Robert Rasch

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Amounts of Feulgen staining in individual sperm nuclei of Drosophila melanogaster were determined with a scanning microdensitometer and compared with the DNA-Feulgen levels found for hen erythrocyte nuclei, taken as a presumed cytophotometric standard of 2.5×10−12 g DNA per cell. Under these conditions, the amount of DNA estimated for the haploid male(More)
Amounts of chromosomal DNA were estimated for Feulgen-stained, ovarian cells from flies carrying certain mutant alleles of the otu (ovarian tumor) gene. Epithelial sheath cells and lumen cells were found to contain the diploid (2C) amount of DNA and therefore served as internal, cytophotometric standards. Mitotically active follicle cells over young(More)
Lack of appropriate software support for microprocessor program development has previously limited the applications of such technology in the field of microspectrophotometry. This paper describes our use of a Vickers M86 integrating microdensitometer coupled through a custom-designed interface circuit to a Processor Technology SOL III microcomputer. W e(More)
A method of improving absorption cytophotometric cellular DNA values by making measurements on Feulgenstained cells at optimal stain absorbances has been developed. Stain intensity can be controlled either by alteration of the Feulgen staining reaction or by selection of "off-peak" wavelengths of light for cytometry. The use of chicken red blood cells as an(More)
Natural populations of triploid females resembling the gynogenetic teleost, Poecilia formosa (Girard), occur in northeastern Mexico where they intermingle with diploid populations of this species and the members of congeneric bisexual species such as P. mexicana or P. latipinna. Mitotic configurations from gill epithelial cells show 46 chromosomes for the(More)
We have developed a method of calculating the average local absorbance (ALA) of a nucleus from the integrated nuclear absorbance and area. One can use the ALA, along with nuclear areas measured at different point absorbance thresholds, to determine whether a nucleus is stained too lightly or too darkly for accurate absorption measurements; this allows(More)
The US Army Battle Command Battle Lab conducted an experiment with the ICCES system -- an integrated decision aid for performing several critical steps of a US Army Brigade Military Decision Making Process: from capturing a high-level Course of Action to producing a detailed analysis and plan of tasks. The system integrated several available technologies(More)