University of Saskatchewan Research Archive
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Measuring and modelling concentrations of plant protection products and trace metals in the South Saskatchewan River
Get PDFOrganic chemical pollutants are delivered to riverine habitats via basin land use and hydrology interactions. Aquatic organisms eventually absorb these substances, where they might have negative consequences. However, our capacity to reliably predict potential future changes in pollutant concentrations is now constrained by information gaps relating to the links between hydrological, chemical, and biological processes. In the South Saskatchewan River, Canada, in the years 2020 and 2021, concentrations of three pesticide classes (organochlorines, organophosphates, and herbicides) in the water, sediments, and fish were examined. Organochlorine pesticides have been prohibited in Canada since the 1970s; however, methoxychlor and lindane were occasionally found in samples of sediment and fish that may have been contaminated in the past. Organophosphate pesticides, with the exception of malathion and parathion, were close to detection limit in both sampling years in all matrices, while neonicotinoids were below detection in all samples. On the other hand, for both sampling years, consistent levels of the herbicides 2,4-D and dicamba were found in water samples from all locations. Concentrations were on average three times higher in 2020, when river discharge was two times greater, possibly pointing to contaminated sediments being disturbed by high flows, or run-off from the nearby watershed. Of the trace metals, copper and zinc concentrations at several sampling locations exceeded standards for sediment quality. About 18% of the water and sediment samples that were examined had mercury concentrations that were above recommended levels. These discoveries fill in the gaps in monitoring datasets and show significant connections between hydrology and chemistry that can be further investigated in computational models to forecast pollutant trends in freshwater systems.
Trace metal concentrations were used to model transport and fate in the South Saskatchewan River using an existing model developed for another freshwater system. The River Analysis System from the Hydrologic Engineering Center was paired with a well-known 1-D modelling technique (HEC-RAS). The stream transport module for the WASP (Water Quality Analysis Simulation Program), TOXI, can calculate the flow of water, sediment, and dissolved constituents through branching and ponded segments and is integrated with flow routing for free-flow streams, ponded segments, and backwater reaches. Two metals with primarily anthropogenic and geogenic origins were chosen: copper and nickel. The South Saskatchewan River was analysed in 2020 and 2021 at 10 distinct locations, both upstream and downstream of the City of Saskatoon. By comparing model predictions with copper and nickel concentrations obtained earlier, model performance was assessed. The model functioned reasonably well for sediment samples and did a good job of estimating the levels of copper and nickel in water samples. In both the water and sediment sample segments, the model overestimated concentrations. Diffuse pollutant loads were increased to enable the model to work more precisely. This work shows the predictive power of merging WASP-TOXI and HEC-RAS models for the prediction of contaminant loading, even though numerous default parameter values had to be employed because primary historical data was unavailable. This proof-of-concept study will be useful for future research, including studies on the effects of climate change on the quality of water in the Canadian prairies
Home for a White Season : Measuring precipitation in the Saint John River Valley
Get PDFCanada First Research Excellence FundNon-Peer ReviewedPersonal account of a scientist's engagement with government agencies and local citizens to produce new understanding of rain and snow patterns in New Brunswick's Saint John River valley
Investigating Local Interactions of Transition Metal Ions in Correlated Materials
No full textThe abstract of this item is unavailable due to an embargo
Locating social perspectives relevant to genomically-enhanced bioremediation strategies
Get PDFGlobal Water Futures, Genomics Research for Optimization of constructed treatment Wetlands for water remediation, Genome Canad
EXPERIENCES AND PERSPECTIVES OF CANADIAN UNIVERSITY EDUCATORS IN INCORPORATING FOOD LITERACY INTO UNDERGRADUATE FOOD AND NUTRITION PROGRAMS
No full textThe abstract of this item is unavailable due to an embargo
DNA VIRUSES OF BIG BROWN BATS: LESIONS, PATHOGENESIS, AND INNATE IMMUNE RESPONSE
No full textThere have been numerous pandemics and epidemics throughout human history with varied origins but presently bats are being singled out as the harbingers of current and future plagues. Is there something special about the relationship bats have with their viruses that merits this claim or are they just like other mammals? Bats are unique among mammals in their ability to fly and differences found in their immune system are proposed to be secondary to evolutionary adaptations to flight. These adaptations may allow them to tolerate viruses without developing associated disease. The large numbers of viruses found across bat species could reflect this tolerance, but it may also reflect the sheer number of bat species and therefore viruses of this mammalian order. The perceived tolerance could also reflect our limited understanding of infectious diseases in bats. To address this question, we reviewed the literature on viral diseases in bats, looked for pathological changes that were potentially associated with viral infection in routine post-mortem evaluations of Western Canadian bats, and examined the innate response to DNA in big brown bat cells. We isolated two DNA viruses from naturally infected big brown bats. One, a herpesvirus, was not associated with any disease and the other, a poxvirus, was associated with oral ulcerations and joint swelling. Novel features were noted with both viruses: an atypical cell type supporting replication for the herpesvirus and an abnormal cellular site of replication for the poxvirus. Big brown bat cells expressed an array of DNA sensors and used multiple transcription factors to generate an innate response to a DNA surrogate. These bat cells produced a comparable innate response when they were infected with inactivated forms of these viruses. Whereas the innate of response of human cells stimulated with this surrogate was markedly proinflammatory. This proinflammatory induction was not observed in bat cells. One of these proinflammatory products, interleukin 8, was expressed at high levels in bat cells independent of treatment, including viral infections. A different proinflammatory product, interleukin 6, was inhibited in response to the DNA surrogate, but the inhibition was overcome upon infection with live poxvirus. The herpesvirus, which was not associated with any pathological changes, was able to control the innate response, whereas the poxvirus, which was associated with disease, was not. This work suggests bats are susceptible to disease caused by viruses, they are not generally tolerant to viruses, and the development of disease is dependent on the type of virus, which is similar to other mammalian species
LAW WITHOUT ORDER: LOWER COURT SENTENCING, THE APPLICATION OF GLADUE PRINCIPLES, AND JOINT SENTENCING PRACTICES IN CANADA
No full textThe abstract of this item is unavailable due to an embargo
EFFECT OF INTERCROPPING WITH FABA BEAN ON LAND EQUIVALENCY RATIO AND SOIL HEALTH IN SASKATCHEWAN
No full textIntercropping has a host of benefits, including increased yields and greater yield stability; lower disease, pest, and weed pressure; complementary resource use; and lower inputs of commercial fertilizer and pesticides. What is not known is how increasing biodiversity within a field impacts the soil health, as preserving and building soil health is important for maintaining productivity within an agricultural system. While legumes are often included within an intercrop, faba bean (Vicia faba L.) has particular potential to be a successful intercropping partner due to its high nitrogen fixation rate, disease resistance, and high protein content in the seed. A 2-year field study in Saskatoon, SK examined intercropping with faba bean including the following combinations:(faba-oat (Avena sativa), faba-canola (Brassica napus), faba-flax (Linum usitatissimum), faba-wheat (Triticum aestivum) along with other popular intercropping systems in the Canadian prairies: pea (Pisum sativum) -canola, lentil (Lens culinaris) -wheat, chickpea (Cicer arietinum) -flax. The land equivalency ratio and yield of different intercrops and their effect on soil health indicators including total nitrogen, soil protein, organic carbon, and active protein, along with water soluble nitrogen, and available nitrogen and phosphorus supply rates were evaluated. Pea-canola, faba-flax, and chickpea-flax over yielded, with LER values of 1.25, 1.09, and 1.07, respectively, showing land use efficiency benefits. Urea fertilization, more than crop type, impacted water soluble nitrogen levels. Supplies of plant available N and P in the soil during the growing season were influenced by legume type and soil moisture conditions. While no effects on soil health indicators were observed early in the growing season, after flowering legumes showed a greater increase in soil protein and a greater active protein value at harvest than nonlegumes. Long-term soil health factors of total nitrogen and organic carbon were unaffected in a one-year period by different cropping strategies. Further research is needed on the microbial association with legume rhizodeposition and later season root and nodule senescence to determine the mechanisms that legumes possess that affect soil protein and active carbon
PRENATAL HEALTHCARE AMONG IMMIGRANT MOTHERS IN CANADA: AN EXPLORATION OF BARRIERS TO ADEQUATE AND CULTURALLY COMPETENT CARE
No full textImmigrants in Canada make up more than 20% of the population and are quite diverse, many migrating under the economic category to amplify economic development (Statistics Canada, 2017a). Despite the growing number of immigrants in the country, there remain gaps in culturally competent and adequate care for immigrant mothers who live in Canada. This thesis examined prenatal care barriers experienced by immigrant mothers in Canada.
First, a systematic scoping review was undertaken. A total of 17 studies were included and analyzed. Cultural and institutional factors affected mothers’ access to and perception of prenatal care in the Canadian healthcare system. Second, an online survey was conducted with immigrant women in Saskatchewan who had received prenatal care within the past 3 years (N=70) between September 2021 and March 2022. This included participants from Africa (n=56), Asia (n=9), Europe (n=2), North America (n=2), and South America (n=1). 15.71% of the participants were pregnant when completing the survey. Factors such as transportation, no health problems, affordability of prenatal care, and social support increased participants’ access to prenatal care, while work schedules and COVID-19 had the opposite effect
Moisture Content and Mechanical Properties of Bio-Waste Pellets for Fuel and/or Water Remediation Applications
No full text© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).Government of Canada through the Natural Sciences and Engineering Research Council of Canada (Discovery Grant Number: RGPIN 04315-2021). The APC was funded by the Journal of Composites Science editorial office.Peer ReviewedThe current research is focused on the mutual comparison (mechanical properties, response to humidity) of agro-waste composite materials. The purpose of this work is directed at the valorization of agro-waste biomass products and to investigate their mechanical stability for transport or other applications (in dry and wet states). Three different types of agro-waste (oat hull (Oh), torrefied wheat straw (S), and spent coffee grounds (SCG)) were blended with kaolinite (K) and chitosan (CHT) at variable weight ratios to yield ternary composites. Mechanical properties were represented by measuring hardness (in compression mode) and elastic modulus (under tension mode). Young’s (elastic) modulus was measured both for dried and hydrated samples. The pelletized materials were prepared in two forms: crosslinked (CL) with epichlorohydrin and non-crosslinked (NCL). The hardness of the Oh pellets was poor (75 N) and decreased by four times with greater agro-waste content, while crosslinking affected the hardness only slightly. S pellets had the highest level of hardness at 40% agro-waste content (160 N), with a concomitant decrease to 120 N upon crosslinking. SCG pellets had the least change in hardness for both CL and NCL specimens (105–120 N). The trends of Young’s modulus were similar to hardness. Hydration caused the elastic modulus to decrease ca. 100-fold. In general, S and SCG composites exhibit the greatest hardness and Young’s modulus compared to Oh composites (CL or NCL) in their dry state