Disaster response on September 11, 2001 through the lens of statistical network analysis

The rescue and relief operations triggered by the September 11, 2001 attacks on the World Trade Center in New York City demanded collaboration among hundreds of organisations. To shed light on the response to the September 11, 2001 attacks and help to plan and prepare the response to future disasters, we study the inter-organisational network that emerged in response to the attacks. Studying the inter-organisational network can help to shed light on (1) whether some organisations dominated the inter-organisational network and facilitated communication and coordination of the disaster response; (2) whether the dominating organisations were supposed to coordinate disaster response or emerged as coordinators in the wake of the disaster; and (3) the degree of network redundancy and sensitivity of the inter-organisational network to disturbances following the initial disaster. We introduce a Bayesian framework which can answer the substantive questions of interest while being as simple and parsimonious as possible. The framework allows organisations to have varying propensities to collaborate, while taking covariates into account, and allows to assess whether the inter-organisational network had network redundancy—in the form of transitivity—by using a test which may be regarded as a Bayesian score test. We discuss implications in terms of disaster management

Community Readiness for Increasing Older Adult Physical Activity Levels in Kazakhstan

Introduction: Physical activity is proven to be a significant element of successful aging, but many seniors worldwide fail to achieve the recommended levels. This study aimed to assess the readiness of the community in Nur-Sultan, Kazakhstan, to act on the issue of physical inactivity among older adults.Methods: In order to achieve this purpose, we conducted qualitative interviews with key informants in the community and applied a validated community readiness tool.Results: The results suggest that the local community is at early stages of readiness to act on the issue of older adult physical inactivity. We identified a number of barriers that prevented seniors from leading active lifestyles, which included community misconceptions about older adult physical activity, family centeredness in older adulthood, scarcity of resources, passive support from the leadership, and lack of efforts in the community. Research findings also highlighted the importance of conducting in-depth analysis of key informant responses in addition to calculating readiness scores, when using the community readiness tool.Conclusion: Community-specific strategies for enhancing the level of physical activity among seniors are required to offset the disease burden associated with aging and to prolong life expectancy in Kazakhstan, and it is of paramount importance to tailor potential efforts as to address the current readiness of the community and its needs

Discrete exponential family models for the study of ethnic residential segregation

Previous studies of ethnic residential segregation within urban environments have suggested several factors as potential determinants of the phenomenon. Physical characteristics of the urban environment, demographic and socioeconomic characteristics, preferences for neighborhood composition, and discrimination have all been identified as playing a major role in determining the spatial distribution of ethnic groups within modern cities. However, few studies have attempted to explicitly identify the manner in which residential patterns emerge from the interaction of these factors in field settings. Recently, important strides have been made in this direction by researchers using agent-based and cellular automata models; unfortunately, these efforts have been hampered by a lack of inferential tools to connect theoretical models with extant data. Using a recently developed statistical framework based on discrete exponential family models that bridges this “inferential gap,” this project addresses the following questions: (1) What are, in general, the conditions under which residential systems become segregated? (2) Given information on the current configuration of a residential system, how can we plausibly identify the mechanisms that could have led to that particular configuration? (3) How do metropolitan areas across the United States differ in terms of the mechanisms that drive residential settlement? I first explore the circumstances in which settlement processes lead to segregation through simulations of both artificial and real urban residential systems with two racial/ethnic groups, focusing in particular on in-group preference (homophily) and out-group avoidance (xenophobia). I then turn to a sample of metropolitan areas and seek to identify the types of processes that could have led to their present residential system configuration, as captured by the 2000 U.S. census. My research shows that homophily and xenophobia shape residential systems in distinct ways: the former is associated with the clustering of households of the same ethnicity, the latter with the separation in space of households of different ethnicities. These mechanisms have the biggest segregating effect on residential systems when acting together. However, spatial residential patterns differ depending on whether one or both ethnic groups are homophilous, and the influence of homophily can be countered by even slight tendencies toward integration. The influence of xenophobia, on the other hand, is more pervasive, and can only be mitigated by equal or higher levels of in-group avoidance. These results suggest that reducing xenophobia and encouraging integration is a more effective policy lever than reducing homophily. My analysis of Census 2000 data suggests that metropolitan areas in the United States that have only two major racial/ethnic groups show remarkable similarity in terms of xeno-phobia, the tendency of the groups to separate spatially based on ethnicity. On the other hand, they show much wider variation in the levels of ethnic homophily manifested by the minority and majority groups, which are linked mainly to the proportion minority in the metropolitan area: the bigger the minority group, the weaker the minority homophily effect and the stronger the majority homophily effect. I discuss the contribution of the project to our understanding of residential settlement and segregation and suggest some directions for future work

Emergent Coordination in the World Trade Center Disaster

In this paper, we investigate coordination within responder radio communications during the World Trade Center disaster. Using a network analytic approach, we identify agents who exhibit high levels of coordinative activity. Agents are further classified by whether they appear to occupy formal roles whose responsibilities include coordination of communication, and by whether the agents belong to organizations whose mission includes emergency response. We find that, regardless of organizational type, the great majority of coordinators are emergent (i.e., do not occupy formal coordinative roles). At the same time, where agents with formal coordinative roles are present, they are substantially more likely to become actual coordinators. Uniformity of e#ects across organizational types suggests that emergent coordination in crisis situations is not strongly contingent on responder training or organizational structure

Radio Communication Networks in the World Trade Center Disaster

In this paper, we analyze networks of responder radio communications during the early hours of the World Trade Center disaster