bluuebunny/crossref_metadata_2025_split huggingface dataset:
Local ionization energy and local polarizability
Authors: Jin Ping , Murray Jane S. , Politzer Peter 
Published: December 2003

AbstractWe investigate relationships between molecular polarizability α, volume V, ionization energy I, and average local ionization energy I(). The last of these is a measure of the energy required to remove an electron from any point in the space of an atom or molecule. Molecular polarizability shows a good direct correlation with volume, which can be improved to a minor extent by including an inverse dependence on I and more so by using I() averaged over the surface of the molecule, IS,ave. The pattern of I() on a molecular surface, IS(), exhibits significant variability, and it is shown through a series of examples that this can be related to the electronic structure of the molecule and to local polarizability. Thus, IS() will provide a means of assessing the transferability of regional (e.g., group/bond) polarizabilities from one molecule to another. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
CATIVIC: Parametric quantum chemistry package for catalytic reactions: I
Authors: Ruette F. , Sánchez M. , Martorell G. , González C. , Añez R. , Sierraalta A. , Rincón L. , Mendoza C. 
Published: December 2003

AbstractA quantum chemistry package for catalytic reactions, referred to as CATIVIC and based on simulation techniques of parametric Hamiltonians, is presented. We describe in detail the computational procedures for modeling adsorption on a catalytic substrate, especially the parameterization scheme using examples of atomic Al and AlX bonds (X = H, N, O, Si, Fe) for atomic and molecular parameters. The code features are illustrated with the adsorption of NO on models of ZSM‐5 zeolite doped with Fe. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Ab initio study of dissolution reactions of five‐membered aluminosilicate framework rings
Authors: Xu Hua , Van Deventer J. S. J. , Roszak Szczepan , Leszczynski Jerzy 
Published: December 2003

AbstractA theoretical study of five‐membered aluminosilicate framework rings and their dissolution products is presented as an approach to model the first step of stilbite geopolymerization in alkaline conditions. The molecular structures, charge distribution, thermodynamic properties, and vibrational spectra were studied for reactants and products of the dissolution process. The properties determined theoretically simulate satisfactorily the available experimental data, indicating that the chosen model of complexes is realistic. These results suggest that the short directional forces operating in minerals are important. The properties calculated for the restricted cluster are a reasonable first‐order representation of those found in the solid state. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Extending the ONIOM integrated MO/MO approach to hydrogen bonding in biologic systems: Serine–water and threonine–water dimers
Authors: Hopkins Brian W. , Tschumper Gregory S. 
Published: December 2003

AbstractA series of two‐layer ONIOM (MO:MO) methods have been systematically applied to two biologically important hydrogen‐bonded dimers. Single conformations of the serine–water dimer and of the threonine–water dimer were optimized with the MP2 technique and a DZP++ basis set. The counterpoise corrected and uncorrected dissociation energies of the dimers were then computed with RHF, B3LYP, MP2, and CCSD(T) electronic structure techniques with 3‐21G, 6‐31+G(d), and DZP++ basis sets as well as every possible two‐layer ONIOM permutation using either CCSD(T)/DZP++ or MP2/DZP++ as the high‐level method. To judge the performance of each technique, the data are compared to results obtained with the CCSD(T) method and a double‐zeta basis set with diffuse and polarization functions on all atoms [the largest basis set for which CCSD(T) computations were feasible]. MP2 theory reproduces the target CCSD(T) data extremely well. ONIOM schemes that employ model systems including the side‐chain and α‐carbon perform well, introducing errors of less than 0.21 kcal/mol. We observe that MP2:RHF approaches that use this large model system require almost the same CPU time as a B3LYP computation on the entire system but are far more accurate. Guidelines are presented for the application of two‐layer ONIOM methods to hydrogen bonding between similar functional groups in larger biologic systems. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Intrinsic band gap shift in Ti silicalites modified by V ion implantation: Ab initio and density functional theory study
Authors: Zhanpeisov Nurbosyn U. , Kanazawa Yukiya , Yamashita Hiromi , Anpo Masakazu 
Published: December 2003

AbstractAb initio and density functional theory quantum chemical calculations show that both the tetrahedrally coordinated V ions and highly dispersed titanium oxide species in the V ion‐implanted Ti silicalites have the tendency to locate in next‐neighboring positions via the formation of a Ti–O–V linkage. The latter was found to play an important role in modifying the electronic nature of the Ti silicalite photocatalysts to enable the absorption band to shift to longer wavelength regions. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Conformational conversion of the boat and chair structures of bicyclo[3.2.0]hept‐6‐ene
Authors: Qin Changyong , Davis Steven R. 
Published: December 2003

AbstractThe conversion between the chair and boat forms of bicyclo[3.2.0]hept‐6‐ene have been studied using ab initio calculations at the Hartree–Fock and MP2 levels using the 6‐31G(d,p) basis set with relative energies determined at the CCSD(T)/MP2 level. The transition state has been located and the activation barrier calculated to be 6.6 kcal/mol; and, the relative energies for the two conformers are close, with the boat form being 4 kcal/mol more stable. Transition‐state theory was used to evaluate the equilibrium thermodynamics. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Computational study of the conformational interconversion of 5,5‐dimethyl‐1,2,3‐trithiacyclohexane (5,5‐dimethyl‐1,2,3‐trithiane)
Authors: Freeman Fillmore , Cha Chansa 
Published: December 2003

AbstractAb initio molecular orbital theory and density functional theory (DFT) with the 6‐31G(d), 6‐31G(d,p), 6‐31+G(d,p), and 6‐311+G(d,p) basis sets have been used to study the mechanism of conformational interconversion of 5,5‐dimethyl‐1,2,3‐trithiacyclohexane (5,5‐dimethyl‐1,2,3‐trithiane). The relative energies, enthalpies, entropies, free energies, and structural parameters of the chair, 1,4‐twist, and 2,5‐twist conformers, the 1,4‐boat transition state, and the 2,5‐boat transition state were calculated. B3LYP/6‐31+G(d,p) calculated the chair conformer of 5,5‐dimethyl‐1,2,3‐trithiane to be 8.38 and 8.72 kcal/mol, respectively, lower in energy than the 1,4‐twist and 2,5‐twist conformers. The energy differences (ΔE) between the chair conformer of 5,5‐dimethyl‐1,2,3‐trithiane and the 1,4‐boat transition state and the 2,5‐boat transition state were 8.95 and 11.46 kcal/mol, respectively. Intrinsic reaction coordinate [IRC, minimum energy path (MEP)] calculations were used to connect the transition state between the chair conformer and 2,5‐twist conformer. B3LYP/6‐31+G(d,p) calculated energy differences (ΔE) between the chair conformer and the transition state [TS‐1]‡ connecting the chair and 2,5‐twist conformers to be 14.23 kcal/mol. In the chair, 1,4‐twist, and 2,5‐twist conformers, the C4Heq bond is slightly longer than the C4Hax bond. The C5C8eq bond is longer than the C5C7ax bond in the chair and 1,4‐twist conformers. In the 1,4‐twist conformer, the S1S2 bond is longer than the S3S3 bond and the S1C6 bond is longer than the S3C4 bond. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Electron transport throughout the DNA base pair
Authors: Yanov Ilya , Leszczynski Jerzy 
Published: December 2003

AbstractWe present here the results of a semiempirical nonequilibrium Green's function study of the electron transport properties of the adenine–thymine DNA base pair. Current‐voltage dependence I(V), conductance spectrum G(V), and transmission coefficients are calculated. The influence of the hydrogen bonds on the resistance of the base pair is discussed. The obtained results are compared with the data for the benzene‐1,4‐dithiolate molecule. It is shown that although the overall conductance of the DNA base pair is much smaller than in the case of benzene‐1,4‐dithiolate it exhibits significant conductance at small voltage biases that gives a natural way to construct wires, switches, and diodes using the single DNA molecule. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
The morality of socioscientific issues: Construal and resolution of genetic engineering dilemmas
Authors: Sadler Troy D. , Zeidler Dana L. 
Published: December 2003

AbstractThe ability to negotiate and resolve socioscientific issues has been posited as integral components of scientific literacy. Although philosophers and science educators have argued that socioscientific issues inherently involve moral and ethical considerations, the ultimate arbiters of morality are individual decision‐makers. This study explored the extent to which college students construe genetic engineering issues as moral problems. Twenty college students participated in interviews designed to elicit their ideas, reactions, and feelings regarding a series of gene therapy and cloning scenarios. Qualitative analyses revealed that moral considerations were significant influences on decision‐making, indicating a tendency for students to construe genetic engineering issues as moral problems. Students engaged in moral reasoning based on utilitarian analyses of consequences as well as the application of principles. Issue construal was also influenced by affective features such as emotion and intuition. In addition to moral considerations, a series of other factors emerged as important dimensions of socioscientific decision‐making. These factors included personal experiences, family biases, background knowledge, and the impact of popular culture. The implications for classroom science instruction and future research are discussed. © 2003 Wiley Periodicals, Inc. Sci Ed 88:4–27, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/.sce10101
The laboratory in science education: Foundations for the twenty‐first century
Authors: Hofstein Avi , Lunetta Vincent N. 
Published: December 2003

AbstractThe laboratory has been given a central and distinctive role in science education, and science educators have suggested that rich benefits in learning accrue from using laboratory activities. Twenty years have been elapsed since we published a frequently cited, critical review of the research on the school science laboratory (Hofstein & Lunetta, Rev. Educ. Res. 52(2), 201–217, 1982). Twenty years later, we are living in an era of dramatic new technology resources and new standards in science education in which learning by inquiry has been given renewed central status. Methodologies for research and assessment that have developed in the last 20 years can help researchers seeking to understand how science laboratory resources are used, how students' work in the laboratory is assessed, and how science laboratory activities can be used by teachers to enhance intended learning outcomes. In that context, we take another look at the school laboratory in the light of contemporary practices and scholarship. This analysis examines scholarship that has emerged in the past 20 years in the context of earlier scholarship, contemporary goals for science learning, current models of how students construct knowledge, and information about how teachers and students engage in science laboratory activities. © 2003 Wiley Periodicals, Inc. Sci Ed 88:28–54, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/.sce10106
Thomas Kuhn's impact on science education: What lessons can be learned?
Authors: Matthews Michael R. 
Published: December 2003

AbstractThomas Kuhn has had an impact in all academic fields. In science education, Kuhnian themes are especially noticeable in conceptual change research, constructivist theorizing, and multicultural education debates. Unfortunately the influence is frequently compromised by researchers having a limited understanding of Kuhn's original ideas, little exposure to the tradition of philosophical opposition to Kuhn's theories, and minimal appreciation of how Kuhn progressively qualified his initial “irrationalist'' views of scientific development. One lesson to be learnt is that the science education community should more seriously and effectively engage with on‐going debates and analysis in the history and philosophy of science. This is the same lesson that was learnt from the science education community's wholesale embrace of logical empiricism during the 1950s and 1960s. Another lesson is that there are powerful disciplinary, institutional, and subcultural barriers that mitigate against science educators seriously engaging with historical and philosophical scholarship. © 2003 Wiley Periodicals, Inc. Sci Ed 88:90–118, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/sce.10111
Images of nature in greek primary school textbooks
Authors: Korfiatis Kostas J. , Stamou Anastasia G. , Paraskevopoulos Stephanos 
Published: December 2003

AbstractIn this article, the environmental content of the textbooks used for the teaching of natural sciences in Greek primary schools was examined. Specifically, by employing the method of content analysis, both representational (metaphors, depictions, values, etc.) and cognitive (ecological concepts) elements, building images of nature, and shaping our opinion and attitudes towards the environment were examined. The results of the analysis revealed that a coherent whole was produced, where nature was in a condition of oscillating balance, with everything being connected with something else, and humans having absolute control over a nature whose only value was its usefulness as a resource for food and raw material. However, seen qualitatively, the edifice included many contradictory elements and inconsistencies, which, having evolved out of a specific context, might spread confusion and deprive pupils from critical thinking. On the other hand, the image of nature dominating disagreed with both a standpoint advocating an equal relationship between humans and nature and with that supporting a relationship of stewardship and care for nature, while it failed to provide students with proper and sufficient environmental knowledge. © 2003 Wiley Periodicals, Inc. Sci Ed 88:72–89, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/.sce10133
A systematic assessment of the empirical support for transaction cost economics
Authors: David Robert J. , Han Shin‐Kap 
Published: December 2003

AbstractTransaction cost economics (TCE) is one of the leading perspectives in management and organizational studies, yet debate continues regarding its empirical support. In this paper, we take stock of the large body of extant research and provide a systematic assessment of empirical evidence. In all, 308 statistical tests from 63 articles, selected according to a set of clear criteria, were examined across various dimensions. We assess not only the level of empirical support for the theory, but also the degree of paradigm consensus present in the empirical literature. Our analysis shows that results are mixed: while we found support in some areas (e.g., with regard to asset specificity), we also found considerable disagreement on how to operationalize some of TCE's central constructs and propositions, and relatively low levels of empirical support in other core areas (e.g., surrounding uncertainty and performance). We conclude that a more thorough empirical grounding of the theory's foundation is crucial to its future development, and offer several strategies for doing this. Copyright © 2003 John Wiley & Sons, Ltd.
Strategic positioning, human capital, and performance in service organizations: a customer interaction approach
Authors: Skaggs Bruce C. , Youndt Mark 
Published: December 2003

AbstractThis study employs a customer interaction approach to examine how service organizations' strategic positioning relates to their human capital, and how the interaction between strategic positioning and human capital impacts organizational performance. Results from 234 service organizations in 96 different industries indicate very strong relationships between strategic positioning choices and human capital. We also find that certain combinations of strategic positioning and human capital result in superior performance. Copyright © 2003 John Wiley & Sons, Ltd.
Guaranteed inconsistency avoidance during software evolution
Authors: Gallagher Keith , Harman Mark , Danicic Sebastian 
Published: December 2003

AbstractThe attempt to design and integrate consistent changes to an existing system is the essence of software maintenance. Software developers also confront similar problems: there are changes during testing and the release of new system builds. Whether in development or maintenance, changes to evolving systems must be made consistently; that is, without damaging correct computations. It is difficult for the programmer to ascertain the complete effect of a code change; the programmer may make a change to a program that is syntactically and semantically legal, but which has ripples into the parts of the program that were intended to remain unchanged.Using the standard denotational semantics for procedural programming languages, this paper formalizes decomposition slicing, which identifies interferences between software components and isolates the components to be changed. We enumerate the conditions for changing one component in ways that will guarantee that changes to it will not interact inconsistently and prove that changes made under these conditions are sound. Thus, the programmer can then execute changes secure in the knowledge that the semantics of the new system are guaranteed to be consistent with the projection of the semantics of the original for which it behaved correctly. Validating that the changes do not interfere not only guarantees consistency with respect to previous unchanging behaviors, but can also be achieved with a complexity proportional to the size of the change to be made. Copyright © 2003 John Wiley & Sons, Ltd.
Automated elicitation of inclusion dependencies from the source code for database transactions
Authors: Tan Hee Beng Kuan , Zhao Yuan 
Published: December 2003

AbstractInclusion dependency is an important data dependency in databases. Enforcement of data dependencies is a major component in any database application. Due to the nature of software development and maintenance and the limitation of database management systems (DBMSs) in handling the enforcement of inclusion dependency, many inclusion dependencies are enforced not through the DBMS, but through the transactions that update the database. It is very difficult and time consuming to elicit (to extract or to recover) inclusion dependencies from transactions manually during the reengineering, verification and maintenance of database applications. With the use of program analysis, this paper proposes a novel approach for the automated elicitation of inclusion dependencies from the source code of transactions that update the database. The approach is based on detecting program path patterns for enforcing inclusion dependency. Copyright © 2003 John Wiley & Sons, Ltd.
New modules for PCR‐based gene targeting in Candida albicans: rapid and efficient gene targeting using 100 bp of flanking homology region
Authors: Gola Susanne , Martin Ronny , Walther Andrea , Dünkler Alexander , Wendland Jürgen 
Published: December 2003

AbstractThe use of PCR‐based techniques for directed gene alterations has become a standard tool in Saccharomyces cerevisiae. In our efforts to increase the speed of functional analysis of Candida albicans genes, we constructed a modular system of plasmid vectors and successfully applied PCR‐amplified functional analysis (FA)‐cassettes in the transformation of C. albicans. These cassettes facilitate: (a) gene disruptions; (b) tagging of 3′‐ends of genes with green fluorescent protein (GFP); and (c) replacements of endogenous promoters to achieve regulated expression. The modules consists of a core of three selectable marker genes, CaURA3, CaHIS1 and CaARG4. Modules for C‐terminal GFP‐tagging were generated by adding GFP‐sequences flanked at the 5′‐end by a (Gly‐Ala)3‐linker and at the 3′‐end by the S. cerevisiae URA3‐terminator to these selection markers. Promoter exchange modules consist of the respective marker genes followed by the regulatable CaMAL2 or CaMET3 promoters at their 3′‐ends. In order to ensure a reliably high rate of homologous gene targeting, the flanking homology regions required a size of 100 bp of gene‐specific sequences, which were provided with the oligonucleotide primers. The use of shorter flanking homology regions produced unsatisfactory results with C. albicans strain BWP17. With these new modules only a minimal set of primers is required to achieve the functional analysis of C. albicans genes and, therefore, provides a basic tool to increase the number of functionally characterized C. albicans genes of this human pathogen in the near future. Copyright © 2003 John Wiley & Sons, Ltd.
Genome‐wide monitoring of wine yeast gene expression during alcoholic fermentation
Authors: Rossignol Tristan , Dulau Laurent , Julien Anne , Blondin Bruno 
Published: December 2003

AbstractThe transcriptome of a wine yeast was monitored throughout an alcoholic fermentation under conditions mimicking an enological environment. Major changes in gene expression occurred during fermentation, affecting more than 2000 genes, as the yeast adapted to changing nutritional, environmental and physiological conditions. The genes of many pathways are regulated in a highly coordinated manner, and genes involved in the key metabolic pathways of fermentation are strongly expressed. We showed that, during fermentation of a synthetic medium mimicking a natural must in which growth arrest was caused by nitrogen exhaustion, entry into the stationary phase triggered major transcriptional reprogramming. Many TOR target genes involved in nitrogen utilization or other functions are induced at this stage, suggesting that this signalling pathway plays a critical role in changes in gene expression in response to nitrogen depletion. Entry into stationary phase is a key physiological event and is followed by a general stress response. The superimposition of multiple stresses, including starvation and ethanol stress, gives rise to a unique stress response, involving hundreds of genes encoding proteins involved in various cellular processes, many of unknown function. Copyright © 2003 John Wiley & Sons, Ltd.