bluuebunny/crossref_metadata_2025_split huggingface dataset:
The use of Arena simulation programming for decision making in a workshop study
Authors: Guneri Ali Fuat , Seker Sukran 
Published: February 2008

AbstractComputer simulations are used to represent the essential features of a real system so that learners can test their analytical and design skills in a convenient and safe environment. This article describes Arena, a commercially available, highly specialized, off‐the‐shelf software simulation package. Also an Arena model has been investigated in a workshop. © 2008 Wiley Periodicals, Inc. Comput Appl Eng Educ 16: 1–11, 2008; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20182
On the numerical stability of two widely used PLS algorithms
Authors: M. Faber Nicolaas (Klaas) , Ferré Joan 
Published: February 2008

AbstractIdeally, the score vectors numerically computed by an orthogonal scores partial least squares (PLS) algorithm should be orthogonal close to machine precision. However, this is not ensured without taking special precautions. The progressive loss of orthogonality with increasing number of components is illustrated for two widely used PLS algorithms, i.e., one that can be considered as a standard PLS algorithm, and SIMPLS. It is shown that the original standard PLS algorithm outperforms the original SIMPLS in terms of numerical stability. However, SIMPLS is confirmed to perform much better in terms of speed. We have investigated reorthogonalization as the special precaution to ensure orthogonality close to machine precision. Since the increase of computing time is relatively small for SIMPLS, we therefore recommend SIMPLS with reorthogonalization. Copyright © 2008 John Wiley & Sons, Ltd.
Error removal by orthogonal subtraction (EROS): a customised pre‐treatment for spectroscopic data
Authors: Zhu Ying , Fearn Tom , Samuel Douglas , Dhar Anjan , Hameed Omair , Bown Stephen G. , Lovat Laurence B. 
Published: February 2008

AbstractIn some applications of diffuse reflectance spectroscopy there may be substantial variability between the spectra from replicate measurements of what is nominally the same sample. A method called error reduction by orthogonal subtraction (EROS) is proposed to ameliorate the effects of this. The first step is to use principal component analysis (PCA) to identify the structure in the variability of replicate measurements. This is followed by subtraction of the modelled effects from the original spectral data matrix X by projection onto the subspace orthogonal to factors derived from the PCA. An application to the clinical diagnosis of colon lesions is presented, in which pre‐treatment of spectra using the proposed method is successful in reducing the complexity and increasing both the accuracy and interpretability of the subsequent classification model. Copyright © 2008 John Wiley & Sons, Ltd.
Multivariate calibration by partial least squares for the quantitative phase analysis using Rietveld method
Authors: de Oliveira Terezinha Ferreira , Epprecht Eugenio Kahn , Ziolli Roberta Lourenço , Saraiva Augusto Cesar Fonseca , de Avillez Roberto Ribeiro 
Published: February 2008

AbstractThe present work used multivariate calibration by Partial Least Squares (PLS) to produce a Net Analyte Signal as a way of establishing the independent influence of each phase in the Quantitative Phase Analysis with the Rietveld method for three sources of potential error: preferred orientation, linear absorption and counting statistics. Ternary mixtures of Al2O3, MgO and NiO were employed and organized in three groups with different degrees of variation in the weight fractions of the three constituents. An analysis of variance indicated that the partial selectivity of the least variation group differed significantly from the other groups. As for the phases, MgO partial selectivity was significantly different. This is due to a strong correlation between the linear absorption and counting statistics in the region of the (2 0 0) reflection of the MgO phase that is strongly affected by preferred orientation and also corresponds to the strongest reflection for MgO as well as for NiO. On the whole, by using matrices of similarity, a great similarity was observed between the nominal weight fractions of the phases and the weight fractions observed by means of the Rietveld method. However, such similarity diminishes as the weight fractions of the phases of the mixture become closer to each other and, in the group of mixtures with least variation of weight fractions, the method is unable to quantify the small differences between the phases, even if these errors may be considered small relative to the weight fractions themselves. Copyright © 2008 John Wiley & Sons, Ltd.
Highly Selective Synthesis of a 1,3,5‐Tris‐Protected Calix[6]arene‐Type Molecular Platform through Coordination and Host–Guest Chemistry
Authors: Le Gac Stéphane , Marrot Jérôme , Jabin Ivan 
Published: February 2008

AbstractAn elegant methodology based on the synergistic combination of coordination and host–guest chemistry led to the highly efficient synthesis of a uniqueC3v‐symmetrical, calix[6]arene‐based molecular platform with three protected amino arms in alternating positions. The key step involves the formation of a stable supramolecular host–guest ZnIIcomplex from aC6v‐symmetrical calix[6]hexaamine. Indeed, in the presence of a polar neutral guest and a strong donor that acts as an exogenous ligand, three alternating amino groups of this calix[6]hexaamine are selectively coordinated to the ZnIIion while the three others remain free and are thus much more reactive toward chemical reagents. In addition to this protective role, the metal centre preorganises theC3v‐symmetrical complex in such a way that the uncoordinated NH2groups are directed toward the outside of the cavity; they are then accessible for a chemical transformation. Hence, reaction of these alternating free amino groups with a protective reagent (i.e., Boc2O) followed by zinc decoordination quantitatively and selectively yielded the 1,3,5‐tris‐Boc‐protected calixarene derivative on a gram scale. It was shown that the presence of all the partners of the key intermediate Zn complex (i.e., the metal centre, the exogenous ligand and the included guest) is crucial for a high selectivity. Finally, a two step sequence that led to aC3v‐symmetrical 1,3,5‐tris‐acetylated calix[6]hexaamine through the removal of the Boc groups illustrates that the 1,3,5‐tris‐protected calix[6]hexaamine is a promising molecular platform. Examples of such readily availableC3v‐symmetrical calixarene‐based building blocks are extremely rare in the literature.
Chemistry of Energetically Activated Cumulenes—From Allene (H2CCCH2) to Hexapentaene (H2CCCCCCH2)
Authors: Gu Xibin , Kaiser Ralf I. , Mebel Alexander M. 
Published: February 2008

AbstractDuring the last decade, experimental and theoretical studies on the unimolecular decomposition of cumulenes (H2CnH2) from propadiene (H2CCCH2) to hexapentaene (H2CCCCCCH2) have received considerable attention due to the importance of these carbon‐bearing molecules in combustion flames, chemical vapor deposition processes, atmospheric chemistry, and the chemistry of the interstellar medium. Cumulenes and their substituted counterparts also have significant technical potential as elements for molecular machines (nanomechanics), molecular wires (nano‐electronics), nonlinear optics, and molecular sensors. In this review, we present a systematic overview of the stability, formation, and unimolecular decomposition of chemically, photo‐chemically, and thermally activated small to medium‐sized cumulenes in extreme environments. By concentrating on reactions under gas phase thermal conditions (pyrolysis) and on molecular beam experiments conducted under single‐collision conditions (crossed beam and photodissociation studies), a comprehensive picture on the unimolecular decomposition dynamics of cumulenes transpires.
Aqueous Foams: A Field of Investigation at the Frontier Between Chemistry and Physics
Authors: Langevin Dominique 
Published: February 2008

AbstractThis paper reviews the properties of aqueous foams. The current state of knowledge is summarized briefly and the interdisciplinary aspects of this field of investigation are emphasized. Many phenomena are controlled by physical laws, but they are highly dependent upon the chemicals used as foam stabilizers: surfactants, polymers, particles. Most of the existing work is related to surfactants and polymer foams, and little is known yet for particle foams although research in this field is becoming popular. This article presents the general concepts used to describe the monolayers and the films and also some of the recent advances being made in this area.
Highly Coherent Spectroscopy of Ultracold Atoms and Molecules in Optical Lattices
Authors: Zelevinsky Tanya , Blatt Sebastian , Boyd Martin M. , Campbell Gretchen K. , Ludlow Andrew D. , Ye Jun 
Published: February 2008

AbstractCooling and trapping of neutral atoms using laser techniques has enabled extensive progress in precise, coherent spectroscopy. In particular, trapping ultracold atoms in optical lattices in a tight confinement regime allows us to perform high‐resolution spectroscopy unaffected by atomic motion. We report on the recent developments of optical lattice atomic clocks that have led to optical spectroscopy coherent at the one second timescale. The lattice clock techniques also open a promising pathway toward trapped ultracold molecules and the possible precision measurement opportunities such molecules offer.
A Valence Photoelectron Imaging Investigation of Chiral Asymmetry in the Photoionization of Fenchone and Camphor
Authors: Powis Ivan , Harding Chris J. , Garcia Gustavo A. , Nahon Laurent 
Published: February 2008

AbstractPhotoelectron circular dichroism (PECD) is investigated in the valence ionization of selected fenchone enantiomers using a photoelectron imaging technique and circularly polarized synchrotron radiation. Theoretical modelling of the results using electron scattering calculations demonstrates that the observed chiral asymmetry in the photoelectron angular distributions depends strongly upon the final state scattering, and upon the quality of the molecular potential used for these calculations. However, very pronounced dependence on the orbital from which ionization occurs is also observed. Comparison with analogous results previously obtained for camphor reveals striking differences in the PECD, even when the ionizing orbitals are themselves left substantially unaffected by the changes in methyl groups’ substitution site. PECD measurements readily differentiate these molecules despite their very similar photoelectron spectra, demonstrating PECD to be a structurally sensitive probe.
The role of organizational size in the adoption of green supply chain management practices in China
Authors: Zhu Qinghua , Sarkis Joseph , Lai Kee‐hung , Geng Yong 
Published: February 2008

AbstractEconomic globalization, increasing resource scarcity and environmental degradation have caused green supply chain management (GSCM) to become an important competitive approach for organizations involved in international trade. Using survey data collected from over 200 China‐based organizations, we compare the implementation levels of five GSCM practices among small‐, medium‐ and large‐sized organizations in China. We find that medium‐ and large‐sized organizations are more advanced than their smaller‐sized counterparts on most aspects, but not necessarily all, of these GSCM practices. Future research includes possible studies on GSCM practices and promotion, especially targeting small manufacturing organizations. In addition, the influence of globalization and foreign direct investment, especially after China's entry into the WTO, could be more carefully examined. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment.
Using the Kalman filter for parameter estimation in biogeochemical models
Authors: Trudinger C. M. , Raupach M. R. , Rayner P. J. , Enting I. G. 
Published: February 2008

AbstractWe investigate application of nonlinear variants of the Kalman filter (KF) to sequential parameter estimation in biogeochemical models, with particular focus on two components of the statistical model: Q, the covariance of the stochastic forcing which we use to represent model error, and R, the observation error covariance matrix. We explored sensitivity of parameter estimates from the extended and ensemble Kalman filters (EKF and EnKF) to the choice of Q, R, initial parameters and ensemble size using pseudo‐data from a simple yet highly nonlinear test model with many characteristics similar to real terrestrial biogeochemistry models. We found for our application that the use of inflated observation uncertainties led to the best and most stable parameter estimates. Although this reduced the rate of convergence to a solution, it also reduced the sensitivity of the solution to model error or ensemble size in the EnKF. Neither the use of model error for the parameters nor inflation of the state error covariance was particularly successful. Copyright © 2008 John Wiley & Sons, Ltd.
Wood as a driver of past landscape change along river corridors
Authors: Francis Robert A. , Petts Geoff E. , Gurnell Angela M. 
Published: February 2008

AbstractThe role of wood as a driver of landform development appears to have been overlooked in the interpretation of palaeo‐landscape change along river corridors. Deforested river corridors and wood‐free rivers characterize ‘modern’, managed landscapes, but along natural river corridors both driftwood dynamics and tree reproductive strategies can have a dramatic impact on the style and rate of channel and floodplain development. Therefore, we believe that interpretations of the post‐glacial history of river valleys across the northern temperate climatic zone could be usefully reassessed, incorporating the roles of riparian trees. Copyright © 2008 John Wiley & Sons, Ltd.
A stochastic model for initial movement of sand grains by wind
Authors: Li Zhen‐shan , Zhao Xiao‐hu , Huang Wen 
Published: February 2008

AbstractA stochastic model for entrainment of sand grains by wind is presented through analysis of the forces exerted on a single spherical grain, coupled with fluctuations of wind velocity and the change in grain position on the surface. The structure of the stochastic model is consistent with experimental data in the literature. The probability of initial motion increases first, and then decreases, with grain size. It reaches a maximum at diameters of about 0·9 mm. Some sand grains are still in motion at less than the conventional threshold velocity, even at very low velocities. The probability of sand grain movement reaches unity at twice the conventional threshold velocity. Considerable discrepancies amongst conventional threshold formulae may result from the different probabilities of initial movement implied in these formulae. Copyright © 2008 John Wiley & Sons, Ltd.
Fracture Propagation in Anisotropic Rock During Drilling and Cutting
Authors: Thuro Kurosch , Schormair Nik 
Published: February 2008

AbstractAnisotropy plays a key role in fracture propagation models and rock fragmentation processes during rock drilling and cutting. Drilling tests with a percussive rock drill have been performed to examine the influence of anisotropy and inhomogeneity on fracture propagation in different rock types. Subsequently, thin sections of the bottom of the borehole were analysed to investigate the associated crack patterns. Based on these observations an attempt was made to simulate the drilling process in a specific rock material using the Particle Flow Code (PFC2D). Since the Particle Flow Code is based on a discontinuum mechanics approach, the rock sample is converted into an assembly of spheres, where the particles are able to interact with each other and fractures are able to propagate. Different rock cutting tools were assumed including button bits, disc cutters and roadheader bits to simulate the penetration of varying rock samples. The latter have been omitted in this paper due to space limitations. The aim of the numerical simulation of the drilling and cutting processes was to examine the crack patterns and correlate with existing foliation. In this paper preliminary results of the 2‐dimensional PFC modelling are presented.
Abrasiveness Testing, Quo Vadis? – A Commented Overview of Abrasiveness Testing Methods
Authors: Plinninger Ralf J. , Restner Uwe 
Published: February 2008

AbstractThe growing economic pressure on tunnelling and mining operations has lead to an increasing importance of investigation methods for assessing the abrasiveness of rock and soil. Such investigations can be based on a wide variety of testing procedures and standards covering a wide span of scale, ranging from real‐scale tests on site to model tests with simplified tools and microscopic and chemical analyses of rocks and minerals. This paper gives an overview over some of the most important procedures, technical aspects of their application, classification of testing results and the current state of experience.
Impact of Grain Size on the Cerchar Abrasiveness Test
Authors: Lassnig Klaus , Latal Christine , Klima Kurt 
Published: February 2008

AbstractThe Cerchar abrasiveness test is a common testing procedure for the prediction of tool wear but consistent and detailed recommendations of the testing procedure are inexistent until now. One point of disagreement is the required number of scratch tests per sample to obtain reliable results depending on the grain size of the samples. The focus of this work was to verify the influence of grain size on the number of required single examinations per sample. Grain size analyses were performed to get sum‐curves of each tested rock sample. From the grain size data the median and the interquartile range of the grain sizes were calculated. CAI values after 5 and after 10 scratch tests were compared with the median and the interquartile‐range of the grain size. No grain size dependency of the CAI deviation between 5 and 10 tests in the analysed range was observed.
The convergence of health care expenditure in the US states
Authors: Wang Zijun 
Published: February 2008

AbstractIn response to rising health care costs, many have called for more effective regional health policy coordination. In this paper, we address the issue by examining the degree of convergence in per capita health care expenditure and its nine components across the US states from 1980 to 2004. The major finding is the moderate evidence of convergence in total health care expenditure and the diverse performance of the expenditure components regarding convergence. We also find hospital care to be responsible for the bulk of cross‐state convergence in total expenditure. The expenditure on prescription drugs is the most important diverging factor. Policy implications of these empirical results are discussed. Copyright © 2008 John Wiley & Sons, Ltd.
DNA damage and cell necrosis induced by naphthalene due to the modulation of biotransformation enzymes in an estuarine crab Scylla serrata
Authors: Vijayavel K. , Balasubramanian M. P. 
Published: February 2008

AbstractThe sublethal effect of naphthalene (2.5, 5, and 10 mg L−1) was studied in an estuarine crab Scylla serrata with reference to macromolecular changes. Biotransformation enzymes such as cytochrome P450, cytochrome b5, NADPH cytochrome P450 reductase, aryl hydrocarbon hydroxylase, glutathione‐S‐transferase, and UDP‐glucuronyl transferase were elevated in the hepatopancreas of naphthalene‐exposed crabs in comparison with control. Remarkable amount of DNA damage and cell necrosis was observed in hepatopancreas, hemolymph, and ovary of the crabs exposed to naphthalene, when compared with control. For all the parameters studied, a concentration‐dependent gradient of the changes was observed. The expression of DNA damage and cell necrosis suggests an increased production of oxidants during naphthalene metabolism. © 2008 Wiley Periodicals, Inc. J Biochem Mol Toxicol 22:1–7, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20207
Liver prenylated methylated protein methyl esterase is the same enzyme as sus scrofa carboxylesterase
Authors: Oboh Onovughode T. , Lamango Nazarius S. 
Published: February 2008

AbstractThe C‐terminal COOH of prenylated proteins is methylated to COOCH3. The COOCH3 ester forms are hydrolyzed by prenylated methylated protein methyl esterase (PMPMEase) to the original acid forms. This is the only reversible step of the prenylation pathway. PMPMEase has not been purified and identified and is therefore understudied. Using a prenylated‐L‐cysteine methyl ester as substrate, PMPMEase was purified to apparent homogeneity from porcine liver supernatant. SDS‐PAGE analysis revealed an apparent mass of 57 kDa. Proteomics analyses identified 17 peptides (242 amino acids). A Mascot database search revealed these as portions of the Sus scrofa carboxylesterase, a 62‐kDa serine hydrolase with the C‐terminal HAEL endoplasmic reticulum‐retention signal. It is at least 71% identical to such mammalian carboxylesterases as human carboxylesterase 1 with affinities toward hydrophobic substrates and known to activate prodrugs, metabolize active drugs, as well as detoxify various substances such as cocaine and food‐derived esters. The purified enzyme hydrolyzed benzoyl‐Gly‐farnesyl‐L‐cysteine methyl ester and hydrocinamoyl farnesyl‐L‐cysteine methyl ester with Michaelis–Menten constant (Km) values of 33 ± 4 and 25 ± 4 μM and Vmax values of 4.51 ± 0.28 and 6.80 ± 0.51 nmol/min/mg of protein, respectively. It was inhibited by organophosphates, chloromethyl ketones, ebelactone A and B, and phenylmethylsulfonyl fluoride. © 2008 Wiley Periodicals, Inc. J Biochem Mol Toxicol 22:51–62, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20214
Characterization of TBX20 in human hearts and its regulation by TFAP2
Authors: Hammer Stefanie , Toenjes Martje , Lange Martin , Fischer Jenny J. , Dunkel Ilona , Mebus Siegrun , Grimm Christina H. , Hetzer Roland , Berger Felix , Sperling Silke 
Published: February 2008

AbstractThe T‐box family of transcription factors has been shown to have major impact on human development and disease. In animal studies Tbx20 is essential for the development of the atrioventricular channel, the outflow tract and valves, suggesting its potential causative role for the development of Tetralogy of Fallot (TOF) in humans. In the presented study, we analyzed TBX20 in cardiac biopsies derived from patients with TOF, ventricular septal defects (VSDs) and normal hearts. Mutation analysis did not reveal any disease causing sequence variation, however, TBX20 is significantly upregulated in tissue samples of patients with TOF, but not VSD. In depth analysis of TBX20 transcripts lead to the identification of two new exons 3′ to the known TBX20 message resembling the mouse variant Tbx20a, as well as an extended 5′UTR. Functional analysis of the human TBX20 promoter revealed a 100 bp region that contains strong activating elements. Within this core promoter region we recognized functional binding sites for TFAP2 transcription factors and identified TFAP2 as repressors of the TBX20 gene in vitro and in vivo. Moreover, decreased TFAP2C levels in cardiac biopsies of TOF patients underline the biological significance of the pathway described. In summary, we provide first insights into the regulation of TBX20 and show its potential for human congenital heart diseases. J. Cell. Biochem. 104: 1022–1033, 2008. © 2008 Wiley‐Liss, Inc.