Browsing Biological Sciences - Student Works by Issue Date
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- ItemBed bugs (cimex lectularius): biology, control methods, and their role as pests(2014) Fedor, Dreann NicoleBed bugs (Cimex lectularius) are blood feeding ectoparasites that have evolved as human pests due to their unique biology and reproduction. Common side effects of bed bug bites include: skin lesions, localized inflammation, itchiness and anxiety. There are numerous control methods to reduce bed bug populations such as vacuuming, steaming, laundering, exposure to extreme temperatures and chemical eradication methods. Bed bugs have become resistant to pyrethroid insecticides and DDT, supporting the cosmopolitan reemergence of bed bugs in the last couple decades.
- ItemA comparison between real and DLA simulated liver lobules using a population density analysis(2014) Wisk, Sara; Rezania, VahidA liver lobule is comprised of networks of sinusoids and hepatocytes. Here, a liver lobule was computationally constructed by using diffusion-limited aggregation (DLA) method. A population density analysis of the sinusoids and hepatocytes was performed and then compared with a real lobule image. The resulting images were compared using a histogram to interpret the ratio of hepatocytes to sinusoids.
- ItemBrittle stars: a story of success in biodiversity(2015) Beatty, AlexThe brittle star is found in a wide range of habitats all over the world. The regenerative and adaptive capabilities have allowed them to diversify. Huge photo evidence has determined several species to be invasive as they disperse into new habitats.
- ItemDoes the MMR vaccine cause autism? How uncritical acceptance of information can have disastrous consequences(2015) Vowel, AlanaOne of the most damaging medical controversies in several decades has been sparked by the publication of a fraudulent paper in 1998 claiming that a link between autism and the administration of the MMR vaccine had been found. The crisis is proving to be very difficult to remedy, as vaccination rates plummeted and have still not fully recovered. Fueled by media attention and ill-informed celebrity spokespeople, this poorly conducted study has received dangerous amounts of attention and support. Even with ever-increasing scientific evidence against the claim, the lack of skepticism and critical analysis of research has resulted in children being put in danger of preventable diseases by leaving them unvaccinated.
- ItemBreathing easy in an oligoxic world: Vampyroteuthis infernalis (Phy. Mollusca, Cl. Cephalopoda) adaptations to the oxygen minimum zone(2015) Steckler, DeannaThis review explores the existing literature on the Vampire Squid from Hell, Vampyroteuthis infernalis (Phylum Mollusca, Class Cephalopoda, Order Vampyromorpha). They are largely unstudied deep water cephalopods found in the oxygen minimum zone (OMZ) throughout the world’s temperate and tropical oceans. Their unique morphology and genetic ambiguity has contributed to scientific debate regarding their phylogenetic relationships, to which there is still no definitive answer. Vampyroteuthis are so well adapted to life in the OMZ that foraging, locomotion and antipredator behaviours are entirely unique among cephalopods and perfectly well-adapted to the oxygen-starved environment. Despite a lack of direct research, inferences are made to determine the effects of anthropogenic disturbance on the vampire squid.
- ItemEcology of the Caribbean reef squid Sepiotheuthis sepioidea (Phylum mollusca, class cephalopoda)(2015) Ghadially, MelissaCephalopod molluscs evolved from ancient cephalopods found during the Cambrian period around 550 million years ago. The Caribbean reef squid (Sepiotheuthis sepioidea) is a small species of cephalopod, up to 30cm in length, found in the tropical and subtropical waters of the western Atlantic Ocean. Throughout their lives these squid can be found in various places in the water column and on the reef. Aside from being a predator, the Caribbean reef squid is also prey for many species of fish as well as humans. Global warming and potential fishing threats are altering the reef squid’s habitat.
- ItemBiochemical characterization of the kinase activity of DNA repair enzyme, PNKP from C. elegans(2015) Oladogba, Oluwatosin; Bernstein, NinaDNA damage by genotoxic agents such as ionizing radiation or reactive oxygen species is likely to occur in the DNA of all living organisms. Therefore the cells of living organisms have developed complex protein networks overtime to help discover and repair DNA damage (Bernstein et al. 2005). Polynucleotide Kinase/Phosphatase (PNKP) is an enzyme that plays a crucial role in repairing a type of DNA damage known as DNA strand breaks (Bernstein et al. 2005). This enzyme has 3 domains, a kinase domain at the C-terminal, a phosphatase domain at the center, and an FHA domain at the N-terminal (Figure 1) (Bernstein et al. 2008). The kinase and phosphatase domains are responsible for directly repairing DNA strand breaks while the FHA domain is responsible for binding PNKP to other DNA repair enzymes (Bernstein et al. 2008). The general objective of this study is to analyze the kinase activity of PNKP derived from C. elegans (CePNKP) in comparison to PNKP derived from humans (hPNKP) by conducting kinase assays. A long term goal for this research is to characterize useful orthologs of PNKP for structural studies of an inhibitor binding to this enzyme. Results from this research showed that the kinase activity of CePNKP is more selective for the recessed 5’ terminus compared to the kinase activity of hPNKP, and this suggests that it might possibly be a good model for hPNKP.
- ItemImmune response of field crickets (Gryllus firmus) to eugregarine parasites (apicomplexan protoza)(2015) Shaw, Ashley; Judge, Kevin; Stock, MichaelThis research concerns the immunity response of the crickets Gryllus firmus. The immunity response is measured by the crickets' encapsulation response, which is a response of the insects blood cells which surround the insect and darken, or become melanized. It is assumed that the higher the melanization, the higher the immune response. The unique feature of these crickets is that they are infected with eugregarine gut parasites, and there has been no previous studies on these parasites within this species of crickets.
- ItemImmunity, sex and parasites: does sex of sand-field cricket (Gryllus firmus) affect immune response to eugregarine parasites?(2016) Shaw, AshleyThere is controversy about the effects gut-dwelling eugregarine parasites have on their invertebrate hosts. If crickets (Gryllus firmus) apportion resources to reproduction differently in males vs. females, then resources used to mount immune responses to parasites may also differ – especially if the parasites are pathogenic. I investigated the possible differences in immune response between male and female crickets and attempted to determine whether these differences are related to intensity of parasitic infection. To do this, pieces of nylon filament were implanted into the hemocoel of crickets which tested the immune response where hemocytes surround the filament (encapsulation). These responses were compared to intensity of parasitic infection. No statistically significant relationship between sex and melanisation, or sex and parasite load were found. I found that the duration of melanization was negatively correlated to parasite abundance and that there was a positive correlation between body size and parasite number. This result suggests the existence of a relationship between the parasite and host that could be conflicting with sexual selection theory, such as host manipulation by the parasite.
- ItemOur success was no fluke: the life and times of Schistosoma mansoni(2016) Doyle, Megan MarieParasitic organisms have a particularly close relationship with their hosts, with both parasite and host influencing each other's lives. This paper looks at some aspects of the parasitic organism Schistosoma mansoni, including the lifecycle, infection mechanism and the implications of these features for humans. The symptoms caused by infection, both acute and chronic are discussed. Next, a review of some recent studies regarding vaccine development, efforts to mitigate drug resistant properties of the organism and current treatment efficacy is included. Finally, the impact of humans on the spread of S.mansoni is also discussed, with particular emphasis on the spread in Egypt via the construction of the Aswan Dam.
- ItemTrends in wildlife intake at a rehabilitation centre in Central Alberta: a retrospective analysis of birds, mammals and herptiles, 1990-2012(2016) Doell, Dawn; Locky, DavidUsing patient data from the Wildlife Rehabilitation Society of Edmonton, we assessed reasons for admission, overall success of rehabilitation, and compared temporal trends with human population growth in the region. Over the survey period 13,375 individuals from 271 species were admitted. These included 11,637 birds (87%), 1,727 mammals (13%), and 11 herptiles (<0.1%). Outcome data were not reliably collected from 1990 through 2007 so it is not possible to provide a valid rate of the rehabilitated animal release for thoseyears. However, starting in 2008 outcome data was collected for the majority of animals with the average release rate of 45.7% from 2008 through 2012. There was a strong relationship between Edmonton’s population growth and the annual intake of wildlife (R² = 0.84, F = 104.6, P = 0.001). This study provides an overview of wildlife intake trends from 1990 through 2012 and is the first known published retrospective of wildlife intake in Alberta.
- ItemIntermolecular forces at play in the active site of lactoperoxidase(2016) Manary, Brandon; Llano, JorgeLactoperoxidase (LPO) is an enzyme that fights in the first line of defense against infection. LPO catalyzes the formation of toxic chemicals which indiscriminately kill foreign microbes and viruses caught in the mucous membranes of vulnerable body parts (namely, the eyes and upper airways). Because of its importance for the immune system, LPO is largely studied for potential applications in medical therapies. However, while much research has been done to determine the protein's structure and its efficacy against various pathogens, the chemical mechanism by which the enzyme's active-site transforms common ions into germ-killing agents is not known in detail. The aim of this project is to apply methods of computational chemistry and bioinformatics implemented in state-of-the-art software to elucidate the catalytic mechanism of LPO with common substrates found in the body fluids.
- ItemMedical therapeutics derived from leeches (Phy. Annelida; Cl. Hirudinea)(2016) Clarke, Christopher Everett WarrenOf all blood feeding invertebrates, few are more notorious than leeches. Throughout their existence as ectoparasites, leeches have evolved to release biological molecules in their saliva that act to counter the responses of the prey’s body to vascular trauma. Inadvertently, these very molecules have been used by humans for centuries for medicinal purposes; however, it is only recently that their cellular action has been elucidated. As a result, these compounds have been isolated and mass produced to treat a wide variety of conditions ranging from heart attack to Alzheimer’s disease and continued work suggests that these isolates will be an important future treatment for metastasis.
- ItemFirst and second year survival of invasive garlic mustard (Alliaria petiolata) in Edmonton(2016) Kuczmarski, Paige; Hills, MelissaGarlic mustard (Alliaria petiolata), a highly invasive biennial plant species, was first discovered in Alberta in 2010. It is present in two urban ravines in Edmonton and one in St. Albert. Introduced from Europe, this invasive species can be found in 37 US states and 7 Canadian provinces. This species rapidly invades forest ecosystems by dominating native vegetation. Garlic mustard is a threat to Edmonton’s River Valley due to its highly interconnected nature and the many native flora and fauna that inhabit this area. Understanding the population dynamics of an invasive species is critical to making informed management decisions. Previous research on the population dynamics of garlic mustard in other regions has reported high mortality in the first year and low second year mortality. The goal of our project was to assess garlic mustard mortality in its first and second year of growth within Edmonton’s central parkland subregion. To assess first year mortality fifteen 0.5 m2 quadrats were established in spring and monitored with biweekly counts over the first growing season in 2014 and 2015. To assess second year mortality fifteen 0.5 m2 quadrats were established in fall and then relocated in spring and monitored with biweekly counts over the second growing season in 2013-2014 and 2014-2015. Overall, first year mortality was 27% in 2014 and 2015 and second year mortality was 31% and 47%, respectively. This research will contribute to a broader understanding of the population dynamics of this species and may inform management decisions.
- ItemParasites of urban coyotes(2017) Chambers, Jackson; Stock, MichaelInteractions between coyotes (Canis latrans) and humans are an increasing problem, not only because of potential injuries from aggressive coyotes, but also because of potential transmission of zoonotic parasites and infections. Through the Edmonton Urban Coyote Project at the University of Alberta, seventeen coyotes were donated to MacEwan University where they were examined for internal parasites. As well, overall body condition of coyotes was assessed. This work provides data that illustrates how heavily parasitized the coyotes in the metropolitan Edmonton area are as well as data on parasite site-specificity and relationship between the number of parasites and splenic weight to body ratio in coyotes. Similar studies have been done throughout North America, namely Edmonton’s neighboring city to the south, Calgary, which had a much lower species richness than this study. This information will be useful in educating the general population on the dangers of urban coyotes and the importance of exercising caution when walking and cleaning up after pets.
- ItemThe effect of garlic mustard (Alliaria petiolata, Brassicaceae) on the diversity and composition of oribatid mite communities(2017) Kuczmarski, Paige; Flaherty, LeahGarlic mustard (Alliaria petiolata, Brassicaceae) is a non-native plant that rapidly invades North American forest understories. While garlic mustard has been shown to impact native vegetation, the effect on belowground communities, which are essential in controlling nutrient availability and decomposition, is unclear. My objectives were to investigate the impact of garlic mustard invasion on the community composition and species richness of oribatid mites (Acari: Oribatidae), which are bioindicators of soil health in forest ecosystems. Soil samples were obtained in June 2016 from two sites: Mill Creek Ravine, Edmonton AB and Broadmoor Public Golf Course, Sherwood Park AB. A paired sampling strategy was used to compare areas colonized with garlic mustard to those with native vegetation. Soil samples were collected from six pairs of plots, equalling 12 samples at each of the two sites, for a total of 24 samples. Following Berlese funnel extraction, oribatid mites ≥300 µm were identified. The effect of site and garlic mustard invasion on oribatid species richness, will be evaluated using mixed-model ANOVA and individual-based rarefaction. Oribatid community composition will be assessed with non-metric multidimensional scaling. This project will improve understanding of the impact of invasive species, particularly garlic mustard, on belowground communities.
- ItemToxic heavy metal removal (of arsenic, cadmium, lead, and mercury) by marine phytoplankton(2017) Andruchow, Daniel; Shaw, RossTwo species of marine phytoplankton, Tetraselmis sp. and Nannochloropsis sp., were grown for six days in 1 ppm solutions of As, Cd, Hg, and Pb, as four individual metal samples and as a four-metal mixture. Tetraselmis sp. cell density was lowest in the four-metal mixture, at 2.385 x 106 cells/mL, indicating growth was partially inhibited by these metals. Nannochloropsis sp. showed a higher overall growth rate, and exhibited the cell density in this combined metal sample at 9.03 x 106 cells/mL. Heavy metal concentrations were analyzed via ICP-OES. Nannochloropsis sp. exhibited the highest biosorption of As, followed by Pb, at concentrations of 18.555 mg/kg and 12.165 mg/kg, respectively. In the four-metal mixture, Nannochloropsis sp. had decreased levels of As and Pb sequestered by cells, implying there was preferential uptake. Levels of Cd were low in the cells of each species. Tetraselmis sp. showed most effective biosorption of Pb, at a concentration of 10.825 mg/kg, and 11.36 mg/kg in the mixed metal samples, but showed unreliable results for other metals samples. Concentrations for Hg were not determined due to machine error. The data suggested that Nannochloropsis sp. is a better phycoremediation candidate for these metals; however, a more comprehensive follow-up study is needed to confirm this assertion.
- ItemEffect of thermal stress on fluorescence and dinoflagellate density in the captive coral, Anthelia spp.(2018) Santos, Joleen; Shaw, RossThe obligate mutualistic relationship between corals and dinoflagellates is a classic example of symbiosis. Over the last few decades, coral reefs have been devastated by warm temperatures, hence, the necessity to develop a method to predict future mass bleaching events is higher than ever. Fluorescence might be used as an indicator of coral health, but very few studies have attempted to utilize it as a proxy for dinoflagellate density, which was the scope of the present research. The goal of this study was to determine the effects of thermal stress on fluorescence and dinoflagellate density in the captive coral, Anthelia spp.. Over a five-week period, tanks filled with Anthelia spp. underwent gradual increases in temperature, beginning at 28°C and ending at 33°C. Samples were quantified for fluorescence and dinoflagellate density using fluorescence microscopy and a maceration method. As the temperature gradually increased, fluorescence values subsequently decreased. In contrast, dinoflagellate density first increased until it reached a threshold, followed by a sudden drop in numbers. Symbionts might be increasing their mitotic rate in response to thermal stress to compensate for the shortage of photosynthate supply for their host. Therefore, fluorescence analysis may be a potential predictor of coral bleaching in Anthelia spp.
- ItemEffects of thermal stress on fluorescence and dinoflagellate density in the captive coral, Anthelia spp.(2018) Santos, Joleen; Shaw, RossThe obligate mutualistic relationship between corals and dinoflagellates is a classic example of symbiosis. Over the last few decades, coral reefs have been devastated by warm temperatures, hence, the necessity to develop a method to predict future mass bleaching events is higher than ever. Fluorescence might be used as an indicator of coral health, but very few studies have attempted to utilize it as a proxy for dinoflagellate density, which was the scope of the present research. The goal of this study was to determine the effects of thermal stress on fluorescence and dinoflagellate density in the captive coral, Anthelia spp. Over a five-week period, tanks filled with Anthelia spp. underwent gradual increases in temperature, beginning at 28°C and ending at 33°C. Samples were quantified for fluorescence and dinoflagellate density using fluorescence microscopy and a maceration method. As temperature gradually increased, fluorescence values subsequently decreased. In contrast, dinoflagellate density first increased until it reached a threshold, followed by a sudden drop in numbers. Symbionts might be increasing their mitotic rate in response to thermal stress to compensate for the shortage of photosynthate supply for their host. Therefore, fluorescence analysis may be a potential predictor of coral bleaching in Anthelia spp.
- ItemSpatial navigation in corn snakes(2018) Shahab, Aaizah; Nankoo, Jean-FrançoisResearch has shown that a variety of organisms encode the geometry of their environment to re-establish orientation (i.e., reorientation). This has been shown in species ranging from rats to bees, and has been shown to be an automatic process. This automatic process of encoding geometry has been taken as evidence for a geometric module in the brain of these species. However, it is currently not known whether reptiles also use geometry to reorient. This study will investigate the use of geometric cues for reorientation in a corn snake. The snake will be trained to locate a goal in a corner of a rectangular arena. At each corner, a unique landmark will be available. Once the snake has learned to locate the target corner, it will attempt to relocate the corner in the absence of the landmarks. If the snake has encoded the geometry of the arena during training, it should be able to locate the goal, and will make rotational errors (i.e., mistaking the diagonally opposite corner for the correct corner). This rotational error would provide evidence that the snake has encoded the geometry even though it was trained to rely on the landmarks during training. This would provide support for the existence of a geometric module in the snake’s brain, and potentially in the general reptilian brain as well.