A5004626306- Environmental Toxicology and Ecotoxicology
- Pesticide and Herbicide Environmental Studies
- Pharmaceutical and Antibiotic Environmental Impacts
- Petroleum Processing and Analysis
- Marine Biology and Environmental Chemistry
- Insect and Pesticide Research
- Hydrocarbon exploration and reservoir analysis
- Toxic Organic Pollutants Impact
- Enhanced Oil Recovery Techniques
- Insect and Arachnid Ecology and Behavior
- Marine Ecology and Invasive Species
- Environmental Chemistry and Analysis
- Analytical chemistry methods development
- Phosphodiesterase function and regulation
- Microplastics and Plastic Pollution
- Receptor Mechanisms and Signaling
- Respiratory Support and Mechanisms
- Per- and polyfluoroalkyl substances research
- Neonatal Respiratory Health Research
- Microbial bioremediation and biosurfactants
- Aquatic Invertebrate Ecology and Behavior
- Insect Pest Control Strategies
- Smart Materials for Construction
- Urban Stormwater Management Solutions
- Cholinesterase and Neurodegenerative Diseases
Environment and Climate Change Canada
2016-2025
Fisheries and Oceans Canada
2015-2025
University of Waterloo
2004-2007
Merck Canada Inc. (Canada)
2000-2002
Lawson Health Research Institute
1998
St Joseph's Health Centre
1998
Western University
1998
Reckitt Benckiser (Netherlands)
1980
This study evaluated the effects of varying tidal volumes (VT) and positive end-expiratory pressure (PEEP) levels on surfactant aggregate conversion lung function in an animal model injury induced by N-nitroso-N-methylurethane. Lung-injured adult rabbits were initially ventilated using a VT 10 ml/kg (VT10), respiratory rate 30 breaths/min (RR30), PEEP 3.5 cm H2O. A trace dose radiolabeled rabbit large aggregates was instilled after onset ventilation, animals then at different ventilator...
The process of surface mining and extracting bitumen from oil sand produces large quantities tailings sands process-affected water (OSPW). industry is currently storing OSPW on-site while investigating strategies for their detoxification. One such strategy relies on the biodegradation organic compounds by indigenous microbes, resulting in aged waters with reduced toxicity. This study assessed toxicity statically approximately 18 years. Dissolved organics were fractionated using a preparative...
The type 4 cAMP-specific phosphodiesterases (PDE4s) are Mg(2+)-dependent hydrolases that catalyze the hydrolysis of 3', 5'-cAMP to AMP. Previous studies indicate PDE4 exists in two conformations bind inhibitor rolipram with affinities differing by more than 100-fold. Here we report these consequence binding its metal cofactor such as Mg(2+). Using a fluorescence resonance energy transfer (FRET)-based equilibrium assay, identified L-791,760, fluorescent inhibitor, binds apoenzyme (free...
Abstract Substituted phenylamine antioxidants (SPAs) are high production volume chemicals that incorporated into a variety of commercial products (e.g., polymers, dyes, lubricants). There few data on chronic toxicity SPAs to fish and no the early life stages fish. The physicochemical properties would suggest if they were enter an aquatic ecosystem partition sediment. Therefore, present study focused investigating effect sediment‐associated fathead minnow ( Pimephales promelas) . Eggs larvae...
Oil sand operations in Alberta, Canada will eventually include returning treated process-affected waters to the environment. Organic constituents oil water (OSPW) represent complex mixtures of nonionic and ionic (e.g., naphthenic acids) compounds, compositions can vary spatially temporally, which has impeded development quality benchmarks. To address this challenge, it was hypothesized that solid phase microextraction fibers coated with polydimethylsiloxane (PDMS) could be used as a...
Short-chain perfluoroalkyl carboxylic acids (PFCAs) have been detected in the environment globally. The presence and persistence of these compounds may lead to chronic wildlife exposure. We used northern leopard frog (Rana pipiens) tadpoles investigate toxicity bioconcentration two short-chain PFCAs, perfluorobutanoic acid (PFBA) perfluorohexanoic (PFHxA). exposed Gosner stage 25 PFBA PFHxA (as individual chemicals) at nominal concentrations 0.1, 1, 10, 100, 1000 µg/L for 43-46 days....
Abstract Bioindicators add valuable understanding of biological impacts to contaminant monitoring programs. However, attributing effects (e.g., mortality and growth impairment) exposures is challenging because potential confounding by environmental variables. We assessed the influence four water quality variables (temperature, dissolved oxygen, pH, conductivity) on assessments during in situ amphipod Hyalella azteca six agricultural urban watersheds southern Ontario, Canada (2005–06,...
Alkylbenzene sulfonates (ABS) are surfactants widely used in residential and commercial products. To support the environmental risk assessment of these compounds, acute toxicity three ABS, linear (n-ABS), branched (BABS), alkyl phenoxybenzene (APBS), was evaluated using six aquatic organisms from different trophic levels (algae, daphnid, amphipod, mussel, snail, fish). This approach allowed direct comparisons among species to provide insights into sensitivity surfactants, compounds...
Type 4 phosphodiesterases (PDE4s) are metallohydrolases that catalyze the hydrolysis of cAMP to AMP. At bottom its active site lie two divalent metal ions in a binuclear motif which involved both binding and catalysis [(2000) Science 288, 1822−1825; (2000) Biochemistry 39, 6449−6458]. Using SPA-based equilibrium [3H]rolipram assay, we have determined Mg2+, Mn2+, Co2+ all mediated high-affinity (Kd between 3 8 nM) near stoichiometric (R)-rolipram PDE4. In their absence, binds...
Abstract Neonicotinoid insecticides are used extensively in agriculture and, as a consequence, now detectable nearby aquatic environments. Few studies have evaluated the effects of neonicotinoids on amphibians these In present study, we examined 2 commercial formulations (active ingredients clothianidin and thiamethoxam) survival life‐history traits wood frogs ( Lithobates sylvaticus ) northern leopard pipiens ). We artificial pond mesocosms to assess neonicotinoids, at nominal...
Perfluoroalkyl substances (PFAS), including perfluorooctanoic acid (PFOA), are industrial chemicals that of concern due to their environmental presence, persistence, bioaccumulative potential, toxicity, and capacity for long-range transport. Despite a large body research on exposure, insufficient chronic aquatic toxicity data exist develop water quality targets clean-up federal contaminated sites in Canada. Thus, our objective was assess the aqueous PFOA tests with Hyalella azteca (amphipod)...
We evaluated the effects of various ventilation strategies on efficacy exogenous surfactant therapy in lung-injured adult rabbits. Lung injury was induced by repetitive whole-lung saline lavage followed mechanical ventilation. Three hours after final lavage, 100 mg lipid/kg bovine lipid extract instilled. After confirmation similar responses to surfactant, animals were then randomized one four groups; (1) Normal tidal volume (Vt) (5 cm H2O): Vt = 10 ml/kg, respiratory rate (RR) 30/min,...