Urbanization homogenizes the interactions of plant-frugivore bird networks

Urban Ecosystems - Anthropogenic activities are the main cause of habitat loss and fragmentation, which directly affects biodiversity. Disruption in landscape connectivity among populations may...     

New perspective on the benefits of the gene–environment independence in case–control studies

We study the benefit of exploiting the gene–environment independence (GEI) assumption for inferring the joint effect of genotype and environmental exposure on disease risk in a case–control study. By transforming the problem into a constrained maximum likelihood estimation problem we derive the asymptotic distribution of the maximum likelihood estimator (MLE) under the GEI assumption (MLE‐GEI) in a closed form. Our approach uncovers a transparent explanation of the efficiency gained by exploiting the GEI assumption in more general settings, thus bridging an important gap in the existing literature. Moreover, we propose an easy‐to‐implement numerical algorithm for estimating the model parameters in practice. Finally, we conduct simulation studies to compare the proposed method with the traditional prospective logistic regression method and the case‐only estimator. The Canadian Journal of Statistics 47: 473–486; 2019 © 2019 Statistical Society of Canada     

Stimulus equivalence, generalization, and contextual stimulus control in verbal classes

Stimulus generalization and contextual control affect the development of equivalence classes. Experiment 1 demonstrated primary stimulus generalization from the members of trained equivalence classes. Adults were taught to match six spoken Icelandic nouns and corresponding printed words and pictures to one another in computerized three-choice matching-to-sample tasks. Tests confirmed that six equivalence classes had formed. Without further training, plural forms of the stimuli were presented in tests for all matching performances. All participants demonstrated virtually errorless performances. In Experiment 2, classifications of the nouns used in Experiment 1 were brought under contextual control. Three nouns were feminine and three were masculine. The match-to-sample training taught participants to select a comparison of the same number as the sample (i.e., singular or plural) in the presence of contextual stimulus A regardless of noun gender. Concurrently, in the presence of contextual stimulus B, participants were taught to select a comparison of the same gender as the sample (i.e., feminine or masculine), regardless of number. Generalization was assessed using a card-sorting test. All participants eventually sorted the cards correctly into gender and number stimulus classes. When printed words used in training were replaced by their picture equivalents, participants demonstrated almost errorless performances.     

Interface design and contemporary: human creating new guidelines for high-tech products

Contemporary electronic industry offers a wide range of products. Usually touch sensitive and with few buttons and a lot of functions these products not always have a friendly interface. The human x design interface based on electronics' ergonomics is the focus of this research. An evolutionary analysis of the electronics industry design within a contemporary context clarifies this relation and proposes new guidelines for a more conscious design.     

The perception of fear when using urban furniture

This article presents a study on the perception of fear related to the use of three different types of urban furniture, qualitatively evaluated based on interviews while people were using them in the city of Porto Alegre, Brazil: the bus shelter, the playground, and the gymnastic equipment. The fear related to the lack of safety of the urban space was associated with the use of the three types of products. The fear experienced by the use of the playground and the bus shelter was related to the occurrence of accidents, since both products are often unsafe and do not fulfill ergonomic parameters. The fear experienced from the use of the gymnastic equipment is related to the possibility of incorrect use of the product and the occurrence of harassment. Both ergonomics and emotion are important aspects to be considered in design, in order to make the use of social/ collective products a pleasant experience.     

Protective and Promotive Effects of Latino Early Adolescents' Cultural Assets Against Multiple Types of Discrimination

Given adversity associated with discrimination, it is important to identify culturally relevant factors that may protect against its harmful effects. Using latent variable interactions, this study examined the moderating effects of cultural assets on the association between multiple types of discrimination and adolescents' adjustment. Participants included 174 seventh‐ and eighth‐grade Latino adolescents (51% girls); majority were of Mexican origin. Peer discrimination was associated with higher internalizing symptoms, whereas cultural assets predicted higher academic motivation above and beyond racial–ethnic discrimination, demonstrating a promotive effect. Adolescents' Latino cultural assets also protected against higher levels of externalizing symptoms in the context of high peer discrimination and foreigner objectification. The discussion focuses on the conceptual and applied implications of these findings.     

Truncated location-scale non linear regression models

We present a class of truncated non linear regression models for location and scale where the truncated nature of the data is incorporated into the statistical model by assuming that the response variable follows a truncated distribution. The location parameter of the response variable is assumed to be modeled by a continuous non linear function of covariates and unknown parameters. In addition, the proposed model also allows for the scale parameter of the responses to be characterized by a continuous function of the covariates and unknown parameters. Three particular cases of the proposed models are presented by considering the response variable to follow a truncated normal, truncated skew normal, and truncated beta distribution. These truncated non linear regression models are constructed assuming fixed known truncation limits and model parameters are estimated by direct maximization of the log-likelihood using a non linear optimization algorithm. Standardized residuals and diagnostic metrics based on the cases deletion are considered to verify the adequacy of the model and to detect outliers and influential observations. Results based on simulated data are presented to assess the frequentist properties of estimates, and a real data set on soil-water retention from the Buriti Vermelho River Basin database is analyzed using the proposed methodology.     

FINANCIAL MARKETS' SHUTDOWN AND REACCESS

We employ a discrete‐time parametric duration model on a group of 121 countries over the period 1970–2011 and find that the probability of the end of financial markets' shutdown and reaccess falls as these events become longer. We also show that: (1) shutdown episodes are longer when economic prospects are poor and the degree of financial openness falls, the chief executive has been in office for long periods, and the country has a default history and (2) spells of reaccess tend to be longer when economic growth improves and financial openness increases, there are neither government crises nor government instability, and the country did not default in the past. (JEL C41, G15)     

How leader humility helps teams to be humbler,psychologically stronger,and more effective: A moderated mediation model

We hypothesize that (a) the level of humility expressed by leaders predicts team performance through, serially, team humility and team PsyCap, and (b) the strength (i.e., consensus within the team) of the leader humility, team humility and team PsyCap moderates the paths of that hypothesized model. A sample comprising 82 teams (82 leaders; 332 team members) was collected. Team members reported leader humility, team humility and team PsyCap. Leaders reported team performance. To handle the risks of common method bias, each mediating path of the hypothesized model is based on data from two different subsamples within each team. Our model's most novel theoretical contribution is the (moderated mediated) connection between leader humility, collective humility, and team PsyCap, and this was consistently supported in our data. Our inconsistent findings dealing with the relationship between team PsyCap and performance is well established in the literature and our results in both sub-samples were in the theorized direction. The study contributes to understand why, how and when humble leaders are more effective.     

Real men, real husbands: Caregiving and masculinities in later life

Drawing on data from in-depth personal interviews with a sample of fifty-three older men caring for their impaired wives, authors report findings on these men's caregiving experience, specifically on the way they see themselves as men within such role. Through analytic methods based upon content analysis and open coding, authors found that when describing their gendered understanding of themselves participants evidenced several negotiations with the dominant masculine ideology in order to maintain their sense of masculinity and legitimate their presence in a feminine role. This was accomplished by reframing their definition of a man and reinforcing that of a husband and by retaining varying degrees of power over the caregiving relationship. The social visibility of the role within particular gendered community-based social networks was found to be important in shaping these older men's masculinities.