920 resultados para social production of signs


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Ultrasonic vocalization plays an important role in intraspecies communication for rats. It has been well demonstrated that rats will emit 22kHz vocalization in stressfiil or threatening situations. Although the neural mechanism underlying vocahzation is not well understood, it is known that chohnergic input to the basal forebrain induces such alarm calls. A number of experiments have found that intracerebral injection of carbachol, a predominantly muscarinic agonist, into die anterior hypothalamic/preoptic area (AH/POA) rehably induces vocalization similar to naturally emitted ultrasonic calls. It has also been shown that carbachol has extensive inhibitory effects on neuronal firing in the same area. This result impUes that the inhibitory effects of carbachol in the AH/POA could trigger vocahzation, and that the GABAergic system could be involved. The purpose of this study is to investigate the effects ofGABA agonists and antagonists on flie production of carbachol induced 22kHz vocalization. The following hypotheses were examined: 1) apphcation ofGABA (a naturally occurring inhibitory neurotransmitter) will have a synergistic effect with carbachol, increasing vocalization; and 2) tiie apphcation ofGABA antagonists (picrotoxin or bicuculline) will reduce caibachol-induced vocalization. A total of sixty rats were implanted with stainless steel guide cannulae in the AH/POA area. After recovery, animals were locally pretreated with 1) GABA (l-40ng), 2) picrotoxin (1 .5^g) or bicuculhne (0.03ng), or 3) sahne; before injection with carbachol (1 .5^g). The resulting vocalization was measured and quantitated. The results indicate that pretreatment with GABA or GABA antagonists had no significant effect on vocalization. Local pretreatment with GABA did not potentiate the vocal response as measured by its duration, latraicy, and total number of calls. Similarly, pretreatment with picrotoxin or bicuculline had no effects on the same measures of vocalization. The results suggest tfiat chohnoceptive neurons involved in the production of alarm calls are not under direct GABAergic control.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The fatty acid composition of the total cellular lipids of Choanephora cucurbitarum incubated for 96 hrs on either glucose-ammonium sulfate or malt-weast extract media was determined. The major fatty acids were palmitic, palmitoleic, stearic and linoleic acids. The saturated fatty acid possessing the longest acyl chain was stearate (C 18:0). The presence of glutamic acid (2.0 x 10-1% or 1.36 x la-2M) in either of the above growth media resulted in increase in percent of 1f-linolenic acid, decrease in percent of linoleic ~iCid and appearance of a new series of fatty acid> C ~8 e.g. C ",,,,'V' C2k:O, C26,O. The addition of glutamic acid had no effect on the lipid yield but slightly decreased the degree of unsaturation. Compounds which duplicated the effect of glutamic acid were acetate, malate, citrate, succinate, 0( -ketoglutarate, prOline, -y -aminobutyric acid and glucose (3%) but not aspartic acid or alanine. ~o correlation was found between glutamic acid pool concentration and the presence in the growth medium of those compounds which stimulate long chain fatty acid production. Four hours of incubation with 27 JJ 1-1 glutamate supported the production of long chain fatty acids. This stimulation is inhibited if 272 .u M isophthalic acid is added with 27 AJ M glutamate. But, long chain fatty acids were detected when 27 JJ M eX -ketoglutarate is also present in the incubation mixture. Five hours of incubation with 100 ,Mg/ml of cycloheximide resulted in over 9CY/o inhibition of cytoplasmic :protein synthesise Glutamate (27 .uM) enhanced the synthesis of long chain fatty acids under these conditions. These findings are discussed in an attempt to provide a plausible explanation COmmon to compounds that support the production of long chain fatty acids.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Rats produce ultrasonic vocalizations that can be categorized into two types of ultrasonic calls based on their sonographic structure. One group contains 22-kHz ultrasonic vocalization (USVs), characterized by relatively constant (flat) frequency with peak frequency ranging from 19 to 28-kHz, and a call duration ranging between 100 – 3000 ms. These vocalization can be induced by cholinomimetic agents injected into the ascending mesolimbic cholinergic system that terminates in the anterior hypothalamic-preoptic area (AH-MPO) and lateral septum (LS). The other group of USVs contains 50-kHz USVs, characterized by high peak frequency, ranging from 39 to 90-kHz, short duration ranging from 10-90 ms, and varying frequency and complex sonographic morphology. These vocalizations can be induced by dopaminergic agents injected into the nucleus accumbens, the target area for the mesolimbic dopaminergic system. 22-kHz USVs are emitted in situations that are highly aversive, such as proximity of a predator or anticipation of a foot shock, while 50 kHz USVs are emitted in rewarding and appetitive situations, such as juvenile play behaviour or anticipation of rewarding electrical brain stimulation. The activities of these two mesolimbic systems were postulated to be antagonistic to each other. The current thesis is focused on the interaction of these systems indexed by emission of relevant USVs. It was hypothesized that emission of 22 kHz USVs will be antagonized by prior activation of the dopaminergic system while emission of 50 kHz will be antagonized by prior activation of the cholinergic system. It was found that injection of apomorphine into the shell of the nucleus accumbens significantly decreased the number of carbachol-induced 22 kHz USVs from both AH-MPO and LS. Injection of carbachol into the LS significantly decreased the number of apomorphine-induced 50 kHz USVs from the shell of the nucleus accumbens. The results of the study supported the main hypotheses that the mesolimbic dopaminergic and cholinergic systems function in antagonism to each other.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Rats produce ultrasonic vocalizations that can be categorized into two types of ultrasonic calls based on their sonographic structure. One group contains 22-kHz ultrasonic vocalization (USVs), characterized by relatively constant (flat) frequency with peak frequency ranging from 19 to 28-kHz, and a call duration ranging between 100 – 3000 ms. These vocalization can be induced by cholinomimetic agents injected into the ascending mesolimbic cholinergic system that terminates in the anterior hypothalamic-preoptic area (AH-MPO) and lateral septum (LS). The other group of USVs contains 50-kHz USVs, characterized by high peak frequency, ranging from 39 to 90-kHz, short duration ranging from 10-90 ms, and varying frequency and complex sonographic morphology. These vocalizations can be induced by dopaminergic agents injected into the nucleus accumbens, the target area for the mesolimbic dopaminergic system. 22-kHz USVs are emitted in situations that are highly aversive, such as proximity of a predator or anticipation of a foot shock, while 50 kHz USVs are emitted in rewarding and appetitive situations, such as juvenile play behaviour or anticipation of rewarding electrical brain stimulation. The activities of these two mesolimbic systems were postulated to be antagonistic to each other. The current thesis is focused on the interaction of these systems indexed by emission of relevant USVs. It was hypothesized that emission of 22 kHz USVs will be antagonized by prior activation of the dopaminergic system while emission of 50 kHz will be antagonized by prior activation of the cholinergic system. It was found that injection of apomorphine into the shell of the nucleus accumbens significantly decreased the number of carbachol-induced 22 kHz USVs from both AH-MPO and LS. Injection of carbachol into the LS significantly decreased the number of apomorphine-induced 50 kHz USVs from the shell of the nucleus accumbens. The results of the study supported the main hypotheses that the mesolimbic dopaminergic and cholinergic systems function in antagonism to each other.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The word ‘sovereignty’ provides a forceful example of the social power of language as an organic instrument playing a leading role in the continuous and continuing process of creating and transforming human reality. The paper examines a pivotal episode in the history of the word ‘sovereignty’ — its formal introduction in the 16th century by Jean Bodin in his Six Livres de la Republique. It focuses on the social effects ‘sovereignty’ has had on the shared consciousness of humanity, including that of the international community. The proposed metalogical inquiry adopts a method that draws from the hermeneutic school of historical knowledge. The argument is that Bodin used ‘sovereignty’ for the purpose of attributing to the ruler (the French king) supreme power in the hierarchical organisational structure of society. This idea of a pyramid of authority is found in different elements of the discourse in Six Livres de la Republique, which is examined in the immediate context of Bodin’s personal background as well as the extended social, political and intellectual context of 16th century France. The conclusion shows that Bodin’s work was the first seminal step in the development of contemporary ideas of ‘internal sovereignty’ and ‘external sovereignty’. It is thus part of the history of the true power that the word at hand has exercised in framing the international state system and hence the international legal system.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

As long as the social rented sector - which comprised 6% of the housing stock - housed traditional families and the allocation procedures were rather loose, little commotion came about. A combination of changes in family structures (leading to the in stream of ethnic minorities), economic changes (leading to the in stream of poor people), and the strengthening of allocation procedures towards those most in need, did change perceptions. Marginalisation and ghettoisation became during the 1990s the buzzwords when talking and writing about social rented housing. In this article, we will explain the background of the scapegoat trends and the possible consequences for social tenants in particular and for the social rental housing in general.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Contexte: Les facteurs de risque comportementaux, notamment l’inactivité physique, le comportement sédentaire, le tabagisme, la consommation d’alcool et le surpoids sont les principales causes modifiables de maladies chroniques telles que le cancer, les maladies cardiovasculaires et le diabète. Ces facteurs de risque se manifestent également de façon concomitante chez l’individu et entraînent des risques accrus de morbidité et de mortalité. Bien que les facteurs de risque comportementaux aient été largement étudiés, la distribution, les patrons d’agrégation et les déterminants de multiples facteurs de risque comportementaux sont peu connus, surtout chez les enfants et les adolescents. Objectifs: Cette thèse vise 1) à décrire la prévalence et les patrons d’agrégation de multiples facteurs de risque comportementaux des maladies chroniques chez les enfants et adolescents canadiens; 2) à explorer les corrélats individuels, sociaux et scolaires de multiples facteurs de risque comportementaux chez les enfants et adolescents canadiens; et 3) à évaluer, selon le modèle conceptuel de l’étude, l’influence longitudinale d’un ensemble de variables distales (c’est-à-dire des variables situées à une distance intermédiaire des comportements à risque) de type individuel (estime de soi, sentiment de réussite), social (relations sociales, comportements des parents/pairs) et scolaire (engagement collectif à la réussite, compréhension des règles), ainsi que de variables ultimes (c’est-à-dire des variables situées à une distance éloignée des comportements à risque) de type individuel (traits de personnalité, caractéristiques démographiques), social (caractéristiques socio-économiques des parents) et scolaire (type d’école, environnement favorable, climat disciplinaire) sur le taux d’occurrence de multiples facteurs de risque comportementaux chez les enfants et adolescents canadiens. Méthodes: Des données transversales (n = 4724) à partir du cycle 4 (2000-2001) de l’Enquête longitudinale nationale sur les enfants et les jeunes (ELNEJ) ont été utilisées pour décrire la prévalence et les patrons d’agrégation de multiples facteurs de risque comportementaux chez les jeunes canadiens âgés de 10-17 ans. L’agrégation des facteurs de risque a été examinée en utilisant une méthode du ratio de cas observés sur les cas attendus. La régression logistique ordinale a été utilisée pour explorer les corrélats de multiples facteurs de risque comportementaux dans un échantillon transversal (n = 1747) de jeunes canadiens âgés de 10-15 ans du cycle 4 (2000-2001) de l’ELNEJ. Des données prospectives (n = 1135) à partir des cycle 4 (2000-2001), cycle 5 (2002-2003) et cycle 6 (2004-2005) de l’ELNEJ ont été utilisées pour évaluer l’influence longitudinale des variables distales et ultimes (tel que décrit ci-haut dans les objectifs) sur le taux d’occurrence de multiples facteurs de risque comportementaux chez les jeunes canadiens âgés de 10-15 ans; cette analyse a été effectuée à l’aide des modèles de Poisson longitudinaux. Résultats: Soixante-cinq pour cent des jeunes canadiens ont rapporté avoir deux ou plus de facteurs de risque comportementaux, comparativement à seulement 10% des jeunes avec aucun facteur de risque. Les facteurs de risque comportementaux se sont agrégés en de multiples combinaisons. Plus précisément, l’occurrence simultanée des cinq facteurs de risque était 120% plus élevée chez les garçons (ratio observé/attendu (O/E) = 2.20, intervalle de confiance (IC) 95%: 1.31-3.09) et 94% plus élevée chez les filles (ratio O/E = 1.94, IC 95%: 1.24-2.64) qu’attendu. L’âge (rapport de cotes (RC) = 1.95, IC 95%: 1.21-3.13), ayant un parent fumeur (RC = 1.49, IC 95%: 1.09-2.03), ayant rapporté que la majorité/tous de ses pairs consommaient du tabac (RC = 7.31, IC 95%: 4.00-13.35) ou buvaient de l’alcool (RC = 3.77, IC 95%: 2.18-6.53), et vivant dans une famille monoparentale (RC = 1.94, IC 95%: 1.31-2.88) ont été positivement associés aux multiples comportements à risque. Les jeunes ayant une forte estime de soi (RC = 0.92, IC 95%: 0.85-0.99) ainsi que les jeunes dont un des parents avait un niveau d’éducation postsecondaire (RC = 0.58, IC 95%: 0.41-0.82) étaient moins susceptibles d’avoir de multiples facteurs de risque comportementaux. Enfin, les variables de type social distal (tabagisme des parents et des pairs, consommation d’alcool par les pairs) (Log du rapport de vraisemblance (LLR) = 187.86, degrés de liberté = 8, P < 0,001) et individuel distal (estime de soi) (LLR = 76.94, degrés de liberté = 4, P < 0,001) ont significativement influencé le taux d’occurrence de multiples facteurs de risque comportementaux. Les variables de type individuel ultime (âge, sexe, anxiété) et social ultime (niveau d’éducation du parent, revenu du ménage, structure de la famille) ont eu une influence moins prononcée sur le taux de cooccurrence des facteurs de risque comportementaux chez les jeunes. Conclusion: Les résultats suggèrent que les interventions de santé publique devraient principalement cibler les déterminants de type individuel distal (tel que l’estime de soi) ainsi que social distal (tels que le tabagisme des parents et des pairs et la consommation d’alcool par les pairs) pour prévenir et/ou réduire l’occurrence de multiples facteurs de risque comportementaux chez les enfants et les adolescents. Cependant, puisque les variables de type distal (telles que les caractéristiques psychosociales des jeunes et comportements des parents/pairs) peuvent être influencées par des variables de type ultime (telles que les caractéristiques démographiques et socioéconomiques), les programmes et politiques de prévention devraient également viser à améliorer les conditions socioéconomiques des jeunes, particulièrement celles des enfants et des adolescents des familles les plus démunies.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Les études antérieures ont démontré les bénéfices de la satisfaction des besoins intrinsèques et du soutien à l’autonomie dans le domaine de l’éducation. Or, l’applicabilité des tenants principaux de la Théorie de l’Auto-Détermination (TAD; Deci & Ryan, 2000) n’a pas été investiguée auprès d’une population clinique d’adolescents. L’objectif de cette thèse doctorale est de faire la lumière sur la façon dont l'adaptation scolaire et sociale peut être favorisée par les agents de socialisation dans le contexte de la réadaptation sociale. Cette thèse est composée de deux études s’intéressant à l’application des tenants clés de la TAD auprès de deux échantillons d’adolescents vivant des problèmes d’adaptation et recevant des services d’éducation spécialisée et de réadaptation sociale. Les relations entre les concepts motivationnels de base sont étudiés afin de déterminer si, comme la TAD le propose, la satisfaction des besoins intrinsèques des jeunes peut être soutenue par le style interpersonnel des agents de socialisation (c.-à-d., le soutien à l’autonomie, l’implication et la structure). Il est aussi vérifié si ces concepts motivationnels améliorent la motivation ainsi que d’autres conséquences qui résultent de leur expérience, proposées par la TAD. La première étude a évalué si le style interpersonnel des enseignants peut favoriser la satisfaction des besoins des élèves, leur style de motivationl, tout comme leur ajustement scolaire. Les élèves en difficulté d’adaptation (N = 115) inscrits aux écoles internes des Centres de Réadaptation en raison de leurs problématiques émotionnelles et comportementales ont rempli les questionnaires à deux reprises, au début et à la fin de l’année scolaire. Les analyses de modèles d’équations structurelles révèlent que l’augmentation du soutien à l’autonomie et de l’implication (mais pas de la structure) des enseignants pendant l’année est associée à une augmentation de la satisfaction des besoins des élèves qui, conséquemment, conduit à une motivation scolaire plus auto-déterminée et à une diminution d’intentions de décrochage à la fin de l’année scolaire. De plus, l’amélioration de la satisfaction des besoins mène directement à une meilleure expérience affective à l’école. La deuxième étude consiste en une recherche expérimentale conduite auprès d’adolescentes en difficulté d’adaptation (N = 29). Le devis expérimental a permis de comparer l’impact de la présence (c. absence) du soutien à l’autonomie sur l’internalisation d’une tâche et sur les conséquences motivationnelles et expérientielles des jeunes. La tâche, fastidieuse mais importante, consistait à de la résolution de problèmes interpersonnels (activité clinique). Les résultats suggèrent qu’un style interpersonnel soutenant l’autonomie a augmenté la motivation auto-déterminée, la perception de la valeur de la tâche et son appréciation, ainsi que diminué les affects négatifs comparativement à la condition sans soutien à l’autonomie. Les résultats sont discutés en lien avec les implications théoriques et pratiques d’étendre la portée de la TAD à une population clinique d’adolescents aux prises avec des difficultés d’adaptation.