bluuebunny/crossref_metadata_2025_split huggingface dataset:
Being there: the acceptance and marginalization of part‐time professional employees
Authors: Lawrence Thomas B. , Corwin Vivien 
Published: November 2003

AbstractPart‐time professional employees represent an increasingly important social category that challenges traditional assumptions about the relationships between space, time, and professional work. In this article, we examine both the historical emergence of part‐time professional work and the dynamics of its integration into contemporary organizations. Professional employment has historically been associated with being continuously available to one's organization, and contemporary professional jobs often bear the burden of that legacy as they are typically structured in ways that assume full‐time (and greater) commitments of time to the organization. Because part‐time status directly confronts that tradition, professionals wishing to work part‐time may face potentially resistant work cultures. The heterogeneity of contemporary work cultures and tasks, however, presents a wide variety of levels and forms of resistance to part‐time professionals. In this paper, we develop a theoretical model that identifies characteristics of local work contexts that lead to the acceptance or marginalization of part‐time professionals. Specifically, we focus on the relationship between a work culture's dominant interaction rituals and their effects on co‐workers' and managers' reactions to part‐time professionals. We then go on to examine the likely responses of part‐time professionals to marginalization, based on their access to organizational resources and their motivation to engage in strategies that challenge the status quo. Copyright © 2003 John Wiley & Sons, Ltd.
Statistical prediction of global sea‐surface temperature anomalies
Authors: Colman A. W. , Davey M. K. 
Published: November 2003

AbstractSea‐surface temperature (SST) is one of the principal factors that influence seasonal climate variability, and most seasonal prediction schemes make use of information regarding SST anomalies. In particular, dynamical atmospheric prediction models require global gridded SST data prescribed through the target season. The simplest way of providing those data is to persist the SST anomalies observed at the start of the forecast at each grid point, with some damping, and this strategy has proved to be quite effective in practice. In this paper we present a statistical scheme that aims to improve that basic strategy by combining three individual methods together: simple persistence, canonical correlation analysis (CCA), and nearest‐neighbour regression. Several weighting schemes were tested: the best of these is one that uses equal weight in all areas except the east tropical Pacific, where CCA is preferred. The overall performance of the combined scheme is better than the individual schemes. The results show improvements in tropical ocean regions for lead times beyond 1 or 2 months, but the skill of simple persistence is difficult to beat in the extratropics at all lead times. Aspects such as averaging periods and grid size were also investigated: results showed little sensitivity to these factors. The combined statistical SST prediction scheme can also be used to improve statistical regional rainfall forecasts that use SST anomaly patterns as predictors. Copyright © Crown Copyright 2003. Published by John Wiley & Sons, Ltd.
Climatic analyses on increasing dust storm frequency in the springs of 2000 and 2001 in Inner Mongolia
Authors: Gao Tao , Su Lijuan , Ma Qingxia , Li Haiying , Li Xicang , Yu Xiao 
Published: November 2003

AbstractTo study the climatic contribution to dust storm increases in Inner Mongolia in recent years, an analysis has been conducted of such factors in the last 40 years as annual and spring (March–May) precipitation, temperature, cold waves and strong gusty winds. In addition, such factors have been studied statistically regarding their impact upon atmospheric circulation with regard to the zonal circulation of Asia, the deep trough over East Asia and the geopotential height of Qinghai–Xizang Plateau. This study shows that the increased occurrences of dust storms likely result from a decrease in annual precipitation during 1999–2001; the precipitation recorded proved to be constantly below average, especially in spring. In addition, warmer temperatures with frequent cold‐air outbreaks created unstable atmospheric stratification, thus leading to more gales and subsequently, more dust storms. In the springs of 2000 and 2001, large‐scale atmospheric circulations provided the conditions for increased occurrences of dust storms due to stronger zonal circulation and a more westerly positioned trough over East Asia that became more intense in the winters. Furthermore, geopotential height over the Qinghai–Xizang Plateau seems to have an opposite trend as against dust storm frequency tendency. El Niño–southern oscillation activity might be an indirect factor. Copyright © 2003 Royal Meteorological Society
Connectivity–splitting models for survivable network design
Authors: Balakrishnan Anantaram , Magnanti Thomas L. , Mirchandani Prakash 
Published: November 2003

AbstractThe survivable network design (SND) problem seeks a minimum‐cost robust network configuration that provides a specified number of alternate (edge‐disjoint) paths between nodes of the network. For this problem, we present a family of new mixed‐integer programming formulations whose associated linear programming relaxations can be tighter than that of the usual cutset formulation. The new formulations, called connectivity‐splitting models, strengthen the cutset formulation by splitting the connectivity requirements across critical cutsets (with crossing requirements of at least two) into two separate requirements and strengthening the connectivity constraints across regular cutsets (with crossing requirements of one). As special cases of this broad modeling approach, we obtain three intuitive versions of the model. A connectivity‐peeling version peels off the lowest connectivity level, a connectivity‐dividing version divides the connectivity requirements for all critical cutsets, and an access‐completion version separates the design decisions for critical cutsets from those for regular cutsets. These stronger formulations motivate several SND combinatorial heuristics and facilitate the analysis of their worst‐case performance. Our bounds on the heuristic costs relative to the optimal values of the integer program and the linear programming relaxation of our tighter formulation are stronger than some previously known performance bounds for combinatorial heuristics. © 2003 Wiley Periodicals, Inc.
Fault‐tolerant cycle embedding in hierarchical cubic networks
Authors: Fu Jung‐Sheng , Chen Gen‐Huey 
Published: November 2003

AbstractA hierarchical cubic network was proposed as an alternative to the hypercube. By HCN(n), we denote the hierarchical cubic network that contains 2nn‐dimensional hypercubes. In this paper, using Gray codes, we construct fault‐free Hamiltonian cycles in an HCN(n) withn− 1 link faults. Since the HCN(n) is regular of degreen+ 1, the result is optimal. We also construct longest fault‐free cycles of length 22n− 1 in an HCN(n) with a one‐node fault and fault‐free cycles of length at least 22n− 2fin an HCN(n) withf‐node faults, where 22nis the number of nodes in the HCN(n),f≤n− 1 ifn= 3 or 4 andf≤nifn≥ 5. Our results can be applied to the hierarchical folded‐hypercube network as well. © 2003 Wiley Periodicals, Inc.
Edge‐superconnectivity of cages
Authors: Marcote X. , Balbuena C. 
Published: November 2003

AbstractA graph with minimum degree δ is said to be edge‐superconnected if each minimum edge‐cut consists of all the edges incident with some vertex (so λ = δ). A smallest δ‐regular graph G with girth g is said to be a (δ, g)‐cage. We show that every (δ, g)‐cage with odd girth is edge‐superconnected. This result strengthens one obtained by Wang et al. (λ = δ for every such cage) and supports the conjecture of Fu et al. that all (δ, g)‐cages are δ‐connected. © 2003 Wiley Periodicals, Inc.
Three complete turns of a 310‐helix at atomic resolution: the crystal structure of Z‐(Aib)11‐OtBu
Authors: Gessmann Renate , Brückner Hans , Petratos Kyriacos 
Published: November 2003

AbstractThe crystal structure of the synthetic protected oligopeptide Z‐(Aib)11‐OtBu was determined by x‐ray crystallography. The undecapeptide folds in a regular 310‐helix with nine consecutive 4 → 1 hydrogen bonds. At present, this is the largest available structure of a homopeptide (including homopeptides consisting of standard amino acids) and also the longest observed regular 310‐helix at atomic resolution. Z‐(Aib)11‐OtBu crystallizes readily from hot ethanol–water mixture and is one of the crystals in which no solvent molecule is co‐crystallized. In the crystal head‐to‐tail hydrogen bonded columns are formed in the [1 0 1] direction. Each helical column is surrounded by six others, whereby two are packed in parallel and four in antiparallel fashion. Helical columns are packed via apolar crystal contacts. The crystal structure of Z‐(Aib)11‐OtBu is compared with the crystal structures of Z‐(Aib)10‐OtBu and Z‐(Aib)9‐OtBu. The similarities and differences are analysed. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.
Crystal structure and conformational analysis of ampullosporin A
Authors: Kronen Matthias , Görls Helmar , Nguyen Hoai‐Huong , Reißmann Siegmund , Bohl Martin , Sühnel Jürgen , Gräfe Udo 
Published: November 2003

AbstractAmpullosporin A is a 15‐mer peptaibol type polypeptide that induces pigment formation by the fungus Phoma destructiva, forms voltage‐dependent ion channels in membranes and exhibits hypothermic effects in mice. The structure of ampullosporin A has been determined by x‐ray crystallography. This is the first three‐dimensional (3D) structure of the peptaibol subfamily SF6. From the N‐terminus to residue 13 the molecule adopts an approximate right‐handed α‐helical geometry, whereas a less regular structure pattern with β‐turn characteristics is found in the C‐terminus. Even though ampullosporin A does not contain a single proline or hydroxyproline it is significantly bent. It belongs to both the shortest and the most strongly bent peptaibol 3D structures. The straight structure part encompasses residues Ac‐Trp1‐Aib10 and is thus less extended than the α‐helical subunit. The 3D structure of ampullosporin A is discussed in relation to other experimentally determined peptaibol structures and in the context of its channel‐forming properties. As a part of this comparison a novel bending analysis based on a 3D curvilinear axis describing the global structural characteristics has been proposed and applied to all 3D peptaibol structures. A sampling of 2500 conformations using different molecular dynamics protocols yields, for the complete ampullosporin A structure, an α‐helix as the preferred conformation in vacuo with almost no bend. This indicates that solvent or crystal effects may be important for the experimentally observed peptide backbone bending characteristics of ampullosporin A. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.
Differences in membrane pore formation by peptaibols
Authors: Grigoriev Pavel A. , Schlegel Brigitte , Kronen Matthias , Berg Albrecht , Härtl Albert , Gräfe Udo 
Published: November 2003

AbstractThe efficiencies of membrane pore formation by 14 naturally occurring peptaibols and two structurally modified ampullosporins were compared using an artificial bilayer membrane model. Major differences were found in the dependence on peptide sequences and the constituting amino acids. Alamethicin F‐30, chrysospermins C/D, paracelsin and texenomycin A displayed higher activity by several orders of magnitude in comparison with smaller peptaibols containing <17 amino acids such as ampullosporins, trichofumins, bergofungins and cephaibols. Biological activities such as the induction of pigment formation by the fungus Phoma destructiva and long acting hypothermia and depression of locomotor activity in mice were correlated with moderate membrane permeabilization. No or weak membrane activities corresponded with biological inactivity. Highly membrane‐active structures such as alamethicin F‐30, chrysospermin C, texenomycin A and paracelsin A displayed antibiotic effects against the fungus and toxicity in mice. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.
Self‐assembling and membrane modifying properties of a lipopeptaibol studied by CW‐ESR and PELDOR spectroscopies
Authors: Milov A. D. , Tsvetkov YU. D. , Formaggio F. , Crisma M. , Toniolo C. , Raap J. 
Published: November 2003

AbstractTrichogin GA IV is a short lipopeptaibol antibiotic that is capable of enhancing the transport of small cations through the phospholipid double layer of the membrane. The antibiotic activity of the undecapeptide is thought to be based on either its self‐assembling or membrane‐modifying property. The chemical equilibrium between self‐aggregated and non‐aggregated molecular states was studied by CW‐ESR spectroscopy using solutions of TOAC nitroxide spin‐labelled trichogin analogues in an apolar solvent to mimic the membrane bound state. At room temperature the two different sets of signals observed in the spectrum were attributed to the presence of both monomers and aggregates in the sample. The ESR spectra of the monomeric and aggregated forms were separated and the dependence of the fraction of monomeric peptide molecules on concentration was obtained over the range 5 × 10−6 to 7 × 10−4 M. A two‐step aggregation mechanism is proposed: dimerization of peptide molecules followed by aggregation of dimers to assemblies of four peptide molecules per aggregate. The equilibrium constants were estimated for both steps. In addition, the lower lifetime limit was determined for dimers and tetramers. It is shown that when the peptide concentration exceeds 10−5 M, the major part of the peptide molecules in solution has the form of tetrameric aggregates. Independently, the PELDOR technique was used to investigate the concentration dependence of the parameters of the dipole–dipole interaction between spin labels in frozen (77 K) glassy solutions of aggregates of mono‐labelled TOAC analogues. The number of molecules in aggregates as well as the frequency and amplitude of PELDOR signal oscillations were found to be concentration independent in the range 5 × 10−4 to 8 × 10−3 M. In the frozen glassy solution state, the number of peptide molecules per aggregate was determined to be close to four, which is in agreement with the value obtained for spin‐labelled trichogin at room temperature. The present data provide experimental evidence in favour of a self‐assembling rather than a membrane‐modifying ion conduction mechanism. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.
The peptaibol database: a sequence and structure resource
Authors: Whitmore L. , Chugh J. K. , Snook C. F. , Wallace B. A. 
Published: November 2003

AbstractThe peptaibols are a large family of membrane‐active peptides with considerable sequence homology, but with different biological properties and three‐dimensional structures. They constitute a rich resource of naturally occurring ‘mutants’ which are potentially valuable for structure/function studies of ion channels.A searchable on‐line database of sequences and structures of the peptaibols has been created at http://www.cryst.bbk.ac.uk/peptaibol, as a resource for the biological and structural community. In this paper, the contents and organization of the website are discussed as well as procedures for submission of new entries to the database.At present, more than 300 peptaibol sequences are stored in the database. Each sequence entry contains its full literature reference and information about its biological source. Tools are provided for searching for specific peptaibol sequences or groupings of sequences, and for locating peptaibols containing specified sequence motifs. In addition the website acts as a database for structural information. The coordinates of all currently available peptaibol x‐ray and NMR structures are included and complemented, where appropriate, with molecular graphics illustrations. These include figures of model channel structures and comparisons between different peptaibol structures. The peptaibol database thus provides a tool for ready access to information and a means of investigating the sequences and structures of this class of polypeptides. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.
Chemical bond modeling with the energy‐driven orbital localization
Authors: Abarenkov I. V. , Antonova I. M. 
Published: November 2003

AbstractThis article concerns the embedding in covalent materials problem in general and the construction of one‐electron pseudoatoms to substitute the parts of a molecule connected with a chemical bond in particular. For this the procedure to part a molecule into the ion‐radicals and bonds within the Hartree–Fock (HF) approach is proposed. In this procedure the ion‐radical occupied orbitals are defined as solutions of HF equations for ion‐radical in the basis of occupied molecular orbitals (MOs) of the whole molecule. The bond orbitals are constructed to complete the functional space span by the occupied MOs of ion‐radicals to the functional space span by occupied MOs of the whole molecule. In this approach it is easy to decompose the total electron density matrix of the whole molecule into the density matrixes of ion‐radicals and bonds. Therefore, the adiabatic potential of the molecule is expressed as a sum of ion‐radical and bonds self‐energies and various intramolecular interaction energies. The equation for the exact bond orbital is developed that is the HF equation for the two‐electron problem in the nonlocal external field and modified Coulomb exchange potential. An approximation for this equation is given. Test calculations were performed for the H2O molecule and the artificial LiOH molecule. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Intermolecular forces and random fields: Mutual renormalizations in classical statistical mechanics
Authors: Zakharov A. Yu. 
Published: November 2003

AbstractExact representations of generating functional of one‐component systems with arbitrary central interatomic potentials via functional integral over auxiliary field defined in wave‐vector space are obtained. It is proved that the problem of partition function evaluation is equivalent to the problem of statistical integral of nonlinear (self‐acting) temperature‐dependent field. Elementary excitations Hamiltonian for the continuous model of the classical statistical physics from “first principles” is obtained. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Multireference many‐body perturbation theory calculations on negative ions with small electron detachment energies
Authors: Izmailov Arthur , Zaitsevskii Andréi 
Published: November 2003

AbstractWe present a simple method of ab initio calculations on the systems composed of a closed‐shell‐like molecule (atom) and a weakly bound electron via constructing a state‐specific effective Hamiltonian in a model space generated by placing the extra electron on virtual self‐consistent field orbitals of the neutral species in all the possible ways. Correlation contributions are incorporated into the effective Hamiltonian by the second‐order multipartitioning many‐body perturbation theory. The method prevents the appearance of intruder states without destroying the exact size consistency of results and ensures a proper description of the dynamic correlation effects on the spatial localization of the extra electron and continuous behavior of computed characteristics under variations of molecular geometry. A detailed study of perturbative solutions for a model problem with parameter‐dependent Hamiltonian and test calculations of Ca, Sr, and Ba atomic anions are reported. The method is also applied to the description of the hypothetical symmetrical isomer of water dimer anion with the extra electron trapped between the water molecules. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Design of Statically Stable Walking Robot: A Review
Authors: Kar D. C. 
Published: November 2003

AbstractThe superior mobility characteristics of legged animals compared to those of wheeled or tracked vehicles for off‐road locomotion motivated the development of artificial walking machines. The sustained worldwide efforts for the last few decades resulted in a large number of legged robots with different levels of sophistication. Here, various design approaches made so far to realize artificial legged locomotion are discussed. Mainly, different vehicle configurations as well as leg mechanisms which are already explored by researchers are reviewed in brief. The author hopes that this will serve as a brief account of previous research efforts and help future walking robot designers to develop more sophisticated machines. © 2003 Wiley Periodicals, Inc.
Transcardiopulmonary vs Pulmonary Arterial Thermodilution Methods for Hemodynamic Monitoring of Burned Patients
Authors: Küntscher Markus V. , Blome-Eberwein Sigrid , Pelzer Michael , Erdmann Detlev , Germann Günter 
Published: November 2003

Abstract
The objective of this study was to validate a new method of transcardiopulmonary thermodilution for assessment of cardiac index (CI), stroke volume index (SVI), systemic vascular resistance index (SVRI) and additional parameters such as intrathoracic blood volume index and extravascular lung water index (EVLWI) by comparison with conventional pulmonary artery catheter values in a severely burned population. The pulmonary artery measurements were performed continuously with the Vigilance system, and the transcardiopulmonary thermodilution with the PiCCO® system. One hundred thirteen measurements with each system on up to six consecutive days were taken in 14 severely burned patients (average TBSA, 49.6%; average ABSI, 10.3), aged 21 to 61 years (mean, 42.2 years) and compared intraindividually. An excellent correlation between the two methods was shown for CI (r = 0.80) and its derived parameters SVI and SVRI in states of low to normal cardiac output. The correlation was poor for cardiac indices greater then 5.5 up to their maximum values (r = 0.46). No correlation between index of oxygenation (PaO2/FiO2) vs EVLW I was observed. There was no difference between survivors and nonsurvivors, and between patients with and without inhalation injury in EVLWI. The method of transcardiopulmonary thermodilution is suitable to assess SVI, CI and SVRI under the special pathophysiologic condition of a major burn for low to normal cardiac output states. It is less reliable when cardiac output is high. The lower cost and less invasive nature are the advantages of the system compared with use of the pulmonary artery catheter. The role of intrathoracic blood volume index and EVLWI in cardiopulmonary monitoring of severely burned patients remains to be further determined.