Egg morphology and hatching in Mormidea pictiventris (Hemiptera: Pentatomidae)

2001 ◽  
Vol 79 (4) ◽  
pp. 726-736 ◽  
Author(s):  
Klaus W Wolf ◽  
Walton Reid
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Amorphous Material ◽  
Follicle Cells ◽  
Epifluorescence Microscopy ◽  
Stink Bug ◽  
Anterior Plate ◽  
Hexagonal Pattern ◽  
Transmission Electron ◽  
Egg Morphology

Egg morphology and hatching in the stink bug Mormidea pictiventris (Hemiptera: Pentatomidae) are described with the aid of scanning electron microscopy. In addition, the eggshell is analyzed using transmission electron microscopy and the distribution of follicle cells at the surface of ovarian eggs is studied by epifluorescence microscopy using a DNA-specific fluorescent dye. The surface of the barrel-shaped eggs carries numerous slender processes. Binucleate follicle cells, in most cases arranged in a hexagonal pattern, are responsible for the synthesis of this portion of the eggshell. The rim at the anterior pole of the egg is studded at irregular intervals with short columnar processes, the aero-micropylar processes. Hatching occurs at this pole. The prolarva is wrapped in an embryonic cuticle. Its head portion carries a Y-shaped element, the egg-burster. The major features of the inner face of the eggshell are subtle, radially oriented grooves at the anterior plate and a hexagonal pattern to the surface ornamentation throughout the remainder of the eggshell. Transmission electron microscopy revealed that the processes extending from the surface of the eggshell have a coarse texture, while the eggshell proper is composed of amorphous material. The innermost layer, however, has a trabecular organization. The findings in M. pictiventris are compared with morphological observations on the eggshell in other families of Hemiptera and suggestions are made concerning the meaning of the diverse structures.

Structural Investigation of Photoluminescent Porous Si by Transmission Electron Microscopy

1992 ◽  
Vol 281 ◽  
Author(s):  
S. Shih ◽  
K. H. Jung ◽  
D. L. Kwong
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sample Preparation ◽  
Structural Investigation ◽  
Amorphous Material ◽  
Porous Si ◽  
Plan View ◽  
Mesh Structure ◽  
Transmission Electron ◽  
Minimal Damage

ABSTRACTWe have developed a new, minimal damage approach for examination of luminescent porous Si layers (PSLs) by transmission electron microscopy (TEM). In this approach, chemically etched PSLs are fabricated after conventional plan-view TEM sample preparation. A diffraction pattern consisting of a diffuse center spot, characteristic of amorphous material, is primarily observed. However, crystalline, microcrystalline, and amorphous regions could all be observed in selected areas. A crystalline mesh structure could be observed in some of the thin areas near the pinhole. The microcrystallite sizes were 15–150 Å and decreased in size when located further from the pinhole.

Papilla response of barley epidermal cells caused by Erysiphe graminis: rate and method of deposition determined by microcinematography and transmission electron microscopy

1979 ◽  
Vol 57 (8) ◽  
pp. 898-913 ◽  
Author(s):  
Richard J. Zeyen ◽  
W. R. Bushnel
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Amorphous Material ◽  
Time Lapse ◽  
Epidermal Cells ◽  
Erysiphe Graminis ◽  
Sequence Of Events ◽  
Transmission Electron ◽  
Wall Appositions ◽  
Entire Sequence

Papillae were deposited in barley epidermal cells directly beneath appressoria of Erysiphe graminis f. sp. hordei and appeared as hemispherical, internal wall appositions. The papilla response began shortly after the formation of a rapidly moving cytoplasmic aggregate beneath the appressorium. As documented in coleoptile tissue by time-lapse light microcinematography, the papillae grew rapidly for 20–30 min after becoming visible, their radii increasing by 0.1 μm/min. For small papillae, deposition continued for about 30 min; for larger papillae, deposition continued for 120–180 min. Results with transmission electron microscopy on leaf epidermal cells suggested that papilla deposition by host cytoplasmic aggregates can be divided into four sequential stages: (i) the deposition of osmiophilic (lipidic) materials, (ii) the deposition and partial compaction of nonosmiophilic, amorphous material (probably insoluble polysaccharides), (iii) compaction of nonosmiophilic, amorphous material, and (iv) the incorporation of osmiophilic material into the host wall and into the compacted nonosmiophilic, amorphous material. At maturity, the papillae are hardened, electron-opaque wall appositions that may be effective in preventing fungal penetration and development. Failure of papillae to prevent fungal penetration and development may be related to the inability of the epidermal cells to complete the entire sequence of events in papilla deposition before attempted fungal penetration.

scholarly journals Dietary Supplements of Barley and Date-Palm Fruit Improved the Growth Defects of Ovaries of Rat Offspring Maternally Fed on Hypercholesterolemic Diet

2019 ◽  
Vol 16 (2) ◽  
pp. 359-376 ◽  
Author(s):  
Hassan I. H. El-Sayyad ◽  
Ahmed A. El-mansi ◽  
Samia M. Efekrin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Caspase 3 ◽  
Date Palm ◽  
The Other ◽  
Follicle Cells ◽  
Lactation Period ◽  
Palm Fruit ◽  
Transmission Electron ◽  
Hypercholesterolemic Diet

Increased consumption of processing food items rich in fat diet increased lipid laden products in body organs and developed obesity. It is also associated with the development of infertility. The present study designed to illustrate the developmental aspects of ovaries of offspring maternally fed on a high cholesterol diet and how supplementation of barley and date palm fruit to this die improved the ovarian structure and function. Ninety-six pregnant Wister albino rats categorized into eight groups (n=12); control (C), barley (B) (20%), dates (D) (20%) , barley & dates (10+10%) , hypercholesterolemic- (H), hypercholesterolemic & barley (H+B), hypercholesterolemic & dates (H+D) and hypercholesterolemic & barley & dates groups (H+B+D). Hypercholesterolemic diet (3% cholesterol) was intake for 6 weeks before conception and throughout gestation and lactation period. At 2 and 3 weeks post- partum, the offspring were sacrificed and their ovaries were removed and processed for histological, immunohistochemical and transmission electron microscopy. Sera and ovaries of the other groups were kept in refrigerator for biochemical investigations. The present findings revealed loss of ovarian follicles in offspring maternally fed in hypercholesterolemic groups associated with decreased expression of PCNA and over expression of caspase 3 and flow-cytometric analysis of annexin V manifesting cell death. At transmission electron microscopy, the ovaries of hypercholesterolemic group exhibited dense chromatin condensation of the nuclei of oocyte and follicle cells. On the other hand, the ovaries of offspring maternally fed on hypercholesterolemic diet plus barley and date palm fruit improved the decreased activities of catalase, superoxide dismutase and glutathione-s- transferase in comparison with the control. However, there was a marked increase of malondialdehyde, 8-hydroxy-2`-deoxyguanosine, caspase 3 and tumor necrosis factor-α in comparison with the control. Also, the sera levels of hyperocholesterolemic mothers such as follicle stimulating hormone, estradiol, and antimullerian hormone were almost retained to the normal level in animal groups fed on hypercholesterolemic diet containing dates /or barley grains. The authors finally concluded that offspring maternally fed on hypercholesterolemic diet developed reduction of ovarian follicular reserve, increases lipid peroxidation and altered maternal reproductive hormone involved in ovarian development. These dramatic alterations were improved post supplementing date palm fruits and/barley to the hypercholesterolemic diet.

Deformation under nanoindents in Si, Ge, and GaAs examined through transmission electron microscopy

2001 ◽  
Vol 16 (12) ◽  
pp. 3347-3350 ◽  
Author(s):  
S. J. Lloyd ◽  
J. M. Molina-Aldareguia ◽  
W. J. Clegg
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cross Sections ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Amorphous Material ◽  
Face Centered Cubic ◽  
Dislocation Generation ◽  
Transmission Electron ◽  
Face Centered

Cross sections through nanoindents on Si, Ge, and GaAs {001} were examined through transmission electron microscopy. A focused ion beam workstation was used to machine electron transparent windows through the indents. In both Si and Ge there was a transformed zone immediately under the indent composed of amorphous material and a mixture of face-centered-cubic and body-centered cubic crystals. Cracking and dislocation generation were also observed around the transformed zone. In GaAs the dominant deformation mechanism was twinning on the {11} planes. The hardness of these materials is discussed in light of these observations and their macroscopic material properties such as phase transformation pressure.

Chrysanthemum phloem necrosis: detection by epifluorescence microscopy

1989 ◽  
Vol 67 (4) ◽  
pp. 1024-1031
Author(s):  
R. J. McGovern ◽  
R. K. Horst ◽  
H. W. Israel
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nucleic Acid ◽  
Acridine Orange ◽  
Ethidium Bromide ◽  
Diagnostic Procedures ◽  
Epifluorescence Microscopy ◽  
Transmission Electron ◽  
Phloem Necrosis ◽  
Mycoplasmalike Organisms

In epifluorescence diagnostic procedures for chrysanthemum phloem necrosis, autofluorescence, aniline blue, and various nucleic acid "specific" fluorochromes such as 33258-Hoechst, 4′,6-diamidino-2-phenyl-indole-dichloride, berberine sulfate, ethidium bromide, and acridine orange were utilized. Increased fluorescence in foliar phloem correlated precisely with gross symptoms of chrysanthemum phloem necrosis by all techniques and was used, in the case of berberine sulfate, to facilitate detection of mycoplasmalike organisms by transmission electron microscopy.

Ionization-induced effects in amorphous apatite at elevated temperatures

2008 ◽  
Vol 23 (4) ◽  
pp. 962-967 ◽  
Author(s):  
In-Tae Bae ◽  
Yanwen Zhang ◽  
William J. Weber ◽  
Manabu Ishimaru ◽  
Yoshihiko Hirotsu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Beam ◽  
Elevated Temperatures ◽  
Amorphous Material ◽  
Transmission Electron ◽  
Oxygen Migration ◽  
Structural Contrast

Electron-beam-induced effects in preamorphized Sr2Nd8(SiO4)6O2 were investigated in situ using transmission electron microscopy with 200-keV electrons at temperatures ranging from 380 to 780 K. Within the electron-irradiated area, epitaxial recrystallization was observed from the amorphous/crystalline interface toward the surface, with the rate of recrystallization increasing as temperature increased from 380 to 580 K. Structural contrast features (i.e., O deficient amorphous material), as well as recrystallization, were observed outside of the irradiation area at temperatures from 680 to 780 K. Ionization-induced processes and local nonstoichiometry induced by oxygen migration and desorption are possible mechanisms for the electron-beam- induced recrystallization and for the formation of the structural contrast features, respectively.

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