Towards a Comprehensive Understanding of Fertility: The Model of Dyadic Pathways

In this theoretical contribution, we propose a comprehensive and integrative heuristic model to explain fertility, the Model of Dyadic Pathways (MDP). We show how existing models such as the Theory of Planned Behaviour often do not withstand empirical challenges, especially not individual self-reports in qualitative studies. Furthermore, existing models vary in their premises and foci, resulting in a collection of models which do not necessarily align with or supplement one another. For these reasons, these heuristic models have been widely criticised and, in practice, pieced together according to the research question and tradition of the researcher. Against this backdrop, we establish the MDP to reconnect theory with reality and to unify a variety of approaches. The MDP is grounded on the dyad of partners as the prevalent basis of fertility. It integrates reasoned and unreasoned fertility behaviour, the impact of individual- and couple-level life course, soci(et)al conditions, and the body as an “actor”. The model explicitly accounts for the variety of different real-life pathways that lead to fertility. It thereby encourages researchers to, first, consider all potentially relevant factors and their mechanisms and, second, think of fertility and its measurement as a multilinear process. Based on the presented elements a comprehensive model of fertility must cover, we suggest ways to improve surveys accordingly. Furthermore, we elaborate on the contributions and challenges the MDP presents to future fertility research

Towards a Comprehensive Understanding of Fertility: The Model of Dyadic Pathways

In this theoretical contribution, we propose a comprehensive and integrative heuristic model to explain fertility, the Model of Dyadic Pathways (MDP). We show how existing models such as the Theory of Planned Behaviour often do not withstand empirical challenges, especially not individual self-reports in qualitative studies. Furthermore, existing models vary in their premises and foci, resulting in a collection of models which do not necessarily align with or supplement one another. For these reasons, these heuristic models have been widely criticised and, in practice, pieced together according to the research question and tradition of the researcher. Against this backdrop, we establish the MDP to reconnect theory with reality and to unify a variety of approaches. The MDP is grounded on the dyad of partners as the prevalent basis of fertility. It integrates reasoned and unreasoned fertility behaviour, the impact of individual- and couple-level life course, soci(et)al conditions, and the body as an "actor". The model explicitly accounts for the variety of different real-life pathways that lead to fertility. It thereby encourages researchers to, first, consider all potentially relevant factors and their mechanisms and, second, think of fertility and its measurement as a multilinear process. Based on the presented elements a comprehensive model of fertility must cover, we suggest ways to improve surveys accordingly. Furthermore, we elaborate on the contributions and challenges the MDP presents to future fertility research

Labor market participation and informal family care among older adults in Germany: Role substitution, role expansion, role extension or dis-/nonengagement?

Despite increasing research, the diversity of role transitions and the interplay between productive roles among older adults are still not adequately understood. This also applies to labor force participation and family care at the transition to retirement. In order to narrow this research gap, this article examines the diversity of transitions/continuities between employment and informal family care among older adults in Germany. Based on role theory and disengagement approach, a typology of transitions/continuities between employment and informal family care was created using data from three waves of the study "Transitions and Old Age Potential" (TOP) over a period of six years (2013-2019). Transitions/continuities between labor market participation and family roles can be described empirically in terms of four main types: role substitution, role expansion, role extension, and dis-/nonengagement. These can be broken down further into subtypes, which reveals the diversity of role transitions/continuities among older adults and suggests different causal relationships. Continuity and fluctuation are found to coexist, with strong evidence for either episodic or gradual/fluid patterns of role transitions. Time commitment in productive roles has a noticeable influence on transition/continuity types. However, the impact of sociodemographic, occupational and personal predictors suggests that labor market-related inequalities and subjective preferences are also influencing the transitions between employment and family care. The findings are innovative in terms of a theory-based typology of role transitions/continuities that offers new insights into the diversity of role transitions and their determinants among older adults not only in Germany, but also in other countries with aging populations

The occurrence of classical Cepheids in binary systems

Classical Cepheids, like binary stars, are laboratories for stellar evolution and Cepheids in binary systems are especially powerful ones. About one-third of Galactic Cepheids are known to have companions and Cepheids in eclipsing binary systems have recently been discovered in the Large Magellanic Cloud. However, there are no known Galactic binary Cepheids with orbital periods less than one year. We compute population synthesis models of binary Cepheids to compare to the observed period and eccentricity distributions of Galactic Cepheids as well as to the number of observed eclipsing binary Cepheids in the LMC. We find that our population synthesis models are consistent with observed binary properties of Cepheids. Furthermore, we show that binary interaction on the red giant branch prevents some red giant stars from becoming classical Cepheids. Such interactions suggest that the binary fraction of Cepheids should be significantly less than that of their main-sequence progenitors, and that almost all binary Cepheids have orbital periods longer than one year. If the Galactic Cepheid spectroscopic binary fraction is about 35%, then the spectroscopic binary fraction of their intermediate mass main sequence progenitors is about 40-45%.Comment: 7 pages, 3 figures, resubmitted to A&

Living arrangements and consumption: plead for lifestyle oriented market research

Der vorliegende Beitrag geht der Frage nach, ob die Veränderungen in der Haushaltsstruktur, der demographischen Struktur und der Lebensgestaltung zu einem veränderten privaten Konsumverhalte führt und welche Faktoren in diesem Zusammenhang von Bedeutung sind. Dabei verknüpfen die Autoren Familiensoziologie und Ansätze der Marktforschung. Die Autoren greifen auf Daten des GfK Verbraucherpanels aus dem Jahr 1995 zurück, für das 4386 Haushalte befragt wurden. Zwei Fragen stehen im Mittelpunkt : (1) Gibt es Unterschiede zwischen soziologisch definierter Lebensarrangements bezogen auf den Konsum ausgewählter Produkte? (2) Welchen Einfluss haben familiäre Übergänge auf das Konsumverhalten? (ICD

Job Mobilities and Family Lives in Europe: Documentation of the Panel Dataset

Der Methodenbericht beschreibt die Erhebung der zweiten Welle der Studie "Job Mobilities and Family Lives in Europe - Modern Mobile Living and its Relation to Quality of Life" sowie die Struktur der resultierenden Paneldaten. Eine erste Welle wurde im Jahr 2007 in sechs europäischen Ländern durchgeführt: Deutschland, Frankreich, Spanien, Polen, Belgien und der Schweiz. Insgesamt wurden 7.220 zufällig ausgewählte Personen befragt. Die Studie fokussierte auf drei zentrale Aspekte: Erstens, die Verbreitung und Vielfalt berufsbedingter räumlicher Mobilität in Europa, zweitens, die Ursachen und Entstehungszusammenhänge, sowie, drittens, die Konsequenzen von berufsbedingter räumlicher Mobilität für subjektives Wohlbefinden, Familie, Beruf und soziale Beziehungen. Zwischen 2010 und 2012 wurde eine Wiederholungsbefragung unter 1.735 Personen in vier Ländern durchgeführt: Deutschland, Frankreich, Spanien und der Schweiz (Wiederbefragungsquote: 34,5 %). Das Paneldesign eröffnet neue Möglichkeiten durch Längsschnittanalysen und damit tiefere Einblicke in die genannten Forschungsfragen. Diese Möglichkeiten werden zudem ergänzt durch eine retrospektive Erfassung umfangreicher Biographien zu Mobilität, Berufen, Familie und Partnerschaften. Daneben wurden im Rahmen der zweiten Welle neue Befragungsinhalte zu Themen wie soziale Integration, freiwilliges bürgerschaftliches Engagement und soziale Mobilität aufgenommen. Die Datendokumentation bietet eine Beschreibung der erhobenen Formen von Mobilität, der Inhalte des Erhebungsinstruments, der Stichprobengewinnung, der Feldphase, der Panelselektivität sowie der Datengewichtung.This data documentation describes the realisation of the second wave of the study Job Mobilities and Family Lives in Europe - Modern Mobile Living and its Relation to Quality of Life and the basic structure of the panel data thus obtained. A first wave was conducted in 2007 in six European countries: Germany, France, Spain, Switzerland, Poland and Belgium. Overall, 7,220 randomly selected individuals were interviewed. The study focused on three main aspects: firstly, on the prevalence and variety of job-related spatial mobility in Europe, secondly, on the causes and circumstances of people’s mobility decisions, and thirdly, on the consequences of job-related spatial mobility for subjective well-being, family life, occupational career and social integration. Between 2010 and 2012, a follow-up survey was carried out in four countries: Germany, Spain, Switzerland and France. 1,735 respondents of the initial survey could be interviewed again (overall response rate: 34.5%). The panel structure provides a deeper insight into the mentioned research interests by providing an opportunity for longitudinal analysis. Moreover, this opportunity is enhanced by a collection of extensive retrospective data about spatial mobility, employment, partnership and family. Furthermore, the second wave includes new contents with topics such as social integration, volunteerism and social mobility. This documentation features a description of the forms of mobility investigated, the contents of the questionnaire, the sampling procedure, the fieldwork, the sample drop-outs and the weighting of the data

BONNSAI: a Bayesian tool for comparing stars with stellar evolution models

Powerful telescopes equipped with multi-fibre or integral field spectrographs combined with detailed models of stellar atmospheres and automated fitting techniques allow for the analysis of large number of stars. These datasets contain a wealth of information that require new analysis techniques to bridge the gap between observations and stellar evolution models. To that end, we develop BONNSAI (BONN Stellar Astrophysics Interface), a Bayesian statistical method, that is capable of comparing all available observables simultaneously to stellar models while taking observed uncertainties and prior knowledge such as initial mass functions and distributions of stellar rotational velocities into account. BONNSAI can be used to (1) determine probability distributions of fundamental stellar parameters such as initial masses and stellar ages from complex datasets, (2) predict stellar parameters that were not yet observationally determined and (3) test stellar models to further advance our understanding of stellar evolution. An important aspect of BONNSAI is that it singles out stars that cannot be reproduced by stellar models through $\chi^{2}$ hypothesis tests and posterior predictive checks. BONNSAI can be used with any set of stellar models and currently supports massive main-sequence single star models of Milky Way and Large and Small Magellanic Cloud composition. We apply our new method to mock stars to demonstrate its functionality and capabilities. In a first application, we use BONNSAI to test the stellar models of Brott et al. (2011a) by comparing the stellar ages inferred for the primary and secondary stars of eclipsing Milky Way binaries. Ages are determined from dynamical masses and radii that are known to better than 3%. We find that the stellar models reproduce the Milky Way binaries well. BONNSAI is available through a web-interface at http://www.astro.uni-bonn.de/stars/bonnsai.Comment: Accepted for publication in A&A; 15 pages, 10 figures, 4 tables; BONNSAI is available through a web-interface at http://www.astro.uni-bonn.de/stars/bonnsa

X-Ray Irradiation Apparatus in Which an X-Ray Source is Energized Upon the Recording of Irradiation Dosage Data

Apparatus for use in examining or treating patients with X-radiation or the like requires the making of a permanent record of the radiation applied. The operation of the radiation source is controlled in dependence upon the making of the record and the to radiation, or dose exposure is limited to a predetermined amount. A method is disclosed for safeguarding the patient and for producing a tangible record of the dose to which the patient is subjected