Advances in development of gene-gene interaction analy-sis methods based on SNP data: a review

Abstract

The SNP-based association analysis has become one of the most important approaches to interpret the underlying molecular mechanisms for human complex diseases. Nevertheless, the widely-used singe-locus analysis is only capable of capturing a small portion of susceptible SNPs with prominent marginal effects, leaving the important genetic component, epistasis or joint effects, to be undetectable. Identifying the complex interplays among multiple genes in the genome-wide context is an essential task for systematically unraveling the molecular mechanisms for complex diseases. Many approaches have been used to detect genome-wide gene-gene interactions and provided new insights into the genetic basis of complex diseases. This paper reviewed recent advances of the methods for detecting gene-gene interaction, categorized into three types, model-based and model-free statistical methods, and data mining methods, based on their characteristics in theory and numerical algorithm. In particular, the basic principle, numerical implementation and cautions for application for each method were elucidated. In addition, this paper briefly discussed the limitations and challenges associated with detecting genome-wide epistasis, in order to provide some methodological consultancies for scientists in the related fields.

Correlation Between Bentonite’s Cation Exchange Capacity (CEC) , Activated Clay Quality Indexes and Activation Strength

“…Analyzed via X-ray diffraction, the primary mineral composed in the three kind bentonites are montmorillonite, quartz, feldspar and other impurity mineral. According to X-ray diffraction of -2µm bentonite purified by wet method, they all belong to calcium bentonite because the peak value of d (001) in Weifang, Laiyang and Laixi are 1.51731nm, 1.51731nm and 1.49676 nm respectively [1].…”

“…where C is the actual concentration of the sodium hydroxide solution, generally at 0.1mol/L or so. V is the volume(mL) of the sodium hydroxide solution consumed by the 1 gramme bentonite [1]. Activation degree was tested through acid base titration.…”

“…Montmorillonite's ions exchange is mainly cation exchange. In addition, ions adsorbed onto the montmorillonite crystal end face also have the capacity of ions exchange, but they are in tiny proportion in all [1]. Various kinds of montmorillonite isomorphism replacement lead to form a series complex subtribe minerals, so there are some differences among acid activation technics parameters and among properties of acid bentonites.…”