172 research outputs found
Emerging diet-related surrogate end points for colorectal cancer: UK Food Standards Agency diet and colonic health workshop report
The UK Food Standards Agency convened a group of expert scientists to review current research investigating emerging diet-related surrogate end points for colorectal cancer (CRC). The workshop aimed to overview current research and establish priorities for future research. The workshop considered that the validation of current putative diet-related surrogate end points for CRC and the development of novel ones, particularly in the emerging fields of proteomics, genomics and epigenomics, should be a high priority for future research
Nucleation of a sodium droplet on C60
We investigate theoretically the progressive coating of C60 by several sodium
atoms. Density functional calculations using a nonlocal functional are
performed for NaC60 and Na2C60 in various configurations. These data are used
to construct an empirical atomistic model in order to treat larger sizes in a
statistical and dynamical context. Fluctuating charges are incorporated to
account for charge transfer between sodium and carbon atoms. By performing
systematic global optimization in the size range 1<=n<=30, we find that Na_nC60
is homogeneously coated at small sizes, and that a growing droplet is formed
above n=>8. The separate effects of single ionization and thermalization are
also considered, as well as the changes due to a strong external electric
field. The present results are discussed in the light of various experimental
data.Comment: 17 pages, 10 figure
FracPaQ: A MATLABâą toolbox for the quantification of fracture patterns
The patterns of fractures in deformed rocks are rarely uniform or random. Fracture orientations, sizes, and spatial distributions often exhibit some kind of order. In detail, relationships may exist among the different fracture attributes, e.g. small fractures dominated by one orientation, larger fractures by another. These relationships are important because the mechanical (e.g. strength, anisotropy) and transport (e.g. fluids, heat) properties of rock depend on these fracture attributes and patterns. This paper describes FracPaQ, a new open source, cross-platform toolbox to quantify fracture patterns, including distributions in fracture attributes and their spatial variation. Software has been developed to quantify fracture patterns from 2-D digital images, such as thin section micrographs, geological maps, outcrop or aerial photographs or satellite images. The toolbox comprises a suite of MATLABâą scripts based on previously published quantitative methods for the analysis of fracture attributes: orientations, lengths, intensity, density and connectivity.An estimate of permeability in 2-D is made using a parallel plate model. The software provides an objective and consistent methodology for quantifying fracture patterns and their variations in 2-D across a wide range of length scales, rock types and tectonic settings. The implemented methods presented are inherently scale independent, and a key task where applicable is analysing and integrating quantitative fracture pattern data from micro-to macro-scales. The toolbox was developed in MATLABâą and the source code is publicly available on GitHubâą and the Mathworksâą FileExchange. The code runs on any computer with MATLAB installed, including PCs with Microsoft Windows, Apple Macs with Mac OS X, and machines running different flavours of Linux. The application, source code and sample input files are available in open repositories in the hope that other developers and researchers will optimise and extend the functionality for the benefit of the wider community
Computational Analysis and Experimental Validation of Gene Predictions in Toxoplasma gondii
Toxoplasma gondii is an obligate intracellular protozoan that infects 20 to 90% of the population. It can cause both acute and chronic infections, many of which are asymptomatic, and, in immunocompromised hosts, can cause fatal infection due to reactivation from an asymptomatic chronic infection. An essential step towards understanding molecular mechanisms controlling transitions between the various life stages and identifying candidate drug targets is to accurately characterize the T. gondii proteome.We have explored the proteome of T. gondii tachyzoites with high throughput proteomics experiments and by comparison to publicly available cDNA sequence data. Mass spectrometry analysis validated 2,477 gene coding regions with 6,438 possible alternative gene predictions; approximately one third of the T. gondii proteome. The proteomics survey identified 609 proteins that are unique to Toxoplasma as compared to any known species including other Apicomplexan. Computational analysis identified 787 cases of possible gene duplication events and located at least 6,089 gene coding regions. Commonly used gene prediction algorithms produce very disparate sets of protein sequences, with pairwise overlaps ranging from 1.4% to 12%. Through this experimental and computational exercise we benchmarked gene prediction methods and observed false negative rates of 31 to 43%.This study not only provides the largest proteomics exploration of the T. gondii proteome, but illustrates how high throughput proteomics experiments can elucidate correct gene structures in genomes
Excavation of an early 17th-century glassmaking site at Glasshouse, Shinrone, Co. Offaly, Ireland
An archaeological research excavation was conducted in the area immediately surrounding an upstanding glassmaking furnace near Shinrone, Co. Offaly, Ireland. It dates to the early to mid 17th century and was built and operated by French Huguenots, probably de Hennezells (de Hennezel/Henzeys/Hensie) who had settled in this region as part of the Crown plantation of Kingâs County (now Co. Offaly). This furnace, which employed wood rather than coal as a fuel, is a very rare survival, with no other upstanding examples known in Ireland, Britain or the Lorraine region of France where the form probably originated
Models of KPTN-related disorder implicate mTOR signalling in cognitive and overgrowth phenotypes
KPTN-related disorder is an autosomal recessive disorder associated with germline variants in KPTN (previously known as kaptin), a component of the mTOR regulatory complex KICSTOR. To gain further insights into the pathogenesis of KPTN-related disorder, we analysed mouse knockout and human stem cell KPTN loss-of-function models.Kptnâ/â mice display many of the key KPTN-related disorder phenotypes, including brain overgrowth, behavioural abnormalities, and cognitive deficits. By assessment of affected individuals, we have identified widespread cognitive deficits (n = 6) and postnatal onset of brain overgrowth (n = 19). By analysing head size data from their parents (n = 24), we have identified a previously unrecognized KPTN dosage-sensitivity, resulting in increased head circumference in heterozygous carriers of pathogenic KPTN variants.Molecular and structural analysis of Kptnâ/â mice revealed pathological changes, including differences in brain size, shape and cell numbers primarily due to abnormal postnatal brain development. Both the mouse and differentiated induced pluripotent stem cell models of the disorder display transcriptional and biochemical evidence for altered mTOR pathway signalling, supporting the role of KPTN in regulating mTORC1.By treatment in our KPTN mouse model, we found that the increased mTOR signalling downstream of KPTN is rapamycin sensitive, highlighting possible therapeutic avenues with currently available mTOR inhibitors. These findings place KPTN-related disorder in the broader group of mTORC1-related disorders affecting brain structure, cognitive function and network integrity.Genetics of disease, diagnosis and treatmen
African-specific improvement of a polygenic hazard score for age at diagnosis of prostate cancer
Polygenic hazard score (PHS) models are associated with age at diagnosis of prostate cancer. Our model developed in Europeans (PHS46) showed reduced performance in men with African genetic ancestry. We used a cross-validated search to identify single nucleotide polymorphisms (SNPs) that might improve performance in this population. Anonymized genotypic data were obtained from the PRACTICAL consortium for 6253 men with African genetic ancestry. Ten iterations of a 10-fold cross-validation search were conducted to select SNPs that would be included in the final PHS46+African model. The coefficients of PHS46+African were estimated in a Cox proportional hazards framework using age at diagnosis as the dependent variable and PHS46, and selected SNPs as predictors. The performance of PHS46 and PHS46+African was compared using the same cross-validated approach. Three SNPs (rs76229939, rs74421890 and rs5013678) were selected for inclusion in PHS46+African. All three SNPs are located on chromosome 8q24. PHS46+African showed substantial improvements in all performance metrics measured, including a 75% increase in the relative hazard of those in the upper 20% compared to the bottom 20% (2.47-4.34) and a 20% reduction in the relative hazard of those in the bottom 20% compared to the middle 40% (0.65-0.53). In conclusion, we identified three SNPs that substantially improved the association of PHS46 with age at diagnosis of prostate cancer in men with African genetic ancestry to levels comparable to Europeans
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