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Showing papers by "University of Rhode Island published in 1985"



Journal ArticleDOI
TL;DR: In this paper, the authors examined the construct of self-efficacy in the self-change of smoking behavior and used a 31-item measure of selfefficacy that included ratings of both temptation (cue strength) and confidence (efficacy).
Abstract: Efficacy expectations are postulated to mediate all behavior change. This study examined the construct of self-efficacy in the self-change of smoking behavior. A 31-item measure of self-efficacy was used that included ratings of both temptation (cue strength) and confidence (efficacy). The subjects were 957 volunteers representing five stages of self change: (1) immotives, (2) contemplators, (3) recent quitters, (4) long-term quitters, and (5) relapsers. Subjects were assessed initially and at a 3- to 5-month follow-up. The self-efficacy scale proved to be an extremely reliable and coherent instrument with identifiable but not clearly interpretable subcomponents. Groups of subjects demonstrated significant differences in total self-efficacy scores. Efficacy expectations demonstrated small but significant relationships with smoking history variables and the pros and cons of smoking, but not with demographic, life stress, or persistence measures. Subject's efficacy evaluations at the initial assessment were related to changes in status for recent quitters and contemplators at the follow-up. The relationship between temptation and efficacy ratings is complex and varies for subjects in the various stages of change. Correlations between total self-efficacy and temptation scores were largest for contemplators (r = −.65) and relapsers (r = −.67) and smallest for the recent quitters (r = −.18). Finally, the magnitude of the difference between temptation and efficacy increased with length of abstinence for subjects in maintenance.

549 citations


Journal ArticleDOI
TL;DR: A general pattern emerged in which processes oriented more toward environmental events, such as dramatic relief and social liberation, tended to predict failure or no progress whereas more experientially oriented processes predicted progress.

507 citations


Journal ArticleDOI
TL;DR: Previously unknown sufficient conditions, a necessary condition, and reconstruction methods for image reconstruction from cone-beam projections are developed, and by requiring additional conditions on the configuration of source points a more efficient reconstruction method is developed.
Abstract: Previously unknown sufficient conditions, a necessary condition, and reconstruction methods for image reconstruction from cone-beam projections are developed. A sufficient condition developed is contained in the following statement. Statement 5: If one every plane that intersects the object, there exists at least one cone-beam source point, then the object can be reconstructed. Reconstruction methods for an arbitrary configuration of source points that satisfy Statement 5 are derived. By requiring additional conditions on the configuration of source points, a more efficient reconstruction method is developed. It is shown that when the configuration of source points is a circle, Statement 5 is not satisfied. In spite of this, several suggestions are made for reconstruction from a circle of source points.

466 citations


Journal ArticleDOI
TL;DR: Over a range of temperatures, respiration and excretion were linearly related and exhibited significant linear relationships with ingestion and curvilinear relationships with growth.
Abstract: Clearance, ingestion, and growth rates of two coastal tintinnid ciliates were measured in batch culture as a function of temperature and phytoplankton concentration. Oxygen consumption and ammonium excretion rates were determined at food concentrations which supported maximum growth rates at each temperature. Clearance, ingestion, respiration, excretion, and growth rates of both species increased with temperature. Clearing rates declined with increasing phytoplankton abundance. Ingestion and growth rates increased asymptotically with phytoplankton abundance and declined at high food concentrations. Gross growth efficiency was highest at phytoplankton concentrations which supported maximum growth rates. Over a range of temperatures, respiration and excretion were linearly related and exhibited significant linear relationships with ingestion and curvilinear relationships with growth. 0 : N ratios were 4-7, assuming an RQ of 1 .O. The metabolic data were combined with previous measurements of in situ production by tintinnids to estimate their potential carbon requirements and NH,+ regeneration in Narragansett Bay, Rhode Island. Tintinnids ingested a carbon equivalent of 16-26% of the total annual net primary production and 32-52% of < IO-urn nanonlankton oroduction. Nitrogen excretion was sufficient to support 1 l18% of net primary production.

286 citations


Journal ArticleDOI
TL;DR: In this article, an extractor-stripper removes CO2 that is measured coulometrically by the quantity of electricity (coulombs) used to electrogenerate OH− ions for the titration of the acid formed by the reaction of CO2 and ethanolamine.

286 citations


Journal ArticleDOI
TL;DR: In this article, a one-dimensional transient thermal model with an nth order ap proximation for the rate of decomposition of a polymer composite material undergoing decomposition was applied.
Abstract: The thermal response of a polymer composite material undergoing decomposition has been modeled. A one-dimensional transient thermal model with an nth order ap proximation for the rate of decomposition was applied. The model was tested by ex perimentally measuring the temperature profiles during decomposition for a glass- filled phenol-formaldehyde polymer composite. Additionally, the specific heat and thermal conductivity of the virgin and char components, heat of decomposition, and the kinetic parameters were experimentally determined and used as input to the model. The predicted temperature profiles are in good agreement with experimental temperatures obtained using a radiant heat flux apparatus.

266 citations


Journal ArticleDOI
15 Feb 1985-Science
TL;DR: Analysis of the particle size, composition, and mass accumulation rate of dust grains provide independent evidence of the intensity of atmospheric circulation and the availability of material in the eolian source region at time scales ranging from 103 to 108 years.
Abstract: Eolian dust preserved in deep-sea pelagic sediments can be used as a proxy indicator of paleoclimate. Analyses of the particle size, composition, and mass accumulation rate of dust grains provide independent evidence of the intensity of atmospheric circulation and the availability of material in the eolian source region. These data provide information on atmospheric circulation and on the climate of the source area at time scales ranging from 103 to 108 years and have the potential to test computer-generated global circulation models.

254 citations


Book ChapterDOI
TL;DR: In this article, the authors present the results of a study on the relationship between geology and geophysics, focusing on the geophysical properties of the Earth's magnetic field.
Abstract: •Present address: Department of Geological and Geophysical Science, Princeton University, Princeton, New Jersey 08544.

253 citations


Journal ArticleDOI
01 Jan 1985
TL;DR: In this paper, three methods of estimating the particulate organic carbon fluxes to the sediment-water interface of the deep Pacific Ocean agree to within the error of the measurements at MANOP sites M, H, and C.
Abstract: Three methods of estimating the particulate organic carbon fluxes to the sediment-water interface of the deep Pacific Ocean agree to within the error of the measurements at MANOP sites M, H, and C. Sediment trap experiments, pore water results, and surface sediment organic carbon data suggest that a major fraction of the particulate organic carbon raining to abyssal depths at these locations is degraded within the surface sediments rather than at the sediment-water interface or in the nephloid layer. Organic carbon rain rates at the three sites are similar—within a factor of two; however, the preservation rate of organic carbon and the chemistry of sediment pore waters are very different. A model developed to describe the pore water oxygen and sedimentary carbon distributions indicates model developed to describe the pore water oxygen and sedimentary carbon distributions indicates that changes in the rate constant for organic matter degradation and the bioturbation rate may contribute significantly to the observed differences in character of both pore water and sediment chemistry at these locations. The implication with respect to interpreting the sedimentary record is that cycles of organic carbon and redox sensitive metals (i.e., manganese) are not simply related to particulate organic carbon flux or surface water primary productivity. The residence time of organic carbon with respect to degradation in the surface sediments is on the order of 15 to 150 y.

237 citations


Journal ArticleDOI
TL;DR: For Narragansett Bay, Rhode Island, newly calculated and archival data for the area, mean depth, total volume, mean salinity and fresh water input are presented in this paper.
Abstract: For Narragansett Bay, Rhode Island, newly calculated and archival data for the area, mean depth, total volume, mean salinity and fresh water input are presented Estimates of the residence time of the water, derived from 22 sets of monthly mean values, were related to estimates of the fresh water input according to the empirical relationship T=418 e−000435(FW), where T is the flushing time in days, and FW is the fresh water input in m3 per s; the r2 value is 0841 Adding estimates of the mean wind speed into a multiple regression increased the correlation coefficient only to 0864 At the long-term mean rate of fresh water input (105 m3 per s) the flushing time is 26 days At the lowest mean monthly input rate observed the flushing time was nearly 40 days, while at the highest mean monthly input rate in the data set (325 m3 per s) the flushing time was about 10 days Known sources of random error appear sufficient to account for most of the deviations from the relationship The evidence suggests that variation in the flushing time is largely determined by variation in the fresh water input

Journal ArticleDOI
TL;DR: In this paper, the Pegasus instrument was used along a transect crossing the Gulf Stream at 73°W to estimate the mean temperature and velocity fields of the upper 2000 meters, and a comparison with mass flux measurements obtained by previous investigators at Cape Fear indicated that the addition to the transport of the Stream in the region was uniform with depth above 800 meters.
Abstract: Between September 1980 and May 1983, 16 sections of temperature and velocity were obtained with the Pegasus instrument along a transect crossing the Gulf Stream at 73°W. The mean temperature and velocity fields of the upper 2000 meters were calculated. The transport above 2000 meters calculated from the sections had a mean of 87.8 (± 17.3) × 106 m3 s−1. A comparison with mass flux measurements obtained by previous investigators at Cape Fear indicated that the addition to the transport of the Stream in the region was uniform with depth above 800 meters. The mean inflow measured at the Pegasus line was found to be uniform above 800 meters and to decrese substantially below this depth. The increase in transport at the line estimated from the mean cross-stream velocity field was 15.4 (± 5.8) × 106 m3 s−1 per 100 km downstream distance. The temporal fluctuation of the Pegasus transport measurements was consistent with an annual cycle with a maximum in April. The mean eddy kinetic energy at the surface...

Journal ArticleDOI
TL;DR: In this article, an extensive review of theoretical and experimental investigations conducted over the last two decades since the advent of the laser and relating to the simultaneous absorption of one or more photons by the valence electrons of a crystalline solid is given.
Abstract: An extensive review of theoretical and experimental investigations conducted over the last two decades since the advent of the laser and relating to the simultaneous absorption of one or more photons by the valence electrons of a crystalline solid is given. The following topics are addressed, with greatest emphasis on the most recent results: the pioneering models of Braunstein and Ockman and that of Basov for two-photon absorption in direct-gap crystals, based on second-order time-dependent perturbation theory and parabolic and isotropic energy bands; extensions and modifications of the above models by various authors to take into account the effects of excitons, crystal anisotropy, laser polarization, and nonparabolicity as well as degeneracy of the electronic energy bands; rigorous band-structure calculations that employ realistic energy bands and momentum matrix elements that include many intermediate states to obtain good convergence in the perturbation calculation; the semiclassical theory of Keldysh that takes into account electric-field effects on the electronic energies and wave functions and that employs first-order perturbation theory to obtain multiphoton transitions of all orders; the fully quantized treatment of the multiphoton absorption (MPA) process along the above lines by Kovarskii and Perlin; the Volkov approximation method of Jones and Reiss; descriptions of the various experimental techniques that are usually employed to study nonlinear phenomena in solids; critical comparison between different theoretical predictions and experimental data; and finally, theoretical and experimental work relating to phonon-assisted two-photon transitions, three-photon absorption, four-photon absorption, and higher-order MPA processes in crystalline solids.

Journal ArticleDOI
TL;DR: In this paper, the authors measured the total deposition of atmospheric mineral particles (wet plus dry) during consecutive two-week sampling intervals from January, 1981 to March, 1982 at four island stations (Midway, Oahu, Enewetak, and Fanning) of the SEAREX Asian Dust Study Network in the North Pacific.
Abstract: Total deposition of atmospheric mineral particles (wet plus dry) has been measured during consecutive two-week sampling intervals from January, 1981 to March, 1982 at four island stations (Midway, Oahu, Enewetak, and Fanning) of the SEAREX Asian Dust Study Network in the North Pacific. The total deposition of mineral aerosol during the period from February to June is higher than that during the period from July to January at most of the stations. A systematic geographical trend is apparent in the dust flux, with greater fluxes at higher latitudes. The deposition values are correlated with the atmospheric mineral particle concentrations at these stations. The mineral particles are transported from arid regions in Asia to the North Pacific, and the annual dust deposition to the ocean appears to be dominated by sporadic dust events of short duration. Wet deposition dominates the removal of dust particles from the atmosphere over the North Pacific. The total deposition of atmospheric mineral material to the central North Pacific is estimated to be ∼20×1012 g yr-1.

Journal ArticleDOI
01 Jan 1985-Nature
TL;DR: In this paper, short-wavelength geochemical anomalies in the basaltic layer 2A occur along the South Atlantic mid-ocean ridge opposite Ascension, St Helena and Tristan hotspots, further evidence that preferential subcrustal flow channels develop between mantle upwelling zones (hotspots) and migrating ridge axes.
Abstract: Short-wavelength geochemical anomalies in the basaltic layer 2A occur along the South Atlantic mid-ocean ridge opposite Ascension, St Helena and Tristan hotspots, further evidence that preferential subcrustal flow channels develop between mantle upwelling zones (hotspots) and migrating ridge axes. Geochemical variability suggests that the plume along these channels would be schlieren-like rather than continuous.

Journal ArticleDOI
01 May 1985-Nature
TL;DR: In this paper, the authors conclude that marine photosynthesis in mid-Cretaceous and earlier oceans generally resulted in a greater fractionation of C isotopes and produced organic C having lighter δ13C values.
Abstract: Marine organic carbon is heavier isotopically (13C enriched) than most land-plant or terrestrial organic C1. Accordingly, δ13C values of organic C in modern marine sediments are routinely interpreted in terms of the relative proportions of marine and terrestrial sources of the preserved organic matter2,3. When independent geochemical techniques are used to evaluate the source of organic matter in Cretaceous or older rocks, those rocks containing mostly marine organic C are found typically to have lighter (more-negative) δ13C values than rocks containing mostly terrestrial organic C. Here we conclude that marine photosynthesis in mid-Cretaceous and earlier oceans generally resulted in a greater fractionation of C isotopes and produced organic C having lighter δ13C values. Modern marine photosynthesis may be occurring under unusual geological conditions (higher oceanic primary production rates, lower ) that limit dissolved CO2 availability and minimize carbon isotope fractionation4.

Journal ArticleDOI
01 Mar 1985-Nature
TL;DR: The width of geochemical and residual elevation anomalies along the mid-Ocean Ridge System decrease as both the distance between migrating ridge segments and related hotspots and local geochemical dispersion in the anomalies increase as discussed by the authors.
Abstract: The width of geochemical and residual elevation anomalies along the Mid-Ocean Ridge System decrease as both the distance between migrating ridge segments and related hotspots and the local geochemical dispersion in the anomalies increase. These observations provide further evidence that flows of mantle plumes in the upper mantle are deflected by migrating ridge sinks once they override hotspots.

Journal ArticleDOI
TL;DR: In this article, the effect of nutrient loading and eutrophication in coastal marine ecosystems on the rates of benthic denitrification and N/sub 2/O production was measured.
Abstract: Large (13 m/sup 3/, 5 m deep) microcosms with coupled pelagic and benthic components were used to measure the effect of nutrient loading and eutrophication in coastal marine ecosystems on the rates of benthic denitrification (N/sub 2/) and N/sub 2/O production. After 3 months or daily nutrient addition, average denitrification rates ranged from about 300 ..mu..mol N m/sup -2/ h/sup -1/ in the sediments of the control microcosm to 880 in the most enriched microcosm, which received 65 times the nutrient input of the control. Increases in the production of N/sub 2/O were more dramatic and increased by a factor of about 100, from 0.56 ..mu..mol N m/sup -2/ h/sup -1/ in the control to 51 in the most enriched microcosm. Although there was a clear increase in the denitrification rate in the more eutrophic systems, the amount of fixed nitrogen removed was a constant or progressively smaller fraction of the nitrogen input. Even in the most enriched microcosm, at least 16% of the N input was removed by denitrification.

Journal ArticleDOI
TL;DR: It is concluded that heterotrophic dinoflagellates may have an equally important impact as microheterotrophic grazers of phytoplankton and bacteria in oceanic waters.
Abstract: A dual-isotope method was developed to measure grazing rates and food preferences of individual species of heterotrophic dinoflagellates from natural populations, collected from the Slope, Gulf Stream, and Sargasso Sea and from a transect from Iceland to New England, in 1983 The isotope method measures the grazing rates of microzooplankton which cannot be separated in natural populations on the basis of size Tritiated-thymidine and 14C-bicarbonate were used to label natural heterotrophic and autotrophic food, respectively Nine oceanic dinoflagellate species in the genera Protoperidinium, Podolampas, and Diplopsalis fed on both heterotrophic and autotrophic food particles with clearance rates of 04 to 80 μl cell-1 h-1, based on 3H incorporation, and 00 to 283 μl cell-1 h-1, based on 14C incorporation Two dinoflagellate species, Protoperidinium ovatum and Podolampas palmipes, fed only on 3H-labelled food particles Several species of dinoflagellates fed on bacteria (<1 μm) which had been prelabelled with 3H-thymidine The clearance rates of heterotrophic dinoflagellates and ciliates were similar and within the range of tintinnid ciliate clearance rates reported in the literature As heterotrophic dinoflagellates and ciliates can have comparable abundances in oceanic waters, we conclude that heterotrophic dinoflagellates may have an equally important impact as microheterotrophic grazers of phytoplankton and bacteria in oceanic waters

Journal ArticleDOI
TL;DR: The Gulf Stream ’60 hydrographic survey has been used to examine the distribution of water properties across the Gulf Stream as a function of potential density, including acceleration potential, potential temperature, desso1ved oxygen and potential vorticity.
Abstract: The Gulf Stream ’60 hydrographic survey has been used to examine the distribution of water properties across the Gulf Stream as a function of potential density. This survey covered a half million square miles of Slope, Gulf Stream and Sargasso Sea Waters in the western North Atlantic. Quantities plotted as a function of density are acceleration potential, potential temperature, desso1ved oxygen and potential vorticity. The transition from Sargasso Sea Water to Slope Water in the upper thermocline (σ0<27.1) is sharp and coincides closely with the dynamical boundary of the Gulf Stream, defined by the gradient of acceleration potential. This indicates that water mass exchanges across the Gulf Stream-Slope Water front are limited at these levels. Below the 27.1 Σ0 surface, the gradient of acceleration potential still reveals the position of the Stream, but there is no coincident water man boundary. This and the uniformity of potential vorticity across the Stream suggest that the deep property fields ...

Journal ArticleDOI
03 May 1985-Science
TL;DR: Histopathologic examinations of hepatic tissues of winter flounder from Boston Harbor revealed a high prevalence of neoplasms, which resembled those experimentally induced in rodents by exposure to carcinogens.
Abstract: The winter flounder, Pseudopleuronectes americanus, is an esteemed food fish and has sustained an important commercial and recreational fishery for many years in the northeastern United States. Histopathologic examinations of hepatic tissues of winter flounder from Boston Harbor revealed a high prevalence of neoplasms. The lesions, designated as cholangiocarcinomas and hepatocarcinomas, were found in 16 of 200 fish examined and resembled those experimentally induced in rodents by exposure to carcinogens.

Journal ArticleDOI
TL;DR: In this article, an assessment of developing eutrophic conditions in small temperate lagoons along the coast of Rhode Island suggests that in such shallow, macrophyte based systems the response to nutrient enrichment differs from that described for plankton based systems.
Abstract: An assessment of developing eutrophic conditions in small temperate lagoons along the coast of Rhode Island suggests that in such shallow, macrophyte based systems the response to nutrient enrichment differs from that described for plankton based systems. The nitrogen loadings per unit area of the salt ponds are 240–770 mmol N per m2 per year. Instead of the high nutrient concentrations, increased phytoplankton biomass and turbidity, leading to eventual loss of benthic macrophytes described for such systems as the Chesapeake, Patuxent and Appalachicola Bay, nutrient enrichment of the Rhode Island lagoons has led to increased growth of marine macroalgae. The increased macroalgal growth appears to alter the benthic habitat and a shift from a grazing to detrital food chain appears to be impacting important shellfisheries. As more extensive areas of organic sediments develop, geochemical cycling changes, resulting in higher rates of nitrogen remineralization and accelerated eutrophication. The major sources of nitrogen inputs to the salt ponds have been identified and a series of management initiatives have been designed to limit inputs from present and potential development within the watersheds of the lagoons.

Journal ArticleDOI
TL;DR: In this article, a link between orbital periodicities, variations of intense precipitation associated with specific paleogeographic situations and Cretaceous bedding patterns has been established for the sensitivity of the atmosphere-hydrosphere-lithosphere system to external forcing.

Journal ArticleDOI
TL;DR: In this paper, boundary spanning theory and role theory are used to examine the product manager's role in consumer industries, and a research model depicting associations between environmental uncertainty, boundary spanning, and role role is presented.
Abstract: Boundary spanning theory and role theory are used to examine the product manager's role in consumer industries. A research model depicting associations between environmental uncertainty, boundary s...

Book ChapterDOI
TL;DR: In this paper, the evolution of oceanographic conditions at single localities during an extended period of time were inferred from <5O values of planktonic foraminifera.
Abstract: Oxygen isotopic analyses of planktonic foraminifera have provided a picture of many aspects of the evolution of the temperature structure of surface and near-surface oceans during the Miocene. In time slice studies oceanographic conditions have been interpreted from synoptic maps of isotopic data at between 22 and 27 locations in the Atlantic, Pacific and Indian Oceans. Three time slice intervals were examined: 22 Ma (foraminifera! zone N4B) and 16 Ma (N8) in early Miocene time; and 8 Ma (N17) in late Miocene time. In time series studies, the evolution of oceanographic conditions at single localities during an extended period of time were inferred from <5O values of planktonic foraminifera. Surface waters warmed throughout the early Miocene at almost all localities examined. At 22 Ma, the Pacific Ocean was characterized by relatively uniform temperatures in the equatorial region but a marked east-west asymmetry in the tropical South Pacific, with higher temperatures in the west. Between 22 Ma and 16 Ma, tropical Pacific surface waters warmed, but wanned more in the east than the west. At 16 Ma, the asymmetric distribution of temperatures in the South Pacific Ocean remained, and the latitudinal temperature gradient, inferred from the isotopic data, was gentler than that of either the late Miocene or Modern ocean. Between the late early Miocene and late Miocene, surface waters at most lowlatitude Pacific sites warmed while those at high latitudes cooled or remained unchanged. However, surface waters at high northern latitudes in the Atlantic Ocean as well as in the eastern equatorial Atlantic cooled, while water temperatures remained •Present address: Department of Geological and Geophysical Science, Princeton University, Princeton, New Jersey 08540.

Proceedings ArticleDOI
26 Apr 1985
TL;DR: The noise statistics are incorporated to reveal that certain processing of the Wigner distribution (WD) signal representation can lead to an optimal, and often easy to compute, detection scheme.
Abstract: A variety of methods have been proposed for the detection of a signal, with unknown signal parameters, in a noisy environment. In this paper, the noise statistics are incorporated to reveal that certain processing of the Wigner distribution (WD) signal representation can lead to an optimal, and often easy to compute, detection scheme. For the special case of linear FM signals in complex white Gaussian noise, it is shown that the optimal detector is equivalent to integrating the WD along the line of instantaneous frequency. If the position and sweep rate of the linear chirp are unknown, then a Generalized Likelihood Ratio Test (GLRT) leads one to integrate the WD along all possible lines in the time-frequency plane and choose the largest integrated value for comparison to a threshold. Simulation examples of the WD detection scheme are given to demonstrate the utility of the proposed method. Finally, some comments concerning the detection of the general phase modulated signal are offered.

Journal ArticleDOI
07 Mar 1985-Nature
TL;DR: The authors compared the compositions of soil aerosols and sediments collected from the western North Pacific and found that their mineralogies are identical, except for one mineral, which supports the hypothesis that the sediments are heavily impacted by aeolian sources.
Abstract: Recent atmospheric chemistry studies have shown that substantial quantities of soil material are being transported out of Asia and across large regions of the North Pacific1,2. In the central North Pacific, the estimated1 (6–12×1012 g yr−1) and measured2 (20×1012 g yr−1) deposition rate of mineral aerosols could account for a substantial fraction of the non-biogenic portion of deep-sea sediments in this region, where sedimentologists have previously estimated that 75–95%3,4 of the surface sediment is derived from atmospheric dust fallout. The quantitative importance of wind-transported (aeolian) material to sedimentation in the North Pacific would be more firmly established if it could be shown that the composition of the present-day soil aerosol is similar to that of mineral particles in the underlying sediments, which have been deposited over a period of thousands of years. Here we compare the compositions of soil aerosols and sediments collected from the western North Pacific and find that their mineralogies are identical, except for one mineral. This supports the hypothesis that the sediments are heavily impacted by aeolian sources.

Journal ArticleDOI
Abstract: During four rain events, stormwater runoff samples from Interstate Highway 95 in Rhode Island were collected and analyzed for petroleum hydrocarbons, 14 polycyclic aromatic hydrocarbons (PAHs) and a variety of trace metals. The concentrations were variable throughout the storm events and some of the components responded similarly and others differently depending on the source and form of the component in the runoff. Loading factors as a function of area and traffic volume were developed from the concentration and flow data. Application of the highway runoff loading factors to the Pawtuxet River adjacent to this interstate highway suggests that highway runoff could be the source of over 50% of the annual pollutant loads of solids, PAHs, Pb, and Zn entering this river. It is recommended that highways as a source of non-point pollution to receiving waterbodies should be included as a part of any river and estuarine water quality management planning exercise.

Journal ArticleDOI
TL;DR: The muds of a shallow site in Narragansett Bay, Rhode Island contained higher abundances of meiofauna than have been found in any other sediment during a 3 year period, hypothesize that phytoplankton detritus accumulated in the sediment during the winter and early spring, and that the benthos responded to this store of food when temperatures rose rapidly in the late spring.
Abstract: The muds of a shallow (7 m) site in Narragansett Bay, Rhode Island contained higher abundances of meiofauna (averaging 17×106 individuals per m2 and ash free dry weight of 2.9 g/m2 during a 3 year period) than have been found in any other sediment. The majority of sublittoral muds, worldwide, have been reported to contain about 106 individuals per m2. This difference is attributed primarily to differences in sampling techniques and laboratory processing.Extremely high meiofaunal abundances may have also occurred because Narragansett Bay sediments were a foodrich environment. While the quantity of organic deposition in the bay is not unusually high for coastal waters, this input, primarily composed of diatom detritus, may contain an unusually high proportion of labile organics. Furthermore, meiofauna could have thrived because of spatial segregation of meiofauna and macrofauna. While meiofauna were concentrated at the sediment-water interface, most macrofauna were subsurface deposit feeders. Macrofaunal competition with, and ingestion of meiofauna may thus have been minimized.The seasonal cycles of meiofauna and macrofauna were similar. Highest abundances and biomass were observed in May and June and lowest values in the late summer and fall. Springtime increases of meiofaunal abundance were observed in all depth horizons, to 10 cm. We hypothesize that phytoplankton detritus accumulated in the sediment during the winter and early spring, and that the benthos responded to this store of food when temperatures rose rapidly in the late spring. By late summer, the stored detritus was exhausted and the benthos declined.

Journal ArticleDOI
TL;DR: In this paper, the influence of the mantle plume on the geochemistry of basalts being erupted at the spreading center of Tristan da Cunha in the South Atlantic has been investigated, and two basaltic types were determined to be erupting in this region based on their major, trace and REE compositions.