This paper presents an analysis of three-dimensional flows based on the concept of stream tubes a... more This paper presents an analysis of three-dimensional flows based on the concept of stream tubes and streamlines. In the case of incompressible liquids, the physical domain can be transformed, under certain assumptions, into a cylinder where the streamlines are parallel straight lines. In contrast to classical methods, the unknown to be determined is the transformation between the two domains. This analysis generalizes the formulation already proposed for plane and axisymmetric flows.
Tomato protoplasts have been transformed with plasmid DNA's, containing a chimeric kanamycin resi... more Tomato protoplasts have been transformed with plasmid DNA's, containing a chimeric kanamycin resistance gene and putative tomato origins of replication. A calcium phosphate-DNA mediated transformation procedure was employed in combination with either polyethylene glycol or polyvinyl alcohol. There were no indications that the tomato DNA inserts conferred autonomous replication on the plasmids. Instead, Southern blot hybridization analysis of seven kanamycin resistant calli revealed the presence of at least one kanamycin resistance locus per transformant integrated in the tomato nuclear DNA. Generally one to three truncated plasmid copies were found integrated into the tomato nuclear DNA, often physically linked to each other. For one transformant we have been able to use the bacterial ampicillin resistance marker of the vector plasmid pUC9 to ‘rescue’ a recombinant plasmid from the tomato genome. Analysis of the foreign sequences included in the rescued plasmid showed that integration had occurred in a non-repetitive DNA region. Calf-thymus DNA, used as a carrier in transformation procedure, was found to be covalently linked to plasmid DNA sequences in the genomic DNA of one transformant. A model is presented describing the fate of exogenously added DNA during the transformation of a plant cell. The results are discussed in reference to the possibility of isolating DNA sequences responsible for autonomous replication in tomato.
This paper presents an analysis of three-dimensional flows based on the concept of stream tubes a... more This paper presents an analysis of three-dimensional flows based on the concept of stream tubes and streamlines. In the case of incompressible liquids, the physical domain can be transformed, under certain assumptions, into a cylinder where the streamlines are parallel straight lines. In contrast to classical methods, the unknown to be determined is the transformation between the two domains. This analysis generalizes the formulation already proposed for plane and axisymmetric flows.
Tomato protoplasts have been transformed with plasmid DNA's, containing a chimeric kanamycin resi... more Tomato protoplasts have been transformed with plasmid DNA's, containing a chimeric kanamycin resistance gene and putative tomato origins of replication. A calcium phosphate-DNA mediated transformation procedure was employed in combination with either polyethylene glycol or polyvinyl alcohol. There were no indications that the tomato DNA inserts conferred autonomous replication on the plasmids. Instead, Southern blot hybridization analysis of seven kanamycin resistant calli revealed the presence of at least one kanamycin resistance locus per transformant integrated in the tomato nuclear DNA. Generally one to three truncated plasmid copies were found integrated into the tomato nuclear DNA, often physically linked to each other. For one transformant we have been able to use the bacterial ampicillin resistance marker of the vector plasmid pUC9 to ‘rescue’ a recombinant plasmid from the tomato genome. Analysis of the foreign sequences included in the rescued plasmid showed that integration had occurred in a non-repetitive DNA region. Calf-thymus DNA, used as a carrier in transformation procedure, was found to be covalently linked to plasmid DNA sequences in the genomic DNA of one transformant. A model is presented describing the fate of exogenously added DNA during the transformation of a plant cell. The results are discussed in reference to the possibility of isolating DNA sequences responsible for autonomous replication in tomato.
Uploads