bluuebunny/crossref_metadata_2025_split huggingface dataset:
An empirical investigation of the g‐index for 26 physicists in comparison with the h‐index, the A‐index, and the R‐index
Authors: Schreiber Michael 
Published: May 2008

AbstractJ.E. Hirsch (2005) introduced the h‐index to quantify an individual's scientific research output by the largest number h of a scientist's papers that received at least h citations. To take into account the highly skewed frequency distribution of citations, L. Egghe (2006a) proposed the g‐index as an improvement of the h‐index. I have worked out 26 practical cases of physicists from the Institute of Physics at Chemnitz University of Technology, and compare the h and g values in this study. It is demonstrated that the g‐index discriminates better between different citation patterns. This also can be achieved by evaluating B.H. Jin's (2006) A‐index, which reflects the average number of citations in the h‐core, and interpreting it in conjunction with the h‐index. h and A can be combined into the R‐index to measure the h‐core's citation intensity. I also have determined the A and R values for the 26 datasets. For a better comparison, I utilize interpolated indices. The correlations between the various indices as well as with the total number of papers and the highest citation counts are discussed. The largest Pearson correlation coefficient is found between g and R. Although the correlation between g and h is relatively strong, the arrangement of the datasets is significantly different depending on whether they are put into order according to the values of either h or g.
A framework for describing correlated excitation of solar p‐modes
Authors: Chaplin W. J. , Elsworth Y. , Toutain T. 
Published: May 2008

AbstractIn a previous paper we suggested that, for a given p mode, the excitation function is the same as the component of the solar background noise that has an identical surface spherical harmonic projection (over the corresponding range of temporal frequency). An important consequence of this surmise is that the excitation of overtones of a given angular degree and azimuthal order will be correlated in time. In this note, we introduce the basic principles and a mathematical description of correlated mode excitation. We use simple, illustrative examples, involving two modes. Our treatment suggests that in the real observations, any signatures of the correlation would not appear as a correlation of the output amplitudes of overtones, but rather as subtle modifications to the power spectral density at frequencies between the central frequencies of the overtones. These modifications give a contribution to the observed peak asymmetries. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A modified peak‐bagging technique for fitting low‐𝓁 solar p‐modes
Authors: Fletcher S.T. , Chaplin W.J. , Elsworth Y. , New R. 
Published: May 2008

AbstractWe introduce a modified version of a standard power spectrum ‘peak‐bagging’ technique which is designed to gain some of the advantages that fitting the entire low‐degree p‐mode power spectrum simultaneously would bring, but without the problems involved in fitting a model incorporating many hundreds of parameters. Employing Monte‐Carlo simulations we show that by using this modified fitting code it is possible to determine the true background level in the vicinity of the p‐mode peaks. In addition to this we show how small biases in other mode parameters, which are related to inaccurate estimates of the true background, are also consequently removed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
YAOPBM – yet another peak bagging method
Authors: Korzennik S. G. 
Published: May 2008

AbstractI present and discuss the fitting methodology I developed for very‐long time series (2088‐day‐long). This new method was first used to fit low degree modes, 𝓁 ≤ 25. That time series was also sub‐divided in somewhat shorter segments (728‐daylong) and also fitted for these low degrees, in order to measure changes with the solar activity level.I have recently extended the fitting in several “directions”: 1) to substantially higher degrees (𝓁 ≤ 125), 2) to shorter time series (364‐ and 182‐day‐long), and, 3) to additional 728‐day‐long segments, covering now some 10 years of observations. I present and discuss issues related to this expansion, namely problems at low frequencies affecting the f and p1 modes, and the inadequacy of the leakage matrix at higher degrees. I also present some of the characteristics of the observed temporal changes in the resulting frequencies. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Update on g‐mode research
Authors: García R.A. , Jiménez A. , Mathur S. , Ballot J. , Eff‐Darwich A. , Jiménez‐Reyes S. J. , Pallé P. L. , Provost J. , Turck‐Chièze S. 
Published: May 2008

AbstractSince the beginning of this century we have attended a blooming of the gravity‐mode research thanks to the unprecedented quality of the data available, either from space with SoHO, or from the ground‐based networks as BiSON or GONG. From the first upper limit of the gravity‐mode amplitudes fixed at 10 mm/s at 200 μ Hz given by Appourchaux et al. (2000), on one hand, a peak was supposed to be a component of the 𝓁 = 1, n = 1 mixed mode (García et al. 2001a, 2001b; Gabriel et al. 2002) and, on the other hand, a couple of patterns – multiplets – were attributed to gravity modes (Turck‐Chièze et al. 2004; Mathur et al. 2007). One of these patterns, found around 220 μ Hz, could be labeled as the 𝓁 = 2, n = –3 g mode, which is expected to be the one with the highest surface amplitude (Cox & Guzik 2004). Finally, in 2007, García et al. were able to measure the fingertips of the dipole gravity modes looking for their asymptotic properties. In the present paper we present an update of the recent developments on this subject with special attention to the 220 μ Hz region, the dipole asymptotic properties and the impact of the incoming g‐mode observations on the knowledge of the solar structure and rotation profile. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preliminary results on the determination of the theoretical nonadiabatic observable phase lag (ψT) using VIRGO color photometry
Authors: Simoniello R. , Garrido R. , Jiménez A. 
Published: May 2008

AbstractThe helioseismic instruments aboard the SOHO satellite make it possible to measure solar oscillations as variations of the irradiance (VIRGO) or as variations of the photospheric velocity (GOLF). Theoretically, phase differences between different photometric bands are expected to be around 0 degrees over the p‐mode frequency range. By using VIRGO (red) and VIRGO (blue) data, we find a mean phase shift of 8.05 ± 1.81°, whereas by using VIRGO (green) and VIRGO (blue) data, we got a mean value of –1.04 ± 0.19°. Hence, when the analysis includes the VIRGO infrared range, the Sun's atmosphere does not follow an exact adiabatic behavior. In this study, we use the phase shifts obtained by VIRGO (green) and VIRGO (blue) to determine the non‐adiabatic parameter phase lag (ψT) as a function of frequency. To this aim, we applied the non radial linearized formula put in the complex form by Garrido: we found a mean value of ψT = 179.95°. The lowest value being ψT = 179.90°, the departure from theoretical predictions is less then a tenth of a degree over the entire p mode frequency range. We can state that the solar atmosphere has a behavior close to the adiabatic case, when the phase shifts and amplitude ratios are computed using VIRGO (green) and VIRGO (blue) data. Nevertheless this small deviation is significant. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The visibility of low‐frequency solar acoustic modes
Authors: Broomhall A. M. , Chaplin W. J. , Elsworth Y. , Fletcher S. T. 
Published: May 2008

AbstractWe make predictions of the detectability of low‐frequency p modes. Estimates of the powers and damping times of these low‐frequency modes are found by extrapolating the observed powers and widths of higher‐frequency modes with large observed signal‐to‐noise ratios. The extrapolations predict that the low‐frequency modes will have small signal‐to‐noise ratios and narrow widths in a frequency‐power spectrum. Monte Carlo simulations were then performed where timeseries containing mode signals and normally distributed Gaussian noise were produced. The mode signals were simulated to have the powers and damping times predicted by the extrapolations. Various statistical tests were then performed on the frequency‐amplitude spectra formed from these timeseries to investigate the fraction of spectra in which the modes could be detected. The results of these simulations were then compared to the number of p‐modes candidates observed in real Sun‐as‐a‐star data at low frequencies. The fraction of simulated spectra in which modes were detected decreases rapidly as the frequency of modes decreases and so the fraction of simulations in which the low‐frequency modes were detected was very small. However, increasing the signal‐to‐noise (S/N) ratio of the low‐frequency modes by a factor of 2 above the extrapolated values led to significantly more detections. Therefore efforts should continue to further improve the quality of solar data that is currently available. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Laboratory performances of the solar multichannel resonant scattering spectrometer prototype of the GOLF‐New Generation instrument
Authors: Turck‐Chièze S. , Carton P.H. , Mathur S. , Barrière J.‐C. , Daniel‐Thomas P. , Lahonde‐Hamdoun C. , Loiseau D. , Nunio F. , Piret Y. , Robillot J.M. 
Published: May 2008

AbstractThis article quickly summarizes the performances and results of the GOLF/SoHO resonant spectrometer, thus justifying to go a step further. We then recall the characteristics of the multichannel resonant GOLF‐NG spectrometer and present the first successful performances of the laboratory tests on the prototype and also the limitations of this first technological instrument. Scientific questions and an observation strategy are discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effect of turbulent mixing on the g‐mode spectrum of MS stars
Authors: Montalbán J. , Miglio A. , Eggenberger P. , Noels A. 
Published: May 2008

AbstractUnderstanding transport processes inside stars is one of the main goals of asteroseismology. Chemical turbulent mixing can affect the internal distribution of μ near the energy generating core, having an effect on the evolutionary tracks similar to that of overshooting. This mixing leads to a smoother chemical composition profile near the edge of the convective core, which is reflected in the behavior of the buoyancy frequency and, therefore, in the frequencies of gravity modes. We describe the effects of convective overshooting and turbulent mixing on the frequencies of gravity modes in B‐type main sequence stars. In particular, the cases of p‐g mixed modes in β Cep stars and high‐order modes in SPBs are considered. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A procedure for modelling asymptotic g‐mode pulsators: The case of γ Doradus stars
Authors: Moya A. , Suárez J.C. , Martín‐Ruiz S. , Amado P.J. , Rodríguez‐López C. , Grigahcène A. , Dupret M.A. , Rodríguez E. , Garrido R. 
Published: May 2008

AbstractMode identification is one of the first and main problems we encounter in trying to develop the complete potential of asteroseismology. In the particular case of g‐mode pulsators, this is still an unsolved problem, from both the observational and theoretical points of view. Nevertheless, in recent years, some observational and theoretical efforts have been made to find a solution. In this work we use the latest theoretical and computational tools to understand asymptotic g‐mode pulsators: 1) the Frequency Ratio Method, and 2) Time Dependent Convection. With these tools, a self‐consistent procedure for mode identification and modelling of these g‐mode pulsators can be constructed. This procedure is illustrated using observational information available for the γ Doradus star 9Aurigae. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of the stellar inclination angle upon theoretical errors of l = 1 p‐mode parameters
Authors: Ballot J. , Appourchaux T. , Toutain T. 
Published: May 2008

AbstractThe asteroseismic observations provided by current and future missions like CoRoT or Kepler will have a quality closer to those obtained for the Sun. In this context, tools and methods developed for helioseismology can be applied to other stars. In this paper, we focus on solar‐like oscillations of stars with an unknown rotation axis inclination and study, by means of maximum‐likelihood estimation, the errors on the determination of l = 1 p‐mode parameters. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Decisional comprehensiveness and firm performance: towards a more complete understanding
Authors: Miller C. Chet 
Published: May 2008

AbstractOrganizational prosperity and even survival can be threatened unless strategic decisions are made through an effective process. But what does an effective decision‐making process look like? Analysts and executives have struggled over the years to answer this question. Recently, however, empirical research has produced a consistent answer for one of the most fundamental aspects of strategic decision‐making: comprehensiveness. This recent work suggests that higher levels of comprehensiveness are positive for firms facing turbulent conditions but are irrelevant for firms facing stable conditions. While this consistency would seem to be positive, it presents a puzzle: Why are comprehensiveness and performance unrelated in stable environments? In such environments, problems generally believed to plague comprehensive decision‐making are less severe. The theory building and empirical results of the present research suggest a solution to the puzzle: comprehensiveness and performance exhibit a relationship more complex than previous studies have been designed to detect. Copyright © 2008 John Wiley & Sons, Ltd.
Herding by attribution of privileged information
Authors: Quiamzade Alain , L'Huillier Jean‐Paul 
Published: May 2008

AbstractWe study a situation where agents take extreme actions and how these actions are imitated by others. First, Experiment 1 showed that an expert first mover had an advantage in obtaining herding by others on his investment decision, when compared to a non‐expert first mover. Experiment 2 showed that this advantage only appeared when the first mover's investment was out‐of‐the‐ordinary (in fact, highly aberrant). We obtained the same level of herding in Experiment 3 when the first mover had privileged information, instead of being an expert. Second, Experiment 4 showed that when people observed the same out‐of‐the‐ordinary investment and did not know whether the first mover had privileged information or not, they herded on him as if he had privileged information. In fact, our data revealed that participants thought that the unknown first mover had privileged information. Furthermore, herding was statistically indistinguishable from the condition where observers knew unambiguously that the first mover had privileged information. Copyright © 2008 John Wiley & Sons, Ltd.
Ultralong Carbon–Carbon Bonds in Dispirobis(10‐methylacridan) Derivatives with an Acenaphthene, Pyracene, or Dihydropyracylene Skeleton
Authors: Kawai Hidetoshi , Takeda Takashi , Fujiwara Kenshu , Wakeshima Makoto , Hinatsu Yukio , Suzuki Takanori 
Published: May 2008

AbstractAcenapthalene, pyracene, and dihydropyracylene attached to two units of spiroacridan are a novel class of hexaphenylethane (HPE) derivatives that have an ultralong CC bond (1.77–1.70 Å). These sterically challenged molecules were cleanly prepared by CC bond formation through two‐electron reduction from the less‐hindered dications. These ultralong bonds were realized based on several molecular‐design concepts including enhanced “front strain” through “multiclamping” by means of fusing or bridging aryl groups in the HPE molecule. The lengths of these ultralong bonds and their relation to the conformation (torsional angle) were also validated by means of theoretical calculations. Bond‐fission experiments revealed that the bonds are more easily cleaved than standard covalent bonds to produce the corresponding dication upon oxidation with an increase in the length of the CC bond.
Hormone‐dependent expression of fasciclin II during ganglionic migration and fusion in the ventral nerve cord of the moth Manduca sexta
Authors: Himes Katherine E. , Klukas Kathleen A. , Fahrbach Susan E. , Mesce Karen A. 
Published: May 2008

AbstractThe ventral nerve cord of holometabolous insects is reorganized during metamorphosis. A prominent feature of this reorganization is the migration of subsets of thoracic and abdominal larval ganglia to form fused compound ganglia. Studies in the hawkmoth Manduca sexta revealed that pulses of the steroid hormone 20‐hydroxyecdysone (20E) regulate ganglionic fusion, but little is known about the cellular mechanisms that make migration and fusion possible. To test the hypothesis that modulation of cell adhesion molecules is an essential component of ventral nerve cord reorganization, we used antibodies selective for either the transmembrane isoform of the cell adhesion receptor fasciclin II (TM‐MFas II) or the glycosyl phosphatidylinositol‐linked isoform (GPI‐MFas II) to study cell adhesion during ganglionic migration and fusion. Our observations show that expression of TM‐MFas II is regulated temporally and spatially. GPI‐MFas II was expressed on the surface of the segmental ganglia and the transverse nerve, but no evidence was obtained for regulation of GPI‐MFas II expression during metamorphosis of the ventral nerve cord. Manipulation of 20E titers revealed that TM‐MFas II expression on neurons in migrating ganglia is regulated by hormonal events previously shown to choreograph ganglionic migration and fusion. Injections of actinomycin D (an RNA synthesis inhibitor) or cycloheximide (a protein synthesis inhibitor) blocked ganglionic movement and the concomitant increase in TM‐MFas II, suggesting that 20E regulates transcription of TM‐MFas II. The few neurons that showed TM‐MFas II immunoreactivity independent of endocrine milieu were immunoreactive to an antiserum specific for eclosion hormone (EH), a neuropeptide regulator of molting. J. Comp. Neurol. 509:319–339, 2008. © 2008 Wiley‐Liss, Inc.
Tauopathy with paired helical filaments in an aged chimpanzee
Authors: Rosen Rebecca F. , Farberg Aaron S. , Gearing Marla , Dooyema Jeromy , M. Long Patrick , Anderson Daniel C. , Davis‐Turak Jeremy , Coppola Giovanni , Geschwind Daniel H. , Paré Jean‐Francois , Duong Timothy Q. , Hopkins William D. , Preuss Todd M. , Walker Lary C. 
Published: May 2008

AbstractAn enigmatic feature of age‐related neurodegenerative diseases is that they seldom, if ever, are fully manifested in nonhuman species under natural conditions. The neurodegenerative tauopathies are typified by the intracellular aggregation of hyperphosphorylated microtubule‐associated protein tau (MAPT) and the dysfunction and death of affected neurons. We document the first case of tauopathy with paired helical filaments in an aged chimpanzee (Pan troglodytes). Pathologic forms of tau in neuronal somata, neuropil threads, and plaque‐like clusters of neurites were histologically identified throughout the neocortex and, to a lesser degree, in allocortical and subcortical structures. Ultrastructurally, the neurofibrillary tangles consisted of tau‐immunoreactive paired helical filaments with a diameter and helical periodicity indistinguishable from those seen in Alzheimer's disease. A moderate degree of Aβ deposition was present in the cerebral vasculature and, less frequently, in senile plaques. Sequencing of the exons and flanking intronic regions in the genomic MAPT locus disclosed no mutations that are associated with the known human hereditary tauopathies, nor any polymorphisms of obvious functional significance. Although the lesion profile in this chimpanzee differed somewhat from that in Alzheimer's disease, the copresence of paired helical filaments and Aβ‐amyloidosis indicates that the molecular mechanisms for the pathogenesis of the two canonical Alzheimer lesions—neurofibrillary tangles and senile plaques—are present in aged chimpanzees. J. Comp. Neurol. 509:259–270, 2008. © 2008 Wiley‐Liss, Inc.
Cardiorespiratory dynamics during transitions between mechanical and spontaneous ventilation in intensive care
Authors: Burykin Anton , Buchman Timothy G. 
Published: May 2008

AbstractLife support devices (e.g., heart pacemakers, ventilators, dialysis machines) are commonly thought to affect mainly their target organ system. This preliminary study attempts to determine the extent to which mechanical support of one organ system (lungs by mechanical ventilator) affects functions of other systems (heart and blood vessels). We studied changes in cardiorespiratory interactions and in dynamics of cardiovascular system during scheduled transitions (spontaneous breathing trials, SBT) between mechanical and spontaneous ventilation in critically ill patients. This initial study population consisted of 13 patients admitted to a surgical intensive care unit (ICU) following surgery, trauma, or complications who were judged candidates for liberation from the ventilator. We collected continuous respiratory, cardiac (ECG), and perfusion (blood pressure and pulse oximetry) signals of mechanically ventilated patients before, during, and after SBT. The data were analyzed using spectral analysis, phase dynamics, and entropy measures. We found that the mechanical ventilation not only drives lung dynamics but also affects the dynamics of cardiac and vascular systems. Spontaneous cardiovascular rhythms are entrained by the mechanical ventilator and are drawn into synchrony. Sudden interruption of mechanical ventilation typically leads to rapid desynchronization. This synchronization is restored upon reinstitution of mechanical ventilation. The initial data suggest that therapies intended to support one organ system may propagate unanticipated effects to other organ systems. Moreover, sustained therapies may disturb mechanisms that promote natural synchronization and variability and thereby adversely affect recovery of normal organ system interactions. We suggest that new measures and displays of synchronization not only could provide insight into the organ–organ coupling but also could yield information to optimize the function of devices used to support the critically ill patient. © 2008 Wiley Periodicals, Inc. Complexity, 2008
Pathogenesis of osteoarthritis: Chondrocyte replicative senescence or apoptosis?
Authors: Takács‐Buia Luminita , Iordachel Catalin , Efimov Nicolae , Caloianu Maria , Montreuil Jean , Bratosin Daniela 
Published: May 2008

AbstractBackground:The aim of this study was to investigate by flow cytometry cellular viability and apoptosis of human chondrocytes isolated from osteoarthritic cartilage and to correlate replicative senescence with apoptosis of these cells.Methods:To understand the mechanisms underlying the process of cell death in cartilage destruction, we investigated by flow cytometry cellular viability (Cell viability calcein‐AM assay) and apoptosis (Light scattering properties of chondrocytes, study of chondrocyte death using Annexin‐V‐FITC and propidium iodide double‐labeling, caspase‐3 activity determination) of human chondrocytes isolated from osteoarthritic and nonosteoarthritic cartilage. Senescent cells were characterized using the senescence‐associated‐β‐galactosidase marker (SA‐β‐Gal marker) by staining with chromogenic substrate (X‐Gal) to produce blue coloration of SA‐β‐Gal‐positive cells and microscopy analysis.Results:The results we obtained show that between 25 and 40% of chondrocytes were in apoptosis and all of them were SA‐β‐Gal‐positive.Conclusions:These results demonstrate that the death of osteoarthritic chondrocytes is an apoptotic phenomenon which is preceded by an accelerated mechanism of replicative senescence. © 2008 Clinical Cytometry Society