Quadratic estimators of covariance components in a multivariate mixed linear model

It is known that the Henderson Method III (Biometrics 9:226–252, 1953) is of special interest for the mixed linear models because the estimators of the variance components are unaffected by the parameters of the fixed factor (or factors). This article deals with generalizations and minor extensions of the results obtained for the univariate linear models. A MANOVA mixed model is presented in a convenient form and the covariance components estimators are given on finite dimensional linear spaces. The results use both the usual parametric representations and the coordinate-free approach of Kruskal (Ann Math Statist 39:70–75, 1968) and Eaton (Ann Math Statist 41:528–538, 1970). The normal equations are generalized and it is given a necessary and sufficient condition for the existence of quadratic unbiased estimators for covariance components in the considered model.     

Resilience in low-income African American women living and aging with HIV

Women are living with HIV into middle and older age and are likely to face multiple comorbidities and stressors as they age. This study focused on understanding how women who experience multiple forms of oppression and ongoing adversity are still able to adapt and stand strong. Using a theoretical framework of resilience and a feminist research ideology, interviews of eight middle-aged and older African American women living with HIV were analyzed. Despite experiences of HIV-related discrimination, trauma, and violence, these women demonstrated a remarkable ability to adapt and maintain support. Implications for research and practice are discussed.     

Latent Profiles of Discrimination and Socialization Predicting Ethnic Identity and Well‐Being Among Asian American Adolescents

Ethnic identity is rooted in sociocultural processes, but little is known about how social interactions predict its longitudinal changes. Using data from 154 Asian American adolescents, latent profile analysis derived four typologies based on unfair treatment (i.e., discrimination, model minority stereotyping) and ethnic socialization (i.e., cultural socialization, preparation for bias, promotion of mistrust): Low Cultural Salience, High Cultural Salience with Marginalization, Culturally Prepared with Low Mistrust, and High Mistrust/Discrimination. Few gender or generational differences in profile membership were found. Positive outcomes were linked to adolescents attuned to both positive and negative experiences, Culturally Prepared with Low Mistrust, who reported increases in ethnic belonging and decreases in negative emotions. The implications for identity formation and adjustment are discussed.     

Customer Use of Virtual Channels in Multichannel Services: Does Type of Activity Matter?

Many firms have recently adopted virtual channels, based most notably on the Internet and the phone, to complement the delivery of services to their customers by their existing physical facilities. The success of such multichannel (MC) strategies relies on the alignment of service design decisions—namely those concerning the allocation of service activities to virtual channels—with customers’ MC behavior. Although prior studies have looked at the intensity with which customers use virtual channels, they have not addressed virtual channel use for different types of service activities. In our study, we investigate whether customers’ use of virtual channels for MC services varies with the type of service activities they engage in, and if so, in what way. In doing so, we address two objectives. First, we investigate the impact of accessibility to the physical channel on the degree of use of virtual channels (Internet and phone, aggregated) for different types of activities. Second, we look at channel preferences (Internet vs. phone) for different types of activities when customers do resort to virtual channels to conduct activities. To address our objectives, we develop and test hypotheses regarding customers’ use of virtual channels based on the match between activity attributes (complexity and volume) and channel attributes (access efficiency, interface efficiency, interface richness). Using data from a MC bank, we find that the impact of accessibility to physical channels (specifically, customer distance) on customers’ use of virtual channels, as well as the relative use of Internet versus phone, depend on the type of activities.     

Stream restoration in Andean cities: learning from contrasting restoration approaches

Urban Ecosystems - The Andes region is one of the fastest urbanizing regions of the world. The current rate of environmental degradation of streams in this region create an urgent need for...     

Landscape urbanization threatens plant phylogenetic diversity in the Brazilian Atlantic Forest

Urbanization causes species loss around the world, but its effects on phylogenetic diversity are poorly known in tropical forests. Using a patch-landscape approach in an urbanizing region of the Brazilian Atlantic Forest, we tested whether the increase in landscape urbanization reduces plant species density, phylogenetic richness and divergence, and increases the relatedness among co-occurring individuals and species. We assessed plant responses to urbanization in adult (diameter at breast height?>?10 cm) and sapling communities (2.5–10 cm diameter) separately, as saplings are proxies of the future flora. We sampled 2860 woody plants belonging to 155 species in nine circular landscapes with urbanization level varying from 0% to 45%, and estimated the relatedness among the species that have increased and decreased in relative abundance in more urbanized landscapes (winner and losers, respectively). As expected, species density and phylogenetic richness decreased with the increase in urbanization. These responses were consistent for adult and sapling communities, suggesting a persistent loss of species and lineages in more urbanized landscapes. Contrary to our expectations, phylogenetic divergence and structure did not respond to urbanization, indicating that the more urbanized landscapes still retain much evolutionary history. However, because the relatedness among winners was greater than among losers, it is likely that the phylogenetic divergence gradually reduces and the relatedness increases, resulting in impoverished forests with uncertain ability to provide ecosystem services such as carbon storage and pest control. This environmental cost should be taken into account to align urban sprawl with biodiversity conservation.     

Evaluation of the exercise intervention with the "Back School" education program in a Brazilian company of cigars: a case study

The purpose of this study was to assess the benefits of an exercise program associated to the educational phase of the "Back School Program" in the quality of life of workers from a cigar factory. This is a case study conducted over four months with three activities a week, two times a day, with the third day devoted to educational activities, focusing on healthy lifestyle, correct posture, postural orientations, daily living and work activities, work motivation, and other issues.     

Ergonomic analysis for elementary school teachers. Preliminary trial for elementary schools in the province of Buenos Aires

This article presents the results of a preliminary trial, in the context of an intervention, developed by a team of ergonomists under the request of the Occupational Health Department of the General Management of Schools in the Province of Buenos Aires, Argentina. We present a reformulation of the request and the results obtained in 2009 from observations and interviews held in three schools in the province of Buenos Aires in which different jobs positions were assessed. From this stage onwards, the tools were validated and new aspects were shown, particularly in relation to the high variety of real situations in the education sector.     

The perception of pleasantness in a product of collective use: the bus shelter

This article presents a study on the identification of a setting whose arrangement of attributes could lead to the perception of pleasantness of a bus shelter: a product that should welcome people while waiting for the bus. Two different bus shelters typologies in the city of Porto Alegre, state of Rio Grande do Sul, Brazil, were evaluated, where four attributes were under consideration. The relation between the shelters subject of the study and the surroundings was significant for defining the attributes. The setting with curve shaped cover, bench, rear wall, and surrounding vegetation was considered the most pleasant one. The seats and the rear wall were associated with the practical function of the product while the curve shaped cover and the surrounding vegetation were associated with the aesthetical function according to the participant users.