1,585 research outputs found
Influence of sediment redox conditions on uranium mobilisation during saline intrusion
This research was funded by the Natural Environment Research Council (grant NE/C506799/1: Studentship NE/H527116/1).In the UK, several coastal nuclear sites have been identified as vulnerable to future sea level rise. Legacy contamination at these sites has accumulated in sub-surface sediments at risk of future seawater inundation and intrusion. Porewater salinization, changes in pH and the influx of oxygen into sediments may impact the stability of sediment associated uranium (U). In this study, saturated column experiments were performed to compare the mobilisation of U from oxic and reduced sediments into seawater under environmentally relevant flow conditions. Uranium release profiles were independent of the initial geochemistry of the sediments. Uranium release from the sediments was kinetically controlled, showing relatively slow desorption kinetics, with release initially limited by the impact of the sediments on the pH of the seawater. Significant U release only occurred when the pH was sufficiently high for the formation of U-carbonate complexes (pHoxic 6.3; pHreduced 7.5). Uranium was more strongly bound to the reduced sediments and after 400 pore volumes of seawater flow, release was more extensive from the initially oxic (46%) compared with initially nitrate reducing (27%) and iron reducing (18%) sediments. The products of iron cycling appeared to act as a buffer limiting U mobilisation, but the on-going dissolution of the Fe-phases suggests that they did not form a permanent protective layer. © 2013 Elsevier B.V
PUK26 THE INFLUENCE OF FUTURE UNRELATED COSTS ON COSTEFFECTIVENESS ESTIMATES:TREATMENT OF HYPERPHOSPHATEMIA WITH LANTHANUM CARBONATE IN PRE-DIALYIS PATIENTS WITH CHRONIC KIDNEY DISEASE
OBJECTIVES: A long-standing controversy in health-economics is whether future unrelated costs should be included in cost-effectiveness analyses. This discussion is relevant in Chronic Kidney Disease (CKD) for treatments that delay progression towards dialysis and prolong survival. In this study, we determined the influence of future unrelated costs on the cost-effectiveness of the non-calcium based phosphate binder lanthanum carbonate (LC) when used as second-line treatment for hyperphosphatemia in predialysis patients. METHODS: Time-dependent Markov models were constructed; cohorts of 1000 patients were followed lifelong. Patients not reaching target serum phosphate (SP) levels on first-line calcium based phosphate binders (CB) were treated with LC. This strategy was compared with continued CB treatment. Patient-level data were pooled from two clinical trials, one in predialysis and one in dialysis. Reductions in SP levels delayed progression towards dialysis and prolonged survival. RESULTS: For the predialysis cohort, 544 did not achieve target SP levels
Declining Sex Ratio in a First Nation Community
Members of the Aamjiwnaang First Nation community near Sarnia, Ontario, Canada, voiced concerns that there appeared to be fewer male children in their community in recent years. In response to these concerns, we assessed the sex ratio (proportion of male births) of the Aamjiwnaang First Nation over the period 1984–2003 as part of a community-based participatory research project. The trend in the proportion of male live births of the Aamjiwnaang First Nation has been declining continuously from the early 1990s to 2003, from an apparently stable sex ratio prior to this time. The proportion of male births (m) showed a statistically significant decline over the most recent 10-year period (1994–2003) (m = 0.412, p = 0.008) with the most pronounced decrease observed during the most recent 5 years (1999–2003) (m = 0.348, p = 0.006). Numerous factors have been associated with a decrease in the proportion of male births in a population, including a number of environmental and occupational chemical exposures. This community is located within the Great Lakes St. Clair River Area of Concern and is situated immediately adjacent to several large petrochemical, polymer, and chemical industrial plants. Although there are several potential factors that could be contributing to the observed decrease in sex ratio of the Aamjiwnaang First Nation, the close proximity of this community to a large aggregation of industries and potential exposures to compounds that may influence sex ratios warrants further assessment into the types of chemical exposures for this population. A community health survey is currently under way to gather more information about the health of the Aamjiwnaang community and to provide additional information about the factors that could be contributing to the observed decrease in the proportion of male births in recent years
Identification of furfural resistant strains of Saccharomyces cerevisiae and Saccharomyces paradoxus from a collection of environmental and industrial isolates
Background Fermentation of bioethanol using lignocellulosic biomass as a raw material provides a sustainable alternative to current biofuel production methods by utilising waste food streams as raw material. Before lignocellulose can be fermented it requires physical, chemical and enzymatic treatment in order to release monosaccharides, a process that causes the chemical transformation of glucose and xylose into the cyclic aldehydes furfural and hydroxyfurfural. These furan compounds are potent inhibitors of Saccharomyces fermentation, and consequently furfural tolerant strains of Saccharomyces are required for lignocellulosic fermentation. Results This study investigated yeast tolerance to furfural and hydroxyfurfural using a collection of 71 environmental and industrial isolates of the baker’s yeast Saccharomyces cerevisiae and its closest relative Saccharomyces paradoxus. The Saccharomyces strains were initially screened for growth on media containing 100 mM glucose and 1.5 mg ml-1 furfural. Five strains were identified that showed a significant tolerance to growth in the presence of furfural and these were then screened for growth and ethanol production in the presence of increasing amounts (0.1-4 mg ml-1) of furfural. Conclusions Of the five furfural tolerant strains S. cerevisiae NCYC 3451 displayed the greatest furfural resistance, and was able to grow in the presence of up to 3.0 mg ml-1 furfural. Furthermore, ethanol production in this strain did not appear to be inhibited by furfural, with the highest ethanol yield observed at 3.0 mg ml-1 furfural. Although furfural resistance was not found to be a trait specific to any one particular lineage or population, three of the strains were isolated from environments where they might be continually exposed to low levels of furfural through the on-going natural degradation of lignocelluloses, and would therefore develop elevated levels of resistance to these furan compounds. Thus these strains represent good candidates for future studies of genetic variation relevant to understanding and manipulating furfural resistance and in the development of tolerant ethanologenic yeast strains for use in bioethanol production from lignocellulose processing
Survey of the needs of patients with spinal cord injury: impact and priority for improvement in hand function in tetraplegics\ud
Objective: To investigate the impact of upper extremity deficit in subjects with tetraplegia.\ud
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Setting: The United Kingdom and The Netherlands.\ud
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Study design: Survey among the members of the Dutch and UK Spinal Cord Injury (SCI) Associations.\ud
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Main outcome parameter: Indication of expected improvement in quality of life (QOL) on a 5-point scale in relation to improvement in hand function and seven other SCI-related impairments.\ud
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Results: In all, 565 subjects with tetraplegia returned the questionnaire (overall response of 42%). Results in the Dutch and the UK group were comparable. A total of 77% of the tetraplegics expected an important or very important improvement in QOL if their hand function improved. This is comparable to their expectations with regard to improvement in bladder and bowel function. All other items were scored lower.\ud
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Conclusion: This is the first study in which the impact of upper extremity impairment has been assessed in a large sample of tetraplegic subjects and compared to other SCI-related impairments that have a major impact on the life of subjects with SCI. The present study indicates a high impact as well as a high priority for improvement in hand function in tetraplegics.\ud
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Discovering patterns in drug-protein interactions based on their fingerprints
<p>Abstract</p> <p>Background</p> <p>The discovering of interesting patterns in drug-protein interaction data at molecular level can reveal hidden relationship among drugs and proteins and can therefore be of paramount importance for such application as drug design. To discover such patterns, we propose here a computational approach to analyze the molecular data of drugs and proteins that are known to have interactions with each other. Specifically, we propose to use a data mining technique called <it>Drug-Protein Interaction Analysis </it>(<it>D-PIA</it>) to determine if there are any commonalities in the fingerprints of the substructures of interacting drug and protein molecules and if so, whether or not any patterns can be generalized from them.</p> <p>Method</p> <p>Given a database of drug-protein interactions, <it>D-PIA </it>performs its tasks in several steps. First, for each drug in the database, the fingerprints of its molecular substructures are first obtained. Second, for each protein in the database, the fingerprints of its protein domains are obtained. Third, based on known interactions between drugs and proteins, an interdependency measure between the fingerprint of each drug substructure and protein domain is then computed. Fourth, based on the interdependency measure, drug substructures and protein domains that are significantly interdependent are identified. Fifth, the existence of interaction relationship between a previously unknown drug-protein pairs is then predicted based on their constituent substructures that are significantly interdependent.</p> <p>Results</p> <p>To evaluate the effectiveness of <it>D-PIA</it>, we have tested it with real drug-protein interaction data. <it>D-PIA </it>has been tested with real drug-protein interaction data including enzymes, ion channels, and protein-coupled receptors. Experimental results show that there are indeed patterns that one can discover in the interdependency relationship between drug substructures and protein domains of interacting drugs and proteins. Based on these relationships, a testing set of drug-protein data are used to see if <it>D-PIA </it>can correctly predict the existence of interaction between drug-protein pairs. The results show that the prediction accuracy can be very high. An AUC score of a ROC plot could reach as high as 75% which shows the effectiveness of this classifier.</p> <p>Conclusions</p> <p><it>D-PIA </it>has the advantage that it is able to perform its tasks effectively based on the fingerprints of drug and protein molecules without requiring any 3D information about their structures and <it>D-PIA </it>is therefore very fast to compute. <it>D-PIA </it>has been tested with real drug-protein interaction data and experimental results show that it can be very useful for predicting previously unknown drug-protein as well as protein-ligand interactions. It can also be used to tackle problems such as ligand specificity which is related directly and indirectly to drug design and discovery.</p
Pulsar Results with the Fermi Large Area Telescope
The launch of the Fermi Gamma-ray Space Telescope has heralded a new era in
the study of gamma-ray pulsars. The population of confirmed gamma-ray pulsars
has gone from 6-7 to more than 60, and the superb sensitivity of the Large Area
Telescope (LAT) on Fermi has allowed the detailed study of their spectra and
light curves. Twenty-four of these pulsars were discovered in blind searches of
the gamma-ray data, and twenty-one of these are, at present, radio quiet,
despite deep radio follow-up observations. In addition, millisecond pulsars
have been confirmed as a class of gamma-ray emitters, both individually and
collectively in globular clusters. Recently, radio searches in the direction of
LAT sources with no likely counterparts have been highly productive, leading to
the discovery of a large number of new millisecond pulsars. Taken together,
these discoveries promise a great improvement in the understanding of the
gamma-ray emission properties and Galactic population of pulsars. We summarize
some of the results stemming from these newly-detected pulsars and their timing
and multi-wavelength follow-up observations.Comment: 21 pages, 9 figures, to appear in Proceedings of ICREA Workshop on
The High-Energy Emission from Pulsars and their Systems, Sant Cugat, Spain,
2010 April 12-16 (Springer
Randomised controlled trial and health economic evaluation of the impact of diagnostic testing for influenza, respiratory syncytial virus and Streptococcus pneumoniae infection on the management of acute admissions in the elderly and high-risk 18- to 64-year-olds
Please cite the published version which is available via the DOI link in this record.Western industrialised nations face a large increase in the number of older people. People over the age of 60 years account for almost half of the 16.8 million hospital admissions in England from 2009 to 2010. During 2009-10, respiratory infections accounted for approximately 1 in 30 hospital admissions and 1 in 20 of the 51.5 million bed-days.HTA ProgrammeNational Institute for Health Research (NIHR
'Choosing shoes': a preliminary study into the challenges facing clinicians in assessing footwear for rheumatoid patients
Background: Footwear has been accepted as a therapeutic intervention for the foot affected
by rheumatoid arthritis (RA). Evidence relating to the objective assessment of footwear in
patients with RA is limited. The aims of this study were to identify current footwear styles,
footwear characteristics, and factors that influence footwear choice experienced by patients
with RA.
Methods: Eighty patients with RA were recruited from rheumatology clinics during the
summer months. Clinical characteristics, global function, and foot impairment and disability
measures were recorded. Current footwear, footwear characteristics and the factors
associated with choice of footwear were identified. Suitability of footwear was recorded using
pre-determined criteria for assessing footwear type, based on a previous study of foot pain.
Results: The patients had longstanding RA with moderate-to severe disability and
impairment. The foot and ankle assessment demonstrated a low-arch profile with both
forefoot and rearfoot structural deformities. Over 50% of shoes worn by patients were opentype
footwear. More than 70% of patients’ footwear was defined as being poor. Poor
footwear characteristics such as heel rigidity and sole hardness were observed. Patients
reported comfort (17%) and fit (14%) as important factors in choosing their own footwear.
Only five percent (5%) of patients wore therapeutic footwear.
Conclusions: The majority of patients with RA wear footwear that has been previously
described as poor. Future work needs to aim to define and justify the specific features of
footwear that may be of benefit to foot health for people with RA
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