Common Features of the Pericentromere and Nucleolus

Both the pericentromere and the nucleolus have unique characteristics that distinguish them amongst the rest of genome. Looping of pericentromeric DNA, due to structural maintenance of chromosome (SMC) proteins condensin and cohesin, drives its ability to maintain tension during metaphase. Similar loops are formed via condensin and cohesin in nucleolar ribosomal DNA (rDNA). Condensin and cohesin are also concentrated in transfer RNA (tRNA) genes, genes which may be located within the pericentromere as well as tethered to the nucleolus. Replication fork stalling, as well as downstream consequences such as genomic recombination, are characteristic of both the pericentromere and rDNA. Furthermore, emerging evidence suggests that the pericentromere may function as a liquid–liquid phase separated domain, similar to the nucleolus. We therefore propose that the pericentromere and nucleolus, in part due to their enrichment of SMC proteins and others, contain similar domains that drive important cellular activities such as segregation, stability, and repair.

Lattice mismatch as the descriptor of segregation, stability and reactivity of supported thin catalyst films

Surface properties of supported bimetallic films can be predicted from the lattice mismatch between the overlayer and the support already there for trilayers.

Workability Evaluation of Self Compacting Concrete

The compactibility, mobility and segregation stability of self compacting concrete (SCC) is essential for its quality control. Completely and reasonably workability evaluation to SCC has an obviously influence in concrete engineering field. The paper introduced the rheology and workability mechanism of SCC. Ten workability assessment methods, such as Slump Flow test, U-box test, J-ring test, L-box test, VSI method, Oriment test, V-funnel test, Inverted Slump Cone test, were presented and the advantages and disadvantages of each appraisal procedure and the evaluation practice were analyzed. It also put forward the prospect direction of workability evaluation of SCC.

Molecular analysis of plasmid pAP4 from Acetobacter pasteurianus

The complete nucleotide sequence of plasmid pAP4 isolated from Acetobacter pasteurianus 2374T has been determined. Plasmid pAP4 was analysed and found to be 3,870 bp in size with a G+C content of 50.1%. Computer assisted analysis of sequence data revealed 2 possible ORFs with typical promoter regions. ORF1 codes for a protein responsible for kanamycin resistance similar with Tn5 transposone, ORF2 encodes a resistance to ampicillin identical with Tn3 transposone. Plasmid has in A. pasteurianus five copies and in E. coli DH1 about 30 copies per chromosome and it segregation stability in both strains is very high. Based on the data on replication region, plasmid does not code for a replication protein and origin region is similar with ColE1-like plasmid.