Tracking nitrate sources in agricultural-urban watershed using dual stable isotope and Bayesian mixing model approach: Considering N transformation by Lagrangian sampling.

A dual isotopes approach and the Bayesian isotope mixing model were applied to trace nitrogen pollution sources and to quantify their relative contribution to river water quality. We focused on two points to enhance the applicability of the method: 1) Direct measurement on the end-members to distinguish "sewage" and "manure" which used to be grouped in one pollution source as their isotope ranges overlap; 2) The Lagrangian sampling method was applied to consider the transport of nitrogen pollutants in a long river so that any fractionation process can be dealt with in the given Bayesian modeling framework. The results of the analysis confirmed the NO isotope composition in the river of interest to be within the range of NO with origins in "NH in fertilizer", "Soil N", and "Manure and sewage" pollution.

A Multi-Elements Isotope Approach to Assess the Geographic Provenance of Manila Clams () via Recombining Appropriate Elements.

The increasing global consumption of seafood has led to increased trade among nations, accompanied by mislabeling and fraudulent practices that have rendered authentication crucial. The multi-isotope ratio analysis is considered as applicable tool for evaluating geographical authentications but requires information and experience to select target elements such as isotopes, through a distinction method based on differences in habitat and physiology due to origin. The present study examined recombination conditions of multi-elements that facilitated geographically distinct classifications of the clams to sort out appropriate elements.

Contribution of petroleum-derived organic carbon to sedimentary organic carbon pool in the eastern Yellow Sea (the northwestern Pacific).

We investigated molecular distributions and stable carbon isotopic compositions (δC) of sedimentary n-alkanes (CC) in the riverbank and marine surface sediments to trace natural and anthropogenic organic carbon (OC) sources in the eastern Yellow Sea which is a river dominated marginal sea. Molecular distributions of n-alkanes are overall dominated by odd-carbon-numbered high molecular weight n-C, n-C, and n-C. The δC signatures of n-C, n-C, and n-C indicate a large contribution of C gymnosperms as the main source of n-alkanes, with the values of -29.

Analyses of porcine public SNPs in coding-gene regions by re-sequencing and phenotypic association studies.

The Porcine SNP database has a huge number of SNPs, but these SNPs are mostly found by computer data-mining procedures and have not been well characterized. We re-sequenced 1,439 porcine public SNPs from four commercial pig breeds and one Korean domestic breed (Korean Native pig, KNP) by using two DNA pools from eight unrelated animals in each breed. These SNPs were from 419 protein-coding genes covering the 18 autosomes, and the re-sequencing in breeds confirmed 690 public SNPs (47.