TY - THES A1 - Winkelmann, Ricarda T1 - The future sea-level contribution from antartica: projections of solid ice discharge Y1 - 2012 CY - Potsdam ER - TY - JOUR A1 - Hogan, Barbara A1 - Rasche, Christoph A1 - Braun von Reinersdorff, Andrea T1 - The First View Concept introduction of industrial flow techniques into emergency medicine organization JF - European journal of emergency medicine : official journal of the European Society for Emergency Medicine N2 - The number of patients seeking treatment in emergency departments is rising, although many governments are seeking to reduce expenditure on health. Emergency departments must achieve more with the same resources or perform the same functions with fewer resources. Patients demand higher emergency clinical care quality, with low waiting times viewed as a key quality criterion by many patients. The objective of this study was to create an improved working system in emergency departments that cuts patient waiting times for first specialty physician contact. Techniques from industrial flow management were applied to the working process of an emergency department and the concept was named 'First View.' A total of 3269 patient contacts using the First View Concept during a treatment month showed statistical significance. Before introduction, a total 3230 patients in a comparative treatment month had a median waiting time before the first doctor contact of 47.6 min, a first quartile waiting time of 36.1 min, and a third quartile waiting time of 62.7 min. After introduction, 3269 patients had a median waiting time before first specialty physician contact of 11.2 min, a first quartile waiting time of 9.1 min, and a third quartile waiting time of 15.2 min. Industrial flow concepts can achieve significant improvements in emergency department workflows in countries in which sufficient numbers of specialty physicians are available. More attention to the organization of emergency department working processes is needed, especially involving lean management. KW - emergency department KW - lean management KW - organization KW - waiting times Y1 - 2012 U6 - https://doi.org/10.1097/MEJ.0b013e32834bbd93 SN - 0969-9546 VL - 19 IS - 3 SP - 136 EP - 139 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Coelho, Catarina A1 - Mahro, Martin A1 - Trincao, Jose A1 - Carvalho, Alexandra T. P. A1 - Ramos, Maria Joao A1 - Terao, Mineko A1 - Garattini, Enrico A1 - Leimkühler, Silke A1 - Romao, Maria Joao T1 - The first mammalian aldehyde oxidase crystal structure insights into substrate specificity JF - The journal of biological chemistry N2 - Aldehyde oxidases (AOXs) are homodimeric proteins belonging to the xanthine oxidase family of molybdenum-containing enzymes. Each 150-kDa monomer contains a FAD redox cofactor, two spectroscopically distinct [2Fe-2S] clusters, and a molybdenum cofactor located within the protein active site. AOXs are characterized by broad range substrate specificity, oxidizing different aldehydes and aromatic N-heterocycles. Despite increasing recognition of its role in the metabolism of drugs and xenobiotics, the physiological function of the protein is still largely unknown. We have crystallized and solved the crystal structure of mouse liver aldehyde oxidase 3 to 2.9 angstrom. This is the first mammalian AOX whose structure has been solved. The structure provides important insights into the protein active center and further evidence on the catalytic differences characterizing AOX and xanthine oxidoreductase. The mouse liver aldehyde oxidase 3 three-dimensional structure combined with kinetic, mutagenesis data, molecular docking, and molecular dynamics studies make a decisive contribution to understand the molecular basis of its rather broad substrate specificity. Y1 - 2012 U6 - https://doi.org/10.1074/jbc.M112.390419 SN - 0021-9258 VL - 287 IS - 48 SP - 40690 EP - 40702 PB - American Society for Biochemistry and Molecular Biology CY - Bethesda ER - TY - JOUR A1 - Jobst, Birgit A1 - Köppen, Eva A1 - Lindberg, Tilmann A1 - Moritz, Josephine A1 - Rhinow, Holger A1 - Meinel, Christoph T1 - The faith-factor in design thinking : creative confidence through education at the design thinking schools Potsdam and Standford? Y1 - 2012 SN - 978-3-642-31990-7 ER - TY - JOUR A1 - Zamagni, Jessica A1 - Mutti, Maria A1 - Kosir, Adrijan T1 - The evolution of mid paleocene-early eocene coral communities how to survive during rapid global warming JF - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences N2 - Today, diverse communities of zooxanthellate corals thrive, but do not build reef, under a wide range of environmental conditions. In these settings they inhabit natural bottom communities, sometimes forming patch-reefs, coral carpets and knobs. Episodes in the fossil record, characterized by limited coral-reef development but widespread occurrence of coral-bearing carbonates, may represent the fossil analogs of these non-reef building, zooxanthellate coral communities. If so, the study of these corals could have valuable implications for paleoenvironmental reconstructions. Here we focus on the evolution of early Paleogene corals as a fossil example of coral communities mainly composed by zooxanthellate corals (or likely zooxanthellate), commonly occurring within carbonate biofacies and with relatively high diversity but with a limited bioconstructional potential as testified by the reduced record of coral reefs. We correlate changes of bioconstructional potential and community compositions of these fossil corals with the main ecological/environmental conditions at that time. The early Paleogene greenhouse climate was characterized by relatively short pulses of warming with the most prominent occurring at the Paleocene-Eocene boundary (PETM event), associated with high weathering rates, nutrient fluxes, and pCO(2) levels. A synthesis of coral occurrences integrated with our data from the Adriatic Carbonate Platform (SW Slovenia) and the Minervois region (SW France), provides evidence for temporal changes in the reef-building capacity of corals associated with a shift in community composition toward forms adapted to tolerate deteriorating sea-water conditions. During the middle Paleocene coral-algal patch reefs and barrier reefs occurred from shallow-water settings, locally with reef-crest structures. A first shift can be traced from middle Paleocene to late Paleocene, with small coral-algal patch reefs and coral-bearing mounds development in shallow to intermediate water depths. In these mounds corals were highly subordinated as bioconstructors to other groups tolerant to higher levels of trophic resources (calcareous red algae, encrusting foraminifera, microbes, and sponges). A second shift occurred at the onset of the early Eocene with a further reduction of coral framework-building capacity. These coral communities mainly formed knobs in shallow-water, turbid settings associated with abundant foraminiferal deposits. We suggest that environmental conditions other than high temperature determined a combination of interrelated stressors that limited the coral-reef construction. A continuous enhancement of sediment load/nutrients combined with geochemical changes of ocean waters likely displaced corals as the main bioconstructors during the late Paleocene-early Eocene times. Nonetheless, these conditions did not affect the capacity of some corals to colonize the substrate, maintain biodiversity, and act as locally important carbonate-sediment producers, suggesting broad environmental tolerance limits of various species of corals. The implications of this study include clues as to how both ancient and modern zooxanthellate corals could respond to changing climate. KW - Zooxanthellate corals KW - Early Paleogene KW - PETM KW - Nutrients KW - Ecological competition KW - Ocean acidification Y1 - 2012 U6 - https://doi.org/10.1016/j.palaeo.2011.12.010 SN - 0031-0182 VL - 317 IS - 2 SP - 48 EP - 65 PB - Elsevier CY - Amsterdam ER - TY - THES A1 - Branding, Volker T1 - The evolution equations for Dirac-harmonic Maps T1 - Die Evolutionsgleichungen für Dirac-harmonische Abbildungen N2 - This thesis investigates the gradient flow of Dirac-harmonic maps. Dirac-harmonic maps are critical points of an energy functional that is motivated from supersymmetric field theories. The critical points of this energy functional couple the equation for harmonic maps with spinor fields. At present, many analytical properties of Dirac-harmonic maps are known, but a general existence result is still missing. In this thesis the existence question is studied using the evolution equations for a regularized version of Dirac-harmonic maps. Since the energy functional for Dirac-harmonic maps is unbounded from below the method of the gradient flow cannot be applied directly. Thus, we first of all consider a regularization prescription for Dirac-harmonic maps and then study the gradient flow. Chapter 1 gives some background material on harmonic maps/harmonic spinors and summarizes the current known results about Dirac-harmonic maps. Chapter 2 introduces the notion of Dirac-harmonic maps in detail and presents a regularization prescription for Dirac-harmonic maps. In Chapter 3 the evolution equations for regularized Dirac-harmonic maps are introduced. In addition, the evolution of certain energies is discussed. Moreover, the existence of a short-time solution to the evolution equations is established. Chapter 4 analyzes the evolution equations in the case that the domain manifold is a closed curve. Here, the existence of a smooth long-time solution is proven. Moreover, for the regularization being large enough, it is shown that the evolution equations converge to a regularized Dirac-harmonic map. Finally, it is discussed in which sense the regularization can be removed. In Chapter 5 the evolution equations are studied when the domain manifold is a closed Riemmannian spin surface. For the regularization being large enough, the existence of a global weak solution, which is smooth away from finitely many singularities is proven. It is shown that the evolution equations converge weakly to a regularized Dirac-harmonic map. In addition, it is discussed if the regularization can be removed in this case. N2 - Die vorliegende Dissertation untersucht den Gradientenfluss von Dirac-harmonischen Abbildungen. Dirac-harmonische Abbildungen sind kritische Punkte eines Energiefunktionals, welches aus supersymmetrischen Feldtheorien motiviert ist. Die kritischen Punkte dieses Energiefunktionals koppeln die Gleichung für harmonische Abbildungen mit Spinorfeldern. Viele analytische Eigenschaften von Dirac-harmonischen Abbildungen sind bereits bekannt, ein allgemeines Existenzresultat wurde aber noch nicht erzielt. Diese Dissertation untersucht das Existenzproblem, indem der Gradientenfluss von einer regularisierten Version Dirac-harmonischer Abbildungen untersucht wird. Die Methode des Gradientenflusses kann nicht direkt angewendet werden, da das Energiefunktional für Dirac-harmonische Abbildungen nach unten unbeschränkt ist. Daher wird zunächst eine Regularisierungsvorschrift für Dirac-harmonische Abbildungen eingeführt und dann der Gradientenfluss betrachtet. Kapitel 1 stellt für die Arbeit wichtige Resultate über harmonische Abbildungen/harmonische Spinoren zusammen. Außerdem werden die zur Zeit bekannten Resultate über Dirac-harmonische Abbildungen zusammengefasst. In Kapitel 2 werden Dirac-harmonische Abbildungen im Detail eingeführt, außerdem wird eine Regularisierungsvorschrift präsentiert. Kapitel 3 führt die Evolutionsgleichungen für regularisierte Dirac-harmonische Abbildungen ein. Zusätzlich wird die Evolution von verschiedenen Energien diskutiert. Schließlich wird die Existenz einer Kurzzeitlösung bewiesen. In Kapitel 4 werden die Evolutionsgleichungen für den Fall analysiert, dass die Ursprungsmannigfaltigkeit eine geschlossene Kurve ist. Die Existenz einer Langzeitlösung der Evolutionsgleichungen wird bewiesen. Es wird außerdem gezeigt, dass die Evolutionsgleichungen konvergieren, falls die Regularisierung groß genug gewählt wurde. Schließlich wird diskutiert, ob die Regularisierung wieder entfernt werden kann. Kapitel 5 schlussendlich untersucht die Evolutionsgleichungen für den Fall, dass die Ursprungsmannigfaltigkeit eine geschlossene Riemannsche Spin Fläche ist. Es wird die Existenz einer global schwachen Lösung bewiesen, welche bis auf endlich viele Singularitäten glatt ist. Die Lösung konvergiert im schwachen Sinne gegen eine regularisierte Dirac-harmonische Abbildung. Auch hier wird schließlich untersucht, ob die Regularisierung wieder entfernt werden kann. KW - Dirac-harmonische Abbildungen KW - Gradientenfluss KW - Wärmefluss KW - Spin Geometrie KW - nichtlineare partielle Differentialgleichung KW - Dirac-harmonic maps KW - Gradient flow KW - Heat Flow KW - Spin Geometry KW - nonlinear partial differential equations Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-64204 ER - TY - JOUR A1 - Brooks, Clare T1 - The EVE curriculum framework BT - developments on the second phase JF - Potsdamer geographische Praxis N2 - 1. Evaluations 2. Main changes to the curriculum Framework 3. Looking Forwards KW - Europäische Werteerziehung KW - Familie KW - Lehrevaluation KW - Studierendenaustausch KW - Unterrichtseinheiten KW - Curriculum Framework KW - European values education KW - Family KW - lesson evaluation KW - student exchange KW - teaching units KW - curriculum framework Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-66128 SN - 2194-1599 SN - 2194-1602 IS - 1 SP - 17 EP - 20 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Meyer-Sahling, Jan-Hinrik A1 - Goetz, Klaus Hermann T1 - The EU timescape : from notion to research agenda Y1 - 2012 SN - 978-0- 415-69633-3 ER - TY - BOOK ED - Goetz, Klaus Hermann ED - Meyer-Sahling, Jan-Hinrik T1 - The Eu Timescape T3 - Journal of european public policy Y1 - 2012 SN - 978-0-415-69633-3 PB - Taylor and Francis CY - Hoboken ER - TY - JOUR A1 - Hennemann, Anja T1 - The epistemic and evidential use of Spanish modal adverbs and verbs of cognitive attitude JF - Folia linguistica N2 - This article deals with Spanish modal adverbs and verbs of cognitive attitude (Capelli 2007) and their epistemic and/or evidential use. The article is based upon the hypothesis that the study of the use of these linguistic devices has to be highly context-sensitive, as it is not always (only) the sentence level that has to be looked at if one wants to find out whether a certain adverb or verb of cognitive attitude is used evidentially or epistemically. In this article, therefore, the context is used to determine which meaning aspects of an element are encoded and which are contributed by the context. The data were retrieved from the daily newspaper El Pais. Nevertheless, the present study is not a quantitative one, but rather a qualitative study. My corpus analysis indicates that it is not possible to differentiate between the linguistic categories of evidentiality and epistemic modality in every case, although it indeed is possible in the vast majority of cases. In verbs of cognitive attitude, evidentiality and epistemic modality seem to be two interwoven categories, while concerning modal adverbs it is usually possible to separate the categories and to distinguish between the different subtypes of evidentiality such as visual evidence, hearsay and inference. KW - evidentiality KW - epistemic modality KW - Spanish modal adverbs KW - Spanish verbs of cognitive attitude KW - context sensitivity Y1 - 2012 U6 - https://doi.org/10.1515/FLIN.2012.5 SN - 0165-4004 VL - 46 IS - 1 SP - 133 EP - 170 PB - De Gruyter CY - Berlin ER - TY - GEN A1 - Hennemann, Anja T1 - The epistemic and evidential use of Spanish modal adverbs and verbs of cognitive attitude T2 - Postprints der Universität Potsdam : Philosophische Reihe N2 - This article deals with Spanish modal adverbs and verbs of cognitive attitude (Capelli 2007) and their epistemic and/or evidential use. The article is based upon the hypothesis that the study of the use of these linguistic devices has to be highly context-sensitive, as it is not always (only) the sentence level that has to be looked at if one wants to find out whether a certain adverb or verb of cognitive attitude is used evidentially or epistemically. In this article, therefore, the context is used to determine which meaning aspects of an element are encoded and which are contributed by the context. The data were retrieved from the daily newspaper El País. Nevertheless, the present study is not a quantitative one, but rather a qualitative study. My corpus analysis indicates that it is not possible to differentiate between the linguistic categories of evidentiality and epistemic modality in every case, although it indeed is possible in the vast majority of cases. In verbs of cognitive attitude, evidentiality and epistemic modality seem to be two interwoven categories, while concerning modal adverbs it is usually possible to separate the categories and to distinguish between the different subtypes of evidentiality such as visual evidence, hearsay and inference. T3 - Zweitveröffentlichungen der Universität Potsdam : Philosophische Reihe - 107 KW - evidentiality KW - epistemic modality KW - Spanish modal adverbs KW - Spanish verbs of cognitive attitude KW - context sensitivity Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-93929 SN - 1866-8380 IS - 107 ER - TY - JOUR A1 - Krahé, Barbara A1 - Bieneck, Steffen T1 - The effect of music-induced mood on aggressive affect, cognition, and behavior JF - Journal of applied social psychology : devoted to applications of experimental behavioral science research to problems of society N2 - Two studies explored the role of pleasant music in buffering the adverse effects of provocation. In the first study, 111 participants listened to aversive, pleasant, or no music before receiving a provocation and completing a measure of aggressive behavior. Participants exposed to pleasant music reported more positive mood. Those in the aversive music condition reported more negative mood than did those in the no-music control condition. The more positive the music-induced mood, the less anger was experienced and aggressive behavior was shown after provocation. In Study 2 (N = 142), listening to pleasant music reduced anger following provocation, compared to aversive music and a no-music control condition. Pleasant music also increased response latencies in recognizing aggressive words after provocation. Y1 - 2012 U6 - https://doi.org/10.1111/j.1559-1816.2011.00887.x SN - 0021-9029 VL - 42 IS - 2 SP - 271 EP - 290 PB - Wiley-Blackwell CY - Hoboken ER - TY - INPR A1 - Krause, S. A1 - Munz, Matthias A1 - Tecklenburg, C. A1 - Binley, Andrew T1 - The effect of groundwater forcing on hyporheic exchange Reply to comment on 'Munz M, Krause S, Tecklenburg C, Binley A. Reducing monitoring gaps at the aquifer-river interface by modelling groundwater-surfacewater exchange flow patterns. Hydrological Processes. DOI: 10.1002/hyp.8080' T2 - Hydrological processes Y1 - 2012 U6 - https://doi.org/10.1002/hyp.9271 SN - 1099-1085 VL - 26 IS - 10 SP - 1589 EP - 1592 PB - Wiley-Blackwell CY - Hoboken ER - TY - CHAP A1 - Reschke, Antje A1 - Wolter, Martin A1 - Schöpflin, Marlene A1 - König, Niklas A1 - Mayer, Frank A1 - Baur, Heiner T1 - The effect of foot orthoses on peroneal H-reflex in treadmill walking a pilot study T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2012 SN - 0195-9131 VL - 44 SP - 943 EP - 943 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - GEN A1 - Lin, Chiao-I A1 - Khajooei, Mina A1 - Engel, Tilman A1 - Nair, Alexandra A1 - Heikkila, Mika A1 - Kaplick, Hannes A1 - Mayer, Frank T1 - The effect of chronic ankle instability on muscle activations in lower extremities T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe N2 - Background/Purpose Muscular reflex responses of the lower extremities to sudden gait disturbances are related to postural stability and injury risk. Chronic ankle instability (CAI) has shown to affect activities related to the distal leg muscles while walking. Its effects on proximal muscle activities of the leg, both for the injured- (IN) and uninjured-side (NON), remain unclear. Therefore, the aim was to compare the difference of the motor control strategy in ipsilateral and contralateral proximal joints while unperturbed walking and perturbed walking between individuals with CAI and matched controls. Materials and methods In a cross-sectional study, 13 participants with unilateral CAI and 13 controls (CON) walked on a split-belt treadmill with and without random left- and right-sided perturbations. EMG amplitudes of muscles at lower extremities were analyzed 200 ms after perturbations, 200 ms before, and 100 ms after (Post100) heel contact while walking. Onset latencies were analyzed at heel contacts and after perturbations. Statistical significance was set at alpha≤0.05 and 95% confidence intervals were applied to determine group differences. Cohen’s d effect sizes were calculated to evaluate the extent of differences. Results Participants with CAI showed increased EMG amplitudes for NON-rectus abdominus at Post100 and shorter latencies for IN-gluteus maximus after heel contact compared to CON (p<0.05). Overall, leg muscles (rectus femoris, biceps femoris, and gluteus medius) activated earlier and less bilaterally (d = 0.30–0.88) and trunk muscles (bilateral rectus abdominus and NON-erector spinae) activated earlier and more for the CAI group than CON group (d = 0.33–1.09). Conclusion Unilateral CAI alters the pattern of the motor control strategy around proximal joints bilaterally. Neuromuscular training for the muscles, which alters motor control strategy because of CAI, could be taken into consideration when planning rehabilitation for CAI. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 712 KW - Electromyography KW - Hip KW - Skeletal joints KW - Knees KW - Legs KW - Musculoskeletal injury KW - Walking KW - Ankles Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-515632 SN - 1866-8364 ER - TY - JOUR A1 - Krause, Uwe T1 - The Dutch school system JF - Potsdamer geographische Praxis KW - Europäische Werteerziehung KW - Familie KW - Lehrevaluation KW - Studierendenaustausch KW - Unterrichtseinheiten KW - Curriculum Framework KW - European values education KW - Family KW - lesson evaluation KW - student exchange KW - teaching units KW - curriculum framework Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-65828 SN - 2194-1599 SN - 2194-1602 IS - 1 SP - 67 EP - 68 PB - Universitätsverlag Potsdam CY - Potsdam 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 - Caliendo, Marco A1 - Clement, Michel A1 - Papies, Dominik A1 - Scheel-Kopeinig, Sabine T1 - The cost impact of spam filters measuring the effect of information system technologies in organizations JF - Information systems research N2 - Dealing with spam is very costly, and many organizations have tried to reduce spam-related costs by installing spam filters. Relying on modern econometric methods to reduce the selection bias of installing a spam filter, we use a unique data setting implemented at a German university to measure the costs associated with spam and the costs savings of spam filters. Our methodological framework accounts for effect heterogeneity and can be easily used to estimate the effect of other IS technologies implemented in organizations. The majority of costs stem from the time that employees spend identifying and deleting spam, amounting to an average of approximately five minutes per employee per day. Our analysis, which accounts for selection bias, finds that the installation of a spam filter reduces these costs by roughly one third. Failing to account for the selection bias would lead to a result that suggests that installing a spam filter does not reduce working time losses. However, cost savings only occur when the spam burden is high, indicating that spam filters do not necessarily reduce costs and are therefore no universal remedy. The analysis further shows that spam filters alone are a countermeasure against spam that exhibits only limited effectiveness because they only reduce costs by one third. KW - spam KW - spam filter KW - selection bias KW - propensity score matching Y1 - 2012 U6 - https://doi.org/10.1287/isre.1110.0396 SN - 1047-7047 VL - 23 IS - 3 SP - 1068 EP - 1080 PB - INFORMS CY - Hannover ER - TY - JOUR A1 - Szurlies, Michael A1 - Geluk, Mark C. A1 - Krijgsman, Wout A1 - Kurschner, Wolfram M. T1 - The continental Permian-Triassic boundary in the Netherlands implications for the geomagnetic polarity time scale JF - Earth & planetary science letters N2 - In Central and NW Europe, the transition from the Permian to the Triassic (i.e., the Zechstein-Buntsandstein boundary interval) is developed mainly in red bed facies. This continental sedimentary succession is marked by relatively high sedimentation rates providing a high temporal resolution favorable for magnetic polarity stratigraphy. Here, we present a Zechstein to Lower Buntsandstein magnetostratigraphy obtained from the c. 100 m thick Everdingen-1 core from the Netherlands. Seven magnetozones (EV1n to EV4n) and five submagnetozones (EV1n.1r to EV3r.1n) have been delineated. The Everdingen-1 magnetostratigraphy has been integrated into the well-established high-resolution Zechstein-Buntsandstein stratigraphic framework, and verifies the geomagnetic polarity record from Central Germany. This confirms the hypothesis of nearly synchronous base-level cycles within the interior of the Central European Basin. These cycles are related to solar-induced similar to 100 ka eccentricity cycles. The most distinctive feature of the Everdingen-1 magnetostratigraphy is a transition from a thin reverse to a thick dominantly normal magnetic polarity interval. This reversal predates both the terrestrial mass extinction, which is indicated by a palynofloral turnover and a major sediment provenance change at the base of the Buntsandstein, and the marine Permian-Triassic Boundary (PTB). The PTB is located within the lowermost Buntsandstein and is approximated by the last occurrence of the conchostracan Falsisca postera and a negative excursion in the carbon isotope record. According to the Buntsandstein cyclostratigraphy, the R/N reversal predates the marine end-Permian extinction event by about 0.1 Ma and the marine biostratigraphic PTB by about 0.2 Ma. The thick normal magnetozone is estimated to have lasted c. 700 ka, and roughly coincides with the main phase of Siberian Trap volcanism. KW - magnetostratigraphy KW - cyclic stratigraphy KW - wireline logs KW - Permian-Triassic boundary KW - Zechstein-Buntsandstein interval KW - The Netherlands Y1 - 2012 U6 - https://doi.org/10.1016/j.epsl.2011.11.043 SN - 0012-821X VL - 317 SP - 165 EP - 176 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Cubitt, Toby S. A1 - Eisert, Jens A1 - Wolf, Michael M. T1 - The complexity of relating quantum channels to master equations JF - Communications in mathematical physics N2 - Completely positive, trace preserving (CPT) maps and Lindblad master equations are both widely used to describe the dynamics of open quantum systems. The connection between these two descriptions is a classic topic in mathematical physics. One direction was solved by the now famous result due to Lindblad, Kossakowski, Gorini and Sudarshan, who gave a complete characterisation of the master equations that generate completely positive semi-groups. However, the other direction has remained open: given a CPT map, is there a Lindblad master equation that generates it (and if so, can we find its form)? This is sometimes known as the Markovianity problem. Physically, it is asking how one can deduce underlying physical processes from experimental observations. We give a complexity theoretic answer to this problem: it is NP-hard. We also give an explicit algorithm that reduces the problem to integer semi-definite programming, a well-known NP problem. Together, these results imply that resolving the question of which CPT maps can be generated by master equations is tantamount to solving P = NP: any efficiently computable criterion for Markovianity would imply P = NP; whereas a proof that P = NP would imply that our algorithm already gives an efficiently computable criterion. Thus, unless P does equal NP, there cannot exist any simple criterion for determining when a CPT map has a master equation description. However, we also show that if the system dimension is fixed (relevant for current quantum process tomography experiments), then our algorithm scales efficiently in the required precision, allowing an underlying Lindblad master equation to be determined efficiently from even a single snapshot in this case. Our work also leads to similar complexity-theoretic answers to a related long-standing open problem in probability theory. Y1 - 2012 U6 - https://doi.org/10.1007/s00220-011-1402-y SN - 0010-3616 VL - 310 IS - 2 SP - 383 EP - 418 PB - Springer CY - New York ER - TY - JOUR A1 - Wolf, Hans-Georg T1 - The cognitive sociolinguistic approach to the lexicon of Cameroon English and other world englishes Y1 - 2012 SN - 978-1-61451-248-6 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 - GEN A1 - Adam, Jos J. A1 - Bovend'Eerdt, Thamar J. H. A1 - Dooren, Fleur E. P. van A1 - Fischer, Martin H. A1 - Pratt, Jay T1 - The closer the better BT - hand proximity dynamically affects letter recognition accuracy T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 607 KW - perception and action Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-432963 SN - 1866-8364 IS - 607 SP - 1533 EP - 1538 ER - TY - JOUR A1 - Wirth, Jonas A1 - Saalfrank, Peter T1 - The chemistry of water on alpha-alumina kinetics and nuclear quantum effects from first principles JF - The journal of physical chemistry : C, Nanomaterials and interfaces N2 - Water adsorption on an alumina (alpha-Al2O3) surface is studied here from first principles using periodic density functional theory in the generalized gradient approximation. Two different coverage regimes, low and high, are considered. For the low-coverage regime (with a coverage of 1/4 with respect to the number of coordinatively unsaturated Al sites), possible reactions at the surface such as dissociation, rotation, and diffusion of water and its fragments are investigated, using first principles thermodynamics and kinetics. A microkinetic model is set up with rates calculated from Eyring's transition state theory in order to cover a wide range of time scales. Special emphasis of this study is on the magnitude of quantum effects and on anharmonic corrections, particularly for reactions and dynamics. These have often been neglected in the past for water/alumina systems but can influence the system. This is particularly true for processes involving hydrogen atoms, where, for example, tunneling corrections to reaction rates are found to be important even at room temperature. For a higher-coverage regime (with a coverage of 2 ML), hydrogen dynamics becomes even more complex and is characterized, e.g., by concerted atom motion, strong anharmonicity, and delocalization. In this regime, classical molecular dynamics becomes questionable as well as quantum mechanical treatments based on the harmonic approximation. Y1 - 2012 U6 - https://doi.org/10.1021/jp310234h SN - 1932-7447 VL - 116 IS - 51 SP - 26829 EP - 26840 PB - American Chemical Society CY - Washington ER - TY - THES A1 - Gassner, Alexandra Carina T1 - The character of the core-mantle boundary : a systematic study using PcP N2 - Assuming that liquid iron alloy from the outer core interacts with the solid silicate-rich lower mantle the influence on the core-mantle reflected phase PcP is studied. If the core-mantle boundary is not a sharp discontinuity, this becomes apparent in the waveform and amplitude of PcP. Iron-silicate mixing would lead to regions of partial melting with higher density which in turn reduces the velocity of seismic waves. On the basis of the calculation and interpretation of short-period synthetic seismograms, using the reflectivity and Gauss Beam method, a model space is evaluated for these ultra-low velocity zones (ULVZs). The aim of this thesis is to analyse the behaviour of PcP between 10° and 40° source distance for such models using different velocity and density configurations. Furthermore, the resolution limits of seismic data are discussed. The influence of the assumed layer thickness, dominant source frequency and ULVZ topography are analysed. The Gräfenberg and NORSAR arrays are then used to investigate PcP from deep earthquakes and nuclear explosions. The seismic resolution of an ULVZ is limited both for velocity and density contrasts and layer thicknesses. Even a very thin global core-mantle transition zone (CMTZ), rather than a discrete boundary and also with strong impedance contrasts, seems possible: If no precursor is observable but the PcP_model /PcP_smooth amplitude reduction amounts to more than 10%, a very thin ULVZ of 5 km with a first-order discontinuity may exist. Otherwise, if amplitude reductions of less than 10% are obtained, this could indicate either a moderate, thin ULVZ or a gradient mantle-side CMTZ. Synthetic computations reveal notable amplitude variations as function of the distance and the impedance contrasts. Thereby a primary density effect in the very steep-angle range and a pronounced velocity dependency in the wide-angle region can be predicted. In view of the modelled findings, there is evidence for a 10 to 13.5 km thick ULVZ 600 km south-eastern of Moscow with a NW-SE extension of about 450 km. Here a single specific assumption about the velocity and density anomaly is not possible. This is in agreement with the synthetic results in which several models create similar amplitude-waveform characteristics. For example, a ULVZ model with contrasts of -5% VP , -15% VS and +5% density explain the measured PcP amplitudes. Moreover, below SW Finland and NNW of the Caspian Sea a CMB topography can be assumed. The amplitude measurements indicate a wavelength of 200 km and a height of 1 km topography, previously also shown in the study by Kampfmann and Müller (1989). Better constraints might be provided by a joined analysis of seismological data, mineralogical experiments and geodynamic modelling. N2 - Unter der Annahme, dass flüssiges Eisen aus dem äußeren Erdkern mit dem festen, silikat-reichen Unteren Mantel reagiert, wird eine Einflussnahme auf die Kern-Mantel Reflexionsphase PcP erwartet. Ist die Kern-Mantel Grenze aufgeweicht, und nicht wie bislang angenommen ein diskreter Übergang, so zeichnet sich dies in der Wellenform und Amplitude von PcP ab. Die Interaktion mit Eisen führt zu teilweise aufgeschmolzenen Bereichen höherer Dichte, welche die seismischen Wellengeschwindigkeiten herabsetzen. Basierend auf den Berechnungen von kurzperiodischen synthetischen Seismogrammen, mittels der Reflektivitäts- und Gauss Beam Methode, soll ein möglicher Modellraum dieser Niedriggeschwindigkeitszonen ermittelt werden. Das Ziel dieser Arbeit ist es das Verhalten von PcP im Distanzbereich von 10° bis 40° unter dem Einfluss dieser Modelle mit diversen Geschwindigkeits- und Dichtekontrasten zu untersuchen. Ferner wird das Auflösungsvermögen hinsichtlich seismischer Daten diskutiert. Entscheidende Parameter wie Anomaliedicke, Quellfrequenz und Topographie werden hierbei analysiert. Tiefe Erdbeben und Kernexplosionen, die sich im entsprechenden Entfernungsbereich zum Gräfenberg und NORSAR Array befinden, werden anschließend im Hinblick auf PcP ausgewertet. Das seismische Auflösungsvermögen von Niedriggeschwindigkeitszonen ist stark begrenzt sowohl in Bezug auf Geschwindigkeits- und Dichtekontraste als auch hinsichtlich der Mächtigkeit. Es besteht sogar die Möglichkeit einer dünnen, globalen Kern-Mantel Übergangszone, selbst mit großen Impedanzkontrasten, ohne dass dies mit seismologischen Methoden detektiert werden könnte: Wird kein precursor zu PcP beobachtet aber das PcPmodel /PcPsmooth Amplitudenverhältnis zeigt gleichzeitig eine Reduktion von mehr als 10%, dann könnte eine sehr dünne Niedriggeschwindigkeitszone von ca. 5 km Mächtigkeit und einer Diskontinuität erster Ordnung vorliegen. Andererseits, ist PcP um weniger als 10% reduziert, könnte dies entweder auf eine dünne, moderate Niedriggeschwindigkeitszone oder einen graduellen Kern-Mantel Übergang hindeuten. Die synthetischen Berechnungen ergeben starke Amplitudenvariationen als Funktion der Distanz, welche auf den Impedanzkontrast zurückzuführen sind. Dabei ergibt sich ein primärer Dichteeffekt im extremen Steilwinkelbereich und ein maßgeblicher Geschwindigkeitseinfluss im Weitwinkelbereich. Im Hinblick auf die modellierten Resultate lässt sich eine 10 - 13.5 km mächtige Niedriggeschwindigkeitszone 600 km südöstlich von Moskau mit einer NW-SE Ausdehnung von mindestens 450 km folgern, wobei eine exakte Aussage über Geschwindigkeiten und Dichte nicht möglich ist. Dies ist im Konsens mit den synthetischen Berechnungen, wonach viele unterschiedliche Modelle ähnliche Amplituden- und Wellenformcharakteristiken erzeugen. Zum Beispiel erklärt ein Modell mit Kontrasten von -5% VP , -15% VS and +5% Dichte die gemessenen PcP Amplituden. Darüber hinaus können unterhalb des südwestlichen Finnlands und nord-nordwestlich des Kaspischen Meeres Undulationen an der Kern-Mantel Grenze selbst vermutet werden. Unter Berücksichtigung früherer Studien, z. B. von Kampfmann and Müller (1989), deuten die Messergebnisse auf eine laterale Topographie von 200 km und eine Höhe von 1 km hin. Eine Eingrenzung der potentiellen Anomaliemodelle kann nur durch eine gemeinsame Auswertung mit mineralogischen Experimenten und geodynamischen Modellierungen erfolgen. KW - Kern-Mantel Grenze KW - Seismologie KW - Ultra-Niedriggeschwindigkeitszonen KW - Steilwinkel-Analyse von PcP KW - Tiefbeben und Kernexplosionen KW - core-mantle boundary KW - seismology KW - ultra-low velocity zones KW - steep-angle analysis of PcP KW - deep earthquakes and nuclear explosions Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-63590 ER - TY - JOUR A1 - Herbert, Beate M. A1 - Pollatos, Olga T1 - The body in the mind On the relationship between interoception and embodiment JF - Topics in cognitive science N2 - The processing, representation, and perception of bodily signals (interoception) plays an important role for human behavior. Theories of embodied cognition hold that higher cognitive processes operate on perceptual symbols and that concept use involves reactivations of the sensory-motor states that occur during experience with the world. Similarly, activation of interoceptive representations and meta-representations of bodily signals supporting interoceptive awareness are profoundly associated with emotional experience and cognitive functions. This article gives an overview over present findings and models on interoception and mechanisms of embodiment and highlights its relevance for disorders that are suggested to represent a translation deficit of bodily states into subjective feelings and self-awareness. KW - Interoception KW - Interoceptive awareness KW - Emotions KW - Time perception KW - Disturbances of embodiment KW - Alexithymia KW - Eating disorder KW - Self Y1 - 2012 U6 - https://doi.org/10.1111/j.1756-8765.2012.01189.x SN - 1756-8757 VL - 4 IS - 4 SP - 692 EP - 704 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Baumann, Otto A1 - Walz, Bernd T1 - The blowfly salivary gland - A model system for analyzing the regulation of plasma membrane V-ATPase JF - Journal of insect physiology N2 - Vacuolar H+-ATPases (V-ATPases) are heteromultimeric proteins that use the energy of ATP hydrolysis for the electrogenic transport of protons across membranes. They are common to all eukaryotic cells and are located in the plasma membrane or in membranes of acid organelles. In many insect epithelia, V-ATPase molecules reside in large numbers in the apical plasma membrane and create an electrochemical proton gradient that is used for the acidification or alkalinization of the extracellular space, the secretion or reabsorption of ions and fluids, the import of nutrients, and diverse other cellular activities. Here, we summarize our results on the functions and regulation of V-ATPase in the tubular salivary gland of the blowfly Calliphora vicina. In this gland, V-ATPase activity energizes the secretion of a KCl-rich saliva in response to the neurohormone serotonin (5-HT). Because of particular morphological and physiological features, the blowfly salivary glands are a superior and exemplary system for the analysis of the intracellular signaling pathways and mechanisms that modulate V-ATPase activity and solute transport in an insect epithelium. KW - Vacuolar-type H+-ATPase KW - Insect epithelia KW - Reversible assembly KW - cAMP KW - Phosphorylation KW - Calliphora vicina Y1 - 2012 U6 - https://doi.org/10.1016/j.jinsphys.2011.11.015 SN - 0022-1910 VL - 58 IS - 4 SP - 450 EP - 458 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Briesemeister, Benny B. A1 - Hofmann, Markus J. A1 - Kuchinke, Lars A1 - Jacobs, Arthur M. T1 - The BAWL databases in research on emotional word processing JF - Potsdam cognitive science series N2 - Inhalt: Introduction A two-dimensional affective space: Valence and arousal effects in word processing Higher dimensional affective space: a role of discrete emotions in word processing? A direct comparison of the affective space models References Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-62377 SN - 2190-4545 SN - 2190-4553 IS - 3 SP - 61 EP - 66 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Kutzinski, Vera M. A1 - Ette, Ottmar T1 - The art of science: Alexander von Humboldt's views of the cultures of the world Y1 - 2012 SN - 0-226-86506-1 ER - TY - JOUR A1 - Yarman, Aysu A1 - Gröbe, Glenn A1 - Neumann, Bettina A1 - Kinne, Mathias A1 - Gajovic-Eichelmann, Nenad A1 - Wollenberger, Ursula A1 - Hofrichter, Martin A1 - Ullrich, Rene A1 - Scheibner, Katrin A1 - Scheller, Frieder W. T1 - The aromatic peroxygenase from Marasmius rutola-a new enzyme for biosensor applications JF - Analytical & bioanalytical chemistry N2 - The aromatic peroxygenase (APO; EC 1.11.2.1) from the agraric basidomycete Marasmius rotula (MroAPO) immobilized at the chitosan-capped gold-nanoparticle-modified glassy carbon electrode displayed a pair of redox peaks with a midpoint potential of -278.5 mV vs. AgCl/AgCl (1 M KCl) for the Fe(2+)/Fe(3+) redox couple of the heme-thiolate-containing protein. MroAPO oxidizes aromatic substrates such as aniline, p-aminophenol, hydroquinone, resorcinol, catechol, and paracetamol by means of hydrogen peroxide. The substrate spectrum overlaps with those of cytochrome P450s and plant peroxidases which are relevant in environmental analysis and drug monitoring. In M. rotula peroxygenase-based enzyme electrodes, the signal is generated by the reduction of electrode-active reaction products (e.g., p-benzoquinone and p-quinoneimine) with electro-enzymatic recycling of the analyte. In these enzyme electrodes, the signal reflects the conversion of all substrates thus representing an overall parameter in complex media. The performance of these sensors and their further development are discussed. KW - Unspecific peroxygenase KW - Cytochrome P450 KW - Biosensors KW - Phenolic substances Y1 - 2012 U6 - https://doi.org/10.1007/s00216-011-5497-y SN - 1618-2642 VL - 402 IS - 1 SP - 405 EP - 412 PB - Springer CY - Heidelberg ER - TY - THES A1 - Anguiano, Borja T1 - The age-metallicity-velocity relation in the nearby disk Y1 - 2012 CY - Potsdam ER - TY - JOUR A1 - Elsner, Birgit A1 - Schellhas, Bernd T1 - The acquisition of flexible tool use in preschoolers the impact of prior experience JF - Zeitschrift für Psychologie = Journal of psychology N2 - To investigate how preschoolers acquire a tool use strategy and how they adapt their tool use to a changed situation, 2- to 4-year-olds were asked to retrieve chips from a transparent box with a rod, either by stabbing and lifting through a top opening or by pushing through a front and a back opening. In both conditions, about 40% of the children acquired effective tool use by individual learning, and 90% of the other children learned this by observing only one demonstration. When confronted with a changed situation (i.e., previous opening covered, alternative opening uncovered), children perseverated with the recently learned, but now ineffective tool use strategy. Neither age nor acquisition type of the first strategy affected preschoolers' perseverations. Results indicate that prior tool use experiences have differential effects in situations that require either transferring known functions to novel objects or using a familiar tool for an alternative purpose. KW - tool use KW - preschoolers (2-4 years) KW - learning KW - transfer KW - action planning Y1 - 2012 U6 - https://doi.org/10.1027/2151-2604/a000090 SN - 2190-8370 VL - 220 IS - 1 SP - 44 EP - 49 PB - Hogrefe CY - Göttingen 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, Andrea 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 - Kraft, Tobias T1 - Textual Differences in Alexander von Humboldt’s Essai politique sur l’île de Cuba BT - An editorial commentary on the first volume of the »Humboldt in English« (HiE) book series JF - Alexander von Humboldt im Netz ; international review for Humboldtian studies N2 - Die vorliegende Studie basiert auf einem Editionsbericht, der 2009 im Rahmen der Konferenz »Alexander von Humboldt and the Hemisphere« an der Vanderbilt University (Nashville, TN) vorgestellt wurde. Die für diese Publikation weiter entwickelte Untersuchung verdeutlicht die Textgenese von Humboldts Essai politique sur l’île de Cuba auf der Basis eines Textvergleichs zwischen allen drei "Originalquellen" des Texts. Der hier in seinen Ergebnissen vorgestellte Textvergleich ist Teil des Editionsprojektes »Humboldt in English« (HiE), bei dem sich ein US-deutsches Editorenteam seit 2007 zum Ziel gesetzt haben, kritische Neuübersetzungen von drei wichtigen Schriften aus Humboldts »Opus Americanum« anzufertigen (s.a. Fußnote). Der Textvergleich des Essai politique sur l’île de Cuba bildete die Textgrundlage für den ersten Band der HiE-Reihe, den 2011 bei Chicago University Press erschienenen The Political Essay on the Island of Cuba (hg. von Vera M. Kutzinski und Ottmar Ette). N2 - This study is based on an editorial report, which was presented at the 2009 working conference »Alexander von Humboldt and the Hemisphere« at Vanderbilt University (Nashville, TN). It demonstrates the textual genesis of Humboldt’s writings on Cuba through examples, which were obtained from a detailed text comparison of the three existing »original« versions of Humboldt’s Essai politique sur l’île de Cuba. The collation was part of a larger strategy to regain philological ground for the »Humboldt in English« (HiE) project. Since 2007 and funded with grants from the National Endowment for the Humanities, the Alexander von Humboldt-Foundation, and the Gerda Henkel Foundation, the US-German research team behind HiE has been working on new and unabridged translations and critical editions of three of Humboldt’s most significant texts from his American oeuvre.1 The following observations will outline the most important results of this collation effort as a complementary contribution to the recent release of the HiE project’s first volume, The Political Essay on the Island of Cuba (Chicago University Press 2011), edited by Vera M. Kutzinski and Ottmar Ette. N2 - El presente artículo se basa en un estudio, que fue presentado en 2009 en la conferencia »Alexander von Humboldt and the Hemisphere« en la Vanderbilt University (Nashville, TN). El estudio ejemplifica la génesis textual del Essai politique sur l’île de Cuba a base de una colación de las tres fuentes »originales« del mismo texto. El estudio forma parte del proyecto editorial »Humboldt in English« (HiE), en el cual un equipo de investigadores estadounidenses-alemanes se han propuesto publicar nuevas ediciones críticas con traducciones nuevas de tres obras claves de la obra americana de Humboldt desde 2007 (véase las informaciones en el pié de nota). La colación crea la base textual para el primer volumen de HiE, The Political Essay on the Island of Cuba (eds. Vera M. Kutzinski y Ottmar Ette), publicado en 2011. KW - Critical edition KW - Essai politique sur l'île de Cuba KW - Humboldt in English (HiE) KW - Ottmar Ette KW - Vanderbilt University KW - Vera Kutzinski Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-61435 SN - 2568-3543 SN - 1617-5239 VL - XIII IS - 24 SP - 75 EP - 85 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Winter, Alette A1 - Zabel, Andre A1 - Strauch, Peter T1 - Tetrachloridocuprates(II)-Synthesis and Electron Paramagnetic Resonance (EPR) Spectroscopy JF - International journal of molecular sciences N2 - Ionic liquids (ILs) on the basis of metal containing anions and/or cations are of interest for a variety of technical applications e.g., synthesis of particles, magnetic or thermochromic materials. We present the synthesis and the results of electron paramagnetic resonance (EPR) spectroscopic analyses of a series of some new potential ionic liquids based on tetrachloridocuprates(II), [CuCl4](2-), with different sterically demanding cations: hexadecyltrimethylammonium 1, tetradecyltrimethylammonium 2, tetrabutylammonium 3 and benzyltriethylammonium 4. The cations in the new compounds were used to achieve a reasonable separation of the paramagnetic Cu(II) ions for EPR spectroscopy. The EPR hyperfine structure was not resolved. This is due to the exchange broadening, resulting from still incomplete separation of the paramagnetic Cu(II) centers. Nevertheless, the principal values of the electron Zeemann tensor (g parallel to and g perpendicular to) of the complexes could be determined. Even though the solid substances show slightly different colors, the UV/Vis spectra are nearly identical, indicating structural changes of the tetrachloridocuprate moieties between solid state and solution. The complexes have a promising potential e.g., as high temperature ionic liquids, as precursors for the formation of copper chloride particles or as catalytic paramagnetic ionic liquids. KW - tetrachloridocuprate(II) KW - electron paramagnetic resonance KW - copper(II) KW - ionic liquid Y1 - 2012 U6 - https://doi.org/10.3390/ijms13021612 SN - 1661-6596 VL - 13 IS - 2 SP - 1612 EP - 1619 PB - MDPI CY - Basel ER - TY - JOUR A1 - Meyer, Katrin M. A1 - Vos, Matthijs A1 - Mooij, Wolf M. A1 - Hol, W. H. Gera A1 - Termorshuizen, Aad J. A1 - van der Putten, Wim H. T1 - Testing the paradox of enrichment along a land use gradient in a multitrophic aboveground and belowground community JF - PLoS one N2 - In the light of ongoing land use changes, it is important to understand how multitrophic communities perform at different land use intensities. The paradox of enrichment predicts that fertilization leads to destabilization and extinction of predator-prey systems. We tested this prediction for a land use intensity gradient from natural to highly fertilized agricultural ecosystems. We included multiple aboveground and belowground trophic levels and land use-dependent searching efficiencies of insects. To overcome logistic constraints of field experiments, we used a successfully validated simulation model to investigate plant responses to removal of herbivores and their enemies. Consistent with our predictions, instability measured by herbivore-induced plant mortality increased with increasing land use intensity. Simultaneously, the balance between herbivores and natural enemies turned increasingly towards herbivore dominance and natural enemy failure. Under natural conditions, there were more frequently significant effects of belowground herbivores and their natural enemies on plant performance, whereas there were more aboveground effects in agroecosystems. This result was partly due to the "boom-bust'' behavior of the shoot herbivore population. Plant responses to herbivore or natural enemy removal were much more abrupt than the imposed smooth land use intensity gradient. This may be due to the presence of multiple trophic levels aboveground and belowground. Our model suggests that destabilization and extinction are more likely to occur in agroecosystems than in natural communities, but the shape of the relationship is nonlinear under the influence of multiple trophic interactions. Citation: Meyer KM, Vos M, Mooij WM, Hol WHG, Termorshuizen AJ, et al. (2012) Testing the Paradox of Enrichment along a Land Use Gradient in a Multitrophic Aboveground and Belowground Community. Y1 - 2012 U6 - https://doi.org/10.1371/journal.pone.0049034 SN - 1932-6203 VL - 7 IS - 11 PB - PLoS CY - San Fransisco ER - TY - GEN A1 - Overholt, Andrew C. A1 - Melott, Adrian L. A1 - Pohl, Martin T1 - Testing the link between terrestrial climate change and galactic spiral-arm transit (vol 705, pg L101, 2009) T2 - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters Y1 - 2012 U6 - https://doi.org/10.1088/2041-8205/751/2/L45 SN - 2041-8205 VL - 751 IS - 2 PB - IOP Publ. Ltd. CY - Bristol ER - TY - JOUR A1 - Delavaud, Elise A1 - Scherbaum, Frank A1 - Kühn, Nicolas A1 - Allen, Trevor T1 - Testing the global applicability of ground-motion prediction equations for active shallow crustal regions JF - Bulletin of the Seismological Society of America N2 - Large research initiatives such as the Global Earthquake Model (GEM) or the Seismic HAzard haRmonization in Europe (SHARE) projects concentrate a great collaborative effort on defining a global standard for seismic hazard estimations. In this context, there is an increasing need for identifying ground-motion prediction equations (GMPEs) that can be applied at both global and regional scale. With increasing amounts of strong-motion records that are now available worldwide, observational data can provide a valuable resource to tackle this question. Using the global dataset of Allen and Wald (2009), we evaluate the ability of 11 GMPEs to predict ground-motion in different active shallow crustal regions worldwide. Adopting the approach of Scherbaum et al. (2009), we rank these GMPEs according to their likelihood of having generated the data. In particular, we estimate how strongly data support or reject the models with respect to the state of noninformativeness defined by a uniform weighting. Such rankings derived from this particular global dataset enable us to explore the potential of GMPEs to predict ground motions in their host region and also in other regions depending on the magnitude and distance considered. In the ranking process, we particularly focus on the influence of the distribution of the testing dataset compared with the GMPE's native dataset. One of the results of this study is that some nonindigenous models present a high degree of consistency with the data from a target region. Two models in particular demonstrated a strong power of geographically wide applicability in different geographic regions with respect to the testing dataset: the models of Akkar and Bommer (2010) and Chiou et al. (2010). Y1 - 2012 U6 - https://doi.org/10.1785/0120110113 SN - 0037-1106 VL - 102 IS - 2 SP - 707 EP - 721 PB - Seismological Society of America CY - El Cerrito ER - TY - INPR A1 - Blanchard, Gilles A1 - Delattre, Sylvain A1 - Roquain, Étienne T1 - Testing over a continuum of null hypotheses N2 - We introduce a theoretical framework for performing statistical hypothesis testing simultaneously over a fairly general, possibly uncountably infinite, set of null hypotheses. This extends the standard statistical setting for multiple hypotheses testing, which is restricted to a finite set. This work is motivated by numerous modern applications where the observed signal is modeled by a stochastic process over a continuum. As a measure of type I error, we extend the concept of false discovery rate (FDR) to this setting. The FDR is defined as the average ratio of the measure of two random sets, so that its study presents some challenge and is of some intrinsic mathematical interest. Our main result shows how to use the p-value process to control the FDR at a nominal level, either under arbitrary dependence of p-values, or under the assumption that the finite dimensional distributions of the p-value process have positive correlations of a specific type (weak PRDS). Both cases generalize existing results established in the finite setting, the latter one leading to a less conservative procedure. The interest of this approach is demonstrated in several non-parametric examples: testing the mean/signal in a Gaussian white noise model, testing the intensity of a Poisson process and testing the c.d.f. of i.i.d. random variables. Conceptually, an interesting feature of the setting advocated here is that it focuses directly on the intrinsic hypothesis space associated with a testing model on a random process, without referring to an arbitrary discretization. T3 - Preprints des Instituts für Mathematik der Universität Potsdam - 1 (2012) 1 Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-56877 ER - TY - JOUR A1 - Ehrmann, Otto A1 - Puppe, Daniel A1 - Wanner, Manfred A1 - Kaczorek, Danuta A1 - Sommer, Michael T1 - Testate amoebae in 31 mature forest ecosystems - Densities and micro-distribution in soils JF - European journal of protistology N2 - We studied testate amoebae and possible correlated abiotic factors in soils of 31 mature forest ecosystems using an easily applicable and spatially explicit method. Simple counting on soil thin-sections with a light microscope resulted in amoeba densities comparable to previously reported values, i.e. 0.1 x 10(8) to 11.5 x 10(8) individuals m(-2) (upper 3 cm of soil). Soil moisture and soil acidity seem to be correlated with amoeba densities. At sites of moderate soil moisture regimes (SMR 2-7) we found higher densities of testate amoebae at pH < 4.5. At wetter sites (SMR >= 8) higher individual densities were recorded also at less acidic sites. The in situ description of amoebae, based on the analysis of a complete soil thin-section, showed a relatively uniform spatial micro-distribution throughout the organic and mineral soil horizons (no testate amoeba clusters). We discuss the pros and cons of the soil thin-section method and suggest it as an additional tool to improve knowledge of the spatial micro-distribution of testate amoebae. KW - Microhabitats KW - Soil thin-section KW - Soil moisture regimes KW - Soil reaction Y1 - 2012 U6 - https://doi.org/10.1016/j.ejop.2012.01.003 SN - 0932-4739 VL - 48 IS - 3 SP - 161 EP - 168 PB - Elsevier CY - Jena ER - TY - CHAP A1 - Weber, Josefine A1 - Müller, Juliane A1 - Otto, Christoph A1 - Scharhag-Rosenberger, Friederike A1 - Carlsohn, Anja A1 - Mayer, Frank T1 - Test-retest-reliability of metabolic and cardiovascular load during isokinetic strength testing T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2012 SN - 0195-9131 VL - 44 SP - 375 EP - 376 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - THES A1 - Rivera Hernández, Sergio T1 - Tensorial spacetime geometries carrying predictive, interpretable and quantizable matter dynamics T1 - Tensorielle Raumzeit-Geometrien, welche prädiktive, interpretierbare und quantisierbare Materiefeld-Dynamiken tragen können N2 - Which tensor fields G on a smooth manifold M can serve as a spacetime structure? In the first part of this thesis, it is found that only a severely restricted class of tensor fields can provide classical spacetime geometries, namely those that can carry predictive, interpretable and quantizable matter dynamics. The obvious dependence of this characterization of admissible tensorial spacetime geometries on specific matter is not a weakness, but rather presents an insight: it was Maxwell theory that justified Einstein to promote Lorentzian manifolds to the status of a spacetime geometry. Any matter that does not mimick the structure of Maxwell theory, will force us to choose another geometry on which the matter dynamics of interest are predictive, interpretable and quantizable. These three physical conditions on matter impose three corresponding algebraic conditions on the totally symmetric contravariant coefficient tensor field P that determines the principal symbol of the matter field equations in terms of the geometric tensor G: the tensor field P must be hyperbolic, time-orientable and energy-distinguishing. Remarkably, these physically necessary conditions on the geometry are mathematically already sufficient to realize all kinematical constructions familiar from Lorentzian geometry, for precisely the same structural reasons. This we were able to show employing a subtle interplay of convex analysis, the theory of partial differential equations and real algebraic geometry. In the second part of this thesis, we then explore general properties of any hyperbolic, time-orientable and energy-distinguishing tensorial geometry. Physically most important are the construction of freely falling non-rotating laboratories, the appearance of admissible modified dispersion relations to particular observers, and the identification of a mechanism that explains why massive particles that are faster than some massless particles can radiate off energy until they are slower than all massless particles in any hyperbolic, time-orientable and energy-distinguishing geometry. In the third part of the thesis, we explore how tensorial spacetime geometries fare when one wants to quantize particles and fields on them. This study is motivated, in part, in order to provide the tools to calculate the rate at which superluminal particles radiate off energy to become infraluminal, as explained above. Remarkably, it is again the three geometric conditions of hyperbolicity, time-orientability and energy-distinguishability that allow the quantization of general linear electrodynamics on an area metric spacetime and the quantization of massive point particles obeying any admissible dispersion relation. We explore the issue of field equations of all possible derivative order in rather systematic fashion, and prove a practically most useful theorem that determines Dirac algebras allowing the reduction of derivative orders. The final part of the thesis presents the sketch of a truly remarkable result that was obtained building on the work of the present thesis. Particularly based on the subtle duality maps between momenta and velocities in general tensorial spacetimes, it could be shown that gravitational dynamics for hyperbolic, time-orientable and energy distinguishable geometries need not be postulated, but the formidable physical problem of their construction can be reduced to a mere mathematical task: the solution of a system of homogeneous linear partial differential equations. This far-reaching physical result on modified gravity theories is a direct, but difficult to derive, outcome of the findings in the present thesis. Throughout the thesis, the abstract theory is illustrated through instructive examples. N2 - Welche Tensorfelder G auf einer glatten Mannigfaltigkeit M können eine Raumzeit-Geometrie beschreiben? Im ersten Teil dieser Dissertation wird es gezeigt, dass nur stark eingeschränkte Klassen von Tensorfeldern eine Raumzeit-Geometrie darstellen können, nämlich Tensorfelder, die eine prädiktive, interpretierbare und quantisierbare Dynamik für Materiefelder ermöglichen. Die offensichtliche Abhängigkeit dieser Charakterisierung erlaubter tensorieller Raumzeiten von einer spezifischen Materiefelder-Dynamik ist keine Schwäche der Theorie, sondern ist letztlich genau das Prinzip, das die üblicherweise betrachteten Lorentzschen Mannigfaltigkeiten auszeichnet: diese stellen die metrische Geometrie dar, welche die Maxwellsche Elektrodynamik prädiktiv, interpretierbar und quantisierbar macht. Materiefeld-Dynamiken, welche die kausale Struktur von Maxwell-Elektrodynamik nicht respektieren, zwingen uns, eine andere Geometrie auszuwählen, auf der die Materiefelder-Dynamik aber immer noch prädiktiv, interpretierbar und quantisierbar sein muss. Diesen drei Voraussetzungen an die Materie entsprechen drei algebraische Voraussetzungen an das total symmetrische kontravariante Tensorfeld P, welches das Prinzipalpolynom der Materiefeldgleichungen (ausgedrückt durch das grundlegende Tensorfeld G) bestimmt: das Tensorfeld P muss hyperbolisch, zeitorientierbar und energie-differenzierend sein. Diese drei notwendigen Bedingungen an die Geometrie genügen, um alle aus der Lorentzschen Geometrie bekannten kinematischen Konstruktionen zu realisieren. Dies zeigen wir im ersten Teil der vorliegenden Arbeit unter Verwendung eines teilweise recht subtilen Wechselspiels zwischen konvexer Analysis, der Theorie partieller Differentialgleichungen und reeller algebraischer Geometrie. Im zweiten Teil dieser Dissertation erforschen wir allgemeine Eigenschaften aller solcher hyperbolischen, zeit-orientierbaren und energie-differenzierenden Geometrien. Physikalisch wichtig sind der Aufbau von frei fallenden und nicht rotierenden Laboratorien, das Auftreten modifizierter Energie-Impuls-Beziehungen und die Identifizierung eines Mechanismus, der erklärt, warum massive Teilchen, die sich schneller als einige masselosse Teilchen bewegen, Energie abstrahlen können, aber nur bis sie sich langsamer als alle masselossen Teilchen bewegen. Im dritten Teil der Dissertation ergründen wir die Quantisierung von Teilchen und Feldern auf tensoriellen Raumzeit-Geometrien, die die obigen physikalischen Bedingungen erfüllen. Eine wichtige Motivation dieser Untersuchung ist es, Techniken zur Berechnung der Zerfallsrate von Teilchen zu berechnen, die sich schneller als langsame masselose Teilchen bewegen. Wir finden, dass es wiederum die drei zuvor im klassischen Kontext identifizierten Voraussetzungen (der Hyperbolizität, Zeit-Orientierbarkeit und Energie-Differenzierbarkeit) sind, welche die Quantisierung allgemeiner linearer Elektrodynamik auf einer flächenmetrischen Raumzeit und die Quantizierung massiver Teilchen, die eine physikalische Energie-Impuls-Beziehung respektieren, erlauben. Wir erkunden auch systematisch, wie man Feldgleichungen aller Ableitungsordnungen generieren kann und beweisen einen Satz, der verallgemeinerte Dirac-Algebren bestimmt und die damit Reduzierung des Ableitungsgrades einer physikalischen Materiefeldgleichung ermöglicht. Der letzte Teil der vorliegenden Schrift skizziert ein bemerkenswertes Ergebnis, das mit den in dieser Dissertation dargestellten Techniken erzielt wurde. Insbesondere aufgrund der hier identifizierten dualen Abbildungen zwischen Teilchenimpulsen und -geschwindigkeiten auf allgemeinen tensoriellen Raumzeiten war es möglich zu zeigen, dass man die Gravitationsdynamik für hyperbolische, zeit-orientierbare und energie-differenzierende Geometrien nicht postulieren muss, sondern dass sich das Problem ihrer Konstruktion auf eine rein mathematische Aufgabe reduziert: die Lösung eines homogenen linearen Differentialgleichungssystems. Dieses weitreichende Ergebnis über modifizierte Gravitationstheorien ist eine direkte (aber schwer herzuleitende) Folgerung der Forschungsergebnisse dieser Dissertation. Die abstrakte Theorie dieser Doktorarbeit wird durch mehrere instruktive Beispiele illustriert. KW - refined spacetime geometries KW - modified dispersion relations KW - modified gravitational dynamics KW - Finsler geometry KW - quantization of field theories Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-61869 ER - TY - JOUR A1 - Wang, Yongbo A1 - Liu, Xingqi A1 - Herzschuh, Ulrike A1 - Yang, Xiangdong A1 - Birks, H. John B. A1 - Zhang, Enlou A1 - Tong, Guobang T1 - Temporally changing drivers for late-Holocene vegetation changes on the northern Tibetan Plateau JF - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences N2 - Fossil pollen records have been widely used as indicators of past changes in vegetation and variations in climate. The driving mechanisms behind these vegetation changes have, however, remained unclear. In order to evaluate vegetation changes that have occurred in the northern part of the Tibetan Plateau and the possible drivers behind these changes, we have applied a moving-window Redundancy Analysis (RDA) to high resolution (10-15 years) pollen and sedimentary data from Lake Kusai covering the last 3770 years. Our analyses reveal frequent fluctuations in the relative abundances of alpine steppe and alpine desert components. The sedimentary proxies (including total organic carbon content, total inorganic carbon content, and "end-member" indices from grain-size analyses) that explain statistically some of the changes in the pollen assemblage vary significantly with time, most probably reflecting multiple underlying driving processes. Climate appears to have had an important influence on vegetation changes when conditions were relatively wet and stable. However, a gradual decrease in vegetation cover was identified after 1500 cal a BP, after which the vegetation appears to have been affected more by extreme events such as dust-storms or fluvial erosion than by general climatic trends. Furthermore, pollen spectra over the last 600 years are shown by Procrustes analysis to be statistically different from those recovered from older samples, which we attribute to increased human impact that resulted in unprecedented changes to the vegetation composition. Overall, changes in vegetation and climate on the northern part of the Tibetan Plateau appear to have roughly followed the evolution of the Asian Summer Monsoon. After taking into account the highly significant millennial (1512 years) periodicity revealed by time-series analysis, the regional vegetation and climate changes also show variations that appear to match variations in the mid-latitude westerlies. KW - Asian Summer Monsoon KW - Late-Holocene KW - Pollen KW - Procrustes analysis KW - Redundancy analysis KW - Tibetan Plateau KW - Vegetation KW - Westerlies Y1 - 2012 U6 - https://doi.org/10.1016/j.palaeo.2012.06.022 SN - 0031-0182 VL - 353 IS - 8 SP - 10 EP - 20 PB - Elsevier CY - Amsterdam ER - TY - THES A1 - Trukenbrod, Hans Arne T1 - Temporal and spatial aspects of eye-movement control : from reading to scanning T1 - Zeitliche und räumliche Aspekte der Blicksteuerung : vom Lesen zum Scannen N2 - Eye movements are a powerful tool to examine cognitive processes. However, in most paradigms little is known about the dynamics present in sequences of saccades and fixations. In particular, the control of fixation durations has been widely neglected in most tasks. As a notable exception, both spatial and temporal aspects of eye-movement control have been thoroughly investigated during reading. There, the scientific discourse was dominated by three controversies, (i), the role of oculomotor vs. cognitive processing on eye-movement control, (ii) the serial vs. parallel processing of words, and, (iii), the control of fixation durations. The main purpose of this thesis was to investigate eye movements in tasks that require sequences of fixations and saccades. While reading phenomena served as a starting point, we examined eye guidance in non-reading tasks with the aim to identify general principles of eye-movement control. In addition, the investigation of eye movements in non-reading tasks helped refine our knowledge about eye-movement control during reading. Our approach included the investigation of eye movements in non-reading experiments as well as the evaluation and development of computational models. I present three main results : First, oculomotor phenomena during reading can also be observed in non-reading tasks (Chapter 2 & 4). Oculomotor processes determine the fixation position within an object. The fixation position, in turn, modulates both the next saccade target and the current fixation duration. Second, predicitions of eye-movement models based on sequential attention shifts were falsified (Chapter 3). In fact, our results suggest that distributed processing of multiple objects forms the basis of eye-movement control. Third, fixation durations are under asymmetric control (Chapter 4). While increasing processing demands immediately prolong fixation durations, decreasing processing demands reduce fixation durations only with a temporal delay. We propose a computational model ICAT to account for asymmetric control. In this model, an autonomous timer initiates saccades after random time intervals independent of ongoing processing. However, processing demands that are higher than expected inhibit the execution of the next saccade and, thereby, prolong the current fixation. On the other hand, lower processing demands will not affect the duration before the next saccade is executed. Since the autonomous timer adjusts to expected processing demands from fixation to fixation, a decrease in processing demands may lead to a temporally delayed reduction of fixation durations. In an extended version of ICAT, we evaluated its performance while simulating both temporal and spatial aspects of eye-movement control. The eye-movement phenomena investigated in this thesis have now been observed in a number of different tasks, which suggests that they represent general principles of eye guidance. I propose that distributed processing of the visual input forms the basis of eye-movement control, while fixation durations are controlled by the principles outlined in ICAT. In addition, oculomotor control contributes considerably to the variability observed in eye movements. Interpretations for the relation between eye movements and cognition strongly benefit from a precise understanding of this interplay. N2 - Blickbewegungen stellen ein wichtiges Instrument dar, um kognitive Prozesse zu untersuchen. In den meisten Paradigmen ist allerdings wenig über die Entstehung von Sakkaden und Fixationen bekannt. Insbesondere die Kontrolle der Fixationsdauern wurde häufig außer acht gelassen. Eine wesentliche Ausnahme stellt die Leseforschung dar, in der sowohl zeitlichliche als auch räumliche Aspekte der Blickbewegungssteuerung im Detail betrachtet wurden. Dabei war der wissenschaftliche Diskurs durch drei Kontroversen gekennzeichnet, die untersuchten, (i), welchen Einfluss okulomotorische bzw. kognitive Prozesse auf die Blicksteuerung haben, (ii), ob Worte seriell oder parallel verarbeitet werden und, (iii), wie Fixationsdauern kontrolliert werden. Die vorliegende Arbeit zielt im wesentlichen darauf ab, die Dynamik von Fixationssequenzen zu erforschen. Ausgehend von den Erkenntnissen beim Lesen untersuchten wir Blickbewegungen in Nichtlese-Aufgaben, mit dem Ziel allgemeine Prinzipien der Blicksteuerung zu identifizieren. Zusätzlich versuchten wir mit Hilfe dieser Aufgaben, Erkenntnisse über Prozesse beim Lesen zu vertiefen. Unser Vorgehen war sowohl von der Durchführung von Experimenten als auch der Entwicklung und Evaluation computationaler Modelle geprägt. Die Hauptbefunde zeigten: Erstens, okulomotorische Phänomene des Lesens lassen sich in Suchaufgaben ohne Wortmaterial replizieren (Kapitel 2 & 4). Dabei bestimmen okulomotorische Prozesse die Fixationsposition innerhalb eines Objektes. Diese wiederum beeinflusst das nächste Sakkadenziel sowie die Fixationsdauer. Zweitens, wesentliche Vorhersagen von Modellen, in denen Blickbewegungen von seriellen Aufmerksamkeitsverschiebungen abhängen, konnten falsifiziert werden (Kapitel 3). Stattdessen legen unsere Erkenntnisse nahe, dass die Blicksteuerung von der parallelen Verarbeitung mehrerer Objekte abhängt. Drittens, Fixationsdauern werden asymmetrisch kontrolliert (Kapitel 4). Während hohe Verarbeitungsanforderungen Fixationsdauern unmittelbar verlängern können, führen niedrige Verarbeitungsanforderungen nur zeitlich verzögert zu einer Reduktion. Wir schlagen ein computationales Modell ICAT vor, um asymmetrische Kontrolle zu erklären. Grundlage des Modells ist ein autonomer Zeitgeber, der unabhängig von der momentanen Verarbeitung nach zufälligen Zeitintervallen Sakkaden initiiert. Unerwartet hohe Verarbeitungsanforderungen können die Initiierung der nächsten Sakkade hinauszögern, während unerwartet niedrige Verarbeitungsanforderungen den Beginn der nächsten Sakkade nicht verändern. Der Zeitgeber passt sich allerdings von Fixation zu Fixation neuen Verarbeitungsanforderungen an, so dass es zu einer zeitlich verzögerten Reduktion der Fixationsdauern kommen kann. In einer erweiterten Version des Modells überprüfen wir die Kompatibilität ICATs mit einer realistischen räumlichen Blicksteuerung. Die Ähnlichkeit von Blickbewegungsphänomenen über Aufgaben hinweg legt nahe, dass sie auf allgemeinen Prinzipien basieren. Grundlage der Blicksteuerung ist die verteilte Verarbeitung des visuellen Inputs, während die Kontrolle der Fixationsdauer auf den Prinzipien von ICAT beruht. Darüber hinaus tragen okulomotorische Phänomene wesentlich zur Variabilität der Blicksteuerung bei. Ein Verständnis dieses Zusammenspiels hilft entscheidend den Zusammenhang von Blickbewegungen und Kognitionen besser zu verstehen. KW - Blickbewegungen KW - Fixationssequenzen KW - Computationale Modellierung KW - Fixationdauern KW - Fixationspositionen KW - Eye movements KW - fixation sequences KW - computational modeling KW - fixation durations KW - fixation positions Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-70206 ER - TY - JOUR A1 - Sperfeld, Erik A1 - Wacker, Alexander T1 - Temperature affects the limitation of Daphnia magna by eicosapentaenoic acid, and the fatty acid composition of body tissue and eggs JF - Freshwater biology N2 - 1. Poikilothermic animals incorporate more polyunsaturated fatty acids (PUFAs) into their cellular membranes as temperature declines, suggesting an increased sensitivity to PUFA limitation in cool conditions. To test this we raised Daphnia magna at different temperatures and investigated the effect of varying dietary PUFA on life history parameters (i.e. growth, reproduction) and the PUFA composition of body tissue and eggs. 2. Upon a PUFA-rich diet (Cryptomonas sp.) females showed higher concentrations of several omega 3 PUFAs in their body tissue at 15 degrees C than at 20 degrees C and 25 degrees C, indicating a greater structural requirement for omega 3 PUFAs at low temperature. Their eggs had an equal but higher concentration of omega 3 PUFAs than their body tissue. 3. In a life history experiment at 15 and 20 degrees C we supplemented a diet of a PUFA-free cyanobacterium with the omega 3 PUFA eicosapentaenoic acid (EPA). The growth of D. magna was more strongly EPA limited at low temperature. A greater requirement for structural EPA at 15 degrees C was indicated by a steeper increase in somatic EPA content with dietary EPA compared to 20 degrees C. 4. At 20 degrees C the development of eggs to successful hatching was high when EPA was supplied to the mothers. At 15 degrees C the hatching success was generally poor, despite of a higher maternal provision of EPA to eggs, compared to that at 20 degrees C, suggesting that EPA alone was insufficient for proper neonatal development at the low temperature. The growth of offspring from mothers raised at 20 degrees C without EPA supplementation was very low, indicating that the negative effects of EPA deficiency can be carried on to the next generation. 5. The fatty acid composition of Daphnia sp. in published field studies shows increasing proportions of saturated fatty acids with increasing environmental temperature, whereas omega 3 PUFAs and EPA show no clear pattern, suggesting that variations in dietary PUFA may mask temperature-dependent adjustments in omega 3 PUFA concentrations of cladocerans in nature. KW - food quality KW - maternal effects KW - polyunsaturated fatty acids KW - resource allocation KW - zooplankton Y1 - 2012 U6 - https://doi.org/10.1111/j.1365-2427.2011.02719.x SN - 0046-5070 VL - 57 IS - 3 SP - 497 EP - 508 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Rademacher, Corinna A1 - Hoffmann, Marie-Christine A1 - Lackmann, Jan-Wilm A1 - Moser, Roman A1 - Pfänder, Yvonne A1 - Leimkühler, Silke A1 - Narberhaus, Franz A1 - Masepohl, Bernd T1 - Tellurite resistance gene trgB confers copper tolerance to Rhodobacter capsulatus JF - BioMetals : an international journal on the role of metal ions in biology, biochemistry and medicine N2 - To identify copper homeostasis genes in Rhodobacter capsulatus, we performed random transposon Tn5 mutagenesis. Screening of more than 10,000 Tn5 mutants identified tellurite resistance gene trgB as a so far unrecognized major copper tolerance determinant. The trgB gene is flanked by tellurite resistance gene trgA and cysteine synthase gene cysK2. While growth of trgA mutants was only moderately restricted by tellurite, trgB and cysK2 mutants were severely affected by tellurite, which implies that viability under tellurite stress requires increased cysteine levels. Mutational analyses revealed that trgB was the only gene in this chromosomal region conferring cross-tolerance towards copper. Expression of the monocistronic trgB gene required promoter elements overlapping the trgA coding region as shown by nested deletions. Neither copper nor tellurite affected trgB transcription as demonstrated by reverse transcriptase PCR and trgB-lacZ fusions. Addition of tellurite or copper gave rise to increased cellular tellurium and copper concentrations, respectively, as determined by inductively coupled plasma-optical emission spectroscopy. By contrast, cellular iron concentrations remained fairly constant irrespective of tellurite or copper addition. This is the first study demonstrating a direct link between copper and tellurite response in bacteria. KW - Copper KW - Tellurite KW - Nudix hydrolase KW - Metal homeostasis KW - Rhodobacter Y1 - 2012 U6 - https://doi.org/10.1007/s10534-012-9566-2 SN - 0966-0844 VL - 25 IS - 5 SP - 995 EP - 1008 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Gumienny, Raja A1 - Gericke, Lutz A1 - Wenzel, Matthias A1 - Meinel, Christoph T1 - Tele-board in use : applying aq digital whiteboard system in different situations and setups Y1 - 2012 SN - 978-3-642-31990-7 ER - TY - JOUR A1 - Gericke, Lutz A1 - Gumienny, Raja A1 - Meinel, Christoph T1 - Tele-board : folow the traces of your design process history Y1 - 2012 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 - Khelifi, N. A1 - Sarnthein, M. A1 - Naafs, B. D. A. T1 - Technical note: Late Pliocene age control and composite depths at ODP Site 982, revisited JF - CLIMATE OF THE PAST N2 - Ocean Drilling Program (ODP) Site 982 provided a key sediment section at Rockall Plateau for reconstructing northeast Atlantic paleoceanography and monitoring benthic delta O-18 stratigraphy over the late Pliocene to Quaternary onset of major Northern Hemisphere glaciation. A renewed hole-specific inspection of magnetostratigraphic reversals and the addition of epibenthic delta O-18 records for short Pliocene sections in holes 982A, B, and C, crossing core breaks in the delta O-18 record published for Hole 982B, now imply a major revision of composite core depths. After tuning to the orbitally tuned reference record LR04, the new composite delta O-18 record results in a hiatus, where the Kaena magnetic subchron might have been lost, and in a significant age reduction for all proxy records by 130 to 20 ky over the time span 3.2-2.7 million years ago (Ma). Our study demonstrates the general significance of reliable composite-depth scales and delta O-18 stratigraphies in ODP sediment records for generating ocean-wide correlations in paleoceanography. The new concept of age control makes the late Pliocene trends in SST (sea surface temperature) and atmospheric pCO(2) at Site 982 more consistent with various paleoclimate trends published from elsewhere in the North Atlantic. Y1 - 2012 U6 - https://doi.org/10.5194/cp-8-79-2012 SN - 1814-9324 VL - 8 IS - 1 SP - 79 EP - 87 PB - COPERNICUS GESELLSCHAFT MBH CY - GOTTINGEN ER - TY - JOUR A1 - Knoops, Femke A1 - Erbil, Fethiye A1 - Ertürk, Mustafa T1 - Teaching patterns and trends JF - Potsdamer geographische Praxis N2 - 1. Outline 2. Definition 3. Why is it important (or not) to teach about patterns and trends? What are the strengths and weaknesses of teaching patterns and trends? 4. How were patterns and trends offered in the original assignments? 5. What did the student teacher change in practice? How did it go? 6. Suggestions for improving patterns and trends KW - Europäische Werteerziehung KW - Familie KW - Lehrevaluation KW - Studierendenaustausch KW - Unterrichtseinheiten KW - Curriculum Framework KW - European values education KW - Family KW - lesson evaluation KW - student exchange KW - teaching units KW - curriculum framework Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-65845 SN - 2194-1599 SN - 2194-1602 IS - 1 SP - 75 EP - 79 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - BOOK A1 - Uhlenwinkel, Anke A1 - Krause, Uwe A1 - Halman, Loek A1 - Rokven, Josja A1 - Sieben, Inge A1 - Pažický, Michal A1 - Blahušiaková, Andrea A1 - Röper-Kühnemann, Christian A1 - Staufenbiel, Christoph A1 - Vozárová, Hana A1 - Hintze, Katarina A1 - Ivaška, Michal A1 - Kallenbach, René A1 - Majer, Zdenko A1 - Röll, Juliane A1 - Pisarčík, Stanislav A1 - Weiser, Ines A1 - Seeger, Anett A1 - Strehmann, Anja A1 - Chovanová, Katarina A1 - Gembický, Kamil A1 - Nern, Luise A1 - Cornelissen, Sebastiaan A1 - Turgut, Pelin A1 - Knoops, Femke A1 - Erbil, Fethiye A1 - Ertürk, Mustafa A1 - Akpinar, Seda A1 - Maas, Desiree A1 - Rooth, Anneke A1 - Azar, Elif Zeynep A1 - Erdönmez, Çağlayan A1 - Verscheijden, Desirée A1 - Altuntas, Kezban A1 - Akçay, Pinar A1 - Kools, Suzanne A1 - Schnabel, Richard A1 - van den Beemt, Martijn A1 - Çinkaya, Muhammed A1 - Erdem, Didem Tuğçe A1 - Janssen, Robert ED - Uhlenwinkel, Anke T1 - Teaching about the religious values of Europeans : critical reflections from the second student exchange of the EVE-project N2 - The European Values Education (EVE) project is a large-scale, cross-national, and longitudinal survey research programme on basic human values. The main topic of its second stage was religion in Europe. Student teachers of several universities in Europe worked together in multicultural exchange groups. Their results are presented in this issue. T3 - Potsdamer Geographische Praxis - 1 KW - Europäische Werteerziehung KW - Religion KW - Lehrevaluation KW - Studierendenaustausch KW - Unterrichtseinheiten KW - Curriculum Framework KW - European values education KW - religion KW - lesson evaluation KW - student exchange KW - teaching units KW - curriculum framework Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-59010 SN - 978-3-86956-175-2 ER - TY - JOUR A1 - Wildish, J. A1 - Pavesi, Laura A1 - Ketmaier, Valerio T1 - Talitrid amphipods (Crustacea: Amphipoda: Talitridae) and the driftwood ecological niche a morphological and molecular study JF - Journal of natural history : an international journal of systematics, interactive biology and biodiversity. - London : Taylor & Francis   1.1967 - N2 - Coastal regions of the North East Atlantic and Mediterranean Seas have four known species of driftwood talitrids. Records are extremely scanty, often limited to the type locality and dating to 1950. We were able to study three of them, all belonging to the genus Macarorchestia, using fresh and archived samples including type material. Allometric and molecular analyses support: (1) a close relationship among all the three classically defined Macarorchestia species, (2) Macarorchestia was well separated from non-driftwood taxa, and (3) a putative new driftwood talitrid discovered during this study was not closely related to Macarorchestia. Genetic divergence between the new species and Macarorchestia remyi is as high as the average distance among a number of talitrid species included in the study for comparison. A key is provided to identify all three of the presently known species of Macarorchestia, using morphological characters employed in the allometric study. KW - Macarorchestia remyi KW - Macarorchestia roffensis KW - Macarorchestia martini KW - Driftwood habitat KW - COI-DNA barcoding KW - allometry Y1 - 2012 U6 - https://doi.org/10.1080/00222933.2012.717971 SN - 0022-2933 VL - 46 IS - 43-44 SP - 2677 EP - 2700 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Herzog, Marc A1 - Schick, Daniel A1 - Leitenberger, Wolfram A1 - Shayduk, Roman A1 - van der Veen, Renske M. A1 - Milne, Christopher J. A1 - Johnson, Steven Lee A1 - Vrejoiu, Ionela A1 - Bargheer, Matias T1 - Tailoring interference and nonlinear manipulation of femtosecond x-rays JF - New journal of physics : the open-access journal for physics N2 - We present ultrafast x-ray diffraction (UXRD) experiments on different photoexcited oxide superlattices. All data are successfully simulated by dynamical x-ray diffraction calculations based on a microscopic model, that accounts for the linear response of phonons to the excitation laser pulse. Some Bragg reflections display a highly nonlinear strain dependence. The origin of linear and two distinct nonlinear response phenomena is discussed in a conceptually simpler model using the interference of envelope functions that describe the diffraction efficiency of the average constituent nanolayers. The combination of both models facilitates rapid and accurate simulations of UXRD experiments. Y1 - 2012 U6 - https://doi.org/10.1088/1367-2630/14/1/013004 SN - 1367-2630 VL - 14 IS - 1 PB - IOP Publ. Ltd. CY - Bristol 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 - Neuvonen, Kari A1 - Neuvonen, Helmi A1 - Koch, Andreas A1 - Kleinpeter, Erich T1 - Taft equation in the light of NBO computations introduction of a novel polar computational substituent constant scale sigma(q)* for alkyl groups JF - Computational and theoretical chemistry N2 - The validity of the Taft equation: log(k(R)/k(CH3)) = rho*sigma* + delta E-S was studied with the aid of NBO computational results concerning cyclohexyl esters RCOOC6H11 [R = Methyl, Ethyl, n-Propyl, Isopropyl, n-Butyl, Isobutyl, sec-Butyl, tert-Butyl, Neopentyl, CH(CH2CH3)(2), CH(CH3)C(CH3)(3), C(CH3)(2)CH2CH3, C(CH3)(2)C(CH3)(3), CH(CH3)(Np), CH(iPr)(tBu), C(Me)(Et)(iPr), C(Et)(2)(tBu) or C(Et)(iPr)(tBu)]. It was proved that the sigma*(alkyl) value is a composite substitutent constant including the polar and steric contributions. A novel computational sigma(q)* substituent constant scale is presented based on the NBO atomic charges of the alpha-carbon and the computational total steric exchange energies E(ster) of the cyclohexyl esters specified above. The method used offers a useful way to calculate sigma*(alkyl) values for alkyl groups for which experimental Taft's polar sigma* parameters are not available. KW - NBO analysis KW - Taft equation KW - Polar substituent constant KW - Steric effect Y1 - 2012 U6 - https://doi.org/10.1016/j.comptc.2011.11.044 SN - 2210-271X VL - 981 IS - 2 SP - 52 EP - 58 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Kleinpeter, Erich A1 - Neuvonen, Kari A1 - Neuvonen, Helmi A1 - Koch, Andreas T1 - Taft equation in the light of NBO computations : Introduction of a novel polar computational substituent constant scale for alkyl groups Y1 - 2012 SN - 2210-271X ER - TY - THES A1 - Irgang, Susann T1 - Systemic characterization of the TOR-signaling pathway in chlamydomonas reinhardtii Y1 - 2012 CY - Potsdam ER - TY - JOUR A1 - Heinz, S. A1 - Jung, I. A1 - Stegmann, Christian T1 - Systematic studies of the Richardson-Lucy deconvolution algorithm applied to VHE gamma data JF - ASTROPARTICLE PHYSICS N2 - The Richardson-Lucy deconvolution algorithm was applied to astronomical images in the very high-energy regime with photon energies above 100 GeV. Through a systematic study with respect to source significance, background level and source morphology we were able to derive optimal deconvolution parameters. The results presented show that deconvolution makes it possible to study structural details well below the angular resolution of the very high-energy gamma-ray experiment. (C) 2012 Elsevier B.V. All rights reserved. KW - Very high energy gamma-ray astronomy KW - Deconvolution Y1 - 2012 U6 - https://doi.org/10.1016/j.astropartphys.2012.05.013 SN - 0927-6505 VL - 36 IS - 1 SP - 146 EP - 150 PB - ELSEVIER SCIENCE BV CY - AMSTERDAM ER - TY - JOUR A1 - Girbig, Dorothee A1 - Grimbs, Sergio A1 - Selbig, Joachim T1 - Systematic analysis of stability patterns in plant primary metabolism JF - PLoS one N2 - Metabolic networks are characterized by complex interactions and regulatory mechanisms between many individual components. These interactions determine whether a steady state is stable to perturbations. Structural kinetic modeling (SKM) is a framework to analyze the stability of metabolic steady states that allows the study of the system Jacobian without requiring detailed knowledge about individual rate equations. Stability criteria can be derived by generating a large number of structural kinetic models (SK-models) with randomly sampled parameter sets and evaluating the resulting Jacobian matrices. Until now, SKM experiments applied univariate tests to detect the network components with the largest influence on stability. In this work, we present an extended SKM approach relying on supervised machine learning to detect patterns of enzyme-metabolite interactions that act together in an orchestrated manner to ensure stability. We demonstrate its application on a detailed SK-model of the Calvin-Benson cycle and connected pathways. The identified stability patterns are highly complex reflecting that changes in dynamic properties depend on concerted interactions between several network components. In total, we find more patterns that reliably ensure stability than patterns ensuring instability. This shows that the design of this system is strongly targeted towards maintaining stability. We also investigate the effect of allosteric regulators revealing that the tendency to stability is significantly increased by including experimentally determined regulatory mechanisms that have not yet been integrated into existing kinetic models. Y1 - 2012 U6 - https://doi.org/10.1371/journal.pone.0034686 SN - 1932-6203 VL - 7 IS - 4 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Kleinpeter, Erich A1 - Lazareva, Nataliya F. A1 - Shainyan, Bagrat A. A1 - Schilde, Uwe A1 - Chipania, Nina N. T1 - Synthesis, Molecular Structure, Conformational Analysis, and Chemical Properties of Silicon-Containing Derivatives of Quinolizidine Y1 - 2012 SN - 0022-3263 ER - TY - JOUR A1 - Lazareva, Nataliya F. A1 - Shainyan, Bagrat A. A1 - Schilde, Uwe A1 - Chipanina, Nina N. A1 - Oznobikhina, Larisa P. A1 - Albanov, Alexander I. A1 - Kleinpeter, Erich T1 - Synthesis, molecular structure, conformational analysis, and chemical properties of silicon-containing derivatives of quinolizidine JF - The journal of organic chemistry N2 - A silicon analog of quinolizidine 3,3,7,7-tetramethylhexahydro-1H-[1,4,2]oxazasilino[4,5-d][1,4,2]oxazasilin-9a-yl)methanol 3 was synthesized. X-ray diffraction analysis confirmed the trans configuration and low temperature NMR spectroscopy both the flexibility (barrier of interconversion 5.8 kcal mol(-1)) and the conformational equilibrium (chair-chair and chair-twist conformers) of the compound. The relative stability of the different isomers/conformers of 3 was calculated also at the MP2/6-311G(d,p) level of theory. Intra- and intermolecular hydrogen bonding in 3 and the appropriate equilibrium between free and self-associated molecules was studied in solvents of different polarity. Both the N-methyl quaternary ammonium salt and the O-trimethylsilyl derivative of 3 could be obtained and their structure determined. Y1 - 2012 U6 - https://doi.org/10.1021/jo202658n SN - 0022-3263 VL - 77 IS - 5 SP - 2382 EP - 2388 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Najafpour, Mohammad Mahdi A1 - Hillier, Warwick A1 - Shamkhali, Amir Nasser A1 - Amini, Mojtaba A1 - Beckmann, Katrin A1 - Jaglicic, Zvonko A1 - Jagodic, Marko A1 - Strauch, Peter A1 - Moghaddam, Atefeh Nemati A1 - Beretta, Giangiacomo A1 - Bagherzadeh, Mojtaba T1 - Synthesis, characterization, DFT studies and catalytic activities of manganese(II) complex with 1,4-bis(2,2 ':6,2 ''-terpyridin-4 '-yl) benzene JF - Dalton transactions : a journal of inorganic chemistry, including bioinorganic, organometallic, and solid-state chemistry N2 - A new di-manganese complex with "back-to-back" 1,4-bis(2,2':6,2 ''-terpyridin-4'-yl) benzene ligation has been synthesized and characterised by a variety of techniques. The back-to-back ligation presents a novel new mononuclear manganese catalytic centre that functions as a heterogeneous catalysis for the evolution of oxygen in the presence of an exogenous oxidant. We discuss the synthesis and spectroscopic characterizations of this complex and propose a mechanism for oxygen evolution activity of the compound in the presence of oxone. The di-manganese complex also shows efficient and selective catalytic oxidation of sulfides in the presence of H2O2. Density functional theory calculations were used to assess the structural optimization of the complex and a proposed reaction pathway with oxone. The calculations show that middle benzene ring is distorted respect to both of metallic centers, and this in turn leads to negligible resonance of electrons between two sides of complex. The calculations also indicate the unpaired electron located on oxyl-ligand emphasizes the radical mechanism of water oxidation for the system. Y1 - 2012 U6 - https://doi.org/10.1039/c2dt31544k SN - 1477-9226 VL - 41 IS - 39 SP - 12282 EP - 12288 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Kleinpeter, Erich A1 - Stojanovic, Milovan A1 - Markovic, Rade A1 - Baranac-Stojanovic, Marija T1 - Synthesis of thiazolidine-fused heterocycles via exo-mode cyclizations of vinylogous N-acyliminium ions N2 - Syntheses of thiazolidine-fused heterocycles via exo-mode cyclizations of vinylogous N-acyliminium ions incorporating heteroatom-based nucleophiles have been examined and discussed. The formation of (5,6)-membered systems was feasible with all nucleophiles tried (O, S and N), while the closing of the five-membered ring was restricted to O- and S-nucleophiles. The closure of a four-membered ring failed. Instead, the bicyclic (5,6)-membered acetal derivative and the tricyclic system with an eight-membered central ring were obtained from the substrates containing O and S nucleophilic moieties, respectively. The reaction outcome and stereochemistry are rationalized using quantum chemical calculations at B3LYP/6-31G(d) level. The exclusive cis-stereoselectivity in the formation of (5,6)- and (5,5)-membered systems results from thermodynamic control, whereas the formation of the eight-membered ring was kinetically controlled. Y1 - 2012 SN - 1477-0520 ER - TY - JOUR A1 - Stojanovic, Milovan A1 - Markovic, Rade A1 - Kleinpeter, Erich A1 - Baranac-Stojanovic, Marija T1 - Synthesis of thiazolidine-fused heterocycles via exo-mode cyclizations of vinylogous N-acyliminium ions JF - Organic & biomolecular chemistry : an international journal of synthetic, physical and biomolecular organic chemistry N2 - Syntheses of thiazolidine-fused heterocycles via exo-mode cyclizations of vinylogous N-acyliminium ions incorporating heteroatom-based nucleophiles have been examined and discussed. The formation of (5,6)-membered systems was feasible with all nucleophiles tried (O, S and N), while the closing of the five-membered ring was restricted to O- and S-nucleophiles. The closure of a four-membered ring failed. Instead, the bicyclic (5,6)-membered acetal derivative and the tricyclic system with an eight-membered central ring were obtained from the substrates containing O and S nucleophilic moieties, respectively. The reaction outcome and stereochemistry are rationalized using quantum chemical calculations at B3LYP/6-31G(d) level. The exclusive cis-stereoselectivity in the formation of (5,6)- and (5,5)-membered systems results from thermodynamic control, whereas the formation of the eight-membered ring was kinetically controlled. Y1 - 2012 U6 - https://doi.org/10.1039/c1ob06451g SN - 1477-0520 VL - 10 IS - 3 SP - 575 EP - 589 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Kleinpeter, Erich A1 - Modarresi-Alam, Ali Reza A1 - Inaloo, Iman Dindarloo T1 - Synthesis of primary thiocarbamates by silica sulfuric acid as effective reagent under solid-state and solution conditions N2 - A simple and efficient method for the conversion of alcohols and phenols to primary O-thiocarbamates and S- thiocarbamates in the absence of solvent (solvent-free condition) using silica sulfuric acid (SiO2OSO3H) as a solid acid is described. The products are easily distinguished by IR, NMR and X-ray data. X-ray data of the compounds reveal a planar trigonal orientation of the NH2 nitrogen atom with the partial C,N double-bond character and the CS or CO groups in synperiplanar position with CarylO and CalkylS moieties, respectively. Moreover, the OCSNH2 group which is perpendicular to the plane of the benzene ring in 1c and the central thiocarbamate SCONH2 group in 2b are essentially planar. Y1 - 2012 SN - 0022-2860 ER - TY - JOUR A1 - Modarresi-Alam, Ali Reza A1 - Inaloo, Iman Dindarloo A1 - Kleinpeter, Erich T1 - Synthesis of primary thiocarbamates by silica sulfuric acid as effective reagent under solid-state and solution conditions JF - Journal of molecular structure N2 - A simple and efficient method for the conversion of alcohols and phenols to primary O-thiocarbamates and S-thiocarbamates in the absence of solvent (solvent-free condition) using silica sulfuric acid (equivalent to SiO2-OSO3H) as a solid acid is described. The products are easily distinguished by IR, NMR and X-ray data. X-ray data of the compounds reveal a planar trigonal orientation of the NH2 nitrogen atom with the partial C,N double-bond character and the C=S or C=O groups in synperiplanar position with C-aryl-O and C-alkyl-S moieties, respectively. Moreover, the -O-CS-NH2 group which is perpendicular to the plane of the benzene ring in 1c and the central thiocarbamate -S-CO-NH2 group in 2b are essentially planar. KW - Solvent-free KW - N-unsubstituted(primary)O-thiocarbamates KW - N-unsubstituted (primary)S-thiocarbamates KW - Isothiocyanic acid KW - Solid acid KW - Silica sulfuric acid Y1 - 2012 U6 - https://doi.org/10.1016/j.molstruc.2012.05.033 SN - 0022-2860 VL - 1024 IS - 9 SP - 156 EP - 162 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Goebel, Ronald A1 - Xie, Zai-Lai A1 - Neumann, Mike A1 - Günter, Christina A1 - Loebbicke, Ruben A1 - Kubo, Shiori A1 - Titirici, Maria-Magdalena A1 - Giordano, Cristina A1 - Taubert, Andreas T1 - Synthesis of mesoporous carbon/iron carbide hybrids with unusually high surface areas from the ionic liquid precursor [Bmim][FeCl4] JF - CrystEngComm N2 - Mesoporous carbon/iron carbide hybrid materials with surface areas reaching 800 m(2) g(-1) were synthesized via an exotemplating route using monolithic mesoporous silica as template and the ionic liquid 1-butyl-3-methylimidazolium tetrachloridoferrate(III) [Bmim][FeCl4] as carbon and iron source. After heat treatment (750 degrees C under argon) of the [Bmim][FeCl4] precursor confined within the silica matrix, the silica exotemplate was removed with HF leaving the mesoporous C/Fe3C hybrid behind. The surface areas and the pore sizes depend on the exotemplate and the surface areas a significantly larger than any other surface area reported for C/Fe3C hybrid materials so far. The approach is thus a prototype for the synthesis of high-surface area iron carbide-based hybrid materials with potential application in catalysis. Y1 - 2012 U6 - https://doi.org/10.1039/c2ce25064k SN - 1466-8033 VL - 14 IS - 15 SP - 4946 EP - 4951 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Koeth, Anja A1 - Tiersch, Brigitte A1 - Appelhans, Dietmar A1 - Gradzielski, Michael A1 - Cölfen, Helmut A1 - Koetz, Joachim T1 - Synthesis of Core-Shell Gold Nanoparticles with Maltose-Modified Poly(Ethyleneimine) JF - Journal of dispersion science and technology N2 - The synthesis of ultrafine gold nanoparticles in presence of maltose-modified hyperbranched poly(ethyleneimines) (PEI) is described. The polymer acted as both a reducing and stabilising agent in the particle formation process. The nanoparticles were characterized by means of dynamic light scattering (DLS), transmission electron microscopy (TEM), analytical ultracentrifugation (AUC), small-angle x-ray scattering (SAXS), and small-angle neutron scattering (SANS). The mechanism of nanoparticle formation can be described in two steps. The reduction process of the Au3+ ions located in the inner coil region of the hyperbranched PEI led to the formation of a compact gold core, and is accompanied by a collapse of the polymer coil. Therefore, in the subsequent reduction process a gold-polymer hybrid shell is formed. By using the PEI of higher molar mass, core-shell gold nanoparticles of about 3.6 nm size with a more narrow size distribution and special fluorescence behavior could be synthesized. KW - Gold nanoparticles KW - gold-polymer hybrid shell KW - maltose-modified poly(ethyleneimine) Y1 - 2012 U6 - https://doi.org/10.1080/01932691.2010.530084 SN - 0193-2691 VL - 33 IS - 1-3 SP - 52 EP - 60 PB - Taylor & Francis Group CY - Philadelphia ER - TY - JOUR A1 - Schmidt, Bernd A1 - Krehl, Stefan A1 - Sotelo-Meza, Veronica T1 - Synthesis of chromanes through RCM-Transfer hydrogenation JF - Synthesis N2 - A sequential ruthenium-catalyzed ring-closing metathesis-transfer hydrogenation sequence has been established as a synthesis of chromanes starting from 2-(allyloxy)styrenes. The sequence requires only one precatalyst, the first-generation Grubbs catalyst, which is converted into a ruthenium hydride species in situ. Propan-2-ol serves as a chemical trigger for the formation of the ruthenium hydride and as hydrogen source. KW - ruthenium KW - chromanes KW - tandem reactions KW - metathesis KW - styrenes Y1 - 2012 U6 - https://doi.org/10.1055/s-0031-1289758 SN - 0039-7881 VL - 44 IS - 11 SP - 1603 EP - 1613 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Schmidt, Bernd A1 - Krehl, Stefan A1 - Kelling, Alexandra A1 - Schilde, Uwe T1 - Synthesis of 8-Aryl-Substituted Coumarins based on Ring-Closing Metathesis and Suzuki-Miyaura coupling - synthesis of a Furyl Coumarin natural product from Galipea panamensis JF - The journal of organic chemistry N2 - The synthesis of 7-methoxy-8-(4-methyl-3-furyl)-2H-chromen-2-one, a natural product with antileishmanial activity recently isolated from the plant Galipea panamensis, is described. The key step is a Suzuki-Miyaura coupling of a furan-3-boronic acid and an 8-halocoumarin, which is advantageously synthesized using a ring-closing metathesis reaction. Several non-natural analogues are also available along these lines. Y1 - 2012 U6 - https://doi.org/10.1021/jo2026564 SN - 0022-3263 VL - 77 IS - 5 SP - 2360 EP - 2367 PB - American Chemical Society CY - Washington 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 - Kleinpeter, Erich A1 - Heydenreich, Matthias A1 - Koch, Andreas A1 - Linker, Torsten T1 - Synthesis and NMR spectroscopic conformational analysis of esters of 4-hydroxy-cyclohexanone-the more polar the molecule the more stable the axial conformer N2 - The esters of 4-hydroxy-cyclohexanone and a series of carboxylic acids R-COOH with R of different electronic and steric influence (R=Me, Et, n-Pr, i-Pr, n-Bu, i-Bu, sec-Bu, t-Bu, CF3, CH2Cl, CHCl2, CCl3, CH2Br, CHBr2, and CBr3) were synthesized and the conformational equilibria studied by 1H and 13C NMR spectroscopy at 103 K and at 295 K, respectively. The geometry of optimized structures of the axial/equatorial chair conformers was computed at the ab initio MO and DFT levels of theory. Only one preferred conformation was obtained for the axial and the equatorial conformer as well. When comparing the conformational equilibria of the cyclohexanone esters with those of the corresponding cyclohexyl esters a certain polarity contribution of the cyclohexanone framework was revealed, which is independent of the substituent effects and increases the stability of the axial conformers by a constant amount. Y1 - 2012 SN - 0040-4020 ER - TY - JOUR A1 - Kleinpeter, Erich A1 - Heydenreich, Matthias A1 - Koch, Andreas A1 - Linker, Torsten T1 - Synthesis and NMR spectroscopic conformational analysis of esters of 4-hydroxy-cyclohexanone-the more polar the molecule the more stable the axial conformer JF - Tetrahedron N2 - The esters of 4-hydroxy-cyclohexanone and a series of carboxylic acids R-COOH with R of different electronic and steric influence (R=Me, Et, n-Pr, i-Pr, n-Bu, i-Bu, sec-Bu, t-Bu, CF3, CH2Cl, CHCl2, CCl3, CH2Br, CHBr2, and CBr3) were synthesized and the conformational equilibria studied by H-1 and C-13 NMR spectroscopy at 103 K and at 295 K, respectively. The geometry of optimized structures of the axial 'equatorial chair conformers was computed at the ab initio MO and DFT levels of theory. Only one preferred conformation was obtained for the axial and the equatorial conformer as well. When comparing the conformational equilibria of the cyclohexanone esters with those of the corresponding cyclohexyl esters a certain polarity contribution of the cyclohexanone framework was revealed, which is independent of the substituent effects and increases the stability of the axial conformers by a constant amount. KW - 4-Substituted cyclohexanones KW - Conformational analysis KW - Dynamic NMR KW - Simulation of H-1 NMR spectra KW - Quantum chemical calculations KW - ALTONA equation Y1 - 2012 U6 - https://doi.org/10.1016/j.tet.2012.01.022 SN - 0040-4020 VL - 68 IS - 10 SP - 2363 EP - 2373 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Lazareva, Nataliya F. A1 - Albanov, Alexander I. A1 - Shainyan, Bagrat A. A1 - Kleinpeter, Erich T1 - Synthesis and conformational properties of substituted 1,4,2-oxazasilinanes: low temperature NMR study and quantum chemical calculations Y1 - 2012 UR - http://www.sciencedirect.com/science/article/pii/S0040402011018321 U6 - https://doi.org/10.1016/j.tet.2011.11.077 ER - TY - JOUR A1 - Lazareva, Nataliya F. A1 - Albanov, Alexander I. A1 - Shainyan, Bagrat A. A1 - Kleinpeter, Erich T1 - Synthesis and conformational properties of substituted 1,4,2-oxazasilinanes low temperature NMR study and quantum chemical calculations JF - Tetrahedron N2 - A number of N-substituted 2,2-dimethyl-1,4,2-oxazasilinanes 1 were synthesized and studied by variable temperature dynamic H-1 and C-13 NMR spectroscopy, room temperature N-15 NMR spectroscopy and theoretical calculations at the DFT and MP2 levels of theory. Both the preferred conformers were assigned and the barrier to the ring inversion of the saturated six-membered ring determined. From 1 the corresponding methyl iodide salts were produced, their structure studied by X-ray analysis and found to be in excellent agreement with the results of the theoretical calculations. KW - 1,4,2-Oxazasilinanes KW - Conformational analysis KW - Dynamic NMR KW - X-ray analysis KW - Quantum chemical calculations Y1 - 2012 U6 - https://doi.org/10.1016/j.tet.2011.11.077 SN - 0040-4020 VL - 68 IS - 4 SP - 1097 EP - 1104 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Shainyan, Bagrat A. A1 - Kirpichenko, Svetlana V. A1 - Kleinpeter, Erich T1 - Synthesis and conformational properties of 1,3-dimethyl-3-phenyl-1,3-azasilinane low temperature dynamic NMR and computational study JF - Arkivoc : free online journal of organic chemistry N2 - 1,3-Dimethyl-3-phenyl-1,3-azasilinane was synthesized and its conformational behavior was studied by the low temperature NMR spectroscopy and quantum chemical calculations. The compound was shown to exist as an equilibrium mixture of the PhaxMeeq and PheqMeax chair conformers with the N-methyl substituent in equatorial position. The barrier to ring inversion was also determined. KW - 1,3-Dimethyl-3-phenyl-1,3-azasilinane KW - conformational analysis KW - low temperature NMR spectroscopy KW - quantum chemical calculations Y1 - 2012 SN - 1551-7004 IS - 24 SP - 175 EP - 185 PB - ARKAT CY - Gainesville ER - TY - JOUR A1 - Kleinpeter, Erich A1 - Schainyan, Bagrat A. A1 - Kirpichenko, Svetlane V. T1 - Synthesis and conformational properties of 1,3-dimethyl-3-phenyl-1,3-azasilinane : low temperature dynamic NMR and computational study N2 - 1,3-Dimethyl-3-phenyl-1,3-azasilinane was synthesized and its conformational behavior was studied by the low temperature NMR spectroscopy and quantum chemical calculations. The compound was shown to exist as an equilibrium mixture of the PhaxMeeq and PheqMeax chair conformers with the N-methyl substituent in equatorial position. The barrier to ring inversion was also determined. Y1 - 2012 SN - 1551-7004 ER - TY - JOUR A1 - Shainyan, Bagrat A. A1 - Kirpichenko, Svetlana V. A1 - Kleinpeter, Erich T1 - Synthesis and conformational analysis of 1,3-azasilinanes JF - Tetrahedron N2 - 1-Isopropyl-3-methyl-3-phenyl-1,3-azasilinane 1 and 1-isopropyl-3,3-dimethyl-1,3-azasilinane 2 were synthesized and a detailed analysis of their NMR spectra, conformational equilibria and ring inversion processes is presented. Low temperature H-1/C-13 NMR spectroscopy, iteration of the H-1 NMR spectra and quantum chemical calculations showed slight predominance of the PheqMeax over the PhaxMeeq conformer of 1 at low temperature. The barrier for the chair to chair interconversion of both compounds was measured to be 8.25 kcal/mol. KW - 1,3-Azasilinanes KW - Conformational analysis KW - Dynamic NMR spectroscopy KW - Quantum chemical calculations KW - Ring current effect Y1 - 2012 U6 - https://doi.org/10.1016/j.tet.2012.05.106 SN - 0040-4020 VL - 68 IS - 36 SP - 7494 EP - 7501 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Melchert, Christian A1 - Yongvongsoontorn, Nunnarpas A1 - Behl, Marc A1 - Lendlein, Andreas T1 - Synthesis and characterization of telechelic oligoethers with terminal cinnamylidene acetic acid moieties JF - Journal of applied biomaterials & functional materials N2 - Purpose: The formation of photoresponsive hydrogels were reported by irradiation of star-shaped poly(ethylene glycol)s with terminal cinnamylidene acetic acid (CAA) groups, which are capable of a photoinduced [2+2] cycloaddition. In this study we explored whether oligo(ethylene glycol) s and oligo(propylene glycol)s of varying molecular architecture (linear or star-shaped) or molecular weights could be functionalized with CAA as terminal groups by esterification or by amide formation. Methods: Oligo(ethylene glycol) (OEG) and oligo(propylene glycol) (OPG) with varying molecular architecture (linear, star-shaped) and weight average molecular weights between 1000 and 5000 g.mol(-1) were functionalized by means of esterification of hydroxyl or amine endgroups with cinnamylidene acetic acid (CAA) or cinnamylidene acetyl chloride (CAC) as telechelic endgroups. The chemical structure, thermal properties, and molecular weights of the oligoethers obtained were determined by NMR spectroscopy, UV spectroscopy, DSC, and MALDI-TOF. Results: CAA-functionalized linear and star-shaped OEGs or OPGs could be obtained with a degree of functionalization higher than 90%. In MALDI-TOF measurements an increase in Mw of about 150 g.mol(-1) (for each terminal end) after the functionalization reaction was observed. OEGCAA and OPGCAA showed an increase in glass transition temperature (T-g) from about -70 degrees C to -50 degrees C, compared to the unfunctionalized oligoethers. In addition, the melting temperature (T-m) of OEGCAA decreased from about 55 C to 30 degrees C, which can be accounted for by the hampered crystallization of the precursors because of the bulky CAA end groups as well as by the loss of the hydroxyl telechelic end groups. Conclusion: The synthesis of photoresponsive oligoethers containing cinnamylidene acetic acid as telechelic endgroup was reported and high degrees of functionalization could be achieved. Such photosensitive oligomers are promising candidates as reactive precursors, for the preparation of biocompatible high molecular weight polymers and polymer networks. KW - Biocompatible polymers KW - Cinnamylidene acetic acid KW - Photoresponsive polymers Y1 - 2012 U6 - https://doi.org/10.5301/JABFM.2012.10364 SN - 2280-8000 VL - 10 IS - 3 SP - 185 EP - 190 PB - Wichtig CY - Milano ER - TY - JOUR A1 - Paz, Cristian A1 - Peter, Martin G. A1 - Schmidt, Bernd A1 - Becerra, Jose A1 - Gutierrez, Margarita A1 - Astudillo, Luis A1 - Silva, Mario T1 - Synthesis and AChE inhibiting activity of 2, 4 substituted 6-Phenyl Pyrimidines JF - Journal of the Chilean Chemical Society N2 - Novel substituted pyrimidines were synthesized from methyl 2,4-dioxo-4-phenyl-butanoate (I-A) and urea, followed by Mitsunobu coupling of I-A with benzyl or allyl alcohol to give the corresponding 2-hydroxypyrimidine ethers in good yields. Saponification of I-A, followed by reaction with benzyl or allyl amines in the presence of TBTU yielded 2-hydroxy-6-phenyl-pyrimidine 4-carboxamides. AChE and BuChE assays revealed 2-hydroxy-6-phenyl-pyrimidine-4-carboxyallyamide as the most active compound, IC50=90 mu M, with no inhibition of BuChE. KW - Pyrimidines KW - inhibition AChE KW - mitsunobu KW - TBTU Y1 - 2012 SN - 0717-9324 VL - 57 IS - 3 SP - 1292 EP - 1294 PB - Sociedad Chilena De Quimica CY - Concepcion ER - TY - JOUR A1 - Kleinpeter, Erich A1 - Csütörtöki, Renáta A1 - Szatmári, István A1 - Koch, Andreas A1 - Fulop, Ferenc T1 - Syntheses and conformational analyses of new naphth[1,2-e][1,3]oxazino[3,2-c]quinazolin-13-ones N2 - The syntheses of naphth[1,2-e][1,3]oxazino[3,2-c]quinazolin-13-one derivatives (3a-f) were achieved by the solvent-free heating of benzyloxycarbonyl-protected intermediates (2a-f) with MeONa. For intermediates 2a-f, prepared by the reactions of substituted aminonaphthols with benzyl N-(2-formylphenyl)carbamate, not only the expected trans ring form B and chain form A1, but also the rearranged chain form A2 as a new tautomer were detected in DMSO at room temperature. The quantity of A2 in the tautomeric mixture was changed with time. Conformational analyses of the target heterocycles 3a-f by NMR spectroscopy and accompanying theoretical calculations at the DFT level of theory revealed that the oxazine ring preferred a twisted chair conformation and the quinazolone ring was planar. Besides the conformations, both the configurations at C-7a and C-15 and the preferred rotamers of the 1-naphthyl substituent at C-15 were assigned, which allowed evaluation of the aryl substituent-dependent steric hindrance in this part of the molecules. Configurational assignments were corroborated by quantifying the ring current effect of 15-aryl in terms of spatial NICS. Y1 - 2012 ER - TY - JOUR A1 - Csütörtöki, Renata A1 - Szatmari, Istvan A1 - Koch, Andreas A1 - Heydenreich, Matthias A1 - Kleinpeter, Erich A1 - Fulop, Ferenc T1 - Syntheses and conformational analyses of new naphth[1,2-e][1,3]oxazino[3,2-c] quinazolin-13-ones JF - Tetrahedron N2 - The syntheses of naphth[1,2-e][1,3]oxazino[3,2-c]quinazolin-13-one derivatives (3a-f) were achieved by the solvent-free heating of benzyloxycarbonyl-protected intermediates (2a-f) with MeONa. For intermediates 2a-f, prepared by the reactions of substituted aminonaphthols with benzyl N-(2-formylphenyl)carbamate, not only the expected trans ring form B and chain form A(1), but also the rearranged chain form A(2) as a new tautomer were detected in DMSO at room temperature. The quantity of A(2) in the tautomeric mixture was changed with time. Conformational analyses of the target heterocycles 3a-f by NMR spectroscopy and accompanying theoretical calculations at the DFT level of theory revealed that the oxazine ring preferred a twisted chair conformation and the quinazolone ring was planar. Besides the conformations, both the configurations at C-7a and C-15 and the preferred rotamers of the 1-naphthyl substituent at C-15 were assigned, which allowed evaluation of the aryl substituent-dependent steric hindrance in this part of the molecules. Configurational assignments were corroborated by quantifying the ring current effect of 15-aryl in terms of spatial NICS. KW - Naphthoxazinoquinazolinones KW - Aminonaphthols KW - NMR spectroscopy KW - Conformational analysis KW - Theoretical calculations KW - Ring current effect Y1 - 2012 U6 - https://doi.org/10.1016/j.tet.2012.04.026 SN - 0040-4020 VL - 68 IS - 24 SP - 4600 EP - 4608 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Risse, Sebastian A1 - Kussmaul, Bjoern A1 - Krüger, Hartmut A1 - Kofod, Guggi T1 - Synergistic improvement of actuation properties with compatibilized high permittivity filler JF - Advanced functional materials N2 - Electroactive polymers can be used for actuators with many desirable features, including high electromechanical energy density, low weight, compactness, direct voltage control, and complete silence during actuation. These features may enable personalized robotics with much higher ability to delicately manipulate their surroundings than can be achieved with currently available actuators; however, much work is still necessary to enhance the electroactive materials. Electric field-driven actuator materials are improved by an increase in permittivity and by a reduction in stiffness. Here, a synergistic enhancement method based on a macromolecular plasticizing filler molecule with a combination of both high dipole moment and compatibilizer moieties, synthesized to simultaneously ensure improvement of electromechanical properties and compatibility with the host matrix is presented. Measurements show an 85% increase in permittivity combined with 290% reduction in mechanical stiffness. NMR measurements confirm the structure of the filler while DSC measurements confirm that it is compatible with the host matrix at all the mixture ratios investigated. Actuation strain measurements in the pure shear configuration display an increase in sensitivity to the electrical field of more than 450%, confirming that the filler molecule does not only improve dielectric and mechanical properties, it also leads to a synergistic enhancement of actuation properties by simple means. KW - allycyanide KW - silicone-based dielectric elastomer actuators KW - permittivity enhancement KW - compatibilized filler molecules Y1 - 2012 U6 - https://doi.org/10.1002/adfm.201200320 SN - 1616-301X VL - 22 IS - 18 SP - 3958 EP - 3962 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Navirian, H. A1 - Shayduk, R. A1 - Leitenberger, Wolfram A1 - Goldshteyn, J. A1 - Gaal, P. A1 - Bargheer, Matias T1 - Synchrotron-based ultrafast x-ray diffraction at high repetition rates JF - Review of scientific instruments : a monthly journal devoted to scientific instruments, apparatus, and techniques N2 - We present a setup for ultrafast x-ray diffraction (UXRD) based at the storage ring BESSY II, in particular, a pump laser that excites the sample using 250 fs laser-pulses at repetition rates ranging from 208 kHz to 1.25 MHz. We discuss issues connected to the high heat-load and spatio-temporal alignment strategies in the context of a UXRD experiment at high repetition rates. The spatial overlap between laser pump and x-ray probe pulse is obtained with 10 mu m precision and transient lattice changes can be recorded with an accuracy of delta a/a(0) = 10(-6). We also compare time-resolved x-ray diffraction signals from a laser excited LSMO/STO superlattice with phonon dynamics simulations. From the analysis we determine the x-ray pulse duration to 120 ps in standard operation mode and below 10 ps in low-alpha mode. Y1 - 2012 U6 - https://doi.org/10.1063/1.4727872 SN - 0034-6748 VL - 83 IS - 6 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Zhong, Qi A1 - Metwalli, Ezzeldin A1 - Kaune, Gunar A1 - Rawolle, Monika A1 - Bivigou Koumba, Achille Mayelle A1 - Laschewsky, André A1 - Papadakis, Christine M. A1 - Cubitt, Robert A1 - Müller-Buschbaum, Peter T1 - Switching kinetics of thin thermo-responsive hydrogel films of poly(monomethoxy-diethyleneglycol-acrylate) probed with in situ neutron reflectivity JF - Soft matter N2 - The switching kinetics of thin thermo-responsive hydrogel films of poly(monomethoxy-diethyleneglycol-acrylate) (PMDEGA) are investigated. Homogeneous and smooth PMDEGA films with a thickness of 35.9 nm are prepared on silicon substrates by spin coating. As probed with white light interferometry, PMDEGA films with a thickness of 35.9 nm exhibit a phase transition temperature of the lower critical solution temperature (LCST) type of 40 degrees C. In situ neutron reflectivity is performed to investigate the thermo-responsive behavior of these PMDEGA hydrogel films in response to a sudden thermal stimulus in deuterated water vapor atmosphere. The collapse transition proceeds in a complex way which can be seen as three steps. The first step is the shrinkage of the initially swollen film by a release of water. In the second step the thickness remains constant with water molecules embedded in the film. In the third step, perhaps due to a conformational rearrangement of the collapsed PMDEGA chains, water is reabsorbed from the vapor atmosphere, thereby giving rise to a relaxation process. Both the shrinkage and relaxation processes can be described by a simple model of hydrogel deswelling. Y1 - 2012 U6 - https://doi.org/10.1039/c2sm25401h SN - 1744-683X VL - 8 IS - 19 SP - 5241 EP - 5249 PB - Royal Society of Chemistry CY - Cambridge ER - TY - THES A1 - Lohmann, Dirk T1 - Sustainable management of semi-arid African savannas under environmental and political change T1 - Nachhaltige Nutzung semiarider Savannen in Afrika unter dem Einfluss von klimatischem und politischem Wandel N2 - Drylands cover about 40% of the earth’s land surface and provide the basis for the livelihoods of 38% of the global human population. Worldwide, these ecosystems are prone to heavy degradation. Increasing levels of dryland degradation result a strong decline of ecosystem services. In addition, in highly variable semi-arid environments changing future environmental conditions will potentially have severe consequences for productivity and ecosystem dynamics. Hence, global efforts have to be made to understand the particular causes and consequences of dryland degradation and to promote sustainable management options for semi-arid and arid ecosystems in a changing world. Here I particularly address the problem of semi-arid savanna degradation, which mostly occurs in form of woody plant encroachment. At this, I aim at finding viable sustainable management strategies and improving the general understanding of semi-arid savanna vegetation dynamics under conditions of extensive livestock production. Moreover, the influence of external forces, i.e. environmental change and land reform, on the use of savanna vegetation and on the ecosystem response to this land use is assessed. Based on this I identify conditions and strategies that facilitate a sustainable use of semi-arid savanna rangelands in a changing world. I extended an eco-hydrological model to simulate rangeland vegetation dynamics for a typical semi-arid savanna in eastern Namibia. In particular, I identified the response of semi-arid savanna vegetation to different land use strategies (including fire management) also with regard to different predicted precipitation, temperature and CO2 regimes. Not only environmental but also economic and political constraints like e.g. land reform programmes are shaping rangeland management strategies. Hence, I aimed at understanding the effects of the ongoing process of land reform in southern Africa on land use and the semi-arid savanna vegetation. Therefore, I developed and implemented an agent-based ecological-economic modelling tool for interactive role plays with land users. This tool was applied in an interdisciplinary empirical study to identify general patterns of management decisions and the between-farm cooperation of land reform beneficiaries in eastern Namibia. The eco-hydrological simulations revealed that the future dynamics of semi-arid savanna vegetation strongly depend on the respective climate change scenario. In particular, I found that the capacity of the system to sustain domestic livestock production will strongly depend on changes in the amount and temporal distribution of precipitation. In addition, my simulations revealed that shrub encroachment will become less likely under future climatic conditions although positive effects of CO2 on woody plant growth and transpiration have been considered. While earlier studies predicted a further increase in shrub encroachment due to increased levels of atmospheric CO2, my contrary finding is based on the negative impacts of temperature increase on the drought sensitive seedling germination and establishment of woody plant species. Further simulation experiments revealed that prescribed fires are an efficient tool for semi-arid rangeland management, since they suppress woody plant seedling establishment. The strategies tested have increased the long term productivity of the savanna in terms of livestock production and decreased the risk for shrub encroachment (i.e. savanna degradation). This finding refutes the views promoted by existing studies, which state that fires are of minor importance for the vegetation dynamics of semi-arid and arid savannas. Again, the difference in predictions is related to the bottleneck at the seedling establishment stage of woody plants, which has not been sufficiently considered in earlier studies. The ecological-economic role plays with Namibian land reform beneficiaries showed that the farmers made their decisions with regard to herd size adjustments according to economic but not according to environmental variables. Hence, they do not manage opportunistically by tracking grass biomass availability but rather apply conservative management strategies with low stocking rates. This implies that under the given circumstances the management of these farmers will not per se cause (or further worsen) the problem of savanna degradation and shrub encroachment due to overgrazing. However, as my results indicate that this management strategy is rather based on high financial pressure, it is not an indicator for successful rangeland management. Rather, farmers struggle hard to make any positive revenue from their farming business and the success of the Namibian land reform is currently disputable. The role-plays also revealed that cooperation between farmers is difficult even though obligatory due to the often small farm sizes. I thus propose that cooperation needs to be facilitated to improve the success of land reform beneficiaries. N2 - Semiaride (halbtrockene) Savannen bedecken große Teile der Erdoberfläche und sichern die Lebensgrundlage von vielen Millionen Menschen. Die häufigste Form der Landnutzung in diesen Trockengebieten ist die Produktion von Vieh in extensiver Weidelandbewirtschaftung. In Folge klimatischer Veränderungen und als Konsequenz aus der teils intensiven Beweidung dieser Trockengebiete kommt es häufig zur Degradierung derselben in Form einer Zunahme von ‚unerwünschter‘ holziger Vegetation auf Kosten von futterverwertbaren Gräsern. Dieser als Verbuschung bezeichnete Prozess hat schwere negative Auswirkungen auf die betroffenen Ökosysteme und ist die Ursache für einen zunehmenden Rückgang der ökonomischen Leistungsfähigkeit der betroffenen Betriebe. In meiner Dissertation befasse ich mich mit den Auswirkungen von Klimawandel und politischen Veränderungen auf die Savannenvegetation im südlichen Afrika und auf die Möglichkeiten für die Nutzung dieser Ökosysteme in Form von Viehwirtschaft. Hierbei möchte ich sowohl das allgemeine Verständnis der ökologischen Zusammenhänge verbessern, als auch Strategien für die nachhaltige Nutzung der Savannen identifizieren und bewerten. Da nicht nur ökologische, sondern auch ökonomische und politische Einflussfaktoren, wie zum Beispiel die umfangreichen Landumverteilungen im Rahmen der Bodenreform im südlichen Afrika auf die tatsächliche Landnutzung wirken, habe ich im Rahmen der Dissertation zudem untersucht, nach welchen Umwelt und Kapitalvariablen sich die Farmer, welche Ihr Land im Rahmen der Bodenreform zugeteilt bekommen haben, bei Ihren Entscheidungen richten. Methodisch verwende ich verschiedene Simulationsmodelle, welche zur Untersuchung der langfristigen Veränderungen von verschiedensten Szenarien (Klimawandel, Landnutzung) geeignet sind. Hierbei habe ich teilweise bestehende Modelle angepasst, aber auch ein neues Modell, welches zur Befragung von Farmern in Namibia verwendet wurde, entwickelt. Meine Dissertation führt im Wesentlichen zu vier Erkenntnissen: Erstens, zeigen meine Ergebnisse, welche große Bedeutung die spezifischen ökologischen Eigenschaften der Bäume und Sträucher in semiariden Savannen für die Vorhersage der Entwicklung dieser Systeme unter Klimawandel hat. Hierbei zeigte sich, dass insbesondere die Sensitivität der Keimlinge gegenüber Trockenheit und Feuer eine entscheidende Rolle spielt. Daraus folgt die zweite wesentliche Erkenntnis: Feuer eignet sich in herausragender Weise, um halbtrockene Savannen vor der Verbuschung zu bewahren. Drittens haben die Rollenspiele mit Farmern in Namibia gezeigt, dass deren Entscheidungen im Wesentlichen von finanziellen Schwierigkeiten und nicht von Umwelteinflüssen getrieben werden. Dennoch zeigten meine Ergebnisse, dass diese Farmer mit Ihrem derzeitigen Verhalten wahrscheinlich nicht zur weiteren Degradierung der Savannenvegetation beitragen. Die vierte, und mit am bedeutendste Erkenntnis aus meiner Arbeit ist, dass konservative Beweidungsstrategien mit geringen und konstanten Viehdichten notwendig sind um semiaride Savannen dauerhaft in ökologisch und ökonomisch nachhaltiger Weise zu Nutzen. KW - Savanne KW - nachhaltige Landnutzung KW - ökohydrologische Modellierung KW - Land Reform KW - Klimawandel KW - Savanna KW - sustainable land use KW - eco-hydrological modelling KW - land reform KW - climate change Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-65069 ER - TY - THES A1 - Falco, Camillo T1 - Sustainable biomass-derived hydrothermal carbons for energy applications T1 - Nachhaltiger, Biomasse-basierter Hydrothermalkohlenstoff für Energieanwendungen N2 - The need to reduce humankind reliance on fossil fuels by exploiting sustainably the planet renewable resources is a major driving force determining the focus of modern material research. For this reason great interest is nowadays focused on finding alternatives to fossil fuels derived products/materials. For the short term the most promising substitute is undoubtedly biomass, since it is the only renewable and sustainable alternative to fossil fuels as carbon source. As a consequence efforts, aimed at finding new synthetic approaches to convert biomass and its derivatives into carbon-based materials, are constantly increasing. In this regard, hydrothermal carbonisation (HTC) has shown to be an effective means of conversion of biomass-derived precursors into functional carbon materials. However the attempts to convert raw biomass, in particular lignocellulosic one, directly into such products have certainly been rarer. Unlocking the direct use of these raw materials as carbon precursors would definitely be beneficial in terms of HTC sustainability. For this reason, in this thesis the HTC of carbohydrate and protein-rich biomass was systematically investigated, in order to obtain more insights on the potentials of this thermochemical processing technique in relation to the production of functional carbon materials from crude biomass. First a detailed investigation on the HTC conversion mechanism of lignocellulosic biomass and its single components (i.e. cellulose, lignin) was developed based on a comparison with glucose HTC, which was adopted as a reference model. In the glucose case it was demonstrated that varying the HTC temperature allowed tuning the chemical structure of the synthesised carbon materials from a highly cross-linked furan-based structure (T = 180oC) to a carbon framework composed of polyaromatic arene-like domains. When cellulose or lignocellulosic biomass was used as carbon precursor, the furan rich structure could not be isolated at any of the investigated processing conditions. These evidences were indicative of a different HTC conversion mechanism for cellulose, involving reactions that are commonly observed during pyrolytic processes. The evolution of glucose-derived HTC carbon chemical structure upon pyrolysis was also investigated. These studies revealed that upon heat treatment (Investigated temperatures 350 – 900 oC) the furan-based structure was progressively converted into highly curved aromatic pre-graphenic domains. This thermal degradation process was observed to produce an increasingly more hydrophobic surface and considerable microporosity within the HTC carbon structure. In order to introduce porosity in the HTC carbons derived from lignocellulosic biomass, KOH chemical activation was investigated as an HTC post-synthesis functionalisation step. These studies demonstrated that HTC carbons are excellent precursors for the production of highly microporous activated carbons (ACs) and that the porosity development upon KOH chemical activation is dependent on the chemical structure of the HTC carbon, tuned by employing different HTC temperatures. Preliminary testing of the ACs for CO2 capture or high pressure CH4 storage yielded very promising results, since the measured uptakes of both adsorbates (i.e. CO2 and CH4) were comparable to top-performing and commercially available adsorbents, usually employed for these end-applications. The combined use of HTC and KOH chemical activation was also employed to produce highly microporous N-doped ACs from microalgae. The hydrothermal treatment of the microalgae substrate was observed to cause the depletion of the protein and carbohydrate fractions and the near complete loss (i.e. 90%) of the microalgae N-content, as liquid hydrolysis/degradation products. The obtained carbonaceous product showed a predominantly aliphatic character indicating the presence of alkyl chains presumably derived from the lipid fractions. Addition of glucose to the initial reaction mixture was found out to be extremely beneficial, because it allowed the fixation of a higher N amount, in the algae derived HTC carbons (i.e.  60%), and the attainment of higher product yields (50%). Both positive effects were attributed to Maillard type cascade reactions taking place between the monosaccharides and the microalgae derived liquid hydrolysis/degradation products, which were in this way recovered from the liquid phase. KOH chemical activation of the microalgae/glucose mixture derived HTC carbons produced highly microporous N-doped carbons. Although the activation process led to a major reduction of the N-content, the retained N-amount in the ACs was still considerable. These features render these materials ideal candidates for supercapacitors electrodes, since they provide extremely high surface areas, for the formation of electric double-layer, coupled to abundant heteroatom doping (i.e. N and O) necessary to obtain a pseudocapacitance contribution. N2 - Die Notwendigkeit, die Abhängigkeit der Menschheit von fossilen Brennstoffen zu reduzieren ist die treibende Kraft hinter aktuellen Forschungsanstrengungen in den Materialwissenschaften. Folglich besteht heutzutage ein erhebliches Interesse daran Alternativen zu Materialien, die aus fossilen Resourcen gewonnen werden, zu finden. Kurzfristig ist zweifellos Biomasse die vielversprechendste Alternative, da sie aus heutiger Sicht die einzige nicht-fossile, nachhaltige und nachwachsende Kohlenstoffquelle ist. Konsequenterweise werden die Antrengungen neue Syntheseansätze zur Konvertierung von Biomasse und ihren Derivaten in kohlenstoffbasierten Materialien forwährend erhöht. In diesem Zusammenhang hat sich die Hydrothermalkarbonisierung (HTC) als sehr vielseitiges Werkzeug zur Konvertierung von Biomasse-basierten Ausgangsstoffen in funktionale Kohlenstoffmaterialien herausgestellt. Dennoch gibt es bisher wenige Ansätze um rohe Biomasse, genauer gesagt Lignicellulose, direkt in funktionale Materialien umzusetzen. Könnte der direkte Einsatz von roher Biomasse Verfahren wie der HTC zugänglich gemacht werden, würde dies die Nachhaltigkeit des Verfahrens immens steigern. Daher wurde in dieser Dissertation die Hydrothermalkarbonisierung von kohlenhydratreicher (d. h. Lignicelluse) und proteinreicher (d. h. Microalgae) Biomasse systematisch analysiert. Diese Untersuchung galt dem Ziel einen besseren Einblick in das Potential dieser thermochemischen Verarbeitungsmethode funktionale Kohlenstoffmaterialien aus unverarbeiteter Biomasse hervorzubringen zu gewinnen. Die hergestellten Materialien wurden mittels chemischer Aktivierung nachträglich weiter behandelt. Dieser zusätzliche Verarbeitungsschritt ermöglichte die Herstellung hochporöser aktiverter Kohlenstoffe (AC). Die aus Lignicellulose gewonnenen ACs zeigten exzellente Eigenschaften bei der Aufnahme von CO2 und der Hochdruckspeicherung von CH4 währen die aus Microalgae gewonnen Eigenschaften an den Tag legten (z. B. hohe Oberfläche und N-Dotierung), welche sie zu vielversprechenden Materialien für Superkondensatoren machen. Die in dieser Dissertation präsentierte Arbeit zeigte außergewöhnliche Fortschritte in Richtung der Anwendung von unbehandelter Biomasse als Ausgangsmaterial für die Produktion von funktionalen Kohlenstoffen. KW - Biomasse KW - Kohlenmaterialien KW - Grüne Chemie KW - Nachhaltigkeit KW - Enegieanwendungen KW - Biomass KW - Carbon materials KW - Green Chemistry KW - Sustainability KW - Energy Applications Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-59785 ER - TY - JOUR A1 - Horovitz, Baruch A1 - Henkel, Carsten T1 - Surface plasmons at composite surfaces with diffusive charges JF - epl : a letters journal exploring the frontiers of physics N2 - Metal surfaces with disorder or with nanostructure modifications are studied, allowing for a localized charge layer (CL) in addition to continuous charges (CC) in the bulk, both charges having a compressional or diffusive nonlocal response. The notorious problem of "additional boundary conditions" is resolved with the help of a Boltzmann equation that involves the scattering between the two charge types. Depending on the strength of this scattering, the oscillating charges can be dominantly CC or CL; the surface plasmon (SP) resonance acquires then a relatively small linewidth, in agreement with a large set of data. With a few parameters our model describes a large variety of SP dispersions corresponding to observed data. Y1 - 2012 U6 - https://doi.org/10.1209/0295-5075/97/57010 SN - 0295-5075 VL - 97 IS - 5 PB - EDP Sciences CY - Mulhouse ER - TY - JOUR A1 - König, Tobias A1 - Sekhar, Y. Nataraja A1 - Santer, Svetlana T1 - Surface plasmon nanolithography impact of dynamically varying near-field boundary conditions at the air-polymer interface JF - Journal of materials chemistry N2 - It is well-known that surface plasmon generated near fields of suitably irradiated metal nano-structures can induce a patterning in an azobenzene-modified photosensitive polymer film placed on top. The change in the topography usually follows closely and permanently the underlying near field intensity pattern. With this approach, one can achieve a multitude of morphologies by additionally changing light intensity, polarization and the kind of metal used for nano-structuring. In this paper, we demonstrate that below a critical value of the polymer film thickness, the receding polymer material induces a change in refractive index of the glass-metal-polymer system, modifying the near field intensity distribution and causing a back-reaction on the flow of polymer material. This has a profound influence on the smallest size of topographical features that can be imprinted into the polymer. Y1 - 2012 U6 - https://doi.org/10.1039/c2jm15864g SN - 0959-9428 VL - 22 IS - 13 SP - 5945 EP - 5950 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Floss, Gereon A1 - Granucci, Giovanni A1 - Saalfrank, Peter T1 - Surface hopping dynamics of direct trans -> cis photoswitching of an azobenzene derivative in constrained adsorbate geometries JF - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr N2 - With ongoing miniaturization of electronic devices, the need for individually addressable, switchable molecules arises. An example are azobenzenes on surfaces which have been shown to be switchable between trans and cis forms. Here, we examine the "direct" (rather than substrate-mediated) channel of the trans -> cis photoisomerization after pi pi* excitation of tetra-tert-butyl-azobenzene physisorbed on surfaces mimicking Au(111) and Bi(111), respectively. In spirit of the direct channel, the electronic structure of the surface is neglected, the latter merely acting as a rigid platform which weakly interacts with the molecule via Van-der-Waals forces. Starting from thermal ensembles which represent the trans-form, sudden excitations promote the molecules to pi pi*-excited states which are non-adiabatically coupled among themselves and to a n pi*-excited and the ground state, respectively. After excitation, relaxation to the ground state by internal conversion takes place, possibly accompanied by isomerization. The process is described here by "on the fly" semiclassical surface hopping dynamics in conjunction with a semiempirical Hamiltonian (AM1) and configuration-interaction type methods. It is found that steric constraints imposed by the substrate lead to reduced but non-vanishing, trans -> cis reaction yields and longer internal conversion times than for the isolated molecule. Implications for recent experiments for azobenzenes on surfaces are discussed. KW - AM1 calculations KW - bismuth KW - configuration interactions KW - excited states KW - gold KW - isomerisation KW - organic compounds KW - photochemistry KW - van der Waals forces Y1 - 2012 U6 - https://doi.org/10.1063/1.4769087 SN - 0021-9606 VL - 137 IS - 23 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Lange, Maik A1 - Braune, Steffen A1 - Luetzow, Karola A1 - Richau, Klaus A1 - Scharnagl, Nico A1 - Weinhart, Marie A1 - Neffe, Axel T. A1 - Jung, Friedrich A1 - Haag, Rainer A1 - Lendlein, Andreas T1 - Surface functionalization of poly(ether imide) membranes with linear, methylated oligoglycerols for reducing thrombogenicity JF - Macromolecular rapid communications N2 - Materials for biomedical applications are often chosen for their bulk properties. Other requirements such as a hemocompatible surface shall be fulfilled by suitable chemical functionalization. Here we show, that linear, side-chain methylated oligoglycerols (OGMe) are more stable to oxidation than oligo(ethylene glycol) (OEG). Poly(ether imide) (PEI) membranes functionalized with OGMes perform at least as good as, and partially better than, OEG functionalized PEI membranes in view of protein resistance as well as thrombocyte adhesion and activation. Therefore, OGMes are highly potent surface functionalizing molecules for improving the hemocompatibility of polymers. KW - hemocompatibility KW - poly(ethylene glycol) KW - polyglycerol KW - polyimides KW - surface chemistry Y1 - 2012 U6 - https://doi.org/10.1002/marc.201200426 SN - 1022-1336 VL - 33 IS - 17 SP - 1487 EP - 1492 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Schildgen, Taylor F. A1 - Cosentino, D. A1 - Caruso, A. A1 - Buchwaldt, Robert A1 - Yildirim, C. A1 - Bowring, S. A. A1 - Rojay, B. A1 - Echtler, Helmut Peter A1 - Strecker, Manfred T1 - Surface expression of eastern Mediterranean slab dynamics: Neogene topographic and structural evolution of the southwest margin of the Central Anatolian Plateau, Turkey JF - TECTONICS N2 - The southwest margin of the Central Anatolian Plateau has experienced multiple phases of topographic growth, including the formation of localized highs prior to the Late Miocene that were later affected by wholesale uplift of the plateau margin. Our new biostratigraphic data limit the age of uplifted marine sediments at the southwest plateau margin at 1.5 km elevation to <7.17 Ma, and regional lithostratigraphic correlations imply that the age is <6.7 Ma. Single-grain CA-TIMS U-Pb zircon analyses from a reworked ash within the marine sediments yield dates as young as 10.6 Ma, indicating a maximum age that is consistent with the biostratigraphy. Our structural measurements within the uplifted region and fault inversion modeling agree with previous findings in surrounding regions, with early contraction followed by strike-slip and extensional deformation during uplift. Focal mechanisms from shallow earthquakes show that the extensional phase has continued to the present. Broad similarities in the change in the tectonic stress regime (after 8 Ma) and the onset of surface uplift (after 7 Ma) imply that deep-seated process(es) caused post-7 Ma uplift. The geometry of lithospheric slabs beneath the plateau margin, Pliocene to recent alkaline volcanism, and the uplift pattern with accompanying normal faulting point toward slab tearing and localized heating at the base of the lithosphere as a probable mechanism for post-7 Ma uplift of the southwest margin. Considering previous work in the region, there appears to be an important link between slab dynamics and surface uplift throughout the Anatolian Plateau’s southern margin. Y1 - 2012 U6 - https://doi.org/10.1029/2011TC003021 SN - 0278-7407 SN - 1944-9194 VL - 31 PB - AMER GEOPHYSICAL UNION CY - WASHINGTON ER - TY - JOUR A1 - Ellis, S. C. A1 - Bland-Hawthorn, Joss A1 - Lawrence, J. A1 - Horton, A. J. A1 - Trinh, C. A1 - Leon-Saval, S. G. A1 - Shortridge, K. A1 - Bryant, J. A1 - Case, S. A1 - Colless, M. A1 - Couch, W. A1 - Freeman, K. A1 - Gers, L. A1 - Glazebrook, K. A1 - Haynes, R. A1 - Lee, S. A1 - Löhmannsröben, Hans-Gerd A1 - O'Byrne, J. A1 - Miziarski, S. A1 - Roth, M. A1 - Schmidt, B. A1 - Tinney, C. G. A1 - Zheng, J. T1 - Suppression of the near-infrared OH night-sky lines with fibre Bragg gratings - first results JF - Monthly notices of the Royal Astronomical Society N2 - The background noise between 1 and 1.8 ?mu m in ground-based instruments is dominated by atmospheric emission from hydroxyl molecules. We have built and commissioned a new instrument, the Gemini Near-infrared OH Suppression Integral Field Unit (IFU) System (GNOSIS), which suppresses 103 OH doublets between 1.47 and 1.7?mu m by a factor of 1000 with a resolving power of 10?000. We present the first results from the commissioning of GNOSIS using the IRIS2 spectrograph at the Anglo-Australian Telescope. We present measurements of sensitivity, background and throughput. The combined throughput of the GNOSIS fore-optics, grating unit and relay optics is 36?per cent, but this could be improved to 46?per cent with a more optimal design. We measure strong suppression of the OH lines, confirming that OH suppression with fibre Bragg gratings will be a powerful technology for low-resolution spectroscopy. The integrated OH suppressed background between 1.5 and 1.7 mu m is reduced by a factor of 9 compared to a control spectrum using the same system without suppression. The potential of low-resolution OH-suppressed spectroscopy is illustrated with example observations of Seyfert galaxies and a low-mass star. The GNOSIS background is dominated by detector dark current below 1.67 mu m and by thermal emission above 1.67 mu m. After subtracting these, we detect an unidentified residual interline component of 860 +/- 210 photons s-1 m-2?arcsec-2?mu m-1, comparable to previous measurements. This component is equally bright in the suppressed and control spectra. We have investigated the possible source of the interline component, but were unable to discriminate between a possible instrumental artefact and intrinsic atmospheric emission. Resolving the source of this emission is crucial for the design of fully optimized OH suppression spectrographs. The next-generation OH suppression spectrograph will be focused on resolving the source of the interline component, taking advantage of better optimization for a fibre Bragg grating feed incorporating refinements of design based on our findings from GNOSIS. We quantify the necessary improvements for an optimal OH suppressing fibre spectrograph design. KW - atmospheric effects KW - instrumentation: miscellaneous KW - infrared: general Y1 - 2012 U6 - https://doi.org/10.1111/j.1365-2966.2012.21602.x SN - 0035-8711 VL - 425 IS - 3 SP - 1682 EP - 1695 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Quasthoff, Matthias A1 - Meinel, Christoph T1 - Supporting object-oriented programming of semantic-web software JF - IEEE transactions on systems, man, and cybernetics : Part C, Applications and reviews N2 - This paper presents the state of the art in the development of Semantic-Web-enabled software using object-oriented programming languages. Object triple mapping (OTM) is a frequently used method to simplify the development of such software. A case study that is based on interviews with developers of OTM frameworks is presented at the core of this paper. Following the results of the case study, the formalization of OTM is kept separate from optional but desirable extensions of OTM with regard to metadata, schema matching, and integration into the Semantic-Web infrastructure. The material that is presented is expected to not only explain the development of Semantic-Web software by the usage of OTM, but also explain what properties of Semantic-Web software made developers come up with OTM. Understanding the latter will be essential to get nonexpert software developers to use Semantic-Web technologies in their software. KW - Resource description framework KW - Software KW - Java KW - Data models KW - Programming KW - Interviews Y1 - 2012 U6 - https://doi.org/10.1109/TSMCC.2011.2151282 SN - 1094-6977 VL - 42 IS - 1 SP - 15 EP - 24 PB - Inst. of Electr. and Electronics Engineers CY - Piscataway ER - TY - JOUR A1 - de Vera, Jean-Pierre Paul A1 - Böttger, Ute A1 - de la Torre Nötzel, Rosa A1 - Sanchez, Francisco J. A1 - Grunow, Dana A1 - Schmitz, Nicole A1 - Lange, Caroline A1 - Hübers, Heinz-Wilhelm A1 - Billi, Daniela A1 - Baque, Mickael A1 - Rettberg, Petra A1 - Rabbow, Elke A1 - Reitz, Günther A1 - Berger, Thomas A1 - Möller, Ralf A1 - Bohmeier, Maria A1 - Horneck, Gerda A1 - Westall, Frances A1 - Jänchen, Jochen A1 - Fritz, Jörg A1 - Meyer, Cornelia A1 - Onofri, Silvano A1 - Selbmann, Laura A1 - Zucconi, Laura A1 - Kozyrovska, Natalia A1 - Leya, Thomas A1 - Foing, Bernard A1 - Demets, Rene A1 - Cockell, Charles S. A1 - Bryce, Casey A1 - Wagner, Dirk A1 - Serrano, Paloma A1 - Edwards, Howell G. M. A1 - Joshi, Jasmin Radha A1 - Huwe, Björn A1 - Ehrenfreund, Pascale A1 - Elsaesser, Andreas A1 - Ott, Sieglinde A1 - Meessen, Joachim A1 - Feyh, Nina A1 - Szewzyk, Ulrich A1 - Jaumann, Ralf A1 - Spohn, Tilman T1 - Supporting Mars exploration BIOMEX in Low Earth Orbit and further astrobiological studies on the Moon using Raman and PanCam technology JF - Planetary and space science N2 - The Low Earth Orbit (LEO) experiment Biology and Mars Experiment (BIOMEX) is an interdisciplinary and international space research project selected by ESA. The experiment will be accommodated on the space exposure facility EXPOSE-R2 on the International Space Station (ISS) and is foreseen to be launched in 2013. The prime objective of BIOMEX is to measure to what extent biomolecules, such as pigments and cellular components, are resistant to and able to maintain their stability under space and Mars-like conditions. The results of BIOMEX will be relevant for space proven biosignature definition and for building a biosignature data base (e.g. the proposed creation of an international Raman library). The library will be highly relevant for future space missions such as the search for life on Mars. The secondary scientific objective is to analyze to what extent terrestrial extremophiles are able to survive in space and to determine which interactions between biological samples and selected minerals (including terrestrial, Moon- and Mars analogs) can be observed under space and Mars-like conditions. In this context, the Moon will be an additional platform for performing similar experiments with negligible magnetic shielding and higher solar and galactic irradiation compared to LEO. Using the Moon as an additional astrobiological exposure platform to complement ongoing astrobiological LEO investigations could thus enhance the chances of detecting organic traces of life on Mars. We present a lunar lander mission with two related objectives: a lunar lander equipped with Raman and PanCam instruments which can analyze the lunar surface and survey an astrobiological exposure platform. This dual use of testing mission technology together with geo- and astrobiological analyses will significantly increase the science return, and support the human preparation objectives. It will provide knowledge about the Moon's surface itself and, in addition, monitor the stability of life-markers, such as cells, cell components and pigments, in an extraterrestrial environment with much closer radiation properties to the surface of Mars. The combination of a Raman data base of these data together with data from LEO and space simulation experiments, will lead to further progress on the analysis and interpretation of data that we will obtain from future Moon and Mars exploration missions. KW - Moon KW - Mars KW - Low Earth Orbit KW - Astrobiology KW - Instrumentation KW - Spectroscopy KW - Biosignature Y1 - 2012 U6 - https://doi.org/10.1016/j.pss.2012.06.010 SN - 0032-0633 VL - 74 IS - 1 SP - 103 EP - 110 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Ohuchi, Tomohiro A1 - Nishihara, Yu A1 - Kawazoe, Takaaki A1 - Spengler, Dirk A1 - Shiraishi, Rei A1 - Suzuki, Akio A1 - Kikegawa, Takumi A1 - Ohtani, Eiji T1 - Superplasticity in hydrous melt-bearing dunite Implications for shear localization in Earth's upper mantle JF - Earth & planetary science letters N2 - Deformation experiments on hydrous melt-bearing dunite (olivine+4 vol% orthopyroxene+4 vol% clinopyroxene with less than 2.5 vol% of the melt phase) were conducted at pressures of 1.3-5.7 GPa and temperatures of 1270-1490 K in order to explore the effect of intergranular fluids on the plastic flow of olivine in Earth's upper mantle. The strain rate was proportional to steady-state creep strength to the 2.1 power, and the creep strength markedly increased with increase in grain size. Developments of the crystallographic preferred orientation of olivine and flattening of olivine grains were hardly observed even after 33-55% shortening of the samples. These observations show that grain boundary sliding (GBS) dominated the deformation of olivine (i.e., superplasticity). The creep strength of hydrous melt-bearing dunite was 2-5 times lower than that of melt-free dunite. The dependence of creep rate on melt fraction is known to be expressed empirically as (epsilon) over dot(phi) = (epsilon) over dot(0) exp(alpha phi), where alpha is a constant and phi is the melt fraction. The experimentally obtained value of alpha was in the range of 150-230, corresponding to 5-7 times the reported values for the olivine-basalt system at 0.3 GPa (i.e., creep strength of dunite was efficiently reduced by the hydrous melt). Superplasticity is the dominant creep mechanism of olivine in fluid-bearing fine-grained peridotites under low-temperature and high-stress conditions (i.e., peridotite shear zones in the upper mantle). Superplasticity induced by geological fluids would play an important role in the shear localization (and thus initiation of subduction) in the upper mantle. KW - olivine KW - hydrous melt KW - grain boundary sliding KW - superplasticity KW - shear localization KW - subduction Y1 - 2012 U6 - https://doi.org/10.1016/j.epsl.2012.04.032 SN - 0012-821X VL - 335 IS - 12 SP - 59 EP - 71 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Böniger, Urs A1 - Tronicke, Jens T1 - Subsurface utility extraction and characterization combining GPR symmetry and polarization attributes JF - IEEE transactions on geoscience and remote sensing N2 - Polarization of the electromagnetic wavefield has significant implications for the acquisition and interpretation of ground-penetrating radar (GPR) data. Based on the geometrical and physical properties of the subsurface scatterer and the physical properties of its surrounding material, strong polarization phenomena might occur. Here, we develop an attribute-based analysis approach to extract and characterize buried utility pipes using two broadside antenna configurations. First, we enhance and extract the utilities by making use of their distinct symmetric nature through the application of a symmetry-enhancing image-processing algorithm known as phase symmetry. Second, we assess the polarization characteristics by calculating two attributes (polarization angle and linearity) using principal component analysis. Combination of attributes derived from these steps into a novel depolarization attribute allows one to efficiently detect and distinguish different utilities present within 3-D GPR data. The performance of our analysis approach is illustrated using synthetic examples and evaluated using field examples (including a dual-configuration 3-D data set) collected across a field site, where detailed ground-truth information is available. Our results demonstrate that the proposed approach allows for a more detailed extraction and combination of utility relevant information compared to approaches relying on single-component data and, thus, eases the interpretation of multicomponent GPR data sets. KW - Multicomponent ground-penetrating radar (GPR) data KW - phase symmetry KW - pipe detection KW - polarization analysis KW - principal component analysis (PCA) Y1 - 2012 U6 - https://doi.org/10.1109/TGRS.2011.2163413 SN - 0196-2892 SN - 1558-0644 VL - 50 IS - 3 SP - 736 EP - 746 PB - Inst. of Electr. and Electronics Engineers CY - Piscataway ER - TY - GEN A1 - Rothweiler, Monika A1 - Chilla, Solveig A1 - Clahsen, Harald T1 - Subject−verb agreement in Specific Language Impairment BT - a study of monolingual and bilingual German-speaking children T2 - Postprints der Universität Potsdam Humanwissenschaftliche Reihe N2 - This study investigates phenomena that have been claimed to be indicative of Specific Language Impairment (SLI) in German, focusing on subject-verb agreement marking. Longitudinal data from fourteen German-speaking children with SLI, seven monolingual and seven Turkish-German successive bilingual children, were examined. We found similar patterns of impairment in the two participant groups. Both the monolingual and the bilingual children with SLI had correct (present vs. preterit) tense marking and produced syntactically complex sentences such as embedded clauses and wh-questions, but were limited in reliably producing correct agreement-marked verb forms. These contrasts indicate that agreement marking is impaired in German-speaking children with SLI, without any necessary concurrent deficits in either the CP-domain or in tense marking. Our results also show that it is possible to identify SLI from an early successive bilingual child's performance in one of her two languages. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 510 KW - verb morphology KW - tense deficit KW - agreement deficit KW - Turkish−German SLI Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-415122 SN - 1866-8364 IS - 510 ER - TY - JOUR A1 - Rothweiler, Monika A1 - Chilla, Solveig A1 - Clahsen, Harald T1 - Subject-verb agreement in specific language impairment BT - a study of monolingual and bilingual German-speaking children JF - Bilingualism : language and cognition. N2 - This study investigates phenomena that have been claimed to be indicative of Specific Language Impairment (SLI) in German, focusing on subject-verb agreement marking. Longitudinal data from fourteen German-speaking children with SLI, seven monolingual and seven Turkish-German successive bilingual children, were examined. We found similar patterns of impairment in the two participant groups. Both the monolingual and the bilingual children with SLI had correct (present vs. preterit) tense marking and produced syntactically complex sentences such as embedded clauses and wh-questions, but were limited in reliably producing correct agreement-marked verb forms. These contrasts indicate that agreement marking is impaired in German-speaking children with SLI, without any necessary concurrent deficits in either the CP-domain or in tense marking. Our results also show that it is possible to identify SLI from an early successive bilingual child's performance in one of her two languages. KW - verb morphology KW - tense deficit KW - agreement deficit KW - Turkish-German SLI Y1 - 2012 U6 - https://doi.org/10.1017/S136672891100037X SN - 1366-7289 VL - 15 IS - 1 SP - 39 EP - 57 PB - Cambridge Univ. Press CY - New York ER -