TY - JOUR
A1 - Bersier, David
A1 - Fruchter, Andrew S.
A1 - Strolger, Louis-Gregory
A1 - Gorosabel, Javier
A1 - Levan, Andrew
A1 - Burud, Ingunn
A1 - Rhoads, James E.
A1 - Becker, Andrew C.
A1 - Cassan, Andrew C.
A1 - Chornock, Ryan
A1 - Covino, Stefano
A1 - De Jong, Roelof S.
A1 - Dominis, Dijana
A1 - Filippenko, Alexei V.
A1 - Hjorth, Jens
A1 - Holmberg, Johan
A1 - Malesani, Daniele
A1 - Mobasher, Bahram
A1 - Olsen, Kurt A. G.
A1 - Stefanon, Mauro
A1 - Castro Cerón, José María C.
A1 - Fynbo, Johan P. U.
A1 - Holland, Stephen T.
A1 - Kouveliotou, Chryssa
A1 - Pedersen, Hans-Georg
A1 - Tanvir, Nieal R.
A1 - Woosley, S. E.
T1 - Evidence for a supernova associated with the X-ray flash 020903
N2 - We present ground-based and Hubble Space Telescope optical observations of the X-ray flash ( XRF) 020903, covering 300 days. The afterglow showed a very rapid rise in the first day, followed by a relatively slow decay in the next few days. There was a clear bump in the light curve after similar to 25 days, accompanied by a drastic change in the spectral energy distribution. The light curve and the spectral energy distribution are naturally interpreted as describing the emergence and subsequent decay of a supernova ( SN), similar to SN 1998bw. At peak luminosity, the SN is estimated to be 0.8 +/- 0.1 mag fainter than SN 1998bw. This argues in favor of the existence of a SN associated with this XRF. A spectrum obtained 35 days after the burst shows emission lines from the host galaxy. We use this spectrum to put an upper limit on the oxygen abundance of the host at [O/H] <= 0.6 dex. We also discuss a possible trend between the softness of several bursts and the early behavior of the optical afterglow, in the sense that XRFs and X-ray-rich gamma- ray bursts ( GRBs) seem to have a plateau phase or even a rising light curve. This can be naturally explained in models in which XRFs are similar to GRBs but are seen off the jet axis.
Y1 - 2006
UR - http://iopscience.iop.org/0004-637X/
U6 - https://doi.org/10.1086/502640
SN - 0004-637X
ER -
TY - CHAP
A1 - Bergmann, Kirsten
A1 - Kopp, Stefan
T1 - Verbal or visual? : How information is distributed across speech and gesture in spatial dialog
N2 - In spatial dialog like in direction giving humans make frequent use of speechaccompanying gestures. Some gestures convey largely the same information as speech while others complement speech. This paper reports a study on how speakers distribute meaning across speech and gesture, and depending on what factors. Utterance meaning and the wider dialog context were tested by statistically analyzing a corpus of direction-giving dialogs. Problems of speech production (as indicated by discourse markers and disfluencies), the communicative goals, and the information status were found to be influential, while feedback signals by the addressee do not have any influence.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10375
ER -
TY - BOOK
A1 - Ben-Rafael, Eliezer
A1 - Jasper, Willi
A1 - Harris, Paul
T1 - Building a diaspora : Russian Jews in Israel, Germany and the USA
Y1 - 2006
SN - 978-90-04-15332-5
VL - 13
PB - Brill
CY - Leiden
ER -
TY - THES
A1 - Bellin, Ingo
T1 - Thermosensitive Polymer Networks with Two Different Shapes in Memory
Y1 - 2006
CY - Potsdam
ER -
TY - JOUR
A1 - Bell, Elanor M.
A1 - Weithoff, Guntram
A1 - Gaedke, Ursula
T1 - Temporal dynamics and growth of Actinophrys sol (Sarcodina: Heliozoa), the top predator in an extremely acidic lake
N2 - 1. The in situ abundance, biomass and mean cell volume of Actinophrys sol (Sarcodina: Heliozoa), the top predator in an extremely acidic German mining lake (Lake 111; pH 2.65), were determined over three consecutive years (spring to autumn, 2001-03). 2. Actinophrys sol exhibited pronounced temporal and vertical patterns in abundance, biomass and mean cell volume. Increasing from very low spring densities, maxima in abundance and biomass were observed in late June/early July and September. The highest mean abundance recorded during the study was 7 x 10(3) Heliozoa L-1. Heliozoan abundance and biomass were higher in the epilimnion than in the hypolimnion. Actinophrys sol cells from this acidic lake were smaller than individuals of the same species found in other aquatic systems. 3. We determined the growth rate of A. sol using all potential prey items available in, and isolated and cultured from, Lake 111. Prey items included: single-celled and filamentous bacteria of unknown taxonomic affinity, the mixotrophic flagellates Chlamydomonas acidophila and Ochromonas sp., the ciliate Oxytricha sp. and the rotifers Elosa worallii and Cephalodella hoodi. Actinophrys sol fed over a wide-size spectrum from bacteria to metazoans. Positive growth was not supported by all naturally available prey. Actinophrys sol neither increased in cell number (k) nor biomass (k(b)) when starved, with low concentrations of single-celled bacteria or with the alga Ochromonas sp. Positive growth was achieved with single- celled bacteria (k = 0.22 +/- 0.02 d(-1); k(b) = -0.06 +/- 0.02 d(-1)) and filamentous bacteria (k = 0.52 +/- < 0.01 d(- 1); k(b) = 0.66 d(-1)) at concentrations greater than observed in situ, and the alga C. acidophila (up to k = 0.43 +/- 0.03 d(-1); k(b) = 0.44 +/- 0.04 d(-1)), the ciliate Oxytricha sp. (k = 0.34 +/- 0.01 d(-1)) and in mixed cultures containing rotifers and C. acidophila (k = 0.23 +/- 0.02-0.32 +/- 0.02 d(-1); maximum k(b) = 0.42 +/- 0.05 d(-1)). The individual- and biomass-based growth of A. sol was highest when filamentous bacteria were provided. 4. Existing quantitative carbon flux models for the Lake 111 food web can be updated in light of our results. Actinophrys sol are omnivorous predators supported by a mixed diet of filamentous bacteria and C. acidophila in the epilimnion. Heliozoa are important components in the planktonic food webs of 'extreme' environments
Y1 - 2006
UR - http://www3.interscience.wiley.com/cgi-bin/issn?DESCRIPTOR=PRINTISSN&VALUE=0046-5070
U6 - https://doi.org/10.1111/j.1365-2427.2006.01561.x
SN - 0046-5070
ER -
TY - JOUR
A1 - Beitz, Toralf
A1 - Laudien, Robert
A1 - Löhmannsröben, Hans-Gerd
A1 - Kallies, Bernd
T1 - Ion mobility spectrometric investigation of aromatic cations in the gas phase
N2 - In this work, ion mobility (IM) spectra of more than 50 aromatic compounds were recorded with a laser-based IM spectrometer at atmospheric pressure. IM spectra of PAH in the laser desorption experiment show a high complexity resulting from the occurrence of monomeric, dimeric, and oligomeric cluster ions. The mobilities of all compounds were determined in helium as drift gas. This allows the calculation of the diffusion cross sections (Omega(calc)) on the basis of the exact hard sphere scattering model and their comparison with the experimentally determined diffusion cross sections (Omega(exp)). Extended Omega(exp)/Omega(calc) and Omega(exp/)mass correlations were performed in order to gain insight into conformational properties of cationic alkyl benzenes and internal rotation of phenyl rings in aromatic ions. This is demonstrated with some examples, such as the evaluation of the dihedral angle of the ions of 9,10- diphenylanthracene, o- and m-terphenyl, and 1,2,3- and 1,3,5-triphenylbenzene. Furthermore, sandwich and T-structures of dimeric PAH cations are discussed. The analysis was extended to oligomeric ions with up to nine monomer units. Experimental evidence is presented suggesting the formation of pi-stacks with a transition toward modified pi-stacks with increasing cluster size. The distance between monomeric units in dimeric and oligomeric ions was obtained
Y1 - 2006
UR - http://pubs.acs.org/journal/jpcafh
U6 - https://doi.org/10.1021/Jp055335n
SN - 1089-5639
ER -
TY - JOUR
A1 - Beissenhirtz, Moritz Karl
A1 - Scheller, Frieder W.
A1 - Viezzoli, Maria Silvia
A1 - Lisdat, Fred
T1 - Engineered superoxide dismutase monomers for superoxide biosensor applications
N2 - Because of its high reaction rate and specificity, the enzyme superoxide dismutase (SOD) offers great potential for the sensitive quantification of superoxide radicals in electrochemical biosensors. In this work, monomeric mutants of human Cu,Zn-SOD were engineered to contain one or two additional cysteine residues, which could be used to bind the protein to gold surfaces, thus making the use of promotor molecules unnecessary. Six mutants were successfully designed, expressed, and purified. All mutants bound directly to unmodified gold surfaces via the sulfur of the cysteine residues and showed a quasireversible, direct electron transfer to the electrode. Thermodynamic and kinetic parameters of the electron transfer were characterized and showed only slight variations between the individual mutants. For one of the mutants, the interaction with the superoxide radical was studied in more detail. For both partial reactions of the dismutation, an interaction between protein and radical could be shown. In an amperometric biosensorial approach, the SOD-mutant electrode was successfully applied for the detection of superoxide radicals. In the oxidation region, the electrode surpassed the sensitivity of the commonly used cytochrome c electrodes by similar to 1 order of magnitude while not being limited by interferences, but the electrode did not fully reach the sensitivity of dimeric Cu,Zn-SOD immobilized on MPA-modified gold
Y1 - 2006
UR - http://pubs.acs.org/journal/ancham
U6 - https://doi.org/10.1021/Ac051465g
SN - 0003-2700
ER -
TY - JOUR
A1 - Beim Graben, Peter
A1 - Atmanspacher, Harald
T1 - Complementarity in classical dynamical systems
N2 - The concept of complementarity, originally defined for non-commuting observables of quantum systems with states of non-vanishing dispersion, is extended to classical dynamical systems with a partitioned phase space. Interpreting partitions in terms of ensembles of epistemic states (symbols) with corresponding classical observables, it is shown that such observables are complementary to each other with respect to particular partitions unless those partitions are generating. This explains why symbolic descriptions based on an ad hoc partition of an underlying phase space description should generally be expected to be incompatible. Related approaches with different background and different objectives are discussed
Y1 - 2006
UR - http://www.springerlink.com/content/101591
U6 - https://doi.org/10.1007/s10701-005-9013-0
SN - 0015-9018
ER -
TY - GEN
A1 - Beck, Michael
A1 - Hildebrandt, Niko
A1 - Löhmannsröben, Hans-Gerd
T1 - Quantum dots as acceptors in FRET-assays containing serum
N2 - Quantum dots (QDs) are common as luminescing markers for imaging in biological applications because their optical properties seem to be inert against their surrounding solvent. This, together with broad and strong absorption bands and intense, sharp tuneable luminescence bands, makes them interesting candidates for methods utilizing Förster Resonance Energy Transfer (FRET), e. g. for sensitive homogeneous fluoroimmunoassays (FIA). In this work we demonstrate energy transfer from Eu3+-trisbipyridin (Eu-TBP) donors to CdSe-ZnS-QD acceptors in solutions with and without serum. The QDs are commercially available CdSe-ZnS core-shell particles emitting at 655 nm (QD655). The FRET system was achieved by the binding of the streptavidin conjugated donors with the biotin conjugated acceptors. After excitation of Eu-TBP and as result of the energy transfer, the luminescence of the QD655 acceptors also showed lengthened decay times like the donors. The energy transfer efficiency, as calculated from the decay times of the bound and the unbound components, amounted to 37%. The Förster-radius, estimated from the absorption and emission bands, was ca. 77 Å. The effective binding ratio, which not only depends on the ratio of binding pairs but also on unspecific binding, was obtained from the donor emission dependent on the concentration. As serum promotes unspecific binding, the overall FRET efficiency of the assay was reduced. We conclude that QDs are good substitutes for acceptors in FRET if combined with slow decay donors like Europium. The investigation of the influence of the serum provides guidance towards improving binding properties of QD assays.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 019
KW - Quantenpunkt
KW - Lumineszenz
KW - Serum
KW - Europium
KW - Immunoassay
KW - Energietransfer
KW - Fluoreszenz-Resonanz-Energie-Transfer
KW - Förster-Resonanz-Energie-Transfer
KW - Quantum Dot
KW - Luminescence
KW - Serum
KW - Europium
KW - Immunoassay
KW - Energy Transfer
KW - FRET
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-9504
ER -
TY - JOUR
A1 - Beauval, Céline
A1 - Hainzl, Sebastian
A1 - Scherbaum, Frank
T1 - Probabilistic seismic hazard estimation in low-seismicity regions considering non-Poissonian seismic occurrence
N2 - In low-seismicity regions, such as France or Germany, the estimation of probabilistic seismic hazard must cope with the difficult identification of active faults and with the low amount of seismic data available. Since the probabilistic hazard method was initiated, most studies assume a Poissonian occurrence of earthquakes. Here we propose a method that enables the inclusion of time and space dependences between earthquakes into the probabilistic estimation of hazard. Combining the seismicity model Epidemic Type Aftershocks-Sequence (ETAS) with a Monte Carlo technique, aftershocks are naturally accounted for in the hazard determination. The method is applied to the Pyrenees region in Southern France. The impact on hazard of declustering and of the usual assumption that earthquakes occur according to a Poisson process is quantified, showing that aftershocks contribute on average less than 5 per cent to the probabilistic hazard, with an upper bound around 18 per cent
Y1 - 2006
UR - http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-246X
U6 - https://doi.org/10.1111/j.1365-246X.2006.02863.x
SN - 0956-540X
ER -
TY - JOUR
A1 - Beauval, Celine
A1 - Hainzl, Sebastian
A1 - Scherbaum, Frank
T1 - The impact of the spatial uniform distribution of seismicity on probabilistic seismic-hazard estimation
JF - Bulletin of the Seismological Society of America
N2 - The first step in the estimation of probabilistic seismic hazard in a region commonly consists of the definition and characterization of the relevant seismic sources. Because in low-seismicity regions seismicity is often rather diffuse and faults are difficult to identify, large areal source zones are mostly used. The corresponding hypothesis is that seismicity is uniformly distributed inside each areal seismic source zone. In this study, the impact of this hypothesis on the probabilistic hazard estimation is quantified through the generation of synthetic spatial seismicity distributions. Fractal seismicity distributions are generated inside a given source zone and probabilistic hazard is computed for a set of sites located inside this zone. In our study, the impact of the spatial seismicity distribution is defined as the deviation from the hazard value obtained for a spatially uniform seismicity distribution. From the generation of a large number of synthetic distributions, the correlation between the fractal dimension D and the impact is derived. The results show that the assumption of spatially uniform seismicity tends to bias the hazard to higher values. The correlation can be used to determine the systematic biases and uncertainties for hazard estimations in real cases, where the fractal dimension has been determined. We apply the technique in Germany (Cologne area) and in France (Alps).
Y1 - 2006
U6 - https://doi.org/10.1785/0120060073
SN - 0037-1106
VL - 96
IS - 6
SP - 2465
EP - 2471
PB - GeoScienceWorld
CY - Alexandria, Va.
ER -
TY - JOUR
A1 - Beaulieu, Jean-Philippe
A1 - Bennett, David P.
A1 - Fouqué, Pascal
A1 - Williams, Andrew
A1 - Dominik, Martin
A1 - Jorgensen, Uffe Grae
A1 - Kubas, Daniel
A1 - Cassan, Arnaud
A1 - Coutures, Christian
A1 - Greenhill, John
A1 - Hill, Kym
A1 - Menzies, John
A1 - Sackett, Penny D.
A1 - Albrow, Michael D.
A1 - Brillant, Stephane
A1 - Caldwell, John A. R.
A1 - Calitz, Johannes Jacobus
A1 - Cook, Kem H.
A1 - Corrales Cosmeli, Esperanza de Santa Cecilia
A1 - Desort, Morgan
A1 - Dieters, Stefan
A1 - Dominis, Dijana
A1 - Donatowicz, Jadzia
A1 - Hoffman, Martie
A1 - Kane, Stephen R.
A1 - Marquette, Jean-Baptiste
A1 - Martin, Ralph
A1 - Meintjes, Pieter
A1 - Pollard, Karen R.
A1 - Sahu, Kailash C.
A1 - Vinter, Christian
A1 - Wambsganss, Joachim
A1 - Woller, Kristian
A1 - Horne, Keith
A1 - Steele, Iain
A1 - Bramich, Daniel M.
A1 - Burgdorf, Martin
A1 - Snodgrass, Colin
A1 - Bode, Mike
A1 - Udalski, Andr
T1 - Discovery of a cool planet of 5.5 Earth masses through gravitational microlensing
N2 - In the favoured core-accretion model of formation of planetary systems, solid planetesimals accumulate to build up planetary cores, which then accrete nebular gas if they are sufficiently massive. Around M-dwarf stars ( the most common stars in our Galaxy), this model favours the formation of Earth-mass (M+) to Neptune-mass planets with orbital radii of 1 to 10 astronomical units (AU), which is consistent with the small number of gas giant planets known to orbit M-dwarf host stars(1-4). More than 170 extrasolar planets have been discovered with a wide range of masses and orbital periods, but planets of Neptune's mass or less have not hitherto been detected at separations of more than 0.15 AU from normal stars. Here we report the discovery of a 5.5(-2.7)(+5.5)M(+) planetary companion at a separation of 2.6(- 0.6)(+1.5) AU from a 0.22(-0.11)(+0.21)M(.) M-dwarf star, where M-. refers to a solar mass. (We propose to name it OGLE- 2005-BLG-390Lb, indicating a planetary mass companion to the lens star of the microlensing event.) The mass is lower than that of GJ876d (ref. 5), although the error bars overlap. Our detection suggests that such cool, sub-Neptune-mass planets may be more common than gas giant planets, as predicted by the core accretion theory.
Y1 - 2006
UR - http://www.nature.com/nature/
U6 - https://doi.org/10.1038/Nature04441
SN - 0028-0836
ER -
TY - JOUR
A1 - Baur, Heiner
A1 - Müller, Steffen
A1 - Hirschmüller, Anja
A1 - Huber, Georg
A1 - Mayer, Frank
T1 - Reactivity, stability, and strength performance capacity in motor sports
JF - British journal of sports medicine : the journal of sport and exercise medicine
N2 - Background: Racing drivers require multifaceted cognitive and physical abilities in a multitasking situation. A knowledge of their physical capacities may help to improve fitness and performance. Objective: To compare reaction time, stability performance capacity, and strength performance capacity of elite racing drivers with those of age-matched, physically active controls. Methods: Eight elite racing drivers and 10 physically active controls matched for age and weight were tested in a reaction and determination test requiring upper and lower extremity responses to visual and audio cues. Further tests comprised evaluation of one-leg postural stability on a two-dimensional moveable platform, measures of maximum strength performance capacity of the extensors of the leg on a leg press, and a test of force capacity of the arms in a sitting position at a steering wheel. An additional arm endurance test consisted of isometric work at the steering wheel at + 30 degrees and -30 degrees where an eccentric threshold load of 30 N.m was applied. Subjects had to hold the end positions above this threshold until exhaustion. Univariate one way analysis of variance (alpha = 0.05) including a Bonferroni adjustment was used to detect group differences between the drivers and controls. Results: The reaction time of the racing drivers was significantly faster than the controls ( p = 0.004). The following motor reaction time and reaction times in the multiple determination test did not differ between the groups. No significant differences (p> 0.05) were found for postural stability, leg extensor strength, or arm strength and endurance. Conclusions: Racing drivers have faster reaction times than age-matched physically active controls. Further development of motor sport-specific test protocols is suggested. According to the requirements of motor racing, strength and sensorimotor performance capacity can potentially be improved.
Y1 - 2006
U6 - https://doi.org/10.1136/bjsm.2006.025783
SN - 0306-3674
VL - 40
SP - 906
EP - 910
PB - BMJ Publ. Group
CY - London
ER -
TY - JOUR
A1 - Baumgärtel, Hellmut
T1 - Generalized eigenvectors for resonances in the Friedrichs model and their associated Gamov vectors
N2 - A Gelfand triplet for the Hamiltonian H of the Priedrichs model on R with multiplicity space K, dim K < infinity, is constructed such that exactly the resonances (poles of the inverse of the Livsic-matrix) are (generalized) eigenvalues of H. The corresponding eigen(anti)linear forms are calculated explicitly. Using the wave matrices for the wave (Moller) operators the corresponding eigen(anti)linear forms on the Schwartz space S for the unperturbed Hamiltonian Ho are also calculated. It turns out that they are of pure Dirac type and can be characterized by their corresponding Gamov vector lambda -> k/(zeta(0)-lambda)(-1), zeta(0) resonance, k epsilon K, which is uniquely determined by restriction of S to S boolean AND H-+(2), where H-+(2) denotes the Hardy space of the upper half-plane. Simultaneously this restriction yields a truncation of the generalized evolution to the well-known decay semigroup for t >= 0 of the Toeplitz type on H-+(2). That is: Exactly those pre-Gamov vectors a lambda -> k/(zeta-lambda)(-1), ( from the lower half-plane, k epsilon K., have an extension to a generalized eigenvector of H if zeta is a resonance and if k is from that subspace of K which is uniquely determined by its corresponding Dirac type antilinear form
Y1 - 2006
UR - http://www.worldscinet.com/rmp/rmp.shtml
U6 - https://doi.org/10.1142/S0129055X06002589
SN - 0129-055X
ER -
TY - JOUR
A1 - Baumann, Otto
A1 - Lutz, Kathleen
T1 - Photoreceptor morphogenesis in the Drosophila compound eye : R1-R6 rhabdomeres become twisted just before eclosion
N2 - The photosensitive microvilli of Drosophila photoreceptors R1-R6 are not aligned in parallel over the entire length of the visual cells. In the distal half of each cell, the microvilli are slightly tilted toward one side and, in the proximal half, extremely toward the opposite side. This phenomenon, termed rhabdomere twisting, has been known for several decades, but the developmental and cell biological basis of rhabdomere twisting has not been studied so far. We show that rhabdomere twisting is also manifested as molecular polarization of the visual cell, because phosphotyrosine- containing proteins are selectively partitioned to different sides of the rhabdomere stalk in the distal. and proximal sections of each R1-R6 photoreceptor. Both the asymmetrical segregation of phosphotyrosine proteins and the tilting of the microvilli occur shortly before eclosion of the flies, when eye development in all other aspects is considered to be essentially complete. Establishment of rhabdomere twisting occurs in a light-independent manner, because phosphotyrosine staining is unchanged in dark-reared wild-type flies and in mutants with defects in the phototransduction cascade, ninaE(17) and norpA(P24). We conclude that antiphosphotyrosine immunofluorescence can be used as a light microscopic probe for the analysis of rhabdomere twisting and that microvilli tilting represents a type of planar cell polarity that is established by an active process in the last phase of photoreceptor morphogenesis, just prior to eclosion of the flies.
Y1 - 2006
UR - http://www3.interscience.wiley.com/cgi-bin/jhome/31248
U6 - https://doi.org/10.1002/Cne.21030
SN - 0021-9967
ER -
TY - JOUR
A1 - Bauer, Joachim
A1 - Stamm, Axel
A1 - Virnich, Katharina
A1 - Wissing, Karen
A1 - Müller, Udo
A1 - Wirsching, Michael
A1 - Schaarschmidt, Uwe
T1 - Correlation between burnout syndrome and psychological and psychosomatic symptoms among teachers
N2 - Objectives: Psychosomatic disorders and symptoms that correlate with the so-called burnout syndrome turned out to be the main cause of increasing rates of premature retirement of school teachers. The aim of this study was to evaluate the relation between occupational burden and psychological strain of teachers who are still in work. Methods: A sample of 408 teachers at ten grammar schools (am: High school; German: Gymnasium) in south-western Germany was evaluated. To determine the styles of coping with occupational burden we used the measure of coping capacity questionnaire (MECCA). To analyse the psychopathological and psychosomatic symptom load we applied SCL 90 R questionnaire. Results: According to the MECCA questionnaire, 32.5% of the sample suffered from burnout (type B), 17.7% suffered severe strain (type A), 35.9% showed an unambitious (type S) and 13.8% showed a healthy-ambitious coping style (type G). Burnout was significantly higher among women, divorced teachers and teachers working part-time. As part of the MECCA, teachers were asked to rate what they regarded as the strongest factor resulting in occupational burden. Teachers indicated that, besides high numbers of pupils in one class, they regarded destructive and aggressive behaviour of pupils as the primary stress factor. According to the SCL 90 R, 20% of the sample showed a severe degree (defined as > 70 points in the SCL90R GSI) of psychological and psychosomatic symptoms. MECCA type B (burnout) correlated significantly with high psychological and psychosomatic symptom load according to the SCL90R. Conclusions: In school teachers, burnout syndrome, a construct that derived from occupational psychology and occupational medicine, is significantly correlated with psychological and psychosomatic symptoms. Teachers rate destructive and aggressive behaviour of pupils as the primary stress factor.
Y1 - 2006
UR - http://www.springerlink.com/content/101165
U6 - https://doi.org/10.1007/s00420-005-0050-y
SN - 0340-0131
ER -
TY - JOUR
A1 - Basso, Heitor Cury
A1 - Aquino, C. V.
A1 - Altafim, Ruy Alberto Pisani
A1 - Altafim, Ruy Alberto Pisani
A1 - Gerhard, Reimund
T1 - Piezoelectricity of a single bubble formed by two oppositely charged Teflon-FEP films
Y1 - 2006
SN - 1-4244-0547-5
ER -
TY - JOUR
A1 - Baptista, Murilo da Silva
A1 - Zhou, Changsong
A1 - Kurths, Jürgen
T1 - Information transmission in phase synchronous chaotic arrays
N2 - We show many versatile phase synchronous configurations that emerge in an array of coupled chaotic elements due to the presence of a periodic stimulus. Then, we explain the relevance of these configurations to the understanding of how information about such a. stimulus is transmitted from one side to the other in this array. The stimulus actively creates the ways to be transmitted, by making the chaotic elements to phase synchronize
Y1 - 2006
UR - http://iopscience.iop.org/0256-307X/
U6 - https://doi.org/10.1088/0256-307X/23/3/010
SN - 0256-307X
ER -
TY - JOUR
A1 - Baptista, Murilo da Silva
A1 - Pereira, Tiago
A1 - Kurths, Jürgen
T1 - Upper bounds in phase synchronous weak coherent chaotic attractors
N2 - An approach is presented for coupled chaotic systems with weak coherent motion, from which we estimate the upper bound value for the absolute phase difference in phase synchronous states. This approach shows that synchronicity in phase implies synchronicity in the time of events, a characteristic explored to derive an equation to detect phase synchronization, based on the absolute difference between the time of these events. We demonstrate the potential use of this approach for the phase coherent and the funnel attractor of the Rossler system, as well as for the spiking/bursting Rulkov map.
Y1 - 2006
UR - http://www.sciencedirect.com/science/journal/01672789
U6 - https://doi.org/10.1016/j.physd.2006.02.007
SN - 0167-2789
ER -
TY - JOUR
A1 - Baptista, Murilo da Silva
A1 - Grebogi, Celso
A1 - Koberle, Roland
T1 - Dynamically multilayered visual system of the multifractal fly
JF - Physical review letters
Y1 - 2006
U6 - https://doi.org/10.1103/PhysRevLett.97.178102
SN - 0031-9007
VL - 97
IS - 17
PB - American Physical Society
CY - College Park
ER -
TY - JOUR
A1 - Balci, Kubilay
A1 - Koch, Andreas
A1 - Kleinpeter, Erich
T1 - A comparative vibrational spectroscopic investigation of free mn-12S(2)O(2) and fn-12S(2)O(2) dithiacrown ethers based on DFT calculations
N2 - A successful assignment for the fundamental bands observed in the experimental IR spectra of mn-12S(2)O(2) and fn-12S(2)O(2) dithiacrown ethers was achieved by the aid of the density functional theory (DFT) based quantum mechanical calculations carried out at the 133LYP/6-31G(d) and B3LYP/6-31 + G(d) level of theory. Two different scaling approaches, '(i) scaled quantum mechanics force field (SQM FF) methodology', and (ii) the 'scaling frequencies with dual empirical scale factors', were used in order to fit the calculated harmonic frequencies to the experimental ones. Potential energy distribution (PED) calculations were carried out to define the internal coordinate contributions to each normal mode and to define the corresponding normal modes of the molecules. The effects of the conformational differences onto the IR active normal modes of the two isomeric molecules and their corresponding experimental frequencies were discussed in the light of the calculated spectral data.
Y1 - 2006
UR - http://www.sciencedirect.com/science/journal/00222860
U6 - https://doi.org/10.1016/j.molstruc.2005.10.048
SN - 0022-2860
ER -
TY - BOOK
A1 - Balan, Sakthin M.
A1 - Jürgensen, Helmut
T1 - Peptide computing : universality and theoretical model
T3 - Preprint / Universität Potsdam, Institut für Informatik
Y1 - 2006
SN - 0946-7580
VL - 2006, 1
PB - Univ.
CY - Potsdam
ER -
TY - BOOK
A1 - Balan, Sakthin M.
A1 - Jürgensen, Helmut
T1 - On the universality of peptide computing
T3 - Preprint / Universität Potsdam, Institut für Informatik
Y1 - 2006
SN - 0946-7580
VL - 2006, 9
PB - Univ.
CY - Potsdam
ER -
TY - JOUR
A1 - Baas, Timo
A1 - Schrooten, Mechthild
T1 - Relationship banking and SMEs: A theoretical analysis
JF - Small business economics : an international journal
N2 - Reliable information on small- and medium-sized enterprises (SMEs) is rare and costly for financial intermediaries. Therefore relationship banking is often considered as the appropriate lending technique. In this paper we offer a theoretical model to analyze relationship banking and the pricing behavior of banks in a Bertrand competition framework with monitoring costs. We show that the lack of reliable information leads to comparable high interest rates even if a long-term relationship between borrower and bank exists. The paper offers a theoretical explanation why SMEs often are faced with borrowing constraints.
KW - accounting
KW - financial constraints
KW - relationship banking
KW - small and medium sized enterprises
Y1 - 2006
U6 - https://doi.org/10.1007/s11187-006-0018-7
SN - 0921-898X
VL - 27
SP - 127
EP - 137
PB - Springer
CY - Dordrecht
ER -
TY - THES
A1 - Ba, Jianhua
T1 - Nonaqueous synthesis of metal oxide nanoparticles and their assembly into mesoporous materials
T1 - Nichtwässrige Synthese von Metalloxid-Nanopartikeln und deren Anordnung zu mesoporösen Materialien
N2 - This thesis mainly consist of two parts, the synthesis of several kinds of technologically interesting crystalline metal oxide nanoparticles via nonaqueous sol-gel process and the formation of mesoporous metal oxides using some of these nanoparticles as building blocks via evaporation induced self-assembly (EISA) technique. In the first part, the experimental procedures and characterization results of successful syntheses of crystalline tin oxide and tin doped indium oxide (ITO) nanoparticles are reported. SnO2 nanoparticles exhibit monodisperse particle size (3.5 nm in average), high crystallinity and particularly high dispersibility in THF, which enable them to become the ideal particulate precursor for the formation of mesoporous SnO2. ITO nanoparticles possess uniform particle morphology, narrow particle size distribution (5-10 nm), high crystallinity as well as high electrical conductivity. The synthesis approaches and characterization of various mesoporous metal oxides, including TiO2, SnO2, mixture of CeO2 and TiO2, mixture of BaTiO3 and SnO2, are reported in the second part of this thesis. Mesoporous TiO2 and SnO2 are presented as highlights of this part. Mesoporous TiO2 was produced in the forms of both films and bulk material. In the case of mesoporous SnO2, the study was focused on the high order of the porous structure. All these mesoporous metal oxides show high crystallinity, high surface area and rather monodisperse pore sizes, which demonstrate the validity of EISA process and the usage of preformed crystalline nanoparticles as nanobuilding blocks (NBBs) to produce mesoporous metal oxides.
N2 - Diese Arbeit besteht hauptsächlich aus zwei Teilen. Der erste Teil befasst sich mit der Synthese von mehreren technologisch wichtigen, kristallinen Metalloxid-Nanopartikeln mittels nichtwässriger Sol-Gel Chemie. Der zweite Teil beinhaltet die Herstellung von mesoporösen Metalloxiden. Dabei wurden ausgewählte Nanopartikel als Bausteine verwendet und durch langsames Verdampfen des Lösungsmittels in die entsprechenden porösen Strukturen überführt. Das experimentelle Vorgehen wie auch die Charakterisierung der erfolgreich hergestellten Zinnoxid- und Indiumzinnoxid-Nanopartikel sind im ersten Teil beschrieben. Die Zinnoxid-Nanpartikel zeichnen sich durch einheitliche Partikelgrösse (im Durchschnitt ca. 3.5 nm), hoher Kristallinität, und guter Dispergierbarkeit in Tetrahydrofuran aus. Diese Eigenschaften machen aus den Zinnoxid-Nanopartikeln die perfekten Bausteine für den Aufbau von mesoporösem Zinnoxid. Die Indiumzinnoxid-Nanopartikel haben eine einheitliche Partikelform, eine schmale Grösseverteilung (5-10 nm), hohe Kristallinität wie auch gute elektrische Leitfähigkeit. Die Synthese und Charakterisierung von verschiedenen mesoporösen Metalloxiden wie TiO2, SnO2, Mischungen von CeO2 und TiO2, wie auch Mischungen von BaTiO3 und SnO2 werden im zweiten Teil der Arbeit diskutiert. Mesoporöses TiO2 und SnO2 werden als besonders gelungene Beispiele herausgehoben. Mesoporöses TiO2 wurde in Form von Dünnfilmen wie auch als Bulkmaterial hergestellt. Im Falle von SnO2 galt das Augenmerk vor allem der hohen Ordnung der Mesoporen. Alle diese mesoporösen Materialien zeigen eine hohe Kristallinität, grosse Oberfläche und relativ einheitliche Porengrössen. Diese Eigenschaften unterstreichen, wie wertvoll der Ansatz ist, vorgeformte Nanopartikel als Bausteine für die Synthese von porösen Materialien zu verwenden.
KW - Nanopartikel
KW - transparent-leitendes Oxid
KW - Selbstorganisation
KW - nanoparticles
KW - oxides
KW - assembly
KW - mesostructure
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10173
ER -
TY - JOUR
A1 - Assmann, Birte
A1 - Thiel, Marco
A1 - Romano, Maria Carmen
A1 - Niemitz, Carsten
T1 - Recurrence plot analyses suggest a novel reference system involved in newborn spontaneous movements
JF - Behavior research methods : a journal of the Psychonomic Society
N2 - The movements of newborns have been thoroughly studied in terms of reflexes, muscle synergies, leg coordination, and target-directed arm/hand movements. Since these approaches have concentrated mainly on separate accomplishments, there has remained a clear need for more integrated investigations. Here, we report an inquiry in which we explicitly concentrated on taking such a perspective and, additionally, were guided by the methodological concept of home base behavior, which Ilan Golard developed for studies of exploratory behavior in animals. Methods from nonlinear dynamics, such as symbolic dynamics and recurrence plot analyses of kinematic data received from audiovisual newborn recordings, yielded new insights into the spatial and temporal organization of limb movements. In the framework of home base behavior, our approach uncovered a novel reference system of spontaneous newborn movements.
Y1 - 2006
U6 - https://doi.org/10.3758/BF03192793
SN - 1554-351X
SN - 1554-3528
VL - 38
IS - 3
SP - 400
EP - 406
PB - Springer
CY - New York
ER -
TY - CHAP
A1 - Artstein, Ron
A1 - Poesio, Massimo
T1 - Identifying reference to abstract objects in dialogue
N2 - In two experiments, many annotators marked antecedents for discourse deixis as unconstrained regions of text. The experiments show that annotators do converge on the identity of these text regions, though much of what they do can be captured by a simple model. Demonstrative pronouns are more likely than definite descriptions to be marked with discourse antecedents. We suggest that our methodology is suitable for the systematic study of discourse deixis.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10357
ER -
TY - JOUR
A1 - Arcay, Diane
A1 - Doin, Marie Pierre
A1 - Tric, Emmanuel
A1 - Bousquet, Romain
A1 - de Capitani, Christian
T1 - Overriding plate thinning in subduction zones : localized convection induced by slab dehydration
N2 - In subduction zones, many observations indicate that the backarc thermal state is particularly hot and that the upper lithosphere is thin, even if no recent extension episode has occurred. This might result from free thermal convection favored by low viscosities in the hydrated mantle wedge. We perform 2-D numerical experiments of the convective mantle wedge interaction with both the downgoing slab and the overriding plate to test this hypothesis, explore its physical mechanism, and assess its dependencies on some relevant rock properties. Water transfers across the subducting plate and the mantle wedge are explicitly modeled by including in the calculation realistic hydration/ dehydration reaction boundaries for a water-saturated mantle and oceanic crust. The rheology is non-Newtonian and temperature-, pressure-, and water content-dependent. For low strength reduction associated to water content, the upper plate is locally thinned by an enhanced corner flow. For larger strength reductions, small convection cells rapidly thin the upper plate ( in less than 15 Myr) over the area in the overriding lithosphere hydrated by slab-derived water fluxes. As a result, the thinned region location depends on the subducting plate thermal state, and it increases with high convergence rates and low subduction dip angles. Other simulations are performed to test the sole effect of hydrous rock weakening on the upper plate/mantle convective interaction. They show that the thinning process is not influenced by the corner flow, but develops at the favor of a decoupling level induced by the formation of hydroxylated minerals inside the hydrated lithosphere. The erosion mechanism identified in these simulations allows us to explain the characteristic duration of erosion as a function of the hydrous strength reduction. We find that the presence of amphibole in the upper lithosphere in significant proportions is required down to a temperature of about 980 degrees C, corresponding to an initial depth of similar to 70 km, to strongly decrease the strength of the base of the lithosphere and trigger a rapid erosion (< 15 Myr).
Y1 - 2006
UR - http://g-cubed.org/
U6 - https://doi.org/10.1029/2005gc001061
SN - 1525-2027
ER -
TY - THES
A1 - Arana-Ceballos, Fernando Alberto
T1 - Biochemical and physiological studies of Arabidopsis thaliana Diacylglycerol Kinase 7 (AtDGK7)
T1 - Biochemische physiologische Studien an der Arabidopsis thaliana Diazylglyzerol Kinase 7 (AtDGK7)
N2 - A family of diacylglycerol kinases (DGK) phosphorylates the substrate diacylglycerol (DAG) to generate phosphatidic acid (PA) . Both molecules, DAG and PA, are involved in signal transduction pathways. In the model plant Arabidopsis thaliana, seven candidate genes (named AtDGK1 to AtDGK7) code for putative DGK isoforms. Here I report the molecular cloning and characterization of AtDGK7. Biochemical, molecular and physiological experiments of AtDGK7 and their corresponding enzyme are analyzed. Information from Genevestigator says that AtDGK7 gene is expressed in seedlings and adult Arabidopsis plants, especially in flowers. The AtDGK7 gene encodes the smallest functional DGK predicted in higher plants; but also, has an alternative coding sequence containing an extended AtDGK7 open reading frame, confirmed by PCR and submitted to the GenBank database (under the accession number DQ350135). The new cDNA has an extension of 439 nucleotides coding for 118 additional amino acids The former AtDGK7 enzyme has a predicted molecular mass of ~41 kDa and its activity is affected by pH and detergents. The DGK inhibitor R59022 also affects AtDGK7 activity, although at higher concentrations (i.e. IC50 ~380 µM). The AtDGK7 enzyme also shows a Michaelis-Menten type saturation curve for 1,2-DOG. Calculated Km and Vmax were 36 µM 1,2-DOG and 0.18 pmol PA min-1 mg of protein-1, respectively, under the assay conditions. Former protein AtDGK7 are able to phosphorylate different DAG analogs that are typically found in plants. The new deduced AtDGK7 protein harbors the catalytic DGKc and accessory domains DGKa, instead the truncated one as the former AtDGK7 protein (Gomez-Merino et al., 2005).
N2 - Wachstum und Entwicklung sind die Kennzeichen lebender Systeme. Diese Prozesse unterliegen einer strengen Regulation im Organismus. Diacylglycerol (DAG) und Phosphatidsäure (PA) sind wesentliche Elemente in der Signalübertragung in Organismen. In Säugetieren kann DAG auf drei verschiedenen Wegen metabolisiert werden, die Entstehung von PA durch Phosphorylierung der freien Hydroxyl-Gruppe von DAG ist jedoch der am häufigsten vorkommende Stoffwechselweg. Die enzymatische Umsetzung dieser Reaktion wird von der Familie der Diacylglycerol-Kinasen (DGKs) katalysiert. Molekulare und biochemische Untersuchungen konnten die Anwesenheit von DGKs in Drosophila melanogaster, Arabidopsis thaliana und jüngst auch in Dictyostelium discoideum zeigen. In der vorliegenden Arbeit wird die Klonierung und Charakterisierung von AtDGK7 aus Arabidopsis thaliana präsentiert, einem Vertreter des pflanzlichen DGK-Clusters II. Das Transkript von AtDGK7 findet sich in der gesamten Pflanze, jedoch sind die Transkriptmengen in Blüten und jungem Gewebe stark erhöht. Rekombinant hergestelltes AtDGK7 ist katalytisch aktiv und akzeptiert DAG-ähnliche Moleküle mit mindestens einer ungesättigten Fettsäure als bevorzugtes Substrat. AtDGK2, ein weiteres Mitglied der DGK-Familie, und AtDGK7 metabolisieren Substrate, welche in Pflanzen physiologisch relevant sind. Das als DGK-Inhibitor beschriebene Molekül 6-{2-{4-[(4-fluorophenyl)phenylmethylene]-1-piperidinyl}ethyl}-7-methyl-5H-thiazolo(3,2-a)pyrimidine-5-one (R59022) inhibiert bei Konzentrationen von 50-100 µM rekombinant hergestelltes AtDGK2 in vitro. In ähnlichen Konzentrationen eingesetzt modifiziert R59022 das Wurzelwachstum. Dies weist darauf hin, dass DGKs in Entwicklungsprozessen eine Rolle spielen. In in vitro Experimenten wurde AtDGK7 von R59022 allerdings erst in Konzentrationen über 100 µM inhibiert. Ferner wird in der vorliegenden Arbeit die erfolgreiche Klonierung einer cDNA beschrieben, die für AtDGK7 aus A. thaliana kodiert und welche im Vergleich zu der bereits bekannten cDNA um 439 bp länger ist. Expressionsanalysen mit Hilfe eines Promotor-ß-glucuronidase (GUS) Fusions-Produktes zeigten die Aktivität von AtDGK7 in vielen Geweben, vor allem aber in Schließzellen, im Konnektiv-Gewebe der Antheren, sowie besonders in den Spitzen der Seitenwurzeln. Physiologische Untersuchungen unter abiotischem Stress (Verwendung verschiedener Konzentrationen von Stickstoff, Saccharose, Auxin und Inhibitoren von Auxin-Transportern) wurden mit AtDGK7 T-DNA-Insertionslinien sowie mit den Promotor-GUS-Linien durchgeführt. AtDGK7 T-DNA-Insertionslinien zeigten eine starke Inhibierung des Seitenwurzel-Wachstums unter limitierenden Stickstoff- und/oder Saccharose-Konzentrationen. In einigen der T-DNA-Insertionslinien inhibierte die Zugabe eines Inhibitors für Auxin-Transport (TIBA; 2,3,5-triiodobenzoic acid) die Bildung von Haupt- und Seitenwurzeln fast vollständig. Die Inhibition des Wurzelwachstums in den T-DNA-Insertionslinien konnte teilweise durch die Zugabe von 50nM NAA (α-naphtalene acetic acid) revertiert werden. Aus den vorliegenden Ergebnissen wird die Hypothese abgeleitet, dass AtDGK7 im Zusammenspiel mit Auxin in Signaltransduktionsprozessen eine Rolle spielt, welche das Wachstum und die Entwicklung in Pflanzen regulieren.
KW - AtDGK gene
KW - Diacylglycerol
KW - Phosphatidsäure
KW - Diacylglycerol-Kinasen
KW - Signaltransduktionsprozesse
KW - AtDGK genes
KW - auxin
KW - diacylglycerol
KW - phosphatidic acid
KW - signaling
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13729
ER -
TY - JOUR
A1 - Apio, Ann
A1 - Plath, Martin
A1 - Wronski, Torsten
T1 - Patterns of gastrointestinal parasitic infections in the bushbuck Tragelaphus scriptus from the Queen Elizabeth National Park, Uganda
JF - Journal of helminthology
N2 - Seasonal, host sex and age-related variations in helminth egg and coccidian oocyst counts were investigated in a naturally infected wild bushbuck (Tragelaphus scriptus) population in Queen Elizabeth National Park, western Uganda from April 2000 to February 2002. The prevalence and mean intensity quantified as the number of eggs and oocysts per gram of faeces were taken as a measure of parasite burdens. Host sex and age-related differences in prevalence values were not found but the overall prevalence of Eimeria sp. was significantly higher during the rainy season, and peak counts were recorded either during or soon after a peak rainfall. A similar trend was observed for Moniezia spp., although the results were marginally not significant. There were also no significant differences in mean intensity values, relative to host sex, age or season.
Y1 - 2006
U6 - https://doi.org/10.1076/JOH2006343
SN - 0022-149X
VL - 80
IS - 3
SP - 213
EP - 218
PB - Univ. Press
CY - Cambridge
ER -
TY - JOUR
A1 - Apio, Ann
A1 - Plath, Martin
A1 - Wronski, Torsten
T1 - Localised defecation sites : a tactic to avoid re-infection by gastro-intestinal tract parasites in bushbuck, Tragelaphus scriptus?
N2 - Bushbuck (Tragelaphus scriptus) often deposit faeces at specific localised defecation sites (LDS). We tested whether LDS have a function in the context of parasite avoidance. In a population of bushbuck in Queen Elizabeth National Park, Uganda, seven radio-collared individuals were observed. We recorded feeding behaviour inside and outside LDS. Furthermore, pasture contamination with gastro-intestinal tract parasites inside and outside LDS was examined. There were significant differences between the expected and the observed feeding rates inside LDS, but, contrary to our prediction, the bushbuck increased their feeding rate inside LDS. There was no significant difference in the parasite contamination of pastures inside and outside LDS. We discuss the hypothesis that LDS mainly serve a social function in bushbuck communities, whereas parasite avoidance seems to play a minor or no role
Y1 - 2006
UR - http://www.springerlink.com/content/105357
U6 - https://doi.org/10.1007/s10164-005-0166-2
SN - 0289-0771
ER -
TY - JOUR
A1 - Anishchenko, Vadim S.
A1 - Nikolaev, S
A1 - Kurths, Jürgen
T1 - Winding number locking on a two-dimensional torus : synchronization of quasiperiodic motions
N2 - We propose a new autonomous dynamical system of dimension N=4 that demonstrates the regime of stable two- frequency motions and period-doubling bifurcations of a two-dimensional torus. It is shown that the period-doubling bifurcation of the two-dimensional torus is not followed by the resonance phenomenon, and the two-dimensional ergodic torus undergoes a period-doubling bifurcation. The interaction of two generators is also analyzed. The phenomenon of external and mutual synchronization of two-frequency oscillations is observed, for which winding number locking on a two- dimensional torus takes place
Y1 - 2006
UR - http://pre.aps.org/
U6 - https://doi.org/10.1103/Physreve.73.056202
SN - 1539-3755
ER -
TY - JOUR
A1 - Anger, Christian
A1 - Gebser, Martin
A1 - Schaub, Torsten H.
T1 - Approaching the core of unfounded sets
Y1 - 2006
UR - http://www.cs.uni-potsdam.de/wv/pdfformat/angesc06a.pdf
ER -
TY - JOUR
A1 - Anger, Christian
A1 - Gebser, Martin
A1 - Janhunen, Tomi
A1 - Schaub, Torsten H.
T1 - What's a head without a body?
Y1 - 2006
ER -
TY - JOUR
A1 - Andrianov, Ivan
A1 - Saalfrank, Peter
T1 - Free vibrational relaxation of H adsorbed on a Si(100) surface investigated with the multi-configurational time-dependent Hartree method
JF - Chemical physics letters
N2 - The results of a quantum-mechanical study of vibrational relaxation of hydrogen adsorbed on a Si(100) surface with the multi-configurational time-dependent Hartree (MCTDH) method are presented. A two-dimensional subsystem is coupled non-linearly to a bath of harmonic oscillators (phonons of the Si bulk), and the relaxation of subsystem vibrations proceeds primarily via a two-phonon process. Characteristic times of the system evolution agree well with our previous perturbation theory study. The vibrational population decay is non-exponential, exhibiting pronounced recurrences due to finite bath size. The dependence of the lifetimes of the vibrational levels on the bath size and on the coupling details is investigated.
Y1 - 2006
U6 - https://doi.org/10.1016/j.cplett.2006.11.067
SN - 0009-2614
VL - 433
SP - 91
EP - 96
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Andrianov, Ivan
A1 - Saalfrank, Peter
T1 - Theoretical study of vibration-phonon coupling of H adsorbed on a Si(100) surface
N2 - In this paper a perturbation-theory study of vibrational lifetimes for the bending and stretching modes of hydrogen adsorbed on a Si(100) surface is presented. The hydrogen-silicon interaction is treated with a semiempirical bond-order potential. Calculations are performed for H-Si clusters of different sizes. The finite lifetime is due to vibration-phonon coupling, which is assumed to be linear or bilinear in the phonon and nonlinear in the H-Si stretching and bending modes. Lifetimes and vibrational transition rates are evaluated with one- and two-phonon processes taken into account. Temperature effects are also discussed. In agreement with the experiment and previous theoretical treatment it is found that the H-Si (upsilon(s)=1) stretching vibration decays on a nanosecond timescale, whereas for the H-Si (upsilon(b)=1) bending mode a picosecond decay is predicted. For higher-excited vibrations, simple scaling laws are found if the excitation energies are not too large. The relaxation mechanisms for the excited H-Si stretching and the H-Si bending modes are analyzed in detail.
Y1 - 2006
UR - http://jcp.aip.org/
U6 - https://doi.org/10.1063/1.2161191
SN - 0021-9606
ER -
TY - JOUR
A1 - Andresen, Katja
A1 - Gronau, Norbert
T1 - Managing Change : determining the adaptability of information systems
Y1 - 2006
ER -
TY - JOUR
A1 - Andresen, Heiko
A1 - Grötzinger, Carsten
A1 - Zarse, Kim
A1 - Birringer, Marc
A1 - Hessenius, Carsten
A1 - Kreuzer, Oliver Johannes
A1 - Ehrentreich-Förster, Eva
A1 - Bier, Frank Fabian
T1 - Peptide microarrays with site-specifically immobilized synthetic peptides for antibody diagnostics
N2 - Peptide microarrays bear the potential to discover molecular recognition events on protein level, particularly in the field of molecular immunology, in a manner and with an efficiency comparable to the performance of DNA microarrays. We developed a novel peptide microarray platform for the detection of antibodies in liquid samples. The system comprises site-specific solution phase coupling of biotinylated peptides to NeutrAvidin, localized microdispensing of peptide-NeutrAvidin conjugates onto activated glass slides and a fluorescence immuno sandwich assay format for antibody capture and detection. Our work includes synthetic peptides deduced from amino acid sequences of immunodominant linear epitopes, such as the T7 phage capsid protein, Herpes simplex virus glycoprotein D, c-myc protein and three domains of the Human coronavirus 229E polymerase polyprotein. We demonstrate that our method produces peptide arrays with excellent spot morphology which are capable of specific and sensitive detection of monoclonal antibodies from fluid samples.
Y1 - 2006
UR - http://www.sciencedirect.com/science/journal/09254005
U6 - https://doi.org/10.1016/j.snb.2005.07.033
SN - 0925-4005
ER -
TY - JOUR
A1 - Andresen, Heiko
A1 - Grotzinger, Carsten
A1 - Zarse, Kim
A1 - Kreuzer, Oliver Johannes
A1 - Ehrentreich-Förster, Eva
A1 - Bier, Frank Fabian
T1 - Functional peptide microarrays for specific and sensitive antibody diagnostics
N2 - Peptide microarrays displaying biologically active small synthetic peptides in a high-density format provide an attractive technology to probe complex samples for the presence and/or function of protein analytes. We present a new approach for manufacturing functional peptide microarrays for molecular immune diagnostics. Our method relies on the efficiency of site-specific solution-phase coupling of biotinylated synthetic peptides to NeutrAvidin (NA) and localized microdispensing of peptide-NA-complexes onto activated glass surfaces. Antibodies are captured in a sandwich manner between surface immobilized peptide probes and fluorescence-labeled secondary antibodies. Our work includes a total of 54 peptides derived from immunodominant linear epitopes of the T7 phage capsid protein, Herpes simplex virus glycoprotein D, c-myc protein, and three domains of the Human coronavirus polymerase polyprotein and their cognate mAbs. By using spacer molecules of different type and length for NA-mediated peptide presentation, we show that the incorporation of a minimum spacer length is imperative for antibody binding, whereas the peptide immobilization direction has only secondary importance for antibody affinity and binding. We further demonstrate that the peptide array is capable of detecting low-picomolar concentrations of mAbs in buffered solutions and diluted human serum with high specificity
Y1 - 2006
UR - http://www3.interscience.wiley.com/cgi-bin/jhome/76510741
U6 - https://doi.org/10.1002/pmic.200500343
SN - 1615-9853
ER -
TY - JOUR
A1 - Andert, Christoph U.
A1 - Sanchaisuriya, Pattara
A1 - Sanchaisuriya, Kanokwan
A1 - Schelp, Frank P.
A1 - Schweigert, Florian J.
T1 - Nutritional status of pregnant women in Northeast Thailand
N2 - A comparative study on the nutritional status of primiparous and multiparous women in the first trimester of pregnancy was conducted in the northeastern province of Thailand, Khon Kaen, to investigate differences in protein- energy-mal nutrition, iron deficiency anaemia, vitamin A deficiency and carotenoid status between both parity groups. 94 subjects were recruited at first attendance of antenatal clinic. Data about weight, height, haemoglobin and haematocrit were obtained from hospital records. Anthropometric measurements of mid-upper arm circumference and triceps skinfold were done on a sub sample. Retinol, carotenoids and alpha-tocopherol were analysed using a reversed-phase high- performance liquid chromatography method. Ferritin, transthyretin and retinol-binding protein were determined by enzyme- linked immunosorbent assay. Primiparous women showed lower body mass index, mid-upper arm circumference, corrected arm muscle area (P <0.001) as well as lower retinol, cholesterol and triceps skinfold (P <0.05). After adjusting for age and socio-economical status the significant difference persisted for all parameters but triceps skinfold. No significant differences of alpha-tocopherol, serum proteins, carotenoids and iron indices could be observed, even though a tendency to higher values for ferritin, haemoglobin and haematocrit was shown in multiparous women. Prevalence of protein-energy- malnutrition (body mass index <18.5 kg/m(2)) in the primiparous group was significantly higher compared to the multiparous group (P<0.05). Prevalence of protein-energy-malnutrition, iron deficiency anaemia and vitamin A deficiency were 15.1%, 6.3% and 3.3%, respectively, in the total study population. No differences between parity groups could be observed for prevalence of iron deficiency anaemia and vitamin A deficiency
Y1 - 2006
UR - http://www.healthyeatingclub.com/APJCN/
SN - 0964-7058
ER -
TY - JOUR
A1 - Andayi, Andrew W.
A1 - Yenesew, Abiy
A1 - Derese, Solomon
A1 - Midiwo, Jacob O.
A1 - Gitu, Peter M.
A1 - Jondiko, Ogoche J. I.
A1 - Akala, Hoseah M.
A1 - Liyala, Pamela
A1 - Wangui, Julia
A1 - Waters, Norman C.
A1 - Heydenreich, Matthias
A1 - Peter, Martin G.
T1 - Antiplasmodial flavonoids from Erythrina sacleuxii
N2 - The acetone extracts of the root bark and stem bark of Erythrina sacleuxii showed antiplasmodial activities against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum. Chromatographic separation of the acetone extract of the root bark afforded a new isoflavone, 7-hydroxy-4 -methoxy-3'- prenylisoflavone (trivial name 5-deoxy-3' - prenylbiochanin A) along with known isoflavonoids as the antiplasmodial principles. Flavonoids and isoflavonoids isolated from the stem bark of E. sucleuxii were also tested and showed antiplasmodial activities. The structures were determined on the basis of spectroscopic evidence
Y1 - 2006
UR - http://www.thieme-connect.com/ejournals/toc/plantamedica
U6 - https://doi.org/10.1055/s-2005-873200
SN - 0032-0943
ER -
TY - JOUR
A1 - Altafim, Ruy Alberto Pisani
A1 - Basso, Heitor Cury
A1 - Altafim, Ruy Alberto Pisani
A1 - Lima, L.
A1 - de Aquino, C. V.
A1 - Goncalves Neto, Luiz
A1 - Gerhard, Reimund
T1 - Piezoelectrets from thermo-formed bubble structures of fluoropolymer-electret films
N2 - The acetone extracts of the root bark and stem bark of Erythrina sacleuxii showed antiplasmodial activities against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum. Chromatographic separation of the acetone extract of the root bark afforded a new isoflavone, 7-hydroxy-4 -methoxy-3'- prenylisoflavone (trivial name 5-deoxy-3' - prenylbiochanin A) along with known isoflavonoids as the antiplasmodial principles. Flavonoids and isoflavonoids isolated from the stem bark of E. sucleuxii were also tested and showed antiplasmodial activities. The structures were determined on the basis of spectroscopic evidence.
Y1 - 2006
UR - http://ieeexplore.ieee.org/servlet/opac?punumber=94
U6 - https://doi.org/10.1109/TDEI.2006.247822
SN - 1070-9878
ER -
TY - JOUR
A1 - Alonso, Ricardo N.
A1 - Bookhagen, Bodo
A1 - Carrapa, Barbara
A1 - Coutand, Isabelle
A1 - Haschke, Michael
A1 - Hilley, George E.
A1 - Schoenbohm, Lindsay M.
A1 - Sobel, Edward
A1 - Strecker, Manfred
A1 - Trauth, Martin H.
A1 - Villanueva, Arturo
T1 - Tectonics, climate and landscape evolution of the Southern Central Andes : the Argentine Puna Plateau and adjacent regions between 22 and 30°S
Y1 - 2006
SN - 978-3-540- 24329-8
ER -
TY - GEN
A1 - Allefeld, Carsten
T1 - About the derivation of the SCA algorithm
N2 - In Allefeld & Kurths [2004], we introduced an approach to multivariate phase synchronization analysis in the form of a Synchronization Cluster Analysis (SCA). A statistical model of a synchronization cluster was described, and an abbreviated instruction on how to apply this model to empirical data was given, while an implementation of the corresponding algorithm was (and is) available from the authors. In this letter, the complete details on how the data analysis algorithm is to be derived from the model are filled in.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 075
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-20137
ER -
TY - JOUR
A1 - Albers, Nicole
A1 - Spahn, Frank
T1 - The influence of particle adhesion on the stability of agglomerates in Saturn's rings
N2 - In planetary rings, binary collisions and mutual gravity are the predominant particle interactions. Based on a viscoelastic contact model we implement the concept of static adhesion. We discuss the collision dynamics and obtain a threshold velocity for restitution or agglomeration to occur. The latter takes place within a range of a few cm s(-1) for icy grains at low temperatures. The stability of such two-body agglomerates bound by adhesion and gravity in a tidal environment is discussed and applied to the saturnian system. A maximal agglomerate size for a given orbit location is obtained. In this way we are able to resolve the borderline of the zone where agglomerates can exist as a function of the agglomerate size and thus gain an alternative to the classical Roche limit. An increasing ring grain size with distance to Saturn as observed by the VIMS-experiment on board the Cassini spacecraft can be found by our estimates and implications for the saturnian system will be addressed.
Y1 - 2006
UR - http://www.sciencedirect.com/science/journal/00191035
U6 - https://doi.org/10.1016/j.icarus.2005.10.011
SN - 0019-1035
ER -
TY - THES
A1 - Albers, Nicole
T1 - On the relevance of adhesion : applications to Saturn's rings
T1 - Zur Relevanz von Teilchenadhäsion : Anwendung auf die Ringe des Saturn
N2 - Since their discovery in 1610 by Galileo Galilei, Saturn's rings continue to fascinate both experts and amateurs. Countless numbers of icy grains in almost Keplerian orbits reveal a wealth of structures such as ringlets, voids and gaps, wakes and waves, and many more. Grains are found to increase in size with increasing radial distance to Saturn. Recently discovered "propeller" structures in the Cassini spacecraft data, provide evidence for the existence of embedded moonlets. In the wake of these findings, the discussion resumes about origin and evolution of planetary rings, and growth processes in tidal environments. In this thesis, a contact model for binary adhesive, viscoelastic collisions is developed that accounts for agglomeration as well as restitution. Collisional outcomes are crucially determined by the impact speed and masses of the collision partners and yield a maximal impact velocity at which agglomeration still occurs. Based on the latter, a self-consistent kinetic concept is proposed. The model considers all possible collisional outcomes as there are coagulation, restitution, and fragmentation. Emphasizing the evolution of the mass spectrum and furthermore concentrating on coagulation alone, a coagulation equation, including a restricted sticking probability is derived. The otherwise phenomenological Smoluchowski equation is reproduced from basic principles and denotes a limit case to the derived coagulation equation. Qualitative and quantitative analysis of the relevance of adhesion to force-free granular gases and to those under the influence of Keplerian shear is investigated. Capture probability, agglomerate stability, and the mass spectrum evolution are investigated in the context of adhesive interactions. A size dependent radial limit distance from the central planet is obtained refining the Roche criterion. Furthermore, capture probability in the presence of adhesion is generally different compared to the case of pure gravitational capture. In contrast to a Smoluchowski-type evolution of the mass spectrum, numerical simulations of the obtained coagulation equation revealed, that a transition from smaller grains to larger bodies cannot occur via a collisional cascade alone. For parameters used in this study, effective growth ceases at an average size of centimeters.
N2 - Seit ihrer Entdeckung im Jahre 1610 durch Galileo Galilei faszinieren die Ringe des Saturn sowohl Laien als auch Experten. Planetare Ringe finden sich in der Äquatorialebene aller vier Riesenplaneten unseres Sonnensystems und sind eines der eindruckvollsten Beispiele granularer Gase. Darunter gehören die Saturnringe zu den Bekanntesten. Sie bergen eine Vielzahl von Strukturen und erstrecken sich über mehr als 240 000 Kilometer, wobei sie weit weniger als 100 Meter dick sind. Unzählige kleinerer Körper bewegen sich auf leicht exzentrischen Kepler-ähnlichen Bahnen um den Zentralplaneten und bestehen dabei vorwiegend aus Eis. Die seit Juli 2004 im Orbit um den Saturn befindliche Raumsonde Cassini liefert atemberaubende Bilder und Daten, die nicht nur neue Erkenntnisse liefern, sondern auch alte Fragestellungen neu aufleben lassen. Dazu gehört z.B. die Frage nach dem Ursprung und den Entwicklungsstufen planetarer Ringe. Kürzlich, im äusseren A-Ring entdeckte Kleinmonde, deren Existenz schon viel früher postuliert wurde, weisen auf eventuell stattfindende Wachstumsprozesse hin. Da sich planetare Ringe jedoch hauptsächlich innerhalb der sogenannten Roche-Zone des jeweiligen Planeten befinden, ist ein effektives, allein auf gravitativen Wechselwirkungen beruhendes Größenwachstum nicht zu erwarten. Der Einfluß von Teilchenadhäsion auf diese Prozesse ist bis dato fraglich. Im Rahmen dieser Dissertation ist ein Kontaktmodell für adhäsive, viskoelastische Binärstöße granularer Teilchen entwickelt worden, welches sowohl deren Agglomeration als auch Restitution gestattet. Chakateristisch für granulare Materie ist die dissipative Wechselwirkung der einzelnen Teilchen untereinander. Dieser Energieverlust wird gewöhnlich mittels des Restitutionskoeffizienten erfaßt, der das Verhältnis von Relativgeschwindigkeiten nach zu vor dem Stoß darstellt. Dieser Parameter ermöglicht es, Agglomeration und Restitution nicht nur qualitativ sondern auch quantitativ voneinander zu unterscheiden. Ferner ergibt sich eine maximale Impaktgeschwindigkeit, bei der eine Agglomeration noch immer möglich ist. Basierend auf der Existenz derartiger Grenzgeschwindigkeiten für Agglomeration und Fragmentation, wurde in dieser Dissertation ein selbstkonsistentes, kinetisches Strukturbildungsmodell vorgestellt und im Hinblick auf die Koagulation von Teilchen weitergehend untersucht. Eine Koagulationsgleichung, die einer eingeschränkten Haftwahrscheinlichkeit Rechnung trägt, ist analytisch hergeleitet worden. Aus ihr läßt sich die allgemein bekannte, aber ansonsten phenomenologische Smoluchowski Gleichung als ein Grenzfall ableiten, bei dem jeder mögliche Kontakt zur Koagulation führt. Qualitative und quantitative Untersuchungen der Relevanz von Adhäsion in kräftefreien und Kepler-gescherten Systemen beziehen sich auf die Stabilität von Zwei-Teilchen-Agglomeraten, die Wahrscheinlichkeit eines gegenseitigen "Einfangens" beider Teilchen, und die zeitliche Entwicklung der Größenverteilung unter Berücksichtigung der im ersten Teil dieser Arbeit eingeführten Kollisionsdynamik. Dabei ergab sich ein kritischer Abstand zum Zentralkörper, der das ansonsten in diesem Rahmen benutzte Roche Kriterium erweitert. Numerische Simulationen der vorgestellten Koagulationsgleichung zeigen deutlich, daß im Vergleich zu Smoluchowski-ähnlichem Verhalten, ein kollisionsbasiertes Wachstum von kleineren zu größeren Körpern nicht notwendigerweise auftritt. Lediglich Größen von Zentimetern konnten an dieser Stelle erreicht werden. Die Relevanz von adhäsiven Teilchenwechselwirkungen konnte damit nachgewiesen werden. Vermögen diese auch nicht für ein effektives Wachstum aufzukommen, so sind sie dennoch von Bedeutung für die kollektive Dynamik planetarer Ringe.
KW - Saturn
KW - Cassini
KW - Adhäsion
KW - Kinetik
KW - Planetare Ringe
KW - Roche Limit
KW - Roche
KW - Agglomeration
KW - Kollisionsdynamik
KW - planetary rings
KW - Saturn
KW - collision dynamics
KW - adhesion
KW - kinetics
KW - kinetic
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10848
ER -
TY - JOUR
A1 - Akpo, Claudia
A1 - Weber, Edwin
A1 - Reiche, Jürgen
T1 - Synthesis, Langmuir and Langmuir-Blodgett film behaviour of new dendritic amphiphiles
JF - New journal of chemistry
N2 - New amphiphilic compounds 1-9 that feature a construction with dendronized hydrophilic and hydrophobic segment groups connected to a specific aromatic or aliphatic spacer unit have been synthesized, following a modular building block strategy. The hydrophilic dendrons are typically branched elements with peripheral carboxylic groups, unlike the hydrophobic dendrons that contain peripheral alkyl chains as part of respective amide functions. The hydrophilic dendrons are in different generations of branching, while the hydrophobic dendrons are all in the first generation of branching (three terminal branching), but differ in the length of the alkyl chains, thus giving rise to designed structure and amphiphilic properties in the new compounds. The resulting surfactants are capable of forming well-defined Langmuir films of remarkable stability when spread from a solution onto an aqueous subphase. Nevertheless, specific packing behaviour and orientation of the amphiphilic molecules were found, depending on the molecular structure, as determined using analysis of the surface pressure-area (pi-A) isotherms. Langmuir-Blodgett transfer of the first monolayer from a pure water subphase to a clean silicon wafer proved possible for the amphiphiles of peripheral alkyl chain length C-12, while the amphiphiles with the longer alkyl chains failed, possibly due to the more rigid monolayers they form, impeding the transfer.
Y1 - 2006
U6 - https://doi.org/10.1039/b609645j
SN - 1144-0546
SN - 1369-9261
VL - 30
SP - 1820
EP - 1833
PB - RSC
CY - Cambridge
ER -
TY - JOUR
A1 - Abel, Markus
A1 - Stojkovic, Dragan
A1 - Breuer, Michael
T1 - Nonlinear stochastic estimation of wall models for LES
N2 - A key technology for large eddy simulation (LES) of complex flows is an appropriate wall modeling strategy. In this paper we apply for the first time a fully nonparametric procedure for the estimation of generalized additive models (GAM) by conditional statistics. As a database, we use DNS and wall-resolved LES data of plane channel flow for Reynolds numbers, Re = 2800, 4000 (DNS) and 10,935, 22,776 (LES). The statistical method applied is a quantitative tool for the identification of important model terms, allowing for an identification of some of the near-wall physics. The results are given as nonparametric functions which cannot be attained by other methods. We investigated a generalized model which includes Schumann's and Piomelli et al.'s model. A strong influence of the pressure gradient in the viscous sublayer is found; for larger wall distances the spanwise pressure gradient even dominates the tau(w,zy). component. The first a posteriori LES results are given.
Y1 - 2006
UR - http://www.sciencedirect.com/science/journal/0142727X
U6 - https://doi.org/10.1016/j.heatfluidflow.2005.10.011
SN - 0142-727X
ER -
TY - JOUR
A1 - Abel, Markus
A1 - Bergweiler, Steffen
A1 - Gerhard, Reimund
T1 - Synchronization of organ pipes : experimental observations and modeling
N2 - We report measurements on the synchronization properties of organ pipes. First, we investigate influence of an external acoustical signal from a loudspeaker on the sound of an organ pipe. Second, the mutual influence of two pipes with different pitch is analyzed. In analogy to the externally driven, or mutually coupled self-sustained oscillators, one observes a frequency locking, which can be explained by synchronization theory. Further, we measure the dependence of the frequency of the signals emitted by two mutually detuned pipes with varying distance between the pipes. The spectrum shows a broad '' hump '' structure, not found for coupled oscillators. This indicates a complex coupling of the two organ pipes leading to nonlinear beat phenomena.
Y1 - 2006
UR - http://scitation.aip.org/jasa/
U6 - https://doi.org/10.1121/1.217044
SN - 0001-4966
ER -
TY - BOOK
ED - Görtemaker, Manfred
T1 - Britain and Germany in the 20th Century
T3 - German historical perspectives
Y1 - 2006
SN - 1-85973-842-7
VL - 18
PB - Berg
CY - Oxford
ET - Engl. ed.
ER -