Accelerated carbonation and leaching behavior of the slag from iron and steel making industry

Ground granulated blast furnace slag(GGBFS)and steelmaking slag have been used as a raw material for cement production or as an aggregate to make concrete,which contribute aluminum,calcium,iron,and silicon oxides.The suitability of the slag for a particular application depends on its reactivity,cost,availability,and its influence on the properties of the resulting concrete.For the interest of durability studying of concrete in the presence of slag,the accelerated carbonation products and leaching behavior of the slag and Portland cement(PC)were studied.The experimental results confirmed that the slag was more resistant to carbonation compared to PC.The carbonation degree of GGBFS reduced by 17.74%;and the carbonation degrees of steelmaking slags reduced by 9.51%-11.94%.Carbonation neutralized the alkaline nature of the hydrated pastes and gave rise to the redox potential of the leachate slightly(30-77 mV).The carbonation also increased the release of most of the elements presented,except for calcium,to the aqueous environment.It is concluded that blend cements(PC plus slag)have economical advantages and better durability compared to PC.     

Evolution of genes and genomes on the Drosophila phylogeny

Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.     

Dynamic evolution of the innate immune system in Drosophila

The availability of complete genome sequence from 12 Drosophila species presents the opportunity to examine how natural selection has affected patterns of gene family evolution and sequence divergence among different components of the innate immune system. We have identified orthologs and paralogs of 245 Drosophila melanogaster immune-related genes in these recently sequenced genomes. Genes encoding effector proteins, and to a lesser extent genes encoding recognition proteins, are much more likely to vary in copy number across species than genes encoding signaling proteins. Furthermore, we can trace the apparent recent origination of several evolutionarily novel immune-related genes and gene families. Using codon-based likelihood methods, we show that immune-system genes, and especially those encoding recognition proteins, evolve under positive darwinian selection. Positively selected sites within recognition proteins cluster in domains involved in recognition of microorganisms, suggesting that molecular interactions between hosts and pathogens may drive adaptive evolution in the Drosophila immune system.