Collective Efficacy and Intimate Partner \Violence: Community Context

Intimate partner violence is a very serious issue in the United States. In spite of improvements, there is still much work to be done. Policies focusing on formal controls such as arrest, orders of protection, and prosecution have questionable potential. However, collective efficacy and the examination of community context have much to offer the field of intimate partner violence. Collective efficacy, comprised of social cohesion, social capital, and informal social control, may be more effective in reducing intimate partner violence than use of traditional formal social controls alone. These community context variables may also be of great assistance in improving the effectiveness of social support. This research study examines intimate partner violence at the community level. Specifically, community context in terms of collective efficacy is studied. Using data from the Chicago Women\u27s Health Risk Study and the Longitudinal Evaluation of Chicago\u27s Community Policing Program, the research uses several indicators of collective efficacy to determine if collective efficacy in conjunction with formal controls is associated with greater success in the reduction of intimate partner violence than formal controls alone. Next, the interaction between formal controls and informal social support networks is examined to determine if greater informal social support networks leads to greater effectiveness of formal controls. Finally, the interaction between social support and collective efficacy is examined to determine if greater collective efficacy leads to greater effectiveness of social support. It is hypothesized that collective efficacy with formal controls will be more valuable in reducing intimate partner violence than use of formal controls alone. It is also hypothesized that support networks with formal controls will be more efficacious in reducing intimate partner violence than formal controls alone. Finally, it is hypothesized that collective efficacy will increase the success of social support in reducing intimate partner violence. The results of the research indicate that increased collective efficacy and social support are not associated with decreases in reported frequency or severity of intimate partner violence. Implications of the results are discussed concerning collective efficacy in general, and for intimate partner violence. The goal is to develop better policy

Optimal design of studies of influenza transmission in households. I: Case-ascertained studies

Case-ascertained household transmission studies, in which households including an index case are recruited and followed up, are invaluable to understanding the epidemiology of influenza. We used a simulation approach parameterized with data from household transmission studies to evaluate alternative study designs. We compared studies that relied on self-reported illness in household contacts vs. studies that used home visits to collect swab specimens for virological confirmation of secondary infections, allowing for the trade-off between sample size vs. intensity of follow-up given a fixed budget. For studies estimating the secondary attack proportion, 2-3 follow-up visits with specimens collected from all members regardless of illness were optimal. However, for studies comparing secondary attack proportions between two or more groups, such as controlled intervention studies, designs with reactive home visits following illness reports in contacts were most powerful, while a design with one home visit optimally timed also performed well. © 2011 Cambridge University Press.published_or_final_versio

Concordance of interim and final estimates of influenza vaccine effectiveness: a systematic review

The World Health Organization's Global Influenza Surveillance and Response System meets twice a year to generate a recommendation for the composition of the seasonal influenza vaccine. Interim vaccine effectiveness (VE) estimates provide a preliminary indication of influenza vaccine performance during the season and may be useful for decision making. We reviewed 17 pairs of studies reporting 33 pairs of interim and final estimates using the test-negative design to evaluate whether interim estimates can reliably predict final estimates. We examined features of the study design that may be correlated with interim estimates being substantially different from their final estimates and identified differences related to change in study period and concomitant changes in sample size, proportion vaccinated and proportion of cases. An absolute difference of no more than 10% between interim and final estimates was found for 18 of 33 reported pairs of estimates, including six of 12 pairs reporting VE against any influenza, six of 10 for influenza A(H1N1)pdm09, four of seven for influenza A(H3N2) and two of four for influenza B. While we identified inconsistencies in the methods, the similarities between interim and final estimates support the utility of generating and disseminating preliminary estimates of VE while virus circulation is ongoing.VK Leung, BJ Cowling, S Feng, SG Sulliva

Transmission of hand, foot and mouth disease and its potential driving factors in Hong Kong

published_or_final_versio

Behavioural changes in relation to risk perception and prevention of avian and human influenza in the general population of Hong Kong, 2006 to 2010

Conference Theme: Translating Health Research into Policy and Practice for Health of the PopulationPoster Presentation: abstract no. P84-Ab0047BACKGROUND: The Hong Kong government has introduced a series of progressive measures on importation, farming and retail of live poultry to minimize risk of A/H5N1 transmission since 1997. Perceived risk of A/H5N1 and related preventions could decline as these macro-level policies minimizing human-chicken contact. This may paradoxically increase population risk of other influenza and respiratory infection due to reduced preventive behaviors. OBJECTIVES: A follow-up survey in 2010 was conducted to investigate change of live poultry exposure, risk perception and prevention of A/H5N1 among respondents who participated in the random household telephone survey in 2006. METHODS: Totally, of 1,760 respondents who completed the 2006 survey, 680 could be traced and ...published_or_final_versio

Experimental Identification of the Kink Instability as a Poloidal Flux Amplification Mechanism for Coaxial Gun Spheromak Formation

The magnetohydrodynamic kink instability is observed and identified experimentally as a poloidal flux amplification mechanism for coaxial gun spheromak formation. Plasmas in this experiment fall into three distinct regimes which depend on the peak gun current to magnetic flux ratio, with (I) low values resulting in a straight plasma column with helical magnetic field, (II) intermediate values leading to kinking of the column axis, and (III) high values leading immediately to a detached plasma. Onset of column kinking agrees quantitatively with the Kruskal-Shafranov limit, and the kink acts as a dynamo which converts toroidal to poloidal flux. Regime II clearly leads to both poloidal flux amplification and the development of a spheromak configuration.Comment: accepted for publication in Physical Review Letter