University of Rhode Island

About: University of Rhode Island is a education organization based out in Kingston, Rhode Island, United States. It is known for research contribution in the topics: Population & Bay. The organization has 11464 authors who have published 22770 publications receiving 841066 citations. The organization is also known as: URI & Rhode Island College of Agriculture and the Mechanic Arts.

Self‐Efficacy, Decision‐Making, and Stages of Change: An Integrative Model of Physical Exercise

Abstract: Exercise has important health benefits but a large proportion of the population is physically inactive. We examined the stages of readiness to exercise and their relationship to self-efficacy, the costs and benefits of exercising, and self-report of physical activity in a sample of Rhode Island worksites. Using a three-step model-building approach, exploratory principal components analyses were followed by an examination of the stages of change model with confirmatory structural equation modeling procedures. The model was then examined with longitudinal data. Confirmatory and longitudinal analyses showed an excellent tit between the model and the data. Results indicated that the costs and benefits of exercise and self-efficacy for exercise were related to physical activity only indirectly, through the mediation of stage of readiness to exercise. Structural modeling fit indices revealed that much of the variation and covariation in physical activity was explained by the model. There is the potential to enhance the impact of exercise interventions, by targeting them so as to address factors related to these different stages of readiness.

Along-axis variations in seafloor spreading in the MARK area

Abstract: Recent investigations with the manned submersible Alvin and the Angus deep-towed camera sled greatly extended the known range of variations in the style of seafloor spreading along the axis of the Mid-Atlantic Ridge. Five transects of the spreading centre at intervals of10–20 km south of the Kane Fracture Zone at 24° N latitude demonstrate dramatic changes in the style and magnitude of tectonic extension, development of the neovolcanic zone, expression of hydrothermal venting, types oflithologic exposures and morphology of the median valley.

Atmospheric gas concentrations over the past century measured in air from firn at the South Pole

Abstract: The extraction and analysis of air from the snowpack (firn) at the South Pole provides atmospheric concentration histories of biogenic greenhouse gases since the beginning of the present century which confirm and expand on those derived from studies of air trapped in ice cores. Furthermore, calculations based on the inferred atmospheric concentrations of oxygen and carbon dioxide indicate that–in contrast to the past few years—the terrestrial biosphere was neither a source nor sink of C02 between ˜1977 and 1985.

Chemical aspects of tool wear in single point diamond turning

Abstract: A hypothesis is proposed that ascribes chemical wear of diamond tools to the presence of unpaired d electrons in the sample being machined. This hypothesis is used to explain a range of results for metals, alloys, and other materials including “electroless” nickel. The hypothesis is further tested by experiments presented here on the machining of a range of high purity elements. The implications for diamond turnability of other materials are discussed.

Episodic fresh surface waters in the Eocene Arctic Ocean

Abstract: It has been suggested, on the basis of modern hydrology and fully coupled palaeoclimate simulations, that the warm greenhouse conditions that characterized the early Palaeogene period (55-45 Myr ago) probably induced an intensified hydrological cycle with precipitation exceeding evaporation at high latitudes. Little field evidence, however, has been available to constrain oceanic conditions in the Arctic during this period. Here we analyse Palaeogene sediments obtained during the Arctic Coring Expedition, showing that large quantities of the free-floating fern Azolla grew and reproduced in the Arctic Ocean by the onset of the middle Eocene epoch (approximately 50 Myr ago). The Azolla and accompanying abundant freshwater organic and siliceous microfossils indicate an episodic freshening of Arctic surface waters during an approximately 800,000-year interval. The abundant remains of Azolla that characterize basal middle Eocene marine deposits of all Nordic seas probably represent transported assemblages resulting from freshwater spills from the Arctic Ocean that reached as far south as the North Sea. The termination of the Azolla phase in the Arctic coincides with a local sea surface temperature rise from approximately 10 degrees C to 13 degrees C, pointing to simultaneous increases in salt and heat supply owing to the influx of waters from adjacent oceans. We suggest that onset and termination of the Azolla phase depended on the degree of oceanic exchange between Arctic Ocean and adjacent seas.