233 research outputs found
Hadronic Resonances from Lattice QCD
The determination of the pattern of hadronic resonances as predicted by
Quantum Chromodynamics requires the use of non-perturbative techniques. Lattice
QCD has emerged as the dominant tool for such calculations, and has produced
many QCD predictions which can be directly compared to experiment. The concepts
underlying lattice QCD are outlined, methods for calculating excited states are
discussed, and results from an exploratory Nucleon and Delta baryon spectrum
study are presented.Comment: 8 pages, VII Latin American Symposium on Nuclear Physics and
Application
Multiple socioeconomic deprivation and impact on survival in patients with primary glomerulonephritis
Background: The impact of multiple socio-economic deprivation on patient outcomes in primary renal diseases is unknown. We aimed to assess whether risk of death or requiring renal replacement therapy (RRT) in patients with primary glomerulonephritis (GN) was higher in patients living in an area of multiple socio-economic deprivation.Methods: Patients undergoing native renal biopsy between 2000 and 2014 were identified. Baseline demographics, postcode at time of biopsy, follow-up blood pressure, proteinuria and time to death or RRT were recorded. The Scottish Index of Multiple Deprivation (SIMD) is a multidimensional model used to measure deprivation based on postcode. Using SIMD, patients were separated into tertiles of deprivation.Results: A total of 797 patients were included, 64.2% were male with mean age of 54.1 (standard deviation 17.0) years. Median follow-up was 6.3 (interquartile range 3.7–9.4) years during which 174 patients required RRT and 185 patients died. Patients in the most deprived tertile of deprivation were significantly more likely to die than those in the least deprived tertile [hazard ratio (HR) 2.2, P < 0.001], independent of age, baseline serum creatinine and blood pressure. They were not more likely to require RRT (P = 0.22). The increased mortality risk in the most deprived tertile was not uniform across primary renal diseases, with the association being most marked in focal segmental glomerulosclerosis (HR 7.4) and IgA nephropathy (HR 2.7) and absent in membranous nephropathy.Conclusion: We have demonstrated a significant independent 2-fold increased risk of death in patients with primary GN who live in an area of multiple socio-economic deprivation at the time of diagnosis as compared with those living in less deprived areas
Results and Frontiers in Lattice Baryon Spectroscopy
The Lattice Hadron Physics Collaboration (LHPC) baryon spectroscopy effort is
reviewed. To date the LHPC has performed exploratory Lattice QCD calculations
of the low-lying spectrum of Nucleon and Delta baryons. These calculations
demonstrate the effectiveness of our method by obtaining the masses of an
unprecedented number of excited states with definite quantum numbers. Future
work of the project is outlined.Comment: To appear in the proceedings for the VII Latin American Symposium of
Nuclear Physics and Application
A complex biostimulant based on plant flavonoids enhances potato growth and commercial yields
IntroductionPotatoes are one of the world’s most important agricultural crops, with potential for making a major contribution to global food security. This study shows how a biostimulant derived from a plant extract can improve potato crop yield and global food supply. Successful potato production currently requires significant levels of inputs including fertiliser, pesticides and irrigation, however non-microbial plant biostimulants or mixtures of biostimulants with synergistic actions, have the capacity to reduce inputs and improve the sustainability of intensive agriculture.MethodsA complex biostimulant containing a number of flavonoids including protocatechuic acid, quercetin, chlorogenic acid, coumaroyl quinic acid and gentistic acid was tested against three potato varieties for its efficacy in improving plant growth characteristics and tuber production in controlled and field environments.ResultsIn containers, complex biostimulant treatment enhanced photosynthetic ability, with elevated levels of chlorophyll, higher specific leaf areas and significantly larger leaf assimilation areas. Treatment also significantly increased tuber yield by an average of 33% in tuber weight across three potato varieties and shifted tuber production toward larger sized tubers. The biostimulant derived from flavonoids was also assessed in 6 commercial potato crops and consistently increased total yield (average 5.2%) and marketable yield, representing an increase in margins of UK£700 per hectare across the 6 crops. Similar increases in yield were seen when comparing chitted and unchitted seed potatoes and both types of seed responded positively to biostimulant application. Biostimulant treatment had no significant effects on tuber specific gravity, dry matter percentage and starch content, except at one location where these quality characteristics were higher in the control plants.ConclusionThe flavonoid based complex biostimulant produced significant effects on potato yield and quality in both container experiments and in field trials indicating its potential for contributing to sustainable potato production
Aromatase Is a Direct Target of FOXL2: C134W in Granulosa Cell Tumors via a Single Highly Conserved Binding Site in the Ovarian Specific Promoter
BACKGROUND: Granulosa cell tumors (GCT) of the ovary often express aromatase and synthesize estrogen, which in turn may influence their progression. Recently a specific point mutation (C134W) in the FOXL2 protein was identified in >94% of adult-type GCT and it is likely to contribute to their development. A number of genes are known to be regulated by FOXL2, including aromatase/CYP19A1, but it is unclear which are direct targets and whether the C134W mutation alters their regulation. Recently, it has been reported that FOXL2 forms a complex with steroidogenic factor 1 (SF-1) which is a known regulator of aromatase in granulosa cells. METHODOLOGY/PRINCIPAL FINDINGS: In this work, the human GCT-derived cell lines KGN and COV434 were heterozygous and wildtype for the FOXL2:C134W mutation, respectively. KGN had abundant FOXL2 mRNA expression but it was not expressed in COV434. Expression of exogenous FOXL2:C134W in COV434 cells induced higher expression of a luciferase reporter for the ovarian specific aromatase promoter, promoter II (PII) (-516bp) than expression of wildtype FOXL2, but did not alter induction of a similar reporter for the steroidogenic acute regulatory protein (StAR) promoter (-1300bp). Co-immunoprecipitation confirmed that FOXL2 bound SF-1 and that it also bound its homologue, liver receptor homologue 1 (LRH-1), however, the C134W mutation did not alter these interactions or induce a selective binding of the proteins. A highly conserved putative binding site for FOXL2 was identified in PII. FOXL2 was demonstrated to bind the site by electrophoretic mobility shift assays (EMSA) and site-directed mutagenesis of this element blocked its differential induction by wildtype FOXL2 and FOXL2:C134W. CONCLUSIONS/SIGNIFICANCE: These findings suggest that aromatase is a direct target of FOXL2:C134W in adult-type GCT via a single distinctive and highly conserved binding site in PII and therefore provide insight into the pathogenic mechanism of this mutation
GLOBAL SIMULATIONS OF PROTOPLANETARY DISKS WITH OHMIC RESISTIVITY AND AMBIPOLAR DIFFUSION
Protoplanetary disks are believed to accrete onto their central T Tauri star
because of magnetic stresses. Recently published shearing box simulations
indicate that Ohmic resistivity, ambipolar diffusion and the Hall effect all
play important roles in disk evolution. In the presence of a vertical magnetic
field, the disk remains laminar between 1-5au, and a magnetocentrifugal disk
wind forms that provides an important mechanism for removing angular momentum.
Questions remain, however, about the establishment of a true physical wind
solution in the shearing box simulations because of the symmetries inherent in
the local approximation. We present global MHD simulations of protoplanetary
disks that include Ohmic resistivity and ambipolar diffusion, where the
time-dependent gas-phase electron and ion fractions are computed under FUV and
X-ray ionization with a simplified recombination chemistry. Our results show
that the disk remains laminar, and that a physical wind solution arises
naturally in global disk models. The wind is sufficiently efficient to explain
the observed accretion rates. Furthermore, the ionization fraction at
intermediate disk heights is large enough for magneto-rotational channel modes
to grow and subsequently develop into belts of horizontal field. Depending on
the ionization fraction, these can remain quasi-global, or break-up into
discrete islands of coherent field polarity. The disk models we present here
show a dramatic departure from our earlier models including Ohmic resistivity
only. It will be important to examine how the Hall effect modifies the
evolution, and to explore the influence this has on the observational
appearance of such systems, and on planet formation and migration.Comment: 18 pages, 12 figures, accepted for publication in Ap
Outcomes in randomised controlled trials in prevention and management of carious lesions:a systematic review
Abstract Background Inconsistent outcome reporting is one significant hurdle to combining results from trials into systematic reviews. Core outcome sets (COS) can reduce this barrier. The aim of this review was to map outcomes reported in caries prevention and management randomised controlled trials (RCT) as a first step to COS development. We also investigated RCT characteristics and reporting of primary outcomes and sample size calculations. Methods PubMed, Embase, Web of Knowledge and Cochrane CENTRAL were systematically searched (1 January 1968 to 25 August 2015). Inclusion criteria: RCTs comparing any technique for prevention or management of caries with another or placebo and RCTs comparing interventions to support patients undergoing treatment of caries (without setting, dentition or age restrictions). Categories were developed through piloting and group consensus and outcomes grouped accordingly. Results Of 4773 search results, 764 were potentially relevant, full text was available for 731 papers and 605 publications met the inclusion criteria and were included. For all outcomes across the time periods 1968–1980 and 2001–2010, reporting of outcome ‘caries experience’ reduced from 39% to 18%; ‘clinical performance of the restoration’ reporting increased from 33% to 42% although there was a reduction to 22% in 2011–2015. Emerging outcome domains include ‘lesion activity’ and ‘pulp health-related outcomes’, accounting for 1% and 0%, respectively, during 1968–1980 and 10% and 4% for 2011–2015. Reporting ‘resource efficiency’ and ‘quality of life measures’ have remained at a low level. No publications reported tooth survival independent of an index such as DMFT or equivalent. Primary outcomes were only identified as such in 414 (68%) of the reports. Conclusions Over the past 50 years, outcome reporting for trials on prevention and management of carious lesions have tended to focus on outcomes measuring caries experience and restoration material clinical performance with lesion activity and cost-effectiveness increasingly being reported. Patient-reported and patient-focused outcomes are becoming more common (although as secondary outcomes) but remain low in use. The challenge with developing a COS will be balancing commonly previously reported outcomes against those more relevant for the future. Trial registration PROSPERO, CRD42015025310 . Registered on 14 August 2015, Trials (Schwendicke et al., Trials 16:397, 2015) and COMET initiative online (COMET, 2017)
A study exploring learners' informal learning space behaviors, attitudes, and preferences
What makes a successful informal learning space is a topic in need of further research. The body of discourse on informal space design is drawn from learning theory, placemaking and architecture, with a need for understanding of the synergy between the three. Findings from a longitudinal, quantitative and qualitative study at Sheffield Hallam University, explore learners' behaviours, attitudes and preferences towards informal learning spaces in higher education, within and outside of the context of the academic library. The learning spaces study contributes to the discourse on informal learning spaces design by producing a typology of nine learning space preference attributes which address aspects of learning theory, placemaking and architecture. The typology can be used to evaluate existing spaces and inform redevelopment of informal learning spaces in higher education institutions. Implementing the typology will be subject to localised conditions, but at Sheffield Hallam University the key conclusions have included developing a portfolio of discrete, interrelated learning environments, offering spaces with a clear identity and encouraging students to translate their learning preferences into space selection
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