The aging of Gomori's aldehyde-fuchsin: the nature of the chemical changes and the chemical structures of the coloured components

The chemical nature of Gomori's aldehyde-fuchsin (GAF) prepared by the method of Mowry et al. (1980) was studied by monitoring the staining characteristics and various chemical properties of ripening GAF solutions. Hydrophilic-hydrophobic characteristics were assessed by reverse-phase thin-layer chromatography; overall molecular sizes, and also the sizes of the conjugated systems, were investigated using hydrophobic gel-filtration. Other properties monitored included the nuclear magnetic resonance and visible spectra, the apparent pH, and the amount of precipitation. It was concluded that for GAF prepared by the Mowry et al. procedure: i. The purple, strongly staining components arising in the first few days of aging are Schiff bases derived from Pararosanilin. ii. These Schiff bases are slowly transformed into a variety of N-ethylated derivatives, which are weakly or non-staining. In addition to these chemical transformations, the quality of staining was markedly influenced by the tendency of GAF to precipitate; as much as three quarters of the dye was sometimes lost in this way during the first few days or weeks.     

Study of molecular heterogeneity and chemical nature of polymeric components of the Meningococcus cell wall]

The high-molecular fraction of substances of the cell wall of meningococci, groups A and B, isolated in free volume in gel filtration through sepharose 4B and containing both group and intergroup antigens proved to be consisting of 2 subfractions in gel-filtration through Bio-Gel A-150m. Molecular weight of the first was within the range of 100--150 million dalton, and of the second--of 3 to 100 million dalton. In dissociation in sodium deoxycholate the high molecular fraction complex compound of the cell wall of meningococcus strain, group A, isolated from the cerebrospinal fluid of a patient suffering from meningitis broke down into 5 fragments differing in chemical nature and mol wt. There were revealed protein and protein-lipopolysaccharide components with a relatively high mol wt. polypeptide components and low molecular residues of the initial lipopolysaccharide.     

The nature of adaptive evolutionary changes: fitness and potential

Ecological potential of an individual can be defined as its viability in the broad sense including the ability to reproduce in various environments. From the biological viewpoint, ecological potential as a fundamental property of an organism is more important than fitness in the genetic sense, which is estimated as the relative rate of reproduction. In essence, fitness reflects the level of implementation of the biological potential. In the process of evolution, regulatory selection results in an increase of fitness: selected forms reproduce more successfully as the population size increases. By contrast, individuals with high ecological potential are more advantageous when the population size decreases, because the probability of their survival in adverse environments is high. Thus, high levels of fitness and ecological potential are achieved via operation of different types of selection.