Universal Scaling in the Aging of the Strong Glass Former SiO2_2

We show that the aging dynamics of a strong glass former displays a strikingly simple scaling behavior, connecting the average dynamics with its fluctuations, namely the dynamical heterogeneities. We perform molecular dynamics simulations of SiO$_2$ with BKS interactions, quenching the system from high to low temperature, and study the evolution of the system as a function of the waiting time $t_{\rm w}$ measured from the instant of the quench. We find that both the aging behavior of the dynamic susceptibility $\chi_4$ and the aging behavior of the probability distribution $P(f_{{\rm s},{\mathbf r}})$ of the local incoherent intermediate scattering function $f_{{\rm s},{\mathbf r}}$ can be described by simple scaling forms in terms of the global incoherent intermediate scattering function $C$. The scaling forms are the same that have been found to describe the aging of several fragile glass formers and that, in the case of $P(f_{{\rm s},{\mathbf r}})$, have been also predicted theoretically. A thorough study of the length scales involved highlights the importance of intermediate length scales. We also analyze directly the scaling dependence on particle type and on wavevector $q$, and find that both the average and the fluctuations of the slow aging dynamics are controlled by a unique aging clock, which is not only independent of the wavevector $q$, but is the same for O and Si atoms.Comment: 13 pages, 21 figures (postscript

Missed Opportunities: Public Health Disaster Management in Canada

Three recent Canadian public health crises present an illustration of both the opportunities for reform and the challenges that may impede progress and public health renewal in federalist nations. While the three crises examined exposed serious flaws in emergency preparedness and fuelled demands for vital public health reform, evidence indicates that fundamental challenges have not been addressed and may have even heightened over the last decade given a move to “open federalism” and the significant fiscal impacts of ongoing austerity measures. With future pandemics inevitable, we identify the missed opportunities to optimize Canada’s emergency response capacity and procedures and examine the seemingly intractable barriers of federalism and path dependency thinking that continue to impede learning and reform and ultimately undermine effective disaster managemen

Gender-based perceptions of the 2001 anthrax attacks: Implications for outreach and preparedness

Extensive research dealing with gender-based perceptions of fear of crime has generally found that women express greater levels of fear compared to men. Further, studies have found that women engage in more self-protective behaviors in response to fear of crime, as well as have different levels of confidence in government efficacy relative to men. The majority of these studies have focused on violent and property crime; little research has focused on gender-based perceptions of the threat of bioterrorism. Using data from a national survey conducted by ABC News / Washington Post, this study contrasted perceptions of safety and fear in response to anthrax attacks among male and female respondents. Results indicated some gender differences in perceptions and responses to possible anthrax exposure, although not all achieved statistical significance. Results are discussed in relation to their implications for criminological theory, security and bioterrorism preparedness

Environmental Dependence of the Fundamental Plane of Galaxy Clusters

Galaxy clusters approximate a planar (FP) distribution in a three-dimensional parameter space which can be characterized by optical luminosity, half-light radius, and X-ray luminosity. Using a high-quality catalog of cluster redshifts, we find the nearest neighbor cluster for those common to an FP study and the cluster catalog. Examining scatter about the FP, we find 99.2% confidence that it is dependent on nearest neighbor distance. Our study of X-Ray clusters finds that those with high central gas densities are systematically closer to neighbor clusters. If we combine results here with those of Fritsch and Buchert, we find an explanation for some of our previous conclusions: Clusters in close proximity to other clusters are more likely to have massive cooling flows because they are more relaxed and have higher central gas densities.Comment: Accepted for publication in Astrophysical Journal Letters. Moderate revisions, including more statistical analysis and discussion. Latex, 7 page

Mapping same-sex couple family households in Australia

The map (1:1,218,987) accompanying this report is the first to depict the distribution of same-sex couple family households across Australia. The map and the report contribute to emerging scholarship combining critical geographies of sexualities with quantitative techniques and GIS in order to advance the political claims of sexual minorities. The data were collected through the 2006 Census and obtained via consultation with the Australian Bureau of Statistics. These data included the number of same-sex couple family households for all Statistical Divisions across Australia and for Statistical Sub-Divisions within metropolitan capital cities. Geographical concentrations of same-sex couple family households were determined by calculating the proportion of couple family households that were same-sex in each Statistical Division and Statistical Sub-Division, since the Census defines same-sex couples as a subset of couple family households. To visualise where the proportions fell above and below the national average, and thus where concentrations were found, these ratios were converted to location quotients using the Australian average as the denominator. The map combines different scales – Statistical Divisions and Statistical Sub-Divisions – to illustrate distributional patterns between inner-city and suburban areas, as well as between urban and regional localities, across Australia. While high concentrations are found in inner-cities, there are also significant suburban and regional concentrations, thus contesting assumptions about same-sex couples’ inner-city residential choices. Moreover, since same-sex couples were found in most Statistical Divisions, those areas below the national average cannot be considered devoid of these families, with implications for the effective operationalisation of equal rights legislation

Mapping same-sex couple family households in Australia

The map (1:1,218,987) accompanying this report is the first to depict the distribution of same-sex couple family households across Australia. The map and the report contribute to emerging scholarship combining critical geographies of sexualities with quantitative techniques and GIS in order to advance the political claims of sexual minorities. The data were collected through the 2006 Census and obtained via consultation with the Australian Bureau of Statistics. These data included the number of same-sex couple family households for all Statistical Divisions across Australia and for Statistical Sub-Divisions within metropolitan capital cities. Geographical concentrations of same-sex couple family households were determined by calculating the proportion of couple family households that were same-sex in each Statistical Division and Statistical Sub-Division, since the Census defines same-sex couples as a subset of couple family households. To visualise where the proportions fell above and below the national average, and thus where concentrations were found, these ratios were converted to location quotients using the Australian average as the denominator. The map combines different scales – Statistical Divisions and Statistical Sub-Divisions – to illustrate distributional patterns between inner-city and suburban areas, as well as between urban and regional localities, across Australia. While high concentrations are found in inner-cities, there are also significant suburban and regional concentrations, thus contesting assumptions about same-sex couples’ inner-city residential choices. Moreover, since same-sex couples were found in most Statistical Divisions, those areas below the national average cannot be considered devoid of these families, with implications for the effective operationalisation of equal rights legislation