468 research outputs found
Water Scarcity and Water Markets: A Comparison of Institutions and Practices in the Murray-Darling Basin of Australia and the Western US
Water markets in Australiaâs Murray-Darling Basin (MDB) and the US west are compared in terms of their ability to allocate scarce water resources among competing uses. Both locations have been in the forefront of the development of water markets with defined water rights and conveyance structures to assist in the reallocation of water across competing demands. They also share the challenge of managing water with climate variability and climate change. As these two markets occur in developed, wealthy countries, their experiences in water markets with different water rights (appropriative, riparian and statutory rights) provide âbest-caseâ scenarios of what institutional arrangements work best, indicate which are less effective, and demonstrate what might be possible for greater use of water markets elsewhere in the world. The paper finds that the gains from trade in the MDB is worth hundreds of millions of dollars in per year, total turnover in water rights exceeds 4.3 billion (2008 $) spent or committed by urban buyers between 1987 and 2008. Despite the clear benefits of water markets in both locations, there are on-going restrictions to trade that limit the potential gains and also third-party effects from use that require resolution.
Using nutrient utilization patterns to determine the source of Escherichia coli found in surface water
Identifying the sources of fecal contaminants in surface water bodies such as rivers, lakes and beaches is of importance for environmental safety, public health safety, food safety and regulatory purposes. Nutrient utilization patterns (NUPs) were used as a bacterial source tracking technique to identify the possible sources of fecal coliform bacteria, Escherichia coli in Silver Lake, Delaware County, Iowa. A total of three hundred (300) E. coli isolates collected from different sources (water, birds, geese, cattle, hogs and soil contaminated by feces) were analyzed. A database was built from these isolates by using discriminant analysis to identify the nutrient utilization patterns that best classify all 300 isolates by source. The average rate of correct classification by source was 89.5% when applying the nutrient utilization patterns database. After this verification, the NUP for E. coli isolates from Silver Lake water were measured. Based on the NUPs of the Silver Lake isolates, 73.1% were found to originate from cattle and hogs. Smaller percentages were predicted to be coming from birds and geese. None of the isolates were predicted to be originating from the human source. The results indicate that livestock are the primary contributors to fecal pollution in this hypereutrophic Iowa lake.Keywords: Nutrient utilization patterns, Escherichia coli, bacterial source tracking, Silver Lake, Delaware, Iow
Limitations of the Standard Gravitational Perfect Fluid Paradigm
We show that the standard perfect fluid paradigm is not necessarily a valid
description of a curved space steady state gravitational source. Simply by
virtue of not being flat, curved space geometries have to possess intrinsic
length scales, and such length scales can affect the fluid structure. For modes
of wavelength of order or greater than such scales eikonalized geometrical
optics cannot apply and rays are not geodesic. Covariantizing thus entails not
only the replacing of flat space functions by covariant ones, but also the
introduction of intrinsic scales that were absent in flat space. In principle
it is thus unreliable to construct the curved space energy-momentum tensor as
the covariant generalization of a geodesic-based flat spacetime energy-momentum
tensor. By constructing the partition function as an incoherent average over a
complete set of modes of a scalar field propagating in a curved space
background, we show that for the specific case of a static, spherically
symmetric geometry, the steady state energy-momentum tensor that ensues will in
general be of the form
where the
anisotropic is a symmetric, traceless rank two tensor which
obeys . Such a type term is absent for an
incoherently averaged steady state fluid in a spacetime where there are no
intrinsic length scales, and in principle would thus be missed in a
covariantizing of a flat spacetime . While the significance of such
type terms would need to be evaluated on a case by case basis,
through the use of kinetic theory we reassuringly find that the effect of such
type terms is small for weak gravity stars where perfect fluid
sources are commonly used.Comment: Final version to appear in General Relativity and Gravitation (the
final publication is available at http://www.springerlink.com). 29 pages, 1
figur
Llama-Derived Single Domain Antibodies Specific for Abrus Agglutinin
Llama derived single domain antibodies (sdAb), the recombinantly expressed variable heavy domains from the unique heavy-chain only antibodies of camelids, were isolated from a library derived from llamas immunized with a commercial abrin toxoid preparation. Abrin is a potent toxin similar to ricin in structure, sequence and mechanism of action. The selected sdAb were evaluated for their ability to bind to commercial abrin as well as abrax (a recombinant abrin A-chain), purified abrin fractions, Abrus agglutinin (a protein related to abrin but with lower toxicity), ricin, and unrelated proteins. Isolated sdAb were also evaluated for their ability to refold after heat denaturation and ability to be used in sandwich assays as both capture and reporter elements. The best binders were specific for the Abrus agglutinin, showing minimal binding to purified abrin fractions or unrelated proteins. These binders had sub nM affinities and regained most of their secondary structure after heating to 95 °C. They functioned well in sandwich assays. Through gel analysis and the behavior of anti-abrin monoclonal antibodies, we determined that the commercial toxoid preparation used for the original immunizations contained a high percentage of Abrus agglutinin, explaining the selection of Abrus agglutinin binders. Used in conjunction with anti-abrin monoclonal and polyclonal antibodies, these reagents can fill a role to discriminate between the highly toxic abrin and the related, but much less toxic, Abrus agglutinin and distinguish between different crude preparations
From AAA to Junk: Credit rating agencies as news sources in the Irish print-media during the economic crisis, 2008â2013
From AAA to Junk: Credit rating agencies as news sources in the Irish print-media during the economic crisis, 2008â201
At Sea Test 2 deployment cruise : cruise 475 on board R/V Oceanus September 22 â 26, 2011 Woods Hole âWoods Hole, MA
The R/V Oceanus, on Cruise 475, carried out the deployment of three moorings for the
Coastal and Global Scale Nodes (CGSN) Implementing Organization of the NSF Ocean
Observatories Initiative. These three moorings are prototypes of the moorings to be used
by CGSN at the Pioneer, Endurance, and Global Arrays. Oceanus departed from Woods
Hole, Massachusetts on September 22, 2011 and steamed south to the location of the
mooring deployments on the shelf break. Over three days, September 23-25, Oceanus
surveyed the bottom at the planned mooring sites, deployed the moorings, and carried out
on site verification of the functioning of the moorings and moored hardware. Oceanus
returned to Woods Hole on September 26, 2011.Funding was provided by the National Science Foundation
through the Consortium for Ocean Leadershi
Biotransformation of Silver Released from Nanoparticle Coated Titanium Implants Revealed in Regenerating Bone
Antimicrobial silver nanoparticle coatings have attracted interest for reducing prosthetic joint infection. However, few studies report in vivo investigations of the biotransformation of silver nanoparticles within the regenerating tissue and its impact on bone formation. We present a longitudinal investigation of the osseointegration of silver nanoparticle-coated additive manufactured titanium implants in rat tibial defects. Correlative imaging at different time points using nanoscale secondary ion mass spectrometry, transmission electron microscopy (TEM), histomorphometry, and 3D X-ray microcomputed tomography provided quantitative insight from the nano- to macroscales. The quality and quantity of newly formed bone is comparable between the uncoated and silver coated implants. The newly formed bone demonstrates a trabecular morphology with bone being located at the implant surface, and at a distance, at two weeks. Nanoscale elemental mapping of the boneâimplant interface showed that silver was present primarily in the osseous tissue and colocalized with sulfur. TEM revealed silver sulfide nanoparticles in the newly regenerated bone, presenting strong evidence that the previously in vitro observed biotransformation of silver to silver sulfide occurs in vivo
Analysis of Dentistsâ Participation in Continuing Professional Development Courses from 2001-2006
Currently in Western Australia (WA) there is no requirement for dentists to participate in continuing professional development (CPD). The aim of this study was to determine the participation pattern of dentists in WA in CPD activities. Data was collated regarding registrants for courses conducted by the University Continuing Dental Education Committee. Information concerned number of courses attended by each dentist, location of work and year of graduation from university. Details of subject, length and type of courses conducted were also gathered. Most courses were half to one day in duration with many subjects covered. Between 10.1-24.4% of dentists registered in WA attended at least one course each year. Low numbers of recently graduated and older dentists attended courses. Similar percentages of metropolitan and rural dentists attended courses. Participation in CPD activities of dentists in WA was low. Half day or evening courses appear to be favoured by dentists
Projected changes in temperature and precipitation over the United States, Central America and the Caribbean in CMIP6 GCMs
The Coupled Model Intercomparison Project Phase 6 (CMIP6) dataset is used to examine projected changes in temperature and precipitation over the United States (U.S.), Central America and the Caribbean. The changes are computed using
an ensemble of 31 models for three future time slices (2021â2040, 2041â2060, and 2080â2099) relative to the reference
period (1995â2014) under three Shared Socioeconomic Pathways (SSPs; SSP1-2.6, SSP2-4.5, and SSP5-8.5). The CMIP6
ensemble reproduces the observed annual cycle and distribution of mean annual temperature and precipitation with biases
between â 0.93 and 1.27 °C and â 37.90 to 58.45%, respectively, for most of the region. However, modeled precipitation is
too large over the western and Midwestern U.S. during winter and spring and over the North American monsoon region in
summer, while too small over southern Central America. Temperature is projected to increase over the entire domain under
all three SSPs, by as much as 6 °C under SSP5-8.5, and with more pronounced increases in the northern latitudes over the
regions that receive snow in the present climate. Annual precipitation projections for the end of the twenty-frst century
have more uncertainty, as expected, and exhibit a meridional dipole-like pattern, with precipitation increasing by 10â30%
over much of the U.S. and decreasing by 10â40% over Central America and the Caribbean, especially over the monsoon
region. Seasonally, precipitation over the eastern and central subregions is projected to increase during winter and spring and
decrease during summer and autumn. Over the monsoon region and Central America, precipitation is projected to decrease
in all seasons except autumn. The analysis was repeated on a subset of 9 models with the best performance in the reference
period; however, no signifcant diference was found, suggesting that model bias is not strongly infuencing the projections.Universidad de Costa Rica/[805-B9-454]/UCR/Costa RicaNational Science Foundation/[AGS-1849654]/NSF/Estados UnidosNational Science Foundation/[AGS-1623912]/NSF/Estados UnidosDepartment of Energy/[2316âT849â08]/DOE/Estados UnidosNational Oceanic and Atmospheric Administration/[2316âT849â08]/NOAA/Estados UnidosUCR::VicerrectorĂa de InvestigaciĂłn::Unidades de InvestigaciĂłn::Ciencias BĂĄsicas::Centro de Investigaciones GeofĂsicas (CIGEFI)UCR::VicerrectorĂa de InvestigaciĂłn::Unidades de InvestigaciĂłn::Ciencias BĂĄsicas::Centro de InvestigaciĂłn en Ciencias del Mar y LimnologĂa (CIMAR
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