@phdthesis{ValverdeSerrano2011, author = {Valverde Serrano, Clara}, title = {Self-assembly behavior in hydrophilic block copolymers}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-54163}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {Block copolymers are receiving increasing attention in the literature. Reports on amphiphilic block copolymers have now established the basis of their self-assembly behavior: aggregate sizes, morphologies and stability can be explained from the absolute and relative block lengths, the nature of the blocks, the architecture and also solvent selectiveness. In water, self-assembly of amphiphilic block copolymers is assumed to be driven by the hydrophobic. The motivation of this thesis is to study the influence on the self-assembly in water of A b B type block copolymers (with A hydrophilic) of the variation of the hydrophilicity of B from non-soluble (hydrophobic) to totally soluble (hydrophilic). Glucose-modified polybutadiene-block-poly(N-isopropylacrylamide) copolymers were prepared and their self-assembly behavior in water studied. The copolymers formed vesicles with an asymmetric membrane with a glycosylated exterior and poly(N-isopropylacrylamide) on the inside. Above the low critical solution temperature (LCST) of poly(N-isopropylacrylamide), the structure collapsed into micelles with a hydrophobic PNIPAM core and glycosylated exterior. This collapse was found to be reversible. As a result, the structures showed a temperature-dependent interaction with L-lectin proteins and were shown to be able to encapsulate organic molecules. Several families of double hydrophilic block copolymers (DHBC) were prepared. The blocks of these copolymers were biopolymers or polymer chimeras used in aqueous two-phase partition systems. Copolymers based on dextran and poly(ethylene glycol) blocks were able to form aggregates in water. Dex6500-b-PEG5500 copolymer spontaneously formed vesicles with PEG as the "less hydrophilic" barrier and dextran as the solubilizing block. The aggregates were found to be insensitive to the polymer's architecture and concentration (in the dilute range) and only mildly sensitive to temperature. Variation of the block length, yielded different morphologies. A longer PEG chain seemed to promote more curved aggregates following the inverse trend usually observed in amphiphilic block copolymers. A shorter dextran promoted vesicular structures as usually observed for the amphiphilic counterparts. The linking function was shown to have an influence of the morphology but not on the self-assembly capability in itself. The vesicles formed by dex6500-b-PEG5500 showed slow kinetics of clustering in the presence of Con A lectin. In addition both dex6500-b-PEG5500 and its crosslinked derivative were able to encapsulate fluorescent dyes. Two additional dextran-based copolymers were synthesized, dextran-b-poly(vinyl alcohol) and dextran-b-poly(vinyl pyrrolidone). The study of their self-assembly allowed to conclude that aqueous two-phase systems (ATPS) is a valid source of inspiration to conceive DHBCs capable of self-assembling. In the second part the principle was extended to polypeptide systems with the synthesis of a poly(N-hydroxyethylglutamine)-block-poly(ethylene glycol) copolymer. The copolymer that had been previously reported to have emulsifying properties was able to form vesicles by direct dissolution of the solid in water. Last, a series of thermoresponsive copolymers were prepared, dextran-b-PNIPAMm. These polymers formed aggregates below the LCST. Their structure could not be unambiguously elucidated but seemed to correspond to vesicles. Above the LCST, the collapse of the PNIPAM chains induced the formation of stable objects of several hundreds of nanometers in radius that evolved with increasing temperature. The cooling of these solution below LCST restored the initial aggregates. This self-assembly of DHBC outside any stimuli of pH, ionic strength, or temperature has only rarely been described in the literature. This work constituted the first formal attempt to frame the phenomenon. Two reasons were accounted for the self-assembly of such systems: incompatibility of the polymer pairs forming the two blocks (enthalpic) and a considerable solubility difference (enthalpic and entropic). The entropic contribution to the positive Gibbs free energy of mixing is believed to arise from the same loss of conformational entropy that is responsible for "the hydrophobic effect" but driven by a competition for water of the two blocks. In that sense this phenomenon should be described as the "hydrophilic effect".}, language = {en} } @article{VallerianiZhangNagaretal.2011, author = {Valleriani, Angelo and Zhang, Gong and Nagar, Apoorva and Ignatova, Zoya and Lipowsky, Reinhard}, title = {Length-dependent translation of messenger RNA by ribosomes}, series = {Physical review : E, Statistical, nonlinear and soft matter physics}, volume = {83}, journal = {Physical review : E, Statistical, nonlinear and soft matter physics}, number = {4}, publisher = {American Physical Society}, address = {College Park}, issn = {1539-3755}, doi = {10.1103/PhysRevE.83.042903}, pages = {4}, year = {2011}, abstract = {A simple measure for the efficiency of protein synthesis by ribosomes is provided by the steady state amount of protein per messenger RNA (mRNA), the so-called translational ratio, which is proportional to the translation rate. Taking the degradation of mRNA into account, we show theoretically that both the translation rate and the translational ratio decrease with increasing mRNA length, in agreement with available experimental data for the prokaryote Escherichia coli. We also show that, compared to prokaryotes, mRNA degradation in eukaryotes leads to a less rapid decrease of the translational ratio. This finding is consistent with the fact that, compared to prokaryotes, eukaryotes tend to have longer proteins.}, language = {en} } @article{ValdiviaOrozco2011, author = {Valdivia Orozco, Pablo Emilio}, title = {Configuraciones del convivir: algunos apuntes sobre el cruce teorico de la novela y el Caribe}, isbn = {978-3-938944-54-7}, year = {2011}, language = {es} } @article{UtechtKlamrothSaalfrank2011, author = {Utecht, Manuel Martin and Klamroth, Tillmann and Saalfrank, Peter}, title = {Optical absorption and excitonic coupling in azobenzenes forming self-assembled monolayers a study based on density functional theory}, series = {Physical chemistry, chemical physics : a journal of European Chemical Societies}, volume = {13}, journal = {Physical chemistry, chemical physics : a journal of European Chemical Societies}, number = {48}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1463-9076}, doi = {10.1039/c1cp22793a}, pages = {21608 -- 21614}, year = {2011}, abstract = {Based on the analysis of optical absorption spectra, it has recently been speculated that the excitonic coupling between individual azobenzene-functionalized alkanethiols arranged in a self-assembled monolayer (SAM) on a gold surface could be strong enough to hinder collective trans-cis isomerization-on top of steric hindrance [Gahl et al., J. Am. Chem. Soc., 2010, 132, 1831]. Using models of SAMs of increasing complexity (dimer, linear N-mers, and two-dimensionally arranged N-mers) and density functional theory on the (TD-) B3LYP/6-31G* level, we determine optical absorption spectra, the nature and magnitude of excitonic couplings, and the corresponding spectral shifts. It is found that at inter-monomer distances of about 20 angstrom and above, TD-B3LYP excitation frequencies (and signal intensities) can be well described by the frequently used point-dipole approximation. Further, calculated blue shifts in optical absorption spectra account for the experimental observations made for azobenzene/gold SAMs, and hint to the fact that they can indeed be responsible for reduced switching probability in densely packed self-assembled structures.}, language = {en} } @phdthesis{Urieta2011, author = {Urieta, Kristin}, title = {Kinder in schwierigen {\"U}bergangssituationen vom Elementar- zum Prim{\"a}rbereich : eine biografieanalytische Studie}, publisher = {Curach Bh{\´a}n Publ}, address = {Berlin}, isbn = {978-3-942002-01-1}, pages = {235 S.}, year = {2011}, language = {de} } @phdthesis{Unterlass2011, author = {Unterlass, Miriam Margarethe}, title = {From monomer salts and their tectonic crystals to aromatic polyimides : development of neoteric synthesis routes}, address = {Potsdam}, pages = {147 S.}, year = {2011}, language = {en} } @phdthesis{Ulrich2011, author = {Ulrich, Mathias}, title = {Permafrost landform studies on Earth : Implications for periglacial landscape evolution and habitability on Mars}, address = {Potsdam}, pages = {VIII, 160 S.}, year = {2011}, language = {en} } @misc{Ulmer2011, author = {Ulmer, Martin}, title = {Stefan Lang, Ausgrenzung und Koexistenz : Judenpolitik und j{\"u}disches Leben in W{\"u}rttemberg und im ‚Land zu Schwaben' (1492-1650). - (Schriften zur s{\"u}dwestdeutschen Landeskunde ; 63) / [rezensiert von] Martin Ulmer}, 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-53474}, pages = {258 -- 260}, year = {2011}, abstract = {rezensiertes Werk: Lang, Stefan: Ausgrenzung und Koexistenz : Judenpolitik und j{\"u}disches Leben in W{\"u}rttemberg und im ‚Land zu Schwaben' (1492-1650). - Ostfildern : Thorbecke Verlag, 2008. - 432 S.. - (Schriften zur s{\"u}dwestdeutschen Landeskunde ; 63) ISBN 978-3-799-55263-9}, language = {de} } @article{UflackerKowarkZeier2011, author = {Uflacker, Matthias and Kowark, Thomas and Zeier, Alexander}, title = {An instrument for real-time design interaction capture}, isbn = {978-3-642-13756-3}, year = {2011}, language = {en} } @article{Uffelmann2011, author = {Uffelmann, Dirk}, title = {Die Mobilisierung subalternen Sprechens}, series = {Mobilisierte Kulturen}, journal = {Mobilisierte Kulturen}, number = {1}, issn = {2192-3019}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57454}, pages = {377 -- 392}, year = {2011}, language = {de} } @misc{Toennies2011, author = {T{\"o}nnies, Sibylle}, title = {Neumann, F., Behemoth, Struktur und Praxis des Nationalsozialismus 1933 - 1944; Frankfurt am Main, Fischer, 2004}, isbn = {978-3-941880-21-4}, year = {2011}, language = {de} } @article{Toennies2011, author = {T{\"o}nnies, Sibylle}, title = {Ganz oder gar nicht!}, series = {WeltTrends-Papiere}, journal = {WeltTrends-Papiere}, number = {16}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1864-0656}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-63313}, pages = {71 -- 76}, year = {2011}, abstract = {Inhalt: Der Nomos der Erde ; Die Moralisierung des V{\"o}lkerrechts ; Weltgesetz ohne Weltexekutive ; „Police Bombing"}, language = {de} } @article{Toennies2011, author = {T{\"o}nnies, Sibylle}, title = {Von allem ein bisschen, keine Bewegung?}, series = {WeltTrends-Papiere}, journal = {WeltTrends-Papiere}, number = {16}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1864-0656}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-63374}, pages = {87 -- 89}, year = {2011}, language = {de} } @phdthesis{Taeger2011, author = {T{\"a}ger, Philipp}, title = {Der Schutz von Menschenrechten im internationalen Investionsrecht : unter besondere Beachtung der Rechte und Pflichten des Exportstaates}, series = {Studien zum internationalen Wirtschaftsrecht}, volume = {4}, journal = {Studien zum internationalen Wirtschaftsrecht}, publisher = {Nomos}, address = {Baden-Baden}, isbn = {978-3-8329-6731-4}, pages = {356 S.}, year = {2011}, language = {de} } @article{TurukinaPikovskij2011, author = {Turukina, L. V. and Pikovskij, Arkadij}, title = {Hyperbolic chaos in a system of resonantly coupled weakly nonlinear oscillators}, series = {Modern physics letters : A, Particles and fields, gravitation, cosmology, nuclear physics}, volume = {375}, journal = {Modern physics letters : A, Particles and fields, gravitation, cosmology, nuclear physics}, number = {11}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0375-9601}, doi = {10.1016/j.physleta.2011.02.017}, pages = {1407 -- 1411}, year = {2011}, abstract = {We show that a hyperbolic chaos can be observed in resonantly coupled oscillators near a Hopf bifurcation, described by normal-form-type equations for complex amplitudes. The simplest example consists of four oscillators, comprising two alternatively activated, due to an external periodic modulation, pairs. In terms of the stroboscopic Poincare map, the phase differences change according to an expanding Bernoulli map that depends on the coupling type. Several examples of hyperbolic chaos for different types of coupling are illustrated numerically.}, language = {en} } @article{TurnerPingelSteyrleuthneretal.2011, author = {Turner, Sarah T. and Pingel, Patrick and Steyrleuthner, Robert and Crossland, Edward J. W. and Ludwigs, Sabine and Neher, Dieter}, title = {Quantitative analysis of bulk heterojunction films using linear absorption spectroscopy and solar cell performance}, series = {Advanced functional materials}, volume = {21}, journal = {Advanced functional materials}, number = {24}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1616-301X}, doi = {10.1002/adfm.201101583}, pages = {4640 -- 4652}, year = {2011}, abstract = {A fundamental understanding of the relationship between the bulk morphology and device performance is required for the further development of bulk heterojunction organic solar cells. Here, non-optimized (chloroform cast) and nearly optimized (solvent-annealed o-dichlorobenzene cast) P3HT:PCBM blend films treated over a range of annealing temperatures are studied via optical and photovoltaic device measurements. Parameters related to the P3HT aggregate morphology in the blend are obtained through a recently established analytical model developed by F. C. Spano for the absorption of weakly interacting H-aggregates. Thermally induced changes are related to the glass transition range of the blend. In the chloroform prepared devices, the improvement in device efficiency upon annealing within the glass transition range can be attributed to the growth of P3HT aggregates, an overall increase in the percentage of chain crystallinity, and a concurrent increase in the hole mobilities. Films treated above the glass transition range show an increase in efficiency and fill factor not only associated with the change in chain crystallinity, but also with a decrease in the energetic disorder. On the other hand, the properties of the P3HT phase in the solvent-annealed o-dichlorobenzene cast blends are almost indistinguishable from those of the corresponding pristine P3HT layer and are only weakly affected by thermal annealing. Apparently, slow drying of the blend allows the P3HT chains to crystallize into large domains with low degrees of intra- and interchain disorder. This morphology appears to be most favorable for the efficient generation and extraction of charges.}, language = {en} } @article{TsegayeDeBleserIribarren2011, author = {Tsegaye, Mulugeta Tarekegne and De Bleser, Ria and Iribarren, Carolina}, title = {The effect of literacy on oral language processing implications for aphasia tests}, series = {Clinical linguistics \& phonetics}, volume = {25}, journal = {Clinical linguistics \& phonetics}, number = {6-7}, publisher = {Taylor \& Francis Group}, address = {London}, issn = {0269-9206}, doi = {10.3109/02699206.2011.567348}, pages = {628 -- 639}, year = {2011}, abstract = {Most studies investigating the impact of literacy on oral language processing have shown that literacy provides phonological awareness skills in the processing of oral language. The implications of these results on aphasia tests could be significant and pose questions on the adequacy of such tools for testing non-literate individuals. Aiming at examining the impact of literacy on oral language processing and its implication on aphasia tests, this study tested 12 non-literate and 12 literate individuals with a modified Amharic version of the Bilingual Aphasia Test (Paradis and Amberber, 1991, Bilingual Aphasia Test. Amharic version. Hillsdale, NJ: Lawrence Erlbaum.). The problems of phonological awareness skills in oral language processing in non-literates are substantiated. In addition, compared with literate participants, non-literate individuals demonstrated difficulties in the word/sentence-picture matching tasks. This study has also revealed that the Amharic version of the Bilingual Aphasia Test may be viable for testing Amharic-speaking non-literate individuals with aphasia when modifications are incorporated.}, language = {en} } @article{TschoepeWallschlaegerBurkartetal.2011, author = {Tsch{\"o}pe, Okka and Wallschl{\"a}ger, Hans-Dieter and Burkart, Michael and Tielb{\"o}rger, Katja}, title = {Managing open habitats by wild ungulate browsing and grazing a case-study in North-Eastern Germany}, series = {Applied vegetation science : official organ of the International Association for Vegetation Science}, volume = {14}, journal = {Applied vegetation science : official organ of the International Association for Vegetation Science}, number = {2}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {1402-2001}, doi = {10.1111/j.1654-109X.2010.01119.x}, pages = {200 -- 209}, year = {2011}, abstract = {Question: Can wild ungulates efficiently maintain and restore open habitats? Location: Brandenburg, NE Germany. Methods: The effect of wild ungulate grazing and browsing was studied in three successional stages: (1) Corynephorus canescens-dominated grassland; (2) ruderal tall forb vegetation dominated by Tanacetum vulgare; and (3) Pinus sylvestris-pioneer forest. The study was conducted over 3 yr. In each successional stage, six paired 4 m(2)-monitoring plots of permanently grazed versus ungrazed plots were arranged in three random blocks. Removal of grazing was introduced de novo for the study. In each plot, percentage cover of each plant and lichen species and total cover of woody plants was recorded. Results: Wild ungulates considerably affected successional pathways and species composition in open habitats but this influence became evident in alteration of abundances of only a few species. Grazing effects differed considerably between successional stages: species richness was higher in grazed versus ungrazed ruderal and pioneer forest plots, but not in the Corynephorus sites. Herbivory affected woody plant cover only in the Pioneer forest sites. Although the study period was too short to observe drastic changes in species richness and woody plant cover, notable changes in species composition were still detected in all successional stages. Conclusion: Wild ungulate browsing is a useful tool to inhibit encroachment of woody vegetation and to conserve a species-rich, open landscape.}, language = {en} } @misc{TrollKulkarniWangetal.2011, author = {Troll, K. and Kulkarni, Amit and Wang, W. and Darko, C. and Koumba, A. M. Bivigou and Laschewsky, Andr{\´e} and M{\"u}ller-Buschbaum, Peter and Papadakis, Christine M.}, title = {The collapse transition of poly(styrene-b-(N-isopropyl acrylamide)) diblock copolymers in aqueous solution and in thin films}, series = {Colloid and polymer science : official journal of the Kolloid-Gesellschaft}, volume = {289}, journal = {Colloid and polymer science : official journal of the Kolloid-Gesellschaft}, number = {2}, publisher = {Springer}, address = {New York}, issn = {0303-402X}, doi = {10.1007/s00396-010-2344-1}, pages = {227 -- 227}, year = {2011}, language = {en} } @book{Tresp2011, author = {Tresp, Uwe}, title = {Das F{\"u}rstentreffen von Eger und die s{\"a}chsisch-b{\"o}hmischen Beziehungen um 1459}, isbn = {978-3-89923-285-1}, year = {2011}, language = {de} }