bluuebunny/crossref_metadata_2025 huggingface dataset:
Zur gasdynamischen Auslegung eines Stosswellenkanals
Authors: Schemperg Katrin , Mundt Christian
Published: December 2004

Ein Stosswellenkanal wird zur experimentellen Simulation von Hochenthalpieströmungen, wie sie beispielsweise beim Wiedereintritt von Raumflugkörpern in eine Atmosphäre auftreten, verwendet. Bei gleichzeitigem Betrieb eines Plasmabrenners (der u. a. der Modellaufheizung dient) kann zusätzlich die Interaktion eines Hochenthalpiestrahles mit einer Hyperschallströmung untersucht werden. Hierbei sind ins besondere Untersuchungen der aerothermodynamischen Phänomene der Hochgeschwindigkeits‐ bzw. Hochenthalpieströmung von Interesse. Die gasdynamische Auslegung des Stosswellenkanals umfasst die adiabatische Treibergaskompression durch einen mit Druckgas angetriebenen Kolben, der durch das komprimierte Treibergas bis zum Ende des Treiberrohres zum Stillstand kommen muss. Gleichzeitig bricht eine am Rohrende angebrachte Stahlmembran und eine Stosswelle läuft in das Stossrohr, bis sie am Rohrende reflektiert wird. Hier bildet sich nun eine ortsfeste Region hohen Druckes und hoher Temperatur aus. Eine zweite Membran bricht, und das Gas expandiert durch eine Düse. Um für einen möglichst langen Zeitraum das Ausströmen der Hochenthalpieströmung zu gewährleisten, muss die Stossreflexion im sog. tailored interface mode erfolgen, das heisst, die ursprünglichen Gaszustandsgrössen werden so gewählt, dass der reflektierte Stoss die nachfolgende Kontaktfläche zum Stillstand bringt. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigations of shear free turbulent diffusion in a rotating frame
Authors: Guenther S. , Oberlack  , Brethouver G. , Johansson A. V.
Published: December 2004

We reconsider the problem of shear free turbulent diffusion in a rotating frame, rotating about x1. Shear free turbulence is generated at a vibrating grid in the x2–x3 plane and diffuses away from the grid in x1 direction. An important property of this flow case is that there is no mean flow‐velocity. With the help of Lie‐group methods Reynolds‐stress transport models can be analyzed for this kind of flow in a rotating frame. From the analysis it can be found, that the turbulent diffusion only influences a finite domain. Implicating this solution in the model equations shows that even fully nonlinear Reynolds‐stress transport models (non‐linear in the Reynolds‐stresses for the pressure‐strain model) are insensitive to rotation for this type of flow. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mass Transfer in Porous Media
Authors: Ricken Tim
Published: December 2004

In this contribution, a constitutive model based on the macromechanical Theory of Porous Media (TPM) for a saturated thermo elastic porous body has been developed. The body under investigation consists of an organic and inorganic moisturized phases and a gas phase. Based on a consistent thermomechanical treatment, the governing equations and constitutive equations will be given. Thus, we obtain a mathematical concept describing the motion of the solid phase, the pressure of the gas phase, the temperature of the mixture and the biodegradation of organic material into a gas mixture of methane and carbon dioxide produced by bacterial decomposition during stable methane fermentation (biogas). (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Time Domain Impedance Boundary Conditions for a Slip Mean FlowBoundary
Authors: Zhuang M. , Zheng S. , Thiele F.
Published: December 2004

In modeling the physical condition of an impedance boundary, the assumption of either particle displacement continuity (PDC) or particle normal velocity continuity (PVC) at the interface between the acoustic treatment and the adjacent fluid needs to be used. Although it is well accepted that the impedance boundary condition derived from the PDC is the appropriate impedance boundary condition when there is a slip mean flow at the liner surface, the time domain impedance boundary condition is however unstable due to the Kelvin‐Helmholtz instability associated with the ”vortex sheet.” In this paper, an effective time domain impedance boundary condition for a slip mean flow boundary is proposed and validated. Several relevant issues related to the PDC and PVC are discussed. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spherical Radon Transform and Wavelets
Authors: Cerejeiras P.
Published: December 2004

In this paper we shall approach the problem of localization and inversion of spherical Radon transform. This motivates the construction of particular wavelets, based on a suitable representation of the unitary group via Gel'fand's projective model Pℝ3
Numerical Simulation of Two‐Phase Flows Through Injection Nozzles
Authors: Dickopp Christian , Ballmann Josef
Published: December 2004

The characteristic properties of an injection jet and the spray behind the exit of an injection nozzle depend on cavitation phenomena within the nozzle. The presented research project aims at modelling the distributions of pressure, velocity and phase fractions at the nozzle exit based on numerical simulation of the two‐phase flow within the nozzle. The mathematical and physical description assumes the liquid and the gas within the cavitation bubbles as compressible, viscous and heat conductive fluids and also includes dynamical processes in the mixture. The solution of the Navier‐Stokes equations for the mixture is approximated by a finite element method in two space dimensions and explicit in time using an improved FCT‐strategy to achieve nonlinear stability. Linear aspects of stability were analyzed as well, especially with respect to the used homogeneous model and provided upper bounds for the time step. The method is applied for the simulation of transient processes in one‐ and two‐phase flow through injection nozzles with constant or variable cross‐section. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Local buckling of a bent flange of a thin walled beam
Authors: Stasiewicz P. , Magnucki K. , Lewiński J. , Kasprzak J.
Published: December 2004

The paper is devoted to stability of repeatedly bent flange of a thin‐walled beam. In classical approach each segment of the flange is considered as a simple plate. The paper provides an analytical description of the whole flange as a thin‐walled structure with the use of an energetic method. An explicit formula defining the critical load of the flange was obtained. This enables to perform a numerical analysis of a family of thin‐walled beams. Additionally, a numerical analysis with FEM was carried out. The results of both approaches have been compared. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical Investigation of the Interaction of Turbulent Wind Flow and Elastic Structures
Authors: Al Farra Anas , Hübner Björn , Dinkler Dieter
Published: December 2004

The Interaction between wind flow and structures plays an important role in the computation of civil engineering application. In case of gravity prestressed membrane roofs, the wind lifting forces may exceed the dead load leading to high amplitude structural oscillations, which interact with the flow field. To investigate the interaction a consistent discretization method based on stabilized space‐time finite elements is applied. The flow field is modeled with the incompressible Reynolds Averaged Navier‐Stokes (RANS) equations with an anisotropic eddy‐viscosity turbulence model. The structural motion is described with the theory for geometrically nonlinear elastic deformation behavior, a strong coupling algorithm for the time‐dependent fluid‐structure interaction is implemented. Two applications show the capability of the turbulence model in representing the anisotropic turbulence structure, the differences in the flow field over a bluff body between two configurations representing a rigid and an elastic membrane roof, discusses the structural responses of the roof at a high Reynolds number. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interactive computing methods for aeroelastic analysis of turbomachinery
Authors: Dumitrache Alexandru
Published: December 2004

An interaction viscous‐inviscid method for efficiently computing steady and unsteady viscous flows is presented. The inviscid domain is modeled using a finite element discretization of the full potential equation. The viscous region is modeled using a finite difference boundary layer technique. The two regions are simultaneously coupled using the transpiration approach. A time linearization technique is applied to this interactive method. For unsteady flows, the fluid is assumed to be composed of a mean or steady flow plus a harmonically varying small unsteady disturbance. Numerically exact nonreflecting boundary conditions are used for the far field conditions. Results for some steady and unsteady, laminar and turbulent flow problems are compared to linearized Navier‐Stokes or time‐marching boundary layer methods. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An Accurate Distance Algorithm for Octree‐Encoded Objects
Authors: Dyllong Eva , Luther Wolfram
Published: December 2004

Distance algorithms are most frequently used in robotics to determine the distance between two obstacles in the environment of a robot or between a sensor point and an object. Bounding volumes are a common technique; this technique relies on a hierarchical model representation of the two surfaces using axis‐aligned bounding boxes. Formoving objects it is interesting to use unaligned octrees to avoid the wrapping effect that occurs when performing octree decomposition in a common coordinate system after several rotations. We discuss the algorithm for computing accurate enclosures for the distance between objects represented by axis‐aligned or unaligned octrees. This algorithm is based on a new, recently published distance algorithm between two objects represented by axis‐aligned octrees. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Generierung kollisionsfreier Fahrzeugbahnen für Fahrerassistenzsysteme mittels der Theorie elastischer Bänder
Authors: Hirsch Karina , Hilgert Jens , Hiller Manfred , Bertram Torsten
Published: December 2004

Zur Verbesserung der Sicherheit im Straßenverkehr werden in Zukunft zunehmend Fahrerassistenzsysteme zur Unterstützung des Fahrers bei der Fahrzeugführung eingesetzt. Insbesondere werden für kritische Situationen Notfalltrajektorien benötigt, deren Planung mit Hilfe der Theorie der elastischen Bänder vorgenommen werden kann. Die zugehörige Ausweichbahn legt sich dabei ähnlich einem physikalischen elastischen Band um das Hindernis. Sowohl die innere Kontraktion als auch die externe Repulsion der Hindernisse werden mit Hilfe von Federpotenzialen realisiert. Lokale äußere Einflüsse auf das Band wirken sich global aus, so dass die Krümmungsänderungen minimiert und somit auch Gefahren f ür das Fahrzeug reduziert werden. Dabei werden die Trajektorien für Fahrmanöver, wie z.B. für einen Spurwechsel, und die zugehörige Ausweichbahn durch kubische Splines generiert. Die fahrdynamische Realisierbarkeit der generierten Notfalltrajektorie unter den gegebenen Randbedingungen, wie Fahrzeuggeschwindigkeit und Witterungsverhältnisse, wird mit Hilfe eines auf ein Fahrdynamikmodell angewandtes Least‐Squares‐Verfahren vorab sichergestellt. Das vorgestellte theoretische Verfahren ist Bestandteil eines deutsch‐niederländischen Kooperationsprojektes und wird am Beispiel des Szenarios einer Kolonnenfahrt auf einer mehrspurigen Fahrbahn mit Ein‐ und Ausfädelvorgängen einzelner Fahrzeuge demonstriert. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
New Aspects For Bifurcation Problems in Continuous Mechanics
Authors: Sburlan Cristina , Sburlan Silviu
Published: December 2004

Consider a semilinear eigenvalue problem

where λ ∈ R, the linear operator $ \cal L $ is defined in a real Hilbert space H and $ \cal N $ : H → H is generaly a nonlinear perturbation.

We can define a coincidence degree of the pair ($ \cal L, \cal N $) under some conditions weaker than the ones when the classical coincidence degree was defined. Our final purpose is to extend the results to the case of the operators from the Banach space X into its dual X*, using the representation theorem due to Browder and Ton.

We use these results to study resonance problems in mechanics of continua, such as the buckling in finite elastostatics and the steady state flow of incompressible fluids. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimally matched wavelets
Authors: Thielemann Henning
Published: December 2004

Several applications require to retrieve a certain pattern from a signal where the actual scaling of the pattern is not known before. We consider applications like evaluation of mass spectrograms, detection of component wearout by observing the current of an engine, detection of pollutions of rotor spinning machines, decomposition of (audio) signals into time‐frequency atoms.

We try to solve this problem with discrete wavelet transforms where the wavelet function is constructed to match the given pattern. An approach for a biorthogonal basis constructed by the lifting scheme is presented. This method is rather simple and fast and allows the choice of the smoothness at least of the primal wavelet in a very natural way. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
New Accurate Expressions in C‐XSC
Authors: Lüderitz Kolberg Mariana , Amaral Hölbig Carlos , Bohlender Gerd , Moraes Claudio Dalcidio
Published: December 2004

C‐XSC is a programming library for Extended Scientific Computing which supports many data types with high accuracy. However, it does not provide the accurate expressions which are already available in the older language PASCAL‐XSC. These expressions have to be replaced by long loops that are more difficult to understand. Therefore, we studied possibilities how these accurate expressions could be implemented in C‐XSC. In this paper we present possibilities like operator overloading with special result types avoiding rounding errors, and a small pre‐processor which converts accurate expressions to function calls. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
CoStLy: A Validated Library for Complex Functions
Authors: Neher Markus , Eble Ingo
Published: December 2004

CoStLy is a new C++ library for the validated computation of function values and of ranges of complex standard functions. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Random Vibration of the Uncertain Parametric Micro‐Periodic Beam ‐ General Solution
Authors: Mazur‐Sniady K. , Sniady P.
Published: December 2004

The subject of the analysis are random vibrations of the beam having uncertain periodic structure. It is assumed that excitation load is described by stationary or nonstationary stochastic process. The parameters of the beam have the uncertain nature and are described by random variables. The problem is solved using the tolerance averaging procedure, the stochastic Green function and the perturbation method. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reliability of Deterioration System
Authors: Sniady Pawel , Sieniawska Roza , Zukowski Stanislaw
Published: December 2004

Mathematical models of the reliability assessment of a structure treated as the time to the first passage of the capacity which is degrading in the time are presented. Two stochastic models of the structure degradation caused by different factors and two stochastic models of loading are considered. The relationships for calculating the probability of failure for presented models of the structure load and the capacity degradation, are given. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimization in aircraft engineering including approximate structural evaluations by support vector machines
Authors: Kaletta Peter , Wolf Klaus , Fischer Andreas , Löschner Kristina
Published: December 2004

The minimum weight design of structures made of fiber reinforced composite materials leads to a class of mixed‐integer optimization problems for which evolutionary algorithms (EA) are well suited. Based on these algorithms the optimization tool package GEOPS has been developed at TU Dresden.

For each design generated by an EA the structural response has to be evaluated. This is often based on a finite element analysis which results in a high computational complexity for each single design. Typical runs of EA require the evaluation of thousands of designs. Thus, an efficient approximation of the structural response could improve the performance considerably. To achieve this aim the constraints on the structural response are approximated by means of support vector machines (SVM). It is trained by means of exact structural evaluations for selected design alternatives only. Several ways to enhance the efficiency of such an optimization procedure are presented.

As an example for a typical aircraft structure, a stiffened composite panel under compressive and shear loading is considered. The SVM is trained on geometrical and material data. Representing the design space of composite panels by ABD matrices turned out to be a valuable means for obtaining well trained SVMs. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimization of Mechanically Coupled Composite Pipes by Genetic Algorithms
Authors: Luxner M. H. , Daxner T. , Rammerstorfer F. G.
Published: December 2004

The optimization of composite components with regard to minimum weight and maximum load bearing capacity in consideration of multiple constraints is an optimization problem of rather high complexity. Genetic Algorithms are a good choice for solving such problems. In this paper the formulation of a Genetic Algorithm for the simultaneous optimization of two thin walled, mechanically coupled composite pipes subjected to a combination of thermal and mechanical loads is presented. The optimization goal is the minimization of the total mass of the pipe arrangement taking into account multiple design constraints. It is shown that Genetic Algorithms are valueable tools for solving optimization problems with a large number of parameters. Furthermore, it is possible to find additional, perhaps practicable, close‐to‐optimal configurations as a byproduct of the optimization process. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Flow Optimization on Traffic Networks
Authors: Kumari Singh Anita , Herty Michael , Klar Axel
Published: December 2004

This work has been motivated by the work of [1]. Here in traffic models for networks based on PDE's are considered. A simplified algebraic model is derived from PDE‐based model. Optimization problem is to minimize cost functional measuring properties of network flows. We use a new approach to solve the minization problem for the reformulated algebraic model. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Weight‐Reduction of Sandwich Structures by an Efficient Topology Optimization Technique
Authors: Tapp Christian , Hansel Wilfried , Mittelstedt Christian , Becker Wilfried
Published: December 2004

A heuristic algorithm for the weight minimization of sandwich structures by a specific kind of topology optimization is presented. The method employs a preexisting algorithm for the layerwise topology optimization of symmetric laminates under in‐plane loads and expands this method for the case of bending. During the optimization procedure the algorithm adds or subtracts material from the layers of the face sheets and the core of the sandwich plate in regions of high or low stresses respectively. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimality Conditions for Mechanical Impacts
Authors: Yunt Kerim , Glocker Christoph
Published: December 2004

In this report the necessary conditions for optimal non‐smooth control of rigid body mechanical systems with multiple impacts will be stated in accordance with Pontryagin's Minimum Principle. Criteria based on the Weierstrass‐Erdmann (WE) conditions and contemporary impact theory will be established in order to assess the optimality of an impact.The determination of post‐impact state and costate values from the pre‐impact values will be possible in some cases. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Eye lens proteomics: from global approach to detailed information about phakinin and gamma E and F crystallin genes
Authors: Hoehenwarter Wolfgang , Kumar Nalin M. , Wacker Maik , Zimny‐Arndt Ursula , Klose Joachim , Jungblut Peter R.
Published: December 2004

Exploration of the lenticular proteome poses a challenging and worthwhile undertaking as cataracts, the products of a disease phenotype elicited by this proteome, remains the leading cause of vision impairment worldwide. The complete ten day old lens proteome of Mus musculus C57BL/6J was resolved into 900 distinct spots by large gel carrier ampholyte based 2‐DE. The predicted amino acid sequences of all 16 crystallins ubiquitous in mammals were corroborated by mass spectrometry (MS). In detailed individual spot analyses, the primary structure of the full murine C57BL/6J beaded filament component phakinin CP49 was sequenced by liquid chromatography/electrospray ionization‐tandem MS and amended at two positions. This definitive polypeptide sequence was aligned to the mouse genome, thus identifying the entire C57BL/6J genomic coding region. Also, two murine C57BL/6J polypeptides, both previously classified as gamma F crystallin, were clearly distinguished by MS and electrophoretic mobility. Both were assigned to their respective genes, one of the polypeptides was reclassified as C57BL/6J gamma E crystallin. Building on these data and previous investigations an updated crystallin reference map was put forth and several non crystallin lenticular components were examined. These results represent the first part of a comprehensive investigation of the mouse lens proteome (http://www.mpiib‐berlin.mpg.de/2D‐PAGE) with emphasis on understanding genetic effects on proteins and disease development.
Transcriptomic and proteomic responses of human renal HEK293 cells to uranium toxicity
Authors: Prat Odette , Berenguer Frédéric , Malard Véronique , Tavan Emmanuelle , Sage Nicole , Steinmetz Gérard , Quemeneur Eric
Published: December 2004

The industrial use of uranium, in particular depleted uranium, has pin‐pointed the need to review its chemical impact on human health. Global methodologies, applied to the field of toxicology, have demonstrated their applicability to investigation of fine molecular mechanisms. This report illustrates the power of toxicogenomics to evaluate the involvement of certain genes or proteins in response to uranium. We particularly show that 25% of modulated genes concern signal transduction and trafficking, that the calcium pathway is heavily disturbed and that nephroblastomas‐related genes are involved (WIT‐1, STMN1, and STMN2). A set of 18 genes was deregulated whatever the concentration of toxicant, which could constitute a signature of uranium exposure. Moreover, a group of downregulated genes, with corresponding disappearing proteins (HSP90, 14‐3‐3 protein, HMGB1) in two‐dimensional polyacrylamide gel electrophoresis (2‐D PAGE), are good candidates for use as biomarkers of uranium effects. These results reveal a cross‐checking between transcriptomic and proteomic technologies. Moreover, our temporal gene expression profiles suggest the existence of a concentration threshold between adaptive response and severe cell deregulation. Our results confirm the involvement of genes already described and also provide new highlights on cellular response to uranium.
Phosphoproteomic analysis using immobilized metal ion affinity chromatography on the basis of cellulose powder
Authors: Feuerstein Isabel , Morandell Sandra , Stecher Guenther , Huck Christian W. , Stasyk Taras , Huang Hong‐Lei , Teis David , Huber Lukas A. , Bonn Guenther K.
Published: December 2004

Detailed characterization of phosphoproteins as well as other post‐translationally modified proteins such as glycoproteins, is required to fully understand protein function and regulatory events in cells and organisms. Therefore, an experimental strategy for the isolation of phosphoproteins using a new immobilized metal ion affinity chromatography (IMAC) material on the basis of cellulose has been developed and characterized. Different approaches have been used to test the material. Recovery rates were determined by 32P labelling of a myelin basic protein fragment and by reversed‐phase high‐performance liquid chromatography‐electrospray ionization mass spectrometry using a tryptic digest of the model protein bovine β‐casein. Selectivity was demonstrated by enrichment and separation of phosphopeptides from different samples, such as from a digest of horse myoglobin as well as from a digest of in vitro phosphorylated extracellular signal regulated kinase 2 (ERK2) mixed with synthetic phosphopeptides, phosphorylated on different amino acid residues. Furthermore, simplification and optimization of sample pretreatment was achieved by combining the separating (IMAC) and desalting (C18) step during preparative high performance liquid chromatography. The comparison between our material and a commercially available IMAC system (POROS 20 MC; Perseptive BioSystems) emphasizes the competitiveness of the cellulose. Confirmed by the obtained data, the cellulose material performed as well as the commercially available sorbent, however with the advantage, that it can be produced rather easily and at very low cost.
Synthesis of a triblock copolymer: Poly(ethylene glycol)‐poly(alkylene phosphate)‐poly(ethylene glycol) as a modifier of CaCO3 crystallization
Authors: Penczek Stanislaw , Pretula Julia , Kaluzynski Krzysztof
Published: December 2004

Triblock copolymer poly(ethylene glycol)‐poly(alkylene phosphate)‐poly(ethylene glycol) was prepared by first reacting hexamethylene glycol with dimethyl‐H‐phosphonate at conditions of transesterification and then replacing the CH3OP(O)(H)O‐… end‐groups by monomethyl ether of poly(ethylene glycol). The course of reaction was studied by 31P NMR indicating complete conversion. After oxidation the poly(alkylene H‐phosphonate was converted into the final triblock polyphosphate. This triblock copolymer was used as a modifier of CaCO3 crystallization. Unusual semi open empty spheres resulted, composed of small crystallites of the size (diameter) equal to 40–90 nm. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 650–657, 2005
Cytoplasmic‐to‐nuclear volume ratio affects AP‐1 complex formation as an indicator of cell cycle responsiveness
Authors: Oney Izzet , Kurnaz Isil Aksan , Kurnaz M. Levent
Published: December 2004

Cytoplasmic volume undergoes a series of changes during mitosis in eukaryotes; in turn, signaling events such as osmotic stress can regulate the cytoplasmic volume in cells. In some organisms, increase in cytoplasmic‐to‐nuclear volume ratio was seen to affect the growth potential in cells, however, the mechanistics of such a regulation, if at all present, was unclear. In a computational model, we have constructed a growth factor‐induced signaling pathway leading to AP‐1 heterodimer formation through transcriptional regulation, and analyzed the effects of increasing the cytoplasmic‐to‐nuclear ratio on c‐jun transcription and AP‐1 complex. We have observed that larger cytoplasmic volumes caused both an increase in the final AP‐1 product and a delay in the time of AP‐1 accumulation.
Novel C‐Raf phosphorylation sites: serine 296 and 301 participate in Raf regulation
Authors: Hekman Mirko , Fischer Andreas , Wennogle Lawrence P. , Wang Y. Karen , Campbell Sharon L. , Rapp Ulf R.
Published: December 2004

The C‐Raf kinase is regulated by numerous phosphorylation steps. To quantify the most prominent phosphorylation sites of C‐Raf, we performed mass spectrometry analysis of wild‐type C‐Raf and the constitutively active C‐Raf mutant C‐Raf‐Y340D/Y341D. We confirmed phosphorylation of most of the sites reported in the literature with the exception that we did not detect phosphorylation of threonine 268/269 (autophosphorylation sites) and threonine 491/serine 494 (kinase activation loop). Importantly, we detected novel phosphorylation sites at the positions of serine 296 and 301. The degree of phosphorylation in these positions depends on the level of activation of C‐Raf. Furthermore, we show here, using point mutant forms of C‐Raf kinases with serine to alanine and serine to aspartic acid substitution, that serines 296 and 301 contribute to negative regulation of C‐Raf.
A novel octameric AMP‐forming acetyl‐CoA synthetase from the hyperthermophilic crenarchaeon Pyrobaculum aerophilum
Authors: Bräsen Christopher , Urbanke Claus , Schönheit Peter
Published: December 2004

AMP‐forming acetyl‐CoA synthetases (ACSs) are ubiquitous in all three domains of life. Here, we report the first characterization of an ACS from a hyperthermophilic organism, from the archaeon Pyrobaculum aerophilum. The recombinant ACS, the gene product of ORF PAE2867, showed extremely high thermostability and thermoactivity at temperatures around 100 °C. In contrast to known monomeric or homodimeric mesophilic ACSs, the P. aerophilum ACS was a 610 kDa homooctameric protein, with a significant lower content of thermolabile (Cys, Asn, and Gln) and higher content of charged (Glu, Lys, and Arg) amino acids. Kinetic analyses revealed an unusual broad substrate spectrum for organic acids and an extremely high affinity for acetate (K
m 3 μM).
Identification of a novel member of yeast mitochondrial Hsp70‐associated motor and chaperone proteins that facilitates protein translocation across the inner membrane
Authors: Yamamoto Hayashi , Momose Takaki , Yatsukawa Yoh-ichi , Ohshima Chié , Ishikawa Daigo , Sato Takehiro , Tamura Yasushi , Ohwa Yukimasa , Endo Toshiya
Published: December 2004

Here, we report the identification of yeast 15‐kD Tim15/Zim17, a new member of mitochondrial Hsp70 (mtHsp70)‐associated motor and chaperone (MMC) proteins. The 15‐kD MMC protein is a peripheral inner membrane protein with a zinc‐finger motif. Depletion of the 15‐kD protein led to impaired import of presequence‐containing proteins into the matrix in vivo and in vitro. Overexpression of the 15‐kD protein rescued the functional defects of mtHsp70 in ssc1‐3 cells, and a fusion protein containing the 15‐kD protein physically interacts with purified mtHsp70. Tim15/Zim17 therefore cooperates with mtHsp70 to facilitate import of presequence‐containing proteins into the matrix.
An elaboration on the syn–anti proton donor concept of glycoside hydrolases: electrostatic stabilisation of the transition state as a general strategy
Authors: Nerinckx W. , Desmet T. , Piens K. , Claeyssens M.
Published: December 2004

An in silico survey of all known 3D‐structures of glycoside hydrolases that contain a ligand in the −1 subsite is presented. A recurrent crucial positioning of active site residues indicates a common general strategy for electrostatic stabilisation directed to the carbohydrate's ring‐oxygen at the transition state. This is substantially different depending on whether the enzyme's proton donor is syn or anti positioned versus the substrate. A comprehensive list of enzymes belonging to 42 different families is given and selected examples are described. An implication for an early evolution scenario of glycoside hydrolases is discussed.
“The last vestige of institutionalized sexism”? Paternalism, Equal Rights and the Death Penalty in Twentieth and Twenty-First Century Sunbelt America: The Case for Florida
Authors: MILLER VIVIEN
Published: December 2004

In February 1941, thirty male San Quentin prisoners petitioned Governor Culbert Levy Olson of California (the state's first Democrat governor in the twentieth century) to stop the execution of Eithel Leta Juanita Spinelli, “a merciless gang leader called the Duchess,” who had been convicted, along with her common-law husband and another male accomplice, of the murder of nineteen-year-old Robert Sherrard. All three defendants were sentenced to die in the gas chamber. Former San Quentin warden, Clinton T. Duffy, remembered Spinelli as “the coldest, hardest character, male or female” that he had “ever known,” and utterly lacking in “feminine appeal.” Thus the presentation of a jailhouse petition to save her from the gas chamber rather perplexed him, and he remained firm in his belief that the majority of San Quentin's inmates were unconcerned by the impending execution. Nonetheless, the petitioners argued that Spinelli should not be executed and offered to take her place either in the death chamber, or to serve out her life term in the event of a commutation of sentence. According to Duffy, the prisoners asserted “that Mrs. Spinelli's execution would be repulsive to the people of California; that no woman in her right mind could commit the crime charged to her; that the execution of a woman would hurt California in the eyes of the world; that both the law and the will of the people were against the execution; that Mrs. Spinelli, as the mother of three children, should have special consideration; that California's proud record of never having executed a woman should not be spoiled”.
Anecdote and the Painting of George Bellows
Authors: FAGG JOHN
Published: December 2004

Excavation at Night (1908), George Bellows' second painting of the construction work undertaken for Pennsylvania Street Station, offers a dramatic depiction of the site that took up two full New York city-blocks. Bellows' decision to paint a nocturnal scene is vital to both the dramatic effect of the painting and its capacity to make an assertion about the ways in which the excavation could be perceived. In Electrifying America, David Nye suggests that the coming of electricity created the possibility of a new form of visual rhetoric. By making it possible to illuminate specific areas of the nocturnal city, electric light facilitated the privileging and deprivileging of certain spaces. By illuminating, and thus privileging, particular areas of the canvas, Bellows implements a similar rhetoric in Excavation at Night. Thus, illuminated by powerful electric lights, the snow covered far wall of the excavation and the row of buildings above it are placed in contrast, and possibly in opposition, with the man silhouetted by the light of the bonfire near the bottom edge of the canvas. The dramatic force of Bellows' “bravura” style raises the stakes in this contrast or opposition between the small-scale human activity around the fire and the large urban story of the excavation. In this article I intend to theorise Bellows' handling of smallness as an “anecdotal mode,” to suggest that “anecdote” may function both negatively and positively, and to show that this mode becomes particularly problematic when it is applied to city scenes.
Examining Political Change and Presidential Power in the US
Authors: DUMBRELL JOHN
Published: December 2004

H. W. Brands, The Strange Death of American Liberalism (New Haven and London: Yale University Press, paperback edition, 2003, £9.95). Pp. 200. ISBN 0 300 098 24 3.

Michael J. Gerhardt, The Federal Appointments Process: A Constitutional and Historical Analysis (Durham NC and London: Duke University Press, revised and expanded paperback edition, 2003, £18.50). Pp. 406. ISBN 0 8223 3199 3.

William G. Howell, Power without Persuasion: The Politics of Direct Presidential Action (Princeton NJ and Oxford: Princeton University Press, 2003, cloth £29.95, paper £12.95). Pp. 239. ISBN 0 691 10269, 0 691 10270 8.

Drew Noble Lanier, Of Time and Judicial Behavior: United States Supreme Court Agenda – Setting and Decision-Making, 1888–1997 (Selinsgrove PA: Susquehanna University Press and London: Associated University Presses, 2003, $42.50). Pp. 276. ISBN 1 57591 067 5.

Byron E. Shafer, The Two Majorities and the Puzzle of Modern American Politics (Lawrence: University Press of Kansas, 2003, cloth $35, paper $19.95). Pp. 356. ISBN 0 7006 1235 1, 0 7006 1236 X.

One does not have to be an especially sophisticated philosopher of explanatory method to appreciate that, in explaining change in human affairs, much depends on the situation of and level of analysis adopted by the would-be explainer. Do the dots connect or are they mostly what they appear to be – just dots? Reality, according to Bertrand Russell's famous aphorism, is either a bowl of connected jelly or a bucket of disconnected shot. It all depends on the observer, who, of course, is also part of the reality being considered.
The Seligenstadt tonary
Authors: BERNHARD MICHAEL
Published: December 2004

The manuscript 3314/15 of the Universitäts- und Landesbibliothek at Darmstadt (originally from Seligenstadt) contains a fragment of a mid-twelfth-century tonary that is essentially identical to interpolations in the tonary of Theoger of Metz transmitted in the manuscript Kassel, 4o Mss. Math. 1. The Seligenstadt tonary is of especial interest, inasmuch as it is one of the first sources to cite differentiae peregrinae in addition to the ordinary differentiae for the psalm tones in each of the ecclesiastical modes. These irregular differentiae were designated ‘peregrinae’ for the first time by Berno. Differentiae peregrinae are occasionally mentioned in the south German cultural sphere during the twelfth century, but by the fourteenth and fifteenth centuries they were being discussed frequently. It is precisely at this time that the fourth differentia of the eighth ecclesiastical mode came to be known as the ‘tonus peregrinus’.
Liturgical chant bibliography 13
Authors: PAUCKER GÜNTHER MICHAEL
Published: December 2004

Liturgical chant bibliography 13 maintains the division of material established in previous editions of the bibliography: (1) Editions and facsimile editions, (2) Books and reprints, (3) Congress reports, (4) Chant journals, (5) Collections of essays and dictionaries, (6) Articles in periodicals and Festschriften. Additions to previous bibliographies (mostly reviews) directly follow this introduction.
The WTO and the poorest countries: the stark reality
Authors: MATTOO AADITYA , SUBRAMANIAN ARVIND
Published: December 2004

Small and poor countries pose a challenge for the World Trade Organization (WTO). These countries have acquired a significant say in WTO decision-making. However, they have limited ability to engage in the reciprocity game that is at the heart of the WTO, and have limited interests in the broader liberalization agenda because of their preferential access to industrial country markets. Accommodating the interests of the small and poor countries is desirable in itself, but would also facilitate expeditious progress in the Doha Round. The stark reality facing the system is that the desirable ways of addressing their concerns – providing them additional financial assistance and nonpreferential market access – is proving infeasible. As a result, the system is gravitating toward the less desirable option of relieving these countries of obligations, including those that might be welfare-enhancing for them.
Common values for the development round
Authors: STIGLITZ JOSEPH E. , CHARLTON ANDREW H.
Published: December 2004

In the traditional theory of international trade, multilateral trade agreements should be easy because self-interested governments unilaterally commit to reduce their own protection and, as a bonus, they reap positive externalities from liberalization by other nations. In practice national governments do not behave as though they are maximizing the welfare of a representative citizen, but instead they respond to pressure from a diverse mix of constituencies and competing special interests. Governments attempt to manage domestic trade-offs within international negotiations, so progress is slow and protection persists. The practical operation of trade negotiations, emblemized by the infamous ‘green rooms’, is characterized by factionalism, horse-trading, and brinkmanship.
Peer commentaries on Keynote articles Trade gains for small island economies
Authors: CHAND SATISH
Published: December 2004

To what extent are the problems of small island economies unique, thus compromising the potential welfare gains from freer international trade? Is comparative advantage enough or even relevant in analysing the benefits from international trade for such economies? If the answer to the latter question is in the negative, then how can the WTO process be modified to maximise gains to the participants? Alan Winters and Pedro Martins (W&M) analyse the first of these two questions, arguing that comparative advantage is not enough, while Aaditya Matoo and Arvind Subramanian (M&S) come to the conclusion that desirable ways of addressing concerns of small countries within the WTO process are proving to be infeasible. Even though W&M and M&S raise legitimate concerns about small economies, I disagree with their policy conclusions. I argue below that comparative advantage is as applicable to small countries as to large countries and that liberal and uniform trading rules for all countries, with the option of temporary lump-sum transfers to the vulnerable ones, can achieve the dual objectives of economic efficiency with redistribution.
Policy reform in small ‘remote economies’
Authors: FINDLAY CHRISTOPHER
Published: December 2004

Winters and Martins (W&M) ask the question of whether small and remote economies are inherently uncompetitive? They conclude that such economies do indeed face ‘huge competitive challenges’ and they discuss options for external sources of income that might contribute to the viability of such communities.
Reply to the commentators
Authors: ALAN WINTERS L. , MARTINS PEDRO M. G.
Published: December 2004

We are grateful to our commentators for their insightful contributions on our paper. We shall not respond to them one-by-one but rather very briefly address the main themes of the commentaries taken as a group.
Cash balance pension plan conversions and the new economy
Authors: CORONADO JULIA LYNN , COPELAND PHILIP C.
Published: December 2004

Many firms that sponsor traditional defined benefit pensions have converted these plans to cash balance plans in the last en years. Cash balance plans in the last ten years combine features of defined benefit and defined contribution plans, and yet their introduction has proven considerably more controversial than has the increasing popularity of defined contribution plans. The goal of this study is to estimate a hierarchy of the influences on the decision of a firm to convert its traditional defined benefit pension plan to a cash balance plan. Our results indicate that cash balance conversions have been undertaken in competitive industries with tight labor markets and thus can be viewed at least in part as a response to better compensate a more mobile labor force. Indeed, many firms appear to increase their pension liabilities through such conversions.
Adopting cash balance pension plans: implications and issues
Authors: CLARK ROBERT L. , SCHIEBER SYLVESTER J.
Published: December 2004

Over the past 15 to 20 years, many companies have converted their traditional defined benefit plans to cash balance or pension equity plans. In a cash balance plan, the worker's ‘account’ is based on an annual contribution rate for each year of employment, plus accumulating interest on annual contributions. A pension equity plan defines the benefit as a percentage of final average earnings for each year of service under the plan. Both types of plans specify the benefit as a lump sum payable at termination. In contrast, traditional defined benefit plans specify benefits in terms of an annuity payable at retirement. From the employees' perspective, cash balance and pension equity plans look somewhat like defined contribution plans. However, they are funded, administered, and regulated as defined benefit plans.
ENSO Influence on Atlantic hurricanes via tropospheric warming
Authors: Tang B. H. , Neelin J. D.
Published: December 2004

A new pathway for the negative impact of ENSO on tropical North Atlantic (NAtl) storm activity is examined empirically. Anomalous tropospheric temperatures communicated from the Pacific by wave dynamics are hypothesized to impact storm development by affecting column stability relative to equilibrium with NAtl sea surface temperature (SST). This combines recent teleconnection theory with the role of tropospheric temperature‐SST differences in hurricane intensity theory. An equilibrium principle component (EQ PC) in which NAtl SST and tropospheric temperature covary, explains most of their variance. A disequilibrium PC (DEQ PC), measuring column stability relative to SST, correlates highly with hurricane season indices for storm frequency and intensity. The hurricane season (Jun.–Nov.) DEQ PC is closely related to ENSO SST just prior to and within the season, consistent with NAtl SST not having had time to adjust to the teleconnected tropospheric warming from onsetting ENSO events. The EQPC is related to prior winter ENSO SST.
Anatomy of cirrus clouds: Results from the Emerald airborne campaigns
Authors: Whiteway James , Cook Clive , Gallagher Martin , Choularton Tom , Harries John , Connolly Paul , Busen Reinhold , Bower Keith , Flynn Michael , May Peter , Aspey Robin , Hacker Jorg
Published: December 2004

The Emerald airborne measurement campaigns have provided a view of the anatomy of cirrus clouds in both the tropics and mid‐latitudes. These experiments have involved two aircraft that combine remote sensing and in‐situ measurements. Results are presented here from two separate flights: one in frontal cirrus above Adelaide, Australia, the other in the cirrus outflow from convection above Darwin. Recorded images of ice crystals are shown in relation to the cloud structure measured simultaneously by an airborne lidar. In mid‐latitude frontal cirrus, columnar and irregular ice crystals were observed throughout the cloud while rosettes were found only at the top. The cirrus outflow from a tropical thunderstorm extended for hundreds of kilometres between the heights of 12.2 and 15.8 km. This was composed mainly of hexagonal plates, columns, and large crystal aggregates that originated from within the main core region of the convection. A small number of bullet rosettes were found at the top of the outflow cirrus and this is interpreted as an indication of in‐situ crystal formation. It was found that the largest aggregates fell to the lower regions of the outflow cirrus cloud while the single crystals and small aggregates remained at the top.
Climate‐driven deformation of the solid Earth from GRACE and GPS
Authors: Davis J. L. , Elósegui P. , Mitrovica J. X. , Tamisiea M. E.
Published: December 2004

GRACE data indicate large seasonal variations in gravity that are assumed to be related to climate‐driven fluxes of surface water. Seasonal redistribution of surface mass should deform the Earth, and our calculations using GRACE data suggest vertical deformations of ∼13 mm in the region of greatest flux, the Amazon River Basin. To test the GRACE gravity‐hydrology connection, we analyzed GPS data acquired from sites in this region. After accounting for degree 1 variations not observable with GRACE, we find that annual deformation measured with GPS correlates highly with predictions calculated from GRACE measurements. These results confirm the variations in surface water sensed by GRACE, which are significantly larger than those predicted by some hydrology models. The results also demonstrate that GRACE can be an important tool for monitoring deformation of the Earth, and suggest that combined analysis of GRACE and GPS may be a useful approach for estimation of geocenter variations.
Sea‐surface temperature induced variability of the Southern Annular Mode in an atmospheric general circulation model
Authors: Zhou Tianjun , Yu Rucong
Published: December 2004

The reproducibility of the Southern Hemisphere Annular Mode (SAM) is examined by using the NCAR CAM2 model forced with historical sea surface temperature covering the time period of 1950–2000. There is some correspondence (low however significant correlation) between the simulation and observation in the temporal evolution of the SAM, indicating if global SSTs are known and prescribed to the model, there would be some predictability to the SAM. The reproducibility is greater during austral summer than winter, and the source of much of the reproducibility is tropical Pacific SST, with equatorial Pacific warm event corresponds to a negative phase SAM in austral summer. There is a hint that this result is model independent. Working with ensembles improves the reproducibility.