bluuebunny/crossref_metadata_2025_split huggingface dataset:
Floodplain sedimentation rates in an alpine watershed determined by radionuclide techniques
Authors: Soster Frederick M. , Matisoff Gerald , Whiting Peter J. , Fornes William , Ketterer Michael , Szechenyi Scott 
Published: April 2007

AbstractVertical profiles of the activities of 137Cs and 210Pb were measured on floodplain sediment cores and upland soil cores along the Soda Butte Creek and the Yellowstone River to determine floodplain sedimentation rates. The position of mine tailings from a 1950 impoundment failure was used as a stratigraphic marker to estimate the sedimentation rates and to make comparisons with rates provided by radionuclide‐based methods. Mass accumulation (sedimentation) rates calculated from the position of the mine tailings ranged from 0·00 to 0·17 g cm−2 yr−1 and were in good agreement with sedimentation rates calculated from the inventories of 137Cs and 210Pb. Sedimentation rates calculated from the position of the 137Cs peak generally overestimated the sedimentation rates, probably because of increased downward migration of 137Cs caused by the low pH of water moving through the mine tailings or the high permeability of floodplain sediments relative to upland reference soils. This study demonstrates that the 137Cs and 210Pb inventory methods for determining sedimentation rates can be applied to an alpine floodplain where sedimentation events are episodic and where orographic effects on precipitation generate strong downstream gradients in the delivery of atmospheric radionuclides. Copyright © 2007 John Wiley & Sons, Ltd.
Turbo modulation and coding: design and evaluation of iterative bit‐interleaved coded modulation methods for wireless systems beyond 3G
Authors: Bauch Gerhard , Schreckenbach Frank , Hausl Christoph , Abe Tetsushi 
Published: April 2007

AbstractWe give an overview of iterative techniques for bit‐interleaved coded modulation. We start with simple methods where a convolutional code is concatenated with a standard QAM modulation scheme. The mapping is carefully chosen different from Gray mapping such that significant gains can be obtained by an iterative (turbo) receiver. The idea can also be applied to transmit antenna diversity as well as spatial multiplexing (MIMO). We then consider various powerful iterative coding schemes which are under discussion in standardisation for wireless systems beyond 3G such as serial or parallel concatenated convolutional codes, repeat accumulate codes and LDPC codes. We give a comparison in terms of complexity and performance.The main intention is to provide an illustrative overview over relevant applications of the turbo principle in demodulation and decoding. It is a summary of results which have been obtained in collaboration between the Institute of Communications Engineering, TUM and DoCoMo Euro‐Labs. Copyright © 2007 John Wiley & Sons, Ltd.
Flavour enhancement through the enzymatic hydrolysis of glycosidic aroma precursors in juices and wine beverages: a review
Authors: Pogorzelski Eugeniusz , Wilkowska Agnieszka 
Published: April 2007

AbstractAroma is one of the most important quality criteria of fruit and wine products. It is known, that aroma compounds are present in fruit in a free state and in the form of glycosides. In this review, the effect of glycosidases on flavour recovery from glycosides in fruit juice production and in winemaking was discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Semi‐distributed flood runoff model at the subcontinental scale for southwestern Iran
Authors: Nourani Vahid , Mano Akira 
Published: April 2007

AbstractRainfall–runoff modelling, as a surface hydrological process, on large‐scale data‐poor basins is currently a major topic of investigation that requires the model parameters be identified by using basin physical characteristics rather than calibration. This paper describes the application of the TOPMODEL framework accompanied by a kinematic wave model to the Karun River sub‐basins in southwestern Iran with just one conceptual parameter for calibration. ISLSCP1, HYDRO1K and Reynolds data sets are presented in a geographical information system and used as data sources for meteorological information, hydrological features and soil characteristics of the study area respectively. The results show that although the model developed can adequately predict flood runoff in the catchment with only one calibrated parameter, it is suggested that the effect of surface reservoirs be considered in the proposed model. Copyright © 2007 John Wiley & Sons, Ltd.
Long‐run trends in internal migrations in italy: a study in panel cointegration with dependent units
Authors: Fachin Stefano 
Published: April 2007

AbstractThe objective of this paper is to examine the long‐run determinants of internal migrations from southern Italy. In order to accomplish this task, the paper develops a bootstrap test for panel cointegration analysis with dependent units. Monte Carlo simulations show that the test, based on the Continuous‐Path Block bootstrap, has good power and size properties and is robust to both short‐ and long‐run dependence across units. The empirical analysis points to income in the sending region as a key factor of the decline of migrations, with unemployment and income differentials playing only a minor role. Copyright © 2007 John Wiley & Sons, Ltd.
Subsampling hypothesis tests for nonstationary panels with applications to exchange rates and stock prices
Authors: Choi In , Chue Timothy K. 
Published: April 2007

AbstractThis paper studies subsampling hypothesis tests for panel data that may be nonstationary, cross‐sectionally correlated, and cross‐sectionally cointegrated. The subsampling approach provides approximations to the finite sample distributions of the tests without estimating nuisance parameters. The tests include panel unit root and cointegration tests as special cases. The number of cross‐sectional units is assumed to be finite and that of time‐series observations infinite. It is shown that subsampling provides asymptotic distributions that are equivalent to the asymptotic distributions of the panel tests. In addition, the tests using critical values from subsampling are shown to be consistent. The subsampling methods are applied to panel unit root tests. The panel unit root tests considered are Levin, Lin, and Chu's (2002) t‐test; Im, Pesaran, and Shin's (2003) averaged t‐test; and Choi's (2001) inverse normal test. Simulation results regarding the subsampling panel unit root tests and some existing unit root tests for cross‐sectionally correlated panels are reported. In using the subsampling approach to examine the real exchange rates of the G7 countries and a group of 26 OECD countries, we find only mixed support for the purchasing power parity (PPP) hypothesis. We then examine a panel of 17 developed stock market indexes, and also find only mixed empirical support for them exhibiting relative mean reversion with respect to the US stock market index. Copyright © 2007 John Wiley & Sons, Ltd.
Digital analysis: A better way to detect fraud
Authors: Tackett James A. 
Published: April 2007

AbstractThe Sarbanes‐Oxley Act (SOX) has put corporate executives under the gun when it comes to detecting financial statement fraud. Unfortunately, most methods for discovering fraud are expensive and time‐consuming. But there is one fast, inexpensive method you may not be using: digital analysis. The author explains what it is and how to use it. © 2007 Wiley Periodicals, Inc.
Characterization of N‐palmitoylated human growth hormone by in situ liquid–liquid extraction and MALDI tandem mass spectrometry
Authors: Sachon Emmanuelle , Nielsen Per Franklin , Jensen Ole Nørregaard 
Published: April 2007

AbstractAcylation is a common post‐translational modification found in secreted proteins and membrane‐associated proteins, including signal transducing and regulatory proteins. Acylation is also explored in the pharmaceutical and biotechnology industry to increase the stability and lifetime of protein‐based products. The presence of acyl moieties in proteins and peptides affects the physico‐chemical properties of these species, thereby modulating protein stability, function, localization and molecular interactions. Characterization of protein acylation is a challenging analytical task, which includes the precise definition of the acylation sites in proteins and determination of the identity and molecular heterogeneity of the acyl moiety at each individual site. In this study, we generated a chemically modified human growth hormone (hGH) by incorporation of a palmitoyl moiety on the Nε group of a lysine residue. Monoacylation of the hGH protein was confirmed by determination of the intact molecular weight by mass spectrometry. Detailed analysis of protein acylation was achieved by analysis of peptides derived from hGH by protease treatment. However, peptide mass mapping by MALDI MS using trypsin and AspN proteases and standard sample preparation methods did not reveal any palmitoylated peptides. In contrast, in situ liquid–liquid extraction (LLE) performed directly on the MALDI MS metal target enabled detection of acylated peptide candidates by MALDI MS and demonstrated that hGH was N‐palmitoylated at multiple lysine residues. MALDI MS and MS/MS analysis of the modified peptides mapped the N‐palmitoylation sites to Lys158, Lys172 and Lys140 or Lys145. This study demonstrates the utility of LLE/MALDI MS/MS for mapping and characterization of acylation sites in proteins and peptides and the importance of optimizing sample preparation methods for mass spectrometry‐based determination of substoichiometric, multi‐site protein modifications. Copyright © 2007 John Wiley & Sons, Ltd.
Bacterial exopolysaccharides – a perception
Authors: Suresh Kumar Anita , Mody Kalpana , Jha Bhavanath 
Published: April 2007

AbstractMicrobial polysaccharides are multifunctional and can be divided into intracellular polysaccharides, structural polysaccharides and extracellular polysaccharides or exopolysaccharides (EPS). Extracellular polymeric substances (EPS), produced by both prokaryotes (eubacteria and archaebacteria) and eukaryotes (phytoplankton, fungi, and algae), have been of topical research interest. Newer approaches are carried out today to replace the traditionally used plant gums by their bacterial counterparts. The bacterial exopolysaccharides represent a wide range of chemical structures, but have not yet acquired appreciable significance. Chemically, EPS are rich in high molecular weight polysaccharides (10 to 30 kDa) and have heteropolymeric composition. They have new‐fangled applications due to the unique properties they possess. Owing to this, exopolysaccharides have found multifarious applications in the food, pharmaceutical and other industries. Hence, the present article converges on bacterial exopolysaccharides. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
New phenyl‐ethanediols from the culture broth of Boletus edulis
Authors: Yang Wan‐Qiu , Qin Xiang‐Dong , Shao Hong‐Jun , Fang Li‐Zhen , Wang Fei , Ding Zhi‐Hui , Dong Ze‐Jun , Liu Ji‐Kai 
Published: April 2007

AbstractA new phenyl‐ethanediol, (1S)‐(4‐acetylphenyl)‐1, 2‐ethanediol (1), and a new natural product, (1S)‐(3‐ethenylphenyl)‐1, 2‐ethanediol (2), were isolated from the culture broth of the basidiomycete Boletus edulis together with three related known compounds, 1‐(4‐ethylphenyl)‐1, 2‐ethanediol (3), 1‐(3‐ethylphenyl)‐1, 2‐ethanediol (4) and 1‐(3‐formylphenyl)‐ethanone (5). Their structures were elucidated by spectroscopic methods including extensive 2D‐NMR techniques. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fast determination of Z‐ligustilide in plasma by gas chromatography/mass spectrometry following headspace single‐drop microextraction
Authors: Dong Ling , Deng Chunhui , Wang Ben , Shen Xizhong 
Published: April 2007

AbstractAngelica sinensis (danggui in Chinese) is a common traditional Chinese medicine (TCM), and its essential oil has been used for the treatment of many diseases such as hepatic fibrosis. Z‐Ligustilide has been found to be an important active component in the TCM essential oil. In this work, for the first time, headspace single‐drop microextraction (HS‐SDME) followed by gas chromatography‐mass spectrometry (GC‐MS) was developed for the determination of Z‐ligustilide in rabbit plasma after oral administration of essential oil of danggui. The extraction parameters of solvent selection, solvent volume, sample temperature, extraction time, stirring rate, and ion strength were systemically optimized. Furthermore, the method linearity, detection limit, and precision were also investigated. It was shown that the proposed method provided good linearity (0.02–20 μg/mL, R2 = 0.997), low detection limit (10 ng/mL), and good precision (RSD value less than 9%). Finally, HS‐SDME followed by GC/MS was used for fast determination of Z‐ligustilide in rabbit plasma at different time intervals after oral administration of danggui essential oil. The experimental results suggest that HS‐SDME followed by GC/MS is a simple, sensitive, and low‐cost method for the determination of Z‐ligustilide in plasma, and a low‐cost approach to pharmacokinetics studies of active components in TCMs.
The role of UHPLC in pharmaceutical development
Authors: Chesnut Stephen M. , Salisbury John J. 
Published: April 2007

AbstractPharmaceutical separations can be divided into three categories: high throughput, high productivity, and high resolution. These categories contain specific pharmaceutical applications, each of which has distinct separation goals. Traditionally, these goals have been achieved utilizing conventional HPLC with typical column dimensions and particle sizes. The recent introduction of ultra‐HPLC (UHPLC) has provided a new potential for method development and analysis. Pharmaceutical chemists must determine the impact of this emerging technology. UHPLC is achieved by using sub‐2 μm particle size column packing at increased linear velocities. In order to utilize this technology, mobile phase viscosity must be minimized or the chromatography system must be redesigned to withstand an increased backpressure. Today, there are many commercially available UHPLC systems capable of exceeding conventional pressure limits of 400 bar. The advantage of UHPLC over conventional HPLC is the capability to increase the speed without sacrificing efficiency. In comparison to traditional HPLC, our research showed that UHPLC can decrease run times up to 7×. In addition, for high resolution applications, UHPLC achieved significant efficiency advantages over traditional HPLC. This paper will evaluate the potential roles for utilizing UHPLC in the pharmaceutical industry.
Temperature stability of reversed phase and normal phase stationary phases under aqueous conditions
Authors: Teutenberg Thorsten , Tuerk Jochen , Holzhauser Maren , Giegold Sascha 
Published: April 2007

AbstractIn this study the temperature stability of several normal phase and RP columns was investigated using a water‐only mobile phase. The temperature was adjusted to 120°C for the bare silica stationary phases and to 185°C for the metal oxide and carbon stationary phases. It could be shown that metal oxide stationary phases exhibited excellent thermal stability over the duration of the test period and are therefore suitable for high temperature LC applications.
High temperature to increase throughput in liquid chromatography and liquid chromatography–mass spectrometry with a porous graphitic carbon stationary phase
Authors: Pereira Luisa , Aspey Stephen , Ritchie Harald 
Published: April 2007

AbstractHigh separation temperatures in liquid chromatography and liquid chromatography–mass spectrometry with a porous graphitic carbon column were investigated. Separation temperature was varied up to 200°C, and the effect on retention, analysis time, and sensitivity was measured. Analysis times were reduced more than six‐fold, whilst baseline resolution was maintained. The impact of the separation temperature on signal‐to‐noise ratio with atmospheric pressure chemical ionisation or electrospray mass spectrometric detection was also investigated. The potential of using superheated water for the analysis of some very polar compounds is illustrated. Monitoring of column stability detected no loss of performance, due to the highly stable nature of the 100% carbon stationary phase.
Anwendung brillanter Diodenlaser beim Schweißen von Aluminium‐Dünnblechen
Authors: Kaierle Stefan , Regaard Boris , Dahmen Martin , Fiedler Wolfgang 
Published: April 2007

AbstractFasergekoppelte Diodenlaser mit optischen Ausgangsleistungen im Multi‐Kilowattbereich konkurrieren zunehmend mit Festkörperlasern als direkte Strahlquelle für die Materialbearbeitung. Vorteile gegenüber konventionellen Strahlquellen sind eine wesentlich kompaktere Bauweise, ein hoher Wirkungsgrad und eine große Zuverlässigkeit bei gleichzeitig geringerem Wartungs‐ und Betriebsaufwand.
Das Strahlprofil von Hochleistungslasern – Genaue Messungen als Basis für die Lasercharakterisierung
Authors: Schwede Harald 
Published: April 2007

AbstractFür die Reproduzierbarkeit jeder Laseranwendung ist eine umfassende Kenntnis der Laserstrahlparameter unabdingbar. Dazu gehören Strahlleistung, Strahldurchmesser, Strahllage, Polarisation etc. Die einfache und dennoch korrekte Erfassung dieser Parameter ist seit langem ein Diskussionsthema. Bei Hochleistungslasern ist sie besonders schwierig, aber auch besonders wichtig.
Von Mikro bis Makro: Rofin‐Sinar baut Laser für die ganze Welt – CEO Günther Braun im Interview
Authors: Braun Günther 
Published: April 2007

AbstractRofin‐Sinar war eine der ersten deutschen Laserfirmen, die den Schritt an die Börse gewagt haben. Der Erfolg hat ihnen recht gegeben. Das Unternehmen konnte sowohl den Umsatz als auch den Börsenkurs vervielfachen. Andreas Thoß sprach für das Laser Technik Journal mit dem CEO von RSTI Günther Braun.
Ethylene/10‐Undecenoic Acid Copolymers Prepared with Different Metallocene Catalysts
Authors: Cerrada María L. , Benavente Rosario , Pérez Ernesto , Moniz‐Santos Jorge , Campos João M. , Ribeiro M. Rosário 
Published: April 2007

AbstractThe synthesis and characterisation of several functionalised polyethylenes, obtained by direct copolymerisation of ethylene with 10‐undecenoic acid (UA), have been carried out. Two metallocene complexes of Cs symmetry with different bridges were used: a dimethylsilyl bridge complex Me2Si(Cp)(Flu)ZrCl2 and a phenylidene bridge complex Ph2C(Cp)(Flu)ZrCl2. For comparison, results obtained with the Cp2ZrCl2/MAO system are also reported. The copolymerisation activity depends strongly on the metallocene complex and on the added amount of the UA comonomer. High incorporation levels of up to 7.3 mol‐% are achieved when using the phenylidene bridged catalyst presenting a rigid structure and a wide bite angle. The effect of comonomer content and catalyst geometry on the crystalline structure and mechanical behaviour of the different copolymers are comprehensively discussed.magnified image
All‐in‐one Layer: Anisotropic Emission due to Light‐Induced Orientation of a Multifunctional Polymer
Authors: Rosenhauer Regina , Stumpe Joachim , Giménez Raquel , Piñol Milagros , Serrano José Luis , Viñuales Ana 
Published: April 2007

AbstractAn efficient procedure to create oriented polymer films with strongly anisotropic properties is described. It is based on a two‐step process combining a photochemical and a thermal aligning step. The orientation of the polymer parallel or perpendicular to linearly polarised incident light can be adjusted. The method presented allows for simple fabrication of films with anisotropic absorption and emission characteristics with a dichroism of 0.7 and a fluorescence anisotropy of about 8.magnified image
Multifunctional Thermally Reversible Nanostructured Thermosetting Materials Based on Block Copolymers Dispersed Liquid Crystal
Authors: Tercjak Agnieszka , Serrano Elena , Mondragon Iñaki 
Published: April 2007

AbstractThermally reversible nanostructured thermosetting materials are prepared for the first time by modification of an epoxy resin with 5 wt.‐% of an amphiphilic polystyrene‐block‐poly(ethylene oxide) block copolymer (PSEO) and 30 wt.‐% of a low‐molecular‐weight liquid crystal, 4′‐(hexyl)‐4‐biphenylcarbonitrile (HBC). The epoxy system modified with 5 wt.‐% PSEO amphiphilic copolymer self‐assembles into spherical microdomains with a size distribution between 32 and 45 nm in diameter. Under the same conditions, the modification of an epoxy system with 5 wt.‐% PSEO and 30 wt.‐% HBC leads to a micro‐phase separated PS‐rich domains embedded in a HBC phase. The morphology of this nanostructured thermosetting system consists in a higher amount of spherical microdomains of PSEO/HBC with the size distribution between 40 and 75 nm in diameter. This implies that the separation of the PS‐rich phase provokes the separation of the liquid crystal and allows one to obtain a novel thermally switchable smart material.magnified image
Novel Wormlike Nanostructures Self‐Assembled in a Well Defined Liquid Crystalline Diblock Copolymer with Azobenzene Moieties
Authors: Yu Haifeng , Shishido Atsushi , Iyoda Tomokazu , Ikeda Tomiki 
Published: April 2007

AbstractNovel wormlike nanostructures were self‐assembled in bulk films of a well defined diblock copolymer with azobenzene moieties, which was prepared by atom transfer radical polymerization (ATRP). For comparison, a homopolymer with almost the same repeat units of azobenzene as those in the copolymer was also prepared. They both had well defined structures and exhibited a smectic liquid crystalline phase. Upon annealing the copolymer films, poly(methyl methacrylate) formed a matrix with excellent optical properties, and the azobenzene segment in the minority phase self‐assembled into a wormlike mesogenic domain in the bulk films. Such block copolymer films exhibited stability and transparency by eliminating the scattering of visible light, indicating their potential application as photoresponsive functional materials. Although wormlike morphologies have been obtained in micelles from block copolymer solutions, to the best of our knowledge, such wormlike nanostructures have never been explored in bulk films.magnified image
Influence of the Position of the Connecting Spacer of the Chromophore on the Nonlinear Optical Response
Authors: Briers David , De Cremer Lieven , Koeckelberghs Guy , Foerier Stijn , Verbiest Thierry , Samyn Celest 
Published: April 2007

AbstractA new chromophore, C1, based on a similar DπA‐structure as in the FTC‐chromophore but with a hydroxyalkyl spacer perpendicular to the direction of the dipole moment was synthesized. Both chromophores and the CLD‐chromophore were used to prepare high Tg nonlinear optical vinyl polymers. The influence of the position of the spacer on the DπA‐system on the NLO response of the resulting polymers was investigated.magnified image
Vanadocene(IV) dicyanide complexes: the evidence super‐hyperfine coupling for compounds with 13CN ligands
Authors: Honzíček Jan , Vinklárek Jaromír , Černošek Zdeněk , Císařová Ivana 
Published: April 2007

AbstractAn EPR study of the vanadocene complexes (C5H5)2V(CN)2 and (CH3C5H4)2V(CN)2 was carried out. Such compounds show strong super‐hyperfine coupling (|aiso(13C)|∼1.27 mT) when 13C labeled cyanide is used for their preparation. Super‐hyperfine splitting was observed in the isotropic spectra of solution samples as well as in the anisotropic spectra of frozen solutions. Such studies were supplemented with structural characterization of the parent compounds. Molecular structure of the complex (CH3C5H4)2V(CN)2 was determined by single‐crystal X‐ray diffraction analysis. Both compounds were characterized by infrared and Raman spectroscopy. Copyright © 2007 John Wiley & Sons, Ltd.