TY - GEN A1 - Vink, Jorick Sandor A1 - Heger, Alexander A1 - Krumholz, Mark R. A1 - Puls, Joachim A1 - Banerjee, Shiladitya A1 - Castro, Norberto A1 - Chen, K.-J. A1 - Chenè, A.-N. A1 - Crowther, P. A. A1 - Daminelli, A. A1 - Gräfener, G. A1 - Groh, J. H. A1 - Hamann, Wolf-Rainer A1 - Heap, S. A1 - Herrero, A. A1 - Kaper, L. A1 - Najarro, F. A1 - Oskinova, Lida A1 - Roman-Lopes, A. A1 - Rosen, A. A1 - Sander, A. A1 - Shirazi, M. A1 - Sugawara, Y. A1 - Tramper, F. A1 - Vanbeveren, D. A1 - Voss, R. A1 - Wofford, A. A1 - Zhang, Y. T1 - Very massive stars in the local universe T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Recent studies have claimed the existence of very massive stars (VMS) up to 300 M⊙ in the local Universe. As this finding may represent a paradigm shift for the canonical stellar upper-mass limit of 150 M⊙, it is timely to discuss the status of the data, as well as the far-reaching implications of such objects. We held a Joint Discussion at the General Assembly in Beijing to discuss (i) the determination of the current masses of the most massive stars, (ii) the formation of VMS, (iii) their mass loss, and (iv) their evolution and final fate. The prime aim was to reach broad consensus between observers and theorists on how to identify and quantify the dominant physical processes. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 601 KW - stars: massive stars KW - stars: mass-loss KW - stars: stellar evolution Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-415220 SN - 1866-8372 IS - 601 ER - TY - THES A1 - Villalobs-Jimenez, Alonso T1 - Small-forest holders and community-based organizations: analyzing perceptions of confidence in land tenure security and trust in potential REDD counterparts in Central America Y1 - 2012 CY - Potsdam ER - TY - JOUR A1 - Vignon-Zellweger, Nicolas A1 - Rahnenführer, Jan A1 - Theuring, Franz A1 - Hocher, Berthold T1 - Analysis of cardiac and renal endothelin receptors by in situ hybridization in mice JF - Clinical laboratory : the peer reviewed journal for clinical laboratories and laboratories related to blood transfusion N2 - Background: Endothelin-1 (ET-1) is a multifunctional peptide, which is implicated in the renal and cardiac physicology as well as in many pathologies of these systems. ET-1's actions take place after the activation of two receptors: ETA and ETB. The expression of these receptors may be modulated during the pathologic process. The analysis of the distribution and level of expression of the receptors in animal models is therefore crucial. Methods: We developed a protocol for non-radioactive in situ hybridization for the mRNA of the two endothelin receptors on paraffin-embedded tissue using digoxigenin-labeled RNA probes. Results: In heart and kidney, the staining was reliable and specific. In a mouse model for endothelin/nitric oxide imbalance, cardiac ETB expression was reduced. The distribution of the receptors was in accordance with the actual knowledge. Differences in cell specific expression are discussed. Conclusions: We developed a protocol for the in situ hybridization of the endothelin receptors in mice. Given that the endothelin system is implicated in the development of many diseases, we believe that this protocol may be useful for a number of future preclinical studies. KW - Endothelin-1 KW - endothelin receptors KW - in situ hybridization KW - mouse Y1 - 2012 U6 - https://doi.org/10.7754/Clin.Lab.2012.120216 SN - 1433-6510 VL - 58 IS - 9-10 SP - 939 EP - 949 PB - Clin Lab Publ., Verl. Klinisches Labor CY - Heidelberg ER - TY - JOUR A1 - Vickers, Steven P. A1 - Cheetham, Sharon C. A1 - Birmingham, Gareth D. A1 - Rowley, Helen L. A1 - Headland, Katie R. A1 - Dickinson, Keith A1 - Grempler, Rolf A1 - Hocher, Berthold A1 - Mark, Michael A1 - Klein, Thomas T1 - Effects of the DPP-4 Inhibitor, Linagliptin, in Diet-Induced obese rats a comparison in Naive and Exenatide-Treated Animals JF - Clinical laboratory : the peer reviewed journal for clinical laboratories and laboratories related to blood transfusion N2 - Background: To assess the chronic effect of the DPP-4 inhibitor, linagliptin, alone, in combination with exenatide, and during exenatide withdrawal, in diet-induced obese (DIO) rats. Methods: Female Wistar rats were exposed to a cafeteria diet to induce obesity. Animals were then dosed with vehicle or linagliptin (3 mg/kg PO) orally once-daily for a 28 day period. In a subsequent study, rats received exenatide (either 3 or 30 mu g/kg/day) or vehicle by osmotic mini-pump for 28 days. In addition, groups of animals were dosed orally with linagliptin either alone or in combination with a 3 mu g/kg/day exenatide dose for the study duration. In a final study, rats were administered exenatide (30 mu g/kg/day) or vehicle by osmotic mini-pump for eleven days. Subsequently, exenatide-treated animals were transferred to vehicle or continued exenatide infusion for a further ten days. Animals transferred from exenatide to vehicle were also dosed orally with either vehicle or linagliptin. In all studies, body weight, food and water intake were recorded daily and relevant plasma parameters and carcass composition were determined. Results: In contrast to exenatide, linagliptin did not significantly reduce body weight or carcass fat in DIO rats versus controls. Linagliptin augmented the effect of exenatide to reduce body fat when given in combination but did not affect the body weight response. In rats withdrawn from exenatide, weight regain was observed such that body weight was not significantly different to controls. Linagliptin reduced weight regain after withdrawal of exenatide such that a significant difference from controls was evident. Conclusions: These data demonstrate that linagliptin does not significantly alter body weight in either untreated or exenatide-treated DIO rats, although it delays weight gain after exenatide withdrawal. This finding may suggest the utility of DPP-4 inhibitors in reducing body weight during periods of weight gain. KW - Dipeptidyl peptidase 4 inhibitor KW - Linagliptin KW - obesity KW - weight loss Y1 - 2012 U6 - https://doi.org/10.7754/Clin.Lab.2011.110919 SN - 1433-6510 VL - 58 IS - 7-8 SP - 787 EP - 799 PB - Clin Lab Publ., Verl. Klinisches Labor CY - Heidelberg ER - TY - JOUR A1 - Verheyen, Kris A1 - Baeten, Lander A1 - De Frenne, Pieter A1 - Bernhardt-Römermann, Markus A1 - Brunet, Jorg A1 - Cornelis, Johnny A1 - Decocq, Guillaume A1 - Dierschke, Hartmut A1 - Eriksson, Ove A1 - Hedl, Radim A1 - Heinken, Thilo A1 - Hermy, Martin A1 - Hommel, Patrick A1 - Kirby, Keith J. A1 - Naaf, Tobias A1 - Peterken, George A1 - Petrik, Petr A1 - Pfadenhauer, Joerg A1 - Van Calster, Hans A1 - Walther, Gian-Reto A1 - Wulf, Monika A1 - Verstraeten, Gorik T1 - Driving factors behind the eutrophication signal in understorey plant communities of deciduous temperate forests JF - The journal of ecology N2 - 1. Atmospheric nitrogen (N) deposition is expected to change forest understorey plant community composition and diversity, but results of experimental addition studies and observational studies are not yet conclusive. A shortcoming of observational studies, which are generally based on resurveys or sampling along large deposition gradients, is the occurrence of temporal or spatial confounding factors. 2. We were able to assess the contribution of N deposition versus other ecological drivers on forest understorey plant communities by combining a temporal and spatial approach. Data from 1205 (semi-)permanent vegetation plots taken from 23 rigorously selected understorey resurvey studies along a large deposition gradient across deciduous temperate forest in Europe were compiled and related to various local and regional driving factors, including the rate of atmospheric N deposition, the change in large herbivore densities and the change in canopy cover and composition. 3. Although no directional change in species richness occurred, there was considerable floristic turnover in the understorey plant community and a shift in species composition towards more shade-tolerant and nutrient-demanding species. However, atmospheric N deposition was not important in explaining the observed eutrophication signal. This signal seemed mainly related to a shift towards a denser canopy cover and a changed canopy species composition with a higher share of species with more easily decomposed litter. 4. Synthesis. Our multi-site approach clearly demonstrates that one should be cautious when drawing conclusions about the impact of atmospheric N deposition based on the interpretation of plant community shifts in single sites or regions due to other, concurrent, ecological changes. Even though the effects of chronically increased N deposition on the forest plant communities are apparently obscured by the effects of canopy changes, the accumulated N might still have a significant impact. However, more research is needed to assess whether this N time bomb will indeed explode when canopies will open up again. KW - atmospheric deposition KW - determinants of plant community diversity and structure KW - Ellenberg indicator values KW - forest herbs KW - forest management KW - large herbivores KW - north-western Europe KW - resurveys KW - (semi-)permanent plots Y1 - 2012 U6 - https://doi.org/10.1111/j.1365-2745.2011.01928.x SN - 0022-0477 VL - 100 IS - 2 SP - 352 EP - 365 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Vergani, Marco A1 - Carminati, Marco A1 - Ferrari, Giorgio A1 - Landini, Ettore A1 - Caviglia, Claudia A1 - Heiskanen, Arto A1 - Comminges, Clement A1 - Zor, Kinga A1 - Sabourin, David A1 - Dufva, Martin A1 - Dimaki, Maria A1 - Raiteri, Roberto A1 - Wollenberger, Ursula A1 - Emneus, Jenny A1 - Sampietro, Marco T1 - Multichannel bipotentiostat integrated with a microfluidic platform for electrochemical real-time monitoring of cell cultures JF - IEEE Transactions on biomedical circuits and systems N2 - An electrochemical detection system specifically designed for multi-parameter real-time monitoring of stem cell culturing/differentiation in a microfluidic system is presented. It is composed of a very compact 24-channel electronic board, compatible with arrays of microelectrodes and coupled to a microfluidic cell culture system. A versatile data acquisition software enables performing amperometry, cyclic voltammetry and impedance spectroscopy in each of the 12 independent chambers over a 100 kHz bandwidth with current resolution down to 5 pA for 100 ms measuring time. The design of the platform, its realization and experimental characterization are reported, with emphasis on the analysis of impact of input capacitance (i.e., microelectrode size) and microfluidic pump operation on current noise. Programmable sequences of successive injections of analytes (ferricyanide and dopamine) and rinsing buffer solution as well as the impedimetric continuous tracking for seven days of the proliferation of a colony of PC12 cells are successfully demonstrated. KW - Electrochemical measurements KW - impedance spectroscopy KW - microfluidics KW - multichannel potentiostat KW - stem cell monitoring Y1 - 2012 U6 - https://doi.org/10.1109/TBCAS.2012.2187783 SN - 1932-4545 VL - 6 IS - 5 SP - 498 EP - 507 PB - Inst. of Electr. and Electronics Engineers CY - Piscataway ER - TY - THES A1 - Vasilevski, Aleksandar T1 - Research in pectin synthesis by analysing the seed coat mucilage Y1 - 2012 CY - Potsdam ER - TY - JOUR A1 - Varshney, Nishant Kumar A1 - Kumar, R. Suresh A1 - Ignatova, Zoya A1 - Prabhune, Asmita A1 - Pundle, Archana A1 - Dodson, Eleanor A1 - Suresh, C. G. T1 - Crystallization and X-ray structure analysis of a thermostable penicillin G acylase from Alcaligenes faecalis JF - Acta crystallographica : Section F, Structural biology communications N2 - The enzyme penicillin G acylase (EC 3.5.1.11) catalyzes amide-bond cleavage in benzylpenicillin (penicillin G) to yield 6-aminopenicillanic acid, an intermediate chemical used in the production of semisynthetic penicillins. A thermostable penicillin G acylase from Alcaligenes faecalis (AfPGA) has been crystallized using the hanging-drop vapour-diffusion method in two different space groups: C2221, with unit-cell parameters a = 72.9, b = 86.0, c = 260.2 angstrom, and P41212, with unit-cell parameters a = b = 85.6, c = 298.8 angstrom. Data were collected at 293 K and the structure was determined using the molecular-replacement method. Like other penicillin acylases, AfPGA belongs to the N-terminal nucleophilic hydrolase superfamily, has undergone post-translational processing and has a serine as the N-terminal residue of the beta-chain. A disulfide bridge has been identified in the structure that was not found in the other two known penicillin G acylase structures. The presence of the disulfide bridge is perceived to be one factor that confers higher stability to this enzyme. KW - thermostability KW - disulfide bridges KW - Ntn hydrolases KW - orthorhombic form KW - tetragonal form KW - calcium binding Y1 - 2012 U6 - https://doi.org/10.1107/S1744309111053930 SN - 1744-3091 VL - 68 IS - 3 SP - 273 EP - 277 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Van der Meeren, T. A1 - Mischke, Steffen A1 - Sunjidmaa, N. A1 - Herzschuh, Ulrike A1 - Ito, E. A1 - Martens, K. A1 - Verschuren, Dirk T1 - Subfossil ostracode assemblages from Mongolia quantifying response for paleolimnological applications JF - Ecological indicators : integrating monitoring, assessment and management N2 - Ostracodes (Ostracoda, Crustacea) are aquatic micro-crustaceans with a significant representation in the fossil record. If the environmental influence on the species composition of their communities is robustly quantified, past changes in ostracode communities reflected in fossil assemblages can be used for paleo-environmental reconstruction. We analyzed ostracode assemblages in recently deposited surface sediments from 56 lakes in western and central Mongolia, and simultaneously recorded local water chemistry and solute concentration in order to elucidate the distribution of individual ostracode species in relation to these broad environmental gradients. Multivariate analysis indicated that the species variation in ostracode assemblages could be mainly attributed to variations in percent calcium (%Ca) relative to total cation content, mean annual precipitation, calcium concentration, alkalinity, percent bicarbonate relative to total anion content, and mean July temperature. This matches well with the results of a similar analysis on presence/absence data of living ostracodes in nearshore samples, even though some differences exist between the faunal composition of both datasets. The documented response of ostracode species to environmental variation tracks the typical solute evolutionary pathway for surface waters in this region, characterized by calcite precipitation and consequent depletion in dissolved calcium. Hence, the best quantitative inference model (WA-PLS model with R-jack(2) = 0.70, RMSEP = 0.40) for paleolimnological application was obtained for %Ca. Comparison between this model and a specific conductance (SC) inference model based on the same dataset, and based on ostracode datasets from different regions, indicated that the %Ca inference model suffers less than the SC inference model from a step-change in reconstructed values. The statistical power of different inference models based on Mongolian ostracodes are variously affected by the common dominance of a single euryhaline species (Limnocythere inopinata), limited faunal turnover in the freshwater portion of the salinity gradient, and the bimodal frequency distribution of SC among regional lakes. The latter probably represents true scarcity of lakes with intermediate salinity rather than a biased representation in our dataset. In a broader context of ostracode ecology, and with respect to regional paleolimnological applications, we highlight the potential of fossil Mongolian ostracode assemblages to trace past hydrological shifts associated with changes in groundwater inflow. KW - Ostracoda KW - Inference model KW - Central Asia KW - Paleo-ecology KW - Solute evolution Y1 - 2012 U6 - https://doi.org/10.1016/j.ecolind.2011.07.004 SN - 1470-160X SN - 1872-7034 VL - 14 IS - 1 SP - 138 EP - 151 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - van den Beemt, Martijn A1 - Çinkaya, Muhammed A1 - Erdem, Didem Tuğçe A1 - Janssen, Robert T1 - Conclusion for future teaching JF - Potsdamer geographische Praxis N2 - 1. The importance of the maps in the Atlas of European Values 2. Team teaching 3. The importance of discussions in secondary schools 4. Assignments 5. Impact 6. Comments 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-65880 SN - 2194-1599 SN - 2194-1602 IS - 1 SP - 99 EP - 104 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Valori, Gherardo A1 - Green, Lucie M. A1 - Demoulin, Pascal A1 - Vargas Dominguez, S. A1 - van Driel-Gesztelyi, L. A1 - Wallace, A. A1 - Baker, Daniel N. A1 - Fuhrmann, Marcel T1 - Nonlinear force-free extrapolation of emerging flux with a global twist and serpentine fine structures JF - Solar physics : a journal for solar and solar-stellar research and the study of solar terrestrial physics N2 - We study the flux emergence process in NOAA active region 11024, between 29 June and 7 July 2009, by means of multi-wavelength observations and nonlinear force-free extrapolation. The main aim is to extend previous investigations by combining, as much as possible, high spatial resolution observations to test our present understanding of small-scale (undulatory) flux emergence, whilst putting these small-scale events in the context of the global evolution of the active region. The combination of these techniques allows us to follow the whole process, from the first appearance of the bipolar axial field on the east limb, until the buoyancy instability could set in and raise the main body of the twisted flux tube through the photosphere, forming magnetic tongues and signatures of serpentine field, until the simplification of the magnetic structure into a main bipole by the time the active region reaches the west limb. At the crucial time of the main emergence phase high spatial resolution spectropolarimetric measurements of the photospheric field are employed to reconstruct the three-dimensional structure of the nonlinear force-free coronal field, which is then used to test the current understanding of flux emergence processes. In particular, knowledge of the coronal connectivity confirms the identity of the magnetic tongues as seen in their photospheric signatures, and it exemplifies how the twisted flux, which is emerging on small scales in the form of a sea-serpent, is subsequently rearranged by reconnection into the large-scale field of the active region. In this way, the multi-wavelength observations combined with a nonlinear force-free extrapolation provide a coherent picture of the emergence process of small-scale magnetic bipoles, which subsequently reconnect to form a large-scale structure in the corona. KW - Active regions, magnetic fields KW - Magnetic field, photosphere, corona Y1 - 2012 U6 - https://doi.org/10.1007/s11207-011-9865-8 SN - 0038-0938 VL - 278 IS - 1 SP - 73 EP - 97 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Valori, Gherardo A1 - Demoulin, Pascal A1 - Pariat, E. T1 - Comparing values of the relative magnetic helicity in finite volumes JF - Solar physics : a journal for solar and solar-stellar research and the study of solar terrestrial physics N2 - Relative magnetic helicity, as a conserved quantity of ideal magnetohydrodynamics, has been highlighted as an important quantity to study in plasma physics. Due to its nonlocal nature, its estimation is not straightforward in both observational and numerical data. In this study we derive expressions for the practical computation of the gauge-independent relative magnetic helicity in three-dimensional finite domains. The derived expressions are easy to implement and rapid to compute. They are derived in Cartesian coordinates, but can be easily written in other coordinate systems. We apply our method to a numerical model of a force-free equilibrium containing a flux rope, and compare the results with those obtained employing known half-space equations. We find that our method requires a much smaller volume than half-space expressions to derive the full helicity content. We also prove that values of relative magnetic helicity of different magnetic fields can be compared with each other in the same sense as free-energy values can. Therefore, relative magnetic helicity can be meaningfully and directly compared between different datasets, such as those from different active regions, but also within the same dataset at different times. Typical applications of our formulae include the helicity computation in three-dimensional models of the solar atmosphere, e.g., coronal-field reconstructions by force-free extrapolation and discretized magnetic fields of numerical simulations. KW - Active regions, magnetic fields KW - Magnetic field, photosphere, corona Y1 - 2012 U6 - https://doi.org/10.1007/s11207-012-9951-6 SN - 0038-0938 VL - 278 IS - 2 SP - 347 EP - 366 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Uusi-Heikkila, Silva A1 - Boeckenhoff, Linda A1 - Wolter, Christian A1 - Arlinghaus, Robert T1 - Differential Allocation by Female Zebrafish (Danio rerio) to Different-Sized Males - An Example in a Fish Species Lacking Parental Care JF - PLOS ONE N2 - Organisms allocate resources to reproduction in response to the costs and benefits of current and future reproductive opportunities. According to the differential allocation hypothesis, females allocate more resources to high-quality males. We tested whether a fish species lacking parental care (zebrafish, Danio rerio) expresses male size-dependent differential allocation in monogamous spawning trials. In addition, we tested whether reproductive allocation by females is affected by previous experience of different-quality males, potentially indicating plasticity in mate choice. To that end, females were conditioned to large, small or random-sized males (controls) for 14 days to manipulate females’ expectations of the future mate quality. Females showed a clear preference for large males in terms of spawning probability and clutch size independent of the conditioning treatment. However, when females experienced variation in male size (random-sized conditioning treatment) they discriminated less against small males compared to females conditioned to large and small males. This might suggest that differential allocation and size-dependent sexual selection is of less relevance in nature than revealed in the present laboratory study. Y1 - 2012 U6 - https://doi.org/10.1371/journal.pone.0048317 SN - 1932-6203 VL - 7 IS - 10 PB - PUBLIC LIBRARY SCIENCE CY - SAN FRANCISCO ER - TY - THES A1 - Uttamchand, Narendra Kumar T1 - Shape-memory properties of magnetically active compositives based on multiphase polymer networks Y1 - 2012 CY - Potsdam ER - TY - THES A1 - Urbach, Tina T1 - What makes or breaks proactivity at work : how personal motives affect the evaluation of improvement suggestions Y1 - 2012 CY - Potsdam ER - TY - JOUR A1 - Unuabonah, Emmanuel Iyayi A1 - El-Khaiary, Mohammad I. A1 - Olu-Owolabi, Bamidele I. A1 - Adebowale, Kayode O. T1 - Predicting the dynamics and performance of a polymer-clay based composite in a fixed bed system for the removal of lead (II) ion JF - Chemical engineering research and design N2 - A polymer-clay based composite adsorbent was prepared from locally obtained kaolinite clay and polyvinyl alcohol. The composite adsorbent was used to remove lead (II) ions from aqueous solution in a fixed bed mode. The increase in bed height and initial metal ion concentration increased the adsorption capacity of lead (II) and the volume of aqueous solution treated at 50% breakthrough. However, the adsorption capacity was reduced by almost 16.5% with the simultaneous presence of Ca2+/Pb2+ and Na+/Pb2+ in the aqueous solution. Regeneration of the adsorbent with 0.1 M of HCl also reduced its adsorption capacity to 75.1%. Adsorption of lead (II) ions onto the polymer-clay composite adsorbent in the presence of Na+ and Ca2+ electrolyte increased the rate of mass transfer, probably due to competition between cationic species in solution for adsorption sites. Regeneration further increased the rate of mass transfer as a result of reduced adsorption sites after the regeneration process. The length of the mass transfer zone was found to increase with increasing bed height but did not change with increasing the initial metal ion concentration. The models of Yoon-Nelson, Thomas, and Clark were found to give good fit to adsorption data. On the other hand, Bohart-Adams model was found to be a poor predictor for the column operation. The polymer-clay composite adsorbent has a good potential for the removal of lead (II) ions from highly polluted aqueous solutions. KW - Fixed bed KW - Adsorption models KW - Polymer-clay composite KW - Regeneration KW - Breakthrough KW - Mass transfer zone Y1 - 2012 U6 - https://doi.org/10.1016/j.cherd.2011.11.009 SN - 0263-8762 VL - 90 IS - 8 SP - 1105 EP - 1115 PB - Inst. of Electr. and Electronics Engineers CY - Rugby ER - TY - JOUR A1 - Ungru, J. A1 - Blüher, M. A1 - Cönen, M. A1 - Raila, Jens A1 - Boston, R. A1 - Vervuert, I. T1 - Effects of body weight reduction on blood adipokines and subcutaneous adipose tissue adipokine mRNA expression profiles in obese ponies JF - The veterinary record N2 - Fifteen obese ponies were used in a body weight (BW) reduction programme (BWRP, daily energy intake: 7.0-8.4 MJ/100 kg BW). A frequently sampled intravenous glucose tolerance test was used to assess insulin sensitivity. Subcutaneous adipose tissue biopsies of the tail head were obtained for mRNA gene expression profiles of adiponectin, retinol-binding protein 4 (RBP4), interleukin 6 (IL-6) and macrophage activation marker (CD68) before and after BWRP. Blood samples were analysed for serum leptin, serum RBP4 and plasma adiponectin. Significant BW losses occurred with 7 MJ DE/100 kg BW. Serum leptin and RBP4 were initially similar between insulin-resistant (IR) and insulin-sensitive (IS) ponies, and both significantly decreased during BWRP. Compared with IS ponies, IR ponies initially had significantly lower plasma adiponectin levels. At the beginning of BWRP, mRNA expression of RBP4, adiponectin, IL-6 and CD68 was similar between IR and IS ponies. Plasma adiponectin was strongly related to IR, whereas serum leptin and RBP4 were closely linked to adiposity, independent of insulin sensitivity. Adipose tissue mRNA expression profiles did not clearly reflect these differences. However, the role of subcutaneous adipose tissue in IR remains open. Y1 - 2012 U6 - https://doi.org/10.1136/vr.100911 SN - 0042-4900 VL - 171 IS - 21 SP - 528 EP - + PB - British Veterinary Association CY - London ER - TY - GEN A1 - Ungelenk, Johannes T1 - Narcissus and Echo BT - A Political Reading of George Eliot's Daniel Deronda N2 - George Eliot’s late novel Daniel Deronda tackles big, fundamental political questions that radiate from the societal circumstances of the novel’s production and reach deep into our present-day life. The novel critically analyses the capitalistic, morally flawed and standard-less English society and narrates the title hero’s proto-Zionist mission to found a Jewish nation that re-establishes history, meaning and ethical values. This study attempts to trace the novel’s two models of society and time by bringing them into resonance with the myth of Narcissus and Echo famously rendered by Ovid. The unloving, self-referential, visual Narcissus is read as the model for the capitalistic world of spectacle and speculation. Echo’s loving, memory-bearing voice forms an important part in the construction of the sublating unity of the Jewish nation-to-come. Guided by this resonance between George Eliot’s novel and Ovid’s myth pieces of critical theory and philosophy are woven into the study’s fabric. The resulting analysis dissects and deconstructs the novel’s fascinating and highly complex patterns of conditions of possibility for the fabrication of the redeeming Jewish nation, the very same conditions that the novel presents as the conditions of possibility for narrating a meaningful story. T3 - Zweitveröffentlichungen der Universität Potsdam : Philosophische Reihe - 186 Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-599966 SN - 1866-8380 IS - 186 ER - TY - JOUR A1 - Ullner, E. A1 - Ares, S. A1 - Morelli, L. G. A1 - Oates, A. C. A1 - Jülicher, F. A1 - Nicola, E. A1 - Heussen, R. A1 - Whitmore, D. A1 - Blyuss, K. A1 - Fryett, M. A1 - Zakharova, A. A1 - Koseska, A. A1 - Nene, N. R. A1 - Zaikin, Alexei T1 - Noise and oscillations in biological sysems multidisciplinary approach between experimental biology, theoretical modelling and synthetic biology JF - International journal of modern physics : B, Condensed matter physics, statistical physics, applied physics N2 - Rapid progress of experimental biology has provided a huge flow of quantitative data, which can be analyzed and understood only through the application of advanced techniques recently developed in theoretical sciences. On the other hand, synthetic biology enabled us to engineer biological models with reduced complexity. In this review we discuss that a multidisciplinary approach between this sciences can lead to deeper understanding of the underlying mechanisms behind complex processes in biology. Following the mini symposia "Noise and oscillations in biological systems" on Physcon 2011 we have collected different research examples from theoretical modeling, experimental and synthetic biology. KW - Systems biology KW - synthetic biology KW - nonlinear dynamics Y1 - 2012 U6 - https://doi.org/10.1142/S0217979212460095 SN - 0217-9792 VL - 26 IS - 25 PB - World Scientific CY - Singapore ER - TY - JOUR A1 - Uhlig, Katja A1 - Madaboosi, Narayanan A1 - Schmidt, Stephan A1 - Jäger, Magnus S. A1 - Rose, Jürgen A1 - Duschl, Claus A1 - Volodkin, Dmitry V. T1 - 3d localization and diffusion of proteins in polyelectrolyte multilayers JF - Soft matter N2 - The interaction of diverse biomaterials with surfaces is more crucial than ever for biomedical applications to ensure efficiency and reproducibility. Very interesting surface materials are micrometer-thick polyelectrolyte multilayers. Not only their surface but also the bulk can be loaded with biomaterials like proteins or DNA for various purposes. Therefore, we established a method to analyze the lateral and vertical distribution of fluorescently labelled proteins of various size and charge in polyelectrolyte films composed of poly(L-lysine) and hyaluronic acid by confocal laser scanning microscopy. This approach enables us to measure the diffusion coefficients of the proteins via fluorescence recovery after photobleaching as a function of their vertical position in the film and facilitates the understanding of molecular interactions in the film with a high resolution in both space and time. As a result, we confirm that protein loading in the film is driven by electrostatic interactions - uncharged dextran molecules of 10 and 500 kDa do not diffuse into the film. Proteins of different sizes (3-11 nm) can diffuse relatively fast (D = 2-4 mm(2) s(-1)) independent of their net charge, indicating complex interpolymer interactions. This approach is a new powerful experimental tool to design the polyelectrolyte multilayers for bio-applications by finding a relationship between intermolecular interactions and mobility and availability of biomolecules to biological samples (e.g. cells) or detection units (e.g. biosensors). Y1 - 2012 U6 - https://doi.org/10.1039/c2sm26500a SN - 1744-683X VL - 8 IS - 47 SP - 11786 EP - 11789 PB - Royal Society of Chemistry CY - Cambridge 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 - Türke, Manfred A1 - Andreas, Kerstin A1 - Gossner, Martin M. A1 - Kowalski, Esther A1 - Lange, Markus A1 - Boch, Steffen A1 - Socher, Stephanie A. A1 - Müller, Jörg A1 - Prati, Daniel A1 - Fischer, Markus A1 - Meyhöfer, Rainer A1 - Weisser, Wolfgang W. T1 - Are gastropods, rather than ants, important dispersers of seeds of myrmecochorous forest herbs? JF - The American naturalist : a bi-monthly journal devoted to the advancement and correlation of the biological sciences N2 - Seed dispersal by ants (myrmecochory) is widespread, and seed adaptations to myrmecochory are common, especially in the form of fatty appendices (elaiosomes). In a recent study, slugs were identified as seed dispersers of myrmecochores in a central European beech forest. Here we used 105 beech forest sites to test whether myrmecochore presence and abundance is related to ant or gastropod abundance and whether experimentally exposed seeds are removed by gastropods. Myrmecochorous plant cover was positively related to gastropod abundance but was negatively related to ant abundance. Gastropods were responsible for most seed removal and elaiosome damage, whereas insects (and rodents) played minor roles. These gastropod effects on seeds were independent of region or forest management. We suggest that terrestrial gastropods can generally act as seed dispersers of myrmecochorous plants and even substitute myrmecochory, especially where ants are absent or uncommon. KW - myrmecochory KW - gastropodochory KW - Arion KW - slug KW - seed dispersal Y1 - 2012 U6 - https://doi.org/10.1086/663195 SN - 0003-0147 VL - 179 IS - 1 SP - 124 EP - 131 PB - Univ. of Chicago Press CY - Chicago ER - TY - JOUR A1 - Turhan, Metehan C. A1 - Sarac, A. Sezai A1 - Gencturk, Asli A1 - Gilsing, Hans-Detlev A1 - Faltz, Heike A1 - Schulz, Burkhard T1 - Electrochemical impedance characterization and potential dependence of poly[3,4-(2,2-dibutylpropylenedioxy)thiophene] nanostructures on single carbon fiber microelectrode JF - Synthetic metals : the journal of electronic polymers and electronic molecular materials N2 - The electropolymerization of 3,4-(2,2-dibutylpropylenedioxy)thiophene (ProDOT-Bu-2) onto single carbon fiber microelectrode (SCFME) was conducted in acetonitrile (ACN) containing sodium perchlorate (NaClO4) as electrolyte and investigated by cyclic voltammetry (CV). The nanostructured films of poly[3,4-(2,2-dibutyl-propyleneclioxy)thiophene] (PProDOT-Bu-2) which were depositing showed complete reversible redox behavior in monomer-free electrolyte solution. The capacitive behavior of the films was investigated by electrochemical impedance spectroscopy (EIS) at applied potentials from 0.1 V to 1.3 V. The analysis by equivalent circuit modeling revealed an applied potential around 0.4V to be most suitable for the system PProDOT-Bu-2/SCFME as a double layer supercapacitor component inducing a double layer capacitance C-d, value of 62 mFcm(-2). KW - Nanostructure KW - Electrochemical impedance spectroscopy KW - Conjugated polymeric thin film KW - Carbon fiber Y1 - 2012 U6 - https://doi.org/10.1016/j.synthmet.2012.01.012 SN - 0379-6779 VL - 162 IS - 5-6 SP - 511 EP - 515 PB - Elsevier CY - Lausanne ER - TY - JOUR A1 - Tschentscher, Nadja A1 - Hauk, Olaf A1 - Fischer, Martin H. A1 - Pulvermüller, Friedemann T1 - You can count on the motor cortex finger counting habits modulate motor cortex activation evoked by numbers JF - NeuroImage : a journal of brain function N2 - The embodied cognition framework suggests that neural systems for perception and action are engaged during higher cognitive processes. In an event-related fMRI study, we tested this claim for the abstract domain of numerical symbol processing: is the human cortical motor system part of the representation of numbers, and is organization of numerical knowledge influenced by individual finger counting habits? Developmental studies suggest a link between numerals and finger counting habits due to the acquisition of numerical skills through finger counting in childhood. In the present study, digits 1 to 9 and the corresponding number words were presented visually to adults with different finger counting habits, i.e. left- and right-starters who reported that they usually start counting small numbers with their left and right hand, respectively. Despite the absence of overt hand movements, the hemisphere contralateral to the hand used for counting small numbers was activated when small numbers were presented. The correspondence between finger counting habits and hemispheric motor activation is consistent with an intrinsic functional link between finger counting and number processing. KW - Embodied cognition KW - Numerical cognaion KW - Finger counting habits KW - SNARC effect Y1 - 2012 U6 - https://doi.org/10.1016/j.neuroimage.2011.11.037 SN - 1053-8119 VL - 59 IS - 4 SP - 3139 EP - 3148 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Tsai, Jie-Li A1 - Kliegl, Reinhold A1 - Yan, Ming T1 - Parafoveal semantic information extraction in traditional Chinese reading JF - Acta psychologica : international journal of psychonomics N2 - Semantic information extraction from the parafovea has been reported only in simplified Chinese for a special subset of characters and its generalizability has been questioned. This study uses traditional Chinese, which differs from simplified Chinese in visual complexity and in mapping semantic forms, to demonstrate access to parafoveal semantic information during reading of this script. Preview duration modulates various types (identical, phonological, and unrelated) of parafoveal information extraction. Parafoveal semantic extraction is more elusive in English; therefore, we conclude that such effects in Chinese are presumably caused by substantial cross-language differences from alphabetic scripts. The property of Chinese characters carrying rich lexical information in a small region provides the possibility of semantic extraction in the parafovea. KW - Semantic preview benefit KW - Chinese reading KW - Eye movements Y1 - 2012 U6 - https://doi.org/10.1016/j.actpsy.2012.06.004 SN - 0001-6918 SN - 1873-6297 VL - 141 IS - 1 SP - 17 EP - 23 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Träger, Juliane A1 - König, Jana A1 - Städtke, Anja A1 - Holdt, Hans-Jürgen T1 - Development of a solvent extraction system with 1,2-bis(2-methoxyethylthio) benzene for the selective separation of palladium(II) from secondary raw materials JF - Hydrometallurgy : an international journal devoted to all aspects of the aqueous processing of metals N2 - The chelating dithioether 1,2-bis(2-methoxyethylthio)benzene. a novel solvent extractant for Pd(II), is aimed to be utilised in the selective recovery of palladium from spent automotive catalysts. For that, the extraction system has been further customised, including the choice of an appropriate diluent (1,2-dichlorobenzene) as well as an effective stripping agent (0.5 M thiourea in 0.1 M HCl), which both have been selected from a number of potential agents. It is shown in batch experiments that the selectivity for Pd(II) is maintained when the organic phase (10(-2) M 1,2-bis(2-methoxyethylthio)benzene in 1,2-dichlorobenzene) is used several times to extract an oxidising leach solution. According to the McCabe-Thiele plot two theoretical stages are needed to extract more than 98% of the Pd(II) contained in that solution. The calculation of the thermodynamic quantities Delta H degrees. Delta S degrees and Delta G degrees reveals that the reaction is entropy driven - the temperature has only a slight influence on the extraction yield. It is demonstrated that the mono-oxidised extractant has a catalytic effect on the extraction kinetics when the aqueous phase contains highly concentrated hydrochloric acid. HPLC measurements prove the presence of small quantities of 1-(2-methoxyethylsulfinyl)-2-(2-methoxyethylthio) benzene in the organic phase. KW - Solvent extraction KW - Palladium KW - S ligands KW - Extraction system development KW - Stripping Y1 - 2012 U6 - https://doi.org/10.1016/j.hydromet.2012.07.002 SN - 0304-386X SN - 1879-1158 VL - 127 IS - 5 SP - 30 EP - 38 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Träger, Juliane A1 - Klamroth, Tillmann A1 - Kelling, Alexandra A1 - Lubahn, Susanne A1 - Cleve, Ernst A1 - Mickler, Wulfhard A1 - Heydenreich, Matthias A1 - Müller, Holger A1 - Holdt, Hans-Jürgen T1 - Complexation of Palladium(II) with unsaturated Dithioethers a systematic development of highly selective ligands for solvent extraction JF - European journal of inorganic chemistry : a journal of ChemPubSoc Europe N2 - There is a demand for new and robust PdII extractants due to growing recycling rates. Chelating dithioethers are promising substances for solvent extraction as they form stable square-planar complexes with PdII. We have modified unsaturated dithioethers, which are known to coordinate PdII, and adapted them to the requirements of industrial practice. The ligands are analogues of 1,2-dithioethene with varying electron-withdrawing backbones and polar end-groups. The crystal structures of several ligands and their palladium complexes were determined as well as their electro- and photochemical properties, complex stability and behaviour in solution. Solvent extraction experiments showed the superiority of some of our ligands over conventionally used extractants in terms of their very fast reaction rates. With highly selective 1,2-bis(2-methoxyethylthio)benzene (4) it is possible to extract PdII from a highly acidic medium in the presence of other base and palladium-group metals. KW - Renewable resources KW - Palladium KW - Chelates KW - Ligand design KW - S li-gands Y1 - 2012 U6 - https://doi.org/10.1002/ejic.201101406 SN - 1434-1948 IS - 14 SP - 2341 EP - 2352 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Träger, J. A1 - Kelling, A. A1 - Schilde, Uwe A1 - Holdt, H. -J. T1 - rac-1-[(2-Methoxyethyl)sulfanyl]-2-[(2-methoxyethyl)sulfinyl]benzene and its PdCl2 complex JF - Acta crystallographica : Section C, Crystal structure communications N2 - As an extension of recent findings on the recovery of palladium with dithioether extractants, single crystals of the chelating vicinal thioether sulfoxide ligand rac-1-[(2-methoxyethyl)sulfanyl]-2-[(2-methoxyethyl)sulfinyl]benzene, C12H18O3S2, (I), and its square-planar dichloridopalladium complex, rac-dichlorido{1-[(2-methoxyethyl)sulfanyl]-2-[(2-methoxyethyl)sulfinyl]benzene-?2S,S'}palladium(II), [PdCl2(C12H18O3S2)], (II), have been synthesized and their structures analysed. The molecular structure of (II) is the first ever characterized involving a dihalogenidePdII complex in which the palladium is bonded to both a thioether and a sulfoxide functional group. The structural and stereochemical characteristics of the ligand are compared with those of the analogous dithioether compound [Traeger et al. (2012). Eur. J. Inorg. Chem. pp. 23412352]. The sulfinyl O atom suppresses the electron-pushing and mesomeric effect of the SC...;CS unit in ligand (I), resulting in bond lengths significantly different than in the dithioether reference compound. In contrast, in complex (II), those bond lengths are nearly the same as in the analogous dithioether complex. As observed previously, there is an interaction between the central PdII atom and the O atom that is situated above the plane. Y1 - 2012 U6 - https://doi.org/10.1107/S0108270112032192 SN - 0108-2701 VL - 68 IS - 9 SP - M238 EP - + PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Trukenbrod, Hans Arne A1 - Engbert, Ralf T1 - Eye movements in a sequential scanning task - evidence for distributed processing JF - Journal of vision N2 - Current models of eye movement control are derived from theories assuming serial processing of single items or from theories based on parallel processing of multiple items at a time. This issue has persisted because most investigated paradigms generated data compatible with both serial and parallel models. Here, we study eye movements in a sequential scanning task, where stimulus n indicates the position of the next stimulus n + 1. We investigate whether eye movements are controlled by sequential attention shifts when the task requires serial order of processing. Our measures of distributed processing in the form of parafoveal-on-foveal effects, long-range modulations of target selection, and skipping saccades provide evidence against models strictly based on serial attention shifts. We conclude that our results lend support to parallel processing as a strategy for eye movement control. KW - eye movements KW - distributed processing KW - sequential attention shifts KW - parafoveal-on-foveal effects KW - skipping costs/benefits Y1 - 2012 U6 - https://doi.org/10.1167/12.1.5 SN - 1534-7362 VL - 12 IS - 1 PB - Association for Research in Vision and Opthalmology CY - Rockville ER - TY - CHAP A1 - Trukenbrod, Hans Arne A1 - Barthelme, S. A1 - Wichmann, Felix A. A1 - Engbert, Ralf T1 - Color does not guide eye movements: Evidence from a gaze-contingent experiment T2 - PERCEPTION Y1 - 2012 SN - 0301-0066 SN - 1468-4233 VL - 41 SP - 88 EP - 88 PB - PION LTD CY - LONDON 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 - Trotzky, S. A1 - Chen, Y-A. A1 - Flesch, A. A1 - McCulloch, I. P. A1 - Schollwöck, U. A1 - Eisert, J. A1 - Bloch, I. T1 - Probing the relaxation towards equilibrium in an isolated strongly correlated one-dimensional Bose gas JF - Nature physics N2 - The problem of how complex quantum systems eventually come to rest lies at the heart of statistical mechanics. The maximum-entropy principle describes which quantum states can be expected in equilibrium, but not how closed quantum many-body systems dynamically equilibrate. Here, we report the experimental observation of the non-equilibrium dynamics of a density wave of ultracold bosonic atoms in an optical lattice in the regime of strong correlations. Using an optical superlattice, we follow its dynamics in terms of quasi-local densities, currents and coherences-all showing a fast relaxation towards equilibrium values. Numerical calculations based on matrix-product states are in an excellent quantitative agreement with the experimental data. The system fulfills the promise of being a dynamical quantum simulator, in that the controlled dynamics runs for longer times than present classical algorithms can keep track of. Y1 - 2012 U6 - https://doi.org/10.1038/NPHYS2232 SN - 1745-2473 VL - 8 IS - 4 SP - 325 EP - 330 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Tronicke, Jens A1 - Paasche, Hendrik A1 - Böniger, Urs T1 - Crosshole traveltime tomography using particle swarm optimization a near-surface field example JF - Geophysics N2 - Particle swarm optimization (PSO) is a relatively new global optimization approach inspired by the social behavior of bird flocking and fish schooling. Although this approach has proven to provide excellent convergence rates in different optimization problems, it has seldom been applied to inverse geophysical problems. Until today, published geophysical applications mainly focus on finding an optimum solution for simple, 1D inverse problems. We have applied PSO-based optimization strategies to reconstruct 2D P-wave velocity fields from crosshole traveltime data sets. Our inversion strategy also includes generating and analyzing a representative ensemble of acceptable models, which allows us to appraise uncertainty and nonuniqueness issues. The potential of our strategy was tested on field data collected at a well-constrained test site in Horstwalde, Germany. At this field site, the shallow subsurface mainly consists of sand- and gravel-dominated glaciofluvial sediments, which, as known from several boreholes and other geophysical experiments, exhibit some well-defined layering at the scale of our crosshole seismic data. Thus, we have implemented a flexible, layer-based model parameterization, which, compared with standard cell-based parameterizations, allows for significantly reducing the number of unknown model parameters and for efficiently implementing a priori model constraints. Comparing the 2D velocity fields resulting from our PSO strategy to independent borehole and direct-push data illustrated the benefits of choosing an efficient global optimization approach. These include a straightforward and understandable appraisal of nonuniqueness issues as well as the possibility of an improved and also more objective interpretation. Y1 - 2012 U6 - https://doi.org/10.1190/GEO2010-0411.1 SN - 0016-8033 SN - 1942-2156 VL - 77 IS - 1 SP - R19 EP - R32 PB - Society of Exploration Geophysicists CY - Tulsa ER - TY - JOUR A1 - Tremblay, Jean Christophe A1 - Füchsel, Gernot A1 - Saalfrank, Peter T1 - Excitation, relaxation, and quantum diffusion of CO on copper JF - Physical review : B, Condensed matter and materials physics N2 - We investigate the effect of intermode coupling and anharmonicity on the excitation and relaxation dynamics of CO on Cu(100). The nonadiabatic coupling of the adsorbate to the surface is treated perturbatively using a position-dependent state-resolved transition rate model. Using the potential energy surface of Marquardt et al. [J. Chem. Phys. 132, 074108 (2010)], which provides an accurate description of intermode interactions, we propose a four-dimensional model that represents simultaneously the diffusion and the desorption of the adsorbate. The system is driven by both rational and optimized infrared laser pulses to favor either selective mode and state excitations or lateral displacement along the diffusion coordinate. The dissipative dynamics is simulated using the reduced density matrix in its Lindblad form. We show that coupling between the degrees of freedom, mediated by the creation and annihilation of electron-hole pairs in the metal substrate, significantly affects the system excitation and relaxation dynamics. In particular, the angular degrees of freedom appear to play an important role in the energy redistribution among the molecule-surface vibrations. We also show that coherent excitation using simple IR pulses can achieve population transfer to a specific target to some extent but does not allow enforcement of the directionality to the diffusion motion. Y1 - 2012 U6 - https://doi.org/10.1103/PhysRevB.86.045438 SN - 1098-0121 SN - 1550-235X VL - 86 IS - 4 PB - American Physical Society CY - College Park ER - TY - JOUR A1 - Tonita, Aaryn T1 - Distributional sources for black hole initial data JF - Classical and quantum gravit N2 - Black hole initial data are usually produced using Bowen-York-type puncture initial data or by applying an excision boundary condition. The benefits of the Bowen-York initial data are the ability to specify the spin and momentum of the system as parameters of the initial data. In an attempt to extend these benefits to other formulations of the Einstein constraints, the puncture method is reformulated using distributions as source terms. It is shown how the Bowen-York puncture black hole initial data and the trumpet variation are generated by distributional sources. A heuristic argument is presented to argue that these sources are the general sources of spin and momentum. In order to clarify the meaning of other distributional sources, an exact family of initial data with generalized sources to the Hamiltonian constraint are studied; spinning trumpet black hole initial data and black hole initial data with higher order momentum sources are also studied. Y1 - 2012 U6 - https://doi.org/10.1088/0264-9381/29/1/015001 SN - 0264-9381 VL - 29 IS - 1 PB - IOP Publ. Ltd. CY - Bristol ER - TY - JOUR A1 - Tomovski, Zivorad A1 - Sandev, Trifce A1 - Metzler, Ralf A1 - Dubbeldam, Johan T1 - Generalized space-time fractional diffusion equation with composite fractional time derivative JF - Physica : europhysics journal ; A, Statistical mechanics and its applications N2 - We investigate the solution of space-time fractional diffusion equations with a generalized Riemann-Liouville time fractional derivative and Riesz-Feller space fractional derivative. The Laplace and Fourier transform methods are applied to solve the proposed fractional diffusion equation. The results are represented by using the Mittag-Leffler functions and the Fox H-function. Special cases of the initial and boundary conditions are considered. Numerical scheme and Grunwald-Letnikov approximation are also used to solve the space-time fractional diffusion equation. The fractional moments of the fundamental solution of the considered space-time fractional diffusion equation are obtained. Many known results are special cases of those obtained in this paper. We investigate also the solution of a space-time fractional diffusion equations with a singular term of the form delta(x). t-beta/Gamma(1-beta) (beta > 0). KW - Fractional diffusion equation KW - Composite fractional derivative KW - Riesz-Feller fractional derivative KW - Mittag-Leffler functions KW - Fox H-function KW - Fractional moments KW - Asymptotic expansions KW - Grunwald-Letnikov approximation Y1 - 2012 U6 - https://doi.org/10.1016/j.physa.2011.12.035 SN - 0378-4371 SN - 1873-2119 VL - 391 IS - 8 SP - 2527 EP - 2542 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Tiseanu, Carmen A1 - Cojocaru, Bogdan A1 - Parvulescu, Vasile I. A1 - Sanchez-Dominguez, Margarita A1 - Primus, Philipp A. A1 - Boutonnet, Magali T1 - Order and disorder effects in nano-ZrO2 investigated by micro-Raman and spectrally and temporarily resolved photoluminescence JF - Physical chemistry, chemical physics : a journal of European Chemical Societies N2 - Pure and europium (Eu3+) doped ZrO2 synthesized by an oil-in-water microemulsion reaction method were investigated by in situ and ex situ X-ray diffraction (XRD), ex situ Raman spectroscopy, high-resolution transmission electron microscopy (HRTEM), steady state and time-resolved photoluminescence (PL) spectroscopies. Based on the Raman spectra excited at three different wavelengths i.e. 488, 514 and 633 nm and measured in the spectral range of 150-4000 cm(-1) the correlation between the phonon spectra of ZrO2 and luminescence of europium is clearly evidenced. The PL investigations span a variety of steady-state and time resolved measurements recorded either after direct excitation of the Eu3+ f-f transitions or indirect excitation into UV charge-transfer bands. After annealing at 500 degrees C, the overall Eu3+ emission is dominated by Eu3+ located in tetragonal symmetry lattice sites with a crystal-field splitting of the D-5(0)-F-7(1) emission of 20 cm(-1). Annealing of ZrO2 at 1000 degrees C leads to a superposition of Eu3+ emissions from tetragonal and monoclinic lattice sites with monoclinic crystal-field splitting of 200 cm(-1) for the D-5(0)-F-7(1) transition. At all temperatures, a non-negligible amorphous/disordered content is also measured and determined to be of monoclinic nature. It was found that the evolutions with calcination temperature of the average PL lifetimes corresponding to europium emission in the tetragonal and monoclinic sites and the monoclinic phase content of the Eu3+ doped ZrO2 samples follow a similar trend. By use of specific excitation conditions, the distribution of europium on the amorphous/disordered surface or ordered/crystalline sites can be identified and related to the phase content of zirconia. The role of zirconia host as a sensitizer for the europium PL is also discussed in both tetragonal and monoclinic phases. Y1 - 2012 U6 - https://doi.org/10.1039/c2cp41946g SN - 1463-9076 VL - 14 IS - 37 SP - 12970 EP - 12981 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Thompson, W. T. A1 - Kliem, Bernhard A1 - Toeroek, Tibor T1 - 3D reconstruction of a rotating erupting prominence JF - Solar physics : a journal for solar and solar-stellar research and the study of solar terrestrial physics N2 - A bright prominence associated with a coronal mass ejection (CME) was seen erupting from the Sun on 9 April 2008. This prominence was tracked by both the Solar Terrestrial Relations Observatory (STEREO) EUVI and COR1 telescopes, and was seen to rotate about the line of sight as it erupted; therefore, the event has been nicknamed the "Cartwheel CME." The threads of the prominence in the core of the CME quite clearly indicate the structure of a weakly to moderately twisted flux rope throughout the field of view, up to heliocentric heights of 4 solar radii. Although the STEREO separation was 48A degrees, it was possible to match some sharp features in the later part of the eruption as seen in the 304 line in EUVI and in the H alpha-sensitive bandpass of COR1 by both STEREO Ahead and Behind. These features could then be traced out in three-dimensional space, and reprojected into a view in which the eruption is directed toward the observer. The reconstructed view shows that the alignment of the prominence to the vertical axis rotates as it rises up to a leading-edge height of a parts per thousand aEuro parts per thousand 2.5 solar radii, and then remains approximately constant. The alignment at 2.5 solar radii differs by about 115A degrees from the original filament orientation inferred from H alpha and EUV data, and the height profile of the rotation, obtained here for the first time, shows that two thirds of the total rotation are reached within a parts per thousand aEuro parts per thousand 0.5 solar radii above the photosphere. These features are well reproduced by numerical simulations of an unstable moderately twisted flux rope embedded in external flux with a relatively strong shear field component. KW - Corona, active KW - Prominences, active KW - Coronal mass ejections KW - Initiation and propagation KW - Magnetic fields, corona Y1 - 2012 U6 - https://doi.org/10.1007/s11207-011-9868-5 SN - 0038-0938 VL - 276 IS - 1-2 SP - 241 EP - 259 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Thomas, Philipp A1 - Matuschek, Hannes A1 - Grima, Ramon T1 - Intrinsic noise analyzer A software package for the exploration of stochastic biochemical kinetics using the system size expansion JF - PLoS one N2 - The accepted stochastic descriptions of biochemical dynamics under well-mixed conditions are given by the Chemical Master Equation and the Stochastic Simulation Algorithm, which are equivalent. The latter is a Monte-Carlo method, which, despite enjoying broad availability in a large number of existing software packages, is computationally expensive due to the huge amounts of ensemble averaging required for obtaining accurate statistical information. The former is a set of coupled differential-difference equations for the probability of the system being in any one of the possible mesoscopic states; these equations are typically computationally intractable because of the inherently large state space. Here we introduce the software package intrinsic Noise Analyzer (iNA), which allows for systematic analysis of stochastic biochemical kinetics by means of van Kampen's system size expansion of the Chemical Master Equation. iNA is platform independent and supports the popular SBML format natively. The present implementation is the first to adopt a complementary approach that combines state-of-the-art analysis tools using the computer algebra system Ginac with traditional methods of stochastic simulation. iNA integrates two approximation methods based on the system size expansion, the Linear Noise Approximation and effective mesoscopic rate equations, which to-date have not been available to non-expert users, into an easy-to-use graphical user interface. In particular, the present methods allow for quick approximate analysis of time-dependent mean concentrations, variances, covariances and correlations coefficients, which typically outperforms stochastic simulations. These analytical tools are complemented by automated multi-core stochastic simulations with direct statistical evaluation and visualization. We showcase iNA's performance by using it to explore the stochastic properties of cooperative and non-cooperative enzyme kinetics and a gene network associated with circadian rhythms. The software iNA is freely available as executable binaries for Linux, MacOSX and Microsoft Windows, as well as the full source code under an open source license. Y1 - 2012 U6 - https://doi.org/10.1371/journal.pone.0038518 SN - 1932-6203 VL - 7 IS - 6 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Thomas, Björn A1 - Lischeid, Gunnar A1 - Steidl, Jörg A1 - Dannowski, Ralf T1 - Regional catchment classification with respect to low flow risk in a Pleistocene landscape JF - Journal of hydrology N2 - The classification of small catchments with respect to low flow risk is needed by water and environmental managers to plan adaptation measures for freshwater streams. In this study a new approach is presented to assess the risk of seasonal low flow in the Pleistocene landscape of the Federal State of Brandenburg in Germany. Seasonal low flow and drought in small streams is very common in this region and is predicted to increase due to climate change within the next decades. Data of 15 years (1991-2006) of daily discharge at 37 small catchments (<500 km(2)) and rainfall data from the same region were used. Principal component analyses were applied to the two data sets separately. The first five principal components of the discharge data, principal components of a precipitation data set covering the same catchments and catchment characteristics were used to explain the patterns found. The first five discharge components explained 72.9% of the total variance in the data set. The first component reflected the general regional discharge pattern. Components 2 and 3 of the discharge data could be related to spatial patterns of precipitation. Components 4 and 5 of the discharge data reflected geohydrologic processes within the catchments. In order to identify catchments with high risk with respect to low flows, component three and five were important as they both identified catchments with faster decrease of flows during summer. These components were used to estimate low flow risk. Catchments located in the northeast of Brandenburg, especially those in the Barnim highlands north and east of Berlin, were identified to be prone to seasonal low flow. There water management measures to adapt to climate change are needed the most. KW - Catchment classification KW - Principal component analysis KW - Catchment characteristics KW - Precipitation pattern KW - Regional scale Y1 - 2012 U6 - https://doi.org/10.1016/j.jhydrol.2012.10.020 SN - 0022-1694 SN - 1879-2707 VL - 475 IS - 2 SP - 392 EP - 402 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Thierbach, Rene A1 - Florian, Simone A1 - Wolfrum, Katharina A1 - Voigt, Anja A1 - Drewes, Gunnar A1 - Blume, Urte A1 - Bannasch, Peter A1 - Ristow, Michael A1 - Steinberg, Pablo T1 - Specific alterations of carbohydrate metabolism are associated with hepatocarcinogenesis in mitochondrially impaired mice JF - Human molecular genetics N2 - Friedreich's ataxia is an inherited neurodegenerative disease caused by the reduced expression of the mitochondrially active protein frataxin. We have previously shown that mice with a hepatocyte-specific frataxin knockout (AlbFxn(-/-)) develop multiple hepatic tumors in later life. In the present study, hepatic carbohydrate metabolism in AlbFxn(-/-) mice at an early and late life stage was analyzed. In young (5-week-old) AlbFxn(-/-) mice hepatic ATP, glucose-6-phosphate and glycogen levels were found to be reduced by similar to 74, 80 and 88%, respectively, when compared with control animals. This pronounced ATP, G6P and glycogen depletion in the livers of young mice reverted in older animals: while half of the mice die before 30 weeks of age, the other half reaches 17 months of age and exhibits glycogen, G6P and ATP levels similar to those in age-matched controls. A key event in this respect seems to be the up-regulation of GLUT1, the predominant glucose transporter in fetal liver parenchyma, which became evident in AlbFxn(-/-) mice being 5-12 weeks of age. The most significant histological findings in animals being 17 or 22 months of age were the appearance of multiple clear cell, mixed cell and basophilic foci throughout the liver parenchyma as well as the development of hepatocellular adenomas and carcinomas. The hepatocarcinogenic process in AlbFxn 2/2 mice shows remarkable differences regarding carbohydrate metabolism alterations when compared with all other chemically and virally driven liver cancer models described up to now. Y1 - 2012 U6 - https://doi.org/10.1093/hmg/ddr499 SN - 0964-6906 VL - 21 IS - 3 SP - 656 EP - 663 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Thienen, Julia von A1 - Noweski, Christine A1 - Rauth, Ingo A1 - Meinel, Christoph A1 - Lange, Sabine T1 - If you want to know who are, tell me where you are : the importance of places Y1 - 2012 ER - TY - JOUR A1 - Thienen, Julia von A1 - Noweski, Christine A1 - Meinel, Christoph A1 - Lang, Sabine A1 - Nicolai, Claudia A1 - Bartz, Andreas T1 - What can design thinking learn from behavior group theraphy? Y1 - 2012 SN - 978-3-642-31990-7 ER - TY - JOUR A1 - Thielemann-Kühn, Nele A1 - Hoffmann, P. A1 - Föhlisch, Alexander T1 - A versatile detector for total fluorescence and electron yield experiments JF - Review of scientific instruments : a monthly journal devoted to scientific instruments, apparatus, and techniques N2 - The combination of a non-coated silicon photodiode with electron repelling meshes makes a versatile detector for total fluorescence yield and electron yield techniques highly suitable for x-ray absorption spectroscopy. In particular, a copper mesh with a bias voltage allows to suppress or transmit the electron yield signal. The performance of this detection scheme has been characterized by near edge x-ray absorption fine structure studies of thermal oxidized silicon and sapphire. The results show that the new detector probes both electron yield and for a bias voltage exceeding the maximum photon energy the total fluorescence yield. Y1 - 2012 U6 - https://doi.org/10.1063/1.4754126 SN - 0034-6748 VL - 83 IS - 9 PB - American Institute of Physics CY - Melville ER - TY - THES A1 - Thalhammer, Anja T1 - Physiological, functional and structural characterization of five closely related COR/LEA (COld Regulated/Late Embroygenesis Abundant) proteins from Arabidopsis thaliana (L.) Y1 - 2012 CY - Potsdam ER - TY - JOUR A1 - Teriaca, Luca A1 - Andretta, Vincenzo A1 - Auchere, Frederic A1 - Brown, Charles M. A1 - Buchlin, Eric A1 - Cauzzi, Gianna A1 - Culhane, J. Len A1 - Curdt, Werner A1 - Davila, Joseph M. A1 - Del Zanna, Giulio A1 - Doschek, George A. A1 - Fineschi, Silvano A1 - Fludra, Andrzej A1 - Gallagher, Peter T. A1 - Green, Lucie A1 - Harra, Louise K. A1 - Imada, Shinsuke A1 - Innes, Davina A1 - Kliem, Bernhard A1 - Korendyke, Clarence A1 - Mariska, John T. A1 - Martinez-Pillet, Valentin A1 - Parenti, Susanna A1 - Patsourakos, Spiros A1 - Peter, Hardi A1 - Poletto, Luca A1 - Rutten, Robert J. A1 - Schuehle, Udo A1 - Siemer, Martin A1 - Shimizu, Toshifumi A1 - Socas-Navarro, Hector A1 - Solanki, Sami K. A1 - Spadaro, Daniele A1 - Trujillo-Bueno, Javier A1 - Tsuneta, Saku A1 - Dominguez, Santiago Vargas A1 - Vial, Jean-Claude A1 - Walsh, Robert A1 - Warren, Harry P. A1 - Wiegelmann, Thomas A1 - Winter, Berend A1 - Young, Peter T1 - LEMUR large european module for solar ultraviolet research JF - Experimental astronomy : an international journal on astronomical instrumentation and data analysis N2 - The solar outer atmosphere is an extremely dynamic environment characterized by the continuous interplay between the plasma and the magnetic field that generates and permeates it. Such interactions play a fundamental role in hugely diverse astrophysical systems, but occur at scales that cannot be studied outside the solar system. Understanding this complex system requires concerted, simultaneous solar observations from the visible to the vacuum ultraviolet (VUV) and soft X-rays, at high spatial resolution (between 0.1'' and 0.3''), at high temporal resolution (on the order of 10 s, i.e., the time scale of chromospheric dynamics), with a wide temperature coverage (0.01 MK to 20 MK, from the chromosphere to the flaring corona), and the capability of measuring magnetic fields through spectropolarimetry at visible and near-infrared wavelengths. Simultaneous spectroscopic measurements sampling the entire temperature range are particularly important. These requirements are fulfilled by the Japanese Solar-C mission (Plan B), composed of a spacecraft in a geosynchronous orbit with a payload providing a significant improvement of imaging and spectropolarimetric capabilities in the UV, visible, and near-infrared with respect to what is available today and foreseen in the near future. The Large European Module for solar Ultraviolet Research (LEMUR), described in this paper, is a large VUV telescope feeding a scientific payload of high-resolution imaging spectrographs and cameras. LEMUR consists of two major components: a VUV solar telescope with a 30 cm diameter mirror and a focal length of 3.6 m, and a focal-plane package composed of VUV spectrometers covering six carefully chosen wavelength ranges between 170 and 1270 . The LEMUR slit covers 280'' on the Sun with 0.14'' per pixel sampling. In addition, LEMUR is capable of measuring mass flows velocities (line shifts) down to 2 km s (-aEuro parts per thousand 1) or better. LEMUR has been proposed to ESA as the European contribution to the Solar C mission. KW - Sun: atmosphere KW - Space vehicles: instruments KW - Techniques: spectroscopy KW - ESA cosmic vision Y1 - 2012 U6 - https://doi.org/10.1007/s10686-011-9274-x SN - 0922-6435 VL - 34 IS - 2 SP - 273 EP - 309 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Tepper-Garcia, Thorsten A1 - Richter, Philipp A1 - Schaye, Joop A1 - Booth, C. M. A1 - Dalla Vecchia, Claudio A1 - Theuns, Tom T1 - Absorption signatures of warm-hot gas at low redshift: broad H?i Lya absorbers JF - Monthly notices of the Royal Astronomical Society N2 - We investigate the physical state of H?i absorbing gas at low redshift (z = 0.25) using a subset of cosmological, hydrodynamic simulations from the OverWhelmingly Large Simulations project, focusing in particular on broad (bHI=40 km s-1) H?i Lya absorbers (BLAs), which are believed to originate in shock-heated gas in the warm-hot intergalactic medium (WHIM). Our fiducial model, which includes radiative cooling by heavy elements and feedback by supernovae and active galactic nuclei, predicts that by z = 0.25 nearly 60?per cent of the gas mass ends up at densities and temperatures characteristic of the WHIM and we find that half of this fraction is due to outflows. The standard H?i observables (distribution of H?i column densities NH?I, distribution of Doppler parameters bHI, bHINH?I correlation) and the BLA line number density predicted by our simulations are in remarkably good agreement with observations. BLAs arise in gas that is hotter, more highly ionized and more enriched than the gas giving rise to typical Lya forest absorbers. The majority of the BLAs arise in warm-hot [log?(T/?K) similar to 5] gas at low (log?? < 1.5) overdensities. On average, thermal broadening accounts for at least 60?per cent of the BLA linewidth, which in turn can be used as a rough indicator of the thermal state of the gas. Detectable BLAs account for only a small fraction of the true baryon content of the WHIM at low redshift. In order to detect the bulk of the mass in this gas phase, a sensitivity at least one order of magnitude better than achieved by current ultraviolet spectrographs is required. We argue that BLAs mostly trace gas that has been shock heated and enriched by outflows and that they therefore provide an important window on a poorly understood feedback process. KW - methods: numerical KW - galaxies: formation KW - intergalactic medium KW - quasars: absorption lines KW - cosmology: theory Y1 - 2012 U6 - https://doi.org/10.1111/j.1365-2966.2012.21545.x SN - 0035-8711 VL - 425 IS - 3 SP - 1640 EP - 1663 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Temirbayev, Amirkhan A. A1 - Zhanabaev, Zeinulla Zh. A1 - Tarasov, Stanislav B. A1 - Ponomarenko, Vladimir I. A1 - Rosenblum, Michael T1 - Experiments on oscillator ensembles with global nonlinear coupling JF - Physical review : E, Statistical, nonlinear and soft matter physics N2 - We experimentally analyze collective dynamics of a population of 20 electronic Wien-bridge limit-cycle oscillators with a nonlinear phase-shifting unit in the global feedback loop. With an increase in the coupling strength we first observe formation and then destruction of a synchronous cluster, so that the dependence of the order parameter on the coupling strength is not monotonic. After destruction of the cluster the ensemble remains nevertheless coherent, i.e., it exhibits an oscillatory collective mode (mean field). We show that the system is now in a self-organized quasiperiodic state, predicted in Rosenblum and Pikovsky [Phys. Rev. Lett. 98, 064101 (2007)]. In this state, frequencies of all oscillators are smaller than the frequency of the mean field, so that the oscillators are not locked to the mean field they create and their dynamics is quasiperiodic. Without a nonlinear phase-shifting unit, the system exhibits a standard Kuramoto-like transition to a fully synchronous state. We demonstrate a good correspondence between the experiment and previously developed theory. We also propose a simple measure which characterizes the macroscopic incoherence-coherence transition in a finite-size ensemble. Y1 - 2012 U6 - https://doi.org/10.1103/PhysRevE.85.015204 SN - 1539-3755 VL - 85 IS - 1 PB - American Physical Society CY - College Park ER - TY - JOUR A1 - Telezhinsky, Igor O. A1 - Dwarkadas, Vikram V. A1 - Pohl, Martin T1 - Time-dependent escape of cosmic rays from supernova remnants, and their interaction with dense media JF - Astronomy and astrophysics : an international weekly journal N2 - Context. Supernova remnants (SNRs) are thought to be the main source of Galactic cosmic rays (CRs) up to the "knee" in CR spectrum. During the evolution of a SNR, the bulk of the CRs are confined inside the SNR shell. The highest-energy particles leave the system continuously, while the remaining adiabatically cooled particles are released when the SNR has expanded sufficiently and decelerated so that the magnetic field at the shock is no longer able to confine them. Particles escaping from the parent system may interact with nearby molecular clouds, producing.-rays in the process via pion decay. The soft gamma-ray spectra observed for a number of SNRs interacting with molecular clouds, however, challenge current theories of non-linear particle acceleration that predict harder spectra. Aims. We study how the spectrum of escaped particles depends on the time-dependent acceleration history in both Type Ia and core-collapse SNRs, as well as on different assumptions about the diffusion coefficient in the vicinity of the SNR. Methods. We solve the CR transport equation in a test-particle approach combined with numerical simulations of SNR evolution. Results. We extend our method for calculating the CR acceleration in SNRs to trace the escaped particles in a large volume around SNRs. We calculate the evolution of the spectra of CRs that have escaped from a SNR into a molecular cloud or dense shell for two diffusion models. We find a strong confinement of CRs in a close region around the SNR, and a strong dilution effect for CRs that were able to propagate out as far as a few SNR radii. KW - ISM: supernova remnants KW - ISM: clouds KW - cosmic rays Y1 - 2012 U6 - https://doi.org/10.1051/0004-6361/201118639 SN - 0004-6361 VL - 541 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Telezhinsky, Igor O. A1 - Dwarkadas, Vikram V. A1 - Pohl, Martin T1 - Particle spectra from acceleration at forward and reverse shocks of young Type Ia Supernova Remnants JF - Astroparticle physics N2 - We study cosmic-ray acceleration in young Type Ia Supernova Remnants (SNRs) by means of test-particle diffusive shock acceleration theory and 1-D hydrodynamical simulations of their evolution. In addition to acceleration at the forward shock, we explore the particle acceleration at the reverse shock in the presence of a possible substantial magnetic field, and consequently the impact of this acceleration on the particle spectra in the remnant. We investigate the time evolution of the spectra for various time-dependent profiles of the magnetic field in the shocked region of the remnant. We test a possible influence on particle spectra of the Alfvenic drift of scattering centers in the precursor regions of the shocks. In addition, we study the radiation spectra and morphology in a broad band from radio to gamma-rays. It is demonstrated that the reverse shock contribution to the cosmic-ray particle population of young Type la SNRs may be significant, modifying the spatial distribution of particles and noticeably affecting the volume-integrated particle spectra in young SNRs. In particular spectral structures may arise in test-particle calculations that are often discussed as signatures of non-linear cosmic-ray modification of shocks. Therefore, the spectrum and morphology of emission, and their time evolution, differ from pure forward-shock solutions. KW - Supernova Remnants KW - Cosmic rays KW - Cosmic-ray acceleration KW - Hydrodynamics KW - Forward and reverse shocks Y1 - 2012 U6 - https://doi.org/10.1016/j.astropartphys.2011.10.001 SN - 0927-6505 VL - 35 IS - 6 SP - 300 EP - 311 PB - Elsevier CY - Amsterdam ER -