Testing for a Unit Root in a Time Series With a Changing Mean: Corrections and Extensions

This article explores the relation between nonexponential waiting times between events and the distribution of the number of events in a fixed time interval. It is shown that within this framework the frequently observed phenomenon of overdispersion—that is, a variance that exceeds the mean—is caused by a decreasing hazard function of the waiting times, whereas an increasing hazard function leads to underdispersion. Using the assumption of iid gamma-distributed waiting times, a new count-data model is derived. Its use is illustrated in two applications, the number of births and the number of doctor consultations.     

Factory to Faculty: Socioeconomic Difference and the Educational Experiences of University Professors

Numerous essays exist on the lived experiences of academics from working‐class or poverty‐class origins. Yet, to date, there exists no systematic analysis of the class origins of university faculty members. This study utilizes surveys from a random sample of full‐time university professors at all 95 Canadian universities affiliated with the Association of Universities and Colleges of Canada (AUCC) to analyze the ways in which socioeconomic background impacts experiences within university and graduate school. Findings indicate that several measures of socioeconomic background are indeed significant predictors of this experience. Qualitative data reveal that working‐class faculty members are hyper‐aware of the ways in which their class backgrounds affected their educational trajectories; while conversely, academics from middle‐class backgrounds were also reflective about the ways in which they were privileged. The paper concludes with implications for developing public policy that shifts focus away from apolitical discussions of diversity, toward promoting inclusivity for those from working‐class or lower‐income backgrounds. Il existe de nombreux travaux concernant les expériences vécues par des académiques qui font parties de différentes classes sociales, particulièrement les classes ouvrières. Par contre, jusqu’à date, il n'existe aucune analyse systématique concernant les classes d'origines des membres du corps professoral qui travaillent aux universités. Cette étude utilise des enquêtes qui ont été obtenues avec un échantillon aléatoire de professeurs qui travaillent à temps plein aux 95 universités Canadiennes affiliées avec “L'association des Universités et Collèges du Canada” (AUCC). Cette étude analyse les façons que le statut socio‐économique de la famille affecte les expériences à l'université et aux études supérieures. Les résultats quantitatifs démontrent que plusieurs mesures de statut socio‐économique prédisent ces expériences. En plus, les résultats qualitatifs démontrent que les membres du corps professoral qui viennent la classe ouvrière sont très conscients des façons que leur statut socio‐économique affecte leurs trajectoires académiques. Par contre, les membres du corps professoral qui viennent la classe moyenne sont aussi conscients et même réfléchissant des façons qu'ils sont privilégiés à cause de leur statut socio‐économique. Les résultats indiquent la nécessité de développer des politiques publiques qui détourne l'attention et les discussions apolitiques sur la diversité, aux discussions sur les façons de promouvoir, aux universités, l'inclusion de ceux qui viennent des milieux socio‐économiques inférieurs et défavorisés.     

Childhood Autism and Proactive Family Coping: Intergenerational Perspectives

This article considers the value of intergenerational and specifically, grandparental support, in the management of adaptive tasks posed by raising a young child with autism. The tasks addressed range from accessing early intervention to enhancing family social functioning. We note unique social, financial, and health-related stressors faced by families of children with autism. We outline an innovative, stress theory-based framework, the Autism Proactive Intergenerational Adaptation (APIA) Model, which delineates the role of grandparents in contributing to family adaptation to the stresses of raising a child with autism. We focus on proactive family coping strategies in building resilience and ameliorating the adverse impact of stressors on quality of life (QOL) for individual family members and for the family unit. We discuss barriers and facilitators of intergenerational alliances involving grandparental participation and support.     

Smallpox-related knowledge and beliefs among recent college graduates

Recent world events have increased concern and preparations for possible bioterror events. Despite worldwide efforts to limit access to bio-weapons, smallpox is still considered a potential bioterror threat. Americans' understanding of smallpox could prevent panic and enhance the willingness of citizens to receive vaccinations. OBJECTIVE: The authors' purpose in this study was to describe graduating college students' levels of smallpox-related knowledge. METHOD SUMMARY: Participants at a graduation ceremony--mostly female, with a mean age of 28.4+/-8.1 years--were handed a 35-item questionnaire that assessed smallpox knowledge and whether respondents would submit to vaccination under hypothetical circumstances. RESULTS: The convenience sample was ignorant of numerous facts about smallpox and unaware of government efforts to prepare for an attack, answering an average of 3.8 out of 10 items correctly. CONCLUSION: These findings raise concern because, in a smallpox event, prompt responses to directives of public health officials will be necessary to maximize the effectiveness of response plans.     

Toward Disaster‐Resilient Cities: Characterizing Resilience of Infrastructure Systems with Expert Judgments

Resilient infrastructure systems are essential for cities to withstand and rapidly recover from natural and human‐induced disasters, yet electric power, transportation, and other infrastructures are highly vulnerable and interdependent. New approaches for characterizing the resilience of sets of infrastructure systems are urgently needed, at community and regional scales. This article develops a practical approach for analysts to characterize a community's infrastructure vulnerability and resilience in disasters. It addresses key challenges of incomplete incentives, partial information, and few opportunities for learning. The approach is demonstrated for Metro Vancouver, Canada, in the context of earthquake and flood risk. The methodological approach is practical and focuses on potential disruptions to infrastructure services. In spirit, it resembles probability elicitation with multiple experts; however, it elicits disruption and recovery over time, rather than uncertainties regarding system function at a given point in time. It develops information on regional infrastructure risk and engages infrastructure organizations in the process. Information sharing, iteration, and learning among the participants provide the basis for more informed estimates of infrastructure system robustness and recovery that incorporate the potential for interdependent failures after an extreme event. Results demonstrate the vital importance of cross‐sectoral communication to develop shared understanding of regional infrastructure disruption in disasters. For Vancouver, specific results indicate that in a hypothetical M7.3 earthquake, virtually all infrastructures would suffer severe disruption of service in the immediate aftermath, with many experiencing moderate disruption two weeks afterward. Electric power, land transportation, and telecommunications are identified as core infrastructure sectors.     

Same Profession,Different People: Stratification,Structure, and Physicians' Employment Choices

Professions such as medicine are in the midst of profound change. This paper explores how recent stratifying forces within the medical profession relate to the trend toward salaried employment for physicians. Specifically, growing segments of female, black and Hispanic, and lower and middle class doctors are focused upon in the analysis. Several important structural forces related to managed care and the nature of medical work are discussed and examined as well. The results suggests that it is useful to consider factors internal to professions in explaining large-scale professional change. This does not mean forgetting about the role played by structure in this change. Instead, it supports incorporating stratification perspectives into studies of professionals and of considering micro levels of analysis which acknowledge and investigate the effects of intraprofessional diversity.     

The paracrisis: The challenges created by publicly managing crisis prevention

Social media is emerging as critical element of scanning for many crisis risks. When these crisis risks emerge online, people often confuse them with crises and that is why we have developed the term paracrisis. Para can mean “like” something. A paracrisis is like a crisis. It can “look like” a crisis and does require action from the organization. However, a paracrisis does not warrant convening the crisis team and operating in a crisis mode. This paper details the value of paracrises, how to evaluate their threat potential, and ways to respond to them and how to evaluate those responses.     

A multi-resolution census algorithm for calculating vortex statistics in turbulent flows

Summary.  The fundamental equations that model turbulent flow do not provide much insight into the size and shape of observed turbulent structures. We investigate the efficient and accurate representation of structures in two-dimensional turbulence by applying statistical models directly to the simulated vorticity field. Rather than extract the coherent portion of the image from the background variation, as in the classical signal-plus-noise model, we present a model for individual vortices using the non-decimated discrete wavelet transform. A template image, which is supplied by the user, provides the features to be extracted from the vorticity field. By transforming the vortex template into the wavelet domain, specific characteristics that are present in the template, such as size and symmetry, are broken down into components that are associated with spatial frequencies. Multivariate multiple linear regression is used to fit the vortex template to the vorticity field in the wavelet domain. Since all levels of the template decomposition may be used to model each level in the field decomposition, the resulting model need not be identical to the template. Application to a vortex census algorithm that records quantities of interest (such as size, peak amplitude and circulation) as the vorticity field evolves is given. The multiresolution census algorithm extracts coherent structures of all shapes and sizes in simulated vorticity fields and can reproduce known physical scaling laws when processing a set of vorticity fields that evolve over time.