bluuebunny/crossref_metadata_2025 huggingface dataset:
Upscaling of Hydraulic Conductivity and Telescopic Mesh Refinement
Authors: Walker Douglas D. , Gylling Björn , Selroos Jan‐Olof
Published: December 2005

Performance assessments of repositories for the underground disposal of nuclear fuel and waste include models of ground water flow and transport in the host rocks. Estimates of hydraulic conductivity, K, based on field measurements may require adjustment (upscaling) for use in numerical models, but the choice of upscaling approach can be complicated by the use of nested modeling, large‐scale fracture zones, and a high degree of heterogeneity. Four approaches to upscaling K are examined using a reference case based on exhaustive site data and an application of nested modeling to evaluate performance assessment of a waste repository. The upscaling approaches are evaluated for their effects on the flow balance between nested modeling domains and on simple measures of repository performance. Of the upscaling approaches examined in this study, the greatest consistency of boundary flows was achieved using the observed scale dependence for the rock domains, measured values from the large‐scale interference test for the conductor domain, and a semivariogram regularization based on the Moye model for packer test interpretation. Making the assumption that large fracture zones are two‐dimensional media results in the greatest changes to the median of travel time and improves the flow balance between the nested models. The uncertainty of upscaling methods apparently has a small impact on median performance measures, but a significant impact on the variances and earliest arrival times.
Regional Estimation of Total Recharge to Ground Water in Nebraska
Authors: Szilagyi Jozsef , Harvey F. Edwin , Ayers Jerry F.
Published: December 2005

Naturally occurring long‐term mean annual recharge to ground water in Nebraska was estimated by a novel water‐balance approach. This approach uses geographic information systems (GIS) layers of land cover, elevation of land and ground water surfaces, base recharge, and the recharge potential in combination with monthly climatic data. Long‐term mean recharge > 140 mm per year was estimated in eastern Nebraska, having the highest annual precipitation rates within the state, along the Elkhorn, Platte, Missouri, and Big Nemaha River valleys where ground water is very close to the surface. Similarly high recharge values were obtained for the Sand Hills sections of the North and Middle Loup, as well as Cedar River and Beaver Creek valleys due to high infiltration rates of the sandy soil in the area. The westernmost and southwesternmost parts of the state were estimated to typically receive < 30 mm of recharge a year.
Mass and Flux Distributions from DNAPL Zones in Sandy Aquifers
Authors: Guilbeault Martin A. , Parker Beth L. , Cherry John A.
Published: December 2005

At three industrial sites in Ontario, New Hampshire, and Florida, tetrachloroethylene (PCE) and trichloroethylene (TCE), released decades ago as dense nonaqueous phase liquids (DNAPLs), now form persistent source zones for dissolved contaminant plumes. These zones are suspended below the water table and above the bottoms of their respective, moderately homogeneous, unconfined sandy aquifers. Exceptionally detailed, depth‐discrete, ground water sampling was performed using a direct‐push sampler along cross sections of the dissolved‐phase plumes, immediately downgradient of these DNAPL source zones. The total plume PCE or TCE mass‐discharge through each cross section ranged between 15 and 31 kg/year. Vertical ground water sample spacing as small as 15 cm and lateral spacing typically between 1 and 3 m revealed small zones where maximum concentrations were between 1% and 61% of solubility. These local maxima are surrounded by much lower concentration zones. A spacing no larger than 15 to 30 cm was needed at some locations to identify high concentration zones, and aqueous VOC concentrations varied as much as four orders of magnitude across 30 cm vertical intervals. High‐resolution sampling at these sites showed that three‐quarters of the mass‐discharge occurs within 5% to 10% of the plume cross sectional areas. The extreme spatial variability of the mass‐discharge occurs even though the sand aquifers are nearly hydraulically homogeneous. Depth‐discrete field techniques such as those used in this study are essential for finding the small zones producing most of the mass‐discharge, which is important for assessing natural attenuation and designing remedial options.
Estimating Ground Water Recharge from Topography, Hydrogeology, and Land Cover
Authors: Cherkauer Douglas S. , Ansari Sajjad A.
Published: December 2005

Proper management of ground water resources requires knowledge of the rates and spatial distribution of recharge to aquifers. This information is needed at scales ranging from that of individual communities to regional. This paper presents a methodology to calculate recharge from readily available ground surface information without long‐term monitoring. The method is viewed as providing a reasonable, but conservative, first approximation of recharge, which can then be fine‐tuned with other methods as time permits.

Stream baseflow was measured as a surrogate for recharge in small watersheds in southeastern Wisconsin. It is equated to recharge (R) and then normalized to observed annual precipitation (P). Regression analysis was constrained by requiring that the independent and dependent variables be dimensionally consistent. It shows that R/P is controlled by three dimensionless ratios: (1) infiltrating to overland water flux, (2) vertical to lateral distance water must travel, and (3) percentage of land cover in the natural state. The individual watershed properties that comprise these ratios are now commonly available in GIS data bases.

The empirical relationship for predicting R/P developed for the study watersheds is shown to be statistically viable and is then tested outside the study area and against other methods of calculating recharge. The method produces values that agree with baseflow separation from streamflow hydrographs (to within 15% to 20%), ground water budget analysis (4%), well hydrograph analysis (12%), and a distributed‐parameter watershed model calibrated to total streamflow (18%). It has also reproduced the temporal variation over 5 yr observed at a well site with an average error < 12%.
Grid Resolution Study of Ground Water Flow and Transport
Authors: Bower Kathleen M. , Gable Carl W. , Zyvoloski George A.
Published: December 2005

Three‐dimensional grids representing a heterogeneous, ground water system are generated at 10 different resolutions in support of a site‐scale flow and transport modeling effort. These grids represent hydrostratigraphy near Yucca Mountain, Nevada, consisting of 18 stratigraphic units with contrasting fluid flow and transport properties. The grid generation method allows the stratigraphy to be modeled by numerical grids of different resolution so that comparison studies can be performed to test for grid quality and determine the resolution required to resolve geologic structure and physical processes such as fluid flow and solute transport. The process of generating numerical grids with appropriate property distributions from geologic conceptual models is automated, thus making the entire process easy to implement with fewer user‐induced errors. The series of grids of various resolutions are used to assess the level at which increasing resolution no longer influences the flow and solute transport results. Grid resolution is found to be a critical issue for ground water flow and solute transport. The resolution required in a particular instance is a function of the feature size of the model, the intrinsic properties of materials, the specific physics of the problem, and boundary conditions. The asymptotic nature of results related to flow and transport indicate that for a hydrologic model of the heterogeneous hydrostratigraphy under Yucca Mountain, a horizontal grid spacing of 600 m and vertical grid spacing of 40 m resolve the hydrostratigraphic model with sufficient precision to accurately model the hypothetical flow and solute transport to within 5% of the value that would be obtained with much higher resolution.
Computer-Assisted Pattern Recognition of Autoantibody Results
Authors: Binder Steven R. , Genovese Mark C. , Merrill Joan T. , Morris Robert I. , Metzger Allan L.
Published: December 2005

Immunoassay-based anti-nuclear antibody (ANA) screens are increasingly used in the initial evaluation of autoimmune disorders, but these tests offer no “pattern information” comparable to the information from indirect fluorescence assay-based screens. Thus, there is no indication of “next steps” when a positive result is obtained. To improve the utility of immunoassay-based ANA screening, we evaluated a new method that combines a multiplex immunoassay with a
k
nearest neighbor (kNN) algorithm for computer-assisted pattern recognition. We assembled a training set, consisting of 1,152 sera from patients with various rheumatic diseases and nondiseased patients. The clinical sensitivity and specificity of the multiplex method and algorithm were evaluated with a test set that consisted of 173 sera collected at a rheumatology clinic from patients diagnosed by using standard criteria, as well as 152 age- and sex-matched sera from presumably healthy individuals (sera collected at a blood bank). The test set was also evaluated with a HEp-2 cell-based enzyme-linked immunosorbent assay (ELISA). Both the ELISA and multiplex immunoassay results were positive for 94% of the systemic lupus erythematosus (SLE) patients. The kNN algorithm correctly proposed an SLE pattern for 84% of the antibody-positive SLE patients. For patients with no connective tissue disease, the multiplex method found fewer positive results than the ELISA screen, and no disease was proposed by the kNN algorithm for most of these patients. In conclusion, the automated algorithm could identify SLE patterns and may be useful in the identification of patients who would benefit from early referral to a specialist, as well as patients who do not require further evaluation.
Gamma Interferon Is Dispensable for Neopterin Production In Vivo
Authors: Sghiri R. , Feinberg J. , Thabet F. , Dellagi K. , Boukadida J. , Ben Abdelaziz A. , Casanova J. L. , Barbouche M. R.
Published: December 2005

Previous studies have indicated that neopterin is synthesized in vitro by human monocyte-derived macrophages and dendritic cells upon stimulation with gamma interferon (IFN-γ). Neopterin production under specific conditions in vitro has also been obtained upon stimulation with IFN-α and/or IFN-β. However, it is unknown if any IFN-γ-independent neopterin synthesis is possible in vivo. In the present study we investigated the serum neopterin concentrations in patients affected by the syndrome of Mendelian susceptibility to mycobacterial disease (MSMD). Indeed, this syndrome is characterized by deeply impaired or absent IFN-γ production or function due to severe mutations in molecules involved in IFN-γ/interleukin-12 (IL-12)/IL-23-dependent pathway. Serum neopterin levels were measured by an enzyme-linked immunosorbent assay in 27 patients with MSMD. We found that serum neopterin levels are elevated in the complete absence of IFN-γ activity due either to a complete deficiency of its receptor or to deleterious mutations of IL-12 or its receptor. These data clearly indicate that, as reported from in vitro studies, other stimuli are able to induce neopterin synthesis in vivo. Consequently, neopterin cannot be used as means of diagnosis of MSMD due to IFN-γ-, IL-12-, and IL-23-dependent pathway defects.
Unidirectional Suppression of
Anaplasma phagocytophilum
Genotypes in Infected Lambs
Authors: Stuen Snorre , Dahl Hilde , Bergström Karin , Moum Truls
Published: December 2005

Five-month-old lambs were simultaneously infected with different doses of two 16S rRNA genetic variants of
Anaplasma phagocytophilum
and thereafter followed for clinical observation and blood sampling. The result of the study indicates a unidirectional suppression of genotypes in infected lambs, at least during a certain period of an
A. phagocytophilum
infection.
DISTRIBUTIONAL ANALYSIS OF RELATED SYNSETS IN WordNet FOR A WORD SENSE DISAMBIGUATION TASK
Authors: FRAGOS KOSTAS , MAISTROS YANIS
Published: December 2005

This work presents a new method for an unsupervised word sense disambiguation task using WordNet semantic relations. In this method we expand the context of a word being disambiguated with related synsets from the available WordNet relations and study within this set the distribution of the related synset that correspond to each sense of the target word. A single sample Pearson-Chi-Square goodness-of-fit hypothesis test is used to determine whether the null hypothesis of a composite normality PDF is a reasonable assumption for a set of related synsets corresponding to a sense. The calculated p-value from this test is a critical value for deciding the correct sense. The target word is assigned the sense, the related synsets of which are distributed more "abnormally" relative to the other sets of the other senses. Our algorithm is evaluated on English lexical sample data from the Senseval-2 word sense disambiguation competition. Three WordNet relations, antonymy, hyponymy and hypernymy give a distributional set of related synsets for the context that was proved quite a good word sense discriminator, achieving comparable results with the system obtained the better results among the other competing participants.
EFFECT OF GRAIN SIZE ON SURFACE MORPHOLOGY AFTER FOCUSED ION BEAM MICRO-MACHINING FOR CEMENTED CARBIDES
Authors: HOSOKAWA HIROYUKI , NAKAJIMA TAKESHI , SHIMOJIMA KOJI , MABUCHI MAMORU
Published: December 2005

The cemented carbides containing various microstructures were machined by scanning a 30 keV Ga + ion beam, with a nominal spot size of 300 nm and a current of 5300 pA, from side to side and up and down and a 100 μs pixel dwell time. In the coarse-grained cemented carbide, the surfaces of the WC phase parts were very smooth while those of the Co phase were rough. In the fine-grained cemented carbides, the surfaces were smoother on the whole and the irregularities were smaller compared with the coarse-grained cemented carbides. It is indicated that preparation of cemented carbide with finer WC grains, and decrease of the mean free path of Co phase are required for the FIB micro-machining to reduce surface irregularities.
FINITE ELEMENT STUDY OF MULTIPASS EQUAL CHANNEL ANGULAR EXTRUSION/PRESSING
Authors: NAGASEKHAR A. V. , YIP TICK-HON , LI S.
Published: December 2005

Equal channel angular extrusion/pressing multipass simulations were carried for two routes, Route A and Route C, by using finite element code Abaqus/Explicit. Realistic parameters like strain hardening behavior of material, friction between the sample and die were considered for simulations. The strain homogeneity and deformation behavior of samples during multipass ECAE with different routes were studied. The deformation behavior of the sample processed through Route A is smooth. Accordingly strain homogeneity of the samples was more of a possibility with Route A than with Route C.
FATIGUE PERFORMANCE OF CLAY-EPOXY NANOCOMPOSITES
Authors: JUWONO ARIADNE , EDWARD GRAHAM
Published: December 2005

This paper presents an investigation of the possibility of improving the fatigue properties of an epoxy resin through dispersion of modified layered silicates within the polymer matrix. Montmorillonite-epoxy nancocomposites were successfully synthesized with a commercially available 1-Methylimidazole curing agent. The morphology of these materials was investigated by XRD and TEM. The findings demonstrated a pattern of clay morphology typically found in nanocomposite systems. Four point loading measurements showed an increase in modulus for 2.5 wt% and 10 wt% clay contents when compared to the unfilled epoxy, whereas the moduli showed a decrease for 5 wt% and 7.5 wt% clay contents. This behavior is typical for most particulate-filled systems. Fracture surfaces were examined using an E-SEM. The failure mechanism of the nanocomposites varied from that of the unfilled epoxy. Below a critical strain amplitude, the fatigue life of the filled epoxy improved significantly compared to that of the unfilled epoxy. In conclusions, the addition of silicates changes the fatigue failure mechanism and improves significantly the fatigue life.
EFFECT OF INTERFACE STRESSES ON ANISOTROPIC STRUCTURE OF THE ARTICULAR SURFACE
Authors: PUNANTAPONG B. , THONGTEM S. , FAGAN M. J. , SOORAPANTH C.
Published: December 2005

Fatigue failure of anisotropic structure of the artificial articular has been implicated in a number of clinical failure scenarios, especially the fatigue behaviour of the articular surface is poorly understood, At the same time, there is no established design and procedure, which is applicable to all load-bearing implants. However, materials degradation significantly may also be increased the life of sample by reducing the peak stresses and redistributing the load to the surrounding tissue. This paper presents the effect of the structural integrity of the shape and stresses distribution on the global material behaviour of articular cartilage. Then modulus degradation appears to be a result of trabecular fracture rather than as a result of tissue level material degradation. Furthermore, we found that Young's modulus normal to the contact surface increases from the superficial to the deep zone in articular cartilage.
NANOFIBERS IN CdTe: IODINE THIN FILMS BY SPRAY DEPOSITION
Authors: ARNEPALLI RANGARAO , DUTTA VIRESH
Published: December 2005

Cadmium Telluride: Iodine nanoparticle thin films were prepared by spraying iodine doped CdTe nanoparticles dispersed in 1-Butanol, on the glass substrates kept at 200°C for 20 min. Iodine doped CdTe nanoparticles had been prepared by adding trace amounts of Iodine powder in addition to stoichiometric ratios of Cd and Te in the Solvothermal synthesis. The films were prepared by applying without a voltage and with a voltage of 700 V to the nozzle during the deposition. The presence of iodine in the films was confirmed by the sign of voltage generated (positive relative to the cold end) in the hot probe method and also from the elemental analysis using X-ray Photoelectron Spectroscopy. X-ray diffraction patterns of the films showed predominantly Hexagonal CdTe peaks in both the cases. From the transmission spectra of the films the bandgap was found to be 1.77 eV against the bulk CdTe bandgap of 1.5 eV. The band edge was not as sharp as compared to that in case of the undoped films. SEM and TEM micrographs of both the films revealed the formation of Nanofibers.
DEMOLDING OF HIGH ASPECT RATIO POLYMERIC MICRO-PATTERNING
Authors: YEO L. P. , LAM Y. C. , CHAN-PARK MARY B. , JOSHI S. C. , HARDT D. E.
Published: December 2005

UV embossing for polymeric micro-patterning thin film is an emerging replication technique. This paper investigates UV curable multifunctional acrylates pre-polymer resin patterned by a micro-structured mold and subsequently cured by UV irradiation. To further enhance this duplication method for high aspect ratio production, demolding must be reliable and repeatable without damage to the embossing or mold. Previously, it has been reported that UV embossed patterns for aspect ratios as high as 14 have been achieved experimentally. Finite element analyses for patterns with aspect ratios of 5 using parallel demolding between two parallel plates have also been reported. However, the parallel demolding method may not be suitable for large area patterns as forces generated were high. As such, an alternative demolding method, namely peel demolding, for micro-patterns with an aspect ratio of 14 was investigated and key parameters identified. The parameters governing the demolding process were the peel angle, the pre-crack condition, shrinkage, interface fracture toughness, tensile strength and modulus of polymer. A pre-crack between the polymer and mold was introduced before peel demolding. Numerical analyses in terms of Cohesive Zone Modeling (CZM) were used to simulate the demolding process. Shrinkage caused by UV exposure was represented by thermal strain effects and the fully cured polymer was peeled off using displacement control. The ultimate tensile strength (U.T.S) of the cured polymer was used as a failure criterion. The stresses involved were crucial for determining clean demolding. As peeling progressed, stresses experienced in the polymer matrix increased rapidly in the region ahead of the crack with little or no stress at the cracked region. When stresses experienced by the polymer were below the U.T.S, demolding was deemed to be successful.
PLASMA ACTIVATED BONDING AND IMPRINTING OF POLYMER BY HOT EMBOSSING FOR PACKAGING APPLICATIONS
Authors: PELZER RAINER , FARRENS SHARON , LEE DENNIS
Published: December 2005

Hot embossing is a well-acknowledged low cost, high resolution, large area 3D patterning process for polymers. This technique allows rapid prototyping for high volume production of fully patterned substrates for a wide range of thermoplastic polymer materials. The advantages of using polymer substrates over common Micro-Electro-Mechanical System (MEMS) processing materials like glass, silicon or quartz are: bio-compatible surfaces, easy manufacturability, low cost for high volume production, suitable for use in micro- and nano-fabrication, low conductivity, wide range of optical properties just to name a few. The article will present experimental results on HE processes with PMMA, mr-I8030, mr-L6000 and NEB22 on full 8" wafer sizes. Packaging of the imprinted features is a key technology for a wide variety of optical and fluidic applications in the μm and nm-range: m-TAS, micro-mixers, micro-reactors, electrophoresis cells, switches, data storage, etc. Most packaging techniques employed today, use glue material or high temperature sintering methods to bond structured polymer wafers together. These techniques are influencing the appearance of the sub-micron structures. A promising low-temperature polymer-to-polymer direct bonding technique utilizing the cleaning and surface activating behavior of plasma should be established here.
PREPARATION AND MORPHOLOGY OF POROUS NANOCALCIUM PHOSPHATE/POLY(L-LACTIC ACID) COMPOSITES
Authors: WENG WENJIAN , GAO YANBO , PAN LILI , LI YANBAO , DU PIYI , SHEN GE , HAN GAORONG
Published: December 2005

Biodegradable porous materials can serve as a scaffold in tissue engineering. In this work, highly porous nano-calcium phosphate (NCP)/poly(L-lactic acid)(PLLA) composites were prepared by a thermally induced phase separation technique. Five calcium phosphates with different biodegradation rate were selected, i.e. amorphous calcium phosphate, α-tricalcium phosphate, β-tricalcium phosphate and biphasic α/β-tricalcium phosphate. The results showed that the NCP particles could be homogenously incorporated into pore walls; the composites had a porosity of ~90%, and a pore size of ~200 μm. From the point of view of materials science, the obtained porous NCP/PLLA composites demonstrate to have a capability of applying in bone tissue engineering.
DEEP UV LITHOGRAPHY FOR PILLAR TYPE NANOPHOTONIC CRYSTAL
Authors: TEO SELIN H. G. , LIU A. Q. , SIA G. L. , LU C. , SINGH J. , YU M. B. , SUN H. Q.
Published: December 2005

The progress made to resolve challenges met in using deep UV lithography for batch fabrication of pillar type nano-photonic crystals is described, using data from experiments carried out based on two degrees, full factorial design of experiments and subsequently processed using variance analysis. A binary mask without phase shift features was used to obtain information on effects of lithographic parameters such as antireflection coatings, resist preparation recipes, exposure latitude and depth of focus biases. The results derived hence enabled successful derivations of high quality arrays of dense nano-pillars.
DEEP REACTIVE ION ETCHING FOR PILLAR TYPE NANOPHOTONIC CRYSTAL
Authors: TEO SELIN H. G. , LIU A. Q. , SIA G. L. , LU C. , SINGH J. , YU M. B.
Published: December 2005

Experimental results and techniques developed for time multiplexed deep reactive ion etching of nano-photonic crystals are presented. Specifically, the high aspect ratio pillar type two-dimensional photonic crystal (PhC) structure on silicon is fabricated and studied for its high potential in application to lightwave circuits and also for discussion of the many unique challenges involved in its fabrication process as opposed to standard larger scale devices. In the experiments, patterns of nano-dots were first obtained using deep UV lithography and transferred to a silicon oxide hardmask prior to DRIE processing. The iteration of DRIE experiments with varying process parameters then allowed for a characterization of the varying impact of each etching parameter such as coil/ platen/ etch power, multiplexing cycling gas flows and timing patterns etc. After much optimization of sidewall etch angle and also reduction of the scalloping effect, the latest result obtained for such nano-pillar type PhC designed for application in communication is derived to have a high AR of 33.
LOW TEMPERATURE HYDROTHERMAL SYNTHESIS OF BISMUTH SODIUM TITANATE NANOPOWDERS
Authors: POOKMANEE PUSIT , PHANICHPHANT SUKON
Published: December 2005

Nanopowders bismuth sodium titanate ( Bi 0.5 Na 0.5 TiO 3, BNT ) were synthesized by the hydrothermal route at low temperature in the range of 150-200°C with different holding periods of 5-20 h. Bismuth nitrate, sodium nitrate and titanium (IV) isopropoxide were used as the starting materials. The phase structure was examined using X-ray diffraction (XRD). The morphology of the formed nanopowders was investigated by scanning electron microscopy (SEM). Rhombohedral BNT nanopowders was obtained without calcination step. The spherical nanopowders were agglomerated. The average sizes of particle size were about 50-200 nm.
THREE-DIMENSIONAL MODEL FOR INTERDIFFUSED QUANTUM DOTS
Authors: GUNAWAN O. , DJIE H. S. , OOI B. S.
Published: December 2005

We report the study of the interdiffusion effect of quantum-dot (QD) heterostructures, focusing on the theoretical calculation of the electronic structure of interdiffused QDs. A computational model has been developed for QD superlattice system using Hamiltonian in reciprocal space domain to analyze the interdiffusion effect on electronic structure. The interdiffusion effects of QDs with various geometries having the same volume and the same lattice constant have been studied. In general, the interdiffusion effect in QDs is significantly pronounced since it occurs in three dimensions. Comparing the interdiffusion effect for the various shapes of QDs, it was found that the spherical QD has the lowest ground state and produces the largest blue-shift during the interdiffusion or intermixing process.
Role of tethering factors in secretory membrane traffic
Authors: Sztul Elizabeth , Lupashin Vladimir
Published: December 2005

Coiled-coil and multisubunit tethers have emerged as key regulators of membrane traffic and organellar architecture. The restricted subcellular localization of tethers and their ability to interact with Rabs and soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) suggests that tethers participate in determining the specificity of membrane fusion. An accepted model of tether function considers them molecular “bridges” that link opposing membranes before SNARE pairing. This model has been extended by findings in various experimental systems, suggesting that tethers may have other functions. Recent reports implicate tethers in the assembly of SNARE complexes, cargo selection and transit, cytoskeletal events, and localized attachment of regulatory proteins. A concept of tethers as scaffolding machines that recruit protein components involved in varied cellular responses is emerging. In this model, tethers function as integration switches that simultaneously transmit information to coordinate distinct processes required for membrane traffic.
Upregulation of endothelial cell Ca2+signaling contributes to pregnancy-enhanced vasodilation of rat uteroplacental arteries
Authors: Gokina Natalia I. , Goecks Tara
Published: December 2005

Normal pregnancy is characterized by an increased uterine blood flow due to growth and remodeling of the maternal uterine vasculature and enhanced vasodilation of the uterine arteries. The objective of the present study was to examine the role of endothelial cell Ca2+signaling in augmented endothelium-mediated vasodilation of uteroplacental arteries in late pregnancy. We performed fura-2-based measurements of the intracellular Ca2+concentration ([Ca2+]i) in the cytoplasm of endothelial cells simultaneously with diameter in pressurized uterine arteries from nonpregnant (NP) and late-pregnant (LP) rats. Basal levels of endothelial cell [Ca2+]iwere higher in arteries from LP rats compared with NP controls. Withdrawal of extracellular Ca2+resulted in a decrease in the level of basal [Ca2+]ithat was significantly larger in arteries of LP than NP rats. The rate of Mn2+-induced quenching of fura-2 fluorescence was significantly elevated in late pregnancy, implicating augmented Ca2+influx as a cause of increased basal levels of [Ca2+]iin endothelial cells. Elevation of intraluminal pressure resulted in a transient increase in endothelial [Ca2+]ithat was markedly potentiated in late gestation. ACh-induced [Ca2+]iand vasodilator responses were significantly augmented in arteries of LP compared with NP rats and were abolished by BAPTA treatment, demonstrating a critical role of [Ca2+]ielevation in the production of endothelium-derived vasodilators. Together, these results indicate that late pregnancy is a state of enhanced basal and stimulated Ca2+signaling in endothelial cells of uterine vessels, which may represent an important underlying mechanism for augmented vasodilation in the maternal uterine circulation.
ETa-receptor blockade, but not ACE inhibition, blunts retinal vessel response during isometric exercise
Authors: Luksch Alexandra , Wimpissinger Barbara , Polak Kaija , Jandrasits Kerstin , Schmetterer Leopold
Published: December 2005

Angiotensin II and endothelin-1 are potent vasoconstrictors that appear to play a role in retinal blood flow regulation. In the present study, we investigated the possible role of the angiotensin and the endothelin system in the regulation of retinal vessel diameters during isometric exercise in healthy humans. The study design was randomized, double-masked, placebo-controlled, and three-way cross over. Twelve healthy subjects performed squatting exercises for 6 min during infusion of either an angiotensin-converting enzyme inhibitor (enalapril), an ETA-receptor antagonist (BQ-123), or placebo. Retinal vessel diameters were measured continuously with the Zeiss retinal vessel analyzer. Systemic hemodynamics were assessed noninvasively, and intraocular pressure was measured with applanation tonometry. Squatting induced a significant increase in blood pressure and pulse rate, which was paralleled by a vasoconstriction in retinal arteries and veins. Intraocular pressure was only slightly increased during the squatting periods. BQ-123 significantly blunted the exercise-induced decrease in venous ( P < 0.01) and arterial ( P < 0.02, ANOVA) vessel diameters but had no effect on basal retinal diameters. By contrast, enalapril did neither influence vessel diameter at baseline conditions nor in response to isometric exercise. The data of the present study indicate that retinal vasoconstriction during isometric exercise is modified by ETA-receptor blockade, whereas it is not altered by angiotensin-converting enzyme inhibition. Hence, the present data indicate that endothelin-1, but not angiotensin II, is involved in retinal blood flow regulation during isometric exercise.
Perfused hearts from Type 2 diabetic (db/db) mice show metabolic responsiveness to insulin
Authors: Hafstad Anne Dragøy , Solevåg Geir Helge , Severson David L. , Larsen Terje S. , Aasum Ellen
Published: December 2005

Diabetic ( db/db) mice provide an animal model of Type 2 diabetes characterized by marked in vivo insulin resistance. The effect of insulin on myocardial metabolism has not been fully elucidated in this diabetic model. In the present study we tested the hypothesis that the metabolic response to insulin in db/db hearts will be diminished due to cardiac insulin resistance. Insulin-induced changes in glucose oxidation (GLUox) and fatty acid (FA) oxidation (FAox) were measured in isolated hearts from control and diabetic mice, perfused with both low as well as high concentration of glucose and FA: 10 mM glucose/0.5 mM palmitate and 28 mM glucose/1.1 mM palmitate. Both in the absence and presence of insulin, diabetic hearts showed decreased rates of GLUox and elevated rates of FAox. However, the insulin-induced increment in GLUox, as well as the insulin-induced decrement in FAox, was similar or even more pronounced in diabetic that in control hearts. During elevated FA and glucose supply, however, the effect of insulin was blunted in db/db hearts with respect to both FAox and GLUox. Finally, insulin-stimulated deoxyglucose uptake was markedly reduced in isolated cardiomyocytes from db/db mice, whereas glucose uptake in isolated perfused db/db hearts was clearly responsive to insulin. These results show that, despite reduced insulin-stimulated glucose uptake in isolated cardiomyocytes, isolated perfused db/db hearts are responsive to metabolic actions of insulin. These results should advocate the use of insulin therapy (glucose-insulin-potassium) in diabetic patients undergoing cardiac surgery or during reperfusion after an ischemic insult.
Adenosine A2Areceptor activation attenuates inflammation and injury in diabetic nephropathy
Authors: Awad Alaa S. , Huang Liping , Ye Hong , Duong Elizabeth Thu Anh , Bolton W. Kline , Linden Joel , Okusa Mark D.
Published: December 2005

We previously demonstrated the anti-inflammatory effects and renal tissue protection in response to adenosine A2A-receptor (A2AR) activation in acute renal injury. We sought to extend these studies and determine the efficacy of A2AR agonists in a chronic model of renal injury. We hypothesized that A2Aagonists mediate renal tissue protection in diabetic nephropathy by reducing glomerular inflammation. Diabetes was induced with single intravenous injection of streptozotocin in Sprague-Dawley rats (50 mg/kg). Increases in urinary albumin excretion (UAE) and plasma creatinine at week 6 in the diabetes group (26- and 6-fold over control, respectively) were markedly reduced by continuous subcutaneous administration of ATL146e (10 ng·kg−1·min−1), a selective A2Aagonist. The increase in UAE in the diabetes group was associated with a significant reduction in the expression of slit diaphragm-associated molecules compared with control (nephrin; P < 0.05 and podocin; P < 0.005) that was reversed by ATL146e treatment. Diabetes led to an increase in urinary excretion of monocyte chemoattractant protein-1 (705% of control), TNF-α (1,586% of control), IFN-γ (298% of control), kidney fibronectin mRNA (457% of control), and glomerular infiltration of macrophages (764% of control), effects significantly reduced by ATL146e treatment. Mesangial expansion and basement membrane thickness were reduced with ATL146e. To further confirm the selectivity of ATL146e, we used wild-type (WT) or A2Aknockout (A2A-KO) mice. Four weeks after diabetes, UAE increased significantly in both WT and A2A-KO diabetic mice (3.0- and 3.3-fold over control). A2Aagonist treatment blocked the increase in UAE in WT diabetic mice ( P < 0.001), whereas it had no effect on the A2A-KO diabetic mice. These results demonstrate that chronic A2AR activation in diabetic rats 1) ameliorates histological and functional changes in kidneys induced by diabetes and 2) causes reduced inflammation associated with diabetic nephropathy.
Transdifferentiation of Endothelial and Renal Tubular Epithelial Cells into Myofibroblast-Like Cells under in vitro Conditions: A Morphological Analysis
Authors: Sommer M. , Gerth J. , Stein G. , Wolf G.
Published: December 2005

Renal fibrosis is a hallmark of progressive kidney disease and is characterized by an accumulation of extracellular-matrix-synthesizing cells in the glomerulus and tubulointerstitium. This population of myofibroblast-like cells (MFLC) is heterogeneous. It has been experimentally shown, for example, that tubular epithelial cells could change their phenotype into MFLC under certain circumstances, a process called epithelial-mesenchymal transdifferentiation. However, MFLC may also originate from other sources. Therefore, we examined whether endothelial cells (EDC) are able to transdifferentiate into MFLC in vitro. We compared potential differences between syngeneic tubular epithelial cells (EPC) and EDC during transdifferentiation into MFLC using bovine and porcine EDC isolated from pulmonary arteries, and glomerular capillaries. Renal tubular EPC were prepared from bovine renal cortical tissue by collagenase digestion and isolation from homogeneous cell monolayers. Bovine renal tubular EPC stained positive for cytokeratin. Furthermore, tubular EPC selectively incoporated labeled bovine serum albumin, a typical property of differentiated renal tubular cells. EDC were characterized by the absence of epithelial markers (e.g. cytokeratin), but stained positive for vWF. The transdifferentiation of EDC into MFLC occurs sequentially in two steps: First, by a rapid reversible transformation in postconfluent or clonal cultures without the need of cytokine stimulation and second, by a prolonged secondary step in the presence of the transformation-accelerating cytokines and the absence of adherently growing EDC. Thus, EDC that are able to sprout can also irreversibly transdifferentiate into MFLC. On the other hand, prolonged incubation of EPC in the presence of cytokines such as transforming growth factor-β1 and tumor necrosis factor-α leads only to a very small number of MFLC without the ability to further proliferate. Our in vitro data suggest that EDC can more easily transdifferentiate into MFLC than syngeneic renal tubular EPC.
Urinary S-100B Concentrations in Term and Preterm Infants at Risk for Brain Damage
Authors: Ruetzler Katharina , Bührer Christoph , Grimmer Ingrid , Müller Christian , Nagdyman Nicole , Obladen Michael
Published: December 2005

Background: Elevated serum concentrations of S-100B, a 21-kDa protein expressed in astroglial cells, has been used to assess cerebral damage after head trauma, infection, ischemia, and perinatal asphyxia. Objective: As S-100B is eliminated by the kidneys, we investigated the feasibility of measuring S-100B in urine of newborns with severe perinatal asphyxia, and in very low birth weight (VLBW) preterm infants at risk for neurodevelopmental impairment. Methods: We first analyzed urine samples of 8 term or near-term newborns without major medical problems, followed by urine samples of 2 term newborns with severe birth asphyxia, and finally urine samples of 8 VLBW (gestational age 24–28 weeks) infants collected every 4 h for up to 10 days. Results: Urinary S-100B concentrations in 8 term or near-term newborns without major medical problems were consistently <1 µg/l. In 2 term newborns with severe asphyxia (Apgar 0/0/0 and 0/2/4) who subsequently had widespread cerebral damage on magnetic resonance imaging, peak urinary S-100B concentrations on the first day of life were 28.1 and 28.4 µg/l, respectively. In 5/8 VLBW infants, urinary S-100B was >1 µg/l in samples obtained on the first day of life (range 1.2–44.9 µg/l, median 6.8 µg/l). Peak S-100B in urine samples collected during the first 12 h of life were negatively related to gestational age (Rs = –0.882, p = 0.009). Three of the 8 preterm infants had peak urinary concentrations >10 µg/l but neither ultrasound signs of brain damage nor neurodevelopmental delay at 1 year corrected age. Conclusions: The determination of urinary S-100B concentrations might be helpful in term infants with severe asphyxia, while high urinary S-100B concentrations in preterm infants are to be attributed to immaturity.
Islam and Secularization
Authors: Zubaida Sami
Published: December 2005

This article looks at the relationship of the religious and the secular from a historical perspective. Contrasting historical facts, including a traditional religious consciousness, and the political religious language of recent times, it is shown that there is no natural given boundary separating the two dimensions. Instead, the whole discussion derives from an advanced state of a secular mind. In nineteenth and the twentieth century thought in institutions in the Middle East, for example, in the fields of law, education, administration and mass culture, there was experienced an irreversible process of change towards secularity. This process was facilitated by the co-existence and intersection of the religious and the secular. The dichotomy of the religious and the secular emerged within popularized fundamentalism, which itself has to be seen as a fruit of the secularization process encouraging religion to turn into a matter of politics and "social engineering".
Negotiating Identity in Malaysia: Multi-Cultural Society, Islam, Theatre and Tourism
Authors: Yaapar Salleh
Published: December 2005

Identity is something quite stable but is also malleable and flexible. Although it is often defended, it is also continuously contested and negotiated. This is even more so for communities in multi-ethnic, multi-cultural countries emerging from colonial experiences. This essay will focus on the negotiation of identity in Malaysia, involving historical and present-day relations between the Malay-Muslim majority and the rest of the citizens of the country. The discussion will be made with specific reference to Islam, multi-cultural society, literature/theatre and tourism. It will show that up to the present, national identity, as more or less an assemblage of a set of markers and values, is still an elusive notion. It is still being negotiated in different domains of life, including literature, theatre and tourism, and probably will continue to be negotiated for sometime to come. The process of negotiation is a painful one. Negotiation among ethnic groups requires a degree of openness and tolerance. It involves the authorities on the one hand, and the people of various ethnic groups on the other in the difficult search for a commonly accepted parameter or basic constituents.
Making Sense of the Plural-Religious Past and the Modern-Secular Present of the Islamic Malay World and Malaysia
Authors:   Shamsul
Published: December 2005

This essay is a brief survey of some fundamental aspects of Islam and Muslims in the Islamic Malay world and Malaysia. Ethnic, linguistic and cultural variation is the norm in the region. In addition, the region is heir to Hindu and Buddhist traditions and also to three European colonial systems of government and administration (Portuguese, Dutch and British). Islam is but one among these. In some aspects of life it has been considerably reformulated by them. Thus, to understand Islam in the Malay world and Malaysia, one must begin with data from the area rather than with some Middle Eastern and theological formulations of Islam. Yet, we have to recognize that Islam is a universal theology originating from the Arabic Middle East. Therefore, a more informed analysis and understanding of Islam and Muslims in the Malay world, Malaysia and in their contemporary articulations must be "embedded" in the historical reality of both the plurality and plural society templates that have become the "moulds" of current secular modern social life in the region.
The Construction and Deconstruction of Secularism as an Ideology in Contemporary Muslim Thought
Authors: Masud Muhammad Khalid
Published: December 2005

This article starts with a sketch of the encounters and experiences of modern secularism in four areas of the Islamic world (Turkey, Arab world, South Asia and Southeast Asia); these point to the diverse conditions and constructions that have become central issues of regional and trans-regional discourse: laizism through reform, nationalism through decolonization, Islamic nationalism through state formation, and tolerance through traditional multi-ethnic environments. In analysing the basic writings of five exemplary modern Muslim thinkers, it is shown that modern Islamic thought, tied to the idea of mutual exclusive ideological constructions of secularism and Islamism, remains ambiguous while at the same time facing the factual unfolding of secularism in Muslim countries: the works of Mawdudi contain absolute denial of secularism; al-Qaradawi argues for the strict opposition and separation of the secular and the religious; al-Attas denies that Western processes of religious secularization are applicable to the development of Islam. On the other hand, Iqbal and Rahman, although maintaining a clear distinction between the secular and the religious, point to coinciding dimensions of religious and secular dimensions in modern political and social life. The reflection of the secular and the religious is highly shaped by historical and political influences as well as by ideologization, thus creating obstacles for fruitful conceptual reconstructions of the given dimensions of the coincidence of both — Islam and the secular conditions of modern society.
The Blind Eye and the Strong Arm: The Colonial Archive and the Imbrication of Knowledge and Power in Mid-Nineteenth Century Java
Authors: Knight G. Roger
Published: December 2005

The argument of this paper relates to on-going debates about the acquisition of knowledge and the enhancement of power in the context of European empire building during the nineteenth and early twentieth centuries. It seeks to locate these debates in the specific context of the Netherlands Indies and its key island of Java in the middle decades of the nineteenth century, at a time when the Dutch colonial power attempted a major fact-finding investigation of the island's sugar industry, and of the social and economic circumstances of "peasant" Java, in which colonial sugar manufacturers operated. It argues that in this particular instance, the attempt to assemble colonial knowledge exposed the potentially counter-productive aspects of such projects. It highlights the limitations of colonial knowledge implicit in the institutional structure of colonial power, and the extent to which, in the circumstances of mid-nineteenth century Java, the blind eye was the necessary corollary of the strong arm. This was because power rested on a carefully and consciously circumscribed quest for knowledge, which might easily be upset by too keen an investigation of the social and economic circumstances of the countryside.
The Euro-Islamic Roots of Secularity: A Difficult Equation
Authors: Salvatore Armando
Published: December 2005

This article probes into the issue of secularity as a main node of the historic construction of modern power and the modern state in Europe. It builds an interpretative arch ranging from the Spanish Reconquista, stretching through the European Wars of Religion and the resistance to the "Turkish Threat" of the encroaching Ottoman armies, and reaching into the contemporary predicament of the presence of a growing population of Muslim background in the key states of Western Europe, notably those involved in the Reconquista, the resistance to the "Turkish Threat", and in the Wars of Religion. The analysis matches the interpretation of these historical traumata with philosophical and sociological reflections, from Spinoza and Vico to Asad and Casanova. The conclusions point to the inherent ambivalence and arbitrary character of the modern secular distinction between religion and politics. They suggest that the philosophical utopia of secularity is still an open issue for the European states and that the growing presence of Islam in Europe helps give evidence of the limits of the secular arrangements reigning in the continent thus far.