A global analysis of Y-chromosomal haplotype diversity for 23 STR loci

In a worldwide collaborative effort, 19,630 Y-chromosomes were sampled from 129 different populations in 51 countries. These chromosomes were typed for 23 short-tandem repeat (STR) loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385ab, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, GATAH4, DYS481, DYS533, DYS549, DYS570, DYS576, and DYS643) and using the PowerPlex Y23 System (PPY23, Promega Corporation, Madison, WI). Locus-specific allelic spectra of these markers were determined and a consistently high level of allelic diversity was observed. A considerable number of null, duplicate and off-ladder alleles were revealed. Standard single-locus and haplotype-based parameters were calculated and compared between subsets of Y-STR markers established for forensic casework. The PPY23 marker set provides substantially stronger discriminatory power than other available kits but at the same time reveals the same general patterns of population structure as other marker sets. A strong correlation was observed between the number of Y-STRs included in a marker set and some of the forensic parameters under study. Interestingly a weak but consistent trend toward smaller genetic distances resulting from larger numbers of markers became apparent.Peer reviewe

A State of the Art Paper on Improving Salt Extraction from Lake Katwe Raw Materials In Uganda

Abstract The characteristics of Katwe salt lake are briefly discussed. The lake is the largest of the eight saline lakes in the Katwe-Kikorongo volcanic field and is a major source of salt production in Uganda. Today, salt production at the lake is carried out using traditional and artisanal mining methods. Attempts to mechanize the production of domestic and commercial grade salt at the lake were unsuccessful due to the use of a wrong technology. In this paper, the most common available technologies for salt extraction from brine are described. These are divided into four broad categories, namely thermal, membrane, chemical and hybrid processes. A review of the state of the art, previous research and developments in these technologies is presented. A detailed analysis of the processes used was done based on studies reported in the literature. From the analysis, it was observed that thermal salt production processes, especially distillation and solar evaporation have the highest share in installed capacities worldwide. Membrane technologies such as Electro-dialysis, Reverse Osmosis and chemical technologies have not found wide application in the commercial salt industry. Electro-dialysis and Reverse Osmosis have been used mainly as pre-concentration processes for subsequent thermal processes. Prospects for application of hybrid systems for salt production through integration of thermal desalting processes should be investigated for better performance efficiencies and recoveries at the salt lake