A simple integrating attachment for Servo recorders.
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Autoanalysis↗
Biomedical subjects
R L Morris
Publications and source records attributed to R L Morris.
Actinomycete: isolation and identification of agent responsible for musty odors.
A compound produced by certain actinomycete cultures is responsible for a persistent musty odor. It has been isolated in high purity and identified by chemical and spectroscopic properties. Possible structures are discussed.
Actinomycetales↗
Pesticide and mercury levels in migrating duck populations.
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Adipose Tissue↗
Some properties of the histone-like protein from Crypthecodinium cohnii (HCc).
The histone-like protein from Crypthecodinium cohnii (HCc) was examined in regard to its amino acid composition and the peptide pattern resulting from protease digestion. A revised amino acid composition indicated a higher lysine and arginine content and a lower glycine content than that determined previously. Comparative peptide mapping of HCc with HTa, a histone-like protein from Thermoplasma acidophilum, and with a histone-like protein from the dinoflagellate Gyrodinium dorsum showed significant differences in the peptide patterns produced.
Amino Acids↗
Analysis of Chlamydomonas reinhardtii histones and chromatin.
Chromatin spreads made from isolated nuclei of the unicellular green alga Chlamydomonas reinhardtii show the beaded fibers typical of eukaryotic polynucleosomes. Micrococcal nuclease digestions confirmed the presence of nucleosomes with a repeat length of 189 base pairs, essentially the same as typical mammalian cells. Basic nuclear proteins extracted from isolated nuclei or chromatin with 1 M calcium chloride and 0.3 M hydrochloric acid are resolved into seven major components by electrophoresis in the presence of sodium dodecyl sulfate (SDS). These seven components were subjected to qualitative peptide mapping with V8 protease on SDS gels for comparison with the major histone components of calf thymus. Finally, the C. reinhardtii basic nuclear proteins were fractionated by reversed phase high performance liquid chromatography and their amino acid composition determined. From these studies, we conclude that C. reinhardtii has a full complement of the five histones with properties very similar to those of both higher animals and higher plants.
Amino Acids↗
Analysis of lysine-rich histones from the unicellular green alga Chlamydomonas reinhardtii.
The H1 histones of the unicellular green alga Chlamydomonas reinhardtii were extracted from isolated nuclei, fractionated by high performance liquid chromatography, and analyzed by two-dimensional electrophoresis, peptide mapping, and N-terminal sequencing. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of 5% perchloric acid extracts of isolated C. reinhardtii nuclei revealed two H1 proteins (H1A and H1B). Two-dimensional gel analysis did not reveal heterogeneity of either algal H1 protein, but did detect differences in the hydrophobic amino acid content of the C. reinhardtii H1A and H1B. Digestion of H1A and H1B with V8 protease revealed two distinctly different peptide maps. C. reinhardtii H1 peptide maps were not at all similar to those of Pisum H1, but algal and pea H2B peptide maps did show some peptides in common. Seventeen amino acid residues were obtained from C. reinhardtii H1A amino terminal sequencing, while the H1B N-terminus was blocked. A search of protein data bases revealed no sequence homology of the H1A N-terminus with any known protein. Chlamydomonas histones fractionated by high performance liquid chromatography revealed minor components (histone variants) for H2A and H2B. The amino acid composition of Chlamydomonas lysine-rich histones was compared to those of various other unicellular algae.
Amino Acid Sequence↗
A water phantom controller for automated acquisition of linac beam parameters.
Three-dimensional water phantoms are routinely used when acquiring the data necessary to commission medical linear accelerators. A new water phantom controller has been developed at our institution that is unique in several aspects. The water phantom controller is based on an IBM XT compatible computer. This has been interfaced to an Artronix three-dimensional water phantom and a commercially available linac setup controller. Some of the unique features of the new controller are (i) its ability to perform three-dimensional coordinate transformations on the fly (this removes the need to level and align the water tank with the beam axes and greatly reduces setup time). (ii) Its ability to communicate with a device which can control the linac operating parameters (this allows the water phantom controller to adjust, for example, the jaw size of the accelerator as it acquires data). (iii) Its ability to output the acquired data in a number of modes, including screen display, hardcopy plot, or disk file that may be transferred to a central treatment planning computer). (iv) Its ability to digitally process the acquired data. This water phantom controller may be used to gather machine data in a highly automated manner, greatly reducing the time required to gather the desired data.
Computers↗
Consulting for clinical engineers.
Part-time consulting provides professional stimulation, supplemental income, and improved professional status, and is very satisfying. Most consults have an end point, resulting in a sense of accomplishment that is sometimes difficult to achieve in the course of normal duties. I encourage everyone with an interest to try consulting.
Biomedical Engineering↗