Reproduction in the temperate crayfish, Orconectes rusticus: intermale aggression, copulatary behaviour, and sperm competition

The chelipeds of Orconectes rusticus are sexually dimorphic; males possessing the larger. Males use their chelae in intermale aggressive interactions, both to threaten, and assault opponents. In dyadic interactions males with larger chelae were dominant over otherwise physically similar opponents. A high frequency of attack behaviour, coupled with a low frequency of threats during these interactions indicates that actual physical contact is required for opponent assessment. Large clawed males oriented females into the copulatory position faster than small clawed males. Females more frequently escaped the precopulatory-grasp attempts of small clawed males. Additionally, male-female pairs that included a large clawed male remained in copula longer than pairs that included a small clawed male. Sperm of the second male to mate took precedence over the sperm of the primary male. Sperm precedence was incomplete; about 900/0 paternity accrued to the second male.

The role of learning and growth hormone-releasing factor in the control of protein intake in rats /

Both learning and basic biological mechanisms have been shown to play a role in the control of protein int^e. It has previously been shown that rats can adapt their dietary selection patterns successfully in the face of changing macronutrient requirements and availability. In particular, it has been demonstrated that when access to dietary protein is restricted for a period of time, rats selectively increase their consumption of a proteincontaining diet when it becomes available. Furthermore, it has been shown that animals are able to associate various orosensory cues with a food's nutrient content. In addition to the role that learning plays in food intake, there are also various biological mechanisms that have been shown to be involved in the control of feeding behaviour. Numerous studies have documented that various hormones and neurotransmitter substances mediate food intake. One such hormone is growth hormone-releasing factor (GRF), a peptide that induces the release of growth hormone (GH) from the anterior pituitary gland. Recent research by Vaccarino and Dickson ( 1 994) suggests that GRF may stimulate food intake by acting as a neurotransmitter in the suprachiasmatic nucleus (SCN) and the adjacent medial preoptic area (MPOA). In particular, when GRF is injected directly into the SCN/MPOA, it has been shown to selectively enhance the intake of protein in both fooddeprived and sated rats. Thus, GRF may play a role in activating protein consumption generally, and when animals have a need for protein, GRF may serve to trigger proteinseeking behaviour. Although researchers have separately examined the role of learning and the central mechanisms involved in the control of protein selection, no one has yet attempted to bring together these two lines of study. Thus, the purpose of this study is to join these two parallel lines of research in order to further our understanding of mechanisms controlling protein selection. In order to ascertain the combined effects that GRF and learning have on protein intake several hypothesis were examined. One major hypothesis was that rats would successfully alter their dietary selection patterns in response to protein restriction. It was speculated that rats kept on a nutritionally complete maintenance diet (NCMD) would consume equal amount of the intermittently presented high protein conditioning diet (HPCD) and protein-free conditioning diet (PFCD). However, it was hypothesized that rats kept on a protein-free maintenance diet (PFMD) would selectively increase their intake of the HPCD. Another hypothesis was that rats would learn to associate a distinct marker flavour with the nutritional content of the diets. If an animal is able to make the association between a marker flavour and the nutrient content of the food, then it is hypothesized that they will consume more of a mixed diet (equal portion HPCD and PFCD) with the marker flavour that was previously paired with the HPCD (Mixednp-f) when kept on the PFMD. In addition, it was hypothesized that intracranial injection of GRF into the SCN/MPOA would result in a selective increase in HPCD as well as Mixednp-t consumption. Results demonstrated that rats did in fact selectively increase their consumption of the flavoured HPCD and Mixednp-f when kept on the NCMD. These findings indicate that the rats successfully learned about the nutrient content of the conditioning diets and were able to associate a distinct marker flavour with the nutrient content of the diets. However, the results failed to support previous findings that GRF increases protein intake. In contrast, the administration of GRF significantly reduced consumption of HPCD during the first hour of testing as compared to the no injection condition. In addition, no differences in the intake of the HPCD were found between the GRF and vehicle condition. Because GRF did not selectively increase HPCD consumption, it was not surprising that GRF also did not increase MixedHP-rintake. What was interesting was that administration of GRF and vehicle did not reduc^Mixednp-f consumption as it had decreased HPCD consumption.

Books on the border land : a Mennonite woman's memoir of reading and remembering the sacred

This arts-based thesis, written from my perspective as a Manitoba Mennonite woman and English Language Arts educator, is a memoir of books and reading. As a voracious reader, I am dismayed by the general perception of literacy in public schools as being a set of measureable tasks, and I have found that reading, in particular, has become divorced from its traditional link to life-giving and sacred things. In this thesis, I used life writing to share some of my reading history to illustrate, in part, the degree to which books may enrich our lives by helping us understand the past, present, and future - but only if we allow them to do so.

The development of norm-based coding and category-specific face prototypes : an examination of 5- and 8-year-olds' face space

The present set of experiments was designed to investigate the organization and refmement of young children's face space. Past research has demonstrated that adults encode individual faces in reference to a distinct face prototype that represents the average of all faces ever encountered. The prototype is not a static abstracted norm but rather a malleable face average that is continuously updated by experience (Valentine, 1991); for example, following prolonged viewing of faces with compressed features (a technique referred to as adaptation), adults rate similarly distorted faces as more normal and more attractive (simple attractiveness aftereffects). Recent studies have shown that adults possess category-specific face prototypes (e.g., based on race, sex). After viewing faces from two categories (e.g., Caucasian/Chinese) that are distorted in opposite directions, adults' attractiveness ratings simultaneously shift in opposite directions (opposing aftereffects). The current series of studies used a child-friendly method to examine whether, like adults, 5- and 8-year-old children show evidence for category-contingent opposing aftereffects. Participants were shown a computerized storybook in which Caucasian and Chinese children's faces were distorted in opposite directions (expanded and compressed). Both before and after adaptation (i.e., reading the storybook), participants judged the normality/attractiveness of a small number of expanded, compressed, and undistorted Caucasian and Chinese faces. The method was first validated by testing adults (Experiment I ) and was then refined in order to test 8- (Experiment 2) and 5-yearold (Experiment 4a) children. Five-year-olds (our youngest age group) were also tested in a simple aftereffects paradigm (Experiment 3) and with male and female faces distorted in opposite directions (Experiment 4b). The current research is the first to demonstrate evidence for simple attractiveness aftereffects in children as young as 5, thereby indicating that similar to adults, 5-year-olds utilize norm-based coding. Furthermore, this research provides evidence for racecontingent opposing aftereffects in both 5- and 8-year-olds; however, the opposing aftereffects demonstrated by 5-year-olds were driven largely by simple aftereffects for Caucasian faces. The lack of simple aftereffects for Chinese faces in 5-year-olds may be reflective of young children's limited experience with other-race faces and suggests that children's face space undergoes a period of increasing differentiation over time with respect to race. Lastly, we found no evidence for sex -contingent opposing aftereffects in 5-year-olds, which suggests that young children do not rely on a fully adult-like face space even for highly salient face categories (i.e., male/female) with which they have comparable levels of experience.

An examination of the role of personality and self-regulation in the gambling behaviours of late adolescents and emerging adults

The purposes of this study were: a) to examine the role of personality and selfregulation in the gambling behaviour participation of late adolescents and emerging adults. In particular, the present study examined i f certain personality traits were more prevalent in high-risk gamblers than in young people considered low or at-risk gamblers; and, b) to examine i f the ability to self-regulate helped distinguish differences among the three groups of gamblers (low-risk, at-risk, and high-risk gamblers). A sample of late adolescents and emerging adults (N = 100) attending Brock University, completed a survey that assessed current gambling behaviour (both frequency and consequence experience), personality, self-esteem, and self-regulation. It was found that high-risk gamblers had lower scores on the personality dimensions Emotionality, Conscientiousness (especially on its Prudence facet), and Honesty-Humility (especially on its Fairness, Greed Avoidance, and Modesty facets) than at-risk or low-risk gamblers and higher scores on impulsive sensation seeking and impulsivity than at-risk or low-risk gamblers. Similarly, high-risk gamblers reported lower levels of self-regulation than both at-risk and low-risk gamblers. The findings from this study support past research which suggests that young people who gamble at problematic levels differ on many personality traits and often have more difficulty self-regulating than young people who do not participate at problematic levels. Findings may aid in the development of intervention and prevention programs that utilize specific self-regulation techniques with a young gambling population.

Educator Evaluation of Academic and Social Competence in Students with Acquired Brain Injury (ABI) Relative to Assessed Performance and Sense of Belonging

Acquired brain injury (ABI) is the leading cause of death and disability amongst children and adolescents andpresents itself with challenges associated in cognitive, social, emotional, and behavioural domains. These changes may interfere with academic performance and social inclusion, influencing self-esteem and personal success. The current study examined a subset of data to capture the sense of academic and social belonging for students with ABI as a function of the classroom teachers’ subjective perception of ability, their ABI knowledge, and student identification. Overall, a discrepancy was found between educators’ subjective ratings of student performance and students’ neurocognitive capacity. Educator knowledge and identification of ABI influenced student success in academic and social domains independent of teaching approach. This research has implications for the identification of ABI in the classroom and related challenges students experience. Educators are underprepared for the reintegration of students returning to school and lack appropriate knowledge and strategies to accommodate individual needs.

The Relationship Between Youth Risk-Taking Behaviour and Activity Engagement

Youth have been found to engage in various risk-taking behaviours at higher rates than any other age group. However, there is a lack of research on the division between adaptive and maladaptive risk behaviours among adolescents and emerging adults. Adaptive risk-taking behaviours may present youth with ways to successfully partake in the risk behaviours that they are naturally inclined to engage in. The relationship between activity engagement and positive youth development has been extensively studied and cited as a way to expose youth to positive experiences and promote successful development. However, the relationship between activity engagement and risk behaviours among youth has yetto be studied in depth. This study investigated the potential relationship between various adaptive and maladaptive risk behaviours and activity engagement among youth, through an indirect link through five mediator variables. These potential mediators represented the three systems in Jessor's Problem Behaviour Theory. Participants included 276 youth (M = 19.06 years, SD = 1.60, 89.1 % female) from Brock University. Results revealed that activity engagement significantly predicted greater adaptive social risk behaviours among youth. However, there was no mediating effect through the problem behaviour systems. Correlations revealed that being male was associated with more maladaptive risk behaviours and fewer adaptive risk behaviours than females. Additionally, behavioural engagement specifically related to less maladaptive physical health risks and psychological engagement related to greater adaptive social risks. Overall, these findings suggest that activity engagement may be differentially related to the various types of risk-taking and gender associations may exist between the various types and dimensions of risk behaviours, but future work is needed to understand the variables that may explain such relationships.

Psychopathic Traits and Endocrine Function as Predictors of Costly and Non-Costly Reactive Aggression

I investigated factors of psychopathy (fearless dominance, self-centered impulsivity) and hormones (testosterone, cortisol, estradiol) in predicting costly and non-costly reactive aggression. I hypothesized that whereas self-centred impulsivity (SCI) would promote costly aggression, fearless dominance (FD) would promote non-costly aggression. Costly aggression was measured using the Point Subtraction Aggression Paradigm and noncostly aggression was measured using one-shot dictator games. In women (n = 97; M age = 19.86 years), greater SCI and lower baseline estradiol predicted greater costly aggression; also, greater FD predicted greater non-costly aggression, particularly among women with lower SCI. In men (n = 104; M age = 20.15 years), psychopathy and endocrine function did not predict costly aggression; however, greater FD and greater increases in testosterone were associated with greater non-costly aggression. Thus, there are sex-specific links between psychopathic personality traits, hormones, and aggressive behaviour, and psychopathic traits and endocrine function predict aggressive behaviour independently of each other.

Comparing motives, goals and weight training behaviours of competitive and recreational weight trainers: An application of organismic integration theory and goal contents theory

The study purpose was to examine differences between competitive and recreational weight trainers on indices of motivation, goals and behaviour. Data was collected from a purposive sample of competitive (n = 177; Mage = 30.86; SDage = 11.35) and recreational (n = 196; Mage = 21.97; SDage = 6.05) weight trainers using a cross-sectional, non-experimental design. Participants completed the Behavioural Regulation in Exercise Questionnaire-2R, Exercise Motivations Inventory-2, assessment of weight training behaviour and demographic questions. Multivariate analyses of variance indicated higher endorsement of autonomous motives and mostly intrinsically-oriented goals, while independent samples t-tests indicated higher frequency of weight training behaviour among the competitive weight trainers. Group differences were independent of demographic factors. Findings suggest that autonomous motives and intrinsic goals may not be undermined by competition among competitive weight trainers. This study also provides support for the utility of organismic integration theory and goal contents theory in examining strength-based exercise.

Investigating Microbial Trace-fossils and Abiotic Alteration in Hydrovolcanic Tuffs of the Fort Rock Volcanic Field, Oregon

Microbial ichnofossils in volcanic rocks provide a significant record of subsurface microbes and potentially extraterrestrial biosignatures. Here, the textures, mineralogy, and geochemistry of two continental basaltic hydrovolcanic deposits - Reed Rocks and Black Hills - in the Fort Rock Volcanic Field (FRVF) are investigated. Methods include petrographic microscopy, micro and powder X-ray diffraction, SEM/BSE/EDF imaging, energy dispersive spectroscopy, stable isotopes, and X-ray fluorescence. Petrographic analysis revealed granular and tubular textures with biogenic morphologies that include terminal enlargements, septate divisions, branching forms, spiral filaments, and ovoid bodies resembling endolithic microborings described in ocean basalts. They display evidence of behaviour and a geologic context expressing their relative age and syngenicity. Differences in abiotic alteration and the abundance/morphotype assemblage of putative microborings between the sites indicate that water/rock ratio, fluid composition and flux, temperature and secondary phase formation are influences on microboring formation. This study is the first report of reputed endolithic microborings in basalts erupted in a continental lacustrine setting.

Investigating the Contribution of Personality and Neurological Disruption to Postinjury Outcome in Athletes with Mild Head Injury

Despite the increase in research regarding mild head injury (MHI), relatively little has investigated whether, or the extent to which, premorbid factors (i.e., personality traits) influence, or otherwise account for, outcomes post-MHI. The current study examined the extent to which postinjury outcome after MHI is analogous to the outcome post-moderate or- severe traumatic brain injury (by comparing the current results to previous literature pertaining to individuals with more severe brain injuries) and whether these changes in function and behaviour are solely, or primarily, due to the injury, or reflect, and are possibly a consequence of, one’s preinjury status. In a quasi-experimental, test-retest design, physiological indices, cognitive abilities, and personality characteristics of university students were measured. Since the incidence of MHI is elevated in high-risk activities (including high-risk sports, compared to other etiologies of MHI; see Laker, 2011) and it has been found that high-risk athletes present with unique, risk-taking behaviours (in terms of personality; similar to what has been observed post-MHI) compared to low-risk and non-athletes. Seventy-seven individuals (42% with a history of MHI) of various athletic statuses (non-athletes, low-risk athletes, and high-risk athletes) were recruited. Consistent with earlier studies (e.g., Baker & Good, 2014), it was found that individuals with a history of MHI displayed decreased physiological arousal (i.e., electrodermal activation) and, also, endorsed elevated levels of sensation seeking and physical/reactive aggression compared to individuals without a history of MHI. These traits were directly associated with decreased physiological arousal. Moreover, athletic status did not account for this pattern of performance, since low- and high-risk athletes did not differ in terms of personality characteristics. It was concluded that changes in behaviour post-MHI are associated, at least in part, with the neurological and physiological compromise of the injury itself (i.e., physiological underarousal and possible subtle OFC dysfunction) above and beyond influences of premorbid characteristics.