bluuebunny/crossref_metadata_2025 huggingface dataset:
Comments on “Incremental Construction and Maintenance of Minimal Finite-State Automata,” by Rafael C. Carrasco and Mikel L. Forcada
Authors: Daciuk Jan
Published: May 2004

In a recent article, Carrasco and Forcada (June 2002) presented two algorithms: one for incremental addition of strings to the language of a minimal, deterministic, cyclic automaton, and one for incremental removal of strings from the automaton. The first algorithm is a generalization of the “algorithm for unsorted data”—the second of the two incremental algorithms for construction of minimal, deterministic, acyclic automata presented in Daciuk et al. (2000). We show that the other algorithm in the older article—the “algorithm for sorted data”—can be generalized in a similar way. The new algorithm is faster than the algorithm for addition of strings presented in Carrasco and Forcada's article, as it handles each state only once.
Neural Network Classifiers for Local Wind Prediction
Authors: Kretzschmar Ralf , Eckert Pierre , Cattani Daniel , Eggimann Fritz
Published: May 2004

This paper evaluates the quality of neural network classifiers for wind speed and wind gust prediction with prediction lead times between +1 and +24 h. The predictions were realized based on local time series and model data. The selection of appropriate input features was initiated by time series analysis and completed by empirical comparison of neural network classifiers trained on several choices of input features. The selected input features involved day time, yearday, features from a single wind observation device at the site of interest, and features derived from model data. The quality of the resulting classifiers was benchmarked against persistence for two different sites in Switzerland. The neural network classifiers exhibited superior quality when compared with persistence judged on a specific performance measure, hit and false-alarm rates.
Minimum Local Emissivity Variance Retrieval of Cloud Altitude and Effective Spectral Emissivity—Simulation and Initial Verification
Authors: Huang Hung-Lung , Smith William L. , Li Jun , Antonelli Paolo , Wu Xiangqian , Knuteson Robert O. , Huang Bormin , Osborne Brian J.
Published: May 2004

This paper describes the theory and application of the minimum local emissivity variance (MLEV) technique for simultaneous retrieval of cloud pressure level and effective spectral emissivity from high-spectral-resolution radiances, for the case of single-layer clouds. This technique, which has become feasible only with the recent development of high-spectral-resolution satellite and airborne instruments, is shown to provide reliable cloud spectral emissivity and pressure level under a wide range of atmospheric conditions. The MLEV algorithm uses a physical approach in which the local variances of spectral cloud emissivity are calculated for a number of assumed or first-guess cloud pressure levels. The optimal solution for the single-layer cloud emissivity spectrum is that having the “minimum local emissivity variance” among the retrieved emissivity spectra associated with different first-guess cloud pressure levels. This is due to the fact that the absorption, reflection, and scattering processes of clouds exhibit relatively limited localized spectral emissivity structure in the infrared 10–15-μm longwave region. In this simulation study it is shown that the MLEV cloud pressure root-mean-square errors for a single level with effective cloud emissivity greater than 0.1 are ∼30, ∼10, and ∼50 hPa, for high (200– 300 hPa), middle (500 hPa), and low (850 hPa) clouds, respectively. The associated cloud emissivity root-mean-square errors in the 900 cm−1 spectral channel are less than 0.05, 0.04, and 0.25 for high, middle, and low clouds, respectively.
Can Satellite Sampling of Offshore Wind Speeds Realistically Represent Wind Speed Distributions? Part II: Quantifying Uncertainties Associated with Distribution Fitting Methods
Authors: Pryor S. C. , Nielsen M. , Barthelmie R. J. , Mann J.
Published: May 2004

Remote sensing tools represent an attractive proposition for measuring wind speeds over the oceans because, in principle, they also offer a mechanism for determining the spatial variability of flow. Presented here is the continuation of research focused on the uncertainties and biases currently present in these data and quantification of the number of independent observations (scenes) required to characterize various parameters of the probability distribution of wind speeds. Theoretical and empirical estimates are derived of the critical number of independent observations (wind speeds derived from analysis of remotely sensed scenes) required to obtain probability distribution parameters with an uncertainty of ±10% and a confidence level of 90% under the assumption of independent samples, and it is found that approximately 250 independent observations are required to fit the Weibull distribution parameters. Also presented is an evaluation of Weibull fitting methods and determination of the fitting method based on the first and third moments to exhibit the “best” performance for pure Weibull distributions. Further examined is the ability to generalize parameter uncertainty bounds presented previously by Barthelmie and Pryor for distribution parameter estimates from sparse datasets; these were found to be robust and hence generally applicable to remotely sensed wind speed data series.
Daytime Cloud Overlap Detection from AVHRR and VIIRS
Authors: Pavolonis Michael J. , Heidinger Andrew K.
Published: May 2004

Two algorithms for detecting multilayered cloud systems with satellite data are presented. The first algorithm utilizes data in the 0.65-, 11-, and 12-μm regions of the spectrum that are available on the Advanced Very High Resolution Radiometer (AVHRR). The second algorithm incorporates two different techniques to detect cloud overlap: the same technique used in the first algorithm and an additional series of spectral tests that now include data from the 1.38- and 1.65-μm near-infrared regions that are available on the Moderate Resolution Imaging Spectroradiometer (MODIS) and will be available on the Visible/Infrared Imager/Radiometer Suite (VIIRS). VIIRS is the imager that will replace the AVHRR on the next generation of polar-orbiting satellites. Both algorithms were derived assuming that a scene with cloud overlap consists of a semitransparent ice cloud that overlaps a cloud composed of liquid water droplets. Each algorithm was tested on three different MODIS scenes. In all three cases, the second (VIIRS) algorithm was able to detect more cloud overlap than the first (AVHRR) algorithm. Radiative transfer calculations indicate that the VIIRS algorithm will be more effective than the AVHRR algorithm when the visible optical depth of the ice cloud is greater than 3. Both algorithms will work best when the visible optical depth of the water cloud is greater than 5. Model sensitivity studies were also performed to assess the sensitivity of each algorithm to various parameters. It was found that the AVHRR algorithm is most sensitive to cloud particle size and the VIIRS near-infrared test is most sensitive to cloud vertical location. When validating each algorithm using cloud radar data, the VIIRS algorithm was shown to be more effective at detecting cloud overlap than the AVHRR algorithm; however, the VIIRS algorithm was slightly more prone to false cloud overlap detection.
A Probabilistic Model to Evaluate the Optimal Density of Stations Measuring Snowfall
Authors: Schneebeli Martin , Laternser Martin
Published: May 2004

Daily new snow measurements are very important for avalanche forecasting and tourism. A dense network of manual or automatic stations measuring snowfall is necessary to have spatially reliable data. Snow stations in Switzerland were built at partially subjective locations. A probabilistic model based on the frequency and spatial extent of areas covered by heavy snowfalls was developed to quantify the probability that snowfall events are measured by the stations. Area–probability relations were calculated for different thresholds of daily accumulated snowfall. A probabilistic model, including autocorrelation, was used to calculate the optimal spacing of stations based on simulated triangular grids and to compare the capture probability of different networks and snowfall thresholds. The Swiss operational snow-stations network captured snowfall events with high probability, but the distribution of the stations could be optimized. The spatial variability increased with higher thresholds of daily accumulated snowfall, and the capture probability decreased with increasing thresholds. The method can be used for other areas where the area–probability relation for threshold values of snow or rain can be calculated.
Microphysical Characteristics of Tropical Updrafts in Clean Conditions
Authors: Stith Jeffrey L. , Haggerty Julie A. , Heymsfield Andrew , Grainger Cedric A.
Published: May 2004

The distributions of ice particles, precipitation embryos, and supercooled water are examined within updrafts in convective clouds in the Amazon and at Kwajalein, Marshall Islands, based on in situ measurements during two Tropical Rainfall Measuring Mission field campaigns. Composite vertical profiles of liquid water, small particle concentration, and updraft/downdraft magnitudes exhibit similar peak values for the two tropical regions. Updrafts were found to be favored locations for precipitation embryos in the form of liquid or frozen drizzle-sized droplets. Most updrafts glaciated rapidly, removing most of the liquid water between −5° and −17°C. However, occasional encounters with liquid water occurred in much colder updraft regions. The updraft magnitudes where liquid water was observed at cold (e.g., −16° to −19°C) temperatures do not appear to be stronger than updrafts without liquid water at similar temperatures, however. The concentrations of small spherical frozen particles in glaciated regions without liquid water are approximately one-half of the concentrations in regions containing liquid cloud droplets, suggesting that a substantial portion of the cloud droplets may be freezing at relatively warm temperatures. Further evidence for a possible new type of aggregate ice particle, a chain aggregate found at cloud midlevels, is given.
Performance of six severity-of-illness scores in cancer patients requiring admission to the intensive care unit: a prospective observational study
Authors: Soares Márcio , Fontes Flávia , Dantas Joana , Gadelha Daniela , Cariello Paloma , Nardes Flávia , Amorim César , Toscano Luisa , Rocco José R
Published: May 2004

Introduction

The aim of this study was to evaluate the performance of five general severity-of-illness scores (Acute Physiology and Chronic Health Evaluation II and III-J, the Simplified Acute Physiology Score II, and the Mortality Probability Models at admission and at 24 hours of intensive care unit [ICU] stay), and to validate a specific score – the ICU Cancer Mortality Model (CMM) – in cancer patients requiring admission to the ICU.

Methods

A prospective observational cohort study was performed in an oncological medical/surgical ICU in a Brazilian cancer centre. Data were collected over the first 24 hours of ICU stay. Discrimination was assessed by area under the receiver operating characteristic curves and calibration was done using Hosmer–Lemeshow goodness-of-fit H-tests.

Results

A total of 1257 consecutive patients were included over a 39-month period, and 715 (56.9%) were scheduled surgical patients. The observed hospital mortality was 28.6%. Two performance analyses were carried out: in the first analysis all patients were studied; and in the second, scheduled surgical patients were excluded in order to better compare CMM and general prognostic scores. The results of the two analyses were similar. Discrimination was good for all of the six studied models and best for Simplified Acute Physiology Score II and Acute Physiology and Chronic Health Evaluation III-J. However, calibration was uniformly insufficient (P < 0.001). General scores significantly underestimated mortality (in comparison with the observed mortality); this was in contrast to the CMM, which tended to overestimate mortality.

Conclusion

None of the model scores accurately predicted outcome in the present group of critically ill cancer patients. In addition, there was no advantage of CMM over the other general models.
Two‐ and three‐dimensional electrical resistivity imaging at a heterogeneous remediation site
Authors: Bentley Laurence R. , Gharibi Mehran
Published: May 2004

Geometrically complex heterogeneities at a decommissioned sour gas plant could not be adequately characterized with drilling and 2D electrical resistivity surveys alone. In addition, 2D electrical resistivity imaging profiles produced misleading images as a result of out‐of‐plane resistivity anomalies and violation of the 2D assumption. Accurate amplitude and positioning of electrical conductivity anomalies associated with the subsurface geochemical distribution were required to effectively analyze remediation alternatives. Forward and inverse modeling and field examples demonstrated that 3D resistivity images were needed to properly reconstruct the amplitude and geometry of the complex resistivity anomalies. Problematic 3D artifacts in 2D images led to poor inversion fits and spurious conductivity values in the images at depths close to the horizontal offset of the off‐line anomaly. Three‐dimensional surveys were conducted with orthogonal sets of Wenner and dipole–dipole 2D resistivity survey lines. The 3D inversions were used to locate source zones and zones of elevated ammonium. Thus, conducting 3D electrical resistivity imaging (ERI) surveys early in the site characterization process will improve cost effectiveness at many remediation sites.
An amplitude-based multiazimuthal approach to mapping fractures using P-wave 3D seismic data
Authors: Luo Mu , Evans Brian J.
Published: May 2004

We have tested an amplitude-based multiazimuthal approach for mapping fractures which requires only a simple azimuth-offset sorting process. By displaying the amplitudes of all traces collected within a superbin, the method predicts fractures by mapping P-wave amplitude variations, in which a lineation within the map indicates the presence and the orientation of fractures within the superbin. Test results using physical model and field data sets suggest that the amplitude-based multiazimuthal approach could help to determine the presence of multiple fracture sets in a single layer, which may be expressed through subtle variations in P-wave multiazimuthal seismic reflections. Our experiments with a physical model containing manmade vertical fractures suggest that transmission effects could be one of the dominant factors which control azimuthal amplitude versus offset (AVO) behavior.

The technique described in this paper can operate on any 3D P-wave seismic data with wide azimuth and offset distributions.
Induced polarization measurements on unsaturated, unconsolidated sands
Authors: Ulrich Craig , Slater Lee
Published: May 2004

Induced polarization (IP) measurements were obtained on unsaturated, unconsolidated sediments during (1) evaporative drying and (2) pressure drainage followed by subsequent imbibition (water reentry). Porous ceramic discs were used with existing laboratory IP instrumentation to permit accurate IP measurements on unsaturated samples. Polarization magnitude during evaporative drying approximates a power law dependence on saturation. Saturation exponents for the polarization term were consistently less than Archie conduction exponents, although no clear relationship between the exponents was observed. The polarization measured over a pressure drainage and imbibition cycle exhibits a complex (yet similar between tested samples) saturation dependence, being a function of saturation range and saturation history. Polarization is observed to increase with saturation over certain saturation intervals, yet decrease with saturation over others. High polarization observed during sample imbibition is consistent with a model for the development of a continuous charged air‐fluid interface as previously proposed to explain hysteresis in resistivity measurements. The saturation dependence of the phase angle measured in IP in large part results from changes in conduction as pores fill and drain. Models of low‐frequency polarization based on grain‐size‐controlled and pore‐size‐controlled relaxation both support dependence of IP measurements on saturation. Our results suggest that saturation dependent polarization must be considered for effective interpretation of IP measurements from the vadose zone.
Accurate spatial directional derivative: Antialiasing Kirchhoff migration
Authors: Wang Chengshu
Published: May 2004

Applying a low‐pass filter to each input trace before performing migration is a common antialiasing method used in Kirchhoff 3D migration. The spatial directional derivative that gives the tangent plane direction of the reflector is key in determining the antialiasing frequency limits. In this paper, we present the formula of the traveltime gradient for the diffraction hyperboloid. We also deduce the formula of the vertical traveltime gradient for the reflection ellipsoid, which can be used to construct the antialiasing low‐pass filter after migration. The migration stretch is easily computed from the ratio of gradient expressions obtained for the reflection ellipsoid and the diffraction hyperboloid.

The gradient formula includes magnitude and direction. The correct direction of the gradient function is from an image point to the dip‐moveout image point (ρ* direction) on the surface. The gradient is not in the direction from the image point to the midpoint (ρ direction) as has been previously concluded. The correct spatial directional derivative along ρ is given, and it is slightly less than the gradient norm. We also prove that the true direction of the tangent plane on the reflection ellipsoid can be determined by the gradient.

We introduce the directional derivative value along ρ that can be approximately applied to calculate the high‐frequency limit. Compared with the maximum directional derivative value (gradient norm), the directional derivative is relatively accurate and is much easier to calculate for use in antialiasing. The different results from the new method and the former method are compared. Numerical examples compare the performance of the different formulae.
High‐quality compression of MWD signals
Authors: Bernasconi Giancarlo , Rampa Vittorio
Published: May 2004

Measurement‐while‐drilling (MWD) services efficiently support drilling decisions and are emerging as a powerful option on well sites. Presently, the main drawbacks of MWD equipment are the low data bandwidth of standard telemetry systems (up to 10 bits/s), and the high cost of storage memory in the downhole tool. Both these limitations can be reduced using data compression. We investigate the application of a lossy compression algorithm based on the wavelet transform to data recorded downhole while drilling. The user can select the maximum level of noise in the reconstructed signal; the compression ratio is adapted automatically. Numerical tests based on real field data achieve compression ratios up to 15:1 without noticeable signal degradation. This allows a significant increase in downhole acquisition time and in real‐time information transmission rate through the telemetry system. We present signal‐quality indicators to analyze the performance of the compression. The algorithm is simple enough to be embedded in current‐generation downhole equipment without major modifications. This implementation can also be achieved using specialized hardware, lowering the computational requirements and synchronization issues of the downhole main controller.
Predictive value of autoantibodies for activity of systemic lupus erythematosus
Authors: Reveille J D
Published: May 2004

There is no serologic test that reliably measures disease activity in systemic lupus erythematosus (SLE). The ‘gold standard’ is the anti-dsDNA antibody test, which has been used as a marker of disease activity by clinicians in SLE for over 35 years. Anti-dsDNA antibodies perform best in those with lupus nephritis, specifically in the presence of a proliferative lesion [World Health Organization (WHO) class III or IV] on renal biopsy. In one recent meta-analysis, the mean positivelikelihood ratio of anti-dsDNA antibodies as a marker of disease activity in SLE was 4.14, implying the overall predictive effect was small. More recently autoantibodyassays have been developed that show greater promise in gauging SLE disease activity, specifically anti-nucleosome and anti-C1q antibodies (especially with renal disease activity). Other tests thought previously to be lacking in specificity that refinements in ELISA technology now render possibly useful include anti-heparan sulfate, anti-ssDNA and anti-Scl-70 autoantibodies. Other tests that as yet have not been shown to be as reliable (and therefore are not as useful in clinical practice for serial determinationto measure disease activity) include other anti-extractablenuclear antibodies (anti-Ro, La, Sm, RNP), anti-cardiolipinantibodies, and anti-nuclear cytoplasmic antibodies (ANCA). New technologies using proteomic determinations show promise as aids in the search for more reliable and feasible autoantibody determinations of disease activity in SLE.
Inhibition of terminal complement: a novel therapeutic approach for the treatment of systemic lupus erythematosus
Authors: Rother R P , Mojcik C F , McCroskery E W
Published: May 2004

The importance of the complement system in the pathophysiology of systemic lupus erythematosus (SLE) is clear although individual complement components play very different roles in the disease process. Early complement proteins are critical in the clearance of immune complexes and apoptotic bodies, and their absencepredisposesindividualsto SLE. Conversely, activationof terminalcomplement is associated with exacerbations of disease and damage to tissues and organs, particularly in lupus nephritis. Monoclonal antibodies that specifically inhibit terminal complement activation while preserving the critical functions of the early complement cascade have now been developed. These antibodies target the C5 complement protein, blocking its cleavage and the subsequent generation of potent proinflammatory molecules. Anti-C5 therapeutics have recently been investigated in an animal model of SLE and in a Phase I single dose study in humans. The results of these studiesand the multiple roles of complement in SLE are discussed.
Tumour necrosis factor and other proinflammatory cytokines in systemic lupus erythematosus: a rationale for therapeutic intervention
Authors: Aringer M , Smolen J S
Published: May 2004

Systemic lupus erythematosus (SLE) is an autoantibody and immune complex mediated disease. However, it is the ensuing inflammatory process that leads to irreversibleorgandamage. In fact several murine models of SLE suggest that this inflammatory organ damage can be prevented even in the presence of autoantibodies. Given data from experimental models as well as from patients, proinflammatory cytokinesincluding tumour necrosis factor (TNF) alpha apparentlyplay a significant role in the inflammatory process, but may have immunoregulatory functions at the same time. Therefore, anti-TNF alpha therapy may constitute an interesting candidate approach for treating SLE inflammatory organ disease, but potentially at the cost of increased autoantibody formation. Clinical trials will be required to answer whether TNF alpha blockade fulfils this hope with an acceptable safety profile. Interferon (IFN)-g, interleukin(IL)-18, IL-6 and possiblyIL-1 are increasedin SLE and likewise involved in the inflammatory process. Specific therapeutic agents for blocking these cytokines should be available in the near future.
Cyclophosphamide: new approaches for systemic lupus erythematosus
Authors: Petri M
Published: May 2004

Cyclophosphamideremains the ‘gold standard’treatment for severe organ threatening systemic lupus erythematosus (SLE), especially renal and central nervous system lupus. Intravenous and oral cyclophosphamide have been compared, retrospectively, with similar two year remission rates of 73% and 90%.1 In a meta-analysis, intravenous cyclophosphamide with oral prednisone is more effective than oral prednisone alone.2 The efficacy of cyclophosphamidein lupus nephritis has been proven in multiple clinical trials, but efficacy has to be balanced with toxicity, including infection, gonadalfailure, and malignancy. Although the continued use of cyclophosphamidefor renal lupus has been challenged by a recent trial of mycophenolate mofetil, and may be challenged in the future by planned trials of biologics, it continues to be widely used. This review will touch on the traditional intravenous ‘pulse’ cyclophosphamide regimen, consider its toxicity, and contrast it with newer approaches to cyclophosphamide.
CTLA4Ig: a novel inhibitor of costimulation
Authors: Dall’Era M , Davis J
Published: May 2004

T cell costimulatory pathways are believed to play important roles in the pathogenesis of various autoimmune diseases including systemic lupus erythematosus(SLE). Animal models of SLE support the role of T cell costimulation in B cell activation and the production of autoantibodies. CTLA4Ig is a novel fusion protein that interferes with T cell costimulation by inhibiting the CD28-B7 interaction. A pivotal study demonstrated the ability of CTLA4Ig to suppress the production of anti-dsDNA antibodies and decrease nephritisin lupus prone mice. In an additionalstudy, the combination of CTLA4Ig and cyclophosphamidesignificantly reduced proteinuria and prolonged survival in mice with advanced nephritis. In small human studies of psoriasis and rheumatoid arthritis, CTLA4Ig improved clinical outcomes and was well tolerated. These promising experienceswith CTLA4Ig have paved the way for future studies in human SLE.
Correlation of circulating CD27high plasma cells and disease activity in systemic lupus erythematosus
Authors: Dörner T , Lipsky P E
Published: May 2004

CD27 is a useful marker in assessing the number of circulating B cells and B cell subsets because it permits one step identification of the major B cell compartments, CD27- naïve and CD27+ memory B cells as well as CD27high plasma cells. Abnormalities in the distributionof CD27+ B cell subsets are useful in assessing disease activity in patients with systemic lupus erythematosus(SLE). In particular, the frequencyof CD27high plasma cells significantly correlates with lupus activity in both children and adults with SLE. Conventional immunosuppressive therapies affect the number of CD27- naive B cells and CD27high plasma cells, but do not target CD27+ memory B cells. These results suggest that disease flares may relate to the retention of CD27+ memory B cells after conventional immunosuppressive therapy and that new therapies that target these cells specifically may offer new opportunities to induce remission in SLE.
Does B cell depletion have a role to play in the treatment of systemic lupus erythematosus?
Authors: Gorman C , Leandro M , Isenberg D
Published: May 2004

B cell dysfunctionand pathogenicautoantibodyformationare thoughtto be criticalin the pathogenesis of systemic lupus erythematosus (SLE). In this review we will summarize the results of attempts to utilize B cell depletion, based on the use of a chimeric monoclonalantibody(MAb) specific for human CD20, rituximab, for the treatment of patients with SLE.
A therapeutic role for BLyS antagonists
Authors: Stohl W
Published: May 2004

B lymphocytestimulator (BLyS) is a vital B cell survivalfactor. Overexpressionof BLyS in mice may lead to systemic lupus erythematosus (SLE)-like disease, and treatment of bona fide SLE mice with BLyS antagonists ameliorates disease progression and enhances survival. BLyS overexpression is common in human SLE, and results from a phase I clinical trial with a BLyS antagonistin human SLE have shown the antagonist to be biologicallyactive and safe. These features collectivelypoint to BLyS as an attractive therapeutic target in human disease.
Targeting interferon-α: a promising approach for systemic lupus erythematosus therapy
Authors: Schmidt K N , Ouyang W
Published: May 2004

System lupus erythematosus (SLE) is an autoimmune disease with multicellular pathogeneic components.Recent studiessuggestan importantrole for interferon-a (IFN) in the immunopathogenesis of SLE. Data demonstrating a correlationbetween IFN-a and SLE disease severity range from elevated IFN-a levels in patients’serum and induction of IFN-regulated genes in peripheral blood mononuclear cells, to drug induced lupus disease in hepatitis C or cancer patients treated with recombinant IFN-a. In addition, mouse models of lupus in which the IFNR is deleted fail to develop disease manifestations. Thus, targetingIFN-a promises to be therapeuticallyefficacious for SLE.
The role of CD40 ligand in systemic lupus erythematosus
Authors: Yazdany J , Davis J
Published: May 2004

CD40 ligand (CD40L, also known as CD154 or gp39) is a member of the tumor necrosis superfamily of transmembrane proteins. The interaction of CD40L on activated T cells with its receptor, CD40 on B cells, is necessary for normal immune function, including B cell differentiation, germinal center formation, and antibody isotype switching. Abnormal expressionof CD40L in patients with systemic lupus erythematosus (SLE) may contribute to autoantibody production and disease pathogenesis. Although murine models of monoclonal antibodies directed against CD40L initially showed promise, human trials either have failed to demonstrate efficacy or have been associated with adverse events. This review will summarize in vitro and murine model data and human clinical trials involving anti-CD40L monoclonal antibody.
B lymphocytes in systemic lupus erythematosus: lessons from therapy targeting B cells
Authors: Looney R J , Anolik J , Sanz I
Published: May 2004

Systemic lupus erythematosus (SLE) is a complex disease characterizedby numerous autoantibodies and clinical involvement in multiple organ systems. Autoantibodies are usually present in serum for years before the onset of clinical disease. Autoimmunity begins with a limited number of autoantibodiesand evolves to become progressivelymore diverse. Eventually clinical disease ensues. The immunological events triggering the onset of clinical manifestations have not yet been defined. While undoubtedly T cells and dendritic cells appear to play major roles in SLE, a central role for B cells in the pathogenesis of this disease has been brought to the fore in the last few years by work performed both in mice and humans by multiple laboratories.As a result, there is little doubt about the importance of B cells in the development of SLE. Yet much remains to be learned about their role in the ongoing disease process and the merit of targeting B cells for the treatment of SLE. This article will review the role of B cells in human SLE as well as the currently available data on the treatment of SLE by depleting B cells with anti-CD20 (rituximab).
Liquefaction Testing of Layered Sand-Gravel Composites
Authors: Amini F , Chakravrty A
Published: May 2004

The liquefaction characteristics of stratified sand-gravel composites are currently poorly understood, yet these materials are often encountered in alluvial and hydraulic fill deposits. To investigate the effect of soil layering on the cyclic resistance of sand-gravel composites, a research program was undertaken in which a series of undrained cyclic triaxial tests was performed on both uniform and layered sand-gravel composite specimens with gravel contents of 10, 30, 50, and 70%. Two methods of sample preparation were used for each soil type. These methods included pluviation through air (representing homogeneous soil conditions) and wet pluviation (representing layered soil conditions). The confining pressures ranged from 50 to 250 KPa. The results indicated that the method of sample preparation and the different soil fabric did not significantly influence the liquefaction resistance of the sand-gravel composites. It is also shown that the effects of confining pressure are similar for both homogeneous and layered soil conditions.
Reduction of Boundary Friction in Model Tests
Authors: Fang YS , Chen T-J , Holtz RD , Lee WF
Published: May 2004

To model plane-strain conditions in the laboratory, the frictional resistance between the soil and side walls of the soil box should be reduced as much as possible. Methods commonly employed for this purpose include a latex sheet with silicon grease (“grease method”) or multiple layers of thin plastic sheeting (“plastic sheet method”). Interface friction angles are often measured by direct shear-type tests.

In this paper, a new sliding block testing device for measuring the friction at the interface between soil and different materials at low stress conditions is described. Interface friction angles for eight different methods for reducing boundary friction were investigated using the proposed testing method. Test results indicated that the friction angle obtained with the plastic sheet method is nearly independent of the normal stress. On the other hand, the interface friction angle of the grease method was quite high under low normal stress conditions. Thus, the plastic sheet method appears to be a more appropriate technique under low normal stress conditions to reduce the boundary friction for laboratory scale model tests. As compared with the grease method, advantages of the plastic sheet method include constant friction angles, less time for preparation and cleanup, and lower cost.

To investigate their applicability, both lubrication systems were used in some large-scale laboratory-retaining wall experiments. Earth pressure measurements obtained near the sidewalls indicated that, under a low normal stress, the plastic sheet method was more effective in reducing sidewall friction.
Free Swell Ratio and Clay Mineralogy of Fine-Grained Soils
Authors: Prakash K , Sridharan A
Published: May 2004

The dominant clay minerals present in fine-grained soils control the physical and engineering behavior of the soils. Determination of the dominant clay minerals in the soils, at present, requires procedures involving sophisticated instrumentation and the knowledge to interpret the results from such tests. A user-friendly approach based on free swell ratio, defined as the ratio of the equilibrium sediment volume of 10-g oven dried soil in distilled water to that in carbon tetra chloride, has emerged as a simple methodology to predict the clay mineral(s) present in the soil as either montmorillonitic or kaolinitic type quite satisfactorily. The validation of the proposed free swell ratio method has been done with exhaustive experimental data.
Determination of the Diffusion Coefficient of Oxygen for a Cover System Including a Pulp and Paper By-Product
Authors: Cabral AR , Tremblay P , Lefebvre G
Published: May 2004

Among the several solutions that have been proposed to curb the problem posed by the generation of acid rock drainage (ARD), the placement of covers with capillary barrier effect (CCBE) has received particular attention. With the creation of a capillary barrier, oxygen has to migrate through a nearly saturated layer, a much slower process than in air. As a consequence, its availability is drastically reduced, reducing ARD generation. An experimental procedure was developed to obtain the diffusion coefficient of oxygen through compacted deinking residues, an organic matter-rich by-product of paper recycling. With the oxygen concentrations obtained as a function of time, it was possible to deduce the diffusion coefficients based on the best reproductions of laboratory results, using the computer code POLLUTE v.6. As expected, it was found that the diffusion coefficient—and the associated flux—is highly influenced by the degree of saturation of the sample. Beyond a threshold in the vicinity of 85%, a one order of magnitude drop in the diffusion coefficient was observed. A comparison of the results obtained with previously published data shows that deinking residues constitute a very effective oxygen barrier material due both to its ability to maintain a high degree of saturation and to rapidly consume oxygen. Given the latter, special care was needed in defining the most appropriate equipment design, sample preparation method, and testing procedure.
Granular Pile Anchor Foundation (GPAF) System for Improving the Engineering Behavior of Expansive Clay Beds
Authors: Phanikumar BR , Sharma RS , Srirama Rao A , Madhav MR
Published: May 2004

Several innovative foundation techniques have been suggested for reducing the detrimental heave of foundations in expansive clays. This paper presents another innovative technique in the form of a granular pile anchor-foundation (GPAF) system for arresting heave and for improving the overall engineering behavior of expansive clay beds. In the GPAF system, the foundation is anchored at the bottom of the granular pile to an anchor plate through an anchor rod. As a result, heave of the foundation is reduced. The laboratory model tests using this new concept of the GPAF system revealed that the heave of the expansive clay beds was reduced by about 96 %. The development of final heave was faster in the case of the expansive clay beds reinforced with the GPAF system. The undrained strength of the clay surrounding the granular pile anchor improved by about 20 %. The tests on two-group granular pile anchors indicated that heave was reduced to a minimum value when the spacing between the granular pile anchors was kept at twice the pile diameter. The compressive load response of the expansive clay bed reinforced with granular pile anchors also improved. The pull-out load of the granular pile anchors increased with increasing diameter and the relative density of the pile.
Design of a Measurement Program for a Bench-Scale PVD Remediation System using Bayesian Updating
Authors: Welker AL , Gilbert RB
Published: May 2004

Two experiments were undertaken to study the effectiveness of a remediation system that utilizes prefabricated vertical drains. The measurement program, which included obtaining head and concentration measurements for these experiments, was designed using a Bayesian decision framework. The First-Order Second-Moment Bayesian method was employed to select the best location for the observation wells as well as when to take the measurements and how long the experiment should last. The selected measurementscheme balanced the reduction in uncertainty realized through taking the head and concentration measurements with the difficulty in obtaining those measurements.
A Flume for Assessing Flux Boundary Characteristics in Rainfall-Induced Slope Failure Studies
Authors: Rahardjo H , Lee TT , Leong EC , Rezaur RB
Published: May 2004

Rainfall-induced slope failure studies and slope hydrological behavior studies often require an assessment of the flux boundary characteristics of a slope. However, quantification of the flux boundary conditions across a slope surface with respect to rainfall, runoff, and infiltration is difficult. This paper introduces the design and field installation of a flume for high resolution monitoring of runoff data from a small catchment, particularly for rainfall-induced slope failure studies. The features of the flume include reliable and continuous runoff measurement at high resolution, options for accommodating various flow rates as dictated by the slope size, and portability. The flume can be used to quantify the flux boundary conditions required for seepage analyses associated with rainfall-induced slope failure studies.
Use of “Zero Controlled Gradient” Tests to Determine EOP Compression Behavior
Authors: Sheahan TC , DeGroot DJ , Fu Q , Ryan RM
Published: May 2004

This paper describes the use of a new consolidation testing method, known as the “zero controlled gradient” (zero CG) test, to measure the one-dimensional (1-D), end-of-primary (EOP) consolidation behavior of soft soils. The conventional incremental loading (IL) consolidation test remains the most common test method for measuring 1-D consolidation behavior; however, data reduction requires graphical constructions to obtain key consolidation parameters. In addition, the IL test provides data only at intervals dictated by the loading increments used, leading to discontinuous stress-strain data that may mask or distort true soil consolidation behavior. The zero CG test mimics the EOP behavior by maintaining approximately zero excess pore pressure throughout the soil specimen as it is being continuously loaded, and thus avoids the problem of strain rate selection in the constant rate of strain (CRS) test. Zero CG tests were performed on three natural soils using a computer-automated Rowe consolidation cell, and these results were compared to conventional IL consolidation tests on the same soils. In general, for a given soil, the results from the two tests were consistent. However, the zero CG results had these advantages: defining the compression curve more accurately and continuously around the preconsolidation stress (σ′p), and giving higher, more realistic compression index values beyond σ′p. The major drawback of the zero CG test is that coefficient of consolidation (cv) data cannot be obtained due to the lack of excess pore pressure. The zero CG test offers both a practical and research tool for determining EOP consolidation states, and can eliminate strain rate problems inherent in both IL and CRS tests.
Interface Strength Evaluation of LSI Devices Using the Weibull Stress
Authors: Minami F , Takahara W , Nakamura T
Published: May 2004

Interface fracture strength is evaluated by the Weibull stress criterion for LSI devices composed of epoxy resin and Fe-Ni alloy sheet. The difference in coefficient of thermal expansion of the epoxy resin and Fe-Ni sheet causes a stress singularity at the corner ends of the device in the cooling process during LSI packaging, which is responsible for the interface fracture of the device. It is shown that the critical Weibull stress, an integrated stress over the stressed body along the interface, at fracture initiation is almost independent of the package geometry, although both the local stresses and the singularity parameters in the LSI device significantly depend on it. Shape design to decrease the Weibull stress values would be effective to improve the LSI devices reliability.
Intimidation in Ice Hockey: An Exploratory Assessment
Authors: Crawford BJ , Stuart MJ , Smith AM , Brennan RD
Published: May 2004

The purpose of this investigation was to examine the components of intimidation in ice hockey and to determine their effects on players, coaches, and referees. In a pilot test, hockey coaches (N = 17) from three levels of participation were invited to an informal, exploratory symposium to assess their opinions on the role of intimidation in ice hockey. The following themes emerged: a) coaches' behavior and expectations, b) observable behavior, c) player's perceived role, and d) sociological factors. A preliminary intimidation model was developed. A survey including 80 open-ended questionnaires designed to stimulate discussion on the definition of intimidation, methods used to intimidate, and factors perceived as intimidating, was distributed to players (N = 66), coaches (N = 8), and referees (N = 6). The data were analyzed using qualitative methods [1,2] and intimidation was defined. Results support a theoretical model, which serves as a point of departure for future research and visually depicts the components of intimidation and their interactions.
Measuring the Effects of Initiating Body Checking at the Atom Age Level
Authors: Montelpare WJ , McPherson MN
Published: May 2004

The purpose of this study was to determine the effects of initiating body checking at the Atom age level. The study used an experimental design in which teams from the Ottawa District Minor Hockey Association (ODMHA) represented the control group, while teams from the Ontario Hockey Federation (OHF) represented the treatment group. The study was conducted over a 3-year period from 1998 to 2001. The comparison sampling between the two leagues was as follows: ODMHA Yr1 = 69 teams versus OHF Yr1 = 74 teams, ODMHA Yr2 = 59 teams versus OHF Yr2 = 101 teams, ODMHA Yr3 = 46 teams versus OHF Yr3 = 90 teams. Measures of interest reported here included player selection bias, injury incidence, and variables that describe the characteristics of the flow of the game such as goals for, goals against, and number of penalties. Athlete exposures for each league by year were computed using 15 players per team for a 20 game plus 20 practice schedule. Statistical analysis of the difference in proportions of injuries reported by the two leagues based on the CHA injury insurance dataset showed that no significant difference occurred per year of the study. In addition, the rates of injuries were lower in each year than those reported by previously published studies. Body checking, which includes body contact is considered by many to be a skill within the game of ice hockey that can be taught at the younger age levels in a manner that does not lead to a higher incidence of injuries, or unfavorable changes in the game. The results of this study support that contention. In the present study, it was assumed that education was an essential component of the introduction process and that coaches were provided the necessary background to enable them to teach the introduction of body checking as a skill.
Psychophysiologic Factors and Performance in Ice Hockey Goalies During Competition
Authors: Smith AM , Finnie SB , Stuart MJ , Meis J , Beaver KM , Laskowski ER , Young WF
Published: May 2004

Studying goalies, who play a key position in hockey requires examining psychophysiologic variables and their relationship to performance during games when the outcome is important [15]. This investigation tested all three aspects of emotion (subjective, physiologic changes, and performance). Nine male goalies completed questionnaires and provided salivary cortisol before, during, and after each game. Heart rate (ECG signal) was integrated with the goalie's performance video. Goalies rated on Likert Scales; headaches, stomach aches, insomnia, nervousness, and awareness of heart pounding. Data from 16 games were obtained. Of nine, two goalies provided data on three games each; one goalie was classified as a responder and the other a non-responder, based on salivary cortisol levels (SCL). The responder's SCL increased 572 % between baseline and post-period assessments, whereas SCL in the non-responder increased 50 % above baseline. The responder's SCL increased eight times baseline when he faced 16 shots in a period. The responder goalie's game heart rates (HRs) were 160, 152, and 167 beats per minute (bpm) and the non-responder's HRs were 147, 132, and 142 bpm for three games. Game performance was similar for both goalies.
Mechanism-Based Variability in Fatigue Life of Ti-6Al-2Sn-4Zr-6Mo
Authors: Jha SK , Larsen JM , Rosenberger AH , Hartman GA
Published: May 2004

The variability in fatigue life of a Ti-6Al-2Sn-4Zr-6Mo alloy was studied. The cumulative life distribution plot was found to be composed of two distinct failure mechanisms, designated as Type-I and Type-II. The likelihood of Type-I vs. Type-II failure shifted with respect to the stress level, such that at lower stress levels, there was increased probability of Type-II failure. It also was found that the variability in life was introduced primarily at the crack nucleation stage, specifically, formation of a stage-I crack across an equiaxed primary-α particle.