Cardiovascular disease has been a leading cause of death worldwide over the last decades (Roth et al., 2015; WHO, 2021a). In countries with middle or elevated gross domestic product indices, stroke and myocardial infarction represent the prevalent causes of death. Over the years, the scientific community has identified significant cognitive and emotional impacts on survivors of coronary heart disease and cardiovascular disease. We know that ageing populations and high-stress levels associated with contemporary lifestyles play a crucial role in the prognosis and recovery of individuals with myocardial infarction. These factors are associated with an increased societal burden related to survivors’ care. As they age, a higher proportion of women than men are affected by coronary heart disease, including myocardial infarction. Nonetheless, women remain under-represented in studies addressing trajectories of recovery associated with myocardial infarction. The arching goal of this thesis is to expand the knowledge on the association of various environmental and physical factors with a history of myocardial infarction in a sample of Canadian women. The accomplished research is presented in the form of two empirical studies carried out on samples of Canadian women with and without a history of myocardial infarction, as well as two systematic reviews of the literature. The first study established the state of knowledge on the Trier Social Stress Test paradigm, a tool that we later used in our laboratory study. Through an in-depth examination of the protocols used by different research groups, this systematic review identified essential elements for valid conclusions and proposed a set of recommendations for standardizing the use of the Trier Social Stress Test in research. The second systematic review updated the current scientific knowledge concerning the cognitive consequences of women with a history of coronary heart disease. Despite cardiovascular disease, including coronary heart disease, remainsunderstudied in women, the last decade has seen an emergence of research supporting cognition to be affected. Our findings support subtle cognitive impairments in women with a history of coronary heart disease. Our literature review was conducted to facilitate interpreting the results obtained in a sample of women with a history of MI in this thesis’ fourth study. Regarding data collection, an online questionnaire validated the presence of specific risk factors and symptoms associated with myocardial infarction in a sample of middle-aged Canadian women (N = 366). Finally, a laboratory study measured alterations in the physiological responses (i.e., heart rate variability and salivary cortisol secretion) associated with exposure to a social stressor (i.e., Trier Social Stress Test) in women with a history of myocardial infarction and age-matched controls (N = 29). This body of data and analytic reviews contribute to expanding the knowledge of physiological and cognitive impairments in women with a MI history. Our research also helps improve testing paradigms to examine deficits and identify areas where further research is needed. Our findings support women experiencing different symptoms than those described in men, and it pleads for these to be no longer described as "atypical." Our work highlights a similar prevalence of certain factors (e.g., hypertension) in Canadian women and women from other parts of the world. In terms of the laboratory study, our results indicate subjective/perceived levels of stress intensity to be comparable between the myocardial infarction and non-myocardial infarction women groups. However, we only found tendencies in changes related to measured physiological variables.

No description available.

It has been suggested that psychosocial stress influences situational fluctuations of tic frequency. However, evidence from experimental studies is lacking. The current study investigated the effects of the Trier Social Stress Test (TSST-C) on tic frequency in 31 children and adolescents with tic disorders. A relaxation and a concentration situation served as control conditions. Patients were asked either to suppress their tics or to “tic freely.” Physiological measures of stress were measured throughout the experiment. The TSST-C elicited a clear stress response with elevated levels of saliva cortisol, increased heart rate, and a larger number of skin conductance responses. During relaxation and concentration, the instruction to suppress tics reduced the number of tics, whereas during stress, the number of tics was low, regardless of the given instruction. Our study suggests that the stress might result in a situational decrease of tic frequency.

It has been suggested that psychosocial stress influences situational fluctuations of tic frequency. However, evidence from experimental studies is lacking. The current study investigated the effects of the Trier Social Stress Test (TSST-C) on tic frequency in 31 children and adolescents with tic disorders. A relaxation and a concentration situation served as control conditions. Patients were asked either to suppress their tics or to “tic freely.” Physiological measures of stress were measured throughout the experiment. The TSST-C elicited a clear stress response with elevated levels of saliva cortisol, increased heart rate, and a larger number of skin conductance responses. During relaxation and concentration, the instruction to suppress tics reduced the number of tics, whereas during stress, the number of tics was low, regardless of the given instruction. Our study suggests that the stress might result in a situational decrease of tic frequency.

Prevalence rates of many types of psychopathology are lower for men than they are for women, but the causes of these discrepancies are not known. This paper focuses on two such psychopathology groups – eating disorders and depressive disorders – and examines gender differences within a transactional theory of stress that takes into account levels of cognitive processing (an expanded transactional theory of stress). Both studies found that men are more physiologically reactive to disorder-relevant, stressful stimuli and stressful events. The study on depression also found that different cognitive processes may be depressogenic for men and women: deployment of attentional resources toward negative stimuli was associated with depression in men, while deployment of attentional resources away from positive stimuli was associated with depression in women. These findings have significant implications for choosing appropriate treatment options for men and women.

Prevalence rates of many types of psychopathology are lower for men than they are for women, but the causes of these discrepancies are not known. This paper focuses on two such psychopathology groups – eating disorders and depressive disorders – and examines gender differences within a transactional theory of stress that takes into account levels of cognitive processing (an expanded transactional theory of stress). Both studies found that men are more physiologically reactive to disorder-relevant, stressful stimuli and stressful events. The study on depression also found that different cognitive processes may be depressogenic for men and women: deployment of attentional resources toward negative stimuli was associated with depression in men, while deployment of attentional resources away from positive stimuli was associated with depression in women. These findings have significant implications for choosing appropriate treatment options for men and women.

L’abeille domestique (Apismellifera) a un rôle majeur dans les écosystèmes naturels et agronomiques mais est exposée à un nombre croissant de pressions environnementales (nouveaux parasites, xénobiotiques, variations climatiques et malnutrition). Dans ce contexte, la compréhension des phénomènes impliqués dans les réponses au stress ainsi que leurs coûts associés devient cruciale pour mieux appréhender l’impact de ces pressions sur les abeilles. L’émergence d’un stress perturbe généralement l’homéostasie de l’organisme qui doit mettre en place une cascade d’adaptations physiologiques et comportementales pour le surmonter. Cependant, du fait de son mode de vie social, il est raisonnable de penser que les réponses vont se faire dans l’intérêt du groupe et non plus seulement dans l’intérêt de l’individu. Afin de caractériser les réponses au stress et de déterminer leur spécificité en fonction de la nature du stimulus (xénobiotiques, immunitaire, thermique, social), j’ai adopté une approche multidisciplinaire en ciblant l’identification des modifications i) physiologiques associées à la division du travail, ii) du métabolisme énergétique, et iii) comportementales. J’ai démontré quequelque soit leur rôle social (nourrice, gardienne, butineuse), les abeilles répondent de la même manière à un stress donné, si celui-­ci est écologiquement pertinent (hyperthermie et stress immunitaire mais pas xénobiotique). Une tendance à la diminution des ressources énergétiques a également été observée suite à un stress suggérant une modification des performances comportementales. Afin de vérifier cela, je me suis concentrée sur l’activité de butinage; le vol chez les insectes étant un des processus physiologiques les plus coûteux du règne animal. Une altération des performances de butinage a été mise en évidence chez les abeilles soumises à un stress immunitaire avec une réorientation des préférences de butinage au dépens du pollen, plus coûteux àc ollecter et moins riche en ressource énergétique que le nectar ; ceci probablement pour pallier au coût énergétique du stress. En revanche, en réponse àune hyperthermie, une augmentation de l’activité de butinage a été observée mais sans engendrer un coût supplémentaire au niveau des ressources collectées.Ces résultats sont discutés à la lumière du coût énergétique du stress et des conséquences potentielles sur les performances des abeilles, qui infine pourrait perturber l’homéostasie énergétique de la colonie. / Honeybees (Apis mellifera), which play an important role in natural and agronomic ecosystems, are exposed to a growing number of environmental pressures(new parasites, pesticides, climatechangeand poor nutrition). In this context, deciphering the mechanisms underlying stress responses and their costs becomes crucial to better understand theim pact of these pressures. Stress usually represents a challenge to the homeostasis of a norganism. In response, a cascade of physiological and behavioural adaptations enables the organism to cope with the stress. However, dueto their sociallife style, we could suggest that stress response in honeybees will occurin the interest of the colony and not only in the interest of the individual. To characterise the stress response and determine its specificity according to the stimulus (xenobiotic, immune, thermal, social), I developed a multidisciplinary approach to identify changes in i) task-­related physiology, ii) energetic metabolism, and iii) behaviour. I demonstrated that, regardless of their social function (nurse, guard, forager), bees respond in the sameway to a given stress, if itis ecologically-­relevant (heat and immune stress but not pesticides). Atendencytoward decreas ingenergetic resources was also observed following stress exposure, which suggests changes in behavioural performance.In order to test this hypothesis, I analysed changes in foraging activity in response to stress, as insect flight is one of the most costly physiological processes in the animal kingdom. I found that for aging performances were affected by animmune stress : bees changed their foraging preferences at the expense of pollen, probably to reduce the stress energetic cost, given that pollen is more costly to collect and provides alower energetic return than nectar. In contrast, in response to heat stress, an increase in colony for aging activity was observed, without an additional cost on resource collection. These results are discussed in the light of stress energetic cost and its potential consequences onhoneybee performances, which could disrupt the colony’s energetic homeostasis.

Drug abuse is becoming an increasing problem in Kenya. A number of studies carried out in the country show that almost every Kenyan youngster at one time or another experiments with drugs, especially beer and cigarettes. The major cause of concern is that a significant proportion of these young people eventually get addicted posing a threat to their own health and safety, while creating difficulties for their families and the public at large into difficulties. This study sought to establish the current trend of drug abuse among students in Kenyan secondary schools, and to analyze the strategies used to address the problem. The ultimate aim was to propose a programme for prevention and intervention. The study is a descriptive survey. In view of this, the field survey method was adopted to collect quantitative and qualitative data, using questionnaires and interviews. Both qualitative and quantitative approaches were used in data analysis, thus there was a mixed model research design approach to data analysis. The analysis of structured items was mainly done using the Statistical Package for Social Sciences (SPSS). The key findings from the study were that drug abuse among students is common; both boys and girls have abused drugs with the majority being in boys‟ schools; the greatest ratio of drug abusers to non-abusers among the sampled schools are aged between 20 and 22 years; there is a significant relationship between drug abuse and age, use of drugs by other family members and easy access to drugs. A variety of factors contribute to drug abuse with the majority of students citing curiosity, acceptance by peers and ignorance as to the dangers of drug abuse as the main reasons. Both the school administrators and teachers face a number of challenges in an attempting to curb drug abuse in schools. The study makes a number of recommendations for policy and further research. A number of guidelines are proposed for developing a programme for prevention and intervention. / Educational Studies / D. Ed. (Socio-Education)

No description available.

Drug abuse is becoming an increasing problem in Kenya. A number of studies carried out in the country show that almost every Kenyan youngster at one time or another experiments with drugs, especially beer and cigarettes. The major cause of concern is that a significant proportion of these young people eventually get addicted posing a threat to their own health and safety, while creating difficulties for their families and the public at large into difficulties. This study sought to establish the current trend of drug abuse among students in Kenyan secondary schools, and to analyze the strategies used to address the problem. The ultimate aim was to propose a programme for prevention and intervention. The study is a descriptive survey. In view of this, the field survey method was adopted to collect quantitative and qualitative data, using questionnaires and interviews. Both qualitative and quantitative approaches were used in data analysis, thus there was a mixed model research design approach to data analysis. The analysis of structured items was mainly done using the Statistical Package for Social Sciences (SPSS). The key findings from the study were that drug abuse among students is common; both boys and girls have abused drugs with the majority being in boys‟ schools; the greatest ratio of drug abusers to non-abusers among the sampled schools are aged between 20 and 22 years; there is a significant relationship between drug abuse and age, use of drugs by other family members and easy access to drugs. A variety of factors contribute to drug abuse with the majority of students citing curiosity, acceptance by peers and ignorance as to the dangers of drug abuse as the main reasons. Both the school administrators and teachers face a number of challenges in an attempting to curb drug abuse in schools. The study makes a number of recommendations for policy and further research. A number of guidelines are proposed for developing a programme for prevention and intervention. / Educational Studies / D. Ed. (Socio-Education)