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61.
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.
Wolfgang LutzEmail:
  相似文献   
62.

The analysis of the factors pulling and pushing students in a foreign country to complete their higher education is key for the implementation of university policies aimed at increasing the number of credits gained by students abroad and hence the degree of internationalisation of institutions. Consistent with previous studies, the present contribution examines the roles played by countries in the Erasmus student mobility flows by considering a joint strategy of analysis based on social network analysis and exploratory data analysis. First, data on Erasmus student exchanges among countries are gathered at macro-level from the European Union Open Data Portal and network data structures are analysed. Second, educational indicators from the Eurostat website are collected to describe the investments in higher education. The main findings suggest the presence of a core-periphery configuration in the student mobility network with few central countries in which the economic benefits and the investments in education seem to act as key elements for university attractiveness.

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Urban Ecosystems - Residential yardscapes are at the forefront of human interaction with nature for those living in urban areas across Europe and North America. In recent years a significant amount...  相似文献   
65.
Over the past decades, men's and women's time use in industrialized nations has changed dramatically, suggesting a gender revolution. Women increased their time in paid work and reduced time in unpaid activities, while men increased their time in unpaid work, but not enough to compensate for women's retreat. We investigate developments regarding men's and women's unpaid work across Europe and the United States, using time diary data from the mid‐1980s and onward. We find evidence for gender convergence in unpaid work over time, but different trends for housework and childcare. Gender convergence in housework primarily resulted from women reducing their time, whereas childcare time increased for both sexes, resulting in convergence only where men increased more than did women. Decomposition analyses show that trends in housework and childcare are explained by changes in behavior rather than compositional changes in population characteristics. Though level differences in unpaid work persist, our findings regarding trends support gender convergence in that they are general across country contexts that vary regarding policy and social norms about gender, family, and work.  相似文献   
66.
We define the odd log-logistic exponential Gaussian regression with two systematic components, which extends the heteroscedastic Gaussian regression and it is suitable for bimodal data quite common in the agriculture area. We estimate the parameters by the method of maximum likelihood. Some simulations indicate that the maximum-likelihood estimators are accurate. The model assumptions are checked through case deletion and quantile residuals. The usefulness of the new regression model is illustrated by means of three real data sets in different areas of agriculture, where the data present bimodality.  相似文献   
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68.

Background

Ice-pack is widely used for alleviating postpartum perineal pain sustained after birth related perineal trauma. However, it lacks robust evidence on timing and frequency of applications, to ensure the effective and safe use of this therapy.

Aims

To evaluate if a 10 min ice-pack application relieved postpartum perineal pain and if the analgesic effect was maintained for up to 2 h.

Methods

A randomised controlled trial conducted from December 2012 to February 2013 with 69 primiparous women ≥18 years old, 6–24 h postpartum, with perineal pain ≥3, who had not received anti-inflammatory medication or analgesics after childbirth, who were randomised to a single ice-pack application on the perineum for 10 min or standard care. The primary and secondary outcomes were a reduction ≥30% in perineal pain intensity, immediately after the application and the maintenance of the analgesic effect for up to 2 h, respectively.

Findings

Immediately post-intervention, the proportion of women whose perineal pain decreased ≥30% was significantly higher in the experimental group. Within 2 h, there was no significant difference in the pain levels in both groups. Within 2 h, for 61.9% and 89.3% of women in the experimental and control group, respectively, the perineal pain levels remained unchanged. For the remaining participants, perineal pain was increasing after an average time of 1 h 45 min and 1 h 56 min for the experimental and control groups, respectively.

Conclusion

By applying an ice-pack for 10 min to the perineum, effective pain relief is achieved, that is maintained for between 1 h 45 min and 2 h.  相似文献   
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Children require considerable resources such as time and money to be raised. Still, despite the heavy costs involved, most people do decide to have children, a fact that raises the question of what motivates them to do so. Moreover, after having one or more children, people decide not to have additional ones, even though they might still be fertile. This raises the question of what motivates people to terminate procreation. The present paper aims to address these questions using a combination of qualitative and quantitative research methods. In Study 1, we used in-depth interviews and open-ended questionnaires that lead to the identification of 66 reasons for which people have children and 23 reasons for which people stop having children. In Study 2, we used principal component analysis that classified these reasons in broader motivation domains, 15 for procreating and 4 for terminating procreation. Sex differences were examined in each domain. By placing procreation in an evolutionary framework, this study aims to provide a deeper understanding of the motives that drive people toward and away from the process of having children.  相似文献   
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