Diss. (sammanfattning) Stockholm : Karolinska institutet., 2005. / Härtill 5 uppsatser.

This research using quantitative and qualitative methods studied the psychosocial well-being of marginalised youth of African descent in South Africa. The study of well-being amongst the youth has been the focus of many research studies in the past two decades (Bach, 2011; Koen, 2010; Ungar, 2005); hence the continuing intellectual debate on the best possible ways to promote youth well-being (Koen, 2010; Shah, Graidage, & Valencia, 2005; Van Schalkwyk, 2010). The major shift within the psychological sphere, i.e. from the illness model to positive psychology focusing on the enhancement of human capabilities as well as well-being (Seligman, 2004), has resulted in a greater need for studies exploring well-being, especially amongst the youth of South Africa. This study of psychosocial well-being was conducted in line with, amongst other theories, the Keyes and Lopez (2002) theory of complete mental health, viewing mental health as not only the absence of mental illness, but as high levels of functioning in the psychological, emotional and social dimensions of human behaviour. Of particular interest to the current author was the degree to which marginalised African youth could experience psychosocial well-being, considered against Jahoda‟s (1958) view of positive mental health, Ryff‟s psychological well-being model (Ryff, 1989, Ryff & Singer, 1995), Keyes‟ mental health continuum (1998, 2002, 2007), Wissing and Van Eeden‟s (2002) general psychological well-being factor, as well as Seligman‟s PERMA model (2011). Although some youth experience well-being and are flourishing, the urgent need for the development of wellness in youth was indicated by the findings of Keyes (2006) on adolescent mental health. In various studies, it was found that approximately 20% of youth experience mental illness, but Keyes (2006) questioned the quality of mental health of the remaining 80%, since he found that only moderate mental health was experienced in youth aged between 15-18 years. Although there have been a number of studies focusing on young people and their psychosocial well being, there is a lot that still needs to be done in terms of research and intervention. Van Schalkwyk (2009) indicated that although there is a dearth of validated data on the psychosocial well-being of the youth within the South African context; there is a need for more in-depth research on this subject. This study hopes to make a contribution in this regard. A mixed method research design was employed and the first quantitative phase (Article 1) used validated self-report questionnaires to measure the prevalence of psychosocial well-being amongst a group of marginalised African youth (N=794). These instruments measured psychological, emotional and social well-being (Mental Health Continuum-Short Form), coping self-efficacy (Coping Self Efficacy Scale) and symptoms of distress (Depression, Anxiety and Stress Scale). A structural equation model was identified explaining the relationships between the three constructs used in the research. The second phase of the research (Article 2) was qualitative in nature and it explored, through the use of semi-structured interviews and focus group discussions (N=30), the personal narratives of the participants who (during the quantitative phase) were identified as high, moderate or low in their well-being. Themes and subthemes were identified that gave a qualitative picture of the well-being or lack thereof of the participants. In the third and final phase of the study, the data obtained from the two preceding phases as well as the literature review was used to formulate guidelines with specific strategies. These can be used by professionals working with the youth to help them harness their strengths in order to enhance their psychosocial well-being as well as lessen their symptoms of depression, anxiety and stress. Results from the quantitative component of this study was mainly that coping self-efficacy proved to positively explain the variance of mental health and well-being and negatively the symptoms of depression, anxiety and stress. Mental health and well-being also proved to be salutary antecedents of symptoms of distress. Themes were analysed from the qualitative data and the following wellness-enhancing themes emerged from the data analysis: altruism, emotional resilience, social strengths, empathy for others, a positive outlook towards life, goals and aspirations, a strong support system, such as a loving and caring mother, and a supportive community. Religion, Christian faith and values further emerged as a common theme across all three groups of participants. The thematic similar findings on wellness-hindering attributes among the participants included loss of family well-being, painful past life experiences, an absent father, emotional turmoil, and poor self-esteem. The results provided by both the empirical components of the study were used in the formulation of guidelines with specific strategies for a strength-based intervention programme aimed at the enhancement of coping self-efficacy and psychosocial well-being amongst the youth. The study was finally evaluated and conclusions were drawn, limitations exposed and recommendations made. / PhD (Psychology)--North-West University, Vaal Triangle Campus,2015

This research using quantitative and qualitative methods studied the psychosocial well-being of marginalised youth of African descent in South Africa. The study of well-being amongst the youth has been the focus of many research studies in the past two decades (Bach, 2011; Koen, 2010; Ungar, 2005); hence the continuing intellectual debate on the best possible ways to promote youth well-being (Koen, 2010; Shah, Graidage, & Valencia, 2005; Van Schalkwyk, 2010). The major shift within the psychological sphere, i.e. from the illness model to positive psychology focusing on the enhancement of human capabilities as well as well-being (Seligman, 2004), has resulted in a greater need for studies exploring well-being, especially amongst the youth of South Africa. This study of psychosocial well-being was conducted in line with, amongst other theories, the Keyes and Lopez (2002) theory of complete mental health, viewing mental health as not only the absence of mental illness, but as high levels of functioning in the psychological, emotional and social dimensions of human behaviour. Of particular interest to the current author was the degree to which marginalised African youth could experience psychosocial well-being, considered against Jahoda‟s (1958) view of positive mental health, Ryff‟s psychological well-being model (Ryff, 1989, Ryff & Singer, 1995), Keyes‟ mental health continuum (1998, 2002, 2007), Wissing and Van Eeden‟s (2002) general psychological well-being factor, as well as Seligman‟s PERMA model (2011). Although some youth experience well-being and are flourishing, the urgent need for the development of wellness in youth was indicated by the findings of Keyes (2006) on adolescent mental health. In various studies, it was found that approximately 20% of youth experience mental illness, but Keyes (2006) questioned the quality of mental health of the remaining 80%, since he found that only moderate mental health was experienced in youth aged between 15-18 years. Although there have been a number of studies focusing on young people and their psychosocial well being, there is a lot that still needs to be done in terms of research and intervention. Van Schalkwyk (2009) indicated that although there is a dearth of validated data on the psychosocial well-being of the youth within the South African context; there is a need for more in-depth research on this subject. This study hopes to make a contribution in this regard. A mixed method research design was employed and the first quantitative phase (Article 1) used validated self-report questionnaires to measure the prevalence of psychosocial well-being amongst a group of marginalised African youth (N=794). These instruments measured psychological, emotional and social well-being (Mental Health Continuum-Short Form), coping self-efficacy (Coping Self Efficacy Scale) and symptoms of distress (Depression, Anxiety and Stress Scale). A structural equation model was identified explaining the relationships between the three constructs used in the research. The second phase of the research (Article 2) was qualitative in nature and it explored, through the use of semi-structured interviews and focus group discussions (N=30), the personal narratives of the participants who (during the quantitative phase) were identified as high, moderate or low in their well-being. Themes and subthemes were identified that gave a qualitative picture of the well-being or lack thereof of the participants. In the third and final phase of the study, the data obtained from the two preceding phases as well as the literature review was used to formulate guidelines with specific strategies. These can be used by professionals working with the youth to help them harness their strengths in order to enhance their psychosocial well-being as well as lessen their symptoms of depression, anxiety and stress. Results from the quantitative component of this study was mainly that coping self-efficacy proved to positively explain the variance of mental health and well-being and negatively the symptoms of depression, anxiety and stress. Mental health and well-being also proved to be salutary antecedents of symptoms of distress. Themes were analysed from the qualitative data and the following wellness-enhancing themes emerged from the data analysis: altruism, emotional resilience, social strengths, empathy for others, a positive outlook towards life, goals and aspirations, a strong support system, such as a loving and caring mother, and a supportive community. Religion, Christian faith and values further emerged as a common theme across all three groups of participants. The thematic similar findings on wellness-hindering attributes among the participants included loss of family well-being, painful past life experiences, an absent father, emotional turmoil, and poor self-esteem. The results provided by both the empirical components of the study were used in the formulation of guidelines with specific strategies for a strength-based intervention programme aimed at the enhancement of coping self-efficacy and psychosocial well-being amongst the youth. The study was finally evaluated and conclusions were drawn, limitations exposed and recommendations made. / PhD (Psychology)--North-West University, Vaal Triangle Campus,2015

The numbers of people with spinal cord injuries (SCI) in Thailand are increasing. Thai rehabilitation care focuses treatment on acute care with little attention to the lives of clients after discharge from institutions. To date, there has been no research on rehabilitation outcomes and factors relevant to these issues for people with SCI at home and in the community in Thailand. The purpose of this study was to identify and compare the outcomes of functional status, depression, anxiety and stress, and health status of people with SCI, both at discharge and at three months post-discharge from hospital. One hundred twenty-one participants with SCI were recruited from ten major hospitals in Thailand. Data was collected at 48 hours pre-discharge and again at three months post-discharge using the Functional Independence Measure (FIM), the Depression, Anxiety, and Stress Scale (DASS), and the SF-36 Health Survey. The results demonstrated that mean scores of functional status at discharge were significantly higher than at three months post-discharge. Depression and anxiety scores at discharge were significantly lower than depression and anxiety scores at three months postdischarge. Stress score had not significantly changed from discharge to post-discharge. Health status scores at discharge were also higher than at three months post-discharge on eight subscales. Factors relevant to or predicting functional status were marital status, attendant care, number of architectural barriers, fulfilled occupational therapy (OT) needs, and number of different services required but not received. Factors predicting depression, anxiety and stress were marital and economic status, age at onset, education level, duration of disability, fulfilled OT needs, number of different services received, and numbers of different service required but not received. / Factors predicting health status were marital status, economic status, age at onset, education level, duration of disability, attendant care, number of architectural barriers, fulfilled OT needs, number of different services received, and number of different services required but not received. Some predictive factors are culture-specific, but on others, rehabilitation professionals could ease the transition from hospital to home for people with SCI.

Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 4 uppsatser.

Respostas adaptativas ao estresse podem ser acompanhadas por alterações nos comportamentos emocionais, em particular relacionados com medo e ansiedade, bem como alterações na sensibilidade dolorosa. Ainda, tem sido investigado o papel do óxido nítrico em áreas encefálicas relacionadas ao comportamento defensivo. Embora várias evidências têm demonstrado que o enriquecimento ambiental promove melhora nos processos de memória, no aprendizado e em respostas nociceptivas, a relação entre o estresse crônico e as vantagens da utilização do enriquecimento ambiental ainda são pouco investigadas. O presente estudo teve como objetivo investigar se o enriquecimento ambiental promove alteração do comportamento emocional, da sensibilidade nociceptiva, bem como na imunorreatividade à nNOS no núcleo central da amígdala, na formação hipocampal e na região dorsolateral da substância cinzenta periaquedutal, em ratos submetidos ao estresse por isolamento social ou estresse crônico variado e mantidos em ambiente enriquecido ou sem enriquecimento. Ratos machos Wistar (~70g) foram divididos aleatoriamente em dois grandes grupos experimentais: Ambiente Padrão (Padrão) ou Ambiente Enriquecido (EE), mantidos por 38 dias. Cada grupo foi subdividido dependendo do tipo de estresse crônico: Controle (sem estresse), Isolamento Social (por 38 dias) e Estresse Crônico Variado (do dia 28 ao dia 37). Ao fim do tempo experimental (dia 38) os ratos foram avaliados quanto ao comportamento emocional pelos testes de labirinto em cruz elevado (LCE) e claro/escuro (TCE) e sensibilidade nociceptiva pelo teste da placa quente (a qual foi realizada em duas etapas, sendo a primeira medida no dia 0 e outra no dia 38). A eutanásia dos ratos ocorreu no dia 39, para coleta do encéfalo para análise da imunorreatividade à óxido nítrico sintase neuronal (nNOS). Levando-se em consideração o comportamento emocional e a sensibilidade nociceptiva, os diferentes tipos de estresse crônico diminuíram a porcentagem de tempo, a frequência de entrada e a exploração da extremidade dos braços abertos e na frequência de mergulho de cabeça no teste do LCE, apesar de não alterar a sensibilidade nociceptiva. Por outro lado, o enriquecimento ambiental aumentou a porcentagem de tempo, a frequência de entrada e a exploração da extremidade dos braços abertos no teste do LCE, apesar de não alterar a sensibilidade nociceptiva. Foi observado aumento da imunorreatividade à nNOS na formação hipocampal em diferentes tipos de estresse crônico. Em particular, na região de CA3 houve interação significante entre os fatores estresse por isolamento social e ambiente de manutenção. Deste modo, os resultados obtidos neste trabalho sugerem que a formação hipocampal desempenha importante função no efeito ansiogênico exercido pelos diferentes tipos de estressores crônicos (aqui representados pelo isolamento social e pelo estresse crônico variado) provavelmente pela ativação do sistema nitrérgico e sugere-se que o enriquecimento possa prevenir o comportamento do tipo ansioso. / Adaptive responses to stress may be accompanied by changes in emotional behaviors, in particular related to fear and anxiety, as well as changes in pain sensitivity. Furthermore, the role of nitric oxide in brain areas related to defensive behavior has been investigated. Although several evidences have shown that environmental enrichment improves memory processes, learning and nociceptive responses, the relationship between chronic stress and the advantages of using environmental enrichment is still poorly investigated. The present study aimed to investigate whether environmental enrichment promotes alteration of the emotional behavior, nociceptive sensitivity, as well as immunoreactivity to neuronal nitric oxide synthase (nNOS) in the central nucleus of the amygdala, hippocampal formation and dorsolateral periaqueductal gray matter in rats submitted to social isolation stress or chronic unpredictable stress and reared in enriched environment or standard environment. Male Wistar rats (~ 70g) were randomly divided into two major experimental groups: Standard Environment (Standard) or Enriched Environment (EE), maintained for 38 days. Each group was subdivided according to the type of chronic stress: Control (without stress), Social Isolation (for 38 days) and Chronic Unpredictable Stress (from day 28 to day 37). At the end of the experimental time (day 38), the rats were evaluated for emotional behavior by elevated plus maze (EPM) and light/dark box (LDBT) tests and nociceptive sensitivity by the hot plate test (which was performed in two steps , the first being measured on day 0 and the other on day 38). Euthanasia of rats occurred on day 39, to collect the brain for nNOS immunoreactivity analysis. Taking into account emotional behavior and nociceptive sensitivity, the different types of chronic stress decreased the percentage of time, the frequency of entry of the open arms, end-arm exploration and the head dipping frequency in the EPM, despite of not altering the nociceptive sensitivity. On the other hand, environmental enrichment increased the percentage of time, the frequency of entry of the open arms and the end arm-exploration in the EPM test, although it did not alter the nociceptive sensitivity. Increased immunoreactivity to nNOS in hippocampal formation was observed in different types of chronic stress. In particular, in the CA3 region there was a significant interaction between stress factors due to social isolation and maintenance environment. Thus, the results obtained in this study suggest that hippocampal formation plays an important role in the anxiogenic effect exerted by the different types of chronic stressors (represented here by social isolation and by chronic chronic stress) probably due to the activation of the nitrergic system and it is suggested that environmental enrichment can prevent of anxiety-like behavior.

Respostas adaptativas ao estresse podem ser acompanhadas por alterações nos comportamentos emocionais, em particular relacionados com medo e ansiedade, bem como alterações na sensibilidade dolorosa. Ainda, tem sido investigado o papel do óxido nítrico em áreas encefálicas relacionadas ao comportamento defensivo. Embora várias evidências têm demonstrado que o enriquecimento ambiental promove melhora nos processos de memória, no aprendizado e em respostas nociceptivas, a relação entre o estresse crônico e as vantagens da utilização do enriquecimento ambiental ainda são pouco investigadas. O presente estudo teve como objetivo investigar se o enriquecimento ambiental promove alteração do comportamento emocional, da sensibilidade nociceptiva, bem como na imunorreatividade à nNOS no núcleo central da amígdala, na formação hipocampal e na região dorsolateral da substância cinzenta periaquedutal, em ratos submetidos ao estresse por isolamento social ou estresse crônico variado e mantidos em ambiente enriquecido ou sem enriquecimento. Ratos machos Wistar (~70g) foram divididos aleatoriamente em dois grandes grupos experimentais: Ambiente Padrão (Padrão) ou Ambiente Enriquecido (EE), mantidos por 38 dias. Cada grupo foi subdividido dependendo do tipo de estresse crônico: Controle (sem estresse), Isolamento Social (por 38 dias) e Estresse Crônico Variado (do dia 28 ao dia 37). Ao fim do tempo experimental (dia 38) os ratos foram avaliados quanto ao comportamento emocional pelos testes de labirinto em cruz elevado (LCE) e claro/escuro (TCE) e sensibilidade nociceptiva pelo teste da placa quente (a qual foi realizada em duas etapas, sendo a primeira medida no dia 0 e outra no dia 38). A eutanásia dos ratos ocorreu no dia 39, para coleta do encéfalo para análise da imunorreatividade à óxido nítrico sintase neuronal (nNOS). Levando-se em consideração o comportamento emocional e a sensibilidade nociceptiva, os diferentes tipos de estresse crônico diminuíram a porcentagem de tempo, a frequência de entrada e a exploração da extremidade dos braços abertos e na frequência de mergulho de cabeça no teste do LCE, apesar de não alterar a sensibilidade nociceptiva. Por outro lado, o enriquecimento ambiental aumentou a porcentagem de tempo, a frequência de entrada e a exploração da extremidade dos braços abertos no teste do LCE, apesar de não alterar a sensibilidade nociceptiva. Foi observado aumento da imunorreatividade à nNOS na formação hipocampal em diferentes tipos de estresse crônico. Em particular, na região de CA3 houve interação significante entre os fatores estresse por isolamento social e ambiente de manutenção. Deste modo, os resultados obtidos neste trabalho sugerem que a formação hipocampal desempenha importante função no efeito ansiogênico exercido pelos diferentes tipos de estressores crônicos (aqui representados pelo isolamento social e pelo estresse crônico variado) provavelmente pela ativação do sistema nitrérgico e sugere-se que o enriquecimento possa prevenir o comportamento do tipo ansioso. / Adaptive responses to stress may be accompanied by changes in emotional behaviors, in particular related to fear and anxiety, as well as changes in pain sensitivity. Furthermore, the role of nitric oxide in brain areas related to defensive behavior has been investigated. Although several evidences have shown that environmental enrichment improves memory processes, learning and nociceptive responses, the relationship between chronic stress and the advantages of using environmental enrichment is still poorly investigated. The present study aimed to investigate whether environmental enrichment promotes alteration of the emotional behavior, nociceptive sensitivity, as well as immunoreactivity to neuronal nitric oxide synthase (nNOS) in the central nucleus of the amygdala, hippocampal formation and dorsolateral periaqueductal gray matter in rats submitted to social isolation stress or chronic unpredictable stress and reared in enriched environment or standard environment. Male Wistar rats (~ 70g) were randomly divided into two major experimental groups: Standard Environment (Standard) or Enriched Environment (EE), maintained for 38 days. Each group was subdivided according to the type of chronic stress: Control (without stress), Social Isolation (for 38 days) and Chronic Unpredictable Stress (from day 28 to day 37). At the end of the experimental time (day 38), the rats were evaluated for emotional behavior by elevated plus maze (EPM) and light/dark box (LDBT) tests and nociceptive sensitivity by the hot plate test (which was performed in two steps , the first being measured on day 0 and the other on day 38). Euthanasia of rats occurred on day 39, to collect the brain for nNOS immunoreactivity analysis. Taking into account emotional behavior and nociceptive sensitivity, the different types of chronic stress decreased the percentage of time, the frequency of entry of the open arms, end-arm exploration and the head dipping frequency in the EPM, despite of not altering the nociceptive sensitivity. On the other hand, environmental enrichment increased the percentage of time, the frequency of entry of the open arms and the end arm-exploration in the EPM test, although it did not alter the nociceptive sensitivity. Increased immunoreactivity to nNOS in hippocampal formation was observed in different types of chronic stress. In particular, in the CA3 region there was a significant interaction between stress factors due to social isolation and maintenance environment. Thus, the results obtained in this study suggest that hippocampal formation plays an important role in the anxiogenic effect exerted by the different types of chronic stressors (represented here by social isolation and by chronic chronic stress) probably due to the activation of the nitrergic system and it is suggested that environmental enrichment can prevent of anxiety-like behavior.

Der globale Klimawandel gehört zu einem der wichtigsten Themen, die in Politik, Wirtschaft und Wissenschaft diskutiert werden. Der Reduzierung des weltweiten CO2-Ausstoßes wird dabei ein besonderer Stellenwert beigemessen. Auch im Transportsektor wird eine Verringerung der CO2-Emissionen angestrebt. Um dieses Ziel zu erreichen sollte die Nachhaltigkeit im Transportwesen erhöht werden. Elektrofahrzeuge können enorm zu diesem Ziel beitragen. Dies setzt voraus, dass sie während ihrer gesamten Nutzungsphase mit Strom aus regenerativen Energien geladen werden. In diesem Zusammenhang ist es wichtig, auch bei der Produktion auf eine möglichst hohe Nachhaltigkeit zu achten. Das bedeutet, dass die Ressourcen, die zur Produktion eines Elektrofahrzeugs (zum Beispiel Energieressourcen oder eingesetzte Materialien für die Batterieproduktion) möglichst gering gehalten werden sollten. Daher wird empfohlen, die maximale Kapazität einer Batterie und somit die verfügbare Reichweite eines Elektroautos gemäß der tatsächlichen Reichweitenanforderungen der Fahrer auszulegen. Dies bedeutet jedoch, dass Elektroautofahrer mit vergleichbar geringeren Reichweiten umgehen müssen als beim Verbrennerfahrzeug. Zusätzlich ist das Wiederherstellen der Reichweitenressourcen, also das Nachladen des Elektrofahrzeugs, mit höherem Aufwand verbunden als das Nachtanken eines Verbrennerfahrzeugs, da es heutzutage vergleichbar weniger öffentliche Schnelllademöglichkeiten gibt und das Nachladen relativ viel Zeit in Anspruch nimmt. Daher wird die Interaktion mit den Reichweitenressourcen eines Elektrofahrzeugs als relativ herausfordernd wahrgenommen. Dies führt dazu, dass die reichweitenbezogene Nutzerzufriedenheit und das Reichweitenerleben der Fahrer beeinträchtigt und die verfügbaren Reichweitenressourcen nicht optimal ausgenutzt werden. Darüber hinaus wird die limitierte Reichweite von Elektrofahrzeugen häufig auch als eine der wichtigsten Barrieren für die generelle Akzeptanz und Nutzung von Elektrofahrzeugen diskutiert. Um das Potenzial eines Elektrofahrzeugs hinsichtlich der Erhöhung der Nachhaltigkeit im Transportsektor voll auszuschöpfen ist es daher unerlässlich, Möglichkeiten zu finden um diese Barriere unter Beachtung der Anforderungen des Fahrers zu überwinden. Ergänzend zu technischen Lösungen wie zum Beispiel der Weiterentwicklung der Batterietechnology oder der Implementierung einer größeren Anzahl von öffentlichen Schnelllademöglichkeiten, sollten weitere Strategien entwickelt werden um das Reichweitenerleben der Elektroautofahrer zu verbessern und sie zu einer möglichst effizienten Ausreizung der verfügbaren Reichweitenressourcen zu befähigen. Reichweitenstress ist ein wichtiges Konzept in diesem Zusammenhang. Reichweitenstress ist besonders relevant in der Interaktion mit Elektrofahrzeugen auf Grund des relativ begrenzten Zugangs zu Schnellladestationen und relativ langer Ladedauern. Das Konzept ist aber auch auf anderen Arten der Mensch-Technik-Interaktion im Transportsektor übertragbar (z.B. auch auf Verbrennerfahrzeuge). Im Rahmen der vorliegenden Dissertation wird davon ausgegangen, dass sich Reichweitenstress und das breiter definierte Phänomen Reichweitenangst negativ auf die Zufriedenheit mit der Reichweite und der effizienten Nutzung von Elektrofahrzeugen auswirken. Um den maximalen Nachhaltigkeitseffekt von Elektrofahrzeugen ausschöpfen zu können, müssen daher Möglichkeiten gefunden werden um den erlebten Reichweitenstress zu verringern und der Entstehung von Stress vorzubeugen. Die vorliegende Dissertation trägt zu diesem Ziel bei, indem sie ein detailliertes Verständnis zu Reichweitenstress und dem Einfluss verschiedener Resilienzfaktoren im Rahmen von 5 Zeitschriftenartikeln (4 veröffentlich, 1 zur Veröffentlichung eingereicht) zur Verfügung stellt. Resilienzfaktoren meint dabei Faktoren, welche die Fähigkeit des Fahrers mit kritischen Situationen umzugehen erhöhen und somit das Erleben von Stress verringern. Das erste Forschungsziel dieser Arbeit bestand darin, das Konzept Reichweitenstress zur Beschreibung des Reichweitenerlebens in kritischen Reichweitensituationen (d.h., Situationen mit geringem Reichweitenpuffer) zu etablieren, ein theoretisches Rahmenmodell zur Erklärung von Reichweitenstress und möglichen Einflussfaktoren zur Verfügung zu stellen sowie eine Methode zur Erfassung von Reichweitenstress im experimentellen Kontext zu prüfen. Die Ergebnisse der Arbeit konnten zeigen, dass sich das Konzept Reichweitenstress dafür eignet, das Erleben der Fahrer zu beschreiben. Das bereits existierende Modell zur adaptiven Reichweitenkontrolle wurde auf den speziellen Fall einer Fahrt in einer kritischen Reichweitensituation angewendet und um das Konzept Reichweitenstress sowie möglicher, aus der Literatur abgeleiteter, Einflussfaktoren erweitert. Dies ermöglicht es, potenzielle stressreduzierende Faktoren abzuleiten um diese empirisch in einem Feldexperiment zu untersuchen, welches im Rahmen dieser Dissertation weiterentwickelt und getestet wurde. Es konnte gezeigt werden, dass es möglich ist, eine kritische Reichweitensituation in einem Feldexperiment herzustellen. Die Nutzung einer Coverstory ist in diesem Zusammenhang zu empfehlen (z.B. längere Strecke kommunizieren als dann tatsächlich gefahren werden muss). Das zweite Forschungsziel bestand darin, den Einfluss potenzieller Resilienzfaktoren auf den erlebten Reichweitenstress empirisch zu untersuchen. Basierend auf dem weiterentwickelten Modell der adaptiven Reichweitenkontrolle wurden mehrere Faktoren abgeleitet, die einen Einfluss auf das Reichweitenerleben haben sollten: (1) Wissen über Einflussfaktoren auf die Reichweitenentwicklung oder Wissen über Möglichkeiten zum energie-effizienten Fahren, (2) praktische Fahrerfahrung mit Elektrofahrzeugen sowie das Erleben einer kritischen Reichweitensituation, (3) Persönlichkeitseigenschaften wie zum Beispiel Kontrollüberzeugungen im Umgang mit Technik und schließlich (4) technische Systemeigenschaften wie zum Beispiel die wahrgenommene Verlässlichkeit des im Fahrzeug integrierten Systems zur Reichweitenschätzung. Die Ergebnisse zeigten, dass die Vermittlung von relevanten Informationen zur Reichweite eines Elektrofahrzeugs das Reichweitenerleben zum Teil verbessern kann. Insbesondere detaillierte Informationen zum energie-effizienten Fahren haben das Potenzial um Reichweitenstress zu verringern. Daher sollten dem Fahrer diese Informationen auf vielfältigen Wegen zur Verfügung gestellt werden. Dies könnte zum Beispiel über Informationsbroschüren, im Rahmen theoretischer Trainings zur Verbesserung der Interaktion mit dem Elektrofahrzeug, bereits vor dem Kauf durch den Berater oder eventuell sogar im Rahmen der theoretischen Fahrschulausbildung geschehen. Ein weiterer vielversprechender Ansatz wäre die Bereitstellung der relevanten Informationen direkt während der Fahrt durch Informations-, Assistenz- und Tutorsysteme. Praktische Fahrerfahrung sowie das Erleben und erfolgreiche Bewältigen einer kritischen Reichweitensituation in einer relativ geschützten Umgebung konnten Reichweitenstress ebenfalls verringern. Daher wird empfohlen Probefahrten mit Elektrofahrzeugen sowie Praxistrainings anzubieten, die im Idealfall auch eine unterstützte Fahrt in einer kritischen Reichweitensituation beinhalten sollten. Durch das aktive Auseinandersetzen mit den Grenzen der Reichweite kann ein Lernprozess angestoßen werden, der zu einem effizienteren Umgang mit den Reichweitenressourcen des Fahrzeugs führt. Auch in diesem Kontext bieten Assistenzsysteme im Fahrzeug ein großes Potenzial. Sie sollten so gestaltet sein, dass sie einen aktiven Umgang mit der Reichweite sowie eine kritische Auseinandersetzung mit der Reichweitendynamik ermöglichen und fördern. In der vorliegenden Dissertation konnte gezeigt werden, dass Persönlichkeitsmerkmal wie hohe Emotionale Stabilität und hohe Kontrollüberzeugungen im Umgang mit Technik mit einem geringeren erlebten Reichweitenstress zusammenhängen. Dies hat vor allem theoretische Implikationen und kann dazu beitragen, relative Unterschiede zwischen Individuen zu verstehen. Zudem konnte gezeigt werden, dass technische Systemeigenschaften wie die wahrgenommene Verlässlichkeit des Systems zur Reichweitenschätzung (z.B. zu Grunde liegender Algorithmus, Aktualität und Genauigkeit der angezeigten Reichweiteninformationen) ein wichtiger Faktor im Zusammenhang mit reduziertem Reichweitenstress darstellt. Daher sollte darauf geachtet werden, die verbliebene Reichweite eines Elektrofahrzeugs möglichst genau und verlässlich zu schätzen (z.B. Integration möglichst vieler Einflussfaktoren in den Algorithmus zur Reichweitenschätzung) sowie gut verständlich und nachvollziehbar zu präsentieren. Das dritte Forschungsziel bestand schließlich darin, die Relevanz des Konzepts Reichweitenstress auch jenseits des experimentellen Settings zu überprüfen. Bisherige Forschung konnte zeigen, dass der alltägliche Umgang mit Elektrofahrzeugen eher durch das Vermeiden kritischer Reichweitensituationen gekennzeichnet ist. Daher stellte sich die Frage, ob Reichweitenstress und der Einfluss der Resilienzfaktoren auch im Alltagserleben eine Rolle spielt. Die Ergebnisse einer Langzeit-Feldstudie konnten zeigen, dass Reichweitenstress in Form von Sorgen oder Bedenken bezüglich der Reichweite durchaus relevant im täglichen Umgang mit Elektrofahrzeugen ist. Zudem konnte gezeigt werden, dass die identifizierten Resilienzfaktoren (z.B. praktische Fahrerfahrung und technische Systemeigenschaften) auch unter alltäglichen Bedingungen das Erleben von Reichweitenstress verringern können. Zusammenfassend lässt sich sagen, dass Reichweitenstress ein relevantes Konzept im Zusammenhang mit der Interaktion mit Elektrofahrzeugen darstellt. Das Erleben von Reichweitenstress kann durch verschiedene Resilienzfaktoren wie zum Beispiel relevante Wissenselemente und Erfahrungen positiv beeinflusst werden. Aus den Ergebnissen lassen sich Strategien und Design-Empfehlungen für Informations- und Assistenzsysteme ableiten. Dadurch kann das Reichweitenerleben verbessert und ein effizienter Umgang mit der Reichweite gefördert werden. Dies trägt schließlich auch dazu bei, die Zufriedenheit mit Elektrofahrzeugen sowie deren Akzeptanz zu verringern. Somit kann ein Beitrag zur Erhöhung der Nachhaltigkeit im Transportsektor geleistet werden. Das Elektrofahrzeug stellt in dem Zusammenhang nur ein Beispiel für Systeme dar, die einen Umgang mit begrenzten Ressourcen erfordern. Die theoretischen Konzepte, Annahmen, Ergebnisse sowie Schlussfolgerungen der vorliegenden Dissertation können auch auf andere Formen der Mensch-Maschine-Interaktion übertragen werden, welche sich dadurch auszeichnen, dass eine Interaktion mit dem technischen System zu einer Verringerung der Ressourcen führt. Diese Arbeit kann also auch einen Betrag dazu leisten, den Stress und die mentale Beanspruchung beim Umgang mit diesen Systemen zu verringern sowie den effizienten Umgang mit begrenzten Ressourcen zu verbessern.:I Synopsis 1 Sustainability in the Context of Road Transport 2 The Challenge of Battery Electric Vehicles‘ Limited Range and the Contribution of the Present Dissertation 3 Overview of the Dissertation 4 Interaction with Battery Electric Vehicles' Range 4.1 Psychological Reference Values for the Regulation of Range Resources 4.2 The Adaptive Control of Range Resources (ACOR) Model 5 User Experience in Critical Range Situations 5.1 The Concept of Range Stress - Conceptual Framework and Empirical Investigation 5.1.1 Range Stress as One Facet of Drivers’ Experience in Critical Range Situations 5.1.2 Adaption of the ACOR Model with the Focus on Range Stress 5.1.3 Empirical Investigation of Range Stress and the Effects of Resilience Factors 5.2 Reduction of Range Stress - Influence of Inter-Individual Differences and Technical System Characteristics 5.2.1 The Influence of Domain Specific Knowledge on Range Stress 5.2.2 The Influence of Practical Driving Experience on Range Stress 5.2.3 The Influence of Personality Traits and Technical System Characteristics on Range Stress 5.3 Everyday Range Stress - Relevance of Range Stress and Resilience Factors in the Daily Interaction with Battery Electric Vehicles 6 Research Objectives of the Dissertation 6.1 Research Objective 1: Providing a Conceptual Framework and Validating a Methodology to Examine Range Stress and the Influence of Resilience Factors 6.2 Research Objective 2: Examining the Influence of Range-Related Knowledge, Practical Driving Experience, Personality Traits and Technical System Characteristics on Range Stress 6.3 Research Objective 3: Investigation of Range Stress and Specific Resilience Factors in the Everyday Usage of Battery Electric Vehicles 7 Overview of the Methodology 7.1 Field-Experimental Studies to Investigate Range Stress in a Critical Range Situation 7.1.1 General Setup of the Field Studies 7.1.2 Specific Characteristics of the Particular Field Studies 7.2 Long-Term Field Trial to Investigate Range Stress in Everyday BEV Interaction 8 Discussion and Critical Reflection of the Results 8.1 Research Objective 1: Providing a Conceptual Framework and Validating a Methodology to Examine Range Stress and the Influence of Resilience Factors 8.1.1 The Adapted ACOR Model (ACOR-c) with the Focus on Range Stress 8.1.2 Empirical Investigation of Range Stress in a Field-Experimental Setting 8.2 Research Objective 2: Examining the Influence of Range-Related Knowledge, Practical Driving Experience, Personality Traits and Technical System Characteristics on Range Stress 8.2.1 Influence of Range-Related Knowledge on Range Stress 8.2.2 Influence of Practical Driving Experience on Range Stress 8.2.3 Subjective Range Competence as Relevant Factor for Drivers’ Range Experience 8.2.4 Influence of Personality Traits and Technical System Characteristics on Range Stress 8.3 Research Objective 3: Investigation of Range Stress and Specific Resilience Factors in the Everyday Usage of Battery Electric Vehicles 9 Implications of the Results 9.1 Implications for the Conceptual Framework and the Methodology 9.2 Implications Regarding Range-Related Knowledge, Practical Driving Experience, Personality Traits and Technical System Characteristics 9.3 Implications Regarding Range Stress in the Everyday Interaction with Battery Electric Vehicles 10 Conclusion 11 References II Preliminary Study: Understanding the impact of electric vehicle driving experience on range anxiety III Paper 1: First-time experience of critical range situations in BEV use and the positive effect of coping information IV Paper 2: User experience with electric vehicles while driving in a critical range situation – a qualitative approach V Paper 3: Individual differences in BEV drivers’ range stress during first encounter of a critical range situation VI Paper 4: Positive influence of practical electric vehicle driving experience and range related knowledge on drivers' experienced range stress VII Paper 5: Which factors can protect against range stress in everyday usage of battery electric vehicles? Towards enhancing sustainability of electric mobility systems VIII Curriculum Vitae IX Publications

Background: Subtle and inconsistent differences in hypothalamic-pituitary-adrenal (HPA) axis activity have been reported for patients with panic disorder. While these patients show little or no alterations in basal ACTH and cortisol levels, it has been hypothesized that HPA hyperresponsivity was a trait in panic patients when exposed to novel and uncontrollable stimulation. Methods: Thirty-four patients (23 females, mean age 35 yrs) diagnosed with panic disorder were compared to 34 healthy controls matched for age, gender, smoking status, and use of oral contraceptives. Both groups were exposed twice to a potent laboratory stress protocol, the Trier Social Stress Test (TSST) on consecutive days. Free salivary cortisol levels and heart rate responses were repeatedly measured before and following the TSST. In addition, the cortisol awakening response (CAR) was assessed to further investigate HPA reactivity in PD patients. Results: While the TSST induced similar heart rate stress responses in both groups, cortisol responses were clearly absent in the panic patients with normal responses in the controls (F(1.96, 66) = 20.16; p < 0.001). No differences in basal cortisol levels were observed in the extended baseline period. The same cortisol stress non-response patterns were observed when patients with/without comorbid depression, or with/without psychotropic medication were compared. In contrast to their non-response to the psychosocial stressor, panic patients showed a significant CAR. Conclusion: These findings provide strong evidence to suggest that PD patients present with a striking lack of cortisol responsivity to acute uncontrollable psychosocial stress under laboratory conditions. This unresponsiveness of the HPA axis appears to be rather specific, since a normal CAR in the morning could be documented in these patients. Thus, the present results do not support the hypothesis that PD patients show a trait HPA hyperresponsiveness to novel and uncontrollable stimulation. In contrast, the data provide support for a hyporesponsive HPA axis under emotional stress in PD patients.

Accumulating evidence suggests that the magnetic resonance imaging (MRI) scanner can act as a stressor, eliciting subjective and neuroendocrine stress responses. Approaches to familiarize subjects with the scanner could help minimizing unintended effects on neural activation patterns of interest. Controlled studies on the effects of a scanner training are however missing. Using a comparative design, we analyzed within- and between session changes in subjective and neuroendocrine stress parameters in 63 healthy, scanner-naïve adults who participated in a two-day training protocol in an MRI, mock, or lab environment. A habituation task was used to assess within-session changes in subjective and neuroendocrine (cortisol) stress parameters; between-session changes were indicated by differences between days. MRI and mock, but not lab training were successful in reducing subjective distress towards the scanner. In contrast, cortisol reactivity towards the training environment generally increased during day 2, and the percentage of cortisol responders particularly rose in the mock and MRI groups. Within-session habituation of subjective arousal and anxiety was observed during both days and irrespective of training condition. Present findings demonstrate that training in a scanner environment successfully reduces subjective distress, but may also induce sensitization of endocrine stress levels during repeated scanning. Subjective distress can further be stabilized by acclimating subjects to the environment prior to the MRI assessment, including a short habituation phase into the assessment protocol. If replicated, present findings should be considered by researchers employing repeated measurement designs where subjects are exposed to a scanner more than once.