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841.
842.
Fatality reductions from increases in safety belt use are estimated taking into account that drivers who change from being nonusers to being users have lower accident involvement rates than the remaining nonusers, a process referred to as "selective recruitment." Analytical functions are derived which express expected fatality reductions in terms of changes in safety belt use rates from an initial rate. The function parameters are determined by requiring that computed average crash rates for nonusers be 53% higher than the rates for users, a recently determined empirical value. These functions show that, depending on the initial use rate and use rate increase, selective recruitment may increase or decrease expected fatality reductions. However, effects are relatively small, in no case exceeding +/- 5.3%.  相似文献   
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844.
An attempt is made to establish primary integration as a major variable in explaining citizen involvement in political life. It is argued that a convincing case requires a demonstration that the variable is both empirically important and theoretically meaningful. The former is examined through data from a sample survey of an English city. Theoretical meaning is established through focussing upon the idea of sociable talk as a key factor in reality construction, including the construction of political events as a proximate world available for the interest and participation by the individual.  相似文献   
845.
Jonsson SH  Rendall MS 《Demography》2004,41(1):129-150
Crucial to the long-term contribution of immigration to a receiving country's population is the extent to which the immigrants reproduce themselves in subsequent, native-born generations. Using conventional projection methodologies, this fertility contribution may be poorly estimated primarily because of problems in projecting the number of immigrants who are at risk of childbearing. We propose an alternative method that obviates the need to project the number of immigrants by using the full sending-country birth cohort as the risk group to project their receiving-country childbearing. This "sending-country birth cohort" method is found to perform dramatically better than conventional methods when projecting to 1999 from base years both before and after the large increase in inflows of Mexican immigrants to the United States in the late 1980s. Projecting forward from 1999, we estimate a cumulative contribution of Mexican immigrant fertility from the 1980s to 2040 of 36 million births, including 25% to 50% more births after 1995 than are projected using conventional methods.  相似文献   
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This study describes depressive symptoms among caregivers following bereavement and connects these trajectories to earlier features of caregiving using life course and stress process theory. Data are from a six-wave longitudinal survey (five years) of spouses and adult children caring for someone with Alzheimer's Disease. The analytic subsample (N = 291) is defined by death of the care-recipient after the baseline interview. A latent class mixture model is used to identify distinctive clusters of depressive symptoms over time. Of the four trajectories identified, three represent stable symptom levels over time, with two-thirds being repeatedly symptomatic (medium symptom levels), compared to two smaller groups of repeatedly asymptomatic (effectively absent of symptoms) and repeatedly distressed (severe symptoms). In contrast, about one in five caregivers experiences improved emotional well-being over time, the temporarily distressed, who progress from severe to moderate symptom levels. Caregivers with few symptoms before bereavement tend to maintain these states afterwards, but emotionally distressed caregivers tend to become more distressed. Role overload before bereavement substantially increases the odds of following an unfavorable trajectory afterwards, whereas self-esteem and socioemotional support play protective roles. These results demonstrate that caregivers are not uniform in their emotional responses to bereavement, but follow several distinct trajectories. These trajectories are linked to their previous experiences as caregivers, in particular exposure to stressors and access to resources. These findings suggest that intervention during caregiving may facilitate adaptation following death of a loved one.  相似文献   
850.
Anecdotal reports have suggested that the use and abuse of methamphetamine is increasing in the United States. To date, however, few scholarly works have explored the prevalence and correlates of methamphetamine use in the United States. To address this limitation, a secondary analysis was undertaken with data collected through the Arrestee Drug Abuse Monitoring (ADAM) Program. An examination of methamphetamine-positive rates among ADAM arrestees interviewed between 1991 and 2001 identified that its use is concentrated within the Western part of the United States. Supplementary analyses of Sacramento arrestees indicated that 71% were diagnosed as needing some form of alcohol or other drug treatment. Compared to those arrestees who were detected methamphetamine-negative, methamphetamine-positive arrestees in Sacramento were three times as likely to be white and to have been diagnosed in need of drug treatment. Implications for drug control policy are discussed.  相似文献   
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