11 Interfakultäre Einrichtungen
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/12
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Item Open Access Association between vitamin D status and eryptosis : results from the German National Cohort study(2023) Ewendt, Franz; Schmitt, Marvin; Kluttig, Alexander; Kühn, Julia; Hirche, Frank; Kraus, Frank B.; Ludwig-Kraus, Beatrice; Mikolajczyk, Rafael; Wätjen, Wim; Bürkner, Paul-Christian; Föller, Michael; Stangl, Gabriele I.Vitamin D, besides its classical effect on mineral homeostasis and bone remodeling, can also modulate apoptosis. A special form of apoptosis termed eryptosis appears in erythrocytes. Eryptosis is characterized by cell shrinkage, membrane blebbing, and cell membrane phospholipid disorganization and associated with diseases such as sepsis, malaria or iron deficiency, and impaired microcirculation. To our knowledge, this is the first study that linked vitamin D with eryptosis in humans. This exploratory cross-sectional trial investigated the association between the vitamin D status assessed by the concentration of plasma 25-hydroxyvitamin D (25(OH)D) and eryptosis. Plasma 25(OH)D was analyzed by LC-MS/MS, and eryptosis was estimated from annexin V-FITC-binding erythrocytes by FACS analysis in 2074 blood samples from participants of the German National Cohort Study. We observed a weak but clear correlation between low vitamin D status and increased eryptosis ( r = − 0.15; 95% CI [− 0.19, − 0.10]). There were no differences in plasma concentrations of 25(OH)D and eryptosis between male and female subjects. This finding raises questions of the importance of vitamin D status for eryptosis in terms of increased risk for anemia or cardiovascular events.Item Open Access On the information obtainable from comparative judgments(2022) Bürkner, Paul-ChristianPersonality tests employing comparative judgments have been proposed as an alternative to Likert-type rating scales. One of the main advantages of a comparative format is that it can reduce faking of responses in high-stakes situations. However, previous research has shown that it is highly difficult to obtain trait score estimates that are both faking resistant and sufficiently accurate for individual-level diagnostic decisions. With the goal of contributing to a solution, I study the information obtainable from comparative judgments analyzed by means of Thurstonian IRT models. First, I extend the mathematical theory of ordinal comparative judgments and corresponding models. Second, I provide optimal test designs for Thurstonian IRT models that maximize the accuracy of people’s trait score estimates from both frequentist and Bayesian statistical perspectives. Third, I derive analytic upper bounds for the accuracy of these trait estimates achievable through ordinal Thurstonian IRT models. Fourth, I perform numerical experiments that complement results obtained in earlier simulation studies. The combined analytical and numerical results suggest that it is indeed possible to design personality tests using comparative judgments that yield trait scores estimates sufficiently accurate for individual-level diagnostic decisions, while reducing faking in high-stakes situations. Recommendations for the practical application of comparative judgments for the measurement of personality, specifically in high-stakes situations, are given.Item Open Access The mediating effects of work characteristics on the relationship between transformational leadership and employee well-being : a meta-analytic investigation(2022) Teetzen, Friederike; Bürkner, Paul-Christian; Gregersen, Sabine; Vincent-Höper, SylvieEvidence points to an indirect relationship between transformational leadership (TFL) and employee well-being, and numerous work characteristics have been identified as mediators. However, the relative mediating effect of different types of job resources and job demands on the TFL–well-being relationship remains unclear, rendering it impossible to determine which ones are the most influential. This study aims to provide a comprehensive analysis of the relative mediation potential of different work characteristics in the TFL–well-being relationship in multiple three-level meta-analytical structural equation models of 243 samples. Based on the JD–R Model, this study extends this theoretical framework by suggesting TFL as a predisposing variable that influences both job resources and job demands, leading to changes in indicators of both positive and negative employee well-being. The results show that, while all the examined job resources and demands mediated the TFL–well-being relationship, organizational resources were identified as the strongest mediators. Furthermore, job demands had a strong mediating effect on the relationship between TFL and negative well-being, while job resources more strongly mediated TFL and positive well-being. We present a differentiated picture of how transformational leaders can influence their employees’ well-being at the workplace, providing valuable knowledge for future research and practice.Item Open Access Interpretation bias across body dysmorphic, social anxiety and generalized anxiety disorder : a multilevel, diffusion model account(2021) Dietel, Fanny Alexandra; Möllmann, Anne; Bürkner, Paul-Christian; Wilhelm, Sabine; Buhlmann, UlrikeInterpretation biases are suggested to be transdiagnostic phenomena, but have rarely been compared across different disorders and current concerns. We investigated explicit, decision-based, and more implicit, reaction time-based interpretation bias in individuals with body dysmorphic disorder (BDD; N = 29), social anxiety disorder (SAD; N = 36), generalized anxiety disorder (GAD; N = 22), and non-clinical controls (NC; N = 32), using an adapted Word Sentence Association Paradigm (WSAP). Results indicated that interpretation bias occurred transdiagnostically, while content-specific bias patterns varied meaningfully across groups. BDD and SAD shared explicit and, more inconsistently, implicit interpretation biases for appearance-related and social situations. The GAD group exhibited an explicit and implicit negative interpretation bias for general situations, and an additional implicit lack of positive bias. Mechanistic Wiener diffusion model analyses revealed that interpretation bias patterns were mainly driven by speeded information uptake, potentially mirroring disorder-specific associative memory organization. These findings have important implications for understanding interpretation biases as both etiological and treatment factors.Item Open Access Daily emotion regulation in major depression and borderline personality disorder(2023) Zetsche, Ulrike; Bürkner, Paul-Christian; Bohländer, Julian; Renneberg, Babette; Roepke, Stefan; Schulze, LarsEmotional disturbances are an inherent aspect of most mental disorders and possibly driven by impaired emotion regulation. In the present study, we examined how exactly affected individuals differ from healthy individuals in regulating their emotions and whether individuals suffering from different mental disorders face similar or distinct difficulty in emotion regulation. We overcome earlier methodological constraints by using a 7-day experience sampling assessing the employment and effectiveness of six regulation strategies real time in 55 individuals with current major depressive disorder, 52 individuals with borderline personality disorder (BPD), and 55 healthy individuals. All participants were female. Both clinical groups employed rumination and suppression more often and acceptance less often than healthy individuals. Depressed individuals ruminated even more often than individuals with BPD. Expressive suppression and rumination showed negative effects on subsequent emotions in all groups. Remarkably, both clinical groups were able to benefit from adaptive regulation strategies if they did select them.Item Open Access Assessing the immediate effects of detached mindfulness on repetitive negative thinking and affect in daily life : a randomized controlled trial(2024) Bolzenkötter, Teresa; Bürkner, Paul-Christian; Zetsche, Ulrike; Schulze, LarsObjectives. Repetitive negative thinking (RNT) is a problematic thinking style that is related to multiple mental disorders. Detached mindfulness is a technique of metacognitive therapy that aims to reduce RNT. Our study set out to investigate the immediate effects of detached mindfulness in daily life. Methods. Participants with elevated trait RNT ( n = 50) were prompted to engage in detached mindfulness exercises three times a day for 5 consecutive days. Immediate effects on RNT and affect were assessed 15 and 30 min after each exercise using experience sampling methodology. We compared the effects of this exercise phase to (1) a 5-day non-exercise baseline phase and (2) a different group of participants that engaged in an active control exercise ( n = 50). Results. Results of Bayesian multilevel models showed that, across groups, improvements in RNT, negative affect, and positive affect were stronger during the exercise phase than during the non-exercise baseline phase (RNT after 15 min: b = -0.26, 95% CI = [-0.38, -0.14]). However, the two exercise groups did not differ in these improvements (RNT after 15 min: b = 0.02, 95% CI = [-0.22, 0.27]). Thus, the detached mindfulness and the active control exercises resulted in similar effects on RNT and affect in daily life. Conclusions. Results of this study imply that there was no additional benefit of having participants observe their thoughts detached and non-judgmentally, compared to excluding these assumed mechanisms of action as done for the active control group. We discuss possible reasons for the non-difference between the groups.