Bacillus mycoides phages and their satellites

1984 ◽  
Vol 30 (5) ◽  
pp. 691-698 ◽  
Author(s):  
Anna S. Tikhonenko ◽  
Nina N. Belyaeva ◽  
Anna F. Kretova
Keyword(s):  
Inner Core ◽  
Structural Elements ◽  
Small Particles ◽  
Electron Microscopic ◽  
Bacillus Mycoides ◽  
Specific Antibodies ◽  
Helper Phage ◽  
Electron Microscopic Technique ◽  
Large Particles ◽  
The Relationship

The relationship between large and small particles of phages No. 1M and H17 reproducing simultaneously in one and the same bacterial cell of Bacillus mycoides was studied by the immune electron microscopic technique. The large particles of phages No. 1M and H17 were morphologically identical with phage No. 1 of B. mycoides, whereas only the tails of small particles of phages No. 1M and H17 were morphologically identical with the tail of phage No. 1. Antigens were identified in phages No. 1, No. 1M, and H17 using specific antibodies against phage No. 1, containing only large phage particles, and specific antibodies against phage H17 small heads. It was shown that (i) all structural elements of large particles and tails of small particles of phage No. 1M were antigenically identical with those of phage No. 1; (ii) all structural elements of small and large particles of phage H17, except the inner core of the tail, were antigenically different from phage No. 1; and (iii) the small heads of phages No. 1M and H17 were antigenically identical. Particles of phage No. 1 are morphologically and antigenically identical with the large particles of phage No. 1M and are antigenically different from the large particles of phage H17. Since the tails of small and large particles are antigenically identical in each phage pair (No. 1M and H17), this suggests that in both cases, the genome of a small defective phage codes for the synthesis of head proteins only, whereas its tail is borrowed from the corresponding helper phage. The small phage may therefore be considered as a satellite of the large phage which depends on a helper partner for production of complete particles and whose tail proteins are identical with those of the helper phage.

scholarly journals Effects of Microstructures on Fatigue Behavior of an Al-Mg-Sc Alloy at an Elevated Temperature

2012 ◽  
Vol 706-709 ◽  
pp. 426-430 ◽  
Author(s):  
Chihiro Watanabe ◽  
Ryoichi Monzen
Keyword(s):  
Fatigue Life ◽  
Fatigue Behavior ◽  
Cyclic Hardening ◽  
Cyclic Softening ◽  
Small Particles ◽  
Factors Affecting ◽  
Slip Bands ◽  
Large Particles ◽  
Fatigue Characteristics ◽  
The Relationship

Polycrystalline Al-1wt%Mg-0.27wt%Sc alloys bearing Al3Sc particles with different average sizes of 4 and 11nm in diameter have been cyclically deformed at 423K under various constant stress amplitudes, and the relationship between fatigue characteristics and microstructure of the alloy has been investigated. The specimen bearing 11 nm particles exhibited a cyclic hardening to saturation, while in specimens with the small particles a cyclic softening was observed after initial hardening. In the specimen with large particles, dislocations were uniformly distributed under all applied stress amplitudes, whereas the specimens bearing small particles, in which cyclic softening occurred exhibited clearly developed slip bands. The cyclic softening for the latter specimen was explained by particle shearing within the strongly strained slip bands. The width of precipitate free zones (PFZs) has been found to be one of the factors affecting the fatigue life of the specimens at 423K. The two-step aging decreases the width of PFZs, resulting in increase in the fatigue life.

Immunocytochemical Localization of Amyloid Protein AA in the “Dense Fibrillar Inclusions” of the Reticuloendothelical Cells

1977 ◽  
Vol 35 ◽  
pp. 438-439
Author(s):  
T. Shirahama ◽  
M. Skinner ◽  
A.S. Cohen
Keyword(s):  
Amyloid Fibril ◽  
Close Association ◽  
Gel Filtration ◽  
Fibril Formation ◽  
Amyloid Protein ◽  
Electron Microscopic ◽  
Amyloid Deposits ◽  
Amyloid Fibril Formation ◽  
Electron Microscopic Technique ◽  
Lysosomal System

A1thought the mechanisms of amyloidogenesis have not been entirely clarified, proteolysis of the parent proteins may be one of the important steps in the amyloid fibril formation. Recently, we reported that "dense fibrillar inclusions" (DFI), which had the characteristics of lysosomes and contained organized fibrillar profiles as well, were observed in the reticuloendothelial cells in close association with the foci of new amyloid deposits. We considered the findings as evidence for the involvement of lysosomal system in amyloid fibril formation (l). In the present study, we attempted to determine the identity of the contents of the DFI by the use of antisera against the amyloid protein (AA) and an immuno-electron microscopic technique.Amyloidosis was induced in CBA/J mice by daily injections of casein (l). AA was isolated from amyloid-laden spleens by gel filtration and antibody to it was produced in rabbits (2). For immunocytochemistry, the unlabeled antibody enzyme method (3) was employed.

An Electron Microscopic Study of an Avian Reovirus that Causes Arthritis

1971 ◽  
Vol 29 ◽  
pp. 254-255
Author(s):  
E, R. Walker ◽  
N. O. Olson ◽  
M. H. Friedman
Keyword(s):  
Electron Microscopy ◽  
Viral Genome ◽  
Inner Core ◽  
Avian Reovirus ◽  
Electron Microscopic ◽  
Outer Coat ◽  
Acid Type ◽  
Chicken Eggs ◽  
Icosahedral Particle ◽  
Mature Virus

An unidentified virus, responsible for an arthritic-like condition in chickens was studied by electron microscopy and other methods of viral investigation. It was characterized in chorio-allantoic membrane (CAM) lesions of embryonating chicken eggs and in tissue culture as to: 1) particle size; 2) structure; 3) mode of replication in the cell; and 4) nucleic acid type.The inoculated virus, coated and uncoated, is first seen in lysosomal-like inclusions near the nucleus; the virions appear to be uncoated in these electron dense inclusions (Figure 1), Although transfer of the viral genome from these inclusions is not observable, replicating virus and mature virus crystals are seen in the cytoplasm subsequent to the uncoating of the virions.The crystals are formed in association with a mass of fibrils 50 to 80 angstroms in diameter and a ribosome-studded structure that appears to be granular endoplasmic reticulum adapted to virus replication (Figure 2). The mature virion (Figure 3) is an icosahedral particle approximately 75 millimicrons in diameter. The inner core is 45 millimicrons, the outer coat 15 millimicrons, and the virion has no envelope.

Studies of Circular DNA Using a New Electron Microscopic Technique

1973 ◽  
Vol 31 ◽  
pp. 596-597
Author(s):  
C. N. Gordon
Keyword(s):  
Electron Microscopy ◽  
Aqueous Salt Solution ◽  
Contour Length ◽  
Cleavage Surface ◽  
Mica Substrate ◽  
Electron Microscopic ◽  
Replica Technique ◽  
Circular Dna ◽  
Transmission Electron ◽  
Electron Microscopic Technique

Gordon and Kleinschmidt have described a new preparative technique for visualizing DNA by electron microscopy. This procedure, which is a modification of Hall's “mica substrate technique”, consists of the following steps: (a) K+ ions on the cleavage surface of native mica are exchanged for Al3+ ions by ion exchange. (b) The mica, with Al3+ in the exchange sites on the surface, is placed in a dilute aqueous salt solution of DNA for several minutes; during this period DNA becomes adsorbed on the surface. (c) The mica with adsorbed DNA is removed from the DNA solution, rinsed, dried and visualized for transmission electron microscopy by Hall's platinum pre-shadow replica technique.In previous studies of circular DNA by this technique, most of the molecules seen were either broken to linears or extensively tangled; in general, it was not possible to obtain suitably large samples of open extended molecules for contour length measurements.

Fortuna in Translation, Fortuna as Translation

2018 ◽  
Author(s):  
Daniele Miano
Keyword(s):  
Fourth Century ◽  
Fifth Century ◽  
Structural Elements ◽  
Magna Graecia ◽  
The Relationship

This chapter considers the relationship between Fortuna and Tyche as one of translatability. The first half of the chapter focuses on Tyche, with the aim of determining semantic and structural elements common with Fortuna. The second part of the chapter looks at instances in which Fortuna is translated in Greek. The appearance of bronze strigils bearing the epithet soteira from Praeneste in the fourth century BC seems to presuppose this translation, and also points to the salvific meanings of Fortuna as a base for the process of translation. This process of translation had probably occurred through early contacts between Latium, Sicily, and Magna Graecia, where Tyche seems to be associated with salvation already from the fifth century BC. Other instances of translations of Fortuna and Tyche are studied across the Aegean.

scholarly journals Titan Cells Confer Protection from Phagocytosis in Cryptococcus neoformans Infections

2012 ◽  
Vol 11 (6) ◽  
pp. 820-826 ◽  
Author(s):  
Laura H. Okagaki ◽  
Kirsten Nielsen
Keyword(s):  
Cryptococcus Neoformans ◽  
Critical Role ◽  
Cell Formation ◽  
Pulmonary Cryptococcosis ◽  
Content Type ◽  
Cell Production ◽  
Human Fungal Pathogen ◽  
Large Size ◽  
Large Particles ◽  
The Relationship

ABSTRACTThe human fungal pathogenCryptococcus neoformansproduces an enlarged “titan” cell morphology when exposed to the host pulmonary environment. Titan cells exhibit traits that promote survival in the host. Previous studies showed that titan cells are not phagocytosed and that increased titan cell production in the lungs results in reduced phagocytosis of cryptococcal cells by host immune cells. Here, the effect of titan cell production on host-pathogen interactions during early stages of pulmonary cryptococcosis was explored. The relationship between titan cell production and phagocytosis was found to be nonlinear; moderate increases in titan cell production resulted in profound decreases in phagocytosis, with significant differences occurring within the first 24 h of the infection. Not only were titan cells themselves protected from phagocytosis, but titan cell formation also conferred protection from phagocytosis to normal-size cryptococcal cells. Large particles introduced into the lungs were not phagocytosed, suggesting the large size of titan cells protects against phagocytosis. The presence of large particles was unable to protect smaller particles from phagocytosis, revealing that titan cell size alone is not sufficient to provide the observed cross-protection of normal-size cryptococcal cells. These data suggest that titan cells play a critical role in establishment of the pulmonary infection by promoting the survival of the entire population of cryptococcal cells.

Structure of Microphase-Separated Silica/Siloxane Molecular Composites

1989 ◽  
Vol 171 ◽  
Author(s):  
Dale W. Schaefer ◽  
James E. Mark ◽  
David Mccarthy ◽  
Li Jian ◽  
C. -C. Sun ◽  
...  
Keyword(s):  
Phase Separation ◽  
Kinetic Studies ◽  
Organic Content ◽  
Small Particles ◽  
X Ray ◽  
Filled Elastomers ◽  
Polymeric Networks ◽  
Large Particles ◽  
Molecular Composites

ABSTRACTThe structure of several classes of silica/siloxane molecular composites is investigated using small-angle x-ray and neutron scattering. These filled elastomers can be prepared through different synthethic protocols leading to a range of fillers including particulates with both rough and smooth surfaces, particulates with dispersed interfaces, and polymeric networks. We also find examples of bicontinuous filler phases that we attribute to phase separation via spinodal decomposition. In-situ kinetic studies of particulate fillers show that the precipitate does not develop by conventional nucleation-and-growth. We see no evidence of growth by ripening whereby large particles grow by consumption of small particles. Rather, there appears to be a limiting size set by the elastomer network itself. Phase separation develops by continuous nucleation of particles and subsequent growth to the limiting size. We also briefly report studies of polymer-toughened glasses. In this case, we find no obvious correlation between organic content and structure.

scholarly journals Immunoglobulin A antibodies directed againstCampylobacter jejuniflagellin present in breast–milk

1994 ◽  
Vol 112 (2) ◽  
pp. 359-365 ◽  
Author(s):  
I. Nachamkin ◽  
S. H. Fischer ◽  
X.-H. Yang ◽  
O. Benitez ◽  
A. Cravioto
Keyword(s):  
Breast Milk ◽  
Protective Effect ◽  
Statistical Significance ◽  
Immunoglobulin A ◽  
Specific Antibodies ◽  
Breastfed Infants ◽  
Milk Samples ◽  
The Difference ◽  
Campylobacter Infection ◽  
The Relationship

SUMMAYWe studied the relationship between IgA anti–campylobacter flagellin antibodies in breast milk samples and protection of breastfed infants living in a rural Mexican village from campylobacter infection. There were fewer episodes of campylobacter infection (symptomatic and asymptomatic combined) in infants breastfed with milk containing specific anti-flagellin antibodies (1.2/child/year, 95% CI 0.6–1.8) versus non–breastfed children (3.3/child/year, 95% CI 1.8–4.8; P < 0.01). Infants breastfed with milk that was antiflagellin antibody negative by ELISA also had fewer episodes of infection compared with non-breastfed children, but the difference did not reach statistical significance (1.8/child/year, 95% CI 0.7–3.0 versus 3.3/child/year, 95% CI 1.8–4.8, P > 0.05). Breastfeeding has a protective effect against campylobacter infection and is associated with the presence of specific antibodies directed against campylobacter flagellin.

Analysis of the Particles’ Movement Over the Flat and Profiled Rotating Discs surface in the Velocity Layer of the Viscous Gas

2021 ◽  
Vol 6 (2) ◽  
pp. 17-23
Author(s):  
Valeriy I. Pinakov ◽  
Konstantin V. Kulik ◽  
Boris E. Grinberg
Keyword(s):  
Qualitative Difference ◽  
Surface Region ◽  
Vertex Angle ◽  
Oscillation Regime ◽  
Small Particles ◽  
Magnus Force ◽  
Near Surface ◽  
Rotating Discs ◽  
Large Particles ◽  
Velocity Layer

Experiments on the rotating in the air cones with vertex angle β = 120º and flat disc shown that on frequencies Ω ≥ 2.5 hertz exists a qualitative difference in movement for the particles with diameters d ≈ 1 mm and d ≈ 0.1 mm. The particles with d ≈ 0.1 mm move in the near-surface region, the particles with d ≈ 1 mm jump up to 3 cm. Comparison of the spherical and aspheric (ellipsoid with axles d, d and 4 /3 d) particles' kinematics moving shown the inevitability of the large particles jump occurrence. Large particles come to self-oscillation regime by reason of periodically appearance of the Magnus force. Small particles are localized in the velocity layer

scholarly journals Complete Mitogenomic Structure and Phylogenetic Implications of the Genus Ostrinia (Lepidoptera: Crambidae)

Insects ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 232
Author(s):  
Nan Zhou ◽  
Yanling Dong ◽  
Pingping Qiao ◽  
Zhaofu Yang
Keyword(s):  
Control Region ◽  
Ostrinia Nubilalis ◽  
Phylogenetic Analyses ◽  
Structural Elements ◽  
Ostrinia Furnacalis ◽  
Protein Coding ◽  
Phylogenetic Implications ◽  
Ostrinia Scapulalis ◽  
The Relationship ◽  
Rna Genes

To understand mitogenome characteristics and reveal phylogenetic relationships of the genus Ostrinia, including several notorious pests of great importance for crops, we sequenced the complete mitogenomes of four species: Ostrinia furnacalis (Guenée, 1854), Ostrinia nubilalis (Hübner, 1796), Ostrinia scapulalis (Walker, 1859) and Ostrinia zealis (Guenée, 1854). Results indicate that the four mitogenomes—O. furnacalis, O. nubilalis, O. scapulalis, and O. zealis—are 15,245, 15,248, 15,311, and 15,208 bp in size, respectively. All four mitogenomes are comprised of 37 encoded genes and a control region. All 13 protein-coding genes (PCGs) initiate with ATN and terminate with TAN, with the exception of cox1 that starts with CGA, and cox1, cox2, and nad5 that terminate with an incomplete codon T. All transfer RNA genes (tRNAs) present the typical clover-leaf secondary structure except for the trnS1 (AGN) gene. There are some conserved structural elements in the control region. Our analyses indicate that nad6 and atp6 exhibit higher evolution rates compared to other PCGs. Phylogenetic analyses based on mitogenomes using both maximum likelihood (ML) and Bayesian inference (BI) methods revealed the relationship (O. palustralis + (O. penitalis + (O. zealis + (O. furnacalis + (O. nubilalis + O. scapulalis))))) within Ostrinia.

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