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.

An Overview of Age-Friendly Cities and Communities Around the World

Abstract: Efforts to make cities and communities more age-friendly have gained significant momentum in recent years. Population aging and increased urbanization have challenged governments and other civic or...

The Fundamental Conductivity and Resistivity of Water

Abstract: The most accurate values to date were determined for conductivity of water from 0-100°C, permitting new determination of high-temperature hydroxide ion equivalent conductance. These values were incorporated into a fundamental water coefficient table including hydroxide and hydrogen ion mobilities, water ionization constant, density, conductivity, and resistivity. The conductivity/resistivity values were measured with a multiple-pass, closed, recirculating flow conductivity system, with improved multiple resistance temperature device measurement, and improved analysis of temperature and impurity effects. An accurate conductivity knowledge is necessary to understand water-limiting processes and to facilitate the analysis of trace ionic impurities in water.

Predation pressure and gastropod foraging: a tropical-temperate comparison.

Abstract: Over the last two decades, theories of species diversity (Huston, 1979), antipredation phenomena (Vermeij, 1978) and reproductive effort (Cody, 1966) have involved a temperate-tropical gradient in predation. Comparative tropical-temperate observations in a number of systems support the case for an increase in predation intensity with a decrease in latitude (Cody, 1966; Bakus, 1974; Jeanne, 1979; Palmer, 1979); however, no experimental evidence has been presented. One of the stronger cases for a latitudinal gradient in predation pressure has been made for littoral gastropods (Vermeij, 1978, and included references). Intertidal gastropods are exposed to shellbreaking predation from two major feeding guilds: fishes and bottom-dwelling Crustacea (Vermeij, 1978; Palmer, 1979; Bertness and Cunningham, 1981). Crustaceans may either crush or peel prey shells. Small snails are generally crushed, while larger shells are grasped and pieces of apex or lip are chipped away until the molluscan soft parts are reached (Zipser and Vermeij, 1978; Bertness and Cunningham, 1981). Fish that feed on snails crush their prey and do not inflict the apical and aperture damage characteristic of crustacean related injury (Zipser and Vermeij, 1978; Palmer, 1979; Bertness, 1981). Birds are also known to feed on intertidal gastropods, but their overall effect seems minor (Gibb, 1956; Feare, 1971; Vermeij, 1978; Zach, 1978). 1 Present address: Smithsonian Tropical Research Institute, APO Miami, Florida 34002. Vermeij (1978) presented evidence indicating that the frequency of gastropod shell characteristics such as narrow or occluded apertures, low spires, thickened shells and strong shell sculpture increases from temperate to tropical seas. These morphological characteristics have been shown to defend gastropods from some kinds and sizes of predators (Vermeij, 1976, 1978; Zipser and Vermeij, 1978; Palmer, 1979; Bertness and Cunningham, 1981). In addition, tropical shell-crushing crabs are more efficient and specialized predators than their temperature equivalents (Shoup, 1968; Zipser and Vermeij, 1978). Palmer (1979) suggested that species of teleost fish and rays that crush gastropods are not only found more commonly in tropical oceans, but also are more specialized on a gastropod diet than their temperate relatives. Gastropod shell characteristics that appear to deter predation by fish are almost exclusively tropical in occurrence (Vermeij, 1978; Palmer, 1979). These lines of evidence strongly suggest that shell-crushing predation is greater on tropical than on temperate shells. The prevalence of shell-crushing predators in tropical waters has led to speculation and experimentation on the architectural defenses of gastropods against shell-crushing predators (Reynolds and Reynolds, 1977; Zipser and Vermeij, 1978; Palmer, 1979; Bertness and Cunningham, 1981). However, there have been no efforts to quantitatively compare the direct effects of crushing predation

Toward a Model of Transculturation

Abstract: The TESOL Quarterly invites commentary on current trends or practices in the TESOL profession. It also welcomes responses to rebuttals to any articles or remarks published here in The Forum or elsewhere in the Quarterly.