bluuebunny/crossref_metadata_2025 huggingface dataset:
Transport of dissolved substances with second‐order reaction
Authors: Yates S. R. , Enfield C. G.
Published: February 2008

A mass transport equation which allows coupled second‐order reaction between two chemical components in groundwater systems is described. Several analytical solutions to the system of nonlinear equations for advective flow systems have been found, and the features of the solution are illustrated by example. The combined effects of hydrodynamic dispersion and second‐order reaction are investigated using a numerical technique, since analytical solutions which allow dispersion were not found. The analytical solutions can be used in the verification of numerical solution techniques especially in advection‐dominated transport regimes and can be used to give insight into how the second‐order reaction mechanism affects the transport and fate process. The solutions can also be used to determine the second‐order reaction coefficient from batch reactor or advective flow experiments.
Relationship between green and ampt parameters based on scaling concepts and field‐measured hydraulic data
Authors: Ahuja L. R. , Nofziger D. L. , Swartzendruber D. , Ross J. D.
Published: February 2008

For possible use in resource management models we examined the relationship aspects of wetting front suction head τwf and near‐saturated hydraulic conductivity Ks, the parameters of the Green and Ampt infiltration equation. Analysis of nonsimilar‐media scaling and a capillary tube bundle implied the power function relationship of negative slope linearity of log τwf versus log Ks. Experimentally, τwf and Ks were obtained from field‐measured hydraulic conductivity versus suction head for five soils. For each soil, of the total variation of log τwf regressed linearly on log Ks, less than half was due to regression, although the correspondingly small correlation coefficients were highly significant statistically. Hence log τwf versus log Ks displayed more independence than dependence. Also, based on regression line intercepts, only three soils could be reasonably grouped together. Whether such an indifferent relationship is useful, as in a large ensemble of τwf and Ks over spatially variable areas, must await further evaluation.
Modeling the transport of solutes influenced by multiprocess nonequilibrium
Authors: Brusseau M. L. , Jessup R. E. , Rao P. S. C.
Published: February 2008

A model that explicitly accounts for multiple sources of nonequilibrium is presented. The multiprocess nonequilibrium (MPNE) model is specifically formulated for cases where nonequilibrium is caused by a combination of transport‐ and sorption‐related processes. Sensitivity analyses were performed to delineate the conditions under which the MPNE model reduces to the bicontinuum and to the local equilibrium models. These conditions are strongly controlled by the magnitude of the dimensionless rate parameters. Performance of the MPNE model was evaluated with several published data sets. An empirical regression equation was successfully used to estimate values for sorption rate constants required in the MPNE model. The MPNE model, with values for all parameters obtained from independent sources, predicted behavior exhibited by the data. This provides support for the validity of the conceptualization upon which the model is based.
Risk equivalent seasonal waste load allocation
Authors: Rossman Lewis A.
Published: February 2008

Seasonal wastewater discharge programs employ different effluent standards during different times of the year to take advantage of the variation in a receiving water's susceptibility to adverse impacts. These programs should try to achieve the maximum economic benefits possible without increasing the risk of water quality impairment. A method is developed for designing seasonal programs for individual dischargers that limits the risk of one or more water quality standard violations in any year. The key elements involve (1) treating seasonal receiving water susceptibility to water quality impairment as a random variable, (2) assuming Markov‐like behavior of these random variables between seasons, and (3) using a nonlinear programming model to find seasonal discharge limits that minimize waste treatment efforts while maintaining an acceptable annual risk of water quality violation. A case study of controlling ammonia toxicity is presented as well as a comparison of the potential savings available from seasonalization for several pollutants on two rivers with differing seasonal regimes.
A numerical spectral approach for the derivation of piezometric head covariance functions
Authors: Van Lent Thomas , Kitanidis Peter K.
Published: February 2008

Relating the variability of permeability to the variability of head is a central part of linear estimation techniques such as cokriging. Only a few analytic relationships between log permeability covariances and head covariances presently exist. This paper describes a general numerical procedure which computes head covariances (ordinary or generalized) and cross covariances for any proper log permeability covariance. The numerical spectral method, a discrete analog of Fourier‐Stieltjes analysis, employs the pertinent linearized (small‐perturbation approximation) equations describing the physics of flow. The domain is taken as finite, with boundary effects considered negligible. The numerical spectral method can reproduce all pertinent analytic results with excellent agreement. Furthermore, we demonstrate the method's generality by finding the covariance relations for a case where no analytical results presently exist.
Risk estimation in partial duration series
Authors: Rasmussen Peter Funder , Rosbjerg Dan
Published: February 2008

The estimation of design floods is, in practice, often based on small samples of data, which may cause a severe uncertainty. For a particular version of the partial duration series (exponentially distributed exceedances and Poissonian occurrence times) the distribution of the T‐year design estimate
is derived along with the distribution of RT; defined as the true risk of exceeding
within a given disposal period. For a fixed flood level the distributions of the return period estimator
and the estimator of the risk in lifetime
are also presented. Analytical closed‐form expressions for mean value and standard deviation are derived for these variables, except for
, which does not possess moments. The concept of “expected risk” is introduced, and an analytical expression describing this property is derived. A risk‐based design technique, which is essentially different from the traditional procedure, is presented, and its applicability is verified using Monte Carlo simulation.
Unidimensional solute transport incorporating equilibrium and rate‐limited isotherms with first‐order loss: 3. Approximate simulations of the front propagating after a step input
Authors: Lassey Keith R.
Published: February 2008

Sorptive processes which accompany unidimensional solute flow through a porous medium can be modeled in terms of rate‐limiting isotherms. Both the rate limitations and dispersive processes combine to degrade or distend an otherwise sharp solute front initially introduced to the “column” as a step. Whenever dispersion is the dominant distending mechanism, the model simulation can be well approximated by replacement of the isotherm with a local equilibrium assumption (LEA). Conversely, if kinetics dominate distension, the neglect of dispersion can provide an efficacious approximant. I develop and illustrate the double Laplace‐like approximation (DLA) as a useful approximant when neither of these extremes is realized. The development is for a simulation model of unidimensional dispersive and advective transport which, in its most general form, incorporates combined linear Freundlich and rate‐limited isotherms, and first‐order loss, as formulated in paper 1 of this series (Lassey, 1988a). The DLA is about as computationally onerous as the LEA and the nondispersive assumption (NDA). The DLA‐predicted gradients of solute and sorbed concentration at the front are related to the Péclet and Damköhler numbers (characteristic of dispersion and kinetics, respectively), and include as special cases those predicted by the LEA and NDA. A numerical survey of the three approximants indicates that, for a propagating solute front of relatively minor distension, the DLA is the superior approximant.
Use of remotely sensed soil moisture content as boundary conditions in soil‐atmosphere water transport modeling: 2. Estimating soil water balance
Authors: Bruckler L. , Witono H.
Published: February 2008

A previously calibrated soil/atmosphere heat and water transport model was used to analyze (1) errors involved in soil water balance estimates under drying periods when soil surface moisture contents derived from microwave measurements were used as soil surface boundary conditions, and (2∥ consequences of time periods separating two consecutive soil surface boundary conditions under evaporation or infiltration conditions on soil water balance calculations. Soil moisture and dry bulk density measurements were performed on a 0.4‐ha bare field (27.2% clay, 61.7% fine and coarse loam) with simultaneous measurements of backscattering coefficients (5.3 GHz, HH polarization, 15° incidence angle). Regression lines between backscattering coefficient and volumetric water content were calculated taking into account different soil depths (0‐1, 0‐2, 0‐3, 0‐4, 0‐5, 0‐6, 0‐7, and 0‐10 cm). Two methods for estimating soil surface moisture contents were proposed. In the first one, moisture contents for an arbitrary soil depth were directly extracted from a single “backscattering coefficient/water content” calibration line. The second method combined several calibration lines relative to several arbitrary soil depths. Results showed that (1) under drying periods (5 days) the methods led generally to moderately biased or unbiased water balances, (2) both errors due to the backscattering coefficient measurements and calibration line parameters had little effect on water balance estimations (≤10%), and (3) under evaporation conditions (5 days) or combined evaporation and infiltration phases (15 days), numerous soil surface boundary conditions versus time should be available to avoid wrong water balance estimates. Under evaporation conditions, one soil surface moisture content per day appeared satisfactory when it corresponded to the mean daily soil surface moisture content. Under combined evaporation and infiltration conditions, results depended strongly on the precise position of water content boundary conditions versus time, connected with rainfall sequences.
Controlling mechanisms for stream water chemistry at the Pristine Ingabekken Site in mid‐Norway: Some implications for acidification models
Authors: Christophersen Nils , Vogt Rolf D. , Neal Colin , Anderson Hamish A. , Ferrier Robert C. , Miller John D. , Seip Hans M.
Published: February 2008

Stream water at the 18.7 ha pristine Ingabekken catchment, on granitic bedrock, in mid‐Norway has been studied for 2 years, including intensive episode studies in the spring and autumn. The pH varied from over 7 at base flow to 5 or slightly below at high flow, while inorganic monomeric Al was <1 μM for all flow conditions. The lowest pH (4.8) was observed in the early snowmelt during release of meltwater highly enriched in sea salts. The cation exchange capacity and base saturation of organic soils were comparable to those found at the acidified Birkenes site in southern Norway, but the ratio of exchangeable Al to exchangeable H+ was much lower at Ingabekken. This suggests that soils could undergo a transition during acidification whereby exchangeable H+ is replaced by aluminium. Such a transition may well be important in understanding long‐term trends in acidification but is not a feature of most models.
Sensitivity analysis of flow in unsaturated heterogeneous porous media: Theory, numerical model, and its verification
Authors: Kabala Z. J. , Milly P. C. D.
Published: February 2008

Sensitivity analysis is one of the tools available for analyzing the effects of parameter uncertainty and soil heterogeneity on the transport of moisture in the unsaturated similar porous media. Direct differentiation of the discretized Richards equation with respect to parameters defining spatial variability leads to linear systems of equations for elementary sensitivities that are readily solved in conjunction with the original equation. These elementary sensitivities can be easily transformed into approximations of functional sensitivities and into sensitivities of boundary fluxes. A numerical implementation of this technique in one space dimension yields results that are consistent with exact analytical solutions and with numerical perturbation calculations. The effects of a given heterogeneity can be modeled adequately provided that the maximum relative change of the scale factor from one grid point to the next not exceed a number on the order of unity.
Effects of core‐scale heterogeneity on steady state and transient fluid flow in porous media: Numerical analysis
Authors: Bachu Stefan , Cuthiell David
Published: February 2008

Numerical simulations are used in an inverse approach to study the effects of actual core‐scale heterogeneity on the steady state and transient fluid flow in aquifers and reservoirs. The heterogeneous porous medium consists of homogeneous and isotropic shale clasts of variable size, geometry, orientation, and distribution, embedded in a homogeneous and isotropic sand matrix. The data was obtained by digitizing shale clasts from cores in a heavy oil reservoir. The presence of the clasts in the sand matrix creates anisotropy at larger scales, due mainly to the predominantly flat shape and subhorizontal orientation of the clasts. The steady state effective hydraulic conductivity generally has values between the geometric and arithmetic averages of the two component values, averages weighted by heterogeneity fraction. The dependence of the effective hydraulic conductivity on the heterogeneity fraction and conductivity contrast between the clasts and the matrix can be described empirically by a power‐average model. The reduction in the effective conductivity exhibits an asymptotic behaviour for conductivity contrasts greater than 2 orders of magnitude. When multiple heterogeneity scales are present, a sequential approach can be used by which heterogeneous media at smaller scales are replaced successively by homogeneous media characterized by corresponding effective hydraulic conductivities. For transient flow, the effective values of hydraulic conductivity and specific storage are time and flow dependent, with asymptotic behaviour toward the steady state effective value for hydraulic conductivity and toward the space‐average value for specific storage. The error in using steady state effective hydraulic conductivity and space‐average specific storage is relatively large for rapidly varying flows but is probably acceptable for slowly varying flows. Generally, the results of the numerical simulations show that the effective values of hydraulic parameters are dependent on both the intrinsic structure of the heterogeneous porous medium and on the flow process.
A quasi‐linear theory of non‐Fickian and Fickian subsurface dispersion: 1. Theoretical analysis with application to isotropic media
Authors: Neuman Shlomo P. , Zhang You‐Kuan
Published: February 2008

A theory is presented which accounts for nonlinearity caused by the deviation of plume “particles” from their mean trajectory in three‐dimensional, statistically homogeneous but anisotropic porous media under an exponential covariance of log hydraulic conductivities. Existing linear theories predict that, in the absence of local dispersion, transverse dispersivities tend asymptotically to zero as Fickian conditions are reached. According to our new quasi‐linear theory these dispersivities ascend to peak values and then diminish gradually toward nonzero Fickian asymptotes which are proportional to σY4 when the log hydraulic conductivity variance σY2 is much less than 1. All existing theories agree that in isotropic media the asymptotic longitudinal dispersivity is proportional to σY2 when σY2 < 1, and all are nominally restricted to mildly heterogeneous media in which this inequality is satisfied. However, the quasi‐linear theory appears to be less prone to error than linear theories when extended to strongly heterogeneous media because it deals with the above nonlinearity without formally limiting σY2. It predicts that when σY ≫ 1 in isotropic media, both the longitudinal and transverse dispersivities ascend monotonically toward Fickian asymptotes proportional to σY.
Nonlinear radial flow in confined aquifers toward large‐diameter wells
Authors: Şen Zekâi
Published: February 2008

Nonlinear flow type curve sets are derived on the basis of Forchheimer flow law for drawdown variations in a large‐diameter well which fully penetrates a confined aquifer. Relevant initial boundary value problem solutions are achieved by Boltzmann transformation. The validity of obtained results are checked against Papadopulos and Cooper type curves which are applicable only in linear radial flows toward large‐diameter wells. The initial portions of all type curves, irrespective of the turbulence factor and the storage coefficient, are all straight lines, indicating well storage effects.
Effective unsaturated hydraulic conductivity of layered sands
Authors: Yeh T.‐C. Jim , Harvey Donald J.
Published: February 2008

Accurate estimates of field‐scale hydraulic conductivities of unsaturated heterogeneous soils are very difficult to obtain. In the present study, various approaches to determining effective conductivity values for heterogeneous sands are compared with laboratory measurements. The unsaturated hydraulic conductivity, K(ψ), of two homogeneous sands and one layered sand composed of the two homogeneous sands was measured using the steady‐state flux control method. The averaged K(ψ) curves of the two homogeneous sands using a direct averaging approach were compared with the measured layered sand K(ψ) data. The result shows that the geometric mean of hydraulic conductivity‐suction curves of the coarse and medium sands approximates the measured hydraulic conductivity‐suction curve of the layered sand. The observed suction variance and effective hydraulic conductivity were compared with expressions developed from a stochastic theory. The results support the stochastic approach.
Water Resources Research: Past, present, and future
Authors: Burges Stephen J.
Published: February 2008

Water Resources Research was established as a multidisciplinary journal largely to satisfy needs perceived by a committee headed by the late Walter Langbein in 1962. The papers in volume 1, number 1, set the tone and high standard of scholarship for all subsequent issues; we are all in debt to the founding co‐editors, Allen Kneese and Walter Langbein, for their leadership and vision. Most research workers consider this journal to be a highly desirable forum to share their ideas and findings with colleagues. What has served the community well for twenty‐five years may or may not be the most appropriate medium as we enter the era of multimedia and multisensorial display of the information from which we distill our knowledge.
The episodic acidification of Adirondack Lakes during snowmelt
Authors: Schaefer Douglas A. , Driscoll Charles T. , Van Dreason Richard , Yatsko Christen P.
Published: February 2008

Maximum values of acid neutralizing capacity (ANC) in Adirondack, New York lake outlets generally occur during summer and autumn. During spring snowmelt, transport of acidic water through acid‐sensitive watersheds causes depression of upper lake water ANC. In some systems lake outlet ANC reaches negative values. We examined outlet water chemistry from 11 Adirondack lakes during 1986 and 1987 snowmelts. In these lakes, SO42− concentrations were diluted during snowmelt and did not depress ANC. For lakes with high baseline ANC values, springtime ANC depressions were primarily accompanied by basic cation dilution. For lakes with low baseline ANC, NO3− increases dominated ANC depressions. Lakes with intermediate baseline ANC were affected by both processes and exhibited larger ANC depressions. Ammonium dilution only affected wetland systems. A model predicting a linear relationship between outlet water ANC minima and autumn ANC was inappropriate. To assess watershed response to episodic acidification, hydrologic flow paths must be considered.
Problems in determining the return of a watershed to pretreatment conditions: Techniques applied to a study at Caspar Creek, California
Authors: Thomas Robert B.
Published: February 2008

Using a previously treated basin as a control in subsequent paired watershed studies requires the control to be stable. Basin stability can be assessed in many ways, some of which are investigated for the South Fork of Caspar Creek in northern California. This basin is recovering from logging and road building in the early 1970s. Three storm‐based discharge characteristics (peak discharge, quick flow, and total storm flow), daily flows, and concentration of suspended sediment were studied to see if the South Fork can be used as a control in a second experiment. Mean sediment concentration in three discharge classes and regression parameters for the other data were tested to estimate remaining treatment effects relative to the North Fork. Patterns of change were similar for most data, with rises in response followed by returns toward pretreatment conditions. The storm and sediment data showed few significant differences, but tests on daily flows indicated that differences still exist. The overall evidence suggests that the South Fork has returned to near pretreatment conditions. Better sediment data are needed for studies of the effects of land management.
A Real‐Time Approach to Management and Monitoring of Groundwater Hydraulics
Authors: Andricevic Roko
Published: February 2008

This paper describes a sequential approach to the management and monitoring program of groundwater hydraulics. The management model, structured as a discrete time optimal control problem, identifies the optimal withdrawal rates by satisfying a penalty type cost function of two conflicting objectives: satisfying withdrawal demands and maintaining target hydraulic head levels. A control action obtained in the feedback form is shown in this study to depend on future uncertainty in the hydraulic head prediction due to the variability in the hydraulic conductivity. As new field observations become available the hydraulic conductivity field is updated in “real‐time.” A numerical example demonstrates the sequential approach and quantifies the benefits of using the monitoring program. The effects of the objective function uncertainty upon the optimal management solution is discussed; a simple case illustrating an optimization bias appearance is presented.
Use of Nuclear Magnetic Resonance as an Experimental Probe in Multiphase Systems: Determination of the Instrument Weight Function for Measurements of Liquid‐Phase Volume Fractions
Authors: Maneval J. E. , McCarthy M. J. , Whitaker S.
Published: February 2008

The relativist approach (Baveye and Sposito (1984)) to the interpretation of measurements in multiphase systems was proposed in order to incorporate the details of measurements into theoretical analyses of multiphase transport processes. To help establish the utility of this approach, the weight functions for actual experimental probes must be determined. In this paper we analyze the measurement of liquid‐phase porosity in a model system by nuclear magnetic resonance imaging. We show how both nuclear magnetic resonance (NMR) physics and experimental technique combine to determine the weight function for the spin‐warp spin‐echo sequence. The analysis shows clearly what aspects of the weight function are determined by the experimental method and what aspects are determined by the system being studied. The results will help establish the utility of the relativist approach as well as improve understanding NMR measurements in multiphase systems.
Series Representation of Flux for the Boussinesq Equation
Authors: Tolikas P. , Damaskinidou A. , Sidiropoulos E.
Published: February 2008

The Boussinesq equation, supplemented with Dirichlet‐type boundary conditions, is used to describe one‐dimensional groundwater flow. After a number of transformations a nonlinear ordinary differential equation is obtained with flux as the dependent variable. Through perturbation the slope of the water profile at the origin is expressed in the form of a rapidly converging series and can, therefore, be calculated to the desired accuracy. Thus, the corresponding two‐point boundary problem is solved without iteration. Also, quantities related to physical aspects of the problem are easily calculated. Furthermore, the same treatment is directly applicable to a number of other physical and engineering situations governed by the same equations.
Linking Hydrological, Geochemical, and Soil Chemical Processes on the Catchment Scale: An Interplay Between Modeling and Field Work
Authors: Christophersen Nils , Neal Colin
Published: February 2008

Quantification of the major processes controlling soil, soil water, and stream water chemistry are hampered by the traditional divisions within the terrestrial sciences. Here a line of investigation within acid rain research starting in Norway in the late 1970s, and characterized by a close connection between modeling and field work, is outlined. In 1982 the Birkenes model offered an integrated picture of the link between acid deposition and acid freshwaters. Since that time, new field data from Birkenes and other sites have been collected to test and improve the model. The picture now emerging is that stream water can be considered as a mixture of observed soil waters (end‐members), with contributions depending on the hydrological conditions. Thus the hydrological question of water flow paths is elucidated using chemical information. It is suggested that sufficient motivation for interdisciplinary research can be obtained if scientists become more willing to pursue problems and not disciplines.
Physics basis and future trends for negative ion sources (invited)
Authors: Bacal M.
Published: February 2008

The explanation of hydrogen negative ion formation in the hydrogen plasma volume is based on the hypothesis that the precursors of H− ions are rovibrationally excited molecules. It will be shown that this hypothesis is confirmed by the agreement between predicted and measured H− densities. The reason for the existence of an optimum pressure for the negative ion density in volume sources is discussed. The role of the magnetic filter in contemporary negative ion sources is analyzed. Experiments indicating the effect of the ion source surfaces (plasma electrode, collar, walls) will be described. It is concluded that vibrationally excited molecules, produced by recombinative desorption from surfaces, play a significant role. It is shown that a high H− ion emission from a high work function surface is very doubtful at the present state of knowledge. Therefore it is considered that the success of the cesium-free accelerator ion sources operating in the 100mA∕cm2 range is due to production of vibrationally excited molecules on the plasma electrode or collar surface. In the collar case, the negative ion production is enhanced due to the absence of plasma in the production region; thus mutual neutralization loss is canceled. The physics of surface production of H− ions and some unexplained features related to it will be discussed.
Two-dimensional complete band gaps in one-dimensional metal-dielectric periodic structures
Authors: Zhang Jin-long , Jiang Hai-tao , Enoch Stefan , Tayeb Gérard , Gralak Boris , Lequime Michel
Published: February 2008

It is widely believed that a one-dimensional (1D) periodic layered structure with ordinary materials can only have a band gap for certain propagation directions. However, we reveal that a 1D metal-dielectric periodic structure can trap transverse magnetic waves for any angle of propagation in a plane, owing to the existence of a two-dimensional (2D) complete band gap. The complete gap comes from Bragg scattering together with the cutoff effect of the metal-dielectric-metal waveguide. We discuss the criteria for the geometric and material parameters to realize a 2D complete gap and illustrate the complete band-gap effects with real structures.
The Modulating Influence of Category Size on the Classification of Exception Patterns
Authors: Homa Donald , Proulx Michael J. , Blair Mark
Published: February 2008

Generalization gradients to exception patterns and the category prototype were investigated in two experiments. In Experiment 1, participants first learned categories of large size that contained a single exception pattern, followed by a transfer test containing new instances that had a manipulated similarity relationship to the exception or a nonexception training pattern as well as distortions of the prototype. The results demonstrated transfer gradients tracked the prototype category rather than the feedback category of the exception category. In Experiment 2, transfer performance was investigated for categories varying in size (5, 10, 20), partially crossed with the number of exception patterns (1, 2, 4). Here, the generalization gradients tracked the feedback category of the training instance when category size was small but tracked the prototype category when category size was large. The benefits of increased category size still emerged, even with proportionality of exception patterns held constant. These, and other outcomes, were consistent with a mixed model of classification, in which exemplar influences were dominant with small-sized categories and/or high error rates, and prototype influences were dominant with larger sized categories.
Two endemic and endangered fishes, Poecilia sulphuraria (Alvarez, 1948) and Gambusia eurystoma Miller, 1975 (Poeciliidae, Teleostei) as only survivors in a small sulphidic habitat
Authors: Tobler M. , Riesch R. , Garcíade León F. J. , Schlupp I. , Plath M.
Published: February 2008

In the Baños del Azufre in Tabasco, Mexico, only two poeciliid species, Poecilia sulphuraria and Gambusia eurystoma, were found in sulphidic habitats, whereas adjacent non‐sulphidic habitats were characterized by a vastly different fish community. Exposure of fishes to water from a sulphidic spring showed that all species except for P. sulphuraria quickly lost motion control, probably because of the toxic properties of H2S. It is suggested that the fishes endemic to the Baños del Azufre are highly specialized, and competitive exclusion allows them to survive only in this particular habitat type.
Photoresponse in allis shad larvae
Authors: Jatteau P. , Bardonnet A.
Published: February 2008

Allis shad Alosa alosa photoresponse was investigated in 3 day‐old to 1 month‐old larvae. Regardless of age, larvae strongly preferred the lit compartment in aquaria experiments. Such response was consistent with other experimental studies which have suggested a pelagic behaviour of allis shad larvae from the time of hatch.
Description of a new cichlid fish species of the genus Benthochromis (Perciformes: Cichlidae) from Lake Tanganyika
Authors: Takahashi T.
Published: February 2008

Benthochromis horii, a new cichlid species is described based on 19 type specimens from the deep waters of Lake Tanganyika. It differs from its congeners by having smaller eyes and longer snout (eye length usually shorter than snout length v. equal to or longer than snout length in Benthochromis tricoti and Benthochromis melanoides), and more dorsal fin rays (total number of spines and soft rays in dorsal fin usually 30 or 31 v. usually 28 or 29 in B. tricoti and B. melanoides). Large males of the new species differ from those of congeneric species in terms of their body colour pattern and long pelvic fins. This species has been confused with B. tricoti and has been traded as an aquarium fish.
Relation between elevated high‐sensitivity C‐reactive protein and anti‐mitochondria antibody in patients with systemic sclerosis
Authors: OHTSUKA Tsutomu
Published: February 2008

Systemic sclerosis (SSc) is a systemic connective tissue disease of unknown etiology which presents immunological, vascular and connective tissue abnormalities. C‐reactive protein (CRP) has been used for the evaluation of inflammation in patients with infection and inflammatory diseases. Recently, high‐sensitivity CRP has been shown to reflect mild and/or moderate inflammation for the prognosis of ischemic heart disease. High‐sensitivity CRP was measured for the evaluation of mild and/or moderate inflammation in SSc. Forty SSc patients (male : female, 7:33; age, 16–78 years; mean, 61.9 years) were studied. High‐sensitivity CRP was measured with a nephelometric assay. The detection limit was 0.0036 mg/dL, linearity from 0.015–1.5 mg/dL. The distribution of high‐sensitivity CRP showed 26 cases (65.0%) low, three cases (7.5%) mild, four cases (10.0%) moderate, four cases (10.0%) high and three cases (7.5%) highest. The occurrence rate of anti‐mitochondria antibody in high‐sensitivity CRP elevated SSc patients (8/14, 57.1%) was significantly elevated compared with that of high‐sensitivity CRP low SSc patients (3/26, 11.5%) (P < 0.01). These results led us to the conclusion that elevated high‐sensitivity CRP shows relation to the occurrence of anti‐mitochondria antibody.
Changing patterns in the frequency of Hodgkin lymphoma subtypes and Epstein–Barr virus association in Taiwan
Authors: Chang Kung‐Chao , Chen Paul Chih‐Hsueh , Jones Dan , Su Ih‐Jen
Published: February 2008

Epstein–Barr virus (EBV) infection is a risk factor for Hodgkin lymphoma (HL). To test whether the frequency of HL subtypes and their association with EBV has shifted with rising socioeconomic status in Taiwan, we compared the pathological features and EBV status, detected by in situ hybridization, of HL diagnosed between 1996 and 2007 (99 cases) and 1982 and 1995 (74 cases). The male‐to‐female ratio was 121:52 (2.3:1) and the mean age at presentation was 41.5 years. The overall EBV positivity rate was 50% (86/173 cases). Comparing the distribution of HL cases diagnosed at two different time periods, we found an increased frequency of the nodular sclerosis (NS) subtype (53 vs 68%, P = 0.045), a decreased frequency of the mixed cellularity subtype (35 vs 13%, P < 0.001), a reduced male‐to‐female ratio (2.9:1 compared to 1.4:1) and mean age (42.4 vs 36.6 years) in the NS subtype, and a significant decrease in EBV positivity rates among the NS and lymphocyte‐depletion subtypes (61 vs 39%, P = 0.03). These data indicate shifts in the frequency of histological subtype and EBV association for HL in Taiwan over the last decade, with a trend closer to that seen in Western countries and Japan. (Cancer Sci 2008; 99: 345–349)
Etiologic value of p53 mutation spectra and differences with histology in lung cancers
Authors: Shimmyo Takuo , Okada Akira , Hashimoto Takehisa , Kobayashi Yasuhito , Miyagi Youhei , Ishikawa Yuichi , Nakagawa Ken , Osada Hiroaki , Tsuchiya Eiju
Published: February 2008

A total of 297 resected Japanese non‐small cell lung cancers (74 squamous cell carcinomas and 223 adenocarcinomas) were analyzed to evaluate the validity of the p53 mutation spectrum as a fingerprint for mutagenic substances as etiological factors. Frequencies of G→T transversions in smokers were significantly higher than in non‐smokers (P = 0.003) and the average incidence of G→T at hot spot codons of adduct formation was higher than that in other codons in smokers and in the hot spots in non‐smokers. Further, the mutation showed a marked strand bias. G→A transitions at CpG sites (CpG→CpA) were equally distributed in smokers and non‐smokers, and on both strands. A→G transitions did not show any variation with smoking status in terms of frequency, but exhibited a marked strand bias. Taken together, the G→T may be a fingerprint of direct mutagenic action of tobacco‐related compounds, the A→G being a new marker for other environmental chemicals, while the CpG→CpA may be attributable to endogenous spontaneous mutation, for active in lung carcinogenesis. (Cancer Sci 2008; 99: 287–295)
Molecular docking analysis of the protein–protein interaction between RelA‐associated inhibitor and tumor suppressor protein p53 and its inhibitory effect on p53 action
Authors: Tomoda Keisuke , Takahashi Naoko , Hibi Yurina , Asamitsu Kaori , Ishida Hirokazu , Kondo Toshiharu , Fujii Yoshitaka , Okamoto Takashi
Published: February 2008

RelA‐associated inhibitor (RAI) was initially identified as a protein that interacts with the p65 subunit (RelA) of nuclear factor‐κB. It was recently found to interact with the p53 tumor suppressor protein. RAI is a structural homolog of the p53‐binding protein 2 and IκB family proteins, and is known to inhibit the DNA‐binding activities of p65 and p53. In the present study, we have attempted to predict the 3‐dimensional structure of RAI in complex with p53 using computational chemistry. In order to evaluate the predicted structure model, we created a series of RAI mutants in which the amino acid residues involved in the interaction with p53 were mutated, and examined their activities in blocking p53‐mediated bax gene expression. Our observations support the validity of the predicted 3‐dimensional model of the p53–RAI protein complex. Based on the p53–RAI complex model, we have demonstrated the biological importance of the R248 and R273 residues of p53, and the D775 and E795 residues of RAI, in the protein–protein interaction between p53 and RAI and the biological actions of these proteins. These findings will further clarify the biological actions of RAI in carcinogenesis and can be used for the development of a novel strategy in blocking the actions of RAI. The possible biological implications of RAI are also discussed. (Cancer Sci 2008; 99: 615–622)
Prognostic impact and immunogenicity of a novel osteosarcoma antigen, papillomavirus binding factor, in patients with osteosarcoma
Authors: Tsukahara Tomohide , Kawaguchi Satoshi , Torigoe Toshihiko , Kimura Shigeharu , Murase Masaki , Ichimiya Shingo , Wada Takuro , Kaya Mitsunori , Nagoya Satoshi , Ishii Takeshi , Tatezaki Shin‐ichiro , Yamashita Toshihiko , Sato Noriyuki
Published: February 2008

To develop peptide‐based immunotherapy for osteosarcoma, we previously identified papillomavirus binding factor (PBF) as a cytotoxic T lymphocytes (CTL)‐defined osteosarcoma antigen in the context of human leukocyte antigen (HLA)‐B55. In the present study, we analyzed the distribution profile of PBF in 83 biopsy specimens of osteosarcomas and also the prognostic impact of PBF expression in 78 patients with osteosarcoma who had completed the standard treatment protocols. Next, we determined the antigenic peptides from PBF that react with peripheral T lymphocytes of HLA‐A24+ patients with osteosarcoma. Immunohistochemical analysis revealed that 92% of biopsy specimens of osteosarcoma expressed PBF. PBF‐positive osteosarcoma conferred significantly poorer prognosis than those with negative expression of PBF (P = 0.025). In accordance with the Bioinformatics and Molecular Analysis Section score, we synthesized 10 peptides from the PBF sequence. Subsequent screening with an HLA class I stabilization assay revealed that peptide PBF A24.2 had the highest affinity to HLA‐A24. CD8+ T cells reacting with a PBF A24.2 peptide were detected in eight of nine HLA‐A24‐positive patients with osteosarcoma at the frequency from 5 × 10−7 to 7 × 10−6 using limiting dilution/mixed lymphocyte peptide culture followed by tetramer‐based frequency analysis. PBF A24.2 peptide induced CTL lines from an HLA‐A24‐positive patient, which specifically killed an osteosarcoma cell line that expresses both PBF and HLA‐A24. These findings suggested prognostic significance and immunodominancy of PBF in patients with osteosarcoma. PBF is the candidate target for immunotherapy in patients with osteosarcoma. (Cancer Sci 2008; 99: 368–375)
The role of lenalidomide in the management of myelodysplasia with del 5q
Authors: Kelaidi Charikleia , Eclache Virginie , Fenaux Pierre
Published: February 2008

Defined by isolated del 5q and no excess of marrow blasts, the ‘5q‐ syndrome’ is a specific type of myelodysplastic syndrome (MDS) with particular characteristics, including severe anaemia, frequent thrombocytosis, typical dysmegakaryopoiesis and favourable outcome. Its pathogenesis remains uncertain, particularly regarding the role of the inactivation of gene(s) situated in 5q. Until the advent of lenalidomide, repeated red blood cell (RBC) transfusions were generally the only treatment for 5q‐ syndrome, which was resistant to other therapeutic approaches. Lenalidomide can lead to RBC transfusion independence in at least two‐thirds of cases of 5q‐ syndrome, and about one half of those responses are maintained after 2 years of treatment. Importantly, frequent complete pathological and cytogenetic responses are also obtained. Grade 3 or 4 neutropenia and thrombocytopenia, especially during the first 6–8 weeks of treatment, are the major side effects of lenalidomide, justifying close clinical and blood counts monitoring. Preliminary results suggest that lenalidomide is also active in MDS with del 5q other than the 5q‐ syndrome. The mechanisms of action of lenalidomide, although uncertain, appear to include targeting of the del 5q clone. Therefore, lenalidomide may have an effect on disease course and survival, which is currently being assessed in clinical trials.
Modulation of the epithelial inflammatory response to rhinovirus in an atopic environment
Authors: Xatzipsalti M. , Psarros F. , Konstantinou G. , Gaga M. , Gourgiotis D. , Saxoni‐Papageorgiou P. , Papadopoulos N. G.
Published: February 2008

Background
Immune responses to rhinovirus (RV) as well as direct effects of RV on respiratory epithelium may contribute to the induction of asthma exacerbations.

Objective
To evaluate the effect of the environment resulting from an atopic immune response on RV‐induced epithelial inflammation, replication and cytotoxicity.

Methods
Peripheral blood mononuclear cells (PBMC) from atopic asthmatic subjects and matched controls (12 pairs) were isolated and stimulated by RVs. Human bronchial epithelial (BEAS‐2B) cells were infected with RV in the presence of conditioned media from RV‐stimulated PBMC cultures. IL‐6, IL‐8, RANTES and TGF‐β1 levels were measured by ELISA, RV‐induced cytotoxicity by a colorimetric method and RV titres on Ohio‐HeLa cells.

Results
RV‐induced epithelial production of IL‐6, IL‐8 and RANTES was significantly lower, while TGF‐β1 was higher when cells were exposed to conditioned media from atopic asthmatic subjects compared with those from normal controls. Exposure to the ‘atopic’ environment also resulted in elevated RV titres and increased RV‐induced cytotoxicity.

Conclusions
Under the influence of an atopic environment, the epithelial inflammatory response to RV is down‐regulated, associated with increased viral proliferation and augmented cell damage, while TGF is up‐regulated. These changes may help explain the propensity of atopic asthmatic individuals to develop lower airway symptoms after respiratory infections and indicate a mechanism through which viral infections may promote airway remodelling.
Selective induction of nerve growth factor and brain‐derived neurotrophic factor by LPS and allergen in dendritic cells
Authors: Noga O. , Peiser M. , Altenähr M. , Schmeck B. , Wanner R. , Dinh Q. T. , Hanf G. , Suttorp N.
Published: February 2008

Background
Neurotrophins are produced by various cells upon different stimuli and participate in the initiation and regulation of inflammation in various diseases including allergy and asthma, but little is known about the production and control of neurotrophins by dendritic cells (DCs). The aim of this study was to assess whether DCs produce the neurotrophins nerve growth factor (NGF) and brain‐derived neurotrophic factor (BDNF), and whether inflammatory stimuli or allergens are able to induce the production of neurotrophic factors.

Methods
Monocyte‐derived dendritic cells (MoDCs) were generated from different donors. The neurotrophins NGF and BDNF were demonstrated by RT‐PCR, Western blotting, flow cytometry analysis and fluorescence microscopy. MoDCs were cultured and stimulated with lipopolysaccharide (LPS) or allergen for 24 h. The supernatants and cells were collected. Measurement for NGF and BDNF was performed by ELISA.

Results
DCs express mRNA for the neurotrophins NGF and BDNF. Proteins were detectable by Western blot, FACS analysis and fluorescence microscopy. LPS led to an up‐regulation of BDNF, while NGF was unaffected. Cell lysates demonstrated an increased amount of BDNF after stimulation with LPS or allergen, while NGF was not affected significantly.

Conclusions
DCs are a source of neurotrophins. LPS selectively regulates the production of BDNF. Allergen stimulation leads to an LPS‐independent regulation. This contributes to a complex involvement of neurotrophins in allergic diseases.
Allergological implication of the quaternary hexameric structure of the cockroach allergen Per a 3
Authors: Bellinghausen I. , Häringer B. , Lafargue B. , Strand D. , König B. , Decker H. , Saloga J.
Published: February 2008

Background
Cockroach allergens play a very important role in allergic diseases, especially asthma. The major allergen of the American cockroach (Periplaneta americana), Per a 3, naturally occurs as isoforms of hexamers.

Objective
The aim of this study was to investigate whether the hexameric structures of Per a 3 influence their allergenicity and immunogenicity.

Methods
Therefore, we compared the different effects of native hexamers and dissociated monomers of cockroach haemolymph (HL), containing almost only Per a 3 proteins (HL‐Per a 3), on proliferation and T‐helper type 1 (Th1)/Th2 cytokine production of human CD4+ T cells in co‐culture with allergen‐pulsed monocyte‐derived autologous dendritic cells (DC) as well as the leukotriene release of basophils.

Results
In P. americana‐sensitized and non‐sensitized donors the HL‐Per a 3 monomers were internalized faster by immature DC and induced higher proliferation and IFN‐γ production than the hexamers. While in non‐sensitized donors IL‐4 and IL‐5 as well as IL‐10 production were also increased after stimulation with monomeric HL‐Per a 3‐pulsed DC, Th2 cytokine and IL‐10 production were only enhanced in P. americana‐sensitized donors using hexameric HL‐Per a 3‐pulsed DC. Furthermore, in the leukotriene release assay the monomers were less effective than the hexamers.

Conclusion
Our data indicate that the quaternary structure can influence both allergenicity and immunogenicity, also depending on the sensitization status. The monomeric variant of Per a 3 allergens could be a possible candidate for a specific immunotherapy because the IgE‐mediated allergic reaction and the Th2‐inducing capacity are diminished while the Th1‐inducing capacity is retained.