Analysis of Gamma and Weibull lifetime data under a general censoring scheme and in the presence of covariates

We consider the problem of estimating the lifetime distributions of survival times subject to a general censoring scheme called “middle censoring”. The lifetimes are assumed to follow a parametric family of distributions, such as the Gamma or Weibull distributions, and is applied to cases when the lifetimes come with covariates affecting them. For any individual in the sample, there is an independent, random, censoring interval. We will observe the actual lifetime if the lifetime falls outside of this censoring interval, otherwise we only observe the interval of censoring. This censoring mechanism, which includes both right- and left-censoring, has been called “middle censoring” (see Jammalamadaka and Mangalam, 2003 Jammalamadaka, S. Rao, Mangalam, V. (2003). Nonparametric estimation for middle censored data. J. Nonparamet. Stat. 15(2):253–265.[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]). Maximum-likelihood estimation of the parameters as well as their large-sample properties are studied under this censoring scheme, including the case when covariates are available. We conclude with an application to a dataset from Environmental Economics dealing with ContingentValuation of natural resources.     

Feeding,growth, and trophic position of redbreast sunfish (Lepomis auritus) in watersheds of differing land cover in the lower Piedmont,USA

One pervasive outcome in the urbanization of an ecosystem is the proliferation and numerical dominance of select tolerant organisms that are often native to the system yet with reduced relative abundances in less-disturbed conditions. As a result of high variation in environmental conditions between urbanized and non-urbanized systems, it is possible that the functional role of a ubiquitous organism is context dependent. Such is the case for redbreast sunfish (Lepomis auritus) in small streams in many parts of the Piedmont of the southeastern USA. To investigate this hypothesis, we evaluated the feeding, growth, and trophic position of redbreast sunfish in 3 streams of increasing levels of watershed urbanization (forested, suburban, urban) in the Lower Piedmont of western Georgia, USA. Through gut contents analysis, we found that sunfish consumed primarily Chironomidae (Diptera) larvae across all streams. However, fish in the suburban stream consumed more terrestrial prey than fish in the forest and urban streams, which corresponded to lower aquatic prey abundances in the suburban stream. Although there was no difference in mean fish age among streams, otolith analysis revealed that fish in the urban stream were larger at age than those in the forest stream. Last, stable isotope analysis revealed that fish in the urban stream occupied a lower trophic position than the other 2 streams. These results suggest that despite the fact that the primary prey resource was similar for sunfish in each stream, their potential functional role, as evidenced by size at age and trophic position, is context dependent.

     

A Multifactorial Approach to Predicting Death Anxiety: Assessing the Role of Religiosity,Susceptibility to Mortality Cues,and Individual Differences

Death anxiety is not only experienced by individuals receiving end-of-life care, but also by family members, social workers, and other service providers who support these individuals. Thus, identifying predictors of individual differences in experienced death anxiety levels may have both theoretical and clinical ramifications. The present study assessed the relative influence of religiosity, susceptibility to mortality cues, state and trait anxiety, and demographic factors in the experience of death anxiety through an online survey distributed to members of two online communities related to end-of-life care. Results indicated that cognitive and emotional susceptibility to mortality cues, as well as gender, predicted differences in death anxiety. Conversely, religiosity and age did not increase the predictive power of the model. Thus, death anxiety may be a function of emotional, cognitive, and sociocultural factors that interact in complex, but predictable, ways to modulate the response to mortality cues that occur in one’s life.     

The construction of maternal identity among Israeli mothers who are welfare clients

Dominant social, cultural, and professional discourses view motherhood as the core of a woman's identity. Thus, the identity of women who do not meet the general expectations of motherhood might be negatively affected. Specifically, mothers who are welfare clients may violate the prevailing norms concerning the maternal role. This qualitative study explores how Israeli mothers who are welfare clients construct their maternal identity. Studies of mothers who are clients of welfare services suggest that they feel blamed for being “bad” or “unfit” mothers. However, women occasionally negotiate or challenge the negative perceptions that are forced on them by hegemonic discourses of motherhood. We postulate that such women experience a troubled maternal identity that they negotiate through interactions with others. Accordingly, this study set to explore how Israeli mothers who are welfare clients negotiate their maternal identity in the context of motherhood and welfare discourses. Fourteen participants were interviewed, and the findings illustrate the vulnerability of the mothers and their strategies to construct a positive maternal identity. We discuss the findings in light of the concept of troubled identity.     

Sexual orientation and self-reported lying

This paper examines empirical links between sexual orientation and self-reported lying using data collected in several waves of Georgia Institute of Technology’s World Wide Web Users Survey. The data include questions about sexual orientation, lying in cyberspace, and a broad range of demographic information. According to the theoretical framework of Gneezy (Am Econ Rev 95: 384–395, 2005) on the economics of deception, individuals conceal or falsify information when the expected benefit of lying exceeds its costs in terms of psychic disutility. If non-heterosexuals expect to benefit more by falsifying information, then this theory predicts higher rates of lying among non-heterosexuals. The data show that gays and lesbians do indeed report lying more often than heterosexuals, both unconditionally in bivariate correlations and after controlling for demographic and geographic differences. These empirical results are consistent with the conclusion that non-heterosexuals expect higher benefits from concealing personal information because of anti-homosexual discrimination.

Two-stage informative cluster sampling—estimation and prediction with applications for small-area models

This paper considers the effects of informative two-stage cluster sampling on estimation and prediction. The aims of this article are twofold: first to estimate the parameters of the superpopulation model for two-stage cluster sampling from a finite population, when the sampling design for both stages is informative, using maximum likelihood estimation methods based on the sample-likelihood function; secondly to predict the finite population total and to predict the cluster-specific effects and the cluster totals for clusters in the sample and for clusters not in the sample. To achieve this we derive the sample and sample-complement distributions and the moments of the first and second stage measurements. Also we derive the conditional sample and conditional sample-complement distributions and the moments of the cluster-specific effects given the cluster measurements. It should be noted that classical design-based inference that consists of weighting the sample observations by the inverse of sample selection probabilities cannot be applied for the prediction of the cluster-specific effects for clusters not in the sample. Also we give an alternative justification of the Royall [1976. The linear least squares prediction approach to two-stage sampling. Journal of the American Statistical Association 71, 657–664] predictor of the finite population total under two-stage cluster population. Furthermore, small-area models are studied under informative sampling.     

The Human‐Environment Dialog in Award‐winning Children’s Picture Books*

Picture books often play an important role in childhood socialization. Given the seriousness of environmental problems, we ask how natural, modified, and built environments have been portrayed in children’s books. To answer this question, we analyze the 296 books receiving Caldecott awards from 1938 to 2008. Two possibilities are explored with respect to content change. Growing concern about critical environmental problems, such as decline in biodiversity and deforestation, may have led to an increase in illustrations and stories about wild animals and the natural environment. Alternatively, the increasing isolation of people from the natural world may have resulted in a decline in the perceived relevance of these environmental issues and resulted in fewer stories and depictions. Our findings support the isolation hypothesis. There have been significant declines in depictions of natural environments and animals while built environments have become much more common. These findings suggest that today’s generation of children are not being socialized, at least through this source, toward an understanding and appreciation of the natural world and the place of humans within it.     

Defining Māori language revitalisation: A project in folk linguistics

The postmodern and critical movements in language policy, with their redefinition of governmentality and attention to power structures, call for localised perspectives on language arrangements. In this way, a polity, in its social and cultural context, can be understood as much as the policies it operates. In the case of Indigenous languages undergoing revitalisation, this allows us to define language revitalisation, and the vitality it should deliver, not through western scholarship but for local purposes with local ideas by examining local knowledge and preferences. To do this, a folk linguistic approach was applied to language policy research. A quantitative and qualitative survey investigated how around 1,300 Indigenous and non‐Indigenous youth in New Zealand define Māori language revitalisation from their own perspective and how they perceive the revitalisation processes and outcomes proposed in scholarship and local discourses. The paper shows that claimed linguistic knowledge not only exists parallel to language attitudes, but informs local policy ideas. The findings indicate that these youth define language revitalisation and vitality in terms contextualised by local ontology, knowledge, ideologies and values, therefore challenging the local applicability of universal theories.     

Cognitive,social, and neural determinants of diminished decision-making and financial exploitation risk in aging and dementia: A review and new model

ABSTRACT

In this article we will briefly review how changes in brain and in cognitive and social functioning, across the spectrum from normal to pathological aging, can lead to decision-making impairments that increase abuse risk in many life domains (e.g., health care, social engagement, financial management). The review will specifically focus on emerging research identifying neural, cognitive, and social markers of declining financial decision-making capacity in older adults. We will highlight how these findings are opening avenues for early detection and new interventions to reduce exploitation risk.