Non-parametric estimation of reciprocal coordinate subtangent for right censored dependent scheme

The concept of reciprocal coordinate subtangent (RCST) has been used as a useful tool to study the monotone behavior of a continuous density function and for characterizing probability distributions. In this paper, we propose a non-parametric estimator for RCST based on the censored dependent data. Asymptotic properties of the estimator are established under suitable regularity conditions. A simulation study is carried out to examine the performance of the estimator. The usefulness of the estimator is also examined through a real data.     

Powerblindness

In the land of the blind, the one‐eyed man may be king. But positions of power may produce their own forms of blindness. This paper reviews multiple theoretical approaches to the concept of powerblindness and categorizes these literatures into five forms through which powerblindness operates: powerblind identity (failure to notice that one belongs to a privileged group), powerblind egalitarianism (belief that all groups are equal in power), powerblind hierarchy (emphasis on one's own subordinate position), powerblind exception (the claim that one is less privileged than others in one's group), and powerblind justification (belief that present‐day hierarchy is merited or inevitable). The paper identifies studies offering evidence for each, drawing on social‐psychological experiments, survey data, and qualitative research, suggesting that power and knowledge do not necessarily go hand in hand – some forms of knowledge about the social order may be more visible to people with less power than to people with more.     

Engaging young people in science education through socioscientific issues of biosecurity

ABSTRACT

The biosecurity system is extremely important to New Zealand because the economy is based largely on exporting products derived from primary industry practices. Recent developments in trade practices such as online trade have put the biosecurity system in New Zealand under further strain. In light of this, engaging young people to support biosecurity initiatives is crucial. A qualitative approach using the interpretive mode of inquiry was used to investigate the message young people got out of biosecurity educational material in the public. One hundred and seventy-one young people completed a questionnaire that consisted of Likert-scale type questions and open-ended questions that focused on getting young people’s understanding of biosecurity related educational material. The findings show that young people emotionally connected with the biosecurity educational material, but were unable to get the biosecurity message. Building prior knowledge about biosecurity through teaching and learning is recommended.     

When Precaution Creates Misunderstandings: The Unintended Effects of Precautionary Information on Perceived Risks,the EMF Case

In the past decade, growing public concern about novel technologies with uncertain potential long‐term impacts on the environment and human health has moved risk policies toward a more precautionary approach. Focusing on mobile telephony, the effects of precautionary information on risk perception were analyzed. A pooled multinational experimental study based on a 5 × 2 × 2 factorial design was conducted in nine countries. The first factor refers to whether or not information on different types of precautionary measures was present, the second factor to the framing of the precautionary information, and the third factor to the order in which cell phones and base stations were rated by the study participants. The data analysis on the country level indicates different effects. The main hypothesis that informing about precautionary measures results in increased risk perceptions found only partial support in the data. The effects are weaker, both in terms of the effect size and the frequency of significant effects, across the various precautionary information formats used in the experiment. Nevertheless, our findings do not support the assumption that informing people about implemented precautionary measures will decrease public concerns.     

An Improved Procedure of Estimating the Finite Population Mean Using Auxiliary Information in the Presence of Random Non Response

This article deals with the problem of estimation of the finite population mean using auxiliary information in the presence of random non response. Three different situations where random non response occurs either in study variate, or in auxiliary variate, or in both the variates, have been discussed. The asymptotically optimum estimators (AOEs) for each strategy are also identified. Expressions of biases and mean squared errors of the proposed estimators have been derived up to the first degree of approximation. Proposed estimators have been compared with the usual unbiased estimator, ratio estimator, and product estimator in the presence of random non response. Empirical studies are also carried out to show the performance of the proposed estimators over other estimators.     

Estimation of the Renyi’s residual entropy of order \alpha with dependent data

In the present paper, we propose nonparametric estimators for the Renyi’s information measure for the residual lifetime distribution based on complete and censored data. This measure plays important roles in reliability and survival analysis in connection with modeling and analysis of life time data. Asymptotic properties of the estimators are established under suitable regularity conditions. Monte-Carlo simulation studies are carried out to compare the performance of the estimators using the mean-squared error. The methods are illustrated using real data sets.     

Does the Stock Market Gender Stereotype Corporate Boards? Evidence from the Market's Reaction to Directors' Trades

Attitudes towards male and female managers within organizations are well documented, but how the stock market perceives their relative capabilities is less studied. Recent evidence documents a negative short‐run market reaction to the appointment of female chief executive officers and suggests that female executives are less informed than their male counterparts about future corporate performance. These results appear to dispute the stock market value of having women on corporate boards. However, such short‐run market reactions may retain a ‘gender bias’, reflecting the prevalence of negative stereotypes, where the market reacts to ‘beliefs’ rather than ‘performance’. This study tests for such bias by examining the stock market reaction to directors' trades in their own companies' shares, by measuring both the short‐run and longer‐term returns after the directors' trades. Allowing for firm and trade effects, some evidence is found that, in the longer term, markets recognize that female executives' trades are informative about future corporate performance, although initially markets underestimate these effects. This has important implications for research that has attempted to assess the value of board diversity by examining only short‐run stock market responses.     

Bayesian Random Segmentation Models to Identify Shared Copy Number Aberrations for Array CGH Data

Array-based comparative genomic hybridization (aCGH) is a high-resolution high-throughput technique for studying the genetic basis of cancer. The resulting data consists of log fluorescence ratios as a function of the genomic DNA location and provides a cytogenetic representation of the relative DNA copy number variation. Analysis of such data typically involves estimation of the underlying copy number state at each location and segmenting regions of DNA with similar copy number states. Most current methods proceed by modeling a single sample/array at a time, and thus fail to borrow strength across multiple samples to infer shared regions of copy number aberrations. We propose a hierarchical Bayesian random segmentation approach for modeling aCGH data that utilizes information across arrays from a common population to yield segments of shared copy number changes. These changes characterize the underlying population and allow us to compare different population aCGH profiles to assess which regions of the genome have differential alterations. Our method, referred to as BDSAcgh (Bayesian Detection of Shared Aberrations in aCGH), is based on a unified Bayesian hierarchical model that allows us to obtain probabilities of alteration states as well as probabilities of differential alteration that correspond to local false discovery rates. We evaluate the operating characteristics of our method via simulations and an application using a lung cancer aCGH data set.     

A modified estimator of population mean using power transformation

Summary In this paper we have suggested two modified estimators of population mean using power transformation. It has been shown that the modified estimators are more efficient than the sample mean estimator, usual ratio estimator, Sisodia and Dwivedi’s (1981) estimator and Upadhyaya and Singh’s (1999) estimator at their optimum conditions. Empirical illustrations are also given for examining the merits of the proposed estimators. Following Kadilar and Cingi (2003) the work has been extended to stratified random sampling, and the same data set has been studied to examine the performance in stratified random sampling.     

Gambling Participation and Social Support Among Older Adults: A Longitudinal Community Study

The purpose of this preliminary study was to examine associations between leaving home to engage in bingo or gambling activity and indices of physical and mental health and social support among a representative community cohort of 1016 elderly people. Cross-sectional and longitudinal data gathered from a prospective epidemiological study in a rural, low socio-economic status, area of Pennsylvania was employed. The cohort had a mean age of 78.8 (SD = 5.1) (range 71–97) and participated in three consecutive biennial waves of data collection. Nearly half (47.7) of the cohort reported gambling. To predict gambling, the independent variables included age, sex, education, employment, social support, depressive symptoms, self-rated health, alcohol use, cigarette use, and cognitive functioning. In cross-sectional, univariate analyses, gambling was associated with younger age, sex (male), fewer years of education, greater social support, lower depression scores, better self-rated health, alcohol use in the past year, and higher cognitive functioning. In a cross-sectional multiple regression model, younger age, greater social support, and alcohol use in the past year remain strongly and independently associated with gambling activity. Longitudinally, age, sex, social support, alcohol use, and gambling are predictive of future gambling activity. The results revealed that gambling may offer a forum of social support to older adults who are often isolated as they age.