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321.
Irmentraut Löw Anneliese M. Lengsfeld Theodor Wieland 《Histochemistry and cell biology》1974,38(3):253-258
Summary The increased occurrence of microfilaments in cell membrane preparations of rat liver poisoned with phalloidin in vitro was shown to be dependent on the age of the preparations. Cytochalasin B inhibits the formation of microfilaments stimulated by pahlloidin. 相似文献
322.
Juha J. Saarinen Alison G. Boyer James H. Brown Daniel P. Costa S. K. Morgan Ernest Alistair R. Evans Mikael Fortelius John L. Gittleman Marcus J. Hamilton Larisa E. Harding Kari Lintulaakso S. Kathleen Lyons Jordan G. Okie Richard M. Sibly Patrick R. Stephens Jessica Theodor Mark D. Uhen Felisa A. Smith 《Proceedings. Biological sciences / The Royal Society》2014,281(1784)
There is accumulating evidence that macroevolutionary patterns of mammal evolution during the Cenozoic follow similar trajectories on different continents. This would suggest that such patterns are strongly determined by global abiotic factors, such as climate, or by basic eco-evolutionary processes such as filling of niches by specialization. The similarity of pattern would be expected to extend to the history of individual clades. Here, we investigate the temporal distribution of maximum size observed within individual orders globally and on separate continents. While the maximum size of individual orders of large land mammals show differences and comprise several families, the times at which orders reach their maximum size over time show strong congruence, peaking in the Middle Eocene, the Oligocene and the Plio-Pleistocene. The Eocene peak occurs when global temperature and land mammal diversity are high and is best explained as a result of niche expansion rather than abiotic forcing. Since the Eocene, there is a significant correlation between maximum size frequency and global temperature proxy. The Oligocene peak is not statistically significant and may in part be due to sampling issues. The peak in the Plio-Pleistocene occurs when global temperature and land mammal diversity are low, it is statistically the most robust one and it is best explained by global cooling. We conclude that the macroevolutionary patterns observed are a result of the interplay between eco-evolutionary processes and abiotic forcing. 相似文献
323.
Theodor Staudenmayer 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1957,39(3):262-273
Zusammenfassung Zur Feststellung des Eintritts einer Schädigung von Eiern von Bombyx mori nach Behandlung mit Kontaktinsektiziden wurde die Atmung derselben mit der Warburg-Apapratur bestimmt.Es wurden folgende Insektizide geprüft: E 600, E 605, Systox, Diazinon, Pestox III, Aldrin, Dieldrin und Toxaphen.E 600 führt schon auf ganz frühen Entwicklungsstadien zu einer Schädigung der Embryonen. Zu diesem Zeitpunkt ist in den Eiern noch keine Cholinesterase nachweisbar.E 605, Systox und Diazinon führen einheitlich erst etwa 2 Tage vor dem Schlüpfen der unbehandelten Kontrollen zu einer Schädigung. Die Wirksamkeit der Mittel nimmt in folgender Reihenfolge ab: E 605, Systox, Diazinon.Pestox III zeigt keine Wirkung auf die Eier.Aldrin, Dieldrin und Toxaphen besitzen keine ovizide Wirkung.Herrn Prof. Dr. H. Schanderl, dem Vorstand des Instituts für Botanik, Gärungsphysiologie und Hefereinzucht, Geisenheim am Rhein, möchte ich an dieser Stelle herzlich danken, daß er mir die Durchführung dieser Arbeit außerhalb meiner Dienstzeit gestattete und die Versuche in jeder Weise unterstützte.Meinem hochverehrten Lehrer, Herrn Prof. Dr. von Frisch, zum 70. Geburtstag ergebenst gewidmet. 相似文献
324.
Nan van Geloven Theodor A. Balan Hein Putter Saskia le Cessie 《Biometrical journal. Biometrische Zeitschrift》2020,62(4):1012-1024
We study the effect of delaying treatment in the presence of (unobserved) heterogeneity. In a homogeneous population and assuming a proportional treatment effect, a treatment delay period will result in notably lower cumulative recovery percentages. We show in theoretical scenarios using frailty models that if the population is heterogeneous, the effect of a delay period is much smaller. This can be explained by the selection process that is induced by the frailty. Patient groups that start treatment later have already undergone more selection. The marginal hazard ratio for the treatment will act differently in such a more homogeneous patient group. We further discuss modeling approaches for estimating the effect of treatment delay in the presence of heterogeneity, and compare their performance in a simulation study. The conventional Cox model that fails to account for heterogeneity overestimates the effect of treatment delay. Including interaction terms between treatment and starting time of treatment or between treatment and follow up time gave no improvement. Estimating a frailty term can improve the estimation, but is sensitive to misspecification of the frailty distribution. Therefore, multiple frailty distributions should be used and the results should be compared using the Akaike Information Criterion. Non-parametric estimation of the cumulative recovery percentages can be considered if the dataset contains sufficient long term follow up for each of the delay strategies. The methods are demonstrated on a motivating application evaluating the effect of delaying the start of treatment with assisted reproductive techniques on time-to-pregnancy in couples with unexplained subfertility. 相似文献
325.
Magdalena Niedziakowska Karolina Doan Marcin Grny Maciej Sykut Krzysztof Stefaniak Natalia Piotrowska Bogumia Jdrzejewska Bogdan Ridush Sawomira Paweczyk Pawe Mackiewicz Ulrich Schmlcke Pavel Kosintsev Daniel Makowiecki Maxim Charniauski Dariusz Krasnodbski Eve Ranname Urmas Saarma Marine Arakelyan Ninna Manaseryan Vadim V. Titov Pavel Hulva Adrian Blescu Ralph Fyfe Jessie Woodbridge Katerina Trantalidou Vesna Dimitrijevi Oleksandr Kovalchuk Jarosaw Wilczyski Theodor Obad Grzegorz Lipecki Alesia Arabey Ana Stankovi 《Journal of Biogeography》2021,48(1):147-159
326.
Theodor Struch Burkard Neuss Stephanie Bringer-Meyer Hermann Sahm 《Applied microbiology and biotechnology》1991,34(4):518-523
Summary The physiological basis of the exceptionally high sugar tolerance of Zymomonas mobilis was investigated. Determinations of the internal metabolite concentrations of Z. mobilis showed that an increase in the extracellular glucose concentration was accompanied by a parallel rise in the intracellular glucose concentration, bringing about an almost complete osmotic balance between internal and external space. Studies of glucose transport confirmed that Z. mobilis has a facilitated diffusion system which enables a rapid equilibration between internal and external glucose concentrations. Studies using the non-metabolisable sugars maltose (impermeable) and xylose (permeable) revealed that these sugars were able to alter the osmotic pressure on the cytoplasmic membrane resulting in volume changes.Dedicated to Professor R. K. Finn on the occasion of his 70th birthday 相似文献
327.
Theodor A. Wohlfahrt 《Zoomorphology》1937,33(3):381-411
Ohne Zusammenfassung 相似文献
328.
Theodor Roemer 《Molecular & general genetics : MGG》1911,5(1):195-196
Ohne Zusammenfassung 相似文献
329.
Isolated lamb hearts were perfused at 13 °C for 24 hr with whole fresh blood using a silicone rubber circuit and a membrane lung (N = 7); there was formation of thrombi, deposition of fibrin, and an increase in resistance to blood flow in the membrane lung. The perfused hearts fibrillated at hypothermia and showed unequal recovery of function upon final rewarming.There was less rise in membrane lung resistance when the perfusion circuit was primed with blood at 38 instead of 13 °C and then cooled progressively to 13 °C. Some hearts perfused in these circuits were well preserved but others became edematous with loss of ventricular contractility (N = 6).Coating the perfusion circuit with a hypothrombogenic material, silica-free silicone rubber and priming the circuit at 38 °C prevented any rise in membrane lung resistance during blood perfusion. All the hearts perfused in these circuits (N = 6) had the same left ventricular function before and after cold perfusion.Thus isolated hearts can be perfused in vitro with whole blood at hypothermic temperature without loss in function when attention is paid to thrombogenicity of materials used to construct the perfusion circuit. 相似文献
330.