus georgianus can consume cyanobacterial cells under specific conditions. By using V. georgianus to bioremediate cyanobacteria, we can not only help mitigate the problem but also prevent the negative impacts of other chemical and physical methods.
Although V. georgianus are already in the lakes where algal blooms are present, they are unable to access it for consumption. There is still the problem of how to overlap the interaction between a benthic snail and CyanoHABs floating colonies. Knowing that maximum oxygenation of the water occurs at the surface and that below a certain depth the snails will not be able to access cyanobacteria, we are interested in implementing floating shallow mesocosms with different snail densities and platform depths. By breaking the barrier between the two species, we could provide a solution to the issue of CyanoHABs without introducing a problematic new element to already troubled water sources. |
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