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Specificity of the Attachment of Agrobacterium to Wound Cells of Kalanchoe? Tumor induction by A. tumefaciens on leaves of Kalanchoe is severely inhibited by cell wall preparations from young and mature tissucs of monocotyledons and dicoryledons and from tumor cells and also by filter paper homogenates and living or dead Pseudomonas cells. The inhibition a demonstrable if the cell wall preparations or Pseudomonas cells are inoculated into the plant wounds at the same time with A tumefaciens or before A. tumefaciens a. Postinoculation does affect tumor These results demonstrate site binding as an important step of tumor induction without any doubt but at the same time they question the specificity of this process. 相似文献
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Growth of tropical trees is largely depending on the seasonality of the local climate. In many trees growing in areas with a distinct dry season, cambial activity ceases resulting in the formation of annual rings. In very humid mountain rainforests, trees stop to grow already after short rainless periods. By a combination of increment measurements and wood anatomical analyses, the climatic control of wood formation can be assessed. Intra‐annual wood density variations and content of various stable isotopes enable the climatological interpretation of the “wood signals”. 相似文献
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Ferdinando Rossi 《Cell and tissue research》1933,17(4):760-766
Ohne Zusammenfassungunterstützt durch Mittel der Edwin-Goldman-Stiftung zu London. 相似文献
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Karl Zagora 《Pal?ontologische Zeitschrift》1966,40(3-4):230-236
The presence of the genusEridoconcha Ulrich & Bassler 1923 (Eridostraca) is reported for the first time from the Lower Paleozoic sediments of Germany. The three speciesE. spinosa n. sp.,E. papillosa n. sp., andE. cf.rugosa Ulr. & Bassl. are described from the Lower Middle Devonian of eastern Thuringia. 相似文献
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《Archives of animal nutrition》2013,67(5):374-388
Zusammenfassungt Nach dem in früheren Untersuchungen festgestellten mikrobiellen Abbau von Calciumoxalat wurde die Resorption von Ca aus Calciumoxalat nachgewiesen. Die Untersuchungen wurden mit jungen, noch wachsenden Merinohammeln ausgeführt, denen nach einer gewissen Ca-Depletierung ein mit 45Ca markiertes Calciumoxalat verabfolgt wurde. Als Vergleichspräparat wurde ein entsprechend markiertes Calciumchlorid gegeben. Aus den Analysen bestimmter Teile des Skeletts (7. Rippe, 3. Halswirbel, Vordermittelfußknochen) und Untersuchungen von Blut und Harn wurde eine Resorption von Ca aus Calciumoxalat deutlich nachgewiesen. Das Ausmaß der Inkorporierung von 45Ca aus Calciumoxalat betrug etwa 20–25% des nach Verabfolgung von markiertem Calciumchlorid. Die hieraus folgende geringere Resorptionsfähigkeit für Ca aus Calciumoxalat gegenüber dem als Vergleichssubstanz verwendeten Calciumchlorid wurde in gleicher Tendenz und Umfang aus den anderen untersuchten Kriterien (Kot, Harn, Blut) bestätigt. 相似文献
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Tony Chevalier 《L'Anthropologie》2006,110(5):698-731
Although much research has been carried out on Australopithecus afarensis locomotion, no consensus has yet been reached. Our new critic study on femoral material brings to the fore a strictly bipedal behaviour within this taxon. Our results are based on the pertinence of human anatomical characteristics among A. afarensis and on the absence of characteristics revealing arboreal displacement. These results have emerged from our different observation and interpretation of some preceding authors concerning the anatomy of these fossil hominids. It is important to underline that apomorphic characteristics of this species are difficult to interpret. They must not however be used to support the idea of arboreal displacement simply based on the fact of a no totally human morphe. We believe that present day humans do not necessarily reflect the earliest strict bipedal anatomic model. An the other hand, it appears that the disagreement between the two locomotor hypothesis for A. afarensis that are bipedalism and arboreal displacement, facing the possibility of bipedalism associated with negligible arboreal displacement, results more from an evolutionary fact than from a real scientific conflict. 相似文献