Speciation of heavy metals in the sidments of Gubi dam, Bauchi state, Nigeria

Speciation of heavy metals in the sediments of Gubi Dam in Bauchi, Nigeria was carried out between December, 2001 and March, 2002. The mean total concentrations showed that Tatimari tributary has high Fe, Zn, and Mn, confirming it source and path. The spillway result suggest intensive farming activity along the dam runway. However, the physio-chemical forms of Fe, Pb, and Cr indicate that these metals are associated in high concentration with the mineral matrix of the sediment, as such it is most unlikely to become biologically available. High levels of Cu, Cd, Zn, Mn, Co and Ni are associated with the exchangeable carbonate bound fractions, indicating that they are in potentially available forms and many pose serious problems to the dam ecosystem.KEY WORDS: Sediments, Speciation, Heavy metals, Gubi Dam, Nigeri

Levels of heavy metals in Gubi dam water Bauchi, Nigeria

The distribution of heavy metals in Gubi Dam, Bauchi, Nigeria was studied covering the highest turbulent and non-turbulent flow periods. The average concentrations of iron, manganese, nickel, zinc, cobalt, chromium and cadmium were generally highest in filtrate water, whereas the concentrations of copper and lead were always highest in the suspended materials which indicate the dominant role played by suspended materials in the transport of these metals. The total metal levels are within WHO safety limits as such do not reflect impaired suitability of the water. The relative levels of the metals at the entry points and spillway reflect the source, the path and stopover of the tributaries of the dam, thus the variation in the amount of metals at each point.KEYWORDS: Distribution, Heavy metals, filtrate water, suspended matter, Gubi dam, Nigeri

Comparative Molecular Analysis of Gastrointestinal Adenocarcinomas

We analyzed 921 adenocarcinomas of the esophagus, stomach, colon, and rectum to examine shared and distinguishing molecular characteristics of gastrointestinal tract adenocarcinomas (GIACs). Hypermutated tumors were distinct regardless of cancer type and comprised those enriched for insertions/deletions, representing microsatellite instability cases with epigenetic silencing of MLH1 in the context of CpG island methylator phenotype, plus tumors with elevated single-nucleotide variants associated with mutations in POLE. Tumors with chromosomal instability were diverse, with gastroesophageal adenocarcinomas harboring fragmented genomes associated with genomic doubling and distinct mutational signatures. We identified a group of tumors in the colon and rectum lacking hypermutation and aneuploidy termed genome stable and enriched in DNA hypermethylation and mutations in KRAS, SOX9, and PCBP1. Liu et al. analyze 921 gastrointestinal (GI) tract adenocarcinomas and find that hypermutated tumors are enriched for insertions/deletions, upper GI tumors with chromosomal instability harbor fragmented genomes, and a group of genome-stable colorectal tumors are enriched in mutations in SOX9 and PCBP1