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.

Geotechnical aspects of the 22 february 2011 christchurch earthquake

Abstract: SUMMARY The 22 February 2011, Mw6.2-6.3 Christchurch earthquake is the most costly earthquake to affect New Zealand, causing 181 fatalities and severely damaging thousands of residential and commercial buildings, and most of the city lifelines and infrastructure. This manuscript presents an overview of observed geotechnical aspects of this earthquake as well as some of the completed and on-going research investigations. A unique aspect, which is particularly emphasized, is the severity and spatial extent of liquefaction occurring in native soils. Overall, both the spatial extent and severity of liquefaction in the city was greater than in the preceding 4 th September 2010 Darfield earthquake, including numerous areas that liquefied in both events. Liquefaction and lateral spreading, variable over both large and short spatial scales, affected commercial structures in the Central Business District (CBD) in a variety of ways including: total and differential settlements and tilting; punching settlements of structures with shallow foundations; differential movements of components of complex structures; and interaction of adjacent structures via common foundation soils. Liquefaction was most severe in residential areas located to the east of the CBD as a result of stronger ground shaking due to the proximity to the causative fault, a high water table approximately 1m from the surface, and soils with composition and states of high susceptibility and potential for liquefaction. Total and differential settlements, and lateral movements, due to liquefaction and lateral spreading is estimated to have severely compromised 15,000 residential structures, the majority of which otherwise sustained only minor to moderate damage directly due to inertial loading from ground shaking. Liquefaction also had a profound effect on lifelines and other infrastructure, particularly bridge structures, and underground services. Minor damage was also observed at flood stop banks to the north of the city, which were more severely impacted in the 4 th September 2010 Darfield earthquake. Due to the large high-frequency ground motion in the Port hills numerous rock falls and landslides also occurred, resulting in several fatalities and rendering some residential areas uninhabitable.

Eutrophication and the rate of denitrification and N20 production in coastal marine sediments

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.

Near-Surface Turbulence in the Presence of Breaking Waves

Abstract: Observations with a three-axis pulse-to-pulse coherent acoustic Doppler profiler and acoustic resonators reveal the turbulence and bubble field beneath breaking waves in the open ocean at wind speeds up to 14 m s−1. About 55%–80% of velocity wavenumber spectra, calculated with Hilbert spectral analysis based on empirical mode decomposition, are consistent with an inertial subrange. Time series of turbulent kinetic energy dissipation at approximately 1 m beneath the free surface and 1-Hz sampling rate are obtained. High turbulence levels with dissipation rates more than four orders larger than the background dissipation are linked to wave breaking. Initial dissipation levels beneath breaking waves yield the Hinze scale of the maximum bubble size aH ≅ 2 × 10−3 m. Turbulence induced by discrete breaking events was observed to decay as e ∝ tn, where n = −4.3 is close to the theoretical value for isotropic turbulence (−17/4). In the crest region above the mean waterline, dissipation increases as e(z) ...

Family of pH (low) insertion peptides for tumor targeting

Abstract: Cancer is a complex disease with a range of genetic and biochemical markers within and among tumors, but a general tumor characteristic is extracellular acidity, which is associated with tumor growth and development. Acidosis could be a universal marker for cancer imaging and the delivery of therapeutic molecules, but its promise as a cancer biomarker has not been fully realized in the clinic. We have discovered a unique approach for the targeting of acidic tissue using the pH-sensitive folding and transmembrane insertion of pH (low) insertion peptide (pHLIP). The essence of the molecular mechanism has been elucidated, but the principles of design need to be understood for optimal clinical applications. Here, we report on a library of 16 rationally designed pHLIP variants. We show how the tuning of the biophysical properties of peptide–lipid bilayer interactions alters tumor targeting, distribution in organs, and blood clearance. Lead compounds for PET/single photon emission computed tomography and fluorescence imaging/MRI were identified, and targeting specificity was shown by use of noninserting variants. Finally, we present our current understanding of the main principles of pHLIP design.

Mesozooplankton prey preference and grazing impact in the Western Arctic Ocean

Abstract: The role of mesozooplankton as consumers and transformers of primary and secondary production in the Beaufort and Chukchi Seas was examined during four cruises in spring and summer of both 2002 and 2004 as part of the western Arctic Shelf–Basin Interactions (SBI) program. Forty-seven grazing experiments using dominant mesozooplankton species and life stages were conducted at locations across the shelf, slope, and basin of the Chukchi and Beaufort Seas to measure feeding rates on both chlorophyll and microzooplankton and to determine mesozooplankton prey preferences. Mesozooplankton biomass was at all times dominated by life stages of four copepod taxa: Calanus glacialis , Calanus hyperboreus , Metridia longa , and Pseudocalanus spp. Significant interannual, seasonal, regional, between species and within species differences in grazing rates were observed. Overall, the dominant zooplankton exhibited typical feeding behavior in response to chlorophyll concentration that could be modeled using species and life-stage specific Ivlev functions. Microzooplankton were preferred prey at almost all times, with the strength of the preference positively related to the proportion of microzooplankton prey availability. Average mesozooplankton grazing impacts on both chlorophyll standing stock (0.6±0.5% d −1 in spring, 5.1±6.3% d −1 in summer) and primary production (12.8±11.8% d −1 in spring, 27.6±24.5% d −1 in summer) were quite low and varied between shelf, slope, and basin. Coincident microzooplankton grazing experiments [Sherr, E.B., Sherr, B.F., Hartz, A.J., 2009. Microzooplankton grazing impact in the Western Arctic Ocean. Deep-Sea Research II] were conducted at most stations. Together, microzooplankton–mesozooplankton grazing consumed only 44% of the total water-column primary production, leaving more than half directly available for local export to the benthos or for offshore transport into the adjacent basin.