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  • Development
  • Rheology
  • Springer  (78)
  • American Geophysical Union
  • American Geophysical Union (AGU)
  • American Physical Society
  • Nature Publishing Group
  • 1980-1984  (78)
  • 1935-1939
  • 1
    Electronic Resource
    Electronic Resource
    Suitability of selected leguminous plants for development of Maruca testulalis larvae (1983)
    Springer
    Entomologia experimentalis et applicata 34 (1983), S. 174-178 
    Details
    ISSN: 1570-7458
    Keywords: Lepidoptera ; Pyralidae ; Maruca testulalis ; Pod borer ; Development ; Nutritional suitability ; Host plant ; Crotalaria ; Vigna unguiculata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les possibilités de développement larvaire de Maruca testulalis sur les fleurs de huit espèces végétales ont été examinées en laboratoire. La comparaison a porté sur Crotalaria retusa, C. juncea, C. saltiana, C. misereniensis, C. mucronata, C. amazonas, Cajanus cajan et l'hôte principal de cette chenille, Vigna unguiculata. En tenant compte de la mortalité larvaire et des indices de croissance (G.I.), ces plantes ont été divisées en trois catégories principales: 1 celles provoquant une mortalité larvaire de 0–30% et ayant des G.I. ≥60%, constituent les plantes hôtes convenables (Vigna unguiculata seule); 2 les plantes qui provoquent une mortalité larvaire de 30≤50% et ont des G.I. de 30 à 60% de la plante hôte principale (Cajanus cajan, Crotalaria amazonas, C. saltiana, C. mucronata; 3 les plantes qui causent 50–100% de mortalité larvaire et dont les G.I. sont inférieurs à 30% de la plante hôte principale (Crotalaria retusa, C. juncea, C. misereniensis). Les résultats déjà publiés sur les choix du lieu de ponte des femelles et l'utilisation de C. juncea comme plante piège, sont discutés à la lumière de ces données nouvelles.
    Notes: Abstract Flowers of eight plant species were evaluated under laboratory conditions for their suitability as larval growth media for the cowpea pod borer, Maruca testulalis. The plants tested were Crotalaria retusa, C. juncea, C. saltiana, C. misereniensis, C. amazonas, Cajanus cajan and the principal host of the borer, Vigna unguiculata (cowpea), was included for comparison. Based on the data obtained on larval mortality and growth indices (GI) the plants were divided into 3 categories namely: I: Those causing 0–30% mortality and having GI value ≥60% form suitable host plants. This group only included V. unguiculata. — II: Those plant species causing 30≤50% larval mortality and having GI value 30%≤60% of the principal host plant (Cajanus cajan, Crotalaria amazonas, C. saltiana, C. mucronata). This group of species is marginally suitable as hosts. — III: Plants causing 50–100% larval mortality and having GI value ≤30% of principal host plant (C. retusa, C. juncea and C. misereniensis). Previously published data on the oviposition preference of the adult moth are discussed in the light of the present findings and the use of C. juncea as a possible trap crop.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00338666
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  • 2
    Electronic Resource
    Electronic Resource
    Cyromazine-sensitive stages of housefly development: Influence of penetration, metabolism and persistence on potency (1983)
    Springer
    Entomologia experimentalis et applicata 34 (1983), S. 251-256 
    Details
    ISSN: 1570-7458
    Keywords: Cyromazine ; Musca domestica ; Housefly ; Development ; Sensitivity ; Penetration ; Insect growth regulator
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé La cyromazine (N-cyclopropyl-1,3,5-triazine-2,4,6-triamine or CGA-72662) est un puissant inhibiteur de développement chez Musca domestica Le traitement des adultes par voie orale n'altère pas l'éclosion des œufs, mais inhibe fortement le développement des larves. Incorporée au milieu larvaire, elle donne une DL50 de 0.11 ppm. La sensibilité des pupes, traitées par application topique, décroit rapidement avec l'âge et est dépendante du solvant utilisé. Une heure après pupaison et avec le tétrahydrofuran comme vecteur, la DL50 est de 3 μg/g, soit 0.2 μg/g pour la pupe sans puparium. Comparé au méthanol. le tétrahydrofuran facilite la pénétration de la cyromazine pendant ce stade critique. La pénétration est également un facteur de la résistance des pupes agées. La toxicité de la cyromazine apparait rait donc principalement dépendante de sa vitesse de pénétration et de son accumulation dans l'organisme plutôt que de son métabolisme. Juste après pupaison, la jeune pupe chez M. domestica s'avère être un matériel sensible et pratique pour l'étude du mode d'action de la cyromazine.
    Notes: Abstract Cyromazine is a potent inhibitor of housefly (Musca domestica L.) larval development when administered orally to adults or incorporated into larval media, and of pupal metamorphosis on topical application shortly before or after pupariation. Pupae are most sensitive to cyromazine within 1 hr after pupariation and with tetrahydrofuran as the carrier solvent, giving topical LD50 values of 3 μg/g for the total puparium plus pupa and 0.2 μg/g calculated for the pupa only. Tetrahydrofuran is more effective than methanol in facilitating rapid cyromazine penetration during this critical pupal stage. The rate of cyromazine penetration or accumulation at sensitive stages appears to be more critical than the extent of metabolism in limiting cyromazine toxicity. Houseflies shortly after pupariation provide a sensitive and convenient organism for studies on cyromazine mode of action.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00186921
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  • 3
    Electronic Resource
    Electronic Resource
    The effect of temperature onshibire ts cell clones in the compound eye ofDrosophila melanogaster (1980)
    Springer
    Development genes and evolution 188 (1980), S. 55-63 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Compound eye ; shibire ts ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have analysed the effect of temperature on both developing and adult eye cell clones homozygous forshi ST139, a temperature-sensitive mutant ofDrosophila melanogaster. The mutant gene, autonomous in its cellular expression, causes structural modifications of ommatidial cells when adult clones of cells are exposed to the restrictive temperature (29°C) for several days. However, the mutant phenotype reverses to normal within 4 days at the permissive temperature (20°C). The results of pulse, shift-up and shift-down experiments show that the temperaturesensitive period for developing compound eye cells is from the late second instar up to the early pupa. Cytodifferentiation of compound eye cells is blocked by restrictive temperature treatment during this period, whereas cell proliferation does not seem to be directly affected. These results are discussed with regard to the other known aspects of the phenotype observed in mutant individuals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848610
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  • 4
    Electronic Resource
    Electronic Resource
    Developmental profiles of gangliosides in mouse and rat cerebral cortex (1982)
    Springer
    Development genes and evolution 191 (1982), S. 281-284 
    Details
    ISSN: 1432-041X
    Keywords: Mammals ; Brain cortex ; Gangliosides ; Glycoproteins ; AChE ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Developmental profiles of 11 gangliosides, concentration of lipid- and glycoprotein-bound sialic acid, and activity of AChE of the rat and mouse cerebral cortex were followed from the 7th day of gestation to the 21st postnatal day. There are three main changes in ganglioside concentration, which are similar in both species. The first occurs from gestation day 10 until birth: parallel to decreased proliferation, cell migration, and neuroblast differentiation, GM3 and GD3 in mouse cortex and GD3 in the rat's decreases in favor of GQ1b, GT1b, and GD1a. The second occurs from birth until the first postnatal week: Parallel to increased growth and arborization of dendrites and axons as well as synaptogenesis in rats and mice, there is a two-fold rise of GD1a, whereas GQ1b and GT1b remain on a nearly constant level. Concomitantly, GM3 and GD3 decreases. The third period of ganglioside changes starts in the second postnatal week, parallel to onset of myelination, and is characterized by an increase of GM1 in parallel with a decrease of the polysialogangliosides GT1b and GQ1b.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848417
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  • 5
    Electronic Resource
    Electronic Resource
    Sequence complexity of poly(A) RNA fromPhysarum polycephalum (1982)
    Springer
    Development genes and evolution 191 (1982), S. 341-347 
    Details
    ISSN: 1432-041X
    Keywords: Physarum ; Development ; RNA ; Sequence complexity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Poly(A) RNA from S phase, G2 phase and starved macroplasmodia of Physarum contain mRNA sequences which when translated in vitro, yield similar patterns of polypeptides after fluorography. Reassociation of nick-translated DNA (Cot) allows the isolation of highly labeled single copy DNA which, after saturation hybridization with poly(A) RNA, gives values of 23% for growth and 17% for starvation. Homologous cDNA/poly(A) RNA hybridization reactions (Rot) indicate that 22–28% of the genome is transcribed during growth and 12% during starvation and that about half of the cDNA reacts with 0.1% of the genome and could represent 50–80 RNA species, each present in about 1,000 copies per nucleus. Up to 25,000 different RNA species, 1–5 copies each per nucleus, are estimated to be present during growth, and about 15,000 during starvation. Heterologous cDNA/poly(A) RNA hybridization reactions (Rot) indicate that the RNA sequences in S and G2 phase of the cell cycle are similar, with RNA sequences being more abundant in G2 phase. During starvation about 25% of the sequences present during growth cannot be detected and those sequences present during growth have become diluted during starvation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00879622
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  • 6
    Electronic Resource
    Electronic Resource
    Sugar binding properties of the vitellogenic proteins in the Colorado beetle, demonstrated by hemagglutination and precipitation experiments (1982)
    Springer
    Development genes and evolution 191 (1982), S. 159-162 
    Details
    ISSN: 1432-041X
    Keywords: Vitellogenin ; Hemagglutinin properties ; Yolk formation ; Insects ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The sugar binding properties of 2 important vitellogenic proteins in Colorado beetle hemolymph were demonstrated by hemagglutination and precipitation experiments. The agglutination of human red blood cells by the hemolymph of reproducing females was observed up to a hemolymph dilution of 1/256, irrespective of the blood-group. It increased significantly after trypsinization of the crythrocytes. Vitellogenin 1 was identified as the hemagglutinin. Hemagglutination and hemagglutination inhibition tests showed that this protein has a low affinity for hexosamines and a higher affinity for sulfated polysaccharides. Precipitation tests demonstrated that besides vitellogenin, another major yolk protein, chromoprotein 2, reacts with sulfated polysaccharides. The possibility that there is a specific reaction of the vitellogenic proteins with well defined saccharides on the oocyte surface is discussed. This lectintype reaction may explain the selectivity of yolk precursor endocytosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848330
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  • 7
    Electronic Resource
    Electronic Resource
    Inhibition of protein synthesis in a polyribosome-dependent cell-free system by a specific ribonuclease prepared from the follicles of two different stages of development of the silkmothAntherea pernyi (1984)
    Springer
    Development genes and evolution 194 (1984), S. 25-31 
    Details
    ISSN: 1432-041X
    Keywords: Protein synthesis ; Development ; Antherea pernyi ; Follicles ; Specific ribonuclease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Crude, cell-free protein-synthesizing systems were prepared from follicles of two different stages of development in the ovariole of the silkmothAntherea pernyi. The efficiency of the translation of natural and synthetic mRNAs in these systems was compared with that in a cell-free wheat germ system. A postmitochondrial extract (S-30) from the follicles almost completely inhibited protein synthesis in a polyribosome-dependent, cell-free systems. A specific ribonuclease, obtained from the post mitochondrial extract by ammonium sulphate precipitation, heat denaturation and DEAE-cellulose chromatography, inhibited polyribosome-dependent protein synthesis. The effect of this specific ribonuclease on the structural integrity of radioactive RNAs and ribosomal subunits, which were isolated from Ehrlich ascites tumor cells, was also studied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848950
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  • 8
    Electronic Resource
    Electronic Resource
    Immunocytochemical and electrophoretic studies on the localization of the major haemolymph proteins (ceratitins) inCeratitis capitata during development (1984)
    Springer
    Development genes and evolution 194 (1984), S. 37-43 
    Details
    ISSN: 1432-041X
    Keywords: Major haemolymph proteins ; Development ; Cuticle ; Immunocytochemistry ; Ceratitis capitata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The developmental profile of the major haemolymph proteins (ceratitins) inCeratitis capitata was studied. Ceratitin concentration in the haemolymph decreases dramatically during the last days of pupal life, while the amounts of ceratitins in whole organism extracts remain unchanged. By electrophoretic, immunological and immunofluorescence techniques it was revealed that ceratitins are reabsorbed by the fat body and a fraction of them is deposited in the cuticle. The possible role of ceratitins is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848952
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  • 9
    Electronic Resource
    Electronic Resource
    Ganglioside changes in the chicken optic lobes and cerebrum during embryonic development (1980)
    Springer
    Development genes and evolution 188 (1980), S. 205-213 
    Details
    ISSN: 1432-041X
    Keywords: Gangliosides ; Development ; Brain ; Chicken
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The developmental profiles of 15 different gangliosides of the optic lobes and cerebrum of the chicken were followed from the 6 th day of incubation to hatching and correlated to morphological development. Five of these gangliosides appearing in both structures between the sixth and tenth day, have not been reported previously in higher vertebrates. Three chromatographed on TLC-plates similarly to GT3, GT2, and GT1c gangliosides, which have been demonstrated in fish brain. One fraction moved just below GQ1b and is suggested, to contain GQ1c. These “novel” gangliosides, which are possibly related to a recently proposed separate and probably phylogenetically older biosynthetic pathway, contained up to 20% of total ganglioside sialic acid. The fifth “novel” fraction, containing up to 16% of total ganglioside-sialic acid, moved below the penta-sialoganglioside GP1 and is suggested to contain hexa-sialogangliosides. There were two main changes in ganglioside synthesis, which were identical in both structures. The first occurred from the sixth to the eleventh day, parallel to decreased proliferation, maximal cell migration and neuroblast differentiation, GD3 and GD2 decreased rapidly in favour of GQ1b, GP1, and to the “novel” fractions, described above. The second occurred from the eleventh to the eighteenth day, parallel to increased growth and arborization of dendrites and axons as well as functional establishment of synaptic contacts, there was a sharp rise in the amount of GD1b, GT1b, and GD1a. Concomitantly the “novel” gangliosides decreased. At hatching GD1a was the predominant ganglioside. GM3, GM2, and GM1 were always minor fractions, each accounting for less than 4% of total ganglioside-sialic acid. GM4 was never detected, indicating neglegible myelinisation until hatching.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00849050
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  • 10
    Electronic Resource
    Electronic Resource
    Studies on the regulation of the branched chain amino acyl-tRNA synthetases of the fungusNeurospora crassa (1980)
    Springer
    Development genes and evolution 189 (1980), S. 171-180 
    Details
    ISSN: 1432-041X
    Keywords: Amino acyl-tRNA synthetases ; Development ; Nuclear-mitochondrial interactions ; Neurospora
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The specific activities of the branched chain amino acyl-tRNA synthetases from the cytosolic and mitochondrial fractions ofN. crassa were low in dormant conidia and increased during germination, reaching a maximum 8 h after inoculation. This stage of development is characterised by high rates of many other cellular activities. The increases in activity of synthetases of both cytosol and mitochondria are inhibited by cycloheximide indicating that they are synthesized on cytoplasmic ribosomes. The mitochondrial synthetases show a stimulation of their specific activity when mitochondrial RNA and protein synthesis are inhibited by either ethidium bromide or chloramphenicol suggesting that a mitochondrial translation product regulates the synthesis of the mitochondrial synthetases. The activities of amino acyl-tRNA synthetases are dependent on energy production. When respiration is uncoupled from oxidative phosphorylation, synthetase specific activities decrease although the activities of other mitochondrial enzymes like NADH-dehydrogenase increase. This phenomenon suggests that more than one mechanism regulates the synthesis of mitochondrial proteins which are formed on cytoplasmic ribosomes. The synthesis of branched chain amino acyl-tRNA synthetases ofNeurospora is neither repressed by their cognate amino acids, nor is there inhibition by the precursors of these amino acids, as has been observed in other amino acyl-tRNA synthetases of various organism includingNeurospora.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00868675
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  • 11
    Electronic Resource
    Electronic Resource
    Electron microscopical investigations of the intercellular contacts during the early cleavage stages ofLymnaea stagnalis (Mollusca, Gastropoda) (1981)
    Springer
    Development genes and evolution 190 (1981), S. 215-220 
    Details
    ISSN: 1432-041X
    Keywords: Mollusca ; Cleavage ; Junctions ; Interaction ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In early cleavage stages ofLymnaea stagnalis, three kinds of intercellular junctions could be distinguished up to the sixth cleavage: intermediate, septate and gap junctions. The first two form “junctional belts” located on the cell border at the periphery of the embryo. For the purpose of our study we were most interested in gap junctions as they are alleged to be structures that allow cell-to-cell communication. Gap junctions first appear at the four cell stage. Up to the sixth cleavage no difference in the distribution pattern could be found between and within each of the four quadrants of the embryo. Some of the cell tiers along the animal-vegetal axis lack gap junctions either between the blastomeres within the tier or between the blastomeres from adjacent tiers. All gap junctions observed in freeze fracture replicas show plaques with an irregular IMP pattern. The average IMP diameter measures 12 nm (SD±2 nm). In stages fixed after the fifth cleavage, gap junctions are found between micromeres at the animal pole and the central 3D macromere. This is in agreement with the presumed interaction between these cells at this stage. The possibility of a transition of non-functional into functional gap junctions after the fifth cleavage is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848305
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  • 12
    Electronic Resource
    Electronic Resource
    Gap junction formation between normal and reaggregated endoderm cells ofXenopus laevis neurulae (1982)
    Springer
    Development genes and evolution 191 (1982), S. 143-148 
    Details
    ISSN: 1432-041X
    Keywords: Amphibia ; Junctions ; Interaction ; Development ; Freeze fracture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Using freeze-fracture electron microscopy and fluorescent dye injection we have analysed the contacts between cells of the deeper endoderm taken from neurulae ofXenopus laevis. Endodermal cells in situ have large 1.5 μm diameter gap junctions composed of 8 nm P-face particles and corresponding E-face pits. Beside gap junctions, particle aggregates typical of desmosomal plaques are present but there are no tight junctions. The dissociation of endoderm into single cells involves profound structural alterations in the surface membrane including the complete disappearance of junctional structures among them gap junctions. The reaggregation of endoderm cells leads to the restoration of the surface membrane IMP (Intra Membrane Particle) pattern and, after ca. 30 min, to the establishment of functional pathways allowing for the intercellular transfer of fluorescent dye. Concomitantly gap junctions reappear. The observation that the dissociation and reaggregation of endodermal cells involves IMP alterations which go beyond the cell junctions themselves is discussed as an adaptation of the plasma membrane to changing environmental conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848328
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  • 13
    Electronic Resource
    Electronic Resource
    Dye-coupling between blastomeres in early embryos ofPatella vulgata (mollusca, gastropoda): Its relevance for cell determination (1983)
    Springer
    Development genes and evolution 192 (1983), S. 262-269 
    Details
    ISSN: 1432-041X
    Keywords: Mollusca ; Interaction ; Development ; Dye-coupling ; Gap junctions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary During the early development of the molluscPatella, the dorsoventral axis is established after the fifth cleavage due to direct interaction between the animal micromeres and one of the vegetal macromeres. This vegetal macromere is thereby induced to become the mesentoblast mother cell (3D). In this study we have examined intercellular communication in earlyPatella embryos by monitoring the transfer of the fluorescent dye, Lucifer Yellow, upon iontophoretic injection into blastomeres between the second and sixth cleavage. Up to the fifth cleavage dye transfer is detectable neither inin toto embryos nor in serial sections. Shortly after the fifth cleavage dye-coupling between blastomeres becomes apparent. This occurs approximately 40 min before the interaction between animal micromeres and the future mesentoblast mother cell. Inspection of serially sectioned embryos after dye-iontophoresis in either animal micromeres or in the central macromere 3D showed the absence of direct dye-transfer between these cells at the stage of interaction. The reduced rate of dye-transfer from the 3D macromere to its dorsal neighbour 2d2 suggests a bilateral symmetrical transfer pattern, the axis of which corresponds with the dorsoventral axis at the sixth cleavage. Cell deletion experiments demonstrated that the establishment of dye-coupling between the vegetal macromeres occurs independently of the interaction between animal and vegetal blastomeres.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848658
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  • 14
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    Major haemolymph proteins inCeratitis capitata: Biosynthesis and secretion during development (1981)
    Springer
    Development genes and evolution 190 (1981), S. 33-39 
    Details
    ISSN: 1432-041X
    Keywords: Ceratitis capitata ; Major haemolymph proteins ; Development ; Fat body ; Secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The accumulation of major haemolymph proteins (a group of proteins immunologically related to Calliphorin) their biosynthesis in vivo and in organ culture as well as their secretion, has been studied during the late larval stages and white pupae of the Mediterranean fruit flyCeratitis capitata. The accumulation of major haemolymph proteins in the haemolymph, shows a twenty fold increase from the 4-day old larvae to the white pupae stage, while in the fat body there is only a seven fold increase. It is evident from the in vivo and organ culture studies, that the major haemolymph proteins are synthesized during the late larval stage and their synthesis declines abruptly during the stage of white pupae. It seems also that each polypeptide has its own characteristic developmental kinetics of synthesis. The major haemolymph proteins are synthesized in the fat body and are very quickly secreted into the haemolymph.
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    URL: http://dx.doi.org/10.1007/BF00868701
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  • 15
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    Wyoming's industrial siting permit process and environmental impact assessment (1982)
    Springer
    Environmental management 6 (1982), S. 1-7 
    Details
    ISSN: 1432-1009
    Keywords: Natural resource planning ; Development ; Policy analysis ; Industrial siting ; Environmental impact assessment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The problem of management of industrial residuals can be reduced through a rational system for siting and planning major industrial facilities. In the United States, Wyoming has moved in the direction of establishing a one-stop permitting system that provides important information for air and water quality planning and solid waste management with a minimum of regulatory overlap. This paper describes Wyoming's Industrial Development Information and Siting Act of 1975 and suggests ways in which the Wyoming permitting system can be improved and applied elsewhere.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01866801
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  • 16
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    Using ecological knowledge for development planning (1980)
    Springer
    Environmental management 4 (1980), S. 13-20 
    Details
    ISSN: 1432-1009
    Keywords: Planning ; Management ; Natural resource planning ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Since October 1977, the East-West Environment and Policy Institute in Honolulu has been conducting a multinational collaborative project to enhance the preparation and utilization of natural systems assessments in developing countries. This paper presents some of the findings to date: 1. Channels are developing rapidly for transferring ecological knowledge into political and administrative decision making. 2. The systematic approach of ecology is replacing “environmental quality” as the organizing concept for information about natural resources and the environment. 3. Benefit-cost analysis is a promising method for integrating ecological knowledge into economic development decision making. 4. The lack of baseline information, inventories, and predictive capability will not be remedied soon or easily; thus priorities for ecological research are essential.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01866216
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  • 17
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    Viability of Rhizobium leguminosarum endosymbionts in different stages of development (1981)
    Springer
    Archives of microbiology 129 (1981), S. 349-352 
    Details
    ISSN: 1432-072X
    Keywords: Rhizobium ; Bacteroids ; Viability ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Viability of Rhizobium leguminosarum bacteroids isolated from Pisum sativum was determined after sucrose gradient centrifugation of the bacteroids resulting in separation according to developmental stage. The results suggest that past a critical stage of development bacteroids lose viability. Similar experiments with R. japonicum bacteroids having a lower degree of morphological differentiation showed an appreciably higher viability in all gradient fractions. The results support the hypothesis that bacteroid morphology and viability is dependent on the nature of—and length of exposure to—the host plant cytoplasm.
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    URL: http://dx.doi.org/10.1007/BF00406460
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  • 18
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    Changes of the cytoplasmic ultrastructure during development of sclerotia in Claviceps purpurea (Fr.) Tul. (1980)
    Springer
    Archives of microbiology 125 (1980), S. 251-257 
    Details
    ISSN: 1432-072X
    Keywords: Claviceps purpurea ; Ultrastructure ; Development ; Sclerotium ; Oleosomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The development of sclerotia of Claviceps purpurea was investigated by light and electron microscopy. During the first days after infection sterigma and conidiospores are formed. The spores show a moderately developed vacuolar system, they are thick walled and contain about 20% lipid (related to the cell volume) embedded in glycogen. The sterigma are cylindrical unicellular hyphae with electron dense cytoplasm and isolated strongly contrasted lipid droplets. In maturing sclerotia the hyphae become septated with increasingly thick cell walls and a large lipid content. The lipid forms small droplets in young cells, while in the mature sclerotium it occurs in the form of very large drops, occupying the major part of the cell. Simultaneously the composition of the lipid is changed. The mature cells have several nuclei. They are partially connected by osmiophilic substances, forming a network of intercellular spaces.
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    URL: http://dx.doi.org/10.1007/BF00446885
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    Antheridiol, RNA polymerase II and sexual development in the aquatic fungus, Achlya (1983)
    Springer
    Archives of microbiology 134 (1983), S. 314-319 
    Details
    ISSN: 1432-072X
    Keywords: Antheridiol ; RNA Polymerase II ; Development ; ELISA ; Achlya ; Transcriptional regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The fungus, Achlya, is one of the most primitive eukaryotes known to secrete and respond to diffusible steroid sex hormones (pheromones). Antheridiol, which is produced by female strains of Achlya induces male strains to differentiate male sex organs. Induction of male strains with antheridiol elicits several changes in macromolecular synthesis including a quantitative enhancement in the synthesis of poly adenylated messenger RNA. We have examined whether this quantitative change is due to the regulation of RNA polymerase II. The level of polymerase increases as a response to the pheromone. This was examined using two different approaches, one of which included an extremely sensitive enzyme-linked immunosorbant assay (ELISA). Furthermore, the specific activities of polymerase II preparations isolated from pheromone-stimulated cultures was significantly higher than the specific activities of enzyme preparations isolated from control. A comparison of the polypeptide subunit composition of polymerase II preparations isolated from both pheromone-treated and control cultures on SDS polyacrylamide gels indicated no qualitative differences. Apparent differences in the stoichiometry of two specific subunits were reproducibly observed. The subunits of 140,000 and of 69,000 stained much more intensely in RNA polymerase II preparations isolated from 4h antheridiol-treated cultures.
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    URL: http://dx.doi.org/10.1007/BF00407809
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    Control of the formation of bacteriochlorophyll, and B 875- and B 850-bacteriochlorophyll complexes in Rhodopseudomonas sphaeroides mutant strain H5 (1983)
    Springer
    Archives of microbiology 136 (1983), S. 312-316 
    Details
    ISSN: 1432-072X
    Keywords: Rhodopseudomonas sphaeroides ; Continuous culture ; Control ; Bacteriochlorophyll ; Pigment protein complexes ; 5-Aminolevulinic acid ; Development ; Light
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Rhodopseudomonas sphaeroides mutant H5 lacking 5-aminolevulinic acid synthase was employed to study the control of the formation of total bacteriochlorophyll as well as of the B875- and B850-bacteriochlorophyll protein complexes. The organisms were grown phototrophically in a chemostat where cell protein formation was limited by iron ions and bacteriochlorophyll by 5-aminolevulinic acid. 0.07 mol of bacteriochlorophyll was formed per mol of 5-aminolevulinic acid consumed. This stoichiometric relationship was not influenced by a twelve-fold variation in light energy flux. However, cell protein levels increased and, consequently, cellular specific bacteriochlorophyll contents decreased with increases in light energy flux. The ratio of B875- to B850-pigment protein complexes was inversely proportional to the velocity of 5-aminolevulinic acid supply (mol per cell protein and time) which in this system equals the velocity of 5-aminolevulinic acid consumption and the velocity of bacteriochlorophyll formation. Light had no direct effect on the ratio of B875- per B850-pigment complexes but an indirect effect via its control of protein formation. Changes in the ratio of the two pigment complexes resulted from the fact that significantly lower amounts of 5-aminolevulinic acid supplied per protein and time were required to saturate the system assembling the B875-complexes than that assembling the B850-complexes. The data suggest lack of light-dependent control in the formation of bacteriochlorophyll and its complexes subsequent to the 5-aminolevulinic acid pool.
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    URL: http://dx.doi.org/10.1007/BF00425223
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    Glandular scale development and essential oil secretion in Origanum dictamnus L. (1982)
    Springer
    Planta 156 (1982), S. 496-504 
    Details
    ISSN: 1432-2048
    Keywords: Development ; Glandular scale ; Origanum dictamnus ; Secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Glandular scales of Origanum dictamnus L. originate from a single protodermal cell. They are composed of a 12-celled head and an unicellular stalk and foot. During the early stages of gland differentiation, the head cells possess a small number of plastids which contain globular inclusions. Similar inclusions are also observed in the plastids of the stalk and the foot cell. The lateral walls of the stalk cell progressively undergo cutinization which does not extend to the upper and lower periclinal walls. At the onset of secretion the electron density of the plasmalemma region lining the apical walls of the head cells remarkably increases. These walls are impregnated with an osmiophilic substance identical in appearance to the content of the subcuticular space. In a following stage of the secretory process osmiophilic droplets of various size arise in the cytoplasm of the secretory cells which undergoes simultaneously a reduction of its initial density. After secretion has been concluded the protoplast of the head cells becomes gradually degenerated. The chlorenchyma cells of the mesophyll possess numerous microbodies closely associated with various organelles. In the cytoplasm of these cells crystalloids occasionally occur.
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    URL: http://dx.doi.org/10.1007/BF00392771
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    Development of the axon cap neuropil of the Mauthner cell in the goldfish (1984)
    Springer
    Cell & tissue research 237 (1984), S. 49-55 
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    ISSN: 1432-0878
    Keywords: Axon ; Synapses ; Medulla oblongata ; Gold-fish ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Development of the axon cap neuropil of the Mauthner neuron in post-hatching larval goldfish brains was observed electron-microscopically. The axonal initial segment of newly hatched (day-4) larvae is completely covered with synaptic terminals containing clear spherical synaptic vesicles. Profiles of thin terminal axons, the spiral fibers, containing similar synaptic vesicles, rapidly increase in number around the initial segment and form glomerular neuropil similar to the central core of the adult axon cap by day 7. Three types of synapses are formed in the core neuropil. Bouton-type synapses contacting the initial segment are most abundant in day-4 to-14 larvae; they decrease thereafter and are rare on the distal half of the initial segment of day-40 larvae. Asymmetric axo-axonic synapses are commonly observed between spiral fibers in the core neuropil of day-7 to -19 larvae, but become fewer by day 40. Unique symmetrical axo-axonic synapses showing accumulation of synaptic vesicles on either side of apposed membrane thickenings first appear in day-14 core neuropil, gradually increase in number, and become the predominant type in day-40 core neuropil. Thick myelinated axons, which lose their myelin sheaths in the glial cap cell layer, start to penetrate into the axon cap on day 10. They gradually increase in number and form the peripheral part of the axon cap together with the cap dendrites, which finally grow into the axon cap from the axon hillock region of the Mauthner cell by day 40.
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    URL: http://dx.doi.org/10.1007/BF00229199
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    Topographical and developmental studies on target sites of 1,25 (OH2) vitamin D3 in skin (1984)
    Springer
    Cell & tissue research 238 (1984), S. 489-496 
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    ISSN: 1432-0878
    Keywords: Vitamin D ; Skin ; Autoradiography ; Hair ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Tritium-labeled 1,25 (OH2) vitamin D3, when injected into vitamin D-deficient adult and pregnant rats is concentrated and retained strongest in nuclei of cells in the outer root sheath of the hair, followed by the stratum granulosum, spinosum, and basale of the epidermis. In the hair follicle, in addition to the most heavily labeled outer root sheath, nuclear labeling exists also in cells of the hair bulb and of the inner root sheath, as well as in basal cells of the sebaceous gland. In contrast, cells of the dermal papilla and the connective tissue of the dermis are generally unlabeled, except for labeled cells in the outer connective tissue sheath at the infundibulum of vibrissae of 20-day fetal rats and a few scattered labeled cells in the dermis, probably macrophages. In the developing hair, in 18- and 20-day fetal rats, a distinct topographic pattern of labeled cells can be seen, which is characteristic of the different stages of hair follicle development. In the hair germ, heavily labeled cells appear first in the stratum spinosum. In the hair peg, they remain in this position in its juxtaepidermal portion; however, when a dermal papilla develops, heavily labeled cells assume a marginal position. This suggests a sequential epidermal-epidermal and mesenchymal-epidermal receptor induction. Injection of tritium labeled 25 (OH) vitamin D3 did not show nuclear concentration in these tissues and excess unlabeled 25 (OH) vitamin D3 — unlike excess 1,25 (OH2) vitamin D3 — did not prevent nuclear uptake of tritium labeled 1,25 (OH2) vitamin D3. The results indicate differential effects of 1,25 (OH2) vitamin D3 on different structures in the epidermis and dermis.
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    URL: http://dx.doi.org/10.1007/BF00219863
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    Prenatal and early postnatal development of the glial cells in the median eminence of the rat (1980)
    Springer
    Cell & tissue research 211 (1980), S. 117-137 
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    ISSN: 1432-0878
    Keywords: Eminentia mediana ; Neurohypophysis ; Development ; Pituicytes ; Tanycytes ; Astrocytic tanycytes ; Oligodendrocytes ; Astrocytes ; Microglia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the glial cells of the rat median eminence (ME), including the supraependymal cells, was investigated from embryonic day (ED) 14 through postnatal day (PD) 7, and pituicyte development from ED 12 through ED 17. The anlage of the ME and neurohypophysis shows a neuroepithelial-like structure at ED 12. From ED 13 to 15, the cells of both regions start to differentiate. At the ultrastructural level, only one cell type appears. At the beginning of ED 16, glioblasts of the oligodendrocyte and astrocyte series migrate laterally (from the region of the arcuate nucleus) into the ME. Also at this time the first distinctive structural features appear in the neurohypophysial anlage, the cells of which later develop into pituicytes. Starting at ED 18, tanycytes and astrocytic tanycytes arise in the ME from local glial cells, and somewhat later oligodendroblasts and astroblasts are formed from immigrant glioblasts. Due to their common features, the pituicytes, tanycytes and astrocytic tanycytes apparently represent different forms of the same parent cell type. Microglial and supraependymal cells are first seen at ED 12. Initially, they resemble the prenatal phagocytic connective tissue cells and mature in the fetus into typical electron-dense microglia and macrophage-like supraependymal cells. Both cell types are apparently of mesodermal origin. The microglial elements of the ME probably migrate from the mesenchyma through the basement into the nervous tissue. The intraventricular macrophages of the infundibular region may originate from microglia, epiplexal cells and subarachnoid macrophages.
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    URL: http://dx.doi.org/10.1007/BF00233728
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    Postnatal development of somatotrophs and mammotrophs in the pars distalis of the C57BL mouse (1980)
    Springer
    Cell & tissue research 211 (1980), S. 441-448 
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    ISSN: 1432-0878
    Keywords: Somatotroph ; Mammotroph ; Development ; Mouse ; Pituitary
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pars distalis of the pituitary gland of the C57BL mouse was studied by means of electron microscopy during postnatal stages of males ranging in age from newborn through 24 days, with particular emphasis on the somatotrophs and mammotrophs. During this period, growth curves were plotted in order to correlate postnatal growth patterns with the state of differentiation of the somatotrophs in the pars distalis. In the newborn, the somatotrophs show well developed organelles, including rough endoplasmic reticulum and Golgi complexes. These cells are not as densely packed with granules as the adult somatotrophs; however, from days 5 through 24, they show a progressive accumulation of granules. Although mammotrophs are scarce in the newborn, they are readily distinguishable in the pars distalis at 5 days. Male mice in small litters show a progressive increase in body weight between birth and 11–12 days, at which time the rate slackens until 18–19 days when the rate again increases. Growth curves for mice from large litters are similar to those from smaller litters, except that the transitory decrease in rate is more prominent.
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    URL: http://dx.doi.org/10.1007/BF00234398
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    The occluding junctions of mouse duodenal enterocytes during development (1981)
    Springer
    Cell & tissue research 217 (1981), S. 65-77 
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    ISSN: 1432-0878
    Keywords: Freeze-fracture ; Occluding junctions ; Enterocytes ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The architecture of occluding junctions during the differentiation of the mouse duodenum was studied in freeze-fractured material. Irregular zonulae occludentes (ZO) (Type I) are numerous during fetal life, and are characterized by their irregular width, and by the presence of basal open-ended extensions fused with the discontinuous basal strand of the ZO. Regular ZOs (Type II), typical of the adult villous epithelium, appear after Type I junctions by day 16 of gestation. Two patterns are distinguishable: in the first, parallel strands of ridges and furrows are found without crossing branches; in the second pattern, the junction zone is organized like a network of short branches forming various types of polygons. In fetal and adult mice fasciae occludentes (FO) (Type III) are present on the lateral cell membranes; in unfixed specimens particles are found in the furrows of the E-face and pits on the ridges of the P-face. In fixed tissues, the particles are aligned on the ridges of the P-face. These results indicate that fixation with glutaraldehyde modifies considerably the affinity of junctional particles toward the P-face during the fracture process. Moreover, the presence of numerous large FOs on the lateral cell membranes of enterocytes during late fetal life and in the adult, is possibly related to cell movement along the intestinal villi.
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    URL: http://dx.doi.org/10.1007/BF00233827
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    Ontogenetic development of the pineal organ, parapineal organ, and retina of the three-spined stickleback, Gasterosteus aculeatus L. (Teleostei) (1983)
    Springer
    Cell & tissue research 233 (1983), S. 593-609 
    Details
    ISSN: 1432-0878
    Keywords: Pineal organ ; Parapineal organ ; Retina ; Photoreceptors ; Development ; Gasterosteus aculeatus L. (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ontogenetic developments of the pineal organ, parapineal organ, and retina were studied by the use of light and electron microscopy in embryos and fry of the teleost, Gasterosteus aculeatus, from 60 to 168 h after fertilization. Sixty to 66 h after fertilization, the primordium of the pineal complex is discernible in the diencephalic roofplate; the parapineal anlage is located rostral to the pineal anlage. Photoreceptor cells endowed with outer segments are present in the embryonic pineal organ already after 72 h, whereas outer segments of retinal photoreceptors could not be demonstrated before 144 h (hatching occurs between 120–144 h). Furthermore, neuropil formations with synaptic specializations are present in the rostral part of the pineal organ 108 h after fertilization. At 72 h, the embryonic parapineal parenchyma is already differentiated into parapinealocytes, which give rise to the parapineal tract, and glia-resembling elements. Although parapinealocytes carry cilia (9 × 2 + 0), only a single outer segment of the photoreceptor type could be demonstrated in the parapineal organ of one adult stickleback. Photoreceptors present in the pineal organ of unhatched embryos are hardly involved in visual functions, but may already at this early developmental stage serve as photoneuroendocrine transducers.
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    URL: http://dx.doi.org/10.1007/BF00212227
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    Spatial relationships between fibroblasts during the growth of rat-tail tendon (1983)
    Springer
    Cell & tissue research 234 (1983), S. 17-29 
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    ISSN: 1432-0878
    Keywords: Tendon (rat) ; Development ; Fibroblasts ; Collagen ; Extracellular space
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Sections of tendons from the base of the tail of rats were taken at eight time intervals from 18 days in utero until 244 days after birth and were examined in the electron microscope. For each time period, measurements were made of the relative area of fibroblasts, collagen and interstitial material, of the number of fibroblasts per unit area of tendon and of the average area of individual fibroblasts. The spatial arrangement of fibroblasts in the tendon sections was described quantitatively using the “nearest neighbor” method. Initially there was a rapid increase in the area of collagen accompanied by a decrease in the area occupied by fibroblasts but after 104 days of age these values changed very little. The numbers of fibroblasts per unit area decreased steadily from the embryo until 104 days whereas the average size of each cell increased to reach a maximum area at 40 days of age and then declined. At all time intervals cells were arranged in a regular, dispersed pattern across the tendon fascicles. Growth in width of the rat tail appears to involve the secretion of collagen and other intercellular material symmetrically around each fibroblast, so as to gradually separate the cells until a stage is reached at which cells are sufficiently far apart that there is little contact between adjacent cell processes. This may interfere with the integration of metabolic activity in the tissue. As a consequence, there is shrinkage of the cell bodies and a reduction in secretory activity so that, between 55 and 104 days of age, the tendon enters a period of terminal senescence.
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    URL: http://dx.doi.org/10.1007/BF00217399
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    Ultrastructural immunocytochemical localization of fibronectin in the developing rat lung (1983)
    Springer
    Cell & tissue research 234 (1983), S. 165-177 
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    ISSN: 1432-0878
    Keywords: Fibronectin ; Lung ; Development ; Ultrastructure ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In a previous study changes in the macrodistribution of fibronectin during rat-lung development were examined. Using the peroxidase-antiperoxidase immunocytochemical technique, we have demonstrated the presence of fibronectin in embryonic, neonatal, and adult rat lung at the ultrastructural level. In the embryo, fibronectin is found both in an intra-and extracellular association with isolated pneumoblasts, and in a periodic distribution along the basal lamina. The neonate displays fibronectin in an intracellular association with early type-I cells and on their basal and luminal surfaces, but not in association with type-II cells. Neonatal basal lamina is diffusely labeled by anti-fibronectin antiserum. Fibronectin in adult tissue is found both intracellularly and on the basal and luminal surfaces of type-I cells but not in type-II cells. The basal lamina and interstitial connective tissue are slightly or non-reactive. These observations confirm and extend our initial suggestion that fibronectin is involved in rat-lung development.
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    URL: http://dx.doi.org/10.1007/BF00217410
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    Electron microscopy of extracellular materials during the development of a sea star, Patiria miniata (Echinodermata: Asteroidea) (1983)
    Springer
    Cell & tissue research 234 (1983), S. 193-200 
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    ISSN: 1432-0878
    Keywords: Sea star ; Development ; Cuticle ; Extracellular materials ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of conspicuous extracellular materials during the life history of a sea star (Patiria miniata) is described. The outer surface of the developing sea star is covered by two morphologically different cuticles that appear sequentially during ontogeny. The primary cuticle, which is about 120 nm thick and two-layered, is present from mid-blastula through the end of the larval stage. The secondary cuticle, which is about 1 μm thick and three-layered, first appears on the epidermis of the rudiment region of the larva and, after metamorphosis, covers the entire epidermis of the juvenile and adult stages. During ontogeny, there are only two conspicuous gut cuticles: the first lines the newly invaginated archenteron at the start of the gastrula stage, and the second lines the esophagus during the larval stage. A blastocoelic basal lamina first appears at mid-blastula and persists as subectodermal and subendodermal basal laminae. Ruthenium red-positive granules are detectable between the lateral surfaces of adjacent ectodermal cells during part of the gastrula stage; this transient intercellular material may possibly aid in lateral adhesion between cells.
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    URL: http://dx.doi.org/10.1007/BF00217412
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    Proliferation and differentiation of intestinal epithelial cells during development of Barbus conchonius (Teleostei, Cyprinidae) (1984)
    Springer
    Cell & tissue research 236 (1984), S. 207-216 
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    ISSN: 1432-0878
    Keywords: Development ; Enterocytes ; Fish ; Mitosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The processes of proliferation, cell division and differentiation of intestinal epithelial cells have been studied during development of the fish, Barbus conchonius. On the 3rd day, nearly all cells of the presumptive gut proliferate. Once the intestinal epithelium begins to differentiate, a decreasing percentage of proliferative cells can be found. On the 7th day, when intestinal folds start to develop, the proliferative cells become restricted to the future basal parts of the folds. Ultrastructural examination of 3H-thymidine-labeled cells and mitotic cells of 6-day-old larvae shows that functional enterocytes are proliferative. The same feature is suggested for older fish. Proliferating undifferentiated “dark” cells, characterized by many free ribosomes and a few organelles, are also present in the intestinal epithelium of larval fish; they are considered to be stem cells, mainly for goblet cells. Proliferating goblet cells and enteroendocrine cells were not observed. The latter cell type is scarce and has a long turnover time. A common feature of all these dividing cells is the presence of isolated spherical to cylindrical lamellar structures which may have lost contact with the cell membrane during prophase; they probably regain this contact by fusion with the cell membrane at the end of mitosis.
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    URL: http://dx.doi.org/10.1007/BF00216533
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    Immunohistochemical study of S-100 protein in the postnatal development of Müller cells and astrocytes in the rat retina (1984)
    Springer
    Cell & tissue research 238 (1984), S. 503-508 
    Details
    ISSN: 1432-0878
    Keywords: S-100 ; Müller cell ; Astrocyte ; Development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The rat retina was studied by immunohistochemistry with antibody to S-100 protein during the first three postnatal weeks. Immunoreactive astrocytes are first detected subjacent to the inner limiting membrane close to the optic disc. They gradually increase in number and spread toward the ora serrata along the inner surface of the retina as the development proceeds. S-100-immunostained Müller cells are first identified on the 12th postnatal day although their immunoreactivity is much weaker than that of astrocytes at the same stage. This differential intensity of the immunoreactivity of the two cell types facilitates observation of the entire shape of the astrocyte. This characteristic reveals that cellular investments of blood vessels in the inner retina are formed by astrocytic processes whereas those in the outer plexiform layer are derived from processes of Müller cells. The cellular investment becomes complete by the 18th postnatal day.
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    URL: http://dx.doi.org/10.1007/BF00219865
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    A Golgi-electron-microscopical study of the structure and development of the lamina ganglionaris of the locust optic lobe (1981)
    Springer
    Cell & tissue research 216 (1981), S. 377-401 
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    ISSN: 1432-0878
    Keywords: Lamina ganglionaris ; Locust ; Neurons ; Development ; Light and electron microscopy ; Golgi study
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The gross structure as well as the neuronal and non-neuronal components of the lamina ganglionaris of the locust Schistocerca gregaria are described on the basis of light- and electron-microscopical preparations of Golgj (selective silver) and ordinary histological preparations. The array of optic cartridges within the lamina neuropile — their order and arrangement — and the composition of the cartridges are described. There are six types of monopolar neurons: three whose branches reach to other cartridges and three whose branches are confined to their own cartridges. Retinula axons terminate either in the lamina or the medulla neuropiles. There are three types of centrifugal neurons, two types of horizontal neuron, as well as glia and trachea in the lamina neuropile. The development of the lamina neuropile is described in terms of developing monopolar and centrifugal axons, growing retinula fibres, and composition of the developing optic cartridges.
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    Role of innervation on the embryonic development of skeletal muscle (1980)
    Springer
    Cell & tissue research 210 (1980), S. 383-393 
    Details
    ISSN: 1432-0878
    Keywords: Avian skeletal muscle ; Development ; Normal, aneural, paralyzed muscle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The extent to which the motor innervation regulates the embryonic development of skeletal muscle was investigated by comparing changes in normal, aneural, and paralyzed superior oblique muscle of the duck embryo. The muscle was made aneural by permanently destroying the trochlear motor neurons with electrocautery on day 7 i.e., three days prior to innervation. Embryos were paralyzed by daily application of α-bungarotoxin onto the chorioallantoic membrane from day 10 onwards. The differentiation of myoblasts and myotubes in the aneural muscle was severely affected and did not progress to the myofiber stage. A mass of dead cells in the aneural muscle was replaced by connective tissue. Although the differentiation of myoblasts and myotubes was also retarded in the paralyzed muscle, numerous muscle cells progressed to the myofiber stage. Neuromuscular junctions of normal ultrastructure were seen in all paralyzed muscles. Degeneration of some cells in the paralyzed muscle occurred but there was no evidence of a massive wave of cell death similar to that observed in the aneural muscle. These observations suggest that both the trophic factors from the nerve and the nerve-evoked muscle activity are essential for the execution of the developmental program of the muscle. Trophic factors may play a larger role in differentiation, and maintenance of the muscle than muscle activity.
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    URL: http://dx.doi.org/10.1007/BF00220196
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    Studies on formation and resorption of fish scales (1980)
    Springer
    Cell & tissue research 211 (1980), S. 303-316 
    Details
    ISSN: 1432-0878
    Keywords: Fish scale ; Fine structure ; Development ; Calcification ; Cyprinodon variegatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Scale formation in Cyprinodon variegatus was found to be initiated at about 26 to 30 days after hatching. Ultrastructural investigation revealed that within 4 to 6 h in the first-formed scales the marginal cells begin to flatten and differentiate into osteogenic cells, which later change to osteoblasts and fibroblasts. These cells are separated from the surrounding epithelial cells by a basal lamina. The osteoid is formed by the marginal and osteogenic cells; the osseous layer by the osteoblasts; and the fibrillary plate by the fibroblasts. The osteoid is formed within 2 to 3 h after the initiation of the scale, and within 20 to 24 h the osseous layer is formed. Hydroxyapatite crystals are deposited in the matrix of the osseous layer without apparent association with collagen fibers. No matrix vesicles or dense bodies are evident at the sites of calcification. The fibrillary plate arises 18 to 20 h after the initiation of the scale. It is also partially calcified, but not before the third week of scale formation. The crystals develop almost exclusively between the collagen fibers at the extreme edge of the calcifying front, but solid calcification of the fibers results with further growth of the crystals. The fibroblasts appear to participate in calcification of the fibrillary plate.
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    URL: http://dx.doi.org/10.1007/BF00236451
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    The parcellation theory and its relation to interspecific variability in brain organization, evolutionary and ontogenetic development, and neuronal plasticity (1980)
    Springer
    Cell & tissue research 213 (1980), S. 179-212 
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    ISSN: 1432-0878
    Keywords: Neocortex ; Evolution ; Development ; Plasticity ; Visual system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Recently discovered neocortical equivalents in anamniotes and certain patterns of interspecific variability in brain organization provide new insights into evolutionary and ontogenetic mechanisms of development. The new data suggest that nervous systems become more complex, not by one system invading another, but by a process of parcellation that involves the selective loss of connections of the newly formed daughter aggregates and subsystems. The parcellation process is reflected in the normal ontogenetic development of the CNS in a given species and can be manipulated, to a certain extent, by deprivation or surgically induced sprouting. The parcellation theory allows certain predictions about the range of variation of a given system at all levels of analysis including the cellular and aggregate levels. For example, the interspecific variability in organization of cortical columns, thalamic nuclei, cortical areas and tectal layers can be explained. The findings, summarized here, suggest that diffuse, undifferentiated systems existed in the beginning of vertebrate evolution and that during the evolution of complex behaviors, and analytical capacities related to these behaviors, a range of patterns of neural systems evolved that relate to these functions. One principle underlying the growth, differentiation and multiplication of neural systems appears to be the process of parcellation as defined by the theory.
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    Catecholamine-storing cells in the adrenal medulla of the pre- and postnatal rat (1981)
    Springer
    Cell & tissue research 217 (1981), S. 155-170 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal medulla ; Development ; Acetylcholinesterase ; Small granule cells ; Ultramorphology ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the rat adrenal medulla was studied at the ultrastructural level with particular emphasis placed on early discrimination of different catecholamine-storing cells. The first granule-containing cells, phaeochromoblasts, were seen at day 15 of gestation migrating into the anlage of the cortex. These cells were characterized by a few small granules (80–120 nm in diameter) and a high nuclear to cytoplasmic ratio. Presumably due to differentiation into chromaffin cells, they were no longer present after the eighth postnatal day. Maturation of phaeochromoblasts was indicated by an increase in number and size of their storage granules and a decrease in the nuclear to cytoplasmic ratio. Noradrenaline and adrenaline cell types were first clearly discernible at day 21 of gestation. Another cell type, a giant cell, was also recognized at this stage. In the adult animal, noradrenaline, two morphologically different types of adrenaline, and small granule-containing cells were observed. By applying acetylcholinesterase histochemistry, it was found that at day 17 of gestation a small population of granule-storing cells showed strong positive staining in the endoplasmic reticulum. In the adult animal this cell type was further characterized by small-storage granules. Other chromaffin cells began to show weak staining within the endoplasmic reticulum at day 19 of gestation. This staining appeared more frequently within adrenaline than noradrenaline cells. However, even in the adult animal many cells of both types were completely negative. It is concluded that acetylcholinesterase histochemistry is a useful method for early discrimination of small granule-containing cells in the developing rat adrenal medulla.
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    Microtubules, dendritic spines and spine apparatuses (1980)
    Springer
    Cell & tissue research 208 (1980), S. 171-181 
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    ISSN: 1432-0878
    Keywords: Microtubules ; Dendritic spine apparatus ; Synapse ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using techniques for enhanced microtubular preservation, including albumin pretreatment (Gray, 1975), occipital cortex of rats was studied electron microscopically at various ages of development. A close structural relationship was seen between microtubules, sacs of SER and the postsynaptic “thickening” in primordial spines and with the dense “plate” material of spine apparatuses. Stereoscopic preparations in addition show a more complicated substructure than previously described for the “plate”. Microtubules may contribute to the formation of the “plate” of the spine apparatus which in turn is associated with the postsynaptic “thickening” of the mature spine. Possible functional correlates are discussed.
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    Postembryonic development of the antennal lobes in Periplaneta americana L. (1981)
    Springer
    Cell & tissue research 215 (1981), S. 563-575 
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    ISSN: 1432-0878
    Keywords: Antennal lobes ; Development ; Sexual dimorphism ; Periplaneta americana
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The postembryonic development of the antennal lobes of Periplaneta americana L. was examined with light- and electron-microscopical methods. There is no difference in the number of glomeruli and neurons in the antennal lobes of larval and adult animals. At hatching, the first larva already possesses the adult number of approximately 125 glomeruli and 500 to 560 deutocerebral neurons in the dorsolateral cell group of each antennal lobe. During postembryonic development the volume of the deutocerebral neurons increases three- to fourfold. The glomeruli of the first larva have about 7 % of the volume of the corresponding adult glomeruli. Since number, pattern, and size ratio of glomeruli (with the exception of the macroglomerulus) are constant in all larval stages and adult animals, it is possible to identify individual glomeruli. During the whole postembryonic development the ordinary glomeruli show a continuous volume increase, which parallels the increase in antennal sensory input. The macroglomerulus develops by way of special growth of two to four neuropil units, but not before the last three to four larval stages and only in males. Its growth precedes the formation of antennal pheromone receptors during the final molt; these receptors are known to project into the macroglomerulus. The development of the macroglomerulus in the last larval stages of the male may be caused by a genetically fixed growth program of specific deutocerebral neurons.
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    Ionic currents traverse growing hyphae and sporangia of the mycelial water moldAchlya debaryana (1983)
    Springer
    Protoplasma 115 (1983), S. 65-69 
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    ISSN: 1615-6102
    Keywords: Achlya ; Development ; Electrophysiology ; Sporogenesis ; Vibrating probe
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This study explores natural ionic currents traversing hyphae and sporangia during the asexual life cycle of the mycelial water moldAchlya debaryana. Ionic current enters the extending hyphal apex at a density of 1–2μAcm−2 in the form of current spikes. Current normal to the surface enters hyphae up to 600 μm behind the growing tip. A large efflux of current lasting 1–2 minutes occurs during the homogeneous stage of sporangium development. Spore release is accompanied by a few spikes of inward current. The results obtained so far suggest that the developmental processes of hyphal elongation and sporangium formation in the asexual life cycle of water molds are correlated with particular ionic currents.
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    Development and ageing of etioplast structures in dark grown leaves ofAvena sativa (L.) (1981)
    Springer
    Protoplasma 108 (1981), S. 83-98 
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    ISSN: 1615-6102
    Keywords: Development ; Etioplast ; Prolamellar body ; Protochlorophyll ; Saponin ; Thylakoid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Etioplasts of dark grown plants contain a large paracrystalline prolamellar body (PLB) and, attached to this there are prothylakoid membranes (PTs). PLB-tubules inAvena are composed mainly of two saponins and include only a low percentage of other lipids, protochlorophyll(ide) and proteins. Following the development of etioplasts in darkness from the very beginning until plants loose turgescence one can observe marked changes in ultrastructure. In the early stage of development predominantly PTs are seen in small etioplasts. Wide-type PLBs are small. After eight days there is a well developed stage with the well-known big and highly crystalline PLBs, which are connected to many long PT-membranes. After 13 days the PLBs are not significantly changed, while number and length of PTs are strongly reduced. These morphological observations are quantified by measurements of PLB-area and PT-length per plastid section. Saponin content as a marker for PLB-tubules and protochlorophyll(ide)-content as a marker for PT-membranes were measured. Both methods of determination show in good agreement a peak of development for PTs around day 6–7, and for PLBs around 9–10. Beginning senescence affects PT-membranes and PChl(ide) strongly, while saponins resp. PLBs persist better. These results are presented in view of thylakoid formation during greening, starting from the different etioplast stages.
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    Calcium oxalate crystals inOpuntia ficusindica (L.) mill.: Development and relation to mucilage cells — A stereological analysis (1981)
    Springer
    Protoplasma 109 (1981), S. 271-283 
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    ISSN: 1615-6102
    Keywords: Calcium-oxalate crystals ; Development ; Mucilage ; Opuntia ficus-indica ; Stereology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In the succulent tissue ofOpuntia ficusindica development of calcium oxalate crystals was followed from the shoot apex to its base, using stereological analysis. The stereological parameters relating to the crystal cells were compared with those of mucilage cells, of the same tissue. A fairly monotonic relation between the stereological parameters of the two populations was noted. The possible physiological relation between the two cell populations is discussed.
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    Zostera capensis setchell: III. Some aspects of wall ingrowth development in leaf blade epidermal cells (1982)
    Springer
    Protoplasma 110 (1982), S. 87-94 
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    ISSN: 1615-6102
    Keywords: Wall ingrowths ; Development ; Leaf ; Zostera capensis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The development of wall ingrowths in leaf blade epidermal cells of the marine angiospermZostera capensis was studied by electron microscopy. Prior to the appearance of ingrowths long profiles of endoplasmic reticulum cisternae become arranged peripherally closely following the contours of the walls. The plasmalemma assumes a wavy appearance and in regions where wall ingrowths first start forming (i.e., along the radial, inner tangential and transverse walls) the plasmalemma becomes separated from the walls by an undulating extracytoplasmic space. Small, irregular projections of secondary wall material make their appearance here. Paramural bodies, dictyosomes, endoplasmic reticulum (ER) and possibly also microtubules seem to be closely associated with the initiation and subsequent development of wall projections. As the cells mature, new ingrowths arise in a centrifugal direction along the radial and transverse walls. When wall ingrowths reach a certain stage of their development, mitochondria become strongly polarized towards them and become closely associated with the plasmalemma which ensheaths the ingrowths. There is often also a close association between ER cisternae and the involuted plasmalemma of the wall projections. Initially ingrowths are slender, curved structures, but become more complex as the cells mature. Ingrowths are most extensively developed along the inner tangential and transverse walls. As epidermal cells age there is a loss of wall material from the ingrowths. The probable significance of the formation of wall ingrowths in the epidermal cells is also discussed.
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    Development of prespore vacuoles inDictyostelium cells differentiating in a liquid shake culture (1984)
    Springer
    Protoplasma 123 (1984), S. 152-159 
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    ISSN: 1615-6102
    Keywords: Cellular slime mold ; Dictyostelium discoideum ; Development ; Electronmicroscopy ; Golgi apparatus ; Prespore vacuole
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary When shaken in a glucose-albumin-cyclic AMP medium, dissociated aggregative cells form small clumps in which prespore cells differentiate fairly synchronously (Okamoto 1981). Formation of prespore vacuoles (PSVs) in differentiating prespore cells was examined in these culture conditions, by electronmicroscopy and immunocytochemistry. After 6 hours of culture, a typical Golgi apparatus composed of vesicles and stacked flat cisternae develops near the nucleus. FITC-conjugated antispore serum stains a crescent-shaped region in the cells which seems to correspond to the Golgi area. After 9 hours, flat sacs which contain electron dense lining membrane similar to that of PSVs appear alongside Golgi cisternae. Later, partially and fully round PSVs are observed in this region, suggesting that flat sacs round up to become mature PSVs. After 12 hours, as mature PSVs increase in number, they become dispersed throughout the cytoplasm and a typical Golgi apparatus with cisternae disappears. When cultured in a medium devoid of cyclic AMP, cells develop neither Golgi cisternae nor PSVs. These results strongly suggest that PSVs form from Golgi cisternae.
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    The formation of intercellular spaces in the cotyledons of developing and germinating pea seeds (1984)
    Springer
    Protoplasma 120 (1984), S. 12-19 
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    ISSN: 1615-6102
    Keywords: Development ; Intercellular spaces ; Parenchyma ; Pisum sativum L. seeds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Electron microscopic observations have shown that the intercellular spaces in the storage parenchyma of the cotyledons of pea (Pisum sativum L.) seeds arise schizogenously. The wall segments adjoining future intercellular spaces display a triple zonation and contain regions with electron-dense material. Space formation starts at the central point of contact between several cells and spreads then further up to the electron-dense, intra-wall structures. As a result of this the electron-dense material is found again in the corners of intercellular spaces. It is proposed that the intra-wall structures may have an important function in limiting the schizogenous process. The localization of the intercellular spaces is thus predetermined. The amount of electron-dense material in their corners increases considerably during further development of the embryo. During germination wall segments between two intercellular spaces diverge resulting in a fusion of several spaces.
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    The ultrastructural development of the macrogamete ofEimeria stiedai (1980)
    Springer
    Protoplasma 104 (1980), S. 33-41 
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    ISSN: 1615-6102
    Keywords: Development ; Eimeria stiedai ; Macrogamete ; Ultrastructural changes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The development of the macrogamete ofEimeria. stiedai in the epithelial cells of the bile ducts of rabbits was studied by electron microscopy. A macrogamete was first identified by the presence of a large central nucleus with prominent nucleolus, and subsequently by the appearance of wall forming bodies. The macrogamete was limited by an outer single membrane under which there were remnants of a second membrane. The parasitophorous vacuole, in which the macrogamete was located, was often narrow and it contained no intravacuolar-tubules or -folds. As macrogametogony proceeded wall forming bodies of Type I and II, canaliculi, electron pale spaces (lipid) and polysaccharide granules increased in number. Granular endoplasmic reticulum, mitochondria and Golgi bodies were present throughout.
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    Development of antennal sensilla during moulting inNeomysis integer (Leach) (Crustacea, Mysidacea) (1980)
    Springer
    Protoplasma 105 (1980), S. 53-67 
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    ISSN: 1615-6102
    Keywords: Crustacean sensilla ; Development ; Sensilla structure ; Moulting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The sensilla are associated with 6 enveloping cells. The innermost enveloping cell (e 1) secretes the dendritic sheath (=thecogen cell). All other enveloping cells are involved in the formation of the outer cuticular apparatus in secreting the cuticle of a definite region of the new hair shaft. The development of the new sensilla begins when an exuvial space expands between old cuticle and epithelium. The newly forming hair shafts lie folded back in an invagination of the epidermal tissue. Only a distal shaft part projects into the free exuvial space. The cuticle of the distal and middle shaft region is secreted by the three middle enveloping cells (e 2–e 4) (=trichogen cells), which are arranged around the dendritic sheath. The wall of the cylinder, in which the distal shaft is situated, is formed by the cuticle of the future proximal shaft region. It is secreted by the outer enveloping cells (e 5 and e 6). Furthermore, both enveloping cells form the hair socket (=trichogen-tormogen cells). The outer dendritic segments encased within a dendritic sheath run up through the newly formed hair shaft and continue to the old cuticular apparatus. The connection between sensory cells and old hair shaft is maintained until ecdysis. On ecdysis the old cuticle is shed and the newly formed shaft of the sensillum is everted like the invaginated finger of a glove. The dendritic sheath and the outer dendritic segments break off at the tip of the new hair shaft. Morphologically this moulting process ensures that the sensitivity of the receptors is maintained until ecdysis. The internal organization of the sensory cells shows no striking changes during the moulting cycle. An increased number of vesicles is accumulated distally within the inner dendritic segments and distributed throughout the outer segments of the dendrites. The cytoplasmic feature of the enveloping cells indicates that synthesis and release of substances for the cuticular apparatus of the new sensillum take place.
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    Cell division in baeocyte producing cyanobacteria (1984)
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    Protoplasma 123 (1984), S. 104-115 
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    ISSN: 1615-6102
    Keywords: Constrictive binary fission ; Cyanobacteria ; Development ; Multiple fission ; Septate binary fission ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary An ultrastructural examination of cell division in two baeocyte producing cyanobacteria,Pleurocapsa minor andDermocarpa violaceae, reveals two distinct patterns of binary (transverse) fission. Septate binary fission, inPleurocapsa minor, involves centripetal synthesis and deposition of the mucopolymer cell wall layer (L 2). The ingrowth of the cytoplasmic membrane and L 1 cell wall layer, along with the synthesis of the L 2 cell wall layer, results in the formation of a prominent septum. Partitioning of the cell occurs by the constriction of the outer cell wall layers (L 3 and L 4) through the septum. InDermocarpa violaceae, constrictive binary fission occurs by the simultaneous ingrowth or constriction of the cytoplasmic membrane and all cell wall layers (L1, L2, L3, L4). Septate and constrictive binary fission may proceed symmetrically (medially) or asymmetrically (nonmedially). Multiple fission occurs regularly inDermocarpa violaceae and provides for a rapid means of reproduction when compared to binary fission. Successive radial and tangential divisions of the protoplast result in formation of many small daughter cells (baeocytes). The process of multiple fission is similar to septate binary fission with reduced septa being formed. However, constriction of the outer cell wall layers, through the septa, proceeds concurrently with septum formation.
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    Description of understory development in a tree plantation with a new method of data structuring (1980)
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    Plant ecology 40 (1980), S. 185-191 
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    ISSN: 1573-5052
    Keywords: Clustering ; Data-processing ; Michigan ; Numerical method ; Phytosociology ; Stratum ; Understory ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary During May and June, 1974, relevés were obtained from 30 plantation stands in the Saginaw Forest in southeastern Michigan. The canopy trees in these plantations were planted between 1904 and 1938. The understory has developed naturally over the years. The forest plantations offer opportunities for study of the effects of the canopy on the structure and species composition of the understory. A new numerical method of data structuring was used, which is based on the detection patterns of associated species within the table of 30 relevés from Saginaw Forest plantations. The method employs two difference measures. DIF 1 uses presence/absence data and DIF 2 the cover/abundance values obtained from the relevés. Both difference measures supply distance values for every pair of relevés. The least dissimilar relevés are then grouped together by the farthest neighbor agglomerative algorithm of Lance & Williams (1967). The DIF 1 analysis was inconclusive, but the DIF 2 analysis gave coherent results. It has shown that relevés with similar canopies have similar understories. The differences in understories among the relevés are due less to species composition than to the relative abundances of the species.
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    Vegetation development in a former orchard under different treatments: A preliminary report (1980)
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    Plant ecology 43 (1980), S. 95-102 
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    ISSN: 1573-5052
    Keywords: Aegopodion podagrariae ; Arrhenatherion elatioris ; Development ; Dynamics ; Experiment ; Fertilization ; Mowing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Vegetation development in a former orchard on loamy moist soil after removal of the fruit trees under different treatment is described with the help of multivariate methods. Data on 20 plots over 9 years are treated with a simple classification program and a PCA ordination. Two main groups of plots are involved: one in a relatively moist part of the area where the trees were removed in 1970, one in a slightly drier area where the trees had been removed earlier. The first group is characterized by forbs such as Urtica dioica and Lamium maculatum, the second by grasses, mainly Arrhenatherum elatius. Under a mowing regime the plots of the first group change in the direction of the second group. Under continued fertilization the Urtica vegetation can be maintained. Establishment and/or rapid spread of Urtica can be brought about in Arrhenatherum dominated sites by (re-) introduction of nitrogen fertiliser. Not mowing leads to a dense Urtica-Lamium stand in which Lamium maculatum finds an optimum some years after mowing is stopped. The methods of summarizing the site-time data are discussed and some new ones announced for further research.
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    Estimates of egg and viable embryo production in a lacustrine perch, Perca fluviatilis (1983)
    Springer
    Environmental biology of fishes 8 (1983), S. 3-16 
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    ISSN: 1573-5133
    Keywords: Mortality ; Incubation ; Hatching ; Temperature ; Carex rostrata ; Development ; Fertilisation ; Fish ; Percidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Egg production and survival of perch in the embryonic period, and spawning observations at Lochs Kinord and Davan in Scotland are described. Spawning began on 20 April in both lochs at water temperatures of 9–11°C and continued for 10 days. The length of the incubation period was related to water temperature and was described by the regression equation: log10 days to hatch = 3.0286 − 1.6728 log10 incubation temperature in °C. Perch shed eggs in a single opaque strand and egg ribbons could be censused at each loch during the spawning period. The pattern of egg strand distribution and substrate used, predominantly the macrophyte Carex rostrata, is described. From eggs collected in the lochs it is estimated that 95.3% of embryos were viable, the nonviable portion comprising 0.5% unfertilised eggs, 2.4% dead and 1.8% with abnormalities. Potential egg deposition was 13.5 and 9.7 eggs m−2 at Kinord in 1976 and 1977 respectively and 9.2 m−2 at Davan in 1976. Egg production as dry weight was assessed as 3.3 and 2.4 mg m−2 for Kinord in 1976 and 1977, and 2.2 mg m−2 for Davan in 1976. Survival form spawning to hatching in all situations was estimated as 95.3% while the figure calculated for the period from hatching to recruitment to the pelagic larval stock varied from 11.5 to 73.2%.
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    Investigations on a detergent system with rodlike micelles (1982)
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    Colloid & polymer science 260 (1982), S. 1042-1056 
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    ISSN: 1435-1536
    Keywords: Rodlike Micelles ; Micellar Interaction ; Rheology ; Light Scattering ; Electric Birefrugence
    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 Conductivity, kinetic, static and dynamic light scattering, electric birefringence and rheological measurements were carried out on aqueous solutions of Tetradecylpyridinium-n-Heptanesulfonate (C14PyC7SO3) up to high concentrations. In dilute solutions between the critical micelle concentration (cmc) and another characteristic concentration (c t) spherical micelles were detected whose radii were independent of detergent concentration and equal to the length of a detergent molecule; the aggregation numbern of these micelles of about 100 monomers per micelle was also in agreement with the existence of normal spherical micelles of aC 14-detergent. Above the concentrationc t, the spherical micelles were found to grow to rodlike aggregates whose short axis was still independent of concentration and equal to the length of a monomer, while the lengthsL of the rods increased with increasing detergent concentration. When the lengthsL of the rods became comparable with the mean distancea between them, the starting interaction between the rods slowed down their growth. In this concentration range of overlapping rods, the data could be evaluated with a recently developed theory by Doi and Edwards for stiff rods. The rods reached finally a maximum length of about 500 å and decreased again in size upon further increase of concentration when the overlap ratioL/a reached a value of about 1,5.
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    Generalized reptation model (1981)
    Springer
    Colloid & polymer science 259 (1981), S. 908-910 
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    ISSN: 1435-1536
    Keywords: Rheology ; concentrated polymer solutions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Zusammenfassung Ein verallgemeinertes Reptationsmodell wird vorgestellt. Entlang einer Polymerkette berücksichtigt es die gehinderte Difussion von Defekten, die Länge speichern. Dieser Effekt wird beschrieben mittels einer Wartezeitverteilung für die Defektplatzwechselvorgänge. In der Folge findet man für wichtige rheologische Größen Molekulargewichtsabhängigkeiten in Form von Potenzgesetzen mit gebrochenen Exponenten an Stelle der ganzzahligen Exponenten des konventionellen Reptationsmodells.
    Notes: Summary The reptation model is generalized on the basis of a theory which accounts for hindered defect diffusion along the chain. A basic ingredient of the theory is a waiting time distribution for the hops of elementary defects which store length. Important rheological quantities are found to generally depend on fractional powers of the molecular mass rather than on integer powers as in the conventional reptation picture.
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    Population structure, reproduction and laboratory behavior of the introduced Belonesox belizanus (Poeciliidae) in Florida (1984)
    Springer
    Environmental biology of fishes 10 (1984), S. 89-100 
    Details
    ISSN: 1573-5133
    Keywords: Brood size ; Development ; Exotic species ; Feeding ; Gestation period ; Livebearer ; Maturation ; Neonate ; Pike killifish ; Sex ratio ; Viviparity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The pike killifish, Belonesox belizanus, is native to Mexico and Central America and was introduced into Dade County, Florida in 1957. This study reports on the structure and reproduction of the Florida population and compares the species with other members of the family Poeciliidae. The mean standard length (SL) of mature females was about 103 mm. Most females larger than 75 mm SL contained yolked ova, fertilized eggs, or embryos. Mature males averaged about 72 mm SL, and most males larger than 55 mm SL were mature. The sex ratio was significantly skewed in favor of females among adults, but it did not differ significantly from 1:1 among immature fish. Average brood size was about 99, and there was a significant positive correlation of brood size with size of the parent female. There was no evidence of superfetation. Sizes and weights of embryos and neonates were the largest reported for the family. There was a significant decrease in mean embryo weight as development proceeded, indicating that developing embryos received little or no nutrient input from the maternal system after fertilization. The average interbrood interval of aquarium-held females was 42 days, and females stored viable sperm at least 47 days. Reproduction continued year round in the field. Laboratory-born neonates were immediately piscivorous and exhibited distinctive behavior associated with filling the swimbladder and with avoiding detection by predators.
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    URL: http://dx.doi.org/10.1007/BF00001665
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    The susceptibility of terrestrial gastropods to experimental infection withElaphostrongylus rangiferi Mitskevich (Nematoda: Metastrongyloidea) (1980)
    Springer
    Parasitology research 62 (1980), S. 7-14 
    Details
    ISSN: 1432-1955
    Keywords: Elaphostrongylus rangiferi ; Rangifer tarandus ; Gastropods ; Susceptibility ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Sixteen species of terrestrial gastropods, collected at Tromsöya, northern Norway, were experimentally brought into contact with first stage larvae ofElaphostrongylus rangiferi, a parasite causing neurological disorders in reindeer,Rangifer tarandus (L.). All species were susceptible to infection but there were considerable variations in incidence and intensity of infections and in the development of the nematode in the different gastropod species. InDiscus ruderatus, Arion silvaticus, Deroceras laeve, Euconulus fulvus, andTrichia hispida, development to infective third stage larvae took about 20 days at 20°C. InSuccinea pfeifferi, Deroceras reticulatum andArianta arbustorum development was somewhat slower. InCochlicopa lubrica, Arion subfuscus, A. hortensis, Vitrina pellucida, Nesovitrea spp., andClausilia bidentata, only small numbers of larvae developed and at a very slow rate. InVertigo lilljeborgi andPunctum pygmaeum, the larvae did not develop. Growth in length ofE. rangiferi inD. ruderatus was rapid and continuous up to the second molt (about 15 days postinfection). Thereafter there was a slower growth rate. Tissue reactions against the infection were observed in eleven of the gastropod species. No obvious relationship between the degree of tissue reactions and susceptibility to infection was found.
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    URL: http://dx.doi.org/10.1007/BF00925362
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    Cytodifferentiation of the paraventricular nucleus in the chick embryo (1983)
    Springer
    Cell & tissue research 229 (1983), S. 281-297 
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    ISSN: 1432-0878
    Keywords: Paraventricular nucleus ; Hypothalamus ; Development ; Golgi study ; Ultrastructure ; Chick embryo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The developmental changes in the cytoarchitecture of the hypothalamic paraventricular nucleus of the chick embryo were studied with particular emphasis on the differentiation of the magnocellular neurons. These cells can be distinguished from the parvocellular elements starting from stages 34–35 (Hamburger and Hamilton 1951) in Golgi-impregnated specimens. At the same stages, electron microscopy reveals dense-core granules, resembling the characteristic elementary granules of the neurosecretory material in the cytoplasm of the larger neurons. In addition, a few immature synapses were observed on these magnocellular perikarya. The present observations suggest that the early onset of neurosecretion in this area may be neurally regulated during early phases of development.
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    URL: http://dx.doi.org/10.1007/BF00214976
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    Calcium-binding protein in the developing rat cerebellum (1983)
    Springer
    Cell & tissue research 233 (1983), S. 389-402 
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    ISSN: 1432-0878
    Keywords: Calcium-binding protein (CaBP) ; Immunocytochemistry ; Rat cerebellum ; Development ; Vitamin D
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Specific antibodies raised against a human 28 000 dalton cerebellar calcium-binding protein (CaBP) were used in an immunocytochemical study during development of the rat cerebellum. Both light and electron microscopy showed (1) that labelling was entirely restricted to the Purkinje cells, (2) that it appeared very early in Purkinje cell development, (3) that the entire cell was labelled from the tip of the smallest dendrites to the axonal terminals, and (4) that with increasing age, the immunoreaction appeared to be progressively restricted to the cell and organelle membranes.
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    URL: http://dx.doi.org/10.1007/BF00238305
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    Microinjection of Lucifer yellow CH into sea urchin eggs and embryos (1983)
    Springer
    Cell & tissue research 234 (1983), S. 309-318 
    Details
    ISSN: 1432-0878
    Keywords: Division ; Dye coupling ; Development ; Embryo ; Microinjection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Eggs and embryos of Arbacia punctulata were microinjected with the fluorescent dye, Lucifer yellow CH, using a simple pressure injection system. When injected into eggs that were subsequently fertilized, the dye was distributed throughout all cells of the developing embryo. If one cell of a two-cell embryo was injected, dye did not diffuse into the uninjected blastomere. During subsequent development, all progeny of the injected cell contained dye resulting in an embryo that was half-fluorescent. Blue light irradiation of a two-cell embryo, one cell of which had been injected with Lucifer yellow, caused the injected blastomere to stop further divisions while the uninjected blastomere developed normally and was free of dye. These results indicate that the first two blastomeres of Arbacia embryos are not electrically coupled, nor up to the time of hatching, is there any coupling between cells in one half of the first cleavage plane and cells in the other half.
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    URL: http://dx.doi.org/10.1007/BF00213770
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    Immunocytochemical localization of cell type-specific markers in reaggregating cell cultures of mouse cerebellum (1982)
    Springer
    Cell & tissue research 227 (1982), S. 677-690 
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    ISSN: 1432-0878
    Keywords: Cell type-specific antigens ; Cerebellum (mouse) ; Reaggregating cell cultures ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Reaggregate cultures were obtained from single-cell suspensions of fetal and early postnatal cerebellum, and fetal telencephalon and mesencephalon from C57BL/6J and NMRI mice and maintained in suspension under constant rotation as described previously (Seeds 1971). The percentage of dead cells in the aggregates as measured by the uptake of the fluorescent dye propidium iodide was always less than 5% of all cells. During the initial phase of reaggregation up to 20 h in vitro (hiv) several immunocytochemically defined cell types had a random distribution within the aggregate. Astrocytes were identified by indirect immunofluorescence by the use of the markers glial fibrillary acidic protein (GFAP), C1 and M1 antigens; neurons by NS-4 antigen and tetanus-toxin receptors; fibroblasts or fibroblast-like cells by fibronectin and laminin; and oligodendrocytes by myelin basic protein (MBP). Choleratoxin receptors and M 2 antigen served to distinguish the more mature from the less mature neurons. In reaggregates of early postnatal cerebellar cells neurons had started to redistribute after 40 hiv, forming an outer region containing more immature neurons and a core with more mature neurons. After 5 days in vitro (div) immature neurons were no longer detectable. From 3–8 div M1-and GFAP-positive astrocytic processes in the outer region showed a tendency for radial orientation. At later stages the processes appeared more randomly distributed and formed a dense glial network. Few oligodendrocytes and fibronectin-positive cells were present in the reaggregates. When reaggregates were prepared from 15 day-old embryonic cerebella, formation of radially oriented astrocytic processes and redistribution of neurons proceeded more slowly, but in a similar pattern as described for early postnatal cerebellum. GFAP was detectable at earlier ages than in situ. In reaggregates of 15 to 17 day old embryonic telencephalic anlage or midbrain, radially oriented astrocytic processes were not detectable. Similar to cerebellar reaggregates, accumulation of neurons in the inner region was observed.
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    URL: http://dx.doi.org/10.1007/BF00204797
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    Development of the larval nervous system of the sand dollar, Dendraster excentricus (1983)
    Springer
    Cell & tissue research 229 (1983), S. 145-154 
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    ISSN: 1432-0878
    Keywords: Pluteus ; Nervous system ; Development ; Larva ; Echinoidea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Transformation of the gastrula to the pluteus includes development of the ability of the larva to control the direction of ciliary beat and coordinate activities of the ciliary band with activities of the esophageal muscles (48–60 h, 15°C). Glyoxylic acid-induced fluorescence shows several cells of the animal plate to contain catecholamines in the 36-h gastrula. As the ectoderm thickens to form the ciliary band (36–48 h), the catecholamine-containing cells increase in number and occur dispersed throughout the band. Tissues with the ultrastructural characteristics of nerves first become apparent associated with the ciliary band in 60-h larvae. The coincident development of coordinated behaviour and the appearance of cells with ultrastructural and histochemical characteristics of nerves suggests that the larval nervous system is derived at least in part from cells of the animal plate and develops in association with the ciliary bands.
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    6-OHDA-induced ectopia of external granule cells in the subarachnoid space covering the cerebellum (1983)
    Springer
    Cell & tissue research 230 (1983), S. 309-336 
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    ISSN: 1432-0878
    Keywords: Neural ectopia ; Cerebellum ; Granule cells ; Development ; 6-Hydroxydopamine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The present report describes the genesis, development and topographical distribution of ectopic cells of the external granular layer in the subarachnoid space covering the rat cerebellum. Following one intracisternal injection to newborn rats of 100 μg 6-hydroxydopamine (6-OHDA), the meningeal cells degenerate and are removed by phagocytosis within 24 h post injection (p.i.), leaving the cerebellar cortex without a pia-arachnoid cover. Defects appear in the basal lamina investing the cerebellar cortex 3 to 5 days p.i., and both external granule cells and ‘sprouts’ from Bergmann-glia endfeet grow into the subarachnoid space. The latter form large, flat glial lamellae and cover extensive areas of the denuded cerebellar surface, although they do not form a glial scar over the exposed neuropil of the cerebellar cortex. The numbers of ectopic external granule cells increase within the subarachnoid space both by proliferation and a continuous efflux of cells from the cerebellar cortex. They migrate, aggregate, and ultimately develop into granule, stellate and basket cells, the morphology of which is indistinguishable from their counterparts in situ; they make specific afferent and efferent connections, both among themselves and with the underlying cerebellar cortex and brainstem. The distribution of ectopic external granule cells and their derivatives is restricted to the anterior vermal fissures and the vermal-hemispheric junctions. The present results indicate that external granule cells and their derivatives are capable of both differentiating normally and surviving in the subarachnoid space if they become associated with glial cells and establish synaptic connections.
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    URL: http://dx.doi.org/10.1007/BF00213807
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    The freeze-fractured median eminence (1983)
    Springer
    Cell & tissue research 233 (1983), S. 81-97 
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    ISSN: 1432-0878
    Keywords: Neuroendocrine system ; Median eminence ; Neurohemal contact zone ; Development ; Freeze-fracture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The neurohemal contact area of the median eminence was examined in adult, young, neonatal, and fetal rats in freeze-fracture preparations. While no specializations of the membranes of axonic terminals abutting on the perivascular space were observed, adjacent areas of the same membranes are rich in signs of hormone release. Signs of exocytosis are defined in the manner of Theodosis et al. (1978). Exocytotic pits with a single dense granule as a core are identified on P-faces along with mounds on corresponding E faces. These features appear near the time of birth, are especially numerous at 3 days, 3 weeks, and 5 weeks, and continue in lesser numbers into adulthood. Even more numerous and appearing even earlier, by the last day of fetal life, were P-face clusters of large particles usually in a pit, and pits without particles. These fall into 2 significantly different categories distinguished by the size of the pit. E face counterparts are large and small protuberances, respectively. Fenestrae of adult size and distribution are observed along the endothelium of portal vessels from the 20th day of fetal life on. Their frequency correlates well with other structural manifestations of a median eminence ready for the onset of functional activity at about the time of birth (Monroe and Paull 1974).
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    URL: http://dx.doi.org/10.1007/BF00222234
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    Ontogenetic studies on the topographical heterogeneity of somatostatin-containing neurons in rat hypothalamus (1983)
    Springer
    Cell & tissue research 233 (1983), S. 347-354 
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    ISSN: 1432-0878
    Keywords: Development ; Somatostatin neuron ; Hypothalamus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ontogeny of the somatostatin-containing neuron system was investigated by light-microscopic immunohistochemistry. During development, immunoreactive somatostatin-containing neurons arise from three discrete regions of the neuroepithelium of the third ventricle and show a chronological difference. The neurons are first evident within the third ventricle floor on day 12.5 of gestation; they move thereafter to the arcuate nucleus. The second generation occurs in the dorsal region of the arcuate nucleus during days 17.5–19.5; these neurons migrate sequentially into the arcuate-ventromedial nuclear region. The third generation is recognized in the neuroepithelial cell layer of the rostral hypothalamus on day 17.5 of gestation; these cells move to the periventricular area. This latter generation is most prominent during days 3–6 after birth, and some of the cells are seen sporadically even up to day 20. The first two generations give rise to the somatostatin neuron system in the arcuate-ventromedial nuclear region, while the latter gives rise to that in the rostral periventricular region in the adult rat hypothalamus.
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    URL: http://dx.doi.org/10.1007/BF00238301
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    The programming of silk-gland development in Bombyx mori (1980)
    Springer
    Cell & tissue research 213 (1980), S. 311-324 
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    ISSN: 1432-0878
    Keywords: Bombyx ; Silk-gland ; Starvation ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cytological development of the silk gland has been studied by light and electron microscopy in silkworms experimentally starved at different periods of the natural feeding stage during the fifth instar. When newly molted animals are not provided with food, no sign of growth is observed. Starvation initiated early during the obligatory feeding period, stops cell growth and development of the organelles involved in protein synthesis and secretion, whereas it induces the appearance of organelles concerned with autolysis. These effects are reversible if starvation is not prolonged beyond two days. Starvation during the facultative feeding period, at the time of massive fibroin production, results in quantitative and qualitative modifications of organelles related to the decrease of fibroin production and the onset of autolysis. Rough endoplasmic reticulum, responsible for fibroin synthesis, forms transitory whorls. Fibroin transport via the Golgi apparatus and secretion of the protein into the gland lumen decrease parallel to fibroin synthesis, so that no fibroin storage can be detected in any organelle. After food deprivation, autophagosomes and secondary lysosomes rapidly develop in the cytoplasm, and if starvation continues portions of the cytoplasm are sequestered and completely destroyed. If animals are refed, fibroin production is resumed and autolysis declines. These ultrastructural alterations of the silk gland during experimental starvation are very similar to those observed during the periods of physiological starvation (molt and cocoon spinning) and generally considered to be under hormonal control. Our results raise the question of the nature of interactions between alimentary and hormonal factors which control silk-gland development.
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    A scanning electron microscopic study of larval development in the marine polychaete, Galeolaria caespitosa Lamarck (Serpulidae) (1981)
    Springer
    Cell & tissue research 215 (1981), S. 171-179 
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    ISSN: 1432-0878
    Keywords: Polychaeta, Serpulidae ; Gamete ; Larva ; Development ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Gametes and developing larvae of the polychaete Galeolaria caespitosa were examined by scanning electron microscopy. The sperm display a primitive morphology. When treated with 0.33 M CaCl2, they release a branched acrosomal process. At spawning, the polygonal oocytes have a granular surface made up of spherules and the tips of microvilli. The oocyte coat develops a ridged appearance as the oocyte rounds up. At fertilization, the microvilli are withdrawn from the coat surface. Microvilli again appear on the coat surface during the trochophore stage, but the egg coat appears to be retained as the larval cuticle until the demersal stage. The surface of the larva now shows many microvilli. Details of the organization of several ciliary structures are clarified. Moreover, the present study shows rapid, sequential development of paired setal sacs, with the most anterior pair appearing first.
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    URL: http://dx.doi.org/10.1007/BF00236257
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    The development of the stomach in Clarias lazera and the intestinal absorption of protein macromolecules (1981)
    Springer
    Cell & tissue research 215 (1981), S. 397-415 
    Details
    ISSN: 1432-0878
    Keywords: Stomach ; Epithelium ; Teleost ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the stomach of the teleost, Clarias lazera, during the early posthatching period, is described, and the developing stomach is compared with that of adult Clarias. The stomach develops in two distinct parts: the corpus, which differentiates first, and the pylorus. The corpus contains a mucous surface epithelium, arranged in folds, and a tubular gland system containing only one type of gland cell, to which the secretion of pepsinogen and HCl is attributed. The pyloric region does not contain tubular glands. From the ultrastructure of the gland cells, the 3H-thymidine labeling index, and the onset of acid production (as determined with pH indicators) it is concluded that a functional stomach is present in juveniles with a standard length of ± 11 mm (approximately 12 days after fertilization at 23–24° C). The ultrastructure of the intestinal epithelium has also been studied. The intestine consists of three segments, similar to those described for stomachless teleosts and a number of fish larvae. In larvae as well as in juveniles, the enterocytes of the second segment show pinocytosis of horseradish peroxidase, although in the juveniles the stomach has already developed. This second segment has the same relative length in all studied larvae and juveniles and is also present in adult Clarias. It is therefore concluded that the capacity to absorb protein macromolecules is not specifically related to the absence of a functional stomach in this teleost species.
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    The freeze-fractured median eminence (1982)
    Springer
    Cell & tissue research 222 (1982), S. 389-408 
    Details
    ISSN: 1432-0878
    Keywords: Neuroendocrine system ; Ependymal junctions ; Third ventricle ; Development ; Freeze-fracture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ependymal junctions in both the ventro-lateral wall and infundibular floor of the 3rd ventricle were examined in adult, young, neonatal, and fetal rats in freeze-fracture preparations. During late fetal and early postnatal life, tight junctions developed in both ventro-lateral and floor ependyma with, first, the appearance of an area of waffle-like or honeycomb texture in the membrane where tight junctions will appear; second, the decoration of P-face crests of this honeycomb with individual particles; and lastly, fusion of these particles into smooth strands. In adults, tight junctions were rare in the lateral ependyma, but persisted on the floor as a loose network. Many small ependymal gap junctions were already present at the earliest fetal stage (17 days) examined. They occupied significantly larger proportions of the membranes on the ventro-lateral wall than on the floor throughout the time course due to an increase in their size but not their numbers. The smallest gap junctions were regarded as the newest in a process of renewal throughout life. The development of both junctional types parallels what is known of the onset of neuroendocrine functions in the median eminence. In the rat, this is apparently just before, at, or just after birth.
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    Development of the tympanal organ in larvae of the migratory locust (Locusta migratoria) (1982)
    Springer
    Cell & tissue research 222 (1982), S. 667-676 
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    ISSN: 1432-0878
    Keywords: Tympanal organ ; Receptor cell ; Scolopidium ; Development ; Locusta migratoria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The tympanal organ of the migratory locust acquires its definitive form during larval development. All the receptor cells (90–100) are present in the 1st instar, whereas the differentiation of the tympanum and the cuticular structures it bears proceeds in steps from one instar to the next. The elevated process is the earliest such structure to appear (2nd instar); it is followed by the pyriform vesicle (3rd instar) and folded body (4th instar). The styliform body first appears in the imago. Although the typical arrangement of the receptor cells is already discernible in the 1st instar, some of the attachment sites change during development, the final configuration appearing only in the imago.
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    The development of the diencephalic choroid plexus in the chick (1981)
    Springer
    Cell & tissue research 219 (1981), S. 297-311 
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    ISSN: 1432-0878
    Keywords: Choroid plexus (chick) ; Third ventricle ; Ependyma ; Development ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The surface morphology of the diencephalic choroid plexus (Pl. ch. v. III) was investigated by light microscopy and scanning electron microscopy in chicks from the 7th embryonic day (ED) to the 8th week after hatching. Pl. ch. v. III develops on the anterior ventricular roof from a sagittally oriented fold and a few posteriorly located transverse folds. On the 7th ED no significant differences in the cell surface morphology between Pl. ch. v. III and the surrounding ependyma are observed: both are covered with cilia. During the next four days, long cell prolongations (one per cell) covered with microvilli develop first on the surface of the posterior ventricular roof and then on the posterior part of Pl. ch. v. III. These structures are transitory. On the 11th ED, round cell prolongations (one per cell) appear progressively on the entire plexus, also replacing the long ones. Now the plexus surface is distinct from the surface of the surrounding ependyma. During the last week before hatching and also after hatching, the round cell prolongations become less prominent. Simultaneously, the number of cilia per unit surface area diminishes. With consideration of earlier reports, this study suggests that the following factors are involved in the increase of the surface area of Pl. ch. v. III: (I) The pseudostratified epithelium changes into columnar epithelium. (2) Ependymal elements of the posterior roof of the 3rd ventricle contribute to the anlage of Pl. ch. v. III. In later stages, however, Pl. ch. v. III grows only by mitoses.
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    Morphologic development of neonatal rat pinealocytes in monolayer culture (1981)
    Springer
    Cell & tissue research 220 (1981), S. 337-347 
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    ISSN: 1432-0878
    Keywords: Pineal ; Monolayer culture ; Development ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphological development of pinealocytes maintained in monolayer culture, without the neural and humoral effects present in the developing rat has been studied and compared with the development that occurs in vivo. Pinealocytes in 5 day cultures contained organelles that were similar to those present in the pineals of intact 5 day old rats. However, light and dark cells were not noted in culture, and the cultured cells did not have the dense granules noted in vivo. As pinealocytes developed in culture, cytoplasmic processes increased in length and number. By 21 days of culture age, synaptic ribbons were found to have decreased in number, the difference between light cell and dark cell cytoplasm had become more prominent, and dense-cored vesicles had become more numerous, just as in the developing gland in vivo. These results suggest that the complex neural and humoral factors impinging upon the developing neonatal pineal in the intact animal may not be necessary for some aspects of its ultrastructural differentiation.
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    Neural control of embryonic acetylcholine receptor and skeletal muscle (1983)
    Springer
    Cell & tissue research 228 (1983), S. 1-12 
    Details
    ISSN: 1432-0878
    Keywords: Avian skeletal muscle ; Development ; Acetylcholine receptor ; Innervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The manner by which motor neurons exert control over the distribution and number of acetylcholine receptors, and muscle development was investigated in the superior oblique muscle of white Peking duck embryos. Clusters of receptors in the normally developing muscle first appeared on day 10 of incubation as determined with I125 α-bungarotoxin autoradiography. The initial appearance of receptor clusters coincided with the arrival of motor nerve fibers in the muscle. Clusters of receptors also appeared in normal fashion in muscles made aneural by destruction of motor neurons on day 7. But after day 14 these clusters had disappeared and no new clusters were seen thereafter in the aneural muscle. Receptor clusters persisted throughout development in muscle in which neuromuscular transmission was blocked with either curare or botulinum toxin and in muscles denervated on day 10.5, i.e., shortly after the initial nerve-muscle contact but prior to the onset of muscle activity. A progressive increase in the total number of receptors and in the total amount of protein occurred during the course of normal development. However, the specific activity of the receptor protein declined sharply following innervation on day 10. The total number of receptors and the specific activity of the receptor was affected depending on whether the motor neurons were destroyed before or after innervation and following chronic blockade of neuromuscular transmission. The half-life of the receptor protein was similar in normal, aneural, and paralyzed muscles (26, 25, 26 h, respectively). Measurements of total protein indicated that essentially no muscle growth occurred in the complete absence of innervation. Paralyzed muscles continued to develop but at a slower pace.
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    URL: http://dx.doi.org/10.1007/BF00206259
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    Development of blood-cerebrospinal fluid barrier to horseradish peroxidase in the avian choroidal epithelium (1981)
    Springer
    Cell & tissue research 214 (1981), S. 271-278 
    Details
    ISSN: 1432-0878
    Keywords: Blood-CSF barrier ; Blood-brain barrier ; Horseradish peroxidase ; Choroid plexus ; Development ; Chick embryo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The penetration of horseradish peroxidase (HRP) from blood into ventricle via the avian choroid plexus was examined by electron microscopy in order to study the development of the blood-cerebrospinal fluid barrier (BCSFB). 1–20 mg HRP was injected into the allantoic vein of chick embryos between the 7th and 21st day of incubation. Until the 8th day (stage 34) the reaction products of injected HRP were observed in the interepithelial clefts at both luminal (ventricular) and abluminal sides. At the 9th day (stage 35), their penetration was blocked at most apical junctional complexes of the choroidal epithelia. At the 10th day (stage 36) and at every subsequent stage, HRP molecules were completely impeded at the apical tight junctions. These results show that the BCSFB to HRP in the avian choroidal epithelium is completely established by the 10th day, when molecules of HRP are still able to permeate between the capillary endothelia in the cerebellum and the spinal cord (Wakai and Hirokawa 1978).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00249211
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    Supraependymal cell clusters in the rat brain (1981)
    Springer
    Cell & tissue research 218 (1981), S. 41-58 
    Details
    ISSN: 1432-0878
    Keywords: Supraependymal cell clusters ; Ventricular system ; Development ; Hypothalamus rat ; Monosodium glutamate ; Androgenized rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The histological patterns of supraependymal cell clusters (CC) in rats of different ages (untreated, androgenized, and treated with monosodium glutamate) were investigated with light (LM)-, scanning-and transmission electron microscopy (SEM, TEM). These clusters were a frequent but not a constant finding. In 18 day-and older embryos, CC were always found in the recess of the olfactory bulb immediately prior to its obliteration. All other CC appear in the infundibular recess between the 3rd and the 6th postnatal day. Independent of age, all cell clusters exhibit small aggregates of subependymal tissue protruding through the ependyma. Both neurons (light cells) and neuroglia (dark cells) were found in the CC. By use of SEM, in the region of the infundibular recess it is possible to distinguish four forms of supraependymal cell clusters according to localization, size, number of cells, and presence of intraventricular axons. CC may be 1) receptors or have an additional secretory function; 2) manifestations of a pathological type of reaction of the ventricular wall; 3) possible excrescences of the neural matrix, or 4) modifications of the ventricular wall in relation to the obliteration of the ventricular recesses. The first two interpretations are not tenable based on the present observations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00210090
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    The mature mesonephric nephron of the rabbit embryo (1981)
    Springer
    Cell & tissue research 221 (1981), S. 431-442 
    Details
    ISSN: 1432-0878
    Keywords: Kidney (rabbit) ; Development ; Mesonephric nephron ; Freeze-fracture electron microscopy ; Intercellular junctions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In freeze-fracture replicas of the entire cross-fractured mesonephros of 18 day rabbit embryos the basolateral and luminal cell faces of the different nephron segments were studied and compared with their metanephric counterparts. In the proximal tubule, the shallow zonula occludens exhibited only 1–2 strands and resembled the corresponding metanephric zonula, a very “leaky” type, which was found with a considerable paracellular flow component in sites of isotonic reabsorption. Gap junctions were restricted to the proximal tubule and were seen more frequently in its terminal segment. The distal tubule harboured two types of tight junctions. The most common type, a band of 5–8 closely parallel strands, matched the zonula occludens of the metanephric straight distal tubule. The observed particle density of the basolateral membrane (2,500±328/μm2) was less than that of the proximal tubule (2,642±306). In addition, the collecting tubule exhibited a zonula occludens of the “tight” variety similar to that which occurred in the metanephric collecting duct. Rod-shaped particles of the luminal membrane were mainly concentrated in some of the intercalated cells but also had developed on principal cells, and occasionally, in the distal tubule. The Wolffian duct, with a deep “tight” zonula occludens, had an obviously rather inactive epithelium with no conspicuous transport-linked membrane specializations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00216746
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    Development of the capillary system in the neurohypophysis of the rat (1983)
    Springer
    Cell & tissue research 228 (1983), S. 685-696 
    Details
    ISSN: 1432-0878
    Keywords: Neurohypophysis (rat) ; Development ; Blood vessels ; Perivascular space
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the vascular system in the neurohypophysis of the rat shows three periods of structural differentiation. The first period lasts until the 17th fetal day. During this period the superficial and the border plexuses are formed, and rapid vascularization of the neural lobe anlage takes place. The end of this period is marked by the formation of the perivascular space. The second period lasts from the 18th fetal day until the 10th day after birth. Its initial phase is characterized by the appearance of the first endothelial pores. During this period the formation of the internal capillaries proceeds, together with the maturation of the previously formed vascular elements. The third period lasts from the 10th postnatal day until the end of the first month after birth. At the end of this period the vascular net of the neural lobe has attained its fully developed state. The results of this study, together with data from previous investigations, lead to the conclusion that at the 18th fetal day the neural lobe displays signs of functional activity, and that the maturation of the vascular network in the neural lobe occurs more rapidly than the maturation of its other structural components.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00211484
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    Embryonic development of the smooth and striated musculatures of the chicken iris (1983)
    Springer
    Cell & tissue research 229 (1983), S. 37-59 
    Details
    ISSN: 1432-0878
    Keywords: Sphincter pupillae ; Smooth muscle ; Development ; Chicken
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Both smooth muscle and striated muscle are present in the iris of the chick embryo. The two types of musculature form mixed clusters which include undifferentiated cells and many nerve fibres, but they are structurally quite distinct and have different origins. The smooth musculature originates around the 10th day from a laminar invagination (iridial lamella) of the posterior epithelium, and is therefore an ectodermal derivative. The striated musculature appears slightly later than the smooth musculature and originates from undifferentiated cells which are regarded as mesenchymal. After the 15th day in ovo the smooth musculature stops growing; its cells become confined to an area very near the pupillary margin and many develop pigment granules in the sarcoplasm. Many smooth muscle cells seem to undergo regressive changes; however, cells with the typical appearance of visceral muscle cells are still present in the iris of 3-month-old chickens. High density of innervation and vasculari/ation, wide range of striated muscle fibre diameters, presence of lipid vacuoles and of large clusters of mitochondria in the striated fibres, occurrence of peripheral couplings of the sarcoplasmic reticulum, and presence of numerous fibroblast processes in the interstices between fibres, characterize the sphincter pupillae of the mature iris.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217879
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    Synaptic development and microtubule organization (1983)
    Springer
    Cell & tissue research 231 (1983), S. 93-102 
    Details
    ISSN: 1432-0878
    Keywords: Synapses ; Microtubules ; Presynaptic dense projections ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using techniques for enhanced microtubular preservation (albumin pretreatment of Gray) occipital and pyriform cortices of rats were studied by electron microscopy at various stages of development. A close structural relationship was seen between microtubules (mts), focal membrane densities, synaptic vesicles, and presynaptic dense projections (pre-dps) during maturation. Mts were seen in the neonates to be focused onto the inner surface of immature axonic profiles merging or sometimes fragmenting there. Focal densities occur at these attachment sites and thereafter synaptic vesicles clothe the mts and abut onto these presumed primordial pre-dps. Thus, mts may contribute to the initial formation of pre-dps as well as their maintenance in the adult and may act to channel the first synaptic vesicles to the site of eventual synaptic contact and transmitter release.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00215777
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    Fracture and flow of rocks and minerals (1982)
    Springer
    In:  Bull., Open-File Rept., Zahlenwerte und Funktionen aus Naturwiss. und Technik, L.B. V-1b, Berlin, Springer, vol. 81A, no. 16, pp. 141-238, (ISBN 0080419208)
    Details
    Publication Date: 1982
    Keywords: Textbook of geophysics ; Fracture ; Rock mechanics ; Rheology
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    BIBLIOGRAPHY SEISMOLOGY
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