TY - JOUR A1 - Shaki, Samuel A1 - Fischer, Martin H. A1 - Goebel, Silke M. T1 - Direction counts A comparative study of spatially directional counting biases in cultures with different reading directions JF - Journal of experimental child psychology N2 - Western adults associate small numbers with left space and large numbers with right space. Where does this pervasive spatial-numerical association come from? In this study, we first recorded directional counting preferences in adults with different reading experiences (left to right, right to left, mixed, and illiterate) and observed a clear relationship between reading and counting directions. We then recorded directional counting preferences in pre-schoolers and elementary school children from three of these reading cultures (left to right, right to left, and mixed). Culture-specific counting biases existed before reading acquisition in children as young as 3 years and were subsequently modified by early reading experience. Together, our results suggest that both directional counting and scanning activities contribute to number-space associations. KW - Counting KW - Numerical cognition KW - Reading direction KW - Number-space association KW - Mental Number KW - Cross-cultural Y1 - 2012 U6 - https://doi.org/10.1016/j.jecp.2011.12.005 SN - 0022-0965 VL - 112 IS - 2 SP - 275 EP - 281 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Türke, Manfred A1 - Andreas, Kerstin A1 - Gossner, Martin M. A1 - Kowalski, Esther A1 - Lange, Markus A1 - Boch, Steffen A1 - Socher, Stephanie A. A1 - Müller, Jörg A1 - Prati, Daniel A1 - Fischer, Markus A1 - Meyhöfer, Rainer A1 - Weisser, Wolfgang W. T1 - Are gastropods, rather than ants, important dispersers of seeds of myrmecochorous forest herbs? JF - The American naturalist : a bi-monthly journal devoted to the advancement and correlation of the biological sciences N2 - Seed dispersal by ants (myrmecochory) is widespread, and seed adaptations to myrmecochory are common, especially in the form of fatty appendices (elaiosomes). In a recent study, slugs were identified as seed dispersers of myrmecochores in a central European beech forest. Here we used 105 beech forest sites to test whether myrmecochore presence and abundance is related to ant or gastropod abundance and whether experimentally exposed seeds are removed by gastropods. Myrmecochorous plant cover was positively related to gastropod abundance but was negatively related to ant abundance. Gastropods were responsible for most seed removal and elaiosome damage, whereas insects (and rodents) played minor roles. These gastropod effects on seeds were independent of region or forest management. We suggest that terrestrial gastropods can generally act as seed dispersers of myrmecochorous plants and even substitute myrmecochory, especially where ants are absent or uncommon. KW - myrmecochory KW - gastropodochory KW - Arion KW - slug KW - seed dispersal Y1 - 2012 U6 - https://doi.org/10.1086/663195 SN - 0003-0147 VL - 179 IS - 1 SP - 124 EP - 131 PB - Univ. of Chicago Press CY - Chicago ER - TY - JOUR A1 - Gossner, Martin M. A1 - Pasalic, Esther A1 - Lange, Markus A1 - Lange, Patricia A1 - Boch, Steffen A1 - Hessenmöller, Dominik A1 - Müller, Jörg A1 - Socher, Stephanie A. A1 - Fischer, Markus A1 - Schulze, Ernst-Detlef A1 - Weisser, Wolfgang W. T1 - Differential responses of herbivores and herbivory to management in temperate Eeuropean beech JF - PLoS one N2 - Forest management not only affects biodiversity but also might alter ecosystem processes mediated by the organisms, i.e. herbivory the removal of plant biomass by plant-eating insects and other arthropod groups. Aiming at revealing general relationships between forest management and herbivory we investigated aboveground arthropod herbivory in 105 plots dominated by European beech in three different regions in Germany in the sun-exposed canopy of mature beech trees and on beech saplings in the understorey. We separately assessed damage by different guilds of herbivores, i.e. chewing, sucking and scraping herbivores, gall-forming insects and mites, and leaf-mining insects. We asked whether herbivory differs among different forest management regimes (unmanaged, uneven-aged managed, even-aged managed) and among age-classes within even-aged forests. We further tested for consistency of relationships between regions, strata and herbivore guilds. On average, almost 80% of beech leaves showed herbivory damage, and about 6% of leaf area was consumed. Chewing damage was most common, whereas leaf sucking and scraping damage were very rare. Damage was generally greater in the canopy than in the understorey, in particular for chewing and scraping damage, and the occurrence of mines. There was little difference in herbivory among differently managed forests and the effects of management on damage differed among regions, strata and damage types. Covariates such as wood volume, tree density and plant diversity weakly influenced herbivory, and effects differed between herbivory types. We conclude that despite of the relatively low number of species attacking beech; arthropod herbivory on beech is generally high. We further conclude that responses of herbivory to forest management are multifaceted and environmental factors such as forest structure variables affecting in particular microclimatic conditions are more likely to explain the variability in herbivory among beech forest plots. Y1 - 2014 U6 - https://doi.org/10.1371/journal.pone.0104876 SN - 1932-6203 VL - 9 IS - 8 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Marcus, Tamar A1 - Boch, Steffen A1 - Durka, Walter A1 - Fischer, Markus A1 - Gossner, Martin M. A1 - Müller, Jörg A1 - Schöning, Ingo A1 - Weisser, Wolfgang W. A1 - Drees, Claudia A1 - Assmann, Thorsten T1 - Living in Heterogeneous Woodlands - Are Habitat Continuity or Quality Drivers of Genetic Variability in a Flightless Ground Beetle? JF - PLoS one N2 - Although genetic diversity is one of the key components of biodiversity, its drivers are still not fully understood. While it is known that genetic diversity is affected both by environmental parameters as well as habitat history, these factors are not often tested together. Therefore, we analyzed 14 microsatellite loci in Abax parallelepipedus, a flightless, forest dwelling ground beetle, from 88 plots in two study regions in Germany. We modeled the effects of historical and environmental variables on allelic richness, and found for one of the regions, the Schorfheide-Chorin, a significant effect of the depth of the litter layer, which is a main component of habitat quality, and of the sampling effort, which serves as an inverse proxy for local population size. For the other region, the Schwabische Alb, none of the potential drivers showed a significant effect on allelic richness. We conclude that the genetic diversity in our study species is being driven by current local population sizes via environmental variables and not by historical processes in the studied regions. This is also supported by lack of genetic differentiation between local populations sampled from ancient and from recent woodlands. We suggest that the potential effects of former fragmentation and recolonization processes have been mitigated by the large and stable local populations of Abax parallelepipedus in combination with the proximity of the ancient and recent woodlands in the studied landscapes. Y1 - 2015 U6 - https://doi.org/10.1371/journal.pone.0144217 SN - 1932-6203 VL - 10 IS - 12 PB - PLoS CY - San Fransisco ER - TY - GEN A1 - Marcus, Tamar A1 - Boch, Steffen A1 - Durka, Walter A1 - Gossner, Martin M. A1 - Müller, Jörg A1 - Schöning, Ingo A1 - Weisser, Wolfgang W. A1 - Drees, Claudia A1 - Assmann, Thorsten T1 - Living in heterogeneous woodlands BT - are habitat continuity or quality drivers of genetic variability in a flightless ground beetle? T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Abstract Although genetic diversity is one of the key components of biodiversity, its drivers are still not fully understood. While it is known that genetic diversity is affected both by environmental parameters as well as habitat history, these factors are not often tested together. Therefore, we analyzed 14 microsatellite loci in Abax parallelepipedus, a flightless, forest dwelling ground beetle, from 88 plots in two study regions in Germany. We modeled the effects of historical and environmental variables on allelic richness, and found for one of the regions, the Schorfheide-Chorin, a significant effect of the depth of the litter layer, which is a main component of habitat quality, and of the sampling effort, which serves as an inverse proxy for local population size. For the other region, the Schwabische Alb, none of the potential drivers showed a significant effect on allelic richness. We conclude that the genetic diversity in our study species is being driven by current local population sizes via environmental variables and not by historical processes in the studied regions. This is also supported by lack of genetic differentiation between local populations sampled from ancient and from recent woodlands. We suggest that the potential effects of former fragmentation and recolonization processes have been mitigated by the large and stable local populations of Abax parallelepipedus in combination with the proximity of the ancient and recent woodlands in the studied landscapes. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 508 KW - forest management intensity KW - lichen Lobaria pulmonaria KW - past land-use KW - carabid beetles KW - distribution patterns KW - environmental-factors KW - conifer plantations KW - population-genetics KW - species composition KW - plant diversity Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-408451 SN - 1866-8372 IS - 508 ER - TY - GEN A1 - Fischer, Martin H. A1 - Sixtus, Elena A1 - Göbel, Silke M. T1 - Commentary BT - a pointer about grasping numbers T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe N2 - kein Abstract vorhanden T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 420 KW - numerical cognition KW - embodied cognition KW - gestures KW - numeracy training KW - mathematical cognition Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-406260 IS - 420 ER - TY - JOUR A1 - Holz, Nathalie E. A1 - Boecker-Schlier, Regina A1 - Jennen-Steinmetz, Christine A1 - Buchmann, Arlette F. A1 - Blomeyer, Dorothea A1 - Baumeister, Sarah A1 - Plichta, Michael M. A1 - Esser, Günter A1 - Schmidt, Martin A1 - Meyer-Lindenberg, Andreas A1 - Banaschewski, Tobias A1 - Brandeis, Daniel A1 - Laucht, Manfred T1 - Positive coping styles and perigenual ACC volume: two related mechanisms for conferring resilience? JF - Frontiers in human neuroscience N2 - Stress exposure has been linked to increased rates of depression and anxiety in adults, particularly in females, and has been associated with maladaptive changes in the anterior cingulate cortex (ACC), which is an important brain structure involved in internalizing disorders. Coping styles are important mediators of the stress reaction by establishing homeostasis, and may thus confer resilience to stress-related psychopathology. Anatomical scans were acquired in 181 healthy participants at age 25 years. Positive coping styles were determined using a self-report questionnaire (German Stress Coping Questionnaire, SVF78) at age 22 years. Adult anxiety and depression symptoms were assessed at ages 22, 23 and 25 years with the Young Adult Self-Report. Information on previous internalizing diagnoses was obtained by diagnostic interview (2-19 years). Positive coping styles were associated with increased ACC volume. ACC volume and positive coping styles predicted anxiety and depression in a sex-dependent manner with increased positive coping and ACC volume being related to lower levels of psychopathology in females, but not in males. These results remained significant when controlled for previous internalizing diagnoses. These findings indicate that positive coping styles and ACC volume are two linked mechanisms, which may serve as protective factors against internalizing disorders. KW - coping styles KW - perigenual anterior cingulate cortex KW - resilience KW - anxiety disorders KW - mood disorders Y1 - 2016 U6 - https://doi.org/10.1093/scan/nsw005 SN - 1749-5016 SN - 1749-5024 VL - 11 SP - 813 EP - 820 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Garofalo, F. A1 - Foti, S. A1 - Hollender, F. A1 - Bard, Pierre-Yves A1 - Cornou, C. A1 - Cox, B. R. A1 - Ohrnberger, Matthias A1 - Sicilia, D. A1 - Asten, M. A1 - Di Giulio, G. A1 - Forbriger, T. A1 - Guillier, B. A1 - Hayashi, K. A1 - Martin, A. A1 - Matsushima, Satoru A1 - Mercerat, D. A1 - Poggi, V. A1 - Yamanaka, H. T1 - InterPACIFIC project: Comparison of invasive and non-invasive methods for seismic site characterization. Part I: Intra-comparison of surface wave methods JF - Soil Dynamics and Earthquake Engineering N2 - The main scope of the InterPACIFIC (Intercomparison of methods for site parameter and velocity profile characterization) project is to assess the reliability of in-hole and surface-wave methods, used for estimating shear wave velocity. Three test-sites with different subsurface conditions were chosen: a soft soil, a stiff soil and a rock outcrop. This paper reports the surface-wave methods results. Specifically 14 teams of expert users analysed the same experimental surface-wave datasets, consisting of both passive and active data. Each team adopted their own strategy to retrieve the dispersion curve and the shear-wave velocity profile at each site. Despite different approaches, the dispersion curves are quite in agreement with each other. Conversely, the shear-wave velocity profiles show a certain variability that increases in correspondence of major stratigraphic interfaces. This larger variability is mainly due to non-uniqueness of the solution and lateral variability. As expected, the observed variability in V-s,V-30 estimatesis small, as solution non-uniqueness plays a limited role. (C) 2015 Elsevier Ltd. All rights reserved. KW - Surface-wave methods KW - Dispersion curve KW - Inversion KW - V-s,V-30 KW - Site characterization KW - MASW KW - Microtremors KW - Rayleigh waves KW - Geophysical methods Y1 - 2016 U6 - https://doi.org/10.1016/j.soildyn.2015.12.010 SN - 0267-7261 SN - 1879-341X VL - 82 SP - 222 EP - 240 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Holz, Nathalie A1 - Boecker-Schlier, Regina A1 - Buchmann, Arlette F. A1 - Blomeyer, Dorothea A1 - Baumeister, Sarah A1 - Hohmann, Sarah A1 - Jennen-Steinmetz, Christine A1 - Wolf, Isabella A1 - Rietschel, Marcella A1 - Witt, Stephanie H. A1 - Plichta, Michael M. A1 - Meyer-Lindenberg, Andreas A1 - Schmidt, Martin H. A1 - Esser, Günter A1 - Banaschewski, Tobias A1 - Brandeis, Daniel A1 - Laucht, Manfred T1 - Evidence for a Sex-Dependent MAOAx Childhood Stress Interaction in the Neural Circuitry of Aggression JF - Cerebral cortex N2 - Converging evidence emphasizes the role of an interaction between monoamine oxidase A (MAOA) genotype, environmental adversity, and sex in the pathophysiology of aggression. The present study aimed to clarify the impact of this interaction on neural activity in aggression-related brain systems. Functional magnetic resonance imaging was performed in 125 healthy adults from a high-risk community sample followed since birth. DNA was genotyped for the MAOA-VNTR (variable number of tandem repeats). Exposure to childhood life stress (CLS) between the ages of 4 and 11 years was assessed using a standardized parent interview, aggression by the Youth/Young Adult Self-Report between the ages of 15 and 25 years, and the VIRA-R (Vragenlijst Instrumentele En Reactieve Agressie) at the age of 15 years. Significant interactions were obtained between MAOA genotype, CLS, and sex relating to amygdala, hippocampus, and anterior cingulate cortex (ACC) response, respectively. Activity in the amygdala and hippocampus during emotional face-matching increased with the level of CLS in male MAOA-L, while decreasing in male MAOA-H, with the reverse pattern present in females. Findings in the opposite direction in the ACC during a flanker NoGo task suggested that increased emotional activity coincided with decreased inhibitory control. Moreover, increasing amygdala activity was associated with higher Y(A)SR aggression in male MAOA-L and female MAOA-H carriers. Likewise, a significant association between amygdala activity and reactive aggression was detected in female MAOA-H carriers. The results point to a moderating role of sex in the MAOAx CLS interaction for intermediate phenotypes of emotional and inhibitory processing, suggesting a possible mechanism in conferring susceptibility to violence-related disorders. KW - aggression KW - amygdala KW - fMRI KW - life stress KW - MAOA Y1 - 2016 U6 - https://doi.org/10.1093/cercor/bhu249 SN - 1047-3211 SN - 1460-2199 VL - 26 SP - 904 EP - 914 PB - Oxford Univ. Press CY - Cary ER - TY - JOUR A1 - Muino, Jose M. A1 - de Bruijn, Suzanne A1 - Pajoro, Alice A1 - Geuten, Koen A1 - Vingron, Martin A1 - Angenent, Gerco C. A1 - Kaufmann, Kerstin T1 - Evolution of DNA-Binding Sites of a Floral Master Regulatory Transcription Factor JF - Molecular biology and evolution N2 - Flower development is controlled by the action of key regulatory transcription factors of the MADS-domain family. The function of these factors appears to be highly conserved among species based on mutant phenotypes. However, the conservation of their downstream processes is much less well understood, mostly because the evolutionary turnover and variation of their DNA-binding sites (BSs) among plant species have not yet been experimentally determined. Here, we performed comparative ChIP (chromatin immunoprecipitation)-seq experiments of the MADS-domain transcription factor SEPALLATA3 (SEP3) in two closely related Arabidopsis species: Arabidopsis thaliana and A. lyrata which have very similar floral organ morphology. We found that BS conservation is associated with DNA sequence conservation, the presence of the CArG-box BS motif and on the relative position of the BS to its potential target gene. Differences in genome size and structure can explain that SEP3 BSs in A. lyrata can be located more distantly to their potential target genes than their counterparts in A. thaliana. In A. lyrata, we identified transposition as a mechanism to generate novel SEP3 binding locations in the genome. Comparative gene expression analysis shows that the loss/gain of BSs is associated with a change in gene expression. In summary, this study investigates the evolutionary dynamics of DNA BSs of a floral key-regulatory transcription factor and explores factors affecting this phenomenon. KW - MADS-domain transcription factor KW - cis-regulatory evolution KW - plant development Y1 - 2016 U6 - https://doi.org/10.1093/molbev/msv210 SN - 0737-4038 SN - 1537-1719 VL - 33 SP - 185 EP - 200 PB - Oxford Univ. Press CY - Oxford ER - TY - INPR A1 - Fischer, Martin H. A1 - Sixtus, Elena A1 - Göbel, Silke M. T1 - Commentary: A pointer about grasping numbers T2 - Frontiers in psychology KW - numerical cognition KW - embodied cognition KW - gestures KW - numeracy training KW - mathematical cognition Y1 - 2015 U6 - https://doi.org/10.3389/fpsyg.2015.00227 VL - 6 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Holz, Nathalie E. A1 - Boecker-Schlier, Regina A1 - Hohm, Erika A1 - Zohsel, Katrin A1 - Buchmann, Arlette F. A1 - Blomeyer, Dorothea A1 - Jennen-Steinmetz, Christine A1 - Baumeister, Sarah A1 - Hohmann, Sarah A1 - Wolf, Isabella A1 - Plichta, Michael M. A1 - Esser, Günter A1 - Schmidt, Martin A1 - Meyer-Lindenberg, Andreas A1 - Banaschewski, Tobias A1 - Brandeis, Daniel A1 - Laucht, Manfred T1 - The Long-Term Impact of Early Life Poverty on Orbitofrontal Cortex Volume in Adulthood: Results from a Prospective Study Over 25 Years JF - Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology N2 - Converging evidence has highlighted the association between poverty and conduct disorder (CD) without specifying neurobiological pathways. Neuroimaging research has emphasized structural and functional alterations in the orbitofrontal cortex (OFC) as one key mechanism underlying this disorder. The present study aimed to clarify the long-term influence of early poverty on OFC volume and its association with CD symptoms in healthy participants of an epidemiological cohort study followed since birth. At age 25 years, voxel-based morphometry was applied to study brain volume differences. Poverty (0 = non-exposed (N = 134), I = exposed (N = 33)) and smoking during pregnancy were determined using a standardized parent interview, and information on maternal responsiveness was derived from videotaped mother infant interactions at the age of 3 months. CD symptoms were assessed by diagnostic interview from 8 to 19 years of age. Information on life stress was acquired at each assessment and childhood maltreatment was measured using retrospective self-report at the age of 23 years. Analyses were adjusted for sex, parental psychopathology and delinquency, obstetric adversity, parental education, and current poverty. Individuals exposed to early life poverty exhibited a lower OFC volume. Moreover, we replicated previous findings of increased CD symptoms as a consequence of childhood poverty. This effect proved statistically mediated by OFC volume and exposure to life stress and smoking during pregnancy, but not by childhood maltreatment and maternal responsiveness. These findings underline the importance of studying the impact of early life adversity on brain alterations and highlight the need for programs to decrease income-related disparities. Y1 - 2015 U6 - https://doi.org/10.1038/npp.2014.277 SN - 0893-133X SN - 1740-634X VL - 40 IS - 4 SP - 996 EP - 1004 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Bahrke, Sven A1 - Einarsson, Jon M. A1 - Gislason, Johannes A1 - Haebel, Sophie A1 - Letzel, Matthias C. A1 - Peter-Katalinic, Jasna A1 - Peter, Martin G. T1 - Sequence analysis of chitooligosaccharides by matrix-assisted laser desorption ionization postsource decay mass spectrometry N2 - Oligosaccharides composed of 2-acetamido-2-deoxy-D-glucopyranose (GlcNAc) and/or 2-amino-2-deoxy-D- glucopyranose (GlcN) were prepd. by chem. degrdn. of chitin or chitosan and sepd. by gel permeation chromatog. Oligosaccharides obtained after enzymic hydrolysis of chitosan [FA 0.19] with a fungal chitinase were derivatized by reductive amination with 2-aminoacridone and sequenced by matrix-assisted laser desorption ionization time-of-flight postsource decay (PSD) mass spectrometry (MS). The sequence of a trimer, D1A2, was established as D-A-A. The compn. of a hexamer D3A3 was .apprx.65% D-A-D-D-A-A and 35% D-D-A-D-A-A. The PSD MS of a nonamer D5A4-amac revealed four isobaric species D-X-Y-D-X-Y-D-A-A, where A is GlcNAc, D is GlcN, and X and Y (X ¹ Y) are mutually either D or A. This structure motif was also obsd. in a dodecamer D7A5 which was composed of eight isobaric sequences of the general formula (D-X-Y)3- D-A-A. Y1 - 2002 ER - TY - JOUR A1 - Houston, Douglas R. A1 - Shiomi, Kazuro A1 - Arai, Noriko A1 - Omura, Satoshi A1 - Peter, Martin G. A1 - Turberg, Andreas A1 - Synstad, Bjoenar A1 - Eijsink, Vincent G. H. A1 - Van Aalten, Daan M. F. T1 - High-resolution structures of a chitinase complexed with natural product cyclopentapeptide inhibitors : mimicry of carbohydrate substrate N2 - Over the past years, family 18 chitinases have been validated as potential targets for the design of drugs against human pathogens that contain or interact with chitin during their normal life cycles. Thus far, only one potent chitinase inhibitor has been described in detail, the pseudotrisaccharide allosamidin. Recently, however, two potent natural-product cyclopentapeptide chitinase inhibitors, argifin and argadin, were reported. Here, we describe high- resoln. crystal structures that reveal the details of the interactions of these cyclopeptides with a family 18 chitinase. The structures are examples of complexes of a carbohydrate-processing enzyme with high-affinity peptide-based inhibitors and show in detail how the peptide backbone and side chains mimic the interactions of the enzyme with chitooligosaccharides. Together with enzymol. characterization, the structures explain why argadin shows an order of magnitude stronger inhibition than allosamidin, whereas argifin shows weaker inhibition. The peptides bind to the chitinase in remarkably different ways, which may explain the differences in inhibition consts. The two complexes provide a basis for structure-based design of potent chitinase inhibitors, accessible by std. peptide chem. Y1 - 2002 ER - TY - JOUR A1 - van Aalten, Daan M. F. A1 - Komander, David A1 - Synstad, Bjoenar A1 - Gaseidnes, Sigrid A1 - Peter, Martin G. A1 - Eijsink, Vincent G. H. T1 - Structural Insights into the catalytic mechanism of a family 18 exochitinase N2 - Chitinase B (ChiB) from Serratia marcescens is a family 18 exochitinase whose catalytic domain has a TIM-barrel fold with a tunnel-shaped active site. We have solved structures of three ChiB complexes that reveal details of substrate binding, substrateassisted catalysis, and product displacement. The structure of an inactive ChiB mutant (E144Q) complexed with a pentameric substrate (binding in subsites 22 to 13) shows closure of the ''roof'' of the active site tunnel. It also shows that the sugar in the 21 position is distorted to a boat conformation, thus providing structural evidence in support of a previously proposed catalytic mechanism. The structures of the active enzyme complexed to Allosamidin (an analogue of a proposed reaction intermediate) and of the active enzyme soaked with pentameric substrate show events after cleavage of the glycosidic bond. The latter structure shows reopening of the roof of the active site tunnel and enzyme-assisted product displacement in the 11 and 12 sites, allowing a water molecule to approach the reaction center. Catalysis is accompanied by correlated structural changes in the core of the TIM barrel that involve conserved polar residues whose functions were hitherto unknown. These changes simultaneously contribute to stabilization of the reaction intermediate and alternation of the pKa of the catalytic acid during the catalytic cycle. Y1 - 2002 ER - TY - BOOK A1 - Bricks, Wolfgang A1 - Bütow, Heike A1 - Bütow, Martin A1 - Herzig, Reinhard A1 - Morgeneyer, Frank A1 - Untisz, M. T1 - Seydlitz Geographie 10 : Arbeitsheft, Gymnasium Sachsen Y1 - 2000 SN - 3-507-52529-1 PB - Schroedel CY - Hannover ER - TY - JOUR A1 - Altenbach, Alexander V. A1 - Pflaum, U. A1 - Scheibel, Thomas R. A1 - Thies, A. A1 - Timm, M. A1 - Trauth, Martin H. T1 - Scaling percentages of benthic forminifera with flux rates of organic carbon Y1 - 1999 ER - TY - JOUR A1 - Laucht, Manfred A1 - Gerold, M. A1 - Esser, Günter A1 - Schmidt, Martin H. T1 - Strukturmodelle der Genese psychischer Störungen in der Kindheit : Ergebnisse einer prospektiven Studie von der Geburt bis zum Schulalter Y1 - 1999 ER - TY - GEN A1 - Mudd, Simon M. A1 - Clubb, Fiona J. A1 - Gailleton, Boris A1 - Hurst, Martin D. T1 - How concave are river channels? T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - For over a century, geomorphologists have attempted to unravel information about landscape evolution, and processes that drive it, using river profiles. Many studies have combined new topographic datasets with theoretical models of channel incision to infer erosion rates, identify rock types with different resistance to erosion, and detect potential regions of tectonic activity. The most common metric used to analyse river profile geometry is channel steepness, or k(s). However, the calculation of channel steepness requires the normalisation of channel gradient by drainage area. This normalisation requires a power law exponent that is referred to as the channel concavity index. Despite the concavity index being crucial in determining channel steepness, it is challenging to constrain. In this contribution, we compare both slope-area methods for calculating the concavity index and methods based on integrating drainage area along the length of the channel, using so-called "chi" (chi) analysis. We present a new chi-based method which directly compares chi values of tributary nodes to those on the main stem; this method allows us to constrain the concavity index in transient landscapes without assuming a linear relationship between chi and elevation. Patterns of the concavity index have been linked to the ratio of the area and slope exponents of the stream power incision model (m/n); we therefore construct simple numerical models obeying detachment-limited stream power and test the different methods against simulations with imposed m and n. We find that chi-based methods are better than slope-area methods at reproducing imposed m/n ratios when our numerical landscapes are subject to either transient uplift or spatially varying uplift and fluvial erodibility. We also test our methods on several real landscapes, including sites with both lithological and structural heterogeneity, to provide examples of the methods' performance and limitations. These methods are made available in a new software package so that other workers can explore how the concavity index varies across diverse landscapes, with the aim to improve our understanding of the physics behind bedrock channel incision. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 718 KW - Oregon coast range KW - BE-10-derived erosion rates KW - rock-uplift rates KW - stream-power KW - longitudinal profiles KW - landscape evolution KW - incision model KW - threshold hillslopes KW - Pacific-Northwest KW - active tectonics Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-426998 SN - 1866-8372 IS - 718 ER - TY - JOUR A1 - Wernet, Philippe A1 - Leitner, T. A1 - Josefsson, Ida A1 - Mazza, T. A1 - Miedema, P. S. A1 - Schroder, H. A1 - Beye, Martin A1 - Kunnus, K. A1 - Schreck, S. A1 - Radcliffe, P. A1 - Dusterer, S. A1 - Meyer, M. A1 - Odelius, Michael A1 - Fohlisch, Alexander T1 - Communication: Direct evidence for sequential dissociation of gas-phase Fe(CO)(5) via a singlet pathway upon excitation at 266 nm JF - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr N2 - We prove the hitherto hypothesized sequential dissociation of Fe(CO)(5) in the gas phase upon photoexcitation at 266 nm via a singlet pathway with time-resolved valence and core-level photoelectron spectroscopy with an x-ray free-electron laser. Valence photoelectron spectra are used to identify free CO molecules and to determine the time constants of stepwise dissociation to Fe(CO)(4) within the temporal resolution of the experiment and further to Fe(CO)(3) within 3 ps. Fe 3p core-level photoelectron spectra directly reflect the singlet spin state of the Fe center in Fe(CO)(5), Fe(CO)(4), and Fe(CO)(3) showing that the dissociation exclusively occurs along a singlet pathway without triplet-state contribution. Our results are important for assessing intra- and intermolecular relaxation processes in the photodissociation dynamics of the prototypical Fe(CO)(5) complex in the gas phase and in solution, and they establish time-resolved core-level photoelectron spectroscopy as a powerful tool for determining the multiplicity of transition metals in photochemical reactions of coordination complexes. Published by AIP Publishing. Y1 - 2017 U6 - https://doi.org/10.1063/1.4984774 SN - 0021-9606 SN - 1089-7690 VL - 146 PB - American Institute of Physics CY - Melville ER -