Predicting burrowing owl flight trajectories in urban environments

Urban Ecosystems - It is important to understand how animals respond to changes in landscape structure, especially when considering habitat alteration and urbanization. Using the burrowing owl...     

Recentering our tendencies: Immigrant youth development and the importance of context in social work research

According to Weiner’s model, help giving has various determinants such as social and individual causes, affective reactions, and responsibility. The aim of this study was (1) to examine the influence of bullying acts, the victim’s behavior at work, and revictimization on equity judgments and the perceived responsibility of perpetrators and victims; and (2) to test the determinants of help decisions. Twelve vignettes of bullying at work submitted to 133 participants varied according to the severity of bullying, the victim’s pro- or antisocial behaviors, and the victim’s antecedents. The results showed that the situation was judged less equitable, the victim less responsible, and the perpetrator more responsible, and the intention of help was increased, (1) when the perpetrator’s acts were serious, and (2) when the bullied person had shown prosocial behavior versus antisocial behavior. The help increased more (1) when the perpetrator’s acts were harmful and (2) when the victim had shown prosocial behaviors.     

AMEMIYA'S FORM OF THE WEIGHTED LEAST SQUARES ESTIMATOR

Amemiya's estimator is a weighted least squares estimator of the regression coefficients in a linear model with heteroscedastic errors. It is attractive because the heteroscedasticity is not parametrized and the weights (which depend on the error covariance matrix) are estimated nonparametrically. This paper derives an asymptotic expansion for Amemiya's form of the weighted least squares estimator, and uses it to discuss the effects of estimating the weights, of the number of iterations, and of the choice of the initial estimate. The paper also discusses the special case of normally distributed errors and clarifies the particular consequences of assuming normality.     

Bayesian item response model: a generalized approach for the abilities' distribution using mixtures

Traditional Item Response Theory models assume the distribution of the abilities of the population in study to be Gaussian. However, this may not always be a reasonable assumption, which motivates the development of more general models. This paper presents a generalized approach for the distribution of the abilities in dichotomous 3-parameter Item Response models. A mixture of normal distributions is considered, allowing for features like skewness, multimodality and heavy tails. A solution is proposed to deal with model identifiability issues without compromising the flexibility and practical interpretation of the model. Inference is carried out under the Bayesian Paradigm through a novel MCMC algorithm. The algorithm is designed in a way to favour good mixing and convergence properties and is also suitable for inference in traditional IRT models. The efficiency and applicability of our methodology is illustrated in simulated and real examples.     

Family and Couple Variables Regarding Adherence in Type 2 Diabetes Patients in the Initial Stages of the Disease

This study analyzed which family and couple variables predicted adherence to standard care treatment, in patients recently diagnosed with type 2 diabetes. The sample comprised 224 dyads assessed during the first year of diagnosis (T1) and 4 months later (T2). The results showed that family stress, dyadic adjustment, family coping, and positive support assessed by patients at T1 predicted medication adherence and glucose monitoring at T2. Positive support and dyadic adjustment, assessed by partners at T1, predicted patients' adherence to glucose monitoring and diet at T2. This study highlights the important role of the partner in patient`s adherence. Therefore, standard care in type 2 diabetes should be offered in the context of the dyad.     

Accessibility of sports facilities for persons with reduced mobility and assessment of their motivation for practice

This study aims to create awareness, both within the scientific community and among providers of sports facilities, for individuals with impaired or reduced mobility, promoting the development of technical solutions that allow greater autonomy and social integration of people with disabilities. The purpose of this work is, on the one hand, to evaluate the accessibility of sports facilities for people with reduced mobility and, on the other hand, to investigate why this user group has such low rates of participation in sporting activities. Firstly, using the Portuguese norms and legislation transcribed from European Community directives, a check list was created comprising all the items that sports facilities should abide by in order to provide accessibility and safety to people with reduced mobility. Another questionnaire was designed aimed at this user group, with questions pertaining to their desire and ability to use sports facilities. This questionnaire was distributed in Portugal, in the greater metropolitan area of Porto, to users of Rehabilitation Centres and Physiotherapy Clinics. The results obtained from the check-list showed the compliances and non-compliances of the respective sports facilities, proving that many barriers preventing the participation of people with reduced mobility still exist. Twenty-four people with permanent impairment of the lower extremities (paraplegia) answered the questionnaire pertaining to the desire and ability to perform physical activity. Two individuals (8%) had sporting activities available to them in their area of residence and only five (21%) performed any physical activity. The main reason given for not taking part in any activity was the lack of adapted sports facilities. All the participants felt that taking part in sports is beneficial. The benefits stated were: general well-being and development of the psychomotor component (e.g. coordination, balance, body posture), of physical condition (e.g. strength, resistance, flexibility) and social integration and quality of life. Besides wellbeing, they also mentioned social interaction, a way of occupying their time and an escape from the routine as the main motives for which they would like to take up physical exercise.     

The Kumaraswamy normal linear regression model with applications

ABSTRACT

For any continuous baseline G distribution, Cordeiro and Castro pioneered the Kumaraswamy-G family of distributions with two extra positive parameters, which generalizes both Lehmann types I and II classes. We study some mathematical properties of the Kumaraswamy-normal (KwN) distribution including ordinary and incomplete moments, mean deviations, quantile and generating functions, probability weighted moments, and two entropy measures. We propose a new linear regression model based on the KwN distribution, which extends the normal linear regression model. We obtain the maximum likelihood estimates of the model parameters and provide some diagnostic measures such as global influence, local influence, and residuals. We illustrate the potentiality of the introduced models by means of two applications to real datasets.     

A New Chart for Monitoring the Covariance Matrix of Bivariate Processes

In this article we consider a control chart based on the sample variances of two quality characteristics. The points plotted on the chart correspond to the maximum value of these two statistics. The main reason to consider the proposed chart instead of the generalized variance | S | chart is its better diagnostic feature, that is, with the new chart it is easier to relate an out-of-control signal to the variables whose parameters have moved away from their in-control values. We study the control chart efficiency considering different shifts in the covariance matrix. In this way, we obtain the average run length (ARL) that measures the effectiveness of a control chart in detecting process shifts. The proposed chart always detects process disturbances faster than the generalized variance | S | chart. The same is observed when the size of the samples is variable, except in a few cases in which the size of the samples switches between small size and very large size.