Velocity Segregation and Systematic Biases In Velocity Dispersion Estimates With the SPT-GMOS Spectroscopic Survey

The velocity distribution of galaxies in clusters is not universal; rather, galaxies are segregated according to their spectral type and relative luminosity. We examine the velocity distributions of different populations of galaxies within 89 Sunyaev Zel'dovich (SZ) selected galaxy clusters spanning $0.28 < z < 1.08$. Our sample is primarily draw from the SPT-GMOS spectroscopic survey, supplemented by additional published spectroscopy, resulting in a final spectroscopic sample of 4148 galaxy spectra---2868 cluster members. The velocity dispersion of star-forming cluster galaxies is $17\pm4$% greater than that of passive cluster galaxies, and the velocity dispersion of bright ($m < m^{*}-0.5$) cluster galaxies is $11\pm4$% lower than the velocity dispersion of our total member population. We find good agreement with simulations regarding the shape of the relationship between the measured velocity dispersion and the fraction of passive vs. star-forming galaxies used to measure it, but we find a small offset between this relationship as measured in data and simulations in which suggests that our dispersions are systematically low by as much as 3\% relative to simulations. We argue that this offset could be interpreted as a measurement of the effective velocity bias that describes the ratio of our observed velocity dispersions and the intrinsic velocity dispersion of dark matter particles in a published simulation result. Measuring velocity bias in this way suggests that large spectroscopic surveys can improve dispersion-based mass-observable scaling relations for cosmology even in the face of velocity biases, by quantifying and ultimately calibrating them out.Comment: Accepted to ApJ; 21 pages, 11 figures, 5 table

Occupational segregation of immigrant women in Spain

The aim of this paper is to analyze occupational segregation in the Spanish labor market from a gender and an immigration perspective. In doing so, several local and overall segregation measures are used. Our results suggest that immigrant women in Spain suffer a double segregation since segregation affects them to a greater extent than it does either native women or immigrant men. There are, however, remarkable discrepancies among the segregation of immigrant women depending on their region of origin. Thus, immigrant women from the European Union (EU) have the lowest occupational segregation, while segregation seems particularly intense in the group of women from European countries outside the EU bloc and Asia (the levels of which are higher than that of Latin American and African women).immigration; gender; occupational segregation; local segregation; overall segregation

Occupational segregation measures: A role for status

This paper extends recent local segregation measures by incorporating status differences across occupations. These new measures are intended to be used to assess, from a normative point of view, the segregation of a target group. They seem appropriate to complement, rather than substitute, other measures by quantifying how things change when taking into account the status of occupations. The usefulness of these tools is shown in the case of occupational segregation of immigrants and natives in Spain.Segregation measures, occupations, status.

Topological Measure Locating the Effective Crossover between Segregation and Integration in a Modular Network

We introduce an easily computable topological measure which locates the effective crossover between segregation and integration in a modular network. Segregation corresponds to the degree of network modularity, while integration is expressed in terms of the algebraic connectivity of an associated hyper-graph. The rigorous treatment of the simplified case of cliques of equal size that are gradually rewired until they become completely merged, allows us to show that this topological crossover can be made to coincide with a dynamical crossover from cluster to global synchronization of a system of coupled phase oscillators. The dynamical crossover is signaled by a peak in the product of the measures of intra-cluster and global synchronization, which we propose as a dynamical measure of complexity. This quantity is much easier to compute than the entropy (of the average frequencies of the oscillators), and displays a behavior which closely mimics that of the dynamical complexity index based on the latter. The proposed toplogical measure simultaneously provides information on the dynamical behavior, sheds light on the interplay between modularity vs total integration and shows how this affects the capability of the network to perform both local and distributed dynamical tasks

'Gender as a multi-layered issue in journalism: ' A multi-method approach to studying barriers for women in Belgian newsrooms

In recent years, in feminist media studies there has been a growing interest in in media production processes, the structures of media organizations and the people working ‘behind the scenes’ of these companies. This research has documented that despite the increase of female journalists in the last decades, journalism remains vertically and horizontally divided along gender lines. Female journalists are strongly under-represented in older age groups, in decision-making positions and in prestigious news areas and media sectors. Although the blending of qualitative and quantitative methods can offer a fuller understanding of the mechanisms sustaining gender inequality in journalism, most studies either quantify the representation of women in journalism or use qualitative methods to explore how female journalists experience these barriers. The purpose of this paper is to fill the lack of multi-method research on gender inequality in journalism. In order to gain insight into the structural position of women in the journalistic workforce, we conducted a large-scale survey in Belgium. All active professional journalists were invited to participate. The response rate was 33.4% (1640 of 4913 journalists). These results are explored more in depth by means of qualitative interviews with 21 female journalists. The analysis confirms the existence of all ‘traditional’ barriers that women experience in the journalistic profession (e.g. the incompatibility of journalism and motherhood, the glass ceiling, sexism, …). The added value of this study is that we registered several additional difficulties for women in journalism, and most importantly that we gained insight in the strategies that our respondents use to deal with these gender-related barriers. These strategies were related to the support of a partner, the flexibility in the newsroom towards journalists with children, the choice to work part-time or freelance and the use of new communication technologies