A review of the mechanisms of pollutant removal in water hyacinth systems

Presence of aquatic plants in natural or constructed wetlands not only reduces the concentration of  problematic nutrients from the wastewater, but also alters the physico-chemical environment of the water, rhizosphere and underlying sediment (Reddy & Patrick, 1984). In addition to plant assimilation of nutrients, changes in the environment of the water also help in reducing the pollutant level of the wastewater through biochemical processes brought about by micro-organisms. This paper gives a review of the biochemical and physico-chemical processes occurring in a floating aquatic plant system. Keywords : Water hyacinth, pollutant removal, biochemical/ physico-chemical processes

Fully Phased Sequence of a Diploid Human Genome Determined de Novo from the DNA of a Single Individual

In recent years, improved sequencing technology and computational tools have made de novo genome assembly more accessible. Many approaches, however, generate either an unphased or only partially resolved representation of a diploid genome, in which polymorphisms are detected but not assigned to one or the other of the homologous chromosomes. Yet chromosomal phase information is invaluable for the understanding of phenotypic trait inheritance in the cases of compound heterozygosity, allele-specific expression or cis-acting variants. Here we use a combination of tools and sequencing technologies to generate a de novo diploid assembly of the human primary cell line WI-38. First, data from PacBio single molecule sequencing and Bionano Genomics optical mapping were combined to generate an unphased assembly. Next, 10x Genomics linked reads were combined with the hybrid assembly to generate a partially phased assembly. Lastly, we developed and optimized methods to use short-read (Illumina) sequencing of flow cytometry-sorted metaphase chromosomes to provide phase information. The final genome assembly was almost fully (94%) phased with the addition of approximately 2.5-fold coverage of Illumina data from the sequenced metaphase chromosomes. The diploid nature of the final de novo genome assembly improved the resolution of structural variants between the WI-38 genome and the human reference genome. The phased WI-38 sequence data are available for browsing and download at wi38.research.calicolabs.com. Our work shows that assembling a completely phased diploid genome de novo from the DNA of a single individual is now readily achievable