The microsporidian spore invasion tube. III. Tube extrusion and assembly.

The polar filaments within microsporidian spores discharges as tubes with subsecond velocity. Populations of discharging tubes of Glugea hertwigi spores pulse-labeled with latex particles for 1-3 s were consistently devoid of label at the distal ends; discharging tubes were completely labeled after 30- to 60-s exposure to latex. This experiment indicates that discharge tubes grow at the tip. Completely assembled discharge tubes consisted of single, empty cylinders; however, incompletely discharged tubes had a cylinder-within-a-cylinder profile at the distal ends. This observation indicates that the discharge tube material emerges at the distal end by an eversion process. Finally, studies with cinematic Nomarski interference optics of spore tubes extruding across a water-air interphase indicate that all the material emerging from the growing tip of the tube is incorporated into the wall of the discharge tube. Evidence indicates that the polar filament of undischarged spores is a homogeneous coil of polar tube protein equivalent to the polar tube protein in discharged tubes.

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The role of resonance radiation in the propagation of a positive pre-breakdown ionization wave in long discharge tubes

Plasma Sources Science and Technology ◽

10.1088/1361-6595/ac3ba0 ◽

2021 ◽

Author(s):

Aleksei V Siasko ◽

Yuri B Golubovskii ◽

Sergei Valin

Keyword(s):

Discharge Tube ◽

Tube Wall ◽

Finite Size ◽

Ionization Wave ◽

Photon Flux ◽

Photon Flux Density ◽

Radiation Trapping ◽

Discharge Tubes ◽

Electron Photoemission

Abstract The work is devoted to calculating the ﬂux of resonance photons towards the boundary of a cylindrical discharge tube of a ﬁnite size during the propagation of a pre-breakdown ionization wave of positive polarity. A cylindrical discharge tube of ﬁnite dimensions with argon at the pressure of p=1 Torr is considered. The propagation mechanisms of metastable and resonance atoms are compared. For the considered discharge conditions, the space-time distributions of metastable and resonance atoms are calculated. The manuscript presents a technique for calculating the ﬂux of resonance photons onto the discharge tube wall with the account of the radiation trapping. It is shown that for the studied conditions the photon ﬂux density towards the longitudinal boundary of the tube ahead of the ionization wave can reach 1013 cm-2s-1. The obtained results allow describing the appearance of seed electrons ahead of the positive ionization wavefront during its propagation due to the electron photoemission from the discharge tube wall.

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The discharge tube material influence on N2–O2 DC glow discharge

Vacuum ◽

10.1016/s0042-207x(02)00240-3 ◽

2002 ◽

Vol 67 (3-4) ◽

pp. 415-420 ◽

Cited By ~ 4

Author(s):

A Kaňka ◽

O Kylián ◽

V Hrachová

Keyword(s):

Glow Discharge ◽

Discharge Tube ◽

Dc Glow Discharge ◽

Tube Material

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Improving Sound Rating of the Out Door Unit by Modifying Discharge Tube Design

Volume 9: Mechanical Systems and Control, Parts A, B, and C ◽

10.1115/imece2007-41078 ◽

2007 ◽

Author(s):

Parag H. Mathuria ◽

Macinissa Me´zache

Keyword(s):

Discharge Tube ◽

Air Conditioning ◽

Power Level ◽

Sound Power ◽

Efficiency Ratio ◽

Air Conditioning System ◽

Sound Power Level ◽

Discharge Tubes ◽

Air Conditioning Systems ◽

Made In

In today competitive market, Seasonal Energy Efficiency Ratio (SEER) and sound rating of the out door unit of an air conditioning system are strong marketing and selling parameters. Air conditioning systems consist of an indoor unit and an outdoor unit. The sound of the indoor unit is mainly radiated by the blower or fan of the unit. The outdoor unit has three major components, namely, a compressor, a condenser coil and a fan. In general, the sound power levels produced by the outdoor unit are dominated by the fan, and in some cases, the fan and the compressor. In more recent designs, significant improvement has been made in the sound performance of the fan itself, resulting in a challenge to compressor manufacturers to produce quieter compressors. In this case, compressor-system interaction becomes a serious issue with reference to noise generation. The vibration energy of the compressor is transmitted to the system through the suction and discharge tubes, and the mounting feet. Air conditioning manufacturers are faced with the challenge of eliminating these sources of excitation to improve the sound rating and, more importantly, design better quality products. The main object of the paper is to modify the design of the discharge tube using an experimental iterative approach. A reduction of 2 dB has been achieved in the total sound power level of the system. On the dominant one third octave bands, sound power levels are reduced up to 7 dB. The results of this investigation will serve as the basis for the development of an analytical designed tool for air conditioning system design. These results were validated on four systems.

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Discharge-Tube Material and Ceramic-to-Metal Seal

The High-Pressure Sodium Lamp ◽

10.1007/978-1-349-09196-6_8 ◽

1986 ◽

pp. 227-257

Author(s):

J. J. de Groot ◽

J. A. J. M. van Vliet

Keyword(s):

Discharge Tube ◽

Tube Material ◽

Metal Seal

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The spectrum of ionized tellurium—extension of Te III

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1937.0040 ◽

1937 ◽

Vol 158 (895) ◽

pp. 562-570 ◽

Cited By ~ 5

Keyword(s):

Discharge Tube ◽

Royal Society ◽

Quartz Window ◽

Adequate Supply ◽

Boiling Points ◽

Considerable Portion ◽

Partial Analysis ◽

Discharge Tubes ◽

Sufficient Intensity ◽

Very High

In a former communication* to the Royal Society, a partial analysis of the spectrum of Te III was reported, wherein the terms and the term combinations of the 5 p ,5 d ,and 6 p configurations were recorded. The multiplets in the quartz region, embodying the combinations of the 6 d , sp 3 , and 7 s terms could not be brought out with sufficient intensity on the photographic plates, owing to the difficulty of maintaining an adequate supply of tellurium vapour in the discharge tube. The melting and boiling points of tellurium being very high, the heating necessary for this purpose was so great that discharge tubes made even of pyrex glass were found to collapse during the experiment. In these later experiments, therefore, a discharge tube made of quartz, and of the design indicated in fig. 1, was used. The end A remained closed permanently, a quartz window being fused to it. This facilitated strong heating of a considerable portion of the tube including the capillary, the capillary itself being kept filled with the vapour of tellurium metal by continuous evacuation of the tube throughout the time of the exposure. This device was found to be very effective, the desired multiplets appearing with sufficient intensity on the photographic plates. The instrument used in photographing the spectrum was the Hilger large Littrow type E 1 . The discharge was maintained by a ½-kilowatt transformer, used in conjunction with a condenser of capacity of 0·02 mf. The exposures lasted for two or three hours. Predicted Terms Of the terms in Te III, predicted by Hund’s theory, those due to the 5 p , 5 d ,and 6 p configurations were identified in the previous work. The remaining terms, i. e .,those due to higher configurations only, are given in Table I.

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The microsporidian spore invasion tube. The ultrastructure, isolation, and characterization of the protein comprising the tube.

The Journal of Cell Biology ◽

10.1083/jcb.71.1.23 ◽

1976 ◽

Vol 71 (1) ◽

pp. 23-34 ◽

Cited By ~ 65

Author(s):

E Weidner

Keyword(s):

Molecular Weight ◽

Sodium Dodecyl ◽

Low Molecular Weight ◽

Two Dimensional ◽

Polar Tube ◽

Isolation And Characterization ◽

Disulfide Linkages ◽

Microsporidian Spore ◽

Ph Range

The extrusion apparatus of the microsporidian parasitic protozoan Nosema michaelis discharges an invasion (or polar) tube with a velocity suitalbe for piercing cells and injecting infective sporoplasm. The tube is composed of a polar tube protein (PTP) which consists of a single, low molecular weight polypeptide slightly smaller than chymotrypsinogen-A. Assembled PTP tubes resist dissociation in sodium dodecyl sulfate and brief exposures in media at extreme ends of the pH range; however, the tubes are reduced by mercaptoethanol and dithiothreitol. When acidified, mercaptoethanol-reduced PTP self-assembles into plastic, two-dimensional monolayers. Dithiothreitol-reduced PTP will not reassemble when acidified. Evidence is presented which indicates that PTP is assembled as a tube within the spore; that the ejected tube has plasticity during sporoplasm passage; and, finally, that the subunits within the tube polymer are bound together, in part, by interprotein disulfide linkages.

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Branching Network of Proteinaceous Filaments within the Parasitophorous Vacuole ofEncephalitozoon cuniculiandEncephalitozoon hellem

Infection and Immunity ◽

10.1128/iai.01152-10 ◽

2011 ◽

Vol 79 (3) ◽

pp. 1374-1385 ◽

Cited By ~ 8

Author(s):

Kaya Ghosh ◽

Eddie Nieves ◽

Patrick Keeling ◽

Jean-Francois Pombert ◽

Philipp P. Henrich ◽

...

Keyword(s):

Host Cell ◽

Parasitophorous Vacuole ◽

Spore Wall ◽

Human Pathogens ◽

Polar Tube ◽

Molecular Approaches ◽

Resting Spore ◽

Intracellular Parasites ◽

Significant Pathology ◽

Microsporidian Spore

ABSTRACTThe microsporidia are a diverse phylum of obligate intracellular parasites that infect all major animal groups and have been recognized as emerging human pathogens for which few chemotherapeutic options currently exist. These organisms infect every tissue and organ system, causing significant pathology, especially in immune-compromised populations. The microsporidian spore employs a unique infection strategy in which its contents are delivered into a host cell via the polar tube, an organelle that lies coiled within the resting spore but erupts with a force sufficient to pierce the plasma membrane of its host cell. Using biochemical and molecular approaches, we have previously identified components of the polar tube and spore wall of the Encephalitozoonidae. In this study, we employed a shotgun proteomic strategy to identify novel structural components of these organelles inEncephalitozoon cuniculi. As a result, a new component of theE. cuniculideveloping spore wall was identified. Surprisingly, using the same approach, a heretofore undescribed filamentous network within the lumen of the parasitophorous vacuole was discovered. This network was also present in the parasitophorous vacuole ofEncephalitozoon hellem. Thus, in addition to further elucidating the molecular composition of seminal organelles and revealing novel diagnostic and therapeutic targets, proteomic analysis-driven approaches exploring the spore may also uncover unknown facets of microsporidian biology.

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