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.

Halogens in the Mantle Beneath the North Atlantic

Abstract: F, Cl and Br contents of tholeiitic volcanic glasses dredged along the Mid-Atlantic Ridge from 53 degrees to 28 degrees N, including the transect over the Azores Plateau, are reported. The halogen variations parallel those of $^{87}$Sr/$^{86}$Sr, La/Sm or other incompatible elements of varying volatility. The latitudinal halogen variation pattern is not obliterated if only Mg-rich lavas are considered. Variations in extent of low-pressure fractional crystallization or partial melting conditions do not appear to be the primary cause of the halogen variations. Instead, mantle-derived heterogeneities in halogens, with major enrichments in the mantle beneath the Azores, are suggested. The Azores platform is not only a 'hotspot' but also a 'wetspot', which may explain the unusually intense Azores volcanic activity. The magnitude of the halogen and incompatible element enrichments beneath the Azores appear strongly dependent on the size of these anions and cations, but independent of relative volatility at low pressure. The large anions Cl and Br behave similarly to large cations Rb, Cs and Ba, and the smaller anion F similarly to Sr and P. Processes involving crystal and liquid (fluid and/or melt), CO$\_{2}$ rahter than H$\_{2}$O dominated, seem to have produced these largescale mantle heterogeneities. Geochemical 'anomalies' beneath the Azores are no longer apparent for coherent element pair ratios of similar ionic size. Values of such 'unfractionated' coherent trace element ratios provide an indication of the mantle composition and its nature before fractionation event(s) which produced the inferred isotopic and trace element heterogeneities apparently present beneath the North Atlantic. The relative trace element composition of this precursor mantle does not resemble that of carbonaceous chondrites except for refractory trace element pairs of similar ionic size. It is strongly depleted in halogens, and to a lesser extent in large alkali ions Rb and Cs relative to refractory Ba. These relative depletions are comparable within a factor of 5 to Ganapathy & Anders's estimates for the bulk Earth, with the exception of Cs. There is also evidence for removal of phosphorus into the iron core during its formation. With the exception of San Miguel, alkali basalts from the Azores Islands appear to have been derived from the same mantle source as tholeiitic basalts from the ridge transect over the Azores Platform but by half as much degree of partial melting. The Azores subaerial basalts seem to have been partly degassed in Cl, Br and F, in decreasing order of intensity. A working model involving metasomatism from release of fluids at phase transformation during convective mantle overturns is proposed to explain the formation of mantle plumes or diapirs enriched in larger relative to smaller halogen and other incompatible trace elements. The model is ad hoc and needs testing. However, any other dynamical model accounting for the 400-1000 km long gradients in incompatible trace elements, halogens and radiogenic isotopes along the Mid-Atlantic Ridge should, at some stage, require either (1) some variable extent of mixing or (2) differential migration of liquid relative to crystals followed by re-equilibration (or both), as a diffusion controlled mechanism over such large distances is clearly ruled out, given the age of the Earth.

Ecological and socioeconomic impacts of invasive alien species in island ecosystems.

Abstract: Minimizing the impact of invasive alien species (IAS) on islands and elsewhere requires researchers to provide cogent information on the environmental and socioeconomic consequences of IAS to the public and policy makers. Unfortunately, this information has not been readily available owing to a paucity of scientific research and the failure of the scientific community to make their findings readily available to decision makers. This review explores the vulnerability of islands to biological invasion, reports on environmental and socioeconomic impacts of IAS on islands and provides guidance and information on technical resources that can help minimize the effects of IAS in island ecosystems. This assessment is intended to provide a holistic perspective on island-IAS dynamics, enable biologists and social scientists to identify information gaps that warrant further research and serve as a primer for policy makers seeking to minimize the impact of IAS on island systems. Case studies have been selected to reflect the most scientifically-reliable information on the impacts of IAS on islands. Sufficient evidence has emerged to conclude that IAS are the most significant drivers of population declines and species extinctions in island ecosystems worldwide. Clearly, IAS can also have significant socioeconomic impacts directly (for example human health) and indirectly through their effects on ecosystem goods and services. These impacts are manifest at all ecological levels and affect the poorest, as well as richest, island nations. The measures needed to prevent and minimize the impacts of IAS on island ecosystems are generally known. However, many island nations and territories lack the scientific and technical information, infrastructure and human and financial resources necessary to adequately address the problems caused by IAS. Because every nation is an exporter and importer of goods and services, every nation is also a facilitator and victim of the invasion of alien species. Wealthy nations therefore need to help raise the capacity of island nations and territories to minimize the spread and impact of IAS.

Marine Reserves for Fisheries Management

Abstract: Conventional methods of regulating commercial fisheries restrict catch by limiting either the quantity or efficiency of fishing effort, or by putting direct limits on catch. These regulatory practices are neither feasible nor desirable for many fisheries, and have failed to conserve fishery stocks in other fisheries. Marine reserves may be an effective alternative management strategy for some fisheries. Here we develop a dynamic model of marine reserves applicable to inshore fisheries. In contrast to previous models of reserves, the model is fully dynamic and provides information on both equilibrium conditions and the path to equilibrium. A simulation model based on red snapper data from the Gulf of Mexico is presented. The simulation results suggest that marine reserves can sustain or increase yields for moderate to heavily fished fisheries but will probably not improve yields for lightly fished fisheries.

High‐throughput mapping of cell‐wall polymers within and between plants using novel microarrays

Abstract: We describe here a methodology that enables the occurrence of cell-wall glycans to be systematically mapped throughout plants in a semi-quantitative high-throughput fashion. The technique (comprehensive microarray polymer profiling, or CoMPP) integrates the sequential extraction of glycans from multiple organs or tissues with the generation of microarrays, which are probed with monoclonal antibodies (mAbs) or carbohydrate-binding modules (CBMs) with specificities for cell-wall components. The profiles generated provide a global snapshot of cell-wall composition, and also allow comparative analysis of mutant and wild-type plants, as demonstrated here for the Arabidopsis thaliana mutants fra8, mur1 and mur3. CoMPP was also applied to Physcomitrella patens cell walls and was validated by carbohydrate linkage analysis. These data provide new insights into the structure and functions of plant cell walls, and demonstrate the potential of CoMPP as a component of systems-based approaches to cell-wall biology.