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  • Electron microscopy  (160)
  • Wheat  (108)
  • Biology
  • Inorganic Chemistry
  • LUNAR AND PLANETARY EXPLORATION
  • Springer  (269)
  • 1980-1984  (269)
  • 1930-1934
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 138 (1984), S. 273-277 
    ISSN: 1432-072X
    Keywords: Cyanobacteria ; Secondary metabolite ; Allelopathy ; Photosynthesis ; Electron transport ; Thylakoids ; Herbicides ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cyanobacterin is a secondary metabolite produced by the cyanobacterium, Scytonema hofmanni. Highly purified cyanobacterin was found to inhibit the growth of many cyanobacteria at a minimum effective dose of 2 μg/ml (4.6 μM). The antibiotic had no effect on eubacteria including the photosynthetic Rhodospirillum rubrum. The site of action of cyanobacterin was further investigated in the unicellular cyanobacterium, Synechococcus sp. Electron micrographs of antibiotic-treated Synechococcus cells indicated that cyanobacterin affects thylakoid membrane structure. The antibiotic also inhibited light-dependent oxygen evolution in Synechococcus cells and in spheroplasts. These data support our conclusion that cyanobacterin specifically inhibits photosynthetic electron transport. This activity is similar to herbicides such as 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (DCMU). The anhydro analog of cyanobacterin had no biological activity.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 140 (1984), S. 265-270 
    ISSN: 1432-072X
    Keywords: EcoRI ; EcoRI-DNA complexes ; EcoRI* activity ; Recognition sites ; Frequency of binding ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Electron microscopy of negatively stained isolated restriction enzyme EcoRI revealed particle projections with triangular or square outlines, indicating that the enzyme, in its tetrameric state, is tetrahedron-like. The two dimers making up the tetramer appear to be arranged in two planes orthogonal to each other. Complexes formed by EcoRI with the plasmids pBR322 or pGW10 were investigated by electron microscopic spreading techniques. In the presence of Mg2+, EcoRI was bound to the DNA molecules to form pearl necklace-like aggregates. The number of bound EcoRI particles was much higher as the sum of EcoRI-and 5′..AATT..3′ sites (with exceptions, the 5′..AATT..3′ sites may function as one type of EcoRI* sites) along the DNAs, indicating unspecific binding. In the absence of Mg2+, EcoRI was bound to the DNA only at the recognition site for EcoRI and the sites where the tetranucleotide sequence 5′..AATT..3′ was present. A direct correlation of the local concentrations of the bases A and T within the flanking sequences of the binding sites with the frequency of EcoRI to the DNA was observed. Dimers and tetramers of the enzyme was found to bind to the DNA. Tetramers occasionally exhibited two binding sites for DNA as indicated by the observation of DNA loops originating at the sites of bound tetrameric EcoRI particles.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 67 (1984), S. 249-255 
    ISSN: 1432-2242
    Keywords: Wheat ; Plant regeneration ; Chromosome variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A cytological study has been made of plants regenerated from cultured immature embryos of four wheat cultivars (Triticum aestivum, 2n = 6x = 42). In total, 29% of the 192 plants examined were aneuploid with a range in chromosome numbers of 38–45. Evidence of chromosome structural changes was also found. This variation occurred in regenerants of all four cultivars, but there were large differences in the proportions of aneuploids arising from individual cultures which meant that no significant differences could be demonstrated between cultivars. Chromosome abnormalities were present in plants regenerated both from embryogenic cultures and from cultures in which the origin of shoots could not be distinctly defined.
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  • 4
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    Electronic Resource
    Springer
    Theoretical and applied genetics 67 (1984), S. 439-442 
    ISSN: 1432-2242
    Keywords: Wheat ; Multicellular pollen grains ; Embryos ; Cytology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cytological analysis of microspore embryogenesis during in vitro culture reveals a high mortality in the first week and a latency phase of about one week before the first embryogénic mitosis. Genotypic differences observed during our wheat anther culture do not seem to originate at the induction level but are linked to the different abortion rates.
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  • 5
    Electronic Resource
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    Springer
    Theoretical and applied genetics 67 (1984), S. 525-528 
    ISSN: 1432-2242
    Keywords: Cryopreservation ; Embryo culture ; Haploids ; Wheat ; Rice ; Germplasm bank
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Anther culture derived pollen embryos and immature zygotic embryos of wheat and rice, frozen in liquid nitrogen in the presence of dimethyl sulfoxide, sucrose and glycerol, have been revived. The retrieved cultures proliferated and/or regenerated shoots and plantlets. The prospects of the cryopreservation of embryos for the conservation and multiplication of germplasm and the possibility of the establishment of ‘Germplasm Banks’ are discussed.
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  • 6
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    Springer
    Theoretical and applied genetics 68 (1984), S. 219-226 
    ISSN: 1432-2242
    Keywords: Hexaploid genotypes ; Allelic variation ; Esterase ; Isozymes ; Isoelectric focusing ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Analysis of grain esterase isozymes in Chinese Spring aneuploid genotypes by IEF confirmed that genes on the long arms of chromosomes 3A, 3B and 3D (Est-5) control the production of 19 isozymes. Allelic variants have been found for the isozyme pattern controlled by each chromosome. Segregational data involving null alleles and complex phenotypic differences indicate that the wheat grain esterases are encoded by three compound and probably homoeoallelic loci, each capable of producing at least six different isozymes. In a sample of 138 hexaploid genotypes, seven alleles were distinguished.
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  • 7
    ISSN: 1432-2242
    Keywords: Electrophoresis ; Endosperm ; Proteins ; Emmer ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Triticum turgidum L. var. dicoccoides (wild emmer) is an important genetic resource for increasing the protein content of common wheat (Triticum aestivum L.). Many studies have shown that the presence or absence of bands in sodium dodecyl sulfate polyacrylamide (SDS-PAGE) electrophoregrams of wheat storage proteins to be of a purely genetic character. A total protein extraction and SDS-PAGE technique was used to estimate the storage protein genetic variability among 841 accessions of wild emmer collected from various ecological regions in the Middle East. In addition, a computer data bank was developed, recording the onedimension electrophoregram bands for each accession by molecular weight (MW) and relative Coomassie Blue staining intensity as determined from densitometer scans. Analyses of this information are being used to identify specific accessions for further study by two dimension electrofocusing-electrophoresis and breeding and genetic analyses. The computer-assisted analyses indicated that the greatest genetic variability occurs for proteins in the high MW region (above 70,000 MW) followed by those in the medium range (70,000 to 33,300 MW). Comparatively little variability was revealed for protein subunits of below 33,300 MW.
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  • 8
    ISSN: 1432-2242
    Keywords: Chromosomal location ; Genetic control ; Salt soluble proteins ; Wheat ; Barley ; Rye
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Salt-soluble proteins from the endosperms of wheat, barley, and rye have been separated by nonequilibrium electrofocusing x electrophoresis. Genes encoding 14 of the 25 components observed in wheat have been unambiguously assigned to 10 different chromosomes (1B, 3B, 3D, 4A, 4D, 5B, 6B, 6D, 7B, 7D) by analysis of the compensated nulli-tetrasomic series. Five more wheat proteins seem to be controlled by group 2 chromosomes. Analysis of wheat-barley and wheat-rye addition lines has led to the location of genes for 6 out of 20 barley proteins in 4 different chromosomes (1H, 3H, 4H, 6H; 1H is homoeologous to group 7 chromosomes of wheat) and of genes for 5 out of 20 rye proteins in two different chromosomes (2R, 4R). The relationship between the proteins reported here and previously characterized ones is discussed.
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  • 9
    ISSN: 1432-2242
    Keywords: Wheat ; Triticum ; Grain protein ; Grain weight ; Maternal effect ; Cytoplasmic effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Reciprocal crosses were made between cultivated wheat (Triticum turgidum var. ‘durum’) and a high-protein line of wild tetraploid wheat (T. turgidum var. ‘dicoccoides’). F1 grains (on maternal spikes) were very similar to the selfed grains on the maternal parent in protein percentage, weight and protein content. These traits were also analyzed in F3 grains developed on F2 spikes of segregating populations derived from reciprocal crosses between the same cultivated parent and another high-protein line of var. ‘dicoccoides’. No significant differences in the mean values of these traits were found between the reciprocal crosses, indicating no cytoplasmic effect. It has been concluded that these grain characteristics are largely determined by the maternal plant.
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  • 10
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    Springer
    Theoretical and applied genetics 68 (1984), S. 21-23 
    ISSN: 1432-2242
    Keywords: Wheat ; Heritability ; Yield ; Height
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Grain yield, plant height and test weight were studied in a population of winter wheat (Triticum aestivum L.). The population consisted of F2 bulk populations of 42 crosses among 11 genotypes adapted to S. W. Ontario. Heritabilities were: 0.30±0.32 for yield, 0.77±0.15 for height and 0.98±0.08 for test weight. Predicted genetic gain with 10% selection intensity was 0.15 t/ha for yield, 10.1 cm for height and 3.00 kg/hl for test weight. The low heritability for yield indicates that effective selection would require pedigree information and progeny tests, while the high heritabilities for height and test weight indicate that selection for these traits using single plots would be appropriate.
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  • 11
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    Springer
    Cell & tissue research 237 (1984), S. 219-226 
    ISSN: 1432-0878
    Keywords: Spermatogonia ; Spermatocytes ; Carbohydrates ; Guppy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structure of guppy (Poecilia reticulata) spermatogonia and spermatocytes has been studied using electron microscopy. The spermatogonia, situated at the apex of the seminiferous tubule, are almost all surrounded by a network of Sertoli cells; they have very diffuse chromatin and one or two large nucleoli. The cytoplasm contains relatively few organelles, although annulate lamellae are found. The mitochondria have few cristae and are concentrated at one pole of the cell; they are sometimes found with intermitochondrial cement. These spermatogonia are separated from each other, having no intercellular bridges or inclusion in Sertoli cells, and are relatively undifferentiated; they correspond to stem cells. The spermatogonia beneath the apex are organized into cysts. First-generation spermatogonia are more dense and heterogeneous, their nuclei becoming smaller and their chromatin becoming denser during successive generations. In spermatocytes, the synaptinemal complex exists as a modified form until metaphase. The concentration of organelles in the cytoplasm increases and the organelles become more diversified as spermatogenesis progresses. Many cytoplasmic bridges are observed (several per cell), indicating that the cells remain in contact after several divisions. These changes in germ cell structure have been related to some of the characteristic features of spermatogenesis in guppy, e.g. the large number of spermatogonial generations and the complexity of spermiogenesis.
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  • 12
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    Cell & tissue research 238 (1984), S. 413-416 
    ISSN: 1432-0878
    Keywords: Peroxisomes ; DAB-cytochemistry ; Electron microscopy ; Liver, amphibian ; Gymnophiona ; Ichthyophis glutinosus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of hepatic peroxisomes was investigated in Ichthyophis glutinosus (Amphibia: Gymnophiona), employing perfusion fixation and the diaminobenzidine (DAB) technique for the visualization of catalase. The majority of peroxisomes is circular or rod-shaped, although elongated particles occasionally occur. They contain a finely granular matrix, lightly stained after the DAB procedure. Their mean diameter is approximately 0.25 μm. Serial sections reveal that the circular and rod-shaped peroxisomal profiles are cross and oblique sections of highly tortuous, tubular organelles exceeding 2 μm in length. In addition to tubular profiles, elongated, rectangular particles, as well as straight dumbbell-shaped organelles with distinct marginal plates are observed. They range from 900 to 1650 nm in length (mean = 1200 nm). In the flattened, thin central portion of the dumbbell-shaped particle, the peroxisomal membranes form a cisterna enclosing one or two uniformly thick marginal plates, which display a definite substructure with a periodicity of 10 nm. These findings indicate that peroxisomes in the liver of Ichthyophis exhibit a complex organization. It is suggested that the organelles undergo a specific differentiation process, morphologically characterized by the formation of enlarged segments of unusual shape.
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  • 13
    ISSN: 1432-0878
    Keywords: Ovulation (rabbit) ; Graafian follicle ; Perfusion ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Isolated ovaries from untreated, sexually mature rabbits were introduced into an in vitro perfusion system and perfused with a chemically defined medium containing albumin. The ovaries were perfused for up to 15 h (mean 11.5 h) and then processed for morphological investigation. Both at the light- and electron-microscopical levels, most of the ovaries exhibited a normal structure comparable with ovaries in situ. In two cases, however, marked accumulations of bacteria were found, although not inside the follicles. Since ovulation in the rabbit normally occurs between 9.5–13 h after mating or human chorionic gonadotrophin treatment, this model seems adequate for studies of ovulation in vitro. It is, however, important to study the ovaries microscopically after the perfusion to detect artifacts, e.g., bacterial infection, that may have influence on the process of ovulation.
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  • 14
    ISSN: 1432-0878
    Keywords: Tannic acid ; Acetylcholine receptors ; Tissue culture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Spinal cord neurons from 9-day chick embryos were maintained in culture for up to 35 days and then fixed in 4% cacodylate-buffered glutaraldehyde containing 2% tannic acid. After about 15 days in culture a small percentage of the synaptic specializations present were characterized by striking electron-dense striations averaging 15 nm in width, oriented perpendicular to the postsynaptic membrane. These structures increased in frequency with time in culture (to a maximum of about 10% of all synapses in the oldest cultures); they were asymmetrical, protruding approximately 8 nm into the synaptic cleft, and more deeply (approximately 15–18 nm), into the postsynaptic cytoplasm. On the basis of earlier work by Sealock (1980) they are interpreted as concentrations of acetylcholine receptors. Similar membrane differentiations were also seen associated with active-zone areas of a few presynaptic membranes, and the possibility that these represent presynaptic acetylcholine receptors is discussed. Additional observations reported are (1) the presence of striations resembling those seen at the postsynaptic membrane in the membranes of some postsynaptic vesicles, and (2) filamentous links between the striations and cytoskeletal elements of the postsynaptic cell.
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  • 15
    ISSN: 1432-0878
    Keywords: Monoamine-containing cells ; Taste bud ; Paracrine cells ; Mechanoreceptors ; Electron microscopy ; Teleosts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The taste buds on the barbels in three species of teleosts (Cyprinus carpio, Misgurnus anguillicaudatus, Parasilurus asotus) were studied by means of fluorescence and electron microscopy. Intensely yellow-fluorescent cells, which are disk-shaped and located exclusively in a basal position, are observed in the barbel-buds of all fishes examined. The basal cells contain a large number of small clear vesicles approximately 40–60 nm in diameter, which show a tendency to aggregate in the cytoplasm facing the junction of the nerve terminals; chemically transmitting synapses are seen in the latter region. It is suggested from the present observations that the basal cells in the barbel-bud may originate from Schwann cells and have a dual function both as mechanoreceptors and paracrine elements. Since the administration of 5,6-DHT results in an appearance of small dense vesicles among the small clear vesicles, the possibility exists that the basal cell may be capable of taking up monoamines and storing them in the small clear vesicles.
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  • 16
    ISSN: 1432-0878
    Keywords: Exocrine pancreas ; Calcium pool ; Calcium release ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In an attempt to identify a cellular Ca2+-pool, from which calcium is released when secretagogues are applied, tissue fragments of the rat exocrine pancreas were incubated and fixed with glutaraldehyde in the presence of calcium. By means of this procedure electron-dense deposits were found on plasma membranes. X-ray microanalysis showed that these deposits contain calcium. Stimulation of tissue fragments with the use of the secretagogues carbachol or cholecystokinin reduced the number of deposits by about 80%. When the antagonist atropine was applied after carbachol stimulation, deposits reappeared on cell membranes, which then disappeared again after a second stimulation with cholecystokinin. In the presence of procaine, carbachol was inhibited and only slightly reduced the Ca2+-deposits on the plasma membranes. These results suggest that a calcium pool, from which calcium is released to induce enzyme secretion on stimulation, is located in the cell membrane
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  • 17
    ISSN: 1432-0878
    Keywords: Chloride cells ; Acid stress ; Gill ; Electron microscopy ; Fathead minnow
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Fathead minnows, Pimephales promelas, were exposed for 129 days to Lake Superior water acidified with sulfuric acid by means of a flow-through toxicant injection system. The effects of chronic acid stress (pH 6.5, 6.0, 5.5, 5.0) on gill histology were examined. Most of the histological effects were seen at pH 5.5 and 5.0 and were confined primarily to changes in numbers, distribution, and morphology of chloride cells. At low pH levels there tend to be more chloride cells in the gill epithelium and an increased percentage of these cells in the secondary lamellae. In contrast to normal chloride cells, chloride cells from fish exposed to low pH frequently had apical pits while some had bulbous apical evaginations. The occurrence of structural changes in chloride cells during exposure to acid water suggests that chloride cells may be involved in acclimation to acid stress.
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  • 18
    ISSN: 1432-0878
    Keywords: Lactating cell ; Lipid droplets ; Secretory vesicles ; Mitochondria ; Intracellular associations ; Electron microscopy ; Milk secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The size, cellular location, and identity of surface-associated components were determined for lipid droplets in lactating cells. Transmission electron-microscopic measurements were made involving 3801 droplets in approximately 211 cells from three rats and 1197 droplets in 66 cells from a mouse. For the purposes of droplet evaluation, cells were divided into seven locations ranging from basal to secreting positions. Droplets were also categorized with respect to contact with other droplets, basolateral plasma membrane, mitochondria, Golgi apparatus, secretory vesicles, and endoplasmic reticulum-cytoplasm (ERC). Data on droplet size showed that droplet growth occurs mainly in the secretory position, confirming previously published findings. Lipid droplets from mouse tissue, although somewhat smaller in size showed similar growth trends to those of the rat. Data on numbers of droplet contacts and percentages of droplet circumferences involved in associations with other cell components showed that the dominant interaction of lipid droplets was with the ERC. However, intimate association of droplets with mitochondria was noted in all cellular locations. In addition, nursed animals exhibited a greater proportion of droplet surface association with secretory vesicles and less in contact with mitochondria in comparison to those not nursed. The significance of these relationships to milk synthesis and secretion is discussed.
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  • 19
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    Cell & tissue research 236 (1984), S. 249-255 
    ISSN: 1432-0878
    Keywords: Oocyte ; Nucleolus ; Silver staining ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The nucleoli of dictyate-stage growing oocytes in rat ovaries were examined both with routine electron microscopy and electron microscopy after silver nitrate and ammoniacal silver nitrate (Ag-AS) staining. The nucleoli of the unilaminar follicular oocytes consist of twisted strands of dense fibrillar components, aggregates of granular components, and small fibrillar centers. After Ag-AS staining, silver grains are numerous on the dense fibrillar strands, fewer on the fibrillar centers, and very sporadic on the granular aggregates. The same stainability of three nucleolar components with the Ag-AS method was also confirmed in the nucleoli segregated by actinomycin D. During the transition of growing oocytes from bilaminar to plurilaminar follicle stage, the nucleolar dense fibrillar strands gradually conglomerate and are transformed into large and compact spherules. The stainability of dense fibrillar components with the Ag-AS method was lost along with this nucleolar transformation. These results may provide some new clues on the functional significance of AgAS-positive proteins in the nucleoli.
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  • 20
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    Cell & tissue research 235 (1984), S. 51-58 
    ISSN: 1432-0878
    Keywords: Parathyroid glands ; Electron microscopy ; Light microscopy ; Quantitative histology ; Mongolian gerbil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Stereology and semi-automatic image analysis were used with the aim of comparing the structure of parathyroid glands from untreated adult Mongolian gerbils fixed by immersion with those fixed by perfusion. Subclassification of the chief cells based upon the staining affinity or electron density of the cytoplasm was readily performed only in glands fixed by immersion, and so-called atrophic cells were observed only in these glands. The atrophic cells were often surrounded by “light” chief cells. In glands fixed by perfusion, “light” chief cells were only rarely encountered. A significant difference between glands fixed by immersion and those fixed by perfusion was found only with regard to the form of cells and nuclei, those fixed by perfusion being more spherical. When comparing individual cells within glands fixed by immersion, “light” chief cells were more spherical and had a significantly larger nuclear and cellular size, and a lower mitochondrial volume density than the “intermediate”/“dark” chief cells. Otherwise there were no significant differences in any of the parameters investigated. These data indicate that occurrence of socalled “light” chief cells and atrophic cells is a result of improper fixation. The results of this study do not favour the concept of a functional cycle with a simultaneous occurrence of active and inactive cells within parathyroid glands.
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  • 21
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    Cell & tissue research 235 (1984), S. 153-158 
    ISSN: 1432-0878
    Keywords: Bovine ; Interdigitating cell ; Lymphoid tissues ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron-microscopic studies of lymphoid tissues from bovine fetuses and from calves disclosed a non-lymphoid cell type in the thymus-dependent zones of secondary lymphoid tissues and in the thymus that is distinguishable from reticulum cells, epithelial and endothelial cells, and macrophages. Based on morphological and topographical criteria, the cell is identified as the interdigitating cell. In addition, studies of the tissues of normal and virus-challenged fetuses, and of conventionally reared calves, indicated that the interdigitating cells originate from monocytoid cells, which undergo differentiation in the thymus-dependent zones during an immune response.
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  • 22
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    Cell & tissue research 235 (1984), S. 243-249 
    ISSN: 1432-0878
    Keywords: Gap junction ; Electron microscopy ; Freeze fracture ; Cell-to-cell communication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Gap junctions exist in the septa between the segments of the lateral giant axons in the ventral nerve cord of the crayfish Procambarus. A large increase in the resistance (uncoupling) of these gap junctions was brought about by mechanical injury to the axonal segments. Both thin sections and freeze-fracture preparations were used to monitor the morphological changes which occurred up to 45 min after injury. There was no apparent change in the organization (a loose polygonal array) of the intramembrane particles which make up the junctional complex up to 45 min after injury. In some instances, however, the intramembrane particles appeared to have moved away from the junctional area. Other junctional regions were internalized and appeared similar to what have been called annular gap junctions. Also at this time (20–25 min after injury), a dense cytoplasmic plug formed in uninjured axon near the junctional region. It is concluded that the gap junctions that exhibit a loose polygonal organization of the intramembrane particles may be either in a state of low resistance (coupled) or a state of high resistance (uncoupled).
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  • 23
    ISSN: 1432-0878
    Keywords: Ovulation ; Perfusion ; Graafian follicle (rabbit) ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ovulation was induced in rabbits by intravenous administration of human chorionic gonadotrophin (HCG), and 4–5 h later the ovaries were isolated and introduced into an in-vitro perfusion system containing synthetic medium with albumin. Rupture of follicles occurred in vitro within the physiological time range (mean 11.3 h after injection of HCG), although with a reduced frequency. Preovulatory and ruptured follicles were studied in detail by light and electron microscopy. In the granulosa layer of ruptured or preovulatory follicles cytoplasmic blebbing activity, disappearance of CallExner bodies and differentiation toward luteinized cells were found. Perhaps the most important sign of normal preovulatory development in vitro was that the basement membrane surrounding the granulosa layer was penetrated by projections of granulosa cells. In the absence of this penetration phenomenon the granulosa layer prolapsed out of the follicle. Immediately before rupture, follicles showed marked degeneration, restricted to the outer layers of the apical wall, which is compatible with the hypothesis that degradative enzymes are released close to the surface of preovulatory follicles. Although the majority of follicles that ovulated under in-vitro conditions showed the same kind of morphological alterations as can be seen in vivo, occasional atypical ruptures occurred without any overt signs during perfusion. Also technical manipulations of the perfusion system, e.g., nonphysiological increase of perfusion pressure, could force follicles to rupture. This illustrates the importance of careful morphological study of all ovaries perfused in vitro before conclusions are drawn.
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  • 24
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    Cell & tissue research 237 (1984), S. 149-154 
    ISSN: 1432-0878
    Keywords: Pituitary gland, pars distalis ; Innervation ; Synaptoid contacts ; Electron microscopy ; Rana temporaria L
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the pars distalis of the hypophysis of adult Rana temporaria, three types of nerve-fiber profiles were found at two distinct sites, in both lateral parts of the bordering regions of the anterior lobe with the intermediate lobe of the hypophysis. The first type of nerve-fiber profile consists of bundles of very fine axonal elements (diameter: 〈0.7 μm). The second type is formed by larger nerve fibers (diameter up to 4 μm) containing a few neurosecretory granules of approximately 100 nm. The third type of nervefiber profile resembles the second type but these nerve fibers make synaptoid contacts on at least two different types of glandular cells. The possible functional significance of these nerve fibers in the pars distalis is discussed. No nerve fibers were found (1) in the central part of the bordering region of the pars distalis with the intermediate lobe, (2) at the bordering region with the median eminence and (3) with the neurohypophysial stalk, and (4) in all other parts of the pars distalis.
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  • 25
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    Cell & tissue research 238 (1984), S. 165-175 
    ISSN: 1432-0878
    Keywords: Mesonephros ; Pig embryo ; Glomerulus ; Microvasculature ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Vascularization of the pig mesonephros was investigated in embryos 5–8 cm in length. Vascular injections with microfil were cleared and dissected; corrosion casts were studied under the scanning electron microscope (SEM). Perfusion-fixed tissue was used for SEM and transmission electron microscope (TEM) studies, including freeze-fracture specimens. The branches of one mesonephric artery carry up to 15 glomeruli. Several glomeruli occupy the same arterial branch, with very short afferent arterioles proper. The efferent vessels, frequently 2–5, leave the extensive vascular pole opposite the entering arteriole and split into peritubular capillaries radiating towards the superficial veins. These capillaries form vascular regions in the shape of flattened pyramids. Along its course, one nephron is supplied by vessels derived from 4–7 glomeruli. The nephrons have less vascular contact than in the definitive kidney. The ultrastructure of the single mesonephric vessels matches the metanephric counterparts. Epithelioid cells with renin granules are common in afferent arterioles, larger arteries, and efferent vessels. The lobulated glomeruli are up to 750 μm long and flattened, showing the usual features of podocytes, mesangial cells, and an attenuated endothelium with fenestrations between 50 and 250 μm. It partially retains its own basement membrane. There is no proximal mesangium.
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    Cell & tissue research 238 (1984), S. 387-394 
    ISSN: 1432-0878
    Keywords: Pacinian corpuscles, cat ; Denervation ; Atrophy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of Pacinian corpuscles of the cat located in the crural region and innervated by the interosseous nerve was studied 1 to 14 months after denervation. Both the Pacinian inner core and capsule remained well preserved one month after denervation. However, the denervated inner cores underwent progressive atrophy and wasting, which resulted in a gradual reduction of the amount of inner-core cells and lamellae, widening of interlamellar clefts, formation of empty spaces in the axial region and a considerable increase in the number of collagen fibrils. In spite of the wasting, the inner core still survived 14 months after denervation, but at least half of its volume became occupied by collagen fibrils which surrounded the remaining inner-core cells and lamellae. Collagen fibrils assembled in the denervated core were markedly thinner than those found in the capsule, as is also the case in normal Pacinian corpuscles. In the capsule, discrete focal degeneration, occasional pyknosis of the innermost capsular cells and macrophage infiltration were observed from the first month after nerve section onward, but the number of capsular layers remained within the normal range (30–40) up to 14 months after denervation.
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  • 27
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    Protoplasma 119 (1984), S. 48-54 
    ISSN: 1615-6102
    Keywords: Electron microscopy ; Marine alga ; Membrane contrast ; Osmium-azole complexes ; X-ray microanalysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Addition of certain heterocyclic nitrogen-carbon compounds to standard osmium tetroxide solutions used as secondary fixative resulted in an enhanced general membrane contrast in cells of the marine algaEmiliania huxleyi (Lohmann) Kamptner. Ultrastructural cell morphology and the contrast distribution were compared between cells treated according to a standard secondary fixation procedure and cells post-fixed when above mentioned heterocyclic compounds were introduced; in both cases some of the ultrathin sections were post-stained. Different compounds were tested: 1,2,4-triazole (TRA), 3-amino-1,2,4-triazole (A-TRA), 5-amino-tetrazole (A-TEA) and 2,4,6-tri-amino-1,3,5-triazine (melamine). The results were interpreted to indicate the possible bonding types arising from interaction of the heterocyclic compounds with osmium tetroxide and with membrane constituents. Interpretations were partly inspired by considerations from coordination chemistry. All above tests which did not include post-staining of thin sections could be performed at alkaline pH, and consequently calcified structures were preserved. The enhanced osmium accumulation at membranes was verified with X-ray microanalysis, which also showed that in the cases where membranes were visibly contrasted, localization of probable sites of intracellular non-crystalline calcium was facilitated.
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    Plant and soil 76 (1984), S. 127-137 
    ISSN: 1573-5036
    Keywords: Adenylate pool ; Biomass volume ; CO2 evolution ; Chitin ; DNA ; Electron microscopy ; Enzymes ; Fluorescent antibody ; Fumigation-respiration ; Fungi Histochemistry ; Imunofluorecence ; Jones-Mollison technique ; Microcosms ; Monoclonal antibodies ; Nitrogen ; Nutrients ; Oxygen consumption ; Phosphorus ; Phytotoxins ; Plate counts ; Rhizobium ; Rhizosphere ; Sulphur ; Xenobiotics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary There is an immense literature on biological and biochemical analyses of soils. Such analyses have revealed the enormous richness of species in soil and their vast range of metabolic potentials and ecological diversity. Accordingly, the approaches used to investigate the soil biota and its biochemistry usually have to be modified or adapted depending upon the purpose of the investigation. Studies of micro-organisms in the soil environment, are complicated because microbial cells are commonly attached to surfaces where they live side-by-side with other populations in consortia usually containing different morphological and physiological types. Such assemblages of organisms cannot be described quantitatively using cultural techniques, such as plate counts, which underestimate both cell numbers and viable biomass. The development of more powerful observational and staining techniques has improved our knowledge of the diverse morphological and biochemical composition of soil micro-communities. Such findings have been amplified at a grosser level by laboratory studies with multi-component systems (microcosms) to mimic field situations and to assess the range of biochemical potentials of microbial consortia. But despite notable advances in analytical methods we are still, with a few exceptions, unable to detect or identify those microorganisms which carry out specific biochemical transformations or determine whether particular cells are alive, dormant or dead at the time of observation. Considerable work has been done to define some of the fundamental ecological attributes of microbial assemblages in soil. Productive work on the metabolic activities of the soil microbiota, specially geochemical transformations of C, N, S and P, has been under way for more than a century. But only in more recent years have more sensitive and reproducible analytical methods become available to measure viable biomass in soil. This will enable some insight to be gained into the role that microbial biomass plays as a labile source and sink for plant nutrients.
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  • 29
    ISSN: 1573-5036
    Keywords: 14C-labelled plant material ; 14C-labelled soil ; Root exudation ; Sample oxidizer ; Scintillation counting ; Sutton series soil ; Tissue solubilization ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A comparison between a tissue solubilization method and a sample oxidizer technique to measure14C in plant and soil material is described. The solubilization method although not quantitative gives good recoveries and reproducible values of14C-content with soil samples not exceeding 10 mg and should be of value for estimating the14C-content of soils in laboratories without a sample oxidizer.
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    Plant and soil 77 (1984), S. 141-149 
    ISSN: 1573-5036
    Keywords: Cracks ; Crack width ; Lateral roots ; Pea ; Penetration ; Penetrometer ; Rape ; Remoulded soil ; Roots ; Safflower ; Seminal axes ; Soil strength ; Undisturbed soil ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Experimental methods are described for observing the behaviour of roots encountering cracks in soil. The proportions of roots which enter a second soil block after crossing a crack of known width were measured. Soil strength was measured with a penetrometer. Results are presented for the proportions of seminal roots of wheat and primary lateral roots of pea which enter moulded soil of various strengths after crossing cracks. Results are also presented for the proportions of seminal roots of pea, rape and safflower which enter undisturbed soil after crossing cracks. It was found that, in all cases, the proportion of roots penetrating the second soil block decreased with increasing crack width and increasing soil strength. Also, a smaller proportion of thinner roots penetrated the second soil block than thicker roots under similar conditions. Root diameter in the cracks was influenced by both crack width and soil strength, and an empirical equation is presented to describe this effect.
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    Plant and soil 76 (1984), S. 319-337 
    ISSN: 1573-5036
    Keywords: Aggregates ; Aluminium ; Bacterial mucilage ; Binding agents ; Calcium ; Cation bridges ; Complexing agents ; Dispersion ; Electron microscopy ; Electrophoretic mobility ; Fungal hyphae ; Glues Iron ; Management Periodate ; Polysaccharides ; Rhizosphere ; Roots ; Slaking
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The stability of pores and particles is essential for optimum growth of plants. Two categories of aggregates macro- (〉 250 μm) and micro- (〈250 μm) depend on organic matter for stability against disruptive forces caused by rapid wetting. Dispersion of clay particles from microaggregates is promoted by adsorption of complexing organic acids which increase the negative charge on clays. The acids are produced by plants, bacteria and fungi. However, the dispersibility of clay in microaggregates is offset by the binding action of polysaccharides, mainly mucilages produced by bacteria, but also by plant roots and fungal hyphae. The stability of microaggregates is also enhanced by multivalent cations which act as bridges between organic colloids and clays. Macroaggregates are enmeshed by plant roots, both living and decomposing, and are thus sensitive to management, and increase in number when grasses are grown and the soil is not disturbed. Lack of root growth,i.e. fallow, has the opposite effect. Various implications for management of soil structure are discussed.
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  • 32
    ISSN: 1573-5036
    Keywords: Ammonium acetate extractable potassium ; Inceptisol soil ; Minimum level ; Non-exchangeable potassium ; Pearl millet ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Ammonium acetate extractable potassium in the soil reached a minimum value of 6.8 mg K/100g soil after 14 crops of wheat and pearl millet in the field without applying any potassium fertilizer. At this level of ammonium acetate extractable K both wheat and pearl millet utilized about, 90 per cent of the total K from non-exchangeable sources. Wheat and pearl millet were grown in this soil in the greenhouse at different levels of K. At K0 level wheat utilized 86 per cent of the total K uptake from the non-exchangeable source and pearl millet, 95 per cent. At K1 level, wheat utilized only 19 per cent but at higher levels of K, there was build up in the K status of soils. In the case of pearl millet at K1, K2 and K3 levels 59, 13 and 22 per cent of total uptake were contributed by non-exchangeable forms. The total K uptake by pearl millet was more than double that by wheat. Plant analysis showed that 83 per cent of the total K in wheat was contained in the shoot portion and the rest in the roots. The corresponding figures for pearl millet were 94 and 6 per cent.
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    Plant and soil 79 (1984), S. 249-254 
    ISSN: 1573-5036
    Keywords: Acid KMnO4 extraction ; Chemical index ; Incubation ; Mineralizable N ; Mineral N ; N uptake ; Soil ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A chemical measure of soil nitrogen (N) availability has been evaluated. The method involved the estimation of initial mineral N, plus mineralizable N released with 0.05N KMnO4 in 1NH2SO4. The results obtained correlated highly significantly with the N uptake by wheat plants (r=0.72,P〈0.01).
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    Plant and soil 76 (1984), S. 379-387 
    ISSN: 1573-5036
    Keywords: Actinomycetes ; Bacteria ; Chernozemic soil ; Fungi ; Rhizosphere ; Trifluralin herbicide ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary This study examined the effects of trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), a soil incorporated herbicide, on soil microflora both in the general soil environment and in the rhizosphere of trifluralin damaged wheat roots. Two Dark Brown Chernozemic soils were treated with various trifluralin rates in the growth chamber and wheat [Triticum aestivum L. ‘Neepawa’] was seeded. Trifluralin generally had no effect on fungi, bacteria, or actinomycete populations in either the general soil or in the rhizosphere. CO2 evolution was unchanged when trifluralin was added to the soil. In wheat plots, at two field locations, there were no significant effects of trifluralin (1.0 kg ha−1) on soil fungi, bacteria, actinomycete, denitrifying bacteria, and nitrifying Nitrobacter propulations. A pure culture study with 42 soil microorganisms showed that many isolates were inhibited at 400 to 100,000 μg g−1 but not at concentrations 〈16 μg g−1. Similar data were obtained from tests on four different soils. These studies indicate that trifluralin is unlikely to cause changes in the numbers of soil microorganisms when used at recommended levels.
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    Plant and soil 78 (1984), S. 417-428 
    ISSN: 1573-5036
    Keywords: Aphelenchoides spp ; Aphelenchus avenae ; Pinus radiata ; Soil fungi ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The soils of a wheat-field and pine-forest had different mycofloras and supported different populations ofAphelenchus avenae, a mycophagous nematode. The abundance ofA. avenae was correlated with the composition of the mycoflora in these soils; the greater abundance ofA. avenae in wheat-field soil being associated with a more diverse mycoflora.
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    Plant and soil 79 (1984), S. 11-28 
    ISSN: 1573-5036
    Keywords: Beta distribution ; Buckling ; Cracks ; Crack width ; Lateral roots ; Pea ; Penetration ; Penetrometer ; Rape ; Remoulded soil ; Roots ; Safflower ; Seminal axes ; Soil strength ; Undisturbed soil ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary It is shown that probabilities of root penetration across cracks in soil can be calculated effectively using a mathematical model involving root stress and soil distributions and penetrometer/root stress ratios. Penetration criteria are developed, and it is found that the effective penetrometer/root stress ratios take values of about 4 for crack widths smaller than about 2 mm and about 8 for wider cracks. Root swelling does not appear to contribute significantly to the probability of root penetration through any effect on root buckling stress. Suggestions are made for further work on the effects of soil structure and strength on root behaviour.
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    Nutrient cycling in agroecosystems 5 (1984), S. 285-288 
    ISSN: 1573-0867
    Keywords: Wheat ; potassium chloride ; irrigation ; plant water potential
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract ‘The water potential of wheat plants increased during the mid-day noon, probably as an adaptation; the rise was greater with less frequent irrigation and was increased by KCl application.’
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    Plant and soil 80 (1984), S. 135-138 
    ISSN: 1573-5036
    Keywords: Hardpans ; Root growth ; Soil compaction ; Subterranean clover ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Wheat crops with stunted chlorotic patches are widespread in northern Victoria, Australia, and are often associated with dense, compacted layers of soil. Poor growth of subterranean clover, with symptoms of cupped and reddened leaflets, is also a problem in these cropping regions during the pasture phase of the rotation. Artificially compacted soils were created to test the hypothesis that these symptoms of poor growth were caused by soil compaction. Soil compacted from 0–20 cm with a bulk density similar to that measured in problem fields reproduced these symptoms in wheat and subterranean clover. Surface compaction alone also reproduced the symptoms in clover.
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  • 39
    ISSN: 1573-5036
    Keywords: Azospirillum brasilense ; Wheat ; Triticum aestivum ; N-fertilizer
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The yield response of a common spring wheat cultivar,Triticum aestivum, to inoculation withAzospirillum brasilense was studied at four levels of N fertilization. Plant yield increased due to the inoculation treatment only at medium and high levels of N fertilization, with a maximum yield increase of about 8.0 per cent at the highest level (approximately 1.0 g of pure N per plant). Yield increase was mostly due to an increase in the number of grains per spike, and at the highest level of fertilization, also due to a higher number of spikes per plant. At all N levels, the inoculation caused an increase of 0.5–1.4 per cent in the number of fertile spikelets per main spike. Grain protein percentage was unaffected by the inoculation, though significantly increase due to the fertilization treatments. The occurrence of maximum yield response at the highest N level, the response by early-determined yield components, i.e. spikelet number, and the unaffected grain protein content are in accord with the suggestion that the contribution ofAzospirillum brasilense to wheat yield is not through N2-fixation.
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    Colloid & polymer science 261 (1983), S. 373-374 
    ISSN: 1435-1536
    Keywords: Electron microscopy ; short-time staining ; nodular structure ; crystallization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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  • 41
    ISSN: 1432-0983
    Keywords: Allomyces macrogynus ; Mitochondrial DNA ; Electron microscopy ; Restriction enzyme map
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    Topics: Biology
    Notes: Summary The mitochondrial (mt) DNA of the aquatic phycomycete Allomyces macrogynus is a circular molecule with a size of 56.1 kbp. The cleavage sites for the restriction enzymes SalI and PvuI were mapped by comparing the partial denaturation patterns of isolated restriction fragments with the pattern of the intact circle. The genes coding for the small and large ribosomal RNA (rRNA) were located on the restriction map by heteroduplex and R-loop analysis. The gene coding for the large rRNA contains an intervening sequence, app. 0.7 kbp in size, near the 3′-end of the gene. The two rRNA genes are encoded on the same strand of the mtDNA and separated by a region of 17–18 kbp. This rRNA gene organization is similar to that found with members of the Ascomycetes.
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    Archives of microbiology 135 (1983), S. 169-175 
    ISSN: 1432-072X
    Keywords: Photosynthetic membranes ; Electron microscopy ; Image processing ; Ectothiorhodospira halochloris ; Ectothiorhodospira abdelmalekii ; Rhodopseudomonas viridis ; Rhodopseudomonas sulfoviridis ; Thiocapsa pfennigii
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Abstract The photosynthetic membranes of the five bchl b-containing bacteria Ectothiorhodospira halochloris, E. abdelmalekii, Rhodopseudomonas viridis, R. sulfoviridis and Thiocapsa pfennigii have been investigated by electron microscopy and digital image analysis. All five species have the photosynthetic complexes hexagonally arrayed in the membrane with lattice spacings close to 13 nm, except for R. sulfoviridis and T. pfennigii which display somewhat smaller (∼12.5 nm) lattice spacings. Correlation averaging which imposes less stringent requirements on the lattice perfection than conventional Fourier filtration techniques has been employed to elucidate the structure of the photosynthetic complexes. Their basic organization, i.e. a ring, probably containing the light-harvesting (LH) polypeptides, surrounding a core (the “reaction centre”) appears to be almost identical for all species under scrutiny. Despite a resolution of ∼1.6 nm, however, little further significant substructure can be deduced from the averages; possible reasons for the “blurred” appearance of the LH-ring and absence of any subdivision in the reaction centre are discussed along with strategies aimed at obtaining a more detailed model of the molecular architecture of the photosynthetic membranes.
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    Archives of microbiology 135 (1983), S. 25-29 
    ISSN: 1432-072X
    Keywords: Electron microscopy ; Euglena mutabilis ; Flagellate ; Photomovement ; Photoreceptor ; Phototaxis ; Single-cell analysis ; Videomicroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Due to the lack of an emergent flagellum the green flagellate Euglena mutabilis is restricted to gliding motility. During forward movement, the organisms orient positive phototactically in the presence of a suitable light stimulus. The cell contains both a stigma and a paraflagellar body which differ in shape and size from the organelles found in E. gracilis. The degree of orientation in white light follows an optimum curve with a maximum at about 100 lx. The spectral sensitivity shows a number of prominent peaks in the blue and green regions and extends well into the red region of the visible spectrum. Since the cell does not rotate during locomotion a periodic shading mechanism cannot account for phototactic orientation. Thus, phototaxis in the related species, E. gracilis and E. mutabilis differ in their photoreceptor molecules, their sensory transduction chains and their strategies of light direction detection.
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  • 44
    ISSN: 1432-2242
    Keywords: Pollen irradiation ; Wheat ; Differential gene transfer
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    Topics: Biology
    Notes: Summary The use of irradiated pollen to bring about limited gene transfer in wheat has been investigated. Doses of X-rays of 2Kr, 3Kr and 5Kr were used to generate M1 progeny between maternal and paternal genotypes differing in quantitative and major gene characters. Cytological studies of M1 plants revealed hybrids with widespread aneuploidy and structural rearrangements in the paternal genome. These effects resulted in phenotypic variation between M1 progeny and complex multivalent formation at meiosis. All M1 plants at the 5Kr and 3Kr doses were sterile and all but 2 plants at the 2Kr dose. Studies of the two M2 families from these plants revealed disturbances in genotype frequencies for some of the marker loci with an excess of maternal homozygotes and a deficit of paternal homozygotes. This was also reflected in a more maternal appearance for quantitative characters. These results are interpreted as showing that irradiation damage to the paternal genome in M1 plants results in the differential transmission of maternal alleles.
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    Theoretical and applied genetics 65 (1983), S. 171-172 
    ISSN: 1432-2242
    Keywords: Resistance ; Genetic engineering ; Yellow rust ; Wheat ; Chitinase
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    Topics: Biology
    Notes: Summary Virulence and resistance may act on the same biochemical mechanisms. Because Erwinia-virulence on potato depends on the lysis of cell walls of the host, resistance may depend on the lysis of cell walls of the parasite. An example is given with yellow rust on wheat.
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    Theoretical and applied genetics 66 (1983), S. 249-256 
    ISSN: 1432-2242
    Keywords: Wheat ; Dwarfism ; Yield ; Quality
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    Topics: Biology
    Notes: Summary The effects of the ‘Tom Thumb’ Rht3 dwarfing gene in wheat on plant height, yield components and grain quality in field trials of random inbred lines from two ‘Minister Dwarf’ (Rht3) x rht3 crosses are described. Limited genetic increases in Rht3 plant height, up to 70 cm, were achieved by incorporating genes from the extremely tall variety ‘April Bearded’. Amongst lines from the higher yielding cross, the dwarfing gene did not reduce grain yield but was associated with an increase in grain number of over 25%. Although Rht3 reduced grain protein content by up to 0.8%, breadmaking quality, as measured by SDS sedimentation values and baking tests, was not affected. A controlled environment experiment with near-isogenic Rht3 and rht3 lines indicated that reduced grain size in the dwarfs is a competitive response to the increase in fertility rather than a primary effect of the dwarfing gene.
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    Theoretical and applied genetics 64 (1983), S. 255-258 
    ISSN: 1432-2242
    Keywords: Triticum aestivum ; Wheat ; Malate dehydrogenase ; Chromosomal location
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    Topics: Biology
    Notes: Summary The malate dehydrogenase (E.C. no 1.1.1. 37) of Triticum aestivum L. cv. Chinese Spring, shows two activity zones. The results obtained support the hypothesis that the malate dehydrogenase isozymes of zone II are dimers composed of the six possible combinations of subunits coded by triplicate genes located in the long arms of chromosomes of the homoeologous group 1.
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    Theoretical and applied genetics 66 (1983), S. 153-157 
    ISSN: 1432-2242
    Keywords: Inheritance ; Culm-length ; GA insensitivity ; Grain weight ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The study was carried out in the first year on samples of random F5 lines, uniform in height and in heading date, of three crosses between semi dwarf spring wheat cultivars (Triticum aestivum L.), differing in grain weight and in their Rht gene. In the second year only the progenies of the early heading F5 lines were studied. All the material was grown in the absence of lodging. The culm-length genotypes of the different lines were identified by test crosses and by a seedling GA response test. No differences in grain weight were found between the two semi dwarf genotypes (Rht 1Rht1 rht 2rht2 and rht 1rht1 Rht 2Rht2). The tall genotype (rht 1rht1 rht 2rht2) was significantly higher in grain weight than the two semi dwarf genotyes and the grain weight of these genotypes exceeded markedly the grain weight of the dwarf genotype (Rht 1Rht1 Rht 2Rht2). These genotypic effects were independent of differences in plant height, heading date or number of grains per spike.
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    Theoretical and applied genetics 64 (1983), S. 103-107 
    ISSN: 1432-2242
    Keywords: Glutenin ; Wheat ; Co-dominance ; Bread-making
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    Topics: Biology
    Notes: Summary Ten pairs of reciprocal crosses have been made between wheat cultivars which show differences in their glutenin subunit compositions. The F1 seed glutenin subunit composition was studied by means of polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate (SDS). The results indicate that all the high molecular weight (HMW) and medium molecular weight (MMW) subunits (from 133,000 to 65,000 daltons) are transmitted to the F1 seed generation from the parental cultivars. In accordance with the triploid nature of the heterozygous endosperm (3n) and with the maternal and paternal gene dosage ratio (2∶1) in the endosperm itself, a significant effect of maternal parent is registered when comparing pairs of reciprocal seeds. Genes coding for the glutenin subunits are expressed whatever their doses are (one, two, or three) in the hybrid endosperm; thus the glutenin subunits inheritance is consistent with the co-dominant type. For one pair of the reciprocal crosses, two MMW parental bands (MW: 71,000 and 66,000) seemed absent in the F1 seed patterns while a new band with an intermediate, apparent MW (68,000) appears. This phenomenon was observed when the glutenins analyzed by electrophoresis were previously separated from other endosperm proteins, and not when they were directly extracted from the ground seed. We assume that the extraction can cause interactions between moieties attached to the subunits and lead to the formation of a complex having an intermediate electrophoretic mobility.
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    Theoretical and applied genetics 64 (1983), S. 303-307 
    ISSN: 1432-2242
    Keywords: Crossability ; Wheat ; Rye ; Hordeum bulbosum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Crosses of wheat (Triticum aestivum L.) Group 5 chromosome substitution lines from three different cultivar backgrounds indicate that there may be multiple alleles for reduced crossability with rye (Secale cereale L.) and H. bulbosum on both 5A and 5B chromosomes. No reduction in seed set was observed from any of the 5D substitution lines. It was found that the Kr1 locus on chromosome 5B had a more pronounced affect on both rye and H. bulbosum crossability than the Kr2 locus on chromosome 5A and that the effects of both loci were cumulative. The Kr alleles affected both rye and H. bulbosum crossability in a linear, or additive, fashion. The Kr 2 allele was shown to have little effect on H. bulbosum crossability compared to a significant effect on rye crossability. Tests with tetrasomic and nulli-tetrasomic lines of ‘Chinese Spring’ indicated that the kr allele is ‘null’ or inactive in promoting crossability while the Kr allele is active in reducing crossability to both rye and H. bulbosum. Thus, extra doses of the kr allele do not increase rye or H. bulbosum crossability in the presence of the corresponding Kr allele.
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  • 51
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    Theoretical and applied genetics 64 (1983), S. 309-316 
    ISSN: 1432-2242
    Keywords: Wheat ; α-Amylase ; Isozymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary An analysis of the α-amylase isozymes in GA-treated endosperm of wheat nullisomic-tetrasomics shows that there is more variation at the α-Amy-1 and α-Amy-2 homoeoallelic loci than was previously thought. Among the 16 isozymes produced by genes on the group 7 chromosomes, most could be definitely established as products of a single homoeoallele. Inter-varietal allelic differences would be expected at such loci and clear variation was found in isozymes produced by chromosomes 6B and 7B. The latter allele, α-Amy-B2b carried by the variety ‘Hope’, was used to locate the enzyme structural gene within chromosome 7B relative to the centromere and five other gene markers. The nature of the α-Amy-B2b phenotype and the rare non-parental isozyme patterns found among the recombinant lines indicates that the locus is large and compound, probably involving some degree of intra-locus gene duplication.
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  • 52
    ISSN: 1432-2242
    Keywords: Gliadin ; Glutenin ; Tticum ; Wheat ; Endosperm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Gliadins, here defined as those proteins of defatted wheat endosperm which dissolve in 70% (v/v) ethanol at room temperature, were fractionated by gel filtration using Sephadex G-100. The protein which eluted with the void volume of the column, often described as high-molecular-weight (HMW) gliadin, was fractionated by the two different, two dimensional gel electrophoresis procedures of O'Farrell (1975) and O'Farrell et al. (1977). The next two fractions to elute from the gel column, ω-gliadin and α-, β-, γ-gliadin, were analysed similarly. The subunits of HMW gliadin and the classical (i.e. non-aggregated) gliadins map at distinctive positions on the electrophoregrams, the majority of the HMW gliadin subunits being more basic and having a slightly slower electrophoretic mobility than the α-, β-, γ-gliadins. These experiments demonstrate that those gliadins which aggregate to form HMW gliadin are distinct molecular entities and thus coded by different genes to those gliadins which do not aggregate. Glutenin, here prepared by a modification of the pH 6.4 precipitation procedure of Orth and Bushuk (1973), was also analysed by two-dimensional electrophoresis. The low-molecular-weight subunits were found to correspond exactly with the HMW gliadin subunits. Using the nullisomic-tetrasomic lines and the ditelocentric lines of ‘Chinese Spring’, the genes controlling the synthesis of all the major HMW gliadin subunits were shown to be located on the short arms of chromosomes 1A, 1B and 1D, as are the genes coding for the ω-gliadins and the majority of the γ-gliadins.
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  • 53
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    Theoretical and applied genetics 65 (1983), S. 41-46 
    ISSN: 1432-2242
    Keywords: Triticum aestivum ; Wheat ; Protein ; Mutation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Poor adaptability or functional quality of much germplasm used for breeding high-protein hard red winter wheats prompted mutagenesis as an alternative means of increasing grain protein content. Four hard red winter wheat genotypes — KS644 (‘Triumph// Concho/Triumph’), ‘Kaw’, ‘Parker’, and ‘Shawnee’ — were treated with 0.40 M ethyl methanesulfonate (EMS). Advanced lines (M8-M10) were selected that had a 3-year mean grain protein advantage of 0.7% to 2.0% over controls. Increased grain protein content was generally associated with decreased grain yield and kernel weight, but some high-protein mutant lines had yields or kernel weights similar to those of original genotypes. Changes in height and lodging induced by EMS were generally favorable, most mutants being shorter and lodging less than controls, but blooming date was generally delayed, a deleterious change. One line also changed from resistant to segregating for wheat soil-borne mosaic virus. Mutant lines might be utilized in cross-breeding programs, particularly if negative pleiotropic effects and linkages are absent.
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  • 54
    ISSN: 1432-2242
    Keywords: HMW glutenin subunit genes ; cDNA clones ; Tandem DNA repeats ; Chromosomal location ; Gene copy number ; Wheat ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary cDNA clones encoding wheat HMW glutenin subunits have been isolated from a cDNA bank made to poly A+ RNA from developing wheat endosperm var. Chinese Spring. One such clone, pTag 1290, has enabled us to identify the HMW glutenin mRNA species. The DNA sequence of this clone has been partially determined and it contains several tandem DNA repeats. The sequence is discussed in relation to the generation of the HMW glutenin subunit gene family. Analysis of the organization of the HMW glutenin sequences in the wheat genome revealed that the genes encoding HMW glutenin subunits exist in low copy number and are located on the long arm of each of the homoeologous group 1 chromosomes.
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  • 55
    ISSN: 1432-2242
    Keywords: Triticum aestivum ; T. timopheevii ; Wheat ; Photoperiod ; Vernalization ; Male sterility ; Alloplasmic hybrids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Studies were conducted to determine the influence of the male sterility-inducing cytoplasm of Triticum timopheevii (Zhuk.) Zhuk. on response of several common winter wheat (T. aestivum L.) nuclear genotypes to photoperiod and vernalization. Comparative studies of cytoplasmic substitution lines provide information on the role of the cytoplasmic genetic mechanism in growth and development. In the case of cytoplasmic male sterility-based hybrid production systems, ubiquity of sterility-inducing cytoplasm in derived hybrids warrants thorough characterization of its influence on plant phenotype. Factorial combinations of cytoplasm (T. timopheevii and T. aestivum), nuclear genotype, and photoperiod or vernalization treatments were evaluated under hydroponic conditions in controlled environment chambers. Interaction of cytoplasm, photoperiod, and nuclear genotype was significant in one or more experiments for days to anthesis and potential spikelet number, and interaction of cytoplasm, vernalization, and nuclear genotype was significant for days to spike emergence. Long day length was associated with increased percentage seed set in one study, but interactions of photoperiod and cytoplasm were not detected for percentage seed set. Interactions involving cytoplasm and photoperiod or vernalization were interpreted as evidence of the existence of genetic factors in cytoplsam of T. timopheevii which alter photoperiod or vernalization responses of alloplasmic plants relative to responses exhibited by euplasmic plants. Since photoperiod and vernalization responses are critical to adaptation, T. timopheevii cytoplasm can alter adaptability of T. aestivum. The specific effect would be nuclear genotype dependent, and does not appear to be of a magnitude greater than that induced by nuclear genetic variability at loci conditioning photoperiod or vernalization responses or other adaptation-determining characteristics. Normal multilocation/year testing of alloplasmic hybrids should therefore adequately identify zones of adaptation.
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  • 56
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    Theoretical and applied genetics 64 (1983), S. 231-238 
    ISSN: 1432-2242
    Keywords: Maize ; Wheat ; Rape ; Restriction fragments ; Two dimensional electrophoresis ; Melting profiles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This paper deals with the relationship of chloroplast DNA (ctDNA) and cytoplasmic malesterility (CMS) of maize, wheat and rape. Intramolecular heterogeneity and fragment patterns of DNA digested with restriction endonucleases were compared and analyzed. For this purpose methods of agarose gel electrophoresis and two dimensional gel electrophoresis with denaturating solvent concentration gradients were applied. 1) Heat denaturation of ctDNA from a male sterile line in maize yielded a profile with three melting regions. This base sequence heterogeneity was not observed for the ctDNA of its maintainer. 2) Maize ctDNA was digested with EcoR1 and BamH1 restriction endonucleases, wheat and rape ctDNA with EcoR1 only. No significant differences were observed in the comparison of the fragment patterns from the sterile lines and their maintainers with the exception of the sterile line in rape which lacked one fragment present in its maintainer. 3) Two dimensional electrophoresis using a gradient of denaturing agents revealed several differences in number and relative positions of the separated restriction endonuclease fragments between the sterile lines and their respective maintainers in all three tested crops. This raises the possibility that changes in ctDNA may be involved in CMS.
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  • 57
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    Cell & tissue research 234 (1983), S. 469-496 
    ISSN: 1432-0878
    Keywords: Bone marrow (human) ; Neutrophil granulocyte ; Granules ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Bone marrow from hematologically healthy adults was exposed to a number of fixation procedures for investigation of the heterogeneity of the granule population in neutrophil granulocytes at the ultrastructural level. Four main cell stages were distinguished: early promyelocyte, late promyelocyte, myelocyte, and mature neutrophil granulocyte and described separately; metamyelocytes and band-form or stab cells are described together. The characteristic changes in the cytoplasm during myelopoiesis were analysed quantitatively. Special attention was given to the development of the granule population. Three types of granule arise in successive cell stages: granules which develop a sub-structure in the matrix (nucleated granules) are formed in early promyelocytes, granules with a homogeneous electron-dense matrix (azurophil granules) in late promyelocytes, and granules with a less electron-dense matrix (specific granules) in myelocytes. The three types of granule remain present during myelopoiesis. The best results in distinguishing the granule types were obtained by prefixation either in 0.1% glutaraldehyde or in 1.5% glutaraldehyde followed by washing in phosphate-buffered Ringer solution to which aminotriazole had been added. Granule counts revealed for the mature neutrophil a total number of granules of about 220 per ultrathin section. This population of granules is composed of about 12% nucleated, 11% azurophil, and 77% specific granules. When our previous findings are taken into account, the existence of three successively formed and morphologically distinguishable types of granule in heterophil (neutrophil) granulocytes has been demonstrated for three mammalian species: the guinea pig, the rat, and man. A separate term for the early promyelocyte stage is proposed: eomyelocyte.
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    Cell & tissue research 234 (1983), S. 579-593 
    ISSN: 1432-0878
    Keywords: Rods ; Cones ; Retina ; Bullfrog ; Synapse ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Lumps of electron-dense material were observed in synaptic clefts associated with all types of photoreceptors, in the vicinity of the synaptic ribbons, in the retinae of dark-adapted frogs. Frogs were reared under a cyclic illumination (light on at 8:00; light off at 20:00) and then exposed to one of two courses of dark adaptation: one started from 11:00 in the morning, and the other started from 20:00 in the evening. The synaptic clefts of red rods became wider at some places where spherical or polygonal lumps of dense material were accumulated. The frequency and sectional area of the lumps increased faster for the first hour in the regime starting from 20:00 than in the regime starting from 11:00, then they reached the similar saturation levels of about 0.6 (per ribbon) and 1.6 to 1.8×104 (nm2) in both the regimes. In greenrod synapses, plate-shaped lumps of dense material were present in synaptic clefts and interspaces between the processes of second-order neurons. In cone synapses at the end of about 1 h darkness, the frequency and area of the lumps reached maximum values of about 0.12 (per ribbon) and 9×103 (nm2) in the regime starting from 11:00 and, about 0.08 (per ribbon) and 4 × 103 (nm2) in the regime starting from 20:00. On exposure to light, the dense material abruptly disappeared from all types of photoreceptor synaptic clefts. Large dense-core vesicles, occasionally observed in light-adapted rod photoreceptor terminals, seem to participate in exocytosis of the dense material. The number of dense-core vesicles per synaptic ribbon in a terminal was about 0.55 at the end of 3 h light in the morning and about 1.28 at the end of 12 h light in the evening. The increased number of dense-core vesicles during the daytime may contribute to the faster accumulation of dense material in the synaptic clefts. Although the chemical identification or the functional significance of the electron-dense material remains unknown, it is interesting that this material showed a rise and fall in response to darkness and illumination. Also the fact that this material is clearly visible will be helpful for future analysis of frog photoreceptor synapses.
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  • 59
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    Cell & tissue research 232 (1983), S. 593-600 
    ISSN: 1432-0878
    Keywords: Peritrophic membrane ; Insect ; Microvilli ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A double plasma membrane (DPM) surrounding intestinal microvilli of the migratory milkweed bug, Oncopeltus fasciatus, is described. Mutant and wild types of the phytophagous insect have been studied by conventional SEM and TEM procedures with the use of membrane-enhancing staining methods. Longitudinal and transverse sections revealed a DPM surrounding microvilli and continuing over the apical portions of the intestinal cell. The outer membrane of the DPM contributes to an intestinal lining or peritrophic membrane (PTM), which apparently accumulates in layers. SEM studies reveal a rugose intestinal surface and complete PTM in both starved and fed insects. Only rarely are exposed microvilli seen by SEM. SEM examinations also enable the observation of numerous blebs on the luminal side of the PTM apparently held in position by a neck-like attachment and apparently derived from the outer membrane of the DPM. Preliminary TEM studies of microvilli revealed unique microvesicle-like structures, lying just inside the inner membrane of the DPM, which may be of membrane origin based on their typical trilaminar appearance after en bloc staining with uranyl acetate. Highly ordered microfilaments were observed to occupy the most central aspect of the microvilli.
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    Cell & tissue research 234 (1983), S. 125-134 
    ISSN: 1432-0878
    Keywords: Vasopressin ; Immunocytochemistry ; Electron microscopy ; Hypothalamus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Vasopressin-containing neurons, identified by immunocytochemistry, are located predominantly in the posterior magnocellular division of the paraventricular nucleus of the rat hypothalamus. By electron microscopy, the immunoreaction product is seen within the cell bodies and neuronal processes. In the perikarya and dendritic processes, the immunoreactive material is associated primarily with neurosecretory granules. Axonal processes, identified by their content of microtubules and accumulation of neurosecretory granules, show the immunoreaction product in association with both of these organelles. Afferent axo-dendritic, axo-somatic and putative axo-axonic synapses with immunostained vasopressinergic neurons can be identified. The presynaptic profiles do not contain immunoreactive material. This study contributes to the ultrastructural characterization of vasopressinergic neurons in the paraventricular nucleus and of their afferent synaptic input.
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  • 61
    ISSN: 1432-0878
    Keywords: Dictyosome-like structures ; Golgi apparatus ; Phosphatidylcholine ; Laminated figures ; Electron microscopy ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dictyosome-like structures (DLS) of guinea pig spermatocytes, when prefixed in mixtures of glutaraldehyde and tannic acid, exhibited laminated figures with a repeating periodicity of about 4.5 nm in the spaces between DLS saccules or in association with the surfaces of the DLS saccules. These laminated figures were similar to those figures derived from saturated lipids in other tissues. Alternatively, spaces between saccules were collapsed leaving only thin, electron-dense material separating adjacent saccules. These changes were not observed when the DLS were prefixed in glutaraldehyde before exposure to tannic acid. The presence of laminated figures following fixation with tannic acid and osmium tetroxide suggests that saturated lipids are present in, or associated with, the intersaccular regions of the DLS. The distribution of laminated figures in other membrane structures was not affected by post fixation with tannic acid nor were laminated figures comparable to those of the DLS observed between cisternae of the Golgi apparatus. These results support previous conclusions that DLS are distinct from Golgi apparatus and are a unique component of the germ cell cytoplasm.
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  • 62
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    Protoplasma 114 (1983), S. 1-13 
    ISSN: 1615-6102
    Keywords: Embryo ; Endosperm ; Scutellum ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The overall morphology of the developing wheat embryo in relation to its neighbouring tissues is described. The embryo is “isolated” early in development, but appears to be a powerful sink for nutrients. It is supplied initially by hydrolysis of the nucellar parenchyma and later by hydrolysis of neighbouring endosperm cells, which are completely digested. Later on, the nucellar epidermis forms specialised cells that may be transfer cells opposite the groove at the base of the embryo. The accumulation of starch and protein appears to begin first in the basal tissues of the scutellum and coleorhiza.
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  • 63
    ISSN: 1615-6102
    Keywords: Digestion ; Membrane flow ; Electron microscopy ; Sarcodina ; Actinophrys sol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The digestion of food in the heliozoonActinophrys sol is characterized by several distinct membrane events. Initially, extrusomes expand and fuse with each other and with the plasma membrane providing the membrane for the nascent food vacuole. During this process a—presumably lytic—material is secreted. After complete forming of the food vacuole a second type of vesicles fuses with it, whereupon usually lysis of the prey occurs. After denaturation and coagulation of the food, fluid is removed from the food vacuole. This process is accompanied by a high cytotic activity around the periphery of the food vacuole. Following this step, the perinuclear Golgi region shows an active appearance and numerous lysosomes fuse with the food vacuole. In consequence of this the food is degradated. The food vacuole shrinks continuously. Simultaneously vesicles filled with the digested material pinch off from the food vacuole, the content of which shows a more and more condensed mass of undigestible material. The undigestible residues are defecated eventually. The process of digestion is accompanied by an increase in volume and number of electron lucent cytoplasmic vacuoles. These vacuoles gradually become filled with a filamentous material starting with the vacuoles in the cell periphery. As the digestion continues, the vacuolar contents become condensed successively. Synchroneously the vacuoles move towards the cell center. After completion of the digestion, the cytoplasmic vacuoles decrease in volume and number and do not show any longer electron dense contents.
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    Protoplasma 115 (1983), S. 104-113 
    ISSN: 1615-6102
    Keywords: Cereals ; Embryo culture ; Triticum aestivum ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cell proliferation from the mature embryo of wheat occurs on a defined medium in the presence of 2,4-D. Unorganized growth is observed when the 2,4-D concentration is equal to or greater than 2 mg/l, but increasing levels of 2,4-D inhibit cell division. Cell divisions begin after 4 days in culture from parenchyma cells within and near the procambial tissues of the embryo axis. By day 8 continuous meristematic zones are formed in association with vascular tissues, and DNA synthesis and cell divisions are distributed throughout these zones. No morphological evidence exists to show that these zones consist of proliferating root primordia, which are formed only after the level of 2,4-D falls below some critical concentration. When the concentration of 2,4-D is lowered, the meristematic zones first become dissected and then give rise to many root meristems.
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  • 65
    ISSN: 1615-6102
    Keywords: Anacystis nidulans ; Cyanobacterium ; Electron microscopy ; Freeze-fracmres ; Thylakoid degradation ; Ultrathin-sections
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Photooxidative bleaching of the CyanobacteriumAnacystis nidulans was studied by electron microscopic investigation of both freezefractured and thin-sectioned samples. During bleaching four consecutive phases in degradation of photosynthetic membranes (thylakoids) could be characterized: 1. No ultrastructural changes until photosystem II activity is lost. 2. Derangement of characteristic arrangement of thylakoids. 3. Thylakoids visible only in thin-sectioned but not in freeze-fractured samples. 4. Completely bleached cells, only traces in place of former thylakoids visible in thinsectioned samples. Bleaching did not cause lysis of the cells showing that the cytoplasmic membrane was not damaged. Polyhedral bodies also were still detectable in bleached cells.
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  • 66
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    Protoplasma 116 (1983), S. 198-200 
    ISSN: 1615-6102
    Keywords: Chromosome isolation ; Electron microscopy ; Vicia faba ; Vicia narbonensis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Using a formalin fixation technique whole chromosomes from root tips ofVicia species were isolated into a buffer solution. Combining this technique with the use of a set of reciprocal translocations available for this species—Vicia faba— allowed each member of the karyotype to be isolated and identified. Such isolated chromosomes can be used for optical microscopy or for either transmission or scanning electron microscopy where critical point drying clearly reveals chromatin fibre.
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    Protoplasma 116 (1983), S. 209-212 
    ISSN: 1615-6102
    Keywords: Parapharyngeal mass ; Electron microscopy ; Cytochemistry ; Electron microprobe X-ray analysis ; Ciliate ; Homalozoon vermiculare
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    Topics: Biology
    Notes: Summary The structure and elemental composition of the granules which make up the parapharyngeal mass of the ciliateHomalozoon vermiculare are analyzed. The mass is made up of two kinds of granules. One is not membrane-bounded and is composed of paraglycogen. The second type is comprised of concentric lamellae. It is rich in magnesium, phosphorus, potassium, and calcium. These results do not support the contention that the granules are directly involved in the process of food vacuole formation. The role of the parapharyngeal mass remains obscure.
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  • 68
    ISSN: 1615-6102
    Keywords: Cell walls ; Electron microscopy ; Moisture ; Plastic embedding ; Seeds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Aqueous fixatives caused dry seed tissues to swell; mashed peanuts, crushed to remove oil, swelled even more. Use of anhydrous, organic solvents as vehicles for fixatives enabled maintenance of dimensional stability during fixation of dry seed tissues; even crushed seed tissue did not swell significantly when processed anhydrously. However, anhydrously processed specimens proved difficult to section. The difficulty was due to imperfect permeation of plastic into the seed tissues during embedding. An explanation of why anhydrously processed dry seed tissues are so difficult to embed in plastic is offered.
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    Protoplasma 117 (1983), S. 40-44 
    ISSN: 1615-6102
    Keywords: Cereals ; Immature embryo ; Somatic embryogenesis ; Tissue culture ; Triticum aestivum L. ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Tissue cultures derived from the scutellum of immature embryos ofTriticum aestivum L. (wheat) gave rise to somatic embryos with a well-defined scutellum and coleoptile as well as one or more shoot primordia and a root primordium. The normal somatic embryos were formed from compact, white callus tissue which was not observed until 4 or more weeks after culture initiation. The highest frequency of white embryogenic tissue formation and the most normal embryoids were obtained in the dark on Murashige and Skoog's medium with twice the concentration of inorganic salts plus sucrose (2%), inositol (100–200 mg/l), casein hydrolysate (100–200 mg/l), glutamine (500 mg/l), and 2,4-dichlorophenoxyacetic acid (1–2 mg/l).
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    European journal of plant pathology 89 (1983), S. 87-98 
    ISSN: 1573-8469
    Keywords: Wheat ; Septoria ; epidemiology ; crop loss
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Samenvatting In 1980 werden inoculaties verricht metSeptoria tritici in een veldproef met wintertarwe ‘Okapi’. De bladnecrose-voortschrijdingscurves werden bepaald. De S-vormige curves konden getransformeerd worden tot logit-lijnen. De geïnoculeerde en niet geïnoculeerde objecten verschilden aanzienlijk in de hellingen van de logit-lijnen. De halfwaardetijden varieerden al naar inoculatiedosis en vochtbehandeling na inoculatie. De verschillen in opbrengst (kg ha−1) waren significant voor geïnoculeerd tegenover niet-geïnoculeerd. De opbrengstderving van 878 kg ha−1 (gelijk aan 12% van de niet-geïnoculeerde controle 7045 kg ha−1)werd volledig verklaard door de vermindering van het korrelgewicht. De schade is aanzienlijk voor een cultivar die niet bijzonder vatbaar is. De opbrengstderving correleerde goed met de hoeveelheid necrose waargenomen bij de ontwikkelingsstadia DC=75 en DC=77. De necrose geïntegreerd over de tijd correleerde goed met de verlaging van het korrelgewicht.
    Notes: Abstract In 1980, field inoculations withSeptoria tritici were performed on winter wheat cv. Okapi. Leaf necrosis progress curves were established; they were sigmoid and could be transformed into logit lines. There was a great difference in the slope of the logit lines between inoculated plots and non-inoculated controls. The mid-time values varied according to inoculum dosage and post-inoculation humidity treatment. Yields (kg ha−1) and average grain weights (mg grain−1) differed significantly between inoculated and non-inoculated plots, but seldom among inoculation treatments. Decrease of average grain weight completely explained yield loss, which was 878 kg ha−1 or 12% of control (7045 kg ha−1). This crop loss is considerable for a cultivar which is not particularly susceptible. A good correlation was found between the amount of necrosis at development stages DC=75 and 77 and yield depression. The integral of necrosis over time gave a high correlation with loss of kernel weight.
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    Plant and soil 74 (1983), S. 295-300 
    ISSN: 1573-5036
    Keywords: Endoscope ; Potatoes ; Root density ; Root length ; Soil core ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary It was determined experimentally whether the amount of roots, viewed by endoscope in observation tubes (cm cm−2) is related to root density (cm cm−3) in adjacent bulk soil, determined by core sampling. For wheat plants the results can be summarized by the equation: root length (cm cm−2, endoscope)=0.29 times root density (cm cm−3, soil cores). Results for potato plants could not be interpreted as unequivocally as for wheat.
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  • 72
    ISSN: 1573-5036
    Keywords: Fertilizer ; Moisture stress ; Nitrogen-15 ; Nitrogen balance ; Priming effect ; Rainfed ; Recovery ; Utilization ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The fate of nitrogen fertilizer applied to wheat growing on a deep loessial soil in a semi-arid region was studied with15N as KNO3 measured by emission spectrometry. The soil N was monitored at the end of the winter growing season and again at the end of the dry summer period. Nitrogen was applied at rates equivalent to 18 and 6 g m−2. The wheat was grown in 1.25×1.25 m microplots and in 30-cm-diameter plotlets enclosed by a hard plastic pipe that was inserted 60 cm into the ground. The year was relatively dry, with only 200 mm of rainfall, most of it early in the season. Late rains fell after the crop had dried and wet the soil to below 60 cm. Plant growth was less than average and N fertilizer uptake amounted to 22–29% of amount applied. At the end of the summer, 34–65% of the applied fertilizer N was detected in the soil as available mineral N. The amount remaining in the soil organic fraction was difficult to determine but appeared to be between 5 and 19%. Accordingly, gaseous losses between 6 and 16% must have occurred during the growing season, probably during relatively short periods after heavy rains in January and March. The fertilizer application appeared to have caused a “priming effect” because mineral N in soil and plant from non-fertilizer origin, amounted to 12–17 g m−2 in plots where N was applied, compared with 9.5 g m−2 in the control plots. Nitrogen loss from plots with no plants on them was considerable (up to 30%) possibly because they were wet for longer periods.
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  • 73
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    Plant and soil 75 (1983), S. 405-415 
    ISSN: 1573-5036
    Keywords: Barley ; Growth analysis ; Model ; Root growth ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Root development is described by a simple algebraic model which gives the numbers and lengths of root members of different orders in terms of time and a few properties of each order of root member. The model is tested against experimental results for the early growth of the roots of temperate cereals in pots or in liquid culture. The model is then used to simulate root growth and to explain the observed behaviour of four growth measures (relative multiplication rate, relative extension rate, mean extension rate, average root length) used in the growth analysis of root systems. Three principles governing root development emerge from the model and the simulations.
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  • 74
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    Plant and soil 70 (1983), S. 303-307 
    ISSN: 1573-5036
    Keywords: Choline ; Glycinebetaine ; Quaternary ammonium compounds ; Salinity ; Salt tolerance ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The periodide method for quaternary ammonium compounds (QAC) analysis was modified to permit rapid screening of numerous replicate plant samples. This procedure provides a valuable tool for assessing salt tolerance. Aqueous plant extracts were used without further purification. Total QAC were precipitated as the periodide complexes at low pH. In neutral media, only choline periodide crystallized; other major QAC (e.g. glycinebetaine) were soluble at pH 6.8–7.0 QAC concentration was then determined spectrophotometrically. The influence of oven-drying of plant material at 80°C was tested by comparing this technique to lyophilization. Since QAC values were essentially identical from both drying techniques, oven-drying was used routinely because of its economy and practicality. The optimum range of acid concentration for precipitation of total QAC was established.
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  • 75
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    Plant and soil 70 (1983), S. 391-402 
    ISSN: 1573-5036
    Keywords: Intercropping Lupins ; Lupinus albus ; Manganese ; Nitrogen ; Phosphorus ; Triticum aestivum ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Significant interactions between wheat and lupins occur below ground and wheat intercropped with lupins has access to a larger pool of available P, Mn and N than has wheat grown in monoculture. This suggests that the wheat is able to take up nutrients produced or made available by lupins grown in association with it.
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  • 76
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    Plant and soil 71 (1983), S. 463-467 
    ISSN: 1573-5036
    Keywords: Anion uptake ; Barley ; Hordeum vulgare ; Mycorrhiza ; Phosphorus ; pH Rhizosphere ; Triticum aestivum ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary In two field experiments sown in 1982 to test the effect of vesicular-arbuscular mycorrhizas (VAM) on growth and phosphorus nutrition of (i) spring wheat and spring barley, (ii) winter wheat and winter barley, we measured the concentrations of the major cation (K+, Ca2+, Mg2+ and Na+) and anions (Cl−, SO4 2−, H2PO4 − and NO3 −) in shoot tissue. In all cases the sum of the anion concentrations (ΣA) was increased strongly by mycorrhizal infection but not by P additions, confirming earlier observations2 on spring wheat. The concentration of total cations (ΣA) was generally reduced by P additions, hence P and VAM both reduced the cation excess (ΣC−ΣA) but by different mechanisms. These results suggest that increased uptake of anions by plants with VAM may be a general phenomenom which would have important implications for the elemental composition of crops. The effect may also be manifested by other types of mycorrhizal association.
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  • 77
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    Plant and soil 74 (1983), S. 407-416 
    ISSN: 1573-5036
    Keywords: Calcareous soil ; Dry matter ; Grain yield ; Leaching fraction ; Root-zone salinity ; Salinity tolerance ; Sea water ; Soil salinity ; Triticum aestivum L. ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Sea water dilutions having ECi=2, 12, 18 and 24 mmhos/cm, at 20°C were used for weekly irrigations of the wheat line RI 3748 (Triticum aestivum L.) on an initially non-saline calcareous loamy sand soil. The added quantities were 1.1, 1.3 and 1.5 times the weekly evapotranspiration. The vegetative growth (G), grain yield (Y), g/1000 grains and ECe were significantly affected by ECi and not by L. ECiXL affected g/1000 grains and the early G only. Soil salinity ECe (0–60 cm) increased with time. The ration between time-averaged $$EC_e (\overline {EC} _e )$$ and ECi indicated that the higher the ECi the longer the time to reach steady-state condition. These ratios were 1.54, 0.73, 0.63 and 0.56 at ECi=2,12, 18, and 24, respectively. Regression of Y on $$\overline {EC} _e $$ or ECi is a parabola. It indicates that about 27% decrement in Y occurs at ECe=12.35 or ECi=8.3 whereas the given value for wheat in standard tables of crop tolerance to salinity is 50% decrement in Y.
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  • 78
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    Plant and soil 74 (1983), S. 229-235 
    ISSN: 1573-5036
    Keywords: Barley ; Hordeum vulgare ; Mineral composition ; Na−K interaction ; Solonetzic soil ; Solonetz-Solod sequence ; Triticum aestivum ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The growth and mineral composition of barley and wheat was measured across sequences of Solonetz and Solod soils. Growth of both species, along with root penetration was reduced on the Solonetz compared to the Solod soil. Mineral composition of the foliage and roots indicated that a Na−K interaction was present for the barley across the Solonetz-Solod sequences. Such factors were considered to be characteristics of soil—plant relationships on Solonetzic soils.
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  • 79
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    Cell & tissue research 228 (1983), S. 139-148 
    ISSN: 1432-0878
    Keywords: Pineal organ ; Pineal photoreceptors ; Opsin immunoreactivity ; Electron microscopy ; Elasmobranch (Raja clavata)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pineal organ of Raja clavata was studied by light and electron microscopy, including the immunocytochemical antiopsin reaction. The pineal organ of the ray consists of three portions: (i) a large proximal pineal, (ii) a long tube-like connecting stalk, and (iii) a short distal terminal enlargement. This latter end-vesicle lies in the deep connective tissue layers of the braincase. All portions of the pineal are composed of pinealocytes, intrinsic neurons, ependymal/glial cells, and bundles of nerve fibers embedded in thin neuropil formations. The inner segments of the pinealocytes protrude into the lumen in all parts of the organ and usually contain basal bodies and numerous mitochondria. Often, two outer segments were found to arise from the basal bodies of a single inner segment. By means of light-microscopic immunocytochemistry the outer segments showed a strong antiopsin reaction. The axons of the pinealocytes form ribbon-containing synapses on dendritelike profiles, which appear to belong to the intrinsic pineal neurons. There are other axo-dendritic synapses established by presynaptic terminals lacking ribbons and containing granular and synaptic vesicles. Pineal neurons may contain granular vesicles approximately 60–100 nm in diameter; their processes contribute to the bundles of unmyelinated axons. The fine structural organization of the pineal organ and the opsin immunoreactivity of the outer segments of the pinealocytes indicate a photoreceptive capacity of the organ. The double outer segments represent a peculiar multiplication of the photoreceptor structures.
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  • 80
    ISSN: 1432-0878
    Keywords: Innervation ; Decentralisation ; Hypogastric nerve ; Pharmacology ; Electron microscopy ; Vas deferens ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The physiological, pharmacological and morphological characteristics of guinea-pig vas deferens supplied by hypogastric nerves rendered inactive by decentralisation were compared with those of vas deferens in which the nerve supply had been chronically stimulated for 3–9 days using implanted electrodes. No change was seen in decentralised preparations prior to 7 days, but from 8–15 days, increased sensitivity to application of noradrenaline in vitro was observed, which was shown to be related to reduced transmitter uptake by nerve terminals as well as to an increase in postjunctional sensitivity; there was also increased fatigability 7–14 days following decentralisation. Continuous stimulation of hypogastric nerves at 2 Hz for 4–8 h daily for 4–8 days resulted in enhanced transmitter uptake and reduced responses to noradrenaline; this was associated with a slight increase in noradrenaline content and a faster adrenergic neuromuscular response with a shorter latency. No appreciable changes in nerve or muscle structure studied by electron microscopy were observed following decentralisation, but there was an increase of between 12.5 and 29.6% in the number of close (〈 100 nm) neuromuscular junctions following chronic stimulation for 8 days.
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    Cell & tissue research 228 (1983), S. 433-449 
    ISSN: 1432-0878
    Keywords: Bone marrow (rat) ; Heterophil granulocyte ; Granules ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the heterophil granulocyte in the bone marrow of the rat is described, and an electron-microscopical analysis of the changes in the cytoplasm as well as in the granule population in several stages of maturation is reported. Three types of granule originate in consecutive stages of heterophil maturation. Granules with an internal fine structure (nucleated granules) are the first to be formed, i.e., in early promyelocytes; azurophil granules are formed in late promyelocytes; and specific granules appear in myelocytes. Quantitative analysis showed that the granule population in mature cells, i.e., about 160 granules per electron micrograph, is composed of roughly 14% nucleated granules, 10% azurophil granules, and 76% specific granules. Three cell stages were observed in mitosis: the early promyelocyte, the late promyelocyte, and the myelocyte. Granule counts in non-dividing cells confirmed the occurrence of mitosis in the late promyelocyte and myelocyte.
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    Cell & tissue research 228 (1983), S. 489-496 
    ISSN: 1432-0878
    Keywords: Heart ; Tissue culture ; Electron microscopy ; Myocyte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cardiac muscle cells from 3-day-old rat neonates were cultured for periods of 2 to 56 days. In order to facilitate ultrastructural studies on the organization of the sarcoplasmic reticulum, the cells were prepared for transmission electron microscopy according to a regimen including postfixation in reduced osmium ferrocyanide. The nonjunctional sarcoplasmic reticulum (NJSR) was organized as a loose, fenestrated sleeve around the exterior of bundles of myofilaments and was particularly prominent at the level of the Z line. The only recognizable junctional elements of the sarcoplasmic reticulum were in a peripheral location. Reduced osmium ferrocyanide was also useful in distinguishing intermediate (10nm) filaments, since it understained Z substance, which often obscured these structures. Intermediate filaments were arranged both at the Z line and the intercalated disc, in parallel strands, approximately at right angles to the myofilaments.
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  • 83
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    Keywords: CRF ; immunolabelling ; Paraventricular nucleus ; Median eminence ; Electron microscopy
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    Topics: Biology , Medicine
    Notes: Summary The corticotropin releasing factor (CRF)-synthesizing perikarya and neural processes were detected at ultrastructural level in the hypothalamic paraventricular nucleus and in the median eminence of control and colchicine-pretreated rats. The unlabelled antibody peroxidase-antiperoxidase complex (PAP) immunohistochemical method was used in a pre-embedding manner, on thick, non-frozen sections. In CRF-perikarya, neurosecretory granules (80–120 nm in diameter), free ribosomes, and the rough endoplasmic reticulum were labelled. Unlabelled axon terminals formed asymmetric synapses on CRF-containing perikarya and dendrites. Immunolabelled axons terminated in the palisadic zone of the median eminence.
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  • 84
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    Cell & tissue research 232 (1983), S. 379-397 
    ISSN: 1432-0878
    Keywords: Electron microscopy ; Pelvic ganglia ; Autonomic nervous system ; Synapses ; Neurones ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A semi-quantitative electron-microscopic study of neuronal cell bodies, nerve profiles and synapses in the anterior pelvic ganglia of the guinea-pig has been carried out following in vivo labelling of adrenergic nerve endings with 5-hydroxydopamine. Ganglion cells of three main types have been distinguished: 1) the majority (about 70%) not containing granular vesicles, probably cholinergic elements; 2) those containing large granular vesicles of uniform size (80–110 nm), with granules of medium density and prominent halos; and 3) those containing vesicles of variable size (60–150 nm), with very dense eccentrically placed granular cores. Some non-neuronal ‘granule-containing’ cells were present, mainly near small blood vessels. Some 95% of the total axon profiles within the ganglia were cholinergic, the remaining 5% were adrenergic. However, 99% of synapses (i.e. axons within 50 nm of nerve cell membrane with pre-and post-synaptic specialisations) were cholinergic, and 1 % were adrenergic. Only three examples of nerve cell bodies exhibiting both cholinergic and adrenergic synapses were observed. Unlike the para-and prevertebral ganglia, the pelvic ganglia contained large numbers of axo-somatic synapses. As many as 20% of the nucleated neuronal cell profiles displayed two distinct nuclei.
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    Cell & tissue research 232 (1983), S. 399-411 
    ISSN: 1432-0878
    Keywords: Pelvic ganglion ; Reinnervation ; Decentralisation ; Autonomie nervous system ; Electron microscopy ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An electron-microscopic study has been made of adrenergic and cholinergic nerve fibres and synapses in the pelvic ganglion of the guinea-pig at intervals of up to 60 days following section of the hypogastric and pelvic nerves. Transection of the hypogastric nerves led to degeneration of 80–90% of the cholinergic nerve profiles and synapses in the ganglion. The small number of adrenergic nerves and synapses did not change, but 30–60 days after section, this number increased 8–10 times. Transection of the pelvic nerves led to degeneration of about 15% of the cholinergic nerve terminals, but no change in adrenergic terminals. After transection of both hypogastric and pelvic nerves, only about 1% of cholinergic nerves survived, but after 30–60 days, the number of adrenergic nerves increased 8–10 times. It is concluded that following cholinergic nerve degeneration in the ganglion, adrenergic nerves, probably originating as collateral sprouts from postganglionic neurones and granule-containing cells, can replace them to some extent.
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    Cell & tissue research 228 (1983), S. 85-98 
    ISSN: 1432-0878
    Keywords: Basement-membrane production ; Mouse embryos ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Mouse embryos (strain NMRI) of days 9 + 2h, 9 + 12h, 10 + 2h, 10 + 12h, 11 + 2h, 12 + 2h, 13 + 2h, and 14 + 2h were fixed (i) in 3% glutaraldehyde +3% paraformaldehyde, (ii) in 1% glutaraldehyde +1% tannic acid, or (iii) in 1% glutaraldehyde +1.5% ruthenium red. The electronmicroscopic picture of the basement membrane (BM) changed depending on the fixative used. Addition of tannic acid led to a higher staining intensity of glycoproteins, whereas after ruthenium red proteoglycans were more heavily stained. The BM around the neural tube and around the epithelial tubules in the lung anlage were investigated electron microscopically. After fusion, the BM in the dorsal regions of the neural tube is missing; on days 9–10 it is, however, reformed. Between days 11 and 13 wide gaps in the BM of the lung anlage occur at the growth buds of the epithelial tubes, which are bridged on late day 13. In the basal parts of these two epithelial types membrane-bordered granules of different density occur singly or in groups. It is postulated that these structures contain BM-material and represent secretion granules. After secretion, BM-material is first bound to the cell membrane. This process is important for the initiation of the formation of the BM. Further growth, however, proceeds via lateral aggregation (self-assembly). Thus, intercellular gaps are bridged independent of the cell membrane. The process of lateral aggregation may also explain deviations from the normal course of the BM.
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    Cell & tissue research 230 (1983), S. 639-648 
    ISSN: 1432-0878
    Keywords: Non-adrenergic, non-cholinergic autonomic nerves ; Quinacrine ; Fluorescence microscopy ; Electron microscopy ; Anococcygeus muscle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphological changes induced in the autonomic nerves of the rat anococcygeus muscle after the injection of quinacrine (QC, 100 or 200 mg/kg) were examined by electron microscopy in order to clarify the nature of QC-binding nerves seen at the fluorescence-microscopic level. A correspondence between granular QC fluorescence and many lysosomal dense bodies is observed both in the cytoplasm of muscle cells and in non-adrenergic, non-cholinergic (NANC) axons during the first few days following injection. A number of brilliantly fluorescent fibres is observed 1 week after injection. At the ultrastructural level, these fibres seem to correlate with NANC axons which are crowded with many dense bodies and large granular vesicles. Notably, some lysosomal dense bodies contain many large granular vesicles. The effects of QC injection on the ultrastructure of adrenergic axons have also been observed, but are not so marked as in the NANC axons. The administration of QC did not cause complete degeneration of the NANC nerves, though degenerating axons were sometimes observed. The present data indicate that most, if not all, QC-binding nerves observed at the fluorescence-microscopic level correspond to NANC nerves at the electron-microscopic level. Furthermore, NANC axons appear to contain a considerable amount of ATP concentrated in the large granular vesicles.
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  • 88
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    Keywords: Bone marrow (mouse) ; Monocytes ; Neutrophil granulocytes ; Granules ; Electron microscopy ; Peroxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The differentiation and maturation of monocytes and neutrophil granulocytes were studied in bone marrow of normal mice by electron microscopy and cytochemical assessment of peroxidatic activity. The granule populations of the mature cells of bone marrow were identified and investigated to obtain a basis for the analysis of the earlier stages of maturation. Mature monocytes and neutrophils showed primary and secondary granules, and mature neutrophils had more of both kinds. The size, shape, and number of primary granules proved to offer the most reliable criteria for distinguishing promonocytes and promyelocytes. The primary granules of monocytes were smaller than those of mature neutrophils and were either spherical (smallest diameter 50–200 nm) or elongate (100×400 nm). Both granules had a homogeneous matrix. The granules of the granulocytes were either spherical (smallest diameter 200–300 nm) or elongate (150–200×300–500 nm), and some of them had a crystalline inclusion.
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  • 89
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    Keywords: Smooth muscle ; Anura ; Stomach ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The young of the aquatic Australian frog, Rheobatrachus silus (Leptodactylidae) develop from eggs to juvenile frogs in the mother's stomach. During brooding the stomach expands greatly and becomes very thin walled. Transmission electron microscopy showed that the distension of the stomach was accompanied by a severe disruption of the smooth muscle layers. Many of the smooth muscle cells seemed to be highly contracted and resembled smooth muscle cells contracted in the absence of an intact connective tissue matrix. Eight days after the birth of the juveniles through the mouth of the female, the stomach muscle cells had returned to a normal appearance. It is suggested that during gastric incubation of the young, smooth muscle cells become at least partially dissociated from their surrounding connective tissue matrix, allowing maximal distension of the stomach wall.
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    Cell & tissue research 231 (1983), S. 551-563 
    ISSN: 1432-0878
    Keywords: Visual mutants ; Anterior optic tract ; Independent gene actions ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopy shows that in wild-type Drosophila melanogaster the anterior optic tract (AOT) is formed by about 1260 fibers in males and slightly fewer in females. Golgi staining suggests that most AOT fibers connect the lobula with different regions of the central brain. In the sine oculis (so) and small optic lobes (sol) mutants the number of axons is drastically reduced, by 58% in sol and by 35% in so. In the double mutant sol:so there is a loss of up to 83% of the fibers in the AOT. Approximately half of the remaining 220 fibers form a well defined subbundle of very thin axons which is identifiable in wild type as well as in both single mutants. The fibers of this subbundle neither originate nor terminate in the visual ganglia: instead, they connect two different central brain regions. It is concluded that the combined action of the sol and so mutations abolishes more than 90% of the fibers of visual origin or destination in the AOT. Quantitative analysis of electron micrographs shows that the so and sol mutations act independently on nearly exclusive subsets of axons in the AOT.
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  • 91
    ISSN: 1432-0878
    Keywords: Satellite cells ; Skeletal muscle ; Snake-venom toxin ; Muscle regeneration ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Satellite cells were studied in the undamaged part of the rat soleus muscle rendered partially necrotic by a subcutaneous injection of notexin, the myotoxic toxin purified from the venom of the Australian snake Notechis scutatus scutatus. Nuclei of satellite cells were twice as numerous as in the controls, with a decreasing gradient in the number of satellite cells with distance from the necrotic area. The cells were in an activated state with an increased cytoplasmic volume and prominent organelles. Occasionally, mitosis of some satellite cells was observed. Between the satellite cell and the muscle fibre, an unusually wide space was frequently seen, within which a “new” basal lamina was often visible. It is suggested that the role of the satellite cells of undamaged muscle fibres in the regeneration of necrotic muscle is worthy of more detailed investigation.
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    Cell & tissue research 233 (1983), S. 209-213 
    ISSN: 1432-0878
    Keywords: Hamsters ; Harderian glands ; Short photoperiod ; Sexual dimorphism ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A sexual dimorphism of the hamster Harderian gland at the ultrastructural level, has been reported. Castration of males and the administration of testosterone to females are known to alter the male type gland to the female type and vice versa. In this paper we present data that exposure to a short photoperiod (1L:23D) can induce similar structural alterations between the 4th and 10th week of exposure. Changes in the male included reduction in the number of tubular clusters and large vacuoles, while in the female the number of membrane formations decreased with an accompanying appearance of tubular clusters.
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    Colloid & polymer science 260 (1982), S. 564-569 
    ISSN: 1435-1536
    Keywords: lin. Polyethylene ; Single crystals ; Heat of Fusion ; DSC ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Recently published results for solution crystallized PE single crystals have shown, that the experimental heat of fusionΔH * is higher, if the solvent is exchanged to silicon oil (oil suspension samples) as compared with dried mats. This has been interpreted by the collapse of the original hollow pyramids during drying, inducing lateral defects within the lamellae. The present investigation does not confirm this unexpected result.ΔH * of dried mats (T c 66 to 91 °C) and of the corresponding oil suspension samples agree within the rather small limits of experimental error. The crystallinities as derived fromΔH *, density or WAXS are in excellent agreement. SEM micrographs of cold fractured dried mats show their spongy macromorphology, but TEM micrographs of stained ultra-thin sections reveal the lamellar morphology of the walls, consisting of curved lamellae and stacked hollow pyramides. If a dried mat is sintered at room temperature, a dense transparent film is obtained with a rather regular stacked morphology of large flat lamellae.ΔH * of these films agrees with that of the original mat.
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    Development genes and evolution 191 (1982), S. 205-207 
    ISSN: 1432-041X
    Keywords: Chitin inhibition ; Nikkomycin ; Cuticle ; Electron microscopy ; Epilachna varivestis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The nucleoside antibiotic nikkomycin has proved to be an effective inhibitor of chitin synthesis in the Mexican bean beetleEpilachna varivestis. Ultrastructural investigations show defects in the procuticular area after nikkomycin application which suggest the complete absence of chitin. A cuticle like this is inflexible and too brittle to satisfy its normal function as an exoskeleton. The individuals are not able to free themselves from the exuvia and finally die. Therefore nikkomycin seems to be a potential insecticide with high specifity.
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    Archives of microbiology 132 (1982), S. 10-13 
    ISSN: 1432-072X
    Keywords: Calcofluor White ; Cell wall structure ; Chlorella ; Electron microscopy ; Protoplast ; Ruthenium Red
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Among 12 strains ofChlorella ellipsoidea, C. vulgaris, andC. saccharophila tested, 4 strains (1,C. ellpsoidea; 2,C. vulgaris; 1,C. saccharophila) formed osmotically labile protoplasts after treatment with mixtures of polysaccharide degrading enzymes. The relationship between enzymatical digestibility and structure or composition ofChlorella cell walls were studied by electron microscopy and staining techniques with some specific dyes. The cell wall structures of the 12Chlorella strains were grouped into three types: (1) with a trilaminar outer layer, (2) with a thin outer monolayer, and (3) without an outer layer. Protoplasts were formed only from the strains with a cell wall of Type 2. In the strains with a cell wall of Type 1, the outer layer protected the inner major microfibrillar layer against enzymatic digestion. The cell wall of Type 3 was totally resistant to the enzymes; the chemical composition of the cell wall would be somewhat different from that of other types.
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    Archives of microbiology 133 (1982), S. 97-99 
    ISSN: 1432-072X
    Keywords: Cyanobacteria ; Thylakoid centers ; Photosynthetic membranes/thylakoids ; Membranes ; Membrane biogenesis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An ultrastructural study of four cyanobacteria (Anabaena cylindrica, Dermocarpa violaceae, Gleocapsa alpicola, Pleurocapsa minor) indicates the presence of previously undescribed thylakoid centers from which photosynthetic membranes (thylakoids) radiate. These peripherally located thylakoid centers are cylinders 30 nm wide by 320 nm long, consisting of globular subunits oriented in nonparallel stacked arrays. Thylakoids are attached to the outer surface of the cylinder along its longitudinal axis. Thylakoid centers appear to be functionally significant due to their structure, location and thylakoid association.
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  • 97
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    Archives of microbiology 131 (1982), S. 116-123 
    ISSN: 1432-072X
    Keywords: Cell wall ; Wall degradation ; Lysozyme ; Autolysines ; Electron microscopy ; Staphylococcus aureus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In contrast to former findings lysozyme was able to attack the cell walls ofStaphylococcus aureus under acid conditions. However, experiments with14C-labelled cell walls and ribonuclease indicated that, under these conditions, lysozyme acted less as an muralytic enzyme but more as an activator of pre-existing autolytic wall enzymes. Electron microscopic studies showed that under these acid conditions the cell walls were degraded by a new mechanism (i.e. “attack from the inside”). This attack on the cell wall started asymmetrically within the region of the cross wall and induced the formation of periodically arranged lytic sites between the cytoplasmic membrane and the cell wall proper. Subsequently, a gap between the cell wall and the cytoplasmic membrane resulted and large cell wall segments became detached and suspended in the medium. The sequence of lytic events corresponded to processes known to take place during wall regeneration and wall formation. In the final stage of lysozyme action at pH 5 no cell debris but “stabilized protoplasts” were to be seen without detectable alterations of the primary shape of the cells. At the same time long extended ribbon-like structures appeared outside the bacteria. The origin as well as the chemical nature of this material is discussed. Furthermore, immunological implications are considered.
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  • 98
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    Theoretical and applied genetics 61 (1982), S. 27-33 
    ISSN: 1432-2242
    Keywords: Preferential transmission ; In situ hybridization ; C-banding ; Aegilops sharonensis ; Wheat ; Addition ; Substitution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary An attempt to produce a set of addition lines of Aegilops sharonensis to the wheat variety ‘Chinese Spring’ produced only one addition line. This was due to preferential transmission of one chromosome from Ae. sharonensis. This chromosome was studied in detail by established cytological methods of chromosome observation and by the newer techniques of C-banding and in situ hybridization of a cloned DNA sequence. The chromosome was found to be partially homologous to an Ae. sharonensis chromosome of similar behaviour in another wheat addition line. The incomplete homology of the two Ae. sharonensis chromosomes was due to the presence of a translocated segment of a wheat chromosome. — Substitution lines of the Ae. sharonensis chromosome for wheat homoeologous group 4 were produced and the Ae. sharonensis chromosome thereby designated 4 S l .
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  • 99
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    Theoretical and applied genetics 63 (1982), S. 227-233 
    ISSN: 1432-2242
    Keywords: C-banding ; Wheat ; Rye ; Triticale
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Using different stains, wheat chromosomes could be distinguished from rye chromosomes by preferential staining. C-bands of rye chromosomes were preferentially stained with Giemsa while those of wheat chromosomes were preferentially stained with either Leishman or Wright stain. Preferential staining aids the identification of wheat and rye chromosomes and chromosome segments and in particular the recognition of wheat/rye chromosome substitutions and translocations.
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  • 100
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    Theoretical and applied genetics 62 (1982), S. 45-48 
    ISSN: 1432-2242
    Keywords: Wheat ; Rye ; Triticale ; Callus cultures ; Alcohol dehydrogenase ; Isoenzymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Two NAD-dependent alcohol dehydrogenases ADH-1 and ADH-2, under independent genetic control of genes designated as Adh-1 and Adh-2 located on chromosomes 4A, 4B and 4D, have been reported in aestivum wheat (Hart 1980). Only ADH-1 is expressed in developing seeds, dry seeds, pollen and germinating seedlings. ADH-2 can be induced in seedling roots or shoots under conditions of partial anaerobiosis or by certain chemicals. Expression of ADH-1 and ADH-2 isoenzymes was investigated in undifferentiated calli from aestivum and durum wheats, rye, triticale and also in in vitro regenerated roots and leaves from aestivum cultures. Wheat callus cultures originating from seed, mature and immature embryos, mesocotyl and root, as well as cultures grown on media containing different supplements did not show any variation in the overall expression of ADH-1 or ADH-2, although differences in the band intensities were observed. The callus isoenzyme pattern was similar to that observed in roots under anaerobic conditions. Both ADH-1 and ADH-2 were expressed in in vitro regenerated roots but were absent in regenerated leaves. Expression of ADH-1 and ADH-2 in wheat calli seems to be related to the type of differentiation.
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