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.

Quantum Speed Limits across the Quantum-to-Classical Transition.

Abstract: Quantum speed limits set an upper bound to the rate at which a quantum system can evolve. Adopting a phase-space approach, we explore quantum speed limits across the quantum-to-classical transition and identify equivalent bounds in the classical world. As a result, and contrary to common belief, we show that speed limits exist for both quantum and classical systems. As in the quantum domain, classical speed limits are set by a given norm of the generator of time evolution.

Pathways to Labor Force Exit: Work Transitions and Work Instability

Abstract: The purpose of this study is to examine alternative pathways to labor force exit among older men. Based on the life course perspective, we distinguish between crisp exits from the labor force, which are characterized as being unidirectional, and blurred transition patterns, which include repeated exits, entrances, and unemployment spells. Using longitudinal data from the 1984 Survey of Income and Program Participation, we find that one-quarter of the sample of men aged 55 to 74 at first interview experienced at least one transition in labor force status over a 28-month observation period. Fewer than half of these can be characterized as crisp exits from the labor force. Our multivariate analysis suggests that blurred transition patterns are likely part of an effort to maintain economic status in later life.

Recent evidence of the effectiveness of educational interventions for improving complementary feeding practices in developing countries.

Abstract: Inappropriate complementary feeding practices have been identified as the major causes of malnutrition in young children in developing countries. This article reviewed literature on complementary feeding educational interventions from 1998 onwards. The purpose of this study was to provide evidence from published studies in the past decade on the effectiveness of educational intervention programs on improving complementary feeding practices in the developing world. The literature search was performed through PubMed/Medline database with the following key words: infant feeding, weaning and intervention, and identified a total of 15 original educational intervention studies. Evidence from these studies supports that educational intervention can effectively improve complementary feeding practices and child nutrition and growth. The intervention should be culturally sensitive, accessible and integrated with local resources.

The effect of ecological factors on the mating system of a South American shrub species (Helicteres brevispira)

Abstract: Mating systems are influenced by several ecological factors, including plant density, number of flowers per plant, and pollinator movements. In this study, we investigated the simultaneous effects of these three factors on the mating system of a self-compatible Brazilian shrub species: Helicteres brevispira St. Hil. Outcrossing rate is directly correlated with plant density. Changes in the number of flowers per plant affect outcrossing rate through their effect on the density of flowers. Variation in foraging behaviour of hummingbird pollinators is a consequence of the interaction between plant density and number of flowers per plant. Territorialist pollinators are common in high density areas but visit few flowers on each plant, thereby promoting outcrossing. In areas of low plant density, trapliners and rare territorialists visit several flowers per plant, thus increasing selfing. Our results indicate that outcrossing rate is a dynamic parameter, with the extent of variation depending on a number of ecological factors. In successional species such as those in the genus Helicteres, demographic changes may be accompanied by alterations in mating system parameters, with concomitant effects on the genetic structure of populations.