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981.
In studying the complex determinants of human fertility, social scientists have given little attention to population density,
although reproduction has been shown to be density-dependent for a wide variety of other species. Using fixed effects models
on the time series of 145 countries and controlling for key social and economic variables, we find a consistent and significant
negative relationship between human fertility and population density. Moreover, we find that individual fertility preferences
also decline with population density. These findings suggest that population density should be included as a variable in future
studies of fertility determinants.
相似文献
Wolfgang LutzEmail: |
982.
983.
984.
This study explores the prevalence of AIDS and cancer stigma as influenced by attitude toward homosexuality, religiosity, authoritarianism, and androgyny. This study used a quasi-experimental survey design (N = 485) to examine attitude toward people with AIDS and cancer, and interaction with people with AIDS and cancer. Negative attitudes toward homosexuality, high religious intensity and ideology, high authoritarianism, and low expressive emerged as factors related to more negative attitudes toward people with AIDS and unwillingness to interact with people with AIDS. Attitudes toward people with cancer were generally not related to the variables. Findings explore how to campaign efforts to reduce existing negative attitudes toward AIDS and homosexuality, given that gay men with AIDS are especially stigmatized. Implications and directions for future research are discussed, especially for interventions. 相似文献
985.
This paper describes a simulation experiment to evaluate the relative effectiveness of rescheduling policies in capacity-constrained, just-in-time (JIT) make-to-stock production environments. Three performance measures were analyzed: average finished goods inventory, total units of sales lost, and a measure of schedule instability. Among the three loading methods we studied (level loading, front loading, and back loading), none was superior across all three performance measures. Level loading was the most robust, while back loading had an interaction effect with forecasting model and capacity level. Time fence scenario was found not to be as significant a factor in system performance as reported by previous research. Once an acceptable time fence scenario is selected, attempts to optimize this factor do not appear to offer significant improvement. It was found that higher demand variation, larger forecast errors, and tight capacity lead to the degradation of system performance. Judicious use of slack capacity helps a system to incorporate the periodic schedule changes typical of JIT systems. 相似文献
986.
Much of the current knowledge pertaining to information technology (IT) and decision making is based on decades old technologies that revolved around a central computing function and application-specific systems. The purpose of this research is to examine the IT decision-making relationship within the emerging organizational computing (OC) environment permeated by spontaneous utilization of both application-and nonapplication-specific computing and communication technologies. Specifically, this study seeks to explore managers' perceptions of the emerging OC environment as a facilitator of their decision-making activities. To achieve a higher level of clarity than previous works, a two-dimensional research framework is developed with the IT dimension consisting of computing and communication, and the decision-making dimension differentiated between operational and managerial decisions. A survey instrument was constructed that measured the computing and communication dimensions of information technology use and their perceived effects upon operational and managerial decisions. The major findings of the study confirmed that managers recognize the value of general, nonapplication-specific information technologies in decision making, and that this recognition is highly associated with how intensively these information technologies are used. Additionally, it was found that the two dimensions of IT differ in their relationships to decision making, and that IT usage relates to managerial decisions differently than operational decisions. These study findings have significant implication for practice and research, especially in the context of information resource management in which the primary purpose of the IS function is the delivery of general information service to users rather than the development of specific IS applications. 相似文献
987.
Michael L. Gargas Robin L. Norton Mark A. Harris Dennis J. Paustenbach Brent L. Finley 《Risk analysis》1994,14(6):1019-1024
Biomonitoring programs for urinary chromium (Cr) typically attempt to evaluate occupational exposure via the inhalation route. This study investigated whether Cr can be detected in the urine of people following the ingestion of soils that contain relatively high concentrations of chromium in chromite ore processing residue (COPR). To evaluate the reasonableness of using urinary monitoring to assess environmental exposure, six volunteers ingested 400 mg of soil/day (low-dose group), two others ingested 2.0 g of soil/day (high-dose group) for 3 consecutive days, and one person ingested a placebo on each of 3 days. The soil and COPR mixture contained concentrations of total chromium (Cr) and hexavalent chromium [Cr(VI)] of 103 ± 20 and 9.3 ± 3.8 mg/kg, respectively. Therefore, the low-dose group ingested 41 μg Cr/day [including 3.7 μg Cr(VI)] and the high-dose group ingested 206 μg Cr/day [including 18.6 μg Cr(VI)] on each of 3 consecutive days. All urine samples were collected and analyzed individually for total Cr on the day prior to dosing, during the 3 days of dosing, and up to the first void 48 h after the last dose. No significant increases in urinary Cr excretion were found when background excretion data were compared with data following each of the 3 days of dosing or in daily mean urine concentrations of the high- vs the low-dose groups. It appears that Cr present in a soil and COPR mixture at Cr doses up to 200 μg/day is not sufficiently bioavailable for biomonitoring of urine to be informative. These results are consistent with previously published findings suggesting that incidental exposure to dusts and soils containing comparable levels of Cr will not result in increased concentrations of Cr in urine. 相似文献
988.
989.
Auditors' assessment of management's dispositions presumably affects their subsequent judgments. However, little is known about the process by which auditors infer characteristics of management. This paper proposes the theory of correspondent inferences [25] as a framework for examining auditors' assessment of management's dispositions; the model is tested in a laboratory experiment using experienced audit managers. The results are consistent with the proposed theoretical framework. Implications for future research are discussed. 相似文献
990.
Marketing communication intensity (i.e., the ratio of advertising and promotional expenditures to sales) has been an important topic for both business managers and academics. Here, we investigate cross-sectional and time-series variation of communication intensity due to: type of offering (product versus service) and type of market (consumer versus industrial). Overall, we find that both of these factors affect variation of communication intensity across industries and over time. However, the effect of market type is much more dramatic than the effect of offering type. Such knowledge about patterns in communication intensity levels helps managers make decisions about how much to spend on advertising and promotion. 相似文献