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Full-Text Articles in Life Sciences

Cole1 Copy Number Mutants., Londa Schmidt, Joseph Inselburg Aug 1982

Cole1 Copy Number Mutants., Londa Schmidt, Joseph Inselburg

Dartmouth Scholarship

A deletion mutant of the colicin E1-derived plasmid, pDMS6642, exhibited an approximately fourfold increase in copy number. We subsequently isolated hydroxylamine-induced mutants of that plasmid that had a further increase in copy number. Analysis of them suggests that the increased copy number of pDMS6642 is associated with transcriptional readthrough from a Tn3 transposon into the region of ColE1 containing information that influences plasmid replication. The hydroxylamine mutation in one copy number mutant appeared to increase the plasmid copy number by stimulating readthrough transcription from the Tn3 transposon into the ColE1 replication control region, whereas the other hydroxylamine mutation acts by …


Genetic Adaptation In Relation To Animal Welfare, R. G. Beilharz Jan 1982

Genetic Adaptation In Relation To Animal Welfare, R. G. Beilharz

Genetics Collection

In this essay I outline the processes of adaptation of animals and of animal populations and discuss their relevance to the problem of animal welfare. Because "animal welfare" has many different aspects including philosophical, ethical, and biological, it is important to examine some of the fundamental issues that underly the concept. Hence, in this essay, I comment on how people come to "know," how information accumulates, and how what we know influences our actions. I also discuss the biological information that is relevant to animal welfare. It is my hope that, when this topic has been placed within a broader …


Ecotypic Differences In Heat Resistance Of Aspen Leaves, K.M. Peck, S.J. Wallner Jan 1982

Ecotypic Differences In Heat Resistance Of Aspen Leaves, K.M. Peck, S.J. Wallner

Aspen Bibliography

Heat resistance of aspen (Populus tremuloides) leaves was assessed by stressing leaf discs in vitro and measuring electrolyte leakage. Leaves were obtained from trees growing at elevations of 1960, 2195, and 2454 m. Heat tolerance was greatest in leaf samples from trees growing at the lowest site. Trees propagated from these sites and grown at 1520 m for 2 years showed some increase in heat tolerance, but apparent ecotypic differences persisted


Natural Variation In Merchantable Stem Biomass And Volume Among Clones Of Populus Tremuloides Michx, G.A. Lehn, K.O. Higginbotham Jan 1982

Natural Variation In Merchantable Stem Biomass And Volume Among Clones Of Populus Tremuloides Michx, G.A. Lehn, K.O. Higginbotham

Aspen Bibliography

No abstract provided.


Population Genetics And Speciation In The Aedes Triseriatus Group., Leonard E. Munstermann, Terry Matthews, David B. Taylor Dec 1981

Population Genetics And Speciation In The Aedes Triseriatus Group., Leonard E. Munstermann, Terry Matthews, David B. Taylor

David B. Taylor

No abstract provided.