bluuebunny/crossref_metadata_2025_split huggingface dataset:
Convergence in European GDP series: a multivariate common converging trend–cycle decomposition
Authors: Luginbuhl Rob , Koopman Siem Jan 
Published: September 2004

AbstractConvergence in the gross domestic product series of five European countries is empirically identified using multivariate time series models that are based on unobserved components with dynamic converging properties. We define convergence in terms of a decrease in dispersion over time and model this decrease via mechanisms that allow for gradual reductions in the ranks of covariance matrices associated with the disturbance vectors driving the unobserved components of the model. The inclusion of such convergence mechanisms within the formulation of unobserved components makes the identification of various types of convergence possible. The common converging component model is estimated for the per capita gross domestic product of five European countries: Germany, France, Italy, Spain and the Netherlands. It is found that convergence features in trends and cycles are present and are associated with some key events in the history of European integration. Copyright © 2004 John Wiley & Sons, Ltd.
Conditional heteroscedasticity of exchange rates: further results based on the fractionally integrated approach
Authors: Tsui Albert K. , Ho Kin‐Yip 
Published: September 2004

AbstractA recent article (Tse, 1998) published in this journal analysed the conditional heteroscedasticity of the yen–dollar exchange rate based on the fractionally integrated asymmetric power ARCH model. In this paper, we present replication results using Tse's (1998) yen–dollar series. We also examine the robustness of Tse's (1998) findings across different currencies, sample periods and non‐nested GARCH‐type models. Unlike Tse (1998), we find some evidence of asymmetric conditional volatility for daily returns of currencies measured against the dollar or the yen. Copyright © 2004 John Wiley & Sons, Ltd.
Resin penetration through submicrometer hiatus structures: A SEM and CLSM study
Authors: Pioch Thomas , Sorg Tina , Stadler Robin , Hagge Mark , Dörfer Christof E. 
Published: September 2004

AbstractThe purpose of this study was to confirm the existence of submicrometer hiatus structures and to examine the degree of resin penetration through these formations. Dentin disks 2.0 mm in thickness were sectioned from 48 human molars with the use of a microtome saw. Three different fifth‐generation (total‐etch, combined primer/resin) dentin adhesive systems were used to bond a light‐cured, resin‐based composite to the dentin disks (n = 16 each group). Bonded disks from the three groups were then sectioned. Half of each group was examined with the use of a scanning electron microscope (SEM) (n = 8), and the other half with the use of a confocal laser scanning microscope (CLSM) (n = 8). The frequency of submicrometer hiatus formation was recorded and documented with associated imaging techniques. Resin penetration within submicrometer hiati were observed in 41.7% (10/24) of SEM specimens and 83.3% (20/24) of CLSM specimens. The location and size of these structures were found to be quite uniform. Submicrometer hiati approximated 200 μm in each of the three dentin bonding systems examined. Resin penetration through submicrometer hiati does not appear to be an artifact of desiccation. These structures were clearly identified within the hybrid layer of each dentin adhesive system used in this study. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 71B: 238–243, 2004
Effects of different sterilization methods on the morphology, mechanical properties, and cytotoxicity of chitosan membranes used as wound dressings
Authors: Marreco Paula Rulf , Moreira Patrícia da Luz , Genari Selma Candelária , Moraes Ângela Maria 
Published: September 2004

AbstractThe aim of this work was to compare the effects induced by two different sterilization methods (exposure to gamma radiation or ethylene oxide) and an antiseptic technique (immersion in 70% ethanol aqueous solution) on the morphology, tensile strength, percentage of strain at break, and in vitro cytotoxicity to Vero cells on chitosan membranes designed for wound healing. Four distinct membrane compositions were evaluated, with chitosan, glycerol, and chitin used as components. Gamma radiation, in spite of being one of the most commonly employed sterilizing agents, negatively affected the morphology of membranes composed solely by chitosan as well as the percentage of strain at break of the chitosan‐membranes containing glycerol on their composition. Moreover, its use affected the color of the chitosan membranes. The use of 70% ethanol aqueous solution did not change the chitosan‐membrane characteristics significantly, but its use has limitations concerning the process scale up. With ethylene oxide (EtO), chitosan‐membrane morphology, percentage of strain at break, and in vitro cytotoxicity to Vero cells were not significantly affected. The tensile strength of the membranes containing chitin were reduced after the treatment with ethylene oxide; however, the obtained values were comprised in the range verified for normal human skin. Therefore, because the final characteristics of the membranes treated with ethylene oxide are appropriate when considering their use as wound healing devices, and because this sterilization process is easily adjusted to use on an industrial scale, EtO can be considered the most adequate sterilizing agent for chitosan membranes. However, it should be considered that this chemical is associated with toxicity, flammability, and environmental risks, as well as with possible material contamination with ethylene oxide residues. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 71B: 268–277, 2004
Acute phase lipocalin Ex‐FABP is involved in heart development and cell survival
Authors: Gentili C. , Tutolo G. , Zerega B. , Di Marco E. , Cancedda R. , Cancedda F. Descalzi 
Published: September 2004

AbstractEx‐FABP is an extracellular fatty acid binding protein, expressed during chicken embryo development in cartilage, muscle fibers, and blood granulocytes. Transfection of chondrocytes and myoblasts with anti‐sense Ex‐FABP cDNA results in inhibition of cell proliferation and apoptosis induction. Ex‐FABP expression is dramatically enhanced by inflammatory stimuli and in pathological conditions. In this paper, by in situ whole mount and immunohistochemistry analysis we show that, at early developmental stage, Ex‐FABP is diffuse in all tissues of chick embryos. Particularly high level of transcript and protein are expressed in the heart. During acute phase response (APR) induced by endotoxin LPS injection, a marked increase of Ex‐FABP mRNA was observed in embryos, highest Ex‐FABP expression being in heart and liver. To investigate in vivo the biological role of Ex‐FABP, we have directly microinjected chicken embryos with antibody against Ex‐FABP. Almost 70% of chicken embryos died and the target tissue was the heart. We detected in heart of the treated embryos a significant increase of apoptotic cells and high level of fatty acids. We propose that the accumulation of fatty acid, specific ligand of Ex‐FABP, in the cell microenvironment is responsible of heart cell death, and we suggest that Ex‐FABP may act as a survival protein by playing a role as scavenger for fatty acids. © 2004 Wiley‐Liss, Inc.
The impact of relative tenure on newcomer socialization dynamics
Authors: Rollag Keith 
Published: September 2004

AbstractAlthough many researchers have examined the impact of organizational tenure on newcomer socialization dynamics, few have explored whether relative tenure influences perceptions and behaviors inside organizations. This study introduces the concept of relative tenure and shows through a sociometric survey of 200 employees across four organizations that an individual's relative position in his or her firm's tenure distribution explains a significantly greater percentage of variance in newcomer status, social network position, and information‐providing behavior than does absolute measures of tenure. The results suggest that organizational growth and turnover may have a bigger impact on newcomer socialization dynamics than has been discussed in the literature. The implications of the findings for socialization researchers and managers are discussed. Copyright © 2004 John Wiley & Sons, Ltd.
The effect of other orientation on self–supervisor rating agreement
Authors: Korsgaard M. Audrey , Meglino Bruce M. , Lester Scott W. 
Published: September 2004

AbstractEmployees generally rate their performance more favorably than do their supervisors, which can lead to conflict and poor job performance. However, comparative international research indicates that persons from other‐oriented collectivist cultures are less self‐enhancing, suggesting that other‐oriented employees will exhibit greater agreement with ratings provided by their supervisors. We examined the effect of subordinates' other orientation on self‐supervisor performance rating agreement. Consistent with cultural expectations, self‐ratings of other‐oriented subordinates showed greater agreement with ratings provided by their supervisors and less leniency relative to their supervisors' evaluations. These findings have implications for understanding how employees in different professions, organizations, and cultures utilize feedback from their supervisors. Copyright © 2004 John Wiley & Sons, Ltd.
Climatic conditions and crop‐residue quality differentially affect N, P, and S mineralization in soils with contrasting P status
Authors: Kabba Bachitter S. , Aulakh Milkha S. 
Published: September 2004

AbstractThe substitution of the widely practiced crop‐residue burning by residue incorporation in the subtropical zone requires a better understanding of factors determining nutrient mineralization. We examined the effect of three temperature (15°C, 30°C, and 45°C) and two moisture regimes (60% and 90% water‐filled pore space (WFPS)) on the mineralization‐immobilization of N, P, and S from groundnut (Arachis hypogae) and rapeseed (Brassica napus) residues (4 t ha–1) in two soils with contrasting P fertility. Crop‐residue mineralization was differentially affected by incubation temperature, soil aeration status, and residue quality. Only the application of groundnut residues (low C : nutrient ratios) resulted in a positive net N and P mineralization within 30 days of incubation, while net N and P immobilization was observed with rapeseed residues. Highest N and P mineralization and lowest N and P immobilization occurred at 45°C under nearly saturated soil conditions. Especially net P mineralization was significantly higher in nearly saturated than in aerobic soils. In contrast, S mineralization was more from rapeseed than from groundnut residues and higher in aerobic than in nearly saturated soil. The initial soil P content influenced the mineralization of N and P, which was significantly higher in the soil with a high initial P fertility (18 mg P (kg soil)–1) than in the soil with low P status (8 mg P (kg soil)–1). Residue‐S mineralization was not affected by soil P fertility. The findings suggest that climatic conditions (temperature and rainfall‐induced changes in soil aeration status) and residue quality determine N‐ and S‐mineralization rates, while the initial soil P content affects the mineralization of added residue N and P. While the application of high‐quality groundnut residues is likely to improve the N supply to a subsequent summer crop (high temperature) under aerobic and the P supply under anaerobic soil condition, low‐quality residues (rapeseed) may show short‐term benefits only for the S nutrition of a following crop grown in aerobic soil.
Bound amino acids in humic acids from arable cropping systems
Authors: Szajdak Lech , Życzyńska‐Bałoniak Irena , Meysner Teresa , Blecharczyk Andrzej 
Published: September 2004

AbstractWe investigated the varying concentrations of bound amino acids in humic acids (HA) extracted from soils under both crop rotation and continuous cropping of rye. The experiment was created in 1957. Since then, winter rye had been grown continuously and also the sequence of the 7 yr rotation had been started: potato, spring barley, alfalfa, alfalfa, oil seed rape, winter rye, and winter rye. Soils were fertilized with NPK and manure. Continuous cropping of rye increased total acidity of soils and the contents of carboxylic and phenolic groups in HA. The total amounts of the bound amino acids in HA from soils under crop rotation were higher than from continuous cropping of rye. Fertilization with NPK increased the contents of bound amino acids more than manure. Neutral amino acids dominated in all samples of HA, and basic amino acids had the lowest concentrations. In both types of cultivation, glutamic acids, glycine, alanine, valine, and lysine dominated. The proline contents in HA from continuous rye cropping were higher than in HA from soils under crop rotation. The concentrations of β‐alanine and lysine were higher in HA from crop rotation indicating a higher microbial biomass since these compounds are typical constituents of bacteria cell walls.
Short‐term N2O, CO2, NH3 fluxes, and N/C transfers in a Danish grass‐clover pasture after simulated urine deposition in autumn
Authors: Bol Roland , Petersen Søren O. , Christofides Calliopi , Dittert Klaus , Hansen Martin N. 
Published: September 2004

AbstractUrine patches are significant hot‐spots of C and N transformations. To investigate the effects of urine composition on C and N turnover and gaseous emissions from a Danish pasture soil, a field plot study was carried out in September 2001. Cattle urine was amended with two levels of 13C‐ and 15N‐labeled urea, corresponding to 5.58 and 9.54 g urea‐N l–1, to reflect two levels of protein intake. Urine was then added to a sandy‐loam pasture soil equivalent to a rate of 23.3 or 39.8 g urea‐N m–2. Pools and isotopic labeling of nitrous oxide (N2O) and CO2 emissions, extractable urea, ammonium (NH4+), and nitrate (NO3–), and plant uptake were monitored during a 14 d period, while ammonia (NH3) losses were estimated in separate plots amended with unlabeled urine. Ammonia volatilization was estimated to account for 14% and 12% of the urea‐N applied in the low (UL) and high (UH) urea treatment, respectively. The recovery of urea‐derived N as NH4+ increased during the first several days, but isotopic dilution was significant, possibly as a result of stress‐induced microbial metabolism. After a 2 d lag phase, nitrification proceeded at similar rates in UL and UH despite a significant difference in NH4+ availability. Nitrous oxide fluxes were low, but generally increased during the 14 d period, as did the proportion derived from urea‐N. On day 14, the contribution from urea was 23% (UL) and 13% (UH treatment), respectively. Cumulative total losses of N2O during the 14 d period corresponded to 0.021% (UL) and 0.015% (UH) of applied urea‐N. Nitrification was probably the source of N2O. Emission of urea‐derived C as CO2 was only detectable within the first 24 h. Urea‐derived C and N in above‐ground plant material was only significant at the first sampling, indicating that uptake of urine‐C and N via the leaves was small. Urine composition did not influence the potential for N2O emissions from urine patches under the experimental conditions, but the importance of site conditions and season should be investigated further.
Seed priming enhances germination and seedling growth of barley under conditions of P and Zn deficiency
Authors: Ajouri Aziza , Asgedom Haben , Becker Mathias 
Published: September 2004

AbstractLow‐input production of barley on the predominantly calcareous soils in most countries of West Asia and North Africa is affected by drought and a low availability of P and Zn. Especially during the early growth stages, P and Zn deficiencies retard seedling growth, rendering the young plantlets particularly sensitive to the frequently encountered dry spells. Seed priming (soaking in water and drying back to storage moisture until use) has been shown to improve crop establishment and, in some instances, to increase crop yields. While increased seedling vigor will improve barley establishment, possible benefits are likely to be limited when P and Zn are deficient. A promising variation of the priming concept is the seed treatment with solutions containing the limiting nutrient. A series of experiments was conducted in a phytotron in 2003 to develop a nutrient‐priming approach to foster the establishment of barley under marginal growing conditions. Seeds of the traditional barley cultivar Arabi aswad were soaked for 0–48 hours in water and for 12 hours in solutions containing 5–500 mM P, Zn, and P+Zn, and dried back to 12% moisture until further use. Seeds were incubated at 10°C, and germination was evaluated over a 6‐ to 8‐day period. Additionally, growth and nutrient uptake of 4‐week‐old seedlings, grown at 25% and 100% field capacity in a typical Xerosol from Syria were evaluated. Water priming for 12 hours with subsequent seed storage of up to 9 weeks increased germination rate from 65% to 95%, and advanced germination by up to 3 days compared to unprimed seeds. Addition of 10 mM Zn and 50 mM P to the priming solution increased the P and Zn content of the seeds without affecting germination. It furthermore significantly stimulated growth and P and Zn uptake by 4‐week‐old seedlings and improved the water use efficiency of drought‐stressed plants by 44% above that of unprimed seeds.
Establishment ofRetama sphaerocarpaL. seedlings on a degraded semiarid soil as influenced by mycorrhizal inoculation and sewage‐sludge amendment
Authors: del Mar Alguacil María , Caravaca Fuensanta , Díaz Gisela , Marín Purificación , Roldán Antonio 
Published: September 2004

AbstractA field experiment was carried out to evaluate the effectiveness of mycorrhizal inoculation with three arbuscular mycorrhizal (AM) fungi (Glomus intraradicesSchenck & Smith,Glomus deserticola(Trappe, Bloss. & Menge), andGlomus mosseae(Nicol & Gerd.) Gerd. & Trappe) and the addition of composted sewage sludge (SS) with respect to the establishment ofRetama sphaerocarpaL. seedlings, in a semiarid Mediterranean area. Associated changes in soil chemical (nutrient content and labile carbon fractions), biochemical (enzyme activities), and physical (aggregate stability) parameters were observed. Six months after planting, both the addition of composted SS and the mycorrhizal‐inoculation treatments had increased total N content, available‐P content, and aggregate stability of the soil. Values of water‐soluble C and water‐soluble carbohydrates were increased only in the mycorrhizal‐inoculation treatments. Rhizosphere soil from the mycorrhizal‐inoculation treatments had significantly higher enzyme activities (dehydrogenase, protease‐BAA, acid phosphatase, and β‐glucosidase) than the control soil. In the short‐term, mycorrhizal inoculation with AM fungi was the most effective treatment for enhancement of shoot biomass, particularly withG. mosseae(about 146% higher with respect to control plants). The addition of the composted SS alone was sufficient to restore soil structural stability but was not effective with respect to improving the performance ofR. sphaerocarpaplants.
Real‐Time Scanning Force Microscopy of Macromolecular Conformational Transitions
Authors: Gallyamov Marat O. , Tartsch Bernd , Khokhlov Alexei R. , Sheiko Sergei S. , Börner Hans G. , Matyjaszewski Krzysztof , Möller Martin 
Published: September 2004

AbstractSummary: Comb‐like macromolecules were adsorbed on mica and imaged by scanning force microscopy in real time as they underwent a transition from an extended worm‐like conformation to globuli and vice versa. The conformational transition was effected by coadsorption of ethanol and water molecules. Coadsorption of the small molecules allowed manipulation of the adherence and spreading of the macromolecules, thus effecting the reptation like stretching and collapse of the single molecules.SFM images of three individual PMA‐g‐PnBuA brush molecules on mica 27 min (left, first collapse cycle) and 18 min (right, second collapse cycle) after injection of ethanol into the sample space.imageSFM images of three individual PMA‐g‐PnBuA brush molecules on mica 27 min (left, first collapse cycle) and 18 min (right, second collapse cycle) after injection of ethanol into the sample space.
Effect of Surface‐Hydroxylated CdS Nanoparticles on the Morphological Transformation of Polystyrene‐block‐Poly(ethylene oxide) Thin Films
Authors: Yeh Siao‐Wei , Chang Yao‐Te , Chou Chia‐Hung , Wei Kung‐Hwa 
Published: September 2004

AbstractSummary: Polystyrene‐block‐poly(ethylene oxide) (SEO) block copolymer thin films, in which CdS clusters have been sequestered into the PEO domains of the SEO block copolymers, are found to induce the morphological transformation of PEO from cylinders to spheres, as shown by using atomic force microscopy (AFM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). This transformation is caused by the presence of hydrogen‐bonding interactions between surface‐hydroxylated CdS and PEO, as confirmed by nuclear magnetic resonance (NMR) studies.Morphological transformation of PEO cylinders into CdS/PEO spheres by hydrogen‐bonding interactions between surface‐hydroxylated CdS and PEO.imageMorphological transformation of PEO cylinders into CdS/PEO spheres by hydrogen‐bonding interactions between surface‐hydroxylated CdS and PEO.
Grip force behavior during object manipulation in neurological disorders: Toward an objective evaluation of manual performance deficits
Authors: Nowak Dennis A. , Hermsdörfer Joachim 
Published: September 2004

AbstractThe control of prehensile finger forces is an essential feature of skilled manual performance. The basic aspects of healthy grip force behavior have been well documented. In healthy subjects, grip force is precisely adjusted to the mechanical object properties. Grip force is always slightly higher than the minimum necessary to prevent the object from slipping. When we move a hand‐held object, grip force is modulated in parallel with movements‐induced load fluctuations without an obvious delay. The absence of a temporal delay between grip and load force profiles suggests that the central nervous system is able to predict the load variations before the intended manipulation and consequently regulates grip force in anticipation. Feedback from the grasping fingertips is used to adjust the level of applied fingertip force efficiently to the actual loading requirements. Pathologic grip force control affects the efficiency of produced force and the precision of the temporal coupling between grip and load force profiles. Here, we review the characteristics of pathologic grip force behavior in various neurological disorders. Detailed examination of grip force control is simple and well suited for the objective evaluation of impaired motor function of the hand and its rehabilitation. © 2004 Movement Disorder Society
Minimum k‐geodetically connected digraphs
Authors: Plesník Ján 
Published: September 2004

AbstractA strong digraph is k‐geodetically connected (k‐GC) if the removal of at least k vertices is required to increase the distance between at least one pair of vertices or reduce it to a single vertex. Such digraphs can serve as models of distance invulnerable networks (immune to k – 1 or fewer vertex failures) for a system with one‐way communications. For every integer n, we determine the minimum size 2‐GC digraphs of order n. Further, we find the minimum size of a k‐GC digraph of order n if n ≡ 0 (mod k) and give good bounds for all n. Also, several operations on and constructions of k‐GC digraphs are presented. We show that the problem of finding a minimum size k‐GC spanning subdigraph of a given digraph is NP‐hard. © 2004 Wiley Periodicals, Inc. NETWORKS, Vol. 44(4), 243–253 2004