Institution
University of Potsdam
Education•Potsdam, Germany•
About: University of Potsdam is a education organization based out in Potsdam, Germany. It is known for research contribution in the topics: Population & Computer science. The organization has 9629 authors who have published 26740 publications receiving 759745 citations. The organization is also known as: Universität Potsdam.
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TL;DR: In this paper, the influence of the corona-charging process on the piezoelectric transducer coefficient d33 of a cellular electret film has been investigated, and the effect of the gas inside the voids has also been studied.
Abstract: The influence of the corona-charging process on the piezoelectric transducer coefficient d33 of a cellular electret film has been investigated. An increased corona voltage can be considered as a way to enhance the charge density and thus also the resulting piezoelectric effect. Higher corona-charging voltages are possible with increased ambient pressure or in suitable dielectric gases. The effect of the gas inside the voids has also been studied. Enhanced transducer coefficients were obtained by corona charging in N2 or N2O gas atmospheres at 100-450 or 100-140 kPa pressures, respectively. The highest transducer coefficients of about 790 pCN-1 were obtained when N2 gas was filled into the voids of a cellular polymer film by means of consecutive vacuum and high-pressure treatments at 295 or 313 K.
176 citations
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Pennsylvania State University1, Universities Space Research Association2, Goddard Space Flight Center3, West Chester University of Pennsylvania4, Institut d'Astrophysique de Paris5, University of Michigan6, University of Arizona7, Harvard University8, University of Liège9, University of Leeds10, Ludwig Maximilian University of Munich11, University of Illinois at Urbana–Champaign12, Swarthmore College13, University of Maryland, Baltimore County14, University of Exeter15, American Museum of Natural History16, European Space Research and Technology Centre17, Université de Montréal18, University of Potsdam19, Fisk University20, Vanderbilt University21, Penn State Worthington Scranton22, Space Telescope Science Institute23, University of Wisconsin-Madison24, University of Delaware25, Massachusetts Institute of Technology26
TL;DR: In this paper, the authors have mapped the Carina star-forming complex in X-rays, using archival Chandra data and a mosaic of 20 new 60 ks pointings using the Chandra X-ray Observatory's Advanced CCD Imaging Spectrometer.
Abstract: The Great Nebula in Carina provides an exceptional view into the violent massive star formation and feedback that typifies giant H II regions and starburst galaxies. We have mapped the Carina star-forming complex in X-rays, using archival Chandra data and a mosaic of 20 new 60 ks pointings using the Chandra X-ray Observatory's Advanced CCD Imaging Spectrometer, as a testbed for understanding recent and ongoing star formation and to probe Carina's regions of bright diffuse X-ray emission. This study has yielded a catalog of properties of >14,000 X-ray point sources; >9800 of them have multiwavelength counterparts. Using Chandra's unsurpassed X-ray spatial resolution, we have separated these point sources from the extensive, spatially-complex diffuse emission that pervades the region; X-ray properties of this diffuse emission suggest that it traces feedback from Carina's massive stars. In this introductory paper, we motivate the survey design, describe the Chandra observations, and present some simple results, providing a foundation for the 15 papers that follow in this special issue and that present detailed catalogs, methods, and science results.
176 citations
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TL;DR: Using event-related potentials (ERPs), evidence is presented that the current interpretation of the N400 component must be extended because it is elicited in incorrect German sentences with two grammatical subjects, thereby showing its sensitivity to thematic relations between arguments in a sentence.
Abstract: Using event-related potentials (ERPs), we present evidence that the current interpretation of the N400 component must be extended. This component is elicited in incorrect German sentences with two grammatical subjects, thereby showing its sensitivity to thematic relations between arguments in a sentence (who is doing what to whom). Such a violation only elicits an N400 when both arguments are animate but not when one of them is animate and the other inanimate, thus showing that the brain uses animacy information to overcome interpretation problems due to thematic competition. Structures with two subjects additionally elicit a P600 component which occurs independently of the animacy variation. Thus, animacy information does not appear to influence the syntactic processing problems resulting from such violations.
176 citations
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TL;DR: In this paper, the scaling Brownian motion (SBM) model is shown to be weakly nonergodic but does not exhibit a significant amplitude scatter of the time averaged mean squared displacement.
Abstract: Anomalous diffusion is frequently described by scaled Brownian motion (SBM), a Gaussian process with a power-law time dependent diffusion coefficient. Its mean squared displacement is 〈x2(t)〉 ≃ 2(t)t with (t) ≃ tα−1 for 0 < α < 2. SBM may provide a seemingly adequate description in the case of unbounded diffusion, for which its probability density function coincides with that of fractional Brownian motion. Here we show that free SBM is weakly non-ergodic but does not exhibit a significant amplitude scatter of the time averaged mean squared displacement. More severely, we demonstrate that under confinement, the dynamics encoded by SBM is fundamentally different from both fractional Brownian motion and continuous time random walks. SBM is highly non-stationary and cannot provide a physical description for particles in a thermalised stationary system. Our findings have direct impact on the modelling of single particle tracking experiments, in particular, under confinement inside cellular compartments or when optical tweezers tracking methods are used.
176 citations
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TL;DR: The interdependence between the activities of G WD and BAMs offers an explanation for the severe starch excess phenotype of GWD-deficient mutants.
Abstract: Glucan phosphorylating enzymes are required for normal mobilization of starch in leaves of Arabidopsis (Arabidopsis thaliana) and potato (Solanum tuberosum), but mechanisms underlying this dependency are unknown. Using two different activity assays, we aimed to identify starch degrading enzymes from Arabidopsis, whose activity is affected by glucan phosphorylation. Breakdown of granular starch by a protein fraction purified from leaf extracts increased approximately 2-fold if the granules were simultaneously phosphorylated by recombinant potato glucan, water dikinase (GWD). Using matrix-assisted laser-desorption ionization mass spectrometry several putative starch-related enzymes were identified in this fraction, among them β-AMYLASE1 (BAM1; At3g23920) and ISOAMYLASE3 (ISA3; At4g09020). Experiments using purified recombinant enzymes showed that BAM1 activity with granules similarly increased under conditions of simultaneous starch phosphorylation. Purified recombinant potato ISA3 (StISA3) did not attack the granular starch significantly with or without glucan phosphorylation. However, starch breakdown by a mixture of BAM1 and StISA3 was 2 times higher than that by BAM1 alone and was further enhanced in the presence of GWD and ATP. Similar to BAM1, maltose release from granular starch by purified recombinant BAM3 (At4g17090), another plastid-localized β-amylase isoform, increased 2- to 3-fold if the granules were simultaneously phosphorylated by GWD. BAM activity in turn strongly stimulated the GWD-catalyzed phosphorylation. The interdependence between the activities of GWD and BAMs offers an explanation for the severe starch excess phenotype of GWD-deficient mutants.
176 citations
Authors
Showing all 9969 results
Name | H-index | Papers | Citations |
---|---|---|---|
Cyrus Cooper | 204 | 1869 | 206782 |
Markus Antonietti | 176 | 1068 | 127235 |
Marc Weber | 167 | 2716 | 153502 |
Peter Capak | 147 | 679 | 70483 |
Heiner Boeing | 140 | 1024 | 92580 |
Alisdair R. Fernie | 133 | 1010 | 64026 |
Klaus-Robert Müller | 129 | 764 | 79391 |
Claudia Felser | 113 | 1198 | 58589 |
Guochun Zhao | 113 | 406 | 40886 |
Matthias Steinmetz | 112 | 461 | 67802 |
Jürgen Kurths | 105 | 1038 | 62179 |
Peter Schmidt | 105 | 638 | 61822 |
Erwin P. Bottinger | 102 | 342 | 42089 |
Knud Jahnke | 94 | 352 | 31542 |
Gerd Gigerenzer | 94 | 533 | 52356 |