@article{Faber2011, author = {Faber, Eike}, title = {Anti-Germanism in Constantinople or the Revolt of Gainas?}, series = {New perspectives on late antiquity}, journal = {New perspectives on late antiquity}, publisher = {Cambridge Scholars}, address = {Newcastle upon Tyne}, isbn = {978-1-4438-2718-8}, pages = {124 -- 135}, year = {2011}, language = {en} } @misc{EggertRawelPawelzik2011, author = {Eggert, Kai and Rawel, Harshadrai Manilal and Pawelzik, Elke}, title = {In vitro degradation of wheat gluten fractions by Fusarium graminearum proteases}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, number = {877}, issn = {1866-8372}, doi = {10.25932/publishup-43510}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435102}, pages = {697 -- 705}, year = {2011}, abstract = {Fusarium spp. infection of cereal grain is a common problem, which leads to a dramatic loss of grain quality. The aim of the present study was to investigate the effect of Fusarium infection on the wheat storage protein gluten and its fractions, the gliadins and glutenins, in an in vitro model system. Gluten proteins were digested by F. graminearum proteases for 2, 4, 8 and 24 h, separated by Osborne fractionation and characterised by chromatographic (RP-HPLC) and electrophoretic analysis (SDS-Page). Gluten digestion by F. graminearum proteases showed in comparison with gliadins a preference for the glutenins whereas the HMW subfraction was at most affected. In comparison with a untreated control, the HMW subfraction was degraded of about 97\% after 4 h incubation with Fusarium proteases. Separate digestion of gliadin and glutenin underlined the preference for HMW-GS. Analogue to the observed change in the gluten composition, the yield of the proteins extracted changed. A higher amount of glutenin fragments was found in the gliadin extraction solution after digestion and could mask a gliadin destruction at the same time. This observation can contribute to explain the frequently reported reduced glutenin amount parallel to an increase in gliadin quantity after Fusarium infection in grains.}, language = {en} } @misc{BierbachSchulteHerrmannetal.2011, author = {Bierbach, David and Schulte, Matthias and Herrmann, Nina and Tobler, Michael and Stadler, Stefan and Jung, Christian T. and Kunkel, Benjamin and Riesch, R{\"u}diger and Klaus, Sebastian and Ziege, Madlen and Indy, Jeane Rimber and Arias-Rodriguez, Lenin and Plath, Martin}, title = {Predator-induced changes of female mating preferences}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {984}, issn = {1866-8372}, doi = {10.25932/publishup-43109}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-431099}, pages = {12}, year = {2011}, abstract = {Background In many species males face a higher predation risk than females because males display elaborate traits that evolved under sexual selection, which may attract not only females but also predators. Females are, therefore, predicted to avoid such conspicuous males under predation risk. The present study was designed to investigate predator-induced changes of female mating preferences in Atlantic mollies (Poecilia mexicana). Males of this species show a pronounced polymorphism in body size and coloration, and females prefer large, colorful males in the absence of predators. Results In dichotomous choice tests predator-na{\"i}ve (lab-reared) females altered their initial preference for larger males in the presence of the cichlid Cichlasoma salvini, a natural predator of P. mexicana, and preferred small males instead. This effect was considerably weaker when females were confronted visually with the non-piscivorous cichlid Vieja bifasciata or the introduced non-piscivorous Nile tilapia (Oreochromis niloticus). In contrast, predator experienced (wild-caught) females did not respond to the same extent to the presence of a predator, most likely due to a learned ability to evaluate their predators' motivation to prey. Conclusions Our study highlights that (a) predatory fish can have a profound influence on the expression of mating preferences of their prey (thus potentially affecting the strength of sexual selection), and females may alter their mate choice behavior strategically to reduce their own exposure to predators. (b) Prey species can evolve visual predator recognition mechanisms and alter their mate choice only when a natural predator is present. (c) Finally, experiential effects can play an important role, and prey species may learn to evaluate the motivational state of their predators.}, language = {en} } @misc{VanDonkIanoraVos2011, author = {Van Donk, Ellen and Ianora, Adrianna and Vos, Matthijs}, title = {Induced defences in marine and freshwater phytoplankton}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, number = {881}, issn = {1866-8372}, doi = {10.25932/publishup-43513}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435130}, pages = {19}, year = {2011}, abstract = {Many organisms have developed defences to avoid predation by species at higher trophic levels. The capability of primary producers to defend themselves against herbivores affects their own survival, can modulate the strength of trophic cascades and changes rates of competitive exclusion in aquatic communities. Algal species are highly flexible in their morphology, growth form, biochemical composition and production of toxic and deterrent compounds. Several of these variable traits in phytoplankton have been interpreted as defence mechanisms against grazing. Zooplankton feed with differing success on various phytoplankton species, depending primarily on size, shape, cell wall structure and the production of toxins and deterrents. Chemical cues associated with (i) mechanical damage, (ii) herbivore presence and (iii) grazing are the main factors triggering induced defences in both marine and freshwater phytoplankton, but most studies have failed to disentangle the exact mechanism(s) governing defence induction in any particular species. Induced defences in phytoplankton include changes in morphology (e.g. the formation of spines, colonies and thicker cell walls), biochemistry (such as production of toxins, repellents) and in life history characteristics (formation of cysts, reduced recruitment rate). Our categorization of inducible defences in terms of the responsible induction mechanism provides guidance for future work, as hardly any of the available studies on marine or freshwater plankton have performed all the treatments that are required to pinpoint the actual cue(s) for induction. We discuss the ecology of inducible defences in marine and freshwater phytoplankton with a special focus on the mechanisms of induction, the types of defences, their costs and benefits, and their consequences at the community level.}, language = {en} } @article{AbdoAckermannAjelloetal.2011, author = {Abdo, A. A. and Ackermann, Margit and Ajello, M. and Allafort, A. J. and Baldini, L. and Ballet, J. and Barbiellini, G. and Baring, M. G. and Bastieri, D. and Bechtol, K. C. and Bellazzini, R. and Berenji, B. and Blandford, R. D. and Bloom, E. D. and Bonamente, E. and Borgland, A. W. and Bouvier, A. and Brandt, T. J. and Bregeon, Johan and Brez, A. and Brigida, M. and Bruel, P. and Buehler, R. and Buson, S. and Caliandro, G. A. and Cameron, R. A. and Cannon, A. and Caraveo, P. A. and Carrigan, Svenja and Casandjian, J. M. and Cavazzuti, E. and Cecchi, C. and Celik, O. and Charles, E. and Chekhtman, A. and Cheung, C. C. and Chiang, J. and Ciprini, S. and Claus, R. and Cohen-Tanugi, J. and Conrad, Jan and Cutini, S. and Dermer, C. D. and de Palma, F. and do Couto e Silva, E. and Drell, P. S. and Dubois, R. and Dumora, D. and Favuzzi, C. and Fegan, S. J. and Ferrara, E. C. and Focke, W. B. and Fortin, P. and Frailis, M. and Fuhrmann, L. and Fukazawa, Y. and Funk, S. and Fusco, P. and Gargano, F. and Gasparrini, D. and Gehrels, N. and Germani, S. and Giglietto, N. and Giordano, F. and Giroletti, M. and Glanzman, T. and Godfrey, G. and Grenier, I. A. and Guillemot, L. and Guiriec, S. and Hayashida, M. and Hays, E. and Horan, D. and Hughes, R. E. and Johannesson, G. and Johnson, A. S. and Johnson, W. N. and Kadler, M. and Kamae, T. and Katagiri, H. and Kataoka, J. and Knoedlseder, J. and Kuss, M. and Lande, J. and Latronico, L. and Lee, S. -H. and Lemoine-Goumard, M. and Longo, F. and Loparco, F. and Lott, B. and Lovellette, M. N. and Lubrano, P. and Madejski, G. M. and Makeev, A. and Max-Moerbeck, W. and Mazziotta, Mario Nicola and McEnery, J. E. and Mehault, J. and Michelson, P. F. and Mitthumsiri, W. and Mizuno, T. and Moiseev, A. A. and Monte, C. and Monzani, M. E. and Morselli, A. and Moskalenko, I. V. and Murgia, S. and Naumann-Godo, M. and Nishino, S. and Nolan, P. L. and Norris, J. P. and Nuss, E. and Ohsugi, T. and Okumura, A. and Omodei, N. and Orlando, E. and Ormes, J. F. and Paneque, D. and Panetta, J. H. and Parent, D. and Pavlidou, V. and Pearson, T. J. and Pelassa, V. and Pepe, M. and Pesce-Rollins, M. and Piron, F. and Porter, T. A. and Raino, S. and Rando, R. and Razzano, M. and Readhead, A. and Reimer, A. and Reimer, O. and Richards, J. L. and Ripken, J. and Ritz, S. and Roth, M. and Sadrozinski, H. F. -W. and Sanchez, D. and Sander, A. and Scargle, J. D. and Sgro, C. and Siskind, E. J. and Smith, P. D. and Spandre, G. and Spinelli, P. and Stawarz, L. and Stevenson, M. and Strickman, M. S. and Sokolovsky, K. V. and Suson, D. J. and Takahashi, H. and Takahashi, T. and Tanaka, T. and Thayer, J. B. and Thayer, J. G. and Thompson, D. J. and Tibaldo, L. and Torres, F. and Tosti, G. and Tramacere, A. and Uchiyama, Y. and Usher, T. L. and Vandenbroucke, J. and Vasileiou, V. and Vilchez, N. and Vitale, V. and Waite, A. P. and Wang, P. and Wehrle, A. E. and Winer, B. L. and Wood, K. S. and Yang, Z. and Ylinen, T. and Zensus, J. A. and Ziegler, M. and Aleksic, J. and Antonelli, L. A. and Antoranz, P. and Backes, Michael and Barrio, J. A. and Gonzalez, J. Becerra and Bednarek, W. and Berdyugin, A. and Berger, K. and Bernardini, E. and Biland, A. and Blanch Bigas, O. and Bock, R. K. and Boller, A. and Bonnoli, G. and Bordas, Pol and Tridon, D. Borla and Bosch-Ramon, Valentin and Bose, D. and Braun, I. and Bretz, T. and Camara, M. and Carmona, E. and Carosi, A. and Colin, P. and Colombo, E. and Contreras, J. L. and Cortina, J. and Covino, S. and Dazzi, F. and de Angelis, A. and del Pozo, E. De Cea and De Lotto, B. and De Maria, M. and De Sabata, F. and Mendez, C. Delgado and Ortega, A. Diago and Doert, M. and Dominguez, A. and Prester, Dijana Dominis and Dorner, D. and Doro, M. and Elsaesser, D. and Ferenc, D. and Fonseca, M. V. and Font, L. and Lopen, R. J. Garcia and Garczarczyk, M. and Gaug, M. and Giavitto, G. and Godinovi, N. and Hadasch, D. and Herrero, A. and Hildebrand, D. and Hoehne-Moench, D. and Hose, J. and Hrupec, D. and Jogler, T. and Klepser, S. and Kraehenbuehl, T. and Kranich, D. and Krause, J. and La Barbera, A. and Leonardo, E. and Lindfors, E. and Lombardi, S. and Lopez, M. and Lorenz, E. and Majumdar, P. and Makariev, E. and Maneva, G. and Mankuzhiyil, N. and Mannheim, K. and Maraschi, L. and Mariotti, M. and Martinez, M. and Mazin, D. and Meucci, M. and Miranda, J. M. and Mirzoyan, R. and Miyamoto, H. and Moldon, J. and Moralejo, A. and Nieto, D. and Nilsson, K. and Orito, R. and Oya, I. and Paoletti, R. and Paredes, J. M. and Partini, S. and Pasanen, M. and Pauss, F. and Pegna, R. G. and Perez-Torres, M. A. and Persic, M. and Peruzzo, J. and Pochon, J. and Moroni, P. G. Prada and Prada, F. and Prandini, E. and Puchades, N. and Puljak, I. and Reichardt, T. and Reinthal, R. and Rhode, W. and Ribo, M. and Rico, J. and Rissi, M. and Ruegamer, S. and Saggion, A. and Saito, K. and Saito, T. Y. and Salvati, M. and Sanchez-Conde, M. and Satalecka, K. and Scalzotto, V. and Scapin, V. and Schultz, C. and Schweizer, T. and Shayduk, M. and Shore, S. N. and Sierpowska-Bartosik, A. and Sillanpaa, A. and Sitarek, J. and Sobczynska, D. and Spanier, F. and Spiro, S. and Stamerra, A. and Steinke, B. and Storz, J. and Strah, N. and Struebig, J. C. and Suric, T. and Takalo, L. O. and Tavecchio, F. and Temnikov, P. and Terzic, T. and Tescaro, D. and Teshima, M. and Vankov, H. and Wagner, R. M. and Weitzel, Q. and Zabalza, V. and Zandanel, F. and Zanin, R. and Acciari, V. A. and Arlen, T. and Aune, T. and Benbow, W. and Boltuch, D. and Bradbury, S. M. and Buckley, J. H. and Bugaev, V. and Cannon, A. and Cesarini, A. and Ciupik, L. and Cui, W. and Dickherber, R. and Errando, M. and Falcone, A. and Finley, J. P. and Finnegan, G. and Fortson, L. and Furniss, A. and Galante, N. and Gall, D. and Gillanders, G. H. and Godambe, S. and Grube, J. and Guenette, R. and Gyuk, G. and Hanna, D. and Holder, J. and Huang, D. and Hui, C. M. and Humensky, T. B. and Kaaret, P. and Karlsson, N. and Kertzman, M. and Kieda, D. and Konopelko, A. and Krawczynski, H. and Krennrich, F. and Lang, M. J. and Maier, G. and McArthur, S. and McCann, A. and McCutcheon, M. and Moriarty, P. and Mukherjee, R. and Ong, R. and Otte, N. and Pandel, D. and Perkins, J. S. and Pichel, A. and Pohl, M. and Quinn, J. and Ragan, K. and Reyes, L. C. and Reynolds, P. T. and Roache, E. and Rose, H. J. and Rovero, A. C. and Schroedter, M. and Sembroski, G. H. and Senturk, G. D. and Steele, D. and Swordy, S. P. and Tesic, G. and Theiling, M. and Thibadeau, S. and Varlotta, A. and Vincent, S. and Wakely, S. P. and Ward, J. E. and Weekes, T. C. and Weinstein, A. and Weisgarber, T. and Williams, D. A. and Wood, M. and Zitzer, B. and Villata, M. and Raiteri, C. M. and Aller, H. D. and Aller, M. F. and Arkharov, A. A. and Blinov, D. A. and Calcidese, P. and Chen, W. P. and Efimova, N. V. and Kimeridze, G. and Konstantinova, T. S. and Kopatskaya, E. N. and Koptelova, E. and Kurtanidze, O. M. and Kurtanidze, S. O. and Lahteenmaki, A. and Larionov, V. M. and Larionova, E. G. and Larionova, L. V. and Ligustri, R. and Morozova, D. A. and Nikolashvili, M. G. and Sigua, L. A. and Troitsky, I. S. and Angelakis, E. and Capalbi, M. and Carraminana, A. and Carrasco, L. and Cassaro, P. and de la Fuente, E. and Gurwell, M. A. and Kovalev, Y. Y. and Kovalev, Yu. A. and Krichbaum, T. P. and Krimm, H. A. and Leto, Paolo and Lister, M. L. and Maccaferri, G. and Moody, J. W. and Mori, Y. and Nestoras, I. and Orlati, A. and Pagani, C. and Pace, C. and Pearson, R. and Perri, M. and Piner, B. G. and Pushkarev, A. B. and Ros, E. and Sadun, A. C. and Sakamoto, T. and Tornikoski, M. and Yatsu, Y. and Zook, A.}, title = {Insights into the high-energy gamma-Ray emission of markarian 501 fromextensive multifrequency observations in the fermi era}, series = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, volume = {727}, journal = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, number = {2}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, organization = {Fermi-LAT Collaboration, MAGIC Collaboration, VERITAS Collaboration}, issn = {0004-637X}, doi = {10.1088/0004-637X/727/2/129}, pages = {26}, year = {2011}, abstract = {We report on the gamma-ray activity of the blazar Mrk 501 during the first 480 days of Fermi operation. We find that the average Large Area Telescope (LAT) gamma-ray spectrum of Mrk 501 can be well described by a single power-law function with a photon index of 1.78 +/- 0.03. While we observe relatively mild flux variations with the Fermi-LAT (within less than a factor of two), we detect remarkable spectral variability where the hardest observed spectral index within the LAT energy range is 1.52 +/- 0.14, and the softest one is 2.51 +/- 0.20. These unexpected spectral changes do not correlate with the measured flux variations above 0.3 GeV. In this paper, we also present the first results from the 4.5 month long multifrequency campaign (2009 March 15-August 1) on Mrk 501, which included the Very Long Baseline Array (VLBA), Swift, RXTE, MAGIC, and VERITAS, the F-GAMMA, GASP-WEBT, and other collaborations and instruments which provided excellent temporal and energy coverage of the source throughout the entire campaign. The extensive radio to TeV data set from this campaign provides us with the most detailed spectral energy distribution yet collected for this source during its relatively low activity. The average spectral energy distribution of Mrk 501 is well described by the standard one-zone synchrotron self-Compton (SSC) model. In the framework of this model, we find that the dominant emission region is characterized by a size less than or similar to 0.1 pc (comparable within a factor of few to the size of the partially resolved VLBA core at 15-43 GHz), and that the total jet power (similar or equal to 10(44) erg s(-1)) constitutes only a small fraction (similar to 10(-3)) of the Eddington luminosity. The energy distribution of the freshly accelerated radiating electrons required to fit the time-averaged data has a broken power-law form in the energy range 0.3 GeV-10 TeV, with spectral indices 2.2 and 2.7 below and above the break energy of 20 GeV. We argue that such a form is consistent with a scenario in which the bulk of the energy dissipation within the dominant emission zone of Mrk 501 is due to relativistic, proton-mediated shocks. We find that the ultrarelativistic electrons and mildly relativistic protons within the blazar zone, if comparable in number, are in approximate energy equipartition, with their energy dominating the jet magnetic field energy by about two orders of magnitude.}, language = {en} } @article{LueckRuehlmannKirchmann2011, author = {L{\"u}ck, Erika and R{\"u}hlmann, J{\"o}rg and Kirchmann, Holger}, title = {Properties of soils from the Swedish long-term fertility experiments VI. Mapping soil electrical conductivity with different geophysical methods}, series = {Acta agriculturae Scandinavica : Section B, Soil and plant science}, volume = {61}, journal = {Acta agriculturae Scandinavica : Section B, Soil and plant science}, number = {5}, publisher = {Taylor \& Francis Group}, address = {Oslo}, issn = {0906-4710}, doi = {10.1080/09064710.2010.502124}, pages = {438 -- 447}, year = {2011}, abstract = {Swedish long-term soil fertility experiments were used to investigate the effect of texture and fertilization regime on soil electrical conductivity. In one geophysical approach, fields were mapped to characterize the horizontal variability in apparent electrical conductivity down to 1.5 m soil depth using an electromagnetic induction meter (EM38 device). The data obtained were geo-referenced by dGPS. The other approach consisted of measuring the vertical variability in electrical conductivity along transects using a multi-electrode apparatus for electrical resistivity tomography (GeoTom RES/IP device) down to 2 m depth. Geophysical field work was complemented by soil analyses. The results showed that despite 40 years of different fertilization regimes, treatments had no significant effects on the apparent electrical conductivity. Instead, the comparison of sites revealed high and low conductivity soils, with gradual differences explained by soil texture. A significant, linear relationship found between apparent electrical conductivity and soil clay content explained 80\% of the variability measured. In terms of soil depth, both low and high electrical conductivity values were measured. Abrupt changes in electrical conductivity within a field revealed the presence of 'deviating areas'. Higher values corresponded well with layers with a high clay content, while local inclusions of coarse-textured materials caused a high variability in conductivity in some fields. The geophysical methods tested provided useful information on the variability in soil texture at the experimental sites. The use of spatial EC variability as a co-variable in statistical analysis could be a complementary tool in the evaluation of experimental results.}, language = {en} } @phdthesis{Sperfeld2011, author = {Sperfeld, Erik}, title = {Effects of temperature and co-limiting nutritional components on life history traits of Daphnia magna and its biochemical composition}, address = {Potsdam}, pages = {157 S.}, year = {2011}, language = {en} } @article{KonradSchmolkeO'BrienZack2011, author = {Konrad-Schmolke, Matthias and O'Brien, Patrick J. and Zack, Thomas}, title = {Fluid Migration above a Subducted Slab-Constraints on Amount, Pathways and Major Element Mobility from Partially Overprinted Eclogite-facies Rocks (Sesia Zone, Western Alps)}, series = {Journal of petrology}, volume = {52}, journal = {Journal of petrology}, number = {3}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0022-3530}, doi = {10.1093/petrology/egq087}, pages = {457 -- 486}, year = {2011}, abstract = {The Western Alpine Sesia-Lanzo Zone (SLZ) is a sliver of eclogite-facies continental crust exhumed from mantle depths in the hanging wall of a subducted oceanic slab. Eclogite-facies felsic and basic rocks sampled across the internal SLZ show different degrees of retrograde metamorphic overprint associated with fluid influx. The weakly deformed samples preserve relict eclogite-facies mineral assemblages that show partial fluid-induced compositional re-equilibration along grain boundaries, brittle fractures and other fluid pathways. Multiple fluid influx stages are indicated by replacement of primary omphacite by phengite, albitic plagioclase and epidote as well as partial re-equilibration and/or overgrowths in phengite and sodic amphibole, producing characteristic step-like compositional zoning patterns. The observed textures, together with the map-scale distribution of the samples, suggest open-system, pervasive and reactive fluid flux across large rock volumes above the subducted slab. Thermodynamic modelling indicates a minimum amount of fluid of 0 center dot 1-0 center dot 5 wt \% interacting with the wall-rocks. Phase relations and reaction textures indicate mobility of K, Ca, Fe and Mg, whereas Al is relatively immobile in these medium-temperature-high-pressure fluids. Furthermore, the thermodynamic models show that recycling of previously fractionated material, such as in the cores of garnet porphyroblasts, largely controls the compositional re-equilibration of the exhumed rock body.}, language = {en} } @article{KonradSchmolkeZackO'Brienetal.2011, author = {Konrad-Schmolke, Matthias and Zack, Thomas and O'Brien, Patrick J. and Barth, Matthias}, title = {Fluid migration above a subducted slab - Thermodynamic and trace element modelling of fluid-rock interaction in partially overprinted eclogite-facies rocks (Sesia Zone, Western Alps)}, series = {Earth \& planetary science letters}, volume = {311}, journal = {Earth \& planetary science letters}, number = {3-4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0012-821X}, doi = {10.1016/j.epsl.2011.09.025}, pages = {287 -- 298}, year = {2011}, abstract = {The amount and composition of subduction zone fluids and the effect of fluid-rock interaction at a slab-mantle interface have been constrained by thermodynamic and trace element modelling of partially overprinted blueschist-facies rocks from the Sesia Zone (Western Alps). Deformation-induced differences in fluid flux led to a partial preservation of pristine mineral cores in weakly deformed samples that were used to quantify Li, B, Stand Pb distribution during mineral growth, -breakdown and modification induced by fluid-rock interaction. Our results show that Li and 13 budgets are fluid-controlled, thus acting as tracers for fluid-rock interaction processes, whereas Stand Pb budgets are mainly controlled by the fluid-induced formation of epidote. Our calculations show that fluid-rock interaction caused significant Li and B depletion in the affected rocks due to leaching effects, which in turn can lead to a drastic enrichment of these elements in the percolating fluid. Depending on available fluid-mineral trace element distribution coefficients modelled fluid rock ratios were up to 0.06 in weakly deformed samples and at least 0.5 to 4 in shear zone mylonites. These amounts lead to time integrated fluid fluxes of up to 1.4-10(2) m(3) m(-2) in the weakly deformed rocks and 1-8-10(3) m(3) m(-2) in the mylonites. Combined thermodynamic and trace element models can be used to quantify metamorphic fluid fluxes and the associated element transfer in complex, reacting rock systems and help to better understand commonly observed fluid-induced trace element trends in rocks and minerals from different geodynamic environments.}, language = {en} } @article{SchmidtMezgerO'Brien2011, author = {Schmidt, Alexander and Mezger, Klaus and O'Brien, Patrick J.}, title = {The time of eclogite formation in the ultrahigh pressure rocks of the Sulu terrane Constraints from Lu-Hf garnet geochronology}, series = {Lithos : an international journal of mineralogy, petrology, and geochemistry}, volume = {125}, journal = {Lithos : an international journal of mineralogy, petrology, and geochemistry}, number = {1-2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0024-4937}, doi = {10.1016/j.lithos.2011.04.004}, pages = {743 -- 756}, year = {2011}, abstract = {Eclogites from the main borehole of the Chinese Continental Scientific Drilling project yield highly precise Lu-Hf garnet-clinopyroxene ages of 216.9 +/- 1.2 Ma (four samples) and 220.5 +/- 2.7 Ma (one sample). The spatial distribution of the rare earth elements in garnet is consistent with the preservation of primary growth zoning, unmodified by diffusion, which supports the interpretation that the Lu-Hf ages date the time of formation of garnet, the major rock forming mineral in the eclogites. The preservation of primary REE-zoning, despite peak metamorphic temperatures around 800-850 degrees C. indicates that the Lu-Hf chronometer is perfectly suitable to date garnet-forming reactions in high grade rocks. The range of Lu-Hf ages for eclogites in the Dabie-Sulu UHP terrane point to episodic rather than continuous growth of garnets and thus punctuated metamorphism during the collision of the North China Block and the Yangtze Block. The U-Pb ages and Hf-isotope systematics of zircon grains from one eclogite sample imply a protracted geologic history of the eclogite precursors that started around 2 Ga and culminated in the UHP metamorphism around 220 Ma.}, language = {en} } @article{KotkovaO'BrienZiemann2011, author = {Kotkova, Jana and O'Brien, Patrick J. and Ziemann, Martin Andreas}, title = {Diamond and coesite discovered in Saxony-type granulite solution to the Variscan garnet peridotite enigma}, series = {Geology}, volume = {39}, journal = {Geology}, number = {7}, publisher = {American Institute of Physics}, address = {Boulder}, issn = {0091-7613}, doi = {10.1130/G31971.1}, pages = {667 -- 670}, year = {2011}, abstract = {The pressures required for diamond and coesite formation far exceed conditions reached by even the deepest present-day orogenic crustal roots. Therefore the occurrence of metamorphosed continental crust containing these minerals requires processes other than crustal thickening to have operated in the past. Here we report the first in situ finding of diamond and coesite, characterized by micro-Raman spectroscopy, in high-pressure granulites otherwise indistinguishable from granulites found associated with garnet peridotite throughout the European Variscides. Our discovery confirms the provenance of Europe's first reliable diamond, the "Bohemian diamond," found in A.D. 1870, and also represents the first robust evidence for ultrahigh-pressure conditions in a major Variscan crustal rock type. A process of deep continental subduction is required to explain the metamorphic pressures and the granulite-garnet peridotite association, and thus tectonometamorphic models for these rocks involving a deep orogenic crustal root need to be significantly modified.}, language = {en} } @article{SammlerBleidornTiedemann2011, author = {Sammler, Svenja and Bleidorn, Christoph and Tiedemann, Ralph}, title = {Full mitochondrial genome sequences of two endemic Philippine hornbill species (Aves: Bucerotidae) provide evidence for pervasive mitochondrial DNA recombination}, series = {BMC genomics}, volume = {12}, journal = {BMC genomics}, number = {2}, publisher = {BioMed Central}, address = {London}, issn = {1471-2164}, doi = {10.1186/1471-2164-12-35}, pages = {10}, year = {2011}, abstract = {Background: Although nowaday it is broadly accepted that mitochondrial DNA (mtDNA) may undergo recombination, the frequency of such recombination remains controversial. Its estimation is not straightforward, as recombination under homoplasmy (i.e., among identical mt genomes) is likely to be overlooked. In species with tandem duplications of large mtDNA fragments the detection of recombination can be facilitated, as it can lead to gene conversion among duplicates. Although the mechanisms for concerted evolution in mtDNA are not fully understood yet, recombination rates have been estimated from "one per speciation event" down to 850 years or even "during every replication cycle". Results: Here we present the first complete mt genome of the avian family Bucerotidae, i.e., that of two Philippine hornbills, Aceros waldeni and Penelopides panini. The mt genomes are characterized by a tandemly duplicated region encompassing part of cytochrome b, 3 tRNAs, NADH6, and the control region. The duplicated fragments are identical to each other except for a short section in domain I and for the length of repeat motifs in domain III of the control region. Due to the heteroplasmy with regard to the number of these repeat motifs, there is some size variation in both genomes; with around 21,657 bp (A. waldeni) and 22,737 bp (P. panini), they significantly exceed the hitherto longest known avian mt genomes, that of the albatrosses. We discovered concerted evolution between the duplicated fragments within individuals. The existence of differences between individuals in coding genes as well as in the control region, which are maintained between duplicates, indicates that recombination apparently occurs frequently, i. e., in every generation. Conclusions: The homogenised duplicates are interspersed by a short fragment which shows no sign of recombination. We hypothesize that this region corresponds to the so-called Replication Fork Barrier (RFB), which has been described from the chicken mitochondrial genome. As this RFB is supposed to halt replication, it offers a potential mechanistic explanation for frequent recombination in mitochondrial genomes.}, language = {en} } @misc{PokornySharmaGoyaletal.2011, author = {Pokorny, Ina and Sharma, Reeta and Goyal, Surendra Prakash and Mishra, Sudanshu and Tiedemann, Ralph}, title = {MHC class I and MHC class II DRB gene variability in wild and captive Bengal tigers (Panthera tigris tigris) (vol 10, pg 667, 2010)}, series = {Immunogenetics}, volume = {63}, journal = {Immunogenetics}, number = {2}, publisher = {Springer}, address = {New York}, issn = {0093-7711}, doi = {10.1007/s00251-010-0496-2}, pages = {121 -- 121}, year = {2011}, language = {en} } @article{WiesnerLoxdaleKoehleretal.2011, author = {Wiesner, Kerstin R. and Loxdale, Hugh D. and K{\"o}hler, G{\"u}nter and Schneider, Anja R. R. and Tiedemann, Ralph and Weisser, Wolfgang W.}, title = {Patterns of local and regional genetic structuring in the meadow grasshopper, Chorthippus parallelus (Orthoptera: Acrididae), in Central Germany revealed using microsatellite markers}, series = {Biological journal of the Linnean Society : a journal of evolution}, volume = {103}, journal = {Biological journal of the Linnean Society : a journal of evolution}, number = {4}, publisher = {Wiley-Blackwell}, address = {Malden}, issn = {0024-4066}, doi = {10.1111/j.1095-8312.2011.01698.x}, pages = {875 -- 890}, year = {2011}, abstract = {The meadow grasshopper, Chorthippus parallelus (Zetterstedt), is common and widespread in Central Europe, with a low dispersal range per generation. A population study in Central Germany (Frankenwald and Thuringer Schiefergebirge) showed strong interpopulation differences in abundance and individual fitness. We examined genetic variability using microsatellite markers within and between 22 populations in a short-to long-distance sampling (19 populations, Frankenwald, Schiefergebirge, as well as a southern transect), and in the Erzgebirge region (three populations), with the latter aiming to check for effects as a result of historical forest cover. Of the 671 C. parallelus captured, none was macropterous (functionally winged). All populations showed a high level of expected and observed heterozygosity (mean 0.80-0.90 and 0.60-0.75, respectively), whereas there was evidence of inbreeding (F(IS) values all positive). Allelic richness for all locus-population combinations was high (mean 9.3-11.2), whereas alleles per locus ranged from 15-62. At a local level, genic and genotypic differences were significant. Pairwise F(ST) values were in the range 0.00-0.04, indicating little interpopulation genetic differentiation. Similarly, the calculated gene flow was very high, based on the respective F(ST) (19.5) and using private alleles (7.7). A Neighbour-joining tree using Nei's D(A) and principal coordinate analysis separated two populations that were collected in the Erzgebirge region. Populations from this region may have escaped the effects of the historical forest cover. The visualization of the spatial arrangement of genotypes revealed one geographical barrier to gene flow in the short-distance sampling.}, language = {en} } @article{StoofLeichsenringJungingerOlakaetal.2011, author = {Stoof-Leichsenring, Kathleen Rosemarie and Junginger, Annett and Olaka, Lydia A. and Tiedemann, Ralph and Trauth, Martin H.}, title = {Environmental variability in Lake Naivasha, Kenya, over the last two centuries}, series = {Journal of paleolimnolog}, volume = {45}, journal = {Journal of paleolimnolog}, number = {3}, publisher = {Springer}, address = {Dordrecht}, issn = {0921-2728}, doi = {10.1007/s10933-011-9502-4}, pages = {353 -- 367}, year = {2011}, abstract = {Lake Naivasha, Kenya, is one of a number of freshwater lakes in the East African Rift System. Since the beginning of the twentieth century, it has experienced greater anthropogenic influence as a result of increasingly intensive farming of coffee, tea, flowers, and other horticultural crops within its catchment. The water-level history of Lake Naivasha over the past 200 years was derived from a combination of instrumental records and sediment data. In this study, we analysed diatoms in a lake sediment core to infer past lacustrine conductivity and total phosphorus concentrations. We also measured total nitrogen and carbon concentrations in the sediments. Core chronology was established by (210)Pb dating and covered a similar to 186-year history of natural (climatic) and human-induced environmental changes. Three stratigraphic zones in the core were identified using diatom assemblages. There was a change from littoral/epiphytic diatoms such as Gomphonema gracile and Cymbella muelleri, which occurred during a prolonged dry period from ca. 1820 to 1896 AD, through a transition period, to the present planktonic Aulacoseira sp. that favors nutrient-rich waters. This marked change in the diatom assemblage was caused by climate change, and later a strong anthropogenic overprint on the lake system. Increases in sediment accumulation rates since 1928, from 0.01 to 0.08 g cm(-2) year(-1) correlate with an increase in diatom-inferred total phosphorus concentrations since the beginning of the twentieth century. The increase in phosphorus accumulation suggests increasing eutrophication of freshwater Lake Naivasha. This study identified two major periods in the lake's history: (1) the period from 1820 to 1950 AD, during which the lake was affected mainly by natural climate variations, and (2) the period since 1950, during which the effects of anthropogenic activity overprinted those of natural climate variation.}, language = {en} } @article{SchwarteTiedemann2011, author = {Schwarte, Sandra and Tiedemann, Ralph}, title = {A Gene Duplication/Loss Event in the Ribulose-1,5-Bisphosphate-Carboxylase/Oxygenase (Rubisco) Small Subunit Gene Family among Accessions of Arabidopsis thaliana}, series = {Molecular biology and evolution}, volume = {28}, journal = {Molecular biology and evolution}, number = {6}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0737-4038}, doi = {10.1093/molbev/msr008}, pages = {1861 -- 1876}, year = {2011}, abstract = {Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase; EC 4.1.1.39), the most abundant protein in nature, catalyzes the assimilation of CO(2) (worldwide about 10(11) t each year) by carboxylation of ribulose-1,5-bisphosphate. It is a hexadecamer consisting of eight large and eight small subunits. Although the Rubisco large subunit (rbcL) is encoded by a single gene on the multicopy chloroplast genome, the Rubisco small subunits (rbcS) are encoded by a family of nuclear genes. In Arabidopsis thaliana, the rbcS gene family comprises four members, that is, rbcS-1a, rbcS-1b, rbcS-2b, and rbcS-3b. We sequenced all Rubisco genes in 26 worldwide distributed A. thaliana accessions. In three of these accessions, we detected a gene duplication/loss event, where rbcS-1b was lost and substituted by a duplicate of rbcS-2b (called rbcS-2b*). By screening 74 additional accessions using a specific polymerase chain reaction assay, we detected five additional accessions with this duplication/loss event. In summary, we found the gene duplication/loss in 8 of 100 A. thaliana accessions, namely, Bch, Bu, Bur, Cvi, Fei, Lm, Sha, and Sorbo. We sequenced an about 1-kb promoter region for all Rubisco genes as well. This analysis revealed that the gene duplication/loss event was associated with promoter alterations (two insertions of 450 and 850 bp, one deletion of 730 bp) in rbcS-2b and a promoter deletion (2.3 kb) in rbcS-2b* in all eight affected accessions. The substitution of rbcS-1b by a duplicate of rbcS-2b (i.e., rbcS-2b*) might be caused by gene conversion. All four Rubisco genes evolve under purifying selection, as expected for central genes of the highly conserved photosystem of green plants. We inferred a single positive selected site, a tyrosine to aspartic acid substitution at position 72 in rbcS-1b. Exactly the same substitution compromises carboxylase activity in the cyanobacterium Anacystis nidulans. In A. thaliana, this substitution is associated with an inferred recombination. Functional implications of the substitution remain to be evaluated.}, language = {en} } @article{TiedemannPaulusHavensteinetal.2011, author = {Tiedemann, Ralph and Paulus, Kirsten B. and Havenstein, Katja and Thorstensen, Sverrir and Petersen, Aevar and Lyngs, Peter and Milinkovitch, Michel C.}, title = {Alien eggs in duck nests brood parasitism or a help from Grandma?}, series = {Molecular ecology}, volume = {20}, journal = {Molecular ecology}, number = {15}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0962-1083}, doi = {10.1111/j.1365-294X.2011.05158.x}, pages = {3237 -- 3250}, year = {2011}, abstract = {Intraspecific brood parasitism (IBP) is a remarkable phenomenon by which parasitic females can increase their reproductive output by laying eggs in conspecific females' nests in addition to incubating eggs in their own nest. Kin selection could explain the tolerance, or even the selective advantage, of IBP, but different models of IBP based on game theory yield contradicting predictions. Our analyses of seven polymorphic autosomal microsatellites in two eider duck colonies indicate that relatedness between host and parasitizing females is significantly higher than the background relatedness within the colony. This result is unlikely to be a by-product of relatives nesting in close vicinity, as nest distance and genetic identity are not correlated. For eider females that had been ring-marked during the decades prior to our study, our analyses indicate that (i) the average age of parasitized females is higher than the age of nonparasitized females, (ii) the percentage of nests with alien eggs increases with the age of nesting females, (iii) the level of IBP increases with the host females' age, and (iv) the number of own eggs in the nest of parasitized females significantly decreases with age. IBP may allow those older females unable to produce as many eggs as they can incubate to gain indirect fitness without impairing their direct fitness: genetically related females specialize in their energy allocation, with young females producing more eggs than they can incubate and entrusting these to their older relatives. Intraspecific brood parasitism in ducks may constitute cooperation among generations of closely related females.}, language = {en} } @article{EppStoofLeichsenringTrauthetal.2011, author = {Epp, Laura Saskia and Stoof-Leichsenring, Kathleen Rosemarie and Trauth, Martin H. and Tiedemann, Ralph}, title = {Molecular profiling of diatom assemblages in tropical lake sediments using taxon-specific PCR and Denaturing High-Performance Liquid Chromatography (PCR-DHPLC)}, series = {Molecular ecology resources}, volume = {11}, journal = {Molecular ecology resources}, number = {5}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {1755-098X}, doi = {10.1111/j.1755-0998.2011.03022.x}, pages = {842 -- 853}, year = {2011}, abstract = {Here we present a protocol to genetically detect diatoms in sediments of the Kenyan tropical Lake Naivasha, based on taxon-specific PCR amplification of short fragments (approximately 100 bp) of the small subunit ribosomal (SSU) gene and subsequent separation of species-specific PCR products by PCR-based denaturing high-performance liquid chromatography (DHPLC). An evaluation of amplicons differing in primer specificity to diatoms and length of the fragments amplified demonstrated that the number of different diatom sequence types detected after cloning of the PCR products critically depended on the specificity of the primers to diatoms and the length of the amplified fragments whereby shorter fragments yielded more species of diatoms. The DHPLC was able to discriminate between very short amplicons based on the sequence difference, even if the fragments were of identical length and if the amplicons differed only in a small number of nucleotides. Generally, the method identified the dominant sequence types from mixed amplifications. A comparison with microscopic analysis of the sediment samples revealed that the sequence types identified in the molecular assessment corresponded well with the most dominant species. In summary, the PCR-based DHPLC protocol offers a fast, reliable and cost-efficient possibility to study DNA from sediments and other environmental samples with unknown organismic content, even for very short DNA fragments.}, language = {en} } @article{PavesiDeMatthaeisTiedemannetal.2011, author = {Pavesi, Laura and De Matthaeis, Elvira and Tiedemann, Ralph and Ketmaier, Valerio}, title = {Temporal population genetics and COI phylogeography of the sandhopper macarorchestia remyi (Amphipoda: Talitridae)}, series = {Zoological studies}, volume = {50}, journal = {Zoological studies}, number = {2}, publisher = {Institute of Zoology, Academia Sinica}, address = {Taipei}, issn = {1021-5506}, pages = {220 -- 229}, year = {2011}, abstract = {Laura Pavesi, Elvira De Matthaeis, Ralph Tiedemann, and Valerio Ketmaier (2011) Temporal population genetics and COI phylogeography of the sandhopper Macarorchestia remyi (Amphipoda: Talitridae). Zoological Studies 50(2): 220-229. In this study we assessed levels of genetic divergence and variability in 208 individuals of the supralittoral sandhopper Macarorchestia remyi, a species strictly associated with rotted wood stranded on sand beaches, by analyzing sequence polymorphisms in a fragment of the mitochondrial DNA (mtDNA) gene coding cytochrome oxidase subunit I (COI). The geographical distribution and ecology of the species are poorly known. The study includes 1 Tyrrhenian and 2 Adriatic populations sampled along the Italian peninsula plus a single individual found on Corfu Is. (Greece). The Tyrrhenian population was sampled monthly for 1 yr. Genetic data revealed a deep phylogeographic break between the Tyrrhenian and Adriatic populations with no shared haplotypes. The single individual collected on Corfu Is. carried the most common haplotype found in the Tyrrhenian population. A mismatch analysis could not reject the hypothesis of a sudden demographic expansion in almost all but 2 monthly samples. When compared to previous genetic data centered on a variety of Mediterranean talitrids, our results place M. remyi among those species with profound intraspecific divergence (sandhoppers) and dissimilar from beachfleas, which generally display little population genetic structuring.}, language = {en} } @unpublished{WalzAdrianGilbertetal.2011, author = {Walz, Norbert and Adrian, Rita and Gilbert, John J. and Monaghan, Michael T. and Weithoff, Guntram and Zimmermann-Timm, Heike}, title = {Preface}, series = {Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica}, volume = {662}, journal = {Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica}, number = {1}, publisher = {Springer}, address = {Dordrecht}, issn = {0018-8158}, doi = {10.1007/s10750-010-0514-2}, pages = {1 -- 4}, year = {2011}, language = {en} } @article{SharmaStuckasBhaskaretal.2011, author = {Sharma, Reeta and Stuckas, Heiko and Bhaskar, Ranjana and Khan, Imran and Goyal, Surendra Prakash and Tiedemann, Ralph}, title = {Genetically distinct population of Bengal tiger (Panthera tigris tigris) in Terai Arc Landscape (TAL) of India}, series = {Mammalian biology = Zeitschrift f{\"u}r S{\"a}ugetierkunde}, volume = {76}, journal = {Mammalian biology = Zeitschrift f{\"u}r S{\"a}ugetierkunde}, number = {4}, publisher = {Elsevier}, address = {Jena}, issn = {1616-5047}, doi = {10.1016/j.mambio.2010.10.005}, pages = {484 -- 490}, year = {2011}, abstract = {We analyzed mtDNA polymorphisms (a total of 741 bp from a part of conserved control region, ND5, ND2, Cyt b and 12S) in 91 scats and 12 tissue samples of Bengal tiger (Panthera tigris tigris) populations across Terai Arc Landscape (TAL) located at the foothills of Himalayas in North Western India, Buxa Tiger Reserve (BTR), and North East India. In TAL and BTR, we found a specific haplotype at high frequency, which was absent elsewhere, indicating a genetically distinct population in these regions. Within the TAL region, there is some evidence for genetic isolation of the tiger populations west of river Ganges, i.e., in the western part of Rajaji National Park (RNP). Although the river itself might not constitute a significant barrier for tigers, recent human-induced changes in habitat and degradation of the Motichur-Chilla Corridor connecting the two sides of the tiger habitat of RNP might effectively prevent genetic exchange. A cohesive population is observed for the rest of the TAL. Even the more eastern BTR belongs genetically to this unit, despite the present lack of a migration corridor between BTR and TAL. In spite of a close geographic proximity, Chitwan (Nepal) constitutes a tiger population genetically different from TAL. Moreover, it is observed that the North East India tiger populations are genetically different from TAL and BTR, as well as from the other Bengal tiger populations in India.}, language = {en} } @article{NahavandiPlathTiedemannetal.2011, author = {Nahavandi, Nahid and Plath, Martin and Tiedemann, Ralph and Mirzajani, Ali R.}, title = {Sexual and natural selection on morphological traits in a marine amphipod, Pontogammarus maeoticus (Sowinsky, 1894)}, series = {Marine biology research}, volume = {7}, journal = {Marine biology research}, number = {2}, publisher = {Taylor \& Francis Group}, address = {Oslo}, issn = {1745-1000}, doi = {10.1080/17451001003713589}, pages = {135 -- 146}, year = {2011}, abstract = {Sexual selection often leads to sexual dimorphism, where secondary sexual traits are more expressed in the male sex. This may be due, for example, to increased fighting or mate-guarding abilities of males expressing those traits. We investigated sexually dimorphic traits in four populations of a marine amphipod, Pontogammarus maeoticus (Gammaridea: Pontogammaridae), the most abundant amphipod species in the sublittoral zone along the southern shoreline of the Caspian Sea. Male amphipods are typically larger in body size than females, and have relatively larger posterior gnathopods and antennae. However, it remains to be studied for most other body appendages whether or not, and to what extent, they are sexually dimorphic. Using Analysis of Covariance (ANCOVA), we compared the relationships between body size and trait expression for 35 metric characters between males and females, and among the four populations examined by performing three different Discriminant Function Analyses (DFA). We detected several thus far undescribed sexual dimorphic traits such as the seventh peraeopods or the epimeral plates. We also found that the size of the propodus of the first and second gnathopods increases with increasing body size, and this allometric increase was stronger in males than in females. Finally, we found that the degree of sexual dimorphism in the expression of the width of the third epimeral plate varies across sites, suggesting that differences in ecology might affect the strength of sexual selection in different populations.}, language = {en} } @phdthesis{Schulze2011, author = {Schulze, Andreas}, title = {Demographics of supermassive black holes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-54464}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {Supermassive black holes are a fundamental component of the universe in general and of galaxies in particular. Almost every massive galaxy harbours a supermassive black hole (SMBH) in its center. Furthermore, there is a close connection between the growth of the SMBH and the evolution of its host galaxy, manifested in the relationship between the mass of the black hole and various properties of the galaxy's spheroid component, like its stellar velocity dispersion, luminosity or mass. Understanding this relationship and the growth of SMBHs is essential for our picture of galaxy formation and evolution. In this thesis, I make several contributions to improve our knowledge on the census of SMBHs and on the coevolution of black holes and galaxies. The first route I follow on this road is to obtain a complete census of the black hole population and its properties. Here, I focus particularly on active black holes, observable as Active Galactic Nuclei (AGN) or quasars. These are found in large surveys of the sky. In this thesis, I use one of these surveys, the Hamburg/ESO survey (HES), to study the AGN population in the local volume (z~0). The demographics of AGN are traditionally represented by the AGN luminosity function, the distribution function of AGN at a given luminosity. I determined the local (z<0.3) optical luminosity function of so-called type 1 AGN, based on the broad band B_J magnitudes and AGN broad Halpha emission line luminosities, free of contamination from the host galaxy. I combined this result with fainter data from the Sloan Digital Sky Survey (SDSS) and constructed the best current optical AGN luminosity function at z~0. The comparison of the luminosity function with higher redshifts supports the current notion of 'AGN downsizing', i.e. the space density of the most luminous AGN peaks at higher redshifts and the space density of less luminous AGN peaks at lower redshifts. However, the AGN luminosity function does not reveal the full picture of active black hole demographics. This requires knowledge of the physical quantities, foremost the black hole mass and the accretion rate of the black hole, and the respective distribution functions, the active black hole mass function and the Eddington ratio distribution function. I developed a method for an unbiased estimate of these two distribution functions, employing a maximum likelihood technique and fully account for the selection function. I used this method to determine the active black hole mass function and the Eddington ratio distribution function for the local universe from the HES. I found a wide intrinsic distribution of black hole accretion rates and black hole masses. The comparison of the local active black hole mass function with the local total black hole mass function reveals evidence for 'AGN downsizing', in the sense that in the local universe the most massive black holes are in a less active stage then lower mass black holes. The second route I follow is a study of redshift evolution in the black hole-galaxy relations. While theoretical models can in general explain the existence of these relations, their redshift evolution puts strong constraints on these models. Observational studies on the black hole-galaxy relations naturally suffer from selection effects. These can potentially bias the conclusions inferred from the observations, if they are not taken into account. I investigated the issue of selection effects on type 1 AGN samples in detail and discuss various sources of bias, e.g. an AGN luminosity bias, an active fraction bias and an AGN evolution bias. If the selection function of the observational sample and the underlying distribution functions are known, it is possible to correct for this bias. I present a fitting method to obtain an unbiased estimate of the intrinsic black hole-galaxy relations from samples that are affected by selection effects. Third, I try to improve our census of dormant black holes and the determination of their masses. One of the most important techniques to determine the black hole mass in quiescent galaxies is via stellar dynamical modeling. This method employs photometric and kinematic observations of the galaxy and infers the gravitational potential from the stellar orbits. This method can reveal the presence of the black hole and give its mass, if the sphere of the black hole's gravitational influence is spatially resolved. However, usually the presence of a dark matter halo is ignored in the dynamical modeling, potentially causing a bias on the determined black hole mass. I ran dynamical models for a sample of 12 galaxies, including a dark matter halo. For galaxies for which the black hole's sphere of influence is not well resolved, I found that the black hole mass is systematically underestimated when the dark matter halo is ignored, while there is almost no effect for galaxies with well resolved sphere of influence.}, language = {en} } @phdthesis{Avila2011, author = {Avila, Gast{\´o}n}, title = {Asymptotic staticity and tensor decompositions with fast decay conditions}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-54046}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {Corvino, Corvino and Schoen, Chruściel and Delay have shown the existence of a large class of asymptotically flat vacuum initial data for Einstein's field equations which are static or stationary in a neighborhood of space-like infinity, yet quite general in the interior. The proof relies on some abstract, non-constructive arguments which makes it difficult to calculate such data numerically by using similar arguments. A quasilinear elliptic system of equations is presented of which we expect that it can be used to construct vacuum initial data which are asymptotically flat, time-reflection symmetric, and asymptotic to static data up to a prescribed order at space-like infinity. A perturbation argument is used to show the existence of solutions. It is valid when the order at which the solutions approach staticity is restricted to a certain range. Difficulties appear when trying to improve this result to show the existence of solutions that are asymptotically static at higher order. The problems arise from the lack of surjectivity of a certain operator. Some tensor decompositions in asymptotically flat manifolds exhibit some of the difficulties encountered above. The Helmholtz decomposition, which plays a role in the preparation of initial data for the Maxwell equations, is discussed as a model problem. A method to circumvent the difficulties that arise when fast decay rates are required is discussed. This is done in a way that opens the possibility to perform numerical computations. The insights from the analysis of the Helmholtz decomposition are applied to the York decomposition, which is related to that part of the quasilinear system which gives rise to the difficulties. For this decomposition analogous results are obtained. It turns out, however, that in this case the presence of symmetries of the underlying metric leads to certain complications. The question, whether the results obtained so far can be used again to show by a perturbation argument the existence of vacuum initial data which approach static solutions at infinity at any given order, thus remains open. The answer requires further analysis and perhaps new methods.}, language = {en} } @article{Lewy2011, author = {Lewy, Mordechay}, title = {Corporeality in Jewish Thought and Art}, series = {PaRDeS : Zeitschrift der Vereinigung f{\"u}r J{\"u}dische Studien e.V.}, journal = {PaRDeS : Zeitschrift der Vereinigung f{\"u}r J{\"u}dische Studien e.V.}, number = {17}, issn = {1614-6492}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-53319}, pages = {209 -- 223}, year = {2011}, abstract = {The essay compares the dichotomous concepts of corporeality and spirituality in Judaism and Christianity. Through the ages, deviations from normative principles of beliefs could be discerned in both religions. These can be attributed either to the somewhat confrontational interaction between Jews and Christians in the Medieval urban environment or to the impact of Hellenic civilization on both monotheistic religions. Out of this dynamic impact emerged Christian art with a predilection to expressed corporeality, whereas Jewish religiosity found its artistic expression in a spiritual noniconographical mode. A genuine Jewish art and iconography could develop only after a certain degree of assimilation and secularization. Marc Chagall was the first protagonist of a mature expression of Jewish iconography.}, language = {en} } @misc{Winkler2011, type = {Master Thesis}, author = {Winkler, Michael}, title = {Thinning and turbulence in aqueous films}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-53107}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {This thesis covers the topic "Thinning and Turbulence in Aqueous Films". Experimental studies in two-dimensional systems gained an increasing amount of attention during the last decade. Thin liquid films serve as paradigms of atmospheric convection, thermal convection in the Earth's mantle or turbulence in magnetohydrodynamics. Recent research on colloids, interfaces and nanofluids lead to advances in the developtment of micro-mixers (lab-on-a-chip devices). In this project a detailed description of a thin film experiment with focus on the particular surface forces is presented. The impact of turbulence on the thinning of liquid films which are oriented parallel to the gravitational force is studied. An experimental setup was developed which permits the capturing of thin film interference patterns under controlled surface and atmospheric conditions. The measurement setup also serves as a prototype of a mixer on the basis of thermally induced turbulence in liquid thin films with thicknesses in the nanometer range. The convection is realized by placing a cooled copper rod in the center of the film. The temperature gradient between the rod and the atmosphere results in a density gradient in the liquid film, so that different buoyancies generate turbulence. In the work at hand the thermally driven convection is characterized by a newly developed algorithm, named Cluster Imaging Velocimetry (CIV). This routine determines the flow relevant vector fields (velocity and deformation). On the basis of these insights the flow in the experiment was investigated with respect to its mixing properties. The mixing characteristics were compared to theoretical models and mixing efficiency of the flow scheme calculated. The gravitationally driven thinning of the liquid film was analyzed under the influence of turbulence. Strong shear forces lead to the generation of ultra-thin domains which consist of Newton black film. Due to the exponential expansion of the thin areas and the efficient mixing, this two-phase flow rapidly turns into the convection of only ultra-thin film. This turbulence driven transition was observed and quantified for the first time. The existence of stable convection in liquid nanofilms was proven for the first time in the context of this work.}, language = {en} } @phdthesis{Kluth2011, author = {Kluth, Stephan}, title = {Quantitative modeling and analysis with FMC-QE}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-52987}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {The modeling and evaluation calculus FMC-QE, the Fundamental Modeling Concepts for Quanti-tative Evaluation [1], extends the Fundamental Modeling Concepts (FMC) for performance modeling and prediction. In this new methodology, the hierarchical service requests are in the main focus, because they are the origin of every service provisioning process. Similar to physics, these service requests are a tuple of value and unit, which enables hierarchical service request transformations at the hierarchical borders and therefore the hierarchical modeling. Through reducing the model complexity of the models by decomposing the system in different hierarchical views, the distinction between operational and control states and the calculation of the performance values on the assumption of the steady state, FMC-QE has a scalable applica-bility on complex systems. According to FMC, the system is modeled in a 3-dimensional hierarchical representation space, where system performance parameters are described in three arbitrarily fine-grained hierarchi-cal bipartite diagrams. The hierarchical service request structures are modeled in Entity Relationship Diagrams. The static server structures, divided into logical and real servers, are de-scribed as Block Diagrams. The dynamic behavior and the control structures are specified as Petri Nets, more precisely Colored Time Augmented Petri Nets. From the structures and pa-rameters of the performance model, a hierarchical set of equations is derived. The calculation of the performance values is done on the assumption of stationary processes and is based on fundamental laws of the performance analysis: Little's Law and the Forced Traffic Flow Law. Little's Law is used within the different hierarchical levels (horizontal) and the Forced Traffic Flow Law is the key to the dependencies among the hierarchical levels (vertical). This calculation is suitable for complex models and allows a fast (re-)calculation of different performance scenarios in order to support development and configuration decisions. Within the Research Group Zorn at the Hasso Plattner Institute, the work is embedded in a broader research in the development of FMC-QE. While this work is concentrated on the theoretical background, description and definition of the methodology as well as the extension and validation of the applicability, other topics are in the development of an FMC-QE modeling and evaluation tool and the usage of FMC-QE in the design of an adaptive transport layer in order to fulfill Quality of Service and Service Level Agreements in volatile service based environments. This thesis contains a state-of-the-art, the description of FMC-QE as well as extensions of FMC-QE in representative general models and case studies. In the state-of-the-art part of the thesis in chapter 2, an overview on existing Queueing Theory and Time Augmented Petri Net models and other quantitative modeling and evaluation languages and methodologies is given. Also other hierarchical quantitative modeling frameworks will be considered. The description of FMC-QE in chapter 3 consists of a summary of the foundations of FMC-QE, basic definitions, the graphical notations, the FMC-QE Calculus and the modeling of open queueing networks as an introductory example. The extensions of FMC-QE in chapter 4 consist of the integration of the summation method in order to support the handling of closed networks and the modeling of multiclass and semaphore scenarios. Furthermore, FMC-QE is compared to other performance modeling and evaluation approaches. In the case study part in chapter 5, proof-of-concept examples, like the modeling of a service based search portal, a service based SAP NetWeaver application and the Axis2 Web service framework will be provided. Finally, conclusions are given by a summary of contributions and an outlook on future work in chapter 6. [1] Werner Zorn. FMC-QE - A New Approach in Quantitative Modeling. In Hamid R. Arabnia, editor, Procee-dings of the International Conference on Modeling, Simulation and Visualization Methods (MSV 2007) within WorldComp '07, pages 280 - 287, Las Vegas, NV, USA, June 2007. CSREA Press. ISBN 1-60132-029-9.}, language = {en} } @phdthesis{Spreyer2011, author = {Spreyer, Kathrin}, title = {Does it have to be trees? : Data-driven dependency parsing with incomplete and noisy training data}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57498}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {We present a novel approach to training data-driven dependency parsers on incomplete annotations. Our parsers are simple modifications of two well-known dependency parsers, the transition-based Malt parser and the graph-based MST parser. While previous work on parsing with incomplete data has typically couched the task in frameworks of unsupervised or semi-supervised machine learning, we essentially treat it as a supervised problem. In particular, we propose what we call agnostic parsers which hide all fragmentation in the training data from their supervised components. We present experimental results with training data that was obtained by means of annotation projection. Annotation projection is a resource-lean technique which allows us to transfer annotations from one language to another within a parallel corpus. However, the output tends to be noisy and incomplete due to cross-lingual non-parallelism and error-prone word alignments. This makes the projected annotations a suitable test bed for our fragment parsers. Our results show that (i) dependency parsers trained on large amounts of projected annotations achieve higher accuracy than the direct projections, and that (ii) our agnostic fragment parsers perform roughly on a par with the original parsers which are trained only on strictly filtered, complete trees. Finally, (iii) when our fragment parsers are trained on artificially fragmented but otherwise gold standard dependencies, the performance loss is moderate even with up to 50\% of all edges removed.}, language = {en} } @phdthesis{Wulf2011, author = {Wulf, Hendrik}, title = {Seasonal precipitation, river discharge, and sediment flux in the western Himalaya}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57905}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {Rainfall, snow-, and glacial melt throughout the Himalaya control river discharge, which is vital for maintaining agriculture, drinking water and hydropower generation. However, the spatiotemporal contribution of these discharge components to Himalayan rivers is not well understood, mainly because of the scarcity of ground-based observations. Consequently, there is also little known about the triggers and sources of peak sediment flux events, which account for extensive hydropower reservoir filling and turbine abrasion. We therefore lack basic information on the distribution of water resources and controls of erosion processes. In this thesis, I employ various methods to assess and quantify general characteristics of and links between precipitation, river discharge, and sediment flux in the Sutlej Valley. First, I analyze daily precipitation data (1998-2007) from 80 weather stations in the western Himalaya, to decipher the distribution of rain- and snowfall. Rainfall magnitude frequency analyses indicate that 40\% of the summer rainfall budget is attributed to monsoonal rainstorms, which show higher variability in the orogenic interior than in frontal regions. Combined analysis of rainstorms and sediment flux data of a major Sutlej River tributary indicate that monsoonal rainfall has a first order control on erosion processes in the orogenic interior, despite the dominance of snowfall in this region. Second, I examine the contribution of rainfall, snow and glacial melt to river discharge in the Sutlej Valley (s55,000 km2), based on a distributed hydrological model, which covers the period 2000-2008. To achieve high spatial and daily resolution despite limited ground-based observations the hydrological model is forced by daily remote sensing data, which I adjusted and calibrated with ground station data. The calibration shows that the Tropical Rainfall Measuring Mission (TRMM) 3B42 rainfall product systematically overestimates rainfall in semi-arid and arid regions, increasing with aridity. The model results indicate that snowmelt-derived discharge (74\%) is most important during the pre-monsoon season (April to June) whereas rainfall (56\%) and glacial melt (17\%) dominate the monsoon season (July-September). Therefore, climate change most likely causes a reduction in river discharge during the pre-monsoon season, which especially affects the orogenic interior. Third, I investigate the controls on suspended sediment flux in different parts of the Sutlej catchments, based on daily gauging data from the past decade. In conjunction with meteorological data, earthquake records, and rock strength measurements I find that rainstorms are the most frequent trigger of high-discharge events with peaks in suspended sediment concentrations (SSC) that account for the bulk of the suspended sediment flux. The suspended sediment flux increases downstream, mainly due to increases in runoff. Pronounced erosion along the Himalayan Front occurs throughout the monsoon season, whereas efficient erosion of the orogenic interior is confined to single extreme events. The results of this thesis highlight the importance of snow and glacially derived melt waters in the western Himalaya, where extensive regions receive only limited amounts of monsoonal rainfall. These regions are therefore particularly susceptible to global warming with major implications on the hydrological cycle. However, the sediment discharge data show that infrequent monsoonal rainstorms that pass the orographic barrier of the Higher Himalaya are still the primary trigger of the highest-impact erosion events, despite being subordinate to snow and glacially-derived discharge. These findings may help to predict peak sediment flux events and could underpin the strategic development of preventative measures for hydropower infrastructures.}, language = {en} } @misc{Wiese2011, author = {Wiese, Heike}, title = {So as a focus marker in German}, series = {Postprints der Universit{\"a}t Potsdam : Philosophische Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Philosophische Reihe}, number = {102}, issn = {1866-8380}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-93592}, pages = {49}, year = {2011}, abstract = {This paper discusses a hitherto undescribed usage of the particle so as a dedicated focus marker in contemporary German. I discuss grammatical and pragmatic characteristics of this focus marker, supporting my account with natural linguistic data and with controlled experimental evidence showing that so has a significant influence on speakers' understanding of what the focus expression in a sentence is. Against this background, I sketch a possible pragmaticalization path from referential usages of so via hedging to a semantically bleached focus marker, which, unlike particles such as auch 'also'/'too' or nur 'only', does not contribute any additional meaning.}, language = {en} } @book{Murr2011, author = {Murr, R{\"u}diger}, title = {Characterization of L{\´e}vy Processes by a duality formula and related results}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Mathematische Statistik un}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Mathematische Statistik un}, publisher = {Univ.}, address = {Potsdam}, issn = {1613-3307}, pages = {19 S.}, year = {2011}, language = {en} } @article{Goetz2011, author = {Goetz, Klaus Hermann}, title = {The development and current features of the German civil service system}, isbn = {978-1-84844243-6}, year = {2011}, language = {en} } @phdthesis{Hartig2011, author = {Hartig, Juliane}, title = {Learning and innovation a distance : an empirical investigation into the benefits and liabilities of different froms of distance on interactive learning and novelty creation in German biotechnology SMEs}, publisher = {Gabler Verlag / Springer Fachmedien Wiesbaden GmbH Wiesbaden}, address = {Wiesbaden}, isbn = {978-3-8349-3178-8}, doi = {10.1007/978-3-8349-6904-0}, pages = {410 S.}, year = {2011}, language = {en} } @phdthesis{Wichura2011, author = {Wichura, Henry}, title = {Topographic evolution of the East African Plateau : a combined study on lava-flow modeling and paleo-topography}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-52363}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {The East African Plateau provides a spectacular example of geodynamic plateau uplift, active continental rifting, and associated climatic forcing. It is an integral part of the East African Rift System and has an average elevation of approximately 1,000 m. Its location coincides with a negative Bouguer gravity anomaly with a semi-circular shape, closely related to a mantle plume, which influences the Cenozoic crustal development since its impingement in Eocene-Oligocene time. The uplift of the East African Plateau, preceding volcanism, and rifting formed an important orographic barrier and tectonically controlled environment, which is profoundly influenced by climate driven processes. Its location within the equatorial realm supports recently proposed hypotheses, that topographic changes in this region must be considered as the dominant forcing factor influencing atmospheric circulation patterns and rainfall distribution. The uplift of this region has therefore often been associated with fundamental climatic and environmental changes in East Africa and adjacent regions. While the far-reaching influence of the plateau uplift is widely accepted, the timing and the magnitude of the uplift are ambiguous and are still subject to ongoing discussion. This dilemma stems from the lack of datable, geomorphically meaningful reference horizons that could record surface uplift. In order to quantify the amount of plateau uplift and to find evidence for the existence of significant relief along the East African Plateau prior to rifting, I analyzed and modeled one of the longest terrestrial lava flows; the 300-km-long Yatta phonolite flow in Kenya. This lava flow is 13.5 Ma old and originated in the region that now corresponds to the eastern rift shoulders. The phonolitic flow utilized an old riverbed that once drained the eastern flank of the plateau. Due to differential erosion this lava flow now forms a positive relief above the parallel-flowing Athi River, which is mimicking the course of the paleo-river. My approach is a lava-flow modeling, based on an improved composition and temperature dependent method to parameterize the flow of an arbitrary lava in a rectangular-shaped channel. The essential growth pattern is described by a one-dimensional model, in which Newtonian rheological flow advance is governed by the development of viscosity and/or velocity in the internal parts of the lava-flow front. Comparing assessments of different magma compositions reveal that length-dominated, channelized lava flows are characterized by high effusion rates, rapid emplacement under approximately isothermal conditions, and laminar flow. By integrating the Yatta lava flow dimensions and the covered paleo-topography (slope angle) into the model, I was able to determine the pre-rift topography of the East African Plateau. The modeling results yield a pre-rift slope of at least 0.2°, suggesting that the lava flow must have originated at a minimum elevation of 1,400 m. Hence, high topography in the region of the present-day Kenya Rift must have existed by at least 13.5 Ma. This inferred mid-Miocene uplift coincides with the two-step expansion of grasslands, as well as important radiation and speciation events in tropical Africa. Accordingly, the combination of my results regarding the Yatta lava flow emplacement history, its location, and its morphologic character, validates it as a suitable "paleo-tiltmeter" and has thus to be considered as an important topographic and volcanic feature for the topographic evolution in East Africa.}, language = {en} } @phdthesis{Kellermann2011, author = {Kellermann, Thorsten}, title = {Accurate numerical relativity simulations of non-vacuumspace-times in two dimensions and applications to critical collapse}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-59578}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {This Thesis puts its focus on the physics of neutron stars and its description with methods of numerical relativity. In the first step, a new numerical framework the Whisky2D code will be developed, which solves the relativistic equations of hydrodynamics in axisymmetry. Therefore we consider an improved formulation of the conserved form of these equations. The second part will use the new code to investigate the critical behaviour of two colliding neutron stars. Considering the analogy to phase transitions in statistical physics, we will investigate the evolution of the entropy of the neutron stars during the whole process. A better understanding of the evolution of thermodynamical quantities, like the entropy in critical process, should provide deeper understanding of thermodynamics in relativity. More specifically, we have written the Whisky2D code, which solves the general-relativistic hydrodynamics equations in a flux-conservative form and in cylindrical coordinates. This of course brings in 1/r singular terms, where r is the radial cylindrical coordinate, which must be dealt with appropriately. In the above-referenced works, the flux operator is expanded and the 1/r terms, not containing derivatives, are moved to the right-hand-side of the equation (the source term), so that the left hand side assumes a form identical to the one of the three-dimensional (3D) Cartesian formulation. We call this the standard formulation. Another possibility is not to split the flux operator and to redefine the conserved variables, via a multiplication by r. We call this the new formulation. The new equations are solved with the same methods as in the Cartesian case. From a mathematical point of view, one would not expect differences between the two ways of writing the differential operator, but, of course, a difference is present at the numerical level. Our tests show that the new formulation yields results with a global truncation error which is one or more orders of magnitude smaller than those of alternative and commonly used formulations. The second part of the Thesis uses the new code for investigations of critical phenomena in general relativity. In particular, we consider the head-on-collision of two neutron stars in a region of the parameter space where two final states a new stable neutron star or a black hole, lay close to each other. In 1993, Choptuik considered one-parameter families of solutions, S[P], of the Einstein-Klein-Gordon equations for a massless scalar field in spherical symmetry, such that for every P > P⋆, S[P] contains a black hole and for every P < P⋆, S[P] is a solution not containing singularities. He studied numerically the behavior of S[P] as P → P⋆ and found that the critical solution, S[P⋆], is universal, in the sense that it is approached by all nearly-critical solutions regardless of the particular family of initial data considered. All these phenomena have the common property that, as P approaches P⋆, S[P] approaches a universal solution S[P⋆] and that all the physical quantities of S[P] depend only on |P - P⋆|. The first study of critical phenomena concerning the head-on collision of NSs was carried out by Jin and Suen in 2007. In particular, they considered a series of families of equal-mass NSs, modeled with an ideal-gas EOS, boosted towards each other and varied the mass of the stars, their separation, velocity and the polytropic index in the EOS. In this way they could observe a critical phenomenon of type I near the threshold of black-hole formation, with the putative solution being a nonlinearly oscillating star. In a successive work, they performed similar simulations but considering the head-on collision of Gaussian distributions of matter. Also in this case they found the appearance of type-I critical behaviour, but also performed a perturbative analysis of the initial distributions of matter and of the merged object. Because of the considerable difference found in the eigenfrequencies in the two cases, they concluded that the critical solution does not represent a system near equilibrium and in particular not a perturbed Tolmann-Oppenheimer-Volkoff (TOV) solution. In this Thesis we study the dynamics of the head-on collision of two equal-mass NSs using a setup which is as similar as possible to the one considered above. While we confirm that the merged object exhibits a type-I critical behaviour, we also argue against the conclusion that the critical solution cannot be described in terms of equilibrium solution. Indeed, we show that, in analogy with what is found in, the critical solution is effectively a perturbed unstable solution of the TOV equations. Our analysis also considers fine-structure of the scaling relation of type-I critical phenomena and we show that it exhibits oscillations in a similar way to the one studied in the context of scalar-field critical collapse.}, language = {en} } @phdthesis{Federico2011, author = {Federico, Stefania}, title = {Synthetic peptides derived from decorin as building blocks for biomaterials based on supramolecular interactions}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-59661}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {In this work, the development of a new molecular building block, based on synthetic peptides derived from decorin, is presented. These peptides represent a promising basis for the design of polymer-based biomaterials that mimic the ECM on a molecular level and exploit specific biological recognition for technical applications. Multiple sequence alignments of the internal repeats of decorin that formed the inner and outer surface of the arch-shaped protein were used to develop consensus sequences. These sequences contained conserved sequence motifs that are likely to be related to structural and functional features of the protein. Peptides representative for the consensus sequences were synthesized by microwave-assisted solid phase peptide synthesis and purified by RP-HPLC, with purities higher than 95 mol\%. After confirming the desired masses by MALDI-TOF-MS, the primary structure of each peptide was investigated by 1H and 2D NMR, from which a full assignment of the chemical shifts was obtained. The characterization of the peptides conformation in solution was performed by CD spectroscopy, which demonstrated that using TFE, the peptides from the outer surface of decorin show a high propensity to fold into helical structures as observed in the original protein. To the contrary, the peptides from the inner surface did not show propensity to form stable secondary structure. The investigation of the binding capability of the peptides to Collagen I was performed by surface plasmon resonance analyses, from which all but one of the peptides representing the inner surface of decorin showed binding affinity to collagen with values of dissociation constant between 2•10-7 M and 2.3•10-4 M. On the other hand, the peptides representative for the outer surface of decorin did not show any significant interaction to collagen. This information was then used to develop experimental demonstration for the binding capabilities of the peptides from the inner surface of decorin to collagen even when used in more complicated situations close to possible appications. With this purpose, the peptide (LRELHLNNN) which showed the highest binding affinity to collagen (2•10-7 M) was functionalized with an N-terminal triple bond in order to obtain a peptide dimer via copper(I)-catalyzed cycloaddition reaction with 4,4'-diazidostilbene-2,2'-disulfonic acid. Rheological measurements showed that the presence of the peptide dimer was able to enhance the elastic modulus (G') of a collagen gel from ~ 600 Pa (collagen alone) to ~ 2700 Pa (collagen and peptide dimer). Moreover, it was shown that the mechanical properties of a collagen gel can be tailored by using different molar ratios of peptide dimer respect to collagen. The same peptide, functionalized with the triple bond, was used to obtain a peptide-dye conjugate by coupling it with N-(5'-azidopentanoyl)-5-aminofluorescein. An aqueous solution (5 vol\% methanol) of the peptide dye conjugate was injected into a collagen and a hyaluronic acid (HA) gel and images of fluorescence detection showed that the diffusion of the peptide was slower in the collagen gel compared to the HA gel. The third experimental demonstration was gained using the peptide (LSELRLHNN) which showed the lower binding affinity (2.3•10-4 M) to collagen. This peptide was grafted to hyaluronic acid via EDC-chemistry, with a degree of functionalization of 7 ± 2 mol\% as calculated by 1H-NMR. The grafting was further confirmed by FTIR and TGA measurements, which showed that the onset of decomposition for the HA-g-peptide decreased by 10 °C compared to the native HA. Rheological measurements showed that the elastic modulus of a system based on collagen and HA-g-peptide increased by almost two order of magnitude (G' = 200 Pa) compared to a system based on collagen and HA (G' = 0.9 Pa). Overall, this study showed that the synthetic peptides, which were identified from decorin, can be applied as potential building blocks for biomimetic materials that function via biological recognition.}, language = {en} } @phdthesis{Moesta2011, author = {M{\"o}sta, Philipp}, title = {Novel aspects of the dynamics of binary black-hole mergers}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-59820}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {The inspiral and merger of two black holes is among the most exciting and extreme events in our universe. Being one of the loudest sources of gravitational waves, they provide a unique dynamical probe of strong-field general relativity and a fertile ground for the observation of fundamental physics. While the detection of gravitational waves alone will allow us to observe our universe through an entirely new window, combining the information obtained from both gravitational wave and electro-magnetic observations will allow us to gain even greater insight in some of the most exciting astrophysical phenomena. In addition, binary black-hole mergers serve as an intriguing tool to study the geometry of space-time itself. In this dissertation we study the merger process of binary black-holes in a variety of conditions. Our results show that asymmetries in the curvature distribution on the common apparent horizon are correlated to the linear momentum acquired by the merger remnant. We propose useful tools for the analysis of black holes in the dynamical and isolated horizon frameworks and shed light on how the final merger of apparent horizons proceeds after a common horizon has already formed. We connect mathematical theorems with data obtained from numerical simulations and provide a first glimpse on the behavior of these surfaces in situations not accessible to analytical tools. We study electro-magnetic counterparts of super-massive binary black-hole mergers with fully 3D general relativistic simulations of binary black-holes immersed both in a uniform magnetic field in vacuum and in a tenuous plasma. We find that while a direct detection of merger signatures with current electro-magnetic telescopes is unlikely, secondary emission, either by altering the accretion rate of the circumbinary disk or by synchrotron radiation from accelerated charges, may be detectable. We propose a novel approach to measure the electro-magnetic radiation in these simulations and find a non-collimated emission that dominates over the collimated one appearing in the form of dual jets associated with each of the black holes. Finally, we provide an optimized gravitational wave detection pipeline using phenomenological waveforms for signals from compact binary coalescence and show that by including spin effects in the waveform templates, the detection efficiency is drastically improved as well as the bias on recovered source parameters reduced. On the whole, this disseration provides evidence that a multi-messenger approach to binary black-hole merger observations provides an exciting prospect to understand these sources and, ultimately, our universe.}, language = {en} } @phdthesis{Thiele2011, author = {Thiele, Sven}, title = {Modeling biological systems with Answer Set Programming}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-59383}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {Biology has made great progress in identifying and measuring the building blocks of life. The availability of high-throughput methods in molecular biology has dramatically accelerated the growth of biological knowledge for various organisms. The advancements in genomic, proteomic and metabolomic technologies allow for constructing complex models of biological systems. An increasing number of biological repositories is available on the web, incorporating thousands of biochemical reactions and genetic regulations. Systems Biology is a recent research trend in life science, which fosters a systemic view on biology. In Systems Biology one is interested in integrating the knowledge from all these different sources into models that capture the interaction of these entities. By studying these models one wants to understand the emerging properties of the whole system, such as robustness. However, both measurements as well as biological networks are prone to considerable incompleteness, heterogeneity and mutual inconsistency, which makes it highly non-trivial to draw biologically meaningful conclusions in an automated way. Therefore, we want to promote Answer Set Programming (ASP) as a tool for discrete modeling in Systems Biology. ASP is a declarative problem solving paradigm, in which a problem is encoded as a logic program such that its answer sets represent solutions to the problem. ASP has intrinsic features to cope with incompleteness, offers a rich modeling language and highly efficient solving technology. We present ASP solutions, for the analysis of genetic regulatory networks, determining consistency with observed measurements and identifying minimal causes for inconsistency. We extend this approach for computing minimal repairs on model and data that restore consistency. This method allows for predicting unobserved data even in case of inconsistency. Further, we present an ASP approach to metabolic network expansion. This approach exploits the easy characterization of reachability in ASP and its various reasoning methods, to explore the biosynthetic capabilities of metabolic reaction networks and generate hypotheses for extending the network. Finally, we present the BioASP library, a Python library which encapsulates our ASP solutions into the imperative programming paradigm. The library allows for an easy integration of ASP solution into system rich environments, as they exist in Systems Biology.}, language = {en} } @phdthesis{Bordihn2011, author = {Bordihn, Henning}, title = {Contributions to the syntactical analysis beyond context-freeness}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-59719}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {Parsability approaches of several grammar formalisms generating also non-context-free languages are explored. Chomsky grammars, Lindenmayer systems, grammars with controlled derivations, and grammar systems are treated. Formal properties of these mechanisms are investigated, when they are used as language acceptors. Furthermore, cooperating distributed grammar systems are restricted so that efficient deterministic parsing without backtracking becomes possible. For this class of grammar systems, the parsing algorithm is presented and the feature of leftmost derivations is investigated in detail.}, language = {en} } @misc{Zuellich2011, type = {Master Thesis}, author = {Z{\"u}llich, Gunda}, title = {Migration and development in Senegal : a system dynamics analysis of the feedback relationships}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57836}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {This thesis investigates the reciprocal relationship between migration and development in Senegal. Therewith, it contributes to the debate as to whether migration in developing countries enhances or rather impedes the development process. Even though extensive and controversial discussions can be found in the scientific literature regarding the impact of migration on development, research has scarcely examined the feedback relationships between migration and development. Science however agrees with both the fact that migration affects development as well as that the level of development in a country determines migration behaviour. Thus, both variables are neither dependent nor independent, but endogenous variables influencing each other and producing behavioural pattern that cannot be investigated using a static and unidirectional approach. On account of this, the thesis studies the feedback mechanisms existing between migration and development and the behavioural pattern generated by the high interdependence in order to be able to draw conclusions concerning the impact of changes in migration behaviour on the development process. To explore these research questions, the study applies the computer simulation method 'System Dynamics' and amplifies the simulation model for national development planning called 'Threshold 21' (T21), representing development processes endogenously and integrating economic, social and environmental aspects, using a structure that portrays the reasons and consequences of migration. The model has been customised to Senegal, being an appropriate representative of the theoretical interesting universe of cases. The comparison of the model generated scenarios - in which the intensity of emigration, the loss and gain of education, the remittances or the level of dependence changes - facilitates the analysis. The present study produces two important results. The first outcome is the development of an integrative framework representing migration and development in an endogenous way and incorporating several aspects of different theories. This model can be used as a starting point for further discussions and improvements and it is a fairly relevant and useful result against the background that migration is not integrated into most of the development planning tools despite its significant impact. The second outcome is the gained insights concerning the feedback relations between migration and development and the impact of changes in migration on development. To give two examples: It could be found that migration impacts development positively, indicated by HDI, but that the dominant behaviour of migration and development is a counteracting behaviour. That means that an increase in emigration leads to an improvement in development, while this in turn causes a decline in emigration, counterbalancing the initial increase. Another insight concerns the discovery that migration causes a decline in education in the short term, but leads to an increase in the long term, after approximately 25 years - a typical worse-before-better behaviour. From these and further observations, important policy implications can be derived for the sending and receiving countries. Hence, by overcoming the unidirectional perspective, this study contributes to an improved understanding of the highly complex relationship between migration and development and their feedback relations.}, language = {en} } @phdthesis{Hoffmann2011, author = {Hoffmann, Anne}, title = {Comparative aerosol studies based on multi-wavelength Raman LIDAR at Ny-{\AA}lesund, Spitsbergen}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-52426}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {The Arctic is a particularly sensitive area with respect to climate change due to the high surface albedo of snow and ice and the extreme radiative conditions. Clouds and aerosols as parts of the Arctic atmosphere play an important role in the radiation budget, which is, as yet, poorly quantified and understood. The LIDAR (Light Detection And Ranging) measurements presented in this PhD thesis contribute with continuous altitude resolved aerosol profiles to the understanding of occurrence and characteristics of aerosol layers above Ny-{\AA}lesund, Spitsbergen. The attention was turned to the analysis of periods with high aerosol load. As the Arctic spring troposphere exhibits maximum aerosol optical depths (AODs) each year, March and April of both the years 2007 and 2009 were analyzed. Furthermore, stratospheric aerosol layers of volcanic origin were analyzed for several months, subsequently to the eruptions of the Kasatochi and Sarychev volcanoes in summer 2008 and 2009, respectively. The Koldewey Aerosol Raman LIDAR (KARL) is an instrument for the active remote sensing of atmospheric parameters using pulsed laser radiation. It is operated at the AWIPEV research base and was fundamentally upgraded within the framework of this PhD project. It is now equipped with a new telescope mirror and new detection optics, which facilitate atmospheric profiling from 450m above sea level up to the mid-stratosphere. KARL provides highly resolved profiles of the scattering characteristics of aerosol and cloud particles (backscattering, extinction and depolarization) as well as water vapor profiles within the lower troposphere. Combination of KARL data with data from other instruments on site, namely radiosondes, sun photometer, Micro Pulse LIDAR, and tethersonde system, resulted in a comprehensive data set of scattering phenomena in the Arctic atmosphere. The two spring periods March and April 2007 and 2009 were at first analyzed based on meteorological parameters, like local temperature and relative humidity profiles as well as large scale pressure patterns and air mass origin regions. Here, it was not possible to find a clear correlation between enhanced AOD and air mass origin. However, in a comparison of two cloud free periods in March 2007 and April 2009, large AOD values in 2009 coincided with air mass transport through the central Arctic. This suggests the occurrence of aerosol transformation processes during the aerosol transport to Ny-{\AA}lesund. Measurements on 4 April 2009 revealed maximum AOD values of up to 0.12 and aerosol size distributions changing with altitude. This and other performed case studies suggest the differentiation between three aerosol event types and their origin: Vertically limited aerosol layers in dry air, highly variable hygroscopic boundary layer aerosols and enhanced aerosol load across wide portions of the troposphere. For the spring period 2007, the available KARL data were statistically analyzed using a characterization scheme, which is based on optical characteristics of the scattering particles. The scheme was validated using several case studies. Volcanic eruptions in the northern hemisphere in August 2008 and June 2009 arose the opportunity to analyze volcanic aerosol layers within the stratosphere. The rate of stratospheric AOD change was similar within both years with maximum values above 0.1 about three to five weeks after the respective eruption. In both years, the stratospheric AOD persisted at higher rates than usual until the measurements were stopped in late September due to technical reasons. In 2008, up to three aerosol layers were detected, the layer structure in 2009 was characterized by up to six distinct and thin layers which smeared out to one broad layer after about two months. The lowermost aerosol layer was continuously detected at the tropopause altitude. Three case studies were performed, all revealed rather large indices of refraction of m = (1.53-1.55) - 0.02i, suggesting the presence of an absorbing carbonaceous component. The particle radius, derived with inversion calculations, was also similar in both years with values ranging from 0.16 to 0.19 μm. However, in 2009, a second mode in the size distribution was detected at about 0.5 μm. The long term measurements with the Koldewey Aerosol Raman LIDAR in Ny-{\AA}lesund provide the opportunity to study Arctic aerosols in the troposphere and the stratosphere not only in case studies but on longer time scales. In this PhD thesis, both, tropospheric aerosols in the Arctic spring and stratospheric aerosols following volcanic eruptions have been described qualitatively and quantitatively. Case studies and comparative studies with data of other instruments on site allowed for the analysis of microphysical aerosol characteristics and their temporal evolution.}, language = {en} } @book{HauptMarrHirschfeld2011, author = {Haupt, Michael and Marr, Stefan and Hirschfeld, Robert}, title = {CSOM/PL : a virtual machine product line}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-134-9}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-52332}, publisher = {Universit{\"a}t Potsdam}, pages = {26}, year = {2011}, abstract = {CSOM/PL is a software product line (SPL) derived from applying multi-dimensional separation of concerns (MDSOC) techniques to the domain of high-level language virtual machine (VM) implementations. For CSOM/PL, we modularised CSOM, a Smalltalk VM implemented in C, using VMADL (virtual machine architecture description language). Several features of the original CSOM were encapsulated in VMADL modules and composed in various combinations. In an evaluation of our approach, we show that applying MDSOC and SPL principles to a domain as complex as that of VMs is not only feasible but beneficial, as it improves understandability, maintainability, and configurability of VM implementations without harming performance.}, language = {en} } @phdthesis{Bergner2011, author = {Bergner, Andr{\´e}}, title = {Synchronization in complex systems with multiple time scales}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-53407}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {In the present work synchronization phenomena in complex dynamical systems exhibiting multiple time scales have been analyzed. Multiple time scales can be active in different manners. Three different systems have been analyzed with different methods from data analysis. The first system studied is a large heterogenous network of bursting neurons, that is a system with two predominant time scales, the fast firing of action potentials (spikes) and the burst of repetitive spikes followed by a quiescent phase. This system has been integrated numerically and analyzed with methods based on recurrence in phase space. An interesting result are the different transitions to synchrony found in the two distinct time scales. Moreover, an anomalous synchronization effect can be observed in the fast time scale, i.e. there is range of the coupling strength where desynchronization occurs. The second system analyzed, numerically as well as experimentally, is a pair of coupled CO₂ lasers in a chaotic bursting regime. This system is interesting due to its similarity with epidemic models. We explain the bursts by different time scales generated from unstable periodic orbits embedded in the chaotic attractor and perform a synchronization analysis of these different orbits utilizing the continuous wavelet transform. We find a diverse route to synchrony of these different observed time scales. The last system studied is a small network motif of limit cycle oscillators. Precisely, we have studied a hub motif, which serves as elementary building block for scale-free networks, a type of network found in many real world applications. These hubs are of special importance for communication and information transfer in complex networks. Here, a detailed study on the mechanism of synchronization in oscillatory networks with a broad frequency distribution has been carried out. In particular, we find a remote synchronization of nodes in the network which are not directly coupled. We also explain the responsible mechanism and its limitations and constraints. Further we derive an analytic expression for it and show that information transmission in pure phase oscillators, such as the Kuramoto type, is limited. In addition to the numerical and analytic analysis an experiment consisting of electrical circuits has been designed. The obtained results confirm the former findings.}, language = {en} } @phdthesis{Boehme2011, author = {B{\"o}hme, Dimo}, title = {EU-Russia energy relations: What chance for solutions? : A focus on the natural gas sector}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-120-2}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-50210}, school = {Universit{\"a}t Potsdam}, pages = {xix, 322}, year = {2011}, abstract = {Public debate about energy relations between the EU and Russia is distorted. These distortions present considerable obstacles to the development of true partnership. At the core of the conflict is a struggle for resource rents between energy producing, energy consuming and transit countries. Supposed secondary aspects, however, are also of great importance. They comprise of geopolitics, market access, economic development and state sovereignty. The European Union, having engaged in energy market liberalisation, faces a widening gap between declining domestic resources and continuously growing energy demand. Diverse interests inside the EU prevent the definition of a coherent and respected energy policy. Russia, for its part, is no longer willing to subsidise its neighbouring economies by cheap energy exports. The Russian government engages in assertive policies pursuing Russian interests. In so far, it opts for a different globalisation approach, refusing the role of mere energy exporter. In view of the intensifying struggle for global resources, Russia, with its large energy potential, appears to be a very favourable option for European energy supplies, if not the best one. However, several outcomes of the strategic game between the two partners can be imagined. Engaging in non-cooperative strategies will in the end leave all stakeholders worse-off. The European Union should therefore concentrate on securing its partnership with Russia instead of damaging it. Stable cooperation would need the acceptance that the partner may pursue his own goals, which might be different from one's own interests. The question is, how can a sustainable compromise be found? This thesis finds that a mix of continued dialogue, a tit for tat approach bolstered by an international institutional framework and increased integration efforts appears as a preferable solution.}, language = {en} } @phdthesis{Weiss2011, author = {Weiß, Jan}, title = {Synthesis and self-assembly of multiple thermoresponsive amphiphilic block copolymers}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-53360}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {In the present thesis, the self-assembly of multi thermoresponsive block copolymers in dilute aqueous solution was investigated by a combination of turbidimetry, dynamic light scattering, TEM measurements, NMR as well as fluorescence spectroscopy. The successive conversion of such block copolymers from a hydrophilic into a hydrophobic state includes intermediate amphiphilic states with a variable hydrophilic-to-lipophilic balance. As a result, the self-organization is not following an all-or-none principle but a multistep aggregation in dilute solution was observed. The synthesis of double thermoresponsive diblock copolymers as well as triple thermoresponsive triblock copolymers was realized using twofold-TMS labeled RAFT agents which provide direct information about the average molar mass as well as residual end group functionality from a routine proton NMR spectrum. First a set of double thermosensitive diblock copolymers poly(N-n-propylacrylamide)-b-poly(N-ethylacrylamide) was synthesized which differed only in the relative size of the two blocks. Depending on the relative block lengths, different aggregation pathways were found. Furthermore, the complementary TMS-labeled end groups served as NMR-probes for the self-assembly of these diblock copolymers in dilute solution. Reversible, temperature sensitive peak splitting of the TMS-signals in NMR spectroscopy was indicative for the formation of mixed star-/flower-like micelles in some cases. Moreover, triple thermoresponsive triblock copolymers from poly(N-n-propylacrylamide) (A), poly(methoxydiethylene glycol acrylate) (B) and poly(N-ethylacrylamide) (C) were obtained from sequential RAFT polymerization in all possible block sequences (ABC, BAC, ACB). Their self-organization behavior in dilute aqueous solution was found to be rather complex and dependent on the positioning of the different blocks within the terpolymers. Especially the localization of the low-LCST block (A) had a large influence on the aggregation behavior. Above the first cloud point, aggregates were only observed when the A block was located at one terminus. Once placed in the middle, unimolecular micelles were observed which showed aggregation only above the second phase transition temperature of the B block. Carrier abilities of such triple thermosensitive triblock copolymers tested in fluorescence spectroscopy, using the solvatochromic dye Nile Red, suggested that the hydrophobic probe is less efficiently incorporated by the polymer with the BAC sequence as compared to ABC or ACB polymers above the first phase transition temperature. In addition, due to the problem of increasing loss of end group functionality during the subsequent polymerization steps, a novel concept for the one-step synthesis of multi thermoresponsive block copolymers was developed. This allowed to synthesize double thermoresponsive di- and triblock copolymers in a single polymerization step. The copolymerization of different N-substituted maleimides with a thermosensitive styrene derivative (4-vinylbenzyl methoxytetrakis(oxyethylene) ether) led to alternating copolymers with variable LCST. Consequently, an excess of this styrene-based monomer allowed the synthesis of double thermoresponsive tapered block copolymers in a single polymerization step.}, language = {en} } @phdthesis{Bierbaum2011, author = {Bierbaum, Veronika}, title = {Chemomechanical coupling and motor cycles of the molecular motor myosin V}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-53614}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {In the living cell, the organization of the complex internal structure relies to a large extent on molecular motors. Molecular motors are proteins that are able to convert chemical energy from the hydrolysis of adenosine triphosphate (ATP) into mechanical work. Being about 10 to 100 nanometers in size, the molecules act on a length scale, for which thermal collisions have a considerable impact onto their motion. In this way, they constitute paradigmatic examples of thermodynamic machines out of equilibrium. This study develops a theoretical description for the energy conversion by the molecular motor myosin V, using many different aspects of theoretical physics. Myosin V has been studied extensively in both bulk and single molecule experiments. Its stepping velocity has been characterized as a function of external control parameters such as nucleotide concentration and applied forces. In addition, numerous kinetic rates involved in the enzymatic reaction of the molecule have been determined. For forces that exceed the stall force of the motor, myosin V exhibits a 'ratcheting' behaviour: For loads in the direction of forward stepping, the velocity depends on the concentration of ATP, while for backward loads there is no such influence. Based on the chemical states of the motor, we construct a general network theory that incorporates experimental observations about the stepping behaviour of myosin V. The motor's motion is captured through the network description supplemented by a Markov process to describe the motor dynamics. This approach has the advantage of directly addressing the chemical kinetics of the molecule, and treating the mechanical and chemical processes on equal grounds. We utilize constraints arising from nonequilibrium thermodynamics to determine motor parameters and demonstrate that the motor behaviour is governed by several chemomechanical motor cycles. In addition, we investigate the functional dependence of stepping rates on force by deducing the motor's response to external loads via an appropriate Fokker-Planck equation. For substall forces, the dominant pathway of the motor network is profoundly different from the one for superstall forces, which leads to a stepping behaviour that is in agreement with the experimental observations. The extension of our analysis to Markov processes with absorbing boundaries allows for the calculation of the motor's dwell time distributions. These reveal aspects of the coordination of the motor's heads and contain direct information about the backsteps of the motor. Our theory provides a unified description for the myosin V motor as studied in single motor experiments.}, language = {en} } @article{Wolf2011, author = {Wolf, Mark J. P.}, title = {Theorizing navigable space in video games}, series = {DIGAREC Series}, journal = {DIGAREC Series}, number = {6}, issn = {1867-6219}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-49809}, pages = {18 -- 49}, year = {2011}, abstract = {Space is understood best through movement, and complex spaces require not only movement but navigation. The theorization of navigable space requires a conceptual representation of space which is adaptable to the great malleability of video game spaces, a malleability which allows for designs which combine spaces with differing dimensionality and even involve non-Euclidean configurations with contingent connectivity. This essay attempts to describe the structural elements of video game space and to define them in such a way so as to make them applicable to all video game spaces, including potential ones still undiscovered, and to provide analytical tools for their comparison and examination. Along with the consideration of space, there will be a brief discussion of navigational logic, which arises from detectable regularities in a spatial structure that allow players to understand and form expectations regarding a game's spaces.}, language = {en} } @article{Salen2011, author = {Salen, Katie}, title = {Pok{\´e}walkers, mafia dons, and football fans}, series = {DIGAREC Series}, journal = {DIGAREC Series}, number = {6}, issn = {1867-6219}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-49824}, pages = {70 -- 86}, year = {2011}, abstract = {This paper addresses a theoretical reconfiguration of experience, a repositioning of the techno-social within the domains of mobility, games, and play, and embodiment. The ideas aim to counter the notion that our experience with videogames (and digital media more generally), is largely "virtual" and disembodied - or at most exclusively audiovisual. Notions of the virtual and disembodied support an often-tacit belief that technologically mediated experiences count for nothing if not perceived and valued as human. It is here where play in particular can be put to work, be made to highlight and clarify, for it is in play that we find this value of humanity most wholly embodied. Further, it is in considering the design of the metagame that questions regarding the play experience can be most powerfully engaged. While most of any given game's metagame emerges from play communities and their larger social worlds (putting it out of reach of game design proper), mobile platforms have the potential to enable a stitching together of these experiences: experiences held across time, space, communities, and bodies. This coming together thus represents a convergence not only of media, participants, contexts, and technologies, but of human experience itself. This coming together is hardly neat, nor fully realized. It is, if nothing else, multifaceted and worthy of further study. It is a convergence in which the dynamics of screen play are reengaged.}, language = {en} } @article{MaeyraeErmi2011, author = {M{\"a}yr{\"a}, Frans and Ermi, Laura}, title = {Fundamental components of the gameplay experience}, series = {DIGAREC Series}, journal = {DIGAREC Series}, number = {6}, issn = {1867-6219}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-49831}, pages = {88 -- 115}, year = {2011}, abstract = {This co-authored paper is based on research that originated in 2003 when our team started a series of extensive field studies into the character of gameplay experiences. Originally within the Children as the Actors of Game Cultures research project, our aim was to better understand why particularly young people enjoy playing games, while also asking their parents how they perceive gaming as playing partners or as close observers. Gradually our in-depth interviews started to reveal a complex picture of more general relevance, where personal experiences, social contexts and cultural practices all came together to frame gameplay within something we called game cultures. Culture was the keyword, since we were not interested in studying games and play experiences in isolation, but rather as part of the rich meaning- making practices of lived reality.}, language = {en} } @article{BonaventuraSonntagKleber2011, author = {Bonaventura, Klaus and Sonntag, Steffen and Kleber, Franz X.}, title = {Antiplatelet therapy in the era of percutaneous coronary intervention with drug-eluting balloons}, series = {EuroIntervention : official journal of EuroPCR and the European Association of Percutaneous Cardiovascular Interventions (EAPCI)}, volume = {7}, journal = {EuroIntervention : official journal of EuroPCR and the European Association of Percutaneous Cardiovascular Interventions (EAPCI)}, number = {2}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Toulouse}, issn = {1774-024X}, pages = {K106 -- K111}, year = {2011}, abstract = {The high rate of restenosis associated with percutaneous coronary intervention (PCI) procedures can be reduced with the implantation of metallic stents into the stenotic vessels. The knowledge that neointimal formation can result in restenosis after stent implantation led to the development of drug-eluting stents (DES) which require long lasting antiplatelet therapy to avoid thrombotic complications. In the last years, the drug-eluting balloon (DEB) technology has emerged as an alternative option for the treatment of coronary and peripheral arteries. Clinical studies demonstrated the safety and effectiveness of DEB in various clinical scenarios and support the use of paclitaxel-eluting balloons for the treatment of in-stent restenosis, of small coronary arteries and bifurcations lesions. The protocols of DEB studies suggest that the dual antiplatelet therapy with aspirin and clopidogrel of four weeks after DEB is safe and effective.}, language = {en} } @inproceedings{BonaventuraSonntagKleber2011, author = {Bonaventura, Klaus and Sonntag, Steffen and Kleber, Franz Xayer}, title = {Incidence of acute thrombosis after percutaneous coronary intervention with paclitaxel eluting balloons in a clinical setting and in clinical trials}, series = {Journal of the American College of Cardiology}, volume = {58}, booktitle = {Journal of the American College of Cardiology}, number = {20}, publisher = {Elsevier}, address = {New York}, issn = {0735-1097}, pages = {B78 -- B78}, year = {2011}, language = {en} } @misc{GeissSiegrist2011, author = {Geiß, Robin and Siegrist, Michael}, title = {Has the armed conflict in Afghanistan affected the rules on the conduct of hostilities?}, series = {Postprints der Universit{\"a}t Potsdam Rechtswissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Rechtswissenschaftliche Reihe}, number = {4}, doi = {10.25932/publishup-41289}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-412896}, pages = {36}, year = {2011}, abstract = {The armed conflict in Afghanistan since 2001 has raised manifold questions pertaining to the humanitarian rules relative to the conduct of hostilities. In Afghanistan, as is often the case in so-called asymmetric conflicts, the geographical and temporal boundaries of the battlefield, and the distinction between civilians and fighters, are increasingly blurred. As a result, the risks for both civilians and soldiers operating in Afghanistan are high. The objective of this article is to assess whether - and if so how much - the armed conflict in Afghanistan has affected the application and interpretation of the principles of distinction, proportionality, and precaution - principles that form the core of legal rules pertaining to the conduct of hostilities.}, language = {en} } @article{VaterKoessl2011, author = {Vater, Marianne and Koessl, Manfred}, title = {Comparative aspects of cochlear functional organization in mammals}, series = {Hearing research}, volume = {273}, journal = {Hearing research}, number = {1-2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0378-5955}, doi = {10.1016/j.heares.2010.05.018}, pages = {89 -- 99}, year = {2011}, abstract = {This review addresses the functional organization of the mammalian cochlea under a comparative and evolutionary perspective. A comparison of the monotreme cochlea with that of marsupial and placental mammals highlights important evolutionary steps towards a hearing organ dedicated to process higher frequencies and a larger frequency range than found in non-mammalian vertebrates. Among placental mammals, there are numerous cochlear specializations which relate to hearing range in adaptation to specific habitats that are superimposed on a common basic design. These are illustrated by examples of specialist ears which evolved excellent high frequency hearing and echolocation (bats and dolphins) and by the example of subterranean rodents with ears devoted to processing low frequencies. Furthermore, structural functional correlations important for tonotopic cochlear organization and predictions of hearing capabilities are discussed.}, language = {en} } @article{HagemannVaterKoessl2011, author = {Hagemann, Cornelia and Vater, Marianne and Koessl, Manfred}, title = {Comparison of properties of cortical echo delay-tuning in the short-tailed fruit bat and the mustached bat}, series = {Journal of comparative physiology : A, Neuroethology, sensory, neural, and behavioral physiology}, volume = {197}, journal = {Journal of comparative physiology : A, Neuroethology, sensory, neural, and behavioral physiology}, number = {5}, publisher = {Springer}, address = {New York}, issn = {0340-7594}, doi = {10.1007/s00359-010-0530-8}, pages = {605 -- 613}, year = {2011}, abstract = {Target-distance computation by cortical neurons sensitive to echo delay is an essential characteristic of the auditory system of insectivorous bats. To assess if functional requirements such as detection of small insects versus larger stationary surfaces of plants are reflected in cortical properties, we compare delay-tuned neurons in a frugivorous (C. perspicillata, CP) and an insectivorous (P. parnellii, PP) bat species that belong to related families within the superfamily of Noctilionoidea. The bandwidth and shape of delay-tuning curves and the range of characteristic delays are similar in both species and hence are not related to different echolocation strategies. Most units respond at 2-6 ms echo delay with most sensitive thresholds of 20-30 dB SPL. In CP, units tuned to delays > 12 ms are slightly more abundant and are more sensitive than in PP. All delay-tuned neurons in CP reliably respond to single pure-tone stimuli, whereas such responses are only observed in 49\% of delay-tuned units in PP. The cortical representation of echo delay (chronotopy) covers a larger area in CP but is less precise than described in PP. Since chronotopy is absent in certain other insectivorous bat species, it is open if these differences in topography are related to echolocation behaviour.}, language = {en} } @misc{Eckstein2011, author = {Eckstein, Lars}, title = {Agnew, V., Enlightenment Orpheus: the Power of Music in Other Worlds; New York, Oxford Univ. Press, 2008}, year = {2011}, language = {en} } @article{EcksteinKraemer2011, author = {Eckstein, Lars and Kr{\"a}mer, Lucia}, title = {Introduction : postcolonial media cultures}, isbn = {978-3- 86821-332-4}, year = {2011}, language = {en} } @misc{Eckstein2011, author = {Eckstein, Lars}, title = {The white backlash: conservatisms in contemporary british writing}, publisher = {Hard Times}, address = {Berlin}, issn = {0171-1695}, pages = {47}, year = {2011}, language = {en} } @misc{Eckstein2011, author = {Eckstein, Lars}, title = {Carrington, B., Sport and Politics: the Sporting Black Diaspora; London, Sage, 2010}, year = {2011}, language = {en} } @misc{MeyerKuhnertGraef2011, author = {Meyer, Irene and Kuhnert, Oliver and Gr{\"a}f, Ralph}, title = {Functional analyses of lissencephaly-related proteins in Dictyostelium}, series = {Seminars in cell \& developmental biology}, volume = {22}, journal = {Seminars in cell \& developmental biology}, number = {1}, publisher = {Elsevier}, address = {London}, issn = {1084-9521}, doi = {10.1016/j.semcdb.2010.10.007}, pages = {89 -- 96}, year = {2011}, abstract = {Lissencephaly is a severe brain developmental disease in human infants, which is usually caused by mutations in either of two genes, LIS1 and DCX. These genes encode proteins interacting with both the microtubule and the actin systems. Here, we review the implications of data on Dictyostelium LIS1 for the elucidation of LIS1 function in higher cells and emphasize the role of LIS1 and nuclear envelope proteins in nuclear positioning, which is also important for coordinated cell migration during neocortical development. Furthermore, for the first time we characterize Dictyostelium DCX, the only bona fide orthologue of human DCX outside the animal kingdom. We show that DCX functionally interacts with LIS1 and that both proteins have a cytoskeleton-independent function in chemotactic signaling during development. Dictyostelium LIS1 is also required for proper attachment of the centrosome to the nucleus and, thus, nuclear positioning, where the association of these two organelles has turned out to be crucial. It involves not only dynein and dynein-associated proteins such as LIS1 but also SUN proteins of the nuclear envelope. Analyses of Dictyostelium SUN1 mutants have underscored the importance of these proteins for the linkage of centrosomes and nuclei and for the maintenance of chromatin integrity. Taken together, we show that Dictyostelium amoebae, which provide a well-established model to study the basic aspects of chemotaxis, cell migration and development, are well suited for the investigation of the molecular and cell biological basis of developmental diseases such as lissencephaly.}, language = {en} } @article{SamereierBaumannMeyeretal.2011, author = {Samereier, Matthias and Baumann, Otto and Meyer, Irene and Gr{\"a}f, Ralph}, title = {Analysis of dictyostelium TACC reveals differential interactions with CP224 and unusual dynamics of dictyostelium microtubules}, series = {Cellular and molecular life sciences}, volume = {68}, journal = {Cellular and molecular life sciences}, number = {2}, publisher = {Springer}, address = {Basel}, issn = {1420-682X}, doi = {10.1007/s00018-010-0453-0}, pages = {275 -- 287}, year = {2011}, abstract = {We have localized TACC to the microtubule-nucleating centrosomal corona and to microtubule plus ends. Using RNAi we proved that Dictyostelium TACC promotes microtubule growth during interphase and mitosis. For the first time we show in vivo that both TACC and XMAP215 family proteins can be differentially localized to microtubule plus ends during interphase and mitosis and that TACC is mainly required for recruitment of an XMAP215-family protein to interphase microtubule plus ends but not for recruitment to centrosomes and kinetochores. Moreover, we have now a marker to study dynamics and behavior of microtubule plus ends in living Dictyostelium cells. In a combination of live cell imaging of microtubule plus ends and fluorescence recovery after photobleaching (FRAP) experiments of GFP-alpha-tubulin cells we show that Dictyostelium microtubules are dynamic only in the cell periphery, while they remain stable at the centrosome, which also appears to harbor a dynamic pool of tubulin dimers.}, language = {en} } @inproceedings{TikhonenkoMagidsonGraefetal.2011, author = {Tikhonenko, I. and Magidson, V. and Gr{\"a}f, Ralph and Khodjakov, A. and Koonce, M.}, title = {A kinesin-mediated linkage between centrosomes and the nuclear envelope}, series = {Molecular biology of the cell : the official publication of the American Society for Cell Biology}, volume = {22}, booktitle = {Molecular biology of the cell : the official publication of the American Society for Cell Biology}, number = {1}, publisher = {American Society for Cell Biology}, address = {Bethesda}, issn = {1059-1524}, pages = {1}, year = {2011}, language = {en} } @inproceedings{KuhnertBaumannMeyeretal.2011, author = {Kuhnert, Oliver and Baumann, Otto and Meyer, Irene and Gr{\"a}f, Ralph}, title = {Functional characterization of CP148, a novel key component for centrosome integrity in Dictyostelium}, series = {Molecular biology of the cell : the official publication of the American Society for Cell Biology}, volume = {22}, booktitle = {Molecular biology of the cell : the official publication of the American Society for Cell Biology}, publisher = {American Society for Cell Biology}, address = {Bethesda}, issn = {1059-1524}, pages = {2}, year = {2011}, language = {en} } @phdthesis{Samereier2011, author = {Samereier, Matthias}, title = {Functional analyses of microtubule and centrosome-associated proteins in Dictyostelium discoideum}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-52835}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {Understanding the role of microtubule-associated proteins is the key to understand the complex mechanisms regulating microtubule dynamics. This study employs the model system Dictyostelium discoideum to elucidate the role of the microtubule-associated protein TACC (Transforming acidic coiled-coil) in promoting microtubule growth and stability. Dictyostelium TACC was localized at the centrosome throughout the entire cell cycle. The protein was also detected at microtubule plus ends, however, unexpectedly only during interphase but not during mitosis. The same cell cycle-dependent localization pattern was observed for CP224, the Dictyostelium XMAP215 homologue. These ubiquitous MAPs have been found to interact with TACC proteins directly and are known to act as microtubule polymerases and nucleators. This work shows for the first time in vivo that both a TACC and XMAP215 family protein can differentially localize to microtubule plus ends during interphase and mitosis. RNAi knockdown mutants revealed that TACC promotes microtubule growth during interphase and is essential for proper formation of astral microtubules in mitosis. In many organisms, impaired microtubule stability upon TACC depletion was explained by the failure to efficiently recruit the TACC-binding XMAP215 protein to centrosomes or spindle poles. By contrast, fluorescence recovery after photobleaching (FRAP) analyses conducted in this study demonstrate that in Dictyostelium recruitment of CP224 to centrosomes or spindle poles is not perturbed in the absence of TACC. Instead, CP224 could no longer be detected at the tips of microtubules in TACC mutant cells. This finding demonstrates for the first time in vivo that a TACC protein is essential for the association of an XMAP215 protein with microtubule plus ends. The GFP-TACC strains generated in this work also turned out to be a valuable tool to study the unusual microtubule dynamics in Dictyostelium. Here, microtubules exhibit a high degree of lateral bending movements but, in contrast most other organisms, they do not obviously undergo any growth or shrinkage events during interphase. Despite of that they are affected by microtubuledepolymerizing drugs such as thiabendazole or nocodazol which are thought to act solely on dynamic microtubules. Employing 5D-fluorescence live cell microscopy and FRAP analyses this study suggests Dictyostelium microtubules to be dynamic only in the periphery, while they are stable at the centrosome. In the recent years, the identification of yet unknown components of the Dictyostelium centrosome has made tremendous progress. A proteomic approach previously conducted by our group disclosed several uncharacterized candidate proteins, which remained to be verified as genuine centrosomal components. The second part of this study focuses on the investigation of three such candidate proteins, Cenp68, CP103 and the putative spindle assembly checkpoint protein Mad1. While a GFP-CP103 fusion protein could clearly be localized to isolated centrosomes that are free of microtubules, Cenp68 and Mad1 were found to associate with the centromeres and kinetochores, respectively. The investigation of Cenp68 included the generation of a polyclonal anti-Cenp68 antibody, the screening for interacting proteins and the generation of knockout mutants which, however, did not display any obvious phenotype. Yet, Cenp68 has turned out as a very useful marker to study centromere dynamics during the entire cell cycle. During mitosis, GFP-Mad1 localization strongly resembled the behavior of other Mad1 proteins, suggesting the existence of a yet uncharacterized spindle assembly checkpoint in Dictyostelium.}, language = {en} } @book{Koss2011, author = {Koss, Michael}, title = {The politics of party funding}, series = {Comparative politics}, journal = {Comparative politics}, publisher = {Oxford University Press}, address = {Oxford}, isbn = {978-0-19-957275-5}, pages = {XIII, 261}, year = {2011}, abstract = {'The Politics of Party Funding' analyses an increasingly popular institutional choice - the introduction of state funding to political parties - and represents a first step towards a theory which explains differences and similarities in party funding regimes.}, language = {en} } @article{JannFleischer2011, author = {Jann, Werner and Fleischer, Julia}, title = {Shefting discourses, steady learning and sedimentation : the German reform trajectory in the long run}, isbn = {978-0-415-55721-4}, year = {2011}, language = {en} } @misc{BoumaHendriks2011, author = {Bouma, Gerlof J. and Hendriks, Petra}, title = {Partial word order freezing in Dutch}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {625}, issn = {1866-8364}, doi = {10.25932/publishup-43049}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-430496}, pages = {23}, year = {2011}, abstract = {Dutch allows for variation as to whether the first position in the sentence is occupied by the subject or by some other constituent, such as the direct object. In particular situations, however, this commonly observed variation in word order is 'frozen' and only the subject appears in first position. We hypothesize that this partial freezing of word order in Dutch can be explained from the dependence of the speaker's choice of word order on the hearer's interpretation of this word order. A formal model of this interaction between the speaker's perspective and the hearer's perspective is presented in terms of bidirectional Optimality Theory. Empirical predictions of this model regarding the interaction between word order and definiteness are confirmed by a quantitative corpus study.}, language = {en} } @misc{IdzikCywinskiCranfieldetal.2011, author = {Idzik, Krzysztof Ryszard and Cywinski, Piotr J. and Cranfield, Charles G. and Mohr, Gerhard J. and Beckert, Rainer}, title = {Molecular recognition of the antiretroviral drug Abacavir}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, number = {847}, issn = {1866-8372}, doi = {10.25932/publishup-43037}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-430372}, pages = {1195 -- 1204}, year = {2011}, abstract = {Due to their optical and electro-conductive attributes, carbazole derivatives are interesting materials for a large range of biosensor applications. In this study, we present the synthesis routes and fluorescence evaluation of newly designed carbazole fluorosensors that, by modification with uracil, have a special affinity for antiretroviral drugs via either Watson-Crick or Hoogsteen base pairing. To an N-octylcarbazole-uracil compound, four different groups were attached, namely thiophene, furane, ethylenedioxythiophene, and another uracil; yielding four different derivatives. Photophysical properties of these newly obtained derivatives are described, as are their interactions with the reverse transcriptase inhibitors such as abacavir, zidovudine, lamivudine and didanosine. The influence of each analyte on biosensor fluorescence was assessed on the basis of the Stern-Volmer equation and represented by Stern-Volmer constants. Consequently we have demonstrated that these structures based on carbazole, with a uracil group, may be successfully incorporated into alternative carbazole derivatives to form biosensors for the molecular recognition of antiretroviral drugs.}, language = {en} } @misc{LamprechtNaujokatMargariaetal.2011, author = {Lamprecht, Anna-Lena and Naujokat, Stefan and Margaria, Tiziana and Steffen, Bernhard}, title = {Semantics-based composition of EMBOSS services}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {956}, issn = {1866-8372}, doi = {10.25932/publishup-43183}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-431830}, pages = {23}, year = {2011}, abstract = {Background More than in other domains the heterogeneous services world in bioinformatics demands for a methodology to classify and relate resources in a both human and machine accessible manner. The Semantic Web, which is meant to address exactly this challenge, is currently one of the most ambitious projects in computer science. Collective efforts within the community have already led to a basis of standards for semantic service descriptions and meta-information. In combination with process synthesis and planning methods, such knowledge about types and services can facilitate the automatic composition of workflows for particular research questions. Results In this study we apply the synthesis methodology that is available in the Bio-jETI workflow management framework for the semantics-based composition of EMBOSS services. EMBOSS (European Molecular Biology Open Software Suite) is a collection of 350 tools (March 2010) for various sequence analysis tasks, and thus a rich source of services and types that imply comprehensive domain models for planning and synthesis approaches. We use and compare two different setups of our EMBOSS synthesis domain: 1) a manually defined domain setup where an intuitive, high-level, semantically meaningful nomenclature is applied to describe the input/output behavior of the single EMBOSS tools and their classifications, and 2) a domain setup where this information has been automatically derived from the EMBOSS Ajax Command Definition (ACD) files and the EMBRACE Data and Methods ontology (EDAM). Our experiments demonstrate that these domain models in combination with our synthesis methodology greatly simplify working with the large, heterogeneous, and hence manually intractable EMBOSS collection. However, they also show that with the information that can be derived from the (current) ACD files and EDAM ontology alone, some essential connections between services can not be recognized. Conclusions Our results show that adequate domain modeling requires to incorporate as much domain knowledge as possible, far beyond the mere technical aspects of the different types and services. Finding or defining semantically appropriate service and type descriptions is a difficult task, but the bioinformatics community appears to be on the right track towards a Life Science Semantic Web, which will eventually allow automatic service composition methods to unfold their full potential.}, language = {en} } @article{BresselPrevostAppavouetal.2011, author = {Bressel, Katharina and Prevost, Sylvain and Appavou, Marie-Sousai and Tiersch, Brigitte and Koetz, Joachim and Gradzielski, Michael}, title = {Phase behaviour and structure of zwitanionic mixtures of perfluorocarboxylates and tetradecyldimethylamine oxide-dependence on chain length of the perfluoro surfactant}, series = {Soft matter}, volume = {7}, journal = {Soft matter}, number = {23}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1744-683X}, doi = {10.1039/c1sm05618b}, pages = {11232 -- 11242}, year = {2011}, abstract = {Phase behaviour and the mesoscopic structure of zwitanionic surfactant mixtures based on the zwitterionic tetradecyldimethylamine oxide (TDMAO) and anionic lithium perfluoroalkyl carboxylates have been investigated for various chain lengths of the perfluoro surfactant with an emphasis on spontaneously forming vesicles. These mixtures were studied at a constant total concentration of 50 mM and characterised by means of dynamic light scattering (DLS), electric conductivity, small-angle neutron scattering (SANS), viscosity, and cryo-scanning electron microscopy (Cryo-SEM). No vesicles are formed for relatively short perfluoro surfactants. The extension of the vesicle phase becomes substantially larger with increasing chain length of the perfluoro surfactant, while at the same time the size of these vesicles increases. Head group interactions in these systems play a central role in the ability to form vesicles, as already protonating 10 mol\% of the TDMAO largely enhances the propensity for vesicle formation. The range of vesicle formation in the phase diagram is not only substantially enlarged but also extends to shorter perfluoro surfactants, where without protonation no vesicles would be formed. The size and polydispersity of the vesicles are related to the chain length of the perfluoro surfactant, the vesicles becoming smaller and more monodisperse with increasing perfluoro surfactant chain length. The ability of the mixed systems to form well-defined unilamellar vesicles accordingly can be controlled by the length of the alkyl chain of the perfluorinated surfactant and depends strongly on the charge conditions, which can be tuned easily by pH-variation.}, language = {en} } @article{WellertTierschKoetzetal.2011, author = {Wellert, Stefan and Tiersch, Brigitte and Koetz, Joachim and Richardt, Andre and Lapp, Alain and Holderer, Olaf and Gaeb, Juergen and Blum, Marc-Michael and Schulreich, Christoph and Stehle, Ralf and Hellweg, Thomas}, title = {The DFPase from Loligo vulgaris in sugar surfactant-based bicontinuous microemulsions structure, dynamics, and enzyme activity}, series = {European biophysics journal : with biophysics letters ; an international journal of biophysics}, volume = {40}, journal = {European biophysics journal : with biophysics letters ; an international journal of biophysics}, number = {6}, publisher = {Springer}, address = {New York}, issn = {0175-7571}, doi = {10.1007/s00249-011-0689-0}, pages = {761 -- 774}, year = {2011}, abstract = {The enzyme diisopropyl fluorophosphatase (DFPase) from the squid Loligo vulgaris is of great interest because of its ability to catalyze the hydrolysis of highly toxic organophosphates. In this work, the enzyme structure in solution (native state) was studied by use of different scattering methods. The results are compared with those from hydrodynamic model calculations based on the DFPase crystal structure. Bicontinuous microemulsions made of sugar surfactants are discussed as host systems for the DFPase. The microemulsion remains stable in the presence of the enzyme, which is shown by means of scattering experiments. Moreover, activity assays reveal that the DFPase still has high activity in this complex reaction medium. To complement the scattering experiments cryo-SEM was also employed to study the microemulsion structure.}, language = {en} } @article{WeberTierschUnterlassetal.2011, author = {Weber, Nancy and Tiersch, Brigitte and Unterlass, Miriam M. and Heilig, Anneliese and Tauer, Klaus}, title = {"Schizomorphic" Emulsion Copolymerization Particles}, series = {Macromolecular rapid communications}, volume = {32}, journal = {Macromolecular rapid communications}, number = {23}, publisher = {Wiley-Blackwell}, address = {Malden}, issn = {1022-1336}, doi = {10.1002/marc.201100491}, pages = {1925 -- 1929}, year = {2011}, abstract = {Cryo-electron microscopy, atomic force microscopy, and light microscopy investigations provide experimental evidence that amphiphilic emulsion copolymerization particles change their morphology in dependence on concentration. The shape of the particles is spherical at solids content above 1\%, but it changes to rod-like, ring-like, and web-like structures at lower concentrations. In addition, the shape and morphology of these particles at low concentrations are not fixed but very flexible and vary with time between spheres, flexible pearlnecklace structures, and stretched rods.}, language = {en} } @article{KoethAppelhansRobertsonetal.2011, author = {Koeth, Anja and Appelhans, Dietmar and Robertson, Daniela and Tiersch, Brigitte and Koetz, Joachim}, title = {Use of weakly cationic dendritic glycopolymer for morphological transformation of phospholipid vesicles into tube-like networks}, series = {Soft matter}, volume = {7}, journal = {Soft matter}, number = {22}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1744-683X}, doi = {10.1039/c1sm06439h}, pages = {10581 -- 10584}, year = {2011}, abstract = {Using cationic polyelectrolytes with different molecular architectures, only hyperbranched poly(ethyleneimine) with maltose shell is suited to tailor the morphological transformation of anionic vesicles into tube-like networks. The interaction features of those materials partly mimic biological features of tubular proteins in nature.}, language = {en} } @misc{AlterOttvonWebskyetal.2011, author = {Alter, Markus L. and Ott, Ina and von Websky, Karoline and Tsuprykov, Oleg and Sharkovska, Yuliya and Krause-Relle, Katharina and Raila, Jens and Henze, Andrea and Kretschmer, Axel and Stasch, Johannes-Peter and Hocher, Berthold}, title = {Additional stimulation of sGC on top of standard treatment with ARB`s may offer a new therapeutic approach for the treatment of diabetic nephropathy resistant to ARB treatment alone}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {855}, issn = {1866-8372}, doi = {10.25932/publishup-42825}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-428250}, pages = {4}, year = {2011}, abstract = {Background Riociguat is the first of a new class of drugs, the soluble guanylate cyclase (sGC) stimulators. Riociguat has a dual mode of action: it sensitizes sGC to the body's own NO and can also increase sGC activity in the absence of NO. The NO-sGC-pathway is impaired in many cardiovascular diseases such as heart failure, pulmonary hypertension and diabetic nephropathy (DN). DN leads to high cardiovascular morbidity and mortality. There is still a high unmet medical need. The urinary albumin excretion rate is a predictive biomarker for these clinical events. Therefore, we investigated the effect of riociguat, alone and in combination with the angiotensin II receptor antagonist (ARB) telmisartan on the progression of DN in diabetic eNOS knock out mice, a new model closely resembling human pathology. Methods Seventy-six male eNOS knockout C57BL/6J mice were divided into 4 groups after receiving intraperitoneal high-dose streptozotocin: telmisartan (1 mg/kg), riociguat (3 mg/kg), riociguat+telmisartan (3 and 1 mg/kg), and vehicle. Fourteen mice were used as non-diabetic controls. After 12 weeks, urine and blood were obtained and blood pressure measured. Glucose concentrations were highly increased and similar in all diabetic groups. Results Riociguat, alone (105.2 ± 2.5 mmHg; mean±SEM; n = 14) and in combination with telmisartan (105.0 ± 3.2 mmHg; n = 12), significantly reduced blood pressure versus diabetic controls (117.1 ± 2.2 mmHg; n = 14; p = 0.002 and p = 0.004, respectively), whereas telmisartan alone (111.2 ± 2.6 mmHg) showed a modest blood pressure lowering trend (p = 0.071; n = 14). The effects of single treatment with either riociguat (97.1 ± 15.7 µg/d; n = 13) or telmisartan (97.8 ± 26.4 µg/d; n = 14) did not significantly lower albumin excretion on its own (p = 0.067 and p = 0.101, respectively). However, the combined treatment led to significantly lower urinary albumin excretion (47.3 ± 9.6 µg/d; n = 12) compared to diabetic controls (170.8 ± 34.2 µg/d; n = 13; p = 0.004), and reached levels similar to non-diabetic controls (31.4 ± 10.1 µg/d, n = 12). Conclusion Riociguat significantly reduced urinary albumin excretion in diabetic eNOS knock out mice that were refractory to treatment with ARB's alone. Patients with diabetic nephropathy refractory to treatment with ARB's have the worst prognosis among all patients with diabetic nephropathy. Our data indicate that additional stimulation of sGC on top of standard treatment with ARB`s may offer a new therapeutic approach for patients with diabetic nephropathy resistant to ARB treatment.}, language = {en} } @article{MelcherHartmannZopfetal.2011, author = {Melcher, Ralph and Hartmann, Elena and Zopf, Waltraud and Herterich, Sabine and Wilke, Philipp and Mueller, Ludwig and Rosler, Eduard and Kudlich, Theodor and Al-Taie, Oliver and Rosenwald, Andreas and Katzenberger, Tiemo and Scholtka, Bettina and Seibold, Stefan and Rogoll, Dorothee and Scheppach, Wolfgang and Scheurlen, Michael and Luehrs, Hardi}, title = {LOH and copy neutral LOH (cnLOH) act as alternative mechanism in sporadic colorectal cancers with chromosomal and microsatellite instability}, series = {Carcinogenesis : a comprehensive survey}, volume = {32}, journal = {Carcinogenesis : a comprehensive survey}, number = {4}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0143-3334}, doi = {10.1093/carcin/bgr011}, pages = {636 -- 642}, year = {2011}, abstract = {Background and aims. Tumor suppressor genes are often located in frequently deleted chromosomal regions of colorectal cancers (CRCs). In contrast to microsatellite stable (MSS) tumors, only few loss of heterozygosity (LOH) studies were performed in microsatellite instable (MSI) tumors, because MSI carcinomas are generally considered to be chromosomally stable and classical LOH studies are not feasible due to MSI. The single nucleotide polymorphism (SNP) array technique enables LOH studies also in MSI CRC. The aim of our study was to analyse tissue from MSI and MSS CRC for the existence of (frequently) deleted chromosomal regions and tumor suppressor genes located therein. Methods and results. We analyzed tissues from 32 sporadic CRCs and their corresponding normal mucosa (16 MSS and 16 MSI tumors) by means of 50K SNP array analysis. MSS tumors displayed chromosomal instability that resulted in multiple deleted (LOH) and amplified regions and led to the identification of MTUS1 (8p22) as a candidate tumor suppressor gene in this region. Although the MSI tumors were chromosomally stable, we found several copy neutral LOHs (cnLOH) in the MSI tumors; these appear to be instrumental in the inactivation of the tumor suppressor gene hMLH1 and a gene located in chromosomal region 6pter-p22. Discussion. Our results suggest that in addition to classical LOH, cnLOH is an important mutational event in relation to the carcinogenesis of MSS and MSI tumors, causing the inactivation of a tumor suppressor gene without copy number alteration of the respective region; this is crucial for the development of MSI tumors and for some chromosomal regions in MSS tumors.}, language = {en} } @inproceedings{GereckeScholtka2011, author = {Gerecke, Christian and Scholtka, Bettina}, title = {Detection of low level adenomatous polyposis coli(APC) gene mutatons by wild-type blocking-pcr and high resolution melting analysis}, series = {Clinical chemistry and laboratory medicine : journal of the Forum of the European Societies of Clinical Chemistry - the European Branch of the International Federation of Clinical Chemistry and Laboratory Medicine}, volume = {49}, booktitle = {Clinical chemistry and laboratory medicine : journal of the Forum of the European Societies of Clinical Chemistry - the European Branch of the International Federation of Clinical Chemistry and Laboratory Medicine}, number = {1}, publisher = {De Gruyter}, address = {Berlin}, issn = {1434-6621}, pages = {S603 -- S603}, year = {2011}, language = {en} } @phdthesis{Ivakov2011, author = {Ivakov, Alexander}, title = {Metabolic interactions in leaf development in Arabidopsis thaliana}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-59730}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {Das Wachstum und {\"U}berleben von Pflanzen basiert auf der Photosynthese in den Bl{\"a}ttern. Diese beinhaltet die Aufnahme von Kohlenstoffdioxid aus der Atmosph{\"a}re und das simultane Einfangen von Lichtenergie zur Bildung organischer Molek{\"u}le. Diese werden nach dem Eintritt in den Metabolismus in viele andere Komponenten umgewandelt, welche die Grundlage f{\"u}r die Zunahme der Biomasse bilden. Bl{\"a}tter sind Organe, die auf die Fixierung von Kohlenstoffdioxid spezialisiert sind. Die Funktionen der Bl{\"a}tter beinhalten vor allem die Optimierung und Feinregulierung vieler Prozesse, um eine effektive Nutzung von Ressourcen und eine maximale Photosynthese zu gew{\"a}hrleisten. Es ist bekannt, dass sich die Morphologie der Bl{\"a}tter den Wachstumsbedingungen der Pflanze anpasst und eine wichtige Rolle bei der Optimierung der Photosynthese spielt. Trotzdem ist die Regulation dieser Art der Anpassung bisher nicht verstanden. Die allgemeine Zielsetzung dieser vorliegenden Arbeit ist das Verst{\"a}ndnis wie das Wachstum und die Morphologie der Bl{\"a}tter im Modellorganismus Arabidopsis thaliana reguliert werden. Besondere Aufmerksamkeit wurde hierbei der M{\"o}glichkeit geschenkt, dass es interne metabolische Signale in der Pflanze geben k{\"o}nnte, die das Wachstum und die Entwicklung von Bl{\"a}ttern beeinflussen. Um diese Fragestellung zu untersuchen, muss das Wachstum und die Entwicklung von Bl{\"a}ttern oberhalb des Levels des einzelnen Organs und im Kontext der gesamten Pflanze betrachtet werden, weil Bl{\"a}tter nicht eigenst{\"a}ndig wachsen, sondern von Ressourcen und regulatorischen Einfl{\"u}ssen der ganzen Pflanze abh{\"a}ngig sind. Aufgrund der Komplexit{\"a}t dieser Fragestellung wurden drei komplement{\"a}re Ans{\"a}tze durchgef{\"u}hrt. Im ersten und spezifischsten Ansatz wurde untersucht ob eine flussabw{\"a}rts liegende Komponente des Zucker-Signalwegs, Trehalose-6-Phosphat (Tre-6-P), das Blattwachstum und die Blattentwicklung beinflussen kann. Um diese Frage zu beantworten wurden transgene Arabidopsis-Linien mit einem gest{\"o}rten Gehalt von Tre-6-P durch die Expression von bakteriellen Proteinen die in dem metabolismus von trehalose beteiligt sind. Die Pflanzen-Linien wurden unter Standard-Bendingungen in Erde angebaut und ihr Metabolismus und ihre Blattmorphologie untersucht. Diese Experimente f{\"u}hrten auch zu einem unerwarteten Projekt hinsichtlich einer m{\"o}glichen Rolle von Tre-6-P in der Regulation der Stomata. In einem zweiten, allgemeineren Ansatz wurde untersucht, ob {\"A}nderungen im Zucker-Gehalt der Pflanzen die Morphogenese der Bl{\"a}tter als Antwort auf Licht beeinflussen. Dazu wurden eine Reihe von Mutanten, die im Zentralmetabolismus beeintr{\"a}chtigt sind, in derselben Lichtbedingung angezogen und bez{\"u}glich ihrer Blattmorphologie analysiert. In einem dritten noch allgemeineren Ansatz wurde die nat{\"u}rliche Variation von morphologischen Auspr{\"a}gungen der Bl{\"a}tter und Rosette anhand von wilden Arabidopsis {\"O}kotypen untersucht, um zu verstehen wie sich die Blattmorphologie auf die Blattfunktion und das gesamte Pflanzenwachstum auswirkt und wie unterschiedliche Eigenschaften miteinander verkn{\"u}pft sind. Das Verh{\"a}ltnis der Blattanzahl zum Gesamtwachstum der Pflanze und Blattgr{\"o}ße wurde gesondert weiter untersucht durch eine Normalisierung der Blattanzahl auf das Frischgewicht der Rosette, um den Parameter „leafing Intensity" abzusch{\"a}tzen. Leafing Intensity integrierte Blattanzahl, Blattgr{\"o}ße und gesamtes Rosettenwachstum in einer Reihe von Kompromiss-Interaktionen, die in einem Wachstumsvorteil resultieren, wenn Pflanzen weniger, aber gr{\"o}ßere Bl{\"a}tter pro Einheit Biomasse ausbilden. Dies f{\"u}hrte zu einem theoretischen Ansatz in dem ein einfaches allometrisch mathematisches Modell konstruiert wurde, um Blattanzahl, Blattgr{\"o}ße und Pflanzenwachstum im Kontext der gesamten Pflanze Arabidopsis zu verkn{\"u}pfen.}, language = {en} } @phdthesis{Giorgi2011, author = {Giorgi, Federico Manuel}, title = {Expression-based reverse engineering of plant transcriptional networks}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-56760}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {Regulation of gene transcription plays a major role in mediating cellular responses and physiological behavior in all known organisms. The finding that similar genes are often regulated in a similar manner (co-regulated or "co-expressed") has directed several "guilt-by-association" approaches in order to reverse-engineer the cellular transcriptional networks using gene expression data as a compass. This kind of studies has been considerably assisted in the recent years by the development of high-throughput transcript measurement platforms, specifically gene microarrays and next-generation sequencing. In this thesis, I describe several approaches for improving the extraction and interpretation of the information contained in microarray based gene expression data, through four steps: (1) microarray platform design, (2) microarray data normalization, (3) gene network reverse engineering based on expression data and (4) experimental validation of expression-based guilt-by-association inferences. In the first part test case is shown aimed at the generation of a microarray for Thellungiella salsuginea, a salt and drought resistant close relative to the model plant Arabidopsis thaliana; the transcripts of this organism are generated on the combination of publicly available ESTs and newly generated ad-hoc next-generation sequencing data. Since the design of a microarray platform requires the availability of highly reliable and non-redundant transcript models, these issues are addressed consecutively, proposing several different technical solutions. In the second part I describe how inter-array correlation artifacts are generated by the common microarray normalization methods RMA and GCRMA, together with the technical and mathematical characteristics underlying the problem. A solution is proposed in the form of a novel normalization method, called tRMA. The third part of the thesis deals with the field of expression-based gene network reverse engineering. It is shown how different centrality measures in reverse engineered gene networks can be used to distinguish specific classes of genes, in particular essential genes in Arabidopsis thaliana, and how the use of conditional correlation can add a layer of understanding over the information flow processes underlying transcript regulation. Furthermore, several network reverse engineering approaches are compared, with a particular focus on the LASSO, a linear regression derivative rarely applied before in global gene network reconstruction, despite its theoretical advantages in robustness and interpretability over more standard methods. The performance of LASSO is assessed through several in silico analyses dealing with the reliability of the inferred gene networks. In the final part, LASSO and other reverse engineering methods are used to experimentally identify novel genes involved in two independent scenarios: the seed coat mucilage pathway in Arabidopsis thaliana and the hypoxic tuber development in Solanum tuberosum. In both cases an interesting method complementarity is shown, which strongly suggests a general use of hybrid approaches for transcript expression-based inferences. In conclusion, this work has helped to improve our understanding of gene transcription regulation through a better interpretation of high-throughput expression data. Part of the network reverse engineering methods described in this thesis have been included in a tool (CorTo) for gene network reverse engineering and annotated visualization from custom transcription datasets.}, language = {en} } @article{HenkelGaertnerDornetal.2011, author = {Henkel, Janin and G{\"a}rtner, Daniela and Dorn, Christoph and Hellerbrand, Claus and Schanze, Nancy and Elz, Sheila R. and P{\"u}schel, Gerhard Paul}, title = {Oncostatin M produced in Kupffer cells in response to PGE(2) possible contributor to hepatic insulin resistance and steatosis}, series = {Laboratory investigation : the basic and translational pathology research journal ; an official journal of the United States and Canadian Academy of Pathology}, volume = {91}, journal = {Laboratory investigation : the basic and translational pathology research journal ; an official journal of the United States and Canadian Academy of Pathology}, number = {7}, publisher = {Nature Publ. Group}, address = {New York}, issn = {0023-6837}, doi = {10.1038/labinvest.2011.47}, pages = {1107 -- 1117}, year = {2011}, abstract = {Hepatic insulin resistance is a major contributor to hyperglycemia in metabolic syndrome and type II diabetes. It is caused in part by the low-grade inflammation that accompanies both diseases, leading to elevated local and circulating levels of cytokines and cyclooxygenase (COX) products such as prostaglandin E-2 (PGE(2)). In a recent study, PGE(2) produced in Kupffer cells attenuated insulin-dependent glucose utilization by interrupting the intracellular signal chain downstream of the insulin receptor in hepatocytes. In addition to directly affecting insulin signaling in hepatocytes, PGE(2) in the liver might affect insulin resistance by modulating cytokine production in non-parenchymal cells. In accordance with this hypothesis, PGE(2) stimulated oncostatin M (OSM) production by Kupffer cells. OSM in turn attenuated insulin-dependent Akt activation and, as a downstream target, glucokinase induction in hepatocytes, most likely by inducing suppressor of cytokine signaling 3 (SOCS3). In addition, it inhibited the expression of key enzymes of hepatic lipid metabolism. COX-2 and OSM mRNA were induced early in the course of the development of non-alcoholic steatohepatitis (NASH) in mice. Thus, induction of OSM production in Kupffer cells by an autocrine PGE(2)-dependent feed-forward loop may be an additional, thus far unrecognized, mechanism contributing to hepatic insulin resistance and the development of NASH.}, language = {en} } @article{PilzParolaiStupazzinietal.2011, author = {Pilz, Marco and Parolai, Stefano and Stupazzini, Marco and Paolucci, Roberto and Zschau, Jochen}, title = {Modelling basin effects on earthquake ground motion in the Santiago de Chile basin by a spectral element code}, series = {Geophysical journal international}, volume = {187}, journal = {Geophysical journal international}, number = {2}, publisher = {Wiley-Blackwell}, address = {Malden}, issn = {0956-540X}, doi = {10.1111/j.1365-246X.2011.05183.x}, pages = {929 -- 945}, year = {2011}, abstract = {Simulations of strong ground motion within the Santiago de Chile Metropolitan area were carried out by means of 3-D deterministic wave propagation tool based on the spectral element method. The simulated events take into account the pronounced interface between the low-velocity sedimentary basin and the bedrock as well as topography of the area. To verify our model we simulated a regional earthquake recorded by a dense network installed in the city of Santiago for recording aftershock activity after the 2010 February 27 Maule main shock. The results proof the alluvial basin amplification effects and show a strong dependence of spectral amplification in the basin on the local site conditions. Moreover, we studied the seismic response due to a hypothetical M(w) = 6.0 event occurring along the active San Ramon Fault, which is crossing the eastern edge of the city. The scenario earthquakes exhibit that an unfavourable interaction between fault rupture, radiation mechanism and complex geological and topographic conditions in the near-field region may give rise to large values of peak ground velocity in the basin. Finally, 3-D numerical predictions of ground motion are compared with the one computed according to ground motion prediction equations selected among the next generation attenuation relationships, in terms of ground motion peak values and spectral acceleration. The comparison underlines that the 3-D scenario simulations predict a significantly higher level of ground motion in the Santiago basin, especially over deep alluvial deposits. Moreover, also the location of the rupture nucleation largely influences the observed shaking pattern.}, language = {en} } @article{PilzParolaiPicozzietal.2011, author = {Pilz, Marco and Parolai, Stefano and Picozzi, Matteo and Zschau, Jochen}, title = {Evaluation of proxies for seismic site conditions in large urban areas the example of Santiago de Chile}, series = {Physics and chemistry of the earth}, volume = {36}, journal = {Physics and chemistry of the earth}, number = {16}, publisher = {Elsevier}, address = {Oxford}, issn = {1474-7065}, doi = {10.1016/j.pce.2011.01.007}, pages = {1259 -- 1266}, year = {2011}, abstract = {Characterizing the local site response in large cities is an important step towards seismic hazard assessment. To this regard, single station seismic noise measurements were carried out at 146 sites in the northern part of Santiago de Chile. This extensive survey allowed the fundamental resonance frequency of the sedimentary cover, derived from horizontal-to-vertical (H/V) spectral ratios, to be mapped. By inverting the spectral ratios under the constraint of the thickness of the sedimentary cover, known from previous gravimetric measurements, local S-wave velocity profiles have been retrieved. After interpolation between the individual profiles, the resulting high resolution 3D S-wave velocity model allows the entire area, as well as deeper parts of the basin, to be represented in great detail. Since one lithology shows a great scatter in the velocity values only a very general correlation between S-wave velocity in the uppermost 30 m (v(s)(30)) and local geology is found. Local S-wave velocity profiles can serve as a key factor in seismic hazard assessment, since they allow an estimate of the amplification potential of the sedimentary cover. Mapping the intensity distribution of the 27 February 2010 Maule, Chile, event (Mw = 8.8) the results indicate that local amplification of the ground motion might partially explain the damage distribution and encourage the use of the low cost seismic noise techniques for the study of seismic site effects.}, language = {en} } @article{Schmidt2011, author = {Schmidt, Markus G.}, title = {Reform of the United Nations Human Rights Programs}, series = {Die Vereinten Nationen vor globalen Herausforderungen : Referate der Potsdamer UNO-Konferenzen 2000-2008}, journal = {Die Vereinten Nationen vor globalen Herausforderungen : Referate der Potsdamer UNO-Konferenzen 2000-2008}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-60964}, pages = {81 -- 93}, year = {2011}, abstract = {Inhalt: - Kurzzusammenfassung - I. Introduction - II. Current challenges to the United Nations Human Rights Programme - III. The Secretary General's Reform report "In larger Freedom" and its impact for the human rights programme - IV. The High Commissioner's Plan of Action of May 2005 - V. Negotiations on the establishment of the Human Rights Council and first Council activities - VI. Reform of the treaty body system and debates over the creation of a unified standing treaty body}, language = {en} } @book{Luebbe2011, author = {L{\"u}bbe, Alexander}, title = {The effect of tangible media on individuals in business process modeling : a controlled experiment = Der Einfluss greifbarer Medien auf einzelne Personen bei der Gesch{\"a}ftsprozessmodellierung : ein kontrolliertes Experiment}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-108-0}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-49001}, publisher = {Universit{\"a}t Potsdam}, pages = {42}, year = {2011}, abstract = {In current practice, business processes modeling is done by trained method experts. Domain experts are interviewed to elicit their process information but not involved in modeling. We created a haptic toolkit for process modeling that can be used in process elicitation sessions with domain experts. We hypothesize that this leads to more effective process elicitation. This paper brakes down "effective elicitation" to 14 operationalized hypotheses. They are assessed in a controlled experiment using questionnaires, process model feedback tests and video analysis. The experiment compares our approach to structured interviews in a repeated measurement design. We executed the experiment with 17 student clerks from a trade school. They represent potential users of the tool. Six out of fourteen hypotheses showed significant difference due to the method applied. Subjects reported more fun and more insights into process modeling with tangible media. Video analysis showed significantly more reviews and corrections applied during process elicitation. Moreover, people take more time to talk and think about their processes. We conclude that tangible media creates a different working mode for people in process elicitation with fun, new insights and instant feedback on preliminary results.}, language = {en} } @book{Huber2011, author = {Huber, Stefan}, title = {Citizens participation in Latvia : still a long road to go?}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-49715}, publisher = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {On the 20.01.1991 the Latvian people defended the Latvian political elite from the Soviet OMON troops in order to achieve independence. After this impressive sign of civil society the people fell asleep, the level of mobility and the satisfaction with the functioning of democracy therefore is rather weak. The referendum (2008), to gain the right to dissolve the Parliament by the people, initiated by the Trade Unions can be assessed as a sign that there is something on the move. This paper is trying to give an impression of the situation of the civil society in terms of participation in the decision- making process. Hereby the focus lays on NGOs: What is the legal base and which problems do they face. To learn more about the situation interviews were organized with representatives of NGOs from different sectors like community development; Social inclusion; advocating gender issues as well as environment and sustainable development. As a result of the research it can be said that the civil society made some steps forward but it is still struggling with a high level of corruption, lack of interested from the elite and the ordinary people and the insecure financial state.}, language = {en} } @article{Grubic2011, author = {Grubic, Mira}, title = {Ngizim fieldnotes}, series = {Interdisciplinary studies on information structure : ISIS ; working papers of the SFB 632}, journal = {Interdisciplinary studies on information structure : ISIS ; working papers of the SFB 632}, number = {13}, issn = {1614-4708}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-49738}, pages = {1 -- 76}, year = {2011}, abstract = {This chapter presents field notes of the West Chadic language Ngizim, spoken in North-East Nigeria. In Ngizim, subject focus is indicated by subject inversion, whereas the word order of sentences with focused non-subjects can remain unchanged. The goal of the field work was to find out more about focus marking in Ngizim.}, language = {en} } @article{GenzelKuegler2011, author = {Genzel, Susanne and K{\"u}gler, Frank}, title = {How to elicit semi-spontaneous focus realizations with specific tonal patterns}, series = {Interdisciplinary studies on information structure : ISIS ; working papers of the SFB 632}, journal = {Interdisciplinary studies on information structure : ISIS ; working papers of the SFB 632}, number = {13}, issn = {1614-4708}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-49749}, pages = {77 -- 102}, year = {2011}, abstract = {This article presents a situation description production experiment investigating the interaction between syntax and information structure in Akan, a tone language that belongs to the Kwa branch of the Niger- Congo family spoken in Ghana. Information structure was elicited via context questions that put the object in narrow informational focus or narrow corrective focus while controlling for the tonal structure of the target word. Contrary to the prediction that corrective focus is marked by fronting and morphological marking of the focused constituent the data suggest that the in-situ strategy is the preferred one.}, language = {en} } @article{WagnerAntunesRistowetal.2011, author = {Wagner, Viktoria and Antunes, Pedro M. and Ristow, Michael and Lechner, Ute and Hensen, Isabell}, title = {Prevailing negative soil biota effect and no evidence for local adaptation in a widespread eurasian grass}, series = {PLoS one}, volume = {6}, journal = {PLoS one}, number = {3}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0017580}, pages = {8}, year = {2011}, abstract = {Background: Soil biota effects are increasingly accepted as an important driver of the abundance and distribution of plants. While biogeographical studies on alien invasive plant species have indicated coevolution with soil biota in their native distribution range, it is unknown whether adaptation to soil biota varies among populations within the native distribution range. The question of local adaptation between plants and their soil biota has important implications for conservation of biodiversity and may justify the use of seed material from local provenances in restoration campaigns. Methodology/Principal Findings: We studied soil biota effects in ten populations of the steppe grass Stipa capillata from two distinct regions, Europe and Asia. We tested for local adaptation at two different scales, both within (ca. 10-80 km) and between (ca. 3300 km) regions, using a reciprocal inoculation experiment in the greenhouse for nine months. Generally, negative soil biota effects were consistent. However, we did not find evidence for local adaptation: both within and between regions, growth of plants in their 'home soil' was not significantly larger relative to that in soil from other, more distant, populations. Conclusions/Significance: Our study suggests that negative soil biota effects can prevail in different parts of a plant species' range. Absence of local adaptation points to the possibility of similar rhizosphere biota composition across populations and regions, sufficient gene flow to prevent coevolution, selection in favor of plasticity, or functional redundancy among different soil biota. From the point of view of plant - soil biota interactions, our findings indicate that the current practice of using seeds exclusively from local provenances in ecosystem restoration campaigns may not be justified.}, language = {en} } @article{LauterbachRistowGemeinholzer2011, author = {Lauterbach, Dirk and Ristow, Michael and Gemeinholzer, B.}, title = {Genetic population structure, fitness variation and the importance of population history in remnant populations of the endangered plant Silene chlorantha (Willd.) Ehrh. (Caryophyllaceae)}, series = {Plant biology}, volume = {13}, journal = {Plant biology}, number = {4}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {1435-8603}, doi = {10.1111/j.1438-8677.2010.00418.x}, pages = {667 -- 677}, year = {2011}, abstract = {Habitat fragmentation can lead to a decline of genetic diversity, a potential risk for the survival of natural populations. Fragmented populations can become highly differentiated due to reduced gene flow and genetic drift. A decline in number of individuals can result in lower reproductive fitness due to inbreeding effects. We investigated genetic variation within and between 11 populations of the rare and endangered plant Silene chlorantha in northeastern Germany to support conservation strategies. Genetic diversity was evaluated using AFLP techniques and the results were correlated to fitness traits. Fitness evaluation in nature and in a common garden approach was conducted. Our analysis revealed population differentiation was high and within population genetic diversity was intermediate. A clear population structure was supported by a Bayesian approach, AMOVA and neighbour-joining analysis. No correlation between genetic and geographic distance was found. Our results indicate that patterns of population differentiation were mainly caused by temporal and/or spatial isolation and genetic drift. The fitness evaluation revealed that pollinator limitation and habitat quality seem, at present, to be more important to reproductive fitness than genetic diversity by itself. Populations of S. chlorantha with low genetic diversity have the potential to increase in individual number if habitat conditions improve. This was detected in a single large population in the investigation area, which was formerly affected by bottleneck effects.}, language = {en} } @misc{FranselowSchlesewskyVogeletal.2011, author = {Franselow, Gisbert and Schlesewsky, Matthias and Vogel, Ralf and Weskott, Thomas}, title = {Animacy effects on crossing wh-movement in German}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-93630}, pages = {657 -- 683}, year = {2011}, abstract = {This article presents several acceptability rating experiments concerned with crossing wh-movement in German multiple questions. Our results show that there is no general superiority effect in German, thus refuting claims to the contrary by Featherston (2005). However, acceptability is reduced when a whphrase crosses a wh-subject with which it agrees in animacy. We explain this finding in terms of the availability of different sorting keys for the answers to the multiple questions.}, language = {en} } @phdthesis{Wist2011, author = {Wist, Dominic}, title = {Attacking complexity in logic synthesis of asynchronous circuits}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-59706}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {Most of the microelectronic circuits fabricated today are synchronous, i.e. they are driven by one or several clock signals. Synchronous circuit design faces several fundamental challenges such as high-speed clock distribution, integration of multiple cores operating at different clock rates, reduction of power consumption and dealing with voltage, temperature, manufacturing and runtime variations. Asynchronous or clockless design plays a key role in alleviating these challenges, however the design and test of asynchronous circuits is much more difficult in comparison to their synchronous counterparts. A driving force for a widespread use of asynchronous technology is the availability of mature EDA (Electronic Design Automation) tools which provide an entire automated design flow starting from an HDL (Hardware Description Language) specification yielding the final circuit layout. Even though there was much progress in developing such EDA tools for asynchronous circuit design during the last two decades, the maturity level as well as the acceptance of them is still not comparable with tools for synchronous circuit design. In particular, logic synthesis (which implies the application of Boolean minimisation techniques) for the entire system's control path can significantly improve the efficiency of the resulting asynchronous implementation, e.g. in terms of chip area and performance. However, logic synthesis, in particular for asynchronous circuits, suffers from complexity problems. Signal Transitions Graphs (STGs) are labelled Petri nets which are a widely used to specify the interface behaviour of speed independent (SI) circuits - a robust subclass of asynchronous circuits. STG decomposition is a promising approach to tackle complexity problems like state space explosion in logic synthesis of SI circuits. The (structural) decomposition of STGs is guided by a partition of the output signals and generates a usually much smaller component STG for each partition member, i.e. a component STG with a much smaller state space than the initial specification. However, decomposition can result in component STGs that in isolation have so-called irreducible CSC conflicts (i.e. these components are not SI synthesisable anymore) even if the specification has none of them. A new approach is presented to avoid such conflicts by introducing internal communication between the components. So far, STG decompositions are guided by the finest output partitions, i.e. one output per component. However, this might not yield optimal circuit implementations. Efficient heuristics are presented to determine coarser partitions leading to improved circuits in terms of chip area. For the new algorithms correctness proofs are given and their implementations are incorporated into the decomposition tool DESIJ. The presented techniques are successfully applied to some benchmarks - including 'real-life' specifications arising in the context of control resynthesis - which delivered promising results.}, language = {en} } @techreport{Burdack2011, type = {Working Paper}, author = {Burdack, Doreen}, title = {The economic impact of water restrictions on water-dependent business in South East Queensland, Australia}, series = {Finanzwissenschaftliche Diskussionsbeitr{\"a}ge}, journal = {Finanzwissenschaftliche Diskussionsbeitr{\"a}ge}, number = {65}, issn = {1864-1431}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-55947}, pages = {82}, year = {2011}, language = {en} } @article{BalderjahnOloko2011, author = {Balderjahn, Ingo and Oloko, Shamsey}, title = {On the Moral Value of Cause related Marketing}, series = {Marketing : ZFP}, volume = {33}, journal = {Marketing : ZFP}, number = {2}, publisher = {C. H. Beck}, address = {M{\"u}nchen}, issn = {0344-1369}, pages = {159 -- 170}, year = {2011}, language = {en} } @phdthesis{Hainzl2011, author = {Hainzl, Sebastian}, title = {Earthquake triggering and interaction}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-50095}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {Earthquake faults interact with each other in many different ways and hence earthquakes cannot be treated as individual independent events. Although earthquake interactions generally lead to a complex evolution of the crustal stress field, it does not necessarily mean that the earthquake occurrence becomes random and completely unpredictable. In particular, the interplay between earthquakes can rather explain the occurrence of pronounced characteristics such as periods of accelerated and depressed seismicity (seismic quiescence) as well as spatiotemporal earthquake clustering (swarms and aftershock sequences). Ignoring the time-dependence of the process by looking at time-averaged values - as largely done in standard procedures of seismic hazard assessment - can thus lead to erroneous estimations not only of the activity level of future earthquakes but also of their spatial distribution. Therefore, it exists an urgent need for applicable time-dependent models. In my work, I aimed at better understanding and characterization of the earthquake interactions in order to improve seismic hazard estimations. For this purpose, I studied seismicity patterns on spatial scales ranging from hydraulic fracture experiments (meter to kilometer) to fault system size (hundreds of kilometers), while the temporal scale of interest varied from the immediate aftershock activity (minutes to months) to seismic cycles (tens to thousands of years). My studies revealed a number of new characteristics of fluid-induced and stress-triggered earthquake clustering as well as precursory phenomena in earthquake cycles. Data analysis of earthquake and deformation data were accompanied by statistical and physics-based model simulations which allow a better understanding of the role of structural heterogeneities, stress changes, afterslip and fluid flow. Finally, new strategies and methods have been developed and tested which help to improve seismic hazard estimations by taking the time-dependence of the earthquake process appropriately into account.}, language = {en} } @incollection{PetersenMuellerHuetheretal.2011, author = {Petersen, Hans-Georg and M{\"u}ller, Klaus and H{\"u}ther, Michael and Sowada, Christoph and Christev, Atanas and FitzRoy, Felix}, title = {Taxes, transfers, economic efficiency and social justice : essays on public economics 1979 - 2009. - Chapter 4: Economics of transformation}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-50400}, publisher = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {This volume contains the articles and papers which predominately have been published in international journals or edited volumes in the period from 1979 to 2009. The single articles reflect the main research areas of the editor and his co-authors who were engaged at the Kiel Institute of World Economics, the Johannes-Kepler-University Linz/Austria, the Justus- Liebig-University Giessen, the University of Potsdam, and the German Institute for Economic Research (DIW Berlin).}, language = {en} } @incollection{PetersenBrunner2011, author = {Petersen, Hans-Georg and Brunner, Johann K.}, title = {Taxes, transfers, economic efficiency and social justice : essays on public economics 1979 - 2009. - Chapter 3: Impact of taxation and tax reform}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-50395}, publisher = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {This volume contains the articles and papers which predominately have been published in international journals or edited volumes in the period from 1979 to 2009. The single articles reflect the main research areas of the editor and his co-authors who were engaged at the Kiel Institute of World Economics, the Johannes-Kepler-University Linz/Austria, the Justus- Liebig-University Giessen, the University of Potsdam, and the German Institute for Economic Research (DIW Berlin).}, language = {en} } @incollection{PetersenHinterbergerMueller2011, author = {Petersen, Hans-Georg and Hinterberger, Friedrich and M{\"u}ller, Klaus}, title = {Taxes, transfers, economic efficiency and social justice : essays on public economics 1979 - 2009. - Chapter 1: Redistribution - theory and measurement}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-50379}, publisher = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {This volume contains the articles and papers which predominately have been published in international journals or edited volumes in the period from 1979 to 2009. The single articles reflect the main research areas of the editor and his co-authors who were engaged at the Kiel Institute of World Economics, the Johannes-Kepler-University Linz/Austria, the Justus- Liebig-University Giessen, the University of Potsdam, and the German Institute for Economic Research (DIW Berlin).}, language = {en} } @unpublished{Murr2011, author = {Murr, R{\"u}diger}, title = {Characterization of L{\´e}vy Processes by a duality formula and related results}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-43538}, year = {2011}, abstract = {Processes with independent increments are characterized via a duality formula, including Malliavin derivative and difference operators. This result is based on a characterization of infinitely divisible random vectors by a functional equation. A construction of the difference operator by a variational method is introduced and compared to approaches used by other authors for L´evy processes involving the chaos decomposition. Finally we extend our method to characterize infinitely divisible random measures.}, language = {en} } @article{Aarseth2011, author = {Aarseth, Espen}, title = {Define real, Moron!}, series = {DIGAREC Series}, journal = {DIGAREC Series}, number = {6}, issn = {1867-6219}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-49810}, pages = {50 -- 69}, year = {2011}, abstract = {Academic language should not be a ghetto dialect at odds with ordinary language, but rather an extension that is compatible with lay-language. To define 'game' with the unrealistic ambition of satisfying both lay-people and experts should not be a major concern for a game ontology, since the field it addresses is subject to cultural evolution and diachronic change. Instead of the impossible mission of turning the common word into an analytic concept, a useful task for an ontology of games is to model game differences, to show how the things we call games can be different from each other in a number of different ways.}, language = {en} } @unpublished{MeleardRoelly2011, author = {M{\´e}l{\´e}ard, Sylvie and Roelly, Sylvie}, title = {A host-parasite multilevel interacting process and continuous approximations}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-51694}, year = {2011}, abstract = {We are interested in modeling some two-level population dynamics, resulting from the interplay of ecological interactions and phenotypic variation of individuals (or hosts) and the evolution of cells (or parasites) of two types living in these individuals. The ecological parameters of the individual dynamics depend on the number of cells of each type contained by the individual and the cell dynamics depends on the trait of the invaded individual. Our models are rooted in the microscopic description of a random (discrete) population of individuals characterized by one or several adaptive traits and cells characterized by their type. The population is modeled as a stochastic point process whose generator captures the probabilistic dynamics over continuous time of birth, mutation and death for individuals and birth and death for cells. The interaction between individuals (resp. between cells) is described by a competition between individual traits (resp. between cell types). We look for tractable large population approximations. By combining various scalings on population size, birth and death rates and mutation step, the single microscopic model is shown to lead to contrasting nonlinear macroscopic limits of different nature: deterministic approximations, in the form of ordinary, integro- or partial differential equations, or probabilistic ones, like stochastic partial differential equations or superprocesses. The study of the long time behavior of these processes seems very hard and we only develop some simple cases enlightening the difficulties involved.}, language = {en} } @article{Baraldi2011, author = {Baraldi, Luca}, title = {Immobile Tremor}, series = {PaRDeS : Zeitschrift der Vereinigung f{\"u}r J{\"u}dische Studien e.V.}, journal = {PaRDeS : Zeitschrift der Vereinigung f{\"u}r J{\"u}dische Studien e.V.}, number = {17}, issn = {1614-6492}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-53255}, pages = {71 -- 95}, year = {2011}, abstract = {The threshold between the XVth and the XVIth Century represents a historical period during which, both for Christians and for Jews, the geopolitical sceneries and the interior horizons radically change. The modified reality provokes new forms of expectation and the need of new historical interpretations. Ferrara, within this scenery, can be considered, as other Italian cases, as a paradigmatic example, a narrow space where phenomena of spiritual and cultural Jewish rebirth can take shape. The permeability between Christian artistic and cultural world and Jewish intellectual production determines a prosperous context, further strengthened by the introduction of Jewish typography and by a growing claim and restoration of social elective dignity among the Jews of the Este Duchy. After the transfer of the capital city from Ferrara to Modena, the indirect effects of this intellectual resurgence are deeply transformed on a social level, and allows us to catch the persistence of important forms of communication between Christians and Jews in everyday life. The introduction of the Inquisition provides us, through the production of the judicial archive, with the most important instrument to understand social dynamics, which allows us to comprehend a new potential interpretation key for the reality of the ghetto and the choice of its erection. The urban division is nothing else but a new attempt to separate the invisible spaces of the thought. The effective efficacy of the physical separation shows several weak points, which persist during the entire life of the ghetto, since 1638 until 1789.}, language = {en} } @article{AlbeckGidron2011, author = {Albeck-Gidron, Rachel}, title = {The Holocaust as a Changing Presence in Yoel Hoffmann's Texts}, series = {PaRDeS : Zeitschrift der Vereinigung f{\"u}r J{\"u}dische Studien e.V.}, journal = {PaRDeS : Zeitschrift der Vereinigung f{\"u}r J{\"u}dische Studien e.V.}, number = {17}, issn = {1614-6492}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-53307}, pages = {175 -- 207}, year = {2011}, abstract = {Yoel Hoffmann is an Israeli writer born in 1937 in Brasov (Kronstadt), Romania. Brought up in a German-speaking family, already in his first book, Sefer Yosef (1989), he conveys the voice of German-speaking immigrants in Israel (the "Katschen" story, 1986) and that of the East European Jewish community in Berlin in the late 1930s, on the verge of the Second World War. His works are crammed with characters of Jews from Germany gripped by the memory of the language they abandoned following their emigration to Palestine in the 1930s. The classic one is the character of Bernhard, in the eponymous work. The current article focuses on the representation and elaboration of Hoffmann's unique creation, in a language influenced by his deep identification with Zen Buddhism on the one hand, and his attraction to the modernist, Western style of stream of consciousness on the other. In central sections of his works, Hoffman presents his entire literary corpus as a type of explicit, allusive, or secret Holocaust literature, and invites his readers and his critics to decode the allusions and expose the secret in this theme, a surprising statement in relation to Hoffmann's work and its analysis so far. Hoffmann represents the Holocaust as a collective Israeli trauma for which his literary fiction creates a special catalogue of representative characters. In the creation of a catalogue, and particularly one that simultaneously classifies and individualizes, Hoffmann's project resembles the monumental 1920s cataloguing project by the celebrated German photographer August Sander (Menschen des 20. Jahrhunderts). Hoffmann included photographs from this project in his works, and even chose some of them for the covers of his books. The article examines the implicit relationships between these two creative artists as conferring a meaning so far not considered in the research of the Holocaust theme in Yoel Hoffmann's writings.}, language = {en} }