All pairwise comparisons of exponential location parameters under type i censoring — equal scale parameter case

In this paper, procedures for all pairwise comparisons of location parameters of negative exponential populations are developed when the common scale parameter is known or unknown using large sample distributional approximations of the relevant random variables. The small sample performance of these procedures are then examined using Monte Carlo simulation.     

Shared‐use mining infrastructure: Why it matters and how to achieve it

This article considers the cases for and against ‘open access’ regulation of rail and port logistics infrastructure used by ‘bulk’ mining operations, arguing that host governments should proactively impose and then enforce such regulation in almost all cases. The logistics infrastructure needed for this type of mining activity is of critical importance. The costs and potential inefficiencies involved in duplicating such infrastructure confer a significant competitive advantage on its owner in the absence of effective access regulation. In particular, where a first mover develops an ‘integrated’ project incorporating a mine and associated infrastructure, a failure to impose access regulation discourages third‐party investment in mineral exploration and development in the region serviced by the infrastructure, due to the risk of hold‐up by the first mover. An unregulated first mover can also use its infrastructure advantage to capture the state's share of resource rents from the mineral endowment of the region. Open access regulation further benefits host countries by enabling broad‐based economic development through the shared‐use of mining infrastructure with other sectors (e.g., agribusiness). The article highlights contrasting experience with access regulation in Australia: the Pilbara iron ore region has seen protracted disputes involving mining firms and policy‐makers and very few examples of third‐party access, while in the coal region of central Queensland an extensive multi‐user, multi‐purpose railway network operates independently of mining firms. The authors urge governments in sub‐Saharan Africa (in particular) not to underestimate the internal capacity and other challenges associated with developing and enforcing open access regulation of mining infrastructure in a manner that protects their national interests.     

Maternal Conflict Behavior Profiles and Child Social Skills

The current study examined associations between mothers’ behavioral profiles during mother‐child conflict interactions and their children's social skills. This person‐centered approach classified 181 mothers according to their levels of emotional responsiveness, intrusiveness, negativity, and engagement facilitation behaviors during an eight‐minute conflict discussion task with their child. Three distinct classes of mothers were identified using latent profile analysis: sensitive/engaged, moderately sensitive/engaged, and insensitive/disengaged. An analysis of covariance indicated that children of mothers in the sensitive/engaged group had significantly higher social skills than children of mothers in the moderately sensitive/engaged and insensitive/disengaged groups. Results suggest that mother‐child conflict interactions may benefit children's social development when mothers facilitate their children's participation in a highly sensitive manner.     

The Place of Construction in Sociological Realism

In the contemporary epistemological debate on social reality, characterized by the crisis of post‐modern theories and the emergence of new forms of realism, are there any approaches not acknowledging some specific ontological character to the construction of social objects? The question is apparently rhetorical, but the implication of this problem are not obvious. In the sociological literature the opposition between reality and construction is not clearly defined. Sometimes it is considered a dichotomy, in other situations the synthesis of alternative theses in a dialectical horizon. The more systematic attempt considers reality and construction as analytical macro‐dimensions where the relation between social ontology and epistemology operates. From this stance, the acknowledgement of the role of social construction in a wider realist horizon is the true overtaking of postmodern philosophy. If it is true that facts exist beyond representations, it is also true that representations themselves have a specific effect on reality, who continually re‐structures itself around specific relations of emergent power. Stating that reality is socially constructed is an evident limit of postmodern theories. On the other hand, stating that only facts exist constitute an impoverishment of realism and its replacement in neo‐positivism. Social phenomena are real because they are based on specific properties of the inter‐subjective construction of social reality. This thesis represents the revitalization of an advanced, anti‐positivistic realism and the definition of the specificity of social objects. The aim of this essay is to search for a specific place of construction within the development of realist social ontology.     

Quantile Regression for Location‐Scale Time Series Models with Conditional Heteroscedasticity

This paper considers quantile regression for a wide class of time series models including autoregressive and moving average (ARMA) models with asymmetric generalized autoregressive conditional heteroscedasticity errors. The classical mean‐variance models are reinterpreted as conditional location‐scale models so that the quantile regression method can be naturally geared into the considered models. The consistency and asymptotic normality of the quantile regression estimator is established in location‐scale time series models under mild conditions. In the application of this result to ARMA‐generalized autoregressive conditional heteroscedasticity models, more primitive conditions are deduced to obtain the asymptotic properties. For illustration, a simulation study and a real data analysis are provided.     

Bayesian estimation and prediction for Weibull model with progressive censoring

This article presents the statistical inferences on Weibull parameters with the data that are progressively type II censored. The maximum likelihood estimators are derived. For incorporation of previous information with current data, the Bayesian approach is considered. We obtain the Bayes estimators under squared error loss with a bivariate prior distribution, and derive the credible intervals for the parameters of Weibull distribution. Also, the Bayes prediction intervals for future observations are obtained in the one- and two-sample cases. The method is shown to be practical, although a computer program is required for its implementation. A numerical example is presented for illustration and some simulation study are performed.     

A Semiparametric Regression Model for Longitudinal Data with Non‐stationary Errors

Motivated by the need to analyze the National Longitudinal Surveys data, we propose a new semiparametric longitudinal mean‐covariance model in which the effects on dependent variable of some explanatory variables are linear and others are non‐linear, while the within‐subject correlations are modelled by a non‐stationary autoregressive error structure. We develop an estimation machinery based on least squares technique by approximating non‐parametric functions via B‐spline expansions and establish the asymptotic normality of parametric estimators as well as the rate of convergence for the non‐parametric estimators. We further advocate a new model selection strategy in the varying‐coefficient model framework, for distinguishing whether a component is significant and subsequently whether it is linear or non‐linear. Besides, the proposed method can also be employed for identifying the true order of lagged terms consistently. Monte Carlo studies are conducted to examine the finite sample performance of our approach, and an application of real data is also illustrated.     

Foodborne Exposure to Pesticides and Methylmercury in the United Arab Emirates

As part of a comprehensive environmental health strategic planning project initiated by the government of Abu Dhabi, we assessed potential dietary exposure in the United Arab Emirates (UAE) to methylmercury (in seafood) and pesticides (in fruits and vegetables) above international guideline levels. We present results for the UAE population by age, gender, and body mass index. Our results show very low daily risks of exposure to pesticides in fruits and vegetables at levels exceeding WHO guidelines even under the conservative assumption that no pesticides are removed during washing and food preparation. Thus, exposure to pesticides on fruits and vegetables does not appear to be a major public health concern in the UAE. The chances of exposure to methylmercury in seafood are much higher; our model estimates a mean 1 in 5 daily risk of exceeding the FAO/WHO provisional tolerable weekly intake. However, great caution should be used in interpreting these results, as we analyzed only the risks and not the substantial benefits of fish consumption. In fact, previous studies have demonstrated that exposure to the n‐3 polyunsaturated fatty acids in fish can increase IQ in developing children, and it can substantially decrease the risk in adults of coronary heart disease and stroke. Further research is warranted to compare the risk of Me‐Hg exposure from fish to the nutritional benefits of fish consumption in the UAE and to determine appropriate methods to communicate risk and benefit information to the UAE population.     

What is a person‐centred approach? Familiarity and understanding of individualised funding amongst carers in New South Wales

Person‐centred approaches place individuals with a disability at the centre of decision making, with their carers and family invited to be partners in the process. Rather than being required to fit within existing service programs, person‐centred approaches enable individuals to choose the support options that best meet their needs. In order to facilitate this, person‐centred approaches will be accompanied by the introduction of individualised funding. This means the individual will be provided with funding to purchase services of their choosing. Given these significant changes occurring in the disability sector, Carers NSW surveyed informal carers of people with a disability to identify what they knew about person‐centred approaches and how they felt about their introduction. Survey results indicate that there is a need to increase the capacity and willingness of carers significantly in order to engage with person‐centred approaches and individualised funding. Carers require targeted and comprehensive information about these concepts in order to understand fully the changes occurring within the disability sector. These findings also indicate specific areas that need to be addressed in order to increase carers' awareness of these concepts and also to address existing negativity and confusion.