20,879 research outputs found
Reordering of Baryon Chiral Perturbation Theory
Reordering of the chiral perturbation series, proposed recently by Becher and
Leutwyler in the framework of SU(2) baryonic ChPT, is applied to the SU(3)
case. This results in improved convergence of the chiral expansion of static
properties of the lowest lying baryon octet, which in most cases is quite
impressive. Finite renormalization of coupling constants and the role it plays
in the interpretation of effective field theories is discussed. Some future
tests of the viability of the scheme are proposed too.Comment: 9 pages, one reference adde
Prototype construction of a compiler for network analysis feasibility study
Feasibility of unified compilers for network analysi
Features of cancer in teenagers and young adults in primary care: a population-based nested case-control study
This is the final version of the article. Available from the publisher via the DOI in this record.BACKGROUND: Teenagers and young adults (TYA, 15-24 years) diagnosed with cancer report repeated visits to primary care before referral. We investigated associations of symptoms and consultation frequency in primary care with TYA cancers. METHODS: Population-based, case-control study was carried out using data from the Clinical Practice Research Datalink (CPRD). A total of 1064 TYA diagnosed with cancer were matched to 13,206 controls. Symptoms independently associated with specific cancers were identified. Likelihood ratios (LRs) and positive predictive values (PPVs) were calculated. RESULTS: In the 3 months before diagnosis, 397 (42.9%) cases consulted > or =4 times vs 593(11.5%) controls (odds ratio (OR): 12.1; 95% CI: 9.7, 15.1), yielding a PPV for any cancer of 0.018%. The LR of lymphoma with a head/neck mass was 434 (95% CI: 60, 3158), with a PPV of 0.5%. Corresponding figures in other cancers included - LR of leukaemia with lymphadenopathy (any site): 29 (95% CI: 8, 112), PPV 0.015%; LR of CNS tumour with seizure: 56 (95% CI: 19, 163), PPV 0.024%; and LR of sarcoma with lump/mass/swelling: 79 (95% CI: 24, 264), PPV 0.042%. CONCLUSION: Teenagers and young adults with cancer consulted more frequently than controls in the 3 months before diagnosis. Primary care features of cancer match secondary care reports, but were of very low risk; nonetheless, some features increased the likelihood of cancer substantially and should be taken seriously when assessing TYA.RMD is funded by the National Institute for Health Research
(NIHR). WH was, in part, funded by an NIHR postdoctoral
fellowship. This study is based on data from the Full Feature
Clinical Practice Research Datalink (CPRD) obtained under licence
from the UK Medicines and Healthcare Products Regulatory
Agency (MHRA). Access to the CPRD was funded through the
Medical Research Council (MRC) licence agreement with the UK
Medicines and Healthcare Products Regulatory Agency. The
conduct of this study was approved by the Independent Scientific
Advisory Committee (ISAC) of the MHRS (Protocol 10_056A) and
the University of Bristol (reference: 35515
An Exact Renormalization Group analysis of 3-d Well Developed turbulence
We take advantage of peculiar properties of three dimensional incompressible
turbulence to introduce a nonstandard Exact Renormalization Group method. A
Galilean invariance preserving regularizing procedure is utilized and a field
truncation is adopted to test the method. Results are encouraging: the energy
spectrum E(k) in the inertial range scales with exponent -1.666+/- 0.001 and
the Kolmogorov constant C_K, computed for several (realistic) shapes of the
stirring force correlator, agrees with experimental data.Comment: 12 pg, 2figures, LaTex, To be published on Physics Letters
Facile one-pot synthesis of amoxicillin-coated gold nanoparticles and their antimicrobial activity
Nanomaterials have been the object of intense study due to promising applications in a number of different disciplines. In particular, medicine and biology have seen the potential of these novel materials with their nanoscale properties for use in diverse areas such as imaging, sensing and drug vectorisation. Gold nanoparticles (GNPs) are considered a very useful platform to create a valid and efficient drug delivery/carrier system due to their facile and well-studied synthesis, easy surface functionalization and biocompatibility. In the present study, stable antibiotic conjugated GNPs were synthesised by a one-step reaction using a poorly water soluble antibiotic, amoxicillin. Amoxicillin, a member of the penicillin family, reduces the chloroauric acid to form nanoparticles and at the same time coats them to afford the functionalised nanomaterial. A range of techniques including UV-vis spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) were used to ascertain the gold/drug molar ratio and the optimum temperature for synthesis of uniform monodisperse particles in the ca. 30-40 nm size range. Amoxicillin-conjugated gold showed an enhancement of antibacterial activity against Escherichia coli compared to the antibiotic alone
Traditional tales and imaginary contexts in primary design and technology: a case study
Working with contexts is a key component to design and technology activity and education. The most recent iteration of the national curriculum programme of study for design and technology, in England, sets out that children between the ages of 5 and 7 “should work in a range of relevant contexts” (DfE, 2013: 193); suggested contexts including “home and school, gardens and playgrounds, the local community, industry and the wider environment”. Whilst these are real world and familiar contexts, fictional contexts also provide opportunities for developing “creative spaces” in which to speculate and discuss. This intrinsic case study explores the work of two primary teachers’ development of a design and technology activity, where traditional tales provide the context. Children explore design problems and opportunities through the eyes of the Billy Goats Gruff, as they seek assistance to cross the river. Data was gathered through semi-structured interviews and document analysis of children’s design work. The case study reveals how multidisciplinary and imaginative approaches to teaching and learning in the primary classroom simulate and nurture design thinking, dialogue and critique
Novel Schizophrenia Risk Gene TCF4 Influences Verbal Learning and Memory Functioning in Schizophrenia Patients
Background: Recently, a role of the transcription factor 4 (TCF4) gene in schizophrenia has been reported in a large genome-wide association study. It has been hypothesized that TCF4 affects normal brain development and TCF4 has been related to different forms of neurodevelopmental disorders. Schizophrenia patients exhibit strong impairments of verbal declarative memory (VDM) functions. Thus, we hypothesized that the disease-associated C allele of the rs9960767 polymorphism of the TCF4 gene led to impaired VDM functioning in schizophrenia patients. Method: The TCF4 variant was genotyped in 401 schizophrenia patients. VDM functioning was measured using the Rey Auditory Verbal Learning Test (RAVLT). Results: Carriers of the C allele were less impaired in recognition compared to those carrying the AA genotype (13.76 vs. 13.06; p = 0.049). Moreover, a trend toward higher scores in patients with the risk allele was found for delayed recall (10.24 vs. 9.41; p = 0.088). The TCF4 genotype did not influence intelligence or RAVLT immediate recall or total verbal learning. Conclusion: VDM function is influenced by the TCF4 gene in schizophrenia patients. However, the elevated risk for schizophrenia is not conferred by TCF4-mediated VDM impairment. Copyright (C) 2011 S. Karger AG, Base
Features of childhood cancer in primary care: a population-based nested case-control study.
PublishedJournal ArticleResearch Support, Non-U.S. Gov'tBACKGROUND: This study investigated the risk of cancer in children with alert symptoms identified in current UK guidance, or with increased consultation frequency in primary care. METHODS: A population-based, nested case-control study used data from the General Practice Research Database. In all, 1267 children age 0-14 years diagnosed with childhood cancer were matched to 15,318 controls. Likelihood ratios and positive predictive values (PPVs) were calculated to assess risk. RESULTS: Alert symptoms recorded in the 12 and 3 months before diagnosis were present in 33.7% and 27.0% of cases vs 5.4% and 1.4% of controls, respectively. The PPV of having cancer for any alert symptom in the 3 months before diagnosis was 0.55 per 1000 children. Cases consulted more frequently particularly in the 3 months before diagnosis (86% cases vs 41% controls). Of these, 36% of cases and 9% of controls had consulted 4 times or more. The PPV for cancer in a child consulting 4 times or more in 3 months was 0.13 per 1000 children. CONCLUSION: Alert symptoms and frequent consultations are associated with childhood cancer. However, individual symptoms and consultation patterns have very low PPVs for cancer in primary care (e.g., of 10,000 children with a recorded alert symptom, approximately 6 would be diagnosed with cancer within 3 months).RMD is funded by the National Institute for Health Research (NIHR). WH was part funded by a NIHR postdoctoral fellowship. This study is based on data from the Full Feature General Practice Research Database (GPRD) obtained under licence from the UK Medicines and Healthcare Products Regulatory Agency (MHRA). However, the interpretation and conclusions contained in this study are those of the author/s alone. Access to the GPRD was funded through the Medical Research Council (MRC) licence agreement with the UK Medicines and Healthcare Products Regulatory Agency
Extending the applicability of the dose addition model to the assessment of chemical mixtures of partial agonists by using a novel toxic unit extrapolation method
This article has been made available through the Brunel Open Access Publishing Fund.Dose addition, a commonly used concept in toxicology for the prediction of chemical mixture effects, cannot readily be applied to mixtures of partial agonists with differing maximal effects. Due to its mathematical features, effect levels that exceed the maximal effect of the least efficacious compound present in the mixture, cannot be calculated. This poses problems when dealing with mixtures likely to be encountered in realistic assessment situations where chemicals often show differing maximal effects. To overcome this limitation, we developed a pragmatic solution that extrapolates the toxic units of partial agonists to effect levels beyond their maximal efficacy. We extrapolated different additivity expectations that reflect theoretically possible extremes and validated this approach with a mixture of 21 estrogenic chemicals in the E-Screen. This assay measures the proliferation of human epithelial breast cancers. We found that the dose-response curves of the estrogenic agents exhibited widely varying shapes, slopes and maximal effects, which made it necessary to extrapolate mixture responses above 14% proliferation. Our toxic unit extrapolation approach predicted all mixture responses accurately. It extends the applicability of dose addition to combinations of agents with differing saturating effects and removes an important bottleneck that has severely hampered the use of dose addition in the past. © 2014 Scholze et al
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