TY  - JOUR
A1  - Srama, Ralf
A1  - Kempf, S.
A1  - Moragas-Klostermeyer, Georg
A1  - Helfert, S.
A1  - Ahrens, T. J.
A1  - Altobelli, N.
A1  - Auer, S.
A1  - Beckmann, U.
A1  - Bradley, J. G.
A1  - Burton, M.
A1  - Dikarev, V. V.
A1  - Economou, T.
A1  - Fechtig, H.
A1  - Green, S. F.
A1  - Grande, M.
A1  - Havnes, O.
A1  - Hillierf, J.K.
A1  - Horanyii, M.
A1  - Igenbergsj, E.
A1  - Jessberger, E. K.
A1  - Johnson, T. V.
A1  - Krüger, H.
A1  - Matt, G.
A1  - McBride, N.
A1  - Mocker, A.
A1  - Lamy, P.
A1  - Linkert, D.
A1  - Linkert, G.
A1  - Lura, F.
A1  - McDonnell, J.A.M.
A1  - Möhlmann, D.
A1  - Morfill, G. E.
A1  - Postberg, F.
A1  - Roy, M.
A1  - Schwehm, G.H.
A1  - Spahn, Frank
A1  - Svestka, J.
A1  - Tschernjawski, V.
A1  - Tuzzolino, A. J.
A1  - Wäsch, R.
A1  - Grün, E.
T1  - In situ dust measurements in the inner Saturnian system
JF  - Planetary and space science
N2  - In July 2004 the Cassini–Huygens mission reached the Saturnian system and started its orbital tour. A total of 75 orbits will be carried out during the primary mission until August 2008. In these four years Cassini crosses the ring plane 150 times and spends approx. 400 h within Titan's orbit. The Cosmic Dust Analyser (CDA) onboard Cassini characterises the dust environment with its extended E ring and embedded moons. Here, we focus on the CDA results of the first year and we present the Dust Analyser (DA) data within Titan's orbit. This paper does investigate High Rate Detector data and dust composition measurements. The authors focus on the analysis of impact rates, which were strongly variable primarily due to changes of the spacecraft pointing. An overview is given about the ring plane crossings and the DA counter measurements. The DA dust impact rates are compared with the DA boresight configuration around all ring plane crossings between June 2004 and July 2005. Dust impacts were registered at altitudes as high as 100 000 km above the ring plane at distances from Saturn between 4 and 10 Saturn radii. In those regions the dust density of particles bigger than 0.5 can reach values of 0.001m-3.
KW  - Cassini
KW  - dust
KW  - CDA
KW  - E-ring
KW  - water ice
Y1  - 2006
U6  - https://doi.org/10.1016/j.pss.2006.05.021
SN  - 0032-0633
VL  - 54
IS  - 9-10
SP  - 967
EP  - 987
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Steuer, Ralf
A1  - Gross, Thilo
A1  - Selbig, Joachim
A1  - Blasius, Bernd
T1  - Structural kinetic modeling of metabolic networks
JF  - Proceedings of the National Academy of Sciences of the United States of America
N2  - To develop and investigate detailed mathematical models of metabolic processes is one of the primary challenges in systems biology. However, despite considerable advance in the topological analysis of metabolic networks, kinetic modeling is still often severely hampered by inadequate knowledge of the enzyme-kinetic rate laws and their associated parameter values. Here we propose a method that aims to give a quantitative account of the dynamical capabilities of a metabolic system, without requiring any explicit information about the functional form of the rate equations. Our approach is based on constructing a local linear model at each point in parameter space, such that each element of the model is either directly experimentally accessible or amenable to a straightforward biochemical interpretation. This ensemble of local linear models, encompassing all possible explicit kinetic models, then allows for a statistical exploration of the comprehensive parameter space. The method is exemplified on two paradigmatic metabolic systems: the glycolytic pathway of yeast and a realistic-scale representation of the photosynthetic Calvin cycle.
KW  - systems biology
KW  - computational biochemistry
KW  - metabolomics
KW  - metabolic regulation
KW  - biological robustness
Y1  - 2006
U6  - https://doi.org/10.1073/pnas.0600013103
SN  - 0027-8424
SN  - 1091-6490
VL  - 103
IS  - 32
SP  - 11868
EP  - 11873
PB  - National Academy of Sciences
CY  - Washington
ER  - 
TY  - JOUR
A1  - Makuch, Martin
A1  - Brilliantov, Nikolai V.
A1  - Sremcevic, Miodrag
A1  - Spahn, Frank
A1  - Krivov, Alexander V.
T1  - Stochastic circumplanetary dynamics of rotating non-spherical dust particles
JF  - Planetary and space science
N2  - We develop a model of stochastic radiation pressure for rotating non-spherical particles and apply the model to circumplanetary dynamics of dust grains. The stochastic properties of the radiation pressure are related to the ensemble-averaged characteristics of the rotating particles, which are given in terms of the rotational time-correlation function of a grain. We investigate the model analytically and show that an ensemble of particle trajectories demonstrates a diffusion-like behaviour. The analytical results are compared with numerical simulations, performed for the motion of the dusty ejecta from Deimos in orbit around Mars. We find that the theoretical predictions are in a good agreement with the simulation results. The agreement however deteriorates at later time, when the impact of non-linear terms, neglected in the analytic approach, becomes significant. Our results indicate that the stochastic modulation of the radiation pressure can play an important role in the circumplanetary dynamics of dust and may in case of some dusty systems noticeably alter an optical depth. (c) 2006 Elsevier Ltd. All rights reserved.
KW  - Mars
KW  - Deimos
KW  - ejecta
KW  - stochastics
KW  - radiation pressure
Y1  - 2006
U6  - https://doi.org/10.1016/j.pss.2006.05.006
SN  - 0032-0633
VL  - 54
IS  - 9-10
SP  - 855
EP  - 870
PB  - Elsevier
CY  - Oxford
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  - JOUR
A1  - Joulain, Karl
A1  - Henkel, Carsten
A1  - Greffet, Jean-Jacques
T1  - Influence of the dependence in temperature of the optical properties of materials on the Casimir force
JF  - Journal de physique IV
N2  - Nous évaluons la force de Casimir entre deux surfaces planes métalliques constituées d'argent. Nous prenons, pour effectuer cette évaluation, des propriétés optiques de l'argent à différentes températures [1]. Nous montrons que cette dépendance en température modifie la force de Casimir (de 0.2%) y compris à des distances inférieures à la longueur d'onde thermique.
Y1  - 2006
U6  - https://doi.org/10.1051/jp4:2006135021
SN  - 1155-4339
VL  - 135
SP  - 113
EP  - 114
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Diez, Isabel
A1  - Tauer, Klaus
A1  - Schulz, Burkhard
T1  - Unusual polymer dispersions-polypyrrole suspensions made of rings, frames, and platelets
JF  - Colloid and polymer science : official journal of the Kolloid-Gesellschaft
N2  - Experimental results show that the polymerization of pyrrole in the presence of beta-naphthalenesulfonic acid and different fluorosurfactants like perfluorooctanesulfonic acid, perfluorooctyldiethanolamide, and ammonium perfluorooctanoate leads to polypyrrole with special morphologies, such as rings or disks and rectangular frames or plates. The formation of these unusually shaped particles of polymer dispersions is explained by the chemical and colloidal peculiarities of the oxidative pyrrole polymerization with ammonium peroxodisulfate in aqueous medium.
KW  - polypyrrole
KW  - chemical oxidative polymerization
KW  - particle morphology
Y1  - 2006
U6  - https://doi.org/10.1007/s00396-006-1521-8
SN  - 0303-402X
VL  - 284
SP  - 1431
EP  - 1442
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Richter, Lothar
A1  - Vollhardt, Dieter
T1  - Force measuring methods for determination of surface tension of liquids: A comparison
JF  - Tenside, surfactants, detergents
N2  - Three methods for the determination of the surface tension of liquids based on force measurements namely, the vertical plate method of Wilhelmy, the frame method of Lenard and the ring method of du Nouy are compared and studied in respect of a common principle of correction. It is shown that these three most important force-based methods allow the determination of the surface tension under static conditions. The force components of the corresponding liquid column below the measuring wire obtained for the straight part of the withdrawal curve up to the transition in its curved part provides exact surface tension values. The experimentally accessible value of the force component describes the physical background of the measured value correction contrary to the approximate equations obtained by mathematical way. Usually the determination of surface tension of liquids is based merely at the vertical plate method on exact equations thermodynamically derived whereas in the case of the frame and ring methods correction factors in approximate equations are used. At usual application of the force-based methods under the non-static condition of the withdrawal of a liquid column, the force maximum measured at withdrawal of the measuring object (plate, frame, or ring) is the basis for the determination of surface tension. In these cases, the measured surface tension values are compensated by correction equations for the frame and ring methods which are based on an correction factor and correction tables empirically obtained. The surface tension values obtained in this usual way agree with those obtained by using the force component of the corresponding liquid column below the measuring wire for the straight part of the withdrawal curve up to the transition in its curved part. Problems arising at the force measurements with increasing thickness of the measuring wires inside and outside the rings are discussed.
N2  - Drei auf Kraftmessungen basierende Methoden zur Bestimmung der Oberflächenspannung von Flüssigkeiten, nämlich die Vertikalplattenmethode von Wilhelmy, die Bügelmethode von Lenard und die Ringmethode von du Noüy werden miteinander verglichen und auf ein experimentell zugängliches gemeinsames Korrekturprinzip hin untersucht. Auf Basis der Messresultate wird demonstriert, dass diese drei wichtigsten auf Kraftmessungen basierenden Methoden eine exakte Bestimmung der Oberflächenspannung ermöglichen. Dies basiert auf Berücksichtigung der Kraftkomponente der entsprechenden Flüssigkeitssäule unterhalb des Messdrahtes, der für die Austauchgerade bis zum Übergang in den gekrümmten Teil der Austauchkurve erhalten wird. Der experimentell zugängliche Wert der Kraftkomponente beschreibt den physikalischen Hintergrund der Messwertkorrektur im Gegensatz zu den auf mathematischen Weg erhaltenen Näherungsgleichungen. Gebräuchlicher Weise basiert die Bestimmung der Oberflächenspannung von Flüssigkeiten lediglich bei der Vertikalplattenmethode auf thermodynamisch-exakt ableitbaren Gleichungen, während bei Bügel- und Ringmethode Korrekturfaktoren für Näherungsgleichungen bzw. Korrekturtabellen üblich sind. Die so erhaltenen Oberflächenspannungswerte stimmen mit denen überein, die unter Berücksichtigung der Kraftkomponente der entsprechenden Flüssigkeitssäule unterhalb des Messdrahtes erhalten werden. Probleme, die mit zunehmender Dicke des Messdrahtes innerhalb und außerhalb des Rings entstehen, werden diskutiert.
T2  - Kraftmessungsmethoden zur Bestimmung der Oberflächenspannung von Flüssigkeiten: Ein Vergleich
KW  - surface tension
KW  - force methods
Y1  - 2006
U6  - https://doi.org/10.3139/113.100314
SN  - 0932-3414
VL  - 43
IS  - 5
SP  - 256
EP  - 261
PB  - Hanser
CY  - München
ER  - 
TY  - JOUR
A1  - Poeschel, Thorsten
A1  - Brilliantov, Nikolai V.
A1  - Formella, Arno
T1  - Impact of high-energy tails on granular gas properties
JF  - Physical review : E, Statistical, nonlinear and soft matter physics
N2  - The velocity distribution function of granular gases in the homogeneous cooling state as well as some heated granular gases decays for large velocities as f proportional to exp(-const x nu). That is, its high-energy tail is overpopulated as compared with the Maxwell distribution. At the present time, there is no theory to describe the influence of the tail on the kinetic characteristics of granular gases. We develop an approach to quantify the overpopulated tail and analyze its impact on granular gas properties, in particular on the cooling coefficient. We observe and explain anomalously slow relaxation of the velocity distribution function to its steady state.
Y1  - 2006
U6  - https://doi.org/10.1103/PhysRevE.74.041302
SN  - 1539-3755
SN  - 1550-2376
VL  - 74
IS  - 4
PB  - The American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Zaikin, Alexey
A1  - Kurths, Jürgen
T1  - Optimal length transportation hypothesis to model proteasome product size distribution
JF  - Journal of biological physics : emphasizing physical principles in biological research ; an international journal for the formulation and application of mathematical models in the biological sciences
N2  - This paper discusses translocation features of the 20S proteasome in order to explain typical proteasome length distributions. We assume that the protein transport depends significantly on the fragment length with some optimal length which is transported most efficiently. By means of a simple one-channel model, we show that this hypothesis can explain both the one- and the three-peak length distributions found in experiments. A possible mechanism of such translocation is provided by so-called fluctuation-driven transport.
KW  - proteasome
KW  - protein translocation
KW  - stochastic process
KW  - ratchets
Y1  - 2006
U6  - https://doi.org/10.1007/s10867-006-9014-z
SN  - 0092-0606
VL  - 32
IS  - 3-4
SP  - 231
EP  - 243
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Oskinova, Lida
A1  - Feldmeier, Achim
A1  - Hamann, Wolf-Rainer
T1  - High-resolution X-ray spectroscopy of bright O-type stars
JF  - Monthly notices of the Royal Astronomical Society
N2  - Archival X-ray spectra of the four prominent single, non-magnetic O stars zeta Pup, zeta Ori, xi Per and zeta Oph, obtained in high resolution with Chandra HETGS/MEG have been studied. The resolved X-ray emission line profiles provide information about the shocked, hot gas which emits the X-radiation, and about the bulk of comparably cool stellar wind material which partly absorbs this radiation. In this paper, we synthesize X-ray line profiles with a model of a clumpy stellar wind. We find that the geometrical shape of the wind inhomogeneities is important: better agreement with the observations can be achieved with radially compressed clumps than with spherical clumps. The parameters of the model, i.e. chemical abundances, stellar radius, mass-loss rate and terminal wind velocity, are taken from existing analyses of UV and optical spectra of the programme stars. On this basis, we also calculate the continuum-absorption coefficient of the cool-wind material, using the Potsdam Wolf-Rayet (POWR) model atmosphere code. The radial location of X-ray emitting gas is restricted from analysing the FIR line ratios of helium-like ions. The only remaining free parameter of our model is the typical distance between the clumps; here, we assume that at any point in the wind there is one clump passing by per one dynamical time-scale of the wind. The total emission in a model line is scaled to the observation. There is a good agreement between synthetic and observed line profiles. We conclude that the X-ray emission line profiles in O stars can be explained by hot plasma embedded in a cool wind which is highly clumped in the form of radially compressed shell fragments.
KW  - stars : individual : zeta Pup
KW  - stars : individual : zeta Ori
KW  - stars : individual : xi Per
KW  - stars : individual : zeta Oph
KW  - X-rays : stars
Y1  - 2006
U6  - https://doi.org/10.1111/j.1365-2966.2006.10858.x
SN  - 0035-8711
VL  - 372
SP  - 313
EP  - 326
PB  - Oxford University Press
CY  - Oxford
ER  -