The social consequences of mild head injury and executive dysfunction /

Mild head injury (MHI) is a serious cause of neurological impairment as is evident by the substantial percentage (15%) of individuals who remain symptomatic at least 1-year following "mild" head trauma. However, there is a paucity of research investigating the social consequences following a MHI. The first objective of this study was to examine whether measures of executive functioning were predictive of specific forms of antisocial behaviour, such as reactive aggression, impulsive antisocial behaviour, behavioural disinhibition, and deficits in social awareness after controlling for the variance accounted for by sex differences. The second objective was to investigate whether a history of MHI was predictive of these same social consequences after controlling for both sex differences and executive functioning. Ninety university students participated in neuropsychological testing and filled out self-report questionnaires. Fifty-two percent of the sample self-reported experiencing a MHI. As expected, men were more reactively aggressive and antisocial than women. Furthermore, executive dysfunction predicted reactive aggression and impulsive antisocial behaviour after controlling for sex differences. Finally, as expected, MHI status predicted reactive aggression, impulsive antisocial behaviour, and behavioural disinhibition after controlling for sex and executive fimctioning. MHI status and executive functioning did not predict social awareness or sensitivity to reward or punishment. These results suggest that incurring a MHI has serious social consequences that mirror the neurobehavioural profile following severe cases of brain injury. Therefore, the social sequelae after MHI imply a continuum of behavioural deficits between MHI and more severe forms of brain injury.

Comprehensive school health, the social determinants of health, and the health status of children

As children are becoming increasingly inactive and obese, there is an urgent need for effective early prevention and intervention programs. One solution is a comprehensive school health (CSH) program, a health promotion initiative aimed at educating students about healthy behaviours and lifestyles, which also provides a link between the school, students, families, and the surrounding community. The purpose of this study was to explore the relationship between different components of CSH programs, as well as three determinants of health (gender, social support, socio-economic status), and physical activity, on the aerobic fitness and body mass index (BMI) of children. A newly developed and pilot-tested survey derived from Health Canada's fourpart CSH model (instruction, social support, support services, and a healthy physical environment) was sent to elementary school principals. Data on the gender, physical activity, parental education, and social support levels of students from these schools were gathered from a previous study. Multiple regression procedures were conducted to estimate the relationships between CSH components, the social determinants of health, physical activity, and BMI and aerobic fitness. Results showed that three CSH components were significantly associated with both BMI and aerobic fitness values in children, but accounted for less than 5% of the variance in both variables. Physical activity partially mediated the relationship between the significant CSH components, BMI, and particularly aerobic fitness. Furthermore, the social determinant and physical activity variables played independent roles in aerobic fitness values. No moderating effects of the social determinants were discovered.

Construing social dimensions of personality development: nurses as educators

A convenience sample of twenty registered nurses was recruited from two' general hospitals and two community college nursing schools. Kelly's (1955) Personal Construct Theory provided the theoretical framework to discover how nurses perceived themselves as educators. The nurses completed a self-administered Self-Perception Inventory (Soares, 1983) to determine their perception of self as nurse and ideal self as nurse. In an interview, each of the nurses constructed a rank-order repertory grid adapted from Kelly's (1955) Role Repertory Construct Test. Twelve constructs derived from the Self-Perception Inventory (Soares, 1983) were ranked according to a list of ten elements common to a teaching situation. Rank order correlations among the constructs were determined with Spearman's rho. Using a dependent samples t-test, significant differences were found between perceptions of current and ideal self for staff nurses. Significant differences were also found between nurse educators' perceptions of self and ideal self as nurse. No significant differences were determined in perceptions of self as nurse and ideal self as nurse between the staff nurse and nurse educator groups with an independent samples t-test. However, observations of single constructs revealed that although several constructs are shared between the groups in the perception of self in a teaching situation, both groups hold constructs that operate exclusively in their separate domains. The nature and strength of the relationships between the common and unique constructs are different for each group. Nurses I self-perceptions appear to be influenced by the historical development of nursing, role socialization during nursing education, social expectations and gender issues in the health care system.

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.

Social neuroendocrinology of competition

The relationship between testosterone concentrations and aggressive behaviour in studies of people has produced very inconsistent findings. However, one consistent fmding that has emerged is that competitive and aggressive interactions potentiate testosterone release in both human and non-human species. It has been argued that socially-induced alterations in testosterone concentrations may function to influence ongoing and/or future social behaviour. Nonetheless, few studies have empirically tested this hypothesis. The current series of experiments was designed to address the extent to which competitioninduced fluctuations in testosterone concentrations were associated with ongoing and/or subsequent social behaviour. In Study 1, men (n = 38) provided saliva samples prior to, and at the conclusion of, the Point Subtraction Aggression Paradigm (PSAP). Although baseline testosterone concentrations were not related to aggressive behaviour, there was a positive correlation between change in testosterone and aggressive behaviour such that men who were most aggressive on the PSAP demonstrated the largest increase in testosterone concentrations. Furthermore, a rise in testosterone during the PSAP predicted willingness to choose a subsequent competitive task. In Study 2, men and women provided saliva samples prior to and after competing against a same-sex opponent on the Number Tracing Task (NTT). The outcome of the competition was rigged such that half of the individuals won most of the races, while the other half lost most of the races, thus experimentally creating a winner and loser in the laboratory. Following the competitive interaction, men and women played the PSAP with their same-sex partner. Results indicated that men selected the aggressive response (but not reward or protection responses), more frequently than women. For men assigned to the loss condition, an increase in testosterone concentrations in response to the NTT predicted subsequent aggressive behaviour. For men assigned to the win condition, an increase in testosterone concentrations in response to the NTT predicted subsequent aggressive behaviour, but only among those men who scored high on trait dominance. Change in testosterone and trait dominance did not predict aggressive behaviour in women. In Study 3, men provided saliva samples prior to, during, and at the end of the PSAP. They were randomly assigned to one of four experimental conditions that differed in the extent to which they were provoked and whether they received reward for behaving aggressively (i.e., stealing points). Results indicated that baseline testosterone concentrations did not correlate with aggression in any of the experimental conditions. Consistent with Study 1, there was a positive correlation between change in testosterone and aggressive behaviour among men who were provoked, but did not receive reward for aggression (i.e., reactive condition). Men who were provoked but did not receive reward for aggression enjoyed the task the most and were more likely to choose the competitive versus non-competitive task relative to men assigned to the other experimental conditions. Also, individual differences in aggressive behaviour among these men were positively correlated with the extent to which they enjoyed the task. Together, these studies indicate that testosterone dynamics within the context of competition influence subsequent competitive and aggressive behaviours in humans and that testosterone may be a marker of the intrinsically rewarding nature of costly aggressive behaviour.

Social development of primary aged children through a movement education program

Unique in Canada, is a university based movement program offered to children aged 1-12 which is diverse and inclusive in its design to foster healthy physical, cognitive, affective and social development. The purpose of this study is to investigate how children's involvement in a weekly movement education program influences their social development. The primary-aged children involved in this research are participants in the university based Saturday morning program, The Children's Movement Program (CMP), in which creative dance, educational gymnastics and developmental games are employed to enhance optimal development. The 15 participants were systematically observed for 8 weeks as they naturally engaged in the program's activities. Interviews were conducted with both children and their caregivers throughout the duration of the program. Particular attention was paid to the perceptions of caregivers regarding the advantages of a program based upon principles of movement education. Results indicate that participation in the program increases children's opportunity to interact socially and address ways in which program content, pedagogy and context encourage social development. A figure was developed with these components to assist teachers in creating inclusive and meaningful movement experiences. 'Content' is referred to as the material to be learned or the desired outcome for the learner. 'Pedagogy' refers to the process in which the student will engage and 'Context' refers to the environment in which the experience occurs (eg. skating rink with playground balls). It is recommended that each is thoroughly addressed individually for its potential in lesson design.

A Quantitative Study of Social Capital Components, Self-Reported Health Status and Social Determinants of Health

This quantitative descriptive co-relational study used telephone survey interviews and stratified random sampling to collect data related to Social Capital (SC) and its components (trust and safety, reciprocity, civic engagement and collective action) and selected determinants of health variables in Niagara Region, Canada. Among the four components of social capital, trust and safety levels were highest among all participants (m=5.42, SD=1.0), with community engagement yielding the lowest mean score for the sample (m=1.93, SD=.8). Reciprocity had the strongest association with all other components of SC (r=0.51). Those most likely to report low levels of SC and health were unattached and low-income females. Males were more likely to report higher trust and safety levels and higher levels of self-rated health. In this study, a linear relationship between self-reported health status and SC was not found. Marital and employment status were associated with differences in mean scores of SC and self-reported health.

Educating for Community Resilience: How the Work of Thomas Homer-Dixon and JohnDewey's Pattern of Inquiry Can Help Us Prepare for the Ecological and Social Challenges of the 21st Century

Scientists have overwhelmingly concluded that global warming occurs as a consequence of human activities and that climate change, combined with the depletion of resources, could have catastrophic consequences for the human civilization later this century. However, in political circles and in the public sphere these conclusions are not taken seriously, or they are laid aside for future generations to deal with; at the same time, significant efforts are being deployed to discredit the scientific evidence. In this thesis I have studied the positions of climate scientists as well as those of climate change deniers, and I also examined how their points of view are likely to impact the interests and habits of corporations and citizens. The work of Thomas Homer-Dixon was used as an important source for analyzing the complex interaction between our natural, economic, and social systems, and John Dewey's pattern of inquiry provided the theoretical foundation for an analysis of the current crisis and its possible solutions. No concerted action to deal with climate change has yet been taken by the leaders of the Western world; I corroborated data from four reliable sources (Hansen, 2009; IPCC, 2007; Lynas, 2007; Steffen, 2011) regarding several development scenarios and their likely consequences on greenhouse gas emissions, and I concluded that a future temperature increase of more than 2°C appears now as unavoidable. In the light of this conclusion I argue that education for increasing the resilience of smaller communities is a realistic alternative that can offer some hope in dealing with the challenges ahead.

Destigmatizing Child and Adolescent Mental Health through Group Chat: A Workshop to Support the Emotional and Social Needs of Youth

The purpose of this project was to raise awareness surrounding child and adolescent mental health in an effort to reduce preconceived stigmas in relation to this specialized field. This project presented a literature review of the current state of child and adolescent mental health in Canada today, including the prevalence and several treatment options for young people confronting mental health challenges. Consideration of the powerful role of the education system upon youth with mental health issues became evident, specifically regarding early identification and prevention. A needs assessment was conducted to gather feedback from the clinical practitioners of a Section 23 classroom within a Southern Ontario hospital. This assessment was used to develop an informational and pedagogical workshop resource to extend practitioner understanding of this pertinent issue and support the social and emotional needs of young people confronting mental heath challenges. Results of the assessment indicated the significant need for such a workshop resource, and these responses were used to guide the development of Group Chat: A Workshop to Support the Emotional and Social Needs of Youth. The latter was subsequently presented to participants, whereby evaluative questionnaires indicated the efficacy and usefulness of this workshop resource to both practitioners and students alike.

Force potentiation as a modulator of contractile performance: Implications for control of skeletal muscle force and energetics of work

This thesis investigated the modulation of dynamic contractile function and energetics of work by posttetanic potentiation (PTP). Mechanical experiments were conducted in vitro using software-controlled protocols to stimulate/determine contractile function during ramp shortening, and muscles were frozen during parallel incubations for biochemical analysis. The central feature of this research was the comparison of fast hindlimb muscles from wildtype and skeletal myosin light chain kinase knockout (skMLCK-/-) mice that does not express the primary mechanism for PTP: myosin regulatory light chain (RLC) phosphorylation. In contrast to smooth/cardiac muscles where RLC phosphorylation is indispensable, its precise physiological role in skeletal muscle is unclear. It was initially determined that tetanic potentiation was shortening speed dependent, and this sensitivity of the PTP mechanism to muscle shortening extended the stimulation frequency domain over which PTP was manifest. Thus, the physiological utility of RLC phosphorylation to augment contractile function in vivo may be more extensive than previously considered. Subsequent experiments studied the contraction-type dependence for PTP and demonstrated that the enhancement of contractile function was dependent on force level. Surprisingly, in the absence of RLC phosphorylation, skMLCK-/- muscles exhibited significant concentric PTP; consequently, up to ~50% of the dynamic PTP response in wildtype muscle may be attributed to an alternate mechanism. When the interaction of PTP and the catchlike property (CLP) was examined, we determined that unlike the acute augmentation of peak force by the CLP, RLC phosphorylation produced a longer-lasting enhancement of force and work in the potentiated state. Nevertheless, despite the apparent interference between these mechanisms, both offer physiological utility and may be complementary in achieving optimal contractile function in vivo. Finally, when the energetic implications of PTP were explored, we determined that during a brief period of repetitive concentric activation, total work performed was ~60% greater in wildtype vs. skMLCK-/- muscles but there was no genotype difference in High-Energy Phosphate Consumption or Economy (i.e. HEPC: work). In summary, this thesis provides novel insight into the modulatory effects of PTP and RLC phosphorylation, and through the observation of alternative mechanisms for PTP we further develop our understanding of the history-dependence of fast skeletal muscle function.