bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Access to Multifunctional Linear Triquinanes and Their Homologues via α,β‐Unsaturated Fischer Carbene Complexes
Authors: Wu Yao‐Ting , Vidovic Denis , Magull Jörg , de Meijere Armin 
Published: April 2005

AbstractTwelve differently substituted tricyclic hydroxy ketones 7, 8 with [5‐5‐x] (x = 5, 6, 7) combinations of ring sizes were prepared in a single step in 43–91 % yields (10 examples with 74–91 %) from the corresponding protected (2'‐oxocycloalkyl)methyl‐substituted cyclopentadienes 6, which were obtained by cocyclization of the alkynes 5 with the β‐dimethylamino‐substituted α,β‐unsaturated Fischer carbene complexes 4 in 38–81 % yield (6 examples with 66–81 %). In most cases, the cis,anti,cis‐isomers anti‐7 were the major products. While the twofold cis‐fusion is favored by minimal ring strain, hydrogen bonding between the hydroxy and the carbonyl group probably favors the anti‐configuration of the tricyclic skeletons. Acid‐catalyzed dehydration of the hydroxy ketones anti‐7aa, anti‐7ba, anti‐7ca afforded the corresponding tricyclic dienes 15aa/16aa, 15ba, and 15ca/16ca, respectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Electric Field‐Induced Cell Membrane Permeabilization and Gene Transfer: Theory and Experiments
Authors: Faurie C. , Golzio M. , Phez E. , Teissié J. , Rols M.‐P. 
Published: April 2005

AbstractThe permeabilization and gene transfer phenomena in terms of the effect of electric field and cell parameters are reviewed in this paper. Electropermeabilization designates the use of short high‐voltage pulses to overcome the barrier of the cell membrane. A position‐dependent modulation of the membrane potential difference is induced, leading to a transient and reversible local membrane alteration. The electro‐induced permeabilization is long lived. A free exchange of hydrophilic molecules takes place across the membrane. The fraction of the cell surface which is competent for exchange is a function of the field intensity. The level of local exchange is strongly controlled by the pulse duration. This permeabilized state can be used to load cells with a variety of different molecules, either through simple diffusion in the case of small molecules, or through a multi‐step process as is the case for DNA transfer involving the electrophoretically driven association of the macromolecule with the destabilized membrane and its subsequent passage. Electropermeabilization is now in use for the delivery of a large variety of molecules: from ions to drugs, dyes, tracers, antibodies, oligonucleotides, RNA and DNA. While most studies are performed in vitro in cells in culture, an increasing number of data are obtained in vivo on tissues. However, membrane molecular and cell metabolic changes remain for the most part poorly understood. Therefore it is of great importance to elucidate the underlying phenomena both for the in vitro use of the method in terms of efficiency but also for the in vivo use of the method in terms of security.
Source density‐driven independent component analysis approach for fMRI data
Authors: Hong Baoming , Pearlson Godfrey D. , Calhoun Vince D. 
Published: April 2005

AbstractIndependent component analysis (ICA) has become a popular tool for functional magnetic resonance imaging (fMRI) data analysis. Conventional ICA algorithms including Infomax and FAST‐ICA algorithms employ the underlying assumption that data can be decomposed into statistically independent sources and implicitly model the probability density functions of the underlying sources as highly kurtotic or symmetric. When source data violate these assumptions (e.g., are asymmetric), however, conventional ICA methods might not work well. As a result, modeling of the underlying sources becomes an important issue for ICA applications. We propose a source density‐driven ICA (SD‐ICA) method. The SD‐ICA algorithm involves a two‐step procedure. It uses a conventional ICA algorithm to obtain initial independent source estimates for the first‐step and then, using a kernel estimator technique, the source density is calculated. A refitted nonlinear function is used for each source at the second step. We show that the proposed SD‐ICA algorithm provides flexible source adaptivity and improves ICA performance. On SD‐ICA application to fMRI signals, the physiologic meaningful components (e.g., activated regions) of fMRI signals are governed typically by a small percentage of the whole‐brain map on a task‐related activation. Extra prior information (using a skewed‐weighted distribution transformation) is thus additionally applied to the algorithm for the regions of interest of data (e.g., visual activated regions) to emphasize the importance of the tail part of the distribution. Our experimental results show that the source density‐driven ICA method can improve performance further by incorporating some a priori information into ICA analysis of fMRI signals. Hum Brain Mapping, 2005. © 2005 Wiley‐Liss, Inc.
Valuation ratios and long‐horizon stock price predictability
Authors: Rapach David E. , Wohar Mark E. 
Published: April 2005

AbstractUsing annual data for 1872–1997, this paper re‐examines the predictability of real stock prices based on price–dividend and price–earnings ratios. In line with the extant literature, we find significant evidence of increased long‐horizon predictability; that is, the hypothesis that the current value of a valuation ratio is uncorrelated with future stock price changes cannot be rejected at short horizons but can be rejected at longer horizons based on bootstrapped critical values constructed from linear representations of the data. While increased statistical power at long horizons in finite samples provides a possible explanation for the pattern of predictability in the data, we find via Monte Carlo simulations that the power to detect predictability in finite samples does not increase at long horizons in a linear framework. An alternative explanation for the pattern of predictability in the data is nonlinearities in the underlying data‐generating process. We consider exponential smooth‐transition autoregressive models of the price–dividend and price–earnings ratios and their ability to explain the pattern of stock price predictability in the data. Copyright © 2005 John Wiley & Sons, Ltd.
Transforming growth factor‐β1 (TGF‐β1) regulates ATDC5 chondrogenic differentiation and fibronectin isoform expression
Authors: Han Fei , Adams Christopher S. , Tao Zhuliang , Williams Charlene J. , Zaka Raihana , Tuan Rocky S. , Norton Pamela A. , Hickok Noreen J. 
Published: April 2005

AbstractRegulated splicing of fibronectin (FN) occurs during the mesenchymal to chondrocyte transition and ultimately results in the relative enrichment of an extra domain B (EDB) exon‐containing FN isoform with the suggestion that FN isoforms may play a functional role in chondrogenesis. Promotion of chondrogenesis can also be achieved by treatment with transforming growth factor‐β (TGF‐β), which also regulates FN isoform expression. We have examined the effects of TGF‐β treatment on the assumption of the chondrogenic phenotype in the teratoma‐derived cell line ATDC5 and tested whether these effects on chondrogenesis are paralleled by appropriate changes in FN isoform expression. ATDC5 cells were maintained in a pre‐chondrogenic state and, in this state, treated with 10 ng/ml TGF‐β. The cells started to elaborate a matrix rich in sulfated proteoglycans, such that within the first 12 days of culture, TGF‐β1 treatment appeared to slightly accelerate early acquisition of an Alcian blue‐stained matrix, and caused a dose‐ and time‐dependent decrease in collagen type I expression; changes in collagen type II expression were variable. At later times, cells treated with TGF‐β became indistinguishable from those of the controls. Interestingly, TGF‐β treatment caused a significant dose‐ and time‐dependent decrease in the proportion of FN containing the extra domain A (EDA) and the EDB exons. These data suggest that TGF‐β induces the early stages of chondrogenic maturation in this pre‐chondrogenic line and that TGF‐β treatment increases expression of FN isoforms that lack the EDA and EDB exons. Published 2005 Wiley‐Liss, Inc.
An examination of the curvilinear relationship between leader–member exchange and intent to turnover
Authors: Harris Kenneth J. , Kacmar K. Michele , Witt L. A. 
Published: April 2005

AbstractBased on the theoretical identification of three different motivational forces for voluntary turnover—affective, calculative, and alternative—we hypothesize that the relationship between supervisor–subordinate relationship quality (i.e., leader–member exchange) and turnover intentions is best represented as curvilinear as opposed to linear. We test this hypothesis in two organizational samples consisting of 402 employees from a water management district and 183 employees from a distribution services organization. We found support for the hypothesis in both samples. We offer directions for future research. Copyright © 2005 John Wiley & Sons, Ltd.
A review and critique of emotional intelligence measures
Authors: Conte Jeffrey M. 
Published: April 2005

AbstractEmotional intelligence measures vary widely in both their content and in their method of assessment. In particular, emotional intelligence measures tend to use either a self‐report personality‐based approach, an informant approach, or an ability‐based assessment procedure. In this paper, the measurement and psychometric properties of four of the major emotional intelligence measures (Emotional Competence Inventory, Emotional Quotient Inventory, Multifactor Emotional Intelligence Scale, Mayer–Salovey–Caruso Emotional Intelligence Test) are reviewed, the comparability of these measures is examined, and some conclusions and suggestions for future research on emotional intelligence measures are provided. Copyright © 2005 John Wiley & Sons, Ltd.
Psychiatric symptoms and cognitive dysfunction caused by Epstein–Barr virus-induced encephalitis
Authors: Behr Joachim , Schaefer Martin , Littmann Eckhard , Klingebiel Randolf , Heinz Andreas 
Published: April 2005

AbstractEpstein-Barr virus (EBV) encephalitis is rare and shows a wide range of clinical manifestations. We report an immunocompromised patient with EBV encephalitis diagnosed by EBV-specific PCR and antibody testing in the cerebrospinal fluid who presented with psychiatric symptoms and cognitive dysfunction in the absence of any neurological impairments or infectious signs. Clinical recovery and clearance of cerebrospinal fluid EBV DNA appeared following ganciclovir treatment within 6 weeks.
Coordination of Nuclear and Mitochondrial Genome Expression during Mitochondrial Biogenesis in Arabidopsis
Authors: Giegé Philippe , Sweetlove Lee J. , Cognat Valérie , Leaver Christopher J. 
Published: April 2005

AbstractMitochondrial biogenesis and function require the regulated and coordinated expression of nuclear and mitochondrial genomes throughout plant development and in response to cellular and environmental signals. To investigate the levels at which the expression of nuclear and mitochondrially encoded proteins is coordinated, we established an Arabidopsis thaliana cell culture system to modulate mitochondrial biogenesis in response to sugar starvation and refeeding. Sucrose deprivation led to structural changes in mitochondria, a decrease in mitochondrial volume, and a reduction in the rate of cellular respiration. All these changes could be reversed by the readdition of sucrose. Analysis of the relative mRNA transcript abundance of genes encoding nuclear and mitochondrially encoded proteins revealed that there was no coordination of expression of the two genomes at the transcript level. An analysis of changes in abundance and assembly of nuclear-encoded and mitochondrially encoded subunits of complexes I to V of the mitochondrial inner membrane in organello protein synthesis and competence for protein import by isolated mitochondria suggested that coordination occurs at the level of protein-complex assembly. These results further suggest that expression of the mitochondrial genome is insensitive to the stress imposed by sugar starvation and that mitochondrial biogenesis is regulated by changes in nuclear gene expression and coordinated at the posttranslational level.
Numerical modelling of interface scattering of seismic wavefield from a random rough interface in an acoustic medium: comparison between 2D and 3D cases
Authors: Makinde Wasiu , Favretto‐Cristini Nathalie , De Bazelaire Eric 
Published: April 2005

ABSTRACTSeismic wavefield scattering from a statistically randomly rough interface in a multilayered piecewise homogeneous medium is studied in 3D. The influence of the surface roughness on the scattered wavefield is analysed numerically by using a finite‐difference operator in the acoustic domain. Since interface scattering in the real practical sense is a 3D physical phenomenon, we show in this work that the scattering response of a randomly rough interface is not the same in 3D situations as in the 2D cases described in some earlier works. For a given interface roughness height in 3D, an interface roughness height at least three times greater is required to produce an equivalent phase scattering effect in 2D situations, for a given correlation length of the interface roughness scale. Based on observations from spectral analysis, we show that scattering results principally in de‐phasing and frequency band‐limiting of the incident wavefront, the frequency band‐limiting properties being comparable to cases reported in the literature for absorption and thin‐layer filtering. The interface scattering phenomenon should be critically considered when using amplitude and phase information from seismic signal during inversion processes.
A radiomagnetotelluric survey on an oil‐contaminated area near the Brazi Refinery, Romania
Authors: Tezkan B. , Georgescu P. , Fauzi U. 
Published: April 2005

ABSTRACTScalar radiomagnetotelluric measurements were carried out on a contaminated test area close to the Brazi Refinery in Romania in order to detect and to monitor a 1 m thick oil layer expected at 5 m depth. Radio transmitters broadcasting in a frequency range from 10 kHz to 300 kHz were selected to observe the apparent resistivity and the phase data associated with the E‐ and B‐polarizations. They were located parallel and perpendicular to the assumed strike direction of the contamination plume. The data were interpreted by a 2D inversion technique from which the conductivity structure of the area was derived. The 2D inversion models of all profiles on the contaminated area show a poor‐conductivity zone above the groundwater table which could be associated with the oil contamination.A first attempt was also made to monitor the contaminated layer: the radiomagnetotelluric measurements were repeated on the same profiles a year later, but this time in a dry period, not in a rainy one. The 2D inversion results of the measurements in the dry period indicate that the high‐resistivity layer moved closer to the surface. Additional reference measurements were then carried out on a non‐contaminated area situated at a distance from the refinery, in the opposite direction to the flow of the groundwater. These reference measurements were used for the derivation of the unperturbed geology and they were also compared with the measurements of the contaminated test area. There is a significant difference in the frequency dependences of the apparent resistivities of the reference and contaminated areas, which could indicate a contamination at shallow depth. The 2D inversion results show the increase of resistivity at a depth of about 5 m beneath the contaminated area where the oil contamination is expected according to the information from the boreholes.
A field test of imaging properties of rotational invariants of the magnetotelluric impedance tensor
Authors: Szarka László , Ádám Antal , Menvielle Michel 
Published: April 2005

ABSTRACTA part of the Békés Basin (an extensional sub‐basin of the Pannonian Basin, where the basement under thick Pannonian sediments is well known from deep boreholes and from seismic measurements, and where many magnetotelluric (MT) soundings have been carried out for frequencies ranging from 1 to 10−3 Hz) was selected as a test area to assess the imaging performances of various apparent‐resistivity definitions computed with rotational invariants of either the real part of the complex impedance tensor, or its imaginary part, or both. A comparison (based on earlier 3D numerical studies) has been made between the magnetotelluric images obtained in this way and the depths to the high‐resistivity basement, as known from boreholes and seismic investigations. The correlation coefficient between the series of basement depth values at 39 MT sites and the apparent‐resistivity values was found to be stronger and high correlation appeared at a shorter period when it was computed with apparent resistivities based on the real tensor rather than with apparent resistivities based on the imaginary tensor. In the light of our studies, ρReZ and the impedance phase seem to be more informative than any other combination of magnetotelluric interpretation parameters.
Multi‐refractor imaging with stacked refraction convolution section
Authors: De Franco Roberto 
Published: April 2005

ABSTRACTMulti‐refractor imaging is a technique for constructing a single two‐dimensional image of a number of refractors by stacking multiple convolved and cross‐correlated reversed shot records. The method is most effective with high‐fold data that have been obtained with roll‐along acquisition programs because the stacking process significantly improves the signal‐to‐noise ratios. The major advantage of the multi‐refractor imaging method is that all the data can be stacked to maximize the signal‐to‐noise ratios before the measurement of any traveltimes. However, the signal‐to‐noise ratios can be further increased if only those traces that have arrivals from the same refractor are used, and if the correct reciprocal times or traces are employed.A field case study shows that multi‐refractor imaging can produce a cross‐section similar to the familiar reflection cross‐section with substantially higher signal‐to‐noise ratios for the equivalent interfaces.
Nonparametric Estimation of Spatial Segregation in a Multivariate Point Process: Bovine Tuberculosis in Cornwall, UK
Authors: Diggle Peter , Zheng Pingping , Durr Peter 
Published: April 2005

Summary
The paper is motivated by a problem in veterinary epidemiology, in which spatially referenced breakdowns of bovine tuberculosis are classified according to their genotype and year of occurrence. We develop a nonparametric method for addressing spatial segregation in the resulting multivariate spatial point process, with associated Monte Carlo tests for the null hypothesis that different genotypes are randomly intermingled and no temporal changes in spatial segregation. Our spatial segregation estimates use a kernel regression method with bandwidth selected by a multivariate cross-validated likelihood criterion.
Semiparametric Estimation of the Duration of Immunity from Infectious Disease Time Series: Influenza as a Case-Study
Authors: Xia Yingcun , Gog Julia R. , Grenfell Bryan T. 
Published: April 2005

SummaryAn important epidemiological problem is to estimate the decay through time of immunity following infection. For this purpose, we propose a semiparametric time series epidemic model that is based on the mechanism of the susceptible–infected–recovered–susceptible system to analyse complex time series data. We develop an estimation method for the model. Simulations show that the approach proposed can capture the non-linearity of epidemics as well as estimate the decay of immunity. We apply our approach to influenza in France and the Netherlands and show a rapid decline in immunity following infection, which agrees with recent spatiotemporal analyses.
A Nonparametric Bayesian Model for Inference in Related Longitudinal Studies
Authors: Müller Peter , Rosner Gary L. , Iorio Maria De , MacEachern Steven 
Published: April 2005

SummaryWe discuss a method for combining different but related longitudinal studies to improve predictive precision. The motivation is to borrow strength across clinical studies in which the same measurements are collected at different frequencies. Key features of the data are heterogeneous populations and an unbalanced design across three studies of interest. The first two studies are phase I studies with very detailed observations on a relatively small number of patients. The third study is a large phase III study with over 1500 enrolled patients, but with relatively few measurements on each patient. Patients receive different doses of several drugs in the studies, with the phase III study containing significantly less toxic treatments. Thus, the main challenges for the analysis are to accommodate heterogeneous population distributions and to formalize borrowing strength across the studies and across the various treatment levels. We describe a hierarchical extension over suitable semiparametric longitudinal data models to achieve the inferential goal. A nonparametric random-effects model accommodates the heterogeneity of the population of patients. A hierarchical extension allows borrowing strength across different studies and different levels of treatment by introducing dependence across these nonparametric random-effects distributions. Dependence is introduced by building an analysis of variance (ANOVA) like structure over the random-effects distributions for different studies and treatment combinations. Model structure and parameter interpretation are similar to standard ANOVA models. Instead of the unknown normal means as in standard ANOVA models, however, the basic objects of inference are random distributions, namely the unknown population distributions under each study. The analysis is based on a mixture of Dirichlet processes model as the underlying semiparametric model.
ON HISTORY CONSIDERED AS EPIC POETRY
Authors: BERMEJO BARRERA JOSÉ CARLOS 
Published: April 2005

ABSTRACTThis essay defines history as an interaction of three elements: description, evocation, and expression. These three elements should interact and combine without any of them over‐whelming the remaining two. In combining the three elements, history carries on from epic poetry, which was its source. Highlighting the three elements reveals the ways history synthesizes the three historical stages outlined by Comte, namely, the theological, the metaphysical, and the scientific.