Similar effects of residential and non-residential vegetation on bird diversity in suburban neighbourhoods

Estimating the relative importance of vegetation on residential land (gardens, yards, and street-trees) and vegetation on non-residential land (parks and other large green spaces) is important so that competing options for urban conservation planning can be prioritized. We used data from an urban breeding-bird monitoring program to compare the relative effects vegetation on residential land and vegetation on non-residential land (both the amount and type of vegetation at local and landscape scales) on bird species richness and an index of conservation value for the bird community. We then estimated the realised relative benefit of managing the amount of vegetation on these two types of land (i.e., as alternative management options for promoting biodiversity), which might be achieved within the practical limits imposed by human population density. The local effects of increasing residential and non-residential vegetation amount were similar and positive on all measures of bird species richness and conservation value. Non-residential vegetation had an additional landscape-scale influence on bird diversity that residential vegetation did not. Options for managing the amount of non-residential vegetation appear to be more limited by high human population density than for managing the amount of residential vegetation. This suggests that there may be greater realised benefits to bird diversity from managing the amount of vegetation on residential land than from the more common focus of urban planning of managing vegetation on non-residential land.     

东亚国际移民:趋势与政策

回顾了东亚的国际劳工移民的动向和原因,并将注意力转移到东亚的国际劳工流动引起的一些政策变化:提高劳动力输出纯收益,重新整合回国劳工,劳力出口的再构建,推进和控制劳动力招募和保护劳工移民.最后做出了一些结论性的预测:越来越多的人到其他国家追寻赚钱的机会及更高质量的生活.导致这一现象的原因有:亚太地区经济整合性的增长、交流与传媒系统的扩大和交互联系、教育与培训的国际化、交通的日益简易和方便、收入差异、就业机会以及变化的环境等.     

The loss-averse newsvendor problem

Newsvendor models are widely used in the literature, and usually based upon the assumption of risk neutrality. This paper uses loss aversion to model manager's decision-making behavior in the single-period newsvendor problem. We find that if shortage cost is not negligible, then a loss-averse newsvendor may order more than a risk-neutral newsvendor. We also find that the loss-averse newsvendor's optimal order quantity may increase in wholesale price and decrease in retail price, which can never occur in the risk-neutral newsvendor model.     

OPTIMAL DESIGN OF MULTI-PRODUCT MULTI-ECHELON INVENTORY SYSTEMS*

Large scale inventory distribution systems typically comprise a hierarchy of retail stores and warehouses. This paper presents a model for finding the optimal design of such systems. Given the maximum number of facilities under consideration and their locations, the problem is to determine which facilities to include in the system and which products to stock at each in order to minimize the cost of the system. Demand for the products may be deterministic or stochastic. To use the model it is necessary to know the optimal inventory policies for the multi-echelon systems under consideration; however, an important feature of this work is that any multi-echelon model may be used in tandem with this design model. Included is an example to illustrate the model and the two points which are the basis for its formulation: first, there is generally no single design which is best for all products; second, the design which is optimal for a given product is not necessarily the best design to use for that product when trying to minimize the cost of the entire system.     

Laowai as a discourse of Othering: unnoticed stereotyping of American expatriates in Mainland China

ABSTRACT

Homogeneous ethnic labels, deriving from migrants’ phenotypic and cultural distinctness, are frequently utilised to single them out as the Other during intercultural encounters. Nonetheless, the Othering enacted by ethnic labelling has not attracted enough attention from host-nationals who use these labels. In-depth interviews with 35 American expatriates revealed that laowai was perceived as a discourse of Othering, which first categorised Westerners under this label as the Other in mainland China for their noticeable non-Chinese physical appearance, and then exposed them to its Chinese users’ diversely motivated stereotyping in such forms as exclusion, alienation and discrimination. However, Chinese people had not noticed laowai’s nature of being a stereotype-laden discourse of Othering and conversely considered this label as a neutral and even friendly expression. Ultimately, these Americans experienced Chinese people’s habitual use of laowai as a way to separate them as permanent outsiders who were subject to Occidentalism in mainland China.     

A Bayesian approach to sequential analysis in post‐licensure vaccine safety surveillance

With rapid development of computing technology, Bayesian statistics have increasingly gained more attention in various areas of public health. However, the full potential of Bayesian sequential methods applied to vaccine safety surveillance has not yet been realized, despite acknowledged practical benefits and philosophical advantages of Bayesian statistics. In this paper, we describe how sequential analysis can be performed in a Bayesian paradigm in the field of vaccine safety. We compared the performance of the frequentist sequential method, specifically, Maximized Sequential Probability Ratio Test (MaxSPRT), and a Bayesian sequential method using simulations and a real world vaccine safety example. The performance is evaluated using three metrics: false positive rate, false negative rate, and average earliest time to signal. Depending on the background rate of adverse events, the Bayesian sequential method could significantly improve the false negative rate and decrease the earliest time to signal. We consider the proposed Bayesian sequential approach to be a promising alternative for vaccine safety surveillance.     

DETERMINANTS OF REVENUE IN SPORTS LEAGUES: AN EMPIRICAL ASSESSMENT

This study investigates determinants of revenue in North America's four major professional sports leagues. Revenue is positively associated with on‐field success in baseball (MLB), basketball (NBA), and hockey (NHL), but not in football (NFL). The returns to success are not diminishing as commonly assumed, which casts doubt on the uncertainty of outcome hypothesis, and differences across leagues are consistent with revenue sharing arrangements. Estimates indicate a strong negative but diminishing relationship between stadium age and revenue. Teams in larger markets generate more revenue than smaller markets, but the returns to success do not differ according to market size. (JEL Z21)     

Trial Size for Near-Optimal Choice Between Surveillance and Aggressive Treatment: Reconsidering MSLT-II

Abstract

A convention in designing randomized clinical trials has been to choose sample sizes that yield specified statistical power when testing hypotheses about treatment response. Manski and Tetenov recently critiqued this convention and proposed enrollment of sufficiently many subjects to enable near-optimal treatment choices. This article develops a refined version of that analysis applicable to trials comparing aggressive treatment of patients with surveillance. The need for a refined analysis arises because the earlier work assumed that there is only a primary health outcome of interest, without secondary outcomes. An important aspect of choice between surveillance and aggressive treatment is that the latter may have side effects. One should then consider how the primary outcome and side effects jointly determine patient welfare. This requires new analysis of sample design. As a case study, we reconsider a trial comparing nodal observation and lymph node dissection when treating patients with cutaneous melanoma. Using a statistical power calculation, the investigators assigned 971 patients to dissection and 968 to observation. We conclude that assigning 244 patients to each option would yield findings that enable suitably near-optimal treatment choice. Thus, a much smaller sample size would have sufficed to inform clinical practice.     

On the Processes Underlying the Relationship Between Alexithymia and Gambling Severity

A great number of individuals with persistent problematic gambling behavior exhibit alexithymic tendencies, greater impulsivity, impaired working memory and poor mood. However, the relationship between these cognitive, affective and personality factors in problem gambling remains poorly understood. Our aim was to investigate multiple pathways of the alexithymia and problem gambling relationship. One hundred and six male subjects with different levels of gambling problem severity were recruited. Alexithymia, impulsivity and verbal working memory were evaluated, and their relationships to disordered gambling was examined by means of a path analysis. Results indicate that alexithymia is related to an increase in the severity of gambling indirectly, i.e., through distress severity. In addition, a rise of alexithymic tendencies was also associated with problem gambling severity through enhanced impulsivity that directly increased distress. Working memory capacity failed to significantly impact our path model. Overall, our findings contribute a new finding to the literature by highlighting the importance of alexithymia, in addition to impulsivity, in the understanding of gambling problem severity and its clinical course.     

Comparison of Type I error rates and statistical power of different propensity score methods

Propensity score analysis (PSA) is a technique to correct for potential confounding in observational studies. Covariate adjustment, matching, stratification, and inverse weighting are the four most commonly used methods involving propensity scores. The main goal of this research is to determine which PSA method performs the best in terms of protecting against spurious association detection, as measured by Type I error rate, while maintaining sufficient power to detect a true association, if one exists. An examination of these PSA methods along with ordinary least squares regression was conducted under two cases: correct PSA model specification and incorrect PSA model specification. PSA covariate adjustment and PSA matching maintain the nominal Type I error rate, when the PSA model is correctly specified, but only PSA covariate adjustment achieves adequate power levels. Other methods produced conservative Type I Errors in some scenarios, while liberal Type I error rates were observed in other scenarios.