DNA sequence data were used to examine phylogenetic relationships between six species of economically important Tetranychidae mites: Eotetranychus carpini (Oudemans), E. pruni (Reck), Tetranychus pacificus McGregor, T. mcdanieli McGregor, T. turkestani Ugarov & Nikolski and T. urticae Koch. With primers directed toward conserved elements flanking the target region, the Polymerase Chain Reaction was used to amplify the ITS2 spacer of the ribosomal DNA molecule. The nucleotide sequence of a 300-bp fragment of the ITS2 was determined by direct sequencing and nucleotide divergence used for intra-generic comparison in mites. The resulting phylogenetic tree expressing interspecific relationships in genus Tetranychus agrees with morphological data. The study demonstrates the usefulness of the approach in the assessment of the systematics and evolution of the group.
The rate of recombination of hydrogen atoms in fuel-rich hydrogen/oxygen/nitrogen flames containing metal additives has been measured using the lithium/lithium hydroxide method to monitor hydrogen atom concentrations. It is found that the rate of the recombination reaction is accelerated by the addition of alkaline earth metals. The preferred mechanism for catalysis is via the cycle of reactions :MOH+H -+MO+Hzand the rate of the catalyzed recombination is given by the expression Values of k7 and lower limits of ke have been determined for calcium, strontium and barium at 1570 K and 1800 K. The upper limit for the catalysis to be effective is about 2000 K. This is determined by the increase of Ks with temperature.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.