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  • Electron microscopy  (165)
  • Coleoptera  (122)
  • Springer  (287)
  • American Association for the Advancement of Science
  • 2010-2014
  • 2005-2009
  • 2000-2004  (29)
  • 1980-1984  (258)
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  • 1
    Electronic Resource
    Electronic Resource
    Application of the short-time staining for the electron microscopic investigation of the crystallization of polyethylene (1983)
    Springer
    Colloid & polymer science 261 (1983), S. 373-374 
    Details
    ISSN: 1435-1536
    Keywords: Electron microscopy ; short-time staining ; nodular structure ; crystallization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01413947
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  • 2
    Electronic Resource
    Electronic Resource
    Heat of fusion and lamellar structure of polyethylene single crystal mats (1982)
    Springer
    Colloid & polymer science 260 (1982), S. 564-569 
    Details
    ISSN: 1435-1536
    Keywords: lin. Polyethylene ; Single crystals ; Heat of Fusion ; DSC ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Recently published results for solution crystallized PE single crystals have shown, that the experimental heat of fusionΔH * is higher, if the solvent is exchanged to silicon oil (oil suspension samples) as compared with dried mats. This has been interpreted by the collapse of the original hollow pyramids during drying, inducing lateral defects within the lamellae. The present investigation does not confirm this unexpected result.ΔH * of dried mats (T c 66 to 91 °C) and of the corresponding oil suspension samples agree within the rather small limits of experimental error. The crystallinities as derived fromΔH *, density or WAXS are in excellent agreement. SEM micrographs of cold fractured dried mats show their spongy macromorphology, but TEM micrographs of stained ultra-thin sections reveal the lamellar morphology of the walls, consisting of curved lamellae and stacked hollow pyramides. If a dried mat is sintered at room temperature, a dense transparent film is obtained with a rather regular stacked morphology of large flat lamellae.ΔH * of these films agrees with that of the original mat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01422587
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  • 3
    Electronic Resource
    Electronic Resource
    Effect of the ecdysone agonists, methoxyfenozide and tebufenozide, on the lady beetle, Coleomegilla maculata (2000)
    Springer
    Entomologia experimentalis et applicata 94 (2000), S. 103-105 
    Details
    ISSN: 1570-7458
    Keywords: ecdysone agonists ; methoxyfenozide ; tebufenozide ; Ostrinia nubilalis ; Coleomegilla maculata ; Coleoptera ; Coccinellidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003926704520
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  • 4
    Electronic Resource
    Electronic Resource
    Increasing the effectiveness of spring trap crops for Leptinotarsa decemlineata (2000)
    Springer
    Entomologia experimentalis et applicata 96 (2000), S. 193-204 
    Details
    ISSN: 1570-7458
    Keywords: cultural controls ; dispersal ; Colorado potato beetle ; Coleoptera ; Chrysomelidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Insecticide resistance problems have increased interest in trap crops as a cultural control strategy for overwintered Colorado potato beetle adults, Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae). Growers in the north central United States have noticed and treated concentrations of adults at the edge of some of their potato fields each spring. Based on sampling in commercial potato fields over a 2-year period, early planted fields that are adjacent to the previous year's potato crop are most likely to have concentrations of adults at the field edge. Frequency of fields with significantly more adults at the edges than in the center sections as well as adult population density in the center sections of fields declined with both distance from the previous potato field and later planting date. The effects of both physical and chemical barriers to movement into potato fields from the field edges were studied in small plot trials and at the edges of commercial potato fields. In small plot trials, physical barriers had a greater impact than chemical barriers on adult beetle movement from a potato trap crop to the protected potatoes beyond the barrier. Barrier treatments reduced beetle numbers in and just beyond the barrier in commercial fields, but the effects were localized and no significant reduction of beetles was observed further into the field. Beetle flight was hypothesized to be responsible for the localized effects of barrier treatments and the lack of edge concentrations in later planted and more distantly rotated fields. In field studies, larger potato plants attracted more colonizing potato beetles than smaller plants. Attracting Colorado potato beetles to trap crops containing potato plants that were larger than those in the remainder of the field, however, provided no significant reduction of beetles in the remainder of the field. We found little opportunity to reduce beetle populations with trap crops at the edges of potato fields without controlling the adults in the trap crop itself. Growers can exploit naturally occurring concentrations of adults at the edges of early and adjacent potato plantings if they are prepared to monitor and regularly treat the field edges.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004009901244
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  • 5
    Electronic Resource
    Electronic Resource
    The role of chemical cues in host finding and acceptance by Callosobruchus chinensis (2000)
    Springer
    Entomologia experimentalis et applicata 96 (2000), S. 213-219 
    Details
    ISSN: 1570-7458
    Keywords: herbivore ; host finding ; olfactometer ; volatiles ; oviposition ; discrimination ; Coleoptera ; Bruchidae ; pest control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We studied the response of female Callosobruchus chinensis to chemical cues emitted by cowpea seeds at different stages of bruchid infestation (uninfested, egg carrying, L1-, and L4-infested). Olfactory attractiveness was determined in Y-tube olfactometer assays by testing individual seed categories against either clean air or uninfested seeds. Oviposition preferences between uninfested and infested seeds were determined in petri-dish choice-experiments. The olfactometer assays revealed that weevils discriminate between seeds containing different stages of developing bruchids on the basis of olfactory cues. While odors from uninfested and egg-carrying seeds acted as attractants, odors from L1- and L4-infested seeds failed to induce a positive response by the bruchids. When given a choice between uninfested and infested seeds in the olfactometer, weevils preferred uninfested seeds over L1- and L4-infested seeds, but failed to distinguish between uninfested and egg-carrying seeds. In the oviposition experiment as well, bruchids showed a distinct preference for uninfested seeds when offered in combination with L1- and L4-infested seeds. This experiment further showed a reduced acceptance of egg carrying seeds. Our results indicate that C. chinensis females use chemical information during both host searching and host acceptance. Volatiles from uninfested or egg carrying seeds act as attractants, while deterrence increases as development of bruchid immature stages progresses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004016127866
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  • 6
    Electronic Resource
    Electronic Resource
    Selection of hibernation sites by Anthonomus pomorum: preferences and ecological consequences (2000)
    Springer
    Entomologia experimentalis et applicata 95 (2000), S. 241-249 
    Details
    ISSN: 1570-7458
    Keywords: Anthonomus pomorum ; apple blossom weevil ; Coleoptera ; Curculionidae ; hibernation ; mortality ; dispersal ; mark-release-recapture ; apple orchard
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The apple blossom weevil, Anthonomus pomorum (L.) (Coleoptera: Curculionidae), has a long period of aestivo-hibernation in the adult stage lasting from summer to early spring of the following year. Potential hibernation sites within an apple orchard consist of high-stem rough-bark trees or dwarf smooth-bark trees. Field release-recapture experiments in 2 consecutive years showed that 64 and 47% of the weevils remained in the vicinity of the release sites in an area of high-stem trees and dwarf trees, respectively. The dispersing weevils moved over an average distance of 5.5 m in the dwarf tree area, as compared to 3.8 m in the high-stem tree area. The prevalent direction of dispersal was along tree rows in both areas. Some weevils displayed, after release in mid-July, a directional dispersal to the adjacent forests. Others, released in the dwarf tree area, dispersed towards the area of high-stem rough-bark apple trees. Experiments simulating various hibernation sites demonstrated that the litter of dry leaves was the most preferred overwintering shelter, yielding a relatively high survival rate. Branches with rough bark ranked second, while branches with smooth bark, grass and pure soil were not favourable for overwintering. Flight tendency in newly emerged weevils of summer generation was significantly higher in June/July than in August/September. This corresponds to the dispersal behaviour in the field. The timing of spring colonisation of apple trees was similar for weevils overwintering within the orchard and for those from outside. These results suggest that modern, dwarf apple orchards offer unfavourable conditions for overwintering, but that the relatively small proportion of weevils which manage to reach the adjacent forests find optimal hibernation sites there.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004046801897
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  • 7
    Electronic Resource
    Electronic Resource
    Behavioural responses of Oryzaephilus surinamensis, Tribolium castaneum and Tribolium confusum to naturally and artificially damaged durum wheat kernels (2000)
    Springer
    Entomologia experimentalis et applicata 94 (2000), S. 195-200 
    Details
    ISSN: 1570-7458
    Keywords: stored-products ; Coleoptera ; primary pests ; secondary pests ; behaviour ; host selection ; wheat kernel volatiles ; damaged kernels
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Observations on behavioural activity involved in the host selection by secondary pests of stored grains, Oryzaephilus surinamensis (Linnaeus), Tribolium castaneum (Herbst) and Tribolium confusum J. du Val, with respect to intact and mechanically or naturally damaged kernels are reported. Our results indicate that the attraction of secondary pests is facilitated by broken grain kernels, which resulted from either mechanical damage during harvesting and/or binning procedures, or the feeding activity of primary insect pests. Insect damaged kernels were more attractive to O. surinamensis, T. castaneum and T. confusum than whole kernels; in addition insect damaged kernels elicit more attractiveness than mechanically split kernels. The damage caused by primary pests, such as Rhyzopertha dominica (Fabricius) and Sitophilus oryzae (Linnaeus), on whole kernels may facilitate colonization by secondary pests, which continue damaging the cereals. O. surinamensis, T. castaneum and T. confusum utilize the grain volatile odours to distinguish whether the grain kernels of the stored cereals are damaged mechanically or by insects.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003929810978
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  • 8
    Electronic Resource
    Electronic Resource
    Pitfall-trap catches of the carabid beetle Pterostichus melanarius, in relation to gut contents and prey densities, in insecticide treated and untreated spring barley (1984)
    Springer
    Entomologia experimentalis et applicata 36 (1984), S. 23-30 
    Details
    ISSN: 1570-7458
    Keywords: Pterostichus melanarius ; Coleoptera ; Carabidae ; pitfall traps ; insecticides ; prey ; hunger ; activity ; Rhopalosiphum padi ; Fenitrothion ; Sumicidin (Fenvalerate) ; spring barley
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Au cours d'essais à grande échelle, effectués en 1981 et 1982, sur orge de printemps, pour évaleur l'effet des insecticides Fenitrothion et Sumicidine (fenvalerate) sur les arthropodes utiles, un accroissement significatif des captures, dans des trappes pièges de Barber, de Pterostichus melanarius (Illiger) a été observé plusierus semaines après le traitement dans les lots traités par rapport aux lots témoins. Significativement plus de femelles de P. melanarius ont été capturées dans les parcelles traitées pendant cette période d'accroissement après traitement. Une diminution correspondante dans les populations de proies a été observée à la suite des traitements. Chaque femelle de P. melanarius des parcelles traitées avait une fraction significativement moins importance de son intestin remplie d'aliments solides (arthropodes) que celles des parcelles non traitées. Des auteurs précédents avaient observé des taux de capture plus rapides dans les trappes et ne plus grande mobilité des carabes affamés. La réduction des populations proies par l'application d'insecticides affamerait les carabes dont l'activité serait par suite plus élevée. Comme le taux de captures dans les trappes est dû à la fois à la taille de la population et à son activité, on en déduit que la capture par trappes seule ne peut donner une image exacte de l'effet des insecticides sur les populations de carabes dans les champs.
    Notes: Abstract During large-scale field experiments in 1981 and 1982, designed to assess the effects of the insecticides Fenitrothion and Sumicidin (Fenvalerate) on beneficial arthropods in spring barley, significant increases in pitfall-trap catches of Pterostichus melanarius (Illiger) were observed in treated plots compared to untreated controls, several weeks after treatment. Significantly more female P. melanarius were caught in treated plots during these post-treatment increases. Corresponding decreases were observed in prey populations following treatments. Individual female P. melanarius from treated plots had significantly fewer of their gut areas full of solid (arthropod) food when compared to those from untreated control plots. Earlier workers observed both faster recapture rates in pitfalls and higher mobility in hungry carabid beetles. The following hypothesis is suggested: reducing prey populations by the application of insecticides results in hungrier carabid beetles with consequently higher activity. Since pitfall-trap catch is determined not only by population size but also activity, it is argued that pitfall-trap catches alone cannot give a true measure of the effects of insecticides on carabid populations in the field.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00345200
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  • 9
    Electronic Resource
    Electronic Resource
    Ecdysteroids during pupal development of female Xyleborus ferrugineus (1981)
    Springer
    Entomologia experimentalis et applicata 30 (1981), S. 151-156 
    Details
    ISSN: 1570-7458
    Keywords: Xyleborus ferrugineus ; pupae ; ecdysteroids ; pharate adult ; radioimmunoassay ; Coleoptera ; Scolytidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Der Ecdysteroidtiter weiblicher Puppen von Xyleborus ferrugineus (Fabr.) wurde geschätzt, indem ganze Tiere homogenisiert und radioimmunologisch untersucht wurden. Ein ausgeprägtes Maximum an Ecdysteroiden wurde bei 36 Stunden Puppenent-wicklung beobachtet (743 pg/mg Körpergewicht). Der Titer nahm ab auf 299 pg/mg im Pharatstadium und auf 193 pg/mg unmittelbar vor Schlüpfen der Adulten. Qualitative Studien mit HPLC ergaben in frischen Puppen ein Verhältnis von 3:1 Ecdyson zu 20-Hydrooxyecdyson. Pharatstadien enthielten vor allem 20-Hydrooxyecdyson. Das beobachtete einzige Maximum im Titer stimmt überein mit den Resultaten bei andern untersuchten Coleopteren.
    Notes: Abstract Ecdysteroid titers were estimated on the whole body homogenates of Xyleborus ferrugineus (Fabr.) female pupae during development by radioimmunoassay. A distinct peak of ecdysteroids was observed at 36-hr pupal development (743 pg/mg body wt). Titer declined to 299 pg/mg by the pharate adult stage and to 193 pg/mg body wt just before adult emergence. Qualitative studies by HPLC revealed a ratio of 3:1 ecdysone to 20-hydroxyecdysone in the initial pupal stage. Pharate adults had mainly 20-hydroxyecdysone. The observed single peak in ecdysteroid titer agrees with findings in other studied coleopteran species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00300880
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  • 10
    Electronic Resource
    Electronic Resource
    The feeding characteristics and development of larvae of a salvinia weevil Cyrtobagous sp. (1983)
    Springer
    Entomologia experimentalis et applicata 34 (1983), S. 291-296 
    Details
    ISSN: 1570-7458
    Keywords: Coleoptera ; Curculionidae ; Cyrtobagous ; Salvinia weevil ; Feeding characteristics of larvae ; Development of larvae ; Plant nutrition ; Temperature effects on development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Après leur naissance, les larves de Cyrtobagous sp. passent de 1 à 4 jours à brouter les racines, et de 0 à 9 jours dans les bourgeons de la plante hôte, Salvinia molesta, avant d'y creuser une galerie dans le rhizome. Bien que les larves aient été capables de survivre jusqu'à 38 jours en broutant les racines, quant elles furent privées de rhizome, elle ne purent achever leur développement. Quand les galeries furent commencées, le développement larvaire, entre 21° et 31°, dépendit de la température et de la teneur en azote de l'hôte. Les larves ne se développèrent pas à 17°. Une haute valeur nutritive de l'aliment consommé par les larves réduisit la durée du développement, mais n'influença pas la durée ultérieure de leur développement nymphal. Les lieux de prise de nourriture et les dégâts produits par des larves isolées furent précisés.
    Notes: Abstract Newly-emerged larvae of a salvinia weevil, Cyrtobagous sp. spent from 1–4 days browsing on the roots and from 0–9 days in the buds of the host plant, Salvinia molesta, prior to tunnelling into the rhizome of this aquatic weed. Although larvae were able to survive up to 38 days browsing on roots when rhizomes were withheld, they were unable to complete development. After tunnelling began, larval development between 21° and 31° was dependent on temperature and nitrogen levels in the host. Larvae failed to develop at 17°. High nutritional intake by the larvae reduced larval development time but did not influence duration of their subsequent pupal development. The feeding sites and plant damage produced by individual larvae were assessed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00186928
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  • 11
    Electronic Resource
    Electronic Resource
    Distribution of proteinases and carbohydrases in the midgut of larvae of the sweetpotato weevilCylas formicarius elegantulus and response of proteinases to inhibitors from sweet potato (1984)
    Springer
    Entomologia experimentalis et applicata 36 (1984), S. 97-105 
    Details
    ISSN: 1570-7458
    Keywords: Coleoptera ; Curculionidae ; Cylas formicarius elegantulus ; sweetpotato weevil ; sweet potato ; digestion ; enzyme distribution ; trypsin-inhibitors ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'activité endoprotéinase était limitée au liquide de la lumière des régions ventriculaires antérieure et postérieure de l'intestin moyen des larves deCylas formicarius elegantulus Summers. Les aminopeptidases ont été trouvées dans le liquide de la lumière (18%), mais étaient principalement associées avec les fractions insolubles des cellules du ventricule postérieur (82%). Suivant le substrat, l'activité carboxypeptidase était à peu près également répartie entre le liquide de la lumière et les fractions insolubles des cellules du ventricule postérieur. L'amylase, enzyme secrétée, a été observée à la fois dans la lumière antérieure et postérieure. Cinq bandes d'activité amylase ont été révélées sur zymogrammes d'amidon après électrophorèse d'intestins moyens entiers. Trois des bandes d'amylase pouvaient provenir de la plante. Il y avait au moins 2 α-glucosidases, une secrétée et une liée aux cellules du ventricule antérieur. L'activite β-glucosidase était liée aux cellules du ventricule antérieur, fandis que l'activité α-galactosidase était limitée au fluide de la lumière. Les activités β-galactosidase et cellulase ont été trouvées à la fois dans le liquide de la lumière et dans la fraction cellulaire insoluble. Ainsi, la digestion initiale des grosses protéines et des polymères de carbohydrates se produit dans le liquide de la lumière dans les régions ventriculaires antérieure et postérieure. Cependant, l'achèvement de la digestion des oligopeptides se produit principalement dans le ventricule postérieur, tandis que la fin de la digestion des oligosaccharides se produit dans le ventricule antérieur. Les concentrations en inhibiteurs de trypsine de 5 cultivars d'I. batatas L. diffèrent de 1 à 20. Les endoprotéinases deC. formicarius elegantulus ont été inhibées par des extraits de cultivars, mais les cultivars avec des concentrations relativement élevées d'inhibiteur avainent antérieurement montré être susceptibles d'être attaqués par le coléoptère dans des essais en champs.
    Notes: Abstract Endoproteinase activity was confined to luminal fluid from anterior and posterior ventricular regions of midguts of larvae of the sweetpotato weevil,Cylas formicarius elegantulus (Summers). Aminopeptidase was found in luminal fluid (18%) but was primarily associated with insoluble fractions from cells of the posterior ventriculus (82%). Depending on substrate, carboxypeptidase activity was about equally distributed between luminal fluid and insoluble fractions from posterior ventriculus cells. Amylase was found in luminal fluid in both the anterior and posterior ventriculus. Five bands of amylase activity were detected on starch zymograms following electrophoresis of whole midgut samples. Three of the amylase bands may be plant-derived. At least two α-glucosidases were present, one secreted and one bound to anterior ventriculus cells. β-Glucosidase activity was bound to anterior ventriculus cells whereas α-galactosidase activity was confined to luminal fluid. β-Galactosidase and cellulase activities were found in both luminal fluid and the insoluble cell fraction. Thus, initial digestion of large protein and carbohydrate polymers occurs in luminal fluid in both anterior and posterior ventriculus regions. However, terminal digestion of oligopeptides occurs primarily in the posterior ventriculus while terminal digestion of oligosaccharides occurs in the anterior ventriculus. A 20-fold difference in trypsin-inhibitor concentration was found among five sweetpotato cultivars. Endoproteinases from sweetpotato weevil larvae were inhibited by extracts from the cultivars but cultivars with relatively high concentrations of inhibitor were previously shown to be susceptible to weevil attack in field trials.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00569949
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  • 12
    Electronic Resource
    Electronic Resource
    A new, X-linked body colour mutation in Tribolium confusum (1983)
    Springer
    Entomologia experimentalis et applicata 34 (1983), S. 124-126 
    Details
    ISSN: 1570-7458
    Keywords: Negret ; Melanic mutant ; X-linked mutation ; Flour Beetle ; Tribolium confusum ; Coleoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00300913
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  • 13
    Electronic Resource
    Electronic Resource
    Responses of Prostephanus truncatus to components of the aggregation pheromone of Rhyzopertha dominica in the laboratory and field (1983)
    Springer
    Entomologia experimentalis et applicata 34 (1983), S. 266-272 
    Details
    ISSN: 1570-7458
    Keywords: Storage pests ; Coleoptera ; Bostrichidae ; Prostephanus truncatus ; (±)-1-methylbutyl (E)-2-methyl-2-pentenoate ; Rhyzopertha dominica ; (±)-1-methyl-butyl (E)-2,4-dimethyl-2-pentenoate ; Dominicalure ; Aggregation pheromone ; Monitoring
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les réponses de Prostephanus truncatus Horn (Coleoptera: Bostrichidae) à deux constituants de la phéromone d'agrégation de Rhyzopertha dominica Fabricius (Coleoptera: Bostrichidae), le (±)-1-méthylbutyl (E)-2-méthyl-2-penténoate et le (±)-1-méthylbutyl (E)-2,4-diméthyl-2-pentéoate, connus comme “Dominicalure 1” et “Dominicalure 2”, ont été étudiées au laboratoire et au champ. Auslaboratoire ces composés ont été essayés individuellement et en mélange 1:2. Une membrane de caoutchouc imprégnée de phéromone a été utilisée comme émetteur lent, et une courbe de réponse en fonction de la dose a été établie. P. truncatus répondait plus vigoureusement à la Dominicalure 2 seule. Tous ces traitements ont été comparés dans un essai aux champs en Tanzanie, dans lesquels des pièges en carton ondulé contenant des diffuseurs de phéromone étaient placés dans des entrepôts de maïs dans les fermes. La Dominicalure 1 et le mélange de 1 et 2 étaient tous deux efficaces pour piéger R. dominica. La Dominicalure 2 a piégé plus de P. truncatus que les autres traitements et était à peu près aussi efficace que le contrôle visuel pour détecter la présence de cet insecte dans les stocks. On peut envisager que la Dominicalure 2 pourrait servir de base à un programme pour lutter contre P. truncatus en Afrique de l'Est.
    Notes: Abstract Laboratory and field studies have been made of the responses of Prostephanus truncatus (Horn) to two components of the aggregation pheromone of Rhyzopertha dominica (Fabricius) — (±)-1-methylbutyl (E)-2-methyl-2-pentenoate and (±)-1-methylbutyl (E)-2,4-dimethyl-2-pentenoate, known as “Dominicalure 1” and “Dominicalure 2” respectively. In the laboratory, these compounds were tested individually and as a 1:2 mixture; P. truncatus responded most strongly to Dominicalure 2 alone. All three treatments were compared in a field trial in Tanzania to monitor both R. dominica and P. truncatus in farm stores. Dominicalure 1 or a mixture of 1 and 2 were both highly effective for trapping R. dominica. In contrast, Dominicalure 2 trapped more P. truncatus than the other treatments and was about as effective as visual inspection at demonstrating the presence of the beetle in stores. Dominicalure 2 could form the basis of a monitoring programme for P. truncatus in East Africa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00186923
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  • 14
    Electronic Resource
    Electronic Resource
    Nested Coleoptera and Orthoptera on sand dunes in the Basin and Range Province of western North America (2000)
    Springer
    Journal of insect conservation 4 (2000), S. 33-43 
    Details
    ISSN: 1572-9753
    Keywords: biogeography ; nested subsets ; sand dune ; Coleoptera ; Orthoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Abstract The sand dunes of the Basin and Range Province of western North America contain obligate and endemic species of Coleoptera and Orthoptera. These dune habitats represent islands on which the isolated insular faunas are in a state of relaxation. The calculated ‘temperature’ metric used in this study reflects the relative measure of disorder, by which the degree of nestedness can be determined. Sixteen dunes in the Basin and Range Province are shown to comprise a nested subset of obligate Coleoptera and Orthoptera. These sixteen sand dunes remain nested even when the endemic species are excluded from the analysis. The absence of endemic species slightly decreased the calculated ‘temperature’ of the island-dune archipelago. Therefore, endemic species present in the sand dunes do not significantly contribute to the high degree of nestedness of dune obligate Coleoptera and Orthoptera in the Basin and Range Province. The dunes can also be separated into five distinct sub-basins, two of which contain only one sand dune. These sub-basins are not significantly nested, but together define the nested structure of the Basin and Range Province.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009699431838
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  • 15
    Electronic Resource
    Electronic Resource
    Ultrastructural evidence for inhibition of chitin synthesis by nikkomycin (1982)
    Springer
    Development genes and evolution 191 (1982), S. 205-207 
    Details
    ISSN: 1432-041X
    Keywords: Chitin inhibition ; Nikkomycin ; Cuticle ; Electron microscopy ; Epilachna varivestis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The nucleoside antibiotic nikkomycin has proved to be an effective inhibitor of chitin synthesis in the Mexican bean beetleEpilachna varivestis. Ultrastructural investigations show defects in the procuticular area after nikkomycin application which suggest the complete absence of chitin. A cuticle like this is inflexible and too brittle to satisfy its normal function as an exoskeleton. The individuals are not able to free themselves from the exuvia and finally die. Therefore nikkomycin seems to be a potential insecticide with high specifity.
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    URL: http://dx.doi.org/10.1007/BF00848337
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    Effects of cytochalasin B and dihydrocytochalasin B on calcium transport by intestinal absorptive cells (1981)
    Springer
    Calcified tissue international 33 (1981), S. 143-151 
    Details
    ISSN: 1432-0827
    Keywords: Calcium transport ; Cytochalasin B ; Dihydrocytochalasin B ; Colchicine ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary In vivo calcium absorption was studied in normal and rachitic chicks. Cytochalasin B (CB) at a concentration of 25 µg/ml added to the medium inside the duodenal lumen inhibited calcium absorption (20 min) from 82.5±1.9% of calcium absorbed in the controls to 59.2±3% in normal and from 70.0±2.3% to 47.0±2.1% in rachitic chicks. In vitro studies by everted ileal sacs of young rabbits also showed an inhibition of active transport of calcium due to CB. Whereas in the controls the ratio of45Ca concentrations in serosal and mucosal media (60 min) was 7.2±0.32, the ratios were 5.24±0.52; 4.40±0.36; 3.40±0.42; 5.77±0.52; 1.38±0.08; and 1.06±0.02 in the presence of CB at concentrations of 5, 10 and 25 µg/ml; colchicine 10−4M, Na citrate 0.02M, and heat-devitalized conditions, respectively.45Ca concentration in the mucosal scrapings was also affected. It showed an increase from controls (15,101±404 cpm/mg) and correlated with CB concentration: 17,378±489, 19,015±1000, and 20,201±362 at 5, 10, and 25 µg/ml, respectively. Dihydrocytochalasin B also inhibited active calcium transport and caused an increase in45Ca concentration in the mucosal scrapings. Correlated electron microscopic studies showed certain changes in the brush border, especially in some actin microfilaments in the terminal web region. It seems that these morphological alterations may be related to transcytoplasmic movement of calcium.
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    URL: http://dx.doi.org/10.1007/BF02409427
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    Ultrastructure of the rat epiphyseal growth plate following chronic ethanol ingestion (1981)
    Springer
    Calcified tissue international 33 (1981), S. 381-384 
    Details
    ISSN: 1432-0827
    Keywords: Alcohol ; Electron microscopy ; Growth plate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary We have previously demonstrated that ethanol has a direct toxic effect on the rat skeleton characterized by decreased trabecular bone volume. In the present study, we examined the ultrastructure of the distal radial epiphyseal growth plates in these same animals. Eight weeks of ethanol administration to 12 male rats results in serum alcohol levels of 140 mg/dl but did not alter the width or light microscopic appearance of the radial growth plate. Quantitative electron microscopy failed to demonstrate morphologic evidence of toxicity in the skeletal cells. We conclude that although ethanol appears to have a direct effect on rat bone characterized by enhanced resorption, toxicity is not attended by ultrastructural changes in the skeletal cells.
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    URL: http://dx.doi.org/10.1007/BF02409460
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    Biochemical and histological studies on various bone cell preparations (1981)
    Springer
    Calcified tissue international 33 (1981), S. 529-540 
    Details
    ISSN: 1432-0827
    Keywords: Bone cells ; Electron microscopy ; PTH ; PGE1
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Four different cell populations—designated PF, OB, OC, and PC—were isolated from calvaria of 18-day-old chick embryos for analysis of the effects of hormones on bone tissue. The cell populations were studied with histological and biochemical methods. Apart from the well-known cell types present in calvaria, a new cell type was found in the noncalcified organic matrix between the osteoblastic layer and the calcified matrix. These cells were provisionally called osteocytic osteoblasts. They represent the “transition state” between osteoblasts and osteocytes. On the basis of histological studies with light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM), the PF population was considered to originate primarily from the periosteal fibroblasts, the OB population from the osteoblasts and osteocytic osteoblasts. The population of cells still present in calvaria after removal of periosteal fibroblasts and osteoblasts was called the OC population. This cell population was very much enriched with osteocytes. The fourth isolated population (PC) was a mixed population of fibroblasts, osteoblasts, and preosteoblasts. On exposure to parathyroid hormone (PTH), all four cell populations showed increased lactate production, but only the OB and OC populations displayed increased cAMP production. Prostaglandin E1 (PGE1) stimulated cAMP production in both OB and PF cells. From the results of this study it was concluded that PTH receptors are present on all of the cell types studied, but that occupancy of the receptor induces adenylate cyclase stimulation only in osteocytes and fully differentiated osteoblasts.
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    URL: http://dx.doi.org/10.1007/BF02409485
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    A scanning electron microscopic investigation of in vitro osteogenesis (1980)
    Springer
    Calcified tissue international 30 (1980), S. 43-50 
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    ISSN: 1432-0827
    Keywords: Osteogenesis ; In vitro ; Electron microscopy ; Mineralization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Chick limb mesenchymal cells differentiate into muscle, cartilage, fibrous, and bone tissue. Previous reports show that when stage 24 limb mesenchymal cells are cultured in vitro, chondrocytes, myocytes, fibrocytes, and osteoblasts can be identified on the basis of morphological and biochemical parameters. The study reported here demonstrates that phenotypic expression in culture seems to be dependent on the initial plating density, Scanning electron microscopic observations indicate that when stage 24 limb mesenchymal cells are initially seeded at high densities (5 × 106 cells per 35 mm culture dish), mounds of cells appear in culture. These mounds represent cartilage nodules composed of a fine fibrous matrix and chondrocytes, surrounded by a loose fibrous connective tissue matrix. Cultures initially plated at intermediate densities (2.0–2.5 × 106 cells/35 mm culture dish) produce a flattened layer of fibrocytes overlying a matrix of collagen fibers and calcium phosphate deposits as determined by electron-microprobe analysis; these observations are indicative of osteoblast expression. Cells seeded at this intermediate density appear larger and possess greater surface area than cells seeded at high density. It is suggested that conditions that permit such increased cell surface area coupled with a relative compaction due to cell crowding may provide conditions permissive for osteogenesis. Based on morphological criteria, it appears that chick limb mesenchymal cell osteogenesis in vitro is not associated with chondrogenesis but represents a separate route of phenotypic expression.
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    URL: http://dx.doi.org/10.1007/BF02408605
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    Fine structure of fetal rat calvarium; provisional identification of preosteoclasts (1980)
    Springer
    Calcified tissue international 31 (1980), S. 21-28 
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    ISSN: 1432-0827
    Keywords: Rat ; Calvarium ; Electron microscopy ; Preosteoclasts ; Osteoclasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary This is a study of the fine structure of cells of the 20-day fetal rat calvarium. Special attention is given to identifying and characterizing preosteoclasts. These cells are relatively common and located largely, but not exclusively, at the endocranial bone surface. The preosteoclasts are characterized by abundant mitochondria, an incomplete perinuclear Golgi apparatus, and variable-shaped dense granules. The dense granules are unique in appearance in that they contain an internal dense matrix surrounded by a clear halo. Most granules are circular in shape but some are elongate or tubular in form. Granules with identical appearance are observed in osteoclasts. The preosteoclasts are mononucleate, or occasionally binucleate. It is suggested that because preosteoclasts are morphologically distinctive and relatively abundant, it should be feasible to separate these cells from a heterogeneous cell isolate.
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    URL: http://dx.doi.org/10.1007/BF02407163
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    Effects of demineralization in an ethanolic solution of triethylammonium EDTA on solubility of bone matrix components and on ultrastructural preservation (1980)
    Springer
    Calcified tissue international 32 (1980), S. 175-179 
    Details
    ISSN: 1432-0827
    Keywords: Decalcification ; Electron microscopy ; Bone matrix ; Bone glycoproteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A solution of triethylammonium EDTA in 80% ethanol was evaluated as a demineralizing reagent for bone in comparison with aqueous solutions of EDTA. Biochemical analysis and acrylamide gel electrophoresis of extracts of finely powdered bovine bone showed that most of the macromolecular components of the organic matrix extractable in aqueous EDTA were retained when the triethylammonium EDTA reagent was used. Ultrastructural examination of chick tibias decalcified with the reagents showed a better preservation of cellular morphology, especially the membranous components, and more uniformly distributed ground substance, though slightly less in quantity, when the aqueous reagent was used. Use of the two reagents appears to be complementary, the alkylammonium reagent being more appropriate for use in studies of the organic matrix of bone, including immunohistochemical studies of bone glycoproteins. The aqueous reagent is more appropriate for use in studies of cellular ultrastructure.
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    Crystal orientation in the shell of the domestic fowl: An electron diffraction study (1981)
    Springer
    Calcified tissue international 33 (1981), S. 119-124 
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    ISSN: 1432-0827
    Keywords: Avian eggshell ; Microstructure ; Electron microscopy ; Electron diffraction ; Calcite growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The eggshell of the domestic fowl has been studied by transmission electron microscopy and diffraction. Thin sections of shell were prepared by chemical and ion-beam thinning techniques. Each calcite column of the palisade layer consisted of crystallites of diameter 20 to 30 µm with some tendency for crystallite alignment within a single column. Evidence indicates that there was no significant preferred orientation in the palisade layer as a whole. Only in the surface layer was any preferred orientation detected, and here {1014} planes tended to lie parallel to the surface. The results are compared with previously published data, and calcite nucleation and growth are discussed.
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    Defect structure of the low temperature α-cristobalite phase and the cristobalite ⇆ tridymite transformation in (Si-Ge)O2 (2000)
    Springer
    Physics and chemistry of minerals 27 (2000), S. 386-397 
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    ISSN: 1432-2021
    Keywords: Key words Cristobalite ; Tridymite ; Phase transformation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Abstract Using minimum exposure techniques, it is feasible to perform high resolution electron microscopy on the α-cristobalite phase of (Si0.9 Ge0.1)O2, which is extremely radiation sensitive. Such images reveal atomic scale information of twins and tridymite-like stacking faults on (1 1 1)β planes, as well as of domain boundaries resulting from the β→α transition. Polytype structures are formed in certain cases. Morphological features suggest that the phase transformation cristobalite → tridymite proceeds by means of a zonal dislocation mediated synchro-shear process on (1 1 1)β planes; the geometry of this process is analyzed.
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    URL: http://dx.doi.org/10.1007/s002699900082
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    The need for a shared database infrastructure: combining X-ray crystallography and electron microscopy (2000)
    Springer
    European biophysics journal 29 (2000), S. 457-462 
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    ISSN: 1432-1017
    Keywords: Key words X-ray crystallography ; Electron microscopy ; Biological databases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract Advances in structural biology are opening greater opportunities for understanding biological structures from the cellular to the atomic level. Particularly promising are the links that can be established between the information provided by electron microscopy and the atomic structures derived from X-ray crystallography and nuclear magnetic resonance spectroscopy. Combining such different kinds of structural data can result in novel biological information on the interaction of biomolecules in large supramolecular assemblies. As a consequence, the need to develop new databases in the field of structural biology that allow for an integrated access to data from all the experimental techniques is becoming critical. Pilot studies performed in recent years have already established a solid background as far as the basic information that an integrated macromolecular structure database should contain, as well as the basic principles for integration. These efforts started in the context of the BioImage project, and resulted in a first complete database prototype that provided a versatile platform for the linking of atomic models or X-ray diffraction data with electron microscopy information. Analysis of the requirements needed to combine data at different levels of resolution have resulted in sets of specifications that make possible the integration of all these different types in the context of a web environment. The case of a structural study linking electron microscopy and X-ray data, which is already contained within the BioImage data base and in the Protein Data Bank, is used here to illustrate the current approach, while a general discussion highlights the urgent need for integrated databases.
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    Variable planar particle arrangements in the photosynthetic membrane of Rhodopseudomonas viridis (1981)
    Springer
    European biophysics journal 7 (1981), S. 209-212 
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    ISSN: 1432-1017
    Keywords: Photosynthetic bacteria ; Electron microscopy ; Planar lattices
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract The thylakoids of Rhodopseudomonas viridis have been studied by freeze-fracturing whole cells. Depending on growth conditions and treatment before freezing, three different types of particle arrangements in the photosynthetic membrane are reported: a random arrangement, an isometric (quadratic) lattice arrangement with a lattice constant of 12.5 ± 0.8 nm, and a hexagonal lattice arrangement with a lattice constant of 12.5 ± 0.8 nm.
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    Physical map of the mitochondrial DNA from the phycomycete Allomyces macrogynus including the position of the ribosomal RNA genes and of an intervening sequence in the large rRNA gene (1983)
    Springer
    Current genetics 7 (1983), S. 327-333 
    Details
    ISSN: 1432-0983
    Keywords: Allomyces macrogynus ; Mitochondrial DNA ; Electron microscopy ; Restriction enzyme map
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The mitochondrial (mt) DNA of the aquatic phycomycete Allomyces macrogynus is a circular molecule with a size of 56.1 kbp. The cleavage sites for the restriction enzymes SalI and PvuI were mapped by comparing the partial denaturation patterns of isolated restriction fragments with the pattern of the intact circle. The genes coding for the small and large ribosomal RNA (rRNA) were located on the restriction map by heteroduplex and R-loop analysis. The gene coding for the large rRNA contains an intervening sequence, app. 0.7 kbp in size, near the 3′-end of the gene. The two rRNA genes are encoded on the same strand of the mtDNA and separated by a region of 17–18 kbp. This rRNA gene organization is similar to that found with members of the Ascomycetes.
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    The ultrastructure of cell wall formation and of gamma particles during encystment of Allomyces macrogynus zoospores (1980)
    Springer
    Archives of microbiology 128 (1980), S. 179-189 
    Details
    ISSN: 1432-072X
    Keywords: Allomyces ; Zoospores ; Cell wall ; Chitin ; Gamma particle ; Encystment ; Electron microscopy ; Calcofluor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Structural changes during cell wall formation by populations of semisynchronously germinating zoospores were studied in the water mold Allomyces macrogynus. Fluorescence microscopy using Calcofluor white ST (which binds to β-1,4-linked glycans) demonstrated that Calcofluor-specific material was deposited around most cells between 2–10 min after the induction of encystment (beginning when a wall-less zoospore retracts its flagellum and rounds up). During the first 15 min of encystment there was a progressive increase in fluorescence intensity. Ultrastructural analysis of encysting cells showed that within 2–10 min after the induction of encystment small vesicles 35–70 nm diameter were present near the spore surface, and some were in the process of fusing with the plasma membrane. The fusion of vesicles with the zoospore membrane was concomitant with the appearance of electron-opaque fibrillar material outside the plasma membrane. Vesicles similar to those near the spore surface were found within the gamma (γ) particles of encysting cells. These particles had a crystalline inclusion within the electron-opaque matrix. During the period of initial cyst cell wall formation numerous vesicles appeared to arise at the crystal-matrix interface. Approximately 15–20 min was required for the cell wall to be formed. We suggest that the initial response of the zoospore to induction of encystment is the formation of a cell wall mediated by the fusion of cytoplasmic vesicles with the plasma membrane.
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    Freeze fracture studies of reaction centers from Rhodospirillum rubrum in chromatophores and liposomes (1981)
    Springer
    Archives of microbiology 130 (1981), S. 125-128 
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    ISSN: 1432-072X
    Keywords: Rhodospirillum rubrum ; Chromatophores ; Reaction centers ; Liposomes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In freeze-fractures of chromatophores of Rhodospirillum rubrum the reaction centers are seen as hexagonal arranged particles of 13 nm diameter with a density of around 5,500 particles per μm2. Similar regions on the cytoplasmic membrane suggest that these parts are the prospective invagination sites. Isolated reaction centers are easily incorporated into liposomes. In freeze fractures of liposomes particles similar in shape and size, although less dense as in chromatophores are observed. In negative staining much smaller units of only 5 nm in diameter are found indicating that reaction centers occur in the membrane as tri- or tetramers. There is a strong correlation between particle density in chromatophores and titratable reaction centers remaining in these membranes after extraction of reaction centers by detergents; both values are in good agreement with the yield of reaction centers at a given detergent concentration.
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    Evidence for supercoiling in the DNA of bacteriophage heads (1980)
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    Archives of microbiology 126 (1980), S. 277-283 
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    ISSN: 1432-072X
    Keywords: Bacteriophage ; Myxococcus ; λ ; Superooiled DNA ; Cross-linking ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract DNA was partially released from the heads of myxococcus phages and also coliphage λ and examined by electron microscopy by a modification of the Kleinschmidt technique, in which water was used as hypophase. DNA emerged from the heads in patterns suggestive of newly relaxed supercoils. The unreleased DNA appeared to occupy discrete regions in the head. Some closed circles were released from λ heads. When NaCl solution was used as hypophase, the DNA was observed either released from the tail or from the head, in the latter case, supercoiled regions were observed. When NH4OAc solution was used as hypophase, tightly wound structures were released from λ heads; these fields also contained supercoiled circles. The presence of constrained supercoiled domains in newly released phage DNA was confirmed by observing the effects of ethidium bromide on its conformation. Treatment of phage with nitrogen mustard, a bifunctional alkylating agent, preserved supercoiled domains, even when the phage were lysed over water as hypophase. Further experiments suggested that phage inactivation by nitrogen mustard is largely due to restraint of the supercoiled, native, tertiary structure and that DNA-protein cross-linking may be involved in this reaction. The implications of these findings for the conformation of phage DNA in vivo are discussed and a new model for the winding of DNA in phage heads is proposed.
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    Relative numbers of selected bacterial forms in different regions of the cockroach hindgut (1981)
    Springer
    Archives of microbiology 129 (1981), S. 129-134 
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    ISSN: 1432-072X
    Keywords: Cockroach ; Hindgut ; Distribution ; Microbial morphotypes ; Transmission ; Electron microscopy ; Statistical analysis ; Eublaberus posticus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The relative numbers of fourteen microbial morphotypes in transmission electron micrographs of the hindgut of a cockroach, Eublaberus posticus, were counted and their distribution was analyzed statistically. The microbiota of three wall-associated regions (the anterior paunch, the posterior paunch, and the black band region) was clearly different from that of the gut lumen. The three wall fractions were also significantly different from each other. Only one of the fourteen types, prosthecate bacteria, appeared to be distributed randomly in the four fractions. The five main wall-associated morphotypes individually constituted up to 41% of the microbes in some micrographs. They included one type with the characteristic morphology of Methanospirillum. Six morphotypes rarely made up over 2% of the population, but were consistently present. The numbers of the remaining three morphotypes were quite variable between micrographs and between individual insects, but when present often made up 5–10% of the population.
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    Entrapment and lysis of the cyanobacterium Phormidium luridum by aqueous colonies of Myxococcus xanthus PCO2 (1981)
    Springer
    Archives of microbiology 129 (1981), S. 285-294 
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    ISSN: 1432-072X
    Keywords: Biological control ; Cyanobacteria ; Electron microscopy ; Entrapment ; lysis ; Myxococcus ; Phormidium ; Spherule
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A Myxococcus xanthus isolate from a farm drainage ditch, designated strain PCO2, is capable of rapidly inducing lysis of both agar and liquid-grown cultures of the cyanobacterium, Phormidium luridum, var. olivacea. Microscopic studies of the predator-prey interaction demonstrate that lysis of the cyanobacterium occurs within clumps and spherules formed by the cells of M. xanthus PCO2. In the earliest stage, one sees the formation of irregular microclumps of bacteria and cyanobacterial filaments. As these clumps mature, colonies 1 to 6 mm in diameter develops. The center of these densely green colonies contains cyanohacteria in various stages of degradation, while the periphery is almost exclusively a tightly woven mass of myxobacterial cells. Electron microscopy shows that long extrusions from the outer membrane of the M. xanthus PCO2 cells are involved in the formation both of initial clumps and of mature colonial spherules. These extrusions appear to efficiently entangle the cyanobacterial filaments in the culture environment. Predator-to-prey ratios of 1/10, 1/100 and 1/1,000 have resulted in cyanobacterial lysis. Because the entrapment and lysis of P. luridum filaments by M. xanthus PCO2 appears to be independent of any other heterotrophic nutritional requirement, as well as of environmental agitation, this system has potential as a biological control technique for undesirable aquatic cyanobacteria.
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    Site of action of the natural algicide, cyanobacterin, in the blue-green alga, Synechococcus sp. (1984)
    Springer
    Archives of microbiology 138 (1984), S. 273-277 
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    ISSN: 1432-072X
    Keywords: Cyanobacteria ; Secondary metabolite ; Allelopathy ; Photosynthesis ; Electron transport ; Thylakoids ; Herbicides ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cyanobacterin is a secondary metabolite produced by the cyanobacterium, Scytonema hofmanni. Highly purified cyanobacterin was found to inhibit the growth of many cyanobacteria at a minimum effective dose of 2 μg/ml (4.6 μM). The antibiotic had no effect on eubacteria including the photosynthetic Rhodospirillum rubrum. The site of action of cyanobacterin was further investigated in the unicellular cyanobacterium, Synechococcus sp. Electron micrographs of antibiotic-treated Synechococcus cells indicated that cyanobacterin affects thylakoid membrane structure. The antibiotic also inhibited light-dependent oxygen evolution in Synechococcus cells and in spheroplasts. These data support our conclusion that cyanobacterin specifically inhibits photosynthetic electron transport. This activity is similar to herbicides such as 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (DCMU). The anhydro analog of cyanobacterin had no biological activity.
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    Electron microscopy and X-ray microanalysis of a halophilic leptospire (1981)
    Springer
    Archives of microbiology 130 (1981), S. 339-343 
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    ISSN: 1432-072X
    Keywords: Leptospira ; Halophilic ; Electron microscopy ; X-ray analysis ; Inclusions ; Cytoplasmic tubules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The morphology of cells of strain Muggia, a slightly halophilic leptospire, was examined by the negative staining technique. The ultrastructure of the cells was rather similar to that of cells of Leptonema illini, i. e. the cells possessed cytoplasmic tubules. The basal complex of their flagella, however, was similar to the corresponding part of flagella on Gramnegative bacteria. The interior of the cells was densely packed with inclusions, except for the two outermost wavelengths at each end where these inclusions were absent. X-ray microanalysis showed that the inclusions contained sodium and chlorine as their main constituents. The inclusions disappeared upon storage of the cultures at room temperature.
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    Comparative studies onChlorella cell walls: Induction of protoplast formation (1982)
    Springer
    Archives of microbiology 132 (1982), S. 10-13 
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    ISSN: 1432-072X
    Keywords: Calcofluor White ; Cell wall structure ; Chlorella ; Electron microscopy ; Protoplast ; Ruthenium Red
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Among 12 strains ofChlorella ellipsoidea, C. vulgaris, andC. saccharophila tested, 4 strains (1,C. ellpsoidea; 2,C. vulgaris; 1,C. saccharophila) formed osmotically labile protoplasts after treatment with mixtures of polysaccharide degrading enzymes. The relationship between enzymatical digestibility and structure or composition ofChlorella cell walls were studied by electron microscopy and staining techniques with some specific dyes. The cell wall structures of the 12Chlorella strains were grouped into three types: (1) with a trilaminar outer layer, (2) with a thin outer monolayer, and (3) without an outer layer. Protoplasts were formed only from the strains with a cell wall of Type 2. In the strains with a cell wall of Type 1, the outer layer protected the inner major microfibrillar layer against enzymatic digestion. The cell wall of Type 3 was totally resistant to the enzymes; the chemical composition of the cell wall would be somewhat different from that of other types.
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    Electron microscopy of photosynthetic membranes containing bacteriochlorophyll b (1983)
    Springer
    Archives of microbiology 135 (1983), S. 169-175 
    Details
    ISSN: 1432-072X
    Keywords: Photosynthetic membranes ; Electron microscopy ; Image processing ; Ectothiorhodospira halochloris ; Ectothiorhodospira abdelmalekii ; Rhodopseudomonas viridis ; Rhodopseudomonas sulfoviridis ; Thiocapsa pfennigii
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The photosynthetic membranes of the five bchl b-containing bacteria Ectothiorhodospira halochloris, E. abdelmalekii, Rhodopseudomonas viridis, R. sulfoviridis and Thiocapsa pfennigii have been investigated by electron microscopy and digital image analysis. All five species have the photosynthetic complexes hexagonally arrayed in the membrane with lattice spacings close to 13 nm, except for R. sulfoviridis and T. pfennigii which display somewhat smaller (∼12.5 nm) lattice spacings. Correlation averaging which imposes less stringent requirements on the lattice perfection than conventional Fourier filtration techniques has been employed to elucidate the structure of the photosynthetic complexes. Their basic organization, i.e. a ring, probably containing the light-harvesting (LH) polypeptides, surrounding a core (the “reaction centre”) appears to be almost identical for all species under scrutiny. Despite a resolution of ∼1.6 nm, however, little further significant substructure can be deduced from the averages; possible reasons for the “blurred” appearance of the LH-ring and absence of any subdivision in the reaction centre are discussed along with strategies aimed at obtaining a more detailed model of the molecular architecture of the photosynthetic membranes.
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    Immunoferritin labeling of respiratory nitrate reductase in membrane vesicles of Bacillus licheniformis and Klebsiella aerogenes (1980)
    Springer
    Archives of microbiology 127 (1980), S. 39-46 
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    ISSN: 1432-072X
    Keywords: Immunoferritin labeling ; Electron microscopy ; Membrane vesicles ; Nitrate reductase ; Bacillus licheniformis ; Klebsiella aerogenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The indirect immunoferritin labeling method was used to localize the membrane-bound respiratory nitrate reductase in membrane vesicles and protoplasts or spheroplasts of Bacillus licheniformis and Klebsiella aerogenes, respectively. For a comparison of the labeling of the various vesicle preparations, which differed not only in size but also in the percentage of inside-out orientation, a quantification of the results was needed to circumvent the problem of non-specifically bound ferritin. From the results the sidedness of the nitrate reductase in the cytoplasmic membrane of the abovementioned bacteria was determined as being cytoplasmic in B. licheniformis and as transmembranous in K. aerogenes.
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    Chemical composition and ultrastructure of cellular and extracellular Moraxella glucidolytica lipopolysaccharides (1980)
    Springer
    Archives of microbiology 128 (1980), S. 12-18 
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    ISSN: 1432-072X
    Keywords: Moraxella glucidolytica ; Electron microscopy ; Lipopolysaccharide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A cellular (LPS I) and extracellular (LPS II) lipopolysaccharide were isolated from Moraxella glucidolytica cells grown on ethanol and from the culture fluid, respectively. Both LPS were toxic when injected to mice and chick embryos. These LPS contained glucose, galactose, glucosamine, galactosamine, 2-keto-3-deoxyoctonate and lipids. By permethylation studies, glucose was found to be linked (1→6) and (1→3) in LPS I and only (1→6) in LPS II. Galactose was the terminal non-reducing sugar. Branching occurred at positions 3 and 4 of galactose residues. LPS I was rich in α- and β-hydroxylauric and α-hydroxymyristic acids and LPS II contained mainly stearic and α-hydroxymyristic acids. LPS I was detoxified by mild acid and alkaline treatments. It was also dissociated by sodium deoxycholate and chromatographed on Sephadex G-75. The main fraction was reassociated by removing the surfactant by dialysis. The morphology of LPS I and LPS II was examined by electron microscopy. LPS I (original and reassociated fractions) consisted exclusively of ribbons while LPS II contained ribbons and vesicles.
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    Molecular weight and quaternary structure of ribulose bisphosphate carboxylase from the cyanobacterium, Synechococcus sp. (1981)
    Springer
    Archives of microbiology 130 (1981), S. 344-348 
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    ISSN: 1432-072X
    Keywords: Ribulose bisphosphate carboxylase ; Quaternary structure ; Molecular weight ; Electron microscopy ; Cyanobacteria ; Synechococcus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ribulose bisphosphate (RuP2) carboxylase from the marme cyanobacterium, Synechococcus sp., comprised both large (57,000 dalton) and small (12,000 dalton) subunits. The undissociated, purified enzyme was considerably smaller than the spinach enzyme when compared by pore-gradient electrophoresis, gel filtration and density-gradient centrifugation. This suggested that the cyanobacterial enzyme might have a hexameric (L6S6) subunit structure, unlike the enzymes from spinach and many other organisms which are octamers (L8S8). However, the molecular weight of the Synechococcus enzyme was measured by equilibrium sedimentation and found to be 530,000, which is within the range observed for L8S8-type enzymes. Furthermore, electron microscopic studies of negatively stained preparations of both the native enzyme, and a preparation depleted of 87% of its small subunits by repeated mild-acid precipitation, revealed four-fold symmetry characteristic of an octameric, cubical structure. Synechococcus RuP2 carboxylase therefore must be an L8S8 octamer and its anomalous pore-penetration behaviour may be due to an asymmetric shape. Some support for the latter possibility was provided by electron miscoscopic observations of two different types of images which may be different views of the molecule in two planes.
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    Structural analysis of EcoRI-DNA complexes as revealed by electron microscopy (1984)
    Springer
    Archives of microbiology 140 (1984), S. 265-270 
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    ISSN: 1432-072X
    Keywords: EcoRI ; EcoRI-DNA complexes ; EcoRI* activity ; Recognition sites ; Frequency of binding ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Electron microscopy of negatively stained isolated restriction enzyme EcoRI revealed particle projections with triangular or square outlines, indicating that the enzyme, in its tetrameric state, is tetrahedron-like. The two dimers making up the tetramer appear to be arranged in two planes orthogonal to each other. Complexes formed by EcoRI with the plasmids pBR322 or pGW10 were investigated by electron microscopic spreading techniques. In the presence of Mg2+, EcoRI was bound to the DNA molecules to form pearl necklace-like aggregates. The number of bound EcoRI particles was much higher as the sum of EcoRI-and 5′..AATT..3′ sites (with exceptions, the 5′..AATT..3′ sites may function as one type of EcoRI* sites) along the DNAs, indicating unspecific binding. In the absence of Mg2+, EcoRI was bound to the DNA only at the recognition site for EcoRI and the sites where the tetranucleotide sequence 5′..AATT..3′ was present. A direct correlation of the local concentrations of the bases A and T within the flanking sequences of the binding sites with the frequency of EcoRI to the DNA was observed. Dimers and tetramers of the enzyme was found to bind to the DNA. Tetramers occasionally exhibited two binding sites for DNA as indicated by the observation of DNA loops originating at the sites of bound tetrameric EcoRI particles.
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    Ultrastructure of Ascodichaena rugosa on beech bark (1980)
    Springer
    Archives of microbiology 126 (1980), S. 87-95 
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    ISSN: 1432-072X
    Keywords: Ascodichaena ; Beech bark ; Electron microscopy ; Host-fungus relationship
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ascodichaena rugosa Butin is a corkinhabiting fungus, found frequently on the bark of Fagus sylvatica L. The hyphae of the fungus are distributed solely in the phellem cells, stopping their growth in the last-formed cork cell layer. The cell to cell invasion is effected by penetration hyphae, causing no extensive dissolution of the cork wall. Electron microscopical observations revealed fine structural details of the fruit bodies and of the intracellular hyphae. Of special interest were the finger-like hyaline hyphae in the last-formed layer of cork cells, which are interpreted as haustoria on the basis of the fine structure both of hyphae and host cells. This situation is considered as reflecting a parasitic relationship of Ascodichaena to beech bark. The activity of the fungus led also to the increased production of cork cells, perhaps related to the nutrient supply of the fungus.
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    Thylakoid centers: Structures associated with the cyanobacterial photosynthetic membrane system (1982)
    Springer
    Archives of microbiology 133 (1982), S. 97-99 
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    ISSN: 1432-072X
    Keywords: Cyanobacteria ; Thylakoid centers ; Photosynthetic membranes/thylakoids ; Membranes ; Membrane biogenesis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An ultrastructural study of four cyanobacteria (Anabaena cylindrica, Dermocarpa violaceae, Gleocapsa alpicola, Pleurocapsa minor) indicates the presence of previously undescribed thylakoid centers from which photosynthetic membranes (thylakoids) radiate. These peripherally located thylakoid centers are cylinders 30 nm wide by 320 nm long, consisting of globular subunits oriented in nonparallel stacked arrays. Thylakoids are attached to the outer surface of the cylinder along its longitudinal axis. Thylakoid centers appear to be functionally significant due to their structure, location and thylakoid association.
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    Phototaxis in the gliding flagellate, Euglena mutabilis (1983)
    Springer
    Archives of microbiology 135 (1983), S. 25-29 
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    ISSN: 1432-072X
    Keywords: Electron microscopy ; Euglena mutabilis ; Flagellate ; Photomovement ; Photoreceptor ; Phototaxis ; Single-cell analysis ; Videomicroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Due to the lack of an emergent flagellum the green flagellate Euglena mutabilis is restricted to gliding motility. During forward movement, the organisms orient positive phototactically in the presence of a suitable light stimulus. The cell contains both a stigma and a paraflagellar body which differ in shape and size from the organelles found in E. gracilis. The degree of orientation in white light follows an optimum curve with a maximum at about 100 lx. The spectral sensitivity shows a number of prominent peaks in the blue and green regions and extends well into the red region of the visible spectrum. Since the cell does not rotate during locomotion a periodic shading mechanism cannot account for phototactic orientation. Thus, phototaxis in the related species, E. gracilis and E. mutabilis differ in their photoreceptor molecules, their sensory transduction chains and their strategies of light direction detection.
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    Cell wall degradation ofStaphylococcus aureus by lysozyme (1982)
    Springer
    Archives of microbiology 131 (1982), S. 116-123 
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    ISSN: 1432-072X
    Keywords: Cell wall ; Wall degradation ; Lysozyme ; Autolysines ; Electron microscopy ; Staphylococcus aureus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In contrast to former findings lysozyme was able to attack the cell walls ofStaphylococcus aureus under acid conditions. However, experiments with14C-labelled cell walls and ribonuclease indicated that, under these conditions, lysozyme acted less as an muralytic enzyme but more as an activator of pre-existing autolytic wall enzymes. Electron microscopic studies showed that under these acid conditions the cell walls were degraded by a new mechanism (i.e. “attack from the inside”). This attack on the cell wall started asymmetrically within the region of the cross wall and induced the formation of periodically arranged lytic sites between the cytoplasmic membrane and the cell wall proper. Subsequently, a gap between the cell wall and the cytoplasmic membrane resulted and large cell wall segments became detached and suspended in the medium. The sequence of lytic events corresponded to processes known to take place during wall regeneration and wall formation. In the final stage of lysozyme action at pH 5 no cell debris but “stabilized protoplasts” were to be seen without detectable alterations of the primary shape of the cells. At the same time long extended ribbon-like structures appeared outside the bacteria. The origin as well as the chemical nature of this material is discussed. Furthermore, immunological implications are considered.
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    Role of glandular scales of lepidote rhododendrons in insect resistance (1984)
    Springer
    Journal of chemical ecology 10 (1984), S. 1787-1798 
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    ISSN: 1573-1561
    Keywords: Coleoptera ; Curculionidae ; Otiorhynchus sulcatus (F.) ; black vine weevil ; Ericaceae ; Rhododendron ; trichomes ; glandular scales ; essential oils ; volatiles ; plant resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Glandular scales on selected lepidote rhododendron species varied in density from 109 ± 13 to 4180 ± 60/cm2 of leaf surface. Globules contained within the scales stained with Sudan IV, a lipophilic dye. Essential oil contents of the scales varied with species from 24 ± 8 to 151 ± 35 ng/scale. Black vine weevil [(Otiorhynchus sulcatus (F.)] feeding on leaves from a sample of rhododendron species was inversely related to leaf essential oil content, and weevil feeding on membrane filters was inhibited by application of essential oil extracts from leaves of most lepidote rhododendrons tested. Results suggest that the glandular scales of the lepidote rhododendrons function, at least in part, in plant defense against insects.
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    Attraction of bark beetles (Coleoptera: Scolytidae) to a pheromone trap (1984)
    Springer
    Journal of chemical ecology 10 (1984), S. 723-752 
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    ISSN: 1573-1561
    Keywords: Ips typographus ; pheromone ; release ; recapture ; diffusion ; model ; Coleoptera ; Scolytidae ; trap ; marking ; dispersal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The movement of bark beetles near an attractive pheromone source is described in terms of mathematical models of the diffusion type. To test the models, two release experiments involving 47,000 marked spruce bark beetles [Ips typographus (L.)] were performed. The attractive source was a pheromone trap, surrounded by eight concentric rings with eight passive trap stations on each ring. Captures were recorded every 2–10 minutes for the pheromone trap and once for the passive traps. The models were fitted to the distribution in time of the central pheromone trap catch and to the spatial distribution of catch among the passive traps. The first model that gives a reasonable fit consists of two phases: Phase one—After release the beetles move according to a diffusion process with drift towards the pheromone trap. The strength of the drift is inversely proportional to the distance from the traps. Phase two—those beetles attracted to, but not caught by, the pheromone trap are no longer influenced by the pheromone, and their movement is described by a diffusion process without drift. In phase two we work with a loss of beetles, whereas the experiment seems to indicate that the loss of beetles in phase one is negligible. As a second model, the following modification of phase one is considered: After release the beetles move according to a diffusion process without drift, until they start responding to the pheromone (with constant probability per unit time), whereafter they start moving according to a diffusion process with drift. This study, like other release experiments, shows that the efficiency of the pheromone trap is rather low. What is specific for the present investigation is that we try to explain this low efficiency in terms of dynamic models for insect movement. Two factors seem to contribute: Some beetles do not respond to pheromone at all, and some beetles disappear again after having been close to the pheromone trap. It also seems that the motility of the beetles decreased after they ceased responding to the pheromone. Furthermore, the data lend some support to the hypothesis that flight exercise increases the response of the beetles to pheromone.
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    Receptor cells inIps typographus andDendroctonus micans specific to pheromones of the reciprocal genus (1984)
    Springer
    Journal of chemical ecology 10 (1984), S. 759-769 
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    ISSN: 1573-1561
    Keywords: Ips typographus ; Dendroctonus micans ; Coleoptera ; Scolytidae ; exo-brevicomin ; (+)-ipsdienol ; single-cell recordings ; interspecific attraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Olfactory receptor cells were studied electrophysiologically inIps typographus andDendroctonus micans. The investigation revealed cells which were keyed to pheromone compounds characteristic of the reciprocal genus. Thus, cells keyed toexo-brevicomin were found inI. typographus, whereas cells keyed to (+)-ipsdienol were present inD. micans. Laboratory behavioral tests indicated an attractive effect of the two compounds on beetles of the reciprocal genus. InI. typographus the effect ofexo-brevicomin predominantly concerned males and enhanced their response to the pheromone “ipslure.” It is suggested thatexo-brevicomin serves as an interspecific attractant forI. typographus, which may be guided by pheromone compounds of the reciprocal genus in finding suitable breeding material. The function of (+)-ipsdienol inD. micans is more uncertain. It may be either a pheromone or an interspecific messenger.
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    Olfaction in the boll weevil,Anthonomus grandis Boh. (Coleoptera: Curculionidae): Electroantennogram studies (1984)
    Springer
    Journal of chemical ecology 10 (1984), S. 1759-1785 
    Details
    ISSN: 1573-1561
    Keywords: Cotton boll weevil ; Anthonomus grandis ; Coleoptera ; Curculionidae ; pheromone ; kairomone ; plant odor ; olfaction ; electroantennogram ; attractant ; host plant ; green leaf volatiles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Electroantennogram (EAG) techniques were utilized to measure the antennal olfactory responsiveness of adult boll weevils,Anthonomus grandis Boh. (Coleoptera: Curculionidae), to 38 odorants, including both insect and host plant (Gossypium hirsutum L.) volatiles. EAGs of both sexes were indicative of at least two receptor populations: one receptor population primarily responsive to pheromone components and related compounds, the other receptor population primarily responsive to plant odors. Similar responses to male aggregation pheromone components (i.e., compounds I, II, and III + IV) were obtained from both sexes, but females were slightly more sensitive to I. Both sexes were highly responsive to components of the “green leaf volatile complex,” especially the six-carbon saturated and monounsaturated primary alcohols. Heptanal was the most active aldehyde tested. More acceptors responded to oxygenated monoterpenes than to monoterpene hydrocarbons. β-Bisabolol, the major volatile of cotton, was the most active sesquiterpene. In general, males, which are responsible for host selection and pheromone production, were more sensitive to plant odors than were females. In fact, males were as sensitive to β-bisabolol and heptanal as to aggregation pheromone components. Electrophysiological data are discussed with regard to the role of insect and host plant volatiles in host selection and aggregation behavior of the boll weevil.
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    Quantitative variation of pheromone components in the spruce bark beetleIps typographus from different attack phases (1984)
    Springer
    Journal of chemical ecology 10 (1984), S. 1029-1055 
    Details
    ISSN: 1573-1561
    Keywords: Ips typographus ; spruce bark beetle ; Coleoptera ; Scolytidae ; 2-methyl-3-buten-2-ol ; ipsenol ; cis-verbenol ; ipsdienol ; trans-verbenol ; verbenone ; myrtenol ; trans-myrtanol ; 2-phenylethanol ; ß-isophorone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Ips typographus beetles were collected in the field, separated into eight attack phases (from beetles walking on the trunk of a tree under attack to those excavating gallery systems with a mother gallery longer than 4 cm), and immediately frozen in liquid nitrogen. 2-Methyl-3-buten-2-ol,cis- andtrans-verbenol, verbenone, myrtenol, trans-myrtanol, ipsenol, ipsdienol, and 2-phenylethanol were quantified from excised hindguts against an internal standard, heptyl acetate, in the extraction solvent. Methylbutenol, the pinene alcohols, and 2-phenylethanol showed the same pattern of variation between attack phases in males, with the largest amounts present before accepting females and then a fast decline. Ipsenol and ipsdienol were not detected in males before the females were accepted, and the amounts increased when the females start their egg laying. Verbenone occurred only in trace amounts. The beetles were sampled from five Norway spruce trees (Picea abies) of differing resin flow. The correlations between the nine pheromone components and five major host monoterpenes in the gut showed that the variation in the amount of methyl-butenol, ipsenol, and ipsdienol could not be explained by the variation in the amounts of host monoterpenes. In contrast over 80% of the quantitative variation ofcis-verbenol,trans-verbenol, and myrtenol was explained by the amount of α-pinene. The nine pheromone components from 36 individual males were also quantified. Both methylbutenol andcis-verbenol showed a large variation in both amounts and proportions. Females containedtrans-verbenol and traces of most other components found in males. When accepted by the male, they also contained a female-specific compound, β-isophorone. Behavioral and biosynthetic implications of the results are discussed.
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    Multifunctionality of douglas-fir beetle pheromone 3,2-mch confirmed with solvent dibutyl phthalate (1980)
    Springer
    Journal of chemical ecology 6 (1980), S. 193-201 
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    ISSN: 1573-1561
    Keywords: Coleoptera ; Scolytidae ; Dendroctonus pseudotsugae ; pheromone ; multifunctionality ; 3-methylcyclohex-2-en-l-one ; diluent ; dibutyl phthalate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Previous field and laboratory tests withDendroctonus pseudotsugae showing increased attractancy and chirp evocation by very low concentrations of the pheromone 3-methylcyclohex-2-en-1-one (3,2-MCH) dissolved in ethanol with known attractants were repeated with a different diluent, dibutyl phthalate (DBP). Other workers had speculated that the solvent ethanol was actually the synergist. Beetle response was essentially identical with both solvents, confirming the concentration-dependent multifunctionality of 3,2-MCH in Douglas-fir beetle behavior. Contradictions in available data with ethanol indicate unanswered questions about its effect withDendroctonus attractants.
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    Enantiomer-based specificity in pheromone communication by two sympatricGnathoirichus species (Coleoptera: Scolytidae) (1980)
    Springer
    Journal of chemical ecology 6 (1980), S. 445-456 
    Details
    ISSN: 1573-1561
    Keywords: Gnathotrichus retusus ; G. sulcatus ; Coleoptera ; Scolytidae ; ambrosia beetle ; aggregation pheromone ; 6-methyl-5-hepten-2-ol ; sulcatol ; reproductive isolation ; enantiomers ; chiral compounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The aggregation pheromone ofGnathotrichus retusus was isolated and identified as (S)-(+)-sulcatol (6-methyl-5-hepten-2-ol). In laboratory and field experiments,G. retusus responded to (S)-(+)-sulcatol, but not to (±)-sulcatol, which was attractive to the sympatric species,G. sulcatus. G. sulcatus did not respond to optically pure (S)-(+)-sulcatol, but began to respond when ⩾ 1% (R)-(−)-sulcatol was present in an enantiomeric mixture.
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    Estimating western pine beetle-caused tree mortality for evaluating an attractive pheromone treatment (1980)
    Springer
    Journal of chemical ecology 6 (1980), S. 853-866 
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    ISSN: 1573-1561
    Keywords: Ponderosa pine mortality ; Dendroctonus brevicomis ; Coleoptera ; Scolytidae ; aerial photography ; detection ; estimation ; sampling ; mapping ; attractive pheromones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Sequential aerial photography was used to detect ponderosa pine trees killed by successive generations of the western pine beetle (WPB),Dendroctonus brevicomis Lec., over a three-year period during a study to evaluate the effectiveness of attractive pheromones for the suppression and survey of WPB. The total number of WPB-killed trees were estimated for each generation, using probability-proportional-to-size sampling procedures. Infested trees at the beginning of the suppression treatment totaled 283. Attacks by three successive WPB generations in 1970 killed 90,83, and 91 trees, respectively. The first generation in 1971 killed 47 trees and the two subsequent generations combined killed a total of 49 trees. During the suppression treatment, tree mortality was concentrated into the suppression plots in comparison to the check plots and the surrounding area. By 1972, tree mortality distribution returned to its original pattern, but at one-tenth the original level, as shown by maps. Recommendations suggest ways to improve the use of aerial photography for studies of WPB-caused tree mortality and population dynamics.
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    Insect feeding and oviposition deterrents from western red cedar foliage (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 39-48 
    Details
    ISSN: 1573-1561
    Keywords: Insect feeding deterrents ; antifeedants ; Pissodes strobi Peck ; Coleoptera ; Curculionidae ; Thuja plicata Donn
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The feeding deterrent activity of fractions from the foliage of western red cedar,Thujaplicata Donn, was studied in laboratory bioassays using the white pine weevil,Pissodes strobi Peck, as a test insect. The most active fraction was the volatile mixture that comprises the leaf oil of this tree species. Further fractionation of the leaf oil indicated feeding deterrent activity in the monoterpene hydrocarbon, thujone, and terpene alcohol fractions. When tested alone, both (−)-3-isothujone and (+)-3-thujone, which made up 75–88% and 5–10% of the leaf oil, respectively, deterred feeding by the weevils. Western red cedar leaf oil also showed antifeedant activity with the alder flea beetle,Altica ambiens (Le Conte), and served as an oviposition deterrent for the onion root maggot,Hylemya antiqua Meigen. The leaf oil, however, had no inhibitory effect on the feeding of the leaf roller,Epinotia solandriana L., and the red-backed sawfly,Eriocampa ovata L.
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    Chemically Mediated Predator-free Space: Herbivores Can Synergize Intraspecific Communication Without Increasing Risk of Predation (2000)
    Springer
    Journal of chemical ecology 26 (2000), S. 1923-1939 
    Details
    ISSN: 1573-1561
    Keywords: Ips pini ; ipsdienol ; lanierone ; Thanasimus dubius ; Platysoma ; Enoclerus nigrifrons ; kairomone ; aggregation pheromone ; synergism ; Coleoptera ; Scolytidae ; Cleridae ; coevolution ; pest management
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Natural enemies of herbivores often locate cryptic insects by responding to volatiles associated with the prey's feeding and mating. For example, predators of bark beetles (Coleoptera: Scolytidae) exploit the aggregation pheromones that their prey use to attract mates and secure hosts. Bark beetles are cryptic insects that feed and develop in the subcortical tissues of trees and spend all but a portion of their life history within this habitat. The pine engraver, Ips pini, produces the pheromone ipsdienol throughout its transcontinental range. Predators of I. pini exploit this chemical as a kairomonal cue. Eastern and Midwestern I. pini populations also produce lanierone, which synergizes their attraction to ipsdienol. We evaluated the effects of varying amounts of lanierone, in combination with a constant amount of racemic ipsdienol, on the relative attraction of I. pini and its major predators in Wisconsin. Higher numbers of I. pini were captured with increasing release rates of lanierone. In contrast, the numbers of the major predators, such as Thanasimus dubius, Enoclerus nigrifrons, Platysoma cylindrica, and P. parallelum, did not differ among different lanierone release rates. The response of I. pini but not their predators to lanierone at ecologically realistic release rates may be part of a coevolving interaction between predators and prey and offers new strategies for semiochemically based pest management by selectively removing pests and leaving predators.
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    URL: http://dx.doi.org/10.1023/A:1005505009408
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    Electroantennogram responses ofScolytus multistriatus (Coleoptera: Scolytidae) to its pheromone components and to associated compounds (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 1333-1344 
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    ISSN: 1573-1561
    Keywords: Coleoptera ; Scolytidae ; Scolytus multistriatus ; pheromone ; insect olfaction ; electroantennogram ; electrophysiology ; differential adaptation ; multistriatin ; 4-methyl-3-heptanol ; α-cubebene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Electroantennograms were recorded fromScolytus multistriatus in response to 4-methyl-3-heptanol, the four geometric isomers of multistriatin, and cubeb oil. Charateristic dose-response curves for response amplitude and the time required for the voltage trace to return to 1/2 baseline (recovery rate) were established. Recovery rates were significantly more rapid following stimulation with 4-methyl-3-heptanol or cubeb oil than with the multistriatin isomers. At most intensities, α-multistriatin, the isomer that evokes behavioral response, gave significantly larger EAGs with significantly longer recovery rates than the other isomers. Results of differential adaptation experiments suggested that 4-methyl-3-heptanol interacted with the processes involving multistriatin and cubeb oil activity. However, cross-activity of acceptors for these compounds seems unlikely; single sensillum recordings are needed to ascertain the response spectra for individual receptor neurons.
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    Frontalin in the male mountain pine beetle (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 1399-1409 
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    ISSN: 1573-1561
    Keywords: Coleoptera ; Scolytidae ; Dendroctonus ponderosae ; pheromone ; frontalin ; exo-brevicomin ; Pinns contorta ; Pinus ponderosa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Frontalin andexo-brevicomin were identified by GC-MS in air drawn over maleDendroclonus ponderosae Hopk. (MPB) from Oregon that had joined females for 1–2 days in the bark of lodgepole and ponderosa pine logs. Unfed males releasedexo- andendo-brevicomin but not frontalin. These three compounds were not detected in either unfed or fed females. Arrestment of males bytrans-verbenol and terpenes in an olfactory walkway was reduced by the addition of racemic frontalin; production of attractant chirps also diminished. Racemic frontalin also strongly reduced the aggregation of MPB in lodgepole and ponderosa pine stands to sticky traps baited with the aggregation pheromonetrans-verbenol and host terpenes; however, the function of the natural enantiomer of frontalin in MPB is unknown.
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    Defensive secretions of three oxytelinae rove beetles (Coleoptera: Staphylinidae) (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 1411-1420 
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    ISSN: 1573-1561
    Keywords: Coleoptera ; Staphylinidae ; Oxytelinae ; defensive secretion ; glands ; acetates ; lactones ; alkenes ; quinones ; citral
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The secretions of the abdominal glands ofBledius spectabilis Kraatz,Platystethus arenarius Fourcr., andOxytelus piceus L. have been shown to contain four 1-alkenes; toluquinone; toluhydroquinone; C10 −-,C11 −, C12 −-, and C14 − γ-lactones; C12-δ-lactone; citral; and decyl-, undecyl-, and dodecyl acetates. Quantitative results indicate that 1-alkenes are formed probably from present lactones by decarboxylation. According to the known life histories of the beetles, it is suggested that the gland material is not used as an algal growth regulator but represents a unique defensive blend characteristic for the whole subfamily.
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    Olfactory responses of adultTribolium castaneum (Herbst), to volatiles of wheat and millet kernels, milled fractions, and extracts (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 1463-1472 
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    ISSN: 1573-1561
    Keywords: Red flour beetle ; Tribolium castaneum ; Coleoptera ; Tenebrionidae ; food volatiles ; olfactory responses ; olfactometer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Olfactory responses of 72- to 96-hr-old, 24-hr starved adult male, female, or mixed-sex groups of the red flour beetle,Tribolium castaneum (Herbst), to volatiles from wheat and millet kernels, certain milled fractions, and solvent extracts were recorded by using a lightsensitive apparatus. Wheat-germ volatiles from intact germ or solvent extracts were generally more attractive than volatiles of wheat endosperm or wheat bran. Volatiles of whole wheat kernels were the least attractive among test materials of wheat origin, whereas there were no significant differences among whole wheat flour, germ, and endosperm. Wheat-germ extracts, however, were more attractive than were extracts of the other fractions. Whole millet flour or fermented millet flour volatiles were more attractive than those from whole millet kernels or millet starch. Beetles reached maximum responsiveness to grain volatiles by 72–96 hr after adult ecdysis. Groups of virgin female beetles generally were more responsive than male or mixed-sex groups to volatiles of substances tested.
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    Influence of opposite sex on attraction produced by pioneer sex of four bark beetle species cohabiting pine in the Southern United States (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 373-378 
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    ISSN: 1573-1561
    Keywords: Dendroctonus frontalis ; Ips calligraphus ; I. grandicollis ; I. avulsus ; Coleoptera ; Scolytidae ; mating ; attraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Catches ofDendroctonus frontalis andIps avulsus on traps surrounding bolts infested with both sexes of each species in the gallery were not significantly different from catches at bolts infested only with the sex which normally pioneers the host colonization process. In contrast, the presence of the second sex in the gallery significantly reduced catches ofI. grandicollis andI. calligraphus and, additionally, the presence of females in the male galleries ofI. calligraphus significantly reduced the catch ofI. avulsus females as compared with their response to bolts infested with the maleI. calligraphus only.
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    Defensive adaptations of eggs and adults ofGastrophysa cyanea (Coleoptera: Chrysomelidae) (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 453-462 
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    ISSN: 1573-1561
    Keywords: Defensive secretions ; oleic acid ; hydrocarbons ; terpenoids ; eggs ; deterrents ; ants ; predation ; Chrysomelidae ; Coleoptera ; Gastrophysa cyanea ; reflex bleeding ; elytral glands
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Egg clusters and adults ofGastrophysa cyanea are conspicuous and, like their larvae, are chemically protected. The eggs owe their bright yellow color primarily to β-carotene and, in addition, contain substantial quantities of oleic acid. At natural concentrations oleic acid effectively deters many species of ants from feeding. The use of fatty acids as deterrents against ants is discussed as a possible widespread phenomenon among insects. During defensive confrontations, adults ofG. cyanea exhibit avoidance behavior and may also feign death. In addition, the adults may autohemmorhage or secrete a fluid from elytral or pronotal pores in response to traumatic stimuli. The secretions are effective against ants and contain a mixture of hydrocarbons as well as terpenoid components. The pattern of ontogenetic modification in the defensive chemical repertoire ofG. cyanea is discussed.
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    Responses of the olfactory receptors ofScolytus scolytus (F.) (Coleoptera: Scolytidae) to the stereoisomers of 4-methyl-3-heptanol (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 477-492 
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    ISSN: 1573-1561
    Keywords: Scolytus scolytus ; Coleoptera ; Scolytidae ; pheromone ; 4-methyl-3-heptanol stereoisomer ; olfaction ; electrophysiology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Electroantennogram (EAG) and single-cell recording techniques have been used to demonstrate the presence of separate receptors for (−)-threo- and (−)-erythro-4-methyl-3-heptanol on the antenna ofS. scolytus. The majority of single-cell recordings showed spikes of two different amplitudes. The cell giving spikes of larger amplitude responded to the (−)-threo stereoisomer while the cell with the small-amplitude spikes responded to (−)-erythro-4-methyl-3-heptanol. It is suggested that in most recordings the two cells are associated with a single sensillum basiconicum.
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    Regeneration and biosynthesis of dytiscid defensive agents (Coleoptera: Dytiscidae) (1983)
    Springer
    Journal of chemical ecology 9 (1983), S. 1449-1464 
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    ISSN: 1573-1561
    Keywords: Coleoptera ; Dytiscidae ; Agabus seriatus ; Agabus obtusatus ; defensive secretions ; steroids ; regeneration ; pygidial glands ; prothoracic glands ; cholesterol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The defensive secretions of the dytiscid species,Agabus seriatus (Say) andAgabus obtusatus (Say), were qualitatively and quantitatively analyzed by high-pressure liquid chromatography. The intrinsic ability ofA. Seriatus andA. Obtusatus to regenerate their prothoracic gland defensive secretions under laboratory conditions was determined by analyzing the secretions every seventh day for five weeks. Both beetles regenerated ∼ 80% of their prothoracic gland components within two weeks.A. seriatus was injected with [4-14C]cholesterol and after a three-week regeneration period 7.5% of the14Clabel was found in the steroidal defensive secretion from the prothoracic glands.
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    1-Methylcyclohex-2-en-1-ol as an aggregation pheromone ofDendroctonus pseudotsugae (1983)
    Springer
    Journal of chemical ecology 9 (1983), S. 1533-1541 
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    ISSN: 1573-1561
    Keywords: Aggregation pheromone ; attractant ; 1-methylcyclohex-2-en-1-ol ; Dendroctonus pseudotsugae ; Coleoptera ; Scolytidae ; bark beetle ; Douglas-fir beetle ; 3-methylcyclohex-3-en-1-ol ; Pseudotsuga menziesii
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract 1-Methylcyclohex-2-en-1-ol (1,2-MCH-ol) was synthesized, identified as a compound found in volatiles of the female Douglas-fir beetle, and shown by bioassays to be an aggregation pheromone. 1,2-MCH-ol matches in both GC retention index and mass spectrum a compound released by the female after feeding. 3,3-MCH-ol was also synthesized as a candidate compound; its mass spectrum is presented because published mass spectra are incorrect for this compound. Synthetic 1,2-MCH-ol increased arrestment and stridulation of males in olfactory walkways and increased trap catches of flying beetles. Males were more responsive to 1,2-MCH-ol than females.
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    Ethanol and other host-derived volatiles as attractants to beetles that bore into hardwoods (1983)
    Springer
    Journal of chemical ecology 9 (1983), S. 181-190 
    Details
    ISSN: 1573-1561
    Keywords: Coleoptera ; Buprestidae ; Cerambycidae ; Cleridae ; Scolytidae ; wood-boring beetles ; bark beetles ; ethanol ; host attractants ; hardwood tree insects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Ethanol, methanol, acetone, and acetaldehyde—chemicals identified in the inner bark of living trees—were used to bait vane traps placed in crowns of oak trees in Connecticut. Ethanol-baited traps caught more cerambycid, scolytid, and clerid beetles than unbaited traps. Buprestidae were not attracted to ethanol. Acetaldehyde and acetone were not attractive to any family. A mixture of ethanol, methanol, and acetaldehyde was no more attractive than ethanol alone. The vane traps were very effective at catching Cerambycidae and Scolytidae, but ineffective compared to sticky panels at catching Buprestidae.
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    Sensitivity of antennae of male and femaleIps paraconfusus (Coleoptera: Scolytidae) to their natural aggregation pheromone and its enantiomeric components (1983)
    Springer
    Journal of chemical ecology 9 (1983), S. 561-584 
    Details
    ISSN: 1573-1561
    Keywords: Coleoptera ; Scolytidae ; bark beetle ; Ips paraconfusus ; aggregation pheromone ; enantiomer ; electrophysiology ; electroantennogram ; interruption ; allomone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Antennae of male and femaleIps paraconfusus were equally and highly sensitive to their male-produced, multicomponent aggregation pheromone. Female and male antennae were highly sensitive to the pheromonal component, (S)-(−)-ipsenol, but essentially insensitive to its antipode, (R)-(+)-ipsenol. Further, female and male antennae were more sensitive to the pheromonal component, (S)-cis-verbenol, than to its antipode, (R)-cis-verbenol. Dramatic sexual dimorphism in chiral sensitivity to the ipsdienol enantiortiers was found, with female antennae being more sensitive to the conspecific pheromonal enantiomer, (S)-(+)-ipsdienol, and male antennae being more sensitive to the antipode, (R)-(−)-ipsdienol. Since (R)-(−)-ipsdienol is the principal pheromone of CaliforniaIps pini and interruptsI. paraconfusus aggregation, male antennae appear to be more sensitive to an interspecific allomone than a conspecific pheromone. Of the conspecific pheromonal enantiomers, both male and female antennae were most sensitive to (S)-(+)-ipsdienol, intermediately sensitive to (S)-(−)-ipsenol, and least sensitive to (S)-cis-verbenol. However, when enantiomeric sensitivities were compared to the estimated concentrations of these components in the natural pheromone, (S)-(~)-ipsenol tended to equal or approach the potency of (S)-(+)-ipsdienol as an antennal stimulant, while antennal responsiveness to (S)-cis-verbenol was dramatically less than for the other two pheromonal components. The behavioral implications of such physiological sensitivities are discussed in regard to perception of multicomponent synergistic pheromones and the relative efficacy of each component as an orientation cue.
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    Sensitivity of antennae of male and femaleIps paraconfusus (Coleoptera: Scolytidae) to its pheromone and other behavior-modifying chemicals (1983)
    Springer
    Journal of chemical ecology 9 (1983), S. 585-606 
    Details
    ISSN: 1573-1561
    Keywords: Coleoptera ; Scolytidae ; bark beetle ; Ips paraconfusus ; pheromone ; enantiomer ; electrophysiology ; electroantennogram ; interruption ; allomone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The antennal sensitivities of both male and femaleIps paraconfusus were found generally to be greatest for conspecific aggregation pheromones (ipsdienol, ipsenol); intermediate for an additional conspecific pheromone (cis-verbenol), an aggregation synergist (2-phenylethanol), and pheromones/allomones of sympatric species (trans-verbenol, verbenone, and frontalin); and lowest for both host terpenes (alpha-pinene and myrcene) and other bark beetle-produced odorants (exo-brevicomin and linalool). Of the enantiomeric compounds tested, antennae of both sexes did not differ in sensitivity between thetrans-verbenol enantiomers at low dosage levels; but at higher dosages, the conspecific-produced enantiomer, (1R,4S,5R)-(+)-trans-verbenol, elicited larger mean EAG responses than its antipode, (1S,4R, 5S)-(−)-trans-verbenol. At the mid-dosage range, female antennae tended to be slightly more responsive to (S)-(−)-verbenone than to (R)-(+)-verbenone, while male antennae were equally responsive to stimulations by either verbenone enantiomer. In field bioassays there was a large and significant reduction in trap catches ofI. paraconfusus on traps where the (S)-(−)- or (R)-(+)-enantiomers of verbenone were evaporated beside logs containing boring conspecific males. Only when the (S)-(−)-enantiomer of verbenone was evaporated beside logs containing boring males did the sex ratio ofI. paraconfusus trapped shift from female-dominated to male-dominated attraction. Thus both physiological and behavioral data suggest a differential chiral sensitivity of female beetles for the verbenone enantiomers. The relative sensitivities between different chiral compounds derived from one or the other of the common precursoral host terpenes, (S)-(−)- and (R)-(+)alpha-pinene or myrcene, are discussed.
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    Seasonal variation in laboratory response to behavioral chemicals of the southern pine beetle (1982)
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    Journal of chemical ecology 8 (1982), S. 641-652 
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    ISSN: 1573-1561
    Keywords: Dendroctonus frontalis ; Coleoptera ; Scolytidae ; seasonal variation ; pheromone content ; environmental parameters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The response ofDendroctonus frontalis to an attractant mixture (frontalin,trans-verbenol, and loblolly pine turpentine) was measured in the laboratory over a four-year period. Beetle response was highest in late winter and early spring, and lowest in midsummer and early fall. Males consistently responded higher than females. Female beetles displayed significantly higher responses in early morning and late afternoon than in the middle of the day. Analysis of beetle pronotal width and fat content revealed a high degree of correlation between these two parameters in female beetles, but there was no correlation of response with either fat content or pronotal width for either sex. There was no evident relationship between mean monthly beetle response and total amounts of frontalin andtrans-veibenol found in hindgut extracts. Daily temperature in months both during which beetles were bioassayed and immediately prior to bioassay was highly correlated to response to the attractant.
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    Oscillatoria Sp. (Cyanophyta) mat metabolites implicated in habitat selection inBembidion obtusidens (Coleoptera: Carabidae) (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 671-678 
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    ISSN: 1573-1561
    Keywords: Bembidion obtusidens ; Coleoptera ; Carabidae ; Oscillatoria animalis ; Oscillatoria subbrevis ; Cyanophyta ; metabolites ; volatiles ; ecophenes ; methylhexadecanoate ; methyloctadecenoate ; attractant ; habitat selection
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Abstract In laboratory bioassaysBembidion obtusidens Fall adults were attracted to volatile metabolites (methyl esters of hexadecanoic and 9-octadecenoic acid) of mat-forming, filamentous blue-green algae (Oscilalatoria sp.; Cyanophyta) growing in the microhabitat of these beetles on the shores of saline lakes. Commercial preparations of these metabolites also were attractive, suggesting thatOscillatoria metabolites are token stimuli which serve as habitat cues forBembidion adults.
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    Field bioassay ofexo- andendo-brevicomin withDendroctonus ponderosae in lodgepole pine (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 701-707 
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    ISSN: 1573-1561
    Keywords: Coleoptera ; Scolytidae ; Dendroctonus ponderosae ; pheromone ; exo-brevicomin ; endo-brevicomin ; Pinus contorta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Bothexo- andendo-brevicomin reduced the response of flyingDendroctonus ponderosae (Coleoptera: Scolytidae) to an attractant composed oftrans-verbenol and terpenes or oftrans- andcis-verbenol and terpenes in a stand ofPinus contorta var.murrayana. These data suggest that racemicexo- andendo-brevicomin may interrupt aggregation in populations of mountain pine beetle colonizing lodgepole pine; functions of the natural chiral compounds are unknown.
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    Defensive and pheromonal secretion of the tergal gland ofAleochara curtula II. Release and inhibition of male copulatory behavior (1983)
    Springer
    Journal of chemical ecology 9 (1983), S. 13-31 
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    ISSN: 1573-1561
    Keywords: Aleochara curtula (Goeze) ; Coleoptera ; Staphylinidae ; tergal gland secretion ; defense ; mating stimulants ; female sex pheromone ; hydrocarbons ; n-aldehydes ; substituted 1 ; 4-benzoquinones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract At high concentrations, the defensive tergal gland secretion (TGS)3 of the staphylinid beetle,Aleochara curtula, inhibits the male copulatory response (grasping with parameres). Inhibitory chemicals, for which a function as alarm substances is assumed, aren-undecane, 1-undecene,n-dodecanal, toluquinone, and 2-methoxy-3-methyl-1,4-benzoquinone. When emitted in small amounts, however, the TGS releases the male grasping response. The main components with aphrodisiac effect are (Z)-4-tridecene,n-dodecanal, and (Z)-5-tetradecenal. These supplementary mating stimulants, which are not sex specific, work synergistically with the aphrodisiac female sex pheromone from thé epicuticular lipids and are discussed as alerting pheromones of short-term effect. Antennal movements of resting males as an indication of the recognition of a female and the approach to the mate are released at somewhat longer distances, when the TGS is additionally present.
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    Field response of the dutch elm disease vectors,Scolytus multistriatus (Marsham) andS. scolytus (F.) (Coleoptera: Scolytidae) to 4-methyl-3-heptanol baits containing α-, β-,δ-, or δ-multistriatin (1983)
    Springer
    Journal of chemical ecology 9 (1983), S. 67-84 
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    ISSN: 1573-1561
    Keywords: Scolytus multistriatus ; S. scolytus ; Coleoptera ; Scolytidae ; elm bark beetle ; multistriatin stereoisomers ; Dutch elm disease ; aggregation pheromone ; field responses ; attractant baits
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The field responses of English populations of the Dutch elm disease vectors,Scolytus multistriatus andS. scolytus to baits containing 4-methyl-3-heptanol, a host synergist [(−)-α-cubebene or (−)-limonene] and (±)-α-, (+)-β-, (−)-β-, (±)-γ-, or (±)-δ-multistriatin were examined. (±)-α-Multistriatin, released at 5–10 μg/day, enhanced the response ofS. multistriatus to baits containing 4-methyl-3-heptanol and either of the host synergists but had no effect on the capture ofS. scolytus. The release of larger amounts (57 or 365 μg/day) of (±)-α-multistriatin interrupted the response of both species to the 4-methyl-3-heptanol baits. It appears that α-multistriatin has multiple functions as a behavior-modifying substance for the two beetles. The (+)-β-, (−)-β-, (±)-γ-, and (±)-δ-multistriatins were inactive when released at 5–10 μg/day. The results of these field experiments suggest that one bait can be formulated to capture both species.
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    URL: http://dx.doi.org/10.1007/BF00987771
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    Ecological patterns in the glucosinolate content of a native mustard,Cardamine cordifolia, in the rocky mountains (1983)
    Springer
    Journal of chemical ecology 9 (1983), S. 397-422 
    Details
    ISSN: 1573-1561
    Keywords: Cruciferae ; chemical defense ; gradient ; glucosinolate ; herb-ivory ; insect-plant interactions ; Cardamine cordifolia ; Coleoptera ; Chrysomelidae ; Homoptera ; Psyllidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Insect use of native crucifers may be related to patterns in mustard oil content. Consequently, in 1979 we measured glucosinolate content of Rocky Mountain bittercress,Cardamine cordifolia (Cruciferae), using paper and gas chromatography, in relation to: plant organ, phenology, elevation, habitat, leaf position and weight, and plant consumption by two adapted insect herbivores. Results for each are as follows. (1) The predominant constituent in all vegetative organs was 2-butylglucosinolate; concentration of isothiocyanate-yielding glucosinolates (IYG) was highest in roots (1.11 mg/gfr. wt) and lowest in stems (0.07 mg/g). (2) Concentration of IYG appeared to be higher in plants lacking oxazolidinethione-yielding glucosinolates (OYG) than in those with OYG. (3) Terminal cauline leaves had a higher content of IYG than leaves in other positions on a plant. (4) Heavy leaves had significantly higher concentrations of IYG than did lighter leaves. (5) IYG concentrations were not directly related to elevation. (6) Leaves of plants occurring naturally in the sun had concentrations of IYG similar to those of plants in the usual shaded habitat. However, experimental removal of overhanging willows caused a significant, stress-induced increase in IYG concentrations. Finally, (7) feeding by two adapted herbivores, chrysomelids and psyllids, was associated with lower, rather than higher, IYG concentrations. The results demonstrate significant variation in glucosinolate content in a native crucifer and suggest that some of this variation can be partitioned in relation to the ecological and environmental axes examined.
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    URL: http://dx.doi.org/10.1007/BF00988458
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    Isolation and identification of two macrolide pheromones from the frass ofCryptolestes ferrugineus (Coleoptera: Cucujidae) (1983)
    Springer
    Journal of chemical ecology 9 (1983), S. 451-474 
    Details
    ISSN: 1573-1561
    Keywords: Cryptolestes ferrugineus ; rusty grain beetle ; aggregation ; pheromone ; macrolide ; (E,E)-4,8-dimethyl-4,8-decadien-10-olide ; (3Z,11S)-3-dodecen-11-olide ; (Z,Z)-3,6-dodecadien-11-olide ; (Z)-5-tetradecen-13-olide ; 11-dodecanolide ; 4-nonanolide ; Coleoptera ; Cucujidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Two synergistic macrolide aggregation pheromones were isolated from Porapak Q-trapped volatiles obtained from the frass ofCryptolestes ferrugineus (Stephens). These compounds were identified as (E,E)-4,8-dimethyl-4,8-decadien-10-olide (I) and (3Z,11S)-3-dodecen-11-olide (II) and given the trivial names ferrulactone I and II, respectively. Analysis of captured volatiles from separated male and female adults disclosed that the pheromones are male-produced. Additional macrolides were identified in frass volatiles, but were devoid of any pheromonal activity. The structures of I and II were confirmed by comparison with synthetic materials.
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    URL: http://dx.doi.org/10.1007/BF00990219
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    Effect of soybean phytoalexins on the herbivorous insects mexican bean beetle and soybean looper (1983)
    Springer
    Journal of chemical ecology 9 (1983), S. 657-672 
    Details
    ISSN: 1573-1561
    Keywords: Pseudoplusia includens ; soybean looper ; Lepidoptera ; Noctuidae ; Epilachna varivestis ; Mexican bean beetle ; Coleoptera ; Coccinellidae ; feeding preferences ; nutrition ; food utilization ; host-plant resistance ; induced resistance ; glyceollin ; isoflavonoids ; soybean ; phytoalexins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Effects of soybean phytoalexins on the feeding of the soybean looper and Mexican bean beetle were investigated to test the hypothesis that phytoalexins might be a defense mechanism of plants against insects as well as against pathogens. Short-term behavioral responses to the phytoalexins were analyzed using dual-choice tests with phytoalexin-rich and phytoalexin-poor (control) tissues. Phytoalexin production was elicited with ultraviolet radiation. Results from the dual-choice tests indicated that 6th instar soybean looper larvae fed equally on the control and phytoalexin-rich tissues. Feeding by adult and 4th instar Mexican bean beetles, however, was strongly deterred by the phytoalexins as evidenced by “single-bite” mandible scars on the phytoalexin-rich cotyledon discs. Nutritional effects of the isoflavonoid phytoalexin glyceollin on early instar soybean looper larvae were tested by incorporating the phytoalexin into an artificial medium at a level of 1% dry weight (0.15% fresh weight). The larvae were reared for 7 days from emergence on diets of control and glyceollin-containing media. Although survival on the glyceollin diets was initially less than on the control diets, under the experimental conditions glyceollin had no significant effect on the growth, development, or subsequent survival of the larvae. Efficiency of food utilization (ECI) was reduced, indicating that the phytoalexins may be a mild digestibility-reducing factor for the loopers. Implications of the results for host-plant resistance are discussed.
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    URL: http://dx.doi.org/10.1007/BF00988774
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    Avoidance of nonprotein amino acid incorporation into protein by the seed predator,Caryedes brasiliensis (Bruchidae) (1983)
    Springer
    Journal of chemical ecology 9 (1983), S. 1353-1361 
    Details
    ISSN: 1573-1561
    Keywords: Canavanine ; Caryedes brasiliensis ; Coleoptera ; Bruchidae ; Dioclea megacarpa ; plant-insect interactions ; amino acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Larvae of the bruchid beetle,Caryedes brasiliensis (Bruchidae) have the ability to avoid significant incorporation ofl-canavanine, the guanidinooxy structural analog ofl-arginine, into de novo synthesized proteins. This ability is related to a highly discriminatory protein-synthesizing system which exhibits marked ability to avoid processing an array of nonprotein amino acids structurally related to arginine.
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    URL: http://dx.doi.org/10.1007/BF00994804
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    Evidence for stable grain boundary melt films in experimentally deformed olivine-orthopyroxene rocks (2000)
    Springer
    Physics and chemistry of minerals 27 (2000), S. 480-494 
    Details
    ISSN: 1432-2021
    Keywords: Key words Olivine ; Grain boundary ; Partial melt ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Abstract The microstructure of olivine-olivine grain boundaries has been studied in experimentally deformed (1200–1227 °C, 300 MPa) partially molten olivine and olivine-orthopyroxene rocks. In-situ melting produced ∼1 vol% melt in all samples studied. Grain boundary analyses were carried out using a number of transmission electron microscopy techniques. The grain boundary chemistry in undeformed olivine-orthopyroxene starting material showed evidence for the presence of an intergranular phase along some, but not all, of the olivine-olivine boundaries. In the deformed samples, ultrathin Si-rich, Al- and Ca-bearing amorphous films have been observed along all investigated olivine-olivine grain boundaries. The chemistry of the grain boundaries, which is considered to be indicative for the presence of a thin film, was measured with energy-dispersive X-ray spectroscopy (EDX) and energy-filtering imaging. The amorphous nature of the films was confirmed with diffuse dark field imaging, Fresnel fringe imaging, and high-resolution electron microscopy. The films range in thickness from 0.6 to 3.0 nm, and EDX analyses show that the presence of Al and Ca is restricted to this ultrathin film along the grain boundaries. Because thin melt films have been observed in all the samples, they are thought to be stable features of the melt microstructure in deformed partially molten rocks. The transition from the occasional presence of films in the undeformed starting material to the general occurrence of the films in deformed materials suggests that deformation promotes the formation and distribution of the films. Alternatively, hot-pressing may be too short for films to develop along all grain boundaries. A difference in creep strength between the studied samples could not be attributed to grain boundary melt films, as these have been found in all deformed samples. However, a weakening effect of grain boundary melt films on olivine rheology could not be ruled out due to the lack of confirmed melt-film free experiments.
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    URL: http://dx.doi.org/10.1007/s002690000090
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    Ultrastructural changes in the spermatogonia and spermatocytes of Poecilia reticulata during spermatogenesis (1984)
    Springer
    Cell & tissue research 237 (1984), S. 219-226 
    Details
    ISSN: 1432-0878
    Keywords: Spermatogonia ; Spermatocytes ; Carbohydrates ; Guppy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structure of guppy (Poecilia reticulata) spermatogonia and spermatocytes has been studied using electron microscopy. The spermatogonia, situated at the apex of the seminiferous tubule, are almost all surrounded by a network of Sertoli cells; they have very diffuse chromatin and one or two large nucleoli. The cytoplasm contains relatively few organelles, although annulate lamellae are found. The mitochondria have few cristae and are concentrated at one pole of the cell; they are sometimes found with intermitochondrial cement. These spermatogonia are separated from each other, having no intercellular bridges or inclusion in Sertoli cells, and are relatively undifferentiated; they correspond to stem cells. The spermatogonia beneath the apex are organized into cysts. First-generation spermatogonia are more dense and heterogeneous, their nuclei becoming smaller and their chromatin becoming denser during successive generations. In spermatocytes, the synaptinemal complex exists as a modified form until metaphase. The concentration of organelles in the cytoplasm increases and the organelles become more diversified as spermatogenesis progresses. Many cytoplasmic bridges are observed (several per cell), indicating that the cells remain in contact after several divisions. These changes in germ cell structure have been related to some of the characteristic features of spermatogenesis in guppy, e.g. the large number of spermatogonial generations and the complexity of spermiogenesis.
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    URL: http://dx.doi.org/10.1007/BF00217139
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    Marginal plates in hepatic peroxisomes of Ichthyophis glutinosus (Amphibia: Gymnophiona) (1984)
    Springer
    Cell & tissue research 238 (1984), S. 413-416 
    Details
    ISSN: 1432-0878
    Keywords: Peroxisomes ; DAB-cytochemistry ; Electron microscopy ; Liver, amphibian ; Gymnophiona ; Ichthyophis glutinosus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of hepatic peroxisomes was investigated in Ichthyophis glutinosus (Amphibia: Gymnophiona), employing perfusion fixation and the diaminobenzidine (DAB) technique for the visualization of catalase. The majority of peroxisomes is circular or rod-shaped, although elongated particles occasionally occur. They contain a finely granular matrix, lightly stained after the DAB procedure. Their mean diameter is approximately 0.25 μm. Serial sections reveal that the circular and rod-shaped peroxisomal profiles are cross and oblique sections of highly tortuous, tubular organelles exceeding 2 μm in length. In addition to tubular profiles, elongated, rectangular particles, as well as straight dumbbell-shaped organelles with distinct marginal plates are observed. They range from 900 to 1650 nm in length (mean = 1200 nm). In the flattened, thin central portion of the dumbbell-shaped particle, the peroxisomal membranes form a cisterna enclosing one or two uniformly thick marginal plates, which display a definite substructure with a periodicity of 10 nm. These findings indicate that peroxisomes in the liver of Ichthyophis exhibit a complex organization. It is suggested that the organelles undergo a specific differentiation process, morphologically characterized by the formation of enlarged segments of unusual shape.
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    URL: http://dx.doi.org/10.1007/BF00217316
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    Phagocytosis of spermatozoa by the ovum of the domestic fowl, Gallus gallus at the time of fertilization (1980)
    Springer
    Cell & tissue research 206 (1980), S. 55-63 
    Details
    ISSN: 1432-0878
    Keywords: Phagocytosis ; Spermatozoa ; Ovum ; Fertilization ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Spermatozoa with intact acrosomes, as well as those coming into contact with the ovum at a smaller angle, and morphologically abnormal spermatozoa reach the plasma membrane of the ovum via an extensively dissolved zone of the inner layer of the vitelline membrane. This zone is assumed to be formed by overlapping of two or more tunnels formed by spermatozoa that had previously come into contact with the ovum. When a spermatozoon comes into contact with the plasma membrane of the ovum, many cytoplasmic processes extend outwards and cover it. Thereafter, the plasma membranes of the processes fuse, thereby phagocytizing the spermatozoon. It is assumed that the phagocytized spermatozoa cannot undergo transformation into male pronuclei and that they degenerate soon after phagocytosis.
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    URL: http://dx.doi.org/10.1007/BF00233607
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    Fine structure of the compound eyes and interfacetal mechanoreceptors of Cicindela tranquebarica Herbst (Coleoptera: Cicindelidae) (1980)
    Springer
    Cell & tissue research 206 (1980), S. 123-138 
    Details
    ISSN: 1432-0878
    Keywords: Ultrastructure ; Sense organs ; Compound eyes ; Interfacetal mechanoreceptor ; Coleoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structure of the compound eyes of adult Cicindela tranquebarica Herbst was examined by use of light, scanning, and transmission electron microscopy. Each ommatidium of these photopic eyes is eucone and has a “subcorneal layer” situated between the corneal lens and crystalline cone. A distal rhabdomere consisting only of microvilli from retinula cell seven, a more proximal, rectangular, fused rhabdom formed from six retinula cells, and a basal, eighth retinula cell with a spherical rhabdomere comprise the light sensitive portions of the ommatidium. The “subcorneal layer” consists of lamellae of endocuticular microfibrils and, in surface view, shows 11 concave polygons. Proximal extensions of the crystalline thread form inter-retinular fibres containing microtubules between retinula cells 1/2, 3/4, 5/6, and 7/1. The primary pigment cells are devoid of pigment granules, but are rich in rough endoplasmic reticulum. Proximal to each retinula cell nucleus are two basal bodies, one perpendicular to the other. The more proximal basal body extends two fibrillar feet proximally which fuse to form a horizontally-banded ciliary rootlet extending the length of the retinula peripheral to the rhabdom. Each ommatidium is surrounded by 16 secondary pigment cells. Interfacetal mechanoreceptors between some adjacent lenses each have a single bipolar neuron, with a dendritic sheath, tubular body, cilium, outer and inner sheath cells, and an axon surrounded by a neurilemma sheath cell.
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    URL: http://dx.doi.org/10.1007/BF00233613
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    Ca++-induced structural changes in photoreceptor microvilli of diptera (1980)
    Springer
    Cell & tissue research 206 (1980), S. 225-232 
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    ISSN: 1432-0878
    Keywords: Compound eye ; Photoreceptor membrane ; Electron microscopy ; Calcium-induced changes ; Artefacts ; Diptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary When the compound eyes of the fly Lucilia are fixed for electron microscopy with glutaraldehyde in common buffer solutions, artefactual whorls are liable to be formed from the photoreceptor microvilli. The whorls result from two factors: (i) a prolonged time interval prior to osmication, such as the “overnight” primary fixation or wash at 4° C commonly used in studies of compound eyes; (ii) as little as 1–2 mM Ca++ in the primary fixative and wash solutions. Osmication after short (1 h) glutaraldehyde fixation at 4° C, or omission of Ca++ and addition of 2 mM EGTA, prevent whorl-formation. In the tipulid fly Ptilogyna, similar artefacts are produced, but are confined to the distal zone of the microvilli that sheds during turnover.
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    URL: http://dx.doi.org/10.1007/BF00232766
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    Scanning and transmission electron microscopic observations of the cloacal epithelia of the domestic fowl (1980)
    Springer
    Cell & tissue research 211 (1980), S. 83-93 
    Details
    ISSN: 1432-0878
    Keywords: Epithelium ; Cloaca ; Electron microscopy ; Hen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The epithela of the three divisions (coprodaeum, urodaeum, proctodaeum) of the cloaca of the hen, and of the excretory ducts (colon, ureter, vagina) which join the divisions, are described using light microscopy, and scanning and transmission electron microscopy. Each region of the cloaca has its typical epithelium. Special attention is focussed in this study on the boundaries between the different epithelia. The coprodaeal epithelium does not differ considerably from that of the colon; a transitional zone is not visible. Distinct border zones, however, are observed between the other regions (ureter — urodaeum; vagina — urodaeum and proctodaeum; urodaeum-proctodaeum; proctodaeum — cutis). Although the vaginal opening is generally thought to lie in the urodaeum, our investigations show that at the vaginal opening into the cloaca the ciliated epithelium changes, on one border to a secretory epithelium characteristic of the urodaeum and on the other border to that characteristic of the proctodaeum. These observations are discussed in relation to functional aspects.
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    Ultrastructural alterations of the pancreatic D cell in the domestic fowl following vagotomy (1980)
    Springer
    Cell & tissue research 211 (1980), S. 171-174 
    Details
    ISSN: 1432-0878
    Keywords: Pancreatic D cell ; Neural control ; Vagotomy ; Electron microscopy ; Fowl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In an attempt to determine the neural control of pancreatic D cells, the pancreatic islets of the domestic fowl were examined electron microscopically from 1 to 28 days after abdominal vagotomy. Exocytotic release of many secretory granules from D cells occurred one day after vagotomy. Rough endoplasmic reticulum developed and formed an arrangement of concentric whorls in the cytoplasm of D cells after axotomy. The altered D cells were also characterized by the occurrence of many peculiar dense bodies in the apical cytoplasm at all time periods studied. These bodies varied in shape and size, containing several round vesicles. The D cells were extensively depleted of granules after the longer time periods following vagotomy. The present results provide new morphological evidence for the vagus-nerve control of D cells, which may regulate the activity of islet cells.
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    URL: http://dx.doi.org/10.1007/BF00233732
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    Fetal hypothalamic transplants in the third ventricle of the adult rat brain (1980)
    Springer
    Cell & tissue research 211 (1980), S. 191-206 
    Details
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Transplants ; Vasopressin ; Median eminence ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Blocks of anterior hypothalamus were transplanted from 19 day-old fetuses of Wistar/Lewis rats into the third ventricle of adult male Brattleboro rats. Physiological changes in graft recipients and in sham-operated animals were monitored daily. Twenty days after surgery, the graft recipients and shamoperated animals were killed and their brains examined by correlative scanning and transmission electron microscopy. Host animals that exhibited both decreased polydipsia and increased urine concentration were found to have viable grafts within the third ventricle. The observed physiological changes suggested that synthesis and release of vasopressin occurred in the transplanted neurons. Grafts were well vascularized by vessels arising from the host hypothalamus. Neurons, with perikarya ranging from 8 to 30 μm in diameter, glial cells, and neurites were located throughout the transplants. A neurohemal contact zone, similar to that normally seen in the median eminence, could not be demonstrated in the grafts. The absence of complete glial and ependymal barriers indicates a relatively close association between cells in the transplants and the cerebrospinal fluid. A large increase in supraependymal neurons and their processes, including an eruption of neurons through the floor of the third ventricle in one animal, was observed in graft recipients but not in shamoperated animals.
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    URL: http://dx.doi.org/10.1007/BF00236442
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    Development of the granule population in neutrophil granulocytes from human bone marrow (1983)
    Springer
    Cell & tissue research 234 (1983), S. 469-496 
    Details
    ISSN: 1432-0878
    Keywords: Bone marrow (human) ; Neutrophil granulocyte ; Granules ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Bone marrow from hematologically healthy adults was exposed to a number of fixation procedures for investigation of the heterogeneity of the granule population in neutrophil granulocytes at the ultrastructural level. Four main cell stages were distinguished: early promyelocyte, late promyelocyte, myelocyte, and mature neutrophil granulocyte and described separately; metamyelocytes and band-form or stab cells are described together. The characteristic changes in the cytoplasm during myelopoiesis were analysed quantitatively. Special attention was given to the development of the granule population. Three types of granule arise in successive cell stages: granules which develop a sub-structure in the matrix (nucleated granules) are formed in early promyelocytes, granules with a homogeneous electron-dense matrix (azurophil granules) in late promyelocytes, and granules with a less electron-dense matrix (specific granules) in myelocytes. The three types of granule remain present during myelopoiesis. The best results in distinguishing the granule types were obtained by prefixation either in 0.1% glutaraldehyde or in 1.5% glutaraldehyde followed by washing in phosphate-buffered Ringer solution to which aminotriazole had been added. Granule counts revealed for the mature neutrophil a total number of granules of about 220 per ultrathin section. This population of granules is composed of about 12% nucleated, 11% azurophil, and 77% specific granules. When our previous findings are taken into account, the existence of three successively formed and morphologically distinguishable types of granule in heterophil (neutrophil) granulocytes has been demonstrated for three mammalian species: the guinea pig, the rat, and man. A separate term for the early promyelocyte stage is proposed: eomyelocyte.
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    Light-related changes in electron-dense material in photoreceptor synaptic clefts of the frog, Rana catesbeiana (1983)
    Springer
    Cell & tissue research 234 (1983), S. 579-593 
    Details
    ISSN: 1432-0878
    Keywords: Rods ; Cones ; Retina ; Bullfrog ; Synapse ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Lumps of electron-dense material were observed in synaptic clefts associated with all types of photoreceptors, in the vicinity of the synaptic ribbons, in the retinae of dark-adapted frogs. Frogs were reared under a cyclic illumination (light on at 8:00; light off at 20:00) and then exposed to one of two courses of dark adaptation: one started from 11:00 in the morning, and the other started from 20:00 in the evening. The synaptic clefts of red rods became wider at some places where spherical or polygonal lumps of dense material were accumulated. The frequency and sectional area of the lumps increased faster for the first hour in the regime starting from 20:00 than in the regime starting from 11:00, then they reached the similar saturation levels of about 0.6 (per ribbon) and 1.6 to 1.8×104 (nm2) in both the regimes. In greenrod synapses, plate-shaped lumps of dense material were present in synaptic clefts and interspaces between the processes of second-order neurons. In cone synapses at the end of about 1 h darkness, the frequency and area of the lumps reached maximum values of about 0.12 (per ribbon) and 9×103 (nm2) in the regime starting from 11:00 and, about 0.08 (per ribbon) and 4 × 103 (nm2) in the regime starting from 20:00. On exposure to light, the dense material abruptly disappeared from all types of photoreceptor synaptic clefts. Large dense-core vesicles, occasionally observed in light-adapted rod photoreceptor terminals, seem to participate in exocytosis of the dense material. The number of dense-core vesicles per synaptic ribbon in a terminal was about 0.55 at the end of 3 h light in the morning and about 1.28 at the end of 12 h light in the evening. The increased number of dense-core vesicles during the daytime may contribute to the faster accumulation of dense material in the synaptic clefts. Although the chemical identification or the functional significance of the electron-dense material remains unknown, it is interesting that this material showed a rise and fall in response to darkness and illumination. Also the fact that this material is clearly visible will be helpful for future analysis of frog photoreceptor synapses.
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    Studies on the morphology of the isolated perfused rabbit ovary (1984)
    Springer
    Cell & tissue research 235 (1984), S. 59-63 
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    ISSN: 1432-0878
    Keywords: Ovulation (rabbit) ; Graafian follicle ; Perfusion ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Isolated ovaries from untreated, sexually mature rabbits were introduced into an in vitro perfusion system and perfused with a chemically defined medium containing albumin. The ovaries were perfused for up to 15 h (mean 11.5 h) and then processed for morphological investigation. Both at the light- and electron-microscopical levels, most of the ovaries exhibited a normal structure comparable with ovaries in situ. In two cases, however, marked accumulations of bacteria were found, although not inside the follicles. Since ovulation in the rabbit normally occurs between 9.5–13 h after mating or human chorionic gonadotrophin treatment, this model seems adequate for studies of ovulation in vitro. It is, however, important to study the ovaries microscopically after the perfusion to detect artifacts, e.g., bacterial infection, that may have influence on the process of ovulation.
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    URL: http://dx.doi.org/10.1007/BF00213723
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    Regions of putative acetylcholine receptors at synaptic contacts between neurons maintained in culture and subsequently fixed in solutions containing tannic acid (1984)
    Springer
    Cell & tissue research 235 (1984), S. 85-89 
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    ISSN: 1432-0878
    Keywords: Tannic acid ; Acetylcholine receptors ; Tissue culture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Spinal cord neurons from 9-day chick embryos were maintained in culture for up to 35 days and then fixed in 4% cacodylate-buffered glutaraldehyde containing 2% tannic acid. After about 15 days in culture a small percentage of the synaptic specializations present were characterized by striking electron-dense striations averaging 15 nm in width, oriented perpendicular to the postsynaptic membrane. These structures increased in frequency with time in culture (to a maximum of about 10% of all synapses in the oldest cultures); they were asymmetrical, protruding approximately 8 nm into the synaptic cleft, and more deeply (approximately 15–18 nm), into the postsynaptic cytoplasm. On the basis of earlier work by Sealock (1980) they are interpreted as concentrations of acetylcholine receptors. Similar membrane differentiations were also seen associated with active-zone areas of a few presynaptic membranes, and the possibility that these represent presynaptic acetylcholine receptors is discussed. Additional observations reported are (1) the presence of striations resembling those seen at the postsynaptic membrane in the membranes of some postsynaptic vesicles, and (2) filamentous links between the striations and cytoskeletal elements of the postsynaptic cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00213727
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    Fine structure of monoamine-containing basal cells in the taste buds on the barbels of three species of teleosts (1984)
    Springer
    Cell & tissue research 235 (1984), S. 479-484 
    Details
    ISSN: 1432-0878
    Keywords: Monoamine-containing cells ; Taste bud ; Paracrine cells ; Mechanoreceptors ; Electron microscopy ; Teleosts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The taste buds on the barbels in three species of teleosts (Cyprinus carpio, Misgurnus anguillicaudatus, Parasilurus asotus) were studied by means of fluorescence and electron microscopy. Intensely yellow-fluorescent cells, which are disk-shaped and located exclusively in a basal position, are observed in the barbel-buds of all fishes examined. The basal cells contain a large number of small clear vesicles approximately 40–60 nm in diameter, which show a tendency to aggregate in the cytoplasm facing the junction of the nerve terminals; chemically transmitting synapses are seen in the latter region. It is suggested from the present observations that the basal cells in the barbel-bud may originate from Schwann cells and have a dual function both as mechanoreceptors and paracrine elements. Since the administration of 5,6-DHT results in an appearance of small dense vesicles among the small clear vesicles, the possibility exists that the basal cell may be capable of taking up monoamines and storing them in the small clear vesicles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00226942
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  • 89
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    Electron-microscopic demonstration of the distribution of calcium deposits in the exocrine pancreas of the rat after application of carbachol, atropine, cholecystokinin, and procaine (1984)
    Springer
    Cell & tissue research 235 (1984), S. 683-690 
    Details
    ISSN: 1432-0878
    Keywords: Exocrine pancreas ; Calcium pool ; Calcium release ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In an attempt to identify a cellular Ca2+-pool, from which calcium is released when secretagogues are applied, tissue fragments of the rat exocrine pancreas were incubated and fixed with glutaraldehyde in the presence of calcium. By means of this procedure electron-dense deposits were found on plasma membranes. X-ray microanalysis showed that these deposits contain calcium. Stimulation of tissue fragments with the use of the secretagogues carbachol or cholecystokinin reduced the number of deposits by about 80%. When the antagonist atropine was applied after carbachol stimulation, deposits reappeared on cell membranes, which then disappeared again after a second stimulation with cholecystokinin. In the presence of procaine, carbachol was inhibited and only slightly reduced the Ca2+-deposits on the plasma membranes. These results suggest that a calcium pool, from which calcium is released to induce enzyme secretion on stimulation, is located in the cell membrane
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    URL: http://dx.doi.org/10.1007/BF00226969
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  • 90
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    Morphological and morphometrical changes in chloride cells of the gills of Pimephales promelas after chronic exposure to acid water (1984)
    Springer
    Cell & tissue research 236 (1984), S. 121-128 
    Details
    ISSN: 1432-0878
    Keywords: Chloride cells ; Acid stress ; Gill ; Electron microscopy ; Fathead minnow
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Fathead minnows, Pimephales promelas, were exposed for 129 days to Lake Superior water acidified with sulfuric acid by means of a flow-through toxicant injection system. The effects of chronic acid stress (pH 6.5, 6.0, 5.5, 5.0) on gill histology were examined. Most of the histological effects were seen at pH 5.5 and 5.0 and were confined primarily to changes in numbers, distribution, and morphology of chloride cells. At low pH levels there tend to be more chloride cells in the gill epithelium and an increased percentage of these cells in the secondary lamellae. In contrast to normal chloride cells, chloride cells from fish exposed to low pH frequently had apical pits while some had bulbous apical evaginations. The occurrence of structural changes in chloride cells during exposure to acid water suggests that chloride cells may be involved in acclimation to acid stress.
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    URL: http://dx.doi.org/10.1007/BF00216521
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  • 91
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    Morphometric evaluation of lipid droplet associations with secretory vesicles, mitochondria and other components in the lactating cell (1984)
    Springer
    Cell & tissue research 236 (1984), S. 471-475 
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    ISSN: 1432-0878
    Keywords: Lactating cell ; Lipid droplets ; Secretory vesicles ; Mitochondria ; Intracellular associations ; Electron microscopy ; Milk secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The size, cellular location, and identity of surface-associated components were determined for lipid droplets in lactating cells. Transmission electron-microscopic measurements were made involving 3801 droplets in approximately 211 cells from three rats and 1197 droplets in 66 cells from a mouse. For the purposes of droplet evaluation, cells were divided into seven locations ranging from basal to secreting positions. Droplets were also categorized with respect to contact with other droplets, basolateral plasma membrane, mitochondria, Golgi apparatus, secretory vesicles, and endoplasmic reticulum-cytoplasm (ERC). Data on droplet size showed that droplet growth occurs mainly in the secretory position, confirming previously published findings. Lipid droplets from mouse tissue, although somewhat smaller in size showed similar growth trends to those of the rat. Data on numbers of droplet contacts and percentages of droplet circumferences involved in associations with other cell components showed that the dominant interaction of lipid droplets was with the ERC. However, intimate association of droplets with mitochondria was noted in all cellular locations. In addition, nursed animals exhibited a greater proportion of droplet surface association with secretory vesicles and less in contact with mitochondria in comparison to those not nursed. The significance of these relationships to milk synthesis and secretion is discussed.
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    URL: http://dx.doi.org/10.1007/BF00214252
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  • 92
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    Electron-microscopic study of silver staining of nucleoli in growing oocytes of rat ovaries (1984)
    Springer
    Cell & tissue research 236 (1984), S. 249-255 
    Details
    ISSN: 1432-0878
    Keywords: Oocyte ; Nucleolus ; Silver staining ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The nucleoli of dictyate-stage growing oocytes in rat ovaries were examined both with routine electron microscopy and electron microscopy after silver nitrate and ammoniacal silver nitrate (Ag-AS) staining. The nucleoli of the unilaminar follicular oocytes consist of twisted strands of dense fibrillar components, aggregates of granular components, and small fibrillar centers. After Ag-AS staining, silver grains are numerous on the dense fibrillar strands, fewer on the fibrillar centers, and very sporadic on the granular aggregates. The same stainability of three nucleolar components with the Ag-AS method was also confirmed in the nucleoli segregated by actinomycin D. During the transition of growing oocytes from bilaminar to plurilaminar follicle stage, the nucleolar dense fibrillar strands gradually conglomerate and are transformed into large and compact spherules. The stainability of dense fibrillar components with the Ag-AS method was lost along with this nucleolar transformation. These results may provide some new clues on the functional significance of AgAS-positive proteins in the nucleoli.
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    URL: http://dx.doi.org/10.1007/BF00214225
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  • 93
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    Fine structure of ependymal cysts in and around the area postrema of the rat (1980)
    Springer
    Cell & tissue research 206 (1980), S. 303-318 
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    ISSN: 1432-0878
    Keywords: Area postrema, rat ; Ependyma ; Cyst ; Circumventricular organs ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Peculiar cells forming cysts were observed in the area postrema and sometimes also in the choroid plexus and the tela chorioidea near the area postrema, and were studied in detail by electron microscopy. The cytological features of the cyst cell and its junctional relationship to neighboring cells imply that cyst cells are derived from ependymal and choroid epithelial cells. The cyst cells usually contact directly the perivascular spaces of postremal, choroidal or pial capillaries, where the cytoplasm is often considerably attenuated. The cystic lumen is commonly filled with a flocculent material. The limiting membrane of the cystic lumen, which frequently bears cilia and microvilli, has the same thickness as the surface cell membrane. In many cases, the cyst is surrounded by the cytoplasm of a single cell. In some cases, however, two cells participate in the formation of the cyst, although one is only a slender process and joined by a zonula occludens with the main cyst cell. Horseradish peroxidase (HRP) injected into the cerebrospinal fluid (CSF) space failed to enter the cystic lumen. A possible significance of the cyst in relation to the CSF and blood circulation was considered.
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    URL: http://dx.doi.org/10.1007/BF00232774
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  • 94
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    Incorporation of 3H-oleic acid by the proximal convoluted tubule cells of the chick (Gallus domesticus) (1980)
    Springer
    Cell & tissue research 210 (1980), S. 447-459 
    Details
    ISSN: 1432-0878
    Keywords: Lipid ; Kidney tubules, proximal ; Autoradiography ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Lipid metabolism in the cells of the renal proximal convoluted tubules (PCT) was investigated in healthy fowls and in fowls with the Fatty Liver and Kidney Syndrome (FLKS). The tissue was fixed at 10–25 min intervals after intravenous injection of 3H-oleic acid. The distribution of autoradiographic grains was analysed by the “circle method”. In normal cells most of the silver grains were associated with the cytoplasmic organelles. Lipid droplets and Golgi elements had the highest specific activity relative to the nuclear activity, which was little above background level. Lysosome-like bodies and mitochondria had lower values. In the cells of the FLKS-affected birds a large proportion of the grains was located over the lipid droplets, which are abundant in this condition. The specific activity of the cytoplasmic organelles was barely 2-fold higher than the nuclear activity. The results suggest that there is a diminished incorporation of esterified fatty acids by the organelles of these cells and that the excess is transferred to the lipid droplets. The identity of low electron density particles observed in the PCT cells of severely affected birds is discussed.
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    URL: http://dx.doi.org/10.1007/BF00220201
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    Gut hormones in Salamandra salamandra (1980)
    Springer
    Cell & tissue research 211 (1980), S. 331-343 
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    ISSN: 1432-0878
    Keywords: Gut hormones ; Endocrine cells ; Electron microscopy ; Immunocytochemistry ; Peptidergic innervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Histological, cytochemical and immunocytochemical methods were used in light and electron microscopical studies to demonstrate the presence of a neuroendocrine system in the gut of the urodele, Salamandra salamandra. Cytochemical stains capable of detecting peptide-producing endocrine cells demonstrate cells reacting with Masson's silver (argentaffin) method, Grimelius' argyrophil silver method, masked metachromasia method and the lead haematoxylin stain. Using antisera raised to a variety of mammalian gut peptides, cells containing bombesin-, gastrin-, somatostatin-, substance P- and glucagon-like immunoreactivity were identified; vasoactive intestinal polypeptide- and substance P-like immunoreactivities were found in nerve fibres in the submucous and myenteric plexus. No immunoreactivity was detected for motilin, gastric inhibitory polypeptide, cholecystokinin or secretin. The ultrastructure of the immunoreactive cells and nerves was revealed by the semithin/thin method. All the cells identified contained numerous electrondense secretory granules, which varied in their chracteristic morphological structure from one cell type to another. The evidence collected in this study indicates that a complex neuroendocrine system regulating gut function is present in this amphibian and may have developed prior to the emergence of the phylum.
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    URL: http://dx.doi.org/10.1007/BF00236453
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  • 96
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    Double membrane-bounded intestinal microvilli in Oncopeltus fasciatus (1983)
    Springer
    Cell & tissue research 232 (1983), S. 593-600 
    Details
    ISSN: 1432-0878
    Keywords: Peritrophic membrane ; Insect ; Microvilli ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A double plasma membrane (DPM) surrounding intestinal microvilli of the migratory milkweed bug, Oncopeltus fasciatus, is described. Mutant and wild types of the phytophagous insect have been studied by conventional SEM and TEM procedures with the use of membrane-enhancing staining methods. Longitudinal and transverse sections revealed a DPM surrounding microvilli and continuing over the apical portions of the intestinal cell. The outer membrane of the DPM contributes to an intestinal lining or peritrophic membrane (PTM), which apparently accumulates in layers. SEM studies reveal a rugose intestinal surface and complete PTM in both starved and fed insects. Only rarely are exposed microvilli seen by SEM. SEM examinations also enable the observation of numerous blebs on the luminal side of the PTM apparently held in position by a neck-like attachment and apparently derived from the outer membrane of the DPM. Preliminary TEM studies of microvilli revealed unique microvesicle-like structures, lying just inside the inner membrane of the DPM, which may be of membrane origin based on their typical trilaminar appearance after en bloc staining with uranyl acetate. Highly ordered microfilaments were observed to occupy the most central aspect of the microvilli.
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    URL: http://dx.doi.org/10.1007/BF00216431
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  • 97
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    Ultrastructural characteristics of vasopressin-containing neurons in the paraventricular nucleus of the hypothalamus (1983)
    Springer
    Cell & tissue research 234 (1983), S. 125-134 
    Details
    ISSN: 1432-0878
    Keywords: Vasopressin ; Immunocytochemistry ; Electron microscopy ; Hypothalamus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Vasopressin-containing neurons, identified by immunocytochemistry, are located predominantly in the posterior magnocellular division of the paraventricular nucleus of the rat hypothalamus. By electron microscopy, the immunoreaction product is seen within the cell bodies and neuronal processes. In the perikarya and dendritic processes, the immunoreactive material is associated primarily with neurosecretory granules. Axonal processes, identified by their content of microtubules and accumulation of neurosecretory granules, show the immunoreaction product in association with both of these organelles. Afferent axo-dendritic, axo-somatic and putative axo-axonic synapses with immunostained vasopressinergic neurons can be identified. The presynaptic profiles do not contain immunoreactive material. This study contributes to the ultrastructural characterization of vasopressinergic neurons in the paraventricular nucleus and of their afferent synaptic input.
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    URL: http://dx.doi.org/10.1007/BF00217406
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  • 98
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    Laminated figures of the intercisternal regions of dictyosome-like structures from guinea-pig spermatocytes fixed with glutaraldehyde-tannic acid (1983)
    Springer
    Cell & tissue research 234 (1983), S. 633-639 
    Details
    ISSN: 1432-0878
    Keywords: Dictyosome-like structures ; Golgi apparatus ; Phosphatidylcholine ; Laminated figures ; Electron microscopy ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dictyosome-like structures (DLS) of guinea pig spermatocytes, when prefixed in mixtures of glutaraldehyde and tannic acid, exhibited laminated figures with a repeating periodicity of about 4.5 nm in the spaces between DLS saccules or in association with the surfaces of the DLS saccules. These laminated figures were similar to those figures derived from saturated lipids in other tissues. Alternatively, spaces between saccules were collapsed leaving only thin, electron-dense material separating adjacent saccules. These changes were not observed when the DLS were prefixed in glutaraldehyde before exposure to tannic acid. The presence of laminated figures following fixation with tannic acid and osmium tetroxide suggests that saturated lipids are present in, or associated with, the intersaccular regions of the DLS. The distribution of laminated figures in other membrane structures was not affected by post fixation with tannic acid nor were laminated figures comparable to those of the DLS observed between cisternae of the Golgi apparatus. These results support previous conclusions that DLS are distinct from Golgi apparatus and are a unique component of the germ cell cytoplasm.
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    URL: http://dx.doi.org/10.1007/BF00218656
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  • 99
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    Structure of the parathyroid glands, as revealed by different methods of fixation (1984)
    Springer
    Cell & tissue research 235 (1984), S. 51-58 
    Details
    ISSN: 1432-0878
    Keywords: Parathyroid glands ; Electron microscopy ; Light microscopy ; Quantitative histology ; Mongolian gerbil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Stereology and semi-automatic image analysis were used with the aim of comparing the structure of parathyroid glands from untreated adult Mongolian gerbils fixed by immersion with those fixed by perfusion. Subclassification of the chief cells based upon the staining affinity or electron density of the cytoplasm was readily performed only in glands fixed by immersion, and so-called atrophic cells were observed only in these glands. The atrophic cells were often surrounded by “light” chief cells. In glands fixed by perfusion, “light” chief cells were only rarely encountered. A significant difference between glands fixed by immersion and those fixed by perfusion was found only with regard to the form of cells and nuclei, those fixed by perfusion being more spherical. When comparing individual cells within glands fixed by immersion, “light” chief cells were more spherical and had a significantly larger nuclear and cellular size, and a lower mitochondrial volume density than the “intermediate”/“dark” chief cells. Otherwise there were no significant differences in any of the parameters investigated. These data indicate that occurrence of socalled “light” chief cells and atrophic cells is a result of improper fixation. The results of this study do not favour the concept of a functional cycle with a simultaneous occurrence of active and inactive cells within parathyroid glands.
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    URL: http://dx.doi.org/10.1007/BF00213722
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  • 100
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    Interdigitating cells in the lymphoid tissues of bovine fetuses and calves (1984)
    Springer
    Cell & tissue research 235 (1984), S. 153-158 
    Details
    ISSN: 1432-0878
    Keywords: Bovine ; Interdigitating cell ; Lymphoid tissues ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron-microscopic studies of lymphoid tissues from bovine fetuses and from calves disclosed a non-lymphoid cell type in the thymus-dependent zones of secondary lymphoid tissues and in the thymus that is distinguishable from reticulum cells, epithelial and endothelial cells, and macrophages. Based on morphological and topographical criteria, the cell is identified as the interdigitating cell. In addition, studies of the tissues of normal and virus-challenged fetuses, and of conventionally reared calves, indicated that the interdigitating cells originate from monocytoid cells, which undergo differentiation in the thymus-dependent zones during an immune response.
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    URL: http://dx.doi.org/10.1007/BF00213735
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