Biology subjects

Lim, D.

Publications and source records attributed to Lim, D..

3 recordsLinked to original sources

bioRxiv2018

Quality of eyeglass prescriptions from a low-cost wavefront autorefractor evaluated in rural India: results of a 708-participant field study

ABSTACTO_ST_ABSAimC_ST_ABSTo assess the quality of eyeglass prescriptions provided by an affordable wavefront autorefractor operated by a minimally-trained technician in a low-resource setting.\n\nMethods708 participants were recruited from consecutive patients registered for routine eye examinations at Aravind Eye Hospital in Madurai, India, or an affiliated rural satellite vision centre. Visual acuity (VA) and patient preference were compared for eyeglasses prescribed from a novel wavefront autorefractor versus eyeglasses prescribed from subjective refraction by an experienced refractionist.\n\nResultsMean {+/-} standard deviation VA was 0.30 {+/-} 0.37, -0.02 {+/-} 0.14, and -0.04 {+/-} 0.11 LogMAR units before correction, with autorefractor correction, and with subjective refraction correction, respectively (all differences P < 0.01). Overall, 25% of participants had no preference, 33% preferred eyeglasses from autorefractor prescriptions, and 42% preferred eyeglasses from subjective refraction prescriptions (P < 0.01). Of the 438 patients 40 years old and younger, 96 had no preference and the remainder had no statistically-significant difference in preference for subjective refraction prescriptions (51%) versus autorefractor prescriptions (49%) (P = 0.52).\n\nConclusionsAverage VAs from autorefractor-prescribed eyeglasses were one letter worse than those from subjective refraction. More than half of all participants either had no preference or preferred eyeglasses prescribed by the autorefractor. This marginal difference in quality may warrant autorefractor-based prescriptions, given the portable form-factor, short measurement time, low-cost, and minimal training required to use the autorefractor evaluated here.\n\nSYNOPSISEyeglass prescriptions can be accurately measured by a minimally-trained technician using a low-cost wavefront autorefractor in rural India. Objective refraction may be a feasible approach to increasing eyeglass accessibility in low-resource settings.

bioengineering↗

bioRxiv2017

Whole genome hybrid assembly and protein-coding gene annotation of the entirely black native Korean chicken breed Yeonsan Ogye

Yeonsan Ogye (YO), an indigenous Korean chicken breed (gallus gallus domesticus), has entirely black external features and internal organs. In this study, the draft genome of YO was assembled using a hybrid de novo assembly method that takes advantage of high-depth Illumina short-reads (232.2X) and low-depth PacBio long-reads (11.5X). Although the contig and scaffold N50s (defined as the shortest contig or scaffold length at 50% of the entire assembly) of the initial de novo assembly were 53.6Kbp and 10.7Mbp, respectively, additional and pseudo-reference-assisted assemblies extended the assembly to 504.8Kbp for contig N50 (pseudo-contig) and 21.2Mbp for scaffold N50, which included 551 structural variations including the Fibromelanosis (FM) locus duplication, compared to galGal4 and 5. The completeness (97.6%) of the draft genome (Ogye_1) was evaluated with single copy orthologous genes using BUSCO, and found to be comparable to the current chicken reference genome (galGal5; 97.4%), which was assembled with a long read-only method, and superior to other avian genomes (92~93%), assembled with short read-only and hybrid methods. To comprehensively reconstruct transcriptome maps, RNA sequencing (RNA-seq) and representation bisulfite sequencing (RRBS) data were analyzed from twenty different tissues, including black tissues. The maps included 15,766 protein-coding and 6,900 long non-coding RNA genes, many of which were expressed in the tissue-specific manner, closely related with the DNA methylation pattern in the promoter regions.

genomics↗

bioRxiv2017

Non-coding Transcriptome Maps Across Twenty Tissues of the Korean Black Chicken, Yeonsan Ogye

The Yeonsan Ogye (Ogye) is a rare Korean domestic chicken breed, the entire body of which, including its feathers and skin, has a unique black coloring. Although some protein-coding genes related to this unique feature have been examined, non-coding elements have not been globally investigated. In this study, high-throughput RNA sequencing and DNA methylation sequencing were performed to dissect the expression landscape of 14,264 Ogye protein-coding and 6900 long non-coding RNA (lncRNA) genes along with DNA methylation landscape in twenty different Ogye tissues. About 75% of Ogye lncRNAs showed tissue-specific expression whereas about 45% of protein-coding genes did. For some genes, the tissue-specific expression levels were inversely correlated with DNA methylation levels in their promoters. About 39% of the tissue-specific lncRNAs displayed functional association with proximal or distal protein-coding genes. In particular, heat shock transcription factor 2 (HSF2)-associated lncRNAs were discovered to be functionally linked to protein-coding genes that are specifically expressed in black skin tissues, tended to be more syntenically conserved in mammals, and were differentially expressed in black tissues relative to white tissues. Our results not only facilitate understanding how the non-coding genome regulates unique phenotypes but also should be of use for future genomic breeding of chickens.

bioinformatics↗