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There is an increasing interest in understanding how three-dimensional (3D) organization of the genome is regulated. Different strategies have been employed to identify genome-wide chromatin interactions. However, due to current limitations in resolving genomic contacts, visualization and validation of these genomic loci with sub-kilobase resolution remain unsolved to date. Here, we describe Tn5 transposase-based Fluorescencein situhybridization (Tn5-FISH), a PCR-based, cost-effective imaging method, which can co-localize the genomic loci with sub-kilobase resolution, dissect genome architecture, and verify chromatin interactions detected by chromatin configuration capture (3C)-derived methods. To validate this method, short-range interactions in keratin-encoding gene (KRT) locus in topologically associated domain (TAD) were imaged by triple-color Tn5-FISH, indicating that Tn5-FISH is very useful to verify short-range chromatin interactions inside the contact domain and TAD. Therefore, Tn5-FISH can be a powerful molecular tool for the clinical detection of cytogenetic changes in numerous genetic diseases such as cancers.

Landsat-7 enhanced thematic mapper plus (ETM +) imagery was used to identify anomalous areas caused by hydrocarbon leakage in Fula'erji in the western slope of Songliao Basin, China. Three image enhancement techniques, including principal component analysis (PCA), band ratioing, and false-color composition (FCC), were used. Based on the spectral characteristics of hydrocarbon-induced minerals and the eigenvectors of PCA, the best four principal components (PCs), 1345-PC3 (the third component of the PCA on bands 1, 3, 4, and 5), 1357-PC3, 3457-PC4, and 123457-PC4, were selected for FCC combined with band ratios of 3/1, 4/3, and 7/5. According to the tonal characteristics of the surface near wells and their visual expression, four FCC images were acquired for hydrocarbon-induced area delineation. The result indicates that anomalies are expressed as a faint tone blab and are mostly located in the Holocene sediments. An analysis of two cross sections traversing the identified anomalies suggests that they are closely related to the anomalous area interpreted from the four FCC images. Field data of magnetic susceptibility and delta carbonate are consistent with the distribution of the tonal anomalies and suggest a positive spatial association between the identified anomalous area and the hydrocarbon leakage environment. [ABSTRACT FROM AUTHOR]

Abstract Point bars are well developed on the Yellow River delta, among which the Shengli I point bar is the most typical. The point bar, being about 4 km in length and several tens to more than 100 meters in width, is located on the south side of the Shengli Bridge in Kenli County, Dongying, Shandong. It is a typical fine‐grained point bar with silt, which is predominant, some clay and minor plant debris and clay boulders. The Shengli I point bar has complicated 3‐D structures. Firstly, in a plane view, it comprises mainly eight sedimentary units, bar edge, bar ridge, bar platform, bar plain, bar channel, bar gully, bar pond and bar bay, developing side by side and superimposed one by one in a complex way. Secondly, its vertical structures are very complex due to the partial superimposition of the 8 sedimentary units. Besides hydatogenesis, very intensive wind erosion, eolian, ice and meltwater actions are also visible on the Shengli I point bar. The complex form is made even more complicated because of the above co‐actions.

Abstract Fractal dimensions of a terrain quantitatively describe the self‐organized structure of the terrain geometry. However, the local topographic variation cannot be illustrated by the conventional box‐counting method. This paper proposes a successive shift box‐counting method, in which the studied object is divided into small sub‐objects that are composed of a series of grids according to its characteristic scaling. The terrain fractal dimensions in the grids are calculated with the successive shift box‐counting method and the scattered points with values of fractal dimensions are obtained. The present research shows that the planar variation of fractal dimensions is well consistent with fault traces and geological boundaries.