Urban Ecosystems - Urbanization in the Sahel is constantly competing with and greatly affecting the woody flora in urban areas. Urbanization can replace the species mix, leading to changes in plant... 相似文献
Urban Ecosystems - Termites comprise a large group of organisms in urban areas, and this leads us to believe that there is a comprehensive literature on the subject, sufficient for conducting a... 相似文献
A smoothed bootstrap method is presented for the purpose of bandwidth selection in nonparametric hazard rate estimation for iid data. In this context, two new bootstrap bandwidth selectors are established based on the exact expression of the bootstrap version of the mean integrated squared error of some approximations of the kernel hazard rate estimator. This is very useful since Monte Carlo approximation is no longer needed for the implementation of the two bootstrap selectors. A simulation study is carried out in order to show the empirical performance of the new bootstrap bandwidths and to compare them with other existing selectors. The methods are illustrated by applying them to a diabetes data set. 相似文献
An accurate procedure is proposed to calculate approximate moments of progressive order statistics in the context of statistical inference for lifetime models. The study analyses the performance of power series expansion to approximate the moments for location and scale distributions with high precision and smaller deviations with respect to the exact values. A comparative analysis between exact and approximate methods is shown using some tables and figures. The different approximations are applied in two situations. First, we consider the problem of computing the large sample variance–covariance matrix of maximum likelihood estimators. We also use the approximations to obtain progressively censored sampling plans for log-normal distributed data. These problems illustrate that the presented procedure is highly useful to compute the moments with precision for numerous censoring patterns and, in many cases, is the only valid method because the exact calculation may not be applicable. 相似文献
This article presents an alternative perspective regarding the concept of “propaganda” in the historiography of public relations. Recent scholars of public relations have rightly criticized early attempts to write the field’s history as a linear progression, from propaganda to excellence. At the same time, however, the same recent scholars have come to accept a linear conceptual change, and that “propaganda” became an impossible term in liberal democratic countries in the 1960s. By using the empirical case of the massive communication efforts initiated by the Swedish Commission on Right-Hand Traffic, which was assigned to implement right-hand traffic in 1967, this article shows that the concept of “propaganda” both occurred frequently and was used in a neutral sense. To deepen the understanding of this alternative perspective, the article both presents how the historical actors conceptualized their work, and describes how the communication work of the Commission was performed. 相似文献
A debate on masculinity and immigration rose across Europe in 2015 after an incident with sexual harassments taking place in Cologne, Germany. The incident refuelled a debate positioning unaccompanied young men as a possible threat. This article is based on a research project where we during this time ethnographically followed 20 young men, having arrived in Sweden as ‘unaccompanied’ minors. The aim is to examine how the young men themselves talk about, reflect on and negotiate masculinity and gender during this period. The article concludes that masculinity cannot be approached as something stable easily being inherited or transferred from one’s origins. One difference for ‘unaccompanied’ young men is how conflicts or tensions emerging in relation to issues of gender and masculinity tend to be interpreted differently, and publicly, putting the young men in a ‘gendered situation of questioning’. 相似文献
Objective: To describe sexual practices in Mexican lesbian and bisexual women. Materials and method: An online survey was conducted with a nonprobabilistic sample of self-identified lesbian (n?=?768) and bisexual (n?=?371) women from the 32 states of Mexico. Results: Lesbians less frequently reported having had sex with a man than bisexual women. Preferred sexual practices with other women were external genital stimulation with fingers, internal genital stimulation with fingers, and oral genital stimulation. Most (~80%) participants did not use protection to prevent sexually transmitted infections. Conclusions: Our results can inform the design of promotion and prevention programs in sexual health aimed at sexual minority women. 相似文献
Review of Economics of the Household - We provide evidence on the importance of specific inputs for child cognitive skills by estimating alternative specifications of the early childhood production... 相似文献
We analyze cooperation of individuals in a family context, using a Public Good game. In a lab experiment, 165 individuals from 55 three-generation families (youth, parent, and grandparent) play a repeated Public Good game in three different treatments: one in which three members of the same family play each other (family), a second with the youth and two non-family members, while preserving the previous generational structure (inter-generational), and a third in which three randomly-selected players play each other (random). We find that all the age groups cooperate more when playing with relatives, indicating that family ties may have a positive relationship to contributions to the Public Good. We also find that this trend is more evident for the youths and the parents than for the grandparents. Furthermore, young individuals tend to cooperate less than older generations, especially in non-family treatments. Our results serve as evidence of the relationship between family ties and inter-generational cooperative behaviors.
Social Indicators Research - In poverty measurement, differential weighting aims to take into account the unequal importance of the diverse dimensions and aspects of poverty and to add valuable... 相似文献