Estimation of geodesic tortuosity and constrictivity in stationary random closed sets

We investigate the problem of estimating geodesic tortuosity and constrictivity as two structural characteristics of stationary random closed sets. They are of central importance for the analysis of effective transport properties in porous or composite materials. Loosely speaking, geodesic tortuosity measures the windedness of paths, whereas the notion of constrictivity captures the appearance of bottlenecks resulting from narrow passages within a given materials phase. We first provide mathematically precise definitions of these quantities and introduce appropriate estimators. Then, we show strong consistency of these estimators for unboundedly growing sampling windows. In order to apply our estimators to real data sets, the extent of edge effects needs to be controlled. This is illustrated using a model for a multiphase material that is incorporated in solid oxide fuel cells.     

CEO burnout,managerial discretion,and firm performance: The role of CEO locus of control,structural power,and organizational factors

Despite the possibility of burnout resulting from dynamics in firms' upper echelons, little if any work has focused on chief executive officer's (CEO's) burnout and firm performance. Drawing on managerial discretion theory, this article analyzes the influence of CEO burnout on firm performance and the moderating roles of the individual (CEO locus of control), structural power (CEO duality and CEO tenure), and organizational characteristics (size, age, and resource availability) related to managerial discretion. Using a sample of 156 CEOs in Swedish firms, we find a negative association between CEOs who report higher burnout and firm performance. Our results confirm that CEO duality and resource availability ameliorate and firm size exacerbates the negative association between CEO burnout and firm performance. Contrary to our expectations, CEO locus of control, CEO tenure, and firm age do not influence this relationship. We discuss the implications of our research for upper echelons theory and strategic leadership theory.     

Large-scale commonness is the best predictor of bird species presence in European cities

Urban Ecosystems - Urban bird communities are homogenized across large spatial scales, suggesting that the urban environment acts as an environmental filter. We hypothesize that large scale...     

Making Sense of After‐School Care Dilemmas in Mothers' Stories of After‐School Care in Finland and Sweden

The study focuses on dilemmas in storied experiences of everyday after‐school care arrangements among Swedish and Finnish mothers. Finland and Sweden, which share a history of strong labour market attachment among women, arrange institutional after‐school care in similar ways. The data consist of interviews with three Swedish and six Finnish mothers. A positioning analysis of four stories shows how decisions related to children's after‐school hours were allocated among different actors. Two reoccurring dilemmas, Competent‐dependent child stories and Unburdened‐deficient mother stories, emerged from the data analysis as related to prevailing moral discourses on childhood and motherhood.     

Gezi Park and EuroMaidan: social movements at the borders

Both Turkey and Ukraine are located at the external borders of the European Union (EU), and are seen as important partners of the EU, especially in terms of economic relations and strategic partnership. Both countries experienced en masse protest events in 2013: the Gezi Park protests and EuroMaidan, starting, respectively, in May 2013 and November 2013. Although these protests started initially for different reasons – the brutal eviction of a sit-in organized for protecting the trees in Taksim Gezi Park and the Ukrainian government's abandonment of EU trade agreement talks – and seem spatially, temporally and ideologically separate, they both include claims related to a “more just and transparent system”. Such claims are not purely political and are closely linked to a social dimension, especially in terms of local and European space-making. This article aims to understand the importance of Gezi Park and EuroMaidan within the framework of new social movements in terms of space-making and the perception of human rights, democracy, justice, identitarian politics and consensual social relations as Euro-concepts or European ideals.     

Threatened plant species in the river ports of Central Europe: a potential for nature conservation

Industrialized areas represent a special group of urbanized areas, but sufficient attention has not been given to them concerning plant species richness and its importance for biodiversity conservation. These sites are considered the main drivers of biological invasions and biotic homogenization on a global scale, but the question of how and to what degree they contribute to biodiversity has yet to be raised. Data for 62 river ports (16 German, 26 Czech, 7 Hungarian, 4 Slovak, and 9 Austrian) on two important Central European waterways (the Elbe-Vltava and Danube waterways) were gathered for 40 years. In total, 1 240 plant species were found. Of these, 371 were classified as threatened and protected, nearly one third of the total number of species found in all of the studied Elbe, Vltava, and Danube ports. Significant differences in the proportion of threatened species in ports and cities were not found. More threatened species were found in the Danube ports than in the other ports, but their numbers fluctuated depending on the size of the port and the region (country). The results showed that the ports must be regarded as special types of species-rich industrial areas; thus, they should not be considered to be only sources of spreading invasive alien species. When planning port development, uniformity and vegetation management that is too intensive should be avoided. Extensively managed open areas and habitat diversity should be maintained.

     

Women who sacrifice themselves for everybody: qualitative research with mothers of disabled children

This study, from a feminist perspective, aimed at examining the experiences of women whose children with cerebral palsy received a treatment at a physiotherapy and rehabilitation center located in Ankara, Turkey. The study intended to reveal the perceptions of in-family roles of women with disabled children, their participation in public life, and their self-concept within the scope of feminist social work. Thus, the objective of the present study was to contribute to the understanding of the fact that non gender-blind services should be developed in this field on the basis of social justice and human rights, which constitutes the fundamental philosophy of social work. Qualitative research method was employed in the study where data were analyzed through content analysis. The findings of the study were interpreted under four main themes: the lives of the women with disabled children after their disabled children were born; being a woman within the scope of family life, participation in decision-making processes, and domestic division of labor; participation in public life and relations with women's associations; the self-sacrifice; and the suggestions of women concerning self-realization within the scope of self-concept.     

New bounds for locally irregular chromatic index of bipartite and subcubic graphs

A graph is locally irregular if the neighbors of every vertex v have degrees distinct from the degree of v. A locally irregular edge-coloring of a graph G is an (improper) edge-coloring such that the graph induced on the edges of any color class is locally irregular. It is conjectured that three colors suffice for a locally irregular edge-coloring. In the paper, we develop a method using which we prove four colors are enough for a locally irregular edge-coloring of any subcubic graph admiting such a coloring. We believe that our method can be further extended to prove the tight bound of three colors for such graphs. Furthermore, using a combination of existing results, we present an improvement of the bounds for bipartite graphs and general graphs, setting the best upper bounds to 7 and 220, respectively.     

International Transfer of Policies and Practices of Gender Equality in Employment to and among Muslim Majority Countries

This article investigates the premise that it is possible to transpose organizational approaches to equal employment opportunity (EEO) from western countries to Muslim majority countries (MMCs). Drawing on policy interviews and documentary evidence from public sector organizations and international development agencies engaged in the promotion of gender equality in Turkey and Pakistan, we question the effectiveness of diffusion of gender equality policies and practices to and among these two MMCs. Our investigation reveals the primacy of context over essence in developing effective ways to construct EEO policies and practices which can be adopted in MMCs.     

Determinants of retirement timing expectations in the United States and Australia: a cross-national comparison of the effects of health and retirement benefit policies on retirement timing decisions

Data from the U.S. Health and Retirement Study (N = 2,589) and the Australian Household Income and Labour Dynamics survey (N = 1,760) were used to compare the macro-level policy frameworks on individual retirement timing expectations for pre-baby boomers (61+ years) and early baby boomers (45 to 60 years). Australian workers reported younger expected age of retirement compared to the U.S. sample. Reporting poor health was more strongly associated with younger expected retirement age in the United States than in Australia. Cohort and gender differences in the United States were found for the effect of private health insurance on younger expected age at retirement. Our results draw attention to how cross-national comparisons can inform us on the effects of policies on retirement expectations among older workers.