Morphological aspects of surface reactions. Progress report, March 1993--March 1994

I should like to give you a very condensed progress report on some spectrophotometric measurements of objective-prism spectra made in collaboration with H. Leicher at Bonn. The procedure used is almost completely automatic. The measurements are made with the help of a semi-automatic fully digitized registering microphotometer constructed by Hög-Hamburg. The reductions are carried out with the aid of a number of interconnected programmes written for the computer IBM 7090, beginning with the output of the photometer in the form of punched cards and ending with the printing-out of the final two-dimensional classifications.

Download Full-text

Progress report on 21-cm observations at low latitude between longitudes (l 11) 0° and 66°

Symposium - International Astronomical Union ◽

10.1017/s0074180900100907 ◽

1967 ◽

Vol 31 ◽

pp. 177-179

Author(s):

W. W. Shane

Keyword(s):

Preliminary Report ◽

Progress Report ◽

Galactic Centre ◽

Low Latitude ◽

The Third ◽

Introductory Lecture ◽

Centre Region

In the course of several 21-cm observing programmes being carried out by the Leiden Observatory with the 25-meter telescope at Dwingeloo, a fairly complete, though inhomogeneous, survey of the regionl11= 0° to 66° at low galactic latitudes is becoming available. The essential data on this survey are presented in Table 1. Oort (1967) has given a preliminary report on the first and third investigations. The third is discussed briefly by Kerr in his introductory lecture on the galactic centre region (Paper 42). Burton (1966) has published provisional results of the fifth investigation, and I have discussed the sixth in Paper 19. All of the observations listed in the table have been completed, but we plan to extend investigation 3 to a much finer grid of positions.

Download Full-text

Electron Microscopy of Mycoplasma Pneumoniae

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065341 ◽

1971 ◽

Vol 29 ◽

pp. 258-259 ◽

Cited By ~ 1

Author(s):

E. S. Boatman ◽

G. E. Kenny

Keyword(s):

Electron Microscopy ◽

Light Microscopy ◽

Growth Phase ◽

Hela Cells ◽

Sulfonic Acid ◽

Gamma Globulin ◽

Horse Serum ◽

Morphological Aspects ◽

The Family

Information concerning the morphology and replication of organism of the family Mycoplasmataceae remains, despite over 70 years of study, highly controversial. Due to their small size observations by light microscopy have not been rewarding. Furthermore, not only are these organisms extremely pleomorphic but their morphology also changes according to growth phase. This study deals with the morphological aspects of M. pneumoniae strain 3546 in relation to growth, interaction with HeLa cells and possible mechanisms of replication.The organisms were grown aerobically at 37°C in a soy peptone yeast dialysate medium supplemented with 12% gamma-globulin free horse serum. The medium was buffered at pH 7.3 with TES [N-tris (hyroxymethyl) methyl-2-aminoethane sulfonic acid] at 10mM concentration. The inoculum, an actively growing culture, was filtered through a 0.5 μm polycarbonate “nuclepore” filter to prevent transfer of all but the smallest aggregates. Growth was assessed at specific periods by colony counts and 800 ml samples of organisms were fixed in situ with 2.5% glutaraldehyde for 3 hrs. at 4°C. Washed cells for sectioning were post-fixed in 0.8% OSO4 in veronal-acetate buffer pH 6.1 for 1 hr. at 21°C. HeLa cells were infected with a filtered inoculum of M. pneumoniae and incubated for 9 days in Leighton tubes with coverslips. The cells were then removed and processed for electron microscopy.

Download Full-text