Institution
Braunschweig University of Technology
Education•Braunschweig, Germany•
About: Braunschweig University of Technology is a education organization based out in Braunschweig, Germany. It is known for research contribution in the topics: Population & Computer science. The organization has 13268 authors who have published 26707 publications receiving 611590 citations.
Papers published on a yearly basis
Papers
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TL;DR: A synergy of rafting, favourable surface currents and a reduction in salinity of surface waters could allow freshwater paths to open far enough to enable continental flora and fauna to reach these and other isolated oceanic islands.
Abstract: Aim Amphibians are a model group for studies of the biogeographical origins of salt-intolerant taxa on oceanic islands. We used the Gulf of Guinea islands to explore the biogeographical origins of island endemism of one species of frog, and used this to gain insights into potential colonization mechanisms.
Location Sao Tome and Principe, two of the four major islands in the Gulf of Guinea, West Africa, are truly oceanic and have an exceptionally high biodiversity.
Methods Mitochondrial DNA is used to test the endemic status of a frog from Sao Tome and compare it with congeneric taxa from tropical Africa. Existing data on surface currents, surface salinity, atmospheric circulation and bird migration in the Gulf of Guinea are summarized to address hypotheses concerning colonization mechanisms.
Results The endemic status of Ptychadena newtoni (Bocage) is supported here by mitochondrial DNA sequences, and analysis of this and other molecular data indicates that an East African species close to Ptychadena mascareniensis (Dumeril and Bibron) is its nearest relative. We refute the possibility that this population was anthropogenically introduced, in favour of a natural dispersal mechanism.
Main conclusions With six endemic frogs and one caecilian, the Gulf of Guinea islands harbour a diverse amphibian fauna. Five of these species appear to have their closest relatives in East Africa. Insufficient evidence exists for transportation by storms, birds or rafts alone. However, we propose a synergy of rafting, favourable surface currents and a reduction in salinity of surface waters. Catastrophic events, or wet periods in climatic history, could allow freshwater paths to open far enough to enable continental flora and fauna to reach these and other isolated oceanic islands.
163 citations
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TL;DR: In this article, Chen and Wolf used a thin-filament theory to construct a 2D model of a bursty bulk flow (BBF) motion inside the plasma sheet, which revealed that the low-entropy filament overshoots its equilibrium position and executes a heavily damped oscillation about that position.
Abstract: [1] Chen and Wolf (1999) used a thin-filament theory to construct a 2D model of a bursty bulk flow (BBF) motion inside the plasma sheet. The modeling revealed that the low-entropy filament overshoots its equilibrium position and executes a heavily damped oscillation about that position. In this letter we demonstrate, for the first time, the multiple overshoot and rebound of a BBF observed by the five THEMIS probes on 17 March 2008 just after 10:22 UT. We found that the BBF oscillatory braking was accompanied by interlaced enhancements and depletions of radial pressure gradients. The earthward and tailward flow bursts caused formation of vortices with opposite sense of rotation.
163 citations
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TL;DR: In this paper, a new dynamical model of the friction coefficient is proposed, where wear particles are used by the brake system to build up hard contact patches on the brake pad and these contact patches are destroyed after some time.
163 citations
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TL;DR: It is proposed that PIP2-dependent signalling modulates microfilament organization at cellular adhesion sites by regulating vinculin-VASP complexes.
163 citations
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TL;DR: This Letter suggests the use of a sparsity-promoting prior, verified in many inline holography applications, and presents a simple iterative algorithm for 3D object reconstruction under sparsity and positivity constraints.
Abstract: Inline digital holograms are classically reconstructed using linear operators to model diffraction. It has long been recognized that such reconstruction operators do not invert the hologram formation operator. Classical linear reconstructions yield images with artifacts such as distortions near the field-of-view boundaries or twin images. When objects located at different depths are reconstructed from a hologram, in-focus and out-of-focus images of all objects superimpose upon each other. Additional processing, such as maximum-of-focus detection, is thus unavoidable for any successful use of the reconstructed volume. In this Letter, we consider inverting the hologram formation model in a Bayesian framework. We suggest the use of a sparsity-promoting prior, verified in many inline holography applications, and present a simple iterative algorithm for 3D object reconstruction under sparsity and positivity constraints. Preliminary results with both simulated and experimental holograms are highly promising.
163 citations
Authors
Showing all 13486 results
Name | H-index | Papers | Citations |
---|---|---|---|
Wolfgang Wagner | 156 | 2342 | 123391 |
Helmut Sies | 133 | 670 | 78319 |
Cristina Riccardi | 129 | 1627 | 91452 |
Klaus-Robert Müller | 129 | 764 | 79391 |
Alex Zunger | 128 | 826 | 78798 |
Rolf Müller | 104 | 905 | 50027 |
Rudolf Valenta | 102 | 748 | 38349 |
Oliver G. Schmidt | 100 | 1083 | 39988 |
Kenneth N. Timmis | 97 | 365 | 34912 |
Thomas Braun | 96 | 744 | 38576 |
Ursula Keller | 92 | 934 | 33229 |
William Martin | 90 | 348 | 34353 |
Bruce T. Tsurutani | 85 | 605 | 30358 |
Michael Wink | 83 | 938 | 32658 |
Yves-Alain Barde | 83 | 168 | 35485 |