bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rill characteristics and sediment transport as a function of slope length during a storm event on loess soil
Authors: Rejman Jerzy , Brodowski Ryszard 
Published: February 2005

AbstractOn the basis of detailed rill surveys carried out on bare plots of different lengths at slopes of 12 per cent, basic rill parameters were derived. Rill width and maximum depth increased with plot length, whereas rill amount and cross‐sectional area, expressed per unit length, remained similar. On smaller plots, all rills were connected in a continuous transport system reaching the plot outlet, whilst on larger plots (10 and 20 m long) part of the rills ended with a deposition areas inside the plots. Amounts of erosion, calculated from rill volume and soil bulk density, were compared with soil loss measured at the plot outlets. On plots 10 and 20 m long, erosion estimated from volume of all rills was larger than measured soil loss. The latter was larger than erosion estimated from volume of contributing rills. To identify contributing soil loss area on these plots, two methods were applied: (i) ratio of total soil loss to maximum soil loss per unit area, and (ii) partition of plot area according to the ratio of contributing to total rill volume. Both methods resulted in similar areas of 21·8–23·5 m2 for the plot 10 m long and 31·2 m2 for the plot 20 m long. Identification of contributing areas enabled rill (5·9 kg m−2) and interrill (2·6 kg m−2) erosion rate to be calculated, the latter being very close to the value predicted from the Universal Soil Loss Equation. Although rill and interrill rates seemed to be similar on all plots, their ratio increased slightly with plot length. Application of this ratio to compute slope length factor of the Revised Universal Soil Loss Equation resulted in similar values to those predicted with the model. The achieved balance of soil loss suggested that all the sediment measured at the plot outlet originated from contributing rills and associated contributing rill areas. The results confirmed the utility of different plot lengths as a research tool for analysing the dynamic response of soil to rainfall–runoff. Copyright © 2005 John Wiley & Sons, Ltd.
Effects of spatially structured vegetation patterns on hillslope erosion in a semiarid Mediterranean environment: a simulation study
Authors: Boer Matthias , Puigdefábregas Juan 
Published: February 2005

AbstractA general trend of decreasing soil loss rates with increasing vegetation cover fraction is widely accepted. Field observations and experimental work, however, show that the form of the cover‐erosion function can vary considerably, in particular for low cover conditions that prevail on arid and semiarid hillslopes. In this paper the structured spatial distribution of the vegetation cover and associated soil attributes is proposed as one of the possible causes of variation in cover–erosion relationships, in particular in dryland environments where patchy vegetation covers are common. A simulation approach was used to test the hypothesis that hillslope discharge and soil loss could be affected by variation in the spatial correlation structure of coupled vegetation cover and soil patterns alone. The Limburg Soil Erosion Model (LISEM) was parameterized and verified for a small catchment with discontinuous vegetation cover at Rambla Honda, SE Spain. Using the same parameter sets LISEM was subsequently used to simulate water and sediment fluxes on 1 ha hypothetical hillslopes with simulated spatial distributions of vegetation and soil parameters. Storms of constant rainfall intensity in the range of 30–70 mm h−1 and 10–30 min duration were applied. To quantify the effect of the spatial correlation structure of the vegetation and soil patterns, predicted discharge and soil loss rates from hillslopes with spatially structured distributions of vegetation and soil parameters were compared with those from hillslopes with spatially uniform distributions. The results showed that the spatial organization of bare and vegetated surfaces alone can have a substantial impact on predicted storm discharge and erosion. In general, water and sediment yields from hillslopes with spatially structured distributions of vegetation and soil parameters were greater than from identical hillslopes with spatially uniform distributions. Within a storm the effect of spatially structured vegetation and soil patterns was observed to be highly dynamic, and to depend on rainfall intensity and slope gradient. Copyright © 2005 John Wiley & Sons, Ltd.
The role of vegetation patterns in structuring runoff and sediment fluxes in drylands
Authors: Puigdefábregas Juan 
Published: February 2005

AbstractThe dynamics of vegetation‐driven spatial heterogeneity (VDSH) and its function in structuring runoff and sediment fluxes have received increased attention from both geomorphological and ecological perspectives, particularly in arid regions with sparse vegetation cover. This paper reviews the recent findings in this area obtained from field evidence and numerical simulation experiments, and outlines their implications for soil erosion assessment. VDSH is often observed at two scales, individual plant clumps and stands of clumps.At the patch scale, the local outcomes of vegetated patches on soil erodibility and hydraulic soil properties are well established. They involve greater water storage capacity as well as increased organic carbon and nutrient inputs. These effects operate together with an enhanced capacity for the interception of water and windborne resources, and an increased biological activity that accelerates breakdown of plant litter and nutrient turnover rates. This suite of relationships, which often involve positive feedback mechanisms, creates vegetated patches that are increasingly different from nearby bare ground areas. By this way a mosaic builds up with bare ground and vegetated patches coupled together, respectively, as sources and sinks of water, sediments and nutrients.At the stand scale within‐storm temporal variability of rainfall intensity controls reinfiltration of overland flow and its decay with slope length. At moderate rainfall intensity, this factor interacts with the spatial structure of VDSH and the mechanism of overland flow generation. Reinfiltration is greater in small‐grained VDSH and topsoil saturation excess overland flow. Available information shows that VDSH structures of sources and sinks of water and sediments evolve dynamically with hillslope fluxes and tune their spatial configurations to them.Rainfall simulation experiments in large plots show that coarsening VDSH leads to significantly greater erosion rates even under heavy rainfall intensity because of the flow concentration and its velocity increase. Copyright © 2005 John Wiley & Sons, Ltd.
Transgene expression and differentiation of baculovirus‐transduced human mesenchymal stem cells
Authors: Ho Yi‐Chen , Chung Yao‐Chi , Hwang Shiaw‐Min , Wang Kuei‐Chun , Hu Yu‐Chen 
Published: February 2005

AbstractBackgroundMesenchymal stem cells (MSCs) have drawn considerable attention as vehicles for cell‐ or gene‐based therapies, yet various problems still exist for current gene delivery vectors. On the other hand, baculovirus has emerged as a novel gene therapy vector, but its transduction of stem cells has not been reported.MethodsA recombinant baculovirus expressing the enhanced green fluorescent protein (EGFP) was constructed to transduce human MSCs derived from umbilical cord blood (uMSCs) or bone marrow (bMSCs).ResultsIn this study, we demonstrated for the first time that human uMSCs or bMSCs could be transduced by baculovirus with high efficiencies (up to ≈72.8% and 41.1%, respectively) and significantly elevated transgene (enhanced green fluorescent protein, EGFP) expression upon incubation with unconcentrated virus and phosphate‐buffered saline for 4 h at 25 °C. The transduction efficiency into bMSCs could be further increased to ≈72.2% by lowering the cell density. The improved transgene expression was partly attributed to the enhanced virus uptake upon transduction, as determined by quantitative real‐time polymerase chain reaction (Q‐PCR). MSC growth was not obstructed by baculovirus transduction itself, but was somewhat hampered by EGFP expression. Nonetheless, the baculovirus‐transduced cells remained capable of differentiating into adipogenic lineage. The adipogenic progenitors appeared more permissive to baculovirus transduction than the undifferentiated bMSCs, thus allowing for the maintenance and enhancement of transgene expression by repeated transduction after subculture.ConclusionsThese findings implicate the potential applications of baculovirus as an alternative vector to genetically modify MSCs for ex vivo gene therapy. Copyright © 2005 John Wiley & Sons, Ltd.
Nonviral genetic modification mediates effective transgene expression and functional RNA interference in human mesenchymal stem cells
Authors: Hoelters Juergen , Ciccarella Marisa , Drechsel Marei , Geissler Claudia , Gülkan Hülya , Böcker Wolfgang , Schieker Matthias , Jochum Marianne , Neth Peter 
Published: February 2005

AbstractBackgroundHuman mesenchymal stem cells (hMSC) are increasingly the focus of both basic and clinical research due to their ability to strike a balance between self‐renewal and commitment to mesodermal differentiation. However, the promising therapeutic utility of hMSC in regenerative medical approaches requires detailed knowledge about their molecular characteristics. Therefore, genetic modification of hMSC provides a powerful tool to understand their complex molecular regulation mechanisms.MethodsHere we describe a proof of concept approach of separate and combined gene transfer and gene silencing by nonviral DNA transfection of enhanced green fluorescent protein (EGFP) and EGFP‐targeted small interfering RNAs (siRNAs) in hMSC. For optimization of nonviral DNA and siRNA transfer different liposomal‐based transfection strategies were validated.ResultsThe highest fraction of EGFP‐expressing hMSC was obtained using Lipofectamine 2000 (50%) which also mediated the highest transfection rates of siRNAs into hMSC (≥92%). Stably EGFP‐expressing hMSC maintained their proliferation capacity paired with the ability to differentiate into different mesodermal lineages (bone, cartilage, and fat) without loss of transgene expression. Based on our nonviral nucleic acid delivery technique we showed efficient, functional, and long‐term RNA interference (RNAi) in hMSC by gene specific knock‐down of transiently and stably expressed EGFP (88–98%).ConclusionsThis is the first demonstration of efficient nonviral transfer of both nucleic acids (DNA and siRNA) into hMSC, exhibiting the potential of targeted modification of hMSC. In particular, the combination of these techniques represents a powerful gene transfer/silencing strategy, thus facilitating detailed genetic approaches to study regulatory networks in stem cell differentiation processes. Copyright © 2005 John Wiley & Sons, Ltd.
Long‐term expression of the human glucocerebrosidase gene in vivo after transplantation of bone‐marrow‐derived cells transformed with a lentivirus vector
Authors: Kim Eun Young , Hong Young Bin , Lai Zhennan , Cho Youl‐Hee , Brady Roscoe O. , Jung Sung‐Chul 
Published: February 2005

AbstractBackgroundGaucher disease is a lysosomal storage disorder resulting from a deficiency of glucocerebrosidase (GC). Recently, lentivirus vectors have been developed for efficient gene transfer into hematopoietic stem cells (HSCs). A recombinant lentivirus vector was used to evaluate the transduction of the human GC gene into murine bone‐marrow‐derived HSCs and its expression in their progeny.MethodsMurine HSCs were transduced with lentivirus vector (lenti‐EF‐GC; MOI = 10–100). We transplanted female wild‐type C57BL/6J mice with genetically modified male HSCs via the tail vein.ResultsWe show that intravenous transplantation of transduced HSCs has therapeutic potential. Enzyme activity was increased two‐ to three‐fold in various tissues, especially in the hematopoietic system. Numerous transplanted HSCs survived for 6 months and were shown by PCR to contain the provirus genes; the Y chromosome was identified by FISH analysis in the cells of female mouse recipients.ConclusionsThe recombinant lentiviral vector transduces HSCs that are capable of long‐term gene expression in vivo. This approach is potentially useful for the treatment of patents with Gaucher disease and other lysosomal storage disorders. Copyright © 2005 John Wiley & Sons, Ltd.
Combined immunization with fusion genes of mutated E7 gene of human papillomavirus type 16 did not enhance antitumor effect
Authors: Pokorná Dana , Macková Jana , Dušková Martina , Rittich Šimon , Ludvíková Viera , Šmahel Michal 
Published: February 2005

AbstractBackgroundThe E7 oncoprotein of human papillomavirus type 16 (HPV16) is frequently used as a model tumor‐associated antigen. Its immunogenicity has been substantially enhanced by fusion with several proteins of various origins and functions. Different mechanisms have been responsible for increased vaccination efficacy of fusion proteins.Methods and resultsWe linked E7 and its mutated form (E7GGG) with the mouse heat‐shock protein 70.1 (HSP70.1). Enhanced immunogenicity of both fusion genes administered via a gene gun was demonstrated by protection of C57BL/6 mice against oncogenic MHC class I positive TC‐1 cells producing the HPV16 E7 oncoprotein but not against the MHC class I negative TC‐1/A9 subline. To assess if the efficacy of E7‐based DNA vaccines could be increased by combination of various fusion genes, we combined the HSP70.1 fusion genes (i.e. E7HSP or E7GGGHSP) with the fusion construct linking E7GGG with targeting signals of lysosome‐associated membrane protein 1 (Sig/E7GGG/LAMP‐1). Treatment of mice 4 days after TC‐1 cell inoculation showed moderately higher immunization potency of HSP70.1 fusion genes in comparison with the Sig/E7GGG/LAMP‐1 gene. Any combination of two fusion genes given in the same gene gun shot neither was more effective compared with single genes nor protected mice against TC‐1/A9 cells. As fusion of E7GGG with E. coli glucuronidase (E7GGG.GUS) had been previously proven to provide partial protection from TC‐1/A9‐induced tumors, we also combined E7GGGHSP with E7GGG.GUS. The genes were inoculated either in mix in two gene gun shots or separately each gene in one shot into opposite sides of the abdomen. Neither mode of combined immunization induced higher protection than E7GGG.GUS alone. However, doubling the DNA dose considerably enhanced the antitumor efficacy of E7GGG.GUS.ConclusionsWe constructed highly immunogenic fusions of HPV16 E7 and E7GGG with mouse HSP70.1. Furthermore, we substantially enhanced protection against TC‐1/A9 cells with downregulated MHC class I expression by doubling the pBSC/E7GGG.GUS dose, but we failed to demonstrate a beneficial effect of any combination of two fusion genes with different mechanisms causing enhancement of HPV16 E7 immunogenicity. Copyright © 2005 John Wiley & Sons, Ltd.
Modelling the deformation mechanisms, structure–property relationships and applications of auxetic nanomaterials
Authors: Alderson A. , Alderson K. L. , Evans K. E. , Grima J. N. , Williams M. R. , Davies P. J. 
Published: February 2005

AbstractAnalytical and Molecular Mechanics methods have been used to study the structure and deformation mechanisms acting at the molecular level in the auxetic polymorph of crystalline silica (α‐cristobalite). The Molecular Mechanics simulations indicate a stress‐induced phase transition from α‐cristobalite to ‘ordered’ β‐cristobalite occurs for uniaxial loading along the x3 direction. This is in reasonable agreement with the previous prediction from an analytical model assuming deformation is by concurrent dilation and cooperative rotation (about axes in the x1‐x2 plane, passing through the midpoints of opposing edges – the a‐axes) of the SiO4 tetrahedral molecular sub‐units, previously shown to predict the Poisson's ratio for loading in the x3 direction. The analytical models have been extended to include cooperative rotation of each tetrahedron about its axis (the c‐axis) mostly closely aligned with the principal unit‐cell x3‐axis. The new models enable significantly improved prediction of the Poisson's ratios of α‐cristobalite when loaded in one of the transverse (x1 or x2) directions. Parametric fitting of the analytical models indicate that the deformation mechanism for transverse uniaxial loading of α‐cristobalite is by concurrent dilation and cooperative rotation about the local a and c‐axes of the SiO4 tetrahedra. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Deformation degree estimators for several basic structural units in numerically simulated materials
Authors: Bergmanski G. , Bialoskórski M. , Rybicki J. , Feliziani S. 
Published: February 2005

AbstractIn the paper we introduce several deformation degree estimators for a series of basic structural units, CAn (C – cation, A – anion), often encountered in numerically simulated solids. We apply Monte Carlo simulations to calculate the distributions of the estimators' values in the function of the polyhedra deformation degree. The obtained model results provide reference data that may be useful for quantitative analysis of short range correlations in materials' structures obtained with the aid of computer simulations, e.g. Molecular Dynamics. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the elastic contribution to crystal growth in complex environments
Authors: Gadomski A. , Siódmiak J. 
Published: February 2005

AbstractBased on a number of experimental studies, we propose to consider how elastic interactions between a crystal and its surroundings change crystal growing conditions. To aim to do this, we analyze the influence of some nonequilibrium modification of the Gibbs–Thomson thermodynamic condition, prescribed at the crystal boundary, on some properties of a kinetic model of protein crystal growth in a mass‐convection regime. Next, to draw the physical picture more realistically, we study the influence of a certain stochastic perturbation on the crystal growth rate. To fulfill the task we apply the description of crystal growth in terms of nonequilibrium thermodynamics at a mesoscopic level. The proposed model offers a quite comprehensive picture of the formation of modern organic crystalline materials such as non‐Kossel crystals. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermal expansion and contraction of polymer thin films
Authors: Kanaya T. , Miyazaki T. , Inoue R. , Nishida K. 
Published: February 2005

AbstractWe have studied thermal expansion and contraction of polystyrene thin film supported on silicon substrate using X‐ray reflectivity and inelastic neutron scattering techniques. In annealing experiments, we found fast and very slow contraction processes in the thin films above the glass transition temperature. The fast one was attributed to normal relaxation (annealing) process observed in bulk and responsible partly for the reported apparent negative expansivity. In addition, we found extremely slow re‐expansion process in the glassy state. The ultra‐slow contraction and re‐expansion have been assigned to the lateral expansion and contraction of the film, respectively. Using well‐annealed films, we have evaluated thermal expansivity as a function of film thickness, and found that it decreases with film thickness in a thickness range below twice of radius of gyration of a polymer chain 2Rg in the glassy state. The decrease has been attributed to hardening of harmonic force constant due to confinement in a thin film. This idea was confirmed in the inelastic neutron scattering measurements. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Extreme viscoelastic properties of composites of strongly inhomogeneous structures due to negative stiffness phases
Authors: Novikov V. V. , Wojciechowski K. W. 
Published: February 2005

AbstractA fractal model of structure [V. V. Novikov et al., Phys. Rev. E 63, 036120 (2001)] is generalized and applied to study the viscoelastic properties of a two‐component, strongly inhomogeneous medium of chaotic structure with one component exhibiting a negative shear modulus. It is shown that similar to the results obtained recently in frames of the Hashin–Strikman model [R. S. Lakes, Phys. Rev. Lett. 86, 2897 (2001)], the present fractal model predicts the existence of composites having effective shear and damping coefficients much higher than those of the component phases. The viscoelastic properties of the strongly inhomogeneous medium are, however, qualitatively different from the properties of the Hashin‐Strikman medium. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Directional and band‐gap behavior of periodic auxetic lattices
Authors: Ruzzene M. , Scarpa F. 
Published: February 2005

AbstractThe paper investigates the wave propagation characteristics of periodic two dimensional, auxetic lattice structures. Periodic structures in general feature unique wave propagation characteristics, whereby waves are allowed to propagate only within specific frequency bands. Two dimensional periodic structures complement this feature with a low frequency directional behavior. The combination of these unique characteristics makes two dimensional periodic structures ideal candidates for the design of pass‐band directional mechanical filters.Focus is here placed on honeycomb lattice configurations. A sensitivity analysis is first presented to investigate the influence of band‐gap and directional behaviors with respect to changes in the internal angle. The presented results demonstrate how re‐entrant topologies feature enhanced wave attenuation capabilities with respect to hexagonal lay‐outs. An optimization problem is then formulated by considering the internal angle as a design variable, and the width of the attenuation frequency ranges and angular range of propagation at low frequencies as objective functions. The identified optimal configurations feature combined properties which demonstrate the effectiveness of the analysis procedure. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Auxetic compliant flexible PU foams: static and dynamic properties
Authors: Scarpa F. , Pastorino P. , Garelli A. , Patsias S. , Ruzzene M. 
Published: February 2005

AbstractThe paper describes the manufacturing and tensile testing of auxetic (negative Poisson's ratio) thermoplastic polyurethane foams, both under constant strain rate and sinusoidal excitation. The foams are produced from conventional flexible polyurethane basis following a manufacturing route developed in previous works. The Poisson's ratio behaviour over tensile strain has been analyzed using an Image Data processing technique based on Edge Detection from digital images recorded during quasi‐static tensile test. The samples have been subjected to tensile and compressive tests at quasi‐static and constant strain‐rate values (up to 12 s–1). Analogous tests have been performed over iso‐volumetric foams samples, i.e., foams subjected to the same volumetric compression of the auxetic ones, exhibiting a near zero Poisson's ratio behaviour. The auxetic and non‐auxetic foams have been also tested under sinusoidal cycling load up to 10 Hz, with maximum pre‐strain applied of 12%. The hysteresis of the cycling loading curve has been measured to determine the damping hysteretic loss factor for the various foams. The measurements indicate that auxetic foams have increased damping loss factor of 20% compared to the conventional foams. The energy dissipation is particularly relevant in the tensile segment of the curve, with effects given by the pre‐strain level imposed on the samples. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)