bluuebunny/crossref_metadata_2025_split huggingface dataset:
Information source horizons and source preferences of environmental activists: A social phenomenological approach
Authors: Savolainen Reijo 
Published: September 2007

AbstractThis study focuses on the ways in which people define their source preferences in the context of seeking orienting information for nonwork purposes. The conceptual framework of the study combines ideas drawn from social phenomenology and information‐seeking studies. The study utilizes Alfred Schutz's model describing the ways in which actors structure everyday knowledge into regions of decreasing relevance. It is assumed that this structuring based on the actor's interest at hand is also reflected in the ways in which an actor prefers information sources and channels. The concept of information source horizon is used to elicit articulations of source preferences. The empirical part of the study draws on interviews with 20 individuals active in environmental issues. Printed media (newspapers), the Internet, and broadcast media (radio, television) were preferred in seeking for orienting information. The major source preferences were content of information, and availability and accessibility. Usability of information sources, user characteristics such as media habits, and situational factors were mentioned less frequently as preference criteria.
Manifestation of research teams in journal literature: A growth model of papers, authors, collaboration, coauthorship, weak ties, and Lotka's law
Authors: Morris Steven A. , Goldstein Michel L. 
Published: September 2007

AbstractThis article introduces a team‐based model of researchers in a specialty and investigates the manifestation of such teams in a specialty's literature. The proposed qualitative behavioral model, with its mathematical expression as a growth model, is significant because it simultaneously describes the two phenomena of collaboration and author productivity (Lotka's law) in a specialty. The model is nested: A team process models the creation of research teams and the success‐breeds‐success process of their production of articles, while at a lower level the productivity of authors within teams is also modeled as a success‐breeds‐success process. Interteam collaboration (weak ties) is modeled as random events. This simple growth model is shown to faithfully mimic six network metrics of bipartite article‐author networks. The model is demonstrated on three example article collections from specialties that have a wide range of degree of collaboration: (a) a distance education collection with low collaboration degree, (b) a complex networks collection with typical collaboration degree, and (c) an atrial ablation collection with heavy collaboration degree.
Description and search labor for information retrieval
Authors: Warner Julian 
Published: September 2007

AbstractSelection power is taken as the fundamental value for information retrieval systems. Selection power is regarded as produced by selection labor, which itself separates historically into description and search labor. As forms of mental labor, description and search labor participate in the conditions for labor and for mental labor. Concepts and distinctions applicable to physical and mental labor are indicated, including the necessity of labor for survival, the idea of technology as a human construction, and the possibility of the transfer of human labor to technology. Distinctions specific to mental labor, particularly between semantic and syntactic labor, are introduced. Description labor is exemplified by cataloging, classification, and database description, can be more formally understood as the labor involved in the transformation of objects for description into searchable descriptions, and is also understood to include interpretation. The costs of description labor are discussed. Search labor is conceived as the labor expended in searching systems. For both description and search labor, there has been a progressive reduction in direct human labor, with its syntactic aspects transferred to technology, effectively compelled by the high relative costs of direct human labor compared to machine processes.
Dispersive shock waves in the solar wind
Authors: Ballai I. , Forgács‐Dajka E. , Marcu A. 
Published: September 2007

AbstractCompressional waves in the solar wind propagating over large distances are likely to steepen into shock waves where the increase in the amplitude is balanced by dissipation. Dispersive effects caused by, e.g. Hall currents perpendicular to the ambient magnetic field can influence the generation and propagation of shock waves. In the present study the dispersion is considered weak but in time its importance can grow. When the effect of dispersion is strong enough, it can balance the nonlinear steepening of waves leading to the formation of solitons. The obtained results show that the weak dispersion will alter the amplitude and propagation speed of the shock wave. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On transition region convection cells in simulations of p‐mode propagation into the solar atmosphere
Authors: Malins C. 
Published: September 2007

AbstractThis paper examines the way that transition region surface waves, generated in 2‐D numerical simulations of the nonmagnetic solar atmosphere when various synthetic photospheric drivers are applied, drive the granulation of the transition region/lower coronal region into convection cells. It is shown that these cells are generated by both synthetic point drivers and synthetic horizontally coherent p‐mode drivers. These cells cause the conversion of driven signals in vertical velocity into coronal signals predominantly in horizontal velocity, which if carried over to a case with a magnetic field included could cause mode conversion. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
MHD waves at a spherical interface modelling EIT waves
Authors: Douglas M. , Ballai I. 
Published: September 2007

AbstractEruptive events such as flares and coronal mass ejections (CMEs) are known to generate global waves propagating over distances comparable to the solar radius in different layers of the solar atmosphere. Here we investigate the propagation of coronal EIT waves, modelled as fast magnetoacoustic modes propagating at a spherical interface in the presence of a purely radial magnetic field. Based on a simplified equilibrium we derive the dispersion relation of the waves. The generation and propagation of EIT waves at the spherical interface is studied numerically for different values of spherical degree and preliminary conclusions are reached regarding the properties of EIT waves. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Are extrasolar oceans common throughout the Galaxy?
Authors: Ehrenreich D. , Cassan A. 
Published: September 2007

AbstractLight and cold extrasolar planets such as OGLE 2005‐BLG‐390Lb, a 5.5 Earth masses planet detected via microlensing, could be frequent in the Galaxy according to some preliminary results from microlensing experiments. These planets can be frozen rocky‐ or ocean‐planet, situated beyond the snow line and, therefore, beyond the habitable zone of their system. They can nonetheless host a layer of liquid water, heated by radiogenic energy, underneath an ice shell surface for billions of years, before freezing completely. These results suggest that oceans under ice, like those suspected to be present on icy moons in the Solar system, could be a common feature of cold low‐mass extrasolar planets. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The structure of the extended phase space of the Sitnikov problem
Authors: Kovács T. , Érdi B. 
Published: September 2007

AbstractThe extended phase space of the Sitnikov problem is studied by using a stroboscopic map and computing escape times. Comparisons of phase portraits and plots of escape times reveal the intrinsic connection between the geometry of the phase space and the dynamical behaviour of the system. Properties of the phase space are analysed both in the central regular region and far from it. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Results of the photometry of the spotted dM1‐2e star EY Draconis
Authors: Vida K. 
Published: September 2007

AbstractWe have observed EY Draconis with the 60‐cm telescope of Konkoly Observatory in Budapest for 64 nights. In the first observing season the star produced a stable light curve for more than 60 stellar rotations, however, the light curves observed in the next season and the spot modelling show clear evidence of the evolution of the spotted stellar surface. The changes of the maximum brightness level suggests the existence of a longer period of about 300 days, which seems to be confirmed by the ROTSE archival data. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Heating of the solar and stellar coronae: a review
Authors: Erdélyi R. , Ballai I. 
Published: September 2007

AbstractDespite great advances in observations and modelling, the problem of solar and stellar heating still remains one of the most challenging problems of space physics. To find a definite answer to what sort of mechanisms act to heat the plasma to a few million degrees requires a collaborative effort of small scales observations, large capacity numerical modelling and complicated theoretical approaches. A unique theory should incorporate aspects such as the generation of energy, its transport and dissipation. Up to now, the first two problems are rather clarified. However, the modality of transfer of magnetic or kinetic energy into heat is a question still awaiting for an answer. In the present paper we review the various popular heating mechanisms put forward in the existing extensive literature. The heating processes are, somewhat arbitrarily, classified as hydrodynamic, magnetohydrodynamic or kinetic based on the characteristics of the model medium. These mechanisms are further divided based on the time scales of the ultimate dissipation involved (i.e. AC and DC heating, turbulent heating). In particular, special attention is paid to discuss shock dissipation, mode coupling, resonant absorption, phase mixing, and, reconnection. Finally, we briefly review the various heating mechanisms proposed to heat other stars. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the possibility of a bimodal solar dynamo
Authors: Petrovay K. 
Published: September 2007

AbstractA simple way to couple an interface dynamo model to a fast tachocline model is presented, under the assumption that the dynamo saturation is due to a quadratic process and that the effect of finite shear layer thickness on the dynamo wave frequency is analogous to the effect of finite water depth on surface gravity waves. The model contains one free parameter which is fixed by the requirement that a solution should reproduce the helioseismically determined thickness of the tachocline. In this case it is found that, in addition to this solution, another steady solution exists, characterized by a four times thicker tachocline and 4–5 times weaker magnetic fields. It is tempting to relate the existence of this second solution to the occurrence of grand minima in solar activity. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic reconnection via tearing instability in a rotating viscous fluid
Authors: Bian N.H. 
Published: September 2007

AbstractThe resistive tearing instability of a sheet pinch, first investigated by Kuang & Roberts (1990) for the case of a rapidly rotating inviscid fluid, is studied for arbitrary rotation rate in a visco‐resistive fluid. Altogether there are three regimes of the resistive tearing instability which correspond to the particular parameter domain in the (Ω, Pm) plane. Here Ω is the angular velocity of the medium which is normalized to the Alfvén time and Pm is the magnetic Prandtl number. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Searching extra dimensions in compact stars
Authors: Barnaföldi G.G. , Lévai P. , Lukács B. 
Published: September 2007

AbstractThe electro‐magnetic and particle radiation detected from the direction of Cygnus X3 raise the question of the existence of special long‐lived, neutral particles. We investigate the origin of these particles in a special approach: the source object may contain compactified extra dimension and these particles are messengers of this state. We describe hyperon stars in 3 + 1 dimension and introduce the description of a compact stars in 3 + 1c + 1 dimensional space‐time. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Updated catalogue of the light curve solutions of contact binary stars
Authors: Csizmadia Sz. , Marton G. , Klagyivik P. , Spindler Sz. 
Published: September 2007

AbstractThe catalogue of the light curve solutions of contact binary stars was updated. Based on the catalogue data we call the attention to a remarkable gap in the temperature distribution of contact binaries which remained unexplained. The absolute dimensions of the components were calculated in a reliable way. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Molecular cloud abundances and anomalous diffusion
Authors: Marschalkó G. , Forgács‐Dajka E. , Petrovay K. 
Published: September 2007

AbstractThe chemistry of molecular clouds has been studied for decades, with an increasingly general and sophisticated treatment of the reactions involved. Yet the treatment of turbulent diffusion has remained extremely sketchy, assuming simple Fickian diffusion with a scalar diffusivity D. However, turbulent flows similar to those in the interstellar medium are known to give rise to anomalous diffusion phenomena, more specifically superdiffusion (increase of the diffusivity with the spatial scales involved). This paper considers to what extent and in what sense superdiffusion modifies molecular abundances in interstellar clouds. For this first exploration of the subject we employ a very rough treatment of the chemistry and the effect of non‐uniform cloud density on the diffusion equation is also treated in a simplified way. The results nevertheless clearly demonstrate that the effect of superdiffusion is quite significant, abundance values at a given radius being modified by order of unity factors. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Studying Blazhko RR Lyrae stars with the 24‐inch telescope of the Konkoly Observatory
Authors: Sódor Á. 
Published: September 2007

AbstractAbout a dozen field RR Lyrae stars have been observed with the 24‐inch Heyde‐Zeiss telescope of the Konkoly Observatory at Svábhegy, Budapest, since its refurbishment in 2003. Most of the observing time is allocated for the investigation of the Blazhko modulation, a phenomenon that still does not have a satisfactory explanation. The obtained multicolour CCD observations are unique in extent. The accuracy of the measurements makes it possible to detect low amplitude modulation of the light curve as well. The discovery of Blazhko stars with low modulation amplitudes warns that the incidence rate of the Blazhko modulation is, in fact, much larger than it was previously expected. This makes the efforts exploring the cause of the modulation even more important. A summary of our measurements and results achieved during the last 3 years is presented. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The double‐mode RR Lyrae variable BS Com
Authors: Dékány I. 
Published: September 2007

AbstractWe present the frequency analysis of the multicolour time series photometry of the field RRd variable BS Comae. The large number of data points in each of the BV (RI)C bands and the ∼0.01 magnitude accuracy of the individual measurements allow us a high precision analysis of the properties of the combination frequencies due to nonlinear coupling. Through the combination of the frequency spectra in different colors we show that except for the components corresponding to the linear combinations of the two pulsation modes, there are no other components present above the millimagnitude amplitude level. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Blazhko behavior of RV UMa
Authors: Hurta Zs. 
Published: September 2007

AbstractRV UMa is one of the most extensively studied RR Lyrae stars showing Blazhko modulation. Its photometric observations cover more than 90 years. The published photoelectric observations of RV UMa obtained at the Konkoly Observatory (Kanyó 1976) were re‐considered and completed with previously unpublished data. During the time interval of the observations the periods of both the pulsation and the modulation varied within the ranges of 0.000007 and 0.9 days, respectively. We have found a definite but not strict inverse relation between the pulsation and modulation periods of RV UMa. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Radial velocities of five globular clusters obtained with AAOmega
Authors: Székely P. , Kiss L.L. , Szatmáry K. , Csák B. , Bakos G.Á. , Bedding T.R. 
Published: September 2007

AbstractUsing the recently commissioned multi‐object spectrograph AAOmega on the 3.9m AAT we have obtained mediumresolution near‐infrared spectra for 10 500 stars in and around five southern globular clusters. The targets were 47 Tuc, M12, M30, M55 and NGC 288. We have measured radial velocities to ± 1 kms‐ 1 with the cross correlation method and estimated metallicity, effective temperature, surface gravity and rotational velocity for each star by fitting synthetic model spectra. An analysis of the velocity maps and velocity dispersion of member stars revealed systemic rotation in four of the target clusters. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A mixed‐α,β miniprotein stereochemically reprogrammed to high‐binding affinity for acetylcholine
Authors: Rana Soumendra , Kundu Bijoy , Durani Susheel 
Published: September 2007

AbstractThe protein‐structure space is limited to L configuration in the asymmetric α‐amino acid structures; the function space, on other hand, seems limitless because of the chemical diversity in the amino acid side chain structures. The chemical diversity in side chain structure may be multiplied beneficially with the stereochemical diversity in main chain structure; thus, de novo protein design may be explored for customizing molecular structures stereochemically and molecular functions chemically. Illustrating de novo design in the structure space of L and D alphabet, canonical all‐β folds of poly‐L structure were reprogrammed as bracelet, boat, and canoe‐shaped molecules—the “boat” as a receptor‐like pocket and the “canoe” as a metal‐ion receptor—simply by mutating specific L‐amino acid residues to the corresponding D stereochemical structure. Demonstrating customization of molecular shape stereochemically and function chemically, a 15‐residue mixed‐α, β miniprotein of canonical poly‐L structure is now reprogrammed stereochemically as a cup‐shaped receptor for acetylcholine via cation‐π interaction with a triad of aromatic side chains placed in mimicry of the acetylcholine‐receptor sites both natural and artificial. Evidence from CD, fluorescence, NMR, DSC, ITC, MD, and molecular‐docking studies is presented to show that a rationally designed 15‐residue mixed‐L, D peptide is a cooperatively ordered molecular fold in the stereochemically specified molecular morphology, submicromolar in affinity of acetylcholine and thus an acetylcholine receptor exceptionally small and simple. © 2007 Wiley Periodicals, Inc. Biopolymers 87: 231–243, 2007.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
The investigation of protein A and Salmonella antibody adsorption onto biosensor surfaces by atomic force microscopy
Authors: Lee Kyoung G. , Pillai Shreekumar R. , Singh Shree R. , Willing Gerold A. 
Published: September 2007

AbstractThe investigation of Protein A and antibody adsorption on surfaces in a biological environment is an important and fundamental step for increasing biosensor sensitivity and specificity. The atomic force microscope (AFM) is a powerful tool that is frequently used to characterize surfaces coated with a variety of molecules. We used AFM in conjunction with scanning electron microscopy to characterize the attachment of protein A and its subsequent binding to the antibody and Salmonella bacteria using a gold quartz crystal. The rms roughness of the base gold surface was determined to be approximately 1.30 nm. The average step height change between the solid gold and protein A layer was approximately 3.0 ± 1.0 nm, while the average step height of the protein A with attached antibody was approximately 6.0 ± 1.0 nm. We found that the antibodies did not completely cover the protein A layer, instead the attachment follows an island model. Salt crystals and water trapped under the protein A layer were also observed. The uneven adsorption of antibodies onto the biosensor surface might have led to a decrease in the sensitivity of the biosensor. The presence of salt crystals and water under the protein A layer may deteriorate the sensor specificity. In this report, we have discussed the application and characterization of protein A bound to antibodies which can be used to detect bacterial and viral pathogens. Biotechnol. Bioeng. 2008;99: 949–959. © 2007 Wiley Periodicals, Inc.
Metabolite profiling analysis of Methylobacterium extorquens AM1 by comprehensive two‐dimensional gas chromatography coupled with time‐of‐flight mass spectrometry
Authors: Guo Xiaofeng , Lidstrom Mary E. 
Published: September 2007

AbstractMethylobacterium extorquens AM1 is a facultative methylotroph, which is a potential candidate to be used in commercial processes to convert simple one‐carbon compounds to a variety of multicarbon chemicals and products. To better understand C1 metabolism in M. extorquens AM1 at the systems level, metabolite profiling tools were developed and applied in this bacterium. Comprehensive two‐dimensional gas chromatography coupled with time‐of‐flight mass spectrometry (GC × GC‐TOFMS) was used to obtain metabolite profiles of M. extorquens AM1 (primarily organic acids) and to identify the metabolite differences between cells grown on methanol (C1 substrate) and succinate (multicarbon substrate). In this study, a list of compounds that included amino acids and major intermediates of central C1 and multicarbon metabolism were studied as target metabolites. For these, calibration curves were obtained for absolute quantification by spiking different amounts of standard mixtures to cell cultures. Parallel factor analysis (PARAFAC) was used for accurate peak quantification. Unknown chemical differences between cells grown on methanol and succinate were identified by applying Fisher ratio analysis at a selective mass channel (m/z 147). Thirty‐six compounds were discovered to be statistically differentially expressed between C1 and multicarbon metabolism. Among these, 13 were identified by matching to library mass spectra, and the rest were novel compounds that were not included in libraries. These differentially expressed compounds have provided clues to new pathways that are specifically linked to C1 metabolism. Biotechnol. Bioeng. 2008;99: 929–940. © 2007 Wiley Periodicals, Inc.