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971.
This article examines the relationship between personal discount rates and sexual behaviors in a sample of teenagers and young adults. We find that higher discount rates (an indication of less willingness to forego current consumption for future consumption) are significantly associated with a range of sexual behaviors, including ever having sex, having sex before age 16 years, and past or current pregnancy. These associations are consistent with previous studies showing a link between discounting and other, non-sexual health behaviors. JEL Classification D80 · D90 · I10  相似文献   
972.
973.
Monk parakeets (Myiopsitta monachus) are the most abundant and widely distributed of the naturalized parrots in the United States. Their presence is simultaneously encouraged by some humans (through use of bird feeders) and discouraged by others (through removal of their nests) and, as a result, they show an interesting spatial distribution across urban areas. We used an online public survey and field surveys to examine the influence of human activities and land use on the distribution of this exotic species around Chicago, IL (USA). These efforts resulted in detection of 249 nesting structures and approximately 778 birds across the region. A CART analysis successfully separated nesting sites from random sites and correctly classified 90?% of the nesting sites. The most important factor in the model was land use, with nests typically found in areas with less than 84?% residential zoning. We found nests on a wide variety of substrates including trees, cell phone towers, and stadium lights. Spatial point pattern analysis indicated that nests in trees and nests in built substrates were significantly dissociated with each other at all scales. Nests on built substrates were closer to railroads and highways or in areas with lower human population density, suggesting either a difference in substrate availability or human tolerance between these settings. While humans may have a positive effect on distribution of monk parakeets at large spatial scales, at the scale of this study we see a potentially negative effect of too many humans on the distribution of monk parakeet nests.  相似文献   
974.
About 50?years ago, Efron noted some counterintuitive properties of the long-term behavior of contests involving dice. For instance, consider the 6-sided dice whose sides are labeled (4,4,4,4,0,0), (3,3,3,3,3,3), (6,6,2,2,2,2), and (5,5,5,1,1,1). Each die has a 2/3 probability of rolling a higher number than the next one in the list and the last has the same 2/3 probability of rolling a higher number than the first. The non-transitivity of games involving non-identical dice was popularized by Gardner (Sci Am, 223:110–114, 1970). Although Gardner and other authors have observed that non-transitive dice serve to illustrate the complexities of the theory of voting, it does not seem that much attention has been paid to the corresponding voting system. Our purpose in this article is to present this voting system and compare its properties with those of other voting systems. One of the most interesting properties is the fact that cancellation with respect to the Efron dice voting system can replace cancellation with respect to pairwise preferences in Young’s characterization of the social choice function associated with the Borda Count.  相似文献   
975.
We develop a formal theory of legitimate collective choice. In our theory a policy choice is legitimate if the process through which the final choice was determined is consistent with some principle that can be used to (perhaps partially) rank the potential policy choices. The set of principles in any choice situation is taken to be exogenous, but a decision-making process is defined so as to deal with any nontrivial set of principles. Such a process is itself referred to as legitimate if it is guaranteed to select a legitimate outcome for each possible exogenous set of principles. We characterize the class of procedures that are legitimate, prove that legitimate policy decisions consistent with principles always exist and characterize the set of policy decisions that are legitimate for a any given set of principles. As we do not require the principles to be weak orders of the alternatives, our theory provides a notion of legitimacy that can be satisfied even when the guiding principles are potentially cyclic or incomplete. Accordingly, our theory illustrates one nontautological means by which majoritarian principles can be reconciled with legitimacy.  相似文献   
976.
Lesbian, gay, and bisexual (LGB) youths are over-represented in the homeless population. To examine why some LGB youths become homeless, this report compares homeless and non-homeless LGB youths. Of the 156 LGB youths, 48% reported ever being homeless (i.e., running away or being evicted from home). Results indicate that sexual orientation awareness and the initiation of sexual behavior occurred earlier in homeless than in non-homeless LGB youths and predated the first homeless episode. Substance use was more frequent and first occurred at an earlier age in homeless as compared to non-homeless LGB youths; however, substance use occurred subsequent to first homelessness. Childhood sexual abuse was associated with homelessness; and, early sexual orientation development was related to homelessness among youths without a history of sexual abuse. Findings suggest that interventions should help youths cope with their unfolding sexual orientation and work to prevent or address the consequences of sexual abuse.  相似文献   
977.
Almost from the beginning of formal college health programs in the second half of the 19th century, college health nurses were there to care for students in college and university settings. By the end of the 20th century, the role of college health nurses had evolved with the nursing field in general, but with enough unique features for the American Nurses' Credentialing Center to recognize college health nursing as a professional subspecialty and administer the first College Health Nurse Certification examinations. In addition, new nurse practitioner programs provided practicing nurses with more independence, and their duties continued to expand beyond care of the sick to include health promotion, administrative, and teaching activities. As a result of these changes, college health nurses now play a larger role in the life of students and promoting a healthy campus community than ever before in the history of college health.  相似文献   
978.
979.
Psychological abuse of older adults is a hidden and pervasive problem that is not well conceptualized nor well measured. Goals. The goals were to (a) conceptualize psychological abuse using three-dimensional concept maps, and (b) develop theoretical models. Methods. Statements describing the construct were generated by local and national panels. These were sorted and rated using Concept Systems software whereby the concepts were depicted as a map. Results. The concept maps guided development of theoretical hierarchies. Significance. Theoretical models may help to develop measures to estimate prevalence better and may enable more precise screening for triage into appropriate interventions.  相似文献   
980.
Self-perception of aging and health among older adults in Korea   总被引:1,自引:0,他引:1  
The way that each individual perceives his or her own aging and health may be a key indicator of adaptation and well-being in old age. This study explored the determinants of self-perception of aging and health using 291 community-dwelling older adults in Korea (mean AGE=69.9). Older individuals with lower levels of education and economic status and various types of health problems (more chronic conditions, greater disability, poorer vision, and greater numbers of sick days) were found to have more negative self-perception of aging and health. In addition, a significant role of psychological factors was observed. For self-perception of health, sense of mastery was found to be a significant factor, and for self-perception of aging, neuroticism was observed to be significant along with sense of mastery. The mediating role of self-perception of health was supported that positive perception of health intervened the adverse effects of health problems on self-perception of aging. The findings demonstrate the important roles of psychological resources and subjective perceptions and suggest a need to consider them when planning interventions.  相似文献   
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