Road mortality threatens the long-term viability of some wildlife populations, particularly herpetofauna. Wildlife road mortalities were recorded during regular bicycle-based surveys of the 1000 Islands Parkway in south eastern Ontario during 2010 and 2011. These data were grouped with similar data collected in 2008 and 2009 to determine when and where animals were killed along the Parkway to better inform mitigation options. Temporal and spatial clustering was significant for five taxonomic groups: snakes were found dead on the road primarily in September, turtles in June, frogs in July, and birds and mammals in June and July. The majority of turtles found on the Parkway were adult females, which may have implications for long-term population demographics and persistence. Regression tree analysis indicates day-of-year as the most important variable in explaining wildlife road mortality for all taxonomic groups, with higher road mortalities coinciding with higher minimum daily temperature. Precipitation and traffic accounted for little variation in snake road mortality, and had no effect on turtle, frog, bird or mammal road kills. Spatial clustering was found for all taxonomic groups with overlapping areas of significant clustering between years identified as hot spots. In addition, the potential for drainage culverts to reduce wildlife road mortality was tested with two experimental treatments in 2010: (1) blocked culverts to prevent wildlife use, and (2) drift fence installation adjacent to culverts to encourage wildlife use. Wildlife road mortalities at these locations as well as control culverts were compared with 2008 wildlife road mortalities when there were no culvert treatments. The number of road kills in the area of treatments was too low to measure changes for all taxa but frogs, which showed no significant changes in road kills for any culvert treatment. The results of the study are used to evaluate a list of potential options for mitigating wildlife road mortality along the Parkway, and a list of implementable actions is identified. / Thesis (Master, Environmental Studies) -- Queen's University, 2012-05-31 16:33:51.623

No description available.

The effect of potassium silicate fortified with cow manure compost tea and seaweed extract on dollar spot (Sclerotinia homoeocarpa) was studied in creeping bentgrass (Agrostis stolonifera L.) and perennial ryegrass (Lolium perene L.). Application of potassium silicate fortified compost tea increased the silicon content in bentgrass and ryegrass at 5 days after treatment, but there was only a minimal effect on silicon content in the grass at 15 days after treatment. However, the fortified treatments did not affect the susceptibility of grass to dollar spot disease in the greenhouse experiments. Fortified treatments did not have a significant effect on the chlorophyll content, total phenol content and phenylalanine ammonia lyase activity in creeping bentgrass. Similarly, the treatment did not affect area of the lesion and mycelial growth of the fungus. Although the synergistic effect of silica fortification was not investigated in detail, preliminary results of the study indicate potassium silicate fortified with compost tea or seaweed extract was not different from that of non-fortified treatments in reducing dollar spot disease in the greenhouse trial.

British Columbia salmon aquaculture operations use the chemotherapeutant emamectin benzoate (EMB trade name SLICE®), a synthesized avermectin compound, delivered through feed to decrease sea lice (Lepeophtheirus salmonis) parasite abundance on production fish. Avermectins bind to ion channels in crustaceans and disrupts nerve impulse transmission. Detectable amounts of EMB can accumulate in the depositional area around farms during SLICE® treatment periods, thus presenting potential for exposure to populations of proximate non-target species. The distribution of spot prawn (Pandalus platyceros), an economically important crustacean, overlaps with areas of intensive salmon farm activity. The primary objective of this research was to determine if EMB exposure had a measurable biological effect on spot prawns in the field and in the laboratory. The field component was conducted in the Broughton Archipelago, BC, to determine if emamectin benzoate residues could be detected near actively treating salmon farms, and whether farm proximity affected spot prawn size distribution. Three laboratory experiments tested the mortality, molting and behavioural response of spot prawns to SLICE® feed pellet exposure and acute exposure to EMB through sediment over ten, 30 and 45-day durations. Measurable amounts of EMB was detected in the marine sediment near five farm sites during the field survey and was found to persist between treatment periods. Male and transitional stage spot prawns captured near farm sites attained a greater size and had better body condition compared to reference sites, indicating prawns may benefit from direct or indirect farm food subsidies. However, at several farm sites the size distribution of prawns changed over the sampling period, a trend not observed at reference sites, demonstrating that farm activity may alter prawn population dynamics. Laboratory results indicated that only prawns that had been starved prior to exposure would initially consume SLICE® pellets, but feeding rates declined with subsequent exposures. Depressed consumption rates was not a residual effect of EMB, but rather an aversion to the SLICE® pellet diet as prawns resumed feeding when offered a preferred diet. Sediment EMB exposures to doses 808 µg kg-1 and greater increased prawn mortality, largely due to the inability of molting individuals to successfully complete ecdysis. Exposed individuals accumulated EMB in their abdomen tissue with levels increasing with exposure dose. Prawns exposed to EMB through sediment at concentrations 1419 and 3330 µg kg-1 displayed a significant reduction in olfactory detection and orientation behaviours to food stimuli. This research highlights that spot prawns may avoid SLICE® pellets for preferential food sources, and that only short term EMB exposure 50 to 200 magnitude greater than levels present in the marine environment elicited a measurable response in spot prawn mortality rates, molting success and behaviour. However, preliminary trends in the field survey data indicate that there may be population differences occurring in spot prawns inhabiting areas near treating salmon farms that are not observed in reference populations. These results signify the inherent pitfalls in current management policy that base decisions on short-term acute toxicity laboratory exposure results that may not be indicative of the response of marine populations near active salmon farms to long-term chronic EMB exposure. / Graduate / 0792 / 0329 / 0768

A scanning reference electrode technique (SRET) apparatus has been designed and commissioned to investigate the corrosion of friction stir spot welds (FSSW) made in AZ31 magnesium alloys. The operational parameters of the apparatus have been calibrated to give good spatial resolution. By combining the SRET data with material flow data and immersion test data it was found that the FSSW process caused the formation of distinct noble and active regimes within the weld area. The noble region was aligned with the stir zone (SZ) and was caused by a dynamically recrystallized grain structure which is void of dislocations / twins, and β Mg17Al12. Localized corrosion attack was observed in both SRET and immersion testing along the thermo-mechanically affected zone (TMAZ). The same effect was consistently observed with a flat versus concave shoulder tool, and dwell times of 1s and 4s.

A scanning reference electrode technique (SRET) apparatus has been designed and commissioned to investigate the corrosion of friction stir spot welds (FSSW) made in AZ31 magnesium alloys. The operational parameters of the apparatus have been calibrated to give good spatial resolution. By combining the SRET data with material flow data and immersion test data it was found that the FSSW process caused the formation of distinct noble and active regimes within the weld area. The noble region was aligned with the stir zone (SZ) and was caused by a dynamically recrystallized grain structure which is void of dislocations / twins, and β Mg17Al12. Localized corrosion attack was observed in both SRET and immersion testing along the thermo-mechanically affected zone (TMAZ). The same effect was consistently observed with a flat versus concave shoulder tool, and dwell times of 1s and 4s.

Resistance spot welding is used frequently as a successful joining method for a variety of work commonly in automotive and other manufacturing processes. Spot weld nugget is generally hidden between two sheets, causing its inspection difficult and expensive. Undersized nuggets, brittle or cracked nuggets, and excessive indentation of electrodes reveals the lack of fusion between the parts that can make the weld sub-standard. Visual inspection, pry testing and physical teardown with chisel and hammer method or a combination of them are being used traditionally. However, this study presents a more effective nondestructive inspection method based upon an ultrasonic pulse-echo technique. The theory of the technique together with the experimental verification are presented and its advantages over the other destructive and nondestructive techniques are considered.

The fungal pathogen Bipolaris sorokiniana (teleomorph Cochliobolus sativus)causes the foliar disease spot blotch (SB) and the root disease common root rot (CRR). Spot blotch and CRR are serious disease constraints to barley production in warmer growing regions of the world, with estimated yield losses ranging from 30-70% from SB and 15-30% for CRR. Although chemical treatments may assist incontrolling spot blotch infections, the most effective and environmentally sound means of control for each disease is breeding for varieties with natural resistance. InAustralia, no commercially available varieties offer resistance to either SB or CRR. This study has sought to establish molecular markers that will be useful for selecting for resistance to each of these important fungal diseases.Barley cultivars derived from the breeding line NDB112 have provided durable SB resistance in the North Dakota region of the USA for over 40 years. The robustnessof this resistance had not been determined under Australian environmental conditions or with those B. sorokiniana pathotypes present within Australia. Toelucidate the genetics of resistance, two seedling and two field trials were conducted on an ND11231-12/VB9524 (ND/VB) doubled haploid (DH) population (180 lines).A molecular map of the ND/VB population was curated in order to provide a firm basis for mapping of resistance loci. Composite interval mapping revealed thatdifferent gene combinations are effective at different stages of plant development. Seedling resistance was found to be conditioned by a major locus on the short arm ofchromosome 7H and this region was validated in the related population ND11231-11/WI2875*17. A minor quantitative locus on chromosome 5HS was detected in one of the two seedling trials. However, this region requires further investigation to confirm its association to SB resistance in this population. Field resistance to SB in adult plants was found to be associated with two major quantitative trait loci (QTL)on chromosomes 7HS and 3HS; and a putative third minor QTL on chromosome 2HS. The 7H region is common between seedling and field resistance and is the most important locus for the expression of resistance at both stages of plant development. These findings largely concur with genetic studies of this trait in tworowed barley germplasm in North American environments.Common root rot is a difficult disease to phenotype for, and breeding programs will benefit from the identification of molecular markers linked to resistance. Data wasprovided from field trials of subsets of the population over four years. Using a novel approach combining the efficiency of bulked-segregant analysis with highthroughputDiversity Arrays Technology markers (BSA-DArT), CRR resistance was found to be conditioned by three putative QTL in an unmapped Delta/Lindwall population. QTL were identified on chromosomes 2HS, 4HS, and 7HS. To validatethe trait-linkage associations between the DArT markers and the CRR QTL,microsatellite (SSR) markers known to map to the regions identified by BSA-DArT were used. The 2H and 4H regions were validated using marker regression of the SSR markers in most seedling trials, whereas the 7H QTL, which is proximal to the location of the SB resistance QTL in the ND/VB population, was detected in only one seedling trial.The QTL identified in this study offer potential to combat the foliar and root diseases causes by this fungal pathogen. The chromosomal location of QTL for SB and CRR resistance have been found to differ in the ND/VB and D/L populations,which suggests that resistance to each disease is independently inherited. Further research is required to confirm the hypothesis that it is possible to combineresistance to both diseases into a single genotype. Such allelic combinations would provide elite germplasm that would benefit barley breeding programs world-wide.

University, Diss., 2001--München.

University, Diss., 2004--Bremen.