Stability of Shannon Embankments

During the operating life of the Shannon Embankments, stability and seepage problems have occurred which caused concern regarding long term safety. The geology was studied, a comprehensive scheme of field and laboratory investigation was undertaken and the stability was analyzed and back calculated under failure conditions. The relative significance of various parameters was studied and provided the basis for the design of remedial measures. This paper deals in detail with the study of the stability of one embankment section (Fort Henry) and the recommendations on remedial measures

The breeding season of Coryphoblennius galerita in Portuguese waters

Coryphoblennius galerita at three sites on the Portuguese coast breeds from February/March to September/October

Quantitative Real-time PCR based on single copy gene sequence for detection of periodontal pathogens

7 páginas, 3 figuras, 5 tablas -- PAGS nros. 1054-1060Objective: To develop a method for quantification of Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg) and Tannerella forsythensis (Tf) from subgingival plaque samples based on TaqMan real-time polymerase chain reaction (PCR) technology. Material and Methods: Bacterial cells from these species were obtained after culturing reference strains and were counted microscopically. Cellular suspensions in Tris-EDTA buffer were used for DNA extraction after boiling for 20 min. Primers for PCR were selected from sequences of the LktC (Aa), Arg-gingipain (Pg) and BspA antigen (Tf) genes in order to yield amplicons below 100 bp. TaqMan-based real-time PCR was adjusted to quantify each species separately. Cycle threshold (CT) values were calculated for each species according to the initial number of copies. A reliability analysis was carried out using intra-class correlation coefficients (ICCs) with a two-way random effects model. Results: A high sensitivity and specificity was obtained for the detection of the three bacterial species. The TaqMan real-time PCR technology yielded a good repeatability in the obtained cycle threshold (CT) values for each initial number of copies, demonstrating coefficients of variation below 5% for each bacteria. The reproducibility of the technique was also demonstrated by the high ICCs (>0.98; p<0.00001) obtained for each bacteria with and without the addition of subgingival plaque. Conclusion: A novel diagnostic method based on TaqMan real-time PCR was developed for the quantification of Aa, Pg and Tf. It has demonstrated good sensitivity and repeatability on pure cultures. Its diagnostic utility should be demonstrated in subgingival plaque samplesPeer reviewe