Talk Session 3
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Ecology
February 22, 2019
Shultz Theatre
10:30-12:00
Talk Session 4
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Hibernation
Physiology
February 22, 2019
Room 118
10:30-12:00
Speed Talks
February 22, 2019
Shultz Theatre
14:15-15:30
Poster Session
February 22, 2019
Room 108
15:30-17:00
Talk Session 3 Abstracts
Title: Using plant combinations to improve phytoextraction effectiveness
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Author: Gabrielle Neufeld
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Abstract: Phytoextraction is the use of plants to uptake heavy metals from soil, where it is then stored in the roots and shoots of the plant. Phytoextraction of heavy metals from polluted soils reduces the harmful effects that heavy metals have on plant and human health including cancer. The main sources of heavy metal pollution are addressed. The previous mechanical and chemical methods used to clean up heavy metals in soil are reviewed. The history of phytoextraction studies is briefly touched upon pointing out the research gaps. I propose to test whether plants of various root depths used in combination improve phytoextraction effectiveness. The plants that will be researched are Salix sp. and Alyssum murale due to the hyperaccumulator property. Salix sp. specialize in cadmium extraction whereas Alyssum murale extracts nickel. The projected planting plots are explained along with what will be measured and when. A brief description of how the data will be analysed is also included with a graph of expected results. Concluding with the possibilities phytoextraction can offer to both the land and economy. While we continue to pollute our environment, it is crucial that we find a way to clean up our mess.
Title: Pseudomonas syringae as a potential organic herbicide for Canada Thistle
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Author: Alexander Cameron
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Abstract: Canada thistle is a concern for farmers, especially in the organic farming industry, as even a small number of shoots can severely lower crop yields. Currently available chemical herbicides for Canada thistle are not organic, and traditional methods are ineffective as the thistle can reproduce through root fragments. Pseudomonas syringae shows promise as a potential bioherbicide due to its virulence and the fact that its host range is limited to plants in the family Asteraceae, which includes Canada thistle, dandelions, and daisies but not most food crops. My research focuses on assessing the virulence of P. syringae strains and polymicrobial P. syringae mixtures in terms of their ability to cause stunting and chlorosis in Canada thistle. Preliminary results have shown some promising strains and synergistic effects. Using sunflowers as a model system a few strains have resulted in complete chlorosis of new growth, and some small amounts of stunting. Also in sunflower some synergistic combinations have shown chlorosis, severe stunting, and in some cases death. These early results indicate the potential of these P. syringae as a useful organic method for biocontrol of thistle.
Title: Fertilizing fox feces: nutrient deposition on dens alters plant diversity in the boreal forest
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Authors: Jessica Lang, James D. Roth and John Markham
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Abstract: Predators can be important vectors for soil nutrients for plant growth and metabolism by depositing feces, urine and prey remains. Red foxes (Vulpes vulpes), top predators in the Subarctic, occupy dens to rear pups during the breeding season and these dens are reused over many decades. Subarctic soils typically have low nutrient concentrations, yet red fox dens may provide nutrient hotspots. Despite occupying the largest distribution of all carnivores, few studies have examined the impacts of red foxes on local landscapes, such as how denning influences plant communities. Our objective was to examine the influence of denning activity on soil nutrients and vegetation at the taiga-tundra transition zone in the Subarctic near Churchill, Manitoba. We measured nutrient concentrations (inorganic nitrogen and extractable phosphate) from soil samples collected from eight fox dens and paired control sites. We also compared vegetation by quantifying all plant species within five 1-m2 quadrats on each site. Dens had 181% more inorganic nitrogen and 357% more extractable phosphates in organic soils compared to control sites, whereas no difference was found for nutrients in mineral soils. Vegetation was distinct on dens, with a greater proportion of erect shrubs, specifically tall willows (Salix glauca and Salix athabescensis; 25.16 ± 4.73% cover), which were uncommon on control sites (2.93 ± 1.93% cover). In contrast, control sites were dominated by smaller prostrate shrubs. By concentrating nutrients on dens, red foxes alter plant biodiversity in the Subarctic boreal forest. These results highlight another important mechanism by which predators impact other species.
Title: Agroforestry & shifting agriculture: an agricultural model system enabling biodiversity conservation in the Northern Ecuadorian Amazon
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Authors: Roy R. Vera, J. Hugo Cota-Sánchez, and Jorge E. Grijalva
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Abstract: Shifting agriculture (SA) is a common agricultural practice in tropical areas involving fallow intervals between crop cycles. This quiescent time of the land allows the recovery of soil fertility for subsequent crop seasons. However, the fading of resting periods has been one of the leading causes of forest degradation. Agroforestry systems (AFSs) may play an important role in buffering undesirable environmental outcomes caused by the decreasing fallow intervals under SA. In this study we investigated whether AFSs reverse the effect of reduced SA’s fallow intervals in local scale cocoa (Theobroma cacao) agrosystems. We aimed to 1) characterize species diversity in this agroecosystem with short fallow periods; 2) predict the ecological impact of intensification of SA on floristic composition, particularly in endangered endemic species; and 3) identify whether changes in floristic composition and species diversity in this agroecosystem under different resting intervals are restricted to certain strata or whether structural changes are generalized throughout the plant community. Our findings revealed that tree species diversity decreases across cocoa agroforest established in reduced fallow periods. Also, absence of resting intervals of SA affects tree conservation rates in AFSs by changing the floristic composition, in particular, in the upper strata. Nevertheless, the use of AFSs with complex arboreal structures under SA preserves native and endangered endemic species and protects areas by slowing down forest degradation rates.
Title: A messy situation: the toxicological effects of human waste water on aquatic biota
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Authors: Vanessa Schulz, Caleb Hasler and Judith Huebner
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Abstract: Shifting agriculture (SA) is a common agricultural practice in tropical areas involving fallow intervals between crop cycles. This quiescent time of the land allows the recovery of soil fertility for subsequent crop seasons. However, the fading of resting periods has been one of the leading causes of forest degradation. Agroforestry systems (AFSs) may play an important role in buffering undesirable environmental outcomes caused by the decreasing fallow intervals under SA. In this study we investigated whether AFSs reverse the effect of reduced SA’s fallow intervals in local scale cocoa (Theobroma cacao) agrosystems. We aimed to 1) characterize species diversity in this agroecosystem with short fallow periods; 2) predict the ecological impact of intensification of SA on floristic composition, particularly in endangered endemic species; and 3) identify whether changes in floristic composition and species diversity in this agroecosystem under different resting intervals are restricted to certain strata or whether structural changes are generalized throughout the plant community. Our findings revealed that tree species diversity decreases across cocoa agroforest established in reduced fallow periods. Also, absence of resting intervals of SA affects tree conservation rates in AFSs by changing the floristic composition, in particular, in the upper strata. Nevertheless, the use of AFSs with complex arboreal structures under SA preserves native and endangered endemic species and protects areas by slowing down forest degradation rates.
Title: Using non-invasive sampling to identify food-web interactions in the low Arctic
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Authors: Megan Dudenhoeffer, James D. Roth, Stephen D. Petersen, and Lucy K. Johnson
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Abstract: Climate-caused changes in prey abundance may alter predator-prey dynamics in the simple Arctic food web. Lemmings (Dicrostonyx spp.) are important prey for Arctic foxes (Vulpes lagopus) and their annual population fluctuations drive Arctic fox reproduction, creating strongly linked predator-prey population cycles. Winter diet directly impacts Arctic fox reproduction, but few prey species persist on the tundra during winter. Strategies to accommodate for decreased lemming availability, such as foraging in marine habitat, have allowed Arctic foxes to reproduce during years with low lemming abundance, but warming winters have decreased snowpack quality, preventing lemmings from reaching their previous high densities. We reconstructed Arctic fox winter diet at the southern edge of the Arctic, to investigate alternative prey consumption over years of varying lemming abundance. Next-generation sequencing of fecal DNA, from samples collected annually from 2011-2018, provided high taxonomic precision and identified prey previously undetected with traditional methods. Arctic foxes consumed a range of prey items from both terrestrial and marine environments. Lemmings and voles were the most important prey in most year, but alternative prey (seals and shrews) were consumed more when rodent densities were low. Climate change may be reducing historic prey abundances but also creating new foraging opportunities. Identifying novel species interactions in a food-web framework provides information about how disturbances will affect interacting species in a rapidly changing ecosystem.
Talk Session 4 Abstracts
Title: Does huddling reduce metabolic rate and evaporative water loss in hibernating big brown bats (Eptesicus fuscus)?
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Authors: Kristina A. Muise, Yvonne A. Dzal, Craig K.R. Willis
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Abstract: During hibernation, when food is limited and ambient temperature is cold, many mammals lower body temperature and metabolic rate (MR) in periods of torpor. Mammals regularly arouse from torpor, presumably to re-establish homeostasis, which is energetically expensive. Some mammals huddle in groups, possibly to decrease energetic costs and evaporative water loss (EWL). White-nose syndrome (WNS) is a fungal disease, devastating bat populations across North America. WNS increases arousal frequency and EWL and low humidity may exacerbate these costs. Eleven bat species have been affected by WNS, however, Eptesicus fuscus appears resistant. I will test the hypothesis that microclimate affects arousal frequency and drinking behaviour in hibernating bats. I predict that bats in a dry environment will arouse and drink more frequently, and drink larger volumes of water than bats in a humid environment. Secondly, I will test the hypothesis that microclimate influence the effects of huddling on MR and EWL. I predict that MR and EWL will be lower for huddling compared to solitary bats, and the reduction will be lower for bats in dry conditions. To test my hypotheses, I will use a captive colony of E. fuscus and hibernate bats in incubators set at 8°C and either 98% or ~50% relative humidity (n=10 per treatment). After ~5 months of hibernation, I will use respirometry to measure MR and EWL of solitary or huddling bats. Overall, my research will provide insight into the importance of huddling on the energetic costs of hibernation and water conservation in a WNS-resistant species.
Title: Energetic consequences of climate variation in a wild hibernator (Urocitellus columbianus)
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Author: Rebecca Smith
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Abstract: Due to climate change, mountainous terrains like those in southwestern Alberta, Canada are experiencing later snowmelt dates and increasingly variable weather patterns. While some animal species are responding by shifting their geographical ranges or delaying migration, seasonal hibernators, like Columbian ground squirrels (Urocitellus columbianus), are restricted to isolated mountain meadows. As a result, their fitness depends on their ability to optimize energy budgets (income versus expense). My project will investigate some of the mechanisms by which climate (temperature and precipitation) affect Columbian ground squirrel energy budgets before, during, and after hibernation. Using satellite data and an eleven-year dataset gathered from a wild population of Columbian ground squirrels, I will construct a model testing for interactions between weather variables (temperature and climate), vegetation (forage) availability, and pre-hibernation fattening. I will also manipulate abiotic variables through supplemental feeding and snowpack alteration to better understand how Columbian ground squirrels make use of body fat stores to regulate torpor expression during hibernation. Understanding the long-term implications of a shortening active season and fluctuating food source will offer insights into the fate of seasonal hibernators.
Title: Intraspecific variation in hibernation expression in Black-tailed prairie dogs
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Author: Gabriela Heyer
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Abstract: Once abundant throughout the Great Plains, the black-tailed prairie dog (Cynomys ludovicianus) has experienced a drastic population decline and a substantial reduction of its historical range due to persecution, habitat loss, and disease. At the northern edge of their range in Grasslands National Park, black-tailed prairie dogs have also been threatened by changes in climate. As weather patterns change, it is important to understand the phenotypic plasticity of black-tailed prairie dogs in response to a changing environment. Northern populations have been shown to hibernate facultatively throughout the winter, but little is known about whether other populations have the capacity to hibernate. I propose to take black-tailed prairie dogs from populations at the northern and southern extremes of their range and bring them into the lab under a common environment to measure several phenotypes, including body composition, metabolic rate, heart rate, body temperature, and gene expression during hibernation. The black-tailed prairie dog is a keystone species of the prairie ecosystem, providing shelter for animals such as the endangered burrowing owl, and is an important food source for many species, including the black-footed ferret. The results from this study will not only advance our understanding of the plasticity of facultatively hibernating mammals, but could also have implications in the management of declining black-tailed prairie dog populations in a changing climate.
Title: Effects of sex and body condition on hibernation patterns in the northernmost population of black-tailed prairie dogs with consequences for reproduction and survival
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Author: Deborah Hawkshaw
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Abstract: At northern latitudes, species can face prolonged periods of food shortages, such as winter. To cope with this challenge some species have evolved hibernation, a strategy that can allow for substantial energy savings. However, there are several costs associated hibernation which has led to predictions that individuals will hibernate optimally according to their energy reserves. The threatened Canadian black-tailed prairie dog (Cynomys ludovicianus) is one such species that hibernates over winter. Through effects on hibernation patterns, pre-hibernation body condition may be an influential factor in prairie dog survival and reproduction. Recent data suggests that in black-tailed prairie dogs’ female reproduction may be more dependent on spring body condition compare to males. Thus, sexual variation in hibernation patterns under varying body conditions could exist. My study seeks to determine the effect of sex and body condition (both natural and manipulated by food supplementation) on black-tailed prairie dog hibernation patterns, survival and reproductive success. To investigate this, I will record prairie dog hibernation patterns with temperature sensitive data loggers and measure pre and post-hibernation body condition. Select individuals will undergo pre-hibernation supplemental feeding and overwinter survival and female reproductive success will also be measured. This study will provide insight into variation in the allocation of energy during hibernation and the consequence that has for reproductive success. It also will elucidate the role pre-hibernation body condition has in population persistence and inform management strategies for this species.
Title: Development and Optimization of N-myristoyltransferase Enzymatic Assay
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Author: Chyna Ortman
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Abstract: N-myristoylation is an important protein modification that involves addition of a 14-carbon saturated fatty acid to the N-terminal glycine residue of various proteins involved in oncogenesis. An enzyme called N-myristoyltransferase (NMT) catalyzes N-myristoylation. In humans, NMT exists in two isoforms – NMT1 and NMT2. The NMT1 and NMT2 protein isoforms share 77% homology. Although NMT1 and NMT2 catalyze the myristoylation reaction and share common substrates, they are not redundant in function. Many of the oncoproteins such as c-SRC, RAS, cAMP are activated upon myristoylation. In tumors these oncoproteins are overexpressed and hyperactivated. From number of studies, it’s now established that NMT1 and NMT2 are differentially expressed in solid tumors compared to normal tissues. The increased expression and activity is consistent with greater demand of myristoylation by oncoproteins. Recent studies from our research group have indicated that localization of NMT2 alters cancer cell proliferation. Altered localization of NMT2 is attributed to the posttranslational modification (PTM) of NMT2. Therefore, the aim of my research project is to develop and optimize fluorescent-based enzymatic assay to determine NMT activity. I will use this assay to determine whether PTM of NMT2 alters its activity. This would provide insight into mechanistic implication of NMT2 in cancer cell proliferation.
Title: Biogeographical analysis of morphological variation and mitochondrial haplotypes reveals cryptic species and hybrid zones in the Junonia butterflies of the American Southwest and Mexico
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Authors: Melanie M. L. Lalonde and Jeffrey M. Marcus
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Abstract: The American Southwest and Northern Mexico has a high level of endemic diversity, when compared to the rest of North America. The biodiversity found within the American Southwest and Northern Mexico can be attributed to the Pleistocene glaciations and the subsequent dispersal of species from glacial refuges from within this region. The New World species of the genus Junonia are a recently diverged group of butterflies that are thought to have occupied the glacial refuges of this region during periods of glacial advance. Using phenotypic and genotypic information from preserved specimens in museum collections, we reconstructed the plausible historic movements, and the contemporary geographic distributions of the five Junonia taxa (J. coenia, J. coenia grisea, J. litoralis, J. nigrosuffusa, and J. zonalis) that are currently found in the American Southwest and Northern Mexico. Using morphological characteristics and mitochondrial haplotype data, evidence of hybridization between species and a cryptic species pair were revealed. Two morphologically similar taxa thought to be conspecific by some or different subspecies by others, J. coenia coenia and J. coenia grisea, were found to have differences in morphology, native larval host plants, life history traits, nuclear wingless allele frequencies, and district mitochondrial haplotypes suggesting that they are a cryptic species pair. Based on this evidence we have elevated J. grisea nov. stat. to full species status.
Speed Talk Abstracts
Title: Basic and Applied Aspects of Thermal Acclimation in Juvenile Brook Trout
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Author: Theresa Mackey
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Abstract: Rising water temperatures are affecting the health and distribution of aquatic organisms. Brook trout (Salvelinus fontinalis), a freshwater species adapted to cooler environments, is a popular sport fish, and at risk to high temperature due to its habitat preference. Previous studies have been limited on the temperature range studied, the physiological markers used, and combination of stressors tested. Using five acclimation temperatures, we aim to quantify the stress response of juvenile brook trout by collecting physiological and molecular parameters to understand the processes that occur when these fish are stressed. Further, we aim to understand the effect of acclimation temperature on their recovery when exposed to acute stress events that simulate the paired stressors of exhaustive exercise and air exposure induced by catch-and-release angling. We predict that exposure to acclimation temperatures beyond temperatures known to be preferred by brook trout will cause individuals to exhibit an increased stress response compared to those acclimated at preferred temperatures. Also, recovery to the acute stress events will be longer in duration when individuals are acclimated to non-preferred temperatures. Tissues will be sampled to quantify gene expression or other physiological markers associated with stress and temperature-induced cellular mechanisms that are involved in critical biological processes. Additionally, metabolic rate will be monitored to characterize recovery following exposure to the two acute stressors. Our study combines physiological indices and a range of temperatures to understand the implication of global climate change on brook trout and will be useful for managing fish habitat and regulating recreational fishing.
Title: Individual ringed seal diet variation
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Authors: Cassandra Debets, Seth Newsome, Cory Matthews, David Yurkowski, Brent Young and Steve Ferguson
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Abstract: Knowledge of how diets differ among conspecifics within species provides essential insights into trophic interactions within an ecosystem. There are multiple approaches to inves- tigating diet composition of wildlife populations; stable isotopes (δ13C and δ15N) are efficient at quantifying diets of predators and measuring individual- and population-level diet specialization. Ringed seals (Pusa hispida) are an important species in the Arctic food web and an important component of Inuit subsistence and culture. Previous diet studies have documented spatial and temporal changes of ringed seal diets; however, few studies have been able to quantify and document individual temporal changes in diet and foraging strategy. The objective of this study was to examine the individual diet variation of ringed seals from the southern extent of their range (Belcher Islands, Hudson Bay). We used whisker isotopic composition of 42 satellite-tagged seals to determine individual diet composition over time and tested for seasonal shifts and individual variability in dive behavior from tagged seals, 2006-2012. Potential prey species (e.g., amphipods [ Calliopius spp], sand lance [ Ammodytes spp], capelin [Mallotus villosus], and Arctic cod [Boreogadus saida]) were collected from the Hudson Bay ecosystem during the same time period. Stable Isotope mixing models revealed that differences in both δ13C and δ15N values from seal whiskers may be explained by dive behaviours (number of dives, time spent at depth) obtained from satellite tags. There was a wide range of averaged whisker segment isotopic values from individual seals: mean δ13C values range from -18.6‰ to -15.8‰ and mean δ15N values ranged from 12.1‰-17.5‰ which falls within the range of isotopic signatures represented by a diversity of possible prey species. Seals varied from having a wide range of isotopic values (generalized diet) to a narrow range reflecting specialization. Age and dive beha- viour parameters helped explain some of the differences in the degree of diet specialization. For instance, seals that spent more time near the bottom had higher δ13C values in their whiskers than seals that foraged pelagically. Understanding dietary variation of ringed seals will be important information to better inform management of seal populations, which is increasingly important in the face of changing climatic condi- tions that may alter food web dynamics within Hudson Bay.
Title: Killer whale dive behaviour in the eastern Canadian Arctic
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Authors: Kyle Lefort, Cory Matthews and Steve Ferguson
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Abstract: Understanding demographic shifts to top-predator populations is fundamental to understanding how climate change influences ecosystems worldwide. Killer whales (Orcinus orca) are a widely distributed marine top-predator with a broad ecological niche at the species-level, but with evidence of population-level specialization and narrow ecological niches at the population-level. Their occurrence in the Canadian Arctic is thought to be limited by sea ice, and it has been suggested that climate change, which has resulted in decreases in the extent and duration of seasonal sea ice, has led to a northward range expansion and increased killer whale occurrence throughout the region. In this review, we summarize our current ecological knowledge of Canadian Arctic killer whales and identify areas where additional research is required. More specifically, we provide an update on our knowledge of killer whale population size and trends, distribution and seasonality, predation and feeding ecology, and threats, and suggest future killer whale research priorities in the Canadian Arctic. An improved understanding is necessary for effective stock management of killer whale prey species including narwhal (Monodon monoceros), beluga (Delphinapterus leucas), bowhead whale (Balaena mysticetus), and seal (Pusa hispida, Erignathus barbatus, Cystophora cristata, Pagophilus groenlandicus), which are of considerable economic and cultural importance to Inuit and of ecological importance to the Canadian Arctic marine ecosystem. This knowledge will allow us to better understand the ecological consequences of a changing Canadian Arctic climate.
Title: The photo-identification of beluga whales (Delphinapterus leucas) in Cumberland Sound
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Authors: Kasey Ryan, Steve Ferguson, Marianne Marcoux, William R. Koski, Brent Young, and Cortney Watt
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Abstract: Photo-identification is a valuable tool in species monitoring that provides insights into species’ movements and site fidelity, social structure, and reproductive history. The isolated beluga whale population in Cumberland Sound, Baffin Island, Nunavut, was commercially exploited for several decades until the 1970s. The current population estimate is approximately 1,000 whales, compared to historic estimates of over 8,500 whales, and approximately 40 whales are harvested per year by the local community Pangnirtung. The goals of this project were (1) to determine whether photo-identification of the Cumberland Sound beluga population is feasible and (2) to develop a catalog for future analyses, including a capture-mark-recapture technique to estimate population abundance. Photographs of belugas were taken in 2017 and 2018 using a DJI Phantom 4 drone and supplemented with boat-based photographs using a Canon EOS 5D Mark II in 2018. Whales are marked with scars from natural sources and hunting. Initial analyses of some of the 2017 images indicate that at least 20 different whales were photographed with markings that appeared to be unique and were likely to persist over long periods. The analyses of the 2018 images are in the preliminary stages, but there has been one match of a whale photographed in both 2017 and 2018. Creating a photo-identification catalog for this population will assist with gaining a better understanding of life-history characteristics (e.g. calving rate), and with estimating abundance through capture-mark-recapture techniques. Gaining a better understanding of their population demography will allow more effective conservation and management strategies to be developed.
Title: Investigating ringed seal ecology over a latitudinal gradient of sea ice conditions in the eastern Canadian Arctic
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Author: Cody Carlyle
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Abstract: The ringed seal is vulnerable to loss of of sea ice given its dependence on ice for habitat and ice associated prey. Ringed seals occupy a broad latitudinal range that spans transient sea ice coverage in Hudson Bay, to substantial year-round coverage in the high Arctic basin. Therefore, ringed seals as a species likely adjust their seasonal sea ice habitat use to regional sea ice conditions. The southern end of their range in Hudson Bay will likely be the first to suffer from sea ice recession via demographic shifts, diet changes, and range contraction, but how ringed seals will respond over their entire range remains unclear. This study will investigate the habitat selection of ringed seals along this latitudinal gradient of sea ice to identify differences in ringed seal occurrence that are linked to sea ice conditions. We hypothesize that latitudinal variation in ringed seal density will reflect availability of preferred landfast first-year ice habitat, with density decreasing with increasing latitude. We will use aerial surveys from the low Arctic (Churchill, MB), mid-Arctic (Pond Inlet, NU), and high Arctic (Alert, NU), to relate density to differences in remotely sensed sea ice characteristics. Preliminary results indicate ringed seal densities of 0.2-1.2 seals/km2 in Churchill, 0.5-0.7 seals/km2 in Pond Inlet, and 0.05 seals/km2 in Alert. Future work aims to link density to sea ice conditions and the feeding ecology of ringed seals along a similar latitudinal gradient. This knowledge will inform us about how ringed seals adjust to regional sea ice conditions.
Title: Response of rangelands to extreme drought
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Author: Tory Williams, Otfinowski R
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Abstract: Changing climates are altering the availability of water in terrestrial ecosystems, impacting their primary production and other ecosystem functions. The International Drought Experiment was designed to understand impact of extreme drought on aboveground productivity, soil nutrient concentrations, and plant community composition of terrestrial systems around the world. Here, we focus on the impact of drought on grassland and rangeland ecosystems in western Canada. Climate change models for this region predict an increase in the frequency and intensity of droughts. We hypothesize that extreme drought will increase the abundance of native grasses and forbs, increase the diversity of grassland communities, and reduce the productivity of exotic forages. The ongoing, long-term experiment in Brookdale, MB, passively reduces the annual precipitation by 32 percent over four years using fixed exclusion shelters. The shelters were constructed in an area of gently undulating mixed grass prairie, with little historic grazing. Each shelter is bordered by a trench and lined with a plastic membrane (depth of > 0.5m) to hydrologically isolate the experiment. The International Drought Experiment will determine how and why terrestrial ecosystems may differ in their sensitivity to extreme drought. In western Canada, understanding how droughts affect the productivity and composition of grassland and rangeland ecosystems will be key to designing models to help sustainably manage grassland resources. This research, in collaboration with the Manitoba Beef Growers Initiatives Inc., will also provide a forum to exchange practical and technical information with producers, and to communicate the ecological services provided by rangelands with the public.
Title: Flies of a Feather. Testing Candidate Male Accessory Gland Genes for Their Role in Sperm Competition and Conspecific Sperm Precedence in Drosophila melanogaster
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Author: Benoit Morham and Alberto Civetta
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Abstract: Competition between sperm of two different males is known to be affected by some seminal fluid proteins (SFPs) which are transferred from males to females during copulation. Males who mate second with a female will have a larger proportion of the offspring and it is debated if sexual selection (such as sperm competition) can cause separation between species (speciation). Doubly mated females will produce more offspring from sperm of the same species regardless of the order; this is called conspecific sperm preference (CSP). Candidate SFPs within two cytogenic map regions of D. melanogaster confirmed to be integral for CSP will be tested with RNAi interference for both conspecific and heterospecific competition. Female D. melanogaster will be mated first with D. melanogaster or D. mauritiana (conspecific or heterospecific) males with green fluorescent sperm (GFP) and mated second with the RNAi knockdown D. melanogaster males (none or wild type D. melanogaster for control). An SFP’s role in either sperm competition (D. melanogaster) or CSP (D. mauritiana) will be determined by comparing GFP sperm counts of knockdowns and controls. A knockdown with significant results in both sperm competition and CSP will provide a genetic link to sexual selection and speciation.
Title: Soil nematodes as bioindicators of sustainable grazing of wet meadow rangelands in Manitoba
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Author: Ryan Nykvist and R. Otfinowski
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Abstract: Rangelands provide important ecosystem services, including the sequestration of carbon, cycling of nutrients, and the interception of runoff. Ecosystem services offered by rangelands depend on the health of their soils and can be measured by their capacity to support diverse plant communities and soil food webs. In this research we will test whether soil nematodes can be used as bio-indicators of soil health in wet meadow rangelands that have experienced different grazing regimes. Soil nematodes are sensitive to environmental changes and have evolved feeding strategies that allow them to specialize in the consumption of plant roots, fungal hyphae, bacteria, or other soil fauna. Nematodes will be extracted from samples of soil collected from a long-term grazing experiment in Brandon, MB, and assigned to feeding groups to determine how grazing has affected the structure of the soil food web. We hypothesize that as grazing intensity increases, lower root biomass will decrease the abundance of nematodes that parasitize plant roots. In contrast, the rapid turnover of root and plant biomass in intensely grazed rangelands will increase the abundance of nematodes that feed on bacteria. By exploring links between grazing and soil food webs, this research will contribute new knowledge to understand the drivers of soil health in rangeland ecosystems in Canada. Furthermore, in collaboration with the Manitoba Beef Growers Initiatives Inc., this research will also provide a forum to exchange practical and technical information with producers and communicate the ecosystem services provided by rangelands with the public.
Title: An Examination of Sarcolipin Gene Transcription in Extraocular Musculature and Soft Tissues in Lampris incognitus and Thunnus albacares: Examining a Potential Correlation to Thermogenesis
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Author: Joana Salazar and Jens Franck
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Abstract: Endothermy, the ability to maintain a constant body temperature is rarely seen in fish. Lampris incognitus, better known as Opah, is a large mesopelagic fish capable of thermogenesis, particularly in the pectoral muscle and cranial regions. Sarcolipin (SLN) is an uncoupling protein acting upon the SERCA pump of the endoplasmic reticulum resulting in a futile calcium cycle. This thermogenic mechanism has been observed in cold-adapted mammals. Opah encode the sln gene and recent studies reveal increased expression levels in dark red pectoral muscle (DRM.) Yellow-fin tuna (Thunnus albacares) exhibits regional endothermy. The purpose of this project is to investigate the abundance of sln transcripts in a panel of tissues of Lampris incognitus, and Thunnus albacares to determine a potential thermogenic relationship. Using a quantitative PCR (qPCR) approach, sln transcription quantities in extraocular muscle will be measured and compared to a panel of DRM, white muscle, light red muscle, and liver. The same methodology will be used for tissues from Thunnus albacares. Transcript levels will be compared to determine if sln levels are significantly higher in the thermogenic tissues.
Title: Psychedelic plants: a new source of chemotherapy medications
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Author: Moiz Kapasi and Jake Stout
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Abstract: The rising global cancer incidence rate, necessitates’ the search for new and improved treatment options. Many chemotherapy medications are produced from plant extracts. One such medication, vinblastine, which is essential in treating various cancers (i.e. Hodgkin’s lymphoma), is obtained by extracting miniscule amounts of the compound from Madagascar periwinkle. This results in inefficient and expensive production of life saving medication. Tabernanthe iboga is an African shrub plant which produces a psychedelic compound called ibogaine. The biosynthetic pathway involved in producing ibogaine is quite similar to the vinblastine biosynthetic pathway in Madagascar periwinkle, except that ibogaine is produced in much greater quantities. The two pathways diverge at the shared intermediate, catharanthine. My project aims to stop the biosynthetic pathway and accumulate catharanthine which can be then synthetically converted to vinblastine. I have generated an iboga root transcriptome to identify the enzyme that determines the fate of catharanthine. I suspect that this enzyme is a reductase part of the alcohol dehydrogenase family. I plan to search for this enzyme by comparing my iboga transcriptome with known alcohol dehydrogenases in various other plants. The result of which is expected to produce possible enzyme candidates, from which future projects can verify their function. I hope my work will aid in improving the production and accessibility of this vital cancer medication.
Poster Abstracts
Title: Using plants in combination to improve phytoextraction effectiveness
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Author: Gabrielle Neufeld
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Abstract: Phytoextraction is the use of plants to uptake heavy metals from soil, where it is then stored in the roots and shoots of the plant. Phytoextraction of heavy metals from polluted soils reduces the harmful effects that heavy metals have on plant and human health including cancer. The previous mechanical and chemical methods used to clean up heavy metals in soil are reviewed. I propose to test whether plants of various root depths used in combination improve phytoextraction effectiveness. The plants that will be researched are Salix sp. and Alyssum murale due to the hyperaccumulator property. Salix sp. specialize in cadmium extraction whereas Alyssum murale extracts nickel. The projected planting plots are explained along with what will be measured and when. A brief description of how the data will be analysed is also included with a graph of expected results. While we continue to pollute our environment, it is crucial that we find a way to clean up our mess.
Title: Could a common flame retardant be adversely affecting us through the food web?
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Author: Anjelica Bodnaryk
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Abstract: Many manufactured goods include flame retardant (FR) chemicals to inhibit ignition, however many commonly used FRs such as polybrominated diphenyl ethers (PDBEs) have recently come under scrutiny because of their environmental persistence, bioaccumulation and toxicity to organisms. Many PBDE congeners such as PBDE209 are banned by the Stockholm Convention because of these adverse effects. There has been a shift toward replacing harmful PBDEs with other FRs such as 1,2-dibromo-4-(1,2-dibromoethyl) cyclohexane (TBECH). Although relatively new, recent studies suggest TBECH is pervasive in the environment and biota, however little is known about its food web dynamics. Previous studies have shown that TBECH is an androgen receptor agonist and adversely affects reproductive physiology and success through gene regulation and signalling pathways. Two studies thus far have assessed the trophodynamics of TBECH, but there were conflicting findings regarding the trophic magnification factor of TBECH. In order to assess the food web dynamics of TBECH, we have proposed to investigate the trophic transfer of each TBECH isomer (,β, γ and ) in food webs through a 2-step predator prey laboratory experiment. We will be using Daphnia magna, Danio rerio and Rattus norvegicus for the biomagnification study because of their common use in toxicological studies. Samples will be extracted by pressurized fluid extraction, purified and TBECH isomer concentrations will be assessed using gas chromatography with mass spectrometry. This study will be the first to quantify each TBECH isomer in a well-controlled trophodynamics setting and will provide evidence that TBECH requires further assessment for its ecological risks.
Title: Enzymatic Activity of Alcohol and Aldehyde Dehydrogenase in the Plastic-fed Waxworm (Galleria mellonella)
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Author: Harald Grove
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Abstract: Waxworms (Galleria mellonella) are holometabolous insect pests (order: Lepidoptera). They are ubiquitously found wherever beekeeping is practiced. Waxworms are capable of eating and breaking down plastic (a synthetic material similar to their natural diet) and therefore potentially provide a solution to the problem of plastic pollution. This research has investigated the gut transcriptome under treatments: plastic, starved, and honey comb. Transcripts involved in the catalysis of large molecules were uniquely expressed in the plastic treatment. We also investigated survival of all groups in addition to the product of this biodegradation (ethylene glycol) and the requirement of resident gut bacteria. Plastic-fed worms revealed the lowest overall survival. The enzyme alcohol dehydrogenase (ADH) was found to be up-regulated solely in the plastic treatment. This enzyme is known to attack alcohol metabolites such as ethylene glycol. This finding has led to further analysis of these enzymes. First, characterization of overall ADH activity of waxworms fed on several types of plastic. Second, the inhibitor fomepizole can be used to block ADH activity and it is predicted that this would rescue the negative survival effects induced by ethylene glycol. Enzyme activity across tissues can be determined to also indicate unique physiological processes. Finally, since other insects like Tenebrio have been implicated in plastic biodegradation, we can use this insect to compare enzyme activities in Galleria. Additional projects hope to look at identification of bacterial taxa in plastic-fed waxworms as well as an exploration of respiration and metabolic processes that ensue following the consumption of plastic.
Title: Identifying Genes associated with Autism Spectrum Disorder through Hardy-Weinberg Disequilibrium
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Authors: MacKenzie Sarvis, XiaoQing Liu and Sara Good
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Abstract: If autism spectrum disorder (ASD) is an undesirable psychiatric disorder, then why hasn’t natural selection weeded it out yet? Furthermore, why is a persistent 1% rate of ASD seen worldwide? Two plausible hypotheses for these observations are that 1) Common variants associated with ASD confer a survival benefit for the individual or 2) ASD could be a disadvantageous by product of human brain evolution. To investigate this, a genetic epidemiological study using two publicly available ASD datasets was initiated. These datasets consisted of trio data and one million single nucleotide polymorphisms (SNPs) before data cleaning. Pseudo controls were made from trio data using PLINK software. The SNPs were tested for Hardy-Weinberg Equilibrium and Wright’s Coefficient of Inbreeding was calculated from the HWE test results. More genetic markers were found to be in Hardy-Weinberg Disequilibrium (HWD) among the cases and their parents but not in the pseudo controls. A genetic marker can be in HWD if it is associated with a disorder or under selection. Six SNPs that were shared between the two datasets were significant for HWD (p value cut-off = 10-8) and their Wright’s Coefficient of Inbreeding were mostly negative. This indicated an excess of heterozygotes which may be due to selection for heterozygosity. Further research into the six significant SNPs will be done to identify if they are candidates for ASD causal genes. Selection software will also be implemented to see if these SNPs show evidence of selection and specific selection statistics will be analyzed for each of these SNPs.
Title: I’ve got your back: How African ground squirrels change their foraging under predation risk
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Authors: Sean Perry and Jane Waterman
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Abstract: When foraging, animals must balance the costs and benefits of remaining in a location. Vigilance reduces risk of predation, but time spent scanning for predators makes foraging costlier. One strategy to reduce that cost is to forage in groups and collectively watch for predators. We investigated how perceived predation risk affects foraging in Cape ground squirrels (Xerus inauris) an arid-adapted species from Southern Africa. Cape ground squirrels are highly social and very active foragers, living in family groups that inhabit clusters of burrows. Our study site (SA Lombard Nature Reserve) consisted of two predation risk areas: a low-risk residential area and a high-risk floodplain where predators are abundant. To further manipulate the perceived predation risk in these areas we used predator (black-backed jackal) faeces. As a measure of perceived predation risk, we used Giving up Densities (GUD), the mass of food left behind at an artificial foraging patch. Each foraging patch had a motion capture camera positioned to record the foraging behavior and foraging group sizes throughout the day. We found no difference in GUD between the two risk areas or with the faeces treatment. However, the proportion of time spent group feeding at floodplain locations was significantly greater with the faeces treatment. Squirrels in the high-risk area tended to demonstrate a higher proportion of group feeding than those in the low-risk area. These results suggest that Cape ground squirrels may use group feeding as a strategy to counteract actual and perceived predation risk, thereby minimizing the impact on GUDs.
Title: Risk of Wireworm to Manitoba Crop Production
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Author: Ivan Drahun
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Abstract: Wireworms are the soil-dwelling larvae of click beetles. While the adults pose no harm to their host plants, the larvae are serious pests of many agricultural crops including potato, corn, grains and soybean. Species differ in habitat preference, soil activity, feeding behaviour, and size. Wireworms have an extended life cycle spent entirely underground where they feed on seeds. Agricultural areas are invaded by click beetles that enter fields from adjacent non-farmed areas to mate and lay eggs. The wireworms that hatch pose a serious risk to crop in rotation for years to come and cause significant yield losses in infested fields. Lindane was a very effective seed treatment that would control up to 85% of wireworms, however in 2004, it was banned by the Canadian government due to environmental and toxicological concerns. After the government-issued ban, wireworm numbers increased drastically. The biggest issues around wireworms are gaps in knowledge about the biological, ecological and agronomic factors that contribute the most to wireworm crop damage. My objectives are to improve integrated pest management of wireworms by a) surveying crop fields throughout Manitoba to determine species composition and relative abundance of wireworm in Manitoba crop fields; b) performing molecular diagnostics to assess species composition, genetic diversity and unravel cryptic species to determine population structure of major species; c) simulating feeding damage to determine economic thresholds for wireworm in Manitoba and learn about wireworm biology and ecology. This will help develop a scouting protocol and economic thresholds for wireworm in Manitoba.
Title: Molecular Mode of Action of DEET in the American Dog Tick & Pathogen Presence
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Author: Cody Koloski
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Abstract: In Manitoba, the American Dog tick (Dermacentor variabilis) is the most commonly encountered tick in the wild. When going into an environment where there will be ticks, some sort of repellent is used. Ticks detect repellents through the use of a specialized organ called the Haller’s organ. DEET is the active ingredient in most commercially available repellents. Despite DEETs widespread and popular use there is still a lack of information on its mode of action, especially in ticks. My research aims to find out how DEET acts as a repellent on the tick. I will be using bioinformatics and molecular approaches to observe how the genetic expression profile of the tick changes in response to DEET exposure. I will also be surveying the American Dog tick population in Manitoba for both novel and recognized pathogens. This research will be building off of my previous research that points to an inhibition of cytochrome P450 and acetylcholinesterase expression as a mode of action.
Title: Mapping biodiversity on two levels: genetic and species diversity in North American mammals are correlated
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Authors: Chloé Schmidt, Mike Domaratzki, Colin Garroway
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Abstract: Species richness and genetic diversity are thought to be shaped by similar processes acting on both levels. The frequencies of species and alleles can change due to selection, drift, and migration, and their diversity can increase through mutation and speciation. If this is true, we would expect to see positively correlated spatial patterns of genetic and species diversity. Broad patterns of biodiversity, such as the latitudinal species gradient, have received much attention, however similar investigations at the genetic level have been limited by the difficulty of obtaining sufficient data. Increased availability of molecular data in repositories now allows us to explore the geographic distribution of genetic diversity in greater depth. Here, we test the hypothesis that spatial patterns in genetic diversity correlate with those of species richness in North American mammals. Using publicly archived data, we quantified genetic diversity at 810 sites sampled across 41 species. We obtained species richness estimates for each site using overlaid range maps. We used distance-based Moran’s Eigenvector Maps to characterize spatial patterns in both genetic diversity and species richness at multiple scales. Our analysis detected spatial structure at both levels of biodiversity. We found 8 shared axes of spatial variation, however not all were positively correlated between species and genetic diversity. These results lead to interesting questions about how these patterns are formed and maintained. Future investigation of factors that contribute to spatial patterns at the scales identified here can yield insights into the features governing the geographic distributions of biodiversity at multiple levels.
Title: Influence of colony size and nest site quality on reproductive success in Common Murres (Uria aalge)
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Author: Amy Irvine
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Abstract: Coloniality is a type of social reproduction where nest sites of individuals occur in densely populated locations. This strategy benefits marine birds via enhanced predator detection, defense and the “swamping” effect of synchronal breeding, minimizing individual-level risk of predation at the colony. Increased competition for resources (e.g., nest sites, mates, food) limit the benefits of coloniality. This study will examine whether colony size influences breeding success of a marine bird species, the Common Murre (Uria aalge). On the northeast Newfoundland coast, murres breed in both a small colony (10,000 breeding pairs) on South Cabot Island and a large colony (500,000 breeding pairs) on Funk Island. Previous research indicated that breeders at the large colony traveled farther to provision their chicks relative to breeders at the small colony, possibly due to increased competition for limited food resources. As such, we predict the larger colony will have lower reproductive success due to less time devoted to chick supervision. We also hypothesize that nest site characteristics within a colony (e.g., distance to nearest neighbour, distance to edge of colony, nest exposure) influence breeding success, possibly allowing breeders to improve hatching and fledging success regardless of colony size. We predict that nests with larger distances to nearest neighbour, smaller distances to edge of colony and unsheltered nests will have lower reproductive success. By improving our understanding of the costs and benefits of coloniality in marine birds, we will aid in determining appropriate targets for protection of Common Murres and other colonial marine birds.
Title: Paleoecology of the early Eocene macroflora, Allenby Formation, Whipsaw Creek, British Columbia
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Author: Janelle M. Vachon
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Abstract: The Eocene Epoch (34–56 Mya) included several global warming periods, the longest of which was the Early Eocene Climatic Optimum (EECO) from 50–52 Mya. During this time much of North America supported a diverse mix of temperate and tropical plants and insects. Studies outside of Canada have established that plant and insect diversity respond to climate change in the geological past and the EECO provides an ideal setting to study this relationship. The Whipsaw Creek site represents one of several early Eocene localities clustered in British Columbia that are constrained stratigraphically to the EECO. Whipsaw Creek preserves both plants and insects and therefore represents an excellent opportunity to examine the interactions between these groups during a period of past climate change. This project uses an existing fossil collection and further sampling via census technique (>300 specimens sampled for leaf damage) to reconstruct the plant community and insect leaf feeding types during this time. Data from early Eocene sites at Wyoming–Colorado and Alaska show trends for decreasing diversity and frequency of insect leaf damage types with increasing latitude. This leads to an important question–is lower diversity of insect feeding on early Eocene age fossil plant leaves in Alaska due to cooler temperatures or due to being at higher latitude? I hypothesize that insect damage trends along a latitudinal gradient will show intermediate levels at the Whipsaw Creek site (~49°N) compared to the Alaska and Wyoming-Colorado sites, consistent with temperature being the main driver of insect herbivory
Title: Bubbling from Beneath: Exploring Greenhouse Gas Ebullition in Water Bodies Near Urban Areas
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Authors: Emily Kroft, Kody Oleson, Nora Casson, Helen Baulch, Lauren Dyck, Richard Helmle, Rebecca North, Jason Venkiteswaran, Colin Whitfield, Clayton Williams
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Abstract: Inland freshwater ecosystems are an active component of the global carbon cycle and are known sources of biogenic greenhouse gas (GHG) release to the atmosphere. One particularly important source of biogenic greenhouse gas is the production of methane (CH4) in freshwater ecosystems by microbes. This process occurs predominantly in anoxic sediments, where CH4 can eventually be released to the atmosphere or surrounding water column through the process of ebullition; bubble-mediated release. Ebullition is extremely variable in both time and space and is affected by numerous environmental factors. The goal of this research is to determine factors which influence the rate of GHG production from small water bodies near urban areas. We measured the volume of GHG production from ponds in three urban locations: Winnipeg MB, Saskatoon SK and Columbia MO. We measured water temperatures, sediment characteristics, and water chemistry in each pond. Initial results suggest that rates of ebullition are correlated with temperatures, but the strength of this relationship varies by site, particularly for sites occurring at very different latitudes. These results will help constrain our estimates of CH4 emissions from small water bodies and shed light on how human activities may affect these ecosystems in the future.
Title: Quantifying differences in migration timing among populations of purple martins (Progne subis) at different breeding latitudes
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Authors: Leanne Neufeld and Kevin Fraser
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Abstract: Phenology is critical for species that migrate seasonally, as mismatches in migration timing can lead to reduced fitness, and ultimately population declines. Breeding latitude may have a large influence on migration timing around the calendar, but has rarely been investigated using direct tracking methods that provide an annual measure of timing. I examined the influence of breeding latitude on the migration timing of a long-distance migratory songbird (purple martins, Progne subis), that journeys between breeding sites across eastern North America to overwintering sites in South America. I used migration timing data obtained from the direct tracking of individual martins, using light-level geolocators deployed across breeding sites between 26°-53° latitude, over a ten-year time span. I used generalized linear mixed-effect models (GLMMs) to examine the influence of breeding latitude, sex, age class, year, individual, and breeding population on three measures of migration timing (departure date, date of crossing the Tropic of Cancer, and arrival date). I found that breeding latitude was a strong predictor of timing around the calendar, with populations breeding at more southern latitudes migrating 2-3 days earlier than populations breeding at more northern latitudes. Males also migrated 3-5 days earlier than females, and older (2+ years old) individuals migrated 3-7 days earlier than younger (1 year old) individuals. Future studies should examine whether these strong timing patterns driven by latitude limit adaptive phenotypic responses to climate change, and whether mistiming may explain the steep population declines seen in many long-distance migratory songbirds.
Title: Finding New Antibiotic Producers in Compost
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Authors: Fatima Almira Feliciano Deuna, Paul Holloway and Athar Ata
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Abstract: Antibiotic resistance is a threat to successful treatment of bacterial infections. To preserve antibiotic therapy new antibiotics are required. Unfortunately few antibiotics with novel chemical structures have been discovered lately. The problem of dereplication has discouraged antibiotic discovery. To maximize chances of finding a novel antibiotic structure we chose a fairly unexplored environment; compost. Compost is a spatially structured environment similar to soil but with a continuously changing suite of microorganisms. These organisms compete with each other in a densely populated environment where production of antibiotics is an advantage to ensure access to resources. Compost samples were plated on Tryptic Soy Agar, Actinomyces Isolation Agar, and Oat Bran Agar to isolate antibiotic producers. Isolates were then tested for activity against a Gram-positive and a Gram-negative species. A total of 390 isolates were recovered from the 3 media. Of these, 176 inhibited the growth of either a Gram-positive, a Gram-negative, or both. Of the isolates tested 107 inhibited growth of Gram-positive bacteria and 75 isolates inhibited growth of Gram-negative bacteria including 31 isolates which inhibited growth of a Pseudomonas species. Several promising isolates were picked for growth inhibition of further Gram-positive and Gram-negative species. Two isolates were fermented to determine whether the antibiotic was released into the medium and was a small molecule. The antibiotic of each isolate was absorbed onto XAD-7 resin and eluted into methanol. The methanol extract contained antibiotic activity. It appears that compost is a promising source of antibiotics in addition to its known anti-fungal activities
Title: Size versus shape species discrimination in Mesodma (Multituberculata); Does size matter?
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Authors: Austin Ashbaugh, Jessica Theodor and Craig Scott
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Abstract: Species discrimination in the fossil record is difficult, considering there are few specimens and little viable genetic material. However, multituberculate species are notoriously difficult to discriminate amongst other extinct Mammaliaformes. The most practical diagnostic morphological feature that can be used to discriminate amongst species of multituberculates is through analyzing the lower blade-like pre-molars (p4). Smith and Wilson (2017) suggested that size of the p4 was more important for multituberculate species identification compared to the shape. However, Smith and Wilson only considered four species out of many species of Mesodma, yet the authors still proposed that all species of Mesodma would be better discriminated using size over shape based analyses. We re-assessed this hypothesis, and have used a variety of species within the genus Mesodma in attempt to test this claim. To accomplish this, we collected specimens of various known and unknown species of Mesodma from several institutions and conducted similar analyses to those done by Smith and Wilson. Size assessment included principal component analyses (PCA) of p4 blade outlines (centroid included) and another PCA considering a set of three linear measurements of the p4 typically used in species identification (H, L, L1). Shape was assessed using PCA of p4 blade outlines (centroid excluded). All data sets were analyzed using canonical variate analysis (CVA) to determine classification accuracy for size versus shape analyses. Preliminary results suggest that if more Mesodma species are analyzed, the more similar shape and size analyses are in species identification accuracy amongst species
Title: Microfluidic studies of the regulation of myoblats migration in an HGF gradient on ECM protein substratess
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Author: Ziba Rovei Miab
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Abstract: Cell migration is central to development, wound healing, tissue regeneration, and immune responses. Injured skeletal muscle is remarkable in restoring muscle function up to a point: while small injuries heal completely, heroic surgery and rehabilitation for large traumatic burn or warfare injuries may regain only partial function. Despite knowledge of muscle regeneration in vivo, generating muscle for transplantation to treat muscle-loss injuries is a challenge. I examined C2C12 mouse myoblast morphology and migration using triple-docking PDMS-based microfluidic devices in which cell movement occurs under gravity-driven laminar flow on a haptotaxis surface gradient generated with collagen (CN), fibronectin (FN) or competing gradients (CN: FN or FN:CN). Migration speed was faster on FN than on CN. Migration distance from FN:CN was significantly lower than from CN: FN. Cells were more polarized and “hesitant” on collagen and showed more collective, whole-cell forward movement toward FN than toward CN. Hepatocyte growth or scatter factor accelerated migration on the haptotaxis substrate. Further development of innovative microfluidic devices should help us learn to leverage our understanding of muscle cell migration behavior for engineering large muscle-tissue volumes for transplantation in serious muscle-loss injuries.
Title: Understanding Black Crappie Population Characteristics and Movement in Whiteshell Provincial Park
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Authors: McKenzie Hauger, Eric Mullen, Michaela Mckennitt, Derek Kroeker, Lee Murray, Kenneth Jeffries
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Abstract: Black Crappie (Pomoxis nigromaculatus) are a widely distributed freshwater fish in North America. Little is known about population characteristics along the northern edge of their distribution range. In this study we looked at populations of Black Crappie located in the Whiteshell Provincial Park, Manitoba, in a series of inter connected lakes (North Cross, South Cross, and Caddy Lake). We examined age and growth data to determine size structure, age structure, and mortality rate within those lakes. We wanted to examine how age structure varied among the lakes. Between May and August 2018, we collected data on n=372 in North Cross Lake, n=338 in South Cross Lake, and n=301 in Caddy Lake. We also tagged fish with external anchor tags to look at Black Crappie movement, specifically at the use of passage ways between lakes. In order to inform future management decisions, it is important to understand the population characteristics of these fish, as they are a popular recreational sport fish in Manitoba.
Title: Effects of Seasonality and Sediment Properties on Rate of Nutrient Uptake in Tundra Ponds
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Author: Dani Nowosad
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Abstract: The Hudson Bay Lowlands are an expansive area of wetlands that covers parts of Northern Manitoba, Ontario, and Quebec. The freshwater ponds in this region are at high risk of alteration from direct and indirect impacts of climate change due to extremely low nutrient concentrations and short growing seasons. Previous research in the region has indicated that phosphorus and nitrogen dynamics are likely controlled by sediment interactions, although little work has been done to test this hypothesis. A microcosm experimental method was used to test the effects of seasonality and sediment properties on the rate of nutrient uptake with sediment collected from four study ponds, which span a geographic gradient from the coast to the treeline in Churchill, Manitoba. Temperature loggers were placed in several microcosms to measure the thermal regime for the duration of each experiment. Preliminary results indicate that all the pond sites absorb phosphorus and ammonium at varying rates, and that phosphorus is absorbed into the sediments at a faster rate than ammonium. The thermal regime has little impact on nutrient uptake, although a slight variation in rate of uptake has been detected. This research is being undertaken to better understand how climate change will alter freshwater ecosystem health in Canada's sub-arctic.