The effects of temperature on nickel tocicity in goldfish (carassius auratus L.)

Although it is widely assumed that temperature affects pollutant toxicity, few studies have actually investigated this relationship. Moreover, such research as has been done has involved constant temperatures; circumstances which are rarely, if ever, actually experienced by north temperate, littoral zone cyprinid species. To investigate the effects of temperature regime on nickel toxicity in goldfish (Carassius auratus L.), 96- and 240-h LCSO values for the heavy metal pollutant, nickel (NiCI2.6H20), were initially determined at 2DoC (22.8 mg/L and 14.7 mg/L in artificially softened water). Constant temperature bioassays at 10°C, 20°C and 30°C were conducted at each of 0, 240-h and 96-h LCSO nickel concentrations for 240 hours. In order to determine the effects of temperature variation during nickel exposure it was imperative that the effects of a single temperature change be investigated before addressing more complex regimes. Single temperature changes of + 10°C or -10°C were imposed at rates of 2°C/h following exposures of between 24 hand 216 h. The effects of a single temperature change on mortality, and duration of toxicant exposure at high and low temperatures were evaluated. The effects of fluctuating temperatures during exposure were investigated through two regimes. The first set of bioassays imposed a sinewave diurnal cycle temperature (20.±.1DOC) throughout the 10 day exposure to 240-h LeSO Ni. The second set of investigations approximated cyprinid movement through the littoral zone by imposing directionally random temperature changes (±2°C at 2-h intervals), between extremes of 10° and 30°C, at 240-h LC50 Ni. Body size (i.e., total length, fork length, and weight) and exposure time were recorded for all fish mortalities. Cumulative mortality curves under constant temperature regimes indicated significantly higher mortality as temperature and nickel concentration were increased. At 1DOC no significant differences in mortality curves were evident in relation to low and high nickel test concentrations (Le., 16 mg/L and 20 mg/L). However at 20°C and 30°C significantly higher mortality was experienced in animals exposed to 20 mg/L Ni. Mortality at constant 10°C was significantly lower than at 30°C with 16 mg/L and was significantly loWer than each of 2DoC and 39°C tanks at 20 mg/L Ni exposure. A single temperature shift from 20°C to 1DoC resulted in a significant decrease in mortality rate and conversely, a single temperature shift from 20°C to 30°C resulted in a significant increase in mortality rate. Rates of mortality recorded during these single temperature shift assays were significantly different from mortality rates obtained under constant temperature assay conditions. Increased Ni exposure duration at higher temperatures resulted in highest mortality. Diurnally cycling temperature bioassays produced cumulative mortality curves approximating constant 20°C curves, with increased mortality evident after peaks in the temperature cycle. Randomly fluctuating temperature regime mortality curves also resembled constant 20°C tanks with mortalities after high temperature exposures (25°C - 30°C). Some test animals survived in all assays with the exception of the 30°C assays, with highest survival associated with low temperature and low Ni concentration. Post-exposure mortality occurred most frequently in individuals which had experienced high Ni concentrations and high temperatures during assays. Additional temperature stress imposed 2 - 12 weeks post exposure resulted in a single death out of 116 individuals suggesting that survivors are capable of surviving subsequent temperature stresses. These investigations suggest that temperature significantly and markedly affects acute nickel toxicity under both constant and fluctuating temperature regimes and plays a role in post exposure mortality and subsequent stress response.

Diversity among bacteria causing blotch disease on the commercial mushroom, agaricus bisporus /

A total of 251 bacterial isolates were isolated from blotched mushroom samples obtained from various mushroom farms in Canada. Out of 251 stored isolates, 170 isolates were tested for pathogenicity on Agaricus bisporus through mushroom rapid pitting test with three distinct pathotypes observed: dark brown, brovm and yellow/yellow-brown blotch. Phenotypic analysis of 83 isolates showed two distinct proteinase K resistant peptide profiles. Profile group A isolates exhibited peptides with masses of 45, 18, 16 and 14 kDa and fiirther biochemical tests identified them as Pseudomonasfluorescens III and V. Profile group B isolates lacked the 16-kDa peptide and the blotch causing bacterial isolates of this group was identified as Serratia liquefaciens and Cedecea davisae. Comparative genetic analysis using Amplified Fragment Length Polymorphism (AFLP) on 50 Pseudomonas sp. isolates (Group A) showed that various blotch symptoms were caused by isolates distributed throughout the Pseudomonas sp. clusters with the exception of the Pseudomonas tolaasii group and one non-pathogenic Pseudomonas fluorescens cluster. These results show that seven distinct Pseudomonas sp. genotypes (genetic clusters) have the ability to cause various symptoms of blotch and that AFLP can discriminate blotch causing from non-blotch causing Pseudomonasfluorescens. Therefore, a complex of diverse bacterial organisms causes bacterial blotch disease

Electrophysiological and behavioural correlates of facial identity and expression perception deficits following a closed head injury /

A large variety of social signals, such as facial expression and body language, are conveyed in everyday interactions and an accurate perception and interpretation of these social cues is necessary in order for reciprocal social interactions to take place successfully and efficiently. The present study was conducted to determine whether impairments in social functioning that are commonly observed following a closed head injury, could at least be partially attributable to disruption in the ability to appreciate social cues. More specifically, an attempt was made to determine whether face processing deficits following a closed head injury (CHI) coincide with changes in electrophysiological responsivity to the presentation of facial stimuli. A number of event-related potentials (ERPs) that have been linked specifically to various aspects of visual processing were examined. These included the N170, an index of structural encoding ability, the N400, an index of the ability to detect differences in serially presented stimuli, and the Late Positivity (LP), an index of the sensitivity to affective content in visually-presented stimuli. Electrophysiological responses were recorded while participants with and without a closed head injury were presented with pairs of faces delivered in a rapid sequence and asked to compare them on the basis of whether they matched with respect to identity or emotion. Other behavioural measures of identity and emotion recognition were also employed, along with a small battery of standard neuropsychological tests used to determine general levels of cognitive impairment. Participants in the CHI group were impaired in a number of cognitive domains that are commonly affected following a brain injury. These impairments included reduced efficiency in various aspects of encoding verbal information into memory, general slower rate of information processing, decreased sensitivity to smell, and greater difficulty in the regulation of emotion and a limited awareness of this impairment. Impairments in face and emotion processing were clearly evident in the CHI group. However, despite these impairments in face processing, there were no significant differences between groups in the electrophysiological components examined. The only exception was a trend indicating delayed N170 peak latencies in the CHI group (p = .09), which may reflect inefficient structural encoding processes. In addition, group differences were noted in the region of the N100, thought to reflect very early selective attention. It is possible, then, that facial expression and identity processing deficits following CHI are secondary to (or exacerbated by) an underlying disruption of very early attentional processes. Alternately the difficulty may arise in the later cognitive stages involved in the interpretation of the relevant visual information. However, the present data do not allow these alternatives to be distinguished. Nonetheless, it was clearly evident that individuals with CHI are more likely than controls to make face processing errors, particularly for the more difficult to discriminate negative emotions. Those working with individuals who have sustained a head injury should be alerted to this potential source of social monitoring difficulties which is often observed as part of the sequelae following a CHI.

Learning styles and achievement in postsecondary classrooms

The purpose of this study was to investigate the relationship between learning styles and academic achievement in postsecondary education. It was the intent of the study to establish if there was a relationship between student learning style, teacher style, learner/teacher matching and/or mismatching, student gender and age, to the academic grades of students. This study was basically a replication of a study completed by Mary J. Thompson and Terrance P. O'Brien in 1991 on two campuses of a southeast community college in the United States. In the present study, 243 students and 18 teachers from two different campuses of a community college in the Province of Ontario participated in the research. All participants were administered the Gregorc Style Delineator and students identified by program, age and gender. Data were tested by two analysis of variance (ANOVA) models. In the first ANOVA model considered in this study, significant main effects were manifested in regard to the teaching style, age group and gender. With the exception of gender, these findings were very similiar to those of the original study. Duncan's multiple range test revealed that Concrete Sequential (CS) teachers assigned significantly lower grades than did teachers dominant in any of the other three learning styles. Post hoc testing revealed that students 25 years of age and older received significantly higher grades than did younger students. Female students also received significantly higher grades than did male students. In the second ANOVA model student/teacher learning style match/mismatch did emerge as a significant main effect. However, Duncan's multiple range test and Chi square analysis did not substantiate the relationship. Forty-eight references are cited.

Orientation of Non-Native 2-Monosubstituted and 2,3-Disubstituted 1,4-Naphthoquinones in the A1 binding site of PSI and the effect on the rate of electron transfer : an electron paramagnetic resonance spectroscopy study

The proce-ss ofoxygenic photosynthesis is vital to life on Earth. the central event in photosynthesis is light induced electron transfer that converts light into energy for growth. Ofparticular significance is the membrane bound multisubunit protein known as Photosystem I (PSI). PSI is a reaction centre that is responsible for the transfer of electrons across the membrane to reduce NADP+ to NADPH. The recent publication ofa high resolution X-ray structure of PSI has shown new information about the structure, in particular the electron transfer cofactors, which allows us to study it in more detail. In PSI, the secondary acceptor is crucial for forward electron transfer. In this thesis, the effect of removing the native acceptor phylloquinone and replacing it with a series of structurally related quinones was investigated via transient electron paramagnetic resonance (EPR) experiments. The orientation of non native quinones in the binding site and their ability to function in the electron transfer process was determined. It was found that PSI will readily accept alkyl naphthoquinones and anthraquinone. Q band EPR experiments revealed that the non-native quinones are incorporated into the binding site with the same orientation of the headgroup as in the native system. X band EPR spectra and deuteration experiments indicate that monosubstituted naphthoquinones are bound to the Al site with their side group in the position occupied by the methyl group in native PSI (meta to the hydrogen bonded carbonyl oxygen). X band EPR experiments show that 2, 3- disubstituted methyl naphthoquinones are also incorporated into the Al site in the same orientation as phylloquinone, even with the presence of a halogen- or sulfur-containing side chain in the position normally occupied by the phytyl tail ofphylloquinone. The exception to this is 2-bromo-3-methyl --.- _. -. - -- - - 4 _._ _ _ - _ _ naphthoquinone which has a poorly resolved spectrum, making determination of the orientation difficuh. All of the non-native quinones studied act as efficient electron acceptors. However, forward electron transfer past the quinone could only be demonstrated for anthraquinone, which has a more negative midpoint potential than phylloquinone. In the case of anthraquinone, an increased rate of forward electron transfer compared to native PSI was found. From these results we can conclude that the rate ofelectron transfer from Al to Fx in native PSI lies in the normal region ofthe Marcus Curve.

Investigation of motivation strategies used by school teachers for workplace engagement

The purpose of this study was to explore the strategies that elementary school teachers use to be engaged in their work. Participation was solicited from a random sample of schools stratified by location (i.e., urban, inner city, and rural) of a large school board. The study used an anonymous quantitative/qualitative questionnaire. The survey tool was based upon Kahn's (1990) psychological engagement framework, which presents the foundation of availability of self, meaningfulness of work, and safety while at work. Forty-one surveys were analyzed descriptively including a subgroup of self-rated highly engaged teachers. Teachers tended to favour physical and emotional strategies compared to cognitive type strategies, with the exception of the highly engaged subgroup. The theme of preferred strategies reflected a setting outside the school/workplace, that is, a preference for horne based strategies. The study's main contribution highlights the teachers' sense of importance for physical and emotional health in a profession that is heavily focused in the cognitive domain. This may influence administrative and teacher discourse regarding workplace engagement with strategies to help reduce stress and to maintain and increase teacher engagement.

EXPLORING THE DEVELOPMENT AND PSYCHOSOCIAL CORRELATES OF SPIRITUALITY /RELIGIOSITY ACROSS ADOLESCENCE

The goal of the four studies that comprised this dissertation was to examine how spirituality/religiosity (SIR), as both an institutional and personal phenomenon, developed over time, and how its institutional (i.e., religious activity involvement) and personal (i.e., sense of connection with the sacred) components were uniquely linked with psychosocial adjustment. In Study 1, the differential longitudinal correlates of religious service attendance, as compared to involvement in other clubs, were evaluated with a sample of adolescents (n=1050) who completed a survey in grades 9, 11 and 12. Religious attendance and involvement in non-religious clubs were uniquely associated with positive adjustment in terms of lower substance use and better academic marks, particularly when involvement was sustained over time. In Study 2, the direction of effects was tested for the association between religious versus non-religious activities and both substance use and academic marks. Participants (n= 3993) were surveyed in grades 9 through 12. Higher religious attendance (but not non-religious club involvement) in one grade predicted lower levels of substance use in the next grade. Higher levels of nonreligious club involvement (but not religious service attendance) in one grade predicted higher academic achievement in the next grade, and higher academic achievement in one grade predicted more frequent non-religious club involvement in the next grade. The results suggest that different assets may be fostered in religious as compared to nonreligious activities, and, specifically, religious activity involvement may be important for the avoidance of substance use. The goal of Study 3 was to assess the unique associations between the institutional versus personal dimensions of SIR and a wide range of domains of psychosocial adjustment (namely, intrapersonal well-being, substance use, risk attitudes, parental relationship quality, academic orientation, and club involvement), and to examine the direction of effects in these associations. Participants (n=756) completed a survey in grades 11 and 12. Personal and institutional dimensions of SIR were differentially associated with adjustment, but it may only be in the domain of risk-taking (Le., risk attitudes, substance use) that SIR may predict positive adjustment over time. Finally, in Study 4, the goal was to examine how institutional and personal aspects of SIR developed within individual adolescents. Configurations of mUltiple dimensions of spirituality/religiosity were identified across 2 time points with an empirical classification procedure (cluster analysis), and sample- and individual-level development in these configurations were assessed. A five cluster-solution was optimal at both grades. Clusters were identified as aspirituallirreligious, disconnected wonderers, high institutional and personal, primarily personal, and meditators. With the exception of the high institutional and personal cluster, the cluster structures were stable over time. There also was significant intraindividual stability in all clusters over time; however, a significant proportion of individuals classified as high institutional and personal in Grade 11 moved into the primarily personal cluster in Grade 12. This program of research represented an important step towards addressing some of the limitations within the body of literature; namely, the uniqueness of religious activity involvement as a structured club, the differential link between institutional versus personal SIR and psychosocial adjustment, the direction of effects in the associations between institutional versus personal SIR and adjustment, and the way in which different dimensions of SIR may be configured and develop within individual adolescents over time.

Plant rhizosphere specificity and variability in the insect and plant adhesins, Madl and Mad2, within the genus Metarhizium suggest plant adaptation as an evolutionary force

Metarhizium is a soil-inhabiting fungus currently used as a biological control agent against various insect species, and research efforts are typically focused on its ability to kill insects. In section 1, we tested the hypothesis that species of Metarhizium are not randomly distributed in soils but show plant rhizosphere-specific associations. Results indicated an association of three Metarhizium species (Metarhizium robertsii, M. brunneum and M. guizhouense) with the rhizosphere of certain types of plant species. M. robertsii was the only species that was found associated with grass roots, suggesting a possible exclusion of M. brunneum and M. guizhouense, which was supported by in vitro experiments with grass root exudate. M. guizhouense and M. brunneum only associated with wildflower rhizosphere when co-occurring with M. robertsii. With the exception of these co-occurrences, M. guizhouense was found to associate exclusively with the rhizosphere of tree species, while M. brunneum was found to associate exclusively with the rhizosphere of shrubs and trees. These associations demonstrate that different species of Metarhizium associate with specific plant types. In section 2, we explored the variation in the insect adhesin, Madl, and the plant adhesin, Mad2, in fourteen isolates of Metarhizium representing seven different species. Analysis of the transcriptional elements within the Mad2 promoter region revealed variable STRE, PDS, degenerative TATA box, and TATA box-like regions. Phylogenetic analysis of 5' EF-Ia, which is used for species identification, as well as Madl and Mad2 sequences demonstrated that the Mad2 phylogeny is more congruent with 5' EF-1a than Madl. This suggests Mad2 has diverged among Metarhizium lineages, contributing to clade- and species-specific variation. While other abiotic and biotic factors cannot be excluded in contributing to divergence, it appears that plant associations have been the driving factor causing divergence among Metarhizium species.

Admiralty Commissioner's Orders, October 13, 1812.

Sir John Thomas Duckworth (1747-1817) served as Governor and Commander-in-Chief of Newfoundland when the United States declared war against Great Britain in 1812. He effectively prepared for the war by reviving and expanding the militia forces, establishing a signal station to warn of the approach of enemy ships, and strengthening the seaward forces. He resigned the post in December 1812 in order to take a parliamentary seat for New Romney, on the Kent coast. Sir William Domett (1752-1828) and Sir Joseph Sydney (1768-1831) were both naval officers and members of the Board of Admiralty when the United States declared war on Great Britain in 1812. Sir George Warrender, 4th Baronet (1782-1849), served as Lord of the Admiralty from 1812-1822, and as a Member of Parliament for various constituencies in Great Britain from 1807-1832. Sir John Barrow (1764-1848) was secretary of the Admiralty from 1804-1845, with the exception of the period from Feb. 1806-April 1807. He is best known for his support and encouragement of British exploration, especially in West Africa and the Arctic.

Assessing the adaptive capacity of the Ontario wine industry to climate change: A case study

The global wine industry is experiencing the impacts of climate change. Canada’s major wine sector, the Ontario Wine Industry (OWI) is no exception to this trend. Warmer winter and summer temperatures are affecting wine production. The industry needs to adapt to these challenges, but their capacity for this is unclear. To date, only a limited number of studies exist regarding the adaptive capacity of the wine industry to climate change. Accordingly, this study developed an adaptive capacity assessment framework for the wine industry. The OWI became the case study for the implementation of the assessment framework. Data was obtained by means of a questionnaire sent to grape growers, winemakers and supporting institutions in Ontario. The results indicated the OWI has adaptive capacity capabilities in financial, institutional, political, technological, perceptions, knowledge, diversity and social capital resources areas. Based on the OWI case study, this framework provides an effective means of assessing regional wine industries’ capacity to adapt to climate change.

James Monroe letter of marque, ca. 1812

James Monroe (1758-1831) was appointed Secretary of State by President James Madison in 1811. He remained in this position until March, 1817, with the exception of the period from October 1, 1814, to February 28, 1815, when he was ad interim Secretary of State. Monroe encouraged President James Madison and Congress to declare war on Great Britain, feeling it would be the most effective way to change offensive British policies. The United States declared war on June 17, 1812, after which he served as Secretary of War. Monroe later became President of the United States from 1817 until 1824.

Predicting Physical, Verbal, Social, Racial, and Sexual Bullying with Individual and Environmental Factors from an Evolutionary Ecological Framework

Evidence exists for subtypes of bullying, but there is a lack of studies simultaneously investigating the factors that influence each subtype. The purpose of my thesis was to investigate how individual and environmental factors independently and interactively predict physical, verbal, social, racial, and sexual bullying using an evolutionary ecological framework. Adolescents (N = 225, M = 14.05, SD = 1.54) completed self-reports on demographics, HEXACO personality, Rothbart’s temperament, parenting, friendship quality, school connectedness, and socio-economic status. Subtypes were predicted by low Honesty-Humility in addition to other personality and demographic factors with the exception of physical bullying, which was predicted by environmental factors. Results suggest adolescents adaptively and selectively use bullying to exploit victims and obtain resources, although the subtype used may depend on individual factors bullies possess within Bronfenbrenner’s microsystem, instead of the meso- and exo- systems. Anti-bullying efforts should target these factors and reinforce alternative strategies to obtain resources.

L'obligation d'accommodement raisonnable et l'adaptation de la société à la diversité religieuse

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Le Code civil des Français de 1804 : une transaction entre révolution et réaction

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L'erreur judiciaire : une démonstration difficile

"Mémoire présenté à la Faculté des études supérieures en vue de l'obtention du grade de Maîtrise en droit (L.L.M.)"