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Transposon Tn7 was shown to insert specifically into the megaplasmid of different Rhizobium meliloti strains. Tn7 transposition could not be detected in other Rhizobium strains such as R. trifolii, R. leguminosarum, R. phaseoli and R. japonicum. In R. meliloti strains, two unique sites in the megaplasmid were observed into which Tn7 can transpose at different frequencies. Only one copy of Tn7 could be detected in the megaplasmid and the insertion sites for Tn7 are outside the nif and nod region. Tn7 transposition in R. meliloti showed a marked preference for sites on plasmid RP4 compared to the megaplasmid sites. Attempts to cure Tn7 from the megaplasmid were unsuccessful. This site specific transposition of Tn7 in R. meliloti provides an additional genetic tool to further manipulate this important plasmid in symbiotic nitrogen fixation.

Opinion. Explores the possibility that Internet access providers can be held responsible for copyright infringements. Function of copyright; Ease with which copyright-protected works may be duplicated; Issue of electronic copyright infringement in the case Playboy Enterprises Inc. v. Frena; Reasons given by online service providers on why they should not be held liable.

The article presents a reprint of the article "Diesel designs cut health risk," by Patrick Glynn, which appeared in the July-August 2009 issue of "Earthmatters." It focuses on the research project conducted by the Commonwealth Scientific & Industrial Research Organization (CSIRO) utilizing acoustic agglomeration techniques to reduce diesel particulates from coal mine vehicle in Australia. It stresses the need for diesel fuel to have emission control to satisfy occupational health and safety.