A Comparison of Likelihood-Based Spatiotemporal Monitoring Methods Under Non-Homogenous Population Size

This article discusses the spatiotemporal surveillance problem of detecting rate changes of Poisson data considering non-homogenous population sample size. By applying Monte Carlo simulations, we investigate the performance of several likelihood-based approaches under various scenarios depending on four factors: (1) population trend, (2) change magnitude, (3) change coverage, and (4) change time. Our article evaluates the performance of spatiotemporal surveillance methods based on the average run length at different change times. The simulation results show that no method is uniformly better than others in all scenarios. The difference between the generalized likelihood ratio (GLR) approach and the weighted likelihood ratio (WLR) approach depends mainly on population size, not change coverage, change magnitude, or change time. We find that changes associated with a small population in time periods and/or spatial regions favor the WLR approach, but those associated with a large population favor the GLR under any trends of population changes.     

Estimation of the common scale of several shifted exponential distributions with unknown locations

We consider the estimation of the common scale parameter of two or more independent shifted exponential distributions with unknown locations. Under a large class of bowl-shaped loss functions, the best location-scale in-variant estimator is shown to be inadmissible. A class of improved estimators is derived. Some numerical results are presented to show the magnitude of risk reduction.     

The development of gaze following in monolingual and bilingual infants: A multi-laboratory study

Determining the meanings of words requires language learners to attend to what other people say. However, it behooves a young language learner to simultaneously encode relevant non-verbal cues, for example, by following the direction of their eye gaze. Sensitivity to cues such as eye gaze might be particularly important for bilingual infants, as they encounter less consistency between words and objects than monolingual infants, and do not always have access to the same word-learning heuristics (e.g., mutual exclusivity). In a preregistered study, we tested the hypothesis that bilingual experience would lead to a more pronounced ability to follow another's gaze. We used a gaze-following paradigm developed by Senju and Csibra (Current Biology, 18, 2008, 668) to test a total of 93 6- to 9-month-old and 229 12- to 15-month-old monolingual and bilingual infants, in 11 laboratories located in 8 countries. Monolingual and bilingual infants showed similar gaze-following abilities, and both groups showed age-related improvements in speed, accuracy, frequency, and duration of fixations to congruent objects. Unexpectedly, bilinguals tended to make more frequent fixations to on-screen objects, whether or not they were cued by the actor. These results suggest that gaze sensitivity is a fundamental aspect of development that is robust to variation in language exposure.     

Does Listening to Mozart Affect Listening Ability?

Considerable research has been conducted testing Rauscher, Shaw, and Ky's (1993) Rauscher, F. H., Shaw, G. L and Ky, K. N. 1993. Music and spatial task performance. Nature, 365: 611[Crossref], [PubMed], [Web of Science ®] , [Google Scholar] Mozart Effect (ME). This study attempts to replicate, in part, research that tested the ME on listening comprehension abilities. Also included in this study is an examination of control group issues in current day research. We hypothesized that students who listen to Mozart would demonstrate greater listening comprehension than students involved in one of four control groups. Students were exposed to one of five treatments and then completed a listening comprehension test about a videotaped lecture they viewed. Ultimately, results uncovered a ME when comparing the Mozart A (alpha) group with the alternative treatment control groups (Mozart B [beta] music and Rock and Roll music), but no ME when comparing the Mozart A group and the non-music control groups (sitting in silence or working on a crossword puzzle). Discussion focused on the ME and listening comprehension as well as on the nature of control groups in experimental research.     

Gender and Mathematics Achievement in China and the United States

This study examines the relationship between gender and mathematics achievement among students in China and the United States, with an emphasis on the gender gap among mathematically talented students. The results show that in neither the US nor China are there gender differences in eighth grade math-achievement test scores. In China, there are no gender differences in mean college entrance examination math scores among high-school seniors, while in America, the mean SAT-Math score among male high-school seniors has been consistently higher than those of their female counterparts. In both the US and China, there are gender differences among the top math performers on college entrance examinations; boys are over-represented. The Chinese national mathematics curriculum, well-trained teachers, beliefs by students and their parents that academic achievement is more a product of effort than of natural ability, a gender-neutral parental expectation for children’s education, and generous family spending on the education of girls are suggested as possible factors underlying the comparable performance of the Chinese female and male students. The sorting system at Chinese secondary school level and a cultural stereotype favoring boys in mathematics are suggested as possible contributors to the math-achievement gender gap found among the top Chinese high school seniors.

A general equilibrium approach to tourism and welfare: The case of Macao

Macao has been witnessing spectacular economic growth in recent years. The ongoing boom is mainly driven by rapid tourism growth reflected in massive tourist arrivals and foreign capital inflow. Although Macao is praised as an ‘economic wonder’, serious externalities have emerged, raising concerns about the sustainability of the city's long-term development. Using a modified simple general equilibrium model, this paper shows how economic, social, environmental and political externalities accompanying rapid tourism growth may possibly reduce the net welfare of host communities. The paper concludes that comprehensive tourism policies leading to a sustainable development should be developed in a broader social framework.     

Three methods of estimating births averted nationally by contraception

This paper compares the performance of three methods applicable to national-level demographic data of estimating births averted as a consequence of contraceptive practice. Two are based on the relationship between the general fertility rate (GFR) or total fertility (TFR) and contraceptive prevalence, while the third uses Bongaarts' proximate determinants (PD) model. Estimates of the number of births averted and the percentage by which the number would have increased in the absence of contraception are consistent between the GFR-based and TFR-based methods, but in general lower than the estimates generated by the PD-based method, except for a few high-contraceptive-prevalence countries. For 156 countries and areas around the world the estimated number of births that would have occurred in a recent year in the absence of contraception--the average of the estimates of the three methods--is approximately 230 million, which is more than the estimated 129 million births that actually occurred.     

Reliability and Validity of the IPAQ-L in a Sample of Hong Kong Urban Older Adults: Does Neighborhood of Residence Matter?

This study examined reliability and validity of the Chinese version of the International Physical Activity Questionnaire-Long Form (IPAQ-LC) in Chinese seniors, including moderating effects of neighborhood walkability and socioeconomic status (SES) on reliability and validity. The IPAQ-LC was interviewer-administered (n = 96), accelerometer and 7-day walk-diary data were collected (n = 94), and the IPAC-LC was readministered (N = 92). Acceptable reliability was found for all measures of physical activity (PA) overall and across different types of neighborhood. Participants from highly walkable neighborhoods were more reliable at estimating walking for transport. Participants from low-SES areas were less reliable at estimating leisure-time PA and sitting but more reliable at estimating transport-related walking. IPAQ-LC walking was significantly related to light- but not moderate-intensity accelerometry-based PA. It was moderately to strongly related to a 7-day diary of walking. The data imply slow-paced walking, probably due to age, climate, and terrain. The findings suggest that the IPAQ-LC's reliability and validity are acceptable in Chinese seniors.     

Improvement indices of well-being

In recent years, various classes of indices measuring the improvement of well-being have been suggested. Formally, an improvement index is a function Q* (x ₁, x ₂), where x _t is the level of some attribute of well-being, e.g., life expectancy, in period t. This paper extends previous works on improvement indices by introducing a class of multidimensional indices which aggregates the improvement of a group of attributes of well-being. We propose a set of axioms which leads inexorably to a multidimensional generalization of Kakwani's class of improvement indices of well-being (Kakwani 1993).Financial support from the Social Science and Education Panel of the Chinese University of Hong Kong (research grant account no: 220201620) is gratefully acknowledged     

一种特殊耦合振子的运动分析

本文在一维弹簧振子的基础上，对耦合振子的纵向运动一种比较简单的情况进行分析，得出了适用于求解一般二自由度振动系统简正频率的方法