bluuebunny/crossref_metadata_2025_split huggingface dataset:
Light microscopic identification and immunocytochemical characterization of glutamatergic synapses in brain sections
Authors: Melone Marcello , Burette Alain , Weinberg Richard J. 
Published: October 2005

AbstractPresynaptic proteins are readily identified by light microscopic immunocytochemistry, but immunodetection of postsynaptic proteins in brain sections proves difficult. We performed immunofluorescent double labeling for the NR1 subunit of theN‐methyl‐D‐aspartate receptor (NMDAR) and the vesicular glutamate transporter 1 (VGLUT1). In material fixed with 4% paraformaldehyde, NMDAR staining in somatosensory cortex was restricted to the section surface, whereas presynaptic staining extended deeper into the tissue. Staining for postsynaptic proteins was enhanced in weakly fixed material and in tissue treated with pepsin, as previously reported, but tissue quality was impaired. Staining was also markedly enhanced, and without impairment of tissue quality, by treatment during perfusion with a mixture of inhibitors of proteases and the ubiquitin/proteosome system. We performed quantitative analysis of confocal images to study how immunostaining varies with depth into the tissue. Virtually all puncta immunopositive for VGLUT1 colocalized with synaptophysin puncta; these presynaptic puncta were most numerous 1–2 μm beneath the section surface. In contrast, puncta immunopositive for the NR1 subunit were most numerous at the surface, as were puncta immunopositive for the NR2 subunit, SynGAP, and CaMKII. Punctate staining for all postsynaptic proteins, but not presynaptic markers, was substantially enhanced in material pretreated with antiproteolytic agents. The large majority of NR1‐positive puncta at the surface associated with VGLUT1 in this material are likely to represent synaptic contacts. Approximately eighty‐five percent of VGLUT1‐positive puncta in layers II–III of SI are associated with NR1‐positive puncta, and ∼80% are associated with NR2, SynGAP, and CaMKII. This approach may permit systematic analysis of the chemistry of glutamatergic synapses with light microscopic immunocytochemistry. J. Comp. Neurol. 492:495–509, 2005. © 2005 Wiley‐Liss, Inc.
The PDAPP mouse model of Alzheimer's disease: Locus coeruleus neuronal shrinkage
Authors: German Dwight C. , Nelson Omar , Liang Fen , Liang Chang‐Lin , Games Dora 
Published: October 2005

AbstractAlzheimer's disease is characterized by neuronal degeneration in the cerebral cortex and hippocampus and subcortical neuronal degeneration in such nuclei as the locus coeruleus (LC). Transgenic mice overexpressing mutant human amyloid precursor protein V717F, PDAPP mice, develop several Alzheimer's disease‐like lesions. The present study sought to determine whether there is also loss of LC noradrenergic neurons or evidence of degenerative changes in these animals. PDAPP hemizygous and wild‐type littermate control mice were examined at 23 months of age, at a time when there are numerous amyloid‐β (Aβ) plaques in the neocortex and hippocampus. Tissue sections were stained immunohistochemically with an antibody against tyrosine hydroxylase (TH) to identify LC neurons. Computer imaging procedures were used to count the TH‐immunoreactive somata in sections through the rostral‐caudal extent of the nucleus. There was no loss of LC neurons in the hemizygous mice. In a second experiment, homozygous PDAPP and wild‐type mice were examined, at 2 months and 24 months of age. Again there was no age‐related loss of neurons in the homozygous animals. In the portion of the LC where neurons reside that project to the cortex and hippocampus, however, the neurons were decreased in size selectively in the 24‐month‐old transgenic animals. These data indicate that overt LC cell loss does not occur following abundant overexpression of Aβ peptide. However, the selective size reduction of the LC neuronal population projecting to cortical and hippocampal regions containing Aβ‐related neuropathology implies that these cells may be subjected to a retrograde‐mediated stress. J. Comp. Neurol. 492:469–476, 2005. © 2005 Wiley‐Liss, Inc.
Cellular phenotype of androgen receptor‐immunoreactive nuclei in the developing and adult rat brain
Authors: Lorenz Betty , Garcia‐Segura Luis Miguel , DonCarlos Lydia L. 
Published: October 2005

AbstractAndrogen exposure during development and adulthood promotes cell‐to‐cell communication, modulates the size of specific brain nuclei, and influences hormone‐dependent behavioral and neuroendocrine functions. Androgen action involves the activation of androgen receptors (AR). To elucidate the mechanisms involved in AR‐mediated effects on forebrain development, double‐label fluorescent immunohistochemistry and confocal microscopy were employed to identify the cellular phenotype of AR‐immunoreactive (AR+) cells in the developing (embryonic day 20, postnatal days 0, 4, 10) and adult male rat forebrain. Sections were doubly labeled with antibodies directed against AR and one of the following: neurons (immature, nestin; mature, NeuN) or astrocytes [immature, vimentin; mature, glial fibrillary acidic protein (GFAP)] or mature oligodendrocytes (mGalC). In all brain regions examined, by far the majority of AR+ cells were neurons. In addition, small subsets of AR+ cells were identified as mature astrocytes (GFAP+) but only in specific brain regions at specific ages. AR+/GFAP+ cells were observed in the cerebral cortex but only in postnatal day 10 rats and in the arcuate nucleus of the hypothalamus but only in adult rats. Immature neurons, immature astrocytes, and oligodendrocytes were not AR+ at any age, in any region. Thus, both neurons and astrocytes in the male rat forebrain contain ARs, suggesting that androgens, via ARs, may exert effects on both cell types in an age‐ and region‐dependent manner. J. Comp. Neurol. 492:456–468, 2005. © 2005 Wiley‐Liss, Inc.
Application of the second derivative of the Kubelka–Munk function to the semiquantitative analysis of Roman paintings
Authors: Rodríguez José María Fernández , Fernández José Antonio Fernández 
Published: October 2005

AbstractIn the present survey, we have analyzed Roman paintings in two rooms in a villa at El Ruedo (Almedinilla, Córdoba, Spain). We used different techniques and procedures, such as X‐ray diffraction and diffuse reflectance. We established parameters that define colours in every international system. The diffuse reflectance techniques allowed us to identify the pigments, emphasizing that their mixtures are usually based upon a single chromatic pigment. © 2005 Wiley Periodicals, Inc. Col Res Appl, 30, 448–456, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.
Channel adjustments of the lower Trinity River, Texas, downstream of Livingston Dam
Authors: Phillips Jonathan D. , Slattery Michael C. , Musselman Zachary A. 
Published: October 2005

AbstractChannel cross‐sectional changes since construction of Livingston Dam and Lake Livingston in 1968 were studied in the lower Trinity River, Texas, to test theoretical models of channel adjustment, and to determine controls on the spatial extent of channel response. High and average flows were not significantly modified by the dam, but sediment transport is greatly reduced. The study is treated as an opportunistic experiment to examine the effects of a reduction in sediment supply when discharge regime is unchanged. Channel scour is evident for about 60 km downstream, and the general phenomena of incision, widening, coarsening of channel sediment and a decrease in channel slope are successfully predicted, in a qualitative sense, by standard models of channel response. However, there is no consistent channel response within this reach, as various qualitatively different combinations of increases, decreases or no change in width, depth, slope and roughness occur. These multiple modes of adjustment are predicted by the unstable hydraulic geometry model. Between about 60 km and the Trinity delta 175 km downstream of the dam, no morphological response to the dam is observed. Rather than a diminution of the dam's effects on fluvial processes, this is due to a fundamental change in controls of the fluvial system. The downstream end of the scour zone corresponds to the upstream extent of channel response to Holocene sea level rise. Beyond 60 km downstream, the Trinity River is characterized by extensive sediment storage and reduced conveyance capacity, so that even after dam construction sediment supply still exceeds transport capacity. The channel bed of much of this reach is near or below sea level, so that sea level rise and backwater effects from the estuary are more important controls on the fluvial system than upstream inputs. Copyright © 2005 John Wiley & Sons, Ltd.
Discharge and suspended sediment dynamics during two jökulhlaups in the Skaftá river, Iceland
Authors: Old Gareth H. , Lawler Damian M. , Snorrason Árni 
Published: October 2005

AbstractThis paper investigates the dynamics and significance of discharge and suspended sediment transport (SST) during two jökulhlaups (glacier outburst floods) in the Skaftá River, south Iceland. Jökulhlaups occur frequently in many glacial environments and are highly significant in the geomorphological evolution of river basins and coastal environments. However, direct high‐resolution monitoring of jökulhlaups has rarely been accomplished and hardly ever at more than one station in a downstream sequence. Here we present detailed data on jökulhlaup discharge and water quality from an intensive monitoring and sampling programme at two sites in summer 1997 when two jökulhlaups occurred. Evidence is discussed that supports the origin of both jökulhlaups being subglacial reservoirs, produced over several months by subglacial geothermal activity. At the downstream site, Ása‐Eldvatn, the larger jökulhlaup (1) had a peak discharge of 572 m3 s−1 and a peak suspended sediment flux of 4650 kg s−1 (channel‐edge value) or 4530 kg s−1 (cross‐sectional). These values compare to the non‐jökulhlaup flow of 120 m3 s−1 and suspended sediment flux of 190 kg s−1 (channel‐edge) or 301 kg s−1 (cross‐sectional). Significantly, the jökulhlaups transported 18·8 per cent of the annual runoff and 53 per cent of the annual suspended sediment transport in 6·6 per cent of the year. Furthermore, water chemistry, suspended sediment and seismic data suggest that volcanic activity and geothermal boiling (possibly including steam explosions) may have occurred during Jökulhlaup 1. The research illustrates the value of integrating high‐resolution, multi‐point field monitoring of meteorological, hydrological, hydrochemical, geomorphological and seismological data for understanding the dynamics, significance and downstream translation of jökulhlaups. Copyright © 2005 John Wiley & Sons, Ltd.
A key for Aspidistra (Ruscaceae), including fifteen new species from Vietnam
Authors: Tillich H.‐J. 
Published: October 2005

AbstractFifteen species and two subspecies of Aspidistra (Ruscaceae, Monocotyledons) from Vietnam new to science are described. This raises the number of known species to 76 and extends the genus area to South Vietnam at ca. 12° N. Additionally, a detailed new key is given to determine all recently known species in Aspidistra. New species: Aspidistra atroviolaca, A. bicolor, A. bogneri, A. carnosa, A. connata, A. foliosa, A. geastrum, A. lateralis, A. lutea, A. marasmioides, A. opaca, A. petiolata, A. stricta, A. subrotata, A. superba .New subspecies: Aspidistra arnautovii sp. nova, subsp. arnautovii, A. arnautovii subsp. nova catbaensis, A. subrotata subsp. nova crassinervis .New combinations: Aspidistra dodecandra, A. glandulosa . (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Plant regeneration mechanisms during early post‐fire succession in south‐eastern Spain
Authors: Buhk C. , Sánchez Gómez P. , Hensen I. 
Published: October 2005

AbstractRegeneration mechanisms during vegetation succession were quantified on different post‐fire sites (2–3 y after fire) in south‐eastern Spain (Province of Murcia). We distinguished between (a) species regenerating exclusively sexually (obligate seeders), (b) species regenerating to 30–70% sexually (facultative sprouters) and (c) species regenerating mainly vegetatively after fire (sprouters). The importance of the mechanisms at the different fire sites were compared between the different locations (mountains vs. coast) and exposure (north vs. south‐facing) on the one hand and with undisturbed reference sites on the other hand. While patterns of regeneration mechanisms between the recently burnt plots were very similar to the undisturbed reference sites, the quantity of mechanisms between the coastal and the mountainous areas and between northern and southern aspects differed considerably. Facultative sprouters were more abundant close to the coast than in the mountains, while mainly sprouting species covered the largest areas in north‐facing mountainous sites. According to microclimatic data, an altered water balance may be responsible for major differences in regeneration mechanisms between mountainous and coastal sites and contrasting aspects. In conformity with the data available to us, the vegetation of the Murcia region is highly resilient to fire as vegetation returns quickly to a state similar as before the fire. The high differences in the success of regeneration mechanisms between the different exposures, however, indicate a strong sensibility of vegetation toward local climatic differences. We therefore expect that climate change could have a remarkable effect on the vegetation composition. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The numerical solution of the laminar flow in a constricted channel at moderately high Reynolds number using Newton iteration
Authors: Hunt Roland 
Published: October 2005

AbstractThe numerical solution of the flow in a stepped channel constricted to half its width has been obtained for Reynolds numbers up to 2000 using Newton's iteration to solve the ensuing algebraic system. In order to avoid high‐frequency errors, a locally fine grid is effected near the corner by transformation of the independent variables. The results predict a downstream recirculation region, observed in experiments but not found in earlier numerical calculations. The inclusion of the Dennis–Hudson upwinding, added for stability in SOR methods, whilst giving the same characteristics of the flow, is less accurate by at least an order of magnitude.
Computing axisymmetric, laminar internal flows
Authors: Derksen R. W. 
Published: October 2005

AbstractA simple computational scheme is developed to compute laminar flows inside axisymmetric ducts. It is based on the Keller box method where the equations are approximated at the centre of the downstream face of each computational box. The coupling between the pressure gradient and the velocities for internal flow has been observed to introduce stability problems for the Keller box method that are not present for external, boundary layer flow problems. The difference scheme for the velocities is coupled to an iterative scheme to solve for the pressure gradient at each axial step. Example results for developing flow in a pipe and in a 2° conical diffuser are presented.
Numerical solution of the steady incompressible Navier—Stokes equations for the flow past a sphere by a multigrid defect correction technique
Authors: Juncu Gh. , Mihail R. 
Published: October 2005

AbstractA nested non‐linear multigrid algorithm is developed to solve the Navier–Stokes equations which describe the steady incompressible flow past a sphere. The vorticity–streamfunction formulation of the Navier–Stokes equations is chosen. The continuous operators are discretized by an upwind finite difference scheme. Several algorithms are tested as smoothing steps. The multigrid method itself provides only a first‐order‐accurate solution. To obtain at least second‐order accuracy, a defect correction iteration is used as outer iteration. Results are reported for Re = 50, 100, 400 and 1000.
Infinite elements for water wave radiation and scattering
Authors: Chen H. S. 
Published: October 2005

AbstractThe infinite element method is employed to approximate the solutions of Webster's horn equation and Berkhoff's equation for water wave radiation and scattering in an unbounded domain. Functionals based on the first variational principle are presented. Two new infinite elements, which exactly satisfy the one‐ and two‐dimensional Sommerfeld radiation condition, are presented; the simple shape functions are constructed on the basis of the asymptotic behaviour of the scattered wave at infinity. All the integrals in the functionals involving each infinite element are integrated analytically and, as a result, no numerical integration is required. The programming requirements and computational efficiency are essentially no different than those of the conventional finite element method. For the test cases presented, the numerical results are acceptably accurate when compared with the existing solutions and laboratory data.
Finite element formulation for transport equations in a mixed co‐ordinate system: An application to determine temperature effects on the single‐well chemical tracer test
Authors: Park Y. J. , Deans H. A. , Tezduyar T. E. 
Published: October 2005

AbstractHeterogeneous equation systems in a pair of coupled co‐ordinate systems are solved by a finite element method. The specific physical application studied is the effect of temperature on single‐well chemical tracer (SWCT) tests to measure residual oil saturation (volume fraction of immobile oil phase) remaining after waterflooding of an oil reservoir. Since temperature effects are caused by injecting cooler surface fluid down a well into a warm reservoir, the vertical temperature profile in the wellbore as well as the temperature distribution in the porous oil‐bearing layer must be considered.The entire system is modelled to account for the different transport mechanisms. However, it is expedient to divide the connected geometrical region into two model domains. The equations for each submodel are expressed in an appropriate set of co‐ordinates. The variational formulation of each model is then discussed.A significant temperature effect on the estimation of residual oil saturation occurs when the radial temperature and concentration wave propagation speeds in the porous formation are about the same. In this case the temperature gradient is located across the chemical tracer bank, causing the chemical reaction rate to vary radially. The temperature effects are demonstrated for two actual field tests in complex reservoirs.
Finite element analysis of axisymmetric free jet impingement
Authors: Mejak George 
Published: October 2005

AbstractA numerical algorithm to determine the impingement of an axisymmetric free jet upon a curved deflector is presented. The problem is considered within the potential flow theory with the allowance of gravity and surface tension effects. The primary dependent variable is the Stokes streamfunction, which is approximated through finite elements using the isoparametric Hermite Zienkiewicz element. To find the correct position of the free boundaries, a trial‐and‐error method is employed which amounts to solving a boundary value problem (BVP) for the Stokes streamfunction at each iteration step. An efficient method is proposed to solve this BVP. The algorithm to find the correct position of the free boundaries is tested by computing the impingement upon an infinite disc and a hemispherical deflector. To confirm the correctness of the solution, each problem has been solved using several different mesh gradings. A comparison between the Zienkiewicz and the other standard C0 finite elements is also given.
Multigrid flow solutions in complex two‐dimensional geometries
Authors: Rayner D. 
Published: October 2005

AbstractA finite difference solution algorithm is described for use on two‐dimensional curvilinear meshes generated by the solution of the transformed Laplace equation. The efficiency of the algorithm is improved through the use of a full approximation scheme (FAS) multigrid algorithm using an extended pressure correction scheme as smoother. The multigrid algorithm is implemented as a fixed V‐cycle through the grid levels with a constant number of sweeps being performed at each grid level.The accuracy and efficiency of the numerical code are validated using comparisons of the flow over two backward step configurations. Results show close agreement with previous numerical predictions and experimental data. Using a standard Cartesian co‐ordinate flow solver, the multigrid efficiency obtainable in a rectangular system is shown to be reproducible in two‐dimensional body‐fitted curvilinear co‐ordinates. Comparisons with a standard one‐grid method show the multigrid method, on curvilinear meshes, to give reductions in CPU time of up to 93%.
Numerical method for unsteady compressible boundary layers driven by compression or expansion wave
Authors: Kim Jae‐Soo , Chang Keun‐Shik 
Published: October 2005

AbstractA numerical analysis is presented for the unsteady compressible laminar boundary layer driven by a compression or expansion wave. Approximate or series expansion methods have been used for the problems because of the characteristics of the governing equations, such as non‐linearity, coupling with the thermal boundary layer equation and initial conditions. Here a transformation of the governing equations and the numerical linearization technique are introduced to deal with the difficulties. First, the governing equations are transformed for the initial conditions by Howarth and semisimilarity variables. These transformations reduce the number of independent variables from three to two and the governing equations from partial to ordinary differential equations at the initial point. Next, the numerical linearization technique is introduced for the non‐linearity and the coupling with the thermal boundary layer equation. Because the non‐linear terms are linearized without sacrifice of numerical accuracy, the solutions can be obtained without numerical iterations. Therefore the exact numerical solution, not approximate or series expansion, can be obtained. Compared with the approximate or series expansion method, this method is much improved. Results are compared with the series expansion solutions.
Three‐dimensional simulations of natural convection in a sidewall‐heated cube
Authors: Fusegi Toru , Hyun Jae Min , Kuwahara Kunio 
Published: October 2005

AbstractA high‐resolution, finite difference numerical study is reported on three‐dimensional natural convection of air in a differentially heated cubical enclosure over an extensive range of Rayleigh number from 103 to 1010. The maximum number of grid points is 122 × 62 × 62. Solutions to the primitive variable formulation of the incompressible Navier‐Stokes and energy equations are acquired by a control‐volume‐based procedure together with a higher‐order upwind‐differencing technique. The field characteristics at large‐time limits are examined in detail by state‐of‐the‐art numerical visualizations of the three‐dimensional results. The emergence of the well‐defined boundary layers and the interior core at high Rayleigh numbers is captured by elaborate numerical visualizations. Both the similarities and discrepancies between the three‐ and two‐dimensional computations are pointed out. These emphasize the need for three‐dimensional calculations to accurately determine the flow characteristics and heat transfer properties in realistic, high‐Rayleigh‐number situations.