bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimized green fluorescent protein variants provide improved single cell resolution of transgene expression in ascidian embryos
Authors: Zeller Robert W. , Weldon Don S. , Pellatiro Mark A. , Cone Angela C. 
Published: November 2005

AbstractThe green fluorescent protein (GFP) is used extensively to monitor gene expression and protein localization in living cells, particularly in developing embryos from a variety of species. Several GFP mutations have been characterized that improve protein expression and alter the emission spectra to produce proteins that emit green, blue, cyan, and yellow wavelengths. DsRed and its variants encode proteins that emit in the orange to red wavelengths. Many of these commercially available fluorescent proteins have been “codon optimized” for maximal levels of expression in mammalian cells. We have generated several fluorescent protein color variants that have been codon optimized for maximal expression in the ascidian Ciona intestinalis. By analyzing quantitative time‐lapse recordings of transgenic embryos, we demonstrate that, in general, our Ciona optimized variants are detected and expressed at higher levels than commercially available fluorescent proteins. We show that three of these proteins, expressed simultaneously in different spatial domains within the same transgenic embryo are easily detectable using optimized fluorescent filter sets for epifluorescent microscopy. Coupled with recently developed quantitative imaging techniques, our GFP variants should provide useful reagents for monitoring the simultaneous expression of multiple genes in transgenic ascidian embryos. Developmental Dynamics 235:456–467, 2006. © 2005 Wiley‐Liss, Inc.
The design and implementation of session‐based IDS
Authors: Mizutani Masayoshi , Shirahata Shin , Minami Masaki , Murai Jun 
Published: November 2005

AbstractOne of the techniques for detecting malicious communications from network traffic is to use a network‐based intrusion detection system (IDS). However, since an existing IDS handles a low‐risk alert for which an attack failed and a high‐risk alert for which an attack succeeded in a similar manner, malicious communications cannot be detected properly unless a risk analysis is performed for each alert. This means that as the number of detection targets of the IDS increases, the cost of the risk analysis for every alert also increases proportionally. In other words, as the number of detection targets continues to increase, it becomes difficult to effectively deal with network incidents by using the IDS. In this paper, the authors focus on the fact that by continuously monitoring communications after an attack, the success or failure of the attack can be determined from the responses. They define these continuous communications as a session and design and implement a session‐based IDS that enables the risk to be evaluated immediately and automatically. They also evaluate the effectiveness of the session‐based IDS in an actual operating network. The results showed that this research lowered the operational cost of the IDS and enabled network incidents to be dealt with effectively. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 89(3): 46–58, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20251
A VoIP packet loss concealment technique taking account of pitch variation in pitch waveform replication
Authors: Aoki Naofumi 
Published: November 2005

AbstractIn order to realize speech communication by means of best‐effort packet communications, which is inherently unsuitable for real‐time processing, VoIP addresses the fundamental problem of degradation of communications quality by errors such as packet loss and delay. In the present research, based on the two‐sided PWR method, an error concealment technique based on waveform replication, a method of performing error concealment more effectively by taking account of the pitch variations of the speech data in the loss frame is proposed. Evaluation experiments with SNR, PESQ, and DMOS as the metrics suggest the effectiveness of the proposed method. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 89(3): 1–9, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20268
On the Usefulness of Bond Orders and Overlap Populations to Chalcogen–Nitrogen Systems
Authors: Oláh Julianna , Blockhuys Frank , Veszprémi Tamás , Van Alsenoy Christian 
Published: November 2005

AbstractBond orders calculated using the Mayer, Wiberg or NAO methodologies are incompatible with the observed bond lengths in chalcogen–nitrogen systems. To study this discrepancy four types of bond orders and three types of (scaled) overlap populations have been used to determine the bonding in these systems. A new overlap population based on the Hirshfeld partitioning of the electron density is compared to the Mayer, Wiberg, NAO and Fuzzy bond order schemes and the Mulliken and Fuzzy overlap population schemes. The correlation between the investigated bond orders and overlap populations is excellent for common organic molecules, but the (scaled) Hirshfeld and Fuzzy overlap population schemes produce the best results for a series of chalcogen‐nitrogen systems. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Preparation of Semiconductor/Polymer Coaxial Nanocables by a Facile Solution Process
Authors: Xiong Shenglin , Fei Linfeng , Wang Zhenghua , Zhou Hong Yang , Wang Weizhi , Qian Yitai 
Published: November 2005

AbstractWe report on the preparation of ultralong semiconductor tellurium/cross‐linked PVA coaxial nanocables with a core 20–30 nm in diameter and a surrounding sheath about 5–20 nm in thickness by a simple hydrothermal process. The length of these nanocables can be up to 500–800 μm. In the present synthesis PVA was used as the reducing agent to react with Na2TeO3, and it also serves as the capping reagent and the source of the sheaths. The synergistic effects of the interaction of cross‐linked PVA with the tellurium nanowires could play an important role in the formation of the morphology of the resulting products.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Mu‐34: a New Porous Layered Fluorogallophosphate Material Obtained by in Situ Generation of Ethylamine
Authors: Lakiss Louwanda , Simon‐Masseron Angélique , Porcher Florence , Patarin Joël 
Published: November 2005

AbstractA new two‐dimensional microporous fluorogallophosphate with porous layers, named Mu‐34, has been synthesized by in situ generation of ethylamine as the structure‐directing agent, the latter arising from the decomposition of ethylformamide. The fluorogallophosphate Mu‐34, Ga6P8O32FC14N7H56 (Z = 2), crystallizes in the triclinic space group P$\bar {1}$ with the following unit cell parameters: a = 11.0832(6), b = 11.393(6), c = 21.335(1) Å, α = 100.62(4), β = 99.66(5), γ = 108.34(5)°. The structure was solved from single crystal XRD data. This new fluorogallophosphate displays porous layers with apertures delimited by 12‐membered rings intercalated by protonated ethylamine molecules. Mu‐34 was also characterized by powder XRD, SEM, elemental and thermal analyses, and 13C, 19F, and 31P MAS solid state NMR spectroscopy.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Ruthenium Metallodendrimers Based on Nitrile‐Functionalized Poly(alkylidene imine)s
Authors: Ornelas Cátia , Vertlib Viatcheslav , Rodrigues João , Rissanen Kari 
Published: November 2005

AbstractThe preparation of the first‐ and second‐generation of nitrile‐functionalized poly(alkylidene imine) dendrimers with the organometallic ruthenium complex [Ru(η5‐C5H5)(PPh3)2Cl] peripherally attached is described. The reaction of N,N′‐bis(cyanomethyl)piperazine (1), N,N′‐bis[N′′,N′′′‐bis(cyanoethyl)aminoethyl]piperazine (2), or N,N,N′,N′‐tetrakis(cyanoethyl)ethylenediamine (3) with [Ru(η5‐C5H5)(PPh3)2Cl] (4) in the presence of TlPF6 gives the new air‐stable ruthenium metallodendrimers 5, 6, and 7, respectively. These stable metallodendrimers are easily prepared and represent a novel quantitative method to solidify and chromatographically purify the otherwise semi‐liquid nitrile‐functionalized poly(alkylidene imine) dendrimers. The compounds were fully characterized by IR and 1H, 13C, and 31P NMR spectroscopy, and mass spectrometry. These dendrimers represent the first example of the utilization of nitrile‐functionalized poly(alkylidene imine)s as cores in the preparation of metallodendrimers. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Photoreactions of Tricyclic α‐Cyclopropyl Ketones and Unsaturated Enones – Synthesis of Polyquinanes and Analogous Ring Systems
Authors: Tzvetkov Nikolay T. , Neumann Beate , Stammler Hans‐Georg , Mattay Jochen 
Published: November 2005

AbstractPolycyclic systems of both angular and propellane type have been synthesized through intramolecular radical cyclization reactions, by photochemically induced electron transfer of tricyclic α‐cyclopropyl ketones or by photolysis of unsaturated enones. In general, tricyclic α‐cyclopropyl ketones, each bearing an alkynyl or alkenyl side chain at the position γ to the carbonyl group, were used as starting materials. The reactions resulted in regioselective cleavage of one cyclopropyl bond with formation of tri‐ to tetracyclic ring systems by a tandem fragmentation‐radical/radical anionic reaction pathway. The regioselectivity of the cyclization (exo/endo) depends on the length of the unsaturated side chain. In cases involving α‐cyclopropane derivatives with alkoxymethyl side chains, various non‐cyclization processes were observed. In addition, the photoinduced cyclization of the corresponding bicyclic enone derivatives with the same unsaturated side chains afforded tetra‐ and tricyclic products of propellane type in good yields and with high stereoselectivity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Reconfiguration of the Symmetry and Charge‐Transfer Characteristics of a Triply Crowned 1,3,5‐Tris(arylalkynyl)mesitylene by Successive Metal Ion Complexation
Authors: Hennrich Gunther , Rurack Knut , Spieles Monika 
Published: November 2005

AbstractA triply benzocrown‐ether‐functionalized trialkynylmesitylene derivative with C3 symmetry as well as its linear analogue have been synthesized and their optical properties have been studied by UV/Vis absorption, steady‐state and time‐resolved fluorescencece spectroscopy. The spectroscopic investigation of the uncomplexed compounds revealed the nature of the electronic and excitonic communication pathway in the ground and excited states of the all‐meta‐substituted chromophore system. Upon cation complexation, the octopolar character of the free trialkynyl compound becomes dipolar and finally returns to octopolar in the fully complexed species. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Enantioselective Diamination of Alkenes by Use of a Bisimidoosmium Reagent with the Aid of Chiral Catalysts
Authors: Almodovar Iriux , Hövelmann Claas H. , Streuff Jan , Nieger Martin , Muñiz Kilian 
Published: November 2005

AbstractThe development of a new method for the diamination of alkenes is reported. It is based on a reaction in the presence of stoichiometric or catalytic amounts of chiral auxiliaries, which permits the direct synthesis of enantiomerically enriched osmaimidazolidines. The combined application of a catalyst‐directing oxazolidinone group and a titanium catalyst results in enantioselective alkene diamination with enantiomer ratios of up to 95:5. Absolute configurations of representative osmaimidazolidine products were established unambiguously by solid‐state structure analyses. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
A Generalized Procedure for the One‐Pot Preparation of Glycosyl Azides and Thioglycosides Directly from Unprotected Reducing Sugars under Phase‐Transfer Reaction Conditions
Authors: Kumar Rishi , Tiwari Pallavi , Maulik Prakas R. , Misra Anup K. 
Published: November 2005

AbstractPer‐O‐acetylated glycosyl azides and thioglycosides were prepared in excellent yield directly from unprotected reducing sugars through in situ generation of per‐O‐acetylated glycosyl bromides by a generalized one‐pot procedure under phase‐transfer conditions. Stereoselective products were formed with complete inversion at the anomeric centers of the glycosyl bromides to provide a general high‐yielding procedure for the preparation of 1,2‐trans‐glycosyl azides and thioglycosides.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Postsynthesis modification of a cellulose acetate ultrafiltration membrane for applications in water and wastewater treatment
Authors: Morão A. , Escobar I. C. , Pessoa de Amorim M. T. , Lopes A. , Gonçalves I. C. 
Published: November 2005

AbstractA technique for postsynthesis modification of a cellulose acetate ultrafiltration membrane with possible application in water and wastewater treatment is studied. The technique used an oxidizing agent (persulfate) to develop free radicals on the membrane surface, and that was expected to promote grafting of hydrophilic macromolecules (polyethylene glycol). A chain‐transfer agent (2‐mercaptoethanol) was tested to control the grafting process, avoiding the formation of long chains that usually lead to high permeability losses in other graft techniques. The modifications aimed at the decrease of the fouling susceptibility of the membrane studied. The possibility of an increase in rejection was also investigated. The membrane was characterized before and after modification, by attenuated total reflectance–Fourier transform‐infrared spectroscopy, scanning electron microscopy, atomic force microscopy, and in terms of the rejection of neutral reference solutes. The information given by the different techniques of characterization provided strong evidences of the occurrence of modification, although permeation of (real) foulants was the decisive test. To obtain information about the fouling tendency of the nonmodified and modified membranes, two different kinds of foulants were used: a humic acid (usually found in surface waters) and textile auxiliaries (representing one of the most important industries in Portugal). The results showed an increase in the rejections of the humic acid, and significant improvements in the performance of the membrane with respect to fouling tendency in the case of the textile auxiliaries. © 2005 American Institute of Chemical Engineers Environ Prog, 2005
Representing the bed roughness of coarse‐grained streams in computational fluid dynamics
Authors: Carney Shaun K. , Bledsoe Brian P. , Gessler Daniel 
Published: November 2005

AbstractComputational fluid dynamics (CFD) applications are increasingly utilized for modelling complex flow patterns in natural streams and rivers. Although CFD has been successfully implemented to model many complex flow situations in natural stream settings, adequately characterizing the effects of gravel and cobble beds on flow hydraulics in CFD is a difficult challenge due to the scale of roughness lengths and the inadequacy of traditional roughness representations to characterize flow profiles in situations with large roughness elements. An alternative method of representing gravel and cobble beds is presented. Appropriate drag forces associated with different grain sizes are computed and included in the momentum equations to account for the influence of a hydraulically rough bed. Comparisons with field measurements reveal reasonable agreement between measured and modelled profiles of spatially averaged velocity and turbulent kinetic energy, and model fidelity to the non‐logarithmic behaviour of the velocity profiles. The novel method of representing coarse beds expands the utility of CFD for investigating physical processes in natural channels with large bed roughness. Copyright © 2005 John Wiley & Sons, Ltd.
On the interplay between inertial and viscoelastic effects for the flow in weakly modulated channels
Authors: Abu‐Ramadan Ehab , Khayat Roger E. 
Published: November 2005

AbstractThe flow inside a spatially modulated channel is examined for viscoelastic fluids of the Oldroyd‐B type. The lower wall is flat and the upper wall is sinusoidally modulated. The modulation amplitude is assumed to be small. Thus, a regular perturbation expansion of the flow field coupled to a variable‐step finite‐difference scheme is used to solve the problem. Convergence and accuracy assessment against earlier experimental results indicate that there is a significant range of validity of the perturbation approach. The influences of wall geometry, inertia and viscoelasticity on the flow kinematics and stresses are investigated systematically. In particular, the interplay between the flow and fluid parameters effects on the conditions for the onset of backflow, number of vortices, their size and location is revealed. The distance between the flow separation and reattachment locations identifies the vortex size. Non‐monotonic dependence of the vortex size on elasticity is reported. The critical conditions for the onset of negative elasticity effects on vortex size are identified. The critical Reynolds number for the onset of backflow initially decreases then levels off or even increases as elasticity increases. For highly elastic fluid and large enough Reynolds number, more than one vortex appear near the lower wall. Copyright © 2005 John Wiley & Sons, Ltd.
A grid‐free upwind relaxation scheme for inviscid compressible flows
Authors: Balasubramanyam S. , Raghurama Rao S. V. 
Published: November 2005

AbstractA new grid‐free upwind relaxation scheme for simulating inviscid compressible flows is presented in this paper. The non‐linear conservation equations are converted to linear convection equations with non‐linear source terms by using a relaxation system and its interpretation as a discrete Boltzmann equation. A splitting method is used to separate the convection and relaxation parts. Least squares upwinding is used for discretizing the convection equations, thus developing a grid‐free scheme which can operate on any arbitrary distribution of points. The scheme is grid free in the sense that it works on any arbitrary distribution of points and it does not require any topological information like elements, faces, edges, etc. This method is tested on some standard test cases. To explore the power of the grid‐free scheme, solution‐based adaptation of points is done and the results are presented, which demonstrate the efficiency of the new grid‐free scheme. Copyright © 2005 John Wiley & Sons, Ltd.
Second‐order entropy diminishing scheme for the Euler equations
Authors: Coquel F. , Helluy P. , Schneider J. 
Published: November 2005

AbstractIn several papers of Bouchut et al., Coquel and Le Floch (Math. Comput. 1996; 65(216):1439–1461; Numer. Math. 1996; 74(01):1–34), a general methodology has been developed to construct second‐order finite volume schemes for hyperbolic systems of conservation laws satisfying the entire family of entropy inequalities. This approach is mainly based on the construction of an entropy diminishing projection. Unfortunately, the explicit computation of this projection is not always easy. In the first part of this paper, we carry out this computation in the important case of the Euler equations of gas dynamics. In the second part, we present several numerical applications of the projection in the context of finite volume schemes. Copyright © 2005 John Wiley & Sons, Ltd.
On steady state computation of turbulent flows using k–ε models approximated by the time splitting method
Authors: Du Tao , Wu Zi‐Niu , Wang Bing 
Published: November 2005

AbstractThe time splitting method is frequently used in numerical integration of flow equations with source terms since it allows almost independent programming for the source part. In this paper we will consider the question of convergence to steady state of the time splitting method applied to k–ε turbulence models. This analysis is derived from a properly defined scalar study and is carried out with success for the coupled k–ε equations. It is found that the time splitting method does not allow convergence to steady state for any choice of finite values of the time step. Numerical experiments for some typical turbulent compressible flow problems support the fact that the time splitting method is always nonconvergent, while its nonsplitting counterpart is convergent. Copyright © 2005 John Wiley & Sons, Ltd.
Spectral element benchmark simulations of natural convection in two‐dimensional cavities
Authors: Gjesdal Thor , Wasberg Carl Erik , Reif Bjørn Anders Pettersson 
Published: November 2005

AbstractThis paper reports the results of spectral element simulations of natural convection in two‐dimensional cavities. In particular, a detailed comparison is performed with the reference data for the 8:1 cavity at Ra=3.4 × 105 recently described by Christon et al. [Int. J. Numer. Methods Fluids 2002; 40:953–980]. The Navier–Stokes equations augmented by the Boussinesq approximation to represent buoyancy effects are solved by a numerical method based on a spectral element discretization and operator splitting. The computed solutions agree closely with the reference data for both the square and the rectangular cavity configurations. Copyright © 2005 John Wiley & Sons, Ltd.
Third‐order‐accurate semi‐implicit Runge–Kutta scheme for incompressible Navier–Stokes equations
Authors: Nikitin Nikolay 
Published: November 2005

AbstractA semi‐implicit three‐step Runge–Kutta scheme for the unsteady incompressible Navier–Stokes equations with third‐order accuracy in time is presented. The higher order of accuracy as compared to the existing semi‐implicit Runge–Kutta schemes is achieved due to one additional inversion of the implicit operator I‐τγL, which requires inversion of tridiagonal matrices when using approximate factorization method. No additional solution of the pressure‐Poisson equation or evaluation of Navier–Stokes operator is needed. The scheme is supplied with a local error estimation and time‐step control algorithm. The temporal third‐order accuracy of the scheme is proved analytically and ascertained by analysing both local and global errors in a numerical example. Copyright © 2005 John Wiley & Sons, Ltd.
PEM Fuel Cell Stack Cold Start Thermal Model
Authors: Sundaresan M. , Moore R. M. 
Published: November 2005

AbstractFor passenger fuel cell vehicles (FCVs), customers will expect to start the vehicle and drive almost immediately, implying a very short system warmup to full power. While hybridization strategies may fulfill this expectation, the extent of hybridization will be dictated by the time required for the fuel cell system to reach normal operating temperatures. Quick‐starting fuel cell systems are impeded by two problems: (i) the freezing of residual water or water generated by starting the stack at below freezing temperatures and (ii) temperature‐dependent fuel cell performance, improving as the temperature reaches the normal range. Cold start models exist in the literature; however, there does not appear to be a model that fully captures the thermal characteristics of the stack during sub‐freezing startup conditions. Existing models lack the following features: (i) modeling of stack internal heating methods (other than stack reactions) and their impact on the stack temperature distribution and (ii) modeling of endplate thermal mass effect on end cells and its impact on the stack temperature distribution. Unlike a lumped model, which may use a single temperature as an indicator of the stack's thermal condition, a model considering individual cell layers can reveal the effect of the endplate thermal mass on the end cells, and accommodate the evaluation of internal heating methods that may mitigate this effect. This paper presents and discusses results from simulations performed with a new, layered model.