Abstract. We extend Stanley’s work on alternating permutations with extremal number of fixed points in two directions: first, alternating permutations are replaced by permutations with a prescribed descent set; second, instead of simply counting permutations we study their generating polynomials by number of excedances. Several techniques are used: Désarménien’s desarrangement combinatorics, Ge...

Dam breaks of landslide dams are always accompanied by large numbers of casualties, a large loss of property, and negative influences on the downstream ecology and environment. This study uses the Jiadanwan landslide dam, created by the Wenchuan earthquake, as a case study example. Several laboratory experiments are carried out to analyse the dam-break mechanism of the landslide dam. The differ...

The design of a gravity dam is performed through an interactive process involving a preliminary layout of the structure followed by a stability and stress analysis. This study presents a method to define the optimal top width of gravity dam with genetic algorithm. To solve the optimization task (minimize the cost of the dam), an optimization routine based on genetic algorithms (GAs) was impleme...

Along with the development of virtual reality (VR) technology, simulation system as a new perspective of management methods and technical means in the progress of the project management plays an increasingly important role. This paper presents a Virtools-based visual simulation method and realizes a concrete dam pouring process. It proposes that the mode of the dam for a certain period could be...

Edwardsiella tarda is a serious aquaculture pathogen that can infect many cultured fish species. The aim of this study was to investigate the potential importance of DNA adenine methylase (Dam) in E. tarda pathogenesis. The E. tarda dam gene (dam(Et)) was cloned from a pathogenic strain, TXD1, isolated from diseased fish. Dam(Et) shares high (70.2%) sequence identity with the Dam proteins of Ye...

Rubber dam is considered an ideal device for tooth isolation. Nevertheless, its usage is quite rare in the Czech Republic. The aim of this study was: firstly, to gather and evaluate information regarding the use of rubber dam by dentists in the Czech Republic and to compare it with other countries; secondly to find out whether there are any influencing factors as to rubber dam usage; and finall...

DNA adenine methylase mutants of Salmonella typhimurium contain reduced amounts of FinP, an antisense RNA encoded by the virulence plasmid pSLT. Lowered FinP levels are detected in both Dam- FinO+ and Dam- FinO- backgrounds, suggesting that Dam methylation regulates FinP production rather than FinP half-life. Reduced amounts of F-encoded FinP RNA are likewise found in Dam- mutants of Escherichi...

In this study, we demonstrated that the methyltransferase activity associated with Dam was essential for attenuation of Aeromonas hydrophila virulence. We mutated aspartic acid and tyrosine residues to alanine within the conserved DPPY catalytic motif of Dam and transformed the pBAD/damD/A, pBAD/damY/A, and pBAD/damAhSSU (with the native dam gene) recombinant plasmids into the Escherichia coli ...

Uma série de dez novos análogos de 1,3,4-oxadiazóis contendo uma parte dibenzosuberano foram sintetizados usando tanto uma aproximação de síntese linear, quanto convergente. Todos os compostos foram caracterizados por espectrometria de massas, espectroscopias no infravermelho (IR), de ressonância magnética nuclear de H (H NMR ) e C (C NMR) e análise elementar. As atividades bactericidas e antif...