Multi-trait genome-wide association study identifies new loci associated with optic disc parameters.

Funder: All funders per study are acknowledged in the Supplementary FileA 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

Correlation between powder flow properties measured by shear testing and Hausner ratio

Shear testing provides rigorous estimates of flow properties relevant to the characterization, handling, and processing of powders, and is a necessary test procedure in the formal design of powder storage facilities. However, despite the automation of modern test equipment, it can be time consuming and expensive. In contrast, measurement of bulk density is straightforward and less laborious, and tapping devices are cheaper. Here we explore the relationship between Hausner ratio and cohesion and also examine correlation between Hausner ratio, σc/σy, and σpre for a suite of 13 milled and 2 spray-dried lactose powders, 3 sand samples and 3 samples of refractory dust; Hausner ratio is the ratio of tapped bulk density to loose bulk density, σc is major consolidation stress, σy is unconfined yield stress and σpre is preconsolidation stress. Cohesion and flow function were measured with an annular shear cell at values of σpre up to 5 kPa. Loose poured bulk density was measured following a modified New Zealand standard and tapped density measurement was based on a method for dry dairy products and the European Pharmacopoeia; Hausner ratio at 1250 taps was used. Our results show that cohesion at σpre of 0.31 kPa, 0.61 kPa, 1.20 kPa, 2.41 kPa, and 4.85 kPa correlates linearly with Hausner ratio; the slope and intercept of the correlation are functions of σpre. A plot of σc/σy against Hausner ratio shows an exponential decay trend and regression yields two fitting parameters that correlate well with σpre. These correlations are potentially useful for assessing flow characteristics when shear testing cannot be performed.falsePublishe