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  • Springer  (92,711)
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  • 1984  (53,273)
  • 1981  (47,750)
  • 1
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary The mound builderMacrotermes michaelseni forages in Kenya semi-arid pastures. Each colony (4/ha) utilizes 130 to 600 m2 in average per month. The distribution of foraging holes 22 000 to 50 000 per nest) shows an overall spatial activity. The 24h foraging activity is mainly nocturnal and the seasonal variation presents three peaks per year. This activity depends partly on temperature and rainfall but the internal economy (sexual brood production within the colony) plays a decisive role.
    Notes: Resume Macrotermes michaelseni est un constructeur de termitières épigées qui récolte en strate herbacée dans les pâturages semi-arides du Kenya. Chaque colonie (4/ha) exploite en moyenne 130 à 600 m2 par mois. La répartition des orifices de récolte (22 000 à 50 000 par colonie) démontre que l'ensemble du milieu est utilisé. On envisage la variation journalière de l'activité de récolte (essentiellement nocturne) ainsi que sa périodicité saisonnière (3 maximums annuels). Cette activité est partiellement reliée à la température et aux pluies, mais l'économie interne des colonies (production du couvain de sexués) est aussi déterminante.
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  • 2
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    Insectes sociaux 28 (1981), S. 341-342 
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Nestgründung von einer Arbeiterin der japanischen Falten WespePolistes chinensis antennalis wurde im Juni 1979 beobachtet. Diese Arbeiterin ausschlüpft im Juni 1979 aus einem anderen Nest und reparierte ein verlassenes Nest und zog darin einige Larven aus. Diese ist die erste Entdeckung der Nestgrüdung von einer Arbeiterin in der Unterfamilie Polistinae.
    Notes: Summary The nest foundation by a single worker of the Japanese paper waspPolistes chinensis antennalis was observed in July, 1979. This worker had emerged from another nest in June 1979, and repaired an abandoned nest and reared some larvae there. This is the first discovery of nest foundation by a worker in the subfamily Polistinae
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  • 3
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary The present work follows the study ofMacrotermes michaelseni foraging activities (Lepage, 1981) and deals with its food requirements. The yearly food offtake ranges between 800 and 1500 kg/ha. The harvest is 25 to 30% below in lean year (1976). Termites and large mammals offtakes are similar but they take place at different times of the ecosystem cycle: rainy season for mammals and dry season for termites.Macrotermes would prefer grass litter on the ground if available, but can switch to standing crop as the ecosystem becomes more arid. From this work it is possible to understand howMacrotermes could be a pest in these pastures.
    Notes: Resume Cette étude envisage la prise de nourriture du termiteMacrotermes michaelseni en strate herbacée et complète les observations rapportées précédemment sur le cycle de récolte du termite (Lepage, 1981). Le prélèvement varie de 800 à 1500 kg/ha/an et il est de 25 à 30% inférieur lorsque l'année est déficitaire en pluies (1976). Cette récolte est comparée à l'action des grands Mammifères herbivores présents sur le lieu de l'étude: les quantités globales (herbe et litière) sont du même ordre. Mais l'impact sur l'écosystème n'intervient pas au même moment: saison des pluies pour les Mammifères, saison sèche pour les termites.Macrotermes préfère la litière graminéenne au sol mais consomme progressivement l'herbe sur pied à mesure que l'écosystème devient plus aride. Il est possible de comprendre, d'après ces observations, commentMacrotermes peut devenir nuisible pour ces pâturages semi-arides.
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  • 4
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    Insectes sociaux 28 (1981), S. 347-352 
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Ungefähr 18% der Arbeiterinnen vonLasioglossum zephyrum werden unter natürlichen Freilandbedingungen begattet. In der Gefangenschaft variiert die Bereitschaft der Weibchen zur Begattung mit dem Alter und dem Kastenzustand: 1) Von anderen Weibchen isolierte Weibchen paarten sich zu 69% innerhalb von drei Tagen nach dem Schlüpfen. 2) In Nestgruppen von je sechs Bienen paarten sich alle Königinnen, jedoch nur 7,7 % aller Arbeiterinnen. 3) Nach künstlicher Entfernung der Königin verpaarten sich die Ersatzköniginnen in allen von zehn Fällen. Diese Ersatzköniginnen waren alle vorher in Gegenwart der alten Königin unverpaart. 4) In einer Kolonie von fünf Bienen paarten sich alle drei Ersatzköniginnen nachdem der Reihe nach die jeweilige Königin entfernt worden war. Gleichzeitig wurden keine der jeweiligen Restarbeiterinen begattet. Diese Ergebnisse zeigen an, dass die Königin die Paarungsbeitschaft der Arbeiterinnen auch ausserhalb des Nestes inhibiert. Es erscheint möglich, dass sich Inhibition durch eine Königin nicht nur auf die Grösse der Ovarien von Arbeiterinnen auswirkt.
    Notes: Summary About 18 percent ofLasioglossum zephyrum workers mate in the field. In the laboratory female mating receptivity varied with age and caste: 1) sixty-nine percent of bees less than 3 days old mated when kept isolated from other females, 2) in six-bee colonies all of the queens, but only 7,7 percent of their workers, mated, 3) in queen removal experiments involving 10 colonies, all the replacement queens mated (these same individuals were not receptive to mating as workers), 4) in one colony of 5 bees, consecutive queen removal showed that each of the four bees identified as the queen mated, while none of the remaining workers did so. The results indicate that queen inhibition governs behavior of the workers even outside the nest. The inhibition may involve more than differences in ovarian size.
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  • 5
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    Insectes sociaux 28 (1981), S. 353-370 
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary Workers ofMyrmica rubra cluster around living queens from their own colony. Workers also cluster around these same queens after they are killed and kept for one or two hours. The suggestion is that the factors causing these aggregations are at least partly chemical, for dead queens are unable to give movement or acoustical signals. Also, the form of the queens'body is unable to induce the clustering response. The chemical signals causing aggregation, emitted by the queen, are not very volatile and/or they are well adsorbed by her cuticle. They oxidise rapidly after 3–4 hours exposure to the air and they continue to denature, losing their ethological activity, for the subsequent 2–3 days. They deteriorate when warmed to a temperature of 50°C for a few minutes. Organic solvents denature them rapidly and may extract them whereas distilled water has no effect upon them. The chemical factors are uniformly distributed over the external surface of the queen's body and it seems that they are not produced by the metapleural glands. The experiments, producing the above results, are detailed and discussed raising questions and hypotheses that we will consider in future work.
    Notes: Resume Les ouvrières deMyrmica rubra s'agrègent autour de reines indigènes vivantes, et de ces mêmes reines mortes depuis 1 ou 2 heures. Les facteurs responsables de ces agrégations sont, au moins partiellement, de nature chimique. Ils ne sont ni gestuels, ni acoustiques, et la forme du corps des reines est incapable, à elle seule, d'agréger les fourmis. Les facteurs chimiques agrégatifs propres aux reines sont peu volatiles et/ou bien adsorbés sur la cuticule des reines. Ils s'oxydent à l'air au bout de 3 ou 4 heures puis se dégradent encore d'une autre manière, progressivement, au cours du temps. Un passage de quelques minutes à une température voisine de 50°C les altère. Les solvants organiques, mais non l'eau distillée, les dénature rapidement et les extraient peut-être. Enfin, ces facteurs chimiques se répartissent uniformément sur toute la surface externe du corps des reines, et ils ne semblent guère provenir des glandes métapleurales. Après avoir détaillé nos travaux, puis discuté des renseignements acquis, nous posons des questions et hypothèses à envisager dans la suite de notre étude.
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  • 6
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume La «fourmi de feu»,Solenopsis invicta Buren, a trois principaux groupes fonctionnels d'ouvrières: les fourrageuses, les «stockeuses de réserves» et les nourrices. En utilisant un nid spécialement construit, nous avons pu séparer ces groupes fonctionnels. Nous avons donné aux fourmis de l'iode radio-actif (1251) mélangé à de la poudre de jaune d'œuf, de l'huile de soja ou une solution de miel à 50 % pendant 10 minutes. Le nombre de fourmis par nid et la quantité de nourriture marquée, consommée par fourmi, ont ensuite été mesurés. Lorsqu'elles ont reçu du miel ou de l'huile de soja, les colonies répondent en augmentant le nombre de fourrageuses et de «stockeuses de réserves» actives. Avec les deux sortes de nourriture, les fourrageuses consomment de grandes quantités de liquide; elles en transmettent des quantités plus petites aux «stockeuses de réserves» et aux nourrices. Lorsqu'on donne du miel «à 50 %» aux fourmis, moins de 0,2 % du miel recueilli par les fourrageuses parvient à la colonie; seulement 5 % des larves sont nourries après 10 minutes. Lorsqu'on donne de l'huile de soja, 2 % de l'huile recueillie parvient aux larves: à peu près 35 % des larves sont nourries après 10 minutes. Lorsqu'on donne de la poudre de jaune d'œuf, le nombre de fourrageuses est bas, mais celles-ci viennent plusieurs fois; elles laissent la nourriture à la périphérie du nid ou la transmettent aux «stockeuses de réserves». Les «stockeuses de réserves» transmettent rapidement la nourriture aux nourrices de sorte que, par rapport à l'huile et au miel, la quantité de nourriture consommëe par fourmi est la plus élevée parmi les nourrices. A peu près 80 % du couvain est nourri avec de la poudre de jaune d'œuf durant la période de 10 minutes, ce qui représente 6 % du jaune d'œuf recueilli par les fourrageuses. De cette étude, il apparaît que les ouvrières peuvent distinguer différents types de nutriments et, en conséquence, adapter leur comportement.
    Notes: Summary The imported fire ant,Solenopsis invicta Buren has three main functional worker groups: foragers, reserves, and nurses. By using a specially designed nest we were able to separate these functional groups by location. The ants were presented with 125 Iodine mixed with egg yolk powder, soybean oil, or 50 % honey solution for 10 minutes. The number of ants per nest location and the quantity of radiolabelled food consumed per ant were then measured. When presented with honey or soybean oil, colonies responded by increasing the number of foragers and active reserves. With both foods the foragers took in large quantities of liquid, passing on smaller amounts to the reserves and the nurses. When ants were presented with 50 % honey, less than 0.2 % of the honey collected by the foragers reached the brood. Only 5 % of the larvæ were fed after 10 minutes. When soybean oil was presented, 2 % of the oil collected reached the larvæ and approximately 35 % of the larvæ had been fed after 10 minutes. When the ants were presented with egg yolk powder, the number of foragers was low but they made repeated trips, leaving food on the nest periphery or passing it on to the reserves. Reserves relayed food rapidly to the nurses so that, in contrast to oil and honey, the quantity of food consumed per ant was greatest among the nurses and lower among the reserves and the foragers. Approximately 80 % of the brood were fed egg yolk powder within the 10 minutes period receiving 6 % of the egg yolk collected by the foragers. From this study it appears that workers can discriminate between nutrient types and adjust their behaviour accordingly.
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  • 7
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    Insectes sociaux 31 (1984), S. 51-73 
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary Seed harvesting by the antMessor galla has been followed over a 2.5-year period in a woodland savanna of the sahelo soudanian zone, where seeds are produced only once a year, in restricted and fluctuating numbers following a short rainy season. Ants harvesting was highly seasonal. At the onset of the dry season, when new seeds were available, the ants harvested very intensively and exhibited a clear choice of some seeds they stored in their underground granaries. Their activity decreased there-after and remained low and irregular: the ants mainly collected the most abundant seed species found in their nest vicinity. The yearly total collected ranged between 3.105 and 4.106 seeds for each colony studied (1 to 19 kg in fresh weight). In an area studied more precisely in 1978–79, 1979–80 and 1980–81, the ants harvesting amounted to 4, 5 and 4 kg ha−1 yr−1, which represented respectively 0.4, 1.7 and 0.5% of the annual herbaceous seed production. In 1978–79, 3 studied colonies did not seem to have stored in their nest more than one annual harvest. Ants harvesting varied in space and in time, according to the available resources around their nests. This adaptibility is considered to be an effective adjustment to a fluctuating food supply.
    Notes: Resume La récolte des fourmis granivoresMessor galla a été suivie pendant deux ans et demi, dans un milieu sahélo-soudanien où les graines sont produites une fois par an, à l'issue d'une courte saison des pluies, en quantités limitées et variables selon les années. La récolte des fourmis est très saisonnière. En début de saison sèche, lorsque les nouvelles graines de l'année arrivent à maturité, les fourmilières récoltent intensément et montrent une nette préférence pour certaines graines qu'elles mettent en réserve. Leur activité décroît ensuite et reste faible et irrégulière tout le reste de l'année; elles ramènent alors essentiellement les graines les plus abondantes du milieu environnant leur nid. Les récoltes annuelles des fourmilières étudiées ont varié, selon la taille des colonies, de 3×105 à 4×106 graines, et de 1 à 19 kg. Dans un quadrat suivi plus précisément, les fourmis ont récolté successivement chaque année en 1978–80, 1979–80 et 1980–81, 4, 5, puis 4 kg/ha de graines, ce qui a représenté 0,4, 1,7, puis 0,5% de la production annuelle de graines par la végétation herbacée. En 1978–79, 3 colonies étudiées ne semblaient pas avoir stocké dans leurs nids plus d'une année de récolte. La récolte des fourmis a varié dans le temps et dans l'espace en fonction des disponibilités du milieu entourant leur nid. Cette plasticité semble être une réponse adaptée à la variabilité saisonnière et interannuelle des disponibilités alimentaires.
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  • 8
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    Insectes sociaux 31 (1984), S. 74-86 
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume Cette étude faite sur le terrain dans le désert du sud-ouest des Etats-Unis différencie le comportement social de cinq espèces de fourmis moissonneuses:Pogonomyrmex barbatus, P. rugosus, P. maricopa, P. desertorum, P. californicus. Les espèces diffèrent significativement quant à leurs rythmes d'activité pour plusieurs tâches (fourragement, maintien du nid, surveillance, maintien des débris, rassemblement), ainsi que pour l'utilisation de l'espace autour du nid et la réaction de la societé à un dérangement. En général, les différences de comportement peuvent s'organiser en fonction de la quantité habituelle d'ouvrières hors du nid. Chez les espèces ayant une plus grande quantité d'ouvrières à l'extérieur du nid, l'organisation de la société met plus en valeur l'acquisition de la nourriture et la territorialité. Par contre, les espèces ayant moins d'ouvrières hors du nid ont un comportement social qui leur permet de réduire leur contact avec d'autres sociétés. En examinant les régularités temporelles et spatiales du comportment social, on peut mieux comprendre les rapports interspécifiques chez les communautés de fourmis.
    Notes: Summary This field study examines the social behavior of five sympatric species of desert seed-eating ants (Pogonomyrmex barbatus, P. rugosus, P. maricopa, P. desertorum, P. californicus). The species differed significantly in measures of activity rhythms in various colony tasks, use of space around the nest yard, and reaction to disturbance. Species differences were related to the typical size of a colony's outside work force. The behavior ofP. rugosus, P. barbatus, andP. maricopa, which had larger outside work forces, emphasized territoriality and the acquisition of food; that ofP. desertorum andP. californicus, which had smaller outside work forces, emphasized the avoidance of contact with other colonies. Examining the patterns in colony behavior can illuminate interspecific relationships in desert ant communities.
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  • 9
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    Insectes sociaux 31 (1984), S. 103-111 
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Neständerungen der Weibchen einer neotropischen Faltenwespe,Polìstes versicolor, wurde in Panama beobachtet. In erstem Falle wurden häufige Lageänderungen zwischen zwei benachbarten Nestern beobachtet. Einmal wechselte ein ovariell höchstentwickeltes Weibchen häufig die Nester. In zweitem Falle, verliessen vielleicht alle Weibchen desselben Nestes und wurden von einem naheliegenden Neste aufgenommen. In letztem Falle, wurden einige Arbeiterinnen eines Nestes angenommen von einem anderen Nest, deren Gründerinnen wahrscheinlich nicht ihre nahe Verwandten waren. Die Verhalten bei Umnestung wurden beschrieben.
    Notes: Summary Shifts of females ofPolistes versicolor between adjacent nests were observed in Panama. In the first case, females of two neighboring nests frequently changed their positions and one female who had developed eggs in ovaries shifted between the nests repeatedly. In the second case, possibly all females shifted to a nearby nest after abandonment of their original nest and were accepted by females of the new nest. In the third case where workers shifted, relatedness between them and foundresses of the new nest was considered to be low. Behaviours accompanying the shifts are described.
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  • 10
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume Nous avons étudié le cycle biologique de la fourmi myrmicinePristomyrmex pungens. En général, les colonies de cette espèce se composent de plusieurs milliers de petites ouvirères, tandis qu'un petit nombre de mâles (2–3 %) apparaissent occasionnellement en juin et juillet dans les colonies mûres et que de grandes ouvrières à ocelles et spermathèque abortive (reines ergatoïdes) ont pu être observées très rarement. Nous avons démontré que les petites ouvrières vierges peuvent pondre des œufs qui donnent d'autres petites ouvrières. Les cellules des ganglions cérébroïdes et les ovogonies des ouvrières sont diploïdes (2 n=24), mais la formule haploïde (n=12) a pu être observée chez les ovocytes au stade pachytène ainsi que chez les spermatocytes des mâles. Ces mâles possèdent des organes copulatoires normaux et leur spermatogenèse est normale, mais ils ne fécondent probablement pas les petites ouvrières, lesquelles sont dépourvues de spermathèque et d'organes copulatoires fonctionnels. Ces observations indiquent que la reproduction chezP. pungens est assumée de façon prépondérante, et probablement complètement, par les petites ouvrières, de façon par conséquent thélytoque. Nous discutons l'évolution du cycle biologique deP. pungens, en soulignant la difficulté d'appliquer à cette espèce le concept de “reine” ou même de décider si elle est »eusociale» ou non. Au regard de l'isolement génétique présumé entre colonies, le mode de sélection maintenant dans ce cas une structure sociale est probablement davantage une sélection de groupe interdémique plutôt qu'une sélection de parentèle.
    Notes: Summary The life cycle of the myrmicine antPristomyrmex pungens was investigated. Colonies of this species are usually composed of several thousand small workers, although a few males (2–3 %) occasionally appear during June and July in mature colonies, and large workers with ocelli and abortive spermathecae (here termedergatoid queens) were observed extremely rarely. We found that the virgin small workers can lay eggs and that these develop into further small workers. Cerebral ganglion cells and oogonial cells had the diploid chromosome number (2 n=24), but the haploid number (n=12) was observed in oocytes at pachytene, and also in spermatocytes from the rare males. Males have functionally normal copulatory organs and their spermatogenesis is normal, but they probably do not mate, because small workers have no spermatheca and their copulatory organs are degenerative. These observations indicate that reproduction inP. pungens is carried out predominatly or, probably, wholly by the small workers and hence is thelytokous. We discuss the evolution of theP. pungens life cycle, pointing out the difficulty of applying the “queen” concept to this species or even in deciding whether or not it is “eusocial”. In view of the apparent genetic isolation between colonies, the mode of selection maintaining sociality in this case is probably interdemic group selection rather than kin selection.
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  • 11
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary In investigating the antennal positions and movements associated with the transfer of substance from one worker ant to another, during trophallactic contacts, the question arises as to whether these different positions and movements act as particular singals. InCamponotus vagus, these behavioural units are organized into sequences. There is no stereotypy in the sequences: recordings show great variability, particularly in the donor ant. On the other hand, differences in the organization of sequences and in their variability were seen to be related to the worker's social function (forager or broodtender worker). Trophallactic behaviour in the two partners was analysed using different methods (slow motion film with frame by frame analysis; use of radioelements with simultaneous recording of trophallactic flux and antennal movements; cross-correlogrammes). No definite system of signals and responses corresponding to antennal movements was found to underly the ant's trophallactic behaviour. But it does not exclude that the antennæ activity as a whole, owing to its structure may have a function in communication.
    Notes: Resume L'étude des positions et mouvements d'antennes qui accompagnent les transferts de substances d'une ouvrière de Fourmi à l'autre, au cours des contacts trophallactiques, pose le problème de la valeur de signal de ces différents actes. ChezCamponotus vagus, ces unités comportementales sont organisées de manière séquentielle. Il n'y a pas stéréotypie des séquences; on enregistre une grande variablité, en particulier chez l'ouvrière donneuse. D'autre part, il apparaît des différences dans l'organisation des séquences et leur variabilité, en relation avec la fonction sociale exercée par l'ouvrière (récolteuse ou nourrice). L'analyse du comportement trophallactique des deux partenaires, par plusieurs méthodes différentes (cinéma accéléré avec analyse image par image, emploi des radio-éléments avec enregistrement simultané des actes et du flux trophallactique, cross-corrélogrammes), a permis de montrer que leurs actes ne constituent pas, au niveau antennaire, un système précis de signaux et de réponses. Ceci n'exclut pas la possibilité que l'activité antennaire globale ait par sa structure une fonction de communication.
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  • 12
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    Insectes sociaux 31 (1984), S. 132-141 
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume Pour chacune des trois espèces de fourmis de la famille Dolichoderinæ, quatre modèles de reproduction des colonies ont été examinés par électrophorèse: (1) chaque colonie provient d'une seule femelle inséminée une seule fois, (2) chaque colonie provient d'une seule femelle inséminée deux fois, (3) les colonies proviennent de deux reines «égales», chacune inséminée une seule fois, et (4) les colonies proviennent de trois reines «égales», chacune inséminée une seule fois. Pour chacun de ces modèles, la fréquence des colonies de chaque composition génétique a été calculée et comparée avec la distribution observée. Les colonies étudiées deConomyrma insana sont de type monogyne. Un grand nombre des colonies étudiées deConomyrma bicolor sont de type polygyne fonctionnelle. La polygynie se trouve dans toutes les localités examinées. Peut-être la polygynie se trouve-t-elle aussi chezIridomyrmex pruinosum. Sa fréquence est peut-être moins grande que chezC. bicolor.
    Notes: Summary For each of three species of dolichoderine ants, four mating system models were tested electrophoretically. The models tested were: (1) each colony is derived from one, singly-inseminated female, (2) each colony is derived from one female, inseminated twice, (3) colonies have two, coequal, singly-inseminated queens, and (4) colonies have three, coequal, singly-inseminated queens. From each of these models, expected frequencies of colonies of various genotypic compositions were calculated. Goodness of fit of actual colony types were then tested. Conomyrma insana colonies were shown to be monogynous. A large number of theConomyrma bicolor colonies studied are functionally polygynous. Polygyny occurs in all localities examined. Polygyny may also occur inIridomyrmex pruinosum. Its occurence may be less widespread than inC. bicolor.
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  • 13
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary The characteritics of tandem running were analysed in two species of Ponerine ants from tropical Africa, together with the stimuli causing either the leader or the follower to start or to maintain the tandem running. With regard to the genusMesoponera, tandem running allows the recruitment for the capture of a mobile and voluminous prey, the collective transport of a dead insect untransportable by a sole individual, the hunting of small preys and the collection of sugared substances. The genusHypoponera makes use of tandem running to recruit but only in the instance of dismembering of large prey. On the other hand it was shown that in one of the species (Hypoponera sp.), the number of tandems formed can depend on various olfactory stimuli perceived in the nearby environment of the colony. A change in certain elements of the environment can therefore cause specific effects in some of the complex interactions observed in ant societies.
    Notes: Resume J'ai analysé, chez deux espèces de Fourmis Ponérines d'Afrique tropicale, les caractéristiques de la marche en tandem et les stimuli qui interviennent, agissant sur l'ouvrièreguide ou sur l'ouvrière recrutée, pour déterminer la mise en route ou le maintien des tandems. Pour le genreMesoponera, les tandems permettent le recrutement pour la capture d'une proie mobile et volumineuse, mais aussi pour le transport collectif d'un insecte mort qui ne peut être transporté par une seule ouvrière, — ou pour la chasse d'un grand nombre de petites proies, enfin pour la récolte d'une substance sucrée. Le genreHypoponera utilise le tandem pour recruter, mais uniquement lors du dépeçage d'une proie volumineuse. D'autre part, j'ai montré que chezHypoponera sp. le nombre de tandems peut dépendre de stimuli olfactifs déterminés, perçus dans le très proche environnement de la société. Par conséquent, la modification de certains éléments de l'environnement peut avoir une action spécifique sur la manifestation d'interactions complexes observées dans les sociétés de Fourmis.
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    Insectes sociaux 31 (1984), S. 335-340 
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    Topics: Biology
    Description / Table of Contents: Resume Les réponses variées à l'humidité relative chez quatre espèces de fourmis de feu qui se trouvent au Texas (Solenopsis aurea, S. geminata, S. invicta, etS. xyloni) ont été examinées avec une chambre gradient linéaire. Seuls les ouvriers n'ont pas montré de réponse hydrokinétique, tandis que les ouvrières soigneuses de toutes les espèces examinées ont montré une préférence marquée (hydrokinesis négative) pour les atmosphères saturées (près de 100 % d'humidité relative). Les réponses sont probablement causées par la sensibilité plus élevée de la couvée à la dessication.
    Notes: Summary The responses of the four fire ant species found in Texas (Solenopsis aurea Wheeler,Solenopsis geminata Fabricius,Solenopsis invicta Buren, andSolenopsis xyloni McCook) to varied relative humidities were examined. Humidity preferences of worker ants were determined with a linear gradient chamber. Workers alone did not exhibit any hydrokinetic responses, whereas brood tending workers of all species tested showed a marked preference (negative hydrokinesis) for saturated atmospheres (near 100 % RH). The responses are presumably due to the broods' hogher susceptibility to desiccation.
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    Notes: Summary Because social parasites are relatively rare in tropical ant faunas, new or poorly known forms deserve special attention. TwoPheidole species evidently parasitic onP. indica are here described as new species from India (P. lanuginosa, P. parasitica), while a previously known northern South American form,P. microgyna Wheeler, is redescribed and evaluated as a possible parasite ofP. minutula or a closely related host species. Next, all of the nine certain or likely social parasites ofPheidole known worldwide are compared, and an anatomical parasitic syndrome is identified through character state analysis. The nine species appear to be independently evolved. The parasitic character states have tended to evolve within each of these species at different rates, and hence the evolution is interpreted as having been not only parallel among species but mosaic in nature within species (seetable I). In spite of the lesser irregularities in this pattern, an overall trend is evident: the first changes to occur were loss of the worker caste (a loss still incomplete in the overall slightly modifiedP. inquilina), reduction of size, lengthening of the scape, reduction of sculpturing on the body surface, and broadening of the postpetiole. These shifts were followed by reduction of the mandibles and the segments of the funiculus. The generaAnergatides andBruchomyrma, each based on a single extremely advanced species, are placed in synonymy underPheidole. The problematic generaHagioxenus, Parapheidole, andSifolinia are compared withPheidole and their status evaluated. The greater known diversity of parasitic ants in the temperate zones, as compared with the tropics, remains a key problem in the study of ant evolution. Whether the difference is genuine or an artifact of differential sampling cannot be determined until more intensive collecting is undertaken in the tropics.
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    Insectes sociaux 31 (1984), S. 387-402 
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    Description / Table of Contents: Summary A detailed investigation of polyethism was carried out on a colony ofNeoponera (=Pachycondyla sensuBrown, 1973) obscuricornis, involving behavioural observations on its inhabitants, and subsequent dissection of each. Ovariant development in each ant was closely related to its social status. Ovaries are well developed among nuress and totally degenerate in foragers. This is the case in both gynes and workers, and ovarian polymorphism between the two castes is only weakly marked. The evolutionary implications of the observed relationships between nursing behaviour and reproductive ability are discussed.
    Notes: Resume L'étude détaillée du polyéthisme par l'observation des activités individuelles dans une société deNeoponera (=Pachycondyla sensuBrown, 1973)obscuricornis a été suivie de la dissection de tous les individus. L'état ovarien de chaque fourmi est en relation avec son statut social dans la colonie: développé chez les sogneuses, l'ovaire a complètement régressé chez les fourrageuses. Ce phénomène s'observe aussi bien chez les femelles que chez les ouvrières, seul un faible polymorphisme ovarient permettant de distinguer les deux castes. Les implications évolutives d'une liaison entre les conduites parentales et l'aptitude à la ponte sont discutées.
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    Insectes sociaux 31 (1984), S. 375-386 
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    Description / Table of Contents: Resume Les relations génétiques de huit espèces de guêpes d'Europe du nord, représentantVespula s. str. (le grouperufa),Paravespula (le groupevulgaris) etDolichovespula, sont étudiées ici par électrophorèse enzymatique. Le niveau de variation génétique intraspécifique observé est relativement bas, et les populations du sud de la Finlande ne montrent pas de différences géographiques nettes. Les caractères d'allozymes sont ensuite utilisés pour construire des arbres phylogénétiques par quatre techniques de construction. Il est suggéré queDolichovespula media n'est pas étroitement apparentée aux autres espèces deDolichovespula européens, et queParavespula etVespula s. str. ne forment peut-être pas un seul groupe monophylétique. Deux des espèces étudiées,V. austriaca etD. omissa, sont des parasites sociaux obligatoires. Dans les deux cas le parasite est apparenté à son hôte. Cela appuie l'hypothèse que le parasite social apparaît généralement à partir de la même souche ancestrale que l'espèce hôte.
    Notes: Summary Genetic relationships of eight northern European yellowjacket species, representingVespula s. str. (therufa group),Paravespula thevulgaris group) andDolichovespula, are here studied by enzyme electrophoresis. The observed level of intraspecific genic variation is relatively low, and the southern Finnish populations show no clear-cut geographic differences. The allozyme characters are further used to construct phylogenetic trees by four tree-building techniques. It is suggested thatDolichovespula media is not phylogenetically closely related to other EuropeanDolichovespula species, and thatParavespula andVespula s. str. may not form a single monophyletic group. Two of the species studied,V. austriaca andD. omissa, are obligatory social parasites. In both cases the parasite is related to its host. This supports the hypothesis that the social parasite generally arises from the same ancestral stock as the host species.
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    Insectes sociaux 31 (1984), S. 361-374 
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    Description / Table of Contents: Zusammenfassung Im staate New York sind Kolonien gemischter Arten vonPolyergus lucidus undFormica schaufussi untersucht worden. Am späten Nachmittag, nach dem Höhepunkt der Tagestemperatur, wurden Sklavenraubzuge ausgeführt. Mehrfache Raubzüge auf verschiedene Kolonien vonFormica gerichtet waren normal. Dazu gehöten auch wiederholte Raubzüge auf dieselbe Kolonie. In den Laboratoriumnestern wurden etwa 75% des geraubtenFormica Gebrüts gefressen. Aus einer Gruppe von 27 Raubzüge die im Laboratorium stattfanden, wurden 25 aufFormica Nester ausgeführt die am Tage des Überfalles erkundschaftet worden waren.Polyergus Kundschafter gehören zur den ältesten Individuen der Kolonie; frischgeschlüpfte Erwachsene beteiligen sich nicht an Erkundungen während ihrer ganzen Schlüpfungssaison. Die Zusammensetzung der Gruppe vonPolyergus Arbeitern die unmittelbar vor dem Überfall auf der Oberfläche in der Nähe des Nestes umhergehen, wechselt sich kontinuierlich. Die verhaltensänderung die am häufigsten auftrat war die vom Herumgehen an einem Tag zum Kudschaften am nächsten Tag. Die zweithäufigste Änderung war die vom Kundschaften zum Herumstreifen. Das erste kundschaften der frühlingssaison fand nur einen Tag nach Erscheinung derPolyergus Larven staat. Der erste Sklavenraubzug wurde dann 4 Tage später ausgefuhrt.Formica Gebrüt war in frielebenden Kolonien bis zu 4 Wochen früher anwesend alsPolyergus Gebrüt in gemischten Nestern. ObwohlPolyergus Arbeiter gewöhnlich durch Erbrechen des Speisebreies vonFormica gefüttert werden, tranken und frassen sie gelegentlich auch Eier unabhängig vonFormica. DiePolyergus Köningen war immer nur vonFormica Arbeiter umgeben.Polyergus Eier kriechen in etwa 12 Tagen zu Larven aus, worauf das Larvenstadium noch 9 bis 12 Tagen dauert. Schlüpfung der Erwachsenen fand 20 bis 23 Tage nach dem Puppenstadium statt. FrischbefruchtetePolyergus Königinnen folgen Sklavenraubzüge und versuchen von den überfallen Nesten adoptiert zu werden indem sie die Verwirrung derFormica während eines Überfalles benutzen. Abspaltung von Tochterkolonien wurde nie beobachtet.
    Notes: Summary Mixed-species colonies ofPolyergus lucidus andFórmica schaufussi were studied in New York. Slave raids were conducted in late afternoon, past the peak in diurnal temperature. Multiple raids on differentFormica colonies were common, as were re-raids on the same colony. In laboratory nests, about 75% of the raidedFormica brood was eaten. Of 27 days on which raids occurred in the laboratory, 25 were onFormica nests souted on the day of the raid.Polyergus scouts are among the oldest individuals in the colony, and callows do not participate in scouting during the entire season of their eclosion. The group ofPolyergus workers that circle on the surface near the nest prior to raiding has a dynamic composition. The most frequent behavioral transition was from circling on one day to scouting on the next. The next most common change was from scouting to circling. The first scouting of the spring season occurred only one day after the appearance ofPolyergus larvae. The first slave raid was conducted 4 days later.Formica brood was present in freeliving colonies from 1–4 weeks earlier thanPolyergus brood in mixed nests. Although workers ofPolyergus were usually fed by regurgitation fromFormica, they occasionally drank and ate eggs independently. ThePolyergus queen was surrounded only byFormica workers.Polyergus eggs hatched into larvae in approximately 12 days, with the larval stage lasting an additional 9–12 days. Eclosion of callows took place within 20–23 days after pupation. Newly matedPolyergus queens follow slave raids and attempt adoption into target nests when theFormica are scattered during a slave raid. The process of budding was never observed.
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    Insectes sociaux 31 (1984), S. 473-475 
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    Topics: Biology
    Description / Table of Contents: Resume Ce travail contribue à la distinction taxonomique entreGoniomma hispanicum etG. baeticum, à partir de l'utilisation d'analyses multidimensionnelles menées sur dix variables définies sur le système de vénation de la première paire d'ailes de la femelle, et donne des résultats hautement significatifs.
    Notes: Summary This work helps in the taxonomical distinction betweenGoniomma hispanicum andG. baeticum, through the use of multidimensional analyses which were carried out on ten variables defined in the venation system of the first pair of wings on the female and gave highly significative results.
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    Pure and applied geophysics 119 (1981), S. 966-977 
    ISSN: 1420-9136
    Keywords: Streamer interactions
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    Topics: Geosciences , Physics
    Notes: Abstract Investigation was carried out to study the interaction of positive streamers with charged and uncharged drops in a vertical electric field configuration. Results obtained for vertical and horizontal positions of the photographic films show that streamer interactions with neutral and negative drops are similar and further confirmed earlier results byPhelps (1972). It showed that indirect streamer interaction with droplets is effected by branches being sent to the drops from the main channel. The visibility of the branches on the Lichtenberg figures and the degree of interaction of streamers with drops depend on the drop size, its initial charge and shape, and/or the separation of the drops from the main channel. Suppression of streamer propagation among the positively charged drops was observed.
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    Pure and applied geophysics 119 (1981), S. 978-989 
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    Keywords: Ozone maxima ; Dry deposition ; Local cross-valley wind system
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    Notes: Abstract The diurnal cycle of ozone at the surface and within the PBL is examined. It is concluded that the intrusion of air masses from ozone-rich layers in the lower troposphere results in late evening ozone maxima observed at ground stations on mountain slopes as well as within distinct layers of the PBL above the valley bottom. The ozone-rich layers are assumed to exist due to meso- or large-scale horizontal transport of smog air masses and a local cross-valley wind system is shown to be responsible for the occurrence of the intrusion processes.
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    Pure and applied geophysics 119 (1981), S. 934-965 
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    Keywords: Condensation ; effect of entrainment on ; Cloud drop formation ; effect of entrainment on
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    Notes: Abstract It has been speculated for many years that the development of the droplet spectra in cloud is probably influenced by mixing processes. Various theoretical attempts to broaden the droplet spectra by mixing parcels with different velocity histories has shown that that particular effect is small. Similarly, very simpleuniform entrainment procedures did not lead to cloud drop size spectra which were broad enough, although by producing cloud drop size distributions with a double mode these models did substantially improve the drop size spectra of earlier adiabatic models which only exhibited a single mode. Recently a model based on entraining entities representing moving parcels of cloud air within the cloud was detailed byTelford andChai (1980). This study showed that the mixing in of dry air at cumulus turrets could lead to vertical cycling of diluted parcels, and that this cycling, with continual entrainment across the parcel boundaries, will produce much larger drops, as well as smaller drops of all sizes, in the droplet spectra. The ‘entity entrainment’ concept studied there appears to apply to the observations of stratus cloud discussed in this paper. This paper presents data taken in marine stratus off the California coast which give a particularly clear example of how such droplet spectra modification occurs in practice. Both large drops, and the spread of the spectra to smaller sizes, occur in relation to other variables in such a way as to be consistent with an entity entrainment explanation, with no other obvious possibility. In a marine stratus cloud just over 200 m thick and many tens of miles in extent we find clear evidence that dry air is mixing in at cloud tops. Strong vertical motion is to be found in the cloud, large sized drops are found in cloud parcels where the mixing gives lower droplet concentrations, and there is evidence that newly formed cloud parcels are warmer and contain many more smaller droplets. The observations show that immediately following entrainment of dry air drop diameters are not reduced appreciably, but, in the same parcels, drop concentrations have been reduced by a factor of ten or more. Further down in the cloud big drops, able to start growth by coalescence, are found associated with low total droplet concentrations. Overall, it seems likely from the consideration of these observations that the formation of the large drops which lead to precipitation processes in clouds depends critically on the mixing in of dry air at cloud tops, and very little on the size of the small drops resulting from the condensation nucleus counts. As a conclusion it appears reasonable to state that if entrainment occurs at cloud tops, then big drops will be formed!
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    Pure and applied geophysics 119 (1981), S. 1024-1036 
    ISSN: 1420-9136
    Keywords: Electromagnetic scattering ; VLF electromagnetic prospection
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    Topics: Geosciences , Physics
    Notes: Abstract FollowingDmitriev (1960) a rigorous theoretical solution for the problem of scattering by a perfectly conducting inclined half-plane buried in a uniform conductive half-space has been obtained for plane wave excitation. The resultant integral equation for the Laplace transform of scattering current in the half-plane is solved numerically by the method of successive approximation. The scattered fields at the surface of the half-space are found by integrating the half-space Green's function over the transform of the scattering current. The effects of depth of burial and inclination, of the half-plane on the scattered fields are studied in detail. An increase in the depth of burial leads to attenuation of the fields. Inclination introduces asymmetry in the field profiles beside affecting its magnitude. Depth of exploration is greater for quadrature component. An interpretation scheme based on a phasor diagram is presented for the VLF-EM method of exploration for rich vein deposits in a conductive terrain.
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    Pure and applied geophysics 119 (1981), S. 1077-1092 
    ISSN: 1420-9136
    Keywords: Seismic hazard estimation ; Bohemia
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    Notes: Abstract The contribution reviews basic concepts of earthquake hazard assessment for sites of nuclear power plants. Taking into account the delineation of earthquake source regions, intensity-frequency relations, upper intensity thresholdsI max and intensity attenuation curves, we determine the seismic hazard for a site in south Bohemia and calculated the quantities defining the seismic hazard, i.e. return period in years, probability of exceedance for different intensities and different periods of interest. The adopted procedure has some limitations due to the poor definition of seismogenic zones (boundaries,N(I),I max) and lack of strong motion observations in Central Europe.
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    Pure and applied geophysics 119 (1981), S. 1125-1133 
    ISSN: 1420-9136
    Keywords: Seismicity and crustal structure
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    Notes: Abstract Focal solutions of four strong earthquakes and P signals of twenty-four smaller shocks of the active Mur-Mürz Valley, the Semmering Pass and the Vienna Basin. An ‘equivalent slip rate’ of 0.03 This feature agrees with the model of a subsiding Pannonian Basin. An ‘equivalent slip rate’ of 0.03 cm/year is roughly estimated from earthquake data 1903–1978. This rate does not include the creep rate, but it gives an idea of the magnitude of speed of geological processes in this area. Refraction seismic data from the Alpine Longitudinal Profile 75 shows a low velocity zone in the upper crust of the seismic active East Alpine area but not in the aseismic part of the Pannonian Basin. The eastern margin of the Eastern Alps and the Carpathians limits the Pannonian Basin, which has a special and interesting geological history. Many authors (Szadezky-Kardoss, 1966;Stegena, Ceszy andHorvàth, 1975) presented models of the genesis of the Pannonian Basin. They apply the concept of the ‘mantle diapirs’ to explain the following facts: subsiding of the Pannonian Plate in comparison to the Alps, high terrestrial heat flow within the Pannonian Plate, decrease of the Moho depth from 40 km below the Eastern border of the Alps to 27 km below the Pannonian Basin. They claim that the Alpine-Carpathian interarc and basin represent the final stage of an orogenetic system where ‘subcrustal erosion’ leads to a thinning of the crust. Consequently the surface subsides and is covered by young sediments. They proved that this subsidence and sedimentation is more or less in isostatic equilibrium. The aim of this paper is to provide new arguments using focal solutions and refraction seismic investigations.
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    Keywords: Caucasus ; Three-dimensional seismic modelling
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    Notes: Abstract This paper deals with a procedure of a joint analysis of seismic data from earthquakes and those obtained by DSS. The DSS data are used as a first approximation to construct a two-dimensional model of the medium made up of individual blocks. These models serve as a basis when constructing specific three-dimensional travel-time curves. These travel-time curves are further used for the calculation of hypocenter parameters in a laterally inhomogeneous block medium. The hypocenter field and the travel times obtained are input data for the computation of three-dimensional fields of velocities in earthquake focal zones. Results of applying the proposed procedure to the Caucasus region are presented.
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    Pure and applied geophysics 122 (1984), S. 680-693 
    ISSN: 1420-9136
    Keywords: Physical seismic models ; Uniaxial loading ; Shear displacement ; Locked zone ; Seismoactivity
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    Topics: Geosciences , Physics
    Notes: Abstract Square plate models with a diagonally located slit in compression were studied photoelastically. The resulting stress field surrounding the discontinuity (slit) is evaluated before and after seismoactive (seismic-energy-releasing) shear displacement. The mechanism of the fast shear movement (stick-slip), including its radiation properties, in interpreted. The results confirm the existence of a central locked zone in the loaded slit, the limits of which coincide with the initiation points of stick-slip movements. The zone is interpreted as the source of the seismic energy release. The complementary measurements (direct optical and ultrasonic) are presented to verify the results of the photoelastic analysis. The results obtained are discussed in regard to the conclusions that follow from the theory of elasticity.
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    Pure and applied geophysics 122 (1984), S. 763-763 
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    Pure and applied geophysics 122 (1984), S. 747-762 
    ISSN: 1420-9136
    Keywords: Total ozone ; Periodicities
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    Notes: Abstract Total ozone data series for 1957–82 at ten locations were subjected to Maximum Entropy Spectral Analysis. Besides the annual, semi-annual, and quasi-biennial oscillations, peaks were noticed at 3.5–4, 6–7, and 10–11 years. For Arosa, Switzerland, for a longer period (1932–71), an additional peak was indicated at about 16 years.
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    Keywords: precursory ground tilt ; temporal variation of crustal deformation ; the 1944 Tonankai earthquake ; leveling survey ; earthquake prediction
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    Notes: Abstract The temporal variation in precursory ground tilt prior to the 1944 Tonankai (Japan) earthquake, which is a great thrust-type earthquake along the Nankai Trough, is discussed using the analysis of data from repeated surveys along short-distance leveling routes.Sato (1970) pointed out that an anomalous tilt occurred one day before the earthquake at Kakegawa near the northern end of the focal region of the earthquake. From the analysis of additional leveling data, Sato's result is re-examined and the temporal change in the ground tilt is deduced for the period of about ten days beginning six days before the earthquake. A remarkable precursory tilt started two or three days before the earthquake. The direction of the precursory tilt was up towards the south (uplift on the southern Nankai Trough side), but the coseismic tilt was up towards the southeast, perpendicular to the strike of the main thrust fault of the Tonankai earthquake. The postseismic tilt was probably opposite of the coseismic tilt. The preseismic tilt is attributed to precursory slip on part of the main fault. If similar precursory deformation occurs before a future earthquake expected to occur in the adjacent Tokai region, the deformation may help predict the time of the Tokai earthquake.
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    Pure and applied geophysics 122 (1984), S. 781-792 
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    Keywords: Precursory tilt ; aseismic slip ; thrust faulting
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    Notes: Abstract During three years preceding the 1976 Friuli earthquake, a continuous southward ground tilt was recorded by a tiltmeter placed near Tolmezzo, 15 km north-west of the epicentre of the impending earthquake. The cumulative ground tilt amounted to as much as 3 minutes of arc. Since the tiltmeter was placed in the proximity of an active fault, such a tilt can be explained if the fault slipped aseismically on its shallower section during the same three year period. Aseismic slip on the fault might have been caused by the same mechanism which concentrated stress in the region and eventually produced the 1976 earthquake.
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    Pure and applied geophysics 122 (1984), S. 793-811 
    ISSN: 1420-9136
    Keywords: Earthquake prediction ; Instability ; San Andreas fault
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    Notes: Abstract The locked section of the San Andreas fault in southern California has experienced a number of large and great earthquakes in the past, and thus is expected to have more in the future. To estimate the location, time, and slip of the next few earthquakes, an earthquake instability model is formulated. The model is similar to one recently developed for moderate earthquakes on the San Andreas fault near Parkfield, California. In both models, unstable faulting (the earthquake analog) is caused by failure of all or part of a patch of brittle, strain-softening fault zone. In the present model the patch extends downward from the ground surface to about 12 km depth, and extends 500 km along strike from Parkfield to the Salton Sea. The variation of patch strength along strike is adjusted by trial until the computed sequence of instabilities matches the sequence of large and great earthquakes sincea.d. 1080 reported by Sieh and others. The last earthquake was theM=8.3 Ft. Tejon event in 1857. The resulting strength variation has five contiguous sections of alternately low and high strength. From north to south, the approximate locations of the sections are: (1) Parkfield to Bitterwater Valley, (2) Bitterwater Valley to Lake Hughes, (3) Lake Hughes to San Bernardino, (4) San Bernardino to Palm Springs, and (5) Palm Springs to the Salton Sea. Sections 1, 3, and 5 have strengths between 53 and 88 bars; sections 2 and 4 have strengths between 164 and 193 bars. Patch section ends and unstable rupture ends usually coincide, although one or more adjacent patch sections may fail unstably at once. The model predicts that the next sections of the fault to slip unstably will be 1, 3, and 5; the order and dates depend on the assumed length of an earthquake rupture in about 1700.
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    Pure and applied geophysics 119 (1981), S. 901-912 
    ISSN: 1420-9136
    Keywords: Monsoon depression ; Cyclogenesis ; Barotropic instability
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    Notes: Abstract The role of barotropic processes in the development of a monsoon depression, formed on 5 July 1979 during MONEX observational period, is studied by considering it as a quasi-geostrophic divergent barotropic instability problem of zonal flow of 3 July 1979 at 700 mb level. Numerical solutions are obtained by initial value approach. The preferred wave has a wavelength of 2750 km, an e-folding time of 4.3 days, a period of 6.5 days and an eastward phase speed of 4.9 ms−1. Structure of preferred wave is found to be in good agreement with the observed horizontal structure of the depression at 700 mb. Poleward momentum transports are found to predominate over equatorward transports.
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    Pure and applied geophysics 119 (1981), S. 922-933 
    ISSN: 1420-9136
    Keywords: Extreme precipitation ; Tropical meteorology
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    Topics: Geosciences , Physics
    Notes: Abstract The greatest one-day rain amounts recorded at individual stations in the country during the last 41-year period from 1940 onwards were examined for all observatories as well as State rain-gauge stations in an attempt to bring out up-to-date information on the greatest recorded point rainfall for the duration of one day. Outstanding one-day point rainfall amounts recorded prior to 1940 were also examined and have been included in this note along with their date and year of occurrence by way of comparison. A generalized chart has been prepared based on the percentage ratios of the greatest one-day rainfall to the mean annual rainfall of about 300 observatory stations distributed uniformly over the entire country. On the basis of Depth-Area-Duration (DAD) analyses of the most severe rainstorms which occurred over different plain areas of the country, it has been found that the 2 July, 1941, rainstorm gave the highest areal rain depths in the country for different areas. Comparison with similar areal rain depths of the tropical USA has shown that rain depths of the July, 1941, rainstorm were higher for all areas excepting the areas of 500 sq. miles (1295 sq. km) and 1000 sq. miles (2590 sq. km).
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    Pure and applied geophysics 119 (1981), S. 990-997 
    ISSN: 1420-9136
    Keywords: Atmospheric trace gases ; Atmospheric chemistry ; Chemical composition of atmospheric boundary layer
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    Topics: Geosciences , Physics
    Notes: Abstract Weekly air samples were collected at Cape Kumakahi (0 km) and at nearby Mauna Loa Observatory (3.4 km) which is above the boundary layer. EC/GC and GC/FID techniques were used to measure CH3I, CHCl3, CO and CH4, which are largely natural in origin, and C2Cl4, CCl4, CH3, CCl3, CCl3F (F-11), CCl2F2 (F-12), CHClF2 (F-22) and C2F3Cl3 (F-113), which are due to anthropogenic activities. It was found that all these gases are significantly (α≤0.05) more abundant in the boundary layer than above it.
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  • 36
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    Pure and applied geophysics 119 (1981), S. 1003-1023 
    ISSN: 1420-9136
    Keywords: Geoelectric data ; Transmission Line analogy ; Filter theory ; stable stochastic inverse
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    Topics: Geosciences , Physics
    Notes: Abstract A simple numerical inversion scheme for estimatingn-layer model parameters from observed geoelectrical resistivity data can be used in either the space or wavenumber domain. The technique utilizes Madden's Transmission Line Analogy to compute the resistivity transforms and linear filter theory to accomplish the excursions between the space and wavenumber domains. The inversion is effected by an iterative refinement scheme employing the stochastic inverse which is approximate to the generalized inverse. No singular decomposition analysis is required and the scheme is stable under ill conditions. The inversion scheme not only gives the desired estimates; it exposes redundant parameters and irrelevant data and is easily programmed on a desk-top mini computer. Examples of inverse modeling with hypothetical and field data are discussed.
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  • 37
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    Notes: Abstract P- and S-wave velocity distributions obtained from DSS measurement have been used as a constraint in the inversion of surface-wave dispersion data. The combined interpretation was made as an attempt to enhance the resulting velocity models and to test the possibility to draw conclusions about the density distribution. The result indicates a potential value of a combined interpretation but it is obvious that very accurate velocity distributions are needed. The achieved density distribution is in good agreement with reported densities derived from gravimetric studies.
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  • 38
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    Pure and applied geophysics 119 (1981), S. 1093-1099 
    ISSN: 1420-9136
    Keywords: Baltic Shield ; Deep seismic sounding ; Earthquakes in Finland
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    Topics: Geosciences , Physics
    Notes: Abstract The lithospheric models obtained for the Baltic Shield by using deep seismic soundings are discussed and results from different parts of the shield are compared with models achieved by the investigation of surface waves and of P to S converted waves. The results are found to agree rather well with each other particularly with regard to the first interface (at a depth of 10–15 km) and the whole thickness of the crust (c. 40 km). The macroseismic focal depth determinations of regional earthquakes are correlated with lithospheric structure. The main maximum in the focal depth distributions of Finnish earthquakes occur at a depth of 10–12 km. The geographical distribution of the earthquake epicentres suggests several seismo-active zones in the northern Baltic Shield. One new finding in this field concerns the Lapland zone, which runs in a north-westerly direction.
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  • 39
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    Pure and applied geophysics 119 (1981), S. 1116-1124 
    ISSN: 1420-9136
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    Topics: Geosciences , Physics
    Notes: Abstract A long-range Scandinavian seismic profile of August 1979 is subjected to a preliminary evaluation by means of the records of the permanent Swedish network of stations. The resulting travel times confirm those earlier adopted in the calculation of Swedish earthquakes for the period 1951–1976.
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    Pure and applied geophysics 119 (1981), S. 1107-1115 
    ISSN: 1420-9136
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    Topics: Geosciences , Physics
    Notes: Abstract The deep seismic sounding project ‘Blue Norma’ was carried out in the summer of 1977 in northern Scandinavia in order to investigate the deep structure of the Norwegian continental margin and the Caledonian mountain chain. During the measurements, by chance the core phase PKIKP of an earthquake at the New Hebrides was recorded with 30 seismic field stations along a profile through the central Caledonides. The results of the refraction seismic data, as obtained by a ray-tracing method, are presented and compared to the interpretation of the relative residuals of the PKIKP travel times. From both data sets a continentward down-dipping crust-mantle boundary is evaluated. From the interpretation of the refraction seismic measurements a crustal thickness of 32 km below the coastline and 42 km below the central mountain chain is obtained. The increase of the crustal thickness derived by the inversion of the travel-time residuals along this line amounts only to 6 km. This considerable discrepancy can only be explained by an eastward increasing seismic velocity in the mantle.
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  • 41
    ISSN: 1420-9136
    Keywords: Carpathians ; Three-dimensional seismic modelling
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    Notes: Abstract The joint analysis performed for the Carpathian region from seismological data (three-dimensional fields of velocities, areas of concentration of earthquake foci in the Vrancea focal zone) and interpretation of DSS data and those of other geophysical fields have permitted to obtain new evidence for the earth's crust and mantle structure in this region.
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  • 42
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    Pure and applied geophysics 119 (1981), S. 1192-1196 
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    Pure and applied geophysics 119 (1981), S. 1197-1197 
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    Pure and applied geophysics 122 (1984), S. 831-847 
    ISSN: 1420-9136
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    Notes: Abstract Between 1 January 1980 and 28 July 1981, a series of large earthquakes with body-wave magnitudes around 7, took place along the western segment of the Alpide belt. The sequence started in the Azores and migrated eastward along the belt at a rate of about 4400 km/yr with consecutive large events in northern Algeria, southern Italy, southern Greece and Iran. Two different methods are employed to identify similar series and corresponding migration velocities during earlier time periods of this century. The data set used contains all earthquakes with body-wave magnitudes larger than 6.3 and covers the time interval 1901–81. The concept of linear migration is tested for eastward and/or westward propagation, considering high migration velocities from 1600 to 11 000 km/yr. Results obtained are not homogeneous with respect to the two opposite migration directions, west-east and east-west, and we interpret this as a net drift of earthquake activity from the west to the east. Our efforts here are concentrated on analysis of observational data and on estabilishing the uniqueness of migration patterns. Because of the complexity of the tectonic system in question, we did not attempt to establish a mechanism explaining the migration of the observed earthquake sequences.
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    Pure and applied geophysics 122 (1984), S. 1-9 
    ISSN: 1420-9136
    Keywords: Q factor ; Attenuation ; Coda ; Scattering ; Seismic wave
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    Topics: Geosciences , Physics
    Notes: Abstract When the quality factorQ is taken into account in attenuation studies, it is necessary to know the relative losses of wave energy due to scattering and to anelastic absorption. The coda is the most important phenomenon now known which is related to elastic scattering of seismic waves. Utilizing coda, this study presents relationships which give theQ factors of the medium around the recording station and discriminate between attenuations arising from elastic scattering (under the assumption of isotropic scattering) and those arising from anelastic absorption. This work proposes a technique for separately determining the attenuation due to isotropic scattering and that due to absorption from the observed envelope of coda waves.
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  • 46
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    Pure and applied geophysics 122 (1984), S. 86-88 
    ISSN: 1420-9136
    Keywords: Atmospheric electric potential gradients ; orographic effect
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    Notes: Abstract Potential gradients were measured in the valley of the Simhachalam hills and near the top. They were found to be higher at the top than in the valley, where they increased in the forenoon. It was the reverse at the top of the hills. The valley winds were found to play an important role in the variation of potential gradient.
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  • 47
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    Pure and applied geophysics 122 (1984), S. 110-123 
    ISSN: 1420-9136
    Keywords: ageotrophic flow ; vertical redistribution of momentum
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    Notes: Abstract Data from the SESAME storm-scale network are used in computing the momentum budget of the prestorm, storm, and poststorm environment of a severe storm complex. In the prestorm period geostrophic flow dominates the environment. With progression into the storm period all terms in the momentum equation become important, as a significant ageostrophic component in the momentum field develops. Turbulent effects are estimated as a residual, and the results indicate that they are comparable in magnitude to the other terms. Their effect is to decrease the positive momentum, particularly at levels above 500 mbar, where the vertical motion is the strongest. Vertical profiles of area means ofu andv indicate that the storm is apparently redistributing momentum downwards, thus reducing the mean shear. In the poststorm period the flow once again becomes largely geostrophic, and a maximum in wind speed reappears at upper levels.
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  • 48
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    Pure and applied geophysics 122 (1984), S. 143-156 
    ISSN: 1420-9136
    Keywords: Earthquake prediction ; Hydrogeochemical ; Hydrogeodynamic
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    Notes: Abstract The paper reviews the chief results of the hydrogeochemical and hydrogeodynamic investigations conducted for earthquake prediction in all seismic regions of the USSR. An extensive amount of data on the variations of approximately 40 hydrogeochemical and hydrogeodynamic parameters were collected with a broad network of 83 stations. These data are analysed in connection with regional seismic activities. The hydrogeochemical precursors are classified on the basis of statistical treatment of the regular observations. Several features of the hydrogeochemical anomalies that depend on the physicochemical nature of the precursor, geological conditions in a given region, and features of the expected seismic event are pointed out. Some sophisticated statistical methods of data analysis and several examples of actual earthquake predictions based on hydrogeochemical methods are given. Hydrogeochemical and hydrogeodynamic precursors are found to be highly effective for shortterm predictions. Possible mechanisms that may cause hydrogeochemical precursors are discussed. Sophisticated automatic equipment developed in the Soviet Union for hydrogeochemical and hydrogeodynamic observations are briefly mentioned.
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    Pure and applied geophysics 122 (1984), S. 175-184 
    ISSN: 1420-9136
    Keywords: Hydrogen emission ; Seismic activity ; Earthquake prediction
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    Topics: Geosciences , Physics
    Notes: Abstract Measurements of chemical composition of bubbles from a mineral spring at Yuya Spa situated close to the Median Tectonic Line, the longest active fault in Japan, showed that the periods of increased H2 emission coincided with occurrences of the Ohno earthquake swarm nearby. Four cases of the coincidence without exception were observed in the last three years. The fluctuation of H2 concentration ranges between 〈0.5 and 200 ppm, whereas other gases such as He, Ar, N2, and CH4 do not fluctuate much. The H2 concentration is correlated with the energy released by the seismic activity. This field evidence, together with the results of laboratory experiments conducted bySugisaki et al. (1983), leads to the conclusion that H2 observed at the mineral spring was produced by the reaction between groundwater and rock fractured in the seismic activities. The observation that H2 in the mineral spring tends to appear prior to an earthquake suggests that microcracks may occur in rocks prior to earthquakes. The precursory emission of H2 may be useful for earthquake prediction.
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    Pure and applied geophysics 122 (1984), S. 218-230 
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    Notes: Abstract Several kinds of geochemical anomaly before strong earthquakes have been observed in China since 1966. They include changes in groundwater radon levels, ion content of water (Ca+2, Mg+2, Cl−, SO 4 −2 , F−), dissolved gases (H2, CO2), and gases escaping from the aeration zone through abandoned dry wells (Ar, N2, CO2). The radon anomalies may be grouped as long-term and short-term anomalies. Most of the geochemical anomalies observed are characterized by a pattern of increase. The largest amplitude recorded was 37 times the base level. Preliminary study indicates that the types of seismogeochemical anomaly observed prior to strong earthquakes depend on tectonic, geologic, lithologic, and hydrogeological conditions at the monitoring station. Results obtained from modelling experiments on the mechanisms of some anomalies are given.
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    Pure and applied geophysics 122 (1984), S. 340-352 
    ISSN: 1420-9136
    Keywords: Earthquake prediction ; Radon emanation ; Fault creep
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    Notes: Abstract Radon emanation was continuously monitored for several months at two locations along a creeping segment of the San Andreas fault in central California. The recorded emanations showed several impulsive increases that lasted as much as five hours with amplitudes considerably larger than meteorologically induced diurnal variations. Some of the radon increases were accompanied or followed by earthquakes or fault-creep events. They were possibly the result of some sudden outbursts of relatively radon-rich ground gas, sometimes triggered by crustal deformation or vibration.
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    Development genes and evolution 190 (1981), S. 208-214 
    ISSN: 1432-041X
    Keywords: Ascidian egg ; Ooplasmic segregation ; Cortical contraction
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    Topics: Biology
    Notes: Summary The egg cytoplasm of ascidian,Ciona intestinalis, segregates towards both the animal and vegetal poles within a few minutes of fertilization or parthenogetic activation with ionophore A23187. A constriction appears first on the egg surface near the animal pole and then moves to the vegetal pole. Carmine granules and spermatozoa attached to the egg surface move towards the vegetal pole with the movement of the constriction. Microvilli, which are distributed uniformly in unfertilized egg, disappear on the animal side of the constriction and became more dense on the vegetal side of the constriction. Transmission electron microscopy revealed that sub-cortical cytoplasm, containing numerous mitochondria and sub-cortical granules, moves towards the vegetal pole with the movement of the constriction and then concentrates into a cytoplasmic cap at the vegetal pole. An electron-dense layer appears in the cortex of the cap. The ooplasmic segregation and the cortical contraction were inhibited by cytochalasin B and induced by ionophore A23187. These observations suggest that ooplasmic segregation is caused by the cortical contraction which is characterised by a surface constriction and by the formation of an electron-dense layer.
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  • 53
    ISSN: 1432-041X
    Keywords: Mollusca ; Cleavage ; Junctions ; Interaction ; Development
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    Topics: Biology
    Notes: Summary In early cleavage stages ofLymnaea stagnalis, three kinds of intercellular junctions could be distinguished up to the sixth cleavage: intermediate, septate and gap junctions. The first two form “junctional belts” located on the cell border at the periphery of the embryo. For the purpose of our study we were most interested in gap junctions as they are alleged to be structures that allow cell-to-cell communication. Gap junctions first appear at the four cell stage. Up to the sixth cleavage no difference in the distribution pattern could be found between and within each of the four quadrants of the embryo. Some of the cell tiers along the animal-vegetal axis lack gap junctions either between the blastomeres within the tier or between the blastomeres from adjacent tiers. All gap junctions observed in freeze fracture replicas show plaques with an irregular IMP pattern. The average IMP diameter measures 12 nm (SD±2 nm). In stages fixed after the fifth cleavage, gap junctions are found between micromeres at the animal pole and the central 3D macromere. This is in agreement with the presumed interaction between these cells at this stage. The possibility of a transition of non-functional into functional gap junctions after the fifth cleavage is discussed.
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    Development genes and evolution 190 (1981), S. 221-225 
    ISSN: 1432-041X
    Keywords: Oogenesis ; Telotrophic Ovariole ; Vibrating Probe ; Electrophoretic Transport ; Dysdercus intermedius
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    Topics: Biology
    Notes: Summary Two systems of steady extra-cellular currents were found along the surface of the telotrophicDysdercus ovarioles by means of a vibrating probe. The first covers the subgerminal tropharium and all the previtellogenic follicles. The current leaves the 3 or 4 small follicles of early euplasmic growth stages laterally and enters the syncytial tropharium. We presume that a similar intracellular current flows between the trophoplasm and the ooplasm which are interconnected by narrow nurse strands. Preliminary intracellular measurements indicate a potential gradient within this continuous cytoplasm, the ooplasm being electropositive to that of the tropharium. This current system fits into a model of polarized intracytoplasmic transport by electrophoresis. It is possible to explain the well known directed and selective flow of RNA from the tropharium via the nurse strands into the oocytes by means of such a model. The second current system occurs around every one of the 2 to 8 vitellogenic follicles. The pattern is completely different from that described for the first system. In the vitellogenic stages the current enters the follicle laterally all along the now much extended surface. It is balanced by a strong peak current which leaves the interfollicular region. As data on intracellular currents are not yet avialable, it is only a matter of speculation whether the circuit is closed through the ooplasm or only by a tangential loop through the follicle epithelium. The possible significance of this second current system for vitellogenin accumulation and uptake by the vitellogenic oocytes is also uncertain as yet.
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    Development genes and evolution 190 (1981), S. 230-232 
    ISSN: 1432-041X
    Keywords: Regeneration ; Autotomy ; Black Widow spider ; Latrodectus variolus
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    Topics: Biology
    Notes: Summary Crustaceans, insects and to a lesser degree arachnids have been employed in regeneration studies. Amputation and ligation of the legs was used to determine occurring in a Black Widow spider complied with the developmental gradient model of regeneration. The occurrence of autotomy in this species was also documented. Amputation indicated the most proximal point from which regeneration of the leg could occur was the femoral mid-point. Amputation proximal to that area did not result in leg regeneration. Autotomy following amputation was not observed. Ligation of the legs resulted in autotomy when applied at and proximal to the mid-point of the tibia, increasing in frequency as more proximal segments were ligated. Autotomy always occurred at the trochanter-coxa joint. Autotomized legs did not regenerate. The regeneration observed complied with the developmental gradient model.
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    Development genes and evolution 190 (1981), S. 226-229 
    ISSN: 1432-041X
    Keywords: Early neurogenesis ; Mutants ; Drosophila melanogaster
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    Topics: Biology
    Notes: Summary Embryonic lethal mutations at the Notch locus are known to produce a conspicuous central nervous system hypertrophy accompanied by a hypotrophy of the epidermal sheath. We have studied several zygotic mutants belonging to four different autosomal complementation groups which produce the same phenotype. The embryonic development of the new mutants, as well as that of Notch, consists of an initial enlargement of the neurogenic region at the expenses of epidermal cell precursors. The possibility is discussed that these five loci are involved in the determination of neural and epidermal cell precursors.
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  • 57
    ISSN: 1432-041X
    Keywords: Endogenous lectin ; Chick ; Embryonic cell adhesion
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    Topics: Biology
    Notes: Summary Cells from the extraembryonic endoderm of the gastrulating chick embryo contain a β-d-galactoside-binding lectin inhibited by thiodigalactoside (TDG). When cell suspensions are cultured in stationary culture in the presence of exogenously added purified blastoderm lectin or TDG, their attachment to the substratum is delayed and decreased compared to controls. The cells take on a fibroblastic-like morphology and cell to cell contact becomes limited to localized areas of the cell surface. Many lectin or TDG-treated cells appear to be migrating over the substratum. This is in contrast to control cultures where the cells appear epithelial in morphology and tend to maximize their areas of apposition. These data suggest that the endogenous lectin may have a role to play in cell to substratum and cell to cell adhesion.
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    Development genes and evolution 190 (1981), S. 267-273 
    ISSN: 1432-041X
    Keywords: Pigment granules ; Redistribution ; Cortex ; Micromere formation ; Sea urchin embryos
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    Topics: Biology
    Notes: Summary Pigment granules (PGs) are embeded in the cortex of embryos of the Japanese sea urchins,Hemicentrotus pulcherrimus and Anthocidaris crassispina. PGs in the cortex actively retreated from the vegetal pole area at the 4-cell stage and then a notable PG-distribution gradient formed along the egg axis (the polar redistribution of PGs). The polar redistribution of PGs in the cortex occurred at the same time after fertilization even in solutions of microtubule disrupting reagents such as Colcemid, vinblastine sulfate or griseofulvin. Consequently, the polar redistribution of PGs was not associated with the microtubules. However, the polar redistribution of PGs was interrupted in seawater containing cytochalasin B (CB), dithiothreitol (DTT) or tetracaine, and the distribution pattern of PGs in the cortex was definitely disturbed. Moreover, CB, DTT and tetracaine altered the division pattern of vegetal blastomeres at the 4th cleavage which is normally unequal so that all the blastomeres divided equally. Microtubule disrupting reagents did not have such an effect on the cleavage pattern. Thus the cortical movement along the egg axis reflected by the polar redistribution of PGs seems to correlate with the micromere formation.
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    Development genes and evolution 190 (1981), S. 274-282 
    ISSN: 1432-041X
    Keywords: Bunodactis ; Anthozoa ; Regeneration ; Regulation ; Mirror image formation (Specularity)
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    Topics: Biology
    Notes: Summary YoungBunodactis verrucosa Pennant at the 12 tentacle stage are employed to test the applicability of the polar coordinate model to coelenterate regeneration. The animals are cut along every radius into fragments of 3 to 9 segments. Most fragments are patent 3–4 weeks later, but small fragments have a higher mortality rate than large fragments. Some fragments do not regenerate and occasionally tentacles fuse, thereby reducing the number of segments. Small fragments tend to regenerate more tentacies than large fragments, but large fragments may regenerate great numbers of supernumerary tentacles. Twenty-two percent of the fragments restore the missing number of tentacles, while 76% of all fragments produce an even number of tentacles. Fragments restoring the correct numbers of tentacles show a marked tendency to form the correct tentacles (regulative regeneration). Fragments regenerating two less than the number of tentacles already present show a marked tendency to reproduce tentacles of the types already present (miror image formation). Other fragments produce missing segments (forward regeneration), or those already present (reverse regeneration) at lower frequencies. No fragments beginning or ending with the number 1 directive tentacle fail to regenerate entirely, while first cycle segments maximally remote from segment 1 are associated with the absence of regeneration. No fragments beginning or ending with the number 4 directive tentacle fail to undergo forward regeneration, regulate or produce a mirror image when the appropriate number of segments are regenerated. In contrast, segment 4 is associated with a low frequency of reverse regeneration, and second cycle segments cut away from immediate contact with segment 4 show an increase in the frequency of reverse regeneration. Controls through morphogenic substances rather than polar coordinates seem to explain these results. Such substances would control the number and direction of tentacle regeneration.
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    Development genes and evolution 190 (1981), S. 287-296 
    ISSN: 1432-041X
    Keywords: Mouse ; Morula ; Differentiation ; Commitment
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    Topics: Biology
    Notes: Summary The surface properties of newly formed, isolated 1/16 mouse blastomeres have been analyzed over the 10–12 h period prior to their division to 2/32 cells. Two populations of cells are formed at the 8- to 16-cell transition and their surface phenotypes vary with their relative position within the morula. Outer cells are polar, relatively non-adhesive and relatively large; inner cells are apolar, adhesive and smaller. The surface phenotypes of both inner and outer 1/16 cells are stable during culture for 11 h in isolation. However, the surface phenotypes can be induced to change by culture in combination with a second 1/16 cell, in a manner that is dependent upon the identity of the second cell. Two aggregated polar cells never flatten completely against each other, and both cells retain a clearly defined polar phenotype for 11–12 h. In aggregates of two apolar cells, cell outlines are lost as a result of intercellular flattening and microvilli are displaced away from areas of cell contact. However, if the two apolar cells are subsequently separated an even distribution of microvilli is restored. In most aggregates of an apolar and a polar cell, the polar cell envelops the apolar cell completely. These results are discussed in the context of the normal fate and potential of each cell type within the morula.
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    Development genes and evolution 190 (1981), S. 297-300 
    ISSN: 1432-041X
    Keywords: Myosins ; Drosophila ; muscle
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    Topics: Biology
    Notes: Summary Electrophoresis of myosin extracts from larvae and adult tissues ofDrosophila melanogaster under non-dissociating conditions indicate that two of the bands seen are myosins. They stain for Ca2+ ATPase activity and when cut and re-run under dissociating conditions are found to contain a myosin heavy chain that co-migrates with rabbit skeletal muscle myosin heavy chain. One of the forms of myosin seen is found primarily in extracts from the leg. The other is common to the adult fibrillar flight muscles and the larval body wall muscles. The electrophoretic evidence for two myosin types is strengthened by the histochemical demonstration of two myofibrillar ATPases on the basis of their lability to acid or alkali preincubation. The myofibrillar ATPase in the leg and the Tergal Depressor of the Trochanter (TDT) are shown to be relatively acid labile and alkali stable. The larval body wall muscles and the adult fibrillar flight muscles have an ATPase which is acid stable and alkali labile. This distribution of the two myofibrillar ATPase coincides with that predicted by electrophoresis of extracts from whole tissue and also locates the two myosins to specific muscle types.
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    Development genes and evolution 190 (1981), S. 304-304 
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    Development genes and evolution 190 (1981), S. 283-286 
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    Keywords: Transport ; Amino acids ; Valine
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    Notes: Summary 14C-l-Valine uptake by intestinal segments of mice of various ages, ranging between 20-day fetuses and adults, was studied in vitro. 1 mMl-Valine was accumulated against a concentration gradient by processes which showed saturation kinetics. There appeared to be a two-fold increase ofl-valine accumulation after the 2nd postnatal day and a three-fold increase in adult mice. Fetal transport of valine only occurred at pH 7.4 but was not Na+ dependent. In contrast, valine transport became increasingly Na+ dependent and the pH optimum widened, ranging between 5–8. A series of amino acids, including representatives of the imino acid and dibasic groups, failed to inhibit valine uptake while leucine and isoleucine manifested mutual inhibition with valine. It is speculated that in the mouse intestine,l-valine is transported by at least two mechanisms, one functioning in the fetus, not requiring Na+, but pH dependent and another which developes postnatally, is Na-dependent and functions over a wide pH optimum.
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    Development genes and evolution 190 (1981), S. 301-303 
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    Keywords: Drosophila ; Geographic strains ; Chorion genes ; Electrophoretic variants
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    Topics: Biology
    Notes: Summary Further IF screening ofDrosophila melanogaster geographic strains has revealed a variant of the s19 major chorion protein. Developmental analysis of F1 hybrids indicates that the source of the variation is found in the structural gene for this protein. The linkage group of the variant gene was determined to be the third, and the gene was localized by several methods of recombination analysis. The s19 gene was found to be tightly linked to thesepia locus, as had been previously found for the s18 gene (Yannoni and Petri 1980). Lack of recombination between the s19 and s18 genes in double heterozygotes suggested that these two genes are within 0.3 map units of each other. Although more precise localization of the s19 gene failed, the s18 gene could be more specifically located to the right ofsepia, betweensepia andhairy. Contrary to our prediction (ibid.), the s19 and s18 genes have been found to be tightly linked in spite of the fact that they display somewhat different developmental stage specificity.
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    Development genes and evolution 190 (1981), S. 305-307 
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    Keywords: Hydra ; Budding ; Tumor promoter ; Phorbol
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    Notes: Summary A low concentration of 12-O-tetradecanoylphorbol-13-acetate (TPA, 1.0 ng/ml) induced a transient inhibition of bud production in hydra which were fed daily. However, when hydra were starved following TPA-treatment, they produced further buds. Phorbol (1.0 ng/ml) and dimethyl sulfoxide (0.001%) did not influence bud production under either feeding or starvation conditions. These results indicate that TPA modulates asexual reproduction in hydra.
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    Development genes and evolution 190 (1981), S. 308-312 
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    Keywords: Drosophila ; ts-Suppressor mutant ; Glue proteins ; Intermolt puffs ; Electrophoresis
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    Topics: Biology
    Notes: Summary The l(1)su(f)ts67g mutation has been shown to suppress the developmentally regulated expression of glue protein genes at 30°C. Transferring mutant larvae to the restrictive temperature before the end of the second larval instar results in the absence or extreme reduction of glue protein synthesis while general protein synthesis is unaffected. At the same time, the three glue protein correlated chromosomal regions 3C, 25B, and 68C continue to show prominent puffs. The results suggest that the mutation may be affecting the processing or translatability of specific mRNAs rather than the translational machinery itself.
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    Development genes and evolution 190 (1981), S. 331-338 
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    Keywords: Insect oogenesis ; Poly(A)+ RNA ; Storage of maternal RNA ; Calliphora, Diptera
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    Notes: Summary Ovaries ofC. erythrocephala synthesize large amounts of poly(A)+ and poly(A)− RNA during early and middle stages of oogenesis as shown by labelling with3H-uridine in vivo. After incubation for 1 h, a striking difference in the electrophoretic pattern of newly synthesized labelled poly(A)+ RNA and the poly(A)+ RNA present in sufficient amounts for optical density measurements (steady state poly(A)+ RNA) was observed. During early and mid-oogenesis, in the poly(A)− RNA fraction, ≧4S predominantly mature rRNA, 5S RNA and tRNA were labelled. These fractions were no longer synthesized during late oogenesis, whereas poly(A)+ RNA was labelled continously During oogenesis stage specific differences in the size distribution of newly synthesized and steady state poly(A)+ RNA were not obvious. However, different sizes of labelled poly(A)+ RNA species were detected in 0–2h old preblastoderm embryos, after injection of3H-uridine into females either 3–4 days (stage 3–4 of oogenesis) or 24 h before oviposition (stage 5–6 of oogenesis). This difference in RNA synthesis was related to the presence of active nurse cell nuclei. The poly(A)+ RNA fraction represents about 2–3% of the total RNA in both ovaries and freshly laid eggs as judged by measurements of optical density and radioactivity bound to oligo(dT). The length of poly(A)-segments in ovarian poly(A)+ RNA varied from about 30 to 200 nucleotides.
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  • 68
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    Keywords: Salivary gland ; Protein synthesis ; Larval development ; Drosophila melanogaster
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    Notes: Summary Patterns of protein synthesis in the salivary glands ofDrosophila melanogaster have been studied throughout late larval and prepupal development by pulse labelling the tissues with35S-methionine. Specific changes to the pattern of proteins synthesized during development are found and the significance of these changes is discussed in view of the known changes in gene (puffing) activity which occur at the same times. We review the problem of salivary gland function in “prepupal”Drosophila.
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    Development genes and evolution 190 (1981), S. 358-360 
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    Keywords: Morphogenesis ; Cellular differentiation ; Intercellular communication ; Embryogenesis ; Zebra fish
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    Notes: Summary The blastomeres of the zebra fish embryo can be classified into two types-cells stained densely (D) or lightly (L) with a mixture of toluidine and methylene (T-M) blue. The dense staining of D cells is largely due to the high density of mitochondria, rough endoplasmic reticulum and polyribosomes. The presence of partially dense stained cells during early blastula stage shows that L cells are transformed into D cells. That the yolk syncytial layer (YSL) plays some role in this transformation is suggested by the proximity of these cells to the YSL and by their distinct spatial orientation with densely stained cytoplasmic regions always facing towards the interior of the embryo.
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    Development genes and evolution 190 (1981), S. 361-364 
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    Keywords: Regulation ; Positional Information ; Regeneration ; Dictyostelium
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    Notes: Summary Regulating systems, that is, those which exhibit scale-invariant patterns in the adult, are supposed, to do so on account of interactions between cells during development. The nature of these interactions has to be such that the system of positional information (“map”) in the embryo also regulates. To our knowledge, this supposition regarding a regulating map has not been subjected to a direct test in any embryonic system. Here we do so by means of a simple and novel criterion and use it to examine tip regeneration in the mulicellular stage (slug) ofDictyostelium discoideum. When anterior, tip-containing fragments of slugs are amputated, a new tip spontaneously regenerates at the cut surface of the (remaining) posterior fragment. The time needed for regeneration to occur depends on the relative size of the amputated fragment but is independent of the total size of the slug. We conclude from this finding that there is at least one system underlying positional information in the slug which regulates.
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    Development genes and evolution 190 (1981), S. 365-369 
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    Keywords: Selector genes ; Determination ; Homoeotic mutations ; Drosophila melanogaster
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    Notes: Summary New alleles of thetrithorax locus have been isolated and analysed. The phenotypes of different allelic combinations confirm that a decrease or loss of function of the locus is responsible for homoeotic transformations of the adult thoracic and abdominal segments. Since neither these homoeotic transformations nor larval lethality are complemented by the previously described mutationRg-bx, it is concluded that the latter is an allele oftrithorax. The effect of near loss of function of thetrithorax locus after the completion of embryogenesis has been investigated by clonal analysis. This has produced two unexpected results: 1) there is a requirement for the activity of the locus after embryogenesis is completed; 2) the locus is required for the normal development of at least some mesothoracic structures. These results are discussed with respect to the selector gene hypothesis and other putative activator gene mutations.
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    Keywords: Drosophila ; Homoeotic mutants ; Ventral cord
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    Notes: Summary We describe a set of cells in the central nervous system of theDrosophila embryo which are restricted to the thoracic ganglia in the wildtype. Taking these cells as indication of thoracic identity, we find that the ventral cord of embryos homozygous mutant for different bithorax functions and for Polycomb undergoes homoeotic transformations equivalent to those observed in the larval cuticle.
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    Development genes and evolution 190 (1981), S. 374-378 
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    Keywords: Mouse teratocarcinoma ; Cell differentiation ; Nonhistone Proteins ; Two dimensional gel electrophoresis ; Silver staining
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    Notes: Summary The nonhistone protein pattern of four murine teratocarcinomas with different capacities for differentiation were compared: a multidifferentiated teratocarcinoma OTT2289, a nondifferentiated teratocarcinoma OTT2158, a teratocarcinoma-derived rhabdomyosarcoma TDR114, and a teratocarcinoma-derived neuroblastoma TDN2151. Their nonhistone proteins (NHP) were separated by differential salt extraction and hydroxyapatite chromatography into three fractions, NHP-I, NHP-II and NHP-III. Comparison of the NHP fractions by twodimensional gel electrophoresis in combination with a sensitive silver staining method reveals that there are several tumour line specific proteins in each NHP fraction. We suggest that specific NHP, which can be used as biochemical markers for each of the four investigated tumour lines, may be involved in cell lineage specific control of gene expression.
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    Development genes and evolution 190 (1981), S. 379-379 
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    Development genes and evolution 190 (1981), S. 380-380 
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    Development genes and evolution 193 (1984), S. 71-77 
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    Keywords: Sea urchin embryos ; Cell surface ; Con A ; Fibronectin
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    Notes: Summary Some plant lectins, Concanavalin agglutinin (Con A), succinyl Con A and wheat germ agglutinin (WGA) increased the adhesion of dissociated embryonic cells of the sea urchin,Pseudocentrotus depressus, to the substratum (plastic and glass surface) in vitro. Other plant lectins,Ulex europeus agglutinin (UEA) andDolichos biflorus agglutinin (DBA) had no effect on the cell-to-substratum interaction. A specific monocarbohydrate inhibitor of lectins, α-methyl-d-mannoside, inhibited the Con A-induced cell-to-substratum adhesion of dissociated embryonic cells. This observation suggests that the Con A-induced cell-to-substratum adhesion may be attributed to the Con A-carbohydrate interaction. In Millipore-filtered sea water (MPFSW) containing Con A (0.1 mg/ml), dissociated embryonic cells adhered to the substratum for more than 6 h at 18°C, while in MPFSW as control, almost all the dissociated cells were released from the substratum after 1 h. A scanning electron microscopic study showed that dissociated embryonic cells adhered to the substratum were surrounded by an extracellular fibrous material, when the cells were cultured in MPFSW containing Con A. The induction of the extracellular fibrous material by Con A was inhibited by α-methyl-d-mannoside. The appearance of this material may be related to the cell-to-substratum adhesion of dissociated cells. Sequential extractions of Con A-treated dissociated cells with Triton X 100 and urea solubilized most of the cellular components, leaving the fibrous material on the surface. Biochemical conponents of the isolated fibrous material included sea urchin fibronectin, Con A and minor components (88 and 140 kilodalton proteins). Fibronectin preformed in the cells was excreted after the dissociation, while the 88 and 140 kilodalton proteins were synthesized and released to the extracellular space.
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    Development genes and evolution 193 (1984), S. 108-110 
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    Keywords: Avian embryogenesis ; In vitro culture ; Blastoderm formation ; Bilateral symmetry
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    Notes: Summary A method of in vitro culture for uterine quail blastoderms has been developed, which allows them to develop from cleavage throughout gastrulation and further: stages 4–10 of Hamburger and Hamilton (1951). The method consists of cultivating the blastoderms on egg albumen in a vertical position; this permits about 50% of the blastoderms explanted before area pellucida formation to develop bilateral symmetry and to form normal primitive streak, somites and head structures. Development of the blastoderms explanted after their area pellucida was already formed, occurred normally and was not influenced by their spatial position in the culture.
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    Development genes and evolution 190 (1981), S. 22-26 
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    Keywords: Vitellogenesis ; Follicle proteins ; Juvenile hormone ; Locusta
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    Notes: Summary Insoluble proteins from the maturing follicle ofLocusta migratoria were analyzed by SDS-PAGE. A reproducible pattern of low molecular weight proteins was observed. Five of these proteins did not correspond to yolk or haemolymph proteins. At least two of these show marked quantitative changes during oocyte development. By in vitro incubation of follicles and fat body with a labelled precursor, and by the identification of the labelled polypeptides by SDS-PAGE, we could demonstrate that these two proteins are synthesized only during the time of vitellogenin uptake. This protein is probably a follicle product necessary for yolk formation. The other protein might be necessary for vitelline membrane and/or chorion formation.
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    Development genes and evolution 190 (1981), S. 11-21 
    ISSN: 1432-041X
    Keywords: Drosophila ; Imaginal discs ; Ecdysteroid ; Lethal mutant ; Morphogenesis
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    Topics: Biology
    Notes: Summary Imaginal disc development in the non-pupariating lethall(1)npr-1, a mutant that maps to an ecdysone early puff site, is studied in situ, in vitro and in transplanted discs. Disc development is slightly abnormal from the middle of the third instar with severe abnormalities appearing after the rise in 20-hydroxyecdysone that triggers metamorphosis. The mutant discs only partly evaginate and do not undergo any of the detailed morphological changes characteristic of metamorphosis. Treatment of the mutant dises in vitro with colcemid and trypsin facilitates evagination but the appendages remain morphologically abnormal. A number of differentiative processes occur in mutant discs in situ and in discs transplanted into wild type hosts in spite of the absence of normal morphogenesis. Implications of the observations for normal disc development are discussed. Possible modes of action of thel(1)npr-1 gene are also discussed in light of the observation that the mutant gene maps to a locus which is thought to have a regulatory function in development.
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    Development genes and evolution 190 (1981), S. 1-10 
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    Keywords: Drosophila ; Grandchildless ; Pole cells ; ts-mutant ; Cytoplasmic determinant
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    Topics: Biology
    Notes: Summary Two temperature-sensitive sex-linkedgrandchildless (gs)-like mutations (gs(1)N26 andgs(1)N441) were induced by ethylmethane sulphonate inDrosophila melanogaster. They complemented each other and mapped at two different loci (1−33.8±0.7 forgs(1)N26 and 1−39.6±1.7 forgs(1)N441), which were not identical to those of any of thegs-like mutants reported in earlier work. Homozygous females of the newly isolated mutants produced eggs that were unable to form pole cells and developed into agametic adults. Competence of the embryos to form pole cells was not restored by wild-type sperm in either mutant; that is, the sterility caused by these mutations is controlled by a maternal effect. Fecundity and fertility ofgs(1)N26 females were low, and their male offspring showed a higher mortality than that of female offspring, causing an abnormal sex ratio. The frequency of agametic progeny was 93.1% and 55.8%, when the female parents were reared at 25° C and 18° C, respectively. In eggs produced by thegs(1)N26 females reared at 25° C, the migration of nuclei to the posterior pole was abnormal, and almost no pole cell formation occurred in these egg. Furthermore, half of these eggs failed to cellularize at the posterior pole. When the females were reared at 18° C, almost all of the eggs underwent complete blastoderm formation, and in half of these blastoderm embryos normal pole cells were formed. In the other mutant,gs(1)N441, the fecundity and fertility of the females were normal. The agametic frequency in the progeny was 70.8% and 18.6% when the female parents were reared at 25° C and 18° C, respectively. In the eggs laid by females reared either at 25° C or at 18° C, the migration of nuclei to the periphery and cellularization proceeded normally; nevertheless, in the majority of the embryos no pole cell formation occured at the stage when nuclei penetrated into the periplasm. When the females were reared at 18° C, some of the embryos from these females formed some round blastoderm cells with cytologically recognizable polar granules and nuclear bodies, which are attributes of pole cells. The temperature sensitive period ofgs(1)N441 was estimated to extend from stage 9 to 13 of King's stages of oogenesis.
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    Development genes and evolution 193 (1984), S. 90-97 
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    Keywords: Drosophila ; Temperature-sensitive ; Neoplasms ; Differentiation ; Imaginal discs
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    Topics: Biology
    Notes: Summary EMS induced temperature-sensitivelethal (2) giant larva, 1(2)gl, alleles were isolated by screening against a knownl(2)gl allele. Analysis of the lethal phase of thel(2)gl ts-deficiency heterozygotes demonstrated: (1) the majority of thel(2)gl tslarvae survive to late third instar, (2) at 29°C the majority of thel(2)gl tslarvae failed to pupate and only rarely did they differentiate adult cuticular structures, (3) at 15°C the majority of the larvae pupated and frequently differentiated adult cuticular structures. Examination of the imaginal discs ofl(2)gl tslarvae reared at 29°C revealed the presence of morphologically abnormal wing, haltere and leg imaginal discs. No morphologically abnormal discs were found in thel(2)gl tslarvae reared at 15°C. Studies on both the histology and the developmental capacity of the morphologically normal and abnormall(2)gl tsdiscs were performed. The morphologically normal discs are histologically normal and produce a full complement of adult cuticular structures. However, the morphologically abnormal discs contained both regions that maintained the normal monolayer epithelium and regions that had lost the normal tissue architecture. The implants obtained when the morphologically abnormal discs are injected into metamorphosing larvae contained only a limited number of the normal complement of adult structures and usually only structures found in the ventral wing hinge region were recovered. In addition, the “metamorphosed” morphologically abnormal discs contained undifferentiated tissue that gave rise to transplantable neoplasms when cultured in adults. The results of the studies on the pathology of thel(2)gl tslarvae are discussed with respect to the role of thel(2)gl tsfunction during normal development, the autonomy of the neoplastic development of thel(2)gl tstissues, and similarities between neoplastic development inDrosophila and mammals.
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    Development genes and evolution 193 (1984), S. 119-119 
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    Development genes and evolution 193 (1984), S. 121-126 
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    Keywords: Retinoic acid ; Cartilage resorption ; Bone culture ; Ionophore A23187
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    Notes: Summary In fetal rat bones in culture the divalent cation ionophore A23187 inhibited in a dose-dependent manner both the release of proteoglycans and the subsequent degradation of cartilage induced by retinoic acid, indicating that calcium was involved in its action. A23187 had to be present continuously to manifest its inhibitory effect; retrieval of the ionophore abolished the suppression, demonstrating that the effect was reversible and not due to toxicity. A23187 at 1.0 μM, which completely blocked the retinoic acid-induced cartilage resorption, markedly suppressed3H-leucine,3H-mannose and3H-thymidine incorporation in control and retinoic acid-treated cultures. Reduced3H-thymidine incorporation did not appear to be responsible for the inhibition by A23187 of retinoic acid-induced cartilage resorption because inhibitors of DNA synthesis did not affect the retinoic acid response. In the presence of retinoic acid the ionophore at 0.3 μM had no effect on the incorporation of3H-leucine and3H-mannose, but suppressed the retinoic acid-induced proteoglycan release. This suggests that reduced protein and glycoprotein synthesis were not the main causes for the inhibitory effect of A23187. In conclusion, retinoic acid-induced cartilage degradation required calcium at some crucial points.
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    Development genes and evolution 193 (1984), S. 133-138 
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    Keywords: Drosophila melanogaster ; Compartment boundary ; Operculum seam
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    Topics: Biology
    Notes: Summary Histochemical staining of the hypoderm ofDrosophila larvae for aldehyde-oxidase activity allowed detection of a row of cells destined to form the operculum seam, along which the pupal case opens when the adult ecloses. Analysis ofmal clones in hypoderms of gynandromorph larvae showed that the prospective operculum seam coincides, in part, with a line of clonal restriction that divides the thorax into dorsal and ventral halves. We propose that this line represents the embryonic dorsal/ventral compartment boundary
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    Keywords: Cell-coupling ; Vitellogenesis ; Telotrophic-ovary ; Polarized transport
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    Notes: Summary Microinjected dyes were used to study transport routes between cells in the telotrophic ovarioles of the milkweed bug,Oncopeltus fasciatus. Dye movement revealed that transport through the nutritive cords is not dependent upon microtubules, and that the physiological continuity of the cords between the nurse cells and the oocyte is lost shortly after the onset of vitellogenesis. Dye-coupling of epithelial cells to the oocyte is shown to begin in a band of cells at the follicle equator. Coupling begins coincidentally with cord severance and the onset of vitellogenesis.
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  • 86
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    Keywords: Drosophila ; Imaginal disc ; Morphogenesis ; Tissue culture
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    Notes: Summary The thin region of the peripodial membrane is confined to the area overlying the distal anlagen in thoracic discs. During the early stages of evagination the peripodial membrane is greatly stretched, but does not rupture. The appendage then evaginates through the stalk, probably by means of a contraction of the peripodial membrane. The cells of the peripodial membrane of leg and wing discs persist and differentiate sheets of trichomes characteristic of the ventral and lateral thorax. This is discussed in relation to imaginal disc fate maps.
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    Development genes and evolution 193 (1984), S. 205-210 
    ISSN: 1432-041X
    Keywords: Rat early embryo ; Regionalization ; Polarization
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    Notes: Summary In rat pre-implantation embryos, we compared the polarization of cytoplasmic organelles with cell membrane regionalization as revealed by the cytochemical demonstration of 5′-nucleotidase and alkaline phosphatase. The polarization is shown at the eight-cell stage by columns of organelles extending from the nuclei to the embryo periphery. No consistent segregation of cytoplasmic components was recognized prior to the eight-cell stage. As to regionalization, both enzyme activities were demonstrated, from the late four-cell stage onwards on the cell surface between blastomeres of early and late morulae, while the external surface of the embryo lacked these activities. In early blastocysts, these enzyme activities were lost on the inner surface of the blastocyst cavity and in late blastocysts; 5′-nucleotidase activity appeared on the external surface of the embryonal trophoplast and extended to the abembryonal pole. From these observations we conclude that cell membrane regionalization precedes the polarization of the cytoplasm; however, this temporal relationship does not necessarily imply a causal relationship, since both phenomena may be independent expressions of an underlying morphonetic process.
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    Development genes and evolution 193 (1984), S. 211-218 
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    Keywords: Allantoic endoderm ; Heterotypic differentiation ; Intestinal epithelium ; Cloacal epithelium ; Immunofluorescence
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    Topics: Biology
    Notes: Summary Allantoic endoderm of 3.5-day chick embryos was cultured in recombination with digestive-tract mesenchymes of 6-day chick embryos, and the differentiation of the endoderm was studied, with special attention being given to the appearance of brush-border (BB) antigens and sucrase. Irrespective of the origin of the associated digestive-tract mesenchymes, the allantoic endoderm differentiated into a columnar epithelium, expressing BB antigens and sucrase, and also into a BB antigen-negative pseudostratified or stratified epithelium of cuboidal or columnar cells with PAS or alcian blue staining in the apical portion or a BB antigen-negative stratified squamous epithelium. These results suggest that 3.5-day allantoic endoderm has the potency to differentiate into intestinal and cloacal epithelium.
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    Development genes and evolution 193 (1984), S. 242-245 
    ISSN: 1432-041X
    Keywords: Chaetae ; Sensillae ; Differentiation ; Genetic regulation ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mutants in two loci,hairy (h +) andextramacrochaetae (emc +), produce phenotypes corresponding to an excess of function of theachaete-scute complex (AS-C), that is, they cause the appearance of extra chaetae. These mutants, although recessive in normal flies, become dominant in the presence of extra doses of AS-C. Here we study the interactions between these three genes, in an attempt to elucidate their relationships. The results show that the insufficiency produced byh oremc mutants can be titrated by altering the number of copies of AS-C. Moreover, excess of function of AS-C produced by derepression mutants within the complex (Hairy-wing) can also be titrated by altering the number of wild type copies of+ oremc +. These specific interactions indicate that bothh + andemc + code for “repressors” of AS-C that interact with theachaete andscute region of the complex respectively.
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    Development genes and evolution 193 (1984), S. 246-251 
    ISSN: 1432-041X
    Keywords: Chaetae ; Differentiation ; Genetic regulation ; Pattern formation ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have already shown that theachaetae-scute complex (AS-C) ofDrosophila is regulated by two genes,hairy andextramacrochaetae. Using mutants in these genes, we have analysed how different levels of expression of AS-C affect the pattern of chaetae. The results indicate that the spatial distribution of chaetae results from cell interactions, probably by a mechanism of lateral inhibition. The results are discussed in view of the different theories of pattern formation.
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    Development genes and evolution 193 (1984), S. 257-262 
    ISSN: 1432-041X
    Keywords: Ascidian egg ; Ooplasmic segregation ; Cortical actin network ; Egg stratification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ooplasmic segregation in ascidians includes the movement of the myoplasm, a pigmented cytoplasmic region thought to be involved in the determination of the embryonic muscle and mesenchyme cell lineages, into the vegetal hemisphere of the egg. A myoplasmic cytoskeletal domain (MCD), composed of a cortical actin network (the PML) and an underlying filamentous lattice extending deep into the cytoplasm, is present in this region. The MCD gradually recedes into the vegetal hemisphere during ooplasmic segregation. It has been proposed that the segregation of the myoplasm is mediated by the contraction of the PML. To test this possibility we have examined ooplasmic segregation in eggs in which the internal parts of the MCD were separated from the PML by centrifugal force. Transmission and scanning electron microscopy of eggs extracted with Triton X-100 showed that the PML remained intact when the internal portions of the MCD were displaced and stratified by centrifugation. When stratified eggs were fertilized there were no rearrangements of the visible cytoplasmic inclusions, but the cellular deformations and the recession of the PML characteristic of ooplasmic segregation occurred as usual. The results indicate that the recession of the PML occurs independently of the internal constituents of the MCD and suggest that PML contraction is the motive force for ooplasmic segregation.
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    Development genes and evolution 193 (1984), S. 308-325 
    ISSN: 1432-041X
    Keywords: Neurogenesis ; Pattern of neuroblasts ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This paper deals with morphological aspects of early neurogenesis inDrosophila, in particular with the segregation of neuroblasts from the neurogenic region of the ectoderm and the pattern formed by those wells within both the germ band and the procephalic lobe. The neurogenic ectoderm was found to contain neural precursors intermingled with epidermal precursors, extending from the midline up to the primordia of the tracheal tree along the germ band and laterodorsally in the procephalic lobe. Germ band neuroblasts segregate from the neurogenic ectoderm during a period of several hours according to characteristic spatial and temporal patterns. During the first half of the segregation process the pattern of germ band neuroblasts was found to be the same in different animals in both spatial arrangement and number of cells; this permitted the identification of individual neuroblasts from different embryos. Later in development several difficulties were encountered which precluded an exact description of the neuroblast pattern. The constitution of the neurogenic region is discussed in relation to the phenotype of mutants affecting neurogenesis.
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  • 93
    ISSN: 1432-041X
    Keywords: Regeneration ; Prolactin ; Organ culture ; Adult newt
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In vitro experiments were carried out to determine the effects of prolactin, and prolactin in combination with other hormones on the regeneration of adult newt tail blastemata. A total of 271 blastemata were explanted 13 days postamputation and were organ cultured for 96 h at 20 (±1)°C. Treatment with prolactin alone resulted in an increase in the blastema cell density of the tail regenerates. Cell accumulation and cell alignment were observed ventral to the reconstituted spinal cord. Prolactin and thyroxine, in combination, improved development of tail regenerates as compared with treatment with prolactin or thyroxine singly, supporting the results of earlier in vivo studies. Optimal development was obtained only when prolactin, insulin, thyroxine and hydrocortisone were added to the culture medium. Regeneration of tail explants maintained in medium augmented with the four hormones closely resembles that of in vivo tail blastemata 17 days post-amputation.
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    Development genes and evolution 193 (1984), S. 414-417 
    ISSN: 1432-041X
    Keywords: Alanine accumulation ; Anaerobic metabolism ; Embryonic diapause ; Bombyx silkworm ; pnd mutant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The changing pattern in free amino acids following the embryonic development in the non-diapause and diapause eggs of thepnd mutant of theBombyx silkworm was studied. In the diapause eggs, heterozygous for thepnd gene, the levels of most of the amino acids increased concomitantly with the substantial decrease in oxygen consumption. Among the amino acids, alanine was the only amino acid that showed a large accumulation. The accumulation could be induced experimentally in the non-diapause eggs, homozygous for thepnd gene, by reducing the oxygen supply. In contrast, it was prevented in the diapause eggs by increasing the oxygen supply. From these results, it is suggested that the alanine accumulation is the consequence of anaerobic metabolism in the eggs during diapause. The possible significance of the alanine accumulation is discussed in relation to the anaerobic carbohydrate metabolism associated with the embryonic diapause in thepnd mutant.
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    Development genes and evolution 194 (1984), S. 9-17 
    ISSN: 1432-041X
    Keywords: Retinoic acid ; Retinoids ; Chick embryo ; Skin differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The influence of retinoids (vitamin A and its analogues) on epithelial differentiation was examined in explants of foot skin from chick embryos. In the presence of retinoic acid (10 μM) keratinization and differentiation of scale-like structures, which occurred in tarsometatarsal skin explants, was inhibited and a mucous metaplasia developed. Retinoic acid caused club-shaped feathers in skin explants taken from the anterior surface of the tibia — skin which was determined to differentiate into feathers. In skin explants taken from a breed with feathered feet, the differentiation of tarsometatarsal skin was completely blocked; in tibial skin, club-shaped feathers resulted in response to retinoic acid. These findings indicated that skin of the two origins reacted differently to the retinoid, as was noted in the breed with scaly feet. The structure-activity relationship of 22 retinoids with marked differences in their biological activity was investigated in tarsometatarsal skin explants. Comparing the concentration of various retinoids needed to completely inhibit the differentiation of scale-like structures, retinoids containing tetramethylated indane or tetraline were 100 and 1,000 times more active than retinoic acid. Retinoids with a sulphur-containing end group were also active but less so than the corresponding compound with a carboxylic acid end group. The inactive ethyl, ester analogue, etretinate, was activated in the presence of esterase, indicating that the free carboxylic acid group was important for the activity of retinoids. The retinoid-induced inhibition of keratinization followed by mucous metaplasia in cultured chick embryo skin is a simple and useful model system to test new retinoids which may be helpful in the treatment of dermatological and oncological diseases.
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    Development genes and evolution 194 (1984), S. 56-60 
    ISSN: 1432-041X
    Keywords: Hydra ; Pattern formation ; Morphogens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Temporal course of regeneration of the hypostome and basal disc along the body length of the hydra is studied both in the presence and absence of the other determined centre. The regeneration times vary nonlinearly with distance from the original position indicating that the underlying processes are of non-linear nature. The presence of hypostome influences the regeneration of basal disc in an inhibitory manner throughout the body length, whereas, basal disc influences the regeneration of hypostome only in the lower portion of the body in a positive manner. A scheme in terms of the activators and inhibitors specific to hypostome and basal disc, is given. The implication of these results is that the two inhibitors are functionally distinct.
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  • 97
    ISSN: 1432-041X
    Keywords: Thymus ; Irradiation ; Regeneration ; Lymphoid cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The changes in cell numbers of different thymic cell populations and the conditions governing the regeneration of these populations and the thymus itself were examined after X-irradiation (700 rads) of different parts of the body. The general effects of the irradiation were studied in each experimental group in terms of mortality and growth rate. The particular effects on each thymic cell population were studied by the measurement of mitotic activity and of evaluation of the changes in numbers among these populations in the thymus itself, and were compared with the effects in the granulopoietic layer of the liver and in the spleen. The great reduction in the number of lymphocytes after irradiation demonstrates that they are more radiosensitive than other cell types; this reduction can be compensated for by the arrival of new lymphoid cells originating from other lymphoid organs (if they have been protected from irradiation) and by allowing thymic regeneration. Thus, irradiation has indirect effects on non-irradiated areas, and demonstrates that the lymphoid cell population has a high potential for multidirectional migration.
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    Development genes and evolution 194 (1984), S. 87-98 
    ISSN: 1432-041X
    Keywords: Cell differentiation ; Cytochalasin B ; Urochordata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ultrastructural features of histospecific differentiation were found in early cleavage stage ascidian embryos treated with cytochalasin B and held thereby in cleavagearrest until hatching time. Markers characteristic of tissue differentiation during normal embryonic and larval stages ofCiona intestinalis were expressed in muscle and two brain cell lineages of cleavage-arrested whole embryos and in epidermal and notochordal cell lineages of cleavage-arrested partial embryos. These features were muscle myofilaments and myofibrils, melanosomes of the brain pigment cells, cilium-derived structures present in a “proprioceptive” brain cell, extracellular test material of epidermal cell origin, and the sheath filaments, membrane leaflets, and vacuolar colloid associated with notochord cells. All of these ultrastructural markers of differentiation were blocked in their development by treatment of gastrula stage embryos with actinomycin D, an inhibitor of RNA synthesis, and presumably result from the expression of new gene activity. At the time of cleavage-arrest the five cell lineages studies still contained two or more unsegregated lineage pathways. Subsequent developmental autonomy within the lineages is consistent with the hypothesis of segregation during early development of functionally independent gene regulatory factors.
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    Development genes and evolution 194 (1984), S. 107-120 
    ISSN: 1432-041X
    Keywords: Cellular asymmetry reversal ; Cell surface patterns ; Mutations affecting patterns ; Ciliate development ; Tetrahymena thermophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The development of the oral apparatus (OA) and of neighboring ciliary structures ofTetrahymena thermophila was analyzed in cells homozygous for ajanus (jan A) mutation plus a recessiveenhancer of janA (eja). Such cells frequently possess two OAs located on opposite sides of the cell, a primary (1°) OA previously reported to be normal, and a secondary (2°) OA previously reported to express a mirror-reversal of right-left asymmetry. This study confirms the reality of a reversal in the gross orientation of membranelles in most developing 2° OAs. It also shows that there is a reversal of asymmetry in the pattern of resorption of basal bodies of ciliary rows adjacent to the 2° OA, and in the arrangement of basal-body couplets making up the portion of the apical “crown” of the cell situated close to the 2° OA. However, the locations at which membranelles of the 2° OA become modified during late phases of oral development remain normal, so that membranelles of 2° OAs are superimposable on those of 1° OAs. In addition, the membranelles of 2° OAs frequently undergo a rotation during the final phases of oral development, so that even their spatial orientation becomes normal. This mixture of reversed and normal features can be accounted for by postulating a superimposition of a reversed largescale asymmetry on a normal local asymmetry of ciliary units. This postulate predicts that no single mutation can bring about a complete mirror-image reversal of ciliary patterns. 1° OAs appear normal by light microscopy. However, detailed analysis of SEM, preparations of isolated 1° OAs indicate subtle abnormalities of basal body arrangement in some of these OAs.
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    Development genes and evolution 190 (1981), S. 233-236 
    ISSN: 1432-041X
    Keywords: Sulphate ; Glycosaminoglycan ; Autoradiography ; Gastrulation ; Chick
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Chick blastoderms were cultured for 2 h in the presence of35S-sulphate. The distribution of the grains after light microscope autoradiography was compared in blastoderms during the elongation and during the shortening of the primitive streak. A uniform labeling was observed over the cells in both groups. Accumulation of grains was present in both groups at the ventral side of the upper layer, where transmission electron microscope studies have revealed a basal lamina. An additional accumulation of grains occurred over the cells and in the extracellular spaces of the head process and of the rostral part of blastoderms with shortening primitive streaks. This positivity could be correlated with the presence of ingressing and recently ingressed notochordal cells. Treatment of the sections with chondroitinase ABC and/or HNO2 before dipping in the nuclear emulsion demonstrated that at least chondroitin sulphate and N-sulphated heparan sulphate were present.
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