If the years of late adolescence and early adulthood are depicted as rocky, disorderly, and experimental, then how should the life course stage that immediately follows be characterized? Using data from the National Longitudinal Study of the High School Class of 1972, we focus on work and school activities in the latter half of the young adult years (ages roughly 25–31) to empirically address whether the diversity of work and schooling patterns diminishes. Finding a lack of orderliness in work and schooling trajectories, and that holding two or more activities simultaneously is quite common, we question how this stage of the life course should be conceptualized. Moving away from the traditional sequential roles approach, we use multinomial logistic regression to differentiate among activity sequences commonly held by young men and women at these ages, and address how family of origin background factors and prior life experiences influence life course experiences in the later 20s and early 30s.
There is no one definition of leadership. The leadership equation is never set or fixed. Time, place, specific problems, the particular parties involved all play a role in the leadership equation. Nor is there one specific list of attributes, virtues, or skills that all leaders must and do possess. Nonetheless, we argue that at its core, all forms of ethical leadership are based on three elemental ingredients: character, stewardship, and experience. 相似文献
Researchers have recently expanded the scope of study of transmission patterns of AIDS to incorporate spatial and geographical questions. United States diffusion patterns of this disease appear to indicate that it may emanate from urban area epicenters to areas of low and moderate prevalence. The travel patterns of injecting drug users (IDUs) and the extent to which they engage in high risk drug and sexual activities was examined as an explanation of diffusion of the HIV virus from one community to another. The study population of 49,621 was comprised of subjects recruited from approximately 60 sites nationwide from 1988–1991. While the data are limited in some ways, they partially support a diffusion explanation of HIV transmission for males and females. The analysis demonstrates that low prevalence cities were significantly more likely to have been the destinations of both men and women who engaged in high risk drug and sexual activities. In addition, HIV seropositive drug users who engaged in high risk drug and sexual behaviors in destination cities were more likely than seronegatives to travel to high or low seroprevalence areas than to moderate prevalence areas. The findings suggest a need for effective HIV prevention educational messages about the risks of traveling and participating in high risk activities. 相似文献
This paper blends quantitative with qualitative data in an investigation of community and contraceptive choice in Nang Rong, Thailand. Specifically, it develops an explanation of 1) method dominance within villages, coupled with 2) marked differences between villages in the popularity of particular methods. The quantitative analysis demonstrates the importance of village location and placement of family planning services for patterns of contraceptive choice. The qualitative data provide a complementary perspective, emphasizing the importance of social as well as physical space and giving particular attention to the structure of conversational networks. 相似文献
Using data from the 1970 National Fertility Study, the trend in the initiation of contraception prior to the first pregnancy is examined. This trend is of interest because of its relationship to the tempo of familybuilding. Using data from a recent marriage cohort, it is shown that use before the first pregnancy is related to age at marriage, age at termination of first pregnancy and the probability of having a premarital conception. For women first married during the decade of the 1960’s, there was a substantial increase in the proportion using contraception before the first pregnancy. This trend is found among both white Catholics and white non-Catholics, but not among blacks. An examination of the specific method used by women using contraception before the first pregnancy reveals a shift from reliance on the traditional methods of diaphragm, condom and douche by the earlier birth cohorts to the use of the pill by the more recent cohorts. An appendix examines the reliability of various measures of the interval of first use of contraception. 相似文献
Changing fertility expectations and preferences from 1962 to 1977 are compared with final parity in a longitudinal study. Results are strongly affected by initial parity in 1962. Final parity, 27 percent below expectations for those initially childless, illustrates the effect for couples free to change expectations downward of declining fertility preferences. Changes in expectations early in marriage had a significant long-term effect on final parity, as did early differences between wife’s expectations and husband’s preferences. Unplanned births increased final parity significantly. Religion, education, and income had no systematic relation to the discrepancy between initial expectations and final parity. 相似文献
Summary The safe harbor hypothesis includes the suggestion that parental care causes the embryonic stage to be the safest harbor,
and, therefore, egg size will increase in populations with parental care to decrease the duration of subsequent, higher risk
stages. Neither the safe habor hypothesis nor r and K theory seem adequate to explain the correlation between egg size and
the presence/absence of parental care among salamanders, a group in which there is a further correlation between the larval
(hatchling) habitat and egg size/parental care. Pond-breeding salamanders generally have small eggs and lack parental care,
and stream-breeding salamanders generally have large eggs and parental care. I argue that the fundamental difference in the
food available to hatchling salamanders between lentic (plankton-rich) and lotic (plankton-poor) environments selects for
relatively lower parental investment in the lentic environment. From the standpoint of parental fitness, small (more numerous)
hatchlings have a greater payoff where the available food is mall and dense (zooplankton in lentic environments), and large
hatchlings are selectively advantageous where the food is of large size and less dense (benthic invertebrates in lotic environments).
Selection for larger hatchlings in lotic environments results in longer embryonic periods and,ceteris paribus, greater total embryonic mortality. Embryo hiding and guarding have evolved among lotic-breeding salamanders as compensatory
mechanisms to reduce the rate of embryonic mortality. In this view, parental care is a consequence of selection for larger
egg size and not an umbrella that allows egg size to increase, contrary to the safe harbor hypothesis.
The relationship between variance in parental investment and food available to offspring, developed here for salamanders,
may be of general significance. YosiakiIt?, a critic of r and K theory, independently arrived at a similar conclusion from a broader data base. 相似文献
This paper incorporates the insights of the life course perspective in an examination of the determinants of contraceptive use. It views decision-making about contraceptive methods in the context of personal history and the broader social setting. Three stages in the reproductive life course of married women are considered. In the early years, timing decisions dominate. Contraception is used to delay the first birth and control the tempo of fertility. Mid-career, the major concern is whether to have a sterilizing operation. Towards the end of the fecund period, couples must decide when to stop using contraception, given that they have not already opted for sterilization. We examine choice among nonpermanent methods, as well as sterilization, in the context of a theoretical model that explicitly recognizes the permanence of the sterilization decision. Our statistical procedures control for unobserved community influences. The data are from Nang Rong district, Thailand, a relatively poor area near the Cambodian border under going substantial socioeconomic change during the 1980s. Our results clearly show variation in method choice over the reproductive life course, and variation in the effects of specific determinants including age of husband and wife, living arrangements, and village location. They also demonstrate gains in the understanding of any particular stage in the life course that accrue from an integrated examination of all of them. 相似文献