We have applied single determinant ab initio molecular orbital theory to the description of internal rotation in vinylcyclopropane and vinylcyclobutane. Using the minimal STO-3G basis we find the two molecules to be most stable in their s-trans forms but also predict both to possess flat secondary s-cis and gauche minima. Further investigation on vinylcyclopropane with the extended 4-31G basis set confirms the gauche minimum but places doubt on the stability of the s-cis structure. Substitution on the vinyl group in vinylcyclopropane by -

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The diamines putrescine and cadaverine and the polyamines spermine and spermidine inhibited the senescence of nonphotosynthetic cultures of Paul's Scarlet rose. Response was observed when the media of stationary phase cultures was adjusted to either 1 mM of cadaverine or putrescine; or 0.1 μM of either spermine or spermidine along with 2% sucrose in all cases. Senescence of the cultures was followed by microscopic examination of cell aliquots removed at 10 day intervals and treated with the vital stain, fluorescein diacetate.

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