TY  - JOUR
A1  - Aberle-Malzahn, Nicole
A1  - Bauer, Barbara
A1  - Lewandowska, A.
A1  - Gaedke, Ursula
A1  - Sommer, U.
T1  - Warming induces shifts in microzooplankton phenology and reduces time-lags between phytoplankton and protozoan production
JF  - Marine biology : international journal on life in oceans and coastal waters
N2  - Indoor mesocosm experiments were conducted to test for potential climate change effects on the spring succession of Baltic Sea plankton. Two different temperature (Delta 0 A degrees C and Delta 6 A degrees C) and three light scenarios (62, 57 and 49 % of the natural surface light intensity on sunny days), mimicking increasing cloudiness as predicted for warmer winters in the Baltic Sea region, were simulated. By combining experimental and modeling approaches, we were able to test for a potential dietary mismatch between phytoplankton and zooplankton. Two general predator-prey models, one representing the community as a tri-trophic food chain and one as a 5-guild food web were applied to test for the consequences of different temperature sensitivities of heterotrophic components of the plankton. During the experiments, we observed reduced time-lags between the peaks of phytoplankton and protozoan biomass in response to warming. Microzooplankton peak biomass was reached by 2.5 day A degrees C-1 earlier and occurred almost synchronously with biomass peaks of phytoplankton in the warm mesocosms (Delta 6 A degrees C). The peak magnitudes of microzooplankton biomass remained unaffected by temperature, and growth rates of microzooplankton were higher at Delta 6 A degrees C (mu(a dagger 0 A degrees C) = 0.12 day(-1) and mu(a dagger 6 A degrees C) = 0.25 day(-1)). Furthermore, warming induced a shift in microzooplankton phenology leading to a faster species turnover and a shorter window of microzooplankton occurrence. Moderate differences in the light levels had no significant effect on the time-lags between autotrophic and heterotrophic biomass and on the timing, biomass maxima and growth rate of microzooplankton biomass. Both models predicted reduced time-lags between the biomass peaks of phytoplankton and its predators (both microzooplankton and copepods) with warming. The reduction of time-lags increased with increasing Q(10) values of copepods and protozoans in the tritrophic food chain. Indirect trophic effects modified this pattern in the 5-guild food web. Our study shows that instead of a mismatch, warming might lead to a stronger match between protist grazers and their prey altering in turn the transfer of matter and energy toward higher trophic levels.
Y1  - 2012
U6  - https://doi.org/10.1007/s00227-012-1947-0
SN  - 0025-3162
VL  - 159
IS  - 11
SP  - 2441
EP  - 2453
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Abouzar, Maryam H.
A1  - Poghossian, Arshak
A1  - Cherstvy, Andrey G.
A1  - Pedraza, Angela M.
A1  - Ingebrandt, Sven
A1  - Schöning, Michael J.
T1  - Label-free electrical detection of DNA by means of field-effect nanoplate capacitors experiments and modeling
JF  - Physica status solidi : A, Applications and materials science
N2  - Label-free electrical detection of consecutive deoxyribonucleic acid (DNA) hybridization/denaturation by means of an array of individually addressable field-effect-based nanoplate silicon-on-insulator (SOI) capacitors modified with gold nanoparticles (Au-NP) is investigated. The proposed device detects charge changes on Au-NP/DNA hybrids induced by the hybridization or denaturation event. DNA hybridization was performed in a high ionic-strength solution to provide a high hybridization efficiency. On the other hand, to reduce the screening of the DNA charge by counter ions and to achieve a high sensitivity, the sensor signal induced by the hybridization and denaturation events was measured in a low ionic-strength solution. High sensor signals of about 120, 90, and 80 mV were registered after the DNA hybridization, denaturation, and re-hybridization events, respectively. Fluorescence microscopy has been applied as reference method to verify the DNA immobilization, hybridization, and denaturation processes. An electrostatic charge-plane model for potential changes at the gate surface of a nanoplate field-effect sensor induced by the DNA hybridization has been developed taking into account both the Debye length and the distance of the DNA charge from the gate surface.
KW  - DNA
KW  - field-effect
KW  - gold nanoparticle
KW  - label-free detection
KW  - nanoplate capacitor
Y1  - 2012
U6  - https://doi.org/10.1002/pssa.201100710
SN  - 1862-6300
VL  - 209
IS  - 5
SP  - 925
EP  - 934
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Abramowski, Attila
A1  - Acero, F.
A1  - Aharonian, Felix A.
A1  - Akhperjanian, A. G.
A1  - Anton, Gisela
A1  - Balzer, Arnim
A1  - Barnacka, Anna
A1  - de Almeida, U. Barres
A1  - Becherini, Yvonne
A1  - Becker, J.
A1  - Behera, B.
A1  - Bernlöhr, K.
A1  - Birsin, E.
A1  - Biteau, Jonathan
A1  - Bochow, A.
A1  - Boisson, Catherine
A1  - Bolmont, J.
A1  - Bordas, Pol
A1  - Brucker, J.
A1  - Brun, Francois
A1  - Brun, Pierre
A1  - Bulik, Tomasz
A1  - Buesching, I.
A1  - Carrigan, Svenja
A1  - Casanova, Sabrina
A1  - Cerruti, M.
A1  - Chadwick, Paula M.
A1  - Charbonnier, A.
A1  - Chaves, Ryan C. G.
A1  - Cheesebrough, A.
A1  - Clapson, A. C.
A1  - Coignet, G.
A1  - Cologna, Gabriele
A1  - Conrad, Jan
A1  - Dalton, M.
A1  - Daniel, M. K.
A1  - Davids, I. D.
A1  - Degrange, B.
A1  - Deil, C.
A1  - Dickinson, H. J.
A1  - Djannati-Ataï, A.
A1  - Domainko, W.
A1  - Drury, L. O'C.
A1  - Dubus, G.
A1  - Dutson, K.
A1  - Dyks, J.
A1  - Dyrda, M.
A1  - Egberts, Kathrin
A1  - Eger, P.
A1  - Espigat, P.
A1  - Fallon, L.
A1  - Farnier, C.
A1  - Fegan, S.
A1  - Feinstein, F.
A1  - Fernandes, M. V.
A1  - Fiasson, A.
A1  - Fontaine, G.
A1  - Foerster, A.
A1  - Fuessling, M.
A1  - Gallant, Y. A.
A1  - Gast, H.
A1  - Gerard, L.
A1  - Gerbig, D.
A1  - Giebels, B.
A1  - Glicenstein, J. F.
A1  - Glueck, B.
A1  - Goret, P.
A1  - Goering, D.
A1  - Haeffner, S.
A1  - Hague, J. D.
A1  - Hampf, D.
A1  - Hauser, M.
A1  - Heinz, S.
A1  - Heinzelmann, G.
A1  - Henri, G.
A1  - Hermann, G.
A1  - Hinton, James Anthony
A1  - Hoffmann, A.
A1  - Hofmann, W.
A1  - Hofverberg, P.
A1  - Holler, M.
A1  - Horns, D.
A1  - Jacholkowska, A.
A1  - de Jager, O. C.
A1  - Jahn, C.
A1  - Jamrozy, M.
A1  - Jung, I.
A1  - Kastendieck, M. A.
A1  - Katarzynski, K.
A1  - Katz, U.
A1  - Kaufmann, S.
A1  - Keogh, D.
A1  - Khangulyan, D.
A1  - Khelifi, B.
A1  - Klochkov, D.
A1  - Kluzniak, W.
A1  - Kneiske, T.
A1  - Komin, Nu.
A1  - Kosack, K.
A1  - Kossakowski, R.
A1  - Laffon, H.
A1  - Lamanna, G.
A1  - Lennarz, D.
A1  - Lohse, T.
A1  - Lopatin, A.
A1  - Lu, C. -C.
A1  - Marandon, V.
A1  - Marcowith, Alexandre
A1  - Masbou, J.
A1  - Maurin, D.
A1  - Maxted, N.
A1  - Mayer, M.
A1  - McComb, T. J. L.
A1  - Medina, M. C.
A1  - Mehault, J.
A1  - Moderski, R.
A1  - Moulin, Emmanuel
A1  - Naumann, C. L.
A1  - Naumann-Godo, M.
A1  - de Naurois, M.
A1  - Nedbal, D.
A1  - Nekrassov, D.
A1  - Nguyen, N.
A1  - Nicholas, B.
A1  - Niemiec, J.
A1  - Nolan, S. J.
A1  - Ohm, S.
A1  - Wilhelmi, E. de Ona
A1  - Opitz, B.
A1  - Ostrowski, M.
A1  - Oya, I.
A1  - Panter, M.
A1  - Arribas, M. Paz
A1  - Pedaletti, G.
A1  - Pelletier, G.
A1  - Petrucci, P. -O.
A1  - Pita, S.
A1  - Puehlhofer, G.
A1  - Punch, M.
A1  - Quirrenbach, A.
A1  - Raue, M.
A1  - Rayner, S. M.
A1  - Reimer, A.
A1  - Reimer, O.
A1  - Renaud, M.
A1  - de los Reyes, R.
A1  - Rieger, F.
A1  - Ripken, J.
A1  - Rob, L.
A1  - Rosier-Lees, S.
A1  - Rowell, G.
A1  - Rudak, B.
A1  - Rulten, C. B.
A1  - Ruppel, J.
A1  - Sahakian, V.
A1  - Sanchez, David M.
A1  - Santangelo, A.
A1  - Schlickeiser, R.
A1  - Schoeck, F. M.
A1  - Schulz, A.
A1  - Schwanke, U.
A1  - Schwarzburg, S.
A1  - Schwemmer, S.
A1  - Sheidaei, F.
A1  - Skilton, J. L.
A1  - Sol, H.
A1  - Spengler, G.
A1  - Stawarz, L.
A1  - Steenkamp, R.
A1  - Stegmann, Christian
A1  - Stinzing, F.
A1  - Stycz, K.
A1  - Sushch, Iurii
A1  - Szostek, A.
A1  - Tavernet, J. -P.
A1  - Terrier, R.
A1  - Tluczykont, M.
A1  - Valerius, K.
A1  - van Eldik, C.
A1  - Vasileiadis, G.
A1  - Venter, C.
A1  - Vialle, J. P.
A1  - Viana, A.
A1  - Vincent, P.
A1  - Voelk, H. J.
A1  - Volpe, F.
A1  - Vorobiov, S.
A1  - Vorster, M.
A1  - Wagner, S. J.
A1  - Ward, M.
A1  - White, R.
A1  - Wierzcholska, A.
A1  - Zacharias, M.
A1  - Zajczyk, A.
A1  - Zdziarski, A. A.
A1  - Zech, Alraune
A1  - Zechlin, H. -S.
A1  - Aleksic, J.
A1  - Antonelli, L. A.
A1  - Antoranz, P.
A1  - Backes, Michael
A1  - Barrio, J. A.
A1  - Bastieri, D.
A1  - Becerra Gonzalez, J.
A1  - Bednarek, W.
A1  - Berdyugin, A.
A1  - Berger, K.
A1  - Bernardini, E.
A1  - Biland, A.
A1  - Blanch Bigas, O.
A1  - Bock, R. K.
A1  - Boller, A.
A1  - Bonnoli, G.
A1  - Tridon, D. Borla
A1  - Braun, I.
A1  - Bretz, T.
A1  - Canellas, A.
A1  - Carmona, E.
A1  - Carosi, A.
A1  - Colin, P.
A1  - Colombo, E.
A1  - Contreras, J. L.
A1  - Cortina, J.
A1  - Cossio, L.
A1  - Covino, S.
A1  - Dazzi, F.
A1  - De Angelis, A.
A1  - De Cea del Pozo, E.
A1  - De Lotto, B.
A1  - Delgado Mendez, C.
A1  - Diago Ortega, A.
A1  - Doert, M.
A1  - Dominguez, A.
A1  - Prester, Dijana Dominis
A1  - Dorner, D.
A1  - Doro, M.
A1  - Elsaesser, D.
A1  - Ferenc, D.
A1  - Fonseca, M. V.
A1  - Font, L.
A1  - Fruck, C.
A1  - Garcia Lopez, R. J.
A1  - Garczarczyk, M.
A1  - Garrido, D.
A1  - Giavitto, G.
A1  - Godinovic, N.
A1  - Hadasch, D.
A1  - Haefner, D.
A1  - Herrero, A.
A1  - Hildebrand, D.
A1  - Hoehne-Moench, D.
A1  - Hose, J.
A1  - Hrupec, D.
A1  - Huber, B.
A1  - Jogler, T.
A1  - Klepser, S.
A1  - Kraehenbuehl, T.
A1  - Krause, J.
A1  - La Barbera, A.
A1  - Lelas, D.
A1  - Leonardo, E.
A1  - Lindfors, E.
A1  - Lombardi, S.
A1  - Lopez, M.
A1  - Lorenz, E.
A1  - Makariev, M.
A1  - Maneva, G.
A1  - Mankuzhiyil, N.
A1  - Mannheim, K.
A1  - Maraschi, L.
A1  - Mariotti, M.
A1  - Martinez, M.
A1  - Mazin, D.
A1  - Meucci, M.
A1  - Miranda, J. M.
A1  - Mirzoyan, R.
A1  - Miyamoto, H.
A1  - Moldon, J.
A1  - Moralejo, A.
A1  - Munar, P.
A1  - Nieto, D.
A1  - Nilsson, K.
A1  - Orito, R.
A1  - Oya, I.
A1  - Paneque, D.
A1  - Paoletti, R.
A1  - Pardo, S.
A1  - Paredes, J. M.
A1  - Partini, S.
A1  - Pasanen, M.
A1  - Pauss, F.
A1  - Perez-Torres, M. A.
A1  - Persic, M.
A1  - Peruzzo, L.
A1  - Pilia, M.
A1  - Pochon, J.
A1  - Prada, F.
A1  - Moroni, P. G. Prada
A1  - Prandini, E.
A1  - Puljak, I.
A1  - Reichardt, I.
A1  - Reinthal, R.
A1  - Rhode, W.
A1  - Ribo, M.
A1  - Rico, J.
A1  - Ruegamer, S.
A1  - Saggion, A.
A1  - Saito, K.
A1  - Saito, T. Y.
A1  - Salvati, M.
A1  - Satalecka, K.
A1  - Scalzotto, V.
A1  - Scapin, V.
A1  - Schultz, C.
A1  - Schweizer, T.
A1  - Shayduk, M.
A1  - Shore, S. N.
A1  - Sillanpaa, A.
A1  - Sitarek, J.
A1  - Sobczynska, D.
A1  - Spanier, F.
A1  - Spiro, S.
A1  - Stamerra, A.
A1  - Steinke, B.
A1  - Storz, J.
A1  - Strah, N.
A1  - Suric, T.
A1  - Takalo, L.
A1  - Takami, H.
A1  - Tavecchio, F.
A1  - Temnikov, P.
A1  - Terzic, T.
A1  - Tescaro, D.
A1  - Teshima, M.
A1  - Thom, M.
A1  - Tibolla, O.
A1  - Torres, D. F.
A1  - Treves, A.
A1  - Vankov, H.
A1  - Vogler, P.
A1  - Wagner, R. M.
A1  - Weitzel, Q.
A1  - Zabalza, V.
A1  - Zandanel, F.
A1  - Zanin, R.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bouvier, A.
A1  - Bradbury, S. M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Ciupik, L.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickherber, R.
A1  - Duke, C.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Huan, H.
A1  - Hui, C. M.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - LeBohec, S.
A1  - Maier, G.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nunez, P. D.
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pichel, A.
A1  - Pohl, Martin
A1  - Prokoph, H.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Rose, H. J.
A1  - Ruppel, J.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Sentuerk, G. D.
A1  - Telezhinsky, Igor O.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vivier, M.
A1  - Wakely, S. P.
A1  - Weekes, T. C.
A1  - Williams, D. A.
A1  - Zitzer, B.
A1  - de Almeida, U. Barres
A1  - Cara, M.
A1  - Casadio, C.
A1  - Cheung, C. C.
A1  - McConville, W.
A1  - Davies, F.
A1  - Doi, A.
A1  - Giovannini, G.
A1  - Giroletti, M.
A1  - Hada, K.
A1  - Hardee, P.
A1  - Harris, D. E.
A1  - Junor, W.
A1  - Kino, M.
A1  - Lee, N. P.
A1  - Ly, C.
A1  - Madrid, J.
A1  - Massaro, F.
A1  - Mundell, C. G.
A1  - Nagai, H.
A1  - Perlman, E. S.
A1  - Steele, I. A.
A1  - Walker, R. C.
A1  - Wood, D. L.
T1  - The 2010 very high energy gamma-ray flare and 10 years ofmulti-wavelength oservations of M 87
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - The giant radio galaxy M 87 with its proximity (16 Mpc), famous jet, and very massive black hole ((3-6) x 10(9) M-circle dot) provides a unique opportunity to investigate the origin of very high energy (VHE; E > 100 GeV) gamma-ray emission generated in relativistic outflows and the surroundings of supermassive black holes. M 87 has been established as a VHE gamma-ray emitter since 2006. The VHE gamma-ray emission displays strong variability on timescales as short as a day. In this paper, results from a joint VHE monitoring campaign on M 87 by the MAGIC and VERITAS instruments in 2010 are reported. During the campaign, a flare at VHE was detected triggering further observations at VHE (H.E.S.S.), X-rays (Chandra), and radio (43 GHz Very Long Baseline Array, VLBA). The excellent sampling of the VHE gamma-ray light curve enables one to derive a precise temporal characterization of the flare: the single, isolated flare is well described by a two-sided exponential function with significantly different flux rise and decay times of tau(rise)(d) = (1.69 +/- 0.30) days and tau(decay)(d) = (0.611 +/- 0.080) days, respectively. While the overall variability pattern of the 2010 flare appears somewhat different from that of previous VHE flares in 2005 and 2008, they share very similar timescales (similar to day), peak fluxes (Phi(>0.35 TeV) similar or equal to (1-3) x 10(-11) photons cm(-2) s(-1)), and VHE spectra. VLBA radio observations of 43 GHz of the inner jet regions indicate no enhanced flux in 2010 in contrast to observations in 2008, where an increase of the radio flux of the innermost core regions coincided with a VHE flare. On the other hand, Chandra X-ray observations taken similar to 3 days after the peak of the VHE gamma-ray emission reveal an enhanced flux from the core (flux increased by factor similar to 2; variability timescale <2 days). The long-term (2001-2010) multi-wavelength (MWL) light curve of M 87, spanning from radio to VHE and including data from Hubble Space Telescope, Liverpool Telescope, Very Large Array, and European VLBI Network, is used to further investigate the origin of the VHE gamma-ray emission. No unique, common MWL signature of the three VHE flares has been identified. In the outer kiloparsec jet region, in particular in HST-1, no enhanced MWL activity was detected in 2008 and 2010, disfavoring it as the origin of the VHE flares during these years. Shortly after two of the three flares (2008 and 2010), the X-ray core was observed to be at a higher flux level than its characteristic range (determined from more than 60 monitoring observations: 2002-2009). In 2005, the strong flux dominance of HST-1 could have suppressed the detection of such a feature. Published models for VHE gamma-ray emission from M 87 are reviewed in the light of the new data.
KW  - galaxies: active
KW  - galaxies: individual (M 87)
KW  - galaxies: jets
KW  - galaxies: nuclei
KW  - gamma rays: galaxies
KW  - radiation mechanisms: non-thermal
Y1  - 2012
U6  - https://doi.org/10.1088/0004-637X/746/2/151
SN  - 0004-637X
VL  - 746
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Adam, Jos J.
A1  - Bovend'Eerdt, Thamar J. H.
A1  - van Dooren, Fleur E. P.
A1  - Fischer, Martin H.
A1  - Pratt, Jay
T1  - The closer the better hand proximity dynamically affects letter recognition accuracy
JF  - Attention, perception, & psychophysics : AP&P ; a journal of the Psychonomic Society, Inc.
N2  - A growing literature has suggested that processing of visual information presented near the hands is facilitated. In this study, we investigated whether the near-hands superiority effect also occurs with the hands moving. In two experiments, participants performed a cyclical bimanual movement task requiring concurrent visual identification of briefly presented letters. For both the static and dynamic hand conditions, the results showed improved letter recognition performance with the hands closer to the stimuli. The finding that the encoding advantage for near-hand stimuli also occurred with the hands moving suggests that the effect is regulated in real time, in accordance with the concept of a bimodal neural system that dynamically updates hand position in external space.
KW  - Perception and action
Y1  - 2012
U6  - https://doi.org/10.3758/s13414-012-0339-3
SN  - 1943-3921
VL  - 74
IS  - 7
SP  - 1533
EP  - 1538
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Adamcik, Jozef
A1  - Jeon, Jae-Hyung
A1  - Karczewski, Konrad J.
A1  - Metzler, Ralf
A1  - Dietler, Giovanni
T1  - Quantifying supercoiling-induced denaturation bubbles in DNA
JF  - Soft matter
N2  - In both eukaryotic and prokaryotic DNA sequences of 30-100 base-pairs rich in AT base-pairs have been identified at which the double helix preferentially unwinds. Such DNA unwinding elements are commonly associated with origins for DNA replication and transcription, and with chromosomal matrix attachment regions. Here we present a quantitative study of local DNA unwinding based on extensive single DNA plasmid imaging. We demonstrate that long-lived single-stranded denaturation bubbles exist in negatively supercoiled DNA, at the expense of partial twist release. Remarkably, we observe a linear relation between the degree of supercoiling and the bubble size, in excellent agreement with statistical modelling. Furthermore, we obtain the full distribution of bubble sizes and the opening probabilities at varying salt and temperature conditions. The results presented herein underline the important role of denaturation bubbles in negatively supercoiled DNA for biological processes such as transcription and replication initiation in vivo.
Y1  - 2012
U6  - https://doi.org/10.1039/c2sm26089a
SN  - 1744-683X
VL  - 8
IS  - 33
SP  - 8651
EP  - 8658
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Adelsberger, Joseph
A1  - Metwalli, Ezzeldin
A1  - Diethert, Alexander
A1  - Grillo, Isabelle
A1  - Bivigou Koumba, Achille Mayelle
A1  - Laschewsky, André
A1  - Müller-Buschbaum, Peter
A1  - Papadakis, Christine M.
T1  - Kinetics of collapse transition and cluster formation in a thermoresponsive micellar solution of P(S-b-NIPAM-b-S) induced by a temperature jump
JF  - Macromolecular rapid communications
N2  - Structural changes at the intra- as well as intermicellar level were induced by the LCST-type collapse transition of poly(N-isopropyl acrylamide) in ABA triblock copolymer micelles in water. The distinct process kinetics was followed in situ and in real-time using time-resolved small-angle neutron scattering (SANS), while a micellar solution of a triblock copolymer, consisting of two short deuterated polystyrene endblocks and a long thermoresponsive poly(N-isopropyl acrylamide) middle block, was heated rapidly above its cloud point. A very fast collapse together with a multistep aggregation behavior is observed. The findings of the transition occurring at several size and time levels may have implications for the design and application of such thermoresponsive self-assembled systems.
KW  - polymer physics
KW  - thermoresponsive polymers
KW  - small-angle neutron scattering
KW  - time-resolved measurements
Y1  - 2012
U6  - https://doi.org/10.1002/marc.201100631
SN  - 1022-1336
VL  - 33
IS  - 3
SP  - 254
EP  - 259
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Aichner, Bernhard
A1  - Herzschuh, Ulrike
A1  - Wilkes, Heinz
A1  - Schulz, Hans-Martin
A1  - Wang, Yongbo
A1  - Plessen, Birgit
A1  - Mischke, Steffen
A1  - Diekmann, Bernhard
A1  - Zhang, Chengjun
T1  - Ecological development of Lake Donggi Cona, north-eastern Tibetan Plateau, since the late glacial on basis of organic geochemical proxies and non-pollen palynomorphs
JF  - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences
N2  - Organic geochemical proxy data from surface sediment samples and a sediment core from Lake Donggi Cona were used to infer environmental changes on the northeastern Tibetan Plateau spanning the last 18.4 kyr. Long-chain n-alkanes dominate the aliphatic hydrocarbon fraction of the sediment extract from most surface sediment samples and the sediment core. Unsaturated mid-chain n-alkanes (nC(23:1) and nC(25:1)) have high abundances in some samples, especially in core samples from the late glacial and early Holocene. TOC contents, organic biomarker and non-pollen-palynomorph concentrations and results from organic petrologic analysis on selected samples suggest three major episodes in the history of Lake Donggi Cona. Before ca. 12.6 cal ka BP samples contain low amounts of organic matter due to cold and arid conditions during the late glacial. After 12.6 cal ka BP, relatively high contents of TOC and concentrations of Botryococcus fossils, as well as enhanced concentrations of mid-chain n-alkanes and n-alkenes suggest a higher primary and macrophyte productivity than at present This is supported by high contents of palynomorphs derived from higher plants and algae and was possibly triggered by a decrease of salinity and amelioration of climate during the early Holocene. Since 6.8 cal ka BP Lake Donggi Cona has been an oligotrophic freshwater lake. Proxy data suggest that variations in insolation drive ecological changes in the lake, with increased aquatic productivity during the early Holocene summer insolation maximum. Short-term drops of TOC contents or biomarker concentrations (at 9.9 cal ka BP, after 8.0 and between 3.5 and 1.7 cal ka BP) can possibly be related to relatively cool and dry episodes reported from other sites on the north-eastern Tibetan Plateau, which are hypothesized to occur in phase with Northern Hemisphere cooling events.
KW  - Biomarker
KW  - Holocene
KW  - n-alkanes
KW  - Total organic carbon
KW  - Organic matter
KW  - Macerals
KW  - Aquatic macrophytes
Y1  - 2012
U6  - https://doi.org/10.1016/j.palaeo.2011.10.015
SN  - 0031-0182
VL  - 313
IS  - 2
SP  - 140
EP  - 149
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Akal, Cüneyt
A1  - Candan, Osman
A1  - Koralay, O. Ersin
A1  - Oberhänsli, Roland
A1  - Chen, Fukun
A1  - Prelevic, Dejan
T1  - Early Triassic potassic volcanism in the Afyon Zone of the Anatolides/Turkey - implications for the rifting of the Neo-Tethys
JF  - International journal of earth sciences
N2  - Afyon Zone, which was derived from the Anatolide-Tauride platform during closure of the Neo-Tethys, is made up of pre-Mesozoic basement and unconformably overlying Triassic-Early Tertiary cover series. The Afyon Zone contains widespread metavolcanic rocks, which are dominated by rhyolite, dacite, and trachyandesite. They form a distinct volcanic succession, which is separated from the underlying Silurian-Lower Carboniferous metacarbonates and meta-siliciclastics by a regional unconformity. Trachyandesitic metavolcanics are made up of massive lava flows, pyroclastics and epiclastics, less frequently, domes and dikes, which were developed on a deeply eroded subaerial landmass. U/Pb and Pb/Pb zircon geochronology yielded Lower Triassic (similar to 250 Ma) ages, which are interpreted as extrusion age of trachyandesitic volcanics. Based on the stratigraphic, geochronological, and geochemical data, we suggest that these Lower Triassic magmatic rocks represent an extensional tectonic setting on the northern active margin of the Gondwana, which led to the development of the northern branch of the Neo-Tethys.
KW  - Meta-trachyandesite
KW  - Afyon Zone
KW  - Turkey
KW  - Neo-Tethys
KW  - Paleo-tethys
Y1  - 2012
U6  - https://doi.org/10.1007/s00531-011-0654-2
SN  - 1437-3254
VL  - 101
IS  - 1
SP  - 177
EP  - 194
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Al-Mashaikhi, K.
A1  - Oswald, Sascha
A1  - Attinger, Sabine
A1  - Büchel, G.
A1  - Knöller, K.
A1  - Strauch, G.
T1  - Evaluation of groundwater dynamics and quality in the Najd aquifers located in the Sultanate of Oman
JF  - Environmental earth sciences
N2  - The Najd, Oman, is located in one of the most arid environments in the world. The groundwater in this region is occurring in four different aquifers A to D of the Hadhramaut Group consisting mainly of different types of limestone and dolomite. The quality of the groundwater is dominated by the major ions sodium, calcium, magnesium, sulphate, and chloride, but the hydrochemical character is varying among the four aquifers. Mineralization within the separate aquifers increases along the groundwater flow direction from south to north-northeast up to high saline sodium-chloride water in aquifer D in the northeast area of the Najd. Environmental isotope analyses of hydrogen and oxygen were conducted to monitor the groundwater dynamics and to evaluate the recharge conditions of groundwater into the Najd aquifers. Results suggest an earlier recharge into these aquifers as well as ongoing recharge takes place in the region down to present day. Mixing of modern and submodern waters was detected by water isotopes in aquifer D in the mountain chain (Jabal) area and along the northern side of the mountain range. In addition, delta H-2 and delta O-18 variations suggest that aquifers A, B, and C are assumed to be connected by faults and fractures, and interaction between the aquifers may occur. Low tritium concentrations support the mixing assumption in the recharge area. The knowledge about the groundwater development is an important factor for the sustainable use of water resources in the Dhofar region.
KW  - Environmental isotopes
KW  - Groundwater
KW  - Najd aquifer
KW  - Oman
KW  - Recharge
KW  - Water quality
Y1  - 2012
U6  - https://doi.org/10.1007/s12665-011-1331-2
SN  - 1866-6280
VL  - 66
IS  - 4
SP  - 1195
EP  - 1211
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Al-Sa'di, Mahmoud
A1  - Jaiser, Frank
A1  - Bagnich, Sergey A.
A1  - Unger, Thomas
A1  - Blakesley, James C.
A1  - Wilke, Andreas
A1  - Neher, Dieter
T1  - Electrical and optical simulations of a polymer-based phosphorescent organic light-emitting diode with high efficiency
JF  - Journal of polymer science : B, Polymer physics
N2  - A comprehensive numerical device simulation of the electrical and optical characteristics accompanied with experimental measurements of a new highly efficient system for polymer-based light-emitting diodes doped with phosphorescent dyes is presented. The system under investigation comprises an electron transporter attached to a polymer backbone blended with an electronically inert small molecule and an iridium-based green phosphorescent dye which serves as both emitter and hole transporter. The device simulation combines an electrical and an optical model. Based on the known highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels of all components as well as the measured electrical and optical characteristics of the devices, we model the emissive layer as an effective medium using the dye's HOMO as hole transport level and the polymer LUMO as electron transport level. By fine-tuning the injection barriers at the electron and hole-injecting contact, respectively, in simulated devices, unipolar device characteristics were fitted to the experimental data. Simulations using the so-obtained set of parameters yielded very good agreement to the measured currentvoltage, luminancevoltage characteristics, and the emission profile of entire bipolar light-emitting diodes, without additional fitting parameters. The simulation was used to gain insight into the physical processes and the mechanisms governing the efficiency of the organic light-emitting diode, including the position and extent of the recombination zone, carrier concentration profiles, and field distribution inside the device. The simulations show that the device is severely limited by hole injection, and that a reduction of the hole-injection barrier would improve the device efficiency by almost 50%.
KW  - conjugated polymers
KW  - high performance polymers
KW  - organic electronics
KW  - organic light-emitting diode
KW  - simulations
KW  - TCAD
Y1  - 2012
U6  - https://doi.org/10.1002/polb.23158
SN  - 0887-6266
VL  - 50
IS  - 22
SP  - 1567
EP  - 1576
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Albertini, Francesca Yardenit
T1  - Peace and war in Moses Maimonides and Immanuel Kant a comparative study
JF  - The journal of Jewish thought & philosophy
N2  - Francesca Y. Albertini (1974-2011) compares Maimonides' idea of peace, as developed in MT Sefer shofetim (Book of Judges), with Kant's work on the notion of "eternal peace" (Zum ewigen Frieden). Both authors develop a historical vision pointed against the use of force and war in light of a framework not limited by historical time (messianic age, eternity). Despite all differences in method and historical context, the authors agree on the notion that universal ethics provides the basis of a determination of right grounded in the will. Maimonides' universal messianism as well as Kant's universal history emphasize the pivotal role and decisive responsibility of the human being in realizing, through reason, the reign of peace and prosperity on earth first envisioned by the biblical prophets. These utopias continue to challenge us, especially in this day and age.
KW  - Kant
KW  - Maimonides
KW  - peace
KW  - Alfarabi (al-Farabi)
KW  - universal messianism
Y1  - 2012
U6  - https://doi.org/10.1163/1477285X-12341238
SN  - 1053-699X
VL  - 20
IS  - 2
SP  - 183
EP  - 198
PB  - Brill
CY  - Leiden
ER  - 
TY  - JOUR
A1  - Albrecht, Steve
A1  - Janietz, Silvia
A1  - Schindler, Wolfram
A1  - Frisch, Johannes
A1  - Kurpiers, Jona
A1  - Kniepert, Juliane
A1  - Inal, Sahika
A1  - Pingel, Patrick
A1  - Fostiropoulos, Konstantinos
A1  - Koch, Norbert
A1  - Neher, Dieter
T1  - Fluorinated Copolymer PCPDTBT with enhanced open-circuit voltage and reduced recombination for highly efficient polymer solar cells
JF  - Journal of the American Chemical Society
N2  - A novel fluorinated copolymer (F-PCPDTBT) is introduced and shown to exhibit significantly higher power conversion efficiency in bulk heterojunction solar cells with PC70BM compared to the well-known low-band-gap polymer PCPDTBT. Fluorination lowers the polymer HOMO level, resulting in high open-circuit voltages well exceeding 0.7 V. Optical spectroscopy and morphological studies with energy-resolved transmission electron microscopy reveal that the fluorinated polymer aggregates more strongly in pristine and blended layers, with a smaller amount of additives needed to achieve optimum device performance. Time-delayed collection field and charge extraction by linearly increasing voltage are used to gain insight into the effect of fluorination on the field dependence of free charge-carrier generation and recombination. F-PCPDTBT is shown to exhibit a significantly weaker field dependence of free charge-carrier generation combined with an overall larger amount of free charges, meaning that geminate recombination is greatly reduced. Additionally, a 3-fold reduction in non-geminate recombination is measured compared to optimized PCPDTBT blends. As a consequence of reduced non-geminate recombination, the performance of optimized blends of fluorinated PCPDTBT with PC70BM is largely determined by the field dependence of free-carrier generation, and this field dependence is considerably weaker compared to that of blends comprising the non-fluorinated polymer. For these optimized blends, a short-circuit current of 14 mA/cm(2), an open-circuit voltage of 0.74 V, and a fill factor of 58% are achieved, giving a highest energy conversion efficiency of 6.16%. The superior device performance and the low band-gap render this new polymer highly promising for the construction of efficient polymer-based tandem solar cells.
Y1  - 2012
U6  - https://doi.org/10.1021/ja305039j
SN  - 0002-7863
VL  - 134
IS  - 36
SP  - 14932
EP  - 14944
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Albrecht, Steve
A1  - Schaefer, Sebastian
A1  - Lange, Ilja
A1  - Yilmaz, Seyfullah
A1  - Dumsch, Ines
A1  - Allard, Sybille
A1  - Scherf, Ullrich
A1  - Hertwig, Andreas
A1  - Neher, Dieter
T1  - Light management in PCPDTBT:PC70BM solar cells: A comparison of standard and inverted device structures
JF  - Organic electronics : physics, materials and applications
N2  - We compare standard and inverted bulk heterojunction solar cells composed of PCPDTBT:PC70BM blends. Inverted devices comprising 100 nm thick active layers exhibited short circuit currents of 15 mA/cm(2), 10% larger than in corresponding standard devices. Modeling of the optical field distribution in the different device stacks proved that this enhancement originates from an increased absorption of incident light in the active layer. Internal quantum efficiencies (IQEs) were obtained from the direct comparison of experimentally derived and modeled currents for different layer thicknesses, yielding IQEs of similar to 70% for a layer thickness of 100 nm. Simulations predict a significant increase of the light harvesting efficiency upon increasing the layer thickness to 270 nm. However, a continuous deterioration of the photovoltaic properties with layer thickness was measured for both device architectures, attributed to incomplete charge extraction. On the other hand, our optical modeling suggests that inverted devices based on PCPDTBT should be able to deliver high power conversion efficiencies (PCEs) of more than 7% provided that recombination losses can be reduced.
KW  - Organic solar cells
KW  - Inverted solar cells
KW  - PCPDTBT
KW  - Low band-gap
KW  - Optical modeling
Y1  - 2012
U6  - https://doi.org/10.1016/j.orgel.2011.12.019
SN  - 1566-1199
VL  - 13
IS  - 4
SP  - 615
EP  - 622
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Albrecht, Steve
A1  - Schindler, Wolfram
A1  - Kurpiers, Jona
A1  - Kniepert, Juliane
A1  - Blakesley, James C.
A1  - Dumsch, Ines
A1  - Allard, Sybille
A1  - Fostiropoulos, Konstantinos
A1  - Scherf, Ullrich
A1  - Neher, Dieter
T1  - On the field dependence of free charge carrier generation and recombination in blends of PCPDTBT/PC70BM influence of solvent additives
JF  - The journal of physical chemistry letters
N2  - We have applied time-delayed collection field (TDCF) and charge extraction by linearly increasing voltage (CELIV) to investigate the photogeneration, transport, and recombination of charge carriers in blends composed of PCPDTBT/PC70BM processed with and without the solvent additive diiodooctane. The results suggest that the solvent additive has severe impacts on the elementary processes involved in the photon to collected electron conversion in these blends. First, a pronounced field dependence of the free carrier generation is found for both blends, where the field dependence is stronger without the additive. Second, the fate of charge carriers in both blends can be described with a rather high bimolecular recombination coefficients, which increase with decreasing internal field. Third, the mobility is three to four times higher with the additive. Both blends show a negative field dependence of mobility, which we suggest to cause bias-dependent recombination coefficients.
Y1  - 2012
U6  - https://doi.org/10.1021/jz3000849
SN  - 1948-7185
VL  - 3
IS  - 5
SP  - 640
EP  - 645
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Albrecht, Torsten
A1  - Levermann, Anders
T1  - Fracture field for large-scale ice dynamics
JF  - Journal of glaciology
N2  - Recent observations and modeling studies emphasize the crucial role of fracture mechanics for the stability of ice shelves and thereby the evolution of ice sheets. Here we introduce a macroscopic fracture-density field into a prognostic continuum ice-flow model and compute its evolution incorporating the initiation and growth of fractures as well as their advection with two-dimensional ice flow. To a first approximation, fracture growth is assumed to depend on the spreading rate only, while fracture initiation is defined in terms of principal stresses. The inferred fracture-density fields compare well with observed elongate surface structures. Since crevasses and other deep-reaching fracture structures have been shown to influence the overall ice-shelf dynamics, we propose the fracture-density field introduced here be used as a measure for ice softening and decoupling of the ice flow in fracture-weakened zones. This may yield more accurate and realistic velocity patterns in prognostic simulations. Additionally, the memory of past fracture events links the calving front to the upstream dynamics. Thus the fracture-density field proposed here may be employed in fracture-based calving parameterizations. The aim of this study is to introduce the field and investigate which of the observed surface structures can be reproduced by the simplest physically motivated fracture source terms.
Y1  - 2012
U6  - https://doi.org/10.3189/2012JoG11J191
SN  - 0022-1430
SN  - 1727-5652
VL  - 58
IS  - 207
SP  - 165
EP  - 176
PB  - International Glaciological Society
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Ali, Mostafa
A1  - Homann, Thomas
A1  - Kreisel, Janka
A1  - Khalil, Mahmoud
A1  - Puhlmann, Ralf
A1  - Kruse, Hans-Peter
A1  - Rawel, Harshadrai Manilal
T1  - Characterization and modeling of the interactions between coffee storage proteins and phenolic compounds
JF  - Journal of agricultural and food chemistry : a publication of the American Chemical Society
N2  - This study addresses the interactions of coffee storage proteins with coffee-specific phenolic compounds. Protein profiles, of Coffea arabica and Coffea canephora (var robusta) were compared. Major Phenolic compounds were extracted and analyzed with appropriate methods. The polyphenol-protein interactions during protein extraction have been addressed by different analytical setups [reversed-phase high-performance liquid chromatography (RP-HPLC), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS), and Trolox equivalent antioxidant capacity (TEAC) assays], with focus directed toward identification of covalent adduct formation. The results indicate that C. arabica proteins are more susceptible to these interactions and the polyphenol oxidase activity seems to be a crucial factor for the formation of these addition products. A tentative allocation of the modification type and site in the protein has been attempted. Thus, the first available in silico modeling of modified coffee proteins is reported. The extent of these modifications may contribute to the structure and function of "coffee melanoidins" and are discussed in the context of coffee flavor formation.
KW  - Coffee beans
KW  - storage proteins
KW  - phenolic compounds
KW  - antioxidants
KW  - protein-phenol interactions
KW  - modeling
Y1  - 2012
U6  - https://doi.org/10.1021/jf303372a
SN  - 0021-8561
VL  - 60
IS  - 46
SP  - 11601
EP  - 11608
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Archambault, S.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Boettcher, Markus
A1  - Bouvier, A.
A1  - Bradbury, S. M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Coppi, P.
A1  - Cui, W.
A1  - Decerprit, G.
A1  - Dickherber, R.
A1  - Dumm, J.
A1  - Errando, Manel
A1  - Falcone, A.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Hawkins, K.
A1  - Holder, J.
A1  - Huan, H.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - Lee, K.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, Reshmi
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Palma, N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pichel, A.
A1  - Pohl, Martin
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Rose, H. J.
A1  - Ruppel, J.
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Sentuerk, G. D.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Varlotta, A.
A1  - Vivier, M.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Weisgarber, T.
A1  - Williams, D. A.
A1  - Zitzer, B.
A1  - Fortin, P.
A1  - Horan, D.
T1  - Disovery of high-energy and very high energy gamma-ray emission from the blazar RBS 0413
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We report on the discovery of high-energy (HE; E > 0.1 GeV) and very high energy (VHE; E > 100 GeV) gamma-ray emission from the high-frequency-peaked BL Lac object RBS 0413. VERITAS, a ground-based gamma-ray observatory, detected VHE. rays from RBS 0413 with a statistical significance of 5.5 standard deviations (sigma) and a gamma-ray flux of (1.5 +/- 0.6(stat) +/- 0.7(syst)) x 10(-8) photons m(-2) s(-1) (similar to 1% of the Crab Nebula flux) above 250 GeV. The observed spectrum can be described by a power law with a photon index of 3.18 +/- 0.68(stat) +/- 0.30(syst). Contemporaneous observations with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope detected HE gamma rays from RBS 0413 with a (stat)istical significance of more than 9 sigma, a power-law photon index of 1.57 +/- 0.12(stat-0.12sys')(+0.11) and a gamma-ray flux between 300 MeV and 300 GeV of (1.64 +/- 0.43(stat-0.22sys)(+ 0.31)) x 10(-5) photons m(-2) s(-1). We present the results from Fermi-LAT and VERITAS, including a spectral energy distribution modeling of the gamma-ray, quasi-simultaneous X-ray (Swift-XRT), ultraviolet (Swift-UVOT), and R-band optical (MDM) data. We find that, if conditions close to equipartition are required, both the combined synchrotron self-Compton/external-Compton and the lepto-hadronic models are preferred over a pure synchrotron self-Compton model.
KW  - BL Lacertae objects: individual (RBS 0413-VER J0319+187)
KW  - gamma rays: galaxies
Y1  - 2012
U6  - https://doi.org/10.1088/0004-637X/750/2/94
SN  - 0004-637X
VL  - 750
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Archambault, S.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Boettcher, Markus
A1  - Bouvier, A.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Cesarini, A.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickherber, R.
A1  - Duke, C.
A1  - Dumm, J.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Federici, Simone
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Huan, H.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lee, K.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nelson, T.
A1  - de Bhroithe, A. O'Faolain
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pichel, A.
A1  - Pohl, Martin
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Saxon, D. B.
A1  - Sembroski, G. H.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vincent, S.
A1  - Vivier, M.
A1  - Wakely, S. P.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Welsing, R.
A1  - Williams, D. A.
A1  - Zitzer, B.
A1  - Fortin, P.
A1  - Horan, D.
A1  - Fumagalli, M.
A1  - Kaplan, K.
A1  - Prochaska, J. X.
T1  - Veritas observations of six bright, hard-spectrum fermi-lat blazars
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We report on VERITAS very high energy (VHE; E >= 100 GeV) observations of six blazars selected from the Fermi Large Area Telescope First Source Catalog (1FGL). The gamma-ray emission from 1FGL sources was extrapolated up to the VHE band, taking gamma-ray absorption by the extragalactic background light into account. This allowed the selection of six bright, hard-spectrum blazars that were good candidate TeV emitters. Spectroscopic redshift measurements were attempted with the Keck Telescope for the targets without Sloan Digital Sky Survey spectroscopic data. No VHE emission is detected during the observations of the six sources described here. Corresponding TeV upper limits are presented, along with contemporaneous Fermi observations and non-concurrent Swift UVOT and X-Ray Telescope data. The blazar broadband spectral energy distributions (SEDs) are assembled and modeled with a single-zone synchrotron self-Compton model. The SED built for each of the six blazars shows a synchrotron peak bordering between the intermediate-and high-spectrum-peak classifications, with four of the six resulting in particle-dominated emission regions.
KW  - BL Lacertae objects: general
KW  - gamma rays: galaxies
Y1  - 2012
U6  - https://doi.org/10.1088/0004-637X/759/2/102
SN  - 0004-637X
VL  - 759
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Archambault, S.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Boettcher, Markus
A1  - Bouvier, A.
A1  - Bugaev, V.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickherber, R.
A1  - Dumm, J.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Federici, Stefania
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Huan, H.
A1  - Hughes, G.
A1  - Hui, C. M.
A1  - Imran, A.
A1  - Jameil, O.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Kerr, J.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - Lee, K.
A1  - Madhavan, A. S.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nelson, T.
A1  - de Bhroithe, A. O'Faolain
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pichel, A.
A1  - Pohl, Martin
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Ruppel, J.
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Sentuerk, G. D.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Stroh, M.
A1  - Telezhinsky, Igor O.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vivier, M.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weinstein, A.
A1  - Welsing, R.
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - Multiwavelength observations of the AGN 1ES 0414+009 with veritas, FERMI-LAT, SWIFT-XRT, AND MDM
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We present observations of the BL Lac object 1ES 0414+009 in the >200 GeV gamma-ray band by the VERITAS array of Cherenkov telescopes. 1ES 0414+009 was observed by VERITAS between 2008 January and 2011 February, resulting in 56.2 hr of good quality pointed observations. These observations resulted in a detection of 822 events from the source corresponding to a statistical significance of 6.4 standard deviations (6.4 sigma) above the background. The source flux, showing no evidence for variability, is measured as (5.2 +/- 1.1(stat) +/- 2.6(sys)) x 10(-12) photons cm(-2) s(-1) above 200 GeV, equivalent to approximately 2% of the Crab Nebula flux above this energy. The differential photon spectrum from 230 GeV to 850 GeV is well fit by a power law with a photon index of Gamma = 3.4 +/- 0.5(stat) +/- 0.3(sys) and a flux normalization of (1.6 +/- 0.3(stat) +/- 0.8(sys)) x 10(-11) photons cm(-2) s(-1) at 300 GeV. We also present multiwavelength results taken in the optical (MDM), x-ray (Swift-XRT), and GeV (Fermi-LAT) bands and use these results to construct a broadband spectral energy distribution (SED). Modeling of this SED indicates that homogenous one-zone leptonic scenarios are not adequate to describe emission from the system, with a lepto-hadronic model providing a better fit to the data.
KW  - BL Lacertae objects: individual (1ES 0414+009, ERJ0416+011)
KW  - gamma rays: galaxies
Y1  - 2012
U6  - https://doi.org/10.1088/0004-637X/755/2/118
SN  - 0004-637X
VL  - 755
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Archambault, S.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bouvier, A.
A1  - Bradbury, S. M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Christiansen, J. L.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Decerprit, G.
A1  - Dickherber, R.
A1  - Dumm, J.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Feng, Q.
A1  - Ferrer, F.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Huan, H.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lee, K.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pohl, Martin
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Rose, H. J.
A1  - Ruppel, J.
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Sentuerk, G. D.
A1  - Skole, C.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vincent, S.
A1  - Vivier, M.
A1  - Wagner, R. G.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Weisgarber, T.
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - VERITAS deep observations of the dwarf spheroidal galaxy Segue 1
JF  - Physical review : D, Particles, fields, gravitation, and cosmology
N2  - The VERITAS array of Cherenkov telescopes has carried out a deep observational program on the nearby dwarf spheroidal galaxy Segue 1. We report on the results of nearly 48 hours of good quality selected data, taken between January 2010 and May 2011. No significant gamma-ray emission is detected at the nominal position of Segue 1, and upper limits on the integrated flux are derived. According to recent studies, Segue 1 is the most dark matter-dominated dwarf spheroidal galaxy currently known. We derive stringent bounds on various annihilating and decaying dark matter particle models. The upper limits on the velocity-weighted annihilation cross-section are <sigma upsilon >(95%) (CL) less than or similar to 10(-23) cm(3) s(-1), improving our limits from previous observations of dwarf spheroidal galaxies by at least a factor of 2 for dark matter particle masses m(chi) greater than or similar to 300 GeV. The lower limits on the decay lifetime are at the level of tau(95%) (CL) greater than or similar to 10(24) s. Finally, we address the interpretation of the cosmic ray lepton anomalies measured by ATIC and PAMELA in terms of dark matter annihilation, and show that the VERITAS observations of Segue 1 disfavor such a scenario.
Y1  - 2012
U6  - https://doi.org/10.1103/PhysRevD.85.062001
SN  - 1550-7998
VL  - 85
IS  - 6
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Archambault, S.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bouvier, A.
A1  - Bradbury, S. M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Decerprit, G.
A1  - Dickherber, R.
A1  - Duke, C.
A1  - Dumm, J.
A1  - Dwarkadas, Vikram V.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Huan, H.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - Lee, K.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Millis, J.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nunez, P. D.
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Pandel, D.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pohl, M.
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Rose, H. J.
A1  - Ruppel, J.
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Skole, C.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Vincent, S.
A1  - Vivier, M.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Weisgarber, T.
A1  - Welsing, R.
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - Veritas observations of the nova in V407 CYGNI
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We report on very high energy (E > 100 GeV) gamma-ray observations of V407 Cygni, a symbiotic binary that underwent a nova outburst producing 0.1-10 GeV gamma rays during 2010 March 10-26. Observations were made with the Very Energetic Radiation Imaging Telescope Array System during 2010 March 19-26 at relatively large zenith angles due to the position of V407 Cyg. An improved reconstruction technique for large zenith angle observations is presented and used to analyze the data. We do not detect V407 Cygni and place a differential upper limit on the flux at 1.6 TeV of 2.3 x 10(-12) erg cm(-2) s(-1) (at the 95% confidence level). When considered jointly with data from Fermi-LAT, this result places limits on the acceleration of very high energy particles in the nova.
KW  - gamma rays: general
KW  - novae, cataclysmic variables
KW  - white dwarfs
Y1  - 2012
U6  - https://doi.org/10.1088/0004-637X/754/1/77
SN  - 0004-637X
VL  - 754
IS  - 1
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Archambault, S.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bouvier, A.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cesarini, A.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickherber, R.
A1  - Duke, C.
A1  - Dumm, J.
A1  - Falcone, A.
A1  - Federici, S.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Gillanders, G. H.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Huan, H.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - LeBohec, S.
A1  - Lee, K.
A1  - Lyutikov, M.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nelson, T.
A1  - de Bhroithe, A. O'Faolain
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pohl, M.
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Saxon, D. B.
A1  - Schrödter, M.
A1  - Sembroski, G. H.
A1  - Sentuerk, G. D.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Varlotta, A.
A1  - Vincent, S.
A1  - Vivier, M.
A1  - Wagner, R. G.
A1  - Wakely, S. P.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Welsing, R.
A1  - Williams, D. A.
A1  - Zitzer, B.
A1  - Kondratiev, V.
T1  - SEARCH FOR A CORRELATION BETWEEN VERY-HIGH-ENERGY GAMMA RAYS AND GIANT RADIO PULSES IN THE CRAB PULSAR
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We present the results of a joint observational campaign between the Green Bank radio telescope and the VERITAS gamma-ray telescope, which searched for a correlation between the emission of very-high-energy (VHE) gamma rays (E-gamma > 150 GeV) and giant radio pulses (GRPs) from the Crab pulsar at 8.9 GHz. A total of 15,366 GRPs were recorded during 11.6 hr of simultaneous observations, which were made across four nights in 2008 December and in 2009 November and December. We searched for an enhancement of the pulsed gamma-ray emission within time windows placed around the arrival time of the GRP events. In total, eight different time windows with durations ranging from 0.033 ms to 72 s were positioned at three different locations relative to the GRP to search for enhanced gamma-ray emission which lagged, led, or was concurrent with, the GRP event. Furthermore, we performed separate searches on main pulse GRPs and interpulse GRPs and on the most energetic GRPs in our data sample. No significant enhancement of pulsed VHE emission was found in any of the preformed searches. We set upper limits of 5-10 times the average VHE flux of the Crab pulsar on the flux simultaneous with interpulse GRPs on single-rotation-period timescales. On similar to 8 s timescales around interpulse GRPs, we set an upper limit of 2-3 times the average VHE flux. Within the framework of recent models for pulsed VHE emission from the Crab pulsar, the expected VHE-GRP emission correlations are below the derived limits.
KW  - rays: stars
KW  - pulsars: individual: B0531+21
Y1  - 2012
U6  - https://doi.org/10.1088/0004-637X/760/2/136
SN  - 0004-637X
VL  - 760
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bouvier, A.
A1  - Bradbury, S. M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickherber, R.
A1  - Duke, C.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Guenette, R.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Huan, H.
A1  - Hughes, G.
A1  - Hui, C. M.
A1  - Humensky, T. B.
A1  - Imran, A.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - LeBohec, S.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nunez, P. D.
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pichel, A.
A1  - Pohl, Martin
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Rose, H. J.
A1  - Ruppel, J.
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Sentuerk, G. D.
A1  - Skole, C.
A1  - Staszak, D.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vincent, S.
A1  - Vivier, M.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Weisgarber, T.
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - Veritas observations of day-scale flaring of M 87 in 2010 April
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - VERITAS has been monitoring the very-high-energy (VHE; > 100 GeV) gamma-ray activity of the radio galaxy M87 since 2007. During 2008, flaring activity on a timescale of a few days was observed with a peak flux of (0.70 +/- 0.16) x 10(-11) cm(-2) s(-1) at energies above 350 GeV. In 2010 April, VERITAS detected a flare from M 87 with peak flux of (2.71 +/- 0.68) x 10(-11) cm(-2) s(-1) for E > 350 GeV. The source was observed for six consecutive nights during the flare, resulting in a total of 21 hr of good-quality data. The most rapid flux variation occurred on the trailing edge of the flare with an exponential flux decay time of 0.90(-0.15)(+0.22) days. The shortest detected exponential rise time is three times as long, at 2.87(+1.65)(-0.99) days. The quality of the data sample is such that spectral analysis can be performed for three periods: rising flux, peak flux, and falling flux. The spectra obtained are consistent with power-law forms. The spectral index at the peak of the flare is equal to 2.19 +/- 0.07. There is some indication that the spectrum is softer in the falling phase of the flare than the peak phase, with a confidence level corresponding to 3.6 standard deviations. We discuss the implications of these results for the acceleration and cooling rates of VHE electrons in M 87 and the constraints they provide on the physical size of the emitting region.
KW  - galaxies: individual (M 87, VER J1230+123)
KW  - gamma rays: galaxies
Y1  - 2012
U6  - https://doi.org/10.1088/0004-637X/746/2/141
SN  - 0004-637X
VL  - 746
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - AlSa'deh, Ahmad
A1  - Meinel, Christoph
T1  - Secure neighbor discovery Review, challenges, perspectives, and recommendations
JF  - IEEE security & privacy : building confidence in a networked world
N2  - Secure Neighbor Discovery is designed as a countermeasure to Neighbor Discovery Protocol threats. The authors discuss Secure Neighbor Discovery implementation and deployment challenges and review proposals to optimize it.
Y1  - 2012
SN  - 1540-7993
VL  - 10
IS  - 4
SP  - 26
EP  - 34
PB  - Inst. of Electr. and Electronics Engineers
CY  - Los Alamitos
ER  - 
TY  - JOUR
A1  - Altafim, Ruy Alberto Pisani
A1  - Altafim, Ruy Alberto Pisani
A1  - Qiu, Xunlin
A1  - Raabe, Sebastian
A1  - Wirges, Werner
A1  - Basso, Heitor Cury
A1  - Gerhard, Reimund
T1  - Fluoropolymer piezoelectrets with tubular channels resonance behavior controlled by channel geometry
JF  - Applied physics : A, Materials science & processing
N2  - Ferro- or piezoelectrets are dielectric materials with two elastically very different macroscopic phases and electrically charged interfaces between them. One of the newer piezoelectret variants is a system of two fluoroethylenepropylene (FEP) films that are first laminated around a polytetrafluoroethylene (PTFE) template. Then, by removing the PTFE template, a two-layer FEP structure with open tubular channels is obtained. After electrical charging, the channels form easily deformable macroscopic electric dipoles whose changes under mechanical or electrical stress lead to significant direct or inverse piezoelectricity, respectively. Here, different PTFE templates are employed to generate channel geometries that vary in height or width. It is shown that the control of the channel geometry allows a direct adjustment of the resonance frequencies in the tubular-channel piezoelectrets. By combining several different channel widths in a single ferroelectret, it is possible to obtain multiple resonance peaks that may lead to a rather flat frequency-response region of the transducer material. A phenomenological relation between the resonance frequency and the geometrical parameters of a tubular channel is also presented. This relation may help to design piezoelectrets with a specific frequency response.
Y1  - 2012
U6  - https://doi.org/10.1007/s00339-012-6848-z
SN  - 0947-8396
VL  - 107
IS  - 4
SP  - 965
EP  - 970
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Altafim, Ruy Alberto Pisani
A1  - Rychkov, Dmitry
A1  - Wirges, Werner
A1  - Gerhard, Reimund
A1  - Basso, Heitor Cury
A1  - Altafim, Ruy Alberto Pisani
A1  - Melzer, Martin
T1  - Laminated tubular-channel ferroelectret systems from low-density Polyethylene Films and from Fluoroethylene-propylene Copolymer Films - A comparison
JF  - IEEE transactions on dielectrics and electrical insulation
N2  - A template-based lamination technique for the manufacture of ferroelectrets from uniform electret films was recently reported. In the present work, this technique is used to prepare similar ferroelectret structures from low-density polyethylene (LDPE) films and from fluoro-ethylene-propylene (FEP) copolymer films. A comparative analysis of the pressure-, temperature-, and frequency-dependent piezoelectric properties has been performed on the two ferroelectret systems. It is observed that the FEP ferroelectrets exhibit better piezoelectric responses and are thermally more stable. The difference between the piezoelectric d(33) coefficients of the two ferroelectret systems is partially explained here by their different elastic moduli. The anti-resonance peaks of both structures have been investigated by means of dielectric resonance spectroscopy and electroacoustic sound-pressure measurements. A difference of more than 10 kHz is observed between the anti-resonance frequencies of the two ferroelectret systems.
KW  - Ferroelectrets
KW  - piezoelectrets
KW  - piezoelectricity
KW  - electro-mechanical transducers
KW  - static-pressure dependence
KW  - temperature dependence
KW  - frequency response
Y1  - 2012
SN  - 1070-9878
VL  - 19
IS  - 4
SP  - 1116
EP  - 1123
PB  - Inst. of Electr. and Electronics Engineers
CY  - Piscataway
ER  - 
TY  - JOUR
A1  - Altenberger, Uwe
A1  - Mejia Jimenez, D. M.
A1  - Günter, C.
A1  - Sierra Rodriguez, G. I.
A1  - Scheffler, F.
A1  - Oberhänsli, Roland
T1  - The Garzn Massif, Colombia-a new ultrahigh-temperature metamorphic complex in the early Neoproterozoic of northern South America
JF  - Mineralogy and petrology
N2  - The Garzn Complex of the Garzn Massif in SW Colombia is composed of the Vergel Granulite Unit (VG) and the Las Margaritas Migmatite Unit (LMM). Previous studies reveal peak temperature conditions for the VG of about 740 A degrees C. The present study considers the remarkable exsolution phenomena in feldspars and pyroxenes and titanium-in-quartz thermometry. Recalculated ternary feldspar compositions indicate temperatures around 900-1,000 A degrees C just at or above the ultra-high temperature-metamorphism (UHTM) boundary of granulites. The calculated temperatures range of exsolved ortho- and clinopyroxenes also supports the existence of an UHTM event. In addition, titanium-in-quartz thermometry points towards ultra-high temperatures. It is the first known UHTM crustal segment in the northern part of South America. Although a mean geothermal gradient of ca 38 A degrees C km(-1) could imply additional heat supply in the lower crust controlling this extreme of peak metamorphism, an alternative model is suggested. The formation of the Vergel Granulite Unit is supposed to be formed in a continental back-arc environment with a thinned and weakened crust behind a magmatic arc (Guapotn-Mancagua Gneiss) followed by collision. In contrast, rocks of the adjacent Las Margaritas Migmatite Unit display "normal" granulite facies temperatures and are formed in a colder lower crust outside the arc, preserved by the Guapotn-Mancagu Gneiss. Back-arc formation was followed by inversion and thickening of the basin. The three units that form the modern-day Garzn Massif, were juxtaposed upon each other during collision (at ca. 1,000 Ma) and exhumation. The collision leading to the deformation of the studied area is part of the Grenville orogeny leading to the amalgamation of Rodinia.
Y1  - 2012
U6  - https://doi.org/10.1007/s00710-012-0202-1
SN  - 0930-0708
VL  - 105
IS  - 3-4
SP  - 171
EP  - 185
PB  - Springer
CY  - Wien
ER  - 
TY  - JOUR
A1  - Alter, Markus L.
A1  - Kretschmer, Axel
A1  - Von Websky, Karoline
A1  - Tsuprykov, Oleg
A1  - Reichetzeder, Christoph
A1  - Simon, Alexandra
A1  - Stasch, Johannes-Peter
A1  - Hocher, Berthold
T1  - Early urinary and plasma biomarkers for experimental diabetic Nephropathy
JF  - Clinical laboratory : the peer reviewed journal for clinical laboratories and laboratories related to blood transfusion
N2  - Background: As the prevalence of diabetes rises, its complications such as diabetic nephropathy affect an increaseing number of patients. Consequently, the need for biomarkers in rodent models which reflect the stage and course of diabetic nephropathy is high. This article focuses on Heart-type fatty acid binding protein (H-FABP), osteopontin (OPN), nephrin, and Neutrophil gelatinase-associated lipocalin (NGAL) in urine, and kidney injury molecule (KIM)-1, clusterin, and tissue inhibitior of metalloproteinases (TIMP) 1 in plasma in uni-nephrectomized rats with streptocotozin-induced type 1 diabetes mellitus, a common animal model to explore renal impairment in the setting of diabetes mellitus.
 Methods: 23 male Wistar rats were uni-nephrectomized and subsequently divided into two study groups. The diabetic group received streptozotocin (STZ) via tail-vein injection, the non-diabetic group received citrate buffer without STZ. Subsequently, blood glucose, body weight, and blood pressure were checked regularly. After 18 weeks, animals were placed in metabolic cages, blood and urine obtained and subsequently organs were harvested after sacrifice.
 Results: Blood glucose levels were highly increased in diabetic animals throughout the experiment, whereas systolic blood pressure did not differ between the study groups. At study end, classical biomarkers such as urinary albumin and protein and plasma cystatin c were only slightly but not significantly different between groups indicating a very early disease state. In contrast, urinary excretion of H-FABP, OPN, nephrin, and NGAL were highly increased in diabetic animals with a highly significant p-value (p<0.01 each) compared to non-diabetic animals. In plasma, differences were found for calbindin, KIM-1, clusterin, TIMP-1, and OPN. These findings were confirmed by means of the area under the receiver operating characteristic curve (ROC-AUC) analysis.
 Conclusions: In summary, our study revealed elevated levels of new plasma and urinary biomarkers (urinary osteopontin, urinary nephrin, urinary NGAL, urinary H-FABP, plasma KIM-1, plasma TIMP-1) in uni-nephrectomized diabetic rats, an established rat model of diabetic nephropathy. These biomarkers appeared even before the classical biomarkers of diabetic nephropathy such as albuminuria and urinary protein excretion. The new biomarkers might offer advantage to urinary albumin and plasma cystatin c with respect to early detection.
KW  - diabetic nephropathy
KW  - urinary biomarker
KW  - blood biomarker
KW  - heart-type fatty acid binding protein
KW  - osteopontin
KW  - nephrin
KW  - neutrophil gelatinase-associated lipocalin
KW  - kidney injury molecule 1
KW  - clusterin
KW  - tissue inhibitior of metalloproteinases 1
Y1  - 2012
U6  - https://doi.org/10.7754/Clin.Lab.2011.111010
SN  - 1433-6510
VL  - 58
IS  - 7-8
SP  - 659
EP  - 671
PB  - Clin Lab Publ., Verl. Klinisches Labor
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Alter, Markus L.
A1  - Ott, Ina M.
A1  - von Websky, Karoline
A1  - Tsuprykov, Oleg
A1  - Sharkovska, Yuliya
A1  - Krause-Relle, Katharina
A1  - Raila, Jens
A1  - Henze, Andrea
A1  - Klein, Thomas
A1  - Hocher, Berthold
T1  - DPP-4 Inhibition on top of angiotensin receptor blockade offers a new therapeutic approach for diabetic nephropathy
JF  - Kidney & blood pressure research : official organ of the Gesellschaft für Nephrologie
N2  - Background: The need for an improved treatment for diabetic nephropathy is greatest in patients who do not adequately respond to angiotensin II receptor blockers (ARBs). This study investigated the effect of the novel dipeptidyl peptidase-4 inhibitor linagliptin alone and in combination with the ARB telmisartan on the progression of diabetic nephropathy in diabetic endothelial nitric oxide synthase (eNOS) knockout mice. Methods: Sixty male eNOS knockout C57BL/6J mice were divided into four groups after receiving intraperitoneal high-dose streptozotocin: telmisartan (1 mg/kg), linagliptin (3 mg/kg), linagliptin + telmisartan (3 mg/kg + 1 mg/kg) and vehicle. Fourteen mice were used as non-diabetic controls. Results: After 12 weeks, urine and blood were obtained and blood pressure measured. Glucose concentrations were increased and similar in all diabetic groups. Telmisartan alone reduced systolic blood pressure by 5.9 mmHg versus diabetic controls (111.2 +/- 2.3 mmHg vs 117.1 +/- 2.2 mmHg; mean +/- SEM; P = 0.071). Combined treatment significantly reduced albuminuria compared with diabetic controls (71.7 +/- 15.3 mu g/24 h vs 170.8 +/- 34.2 mu g/24 h; P = 0.017), whereas the effects of single treatment with either telmisartan (97.8 +/- 26.4 mu g/24 h) or linagliptin (120.8 +/- 37.7 mu g/24 h) were not statistically significant. DPP-4 inhibition, alone and in combination, led to significantly lower plasma osteopontin levels compared with telmisartan alone. Histological analysis revealed reduced glomerulosclerosis after Linagliptin alone and in combination with telmisartan in comparison to non treated diabetic animals (p < 0.01 and p < 0.05). Kidney malonaldehyde immune-reactivity, a marker of oxidative stress, was significantly lower in animals treated with linagliptin. Conclusions: DPP-4 inhibition on top of ARB treatment significantly reduced urinary albumin excretion and oxidative stress in diabetic eNOS knockout mice. Linagliptin on top of an angiotensin II receptor blocker may offer a new therapeutic approach for patients with diabetic nephropathy.
KW  - Diabetic nephropathy
KW  - DPP-4 inhibitor
KW  - Linagliptin
KW  - Renin-angiotensin system
Y1  - 2012
U6  - https://doi.org/10.1159/000341487
SN  - 1420-4096
VL  - 36
IS  - 1
SP  - 119
EP  - 130
PB  - Karger
CY  - Basel
ER  - 
TY  - JOUR
A1  - Amour, Frederic
A1  - Mutti, Maria
A1  - Christ, Nicolas
A1  - Immenhauser, Adrian
A1  - Agar, Susan M.
A1  - Benson, Gregory S.
A1  - Tomas, Sara
A1  - Alway, Robert
A1  - Kabiri, Lachen
T1  - Capturing and modelling metre-scale spatial facies heterogeneity in a Jurassic ramp setting (Central High Atlas, Morocco)
JF  - Sedimentology : the journal of the International Association of Sedimentologists
N2  - Each simulation algorithm, including Truncated Gaussian Simulation, Sequential Indicator Simulation and Indicator Kriging is characterized by different operating modes, which variably influence the facies proportion, distribution and association of digital outcrop models, as shown in clastic sediments. A detailed study of carbonate heterogeneity is then crucial to understanding these differences and providing rules for carbonate modelling. Through a continuous exposure of Bajocian carbonate strata, a study window (320 m long, 190 m wide and 30 m thick) was investigated and metre-scale lithofacies heterogeneity was captured and modelled using closely-spaced sections. Ten lithofacies, deposited in a shallow-water carbonate-dominated ramp, were recognized and their dimensions and associations were documented. Field data, including height sections, were georeferenced and input into the model. Four models were built in the present study. Model A used all sections and Truncated Gaussian Simulation during the stochastic simulation. For the three other models, Model B was generated using Truncated Gaussian Simulation as for Model A, Model C was generated using Sequential Indicator Simulation and Model D was generated using Indicator Kriging. These three additional models were built by removing two out of eight sections from data input. The removal of sections allows direct insights on geological uncertainties at inter-well spacings by comparing modelled and described sections. Other quantitative and qualitative comparisons were carried out between models to understand the advantages/disadvantages of each algorithm. Model A is used as the base case. Indicator Kriging (Model D) simplifies the facies distribution by assigning continuous geological bodies of the most abundant lithofacies to each zone. Sequential Indicator Simulation (Model C) is confident to conserve facies proportion when geological heterogeneity is complex. The use of trend with Truncated Gaussian Simulation is a powerful tool for modelling well-defined spatial facies relationships. However, in shallow-water carbonate, facies can coexist and their association can change through time and space. The present study shows that the scale of modelling (depositional environment or lithofacies) involves specific simulation constraints on shallow-water carbonate modelling methods.
KW  - 3D facies modelling
KW  - carbonate ramp
KW  - facies heterogeneity
KW  - Jurassic
KW  - modelling algorithms
KW  - scale
Y1  - 2012
U6  - https://doi.org/10.1111/j.1365-3091.2011.01299.x
SN  - 0037-0746
VL  - 59
IS  - 4
SP  - 1158
EP  - 1189
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Amselem, Gabriel
A1  - Theves, Matthias
A1  - Bae, Albert J.
A1  - Beta, Carsten
A1  - Bodenschatz, Eberhard
T1  - Control parameter description of eukaryotic chemotaxis
JF  - Physical review letters
N2  - The chemotaxis of eukaryotic cells depends both on the average concentration of the chemoattractant and on the steepness of its gradient. For the social amoeba Dictyostelium discoideum, we test quantitatively the prediction by Ueda and Shibata [Biophys. J. 93, 11 (2007)] that the efficacy of chemotaxis depends on a single control parameter only, namely, the signal-to-noise ratio (SNR), determined by the stochastic fluctuations of (i) the binding of the chemoattractant molecule to the transmembrane receptor and (ii) the intracellular activation of the effector of the signaling cascade. For SNR less than or similar to 1, the theory captures the experimental findings well, while for larger SNR noise sources further downstream in the signaling pathway need to be taken into account.
Y1  - 2012
U6  - https://doi.org/10.1103/PhysRevLett.109.108103
SN  - 0031-9007
VL  - 109
IS  - 10
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Amselem, Gabriel
A1  - Theves, Matthias
A1  - Bae, Albert J.
A1  - Bodenschatz, Eberhard
A1  - Beta, Carsten
T1  - A stochastic description of dictyostelium chemotaxis
JF  - PLoS one
N2  - Chemotaxis, the directed motion of a cell toward a chemical source, plays a key role in many essential biological processes. Here, we derive a statistical model that quantitatively describes the chemotactic motion of eukaryotic cells in a chemical gradient. Our model is based on observations of the chemotactic motion of the social ameba Dictyostelium discoideum, a model organism for eukaryotic chemotaxis. A large number of cell trajectories in stationary, linear chemoattractant gradients is measured, using microfluidic tools in combination with automated cell tracking. We describe the directional motion as the interplay between deterministic and stochastic contributions based on a Langevin equation. The functional form of this equation is directly extracted from experimental data by angle-resolved conditional averages. It contains quadratic deterministic damping and multiplicative noise. In the presence of an external gradient, the deterministic part shows a clear angular dependence that takes the form of a force pointing in gradient direction. With increasing gradient steepness, this force passes through a maximum that coincides with maxima in both speed and directionality of the cells. The stochastic part, on the other hand, does not depend on the orientation of the directional cue and remains independent of the gradient magnitude. Numerical simulations of our probabilistic model yield quantitative agreement with the experimental distribution functions. Thus our model captures well the dynamics of chemotactic cells and can serve to quantify differences and similarities of different chemotactic eukaryotes. Finally, on the basis of our model, we can characterize the heterogeneity within a population of chemotactic cells.
Y1  - 2012
U6  - https://doi.org/10.1371/journal.pone.0037213
SN  - 1932-6203
VL  - 7
IS  - 5
PB  - PLoS
CY  - San Fransisco
ER  - 
TY  - JOUR
A1  - Andermann, Christoff
A1  - Crave, Alain
A1  - Gloaguen, Richard
A1  - Davy, Philippe
A1  - Bonnet, Stephane
T1  - Connecting source and transport: Suspended sediments in the Nepal Himalayas
JF  - Earth & planetary science letters
N2  - Understanding the dynamics of sediment fluxes is a key issue to constrain modern erosion rates in mountain belts and determine the still debated level of control exerted by precipitation, topography and tectonics. The well defined monsoon seasonality in the Himalayas, together with active tectonics and strong relief provide an ideal environment to assess these possible interactions. For this purpose, we present a new compilation of daily suspended sediment data for 12 stations of the major rivers of the Nepal Himalayas. We analyze the relationships of sediment transport with daily river discharge and precipitation data as well as with morphometric parameters. We show that suspended sediment concentrations vary systematically through the seasons and asynchronously to river discharge displaying a hysteresis effect. This clockwise hysteresis effect disappears when suspended sediment fluxes are directly compared with direct storm discharge. Therefore we attribute the hysteresis effect to groundwater dilution rather than a sediment supply limitation. We infer a rating model to calculate erosion rates directly from long river discharge chronicles. We show that, when normalized by drainage area and mean sediment flux, all rivers exhibit the same trend. This similarity implies that all river basins have the same erosion behavior, independent of location, size and catchment characteristics. Erosion rates calculated from suspended sediment fluxes range between 0.1 and 2.8 mm/yr. The erosion rates of the three main basins of Nepal are in the range 0.9-1.5 mm/yr. Erosion rates in the Higher Himalayas are relatively low ( <0.5 mm/yr, except for Kali Gandaki), while in the Lesser Himalayas they range from 0.2 to 2 mm/yr. We propose that material transport in the rivers depends on hillslope sediment supply, which is, in turn, controlled by those rainfalls producing direct runoff. In other words, the rivers in the Nepal Himalayas are supply-limited and the hillsopes as a contributing source are transport-limited. We also show that erosion processes are not as much controlled by infrequently occurring extreme precipitation events, than by moderate ones with a high recurrence interval.
KW  - suspended sediment transport
KW  - Himalayas
KW  - erosion
KW  - sediment flux hysteresis
KW  - monsoon river hydrology
KW  - Himalayan rivers
Y1  - 2012
U6  - https://doi.org/10.1016/j.epsl.2012.06.059
SN  - 0012-821X
VL  - 351
SP  - 158
EP  - 170
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Andorf, Sandra
A1  - Meyer, Rhonda C.
A1  - Selbig, Joachim
A1  - Altmann, Thomas
A1  - Repsilber, Dirk
T1  - Integration of a systems biological network analysis and QTL results for biomass heterosis in arabidopsis thaliana
JF  - PLoS one
N2  - To contribute to a further insight into heterosis we applied an integrative analysis to a systems biological network approach and a quantitative genetics analysis towards biomass heterosis in early Arabidopsis thaliana development. The study was performed on the parental accessions C24 and Col-0 and the reciprocal crosses. In an over-representation analysis it was tested if the overlap between the resulting gene lists of the two approaches is significantly larger than expected by chance. Top ranked genes in the results list of the systems biological analysis were significantly over-represented in the heterotic QTL candidate regions for either hybrid as well as regarding mid-parent and best-parent heterosis. This suggests that not only a few but rather several genes that influence biomass heterosis are located within each heterotic QTL region. Furthermore, the overlapping resulting genes of the two integrated approaches were particularly enriched in biomass related pathways. A chromosome-wise over-representation analysis gave rise to the hypothesis that chromosomes number 2 and 4 probably carry a majority of the genes involved in biomass heterosis in the early development of Arabidopsis thaliana.
Y1  - 2012
U6  - https://doi.org/10.1371/journal.pone.0049951
SN  - 1932-6203
VL  - 7
IS  - 11
PB  - PLoS
CY  - San Fransisco
ER  - 
TY  - JOUR
A1  - Andres, Dorothee
A1  - Roske, Yvette
A1  - Doering, Carolin
A1  - Heinemann, Udo
A1  - Seckler, Robert
A1  - Barbirz, Stefanie
T1  - Tail morphology controls DNA release in two Salmonella phages with one lipopolysaccharide receptor recognition system
JF  - Molecular microbiology
N2  - Bacteriophages use specific tail proteins to recognize host cells. It is still not understood to molecular detail how the signal is transmitted over the tail to initiate infection. We have analysed in vitro DNA ejection in long-tailed siphovirus 9NA and short-tailed podovirus P22 upon incubation with Salmonella typhimurium lipopolysaccharide (LPS). We showed for the first time that LPS alone was sufficient to elicit DNA release from a siphovirus in vitro. Crystal structure analysis revealed that both phages use similar tailspike proteins for LPS recognition. Tailspike proteins hydrolyse LPS O antigen to position the phage on the cell surface. Thus we were able to compare in vitro DNA ejection processes from two phages with different morphologies with the same receptor under identical experimental conditions. Siphovirus 9NA ejected its DNA about 30 times faster than podovirus P22. DNA ejection is under control of the conformational opening of the particle and has a similar activation barrier in 9NA and P22. Our data suggest that tail morphology influences the efficiencies of particle opening given an identical initial receptor interaction event.
Y1  - 2012
U6  - https://doi.org/10.1111/j.1365-2958.2012.08006.x
SN  - 0950-382X
VL  - 83
IS  - 6
SP  - 1244
EP  - 1253
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Anoop, A.
A1  - Prasad, S.
A1  - Basavaiah, Nathani
A1  - Brauer, Achim
A1  - Shahzad, F.
A1  - Deenadayalan, K.
T1  - Tectonic versus climate influence on landscape evolution: A case study from the upper Spiti valley, NW Himalaya
JF  - Geomorphology : an international journal on pure and applied geomorphology
N2  - We have undertaken structural, geomorphological, and morphometric analyses to investigate the role of tectonism and climate in the landscape evolution in the upper Spiti valley, NW Himalayas. Geomorphometric analyses coupled with field investigations reveal active tectonic deformation in the Spiti region. The calculated geomorphic indices (steepness, concavity and Hack) demonstrate uplift/subsidence along the Kaurik-Chango fault, whereas transverse topographic index (T-index) reveals basin tilting associated with active faulting near Hansa and Lingti valley. Investigation of well-dated Mane palaeolake sediments also provides evidence of regional tectonic instability. Four episodes (ca. 7.8, 7.4, 6.5 and 6.1 cal ka) of neotectonic activity have been identified during the period of the lake's existence. We have also compiled data on the regional climate variability and compared it with the age of the Mane palaeo-landslide. Our results indicate that the landslide occurred towards the end of the early Holocene intensified monsoon phase and is located near an active fault. Our data on regional tectonic instability and the coincidences of modern and palaeo-landslides with zones of active deformation suggest that tectonism is an important factor governing landscape stability in the Spiti region.
KW  - Geomorphic indices
KW  - Holocene
KW  - Palaeo-lake sediments
KW  - Palaeo-landslides
KW  - Monsoon
Y1  - 2012
U6  - https://doi.org/10.1016/j.geomorph.2011.10.028
SN  - 0169-555X
VL  - 145
IS  - 4
SP  - 32
EP  - 44
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Apel, Jens K.
A1  - Cangelosi, Angelo
A1  - Ellis, Rob
A1  - Goslin, Jeremy
A1  - Fischer, Martin H.
T1  - Object affordance influences instruction span
JF  - Experimental brain research
N2  - We measured memory span for assembly instructions involving objects with handles oriented to the left or right side. Right-handed participants remembered more instructions when objects' handles were spatially congruent with the hand used in forthcoming assembly actions. No such affordance-based memory benefit was found for left-handed participants. These results are discussed in terms of motor simulation as an embodied rehearsal mechanism.
KW  - Action simulation
KW  - Affordance
KW  - Embodied cognition
KW  - Rehearsal
KW  - Sequential instruction
KW  - Working memory
Y1  - 2012
U6  - https://doi.org/10.1007/s00221-012-3251-0
SN  - 0014-4819
VL  - 223
IS  - 2
SP  - 199
EP  - 206
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Araujo, Wagner L.
A1  - Nunes-Nesi, Adriano
A1  - Nikoloski, Zoran
A1  - Sweetlove, Lee J.
A1  - Fernie, Alisdair R.
T1  - Metabolic control and regulation of the tricarboxylic acid cycle in photosynthetic and heterotrophic plant tissues
JF  - Plant, cell & environment : cell physiology, whole-plant physiology, community physiology
N2  - The tricarboxylic acid (TCA) cycle is a crucial component of respiratory metabolism in both photosynthetic and heterotrophic plant organs. All of the major genes of the tomato TCA cycle have been cloned recently, allowing the generation of a suite of transgenic plants in which the majority of the enzymes in the pathway are progressively decreased. Investigations of these plants have provided an almost complete view of the distribution of control in this important pathway. Our studies suggest that citrate synthase, aconitase, isocitrate dehydrogenase, succinyl CoA ligase, succinate dehydrogenase, fumarase and malate dehydrogenase have control coefficients flux for respiration of -0.4, 0.964, -0.123, 0.0008, 0.289, 0.601 and 1.76, respectively; while 2-oxoglutarate dehydrogenase is estimated to have a control coefficient of 0.786 in potato tubers. These results thus indicate that the control of this pathway is distributed among malate dehydrogenase, aconitase, fumarase, succinate dehydrogenase and 2-oxoglutarate dehydrogenase. The unusual distribution of control estimated here is consistent with specific non-cyclic flux mode and cytosolic bypasses that operate in illuminated leaves. These observations are discussed in the context of known regulatory properties of the enzymes and some illustrative examples of how the pathway responds to environmental change are given.
KW  - metabolic control analysis
KW  - metabolic regulation
KW  - respiration
KW  - Solanum lycopersicum (tomato)
KW  - TCA cycle
Y1  - 2012
U6  - https://doi.org/10.1111/j.1365-3040.2011.02332.x
SN  - 0140-7791
VL  - 35
IS  - 1
SP  - 1
EP  - 21
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bouvier, A.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickherber, R.
A1  - Dumm, J.
A1  - Falcone, A.
A1  - Federici, S.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Holder, J.
A1  - Huan, H.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Imran, A.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lee, K.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nelson, T.
A1  - de Bhroithe, A. O'Faolain
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pohl, Martin
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Ruppel, J.
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Skole, C.
A1  - Smith, A. W.
A1  - Telezhinsky, Igor O.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Varlotta, A.
A1  - Vivier, M.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weinstein, A.
A1  - Welsing, R.
A1  - Williams, D. A.
A1  - Zitzer, B.
A1  - Pfrommer, C.
A1  - Pinzke, A.
T1  - Constraints on cosmic rays, magnetic fields, and dark matter fromgamma-ray observations of the coma cluster of galaxies with veritas and fermi
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - Observations of radio halos and relics in galaxy clusters indicate efficient electron acceleration. Protons should likewise be accelerated and, on account of weak energy losses, can accumulate, suggesting that clusters may also be sources of very high energy (VHE; E > 100 GeV) gamma-ray emission. We report here on VHE gamma-ray observations of the Coma galaxy cluster with the VERITAS array of imaging Cerenkov telescopes, with complementing Fermi Large Area Telescope observations at GeV energies. No significant gamma-ray emission from the Coma Cluster was detected. Integral flux upper limits at the 99% confidence level were measured to be on the order of (2-5) x 10(-8) photonsm(-2) s(-1) (VERITAS, >220 GeV) and similar to 2 x 10(-6) photonsm(-2) s(-1) (Fermi, 1-3GeV), respectively. We use the gamma-ray upper limits to constrain cosmic rays (CRs) and magnetic fields in Coma. Using an analytical approach, the CR-to-thermal pressure ratio is constrained to be < 16% from VERITAS data and <1.7% from Fermi data (averaged within the virial radius). These upper limits are starting to constrain the CR physics in self-consistent cosmological cluster simulations and cap the maximum CR acceleration efficiency at structure formation shocks to be <50%. Alternatively, this may argue for non-negligible CR transport processes such as CR streaming and diffusion into the outer cluster regions. Assuming that the radio-emitting electrons of the Coma halo result from hadronic CR interactions, the observations imply a lower limit on the central magnetic field in Coma of similar to(2-5.5) mu G, depending on the radial magnetic field profile and on the gamma-ray spectral index. Since these values are below those inferred by Faraday rotation measurements in Coma (for most of the parameter space), this renders the hadronic model a very plausible explanation of the Coma radio halo. Finally, since galaxy clusters are dark matter (DM) dominated, the VERITAS upper limits have been used to place constraints on the thermally averaged product of the total self-annihilation cross section and the relative velocity of the DM particles, <sigma nu >.
KW  - cosmic rays
KW  - dark matter
KW  - galaxies: clusters: general
KW  - galaxies: clusters: individual (Coma (ACO 1656))
KW  - gamma rays: galaxies: clusters
KW  - magnetic fields
Y1  - 2012
U6  - https://doi.org/10.1088/0004-637X/757/2/123
SN  - 0004-637X
VL  - 757
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Ast, Sandra
A1  - Rutledge, Peter J.
A1  - Todd, Matthew H.
T1  - Reversing the triazole topology in a cyclam-triazole-dye ligand gives a 10-fold brighter signal response to Zn2+ in aqueous solution
JF  - European journal of inorganic chemistry : a journal of ChemPubSoc Europe
N2  - The fluorescence response of a set of cyclam-triazole-dye ligands is controlled by the appended dye, but simple reversal of the triazole topology affords a novel probe for Zn2+ with a longer fluorescence lifetime and higher fluorescence quantum yield upon Zn2+ binding (<tau t > = 2.0 ns, Phi(f) = 0.76).
KW  - Sensors
KW  - Zinc
KW  - Click chemistry
KW  - Fluorescence
KW  - Electrochemistry
Y1  - 2012
U6  - https://doi.org/10.1002/ejic.201201072
SN  - 1434-1948
IS  - 34
SP  - 5611
EP  - 5615
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Awad, Ahmed Mahmoud Hany Aly
A1  - Gore, Rajeev
A1  - Hou, Zhe
A1  - Thomson, James
A1  - Weidlich, Matthias
T1  - An iterative approach to synthesize business process templates from
 compliance rules
JF  - INFORMATION SYSTEMS
N2  - Companies have to adhere to compliance requirements. The compliance analysis of business operations is typically a joint effort of business experts and compliance experts. Those experts need to create a common understanding of business processes to effectively conduct compliance management. In this paper, we present a technique that aims at supporting this process. We argue that process templates generated out of compliance requirements provide a basis for negotiation among business and compliance experts. We introduce a semi-automated and iterative approach to the synthesis of such process templates from compliance requirements expressed in Linear Temporal Logic (LTL). We show how generic constraints related to business process execution are incorporated and present criteria that point at underspecification. Further, we outline how such underspecification may be resolved to iteratively build up a complete specification. For the synthesis, we leverage existing work on process mining and process restructuring. However, our approach is not limited to the control-flow perspective, but also considers direct and indirect data-flow dependencies. Finally, we elaborate on the application of the derived process templates and present an implementation of our approach. (C) 2012 Elsevier Ltd. All rights reserved.
KW  - Process synthesis
KW  - Analysis of business process compliance specification
KW  - Process mining
Y1  - 2012
U6  - https://doi.org/10.1016/j.is.2012.05.001
SN  - 0306-4379
VL  - 37
IS  - 8
SP  - 714
EP  - 736
PB  - PERGAMON-ELSEVIER SCIENCE LTD
CY  - OXFORD
ER  - 
TY  - JOUR
A1  - Awad, Duha Jawad
A1  - Koch, Andreas
A1  - Mickler, Wulfhard
A1  - Schilde, Uwe
A1  - Strauch, Peter
T1  - EPR spectroscopy of 4, 4 '-Bis(tert-butyl)-2, 2 '-bipyridine-1, 2-dithiolatocuprates(II) in host lattices with different coordination geometries
JF  - Zeitschrift für anorganische und allgemeine Chemie
N2  - A series of new heteroleptic MN2S2 transition metal complexes with M = Cu2+ for EPR measurements and as diamagnetic hosts Ni2+, Zn2+, and Pd2+ were synthesized and characterized. The ligands are N2 = 4, 4'-bis(tert-butyl)-2, 2'-bipyridine (tBu2bpy) and S2 =1, 2-dithiooxalate, (dto), 1, 2-dithiosquarate, (dtsq), maleonitrile-1, 2-dithiolate, or 1, 2-dicyanoethene-1, 2-dithiolate, (mnt). The CuII complexes were studied by EPR in solution and as powders, diamagnetically diluted in the isostructural planar [NiII(tBu2bpy)(S2)] or[PdII(tBu2bpy)(S2)] as well as in tetrahedrally coordinated[ZnII(tBu2bpy)(S2)] host structures to put steric stress on the coordination geometry of the central CuN2S2 unit. The spin density contributions for different geometries calculated from experimental parameters are compared with the electronic situation in the frontier orbital, namely in the semi-occupied molecular orbital (SOMO) of the copper complex, derived from quantum chemical calculations on different levels (EHT and DFT). One of the hosts, [NiII(tBu2bpy)(mnt)], is characterized by X-ray structure analysis to prove the coordination geometry. The complex crystallizes in a square-planar coordination mode in the monoclinic space group P21/a with Z = 4 and the unit cell parameters a = 10.4508(10) angstrom, b = 18.266(2) angstrom, c = 12.6566(12) angstrom, beta = 112.095(7)degrees. Oxidation and reductions potentials of one of the host complexes, [Ni(tBu2bpy)(mnt)], were obtained by cyclovoltammetric measurements.
KW  - 1
KW  - 2-Dithiosquarate
KW  - 1
KW  - 2-Dithiooxalate
KW  - 1
KW  - 2-Dicyanoethene-1
KW  - 2-dithiolate
KW  - 4
KW  - 4'-Bis(tert-butyl)-2
KW  - 2'-bipyridine
KW  - X-ray structure
KW  - EPR
KW  - Copper
KW  - Nickel
KW  - Zinc
Y1  - 2012
U6  - https://doi.org/10.1002/zaac.201100517
SN  - 0044-2313
VL  - 638
IS  - 6
SP  - 965
EP  - 975
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Aydelott, Jennifer
A1  - Baer-Henney, Dinah
A1  - Trzaskowski, Maciej
A1  - Leech, Robert
A1  - Dick, Frederic
T1  - Sentence comprehension in competing speech dichotic sentence-word priming reveals hemispheric differences in auditory semantic processing
JF  - Language and cognitive processes
N2  - This study examined the effects of competing speech on auditory semantic comprehension using a dichotic sentence-word priming paradigm. Lexical decision performance for target words presented in spoken sentences was compared in strongly and weakly biasing semantic contexts. Targets were either congruent or incongruent with the sentential bias. Sentences were presented to one auditory channel (right or left), either in isolation or with competing speech produced by a single talker of the same gender presented simultaneously. The competing speech signal was either presented in the same auditory channel as the sentence context, or in a different auditory channel, and was either meaningful (played forward) or unintelligible (time-reversed).
 Biasing contexts presented in isolation facilitated responses to congruent targets and inhibited responses to incongruent targets, relative to a neutral baseline. Facilitation priming was reduced or eliminated by competing speech presented in the same auditory channel, supporting previous findings that semantic activation is highly sensitive to the intelligibility of the context signal. Competing speech presented in a different auditory channel affected facilitation priming differentially depending upon ear of presentation, suggesting hemispheric differences in the processing of the attended and competing signals. Results were consistent with previous claims of a right ear advantage for meaningful speech, as well as with visual word recognition findings implicating the left hemisphere in the generation of semantic predictions and the right hemisphere in the integration of newly encountered words into the sentence-level meaning. Unlike facilitation priming, inhibition was relatively robust to the energetic and informational masking effects of competing speech and was not influenced by the strength of the contextual bias or the meaningfulness of the competing signal, supporting a two-process model of sentence priming in which inhibition reflects later-stage, expectancy-driven strategic processes that may benefit from perceptual reanalysis after initial semantic activation.
KW  - Auditory language comprehension
KW  - Semantic priming
KW  - Hemispheric asymmetries
KW  - Lexical access
KW  - Multitalker environments
KW  - Competing speech
Y1  - 2012
U6  - https://doi.org/10.1080/01690965.2011.589735
SN  - 0169-0965
VL  - 27
IS  - 7-8
SP  - 1108
EP  - 1144
PB  - Wiley
CY  - Hove
ER  - 
TY  - JOUR
A1  - Baibolatov, Yernur
A1  - Spahn, Frank
T1  - The role of adhesion for ensembles of mesoscopic particles
JF  - Granular matter
N2  - We present a toy-model for an ensemble of adhering mesoscopic constituents in order to estimate the effect of the granular temperature on the sizes of embedded aggregates. The major goal is to illustrate the relation between the mean aggregate size and the granular temperature in dense planetary rings. For sake of simplicity we describe the collective behavior of the ensemble by means of equilibrium statistical mechanics, motivated by the stationary temperature established by the balance between a Kepler-shear driven viscous heating and inelastic cooling in these cosmic granular disks. The ensemble consists of N' equal constituents which can form cluster(s) or move like a gas-or both phases may coexist-depending on the (granular) temperature of the system. We assume the binding energy levels of a cluster E-c = -N-c gamma a to be determined by a certain contact number N-c, given by the configuration of N constituents of the aggregate (energy per contact: -gamma a). By applying canonical and grand-canonical ensembles, we show that the granular temperature T of a gas of constituents (their mean kinetic energy) controls the size distribution of the aggregates. They are the smaller the higher the granular temperature T is. A mere gas of single constituents is sustained for T >> gamma a. In the case of large clusters (low temperatures T << gamma a) the size distribution becomes a Poissonian.
KW  - Adhesion
KW  - Statistical mechanics
KW  - Planetary rings
Y1  - 2012
U6  - https://doi.org/10.1007/s10035-012-0325-4
SN  - 1434-5021
VL  - 14
IS  - 2
SP  - 197
EP  - 202
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Balazadeh, Salma
A1  - Jaspert, Nils
A1  - Arif, Muhammad
A1  - Müller-Röber, Bernd
A1  - Maurino, Veronica G.
T1  - Expression of ROS-responsive genes and transcription factors after metabolic formation of H2O2 in chloroplasts
JF  - Frontiers in plant science
N2  - Glycolate oxidase (GO) catalyses the oxidation of glycolate to glyoxylate, thereby consuming O-2 and producing H2O2. In this work, Arabidopsis thaliana plants expressing GO in the chloroplasts (GO plants) were used to assess the expressional behavior of reactive oxygen species (ROS)-responsive genes and transcription factors (TFs) after metabolic induction of H2O2 formation in chloroplasts. In this organelle, GO uses the glycolate derived from the oxygenase activity of RubisCO. Here, to identify genes responding to an abrupt production of H2O2 in chloroplasts we used quantitative real-time PCR (qRT-PCR) to test the expression of 187 ROS-responsive genes and 1880 TFs after transferring GO and wild-type (WT) plants grown at high CO2 levels to ambient CO2 concentration. Our data revealed coordinated expression changes of genes of specific functional networks 0.5 h after metabolic induction of H2O2 production in GO plants, including the induction of indole glucosinolate and camalexin biosynthesis genes. Comparative analysis using available microarray data suggests that signals for the induction of these genes through H2O2 may originate in the chloroplast. The TF profiling indicated an up-regulation in GO plants of a group of genes involved in the regulation of proanthocyanidin and anthocyanin biosynthesis. Moreover, the upregulation of expression of IF and IF interacting proteins affecting development (e.g., cell division, stem branching, flowering time, flower development) would impact growth and reproductive capacity, resulting in altered development under conditions that promote the formation of H2O2.
KW  - glycolate oxidase
KW  - H2O2
KW  - ROS-responsive genes
KW  - transcription factors
Y1  - 2012
U6  - https://doi.org/10.3389/fpls.2012.00234
SN  - 1664-462X
VL  - 3
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Balci, Kubilay
A1  - Yapar, G.
A1  - Akkaya, Y.
A1  - Akyuz, S.
A1  - Koch, Andreas
A1  - Kleinpeter, Erich
T1  - A conformational analysis and vibrational spectroscopic investigation on 1,2-bis(o-carboxyphenoxy) ethane molecule
JF  - Vibrational spectroscopy : an international journal devoted to applications of infrared and raman spectroscopy
N2  - The minima on the potential energy surface of 1,2-bis(o-carboxyphenoxy)ethane (CPE) molecule in its electronic ground state were searched by a molecular dynamics simulation performed with MM2 force field. For each of the found minimum-energy conformers, the corresponding equilibrium geometry, charge distribution, HOMO-LUMO energy gap, force field, vibrational normal modes and associated IR and Raman spectral data were determined by means of the density functional theory (DFT) based electronic structure calculations carried out by using B3LYP method and various Pople-style basis sets. The obtained theoretical data confirmed the significant effects of the intra- and inter-molecular hydrogen bonding interactions on the conformational structure, force field, and group vibrations of the molecule. The same data have also revealed that two of the determined stable conformers, both of which exhibit pseudo-crown structure, are considerably more favorable in energy to the others and accordingly provide the major contribution to the experimental spectra of CPE. In the light of the improved vibrational spectral data obtained within the "SQM FF" methodology and "Dual Scale Factors" approach for the monomer and dimer forms of these two conformers, a reliable assignment of the fundamental bands observed in the experimental room-temperature IR and Raman spectra of the molecule was given, and the sensitivities of its group vibrations to conformation, substitution and dimerization were discussed.
KW  - Glycol podands
KW  - Salicylic acid
KW  - IR and Raman spectra
KW  - SQM FF
KW  - Dual Scale Factors
Y1  - 2012
U6  - https://doi.org/10.1016/j.vibspec.2011.11.011
SN  - 0924-2031
VL  - 58
IS  - 1-2
SP  - 27
EP  - 43
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Bande, Alejandro
A1  - Horton, Brian K.
A1  - Ramirez, Juan C.
A1  - Mora, Andres
A1  - Parra, Mauricio
A1  - Stockli, Daniel F.
T1  - Clastic deposition, provenance, and sequence of Andean thrusting in the frontal Eastern Cordillera and Llanos foreland basin of Colombia
JF  - Geological Society of America bulletin
N2  - Sedimentological, provenance, and detrital thermochronological results for basin fill at the modern deformation front of the northern Andes (6 degrees N latitude) provide a long-term, Eocene to Pliocene record of foreland-basin sedimentation along the Eastern Cordillera !Janos basin boundary in Colombia. Lithofacies assemblages and paleocurrent orientations in the upward-coarsening, 5-km-thick succession of the Nunchia syncline reveal a systematic shift from craton-derived, shallow-marine distal foreland (back-bulge) accumulation in the Mirador Formation, to orogen-sourced, deltaic, and coastalinfluenced sedimentation of the distal to medial foreland (foredeep) in the Carbonera and Leon Formations, to anastomosing fluvial and distributive braided fluvial megafan systems of the proximal foreland (foredeep to wedge-top) basin in the lower and upper Guayabo Formation. These changes in depositional processes and sediment dispersal are supported by up-section variations in detrital zircon U-Pb and (U-Th)/He ages that record exhumation of evolving, compartmentalized sediment source areas in the Eastern Cordillera. The data are interpreted in terms of a progressive eastward advance in foldand-thrust deformation, with late Eocene Oligocene deformation in the axial zone of the Eastern Cordillera along the western edge of Floresta basin (Soapaga thrust), early Miocene reactivation (inversion) of the eastern margin of the Mesozoic rift system (Pajarito and Guaicaramo thrusts), and middle late Miocene propagation of a footwall shortcut fault (Vopal thrust) that created the Nunchia syncline in a wedge-top (piggyback) setting of the eastern foothills along the transition from the Eastern Cordillera to Harms foreland basin. Collectively, the data presented here for the frontal Eastern Cordillera define a general in-sequence pattern of eastwardadvancing fold-and-thrust deformation during Cenozoic east-west shortening in the Colombian Andes.
Y1  - 2012
U6  - https://doi.org/10.1130/B30412.1
SN  - 0016-7606
VL  - 124
IS  - 1-2
SP  - 59
EP  - 76
PB  - American Institute of Physics
CY  - Boulder
ER  - 
TY  - JOUR
A1  - Banerjee, Shiladitya
A1  - Kröner, Dominik
A1  - Saalfrank, Peter
T1  - Resonance Raman and vibronic absorption spectra with Duschinsky rotation from a time-dependent perspective application to beta-carotene
JF  - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr
N2  - The time-dependent approach to electronic spectroscopy, as popularized by Heller and co-workers in the 1980s, is applied here in conjunction with linear-response, time-dependent density functional theory to study vibronic absorption and resonance Raman spectra of beta-carotene, with and without a solvent. Two-state models, the harmonic and the Condon approximations are used in order to do so. A new code has been developed which includes excited state displacements, vibrational frequency shifts, and Duschinsky rotation, i.e., mode mixing, for both non-adiabatic spectroscopies. It is shown that Duschinsky rotation has a pronounced effect on the resonance Raman spectra of beta-carotene. In particular, it can explain a recently found anomalous behaviour of the so-called nu(1) peak in resonance Raman spectra [N. Tschirner, M. Schenderlein, K. Brose, E. Schlodder, M. A. Mroginski, C. Thomsen, and P. Hildebrandt, Phys. Chem. Chem. Phys. 11, 11471 (2009)], which shifts with the change in excitation wavelength.
Y1  - 2012
U6  - https://doi.org/10.1063/1.4748147
SN  - 0021-9606
VL  - 137
IS  - 22
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Bang, Guri
A1  - Hovi, Jon
A1  - Sprinz, Detlef F.
T1  - US presidents and the failure to ratify multilateral environmental agreements
JF  - Climate policy
N2  - Whereas the US President signed the Kyoto Protocol, the failure of the US Congress to ratify it seriously hampered subsequent international climate cooperation. This recent US trend, of signing environmental treaties but failing to ratify them, could thwart attempts to come to a future climate agreement. Two complementary explanations of this trend are proposed. First, the political system of the US has distinct institutional features that make it difficult for presidents to predict whether the Senate will give its advice and consent to multilateral environmental agreements (MEAs) and whether Congress will pass the required enabling legislation. Second, elected for a fixed term, US presidents might benefit politically from supporting MEAs even when knowing that legislative support is not forthcoming. Four policy implications are explored, concerning the scope for unilateral presidential action, the potential for bipartisan congressional support, the effectiveness of a treaty without the US, and the prospects for a deep, new climate treaty.
 Policy relevance
 Why does the failure of US ratification of multilateral environmental treaties occur? This article analyses the domestic political mechanisms involved in cases of failed US ratification. US non-participation in global environmental institutions often has serious ramifications. For example, it sharply limited Kyoto's effectiveness and seriously hampered international climate negotiations for years. Although at COP 17 in Durban the parties agreed to negotiate a new agreement by 2015, a new global climate treaty may well trigger a situation resembling the one President Clinton faced in 1997 when he signed Kyoto but never obtained support for it in the Senate. US failure to ratify could thwart future climate agreements.
KW  - enabling legislation
KW  - environmental treaties
KW  - Kyoto Protocol
KW  - political processes
KW  - ratification
KW  - United States
Y1  - 2012
U6  - https://doi.org/10.1080/14693062.2012.699788
SN  - 1469-3062
VL  - 12
IS  - 6
SP  - 755
EP  - 763
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Baranac-Stojanovic, Marija
A1  - Koch, Andreas
A1  - Kleinpeter, Erich
T1  - Density Functional Calculations of the Anisotropic Effects of Borazine and 1,3,2,4-Diazadiboretidine
JF  - ChemPhysChem : a European journal of chemical physics and physical chemistry
N2  - On the basis of the nucleus-independent chemical shift (NICS) concept, the anisotropic effects of two inorganic rings, namely, borazine and planar 1,3,2,4-diazadiboretidine, are quantitatively calculated and visualized as isochemical shielding surfaces (ICSSs). Dissection of magnetic shielding values along the three Cartesian axes into contributions from s and p bonds by the natural chemical shieldingnatural bond orbital (NCSNBO) method revealed that their appearance is not a simple reflection of the extent of (anti)aromaticity.
KW  - anisotropic effects
KW  - aromaticity
KW  - B,N heterocycles
KW  - density functional calculations
KW  - NMR spectroscopy
Y1  - 2012
U6  - https://doi.org/10.1002/cphc.201200732
SN  - 1439-4235
VL  - 13
IS  - 17
SP  - 3803
EP  - 3811
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Baranac-Stojanovic, Marija
A1  - Koch, Andreas
A1  - Kleinpeter, Erich
T1  - Is the conventional interpretation of the anisotropic effects of C=C double bonds and aromatic rings in NMR spectra in terms of the p-electron shielding/deshielding contributions correct?
JF  - Chemistry - a European journal
N2  - Based on the nucleus-independent chemical shift (NICS) concept, isotropic magnetic shielding values have been computed along the three Cartesian axes for ethene, cyclobutadiene, benzene, naphthalene, and benzocyclobutadiene, starting from the molecular/ring center up to 10 angstrom away. These through-space NMR spectroscopic shielding (TSNMRS) values, which reflect the anisotropic effects, have been broken down into contributions from localized- and canonical molecular orbitals (LMOs and CMOs); these contributions revealed that the proton NMR spectroscopic chemical shifts of nuclei that are spatially close to the C?C double bond or the aromatic ring should not be explained in terms of the conventionally accepted p-electron shielding/deshielding effects. In fact, these effects followed the predictions only for the antiaromatic cyclobutadiene ring.
KW  - ab initio calculations
KW  - anisotropic effects
KW  - NMR spectroscopy
KW  - nucleus-independent chemical shift
KW  - pi interactions
Y1  - 2012
U6  - https://doi.org/10.1002/chem.201101882
SN  - 0947-6539
VL  - 18
IS  - 1
SP  - 370
EP  - 376
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Barbosa Pfannes, Eva Katharina
A1  - Theves, Matthias
A1  - Wegner, Christian
A1  - Beta, Carsten
T1  - Impact of the carbazole derivative wiskostatin on mechanical stability
 and dynamics of motile cells
JF  - JOURNAL OF MUSCLE RESEARCH AND CELL MOTILITY
N2  - Many essential functions in eukaryotic cells like phagocytosis, division, and motility rely on the dynamical properties of the actin cytoskeleton. A central player in the actin system is the Arp2/3 complex. Its activity is controlled by members of the WASP (Wiskott-Aldrich syndrome protein) family. In this work, we investigated the effect of the carbazole derivative wiskostatin, a recently identified N-WASP inhibitor, on actin-driven processes in motile cells of the social ameba . Drug-treated cells exhibited an altered morphology and strongly reduced pseudopod formation. However, TIRF microscopy images revealed that the overall cortical network structure remained intact. We probed the mechanical stability of wiskostatin-treated cells using a microfluidic device. While the total amount of F-actin in the cells remained constant, their stiffness was strongly reduced. Furthermore, wiskostatin treatment enhanced the resistance to fluid shear stress, while spontaneous motility as well as chemotactic motion in gradients of cAMP were reduced. Our results suggest that wiskostatin affects the mechanical integrity of the actin cortex so that its rigidity is reduced and actin-driven force generation is impaired.
KW  - Actin dynamics
KW  - Wiskostatin
KW  - Dictyostelium discoideum
Y1  - 2012
U6  - https://doi.org/10.1007/s10974-012-9287-8
SN  - 0142-4319
VL  - 33
IS  - 2
SP  - 95
EP  - 106
PB  - SPRINGER
CY  - DORDRECHT
ER  - 
TY  - JOUR
A1  - Barkai, Eli
A1  - Garini, Yuval
A1  - Metzler, Ralf
T1  - Strange Kinetics of single molecules in living cells
JF  - Physics today
Y1  - 2012
SN  - 0031-9228
VL  - 65
IS  - 8
SP  - 29
EP  - 35
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Bartel, Manuela
A1  - Hartmann, Stefanie
A1  - Lehmann, Karola
A1  - Postel, Kai
A1  - Quesada, Humberto
A1  - Philipp, Eva E. R.
A1  - Heilmann, Katja
A1  - Micheel, Burkhard
A1  - Stuckas, Heiko
T1  - Identification of sperm proteins as candidate biomarkers for the analysis of reproductive isolation in Mytilus: a case study for the enkurin locus
JF  - Marine biology : international journal on life in oceans and coastal waters
N2  - Sperm proteins of the marine sessile mussels of the Mytilus edulis species complex are models to investigate reproductive isolation and speciation. This study aimed at identifying sperm proteins and their corresponding genes. This was aided by the use of monoclonal antibodies that preferentially bind to yet unknown sperm molecules. By identifying their target molecules, this approach identified proteins with relevance to Mytilus sperm function. This procedure identified 16 proteins, for example, enkurin, laminin, porin and heat shock proteins. The potential use of these proteins as genetic markers to study reproductive isolation is exemplified by analysing the enkurin locus. Enkurin evolution is driven by purifying selection, the locus displays high levels of intraspecific variation and species-specific alleles group in distinct phylogenetic clusters. These findings characterize enkurin as informative candidate biomarker for analyses of clinal variation and differential introgression in hybrid zones, for example, to understand determinants of reproductive isolation in Baltic Mytilus populations.
Y1  - 2012
U6  - https://doi.org/10.1007/s00227-012-2005-7
SN  - 0025-3162
VL  - 159
IS  - 10
SP  - 2195
EP  - 2207
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Barth, Johannes
A1  - Siegmann, Rebekka
A1  - Beuermann, Sabine
A1  - Russell, Gregory T.
A1  - Buback, Michael
T1  - Investigations into chain-length-dependent termination in bulk radical polymerization of 1H, 1H, 2H, 2H-Tridecafluorooctyl methacrylate
JF  - Macromolecular chemistry and physics
N2  - The SP-PLP-EPR technique is used to carry out a detailed investigation of the radical termination kinetics of 1H, 1H, 2H, 2H-tridecafluorooctyl methacrylate (TDFOMA) in bulk at relatively low conversion. Composite-model behavior for chain-length-dependent termination rate coefficients, kti,i, is observed. It is found that for TDFOMA, ic approximate to 60 independent of temperature, and as approximate to 0.65 and al approximate to 0.2 at 80 degrees C and above. However, at lower temperatures the situation is strikingly different, with the significantly higher average values of as = 0.89 +/- 0.15 and al = 0.32 +/- 0.10 being obtained at 50 degrees C and below. This makes TDFOMA the first monomer to be found that exhibits clearly different exponent values, as and al, at lower and higher temperature, and that has both a high as, like an acrylate, and a high ic, like a methacrylate.
KW  - ESR
KW  - EPR
KW  - kinetics (polym
KW  - )
KW  - methacrylates
KW  - radical polymerization
KW  - termination
Y1  - 2012
U6  - https://doi.org/10.1002/macp.201100479
SN  - 1022-1352
VL  - 213
IS  - 1
SP  - 19
EP  - 28
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Barthel, Thomas
A1  - Kliesch, Martin
T1  - Quasilocality and efficient simulation of Markovian Quantum Dynamics
JF  - Physical review letters
N2  - We consider open many-body systems governed by a time-dependent quantum master equation with short-range interactions. With a generalized Lieb-Robinson bound, we show that the evolution in this very generic framework is quasilocal; i.e., the evolution of observables can be approximated by implementing the dynamics only in a vicinity of the observables' support. The precision increases exponentially with the diameter of the considered subsystem. Hence, time evolution can be simulated on classical computers with a cost that is independent of the system size. Providing error bounds for Trotter decompositions, we conclude that the simulation on a quantum computer is additionally efficient in time. For experiments and simulations in the Schrodinger picture, our result can be used to rigorously bound finite-size effects.
Y1  - 2012
U6  - https://doi.org/10.1103/PhysRevLett.108.230504
SN  - 0031-9007
VL  - 108
IS  - 23
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Basler, Georg
A1  - Grimbs, Sergio
A1  - Ebenhöh, Oliver
A1  - Selbig, Joachim
A1  - Nikoloski, Zoran
T1  - Evolutionary significance of metabolic network properties
JF  - Interface : journal of the Royal Society
N2  - Complex networks have been successfully employed to represent different levels of biological systems, ranging from gene regulation to protein-protein interactions and metabolism. Network-based research has mainly focused on identifying unifying structural properties, such as small average path length, large clustering coefficient, heavy-tail degree distribution and hierarchical organization, viewed as requirements for efficient and robust system architectures. However, for biological networks, it is unclear to what extent these properties reflect the evolutionary history of the represented systems. Here, we show that the salient structural properties of six metabolic networks from all kingdoms of life may be inherently related to the evolution and functional organization of metabolism by employing network randomization under mass balance constraints. Contrary to the results from the common Markov-chain switching algorithm, our findings suggest the evolutionary importance of the small-world hypothesis as a fundamental design principle of complex networks. The approach may help us to determine the biologically meaningful properties that result from evolutionary pressure imposed on metabolism, such as the global impact of local reaction knockouts. Moreover, the approach can be applied to test to what extent novel structural properties can be used to draw biologically meaningful hypothesis or predictions from structure alone.
KW  - metabolic networks
KW  - significance
KW  - randomization
KW  - null model
KW  - centrality
Y1  - 2012
U6  - https://doi.org/10.1098/rsif.2011.0652
SN  - 1742-5689
VL  - 9
IS  - 71
SP  - 1168
EP  - 1176
PB  - Royal Society
CY  - London
ER  - 
TY  - JOUR
A1  - Basler, Georg
A1  - Grimbs, Sergio
A1  - Nikoloski, Zoran
T1  - Optimizing metabolic pathways by screening for feasible synthetic reactions
JF  - Biosystems : journal of biological and information processing sciences
N2  - Background: Reconstruction of genome-scale metabolic networks has resulted in models capable of reproducing experimentally observed biomass yield/growth rates and predicting the effect of alterations in metabolism for biotechnological applications. The existing studies rely on modifying the metabolic network of an investigated organism by removing or inserting reactions taken either from evolutionary similar organisms or from databases of biochemical reactions (e.g., KEGG). A potential disadvantage of these knowledge-driven approaches is that the result is biased towards known reactions, as such approaches do not account for the possibility of including novel enzymes, together with the reactions they catalyze.
 Results: Here, we explore the alternative of increasing biomass yield in three model organisms, namely Bacillus subtilis, Escherichia coil, and Hordeum vulgare, by applying small, chemically feasible network modifications. We use the predicted and experimentally confirmed growth rates of the wild-type networks as reference values and determine the effect of inserting mass-balanced, thermodynamically feasible reactions on predictions of growth rate by using flux balance analysis.
 Conclusions: While many replacements of existing reactions naturally lead to a decrease or complete loss of biomass production ability, in all three investigated organisms we find feasible modifications which facilitate a significant increase in this biological function. We focus on modifications with feasible chemical properties and a significant increase in biomass yield. The results demonstrate that small modifications are sufficient to substantially alter biomass yield in the three organisms. The method can be used to predict the effect of targeted modifications on the yield of any set of metabolites (e.g., ethanol), thus providing a computational framework for synthetic metabolic engineering.
KW  - Metabolic networks
KW  - Optimization
KW  - Mass-balanced reactions
KW  - Synthetic biology
Y1  - 2012
U6  - https://doi.org/10.1016/j.biosystems.2012.04.007
SN  - 0303-2647
VL  - 109
IS  - 2
SP  - 186
EP  - 191
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Batsios, Petros
A1  - Peter, Tatjana
A1  - Baumann, Otto
A1  - Stick, Reimer
A1  - Meyer, Irene
A1  - Gräf, Ralph
T1  - A lamin in lower eukaryotes?
JF  - Nucleus
N2  - Lamins are the major components of the nuclear lamina and serve not only as a mechanical support, but are also involved in chromatin organization, epigenetic regulation, transcription and mitotic events. Despite these universal tasks, lamins have so far been found only in metazoans. Yet, recently we have identified Dictyostelium NE81 as the first lamin-like protein in a lower eukaryote. Based on the current knowledge, we draw a model for nuclear envelope organization in Dictyostelium in this Extra View and we review the experimental data that justified this classification. Furthermore we provide unpublished data underscoring the requirement of posttranslational CaaX-box processing for proper protein localization at the nuclear envelope. Sequence comparison of NE81 sequences from four Dictyostelia with bona fide lamins illustrates the evolutional relationship between these proteins. Under certain conditions these usually unicellular social amoebae congregate to form a multicellular body. We propose that the evolution of the lamin-like NE81 went along with the invention of multicellularity.
KW  - dictyostelium
KW  - lamin
KW  - intermediate filament
KW  - centrosome
KW  - nucleus
Y1  - 2012
U6  - https://doi.org/10.4161/nucl.20149
SN  - 1949-1034
VL  - 3
IS  - 3
SP  - 237
EP  - 243
PB  - Landes Bioscience
CY  - Austin
ER  - 
TY  - JOUR
A1  - Bauer, Maximilian
A1  - Metzler, Ralf
T1  - Generalized facilitated diffusion model for DNA-binding proteins with search and recognition states
JF  - Biophysical journal
N2  - Transcription factors (TFs) such as the lac repressor find their target sequence on DNA at remarkably high rates. In the established Berg-von Hippel model for this search process, the TF alternates between three-dimensional diffusion in the bulk solution and one-dimensional sliding along the DNA chain. To overcome the so-called speed-stability paradox, in similar models the TF was considered as being present in two conformations (search state and recognition state) between which it switches stochastically. Combining both the facilitated diffusion model and alternating states, we obtain a generalized model. We explicitly treat bulk excursions for rodlike chains arranged in parallel and consider a simplified model for coiled DNA. Compared to previously considered facilitated diffusion models, corresponding to limiting cases of our generalized model, we surprisingly find a reduced target search rate. Moreover, at optimal conditions there is no longer an equipartition between the time spent by the protein on and off the DNA chain.
Y1  - 2012
U6  - https://doi.org/10.1016/j.bpj.2012.04.008
SN  - 0006-3495
VL  - 102
IS  - 10
SP  - 2321
EP  - 2330
PB  - Cell Press
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Baumgartner, Jens
A1  - Lesevic, Paul
A1  - Kumari, Monika
A1  - Halbmair, Karin
A1  - Bennet, Mathieu
A1  - Koernig, Andre
A1  - Widdrat, Marc
A1  - Andert, Janet
A1  - Wollgarten, Markus
A1  - Bertinetti, Luca
A1  - Strauch, Peter
A1  - Hirt, Ann
A1  - Faivre, Damien
T1  - From magnetotactic bacteria to hollow spirilla-shaped silica containing a magnetic chain
JF  - RSC Advances
N2  - Magnetotactic bacteria produce chains of magnetite nanoparticles, which are called magnetosomes and are used for navigational purposes. We use these cells as a biological template to prepare a hollow hybrid material based on silica and magnetite, and show that the synthetic route is nondestructive as the material conserves the cell morphology as well as the alignment of the magnetic particles. The hybrid material can be resuspended in aqueous solution, and can be shown to orient itself in an external magnetic field. We anticipate that chemical modification of the silica can be used to functionalize the material surface in order to obtain multifunctional materials with specialized applications, e.g. targeted drug delivery.
Y1  - 2012
U6  - https://doi.org/10.1039/c2ra20911j
SN  - 2046-2069
VL  - 2
IS  - 21
SP  - 8007
EP  - 8009
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Baumgärtel, Hellmut
T1  - On a critical radiation density in the Friedmann equation
JF  - Journal of mathematical physics
N2  - The paper presents a classification of the basic types of admissible solutions of the general Friedmann equation with non-vanishing cosmological constant and for the case that radiation and matter do not couple. There are four distinct types. The classification uses first the discriminant of a polynomial of the third degree, closely related to the right hand side of the Friedmann equation. The decisive term is then a critical radiation density which can be calculated explicitly.
Y1  - 2012
U6  - https://doi.org/10.1063/1.4771668
SN  - 0022-2488
VL  - 53
IS  - 12
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Baur, Heiner
A1  - Hirschmüller, Anja
A1  - Müller, Steffen
A1  - Cassel, Michael
A1  - Mayer, Frank
T1  - Is EMG of the lower leg dependent on weekly running mileage?
JF  - International journal of sports medicine
N2  - Neuromuscular activity of the lower leg is dependent on the task performed, speed of movement and gender. Whether training volume influences neuromuscular activity is not known. The EMG of physically active persons differing in running mileage was analysed to investigate this. 55 volunteers were allocated to a low (LM: < 30 km), intermediate (IM: > 30 km & < 45 km) or high mileage (HM: > 45 km) group according to their weekly running volume. Neuromuscular activity of the lower leg was measured during running (3.33 m.s(-1)). Mean amplitude values for preactivation, weight acceptance and push-off were calculated and normalised to the mean activity of the entire gait cycle. Higher activity in the gastrocnemius group was observed in weight acceptance in LM compared to IM (+30%) and HM (+25%) but lower activity was present in the push-off for LM compared to IM and HM. For the peroneal muscle, differences were present in the push-off where HM showed increased activity compared to IM (+24%) and LM (+60%). The tibial muscle revealed slightly lower activity during preactivation for the high mileage runners. Neuromuscular activity differs during stance between the high and intermediate group compared to low mileage runners. Slight adaptations in neuromuscular activation indicate a more target-oriented activation strategy possibly due to repetitive training in runners with higher weekly mileage.
KW  - locomotion
KW  - neuromuscular control
KW  - running gait
KW  - training volume
Y1  - 2012
U6  - https://doi.org/10.1055/s-0031-1286250
SN  - 0172-4622
VL  - 33
IS  - 1
SP  - 53
EP  - 57
PB  - Thieme
CY  - Stuttgart
ER  - 
TY  - JOUR
A1  - Baushev, Anton N.
T1  - Interaction of clumpy dark matter with interstellar medium in astrophysical systems
JF  - Monthly notices of the Royal Astronomical Society
N2  - Contemporary cosmological conceptions suggest that the dark matter in haloes of galaxies and galaxy clusters has most likely a clumpy structure. If a stream of gas penetrates through it, a small-scale gravitational field created by the clumps disturbs the flow resulting in momentum exchange between the stream and the dark matter. In this article, we perform an analysis of this effect, based on the hierarchical halo model of the dark matter structure and Navarro-Frenk-White density profiles. We consider the clumps of various masses, from the smallest up to the highest ones M = 10(9) M circle dot. It has been found that in any event the effect grows with the mass of the clump: not only the drag force F acting on the clump but also its acceleration w = F/M increases.
 We discuss various astrophysical systems. The mechanism proved to be ineffective in the case of galaxy or galaxy cluster collisions. On the other hand, it played an important role during the process of galaxy formation. As a result, the dark matter should have formed a more compact, oblate and faster rotating substructure in the halo of our Galaxy. We have shown that this thick disc should be more clumpy than the halo. This fact is very important for the indirect detection experiments since it is the clumps that give the main contribution to the annihilation signal. Our calculations show that the mechanism of momentum exchange between the dark and baryon matter is ineffective on the outskirts of the galactic halo. It means that the clumps from there were not transported to the thick disc, and this region should be more clumpy than the halo on the average.
KW  - elementary particles
KW  - cosmology: theory
KW  - dark matter
Y1  - 2012
U6  - https://doi.org/10.1111/j.1365-2966.2011.20067.x
SN  - 0035-8711
VL  - 420
IS  - 1
SP  - 590
EP  - 595
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Baushev, Anton N.
A1  - Federici, S.
A1  - Pohl, M.
T1  - Spectral analysis of the gamma-ray background near the dwarf MilkyWay satellite Segue 1: Improved limits on the cross section of neutralino dark matter annihilation
JF  - Physical review : D, Particles, fields, gravitation, and cosmology
N2  - The indirect detection of dark matter requires that dark matter annihilation products be discriminated from conventional astrophysical backgrounds. Here, we re-analyze GeV-band gamma-ray observations of the prominent Milky Way dwarf satellite galaxy Segue 1, for which the expected astrophysical background is minimal. We explicitly account for the angular extent of the conservatively expected gamma-ray signal and keep the uncertainty in the dark-matter profile external to the likelihood analysis of the gamma-ray data.
Y1  - 2012
U6  - https://doi.org/10.1103/PhysRevD.86.063521
SN  - 1550-7998
VL  - 86
IS  - 6
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Beauval, Celine
A1  - Tasan, Hilal
A1  - Laurendeau, Aurore
A1  - Delavaud, Elise
A1  - Cotton, Fabrice
A1  - Gueguen, Philippe
A1  - Kühn, Nicolas
T1  - On the testing of ground-motion prediction equations against small-magnitude data
JF  - Bulletin of the Seismological Society of America
N2  - Ground-motion prediction equations (GMPE) are essential in probabilistic seismic hazard studies for estimating the ground motions generated by the seismic sources. In low-seismicity regions, only weak motions are available during the lifetime of accelerometric networks, and the equations selected for the probabilistic studies are usually models established from foreign data. Although most GMPEs have been developed for magnitudes 5 and above, the minimum magnitude often used in probabilistic studies in low-seismicity regions is smaller. Disaggregations have shown that, at return periods of engineering interest, magnitudes less than 5 may be contributing to the hazard. This paper presents the testing of several GMPEs selected in current international and national probabilistic projects against weak motions recorded in France (191 recordings with source-site distances up to 300 km, 3:8 <= M-w <= 4:5). The method is based on the log-likelihood value proposed by Scherbaum et al. (2009). The best-fitting models (approximately 2:5 <= LLH <= 3:5) over the whole frequency range are the Cauzzi and Faccioli (2008), Akkar and Bommer (2010), and Abrahamson and Silva (2008) models. No significant regional variation of ground motions is highlighted, and the magnitude scaling could be the predominant factor in the control of ground-motion amplitudes. Furthermore, we take advantage of a rich Japanese dataset to run tests on randomly selected low-magnitude subsets, and confirm that a dataset of similar to 190 observations, the same size as the French dataset, is large enough to obtain stable LLH estimates. Additionally we perform the tests against larger magnitudes (5-7) from the Japanese dataset. The ranking of models is partially modified, indicating a magnitude scaling effect for some of the models, and showing that extrapolating testing results obtained from low-magnitude ranges to higher magnitude ranges is not straightforward.
Y1  - 2012
U6  - https://doi.org/10.1785/0120110271
SN  - 0037-1106
VL  - 102
IS  - 5
SP  - 1994
EP  - 2007
PB  - Seismological Society of America
CY  - El Cerrito
ER  - 
TY  - JOUR
A1  - Bechir, Mahamat
A1  - Schelling, E.
A1  - Krämer, K.
A1  - Schweigert, Florian J.
A1  - Bonfoh, Bassirou
A1  - Crump, L.
A1  - Tanner, M.
A1  - Zinsstag, J.
T1  - Retinol assessment among women and children in sahelian mobile pastoralists
JF  - EcoHealth : conservation medicine, human health, ecosystem sustainability
N2  - Micronutrient deficiencies are widespread in developing countries, particularly in remote communities such as mobile pastoralists. The nutritional and vitamin A status of this population is not well-documented in Chad. This study assessed serum retinol levels among women and children under five-year-old in nomadic and semi-nomadic pastoralist and rural-settled communities, who are similarly exposed to risk factors such as gastrointestinal parasitic infection, anaemia and emaciation. The novel method of portable fluorometry was used for the first time to measure beta-carotene and retinol levels in a pastoral nomadic area. Moderate level blood retinol deficiency (< 0.7 mu mol/L) was observed in 5% (CI 1-11) of nomadic, 29% (CI 13-45) of semi-nomadic and 22% (CI 8-35) of sedentary women. In children, 1% (CI 0.1-4), 17% (CI 9-25) and 28% (CI 18-39), respectively, had moderate level blood retinol deficiency. In nomadic communities, women and children had blood retinol levels close to normal. Deficiency of retinol was strongly linked with lifestyle (nomadic, semi-nomadic and settled) among women and lifestyle and age among children. The results support an ecological linkage between human retinol levels and livestock milk retinol. This study shows the feasibility of portable retinol and beta-carotene measurement in human blood as well as human and animal milk under remote field conditions, but the approach requires further validation.
KW  - vitamin A
KW  - retinol
KW  - nomadic pastoralist
KW  - Chad
Y1  - 2012
U6  - https://doi.org/10.1007/s10393-012-0781-7
SN  - 1612-9202
VL  - 9
IS  - 2
SP  - 113
EP  - 121
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Becker, Michael
A1  - Lüdtke, Oliver
A1  - Trautwein, Ulrich
A1  - Köller, Olaf
A1  - Baumert, Jürgen
T1  - The differential effects of school racking on psychometric intelligence Do academic-track schools make students smarter?
JF  - The journal of educational psychology
N2  - Prior research has shown that quantity of schooling affects the development of intelligence in childhood and adolescence. However, it is still debated whether other aspects of schooling-such as ability tracking or, more generally, school quality-can also influence intelligence. In this study, the authors analyzed intelligence gains in academic- and vocational-track schools in Germany, testing for differential effects of school quality (academic vs. vocational track) on psychometric intelligence. Longitudinal data were obtained from a sample of N = 1,038 Grade 7 and 10 students in 49 schools. A nonverbal reasoning test was used as an indicator of general psychometric intelligence, and relevant psychological and social background variables were included in the analyses. Propensity score matching was used to control for selection bias. Results showed a positive effect of attending the academic track.
KW  - school quality
KW  - intelligence
KW  - cognitive development
KW  - longitudinal studies
KW  - propensity score matching
Y1  - 2012
U6  - https://doi.org/10.1037/a0027608
SN  - 0022-0663
VL  - 104
IS  - 3
SP  - 682
EP  - 699
PB  - American Psychological Association
CY  - Washington
ER  - 
TY  - JOUR
A1  - Behrends, Andreas
A1  - Scheiner, Ricarda
T1  - Octopamine improves learning in newly emerged bees but not in old
 foragers
JF  - JOURNAL OF EXPERIMENTAL BIOLOGY
N2  - Honey bees (Apis mellifera) are well known for their excellent learning abilities. Although most age groups learn quickly to associate an odor with a sucrose reward, newly emerged bees and old foragers often perform poorly. For a long time, the reason for the poor learning performance of these age groups was unclear. We show that reduced sensitivity for sucrose is the cause for poor associative learning in newly emerged bees but not in old foragers. By increasing the sensitivity for sucrose through octopamine, we selectively improved the learning performance of insensitive newly emerged bees. Interestingly, the learning performance of foragers experiencing the same treatment remained low, despite the observed increase in sensitivity for the reward. We thus demonstrate that increasing sensitivity for the reward can improve the associative learning performance of bees when they are young but not when they had foraged for a long time. Importantly, octopamine can have very different effects on bees, depending on their initial sensory sensitivity. These differential effects of octopamine have important consequences for interpreting the action of biogenic amines on insect behavior.
KW  - honey bee
KW  - PER
KW  - olfactory conditioning
KW  - ageing
KW  - sucrose responsiveness
Y1  - 2012
U6  - https://doi.org/10.1242/jeb.063297
SN  - 0022-0949
VL  - 215
IS  - 7
SP  - 1076
EP  - 1083
PB  - COMPANY OF BIOLOGISTS LTD
CY  - CAMBRIDGE
ER  - 
TY  - JOUR
A1  - Bell, M. J.
A1  - Jones, E.
A1  - Smith, J.
A1  - Smith, P.
A1  - Yeluripati, J.
A1  - Augustin, Jürgen
A1  - Juszczak, R.
A1  - Olejnik, J.
A1  - Sommer, Michael
T1  - Simulation of soil nitrogen, nitrous oxide emissions and mitigation scenarios at 3 European cropland sites using the ECOSSE model
JF  - Nutrient cycling in agroecosystems
N2  - The global warming potential of nitrous oxide (N2O) and its long atmospheric lifetime mean its presence in the atmosphere is of major concern, and that methods are required to measure and reduce emissions. Large spatial and temporal variations means, however, that simple extrapolation of measured data is inappropriate, and that other methods of quantification are required. Although process-based models have been developed to simulate these emissions, they often require a large amount of input data that is not available at a regional scale, making regional and global emission estimates difficult to achieve. The spatial extent of organic soils means that quantification of emissions from these soil types is also required, but will not be achievable using a process-based model that has not been developed to simulate soil water contents above field capacity or organic soils. The ECOSSE model was developed to overcome these limitations, and with a requirement for only input data that is readily available at a regional scale, it can be used to quantify regional emissions and directly inform land-use change decisions. ECOSSE includes the major processes of nitrogen (N) turnover, with material being exchanged between pools of SOM at rates modified by temperature, soil moisture, soil pH and crop cover. Evaluation of its performance at site-scale is presented to demonstrate its ability to adequately simulate soil N contents and N2O emissions from cropland soils in Europe. Mitigation scenarios and sensitivity analyses are also presented to demonstrate how ECOSSE can be used to estimate the impact of future climate and land-use change on N2O emissions.
KW  - Soil N2O emissions
KW  - Process-based models
KW  - Land-use
KW  - Climate change
Y1  - 2012
U6  - https://doi.org/10.1007/s10705-011-9479-4
SN  - 1385-1314
VL  - 92
IS  - 2
SP  - 161
EP  - 181
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Ben Bekhti, Nadya
A1  - Winkel, B.
A1  - Richter, P.
A1  - Kerp, J.
A1  - Klein, U.
A1  - Murphy, M. T.
T1  - An absorption-selected survey of neutral gas in the Milky Way halo New results based on a large sample of Ca II, Na I, and H I spectra towards QSOs
JF  - Astronomy and astrophysics : an international weekly journal
N2  - Aims. We aim at analysing systematically the distribution and physical properties of neutral and mildly ionised gas in the Milky Way halo, based on a large absorption-selected data set.
 Methods. Multi-wavelength studies were performed combining optical absorption line data of Ca II and Na I with follow-up H I 21-cm emission line observations along 408 sight lines towards low-and high-redshift QSOs. We made use of archival optical spectra obtained with UVES/VLT. H I data were extracted from the Effelsberg-Bonn H I survey and the Galactic All-Sky survey. For selected sight lines we obtained deeper follow-up observations using the Effelsberg 100-m telescope.
 Results. Ca II (Na I) halo absorbers at intermediate and high radial velocities are present in 40-55% (20-35%) of the sightlines, depending on the column density threshold chosen. Many halo absorbers show multi-component absorption lines, indicating the presence of sub-structure. In 65% of the cases, absorption is associated with H I 21-cm emission. The Ca II (Na I) column density distribution function follows a power-law with a slope of beta approximate to -2.2 (-1.4).
 Conclusions. Our absorption-selected survey confirms our previous results that the Milky Way halo is filled with a large number of neutral gas structures whose high column density tail represents the population of common H I high-and intermediate-velocity clouds seen in 21-cm observations. We find that Na I/Ca II column density ratios in the halo absorbers are typically smaller than those in the Milky Way disc, in the gas in the Magellanic Clouds, and in damped Lyman a systems. The small ratios (prominent in particular in high-velocity components) indicate a lower level of Ca depletion onto dust grains in Milky Way halo absorbers compared to gas in discs and inner regions of galaxies.
KW  - Galaxy: halo
KW  - ISM: structure
Y1  - 2012
U6  - https://doi.org/10.1051/0004-6361/201118673
SN  - 0004-6361
VL  - 542
IS  - 2
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Bender, Stephan
A1  - Rellum, Thomas
A1  - Freitag, Christine
A1  - Resch, Franz
A1  - Rietschel, Marcella
A1  - Treutlein, Jens
A1  - Jennen-Steinmetz, Christine
A1  - Brandeis, Daniel
A1  - Banaschewski, Tobias
A1  - Laucht, Manfred
T1  - Dopamine inactivation efficacy related to functional DAT1 and COMT variants influences motor response evaluation
JF  - PLoS one
N2  - Background: Dopamine plays an important role in orienting, response anticipation and movement evaluation. Thus, we examined the influence of functional variants related to dopamine inactivation in the dopamine transporter (DAT1) and catechol-O-methyltransferase genes (COMT) on the time-course of motor processing in a contingent negative variation (CNV) task.
 Methods: 64-channel EEG recordings were obtained from 195 healthy adolescents of a community-based sample during a continuous performance task (A-X version). Early and late CNV as well as motor postimperative negative variation were assessed. Adolescents were genotyped for the COMT Val(158) Met and two DAT1 polymorphisms (variable number tandem repeats in the 3'-untranslated region and in intron 8).
 Results: The results revealed a significant interaction between COMT and DAT1, indicating that COMT exerted stronger effects on lateralized motor post-processing (centro-parietal motor postimperative negative variation) in homozygous carriers of a DAT1 haplotype increasing DAT1 expression. Source analysis showed that the time interval 500-1000 ms after the motor response was specifically affected in contrast to preceding movement anticipation and programming stages, which were not altered.
 Conclusions: Motor slow negative waves allow the genomic imaging of dopamine inactivation effects on cortical motor post-processing during response evaluation. This is the first report to point towards epistatic effects in the motor system during response evaluation, i.e. during the post-processing of an already executed movement rather than during movement programming.
Y1  - 2012
U6  - https://doi.org/10.1371/journal.pone.0037814
SN  - 1932-6203
VL  - 7
IS  - 5
PB  - PLoS
CY  - San Fransisco
ER  - 
TY  - JOUR
A1  - Bender, Stephan
A1  - Rellum, Thomas
A1  - Freitag, Christine
A1  - Resch, Franz
A1  - Rietschel, Marcella
A1  - Treutlein, Jens
A1  - Jennen-Steinmetz, Christine
A1  - Brandeis, Daniel
A1  - Banaschewski, Tobias
A1  - Laucht, Manfred
T1  - Time-Resolved influences of functional DAT1 and COMT variants on visual perception and post-processing
JF  - PLoS one
N2  - Background: Dopamine plays an important role in orienting and the regulation of selective attention to relevant stimulus characteristics. Thus, we examined the influences of functional variants related to dopamine inactivation in the dopamine transporter (DAT1) and catechol-O-methyltransferase genes (COMT) on the time-course of visual processing in a contingent negative variation (CNV) task.
 Methods: 64-channel EEG recordings were obtained from 195 healthy adolescents of a community-based sample during a continuous performance task (A-X version). Early and late CNV as well as preceding visual evoked potential components were assessed.
 Results: Significant additive main effects of DAT1 and COMT on the occipito-temporal early CNV were observed. In addition, there was a trend towards an interaction between the two polymorphisms. Source analysis showed early CNV generators in the ventral visual stream and in frontal regions. There was a strong negative correlation between occipito-temporal visual post-processing and the frontal early CNV component. The early CNV time interval 500-1000 ms after the visual cue was specifically affected while the preceding visual perception stages were not influenced.
 Conclusions: Late visual potentials allow the genomic imaging of dopamine inactivation effects on visual post-processing. The same specific time-interval has been found to be affected by DAT1 and COMT during motor post-processing but not motor preparation. We propose the hypothesis that similar dopaminergic mechanisms modulate working memory encoding in both the visual and motor and perhaps other systems.
Y1  - 2012
U6  - https://doi.org/10.1371/journal.pone.0041552
SN  - 1932-6203
VL  - 7
IS  - 7
PB  - PLoS
CY  - San Fransisco
ER  - 
TY  - JOUR
A1  - Berenstein, Igal
T1  - Distinguishing similar patterns with different underlying instabilities  Effect of advection on systems with Hopf, Turing-Hopf, and wave instabilities
JF  - Chaos : an interdisciplinary journal of nonlinear science
N2  - Systems with the same local dynamics but different types of diffusive instabilities may show the same type of patterns. In this paper, we show that under the influence of advective flow the scenario of patterns that is formed at different velocities change; therefore, we propose the use of advective flow as a tool to uncover the underlying instabilities of a reaction-diffusion system.
Y1  - 2012
U6  - https://doi.org/10.1063/1.4766591
SN  - 1054-1500
VL  - 22
IS  - 4
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Berenstein, Igal
T1  - Pattern formation in a reaction-diffusion-advection system with wave instability
JF  - Chaos : an interdisciplinary journal of nonlinear science
N2  - In this paper, we show by means of numerical simulations how new patterns can emerge in a system with wave instability when a unidirectional advective flow (plug flow) is added to the system. First, we introduce a three variable model with one activator and two inhibitors with similar kinetics to those of the Oregonator model of the Belousov-Zhabotinsky reaction. For this model, we explore the type of patterns that can be obtained without advection, and then explore the effect of different velocities of the advective flow for different patterns. We observe standing waves, and with flow there is a transition from out of phase oscillations between neighboring units to in-phase oscillations with a doubling in frequency. Also mixed and clustered states are generated at higher velocities of the advective flow. There is also a regime of "waving Turing patterns" (quasi-stationary structures that come close and separate periodically), where low advective flow is able to stabilize the stationary Turing pattern. At higher velocities, superposition and interaction of patterns are observed. For both types of patterns, at high velocities of the advective field, the known flow distributed oscillations are observed.
Y1  - 2012
U6  - https://doi.org/10.1063/1.4704809
SN  - 1054-1500
VL  - 22
IS  - 2
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Berenstein, Igal
A1  - Beta, Carsten
T1  - Flow-induced transitions in bistable systems
JF  - Physical review : E, Statistical, nonlinear and soft matter physics
N2  - We studied transitions between spatiotemporal patterns that can be induced in a spatially extended nonlinear chemical system by a unidirectional flow in combination with constant inflow concentrations. Three different scenarios were investigated. (i) Under conditions where the system exhibited two stable fixed points, the propagation direction of trigger fronts could be reversed, so that domains of the less stable fixed point invaded the system. (ii) For bistability between a stable fixed point and a limit cycle we observed that above a critical flow velocity, the unstable focus at the center of the limit cycle could be stabilized. Increasing the flow speed further, a regime of damped flow-distributed oscillations was found and, depending on the boundary values at the inflow, finally the stable fixed point dominated. Similarly, also in the case of spatiotemporal chaos (iii), the unstable steady state could be stabilized and was replaced by the stable fixed point with increasing flow velocity. We finally outline a linear stability analysis that can explain part of our findings.
Y1  - 2012
U6  - https://doi.org/10.1103/PhysRevE.86.056205
SN  - 1539-3755
VL  - 86
IS  - 5
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Berenstein, Igal
A1  - Beta, Carsten
T1  - Spatiotemporal chaos arising from standing waves in a reaction-diffusion system with cross-diffusion
JF  - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr
N2  - We show that quasi-standing wave patterns appear in the two-variable Oregonator model of the Belousov-Zhabotinsky reaction when a cross-diffusion term is added, no wave instability is required in this case. These standing waves have a frequency that is half the frequency of bulk oscillations displayed in the absence of diffusive coupling. The standing wave patterns show a dependence on the systems size. Regular standing waves can be observed for small systems, when the system size is an integer multiple of half the wavelength. For intermediate sizes, irregular patterns are observed. For large sizes, the system shows an irregular state of spatiotemporal chaos, where standing waves drift, merge, and split, and also phase slips may occur.
Y1  - 2012
U6  - https://doi.org/10.1063/1.3676577
SN  - 0021-9606
VL  - 136
IS  - 3
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Bergemann, Kay
A1  - Reich, Sebastian
T1  - An ensemble Kalman-Bucy filter for continuous data assimilation
JF  - Meteorologische Zeitschrift
N2  - The ensemble Kalman filter has emerged as a promising filter algorithm for nonlinear differential equations subject to intermittent observations. In this paper, we extend the well-known Kalman-Bucy filter for linear differential equations subject to continous observations to the ensemble setting and nonlinear differential equations. The proposed filter is called the ensemble Kalman-Bucy filter and its performance is demonstrated for a simple mechanical model (Langevin dynamics) subject to incremental observations of its velocity.
Y1  - 2012
U6  - https://doi.org/10.1127/0941-2948/2012/0307
SN  - 0941-2948
VL  - 21
IS  - 3
SP  - 213
EP  - 219
PB  - Schweizerbart
CY  - Stuttgart
ER  - 
TY  - JOUR
A1  - Berger, Frauke
A1  - Höhle, Barbara
T1  - Restrictions on addition
BT  - children’s interpretation of the focus particles auch ‘ also ’ and nur ‘ only ’ in German
JF  - Journal of child language
N2  - Children up to school age have been reported to perform poorly when interpreting sentences containing restrictive and additive focus particles by treating sentences with a focus particle in the same way as sentences without it. Careful comparisons between results of previous studies indicate that this phenomenon is less pronounced for restrictive than for additive particles. We argue that this asymmetry is an effect of the presuppositional status of the proposition triggered by the additive particle. We tested this in two experiments with German-learning three-and four-year-olds using a method that made the exploitation of the information provided by the particles highly relevant for completing the task. Three-year-olds already performed remarkably well with sentences both with auch 'also' and with nur 'only'. Thus, children can consider the presuppositional contribution of the additive particle in their sentence interpretation and can exploit the restrictive particle as a marker of exhaustivity.
Y1  - 2012
U6  - https://doi.org/10.1017/S0305000911000122
SN  - 0305-0009
VL  - 39
IS  - 2
SP  - 383
EP  - 410
PB  - Cambridge Univ. Press
CY  - New York
ER  - 
TY  - JOUR
A1  - Bergner, Andre
A1  - Frasca, M.
A1  - Sciuto, G.
A1  - Buscarino, A.
A1  - Ngamga, Eulalie Joelle
A1  - Fortuna, L.
A1  - Kurths, Jürgen
T1  - Remote synchronization in star networks
JF  - Physical review : E, Statistical, nonlinear and soft matter physics
N2  - We study phase synchronization in a network motif with a starlike structure in which the central node's (the hub's) frequency is strongly detuned against the other peripheral nodes. We find numerically and experimentally a regime of remote synchronization (RS), where the peripheral nodes form a phase synchronized cluster, while the hub remains free with its own dynamics and serves just as a transmitter for the other nodes. We explain the mechanism for this RS by the existence of a free amplitude and also show that systems with a fixed or constant amplitude, such as the classic Kuramoto phase oscillator, are not able to generate this phenomenon. Further, we derive an analytic expression which supports our explanation of the mechanism.
Y1  - 2012
U6  - https://doi.org/10.1103/PhysRevE.85.026208
SN  - 1539-3755
VL  - 85
IS  - 2
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Bernhardt, Anne
A1  - Jobe, Zane R.
A1  - Grove, Marty
A1  - Lowe, Donald R.
T1  - Palaeogeography and diachronous infill of an ancient deep-marine foreland basin, Upper Cretaceous Cerro Toro Formation, Magallanes Basin
JF  - Basin research
N2  - The details of how narrow, orogen-parallel ocean basins are filled with sediment by large axial submarine channels is important to understand because these depositional systems commonly form in through-like basins in various tectonic settings. The Magallanes foreland basin is an excellent location to study an orogen-parallel deep-marine system. Conglomerate lenses of the Upper Cretaceous Cerro Toro Formation have been previously interpreted to represent the fill of a single submarine channel (48 km wide, >100 km long) that funneled coarse detritus southward along the basin axis. This interpretation was based on lithologic correlations. New U/Pb dating of zircons from volcanic ashes and sandstones, coupled with strontium isotope stratigraphy, refine the controls on depositional ages and provenance. Results demonstrate that north-south oriented conglomerate lenses are contemporaneous within error limits (ca. 8482 Ma) supporting that they represent parts of an axial channel belt. Channel deposits 20 km west of the axial location are 8782 Ma in age. These channels are partly contemporaneous with the ones within the axial channel belt, making it likely that they represent feeders to the axial channel system. The northern Cerro Toro Formation spans a Turonian to Campanian interval (ca. 9082 Ma) whereas the formation top, 70 km to the south, is as young as ca. 76 Ma. KolmogorovSmirnoff statistical analysis on detrital zircon age distributions shows that the northern uppermost Cerro Toro Formation yields a statistically different age distribution than other samples from the same formation but shows no difference relative to the overlying Tres Pasos Formation. These results suggest the partly coeval deposition of both formations. Integration of previously acquired geochronologic and stratigraphic data with new data show a pronounced southward younging pattern in all four marine formations in the Magallanes Basin. Highly diachronous infilling may be an important depositional pattern for narrow, orogen-parallel ocean basins.
Y1  - 2012
U6  - https://doi.org/10.1111/j.1365-2117.2011.00528.x
SN  - 0950-091X
VL  - 24
IS  - 3
SP  - 269
EP  - 294
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Bernhardt, Anne
A1  - Stright, Lisa
A1  - Lowe, Donald R.
T1  - Channelized debris-flow deposits and their impact on turbidity currents: The Puchkirchen axial channel belt in the Austrian Molasse Basin
JF  - Sedimentology : the journal of the International Association of Sedimentologists
N2  - Deposits of submarine debris flows can build up substantial topography on the sea floor. The resulting sea floor morphology can strongly influence the pathways of and deposition from subsequent turbidity currents. Map views of sea floor morphology are available for parts of the modern sea floor and from high-resolution seismic-reflection data. However, these data sets usually lack lithological information. In contrast, outcrops provide cross-sectional and lateral stratigraphic details of deep-water strata with superb lithological control but provide little information on sea floor morphology. Here, a methodology is presented that extracts fundamental lithological information from sediment core and well logs with a novel calibration between core, well-logs and seismic attributes within a large submarine axial channel belt in the Tertiary Molasse foreland basin, Austria. This channel belt was the course of multiple debris-flow and turbidity current events, and the fill consists of interbedded layers deposited by both of these processes. Using the core-well-seismic calibration, three-dimensional lithofacies proportion volumes were created. These volumes enable the interpretation of the three-dimensional distribution of the important lithofacies and thus the investigation of sea floor morphology produced by debris-flow events and its impact on succeeding turbidite deposition. These results show that the distribution of debris-flow deposits follows a relatively regular pattern of levees and lobes. When subsequent high-density turbidity currents encountered this mounded debris-flow topography, they slowed and deposited a portion of their sandy high-density loads just upstream of morphological highs. Understanding the depositional patterns of debris flows is key to understanding and predicting the location and character of associated sandstone accumulations. This detailed model of the filling style and the resulting stratigraphic architecture of a debris-flow dominated deep-marine depositional system can be used as an analogue for similar modern and ancient systems.
KW  - Basin axial submarine channel
KW  - debris-flow topography
KW  - deep-marine sedimentary processes
KW  - foreland basin
KW  - lithofacies proportion modeling
KW  - Molasse Basin
KW  - multi-attribute
KW  - multi-scale (MA-MS) proportion calibration
KW  - sea floor morphology
KW  - turbidites
Y1  - 2012
U6  - https://doi.org/10.1111/j.1365-3091.2012.01334.x
SN  - 0037-0746
VL  - 59
IS  - 7
SP  - 2042
EP  - 2070
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Bettenbühl, Mario
A1  - Rusconi, Marco
A1  - Engbert, Ralf
A1  - Holschneider, Matthias
T1  - Bayesian selection of Markov Models for symbol sequences  application to microsaccadic eye movements
JF  - PLoS one
N2  - Complex biological dynamics often generate sequences of discrete events which can be described as a Markov process. The order of the underlying Markovian stochastic process is fundamental for characterizing statistical dependencies within sequences. As an example for this class of biological systems, we investigate the Markov order of sequences of microsaccadic eye movements from human observers. We calculate the integrated likelihood of a given sequence for various orders of the Markov process and use this in a Bayesian framework for statistical inference on the Markov order. Our analysis shows that data from most participants are best explained by a first-order Markov process. This is compatible with recent findings of a statistical coupling of subsequent microsaccade orientations. Our method might prove to be useful for a broad class of biological systems.
Y1  - 2012
U6  - https://doi.org/10.1371/journal.pone.0043388
SN  - 1932-6203
VL  - 7
IS  - 9
PB  - PLoS
CY  - San Fransisco
ER  - 
TY  - JOUR
A1  - Beyreuther, Moritz
A1  - Hammer, Conny
A1  - Wassermann, Joachim
A1  - Ohrnberger, Matthias
A1  - Megies, Tobias
T1  - Constructing a hidden Markov Model based earthquake detector: application to induced seismicity
JF  - Geophysical journal international
N2  - The triggering or detection of seismic events out of a continuous seismic data stream is one of the key issues of an automatic or semi-automatic seismic monitoring system. In the case of dense networks, either local or global, most of the implemented trigger algorithms are based on a large number of active stations. However, in the case of only few available stations or small events, for example, like in monitoring volcanoes or hydrothermal power plants, common triggers often show high false alarms. In such cases detection algorithms are of interest, which show reasonable performance when operating even on a single station. In this context, we apply Hidden Markov Models (HMM) which are algorithms borrowed from speech recognition. However, many pitfalls need to be avoided to apply speech recognition technology directly to earthquake detection. We show the fit of the model parameters in an innovative way. State clustering is introduced to refine the intrinsically assumed time dependency of the HMMs and we explain the effect coda has on the recognition results. The methodology is then used for the detection of anthropogenicly induced earthquakes for which we demonstrate for a period of 3.9 months of continuous data that the single station HMM earthquake detector can achieve similar detection rates as a common trigger in combination with coincidence sums over two stations. To show the general applicability of state clustering we apply the proposed method also to earthquake classification at Mt. Merapi volcano, Indonesia.
KW  - Time-series analysis
KW  - Neural networks
KW  - fuzzy logic
KW  - Seismic monitoring and test-ban treaty verification
KW  - Volcano seismology
Y1  - 2012
U6  - https://doi.org/10.1111/j.1365-246X.2012.05361.x
SN  - 0956-540X
VL  - 189
IS  - 1
SP  - 602
EP  - 610
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Bickel, Samantha L.
A1  - Tang, Kam W.
A1  - Grossart, Hans-Peter
T1  - Ciliate epibionts associated with crustacean zooplankton in German lakes - distribution, motility, and bacterivory
JF  - Frontiers in microbiology
N2  - Ciliate epibionts associated with crustacean zooplankton are widespread in aquatic systems, but their ecological roles are little known. We studied the occurrence of ciliate epibionts on crustacean zooplankton in nine German lakes with different limnological features during the summer of 2011. We also measured the detachment and re-attachment rates of the ciliates, changes in their motility, and the feeding rates of attached vs. detached ciliate epibionts. Epibionts were found in all lakes sampled except an acidic lake with large humic inputs. Epibiont prevalence was as high as 80.96% on the cladoceran Daphnia cucullata, 67.17% on the cladoceran Diaphanosoma brachyurum, and 46.67% on the calanoid copepod Eudiaptomus gracilis. Both cladoceran groups typically had less than 10 epibionts per individual, while the epibiont load on E. gracilis ranged from 1 to >30 epibionts per individual. After the death of the zooplankton host, the peritrich ciliate epibiont Epistylis sp. detached in an exponential fashion with a half-life of 5 min, and 98% detached within 30 min, leaving behind the stalks used for attachment. Immediately after detachment, the ciliates were immotile, but 62% became motile within 60 min. When a new host was present, only 27% reattached after 120 min. The average measured ingestion rate and clearance rate of Epistylis were 11,745 bacteria ciliate(-1) h(-1) and 24.33 mu l ciliate(-1) h(-1), respectively. Despite their high feeding rates, relatively low epibiont abundances were observed in the field, which suggests either diversion of energy to stalk formation, high metabolic loss by the epibionts, or high mortality among the epibiont populations.
KW  - ciliate epibionts
KW  - Epistylis
KW  - crustacean zooplankton
KW  - bacterivory
KW  - epibiont motility
Y1  - 2012
U6  - https://doi.org/10.3389/fmicb.2012.00243
SN  - 1664-302X
VL  - 3
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Bijeljac-Babic, Ranka
A1  - Serres, Josette
A1  - Höhle, Barbara
A1  - Nazzi, Thierry
T1  - Effect of bilingualism on lexical stress pattern discrimination in french-learning infants
JF  - PLoS one
N2  - Monolingual infants start learning the prosodic properties of their native language around 6 to 9 months of age, a fact marked by the development of preferences for predominant prosodic patterns and a decrease in sensitivity to non-native prosodic properties. The present study evaluates the effects of bilingual acquisition on speech perception by exploring how stress pattern perception may differ in French-learning 10-month-olds raised in bilingual as opposed to monolingual environments. Experiment 1 shows that monolinguals can discriminate stress patterns following a long familiarization to one of two patterns, but not after a short familiarization. In Experiment 2, two subgroups of bilingual infants growing up learning both French and another language (varying across infants) in which stress is used lexically were tested under the more difficult short familiarization condition: one with balanced input, and one receiving more input in the language other than French. Discrimination was clearly found for the other-language-dominant subgroup, establishing heightened sensitivity to stress pattern contrasts in these bilinguals as compared to monolinguals. However, the balanced bilinguals' performance was not better than that of monolinguals, establishing an effect of the relative balance of the language input. This pattern of results is compatible with the proposal that sensitivity to prosodic contrasts is maintained or enhanced in a bilingual population compared to a monolingual population in which these contrasts are non-native, provided that this dimension is used in one of the two languages in acquisition, and that infants receive enough input from that language.
Y1  - 2012
U6  - https://doi.org/10.1371/journal.pone.0030843
SN  - 1932-6203
VL  - 7
IS  - 2
PB  - PLoS
CY  - San Fransisco
ER  - 
TY  - JOUR
A1  - Birkhofer, Klaus
A1  - Schöning, Ingo
A1  - Alt, Fabian
A1  - Herold, Nadine
A1  - Klarner, Bernhard
A1  - Maraun, Mark
A1  - Marhan, Sven
A1  - Oelmann, Yvonne
A1  - Wubet, Tesfaye
A1  - Yurkov, Andrey
A1  - Begerow, Dominik
A1  - Berner, Doreen
A1  - Buscot, Francois
A1  - Daniel, Rolf
A1  - Diekötter, Tim
A1  - Ehnes, Roswitha B.
A1  - Erdmann, Georgia
A1  - Fischer, Christiane
A1  - Fösel, Baerbel
A1  - Groh, Janine
A1  - Gutknecht, Jessica
A1  - Kandeler, Ellen
A1  - Lang, Christa
A1  - Lohaus, Gertrud
A1  - Meyer, Annabel
A1  - Nacke, Heiko
A1  - Näther, Astrid
A1  - Overmann, Jörg
A1  - Polle, Andrea
A1  - Pollierer, Melanie M.
A1  - Scheu, Stefan
A1  - Schloter, Michael
A1  - Schulze, Ernst-Detlef
A1  - Schulze, Waltraud X.
A1  - Weinert, Jan
A1  - Weisser, Wolfgang W.
A1  - Wolters, Volkmar
A1  - Schrumpf, Marion
T1  - General relationships between abiotic soil properties and soil biota across spatial scales and different land-use types
JF  - PLoS one
N2  - Very few principles have been unraveled that explain the relationship between soil properties and soil biota across large spatial scales and different land-use types. Here, we seek these general relationships using data from 52 differently managed grassland and forest soils in three study regions spanning a latitudinal gradient in Germany. We hypothesize that, after extraction of variation that is explained by location and land-use type, soil properties still explain significant proportions of variation in the abundance and diversity of soil biota. If the relationships between predictors and soil organisms were analyzed individually for each predictor group, soil properties explained the highest amount of variation in soil biota abundance and diversity, followed by land-use type and sampling location. After extraction of variation that originated from location or land-use, abiotic soil properties explained significant amounts of variation in fungal, meso-and macrofauna, but not in yeast or bacterial biomass or diversity. Nitrate or nitrogen concentration and fungal biomass were positively related, but nitrate concentration was negatively related to the abundances of Collembola and mites and to the myriapod species richness across a range of forest and grassland soils. The species richness of earthworms was positively correlated with clay content of soils independent of sample location and land-use type. Our study indicates that after accounting for heterogeneity resulting from large scale differences among sampling locations and land-use types, soil properties still explain significant proportions of variation in fungal and soil fauna abundance or diversity. However, soil biota was also related to processes that act at larger spatial scales and bacteria or soil yeasts only showed weak relationships to soil properties. We therefore argue that more general relationships between soil properties and soil biota can only be derived from future studies that consider larger spatial scales and different land-use types.
Y1  - 2012
U6  - https://doi.org/10.1371/journal.pone.0043292
SN  - 1932-6203
VL  - 7
IS  - 8
PB  - PLoS
CY  - San Fransisco
ER  - 
TY  - JOUR
A1  - Blanchard, Gilles
A1  - Mathe, Peter
T1  - Discrepancy principle for statistical inverse problems with application to conjugate gradient iteration
JF  - Inverse problems : an international journal of inverse problems, inverse methods and computerised inversion of data
N2  - The authors discuss the use of the discrepancy principle for statistical inverse problems, when the underlying operator is of trace class. Under this assumption the discrepancy principle is well defined, however a plain use of it may occasionally fail and it will yield sub-optimal rates. Therefore, a modification of the discrepancy is introduced, which corrects both of the above deficiencies. For a variety of linear regularization schemes as well as for conjugate gradient iteration it is shown to yield order optimal a priori error bounds under general smoothness assumptions. A posteriori error control is also possible, however at a sub-optimal rate, in general. This study uses and complements previous results for bounded deterministic noise.
Y1  - 2012
U6  - https://doi.org/10.1088/0266-5611/28/11/115011
SN  - 0266-5611
VL  - 28
IS  - 11
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Blaser, Lilian
A1  - Ohrnberger, Matthias
A1  - Krüger, Frank
A1  - Scherbaum, Frank
T1  - Probabilistic tsunami threat assessment of 10 recent earthquakes offshore Sumatra
JF  - Geophysical journal international
N2  - Tsunami early warning (TEW) is a challenging task as a decision has to be made within few minutes on the basis of incomplete and error-prone data. Deterministic warning systems have difficulties in integrating and quantifying the intrinsic uncertainties. In contrast, probabilistic approaches provide a framework that handles uncertainties in a natural way. Recently, we have proposed a method using Bayesian networks (BNs) that takes into account the uncertainties of seismic source parameter estimates in TEW. In this follow-up study, the method is applied to 10 recent large earthquakes offshore Sumatra and tested for its performance. We have evaluated both the general model performance given the best knowledge we have today about the source parameters of the 10 events and the corresponding response on seismic source information evaluated in real-time. We find that the resulting site-specific warning level probabilities represent well the available tsunami wave measurements and observations. Difficulties occur in the real-time tsunami assessment if the moment magnitude estimate is severely over- or underestimated. In general, the probabilistic analysis reveals a considerably large range of uncertainties in the near-field TEW. By quantifying the uncertainties the BN analysis provides important additional information to a decision maker in a warning centre to deal with the complexity in TEW and to reason under uncertainty.
KW  - Probabilistic forecasting
KW  - Tsunamis
KW  - Early warning
KW  - Indian Ocean
Y1  - 2012
U6  - https://doi.org/10.1111/j.1365-246X.2011.05324.x
SN  - 0956-540X
VL  - 188
IS  - 3
SP  - 1273
EP  - 1284
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Blaum, Niels
A1  - Schwager, Monika
A1  - Wichmann, Matthias C.
A1  - Rossmanith, Eva
T1  - Climate induced changes in matrix suitability explain gene flow in a fragmented landscape - the effect of interannual rainfall variability
JF  - Ecography : pattern and diversity in ecology ; research papers forum
N2  - In fragmented landscapes, the survival of species and the maintenance of populations with healthy genetic structures will largely depend on movement/dispersal of organisms across matrix areas. In this article, we highlight that effects of fragmentation and climate change occur simultaneously and may enhance or mitigate each other. We systematically analyzed the effect of increasing interannual variation in rainfall on the genetic structure of two neighbouring small mammal subpopulations in a fragmented savanna landscape. The effect of interannual rainfall variation is analyzed for two contrasting scenarios that differ in mean annual rainfall and are both close to a dispersal threshold. Scenario 1 (low mean annual rainfall) lies slightly below this threshold and scenario 2 (high mean annual rainfall) slightly above, i.e. the amount of rainfall in an average rainfall year prevents dispersal in scenario 1, but promotes gene flow in scenario 2. We show that the temporal dynamics of the matrix was crucial for gene flow and the genetic structure of the neighbouring small mammal subpopulations. The most important result is that the increase in rainfall variability could both increase and decrease the genetic difference between the subpopulations in a complex pattern, depending on the scenario and on the amount of variation in rainfall. Finally, we discuss that the relevance of the matrix as temporarily suitable habitat may become a key aspect for biodiversity conservation. We conclude to incorporate temporal changes in matrix suitability in metapopulation theory since local extinctions, gene flow and re-colonization are likely to be affected in fragmented landscapes with such dynamic matrix areas.
Y1  - 2012
U6  - https://doi.org/10.1111/j.1600-0587.2011.07154.x
SN  - 0906-7590
VL  - 35
IS  - 7
SP  - 650
EP  - 660
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Blumroeder, J.
A1  - Eccard, Jana
A1  - Blaum, Niels
T1  - Behavioural flexibility in foraging mode of the spotted sand lizard (Pedioplanis l. lineoocellata) seems to buffer negative impacts of savanna degradation
JF  - Journal of arid environments
N2  - In this field experiment we investigate the impact of land use induced savanna degradation on movement behaviour of the spotted sand lizard (Pedioplanis l. lineoocellata) in the southern Kalahari. Foraging behaviour of lizards was tested in a factorial design (low vs. high prey availability) in degraded and non-degraded habitats.
 An interaction between habitat structure and prey availability affected movement behaviour. In degraded habitats with low prey availability and in non-degraded habitats with high prey availability the spotted sand lizard moved more like an active forager. In contrast, in degraded habitats with high prey availability and in non-degraded habitats with low prey availability lizards moved like sit-and-wait foragers. Interestingly, the behavioural flexibility of the spotted sand lizard seems to buffer extreme conditions and negative effects of land use impacts.
KW  - Kalahari
KW  - Land use
KW  - Movement ecology
KW  - Overgrazing
KW  - Shrub encroachment
Y1  - 2012
U6  - https://doi.org/10.1016/j.jaridenv.2011.10.005
SN  - 0140-1963
VL  - 77
IS  - 2
SP  - 149
EP  - 152
PB  - Elsevier
CY  - London
ER  - 
TY  - JOUR
A1  - Blüthgen, Nico
A1  - Dormann, Carsten F.
A1  - Prati, Daniel
A1  - Klaus, Valentin H.
A1  - Kleinebecker, Till
A1  - Hoelzel, Norbert
A1  - Alt, Fabian
A1  - Boch, Steffen
A1  - Gockel, Sonja
A1  - Hemp, Andreas
A1  - Müller, Jörg
A1  - Nieschulze, Jens
A1  - Renner, Swen C.
A1  - Schöning, Ingo
A1  - Schumacher, Uta
A1  - Socher, Stephanie A.
A1  - Wells, Konstans
A1  - Birkhofer, Klaus
A1  - Buscot, Francois
A1  - Oelmann, Yvonne
A1  - Rothenwöhrer, Christoph
A1  - Scherber, Christoph
A1  - Tscharntke, Teja
A1  - Weiner, Christiane N.
A1  - Fischer, Markus
A1  - Kalko, Elisabeth K. V.
A1  - Linsenmair, Karl Eduard
A1  - Schulze, Ernst-Detlef
A1  - Weisser, Wolfgang W.
T1  - A quantitative index of land-use intensity in grasslands integrating mowing, grazing and fertilization
JF  - Basic and applied ecology : Journal of the Gesellschaft für Ökologie
N2  - Land use is increasingly recognized as a major driver of biodiversity and ecosystem functioning in many current research projects. In grasslands, land use is often classified by categorical descriptors such as pastures versus meadows or fertilized versus unfertilized sites. However, to account for the quantitative variation of multiple land-use types in heterogeneous landscapes, a quantitative, continuous index of land-use intensity (LUI) is desirable. Here we define such a compound, additive LUI index for managed grasslands including meadows and pastures. The LUI index summarizes the standardized intensity of three components of land use, namely fertilization, mowing, and livestock grazing at each site. We examined the performance of the LUI index to predict selected response variables on up to 150 grassland sites in the Biodiversity Exploratories in three regions in Germany(Alb, Hainich, Schorlheide). We tested the average Ellenberg nitrogen indicator values of the plant community, nitrogen and phosphorus concentration in the aboveground plant biomass, plant-available phosphorus concentration in the top soil, and soil C/N ratio, and the first principle component of these five response variables.
 The LUI index significantly predicted the principal component of all five response variables, as well as some of the individual responses. Moreover, vascular plant diversity decreased significantly with LUI in two regions (Alb and Hainich).
 Inter-annual changes in management practice were pronounced from 2006 to 2008, particularly due to variation in grazing intensity. This rendered the selection of the appropriate reference year(s) an important decision for analyses of land-use effects, whereas details in the standardization of the index were of minor importance. We also tested several alternative calculations of a LUI index, but all are strongly linearly correlated to the proposed index.
 The proposed LUI index reduces the complexity of agricultural practices to a single dimension and may serve as a baseline to test how different groups of organisms and processes respond to land use. In combination with more detailed analyses, this index may help to unravel whether and how land-use intensities, associated disturbance levels or other local or regional influences drive ecological processes.
KW  - Agro-ecosystems
KW  - Biodiversity exploratories
KW  - Grassland management
KW  - Land-use impacts
KW  - Livestock density
KW  - Meadows
KW  - Nitrogen
KW  - Pastures
Y1  - 2012
U6  - https://doi.org/10.1016/j.baae.2012.04.001
SN  - 1439-1791
VL  - 13
IS  - 3
SP  - 207
EP  - 220
PB  - Elsevier
CY  - Jena
ER  - 
TY  - JOUR
A1  - Bodrova, Anna
A1  - Schmidt, Jürgen
A1  - Spahn, Frank
A1  - Brilliantov, Nikolai V.
T1  - Adhesion and collisional release of particles in dense planetary rings
JF  - Icarus : international journal of solar system studies
N2  - We propose a simple theoretical model for aggregative and fragmentative collisions in Saturn's dense rings. In this model the ring matter consists of a bimodal size distribution: large (meter sized) boulders and a population of smaller particles (tens of centimeters down to dust). The small particles can adhesively stick to the boulders and can be released as debris in binary collisions of their carriers. To quantify the adhesion force we use the JKR theory (Johnson, K., Kendall, K., Roberts, A. [1971]. Proc. R. Soc. Lond. A 324, 301-313). The rates of release and adsorption of particles are calculated, depending on material parameters, sizes, and plausible velocity dispersions of carriers and debris particles. In steady state we obtain an expression for the amount of free debris relative to the fraction still attached to the carriers. In terms of this conceptually simple model a paucity of subcentimeter particles in Saturn's rings (French, R.G., Nicholson, P.D. [2000]. Icarus 145, 502-523; Marouf, E. et al. [2008]. Abstracts for "Saturn after Cassini-Huygens" Symposium, Imperial College London, UK, July 28 to August 1, p. 113) can be understood as a consequence of the increasing strength of adhesion (relative to inertial forces) for decreasing particle size. In this case particles smaller than a certain critical radius remain tightly attached to the surfaces of larger boulders, even when the boulders collide at their typical speed. Furthermore, we find that already a mildly increased velocity dispersion of the carrier-particles may significantly enhance the fraction of free debris particles, in this way increasing the optical depth of the system.
KW  - Planetary rings
KW  - Saturn, Rings
KW  - Collisional physics
Y1  - 2012
U6  - https://doi.org/10.1016/j.icarus.2011.11.011
SN  - 0019-1035
SN  - 1090-2643
VL  - 218
IS  - 1
SP  - 60
EP  - 68
PB  - Elsevier
CY  - San Diego
ER  - 
TY  - JOUR
A1  - Boeniger, Urs
A1  - Tronicke, Jens
T1  - High-resolution GPR data analysis using extended tree-based pursuit
JF  - Journal of applied geophysics
N2  - Decomposition of geophysical signals (e.g., seismic and ground-penetrating radar data) into the time-frequency domain can provide valuable information for advanced interpretation (e.g., tuning effects) and processing (e.g., inverse Q-filtering). The quality of these subsequent processing steps is strongly related to the resolution of the selected time-frequency representation (TFR). In this study, we introduce a high-resolution spectral decomposition approach representing an extension of the recently proposed Tree-Based Pursuit (TBP) method. TBP significantly reduces the computational cost compared to the well known Matching Pursuit (MP) technique by introducing a tree structure prior to the actual matching procedure. Following the original implementation of TBP, we additionally incorporate waveforms commonly used in geophysical data processing and present an alternative approach to take phase shifts into account. Application of the proposed method to synthetic data and comparison of the results with other typically used decomposition approaches, illustrate the ability of our approach to provide decomposition results highly localized in both time and frequency. Applying our procedure to field GPR data illustrates its applicability to real data and provides examples for potential applications such as analyzing thin-bed responses and modulating the data frequency content.
KW  - Ground-penetrating radar
KW  - Tree-based pursuit
KW  - Spectral decomposition
KW  - Signal enhancement
Y1  - 2012
U6  - https://doi.org/10.1016/j.jappgeo.2011.04.006
SN  - 0926-9851
VL  - 78
IS  - 5
SP  - 44
EP  - 51
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Boit, Alice
A1  - Martinez, Neo D.
A1  - Williams, Richard J.
A1  - Gaedke, Ursula
T1  - Mechanistic theory and modelling of complex food-web dynamics in Lake Constance
JF  - Ecology letters
N2  - Mechanistic understanding of consumer-resource dynamics is critical to predicting the effects of global change on ecosystem structure, function and services. Such understanding is severely limited by mechanistic models inability to reproduce the dynamics of multiple populations interacting in the field. We surpass this limitation here by extending general consumer-resource network theory to the complex dynamics of a specific ecosystem comprised by the seasonal biomass and production patterns in a pelagic food web of a large, well-studied lake. We parameterised our allometric trophic network model of 24 guilds and 107 feeding relationships using the lakes food web structure, initial spring biomasses and body-masses. Adding activity respiration, the detrital loop, minimal abiotic forcing, prey resistance and several empirically observed rates substantially increased the model's fit to the observed seasonal dynamics and the size-abundance distribution. This process illuminates a promising approach towards improving food-web theory and dynamic models of specific habitats.
KW  - Allometric Trophic Network model
KW  - community ecology
KW  - food web
KW  - multi-trophic dynamics
KW  - seasonal plankton succession
Y1  - 2012
U6  - https://doi.org/10.1111/j.1461-0248.2012.01777.x
SN  - 1461-023X
VL  - 15
IS  - 6
SP  - 594
EP  - 602
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Bojahr, Andre
A1  - Herzog, Marc
A1  - Schick, Daniel
A1  - Vrejoiu, Ionela
A1  - Bargheer, Matias
T1  - Calibrated real-time detection of nonlinearly propagating strain waves
JF  - Physical review : B, Condensed matter and materials physics
N2  - Epitaxially grown metallic oxide transducers support the generation of ultrashort strain pulses in SrTiO3 (STO) with high amplitudes up to 0.5%. The strain amplitudes are calibrated by real-time measurements of the lattice deformation using ultrafast x-ray diffraction. We determine the speed at which the strain fronts propagate by broadband picosecond ultrasonics and conclude that, above a strain level of approx. 0.2%, the compressive and tensile strain components travel at considerably different sound velocities, indicating nonlinear wave behavior. Simulations based on an anharmonic linear-chain model are in excellent accord with the experimental findings and show how the spectrum of coherent phonon modes changes with time.
Y1  - 2012
U6  - https://doi.org/10.1103/PhysRevB.86.144306
SN  - 1098-0121
VL  - 86
IS  - 14
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Bojahr, Andre
A1  - Schick, Daniel
A1  - Märten, Lena
A1  - Herzog, Marc
A1  - Vrejoiu, Ionela
A1  - von Korff Schmising, Clemens
A1  - Milne, Chris
A1  - Johnson, Steven Lee
A1  - Bargheer, Matias
T1  - Comparing the oscillation phase in optical pump-probe spectra to ultrafast x-ray diffraction in the metal-dielectric SrRuO3/SrTiO3 superlattice
JF  - Physical review : B, Condensed matter and materials physics
N2  - We measured the ultrafast optical response of metal-dielectric superlattices by broadband all-optical pump-probe spectroscopy. The observed phase of the superlattice mode depends on the probe wavelength, making assignments of the excitation mechanism difficult. Ultrafast x-ray diffraction data reveal the true oscillation phase of the lattice which changes as a function of the excitation fluence. This result is confirmed by the fluence dependence of optical transients. We set up a linear chain model of the lattice dynamics and successfully simulated the broadband optical reflection by unit-cell resolved calculation of the strain-dependent dielectric functions of the constituting materials.
Y1  - 2012
U6  - https://doi.org/10.1103/PhysRevB.85.224302
SN  - 1098-0121
VL  - 85
IS  - 22
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Bomm, Jana
A1  - Günter, Christina
A1  - Stumpe, Joachim
T1  - Synthesis and optical characterization of thermosensitive, luminescent gold nanodots
JF  - The journal of physical chemistry : C, Nanomaterials and interfaces
N2  - A facile one-pot synthesis for preparing thermosensitive, luminescent gold nanodots with diameters of 1-2 nm is presented. The influence of the alkyl chain length of the surface ligands (alkyl thiols) on the optical properties of the gold nanodots was investigated. The synthesized gold nanodots show strong thermosensitive photoluminescence. A photoluminescence quantum yield of 16.6% was observed at room temperature, which could be improved to a value of 28.6% when cooling the gold nanodot solutions to -7 degrees C. The synthesized thermosensitive, luminescent gold nanodots are interesting candidates for optoelectronic devices, medical imaging, sensing, or security labels.
Y1  - 2012
U6  - https://doi.org/10.1021/jp206260r
SN  - 1932-7447
VL  - 116
IS  - 1
SP  - 81
EP  - 85
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Bonaventura, Klaus
A1  - Leber, Alexander W.
A1  - Sohns, Christian
A1  - Roser, Mattias
A1  - Boldt, Leif-Hendrik
A1  - Kleber, Franz X.
A1  - Haverkamp, Wilhelm
A1  - Dorenkamp, Marc
T1  - Cost-effectiveness of paclitaxel-coated balloon angioplasty and paclitaxel-eluting stent implantation for treatment of coronary in-stent restenosis in patients with stable coronary artery disease
JF  - Clinical research in cardiology : official journal of the German Cardiac Society.
N2  - Recent studies have demonstrated the safety and efficacy of drug-coated balloon (DCB) angioplasty for the treatment of coronary in-stent restenosis (ISR). The cost-effectiveness of this practice is unknown.
 A Markov state-transition decision analytic model accounting for varying procedural efficacy rates, complication rates, and cost estimates was developed to compare DCB angioplasty with drug-eluting stent (DES) placement in patients with bare-metal stent (BMS)-ISR. Data on procedural outcomes associated with both treatment strategies were derived from the literature, and the cost analysis was conducted from a health care payer perspective. Effectiveness was expressed as life-years gained.
 In the base-case analysis, initial procedure costs amounted to a,not sign3,604.14 for DCB angioplasty and to a,not sign3,309.66 for DES implantation. Over a 12-month time horizon, the DCB strategy was found to be less costly (a,not sign4,130.38 vs. a,not sign5,305.30) and slightly more effective in terms of life expectancy (0.983 vs. 0.976 years) than the DES strategy. Extensive sensitivity analyses indicated that, in comparison with DES implantation, the cost advantage of the DCB strategy was robust to clinically plausible variations in the values of key model input parameters. The variables with the greatest impact on base-case results were the duration of dual antiplatelet therapy with acetylsalicylic acid and clopidogrel after DCB angioplasty, the use of generic clopidogrel, and variations in the costs associated with the DCB device.
 DCB angioplasty is a cost-effective treatment option for coronary BMS-ISR. The higher initial costs of DCB are more than offset by later cost-savings, predominantly as a result of reduced medication costs.
KW  - Cost-effectiveness
KW  - Drug-coated balloon
KW  - Drug-eluting stent
KW  - Restenosis
KW  - Revascularization
Y1  - 2012
U6  - https://doi.org/10.1007/s00392-012-0428-2
SN  - 1861-0684
VL  - 101
IS  - 7
SP  - 573
EP  - 584
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Bookhagen, Bodo
A1  - Strecker, Manfred
T1  - Spatiotemporal trends in erosion rates across a pronounced rainfall gradient: Examples from the southern Central Andes
JF  - Earth & planetary science letters
N2  - The tectonic and climatic boundary conditions of the broken foreland and the orogen interior of the southern Central Andes of northwestern Argentina cause strong contrasts in elevation, rainfall, and surface-process regimes. The climatic gradient in this region ranges from the wet, windward eastern flanks (similar to 2 m/yr rainfall) to progressively drier western basins and ranges (similar to 0.1 m/yr) bordering the arid Altiplano-Puna Plateau. In this study, we analyze the impact of spatiotemporal climatic gradients on surface erosion: First, we present 41 new catchment-mean erosion rates derived from cosmogenic nuclide inventories to document spatial erosion patterns. Second, we re-evaluate paleoclimatic records from the Calchaquies basin (66 W, 26 S), a large intermontane basin bordered by high (> 4.5 km) mountain ranges, to demonstrate temporal variations in erosion rates associated with changing climatic boundary conditions during the late Pleistocene and Holocene. Three key observations in this region emphasize the importance of climatic parameters on the efficiency of surface processes in space and time: (1) First-order spatial patterns of erosion rates can be explained by a simple specific stream power (SSP) approach. We explicitly account for discharge by routing high-resolution, satellite derived rainfall. This is important as the steep climatic gradient results in a highly non-linear relation between drainage area and discharge. This relation indicates that erosion rates (ER) scale with ER similar to SSP1.4 on cosmogenic-nuclide time scales. (2) We identify an intrinsic channel-slope behavior in different climatic compartments. Channel slopes in dry areas (< 0.25 m/yr rainfall) are slightly steeper than in wet areas (> 0.75 m/yr) with equal drainage areas, thus compensating lower amounts of discharge with steeper slopes. (3) Erosion rates can vary by an order of magnitude between presently dry (similar to 0.05 mm/yr) and well-defined late Pleistocene humid (similar to 0.5 mm/yr) conditions within an intemontane basin. Overall, we document a strong climatic impact on erosion rates and channel slopes. We suggest that rainfall reaching areas with steeper channel slopes in the orogen interior during wetter climate periods results in intensified sediment mass transport, which is primarily responsible for maintaining the balance between surface uplift, erosion, sediment routing and transient storage in the orogen.
KW  - erosion
KW  - landscape evolution
KW  - specific stream power
KW  - cosmogenic radionuclides
KW  - paleoclimate
KW  - climate-tectonic feedback processes
Y1  - 2012
U6  - https://doi.org/10.1016/j.epsl.2012.02.005
SN  - 0012-821X
VL  - 327
IS  - 8
SP  - 97
EP  - 110
PB  - Elsevier
CY  - Amsterdam
ER  -