Almost sure convergence of vertex degree densities in the vertex splitting model

We study the limiting degree distribution of the vertex splitting model introduced in Ref.^[3 David, F.; Dukes, M.; Jonsson, T.; Stefansson, S.Ö. Random tree growth by vertex splitting. J. Statist. Mech. Theory Exp. 2009, 04. doi:10.1088/1742-5468/2009/04/P04009. [Google Scholar]^]. This is a model of randomly growing ordered trees, where in each time step the tree is separated into two components by splitting a vertex into two, and then inserting an edge between the two new vertices. Under some assumptions on the parameters, related to the growth of the maximal degree of the tree, we prove that the vertex degree densities converge almost surely to constants which satisfy a system of equations. Using this, we are also able to strengthen and prove some previously non-rigorous results mentioned in the literature.     

Does Economic Advancement ‘Cause’ a Re-increase in Fertility? An Empirical Analysis for OECD Countries (1960–2007)

In the light of the recent reversal of fertility trends in several highly developed countries, we investigate the impact of economic development and its components on fertility in OECD countries from 1960 to 2007. We find that the strong negative correlation between GDP per capita does no longer hold for high levels of per capita economic output; the relation and fertility instead seems to turn into positive from a certain threshold level of economic development on. Survival of an inverse J-shaped association between GDP per capita and fertility is found when controlling for birth postponement, omitted variable bias, non-stationarity and endogeneity. However, gaps between actual and predicted fertility rates show implicitly the importance of factors influencing fertility above and over per capita income. By decomposing GDP per capita into several components, we identify female employment as co-varying factor for the fertility rebound that can be observed in several highly developed countries. Pointing out to important differences with regard to the compatibility between childbearing and female employment, our results suggest that fertility increases are likely to be small if economic development is not accompanied by institutional changes that improve parents’ opportunities to combine work and family life.     

Performance et relations de conseil: comment la structure relationnelle de l’élite des chercheurs français en cancérologie a conditionné leur progression entre 1999–2001 et 1996–1998

This article shows that performances of a specific subpopulation of French researchers in cancer research depend on their advice network. They make progress if they maximize access to scarce resources and their connection to other groups in certain cases. The absence of status competition within the group of peers is an advantage as well as a sufficient relational opening beyond the group with a majority of “dependent” researchers. By taking into account a shape of “glass ceiling” and a specific case of hematologists, the researchers who have the right structural qualities are 11 times more likely to make progress in terms of performance.     

Family policies in OECD countries: a comparative analysis

This article discusses the diversity of family policy models in 28 OECD countries in terms of the balance between their different objectives and the mix of instruments adopted to implement the policies. Cross-country policy differences are investigated by applying a principal component analysis to comprehensive country-level data from the OECD Family database covering variables such as parental leave conditions, childcare service provision, and financial support to families. The results find persistent differences in the family policy patterns embedded in different contexts of work-family "outcomes." Country classifications of family policy packages only partially corroborate categorizations in earlier studies, owing to considerable within-group heterogeneity and the presence of group outliers. The Nordic countries outdistance the others with comprehensive support to working parents with very young children. Anglo-Saxon countries provide much less support for working parents with very young children, and financial support is targeted on low-income and large families and focuses on preschool and early elementary education. Continental and Eastern European countries form a more heterogeneous group, while the support received by families in Southern Europe and in Asian countries is much lower in all its dimensions.     

The construction of ‘religions’ during field visits

ABSTRACT

Field visits to churches, mosques, temples or other buildings used by religious groups, are often valued by students of religious education as an opportunity to engage with the ‘reality’ of the subject: religions as they exist in the world. The Council of Europe text Signposts specifies field visits as an important contributor to the religious dimension of intercultural education, but also identifies issues that need to be addressed by researchers and teachers. During an excursion, students interact with representatives who are likely to represent their tradition in one particular way. The aim of this paper is to investigate how the representation of religion and religiosity is constructed during excursions by representatives and visitors. We have developed an analytical tool based on the interpretive approach and the theory of speech genres. Based on our analysis of documentation related to four field visits with students to places of worship, we suggest how the different speech genres in play during an excursion can help in promoting awareness of different levels of religion: individual, group and the whole tradition.     

The development of synchronous text-based instant messaging as an online interviewing tool

The article reports the development of a synchronous text-based online interviewing tool with a continuity of private discussion that is not achieved in open-ended questionnaires, email interviews and online discussion boards. The participants were women who had undergone a surgical or natural menopause, who in a pilot interview highlighted the potential sensitivity of this subject and inspired the implementation of this method. The overall feedback was positive with the main advantages centred on feelings of anonymity, convenience and a more comfortable interview environment. Disadvantages included lack of body language and technical issues with computers. This technique ensures a degree of confidentiality while still obtaining depth of enquiry, where other qualitative methods potentially risk invading a participant’s privacy. It can be offered both alongside other interviewing techniques to allow participant choice and on its own when exploring sensitive and personal topics or when extra participant anonymity is appropriate.     

Exact algorithms for scheduling programs with shared tasks

We study a scheduling problem where the jobs we have to perform are composed of one or more tasks. If two jobs sharing a non-empty subset of tasks are scheduled on the same machine, then these shared tasks have to be performed only once. This kind of problem is known in the literature under the names of VM-PACKING or PAGINATION. Our objective is to schedule a set of these objects on two parallel identical machines, with the aim of minimizing the makespan. This problem is NP-complete as an extension of the PARTITION problem. In this paper we present three exact algorithms with worst-case time-complexity guarantees, by exploring different branching techniques. Our first algorithm focuses on the relation between jobs sharing one or more symbols in common, whereas the two other algorithms branches on the shared symbols.