Subcellular origin of mitochondrial DNA deletions in human skeletal muscle.

in Annals of Neurology (2018), 84(2), 289-301

OBJECTIVE: In patients with mitochondrial DNA (mtDNA) maintenance disorders and with aging, mtDNA deletions sporadically form and clonally expand within individual muscle fibers, causing respiratory chain ... [more ▼]

OBJECTIVE: In patients with mitochondrial DNA (mtDNA) maintenance disorders and with aging, mtDNA deletions sporadically form and clonally expand within individual muscle fibers, causing respiratory chain deficiency. This study aimed to identify the sub-cellular origin and potential mechanisms underlying this process. METHODS: Serial skeletal muscle cryosections from patients with multiple mtDNA deletions were subjected to subcellular immunofluorescent, histochemical, and genetic analysis. RESULTS: We report respiratory chain-deficient perinuclear foci containing mtDNA deletions, which show local elevations of both mitochondrial mass and mtDNA copy number. These subcellular foci of respiratory chain deficiency are associated with a local increase in mitochondrial biogenesis and unfolded protein response signaling pathways. We also find that the commonly reported segmental pattern of mitochondrial deficiency is consistent with the three-dimensional organization of the human skeletal muscle mitochondrial network. INTERPRETATION: We propose that mtDNA deletions first exceed the biochemical threshold causing biochemical deficiency in focal regions adjacent to the myonuclei, and induce mitochondrial biogenesis before spreading across the muscle fiber. These subcellular resolution data provide new insights into the possible origin of mitochondrial respiratory chain deficiency in mitochondrial myopathy. [less ▲]

Subcortical Neural Generators of the Envelope-Following Response in Sleeping Children: A Transfer Function Analysis

in Hearing Research (2020)

Subgroups of problematic behaviour among students of primary school from teacher perspective: A latent profile analysis

Scientific Conference (2014, August)

Subjectivation à deux - Paare als Kollektivsubjekt

in Bosančić, Saša; Brodersen, Folke; Pfahl, Lisa (Eds.) et al Positioning the Subject Methodologien der Subjektivierungsforschung / Methodologies of Subjectivation Research (2022)

Subjectivation has become central in the field of social, cultural and educational studies to examine the effects of power on the individual. However, there is a lack of theorizing subjectivation ... [more ▼]

Subjectivation has become central in the field of social, cultural and educational studies to examine the effects of power on the individual. However, there is a lack of theorizing subjectivation concerning not only individuals, but collectives. In this article the concept of the ‚couple‘ regarding subjectivation will be examined. Furthermore, an empirical approach will be presented, exemplified by a study on dual employed couples with a child categorized as disabled. The findings highlight the interdependencies and contradictions that arise in the subjectivation of two individuals addressed as a couple. [less ▲]

Subjective Age Across the Life Span: A Differentiated, Longitudinal Approach

in Journals of Gerontology. Series B, Psychological Sciences and Social Sciences (2018), 73(5), 767-777

Objectives: How old people feel compared with their actual age, their so-called "subjective age" (SA), is a central indicator of individual aging experiences and predicts developmental outcomes, such as ... [more ▼]

Objectives: How old people feel compared with their actual age, their so-called "subjective age" (SA), is a central indicator of individual aging experiences and predicts developmental outcomes, such as health and mortality, across the life span. We investigated the multidimensional structure of SA with respect to specific life domains, focusing on domain differences as well as age group differences and age-related changes. Furthermore, we inspected the relationship between SA and how people perceive their future as old persons (future self-views). Method: We assessed these variables in a sample of 593 persons who completed a questionnaire at two time points 4 years apart (baseline-T 1; follow up-T 2) and who were aged 30-80 years at T 1. Results: SA differed across life domains and age groups, and the amount of change in SA across time was also contingent on life domain. Future self-views at T 1 predicted subsequent changes in SA, with more negative self-views being associated with an increase in SA, especially for middle-aged participants for whom the transition to older age is imminent. Discussion: Our results provide support for a multidimensional view of subjective aging experiences. They highlight the importance of a differentiated investigation of subjective aging constructs and their relations for understanding how these variables shape the aging process. [less ▲]

SUBJECTIVE AGING: SOMETHING UNIQUE OR JUST ANOTHER EXPRESSION OF GENERAL SELF-BELIEFS?

in Innovation in Aging (2019), 3(Supplement_1), 786-787

Using data from the German Ageing Survey (adults aged 40‒85), this study tested the convergent and discriminant validity of subjective aging measures by comparing three different measures of subjective ... [more ▼]

Using data from the German Ageing Survey (adults aged 40‒85), this study tested the convergent and discriminant validity of subjective aging measures by comparing three different measures of subjective aging with one another and relating them to established measures of general self-beliefs (optimism, self-efficacy, subjective health) and subjective well-being (depression, affect). Correlations between subjective aging measures ranged from ‒.61 (amongst general self-perceptions of aging measures) to ‒.09, with subjective age being least related to the other measures. The highest overlap was observed between optimism and global self-perceptions of aging (.69) and it was for these global self-perceptions that the highest amount of variance could be explained by correlates in a regression analysis (R-square=.55). In contrast, only 10% of variance could be explained for subjective age. Our results underline the merit of taking the multidimensional nature of subjective aging into account since global measures appear less distinct from general personality traits. [less ▲]

Subjective Health Complaints in Adolescence - Validity of the HBSC Symptom Checklist in Luxembourg

Poster (2018)

The HBSC Symptom Checklist (HBSC-SCL) consists on an eight-item scale developed for the Health Behaviour in School-aged Children survey to measure adolescent health complaints. Although it was developed ... [more ▼]

The HBSC Symptom Checklist (HBSC-SCL) consists on an eight-item scale developed for the Health Behaviour in School-aged Children survey to measure adolescent health complaints. Although it was developed based on a RASCH measurement analysis which proved that the items are indicators of a unidimensional latent trait, some studies suggests a two highly correlated dimensions. The objective of this study is to test the validity of the Luxembourgish version of the HBSC-SCL. Methods: The 2014 HBSC Luxembourg survey took place during the 2013/14 school year. A total of 590 classes following the national curriculum were randomly selected and 7 757 students aged from 11 to 18 years old responded to the questionnaire translated to both French and German distributed by their teachers. Findings: First, the Kaiser-Meyer-Olkin criterion and the Bartlett sphericity test indicated the use of a factor analysis (KMO=.88; p<.001). A Principal Component Analysis with Varimax Rotation (with the Eigenvalues over 1) and a scree plot test suggests a one factor matrix with a total variance explained of 47%. Discussion: Factor analysis support the existence of a single factor for the Luxemburgish population in accordance with the preliminary model developed. Literature have mixed results, with the possibility to compute one or two health complaints scores. More studies should confirm these findings but as the internal consistency possibly depends on the country studied, it is recommended this be systematically checked. [less ▲]

Subjective remaining lifetime and concreteness of the future as differential predictors of preparation for age-related changes

in EUROPEAN JOURNAL OF AGEING (2018), 15(1), 67-76

Demographic changes have been linked to the expectation of cuts in government-provided social security services, emphasizing individual responsibility to prepare for old age and concomitant challenges and ... [more ▼]

Demographic changes have been linked to the expectation of cuts in government-provided social security services, emphasizing individual responsibility to prepare for old age and concomitant challenges and changes. Accordingly, the identification of psychological variables predicting preparation is a matter of theoretical as well as practical importance. We thus consider different aspects of a person's future time as theoretically prominent psychological predictors of preparation. The subjectively perceived quantity of remaining lifetime, the concreteness of future time, and preparation for life domains indicative of an active third age as well as of a more dependent fourth age were assessed in a longitudinal study in a core sample of N = 593 participants (30-80 years old at T (1)) at two measurement occasions 4 years apart. The quantity of subjective remaining lifetime predicted subsequent changes in preparation, but this effect was restricted to preparation for the fourth age. In contrast, a more open and concrete outlook on ones' personal future predicted changes in preparation for an active third age. Our findings highlight the importance of distinguishing between different aspects of future time-its quantity versus its relation to goals and action plans-when predicting specific facets of developmental self-regulation. [less ▲]

Subjective well-being in older adults: Current state and gaps of research

in Bovenberg, Lans; Van Soest, Arthur; Zaidi, Asghar (Eds.) Ageing, health and pensions in Europe (2010)

Reviews research on subjective well-being in older adults and describes remaining desiderata. After introducing the topic of subjective well-being (SWB) in older adults, various policy questions related ... [more ▼]

Reviews research on subjective well-being in older adults and describes remaining desiderata. After introducing the topic of subjective well-being (SWB) in older adults, various policy questions related to that topic are formulated. Then the major advances in research are described. These refer to a conceptual clarification and measurement issues of SWB and related concepts (e.g., life satisfaction), the internal structure of SWB, the theoretical status of SWB in causal networks, main findings about the developmental course, causes, and consequences of SWB in older adults, and theoretical models about SWB regulation in this population. Based on that, remaining gaps in knowledge and potential research directions for SWB especially in older adults are highlighted. These are related to the measurement of SWB, the limited age range and age segmentation in empirical studies on SWB, the causes of SWB and its regulation as well as effective policy measures to promote SWB. Then, the current state of European infrastructures and desirable developments related to research on SWB in older adults are described (large-scale longitudinal studies on aging, regular representative surveys of the general and the older population, international research cooperations and networks). Finally, the significance of the available and expected future knowledge for social policy decision making is discussed. [less ▲]

Subjectivité, Démocratie et Raison Pratique

Book published by L'Harmattan (1998)

Le problème du sujet ou de l'intersubjectivité représente, sans aucun doute, une des questions les plus importantes de la philosophie politique et juridique contemporaine. C'est ce que confirme le retour ... [more ▼]

Le problème du sujet ou de l'intersubjectivité représente, sans aucun doute, une des questions les plus importantes de la philosophie politique et juridique contemporaine. C'est ce que confirme le retour de l'éthique dans nos sociétés démocratiques ainsi que les remises en question de tout concept de subjectivité. L'importance des problèmes soulevés par le concept de subjectivité, sa place dans la philosophie contemporaine sans parler des controverses qu'il génère, expliquent et imposent ce nouvel investissement auquel nous consentons. [less ▲]