Browsing by Author "Jackson, Leland"
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Item Open Access Designing Geovisual Analytics Application for Exploring Hydrological Data(2015-05-08) Marbouti, Mahshid; Bhaskar, Rahul; Shakeri, Zahra; Anslow, Craig; Jackson, Leland; Maurer, FrankThe ability to analyze and visualize large amounts of environmental and hydrological data on maps is difficult. Interaction and manipulation of data is crucial for decision making in natural disasters like floods. Hence, we present a Water Management Application (WMA), a geovisual analytics application to help analysts explore large amounts of hydrological data on web-based maps, create early flood warnings, and make strategic decisions in critical situations. With WMA we have provided monitoring and management of environmental resources which can help inform the design of future geospatial and geovisual analytics applications.Item Open Access Development of Best Strategies for the Control of Butomus umbellatus L. (Flowering Rush) In Alberta(2018-01-25) Cahoon, Lisa; Vamosi, Jana; Jackson, Leland; Vamosi, Steven; Blue, GwendolynThe emergent aquatic perennial, Butomus umbellatus L. is a prohibited noxious weed in Alberta. In this thesis I provide (1) the first comprehensive review on its phenology and cytotype in Alberta; (2) an examination of the effect of cytotype on propagation means and (3) an experimental test of different control methods in two infested Alberta lakes. One of the findings of this study is that a full understanding of the propagation of this species is complicated because there are two cytotypes: fertile diploids and sterile triploids. I describe in this thesis how most populations of B. umbellatus in Alberta appear to be the diploid cytotype, except for a triploid population in Innisfail. My studies found that in diploid plants, sexual reproduction is not the primary means of spread. My results also indicate that all control methods currently in use are equally unsuccessful, largely because B. umbellatus invests so heavily in vegetative reproduction that removing the entire rhizome is difficult. Because of this life history feature, B. umbellatus will likely be most effectively controlled by quickly recognizing new populations and removing all plant material. While revegetation of a reclaimed area with indigenous plants could prove beneficial, my results indicated that B. umbellatus quickly reclaims sites that have been replanted with native species.Item Open Access Diel oxygen cycles in the Bow River: Relationships to Calgary's urban nutrient footprint and periphyton and macrophyte biomass(2013-09-23) Chung, Cecilia Wei Ying; Jackson, LelandThe City of Calgary discharges wastewater effluent from three wastewater treatment plants. Although nutrient inputs from effluent increase fish growth, increased productivity may be detrimental to fish populations by increasing primary producer biomass, which subsequently affects the magnitude of diel oxygen (O2) concentrations through photosynthesis and respiration. Overnight depressed O2 concentrations can negatively impact local fish populations. Changes in nitrogen and phosphorus concentrations, periphyton and macrophyte biomass, δ15N isotopes and diel O2 cycles were measured along the Bow River during summer months when primary producer metabolism and water temperatures are highest. A strong urban footprint associated with wastewater effluent inputs was detected. Primary producer biomass is dominated by periphyton upstream, while macrophytes dominate the river beginning downstream of Calgary’s first effluent input. The transition from periphyton to macrophyte dominated communities leads to larger amplitude diel O2 cycles, suggesting macrophytes are the primary driver of larger diel O2 cycles.Item Open Access Patterns of habitat fragmentation and contaminant exposure in longnose dace (Rhinichthys cataractae)(2015-01-08) Tunna, Haley; Jackson, Leland; Rogers, SeanHuman-induced environmental change occurs rapidly and challenges the persistence of organisms. I studied patterns of contaminants and habitat fragmentation on longnose dace (Rhinichthys cataractae). I compared liver biotransformation and age-structured sex ratios at sites upstream and downstream of anthropogenic inputs. Downstream of anthropogenic inputs, female biases in the oldest age classes shift to female biases in all age classes relative to upstream sites. Liver biotransformation reflects an urban footprint. Together these results suggest that contaminants may adversely affect fish health. Dams and weirs are barriers to fish movement and can reduce connectivity and genetic diversity of populations. Results from population genetic analyses using microsatellite DNA markers show substantial gene flow and overall weak population genetic structure across Alberta. Consequently, fragmentation did not alter connectivity of dace in Alberta. Overall, longnose dace in Alberta have spatially and temporally variable sex ratios and exhibit weak population structure in association with human activities.Item Open Access Relationships between Didymosphenia geminata occurrence, blooms and environmental conditions(2013-03-26) Corbett, Lisa Maureen; Jackson, LelandAlgal blooms have often been attributed to an increase of nutrients that results in increases in maximum algal biomass. However, Didymosphenia geminata, a diatom blooming in Canadian streams for the past 30 years, blooms in oligotrophic streams. I examined the environmental conditions and algal nutrient use of low nutrient Rocky Mountain streams where D. geminata experiences significant blooms. I determined that the local variables of low water velocity, low water temperature and low concentrations of total phosphorus were important predictors of D. geminata cell abundance. The conditions that promote algal blooms were not clearly established, as occurrence of blooms was not strongly related to an increase or decrease in phosphorus concentration. These results suggest there may be a complex combination of nutrients and environmental conditions that promote blooms that were not identified within the scope of this study. However, as I had no consistent conditions that related to the presence of D. geminata blooms, an alternative hypothesis is that there may be multiple strains of D. geminata. There may be strains that are able to bloom and others that cannot. This study has opened many doors into further work that needs to be conducted on D. geminata before we can fully understand the factors that cause this diatom to create noxious algal blooms.Item Open Access The influence of Daphnia spp. on resuspended sediments in shallow prairie lakes(2015-06-10) Elgin, Erick; Jackson, LelandLow water transparency in shallow lakes, which may limit macrophyte growth, is usually attributed to excessive phytoplankton biomass. However, abundant resuspended sediments also contribute substantially to reductions in water clarity. The ability of the large-bodied zooplankter, Daphnia to increase water clarity by reducing phytoplankton is well studied, but less is known about Daphnia’s effect on resuspended sediments. To evaluate Daphnia’s ability to reduce suspended detritus and inorganic particles and the resulting effect on late summer macrophyte biomass, I combined field observations with a field enclosure experiment. My field results suggest that abundant Daphnia can reduce detritus concentrations and that this effect is most pronounced in the spring. I also demonstrate that summer macrophyte biomass and plant species richness increases with lower spring turbidity. My field enclosure experiment confirms that Daphnia are capable of clearing resuspended sediments during both low and high turbidity conditions in spring.Item Open Access The response of insects to wastewater effluent in the Red Deer River: A spatial perspective(2013-05-01) Kobryn, Madison Jensen; McCauley, Ed; Jackson, LelandFew studies document the spatial responses of biota to point-source nutrient enrichment in rivers. Even fewer identify the mechanisms acting to create these responses. This study addressed these research shortages by investigating spatial patterns of physicochemical variables, insect abundance, and periphyton abundance, in the Red Deer River, Alberta, Canada, downstream of wastewater input. Additionally, patterns in nitrogen isotope signatures driven by effluent input were used to estimate the scale of insect movements. Analyses of family assemblage spatial structure, and of across-scale explanators of local insect abundance, were used to infer whether movement helps structure the spatial response of insects to effluent addition. Notably, nutrient concentrations peaked downstream of effluent addition, and were significantly correlated with insect abundance. Although insects were estimated to have undergone downstream movements of ~1-5 km per month, broad-scale spatial patterns did not show obvious signs of being affected by downstream movement.Item Open Access The Role of Nuclear Envelope Lipids in Nuclear Shape and Transcription(2023-04-23) Sosa Ponce, Maria Laura; Zaremberg, Vanina; Cobb, Jennifer A.; Chua, Gordon; Moorhead, Greg; Grewal, Savraj; Siniossoglou, Symeon; Jackson, LelandThe nuclear envelope (NE) is a double membrane structure contiguous with the endoplasmic reticulum (ER) encompassing the nucleus. The NE is important in maintaining genome organization, as silenced domains are sequestered at the nuclear periphery, while active domains associate with the nuclear pore complex for rapid export of mRNA. Budding yeast in particular tether silenced telomeres at the NE to prevent aberrant recombination of the chromosome ends. In this thesis, the role of lipids in communication between the NE and telomere regulation was investigated, including how changes in lipid composition impact gene expression and overall nuclear architecture. Yeast cells were treated with the non-metabolizable lysophosphatidylcholine analog edelfosine, a lipid drug known to accumulate at the perinuclear ER. Edelfosine induced NE deformation and disrupted telomere clustering but not anchoring. In addition, the association of Sir4 of the Silent Information Regulator complex with telomeres decreased. RNA-seq analysis showed upregulation of Sir-dependent genes located at sub-telomeric regions, and downregulation of ribosomal protein genes. Transcriptomic analysis also revealed that two lipid metabolic circuits are activated in response to edelfosine, one mediated by the membrane sensing transcription factors, Spt23/Mga2, and the other by a transcriptional repressor, Opi1. Activation of these transcriptional programs resulted in higher levels of unsaturated fatty acids and the formation of nuclear lipid droplets. Interestingly, cells lacking Sir proteins displayed resistance to edelfosine and unsaturated fatty acids. Characterization of the edelfosine mechanism of toxicity in cells lacking SIR4 found that while these cells display similar NE deformations and formation of nuclear lipid droplets as seen in wild type cells, they have less internalization of sterols from the plasma membrane, with a concomitant maintenance of the proton pump Pma1 at the plasma membrane and a reduced acidification of the cytosol. Altogether this body of work presents evidence supporting a cross-talk between NE lipids and nuclear architecture and function.Item Open Access Transitions in Boreal Wetland Macroinvertebrate Community Composition Across a Natural Salinity Gradient(2022-06) Vercruysse, Brenten; Ciborowski, Jan; Jackson, Leland; Reid, Mary; Wytrykush, CarlaNearly 65% of Alberta’s northern boreal landscape is comprised of wetlands (primarily peatlands), which are lost in the process of open pit mining for oil sands. Demonstration wetlands recently created in reclaimed postmining watersheds are productive and support diverse biota. However, their water tends to be sodic due to the presence of salts in the soils used in their construction and residual sodium from the bitumen extraction process. Saline wetland systems occur in northern Alberta in areas where deep aquifer upwellings contribute significantly to a wetland’s water budget. I sampled the water chemistry and aquatic invertebrates in a suite of 52 pools ranging in specific conductance from 3,757 to 20,170 S/cm in a patterned fen southeast of Fort McMurray, Alberta, to identify patterns of community composition along the salinity gradient. Sodium, chloride, magnesium, and calcium were the dominant ions present in the saline fen. Pools with relatively low salinity supported abundant densities of gastropods and odonates whereas the most saline pools were dominated by Diptera larvae, especially genera of mosquitos. Threshold Indicator Taxon Analysis (TITAN) identified a set of 11 sensitive and 9 tolerant taxa diagnostic of specific conductivity. Community composition changed markedly at a threshold of 6,335-9,385 S/cm, equivalent to chloride concentrations of 1,579- 2,535mg/L. These findings may provide a useful frame of reference for anticipating community composition in wetlands forming in sodic areas of the reclaimed postmining landscape of the AOS.Item Open Access Trends and drivers of water clarity in shallow, prairie lakes of southern Alberta(2012-10-03) Maheux, Heather Marie; Jackson, LelandThis research examined water clarity in shallow, prairie lakes of southern Alberta. A combination of water column analyses from 20 lakes and paleolimnological analyses from ten of them were used to examine how water clarity has changed since 1850 and to identify possible explanations for the observed changes. Pigment data from sediment cores showed the lakes experienced accelerated eutrophication since 1850, but that the onset was not synchronous across lakes. The lakes showed evidence that regime shifts between clear and turbid lake regimes since 1850 were possible. Evidence was based based on paleolimnolgical analyses using pigment data and additional sediment core proxies (e.g. fossils, isotopes). Water quality data from 20 lakes did not provide additional support for the existence of alternate regimes based on multimodal distribution between regimes or dual relationships between nutrients and water clarity. Salinity and major ion composition may help explain why some lakes did not provide additional support for the existence of alternate clear and turbid regimes. In most lakes, turbidity was dominated by inorganic matter, rather than phytoplankton, and this was more prevalent in the more saline lakes. High proportions of heterocystous cyanobacteria from four of the 20 shallow lakes provided some evidence for nitrogen limitation in the lakes. It is possible that additional lakes were also nutrient limited. As a result, models that use nutrient-chlorophyll relationships developed in non-saline lakes do not accurately capture turbidity dynamics in the saline, shallow lakes on southern Alberta’s prairie.Item Open Access Urban-Derived Contaminants Cause Reproductive Disruption in an Aquatic Sentinel Species, Longnose Dace(2014-04-09) Henderson, Suzanne; Jackson, LelandWe investigated potential adverse impacts of urban-derived environmental contaminants, such as pharmaceuticals, steroids, surfactants and plasticizers, on Longnose Dace (Rhinichthys cataractae) along two rivers, the Bow and Elbow Rivers, in the City of Calgary. Fish were sampled to evaluate physiological and morphological endpoints associated with reproduction and development, including adult sex ratios, changes in body and organ weight, and gonad malformation. Significant male bias was observed downstream of three wastewater treatment plants (WWTPs) on the Bow River, and significant female bias was observed on the Elbow River, suggesting the presence of environmental contaminants with hormone-like activity, dependent on location. To investigate the mechanisms of adverse fish health effects we quantified the expression of liver vitellogenin, estrogen receptor alpha, cytochrome P450, and insulin-like growth factor-1. Decreased IGF1 and ERα expression levels were observed downstream of WWTP effluent in the Bow River, while increased vitellogenin and ERα expression levels were noted in the Elbow River within Calgary. Results support the hypothesis that waterborne environmental contaminants may be responsible for the adverse health effects, such as biased sex ratios, of Longnose Dace within the City of Calgary.