178 research outputs found
Formation of regular spatial patterns in ratio-dependent predator-prey model driven by spatial colored-noise
Results are reported concerning the formation of spatial patterns in the
two-species ratio-dependent predator-prey model driven by spatial
colored-noise. The results show that there is a critical value with respect to
the intensity of spatial noise for this system when the parameters are in the
Turing space, above which the regular spatial patterns appear in two
dimensions, but under which there are not regular spatial patterns produced. In
particular, we investigate in two-dimensional space the formation of regular
spatial patterns with the spatial noise added in the side and the center of the
simulation domain, respectively.Comment: 4 pages and 3 figure
Turing patterns on networks
Turing patterns formed by activator-inhibitor systems on networks are
considered. The linear stability analysis shows that the Turing instability
generally occurs when the inhibitor diffuses sufficiently faster than the
activator. Numerical simulations, using a prey-predator model on a scale-free
random network, demonstrate that the final, asymptotically reached Turing
patterns can be largely different from the critical modes at the onset of
instability, and multistability and hysteresis are typically observed. An
approximate mean-field theory of nonlinear Turing patterns on the networks is
constructed.Comment: 4 pages, 4 figure
Long-term outcome of patients with newly diagnosed chronic myeloid leukemia: a randomized comparison of stem cell transplantation with drug treatment.
Tyrosine kinase inhibitors represent today's treatment of choice in chronic myeloid leukemia (CML). Allogeneic hematopoietic stem cell transplantation (HSCT) is regarded as salvage therapy. This prospective randomized CML-study IIIA recruited 669 patients with newly diagnosed CML between July 1997 and January 2004 from 143 centers. Of these, 427 patients were considered eligible for HSCT and were randomized by availability of a matched family donor between primary HSCT (group A; N=166 patients) and best available drug treatment (group B; N=261). Primary end point was long-term survival. Survival probabilities were not different between groups A and B (10-year survival: 0.76 (95% confidence interval (CI): 0.69-0.82) vs 0.69 (95% CI: 0.61-0.76)), but influenced by disease and transplant risk. Patients with a low transplant risk showed superior survival compared with patients with high- (P<0.001) and non-high-risk disease (P=0.047) in group B; after entering blast crisis, survival was not different with or without HSCT. Significantly more patients in group A were in molecular remission (56% vs 39%; P=0.005) and free of drug treatment (56% vs 6%; P<0.001). Differences in symptoms and Karnofsky score were not significant. In the era of tyrosine kinase inhibitors, HSCT remains a valid option when both disease and transplant risk are considered
Feilke revisited : 60 Stellenbesuche
Weitere Hrsg.: Thorsten Pohl, Sara Rezat, Torsten Steinhoff, Martin SteinseiferAnlässlich des 60. Geburtstags des Linguisten und Sprachdidaktikers Helmuth Feilke wurden Wegbegleiterinnen und Wegbegleiter gebeten, einzelne Stellen in seinen wissenschaftlichen Schriften erneut zu besuchen.
Entstanden sind pointierte Kommentare, kurze wissenschaftliche Abhandlungen und Analysen, Varianten auch des kritischen und kontroversen Nach- und Weiterdenkens und Ansätze zur Neu- oder Re-Kontextualisierung.
Je nach wissenschaftlicher Vita der Autorinnen und Autoren kann es sich um Stellen handeln, deren Rezeption zeitlich weit zurückliegt, oder um Passagen, die ganz aktuelle Fragen der eigenen Forschungsarbeit tangieren. Abgesehen davon, dass ein kurzes Format für die Beiträge gewählt und die Autorinnen und Autoren gebeten wurden, die ausgewählte Stelle knapp zu verorten und zu erläutern, war die Bearbeitungsform gänzlich freigestellt.
So sind Texte in einer Bandbreite von pointierten Kommentaren, kurzen wissenschaftlichen Abhandlungen und Analysen, Varianten des Nach- und Weiterdenkens, Ansätze zur Neu- oder Re-Kontextualisierung bis hin zu Formen des kritischen Hinterfragens und der kontroversen Auseinandersetzung entstanden
Verschiedene Modelle zur Berechnung des Nuklidtransports in kugelförmigen umhüllten Brennstoffteilchen für Hochtemperaturreaktoren
Der Brennstoff für gasgekühlte Hochtemperaturreaktoren, bestehend aus kleinen Kugeln aus oxidischem oder karbidischem Schwermetall, ist häufig mit einer oder mehreren Schalen aus pyrolytischem Kohlenstoff oder Siliziumkarbid umgeben, wodurch das Wandern von Schwermetallen und Spaltprodukten in das Brennelement oder der Austritt in den Kühlgasstrom weitgehend verhindert werden kann. Diese Brennnstoffteilchen sind unter dem Namen "coated particles" bekannt. [...
What should the voter know? Epistemic trust in democracy
Alvin Goldman develops the concept of co re voter knowledge to capture the kind of knowledge that voters need to have in order that democracy function successfully. As democracy is supposed to promote the people's goals, co re voter knowledge must, according to Goldman, first and foremost answer the question which electoral candidate would successfully perform in achieving that voter's ends. In our paper we challenge this concept of core voter knowledge from different angles. We analyse the dimensions of political trustworthiness and their relevance for the voter; we contrast two alternative orientations that the voter might take-an outcome-orientation and a process-orientation; and we discuss how an expressive account of voting behaviour would shift the focus in regard to the content of voter knowledge. Finally, we discuss some varieties of epistemic trust and their relevance for the availability, acquisition and dissemination of voter knowledge in a democracy
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