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  • Ultrastructure  (12)
  • Coleoptera  (5)
  • Maize  (4)
  • Springer  (21)
  • Annual Reviews
  • National Academy of Sciences
  • Springer Science + Business Media
  • 1980-1984  (21)
  • 1980  (21)
Collection
Keywords
Publisher
  • Springer  (21)
  • Annual Reviews
  • National Academy of Sciences
  • Springer Science + Business Media
Years
  • 1980-1984  (21)
Year
  • 1
    ISSN: 1432-0878
    Keywords: Ecdysteroids ; Moulting hormones ; Xyleborus ferrugineus pupae ; Ultrastructure ; Prothoracic gland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The prothoracic glands of female pupae of Xyleborus ferrugineus at three ages (0-h, 48-h and 72-h-old) were examined for ultrastructural changes that correlate with high titers of ecdysteroids in the entire pupa. In all three ages, the prothoracic gland cells appear compact with a prominent nucleus. Lysosome-like structures with concentrically oriented internal membrane are observed in both 0-h and 72-h-old gland cells. Mitochondria are abundant in the glands of both ages, and rough endoplasmic reticulum is relatively sparse. Numerous microtubules are present in the prothoracic gland cells of 48-h-old female pupae that contain relatively high titers of ecdysteroids. Rough endoplasmic reticulum also is especially abundant at this age of the pupa. Ecdysone titers, estimated by the radioimmunoassay method (RIA), were 161.04±22.61 pg/mg, 704.25±69.02 pg/mg and 298.72±26.80pg/mg body weight in 0-h, 48-h and 72-h-old female pupae, respectively.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 211 (1980), S. 391-403 
    ISSN: 1432-0878
    Keywords: Ocelli ; Dinopid spider ; Ultrastructure ; Optics ; Evolution of nocturnal eye
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The posterior median (pm) eyes of the dinopid spider Menneus unifasciatus L. Koch are described and compared with the pm eyes of Dinopis, which are highly specialised for night vision. The lenses of Menneus have F-numbers of 0.72 compared to 0.58 in Dinopis, the distance between receptors is ca. 4.0 μm compared to 20–22 μm for Dinopis, and image quality is matched to receptor spacing. The lens of Menneus is simple, while that of Dinopis comprises two components of different refractive indices (Blest and Land 1977). Receptive segments of the pm eyes of Dinopis are hexagonal in transverse section and those of adjacent cells are tightly contiguous, allowing the possibility of both optical and electrical coupling (Blest 1978). Receptive segments of Menneus are separated from each other by glial processes containing little pigment, and each segment possesses two rhabdomeres on opposite faces of the cell. Rhabdomere volumes undergo a daily cycle similar to that described for Dinopis, but of relatively minor extent. It is shown that the pm eye of Dinopis could have evolved from that of Menneus by a simple series of transformations, and that a gain of two logarithmic units of sensitivity can be attributed to changes in optical design alone.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 30 (1980), S. 27-34 
    ISSN: 1432-0827
    Keywords: Ultrastructure ; Calcium ; Cartilage ; Vesicles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The potassium pyroantimonate technique was utilized for the selective subcellular localization of calcium in the mandibular condylar cartilage of 1-day-old rats. Electron dense calcium pyroantimonate precipitates were localized principally in mitochondria and at the cell membrane of the chondrocytes. In addition, small intracellular vesicles 0.1–0.2µm in diameter were observed in proximity to the cell membrane of chondrocytes of the mid-hypertrophic zone. The results suggest that these vesicles were being extruded from the cell into the extracellular matrix. Energy-dispersive analysis by X-rays confirmed that calcium is the principal cation of the electron-dense precipitates.
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  • 4
    ISSN: 1573-1561
    Keywords: Gnathotrichus retusus ; G. sulcatus ; Coleoptera ; Scolytidae ; ambrosia beetle ; aggregation pheromone ; 6-methyl-5-hepten-2-ol ; sulcatol ; reproductive isolation ; enantiomers ; chiral compounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The aggregation pheromone ofGnathotrichus retusus was isolated and identified as (S)-(+)-sulcatol (6-methyl-5-hepten-2-ol). In laboratory and field experiments,G. retusus responded to (S)-(+)-sulcatol, but not to (±)-sulcatol, which was attractive to the sympatric species,G. sulcatus. G. sulcatus did not respond to optically pure (S)-(+)-sulcatol, but began to respond when ⩾ 1% (R)-(−)-sulcatol was present in an enantiomeric mixture.
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  • 5
    ISSN: 1573-1561
    Keywords: Ponderosa pine mortality ; Dendroctonus brevicomis ; Coleoptera ; Scolytidae ; aerial photography ; detection ; estimation ; sampling ; mapping ; attractive pheromones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Sequential aerial photography was used to detect ponderosa pine trees killed by successive generations of the western pine beetle (WPB),Dendroctonus brevicomis Lec., over a three-year period during a study to evaluate the effectiveness of attractive pheromones for the suppression and survey of WPB. The total number of WPB-killed trees were estimated for each generation, using probability-proportional-to-size sampling procedures. Infested trees at the beginning of the suppression treatment totaled 283. Attacks by three successive WPB generations in 1970 killed 90,83, and 91 trees, respectively. The first generation in 1971 killed 47 trees and the two subsequent generations combined killed a total of 49 trees. During the suppression treatment, tree mortality was concentrated into the suppression plots in comparison to the check plots and the surrounding area. By 1972, tree mortality distribution returned to its original pattern, but at one-tenth the original level, as shown by maps. Recommendations suggest ways to improve the use of aerial photography for studies of WPB-caused tree mortality and population dynamics.
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  • 6
    ISSN: 1432-0878
    Keywords: Preputial glands ; Nude mice ; Ultrastructure ; Gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The preputial glands of male nude (nu/nu) mice were analyzed by a combination of electron microscopy and gas chromatography to determine whether or not they are affected, like developing hairs and nails, by the nu/nu genotype. Results of the analyses revealed no differences between the glands of nude and normal male mice in either their ultrastructural characteristics or lipid secretory products.
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  • 7
    ISSN: 1432-0878
    Keywords: Rat ; Preovulatory follicle ; Ultrastructure ; Degeneration ; Atresia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To identify and describe ovarian follicles committed to undergo follicular degeneration (atresia), immature rats were primed with pregnant mare serum gonadotropin (PMSG). After PMSG treatment, preovulatory follicles develop but subsequently degenerate. Prior to the appearance of pyknotic nuclei (Stage I of atresia), degenerative changes were observed in focal areas of the granulosa cell layer. These changes include “blebbing” of the cytoplasm and alterations in the shape of the granulosa cells. The appearance of these degenerative changes coincides with a decrease in ovarian concentrations of estradiol and testosterone. Since estrogens and androgens maintain the follicle, the decline in estradiol and testosterone could be responsible for the further degenerative alterations that lead to complete deterioration of the preovulatory follicle. In Stage I atretic follicles, lysosome-derived autophagic vacuoles develop and macrophages invade both the thecal and granulosa cell layers. The combined actions of the autophagic vacuoles and macrophages could destroy both the granulosa-cell and thecal layers and thereby transform the preovulatory follicle into an ovarian cyst.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 208 (1980), S. 123-133 
    ISSN: 1432-0878
    Keywords: Lesioned axons ; Ultrastructure ; Crayfish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distal stumps of severed medial giant axons (MGAs) and of non-giant axons (NGAs) in the CNS of the crayfish Procambarus clarkii show long-term (5–9 months) survival associated with disorientation of mitochondria and thickening of the glial sheath. However, the morphological responses of the two axonal types differ in that neither the proximal nor the distal stump of severed MGAs ever fills with mitochondria as is observed in some severed NGAs. Furthermore, the adaxonal glial layer never completely encircles portions of MGA axoplasm as occurs in many severed NGAs; in fact, ultrastructural changes in the adaxonal layer around severed MGAs are often difficult to detect. No multiple axonal profiles are ever seen within the glial sheath of the proximal or distal stumps of severed MGAs whereas these structures are easily located within severed NGAs.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 54 (1980), S. 313-316 
    ISSN: 1573-5036
    Keywords: Cereal ; Green gram ; Groundnut ; Improved nodulation ; Inoculation ; Legume-Rhizobium symbiosis ; Maize
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary In cereal-legume crop rotation system, better Rhizobium symbiosis was obtained by double inoculation,i.e., when the preceeding cereal crop of maize was also inoculated with the same Rhizobium strain, used to inoculate the following legume crop of green gram or groundnut.
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  • 10
    ISSN: 1573-5036
    Keywords: Actinomycetes ; Azotobacter ; Alluvial soil ; Available nitrogen ; Available phosphorus ; Bacteria ; Fungi ; Green gram ; Maize ; Mulching ; Organic matter ; Recyling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Field experiments were conducted to investigate the effect of organic mulching on the nutrient status, microbiological properties and the yield of maize and green gram crops. Soil organic carbon and humin and humus carbon of the fallow and the cropped soils were augmented by mulching. More of nitrogen, available phosphorus and ammoniacal and nitrate nitrogen were found in mulched soils. Soil reaction was not affected by mulching. Mulched treatments maintained more of soil moisture and soil temperature lowered during summer and rainy seasons. Population of bacteria, fungi, actinomycetes and Azotobacter were augmented in mulched treatments at all the stages of sampling. Mulching significantly increased the grain and straw yield of both the crops. The nitrogen uptake by grain was higher in mulched than in the unmulched treatments.
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