Increasingly Parallel Pressure Anisotropic Ballooning: Substorm Growth Phase Drift Orbits Resulting in a Locally Ballooning Unstable Geomagnetic Tail

2020 ◽  
Vol 125 (10) ◽  
Author(s):  
L. R. Oberhagemann ◽  
I. R. Mann
Keyword(s):  
Growth Phase ◽  
Phase Drift ◽  
Geomagnetic Tail ◽  
Drift Orbits

Particle scattering and current sheet stability in the geomagnetic tail during the substorm growth phase

1992 ◽  
Vol 97 (A12) ◽  
pp. 19283 ◽  
Author(s):  
T. I. Pulkkinen ◽  
D. N. Baker ◽  
R. J. Pellinen ◽  
J. Büchner ◽  
H. E. J. Koskinen ◽  
...  
Keyword(s):  
Current Sheet ◽  
Growth Phase ◽  
Particle Scattering ◽  
Geomagnetic Tail

The Reconnection Substorm

1996 ◽  
Author(s):  
Charles F. Kennel
Keyword(s):  
Growth Phase ◽  
Magnetospheric Substorms ◽  
Geomagnetic Tail ◽  
Polar Caps ◽  
Auroral Substorm ◽  
Reconnection Region ◽  
Dayside Magnetopause ◽  
Ionospheric Electric Field ◽  
Propagation Of Waves ◽  
Reconnection Model

The reconnection model of magnetospheric substorms was designed 20 years ago to rationalize the time-dependent changes in the magnetospheric structure associated with auroral substorms. By 1970, it was becoming apparent that there was a characteristic sequence of events prior to auroral onset: The dayside magnetopause moved earthward, the inner edge of the cross-tail current sheet approached the earth, the field strength in the tail lobes increased, and the magnetic flux in the polar caps and tail lobes increased, all while the evening side aurora were migrating equatorward prior to onset. The increase in lobe magnetic field clearly suggested that the growth phase commenced with an increase in the dayside reconnection rate. By the early 1980s, studies quantitatively correlating the ionospheric electric field with southward interplanetary field had confirmed that the changes in structure accompanied enhanced convection as had been suspected all along. Both were related somehow to substorms. There was no other choice in the reconnection model but to spotlight its two reconnection events, at the dayside magnetopause and in the plasma sheet on the nightside, as the “main events” in the magnetospheric substorm. Dayside reconnection clearly initiated the growth phase, and tail reconnection had to follow with some delay. It seemed natural to associate tail reconnection with the onset of the auroral substorm. Sections 7.2 through 7.6 are devoted to growth-phase phenomenology. Section 7.2 deals with the changes in magnetopause position that follow a single isolated southward shift of the interplanetary field, and Section 7.3 deals with the changes in the geomagnetic tail that occur as a result. These changes take place as the rate of convection builds up in the ionosphere (Section 7.4) and the dayside magnetosphere (Section 7.5). A growth phase that begins with enhanced dayside reconnection has to lead to enhanced tail reconnection—the second key event in the reconnection model of substorms. In an MHD model, the time and place where the new reconnection event takes place is determined by the propagation of waves along the characteristics connecting the dayside reconnection region to the tail lobes (Section 7.6).

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

Electron Microscopy of Mycoplasma Pneumoniae

1971 ◽  
Vol 29 ◽  
pp. 258-259 ◽  
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.

Immunocytochemical studies on the behavior of RuBisCO and LHCP II during the cell cycle of synchronized Euglena gracilis

1990 ◽  
Vol 48 (3) ◽  
pp. 662-663
Author(s):  
Tetsuaki Osafune ◽  
Shuji Sumida ◽  
Tomoko Ehara ◽  
Eiji Hase ◽  
Jerome A. Schiff
Keyword(s):  
Cell Cycle ◽  
Immunoelectron Microscopy ◽  
Growth Phase ◽  
Euglena Gracilis ◽  
Dark Period ◽  
Light Period ◽  
Carboxylase Activity ◽  
Immunocytochemical Studies ◽  
Lhcp Ii

Changes in the morphology of pyrenoid and the distribution of RuBisCO in the chloroplast of Euglena gracilis were followed by immunoelectron microscopy during the cell cycle in a light (14 h)- dark (10 h) synchronized culture under photoautotrophic conditions. The imrnunoreactive proteins wereconcentrated in the pyrenoid, and less densely distributed in the stroma during the light period (growth phase, Fig. 1-2), but the pyrenoid disappeared during the dark period (division phase), and RuBisCO was dispersed throughout the stroma. Toward the end of the division phase, the pyrenoid began to form in the center of the stroma, and RuBisCO is again concentrated in that pyrenoid region. From a comparison of photosynthetic CO2-fixation with the total carboxylase activity of RuBisCO extracted from Euglena cells in the growth phase, it is suggested that the carboxylase in the pyrenoid functions in CO2-fixation in photosynthesis.

A freeze-fracture-etched study of the physarum polycephalum plasma membrane during early formation of the macroplasmodial stage

1993 ◽  
Vol 51 ◽  
pp. 346-347
Author(s):  
Randolph W. Taylor ◽  
Henrie Treadwell
Keyword(s):  
Plasma Membrane ◽  
Life Cycle ◽  
Growth Phase ◽  
Filter Paper ◽  
Physarum Polycephalum ◽  
Freeze Fracture ◽  
Petri Dish ◽  
Wire Screen ◽  
Wide Mouth ◽  
Sterile Filter

The plasma membrane of the Slime Mold, Physarum polycephalum, process unique morphological distinctions at different stages of the life cycle. Investigations of the plasma membrane of P. polycephalum, particularly, the arrangements of the intramembranous particles has provided useful information concerning possible changes occurring in higher organisms. In this report Freeze-fracture-etched techniques were used to investigate 3 hours post-fusion of the macroplasmodia stage of the P. polycephalum plasma membrane.Microplasmodia of Physarum polycephalum (M3C), axenically maintained, were collected in mid-expotential growth phase by centrifugation. Aliquots of microplasmodia were spread in 3 cm circles with a wide mouth pipette onto sterile filter paper which was supported on a wire screen contained in a petri dish. The cells were starved for 2 hrs at 24°C. After starvation, the cells were feed semidefined medium supplemented with hemin and incubated at 24°C. Three hours after incubation, samples were collected randomly from the petri plates, placed in plancettes and frozen with a propane-nitrogen jet freezer.

Phase Drift Phenomenon in Dual Active Bridge Converter – Analysis and Compensation

2015 ◽  
Vol 10 (1) ◽  
pp. 1 ◽  
Author(s):  
Vesa Väisänen ◽  
Jani Hiltunen ◽  
Raimo Juntunen
Keyword(s):  
Phase Drift ◽  
Dual Active Bridge
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