TY - JOUR A1 - Wright, Michelle F. A1 - Wachs, Sebastian T1 - Self-isolation practices and perceived social support from friends BT - the impact on adolescents' mental health JF - European journal of developmental psychology N2 - The purpose of the present study was to investigate the moderating effect of perceived social support from friends in the associations between self-isolation practices during the COVID-19 pandemic and adolescents' mental health (i.e., depression, subjective health complaints, self-harm), measured six months later (Time 2). Participants were 1,567 7(th) and 8(th) graders (51% female; 51% white; M age = 13.67) from the United States. They completed questionnaires on perceived social support from friends, depression, subjective health complaints, and self-harm at Time 1, and self-isolation practices during COVID-19, depression, subjective health complaints, and self-harm at Time 2. The findings revealed that self-isolation practices during COVID-19 was related positively to Time 1 perceived social support from friends, and negatively to Time 2 depression, subjective health complaints, and self-harm, while accounting for Time 1 mental health outcomes. Higher perceived social support from friends at Time 1 buffered against the negative impacts on adolescents' mental health outcomes at Time 2 when they practiced greater self-isolation during COVID-19, while lower perceived social support at Time 1 had the opposite effects on Time 2 mental health outcomes. KW - Friends KW - self-isolation KW - pandemic KW - mental health KW - depression KW - subjective KW - health complaints KW - self-harm Y1 - 2022 U6 - https://doi.org/10.1080/17405629.2022.2146090 SN - 1740-5629 SN - 1740-5610 VL - 20 IS - 4 SP - 635 EP - 648 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Wachs, Sebastian A1 - Gamez-Guadix, Manuel A1 - Wright, Michelle F. T1 - Online hate speech victimization and depressive symptoms among adolescents BT - the protective role of resilience JF - Cyberpsychology, behavior and social networking N2 - Online hate speech has become a widespread problem in the daily life of adolescents. Despite growing societal and academic interest in this online risk, not much is known about the relationship between online hate speech victimization (OHSV) and adolescents' mental well-being. In addition, potential factors influencing the magnitude of this relationship remain unclear. To address these gaps in the literature, this study investigated the relationship between OHSV and depressive symptoms and the buffering effects of resilience in this relationship. The sample consists of 1,632 adolescents (49.1% girls) between 12 and 18 years old (M-age = 13.83, SDage = 1.23), recruited from nine schools across Spain. Self-report questionnaires were administered to assess OHSV, depressive symptoms, and resilience. Regression analyses revealed that OHSV was positively linked to depressive symptoms. In addition, victims of online hate speech were less likely to report depressive symptoms when they reported average or high levels of resilience (i.e., social competence, personal competence, structured style, social resources, and family cohesion) compared with those with low levels of resilience. Our findings highlight the need for the development of intervention programs and the relevance of focusing on internal and external developmental assets to mitigate negative outcomes for victims of online hate speech. KW - hate speech KW - cyberhate KW - depression KW - resilience KW - adolescents Y1 - 2022 U6 - https://doi.org/10.1089/cyber.2022.0009 SN - 2152-2715 SN - 2152-2723 VL - 25 IS - 7 SP - 416 EP - 423 PB - Liebert CY - New Rochelle ER - TY - THES A1 - Schell, Mareike T1 - Investigating the effect of Lactobacillus rhamnosus GG on emotional behavior in diet-induced obese C57BL/6N mice T1 - Untersuchung der Wirkung von Lactobacillus rhamnosus GG bei Störungen des emotionalen Verhaltens in einem Mausmodell Diät-induzierter Adipositas N2 - The prevalence of depression and anxiety is increased in obese patients compared to healthy humans, which is partially due to a shared pathogenesis, including insulin resistance and inflammation. These factors are also linked to intestinal dysbiosis. Additionally, the chronic consumption of diets rich in saturated fats results in body weight gain, hormonal resistances and unfavorable changes in the microbiome composition. The intake of Lactobacilli has already been shown to improve dysbiosis along with metabolism and mood. Yet, the beneficial role and the underlying mechanism of Lactobacillus rhamnosus GG (LGG) to improve emotional behavior in established diet-induced obese conditions are, so far, unknown. To characterize the role of LGG in diet-induced obesity, female and male C57BL/6N mice were fed a semi-synthetic low-fat diet (LFD, 10 % kcal from fat) or a conventional high-fat diet (HFD, 45 % kcal from fat) for initial 6 weeks, which was followed by daily oral gavage of vehicle or 1x10^8 CFU of LGG until the end of the experiment. Mice were subjected to basic metabolic and extensive behavioral phenotyping, with a focus on emotional behavior. Moreover, composition of cecal gut microbiome, metabolomic profile in plasma and cerebrospinal fluid was investigated and followed by molecular analyses. Both HFD-feeding and LGG application resulted in sex-specific differences. While LGG prevented the increase of plasma insulin, adrenal gland weight and hyperactivity in diet-induced obese female mice, there was no regulation of anxiodepressive-like behavior. In contrast, metabolism of male mice did not benefit from LGG application, but strikingly, LGG decreased specifically depressive-like behavior in the Mousetail Suspension Test which was confirmed by the Splash Test characterizing motivation for ’self-care’. The microbiome analysis in male mice revealed that HFD-feeding, but not LGG application, altered cecal microbiome composition, indicating a direct effect of LGG on behavioral regulation. However, in female mice, both HFD-feeding and LGG application resulted in changes of microbiome composition, which presumably affected metabolism. Moreover, as diet-induced obese female mice unexpectedly did not exhibit anxiodepressive-like behavior, follow-up analyses were conducted in male mice. Here, HFD-feeding significantly altered abundance of plasma lipids whereas LGG decreased branched chain amino acids which associated with improved emotional behavior. In nucleus accumbens (NAcc) and VTA/SN, which belong to the dopaminergic system, LGG restored HFD-induced decrease of tyrosine hydroxylase, the rate-limiting enzyme in dopamine synthesis, on gene expression level. Lastly, transcriptome analysis in the NAcc identified gene expression of cholecystokinin as a potential mediator of the effect of LGG on HFD-induced emotional alterations. In summary, this thesis revealed the beneficial effects of LGG application on emotional alterations in established diet-induced obesity. Furthermore, both HFD-feeding and LGG treatment exhibited sex-specific effects, resulting in metabolic improvements in female mice while LGG application mitigated depressive-like behavior in obese male mice along with a molecular signature of restored dopamine synthesis and neuropeptide signaling. N2 - n adipösen Patienten liegt eine erhöhte Prävalenz von Depressionen und Angsterkrankungen vor. Dies liegt unter anderem an einer gemeinsamen Pathogenese, der eine Insulinresistenz sowie ein chronischer Entzündungszustand zugrunde liegen. Diese Faktoren sind mit einer intestinalen Dysbiose assoziiert, die auch durch eine Fehlernährung, beispielsweise mit einer fettreichen Diät, hervorgerufen werden kann. Es konnte bereits gezeigt werden, dass die Aufnahme von Laktobazillen nicht nur eine Dysbiose und den Stoffwechsel verbessert, sondern sich auch positiv auf das Gemüt auswirken kann. Ob jedoch Lactobacillus rhamnosus GG in der Lage ist, in einem Zustand der etablierten ernährungsbedingten Fettleibigkeit das emotionale Verhalten zu verbessern und welche Mechanismen zugrunde liegen, ist noch ungeklärt. Um die Rolle von LGG bei ernährungsbedingter Fettleibigkeit zu charakterisieren, wurden weibliche und männliche C57BL/6N Mäuse mit einer semi-synthetischen Niedrigfettdiät (LFD, 10 % kcal aus Fett) oder einer konventionellen Hochfettdiät (HFD, 45 % kcal aus Fett) für die ersten 6 Wochen gefüttert, um den Zustand einer Adipositas zu etablieren. Anschließend haben die Mäuse eine tägliche perorale Applikation eines Vehikels oder 1x10^8 KBE LGG bis zum Versuchsende erhalten. Die Mäuse wurden einer allgemeinen metabolischen Charakterisierung und einer umfassenden Verhaltensphänotypisierung unterzogen, die Aufschlüsse über das emotionale Verhalten liefern sollen. Darüber hinaus wurde die Zusammensetzung des Darmmikrobioms bestimmt, im Plasma und in der Zerebrospinalflüssigkeit das Metabolitprofil untersucht und durch molekulare Analysen ergänzt. Sowohl die HFD-Fütterung als auch die LGG-Applikation führten zu geschlechtsspezifischen Unterschieden. Während LGG den diätinduzierten Anstieg von Plasmainsulin, ein erhöhtes Nebennierengewicht und Hyperaktivität in weiblichen Mäusen verhinderte, wurde das emotionale Verhalten nicht reguliert. Im Gegensatz dazu profitierte der Stoffwechsel männlicher Mäuse nicht von der LGG-Anwendung, jedoch war LGG in der Lage, spezifisch das depressiv-ähnliches Verhalten zu verbessern, was durch eine Analyse des zielgerichteten Verhaltens bestätigt wurde. Die Mikrobiomanalyse ergab, dass die Diät, jedoch nicht LGG, die Zusammensetzung des Darmmikrobioms in männlichen Mäusen verändert, was auf eine direkte Rolle von LGG in der Verhaltensregulation hindeutet. Im Vergleich dazu war das Darmmikrobiom in weiblichen Mäusen durch die Diät als auch durch LGG verändert, was zu den positiven Veränderungen der Stoffwechselparameter geführt haben könnte. Da weibliche Mäuse weder durch die HFD-Fütterung noch durch die LGG-Gabe einen Effekt auf emotionales Verhalten aufwiesen, wurden die Folgeanalysen bei männlichen Mäusen durchgeführt. Während die HFD-Fütterung das Vorkommen von Plasmalipiden veränderte, lagen aufgrund der LGG-Gabe verzweigtkettige Aminosäuren verringert vor, was mit einem verbessertem emotionalen Verhalten assoziierte. In den dopaminergen Gehirnregionen Nucleus Accumbens (NAcc) und VTA/SN revertierte LGG die HFD-induzierte Reduktion der Tyrosinhydroxylase Genexpression, des geschwindigkeitsbegrenzenden Enzyms in der Dopaminsynthese. Abschließend wurde eine Transkriptomanalyse mittels RNA Sequencing durchgeführt, welche die Genexpression von Cholezystokinin im NAcc als potenzieller Mediator in der Wirkung von LGG bei HFD-induzierten emotionalen Veränderungen identifizierte. Zusammenfassend konnten in dieser Arbeit die positiven Auswirkungen der LGG-Gabe auf emotionales Verhalten bei etablierter ernährungsbedingter Fettleibigkeit gezeigt werden.. Sowohl die HFD-Fütterung als auch die LGG-Gabe führten zu geschlechtsspezifischen Effekten, was zu Stoffwechselverbesserungen bei weiblichen Mäusen führte, während die LGG-Gabe das depressiv-ähnliche Verhalten bei männlichen Mäusen abschwächte. Zudem wurden auf Genexpressionsebene Tyrosinhydroxylase und Cholezystokinin identifiziert, die potentiell den Effekt von LGG auf das emotionale Verhalten in einem Modell etablierter ernährungsbedingter Fettleibigkeit vermitteln. KW - obesity KW - insulin resistance KW - probiotics KW - lactobacillus KW - depression KW - emotionality Y1 - 2022 ER - TY - JOUR A1 - Pérez Chaparro, Camilo Germán Alberto A1 - Kangas, Maria A1 - Zech, Philipp A1 - Schuch, Felipe B. A1 - Rapp, Michael A. A1 - Heißel, Andreas T1 - Recreational exercise is associated with lower prevalence of depression and anxiety and better quality of life in German people living with HIV JF - AIDS care : psychological and socio-medical aspects of AIDS/HIV N2 - Sedentarism is a risk factor for depression and anxiety. People living with the human immunodeficiency virus (PLWH) have a higher prevalence of anxiety and depression compared to HIV-negative individuals. This cross-sectional study (n = 450, median age 44 (19-75), 7.3% females) evaluates the prevalence rates and prevalence ratio (PR) of anxiety and/or depression in PLWH associated with recreational exercise. A decreased likelihood of having anxiety (PR=0.57; 0.36-0.91; p = 0.01), depression (PR=0.41; 0.36-0.94; p=0.01), and comorbid anxiety and depression (PR = 0,43; 0.24-0.75; p=0.002) was found in exercising compared to non-exercising PLWH. Recreational exercise is associated with a lower risk for anxiety and/or depression. Further prospective studies are needed to provide insights on the direction of this association. KW - HIV KW - depression KW - anxiety KW - exercise Y1 - 2022 U6 - https://doi.org/10.1080/09540121.2021.1889951 SN - 1360-0451 VL - 34 IS - 2 SP - 182 EP - 187 PB - Taylor & Francis Group CY - London [u.a.] ER - TY - THES A1 - Pérez Chaparro, Camilo Germán Alberto T1 - Non-HIV comorbidities and exercise in German people living with HIV T1 - Nicht-HIV-Komorbiditäten und Bewegung bei deutschen Menschen, die mit HIV leben N2 - The post-antiretroviral therapy era has transformed HIV into a chronic disease and non-HIV comorbidities (i.e., cardiovascular and mental diseases) are more prevalent in PLWH. The source of these non-HIV comorbidities aside from traditional risk factor include HIV infection, inflammation, distorted immune activation, burden of chronic diseases, and unhealthy lifestyle like sedentarism. Exercise is known for its beneficial effects in mental and physical health; reasons why exercise is recommended to prevent and treat difference cardiovascular and mental diseases in the general population. This cumulative thesis aimed to comprehend the relation exercise has to non-HIV comorbidities in German PLWH. Four studies were conducted to 1) understand exercise effects in cardiorespiratory fitness and muscle strength on PLWH through a systematic review and meta-analyses and 2) determine the likelihood of German PLWH developing non-HIV comorbidities, in a cross-sectional study. Meta-analytic examination indicates PLWH cardiorespiratory fitness (VO2max SMD = 0.61 ml·kg·min-1, 95% CI: 0.35-0.88, z = 4.47, p < 0.001, I2 = 50%) and strength (of remark lowerbody strength by 16.8 kg, 95% CI: 13–20.6, p< 0.001) improves after an exercise intervention in comparison to a control group. Cross-sectional data suggest exercise has a positive effect on German PLWH mental health (less anxiety and depressive symptoms) and protects against the development of anxiety (PR: 0.57, 95%IC: 0.36 – 0.91, p = 0.01) and depression (PR: 0.62, 95%IC: 0.41 – 0.94, p = 0.01). Likewise, exercise duration is related to a lower likelihood of reporting heart arrhythmias (PR: 0.20, 95%IC: 0.10 – 0.60, p < 0.01) and exercise frequency to a lower likelihood of reporting diabetes mellitus (PR: 0.40, 95%IC: 0.10 – 1, p < 0.01) in German PLWH. A preliminary recommendation for German PLWH who want to engage in exercise can be to exercise ≥ 1 time per week, at an intensity of 5 METs per session or > 103 MET·min·day-1, with a duration ≥ 150 minutes per week. Nevertheless, further research is needed to comprehend exercise dose response and protective effect for cardiovascular diseases, anxiety, and depression in German PLWH. N2 - In der Zeit seit der antiretroviralen Therapie hat sich HIV zu einer chronischen Erkrankung entwickelt und Nicht-HIV-Komorbiditäten, z.B. Herz-Kreislauf-Erkrankungen und psychische Erkrankungen, treten bei Menschen, die mit HIV leben, häufiger auf. Die Herkunft dieser Nicht-HIV-Komorbiditäten, neben den traditionellen Risikofaktoren, sind HIV-Infektion, chronische Entzündung, eine gestörte Immunaktivierung, chronische Erkrankungen und eine ungesunde Lebensweise wie Bewegungsmangel. Bewegung ist bekannt für seine positive Wirkung auf die mentale und körperliche Gesundheit; das ist der Grund, warum Bewegung in der Prävention und der Behandlung verschiedener Herz-Kreislauf- und psychischer Erkrankungen in der Allgemeinbevölkerung empfohlen wird. Ziel dieser kumulativen Arbeit war es, den Zusammenhang zwischen körperlicher Bewegung und nicht-HIV-Komorbiditäten bei deutschen Menschen, die mit HIV leben zu untersuchen. Vier Studien wurden durchgeführt, um 1) die Auswirkungen von Bewegung auf die kardiorespiratorische Fitness und die Muskelkraft von HIV-Infizierten durch eine systematische Übersichtsarbeit und Meta-Analysen zu verstehen und 2) zu bestimmen, ob HIV-positive Menschen, die Bewegung treiben, entwickeln einen Nicht-HIV-Komorbiditäten. Die metaanalytische Untersuchung zeigt, dass sich die kardiorespiratorische Fitness (VO2max SMD = 0.61 mlkgmin-1, 95 % CI: 0.35-0.88, z = 4.47, p < 0.001, I2 = 50 %) und Kraft (Besonders in den unteren Extremitäten 16.8 kg, 95 % CI: 13–20.6, p< 0.001) nach einer Trainingsintervention im Vergleich zu einer Kontrollgruppe verbessert. Querschnittdaten deuten darauf hin, dass Bewegung eine positive Wirkung auf die psychische Gesundheit den deutschen Menschen, die mit HIV leben hat (weniger Angst und depressive Symptome) und vor der Entwicklung von Angst (PR: 0,57, 95 % IC: 0,36 - 0,91, p = 0,01) und Depression (PR: 0,62, 95 % IC: 0,41 - 0,94, p = 0,01) schützt. Ebenso geht die Dauer der Bewegung mit einer geringeren Wahrscheinlichkeit für Herzrhythmusstörungen einher, (PR: 0,20, 95 % IC: 0,10 - 0,60, p < 0,01). Eine vorläufige Empfehlung für deutsche Menschen, die mit HIV leben und die sich sportlich betätigen wollen, kann sein, ³ 1-mal pro Woche mit einer Intensität von 5 METs und einer Dauer von ³ 60 Minuten zu trainieren. Dennoch sind weitere Forschungen erforderlich, um die Dosiswirkung und die schützende Wirkung von Bewegung auf Herz-Kreislauf-Erkrankungen, Angst und Depression bei deutschen Menschen, die mit HIV leben zu verstehen. KW - HIV KW - cardiovascular disease KW - anxiety KW - depression KW - exercise KW - Menschen, die mit HIV leben KW - Angst KW - Depression KW - kardiovaskuläre Erkrankungen KW - Bewegung Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-560842 ER - TY - JOUR A1 - Hong, Jun Sung A1 - Kim, Dong Ha A1 - Thornberg, Robert A1 - Wachs, Sebastian A1 - Wright, Michelle F. T1 - Racial discrimination to bullying behavior among White and Black adolescents in the USA: from parents' perspectives JF - International journal of environmental research and public health N2 - The present study proposes and tests pathways by which racial discrimination might be positively related to bullying victimization among Black and White adolescents. Data were derived from the 2016 National Survey of Children's Health, a national survey that provides data on children's physical and mental health and their families. Data were collected from households with one or more children between June 2016 to February 2017. A letter was sent to randomly selected households, who were invited to participate in the survey. The caregivers consisted of 66.9% females and 33.1% males for the White sample, whose mean age was 47.51 (SD = 7.26), and 76.8% females and 23.2% males for the Black sample, whose mean age was 47.61 (SD = 9.71). In terms of the adolescents, 49.0% were females among the White sample, whose mean age was 14.73 (SD = 1.69). For Black adolescents, 47.9% were females and the mean age was 14.67(SD = 1.66). Measures for the study included bullying perpetration, racial discrimination, academic disengagement, and socio-demographic variables of the parent and child. Analyses included descriptive statistics, bivariate correlations, and structural path analyses. For adolescents in both racial groups, racial discrimination appears to be positively associated with depression, which was positively associated with bullying perpetration. For White adolescents, racial discrimination was positively associated with academic disengagement, which was also positively associated with bullying perpetration. For Black adolescents, although racial discrimination was not significantly associated with academic disengagement, academic disengagement was positively associated with bullying perpetration. KW - academic disengagement KW - bullying KW - depression KW - racial discrimination KW - race Y1 - 2022 U6 - https://doi.org/10.3390/ijerph19127084 SN - 1660-4601 VL - 19 IS - 12 PB - MDPI AG CY - Basel ER - TY - JOUR A1 - Gámez-Guadix, Manuel A1 - Mateos, Estibaliz A1 - Wachs, Sebastian A1 - Blanco, Marta T1 - Self-harm on the internet among adolescents BT - prevalence and association with depression, anxiety, family cohesion, and social resources JF - Psicothema N2 - Background: Using the internet to search for information or share images about self-harm is an emerging risk among young people. The aims of this study were (a) to analyze the prevalence of different types of self-harm on the internet and differences by sex and age, and (b) to examine the relationship of self-harm on the internet with intrapersonal factors (i.e., depression and anxiety) and interpersonal factors (i.e., family cohesion and social resources). Method: The sample consisted of 1,877 adolescents (946 girls) between 12 and 17 years old (Mage = 13.41, SD = 1.25) who completed self-report measures. Results: Approximately 11% of the participants had been involved in some type of self-harm on the internet. The prevalence was significantly higher among girls than boys and among adolescents older than 15 years old. Depression and anxiety increased the risk of self-harm on the internet, whereas family cohesion decreased the probability of self-harm on the internet. Conclusions: Self-harm on the internet is a relatively widespread phenomenon among Spanish adolescents. Prevention programs should include emotional regulation, coping skills, and resilience to reduce in this behavior. N2 - Antecedentes: el uso de Internet para buscar información o compartir imágenes sobre autolesiones físicas es un riesgo emergente entre jóvenes. Los objetivos de este estudio fueron: 1) analizar la prevalencia de diferentes conductas relacionadas con las autolesiones en Internet y las diferencias por sexo y edad; y 2) examinar la relación de las autolesiones en Internet con factores intrapersonales (depresión y ansiedad) e interpersonales (cohesión familiar, recursos sociales). Método: la muestra estuvo compuesta por 1.877 adolescentes (946 mujeres) entre 12 y 17 años (edad media = 13,41, DT = 1,255) que completaron medidas de autoinforme. Resultados: aproximadamente el 11% de la muestra se había implicado en algún tipo de autolesión en Internet. La prevalencia fue mayor entre las chicas y entre los adolescentes mayores de 15 años. La depresión y la ansiedad incrementaron el riesgo de autolesiones en Internet. La cohesión familiar fue un factor de protección contra las autolesiones en Internet. Conclusiones: el uso de Internet para compartir o buscar información sobre autolesiones es un problema relativamente frecuente entre adolescentes. Los programas de prevención deberían incluir habilidades de regulación emocional, afrontamiento y resiliencia para reducir la implicación en este comportamiento. KW - engagement self-harm KW - self-injury KW - adolescence KW - depression KW - anxiety KW - family cohesion KW - social support Y1 - 2022 U6 - https://doi.org/10.7334/psicothema2021.328 SN - 0214-9915 SN - 1886-144X VL - 34 IS - 2 SP - 233 EP - 239 PB - Departamento de Psicología de la Universidad de Oviedo, Colegio Oficial de Psicólogos del Principado de Asturias, Vicerrectorado de Investigación de la Universidad de Oviedo CY - Oviedo ER - TY - JOUR A1 - Caliendo, Marco A1 - Mahlstedt, Robert A1 - van den Berg, Gerard J. A1 - Vikström, Johan T1 - Side effects of labor market policies JF - The Scandinavian journal of economics N2 - Labor market policies, such as training and sanctions, are commonly used to bring workers back to work. By analogy to medical treatments, exposure to these tools can have side effects. We study the effects on health using individual-level population registers on labor market outcomes, drug prescriptions, and sickness absence, comparing outcomes before and after exposure to training and sanctions. Training improves cardiovascular and mental health, and lowers sickness absence. This is likely to be the result of the instantaneous features of participation, such as the adoption of a more rigorous daily routine, rather than improved employment prospects. Benefits sanctions cause a short-run deterioration of mental health. KW - Cardiovascular disease KW - depression KW - drugs KW - health KW - mental health KW - prescriptions KW - sanctions KW - sickness KW - training KW - unemployment Y1 - 2022 U6 - https://doi.org/10.1111/sjoe.12514 SN - 0347-0520 SN - 1467-9442 N1 - The authors thank Anders Forslund, Markus Gehrsitz, Aderonke Osikominu, Ulrika Vikman, two anonymous reviewers, and participants at conferences and workshops in Lyon, Nuremberg, Bath, Leipzig, and Basel, and at seminars in Copenhagen, Potsdam, Hamburg, and Uppsala for valuable comments. M. Caliendo gratefully acknowledges funding from the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG, 405629508). J. Vikström acknowledges support from FORTE (2015-00971). VL - 125 IS - 2 SP - 339 EP - 375 PB - Wiley-Blackwell CY - Oxford ER -