University of Massachusetts Boston

About: University of Massachusetts Boston is a education organization based out in Boston, Massachusetts, United States. It is known for research contribution in the topics: Population & Health care. The organization has 6541 authors who have published 12918 publications receiving 411731 citations. The organization is also known as: UMass Boston.

Lytic infection of Escherichia coli biofilms by bacteriophage T4

Abstract: Escherichia coli 3000 XIII formed biofilms on the surface of polyvinylchloride coupons in a modified Robbins device. Bacteriophage T4D+ infected cells in the biofilm and replicated. It is commonly held that bacteriophage cannot infect surface-attached bacteria (biofilms) because such bacteria are protected by an exopolymeric matrix that binds macromolecules and prevents their diffusion into the biofilm. To our knowledge this is the first observation that a bacteriophage can infect and multiply within cells growing as a biofilm.

Stress, Social Support, and Adjustment of Adolescents in Middle School

Abstract: Examined in this study were middle school stress, social supports, and adjustment of 482 sixth-, seventh-, and eighth-grade adolescents. Multiple regression analyses were used to relate differing types of stress and social support to students' self-concept, feelings of depression, and liking of school. The effects of adolescent characteristics (gender, grade level, grade point average, and education placement status) also were assessed. Results showed that higher academic stress and less emotional support from the family were related to lower academic self-concept, and higher peer stress and less companionship support from peers were associated with lower social self-concept. Emotional support from the family moderated the influence of peer stress on feelings of depression. Problem-solving support from adults outside the family moderated the effects of teacher/rules stress on adolescents' liking of school. The importance of identifying the linkages between types of stress, social support, and adjustment, ...

A theoretical model of job retention for home health care nurses

Abstract: Background. Predicted severe nursing shortages and an increasing demand for home health care services have made the retention of experienced, qualified nursing staff a priority for health care organizations. Aims. The purpose of this paper is to describe a theoretical model of job retention for home health care nurses. Methods. The theoretical model is an integration of the findings of empirical research related to intent to stay and retention, components of Neal's theory of home health care nursing practice and findings from earlier work to develop an instrument to measure home health care nurses’ job satisfaction. Discussion. The theoretical model identifies antecedents to job satisfaction of home health care nurses. The antecedents are intrinsic and extrinsic job characteristics. The model also proposes that job satisfaction is directly related to retention and indirectly related to retention though intent to stay. Individual nurse characteristics are indirectly related to retention through intent to stay. The individual characteristic of tenure is indirectly related to retention through autonomy, as an intrinsic characteristic of job satisfaction, and intent to stay. Conclusions. The proposed model can be used to guide research that explores gaps in knowledge about intent to stay and retention among home health care nurses.

Functional composition controls invasion success in a California serpentine grassland

Abstract: Summary 1. Recent debates about the role of biotic resistance in controlling invasion success have focused on effects of species richness. However, functional composition could be a stronger control: species already in the community with similar functional traits to those of the invaders should have the greatest competitive effect on invaders. Still, experiments assessing effects of functional similarity have found contradictory results. 2. We used experimental communities in a serpentine grassland in California, USA, to assess the extent to which functional composition and functional diversity influenced success of two different types of invading plants: early season annuals (E) and late-season annuals (L) that have been previously shown to differ in patterns of resource acquisition. 3. We seeded known quantities of seed of six different species (three in each functional group) into experimental plots containing established communities differing in functional composition and functional diversity. The experimental communities contained different combinations of E, L, perennial bunchgrass (P) and nitrogen-fixer (N) functional groups, with functional diversity ranging from 0 to 4 groups. Each invading species was seeded into a separate quadrat within each plot to minimize competitive effects of invaders on each other. We measured both seedling and adult success of invaders for two full growing seasons to further understand mechanisms underlying biotic resistance. 4. More functionally diverse communities were less invaded overall, as measured by the average success of individual invaders. However, assessment of invaders by functional groups was more informative: Es in the extant community suppressed E invaders the most, and Ls in the extant community suppressed L invaders the most. 5. We observed a variety of interactions among extant functional groups in reducing invader success, including synergism, complementarity and ‘basement’ effects, where two or more groups negatively affected invaders, but combinations of groups were no more suppressive than single groups. The extant community influenced invaders more strongly through suppression of adult plant growth than through effects on seedling establishment. 6. Synthesis. Contrary to predictions from neutral theory, these results indicate that niche overlap was an important component of biotic resistance in these experimental plant communities and summed up to significant effects of species richness.

Analyzing qualitative data with computer software.

Abstract: OBJECTIVE: To provide health services researchers with an overview of the qualitative data analysis process and the role of software within it; to provide a principled approach to choosing among software packages to support qualitative data analysis; to alert researchers to the potential benefits and limitations of such software; and to provide an overview of the developments to be expected in the field in the near future. DATA SOURCES, STUDY DESIGN, METHODS: This article does not include reports of empirical research. CONCLUSIONS: Software for qualitative data analysis can benefit the researcher in terms of speed, consistency, rigor, and access to analytic methods not available by hand. Software, however, is not a replacement for methodological training.