Die Dissertation beschäftigt sich mit der Frage, ob und wie Feedback-basiertes Lernen durch Stress moduliert wird. Der Zusammenhang zwischen Stress und Kognition sowie die zugrunde liegenden biologischen Mechanismen sind Gegenstand der kognitiven Stressforschung. Während der Einfluss von Stress und Stresshormonen auf andere Lernformen bereits gut etabliert ist, gibt es bisher kaum Studien, die Feedback-basiertes Lernen unter Stress bei Menschen betrachtet haben. In der vorliegenden Arbeit werden daher die Auswirkungen akuten Stresses auf diese Lernform untersucht. Es werden gezielt Auswirkungen auf die generelle Akquisition einer Lernaufgabe mittels Feedback, auf die Nutzung sowohl positiven als auch negativen Feedbacks beim Lernen sowie auf die Fähigkeit der flexiblen Anpassung an sich änderndes Feedback betrachtet. Dafür werden in den experimentellen Untersuchungen der Arbeit Feedback-basierte Aufgaben mit einer vorangestellten Induktion akuten psychosozialen Stresses kombiniert. Die Ergebnisse der vorliegenden Arbeit deuten darauf hin, dass akuter psychosozialer Stress das generelle Erlernen Feedback-basierter Aufgaben nicht beeinflusst, jedoch die Nutzung positiven und negativen Feedbacks beim Lernen verändert. Im Speziellen wird negatives Feedback nach einer Stressinduktion weniger genutzt, während über eine möglicherweise stärkere Nutzung positiven Feedbacks aufgrund der vorliegenden Ergebnisse keine fundierte Aussage getroffen werden kann. Zudem finden sich in der vorliegenden Arbeit Hinweise auf einen positiven Zusammenhang zwischen Cortisolwerten und der Flexibilität in Feedback-basierten Lernaufgaben. Als Erklärungsansätze werden veränderte Aufmerksamkeitsprozesse nach einer Stressinduktion sowie andere psychologische Faktoren wie eine kognitive Nachbeschäftigung mit dem Stresstest und eine geringere Involviertheit in die kognitiven Aufgaben diskutiert. Die berichteten Korrelationen zwischen Cortisolwerten und kognitiven Parametern werden dahingehend interpretiert, dass Cortisol ein vermittelnder Faktor des Stresseffekts auf die Nutzung und neuronale Verarbeitung negativen Feedbacks sein könnte. Zur Integration der Ergebnisse aller Studien wird eine Modulation der dopaminergen Signalübertragung durch Stress und erhöhte Cortisolspiegel und damit verbundene Auswirkung auf Feedback-basiertes Lernen vorgeschlagen. Die vorliegende Arbeit gibt zum ersten Mal Hinweise auf eine veränderte Nutzung und Verarbeitung von Feedback nach psychosozialem Stress und bestätigt frühere Befunde eines Zusammenhangs zwischen Cortisol und der Flexibilität beim Lernen.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Esta tese tem o objetivo geral de investigar a associação entre estresse e acidentes no trabalho em funcionários técnico-administrativos efetivos de uma universidade pública no Rio de Janeiro por meio de modelos multiníveis. Para alcançar tal objetivo, a tese foi distribuída em dois artigos. O primeiro artigo investiga a associação entre estresse e acidentes no trabalho considerando componentes hierárquicos da estrutura dos dados por meio de modelos multiníveis com funcionários no primeiro nível agrupados em setores de trabalho no segundo nível. O segundo artigo investiga o comportamento dos coeficientes fixos e aleatórios dos modelos multiníveis com classificação cruzada entre setores de trabalho e grupos ocupacionais em relação aos modelos multiníveis que consideram apenas componentes hierárquicos dos setores de trabalho, ignorando o ajuste dos grupos ocupacionais. O estresse psicossocial no trabalho foi abordado a partir das relações entre alta demanda psicológica e baixo controle do processo laboral, Estas dimensões foram captadas por meio da versão resumida da escala Karasek, que também contém informações sobre o apoio social no trabalho. Dimensões isoladas do estresse no trabalho (demanda e controle), razão entre demanda psicológica e controle do trabalho (Razão D/C) e o apoio social no trabalho foram mensurados no nível individual e nos setores de trabalho. De modo geral, os resultados destacam a demanda psicológica mensurada no nível individual como um importante fator associado à ocorrência de acidentes de trabalho. O apoio social no trabalho, mensurado no nível individual e no setor de trabalho, apresentou associação inversa à prevalência de acidentes de trabalho, sendo, no setor, acentuada entre as mulheres. Os resultados também mostram que os parâmetros fixos dos modelos com e sem classificação cruzada foram semelhantes e que, de modo geral, os erros padrões (EP) foram um pouco maiores nos modelos com classificação cruzada, apesar deste comportamento do EP não ter sido observado quando relacionado aos coeficientes fixos das variáveis agregadas no setor de trabalho. A maior distinção entre as duas abordagens foi observada em relação aos coeficientes aleatórios relacionados aos setores de trabalho, que alteraram substancialmente após ajustar o efeito da ocupação por meio dos modelos com classificação cruzada. Este estudo reforça a importância de características psicossociais na ocorrência de acidentes de trabalho e contribui para o conhecimento dessas relações a partir de abordagens analíticas que refinam a captação da estrutura de dependência dos indivíduos em seu ambiente de trabalho. Sugere-se a realização de outros estudos com metodologia similar, que permitam aprofundar o conhecimento sobre estresse e acidentes no trabalho. / This thesis has the general aim of investigating the association between stress and accidents at work with public employees at a public university in Rio de Janeiro, by means of multilevel models. To reach this goal, this study has been distributed into two articles. The first one investigates the association between stress and accidents at work taking into consideration hierarchic components in the data structure by means of multilevel models with employees in the first level grouped in working areas in the second level. The second article investigates the behavior of random and fixed coefficients of the multilevel models with cross classification between working areas and occupational groups in relation to the multilevel models which only take into consideration hierarchic components of the working areas, ignoring the adjustment of occupational groups. The psychosocial stress at work was approached from the relation between high psychological demand and low labor process control. These dimensions were taken by means of the summarized version of the Karasek scale, which also contains information about the social support at work. Isolated dimensions of work stress (demand and control), the ratio between psychological demand and work control (ratio D/C) and the social support at work were measured at individual level and at working areas. Generally speaking, the results highlighted the psychological demand measured at individual level with a major aspect associated to accidents occurrence at work. The social support at work, measured at individual level and in the working area, presented inverted association to the prevalence of accidents at work, that association being more present among women. The results also show that the fixed parameters of the models with and without cross classification were similar and that, in general, the stander errors (SE) were a little bigger in the models with cross classification, although this behavior of the SE hasnt been observed when related to the fixed coefficient of the variable measured at working area. The major distinction between the two approaches was observed in relation to random coefficients related to the working areas, which were highly altered after adjusting the effect of the occupation by means of models with cross classification. This thesis reinforces the importance of psychosocial characteristics in the occurrence of accidents at work and contributes to the knowledge of these relations from analytical approaches which refine the gathering of the dependence structure of individuals in their working place. Its suggested that other studies with similar methodologies are made, that would allow us to go deep in the knowledge of stress and accidents at work.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Esta tese tem o objetivo geral de investigar a associação entre estresse e acidentes no trabalho em funcionários técnico-administrativos efetivos de uma universidade pública no Rio de Janeiro por meio de modelos multiníveis. Para alcançar tal objetivo, a tese foi distribuída em dois artigos. O primeiro artigo investiga a associação entre estresse e acidentes no trabalho considerando componentes hierárquicos da estrutura dos dados por meio de modelos multiníveis com funcionários no primeiro nível agrupados em setores de trabalho no segundo nível. O segundo artigo investiga o comportamento dos coeficientes fixos e aleatórios dos modelos multiníveis com classificação cruzada entre setores de trabalho e grupos ocupacionais em relação aos modelos multiníveis que consideram apenas componentes hierárquicos dos setores de trabalho, ignorando o ajuste dos grupos ocupacionais. O estresse psicossocial no trabalho foi abordado a partir das relações entre alta demanda psicológica e baixo controle do processo laboral, Estas dimensões foram captadas por meio da versão resumida da escala Karasek, que também contém informações sobre o apoio social no trabalho. Dimensões isoladas do estresse no trabalho (demanda e controle), razão entre demanda psicológica e controle do trabalho (Razão D/C) e o apoio social no trabalho foram mensurados no nível individual e nos setores de trabalho. De modo geral, os resultados destacam a demanda psicológica mensurada no nível individual como um importante fator associado à ocorrência de acidentes de trabalho. O apoio social no trabalho, mensurado no nível individual e no setor de trabalho, apresentou associação inversa à prevalência de acidentes de trabalho, sendo, no setor, acentuada entre as mulheres. Os resultados também mostram que os parâmetros fixos dos modelos com e sem classificação cruzada foram semelhantes e que, de modo geral, os erros padrões (EP) foram um pouco maiores nos modelos com classificação cruzada, apesar deste comportamento do EP não ter sido observado quando relacionado aos coeficientes fixos das variáveis agregadas no setor de trabalho. A maior distinção entre as duas abordagens foi observada em relação aos coeficientes aleatórios relacionados aos setores de trabalho, que alteraram substancialmente após ajustar o efeito da ocupação por meio dos modelos com classificação cruzada. Este estudo reforça a importância de características psicossociais na ocorrência de acidentes de trabalho e contribui para o conhecimento dessas relações a partir de abordagens analíticas que refinam a captação da estrutura de dependência dos indivíduos em seu ambiente de trabalho. Sugere-se a realização de outros estudos com metodologia similar, que permitam aprofundar o conhecimento sobre estresse e acidentes no trabalho. / This thesis has the general aim of investigating the association between stress and accidents at work with public employees at a public university in Rio de Janeiro, by means of multilevel models. To reach this goal, this study has been distributed into two articles. The first one investigates the association between stress and accidents at work taking into consideration hierarchic components in the data structure by means of multilevel models with employees in the first level grouped in working areas in the second level. The second article investigates the behavior of random and fixed coefficients of the multilevel models with cross classification between working areas and occupational groups in relation to the multilevel models which only take into consideration hierarchic components of the working areas, ignoring the adjustment of occupational groups. The psychosocial stress at work was approached from the relation between high psychological demand and low labor process control. These dimensions were taken by means of the summarized version of the Karasek scale, which also contains information about the social support at work. Isolated dimensions of work stress (demand and control), the ratio between psychological demand and work control (ratio D/C) and the social support at work were measured at individual level and at working areas. Generally speaking, the results highlighted the psychological demand measured at individual level with a major aspect associated to accidents occurrence at work. The social support at work, measured at individual level and in the working area, presented inverted association to the prevalence of accidents at work, that association being more present among women. The results also show that the fixed parameters of the models with and without cross classification were similar and that, in general, the stander errors (SE) were a little bigger in the models with cross classification, although this behavior of the SE hasnt been observed when related to the fixed coefficient of the variable measured at working area. The major distinction between the two approaches was observed in relation to random coefficients related to the working areas, which were highly altered after adjusting the effect of the occupation by means of models with cross classification. This thesis reinforces the importance of psychosocial characteristics in the occurrence of accidents at work and contributes to the knowledge of these relations from analytical approaches which refine the gathering of the dependence structure of individuals in their working place. Its suggested that other studies with similar methodologies are made, that would allow us to go deep in the knowledge of stress and accidents at work.

Contexte : Le personnel non médical des Etablissements d’Hébergements pour Personnes Agées Dépendantes (EHPAD) est exposé à des contraintes physiques et psychiques élevées du fait de la prise en charge de résidents de plus en plus dépendants et polypathologiques. Notre démarche de recherche s’appuie sur le modèle de santé publique de Green et Kreuter. Il s’agit de préciser l’état de santé physique et psychique du personnel (diagnostic épidémiologique) et d’explorer les conditions de travail perçues par les salariés (diagnostic comportemental et environnemental). Matériels et Méthode : Une étude transversale a été menée par 78 médecins du travail auprès 2649 salariés (706 agents de service, 1565 agents de soins et 378 infirmiers) provenant de 105 maisons de retraite de la Région Rhône Alpes. Plusieurs questionnaires standardisés validés ont été utilisés pour recueillir des informations auprès des salariés. Les analyses statistiques ont été réalisées à partir du logiciel SAS, version 9.3. Résultats : Le personnel interrogé exprime un fort niveau de pénibilité et souhaite recevoir plus fréquemment une formation continue aux soins palliatifs. Il est fortement exposé aux contraintes psychosociales (efforts élevés, récompenses faibles, déséquilibre effort/récompense et surinvestissement). Les plaintes musculo-squelettiques du cou et des membres supérieurs et les signes de détresse psychique de ce personnel sont significativement liées à l’exposition aux contraintes psychosociales. Conclusions : La prochaine étape de recherche consisterait à établir le diagnostic éducationnel en précisant les facteurs organisationnels associés aux contraintes psychosociales de ce personnel / Background: Non-medical staff in nursing homes for the elderly are exposed to high levels of physical and psychological stress related to managing increasingly dependent residents with multiple pathologies. Our research approach is based on Green and Kreuter's public health model. This is intended to describe the physical and mental health (epidemiological diagnosis) and to explore working conditions as experienced by nursing home staff (behavioral and environmental diagnosis). Methods: A cross-sectional descriptive survey was conducted by 78 occupational physicians on 2,649 employees (706 housekeepers, 1,565 nursing assistants and 378 nurses) in 105 nursing homes for the elderly in the Rhône-Alpes Region of France. Employee data were collected on several validated questionnaires. All statistical analyses were performed on SAS software, version 9.3. Results: Respondents related elevated hardship and desired more continuous training in palliative care. They were highly exposed to psychosocial stress (strong effort, low reward, effort/reward imbalance, overcommitment). Neck and upper limb musculoskeletal complaints and signs of psychological distress were significantly associated with exposure to psychosocial stress. Conclusions: The next phase of the research plan should consist in establishing an educational diagnosis by assessing the organizational factors associated with psychosocial stress in nursing home staff

No description available.

Die Dissertation beschäftigt sich mit der Frage, ob und wie Feedback-basiertes Lernen durch Stress moduliert wird. Der Zusammenhang zwischen Stress und Kognition sowie die zugrunde liegenden biologischen Mechanismen sind Gegenstand der kognitiven Stressforschung. Während der Einfluss von Stress und Stresshormonen auf andere Lernformen bereits gut etabliert ist, gibt es bisher kaum Studien, die Feedback-basiertes Lernen unter Stress bei Menschen betrachtet haben. In der vorliegenden Arbeit werden daher die Auswirkungen akuten Stresses auf diese Lernform untersucht. Es werden gezielt Auswirkungen auf die generelle Akquisition einer Lernaufgabe mittels Feedback, auf die Nutzung sowohl positiven als auch negativen Feedbacks beim Lernen sowie auf die Fähigkeit der flexiblen Anpassung an sich änderndes Feedback betrachtet. Dafür werden in den experimentellen Untersuchungen der Arbeit Feedback-basierte Aufgaben mit einer vorangestellten Induktion akuten psychosozialen Stresses kombiniert. Die Ergebnisse der vorliegenden Arbeit deuten darauf hin, dass akuter psychosozialer Stress das generelle Erlernen Feedback-basierter Aufgaben nicht beeinflusst, jedoch die Nutzung positiven und negativen Feedbacks beim Lernen verändert. Im Speziellen wird negatives Feedback nach einer Stressinduktion weniger genutzt, während über eine möglicherweise stärkere Nutzung positiven Feedbacks aufgrund der vorliegenden Ergebnisse keine fundierte Aussage getroffen werden kann. Zudem finden sich in der vorliegenden Arbeit Hinweise auf einen positiven Zusammenhang zwischen Cortisolwerten und der Flexibilität in Feedback-basierten Lernaufgaben. Als Erklärungsansätze werden veränderte Aufmerksamkeitsprozesse nach einer Stressinduktion sowie andere psychologische Faktoren wie eine kognitive Nachbeschäftigung mit dem Stresstest und eine geringere Involviertheit in die kognitiven Aufgaben diskutiert. Die berichteten Korrelationen zwischen Cortisolwerten und kognitiven Parametern werden dahingehend interpretiert, dass Cortisol ein vermittelnder Faktor des Stresseffekts auf die Nutzung und neuronale Verarbeitung negativen Feedbacks sein könnte. Zur Integration der Ergebnisse aller Studien wird eine Modulation der dopaminergen Signalübertragung durch Stress und erhöhte Cortisolspiegel und damit verbundene Auswirkung auf Feedback-basiertes Lernen vorgeschlagen. Die vorliegende Arbeit gibt zum ersten Mal Hinweise auf eine veränderte Nutzung und Verarbeitung von Feedback nach psychosozialem Stress und bestätigt frühere Befunde eines Zusammenhangs zwischen Cortisol und der Flexibilität beim Lernen.

No description available.

No description available.

The topic of gig-work has been widely debated in the western world for its laborrights and work environment issues. Whereas companies operating within thegig-economy boast the freedom and flexibility of gig-work as perks for workers,unions highlight the precarious nature and poor working conditions of gig-workas exploitative of workers and push for unionizing gig-workers and getting themcovered by collective bargaining agreements. However, due to the novelty of thephenomenon, not much scholarly work has been done on the subject and its longterm implications for the labor markets of developed capitalist countries.In Sweden, conditions caused by the Covid-19 pandemic led to an influx ofworkers in the food-delivery sector due to increased demands for services andhigh unemployment as gig-work was regarded as a means to sustain one’slivelihood during a time of economic uncertainty. As these food-delivery couriershad to work outside the home, where the chance of contracting the virus was high,while also having jobs where they were not regarded as employees, the aim ofthis thesis project was to investigate how the Covid-19 pandemic has affectedfood-delivery couriers’ perceived exposure to psychosocial stressors and risksthrough a qualitative interview study. The findings were generated throughinductive reasoning from analyzing conducted six interviews and discussedthrough the lens of the Human, Technology and Organization (HTO)-model andthe Job-Demands-Control-Support (JDCS)-model. / Gig-arbete har diskuterats i stor utsträckning i västvärlden för dess arbetsmiljöoch rättighetsrelaterade problem. Medan företag som verkar inom gig-ekonominframhäver flexibilitet och frihet av gig-arbete som förmåner för arbetare, menarfackföreningar att de prekära och osäkra arbetsförhållandena gällande gig-arbeteär exploaterande gentemot arbetare och vill därmed se dem organiserade ifackföreningar och täckta av kollektivtal. På grund av att området är nytt, så harinte mycket vetenskaplig forskning skett i detta ämne och dess långsiktigakonsekvenser på de utvecklade kapitalistiska ländernas arbetsmarknader.I Sverige ledde förhållandena orsakade av Covid-19-pandemin till entillströmning av arbetare i matleveranssektorn på grund av ökad efterfrågan frånkunder och hög arbetslöshet eftersom gig-arbete betraktades som ett sätt attupprätthålla sitt levebröd under en tid av ekonomisk osäkerhet. Dåmatleveranskurirerna var tvungna att arbeta utanför hemmet, där chansen att fåviruset var hög, samtidigt som de hade jobb där de inte betraktades som anställda,var syftet med detta examensarbete att undersöka hur Covid-19-pandemin hadepåverkat matleveranskurirernas upplevda exponering för psykosociala stress- ochriskfaktorer genom en kvalitativ intervjustudie. Resultaten genererades genominduktivt resonemang från analyser av sex genomförda intervjuer som sedandiskuterades utifrån Människa, Teknologi, Organisation (MTO)-modellen samtJob-Demands-Control-Support (JDCS)-modellen.

[Truncated abstract] Early psychosocial stress is conjectured to place individuals on a developmental trajectory leading to earlier pubertal maturation, earlier initiation of sexual activity and earlier reproduction than those with less early psychosocial stress. This may have an adaptive function to minimise the chances of lineage extinction, which is more likely in environments of high risk and uncertainty. Previous studies have examined the relationship between early psychosocial stress and life history stages (e.g., age at puberty, age at first sex and age at first birth). However, these studies are limited in that they either examined only a few early psychosocial stressors, examined psychosocial stress relatively late in individuals' lives and/or were restricted to women. Thus, the first aim of the present thesis was to examine these findings in both genders using a measure of early psychosocial stress comprised of 24 categories of retrospectively assessed stressors (e.g., sexual abuse, physical abuse, parental divorce, rated quality of family life) during the first 7 years of life. It was hypothesised that individuals with high, as opposed to low, levels of early psychosocial stress would pass through life history stages earlier. The second aim was to examine how early psychosocial stress affects characteristics associated with life history traits, such as individuals? length, number and type of heterosexual relationships, number of sex partners, adult attachment styles, number of pregnancy terminations, and attitudes and behaviours towards contraceptive use. High levels of early psychosocial stress were predicted to be associated with characteristics reflecting a quantitative, as opposed to a qualitative, reproductive approach (e.g., more sex partners, more short-term relationships, insecure attachment styles). The third aim was to examine how early psychosocial stress is related to mate choice because numerous studies have identified what traits individuals' desire in a mate but not whether early psychosocial stress affects these choices. ... Early psychosocial stress generally had no effects on age at first sex, age at first birth, the number of pregnancy terminations, and mate choices. On the other hand, individuals with high, as opposed to low, levels of early psychosocial stress were more likely to be insecurely attached, had more short-term sexual relationships (men only), had more extra-pair copulations, were more likely to be divorced/separated, had a greater lifetime number of sex partners (men only), and had lower self-rated frequencies of contraception use. Overall, some of these findings are consistent with life history theory, which suggests that individuals with high levels of early psychosocial stress (i.e., those living in environments of high risk and uncertainty) should reach biological maturation earlier, engage in behaviours that facilitate earlier and more frequent reproduction to minimise the chances of lineage extinction. Implications for public health, limitations of the present study and future directions are also discussed.