Elder Abuse:

Perpetrator and incident characteristics were studied in regard to incidents of emotional, physical, and sexual mistreatment of older adults (age 60+) in a national sample of older men and women. Random digit dialing across geographic strata was used to compile a nationally representative sample; computer assisted telephone interviewing was used to standardize collection of demographic, mistreatment, and perpetrator and incident characteristics data. The final sample size consisted of 5,777 older adults. Approximately one in ten adults reported at least one form of mistreatment, and the majority of incidents were not reported to authorities. Perpetrators of physical mistreatment against men had more “pathological” characteristics compared to perpetrators of physical mistreatment against women. Perpetrators of physical mistreatment (compared to emotional and sexual mistreatment) also evidenced increased likelihood of legal problems, psychological treatment, substance use during incident, living with the victim, and being related to the victim. Implications for future research and social policy are discussed.     

The beta exponentiated Weibull distribution

The Weibull distribution is one of the most important distributions in reliability. For the first time, we introduce the beta exponentiated Weibull distribution which extends recent models by Lee et al. [Beta-Weibull distribution: some properties and applications to censored data, J. Mod. Appl. Statist. Meth. 6 (2007), pp. 173–186] and Barreto-Souza et al. [The beta generalized exponential distribution, J. Statist. Comput. Simul. 80 (2010), pp. 159–172]. The new distribution is an important competitive model to the Weibull, exponentiated exponential, exponentiated Weibull, beta exponential and beta Weibull distributions since it contains all these models as special cases. We demonstrate that the density of the new distribution can be expressed as a linear combination of Weibull densities. We provide the moments and two closed-form expressions for the moment-generating function. Explicit expressions are derived for the mean deviations, Bonferroni and Lorenz curves, reliability and entropies. The density of the order statistics can also be expressed as a linear combination of Weibull densities. We obtain the moments of the order statistics. The expected information matrix is derived. We define a log-beta exponentiated Weibull regression model to analyse censored data. The estimation of the parameters is approached by the method of maximum likelihood. The usefulness of the new distribution to analyse positive data is illustrated in two real data sets.     

Adaptive PORT–MVRB estimation: an empirical comparison of two heuristic algorithms

In this article, we deal with an empirical comparison of two data-driven heuristic procedures of estimation of a positive extreme value index (EVI), working thus with heavy right tails. The semi-parametric EVI-estimators under consideration, the so-called peaks over random threshold (PORT)–minimum-variance reduced-bias (MVRB) EVI-estimators, are location and scale-invariant estimators, based on the PORT methodology applied to second-order MVRB EVI-estimators. Trivial adaptations of these algorithms make them work for a similar estimation of other parameters of extreme events, such as the Value-at-Risk at a level p, the expected shortfall and the probability of exceedance of a high level x, among others. Applications to simulated data sets and to real data sets in the field of finance are provided.     

Bias reduction of a tail index estimator through an external estimation of the second-order parameter

In this paper, we first consider a class of consistent semi-parametric estimators of a positive tail index γ, parameterised in a tuning or control parameter α. Such a control parameter enables us to have access, for any available sample, to an estimator of the tail index γ with a null dominant component of asymptotic bias, and consequently with a reasonably flat mean squared error pattern, as a function of k, the number of top-order statistics considered. Such a control parameter depends on a second-order parameter ρ, which will be adequately estimated so that we may achieve a high efficiency relative to the classical Hill estimator, provided we use a number of top-order statistics larger than the one usually required for the estimation through the Hill estimator. An illustration of the behaviour of the estimators is provided, through the analysis of the daily log-returns on the Euro–US$ exchange rates.     

Are vascular epiphytes in urban green areas subject to the homogenization of biodiversity? A case study in the Brazilian Atlantic Forest

Urbanization is a disturbance process that can select species and result in biodiversity homogenization. Despite this, urban green areas shelter nature and are also important to human welfare. Epiphytes are an important functional group present in such areas, that are rarely studied. We evaluated the vascular epiphytic component in 26 urban green areas in the Brazilian Atlantic Forest and tested hypotheses related to the anthropogenic disturbances: 1) the community of epiphytes in urban green areas presents low richness and diversity of species; 2) there is low beta diversity due to flora homogenization represented by a reduced set of more tolerant species to disturbance. A total of 2288 trees (1563 representing phorophytes) and 110 epiphytic species were sampled. Six species were dominant, resulting in low diversity values, but some green areas had relatively high richness. The similarity found between the majority of the sampled areas suggests that epiphytic flora is subject to homogenization due to environmental filters. We found a high richness of species without adaptations to the epiphytic lifeform (accidental epiphytes) (42% of total sampled). Some results suggest that more comprehensive ecological and/or floristic studies about the epiphytes in the urban environment are necessary, such as Orchidaceae as the second richest family (since it is often poor in urban areas). More information about the species distribution patterns are necessary, both regarding the anthropized environments and the relationships with exotic or native phorophytes, as well as to enhance the knowledge of the ecological functions played by the epiphytes in these places.

     

Statistical choice of extreme value domains of attraction — a comparative analysis

In recent years there has been a significant development of several procedures to infer about the extremal model that most conveniently describes the distribution function of the underlying population from a data set. The problem of choosing one of the three extremal types, giving preference to the Gumbel model for the null hypothesis, has frequently received the general designation of statistical choice of extremal models and has been handled under different set-ups by numerous authors. Recently, a test procedure, referred by Hasofer and Wang (1992), gave place to a comparison with some of other connected perspectives. Such a topic, jointly with some suggestions for applicability to real data, is the theme of the present paper.     

The Exponentiated G Poisson Model

We study a new family of distributions defined by the minimum of the Poisson random number of independent identically distributed random variables having a general exponentiated G distribution. Some mathematical properties of the new family including ordinary and incomplete moments, quantile and generating functions, mean deviations, order statistics and their moments, reliability, and Shannon entropy are derived. Maximum likelihood estimation of the model parameters is investigated. Two special models of the new family are discussed. We perform an application to a real data set to show the potentiality of the proposed family.     

Reduced-Bias Location-Invariant Extreme Value Index Estimation: A Simulation Study

In this article, we deal with semi-parametric corrected-bias estimation of a positive extreme value index (EVI), the primary parameter in statistics of extremes. Under such a context, the classical EVI-estimators are the Hill estimators, based on any intermediate number k of top-order statistics. But these EVI-estimators are not location-invariant, contrarily to the PORT-Hill estimators, which depend on an extra tuning parameter q, with 0 ≤ q < 1, and where PORT stands for peaks over random threshold. On the basis of second-order minimum-variance reduced-bias (MVRB) EVI-estimators, we shall here consider PORT-MVRB EVI-estimators. Due to the stability on k of the MVRB EVI-estimates, we propose the use of a heuristic algorithm, for the adaptive choice of k and q, based on the bias pattern of the estimators as a function of k. Applications in the fields of insurance and finance will be provided.     

Xenophobia online: unmasking Singaporean attitudes towards ‘foreign talent’ migrants

In recent years, Singaporeans have become highly anxious about the future of their country and their own personal livelihood due to the influx of educated and professional migrants known as ‘foreign talent’ and express their ire at the presence of these migrants through xenophobic posts online. This article suggests that such comments, however, are indicative of the feelings of disillusionment and abandonment Singaporeans have towards the People's Action Party – the only government Singaporeans have ever known. While Singaporeans have been critical of their government on economic issues that impact their lifestyle and existence, it is the presence of foreign talent migrants that have pushed Singaporeans into using the migrant situation to emotively express their opinions of disappointment in the government and its policies online like no other issue, functioning as the unlikely glue that has galvanised and united an ethnically disparate Singaporean population.     

Radiological emergency response for community agencies with cognitive task analysis, risk analysis, and decision support framework

Radiological nuclear emergency responders must be able to coordinate evacuation and relief efforts following the release of radioactive material into populated areas. In order to respond quickly and effectively to a nuclear emergency, high-level coordination is needed between a number of large, independent organizations, including police, military, hazmat, and transportation authorities. Given the complexity, scale, time-pressure, and potential negative consequences inherent in radiological emergency responses, tracking and communicating information that will assist decision makers during a crisis is crucial. The emergency response team at the Angra dos Reis nuclear power facility, located outside of Rio de Janeiro, Brazil, presently conducts emergency response simulations once every two years to prepare organizational leaders for real-life emergency situations. However, current exercises are conducted without the aid of electronic or software tools, resulting in possible cognitive overload and delays in decision-making. This paper describes the development of a decision support system employing systems methodologies, including cognitive task analysis and human-machine interface design. The decision support system can aid the coordination team by automating cognitive functions and improving information sharing. A prototype of the design will be evaluated by plant officials in Brazil and incorporated to a future trial run of a response simulation.