TY - JOUR A1 - Rolfs, Martin A1 - Dambacher, Michael A1 - Cavanagh, Patrick T1 - Visual adaptation of the perception of causality JF - Current biology N2 - We easily recover the causal properties of visual events, enabling us to understand and predict changes in the physical world. We see a tennis racket hitting a ball and sense that it caused the ball to fly over the net; we may also have an eerie but equally compelling experience of causality if the streetlights turn on just as we slam our car's door. Both perceptual [1] and cognitive [2] processes have been proposed to explain these spontaneous inferences, but without decisive evidence one way or the other, the question remains wide open [3-8]. Here, we address this long-standing debate using visual adaptation-a powerful tool to uncover neural populations that specialize in the analysis of specific visual features [9-12]. After prolonged viewing of causal collision events called "launches" [1], subsequently viewed events were judged more often as noncausal. These negative aftereffects of exposure to collisions are spatially localized in retinotopic coordinates, the reference frame shared by the retina and visual cortex. They are not explained by adaptation to other stimulus features and reveal visual routines in retinotopic cortex that detect and adapt to cause and effect in simple collision stimuli. Y1 - 2013 U6 - https://doi.org/10.1016/j.cub.2012.12.017 SN - 0960-9822 VL - 23 IS - 3 SP - 250 EP - 254 PB - Cell Press CY - Cambridge ER - TY - JOUR A1 - Kleinpeter, Erich A1 - Koch, Andreas T1 - (Anti)aromaticity of dehydroannulenes of various ring size proved by the ring current effect in H-1 NMR spectra JF - Tetrahedron N2 - The spatial magnetic properties (Through-Space NMR Shieldings-TSNMRS) of already synthesized dehydro[n]annulenes of various ring size (from C-12 to C-20) have been computed, visualized as Isochemical Shielding Surfaces (ICSS) of various size and direction, and were examined subject to present (anti)aromaticity. For this purpose the thus quantified ring current effect of the macro cycles on proximate protons in proton NMR spectra was employed. KW - Dehydro[n]annulenes KW - (Anti)aromaticity KW - TSNMRS KW - H-1 NMR spectroscopy KW - Anisotropic effect KW - Theoretical calculations KW - ICSS Y1 - 2013 U6 - https://doi.org/10.1016/j.tet.2012.12.019 SN - 0040-4020 VL - 69 IS - 5 SP - 1481 EP - 1488 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Hoffmann, Sebastian T. A1 - Jaiser, Frank A1 - Hayer, Anna A1 - Baessler, Heinz A1 - Unger, Thomas A1 - Athanasopoulos, Stavros A1 - Neher, Dieter A1 - Koehler, Anna T1 - How Do Disorder, Reorganization, and Localization Influence the Hole Mobility in Conjugated Copolymers? JF - JOURNAL OF THE AMERICAN CHEMICAL SOCIETY N2 - In order to unravel the intricate interplay between disorder effects, molecular reorganization, and charge carrier localization, a comprehensive study was conducted on hole transport in a series of conjugated alternating phenanthrene indenofluorene copolymers. Each polymer in the series contained one further comonomer comprising monoamines, diamines, or amine-free structures, whose influence on the electronic, optical, and charge transport properties was studied. The series covered a wide range of highest occupied molecular orbital (HOMO) energies as determined by cyclovoltammetry. The mobility, inferred from time-of-flight (ToF) experiments as a function of temperature and electric field, was found to depend exponentially on the HOMO energy. Since possible origins for this effect include energetic disorder, polaronic effects, and wave function localization, the relevant parameters were determined using a range of methods. Disorder and molecular reorganization were established first by an analysis of absorption and emission measurements and second by an analysis of the ToF measurements. In addition, density functional theory calculations were carried out to determine how localized or delocalized holes on a polymer chain are and to compare calculated reorganization energies with those that have been inferred from optical spectra. In summary, we conclude that molecular reorganization has little effect on the hole mobility in this system while both disorder effects and hole localization in systems with low-lying HOMOs are predominant. In particular, as the energetic disorder is comparable for the copolymers, the absolute value of the hole mobility at room temperature is determined by the hole localization associated with the triarylamine moieties. Y1 - 2013 U6 - https://doi.org/10.1021/ja308820j SN - 0002-7863 VL - 135 IS - 5 SP - 1772 EP - 1782 PB - AMER CHEMICAL SOC CY - WASHINGTON ER - TY - JOUR A1 - Broedel, A. K. A1 - Raymond, J. A. A1 - Duman, J. G. A1 - Bier, Frank Fabian A1 - Kubick, Stefan T1 - Functional evaluation of candidate ice structuring proteins using cell-free expression systems JF - JOURNAL OF BIOTECHNOLOGY N2 - Ice structuring proteins (ISPs) protect organisms from damage or death by freezing. They depress the non-equilibrium freezing point of water and prevent recrystallization, probably by binding to the surface of ice crystals. Many ISPs have been described and it is likely that many more exist in nature that have not yet been identified. ISPs come in many forms and thus cannot be reliably identified by their structure or consensus ice-binding motifs. Recombinant protein expression is the gold standard for proving the activity of a candidate ISP. Among existing expression systems, cell-free protein expression is the simplest and gives the fastest access to the protein of interest, but selection of the appropriate cell-free expression system is crucial for functionality. Here we describe cell-free expression methods for three ISPs that differ widely in structure and glycosylation status from three organisms: a fish (Macrozoarces americanus), an insect (Dendroides canadensis) and an alga (Chlamydomonas sp. CCMP681). We use both prokaryotic and eukaryotic expression systems for the production of ISPs. An ice recrystallization inhibition assay is used to test functionality. The techniques described here should improve the success of cell-free expression of ISPs in future applications. (C) 2012 Elsevier B.V. All rights reserved. KW - Ice structuring protein KW - Antifreeze protein KW - Ice binding protein KW - Cell-free protein synthesis KW - In vitro translation Y1 - 2013 U6 - https://doi.org/10.1016/j.jbiotec.2012.11.001 SN - 0168-1656 VL - 163 IS - 3 SP - 301 EP - 310 PB - ELSEVIER SCIENCE BV CY - AMSTERDAM 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 - 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 - Dwarkadas, Vikram V. A1 - Errando, M. 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 - Gotthelf, E. V. A1 - Griffin, S. A1 - Grube, J. A1 - Gyuk, G. A1 - Hanna, D. A1 - Holder, J. A1 - Hughes, G. A1 - Humensky, T. B. A1 - Kaaret, P. A1 - Kargaltsev, O. A1 - Karlsson, N. 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, R. A1 - Nelson, T. A1 - de Bhroithe, A. O&rsquo A1 - 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 - Roberts, M. A1 - Saxon, D. B. A1 - Schroedter, M. A1 - Sembroski, G. H. A1 - Slane, P. 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 - 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. T1 - DISCOVERY OF TeV GAMMA-RAY EMISSION FROM CTA 1 BY VERITAS JF - ASTROPHYSICAL JOURNAL N2 - We report the discovery of TeV gamma-ray emission coincident with the shell-type radio supernova remnant (SNR) CTA 1 using the VERITAS gamma-ray observatory. The source, VER J0006+729, was detected as a 6.5 standard deviation excess over background and shows an extended morphology, approximated by a two-dimensional Gaussian of semimajor (semiminor) axis 0.degrees 30 (0.degrees 24) and a centroid 5’ from the Fermi gamma-ray pulsar PSR J0007+7303 and its X-ray pulsar wind nebula (PWN). The photon spectrum is well described by a power-law dN/dE = N-0(E/3 TeV)(-Gamma), with a differential spectral index of Gamma = 2.2 +/- 0.2(stat) +/- 0.3(sys), and normalization N-0 = (9.1 +/- 1.3(stat) +/- 1.7(sys)) x 10(-14) cm(-2) s(-1) TeV-1. The integral flux, F-gamma = 4.0 x 10(-12) erg cm(-2) s(-1) above 1 TeV, corresponds to 0.2% of the pulsar spin-down power at 1.4 kpc. The energetics, colocation with the SNR, and the relatively small extent of the TeV emission strongly argue for the PWN origin of the TeV photons. We consider the origin of the TeV emission in CTA 1. KW - gamma-rays: stars KW - pulsars: individual (PSR J0007+7303) KW - supernovae: individual (G119.5+10.2) KW - X-rays: individual (RX J0007.0+7303) Y1 - 2013 U6 - https://doi.org/10.1088/0004-637X/764/1/38 SN - 0004-637X VL - 764 IS - 1 PB - IOP PUBLISHING LTD CY - BRISTOL ER - TY - JOUR A1 - Meli, Mattia A1 - Auclerc, Apolline A1 - Palmqvist, Annemette A1 - Forbes, Valery E. A1 - Grimm, Volker T1 - Population-level consequences of spatially heterogeneous exposure to heavy metals in soil an individual-based model of springtails JF - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog N2 - Contamination of soil with toxic heavy metals poses a major threat to the environment and human health. Anthropogenic sources include smelting of ores, municipal wastes, fertilizers, and pesticides. In assessing soil quality and the environmental and ecological risk of contamination with heavy metals, often homogeneous contamination of the soil is assumed. However, soils are very heterogeneous environments. Consequently, both contamination and the response of soil organisms can be assumed to be heterogeneous. This might have consequences for the exposure of soil organisms and for the extrapolation of risk from the individual to the population level. Therefore, to explore how soil contamination of different spatial heterogeneity affects population dynamics of soil invertebrates, we developed a spatially explicit individual-based model of the springtail, Folsomia candida, a standard test species for ecotoxicological risk assessment. In the model, individuals were assumed to sense and avoid contaminated habitat with a certain probability that depends on contamination level. Avoidance of contaminated areas thus influenced the individuals' movement and feeding, their exposure, and in turn all other biological processes underlying population dynamics. Model rules and parameters were based on data from the literature, or were determined via pattern-oriented modelling. The model correctly predicted several patterns that were not used for model design and calibration. Simulation results showed that the ability of the individuals to detect and avoid the toxicant, combined with the presence of clean habitat patches which act as "refuges", made equilibrium population size due to toxic effects less sensitive to increases in toxicant concentration. Additionally, the level of heterogeneity among patches of soil (i.e. the difference in concentration) was important: at the same average concentration, a homogeneously contaminated scenario was the least favourable habitat, while higher levels of heterogeneity corresponded to higher population growth rate and equilibrium size. Our model can thus be used as a tool for extrapolating from short-term effects at the individual level to long-term effects at the population level under more realistic conditions. It can thus be used to develop and extrapolate from standard ecotoxicological tests in the laboratory to ecological risk assessments. KW - Avoidance KW - Folsomia candida KW - Copper KW - Heterogeneity KW - Pattern-oriented modelling KW - Soil ecology Y1 - 2013 U6 - https://doi.org/10.1016/j.ecolmodel.2012.11.010 SN - 0304-3800 VL - 250 IS - 1 SP - 338 EP - 351 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bhabak, Krishna P. A1 - Kleuser, Burkhard A1 - Huwiler, Andrea A1 - Arenz, Christoph T1 - Effective inhibition of acid and neutral ceramidases by novel B-13 and LCL-464 analogues JF - Bioorganic & medicinal chemistry : a Tetrahedron publication for the rapid dissemination of full original research papers and critical reviews on biomolecular chemistry, medicinal chemistry and related disciplines N2 - Induction of apoptosis mediated by the inhibition of ceramidases has been shown to enhance the efficacy of conventional chemotherapy in several cancer models. Among the inhibitors of ceramidases reported in the literature, B-13 is considered as a lead compound having good in vitro potency towards acid ceramidase. Furthermore, owing to the poor activity of B-13 on lysosoamal acid ceramidase in living cells, LCL-464 a modified derivative of B-13 containing a basic omega-amino group at the fatty acid was reported to have higher potency towards lysosomal acid ceramidase in living cells. In a search for more potent inhibitors of ceramidases, we have designed a series of compounds with structural modifications of B-13 and LCL-464. In this study, we show that the efficacy of B-13 in vitro as well as in intact cells can be enhanced by suitable modification of functional groups. Furthermore, a detailed SAR investigation on LCL-464 analogues revealed novel promising inhibitors of aCDase and nCDase. In cell culture studies using the breast cancer cell line MDA-MB-231, some of the newly developed compounds elevated endogenous ceramide levels and in parallel, also induced apoptotic cell death. In summary, this study shows that structural modification of the known ceramidase inhibitors B-13 and LCL-464 generates more potent ceramidase inhibitors that are active in intact cells and not only elevates the cellular ceramide levels, but also enhances cell death. KW - Sphingolipids KW - Ceramide KW - Ceramidase inhibitors KW - Structure-activity-relationship Y1 - 2013 U6 - https://doi.org/10.1016/j.bmc.2012.12.014 SN - 0968-0896 VL - 21 IS - 4 SP - 874 EP - 882 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Pieplow, Gregor A1 - Henkel, Carsten T1 - Fully covariant radiation force on a polarizable particle JF - New journal of physics : the open-access journal for physics N2 - The electromagnetic force on a polarizable particle is calculated in a covariant framework. Local equilibrium temperatures for the electromagnetic field and the particle's dipole moment are assumed, using a relativistic formulation of the fluctuation-dissipation theorem. Two examples illustrate radiative friction forces: a particle moving through a homogeneous radiation background and above a planar interface. Previous results for arbitrary relative velocities are recovered in a compact way. Y1 - 2013 U6 - https://doi.org/10.1088/1367-2630/15/2/023027 SN - 1367-2630 VL - 15 IS - 4 PB - IOP Publ. Ltd. CY - Bristol ER - TY - JOUR A1 - Sirocko, Frank A1 - Dietrich, Stephan A1 - Veres, Daniel A1 - Grootes, Pieter M. A1 - Schaber-Mohr, Katja A1 - Seelos, Klemens A1 - Nadeau, Marie-Josee A1 - Kromer, Bernd A1 - Rothacker, Leo A1 - Roehner, Marieke A1 - Krbetschek, Matthias A1 - Appleby, Peter G. A1 - Hambach, Ulrich A1 - Rolf, Christian A1 - Sudo, Masafumi A1 - Grim, Stephanie T1 - Multi-proxy dating of Holocene maar lakes and Pleistocene dry maar sediments in the Eifel, Germany JF - Quaternary science reviews : the international multidisciplinary research and review journal N2 - During the last twelve years the ELSA Project (Eifel Laminated Sediment Archive) at Mainz University has drilled a total of about 52 cores from 27 maar lakes and filled-in maar basins in the Eifel/Germany. Dating has been completed for the Holocene cores using 6 different methods (Pb-210 and Cs-137 activities, palynostratigraphy, event markers, varve counting, C-14) In general, the different methods consistently complement one another within error margins. Event correlation was used for relating typical lithological changes with historically known events such as the two major Holocene flood events at 1342 AD and ca 800 BC. Dating of MIS2-MIS3 core sections is based on greyscale tuning, radiocarbon and OSL dating, magnetostratigraphy and tephrochronology. The lithological changes in the sediment cores demonstrate a sequence of events similar to the North Atlantic rapid climate variability of the Last Glacial Cycle. The warmest of the MIS3 interstadials was GI14, when a forest with abundant spruce covered the Eifel area from 55 to 48 ka BP, i.e. during a time when also other climate archives in Europe suggested very warm conditions. The forest of this "Early Stage 3 warm phase" developed subsequently into a steppe with scattered birch and pine, and finally into a glacial desert at around 25 ka BP. Evidence for Mono Lake and Laschamp geomagnetic excursions is found in two long cores. Several large eruptions during Middle and Late Pleistocene (Ulmener Maar - 11,000 varve years BP, Laacher See - 12,900 varve years BP, Mosenberg volcanoes/Meerfelder Maar 41-45 cal ka BP, Dumpel Maar 116 ka BP, Glees Maar - 151 ka BP) produced distinct ash-layers crucial for inter-core and inter-site correlations. The oldest investigated maar of the Eifel is Ar-40/Ar-39 dated to the time older than 520 ka BP. KW - Eifel maar KW - Laminated lake sediments KW - Tuning KW - Historical events KW - C-14-derived chronology KW - Varve counting KW - Luminescence dating KW - Palynostratigraphy KW - (CS)-C-137 and Pb-210 dating KW - Palaeomagnetism KW - Tephrostratigraphy KW - Argon-Argon dating KW - GIS Y1 - 2013 U6 - https://doi.org/10.1016/j.quascirev.2012.09.011 SN - 0277-3791 VL - 62 SP - 56 EP - 76 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Gorum, Tolga A1 - van Westen, Cees J. A1 - Korup, Oliver A1 - van der Meijde, Mark A1 - Fan, Xuanmei A1 - van der Meer, Freek D. T1 - Complex rupture mechanism and topography control symmetry of mass-wasting pattern, 2010 Haiti earthquake JF - GEOMORPHOLOGY N2 - The 12 January 2010 M-w 7.0 Haiti earthquake occurred in a complex deformation zone at the boundary between the North American and Caribbean plates. Combined geodetic, geological and seismological data posited that surface deformation was driven by rupture on the Leogane blind thrust fault, while part of the rupture occurred as deep lateral slip on the Enriquillo-Plantain Garden Fault (EPGF). The earthquake triggered >4490 landslides, mainly shallow, disrupted rock falls, debris-soil falls and slides, and a few lateral spreads, over an area of similar to 2150 km(2). The regional distribution of these slope failures defies those of most similar earthquake-triggered landslide episodes reported previously. Most of the coseismic landslides did not proliferate in the hanging wall of the main rupture, but clustered instead at the junction of the blind Leogane and EPGF ruptures, where topographic relief and hillslope steepness are above average. Also, low-relief areas subjected to high coseismic uplift were prone to lesser hanging wall slope instability than previous studies would suggest. We argue that a combined effect of complex rupture dynamics and topography primarily control this previously rarely documented landslide pattern. Compared to recent thrust fault-earthquakes of similar magnitudes elsewhere, we conclude that lower static stress drop, mean fault displacement, and blind ruptures of the 2010 Haiti earthquake resulted in fewer, smaller, and more symmetrically distributed landslides than previous studies would suggest. Our findings caution against overly relying on across-the-board models of slope stability response to seismic ground shaking. (C) 2012 Elsevier B.V. All rights reserved. KW - Landslide KW - Earthquake KW - Thrust fault KW - Fault rupture dynamics KW - Topography KW - Haiti Y1 - 2013 U6 - https://doi.org/10.1016/j.geomorph.2012.11.027 SN - 0169-555X VL - 184 SP - 127 EP - 138 PB - ELSEVIER SCIENCE BV CY - AMSTERDAM ER -