34 research outputs found
Genome-wide association meta-analysis of corneal curvature identifies novel loci and shared genetic influences across axial length and refractive error.
Corneal curvature, a highly heritable trait, is a key clinical endophenotype for myopia - a major cause of visual impairment and blindness in the world. Here we present a trans-ethnic meta-analysis of corneal curvature GWAS in 44,042 individuals of Caucasian and Asian with replication in 88,218 UK Biobank data. We identified 47 loci (of which 26 are novel), with population-specific signals as well as shared signals across ethnicities. Some identified variants showed precise scaling in corneal curvature and eye elongation (i.e. axial length) to maintain eyes in emmetropia (i.e. HDAC11/FBLN2 rs2630445, RBP3 rs11204213); others exhibited association with myopia with little pleiotropic effects on eye elongation. Implicated genes are involved in extracellular matrix organization, developmental process for body and eye, connective tissue cartilage and glycosylation protein activities. Our study provides insights into population-specific novel genes for corneal curvature, and their pleiotropic effect in regulating eye size or conferring susceptibility to myopia
Multi-trait genome-wide association study identifies new loci associated with optic disc parameters
A new avenue of mining published genome-wide association studies includes the joint analysis of related traits. The power of this approach depends on the genetic correlation of traits, which reflects the number of pleiotropic loci, i.e. genetic loci influencing multiple traits. Here, we applied new meta-analyses of optic nerve head (ONH) related traits implicated in primary open-angle glaucoma (POAG); intraocular pressure and central corneal thickness using Haplotype reference consortium imputations. We performed a multi-trait analysis of ONH parameters cup area, disc area and vertical cup-disc ratio. We uncover new variants; rs11158547 in PPP1R36-PLEKHG3 and rs1028727 near SERPINE3 at genome-wide significance that replicate in independent Asian cohorts imputed to 1000 Genomes. At this point, validation of these variants in POAG cohorts is hampered by the high degree of heterogeneity. Our results show that multi-trait analysis is a valid approach to identify novel pleiotropic variants for ONH
Recommended from our members
Optical properties of flyash
The chemical composition and size distribution of representative flyashes are being measured by appropriate microanalytical techniques to provide information required. Measurements of the infrared optical constants (i.e., the complex refractive index m = n - ik) of synthetic slags are being made as a function of wavelength and temperature for controlled compositions. Particular attention will be given to the contribution of the Fe{sub 2}O{sub 3} content and its valence state. The data is being reduced to yield formulae giving the complex refractive index over relevant ranges of wavelength and temperature, as a function of the relevant metal oxide constituents. A benchscale experiment is planned to compare the measured radiant properties of a dispersion of well-characterized ash with computations based on data developed under the first two tasks
Recommended from our members
Optical properties of fly ash. Volume 1, Final report
Research performed under this contract was divided into four tasks under the following headings: Task 1, Characterization of fly ash; Task 2, Measurements of the optical constants of slags; Task 3, Calculations of the radiant properties of fly ash dispersions; and Task 4, Measurements of the radiant properties of fly ash dispersions. Tasks 1 and 4 constituted the Ph.D. research topic of Sarbajit Ghosal, while Tasks 2 and 3 constituted the Ph.D. research topic of Jon Ebert. Together their doctoral dissertations give a complete account of the work performed. This final report, issued in two volumes consists of an executive summary of the whole program followed by the dissertation of Ghosal. Volume 1 contains the dissertation of Ghosal which covers the characterization of fly ash and the measurements of the radiant properties of fly ash dispersions. A list of publications and conference presentations resulting from the work is also included
Recommended from our members
Optical properties of fly ash. Volume 2, Final report
Research performed under this contract was divided into four tasks under the following headings: Task 1, Characterization of fly ash; Task 2, Measurements of the optical constants of slags; Task 3, Calculations of the radiant properties of fly ash dispersions; and Task 4, Measurements of the radiant properties of fly ash dispersions. Tasks 1 and 4 constituted the Ph.D. research topic of Sarbajit Ghosal, while Tasks 2 and 3 constituted the Ph.D. research topic of Jon Ebert. Together their doctoral dissertations give a complete account of the work performed. This final report, issued in two volumes consists of an executive summary of the whole program followed by the dissertation of Ghosal and Ebert. Volume 2 contains the dissertation of Ebert which covers the measurements of the optical constants of slags, and calculations of the radiant properties of fly ash dispersions. A list of publications and conference presentations resulting from the work is also included
Recommended from our members
Optical properties of flyash
The purpose of this task is to validate the whole approach adopted in this program. Specifically, this bench-scale experiment is intended to compare the measured optical/radiative properties of a dispersion of well characterized ash with those calculated on the basis of the known size/composition distribution using the correlation formulae relating the composition and complex refractive index resulting from measurements on bulk samples of synthetic slag. Considerable thought has been given to the various possible approaches to satisfying the objectives of this task. Several experiments were done to guide our design of an apparatus for measuring the scattering and absorption properties of dispersions of flyash. As a result of these experiments, and from extensive prior experience in connection with research on electrostatic precipitation, it has been determined that there is no satisfactory way to satisfy the aims of this task using a gaseous dispersion of flyash because it is not possible to adequately disperse and deagglomerate flyash into a gas stream. Unless the ash is adequately dispersed, as it exists in the radiant boiler of a pulverized coal-fired combustion system, one cannot expect calculations, based on Mie calculations for a dispersion of spheres to properly agree with laboratory measurements. For these reasons, our design efforts are based on making measurements on a dispersion of flyash in liquid, for which our experience shows we can obtain stable, well-deagglomerated dispersions of ash. Because there is not single liquid which is adequately transparent over the wavelength range 1--12 {mu}m, we plan to use a combination of three liquids, C Cl{sub 4}, C S{sub 2} and bromoform to cover the full range. Windows of BaF{sub 2} will be used to contain the liquid suspension in an absorption/scattering cell
Recommended from our members
Optical properties of flyash
During the past quarter we have successfully measured the near normal reflectance of synthetic slags SA00, SA01, and SA05 at 1600[degree]C. The expected similarity of the measurements for slags SA00 and SA01 (which have nearly the same composition) reinforces our conclusion that the experiment is repeatable, although more data will certainly be taken to ensure this. The Kramers-Kronig relations have been applied to the reflectance data to obtain n in the wavelength range 1--13 [mu]m and k in the wavelength range 8--13 [mu]. The results show the expected strong SiO[sub 2] absorption band in k and the related dispersion in n. Currently we are examining the results from Task 1 to establish the slag compositions that are most representative of the majority of ash particles so that appropriate measurements can be made. Compositions will be limited to those which bear significantly on the radiation heat transfer in coal combustors. Once these compositions are established, a limited number of new synthetic slags will be made and their optical properties will be measured
Recommended from our members
Optical properties of flyash
The general aims of this research are to provide a fundamental scientific basis for the physical understanding and reliable calculation of radiative heat transfer in coal combustion systems, particularly as it is influenced by the presence of inorganic constituents deriving from the mineral matter in coal. Work is organized under four tasks: Characterization of Flyash: The chemical composition and size distribution of representative flyashes are being measured by appropriate microanalytical techniques; Measurements of the Optical Constants of Slags: Measurements of the infrared optical constants (i.e., the complex reflective index m = n {minus} ik) of synthetic slags are being made as a function of wavelength and temperature for controlled compositions. Particular attention will be given to the contribution of the Fe{sub 2}O{sub 3} content and its valence state. The data is being reduced to yield formulae giving the complex refractive index over relevant ranges of wavelength and temperatures, as a function of the relevant metal oxide constituents; Sample Calculations of the Radiant Properties of Flyash Dispersions: This component comprises various calculations to guide and evaluate the experimental work under the other three tasks; and Measurement of the Radiant Properties of Flyash Dispersions: This bench-scale experiment is planned to compare the measured radiant properties of a dispersion of well-characterized ash with computations based on data developed under the first two tasks. Progress is described in all areas. 10 refs., 20 figs., 5 tabs
Recommended from our members
Optical properties of flyash
The general aims of this research are to provide a fundamental scientific basis for the physical understanding and reliable calculation of heat transfer in coal combustion systems, particularly as it is influenced by the presence of inorganic constituents deriving from mineral matter in coal. (VC