Bootstrap tests for multivariate directional alternatives

Tests on multivariate means that are hypothesized to be in a specified direction have received attention from both theoretical and applied points of view. One of the most common procedures used to test this cone alternative is the likelihood ratio test (LRT) assuming a multivariate normal model for the data. However, the resulting test for an ordered alternative is biased in that the only usable critical values are bounds on the null distribution. The present paper provides empirical evidence that bootstrapping the null distribution of the likelihood ratio statistic results in a bootstrap test (BT) with comparable power properties without the additional burden of assuming multivariate normality. Additionally, the tests based on the LRT statistic can reject the null hypothesis in favor of the alternative even though the true means are far from the alternative region. The BT also has similar properties for normal and nonnormal data. This anomalous behavior is due to the formulation of the null hypothesis and a possible remedy is to reformulate the null to be the complement of the alternative hypothesis. We discuss properties of a BT for the modified set of hypotheses (MBT) based on a simulation study. The resulting test is conservative in general and in some specific cases has power estimates comparable to those for existing methods. The BT has higher sensitivity but relatively lower specificity, whereas the MBT has higher specificity but relatively lower sensitivity.     

RigiScan data under long-term testosterone therapy: improving long-term blood circulation of penile arteries,penile length and girth,erectile function,and nocturnal penile tumescence and duration

Background: Late-onset hypogonadism (LOH) presents with low serum testosterone (TT) levels and sexual and nonsexual symptoms. Erectile dysfunction affects a man’s self-esteem and as a result partner relationship and quality of life.

Objectives: To investigate the andrological clinical profile outcomes of testosterone therapy (TTh) in men (n?=?88) with symptomatic LOH complaints and symptoms.

Main outcome measures: Erectile function was assessed using the International Index of Erectile Function-5 questionnaire at baseline and at 6 and 12 months of TTh. In addition, penile length was measured at baseline and 12 months. We also evaluated nocturnal penile tumescence (NPT, using RigiScan) and blood flow of cavernous arteries (penile Doppler ultrasonography) at baseline and 12 months of TT.

Materials and methods: Eighty-eight LOH men (M_age 51.1 years) with erectile dysfunction, all with serum TT?<10.4?nmol/L before TTh. Patients received intramuscular long-acting testosterone undecanoate for 12 months.

Results: Following TTh, in all patients, serum TT levels were restored within 3 months to normal levels. Compared with baseline values, erectile function significantly improved at 6 (mean score increase 1.95) and 12 months (mean score increase 2.16). No significant changes in penile length were observed. NPT significantly improved at 12 months in terms of both the frequency (mean increase 1.27 times) and duration of rigidity (mean increase 5.12?min). As regards the blood flow of the cavernous arteries, we observed a significant improvement (decrease of 1.16?cm/s) and end diastolic velocity of the penile arteries.

Conclusion: TTh in men with LOH resulted in improvement of the erectile function, NPT, and to some extent the blood flow of the cavernous arteries.     

Statistical Inference Based on Progressively Type II Censored Data from Weibull Model

In this article, we consider the problem of estimating the shape and scale parameters and predicting the unobserved removed data based on a progressive type II censored sample from the Weibull distribution. Maximum likelihood and Bayesian approaches are used to estimate the scale and shape parameters. The sampling-based method is used to draw Monte Carlo (MC) samples and it has been used to estimate the model parameters and also to predict the removed units in multiple stages of the censored sample. Two real datasets are presented and analyzed for illustrative purposes and Monte carlo simulations are performed to study the behavior of the proposed methods.     

On the robustness of right and middle censoring schemes in parametric survival models

This article considers the exponential and Weibull distributions for studying the robustness of their parameters estimates in the case of right and middle types of censoring. As might be expected, the simulation studies indicate that the mean square error (MSE) decreases with larger sample sizes, increases with the contamination level and censoring proportion. But somewhat surprisingly, our study shows that, regardless the parametric model and for given values of the other factors, estimates for middle censoring are more robust compared to those for right censoring.     

Poverty and Income Replacement Profile Among EPF Retiree in Malaysia

Social security policies often focus on replacement rates, which indicate retirement income or social security benefits in relation to preretirement income. The higher replacement rate among the pensioners would ensure that the ageing society would have sufficient income to lead a normal life after retirement. This study examined factors that influencing the income replacement rate of Malaysian Employee Provident Fund (EPF) retirees. The analysis was based on a nationwide survey conducted in 2013–2014 among EPF retiree. A logit model was used to evaluate the likelihood of selected socio-demographic and economic factors contributing to income of the retirees. The results indicated that around 62 % of elderly has lower retirement income compared to their preretirement income and it makes them more vulnerable to unpredictable events and financial conditions. The study suggested that the income replacement rate of elderly could be strengthened by investing in ageing workforce, raising retirement age, enhancing educational achievements of low income groups and restructuring employment. These may in turn increase the availability of skilled workers, enhancing the national productivity, increase the income security of retirees, reduce poverty, and develop economic growth of the country.     

The Distress and the Meaning Making of Divorced Abused Arab Women in Israel

Women’s divorce in the Arab society in Israel goes against patriarchal social values. The aim of this research is to explore the meaning that abused Arab women gave to their divorce. The present study based on interviews with 13 women, who had been divorced for 2 to 5 years. Analysis revealed that the women perceived their coping as navigation between the cost of stigma and familial and social distress, and the gains of their connection to sources of strength and self-worth. The discussion based on the interviewees’ existential experience their self-identity as meaning makers and choosers.     

The Emerging Perspective of Governance and Poverty Alleviation: A Case of Bangladesh

The majority of the rural people in the developing world are subject to severe poverty, inequality and unemployment. Over the years, a number of institutional approaches have been experimented to eradicate poverty from society. Despite the historical role accorded to the state, the states in many developing countries have not been quite effective in poverty alleviation. Following the global trends many developing country states have created space for the market forces and civil society organizations to contribute to poverty alleviation. This is what is popularly known as the new perspective of governance. This article intends to analyze the new perspective of governance and its role in poverty alleviation with empirical evidence from Bangladesh.

Stock Market and Aggregate Investment Behavior in Malaysia: An Empirical Analysis

The present paper analyzes the role of stock market, more specifically real stock prices and stock market uncertainty/volatility, on aggregate investment behavior for an emerging market, Malaysia. Employing the autoregressive distributed lags approach to cointegration test, the paper establishes a long run equilibrium that ties the aggregate investment to its determinants—real income, real stock prices, real lending rate and stock market volatility. In the long run, we document a positive relation between aggregate investment and real stock prices and a negative relation between aggregate investment and stock market volatility. These results are further supported by our analyses of their dynamic interactions based on Granger causality and impulse-response functions. Based on the results, the real stock market prices, which has yet reached the level recorded prior to the crisis, may have explained the low investment in Malaysia after the Asian crisis. Moreover, the stock market volatility can also post a threat to the investment performance.     

Human resource development competencies as predictors of agricultural extension agents' performance in Yemen

Human resource development (HRD) issue is recognized as a significant factor for survival of organizations and professionals, including those in the sector of agricultural extension. Few empirical studies have examined the influence of HRD competency variables on agricultural extension agents' performance. The authors argue that HRD competency variables such as leadership development, communication, programme planning, programme implementation and programme evaluation could predict agricultural extension agents' performance. Questionnaire data were collected from a sample of 290 extension agents in Yemen to discover if HRD competencies affect the performance of extension agents. Regression analysis shows that three variables – competencies in programme implementation, programme evaluation and programme planning – contributed significantly to the performance of extension agents. These predictors explain 42.2% of the variance in the job performance model.     

外语能力磨蚀的性别差异初探

对300余名大学生进行了英语阅读和听力测试,并从中随机抽取男女生各50名进行了写作测试,得出如下结论:(1)外语磨蚀程度存在明显的性别差异;(2)男女生在深度阅读、短对话听力以及段落听力方面的磨蚀差异不显著;(3)女生在快速阅读能力方面的磨蚀程度明显超过男生;(4)女生写作能力在切题性、连贯性以及清楚性方面的磨蚀程度显著大于男生,而在语言的正确性方面的磨蚀没有明显超过男生.