bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlation between visual and instrumental colour differences of metallic paint films
Authors: Saris H. J. A. , Gottenbos R. J. B. , Van Houwelingen H.
Published: June 2007

Because of the importance of metallic paints particularly in the automobile industry, there is a need for colour measurement techniques which show a high correlation with visual judgments. The present study uses recently developed spectrophotometers with variable geometries to optimize this correlation. Visual and instrumental data have been analyzed by means of statistical techniques. The investigations have led to the conclusion that three different geometries are sufficient to describe the optical behaviour of metallic paint films, provided that the geometries are well distributed with respect to the angle between the direction of observation and the direction of the specular component. In addition to this measurement technique a calculation procedure has been developed that yields judgments that highly correlate with visual judgments.
Serial position curves for colored light patches
Authors: Avons S. E. , Daley Shelley A.
Published: June 2007

Previous studies have shown a distinction between short‐term and long‐term visual memory by measuring serial position curves for achromatic visual patterns. Three experiments are reported in which serial position curves were measured for homogeneous colored light patches displayed on a color monitor. In experiment 1 three color patches were displayed in series followed by reverse serial order recognition testing. Experiment 2 used the same paradigm but with different colors and with four items in the presentation series. The results of both experiments showed a recency effect confined to the last item, but no evidence of any primacy effect. These results correspond to those observed with achromatic patterns, suggesting that similar memory processes are used for color and pattern information. In experiment 3, the presentation series of four colors was followed by a single a recognition probe for one of these colors, chosen randomly. Under these conditions, the pronounced recency effect disappeared. The results are consistent with the view that both color memory and achromatic pattern memory utilise a voluntary visualization strategy. This has important implications for theories of visual memory, and practical issues concerning color matching by visual inspection.
Absolute reflectance factor calibration for goniospectrophotometry
Authors: Fairchild Mark D. , Daoust Denis J. O. , Peterson Jason , Berns Roy S.
Published: June 2007

Currently, spectrophotometric standard reference materials are calibrated only using the CIE recommended illumination and viewing geometries. A need exists for standards that have been calibrated at many other combinations of illumination and viewing angles. The common practice has been to assume that a primary transfer standard such as BaSO4 is Lambertian even though its non‐Lambertian behavior is well documented. This study was undertaken to develop a practical standard for this type of metrology. Two diffuse materials, BaSO4 and PTFE, were characterized goniospectrophotometrically. Bidirectional absolute spectral reflectance factors were determined for 60 combinations of illumination and view angles in a single plane. Neither material was found to be Lambertian and both failed to completely depolarize reflected radiation. The results were modeled using principal components analysis. The resulting model allows the determination of bidirectional spectral reflectances factors with a minimum effort. PTFE powder can be prepared repeatably with no significant effect on the measured reflectance properties, thus indicating that it would be a suitable primary transfer standard for goniospectrophotometry.
Model of saturation and brightness: Relations with luminance
Authors: Pridmore Ralph W.
Published: June 2007

The model is simple: For flicker luminance stimuli and maximum purity, the hue cycle's relative luminance (computed from CIE data) is reciprocal to relative saturation. Brightness/luminance ratio B/L is proportional to relative saturation S, i.e., B/L = 1.5 S1/4. S times B/L ratio gives relative saturation for brightness stimuli; just as relative luminance times B/L ratio gives brightness. Predictions for any purity agree with data on saturation discrimination, color appearance in CIE space, B/L, and CIE brightness Vb. Predictions support Hunt's concept of “colorfulness” and indicate its causal role in proporitionality of S and B/L.
Application of neural networks to computer recipe prediction
Authors: Bishop J. M. , Bushnell M. J. , Westland S.
Published: June 2007

Conventional mechanisms for computer colorant formulation commonly employ the Kubelka‐Munk theory to relate reflectance values to colorant concentrations. However, there are situations where this approach is not applicable and hence an alternative is desirable. One such method is to utilize artificial intelligence techniques to mimic the behavior of the professional colorist. The purpose of this paper is to describe recent research being carried out at Reading University, sponsored by Courtaulds Research, that utilizes collections of cellular automata, known as neural networks, in the problem of recipe prediction.
Applications of set theoretic methods to color systems
Authors: Trussell H. J.
Published: June 2007

A vector‐space approach to color systems has been shown to be useful in describing metameric effects and producing metamers under different illuminations. The vector‐space approach has also been used to describe color scanning and reproduction systems. This article extends the applications presented in previous work by introducing set theoretic concepts which allow the addition of realistic constraints. The set theoretic methods allow the full range of solutions of color problems to be explored by allowing a set of solutions to a particular problem formulation. The applications discussed here include producing realizable metamers and the design of scanning filters.
Optimization algorithm for designing colored glass filters to simulate CIE illuminant D65
Authors: Liu Yan , Berns Roy S. , Shu Yuexin
Published: June 2007

An optimization algorithm is described and was used to design colored glass filters arranged either side‐by‐side, or side‐by‐side in series for simulating CIE illuminant D65. Many optimal results were obtained in acceptable CPU time; the category of the D65 daylight simulators that were constructed was BE (CIELUV). These D65 daylight simulators have the advantages of metamerism index B in the visible range, a high color‐rendering index, and high light efficiency. Additionally, they use tungsten‐halogen lamps of low correlated color temperature.
Cesia: A system of visual signs complementing color
Authors: Caivano José Luis
Published: June 2007

Color theory has been worked up by some researchers in order to consider factors such as transparence, brightness, opacity, etc., but no color order system has been devised to include these variables in addition to the usual three. This work proposes to treat these factors as theoretically separate from color (even if they are related with it), developing an order system for them. When it is taken parallel to color, this system helps to describe all the visual perceptions produced by light stimuli.
Effects of luminance level on the saturation function: Sensitivities based on saturation discrimination
Authors: Kimura Eiji
Published: June 2007

The saturation of a monochromatic light λ is defined as the reciprocal of the just noticeable colorimetric purity ΔP(λ) from a white, which is a conventional definition having been used previously often. The present study measures saturation functions of monochromatic lights at various luminance levels ranging from 10 to 1000 Td. The main result of this article is that the saturation function systematically changes in shape with the luminance level; as the luminance increases, the values of 1/ΔP(λ) relatively increase for shorter wavelengths. The chromatic sensitivity function C(λ) is defined by the reciprocal of the radiance of a monochromatic light λ added to the white field in order to detect a difference in chromaticity from the equal‐luminance reference white. The C(λ) functions at various luminance levels are shown to have three peaks at the short‐, middle‐, and long‐wavelength regions. These peaks are similar to those of the increment threshold functions, and the saturation function can be approximated by the ratio of the increment threshold spectral sensitivity to the relative luminous efficiency, except for the 570 nm data.
Psychophysical verification of the accuracy of color and color‐difference simulations of surface samples on a CRT display
Authors: Rich Danny C. , Alston David L. , Allen Larry H.
Published: June 2007

We describe an experiment to visually quantify the accuracy of the simulation of the color and color‐difference of surface samples on a CRT display unit. A gray‐scale‐anchored, magnitude‐estimation experiment was performed to assess the absolute quality of the simulations and a forced‐choice, paired‐comparisons experiment was performed to assess the relative quality of the simulations. Results indicate that an average color difference for overall simulation accuracy can be under 3.0 CIELAB color‐difference units for highcolor‐temperature sources, and slightly worse for low‐colortemperature sources. All simulations were well under the 6 to 12 unit differences reported for typical color reproduction. Possible reasons for the residual color differences between the current simulations and the theoretical limit are presented.
Use of calibrants in food colour measurement: An international cooperative study
Authors: Kent M. , Calvert A. , Macdougall D. , Malkin F. , Witt K.
Published: June 2007

The agreement between a number of laboratories and instrument types (tristimulus colorimeters, spectrophotometers) in the measurement of colours distributed around a central point in colour space was studied. The improvement gained by calibration against the central colour as opposed to calibration against a white standard is quantified and its variation with distance from the centroid is shown. In this way the limits of applicability of the so‐called hitching post procedure are defined.
Spatial sensitization and adaptation in a long‐wavelength cone pathway
Authors: Finkelstein Marcia A.
Published: June 2007

Flashed‐field sensitivities measured with a long‐wavelength probe have a red/green shape when stimuli are presented on a steady background but resemble the L‐cone absorption spectrum in the dark [M. A. Finkelstein, M. Harrison, and D. C. Hood, Sites of sensitivity control within a long‐wavelength cone pathway, Vision Res. 30, 1145–1158 (1990)]. We previously speculated that this could be due to concealed color opponency; receptive‐field surrounds, fed by M cones, are eliminated under dark adaptation. The current study tested this hypothesis with a sensitization paradigm. Thresholds were measured for a 640‐nm probe presented on flashes of two sizes. Data were obtained in the dark and on a 4.0‐log10 td steady background. The results suggest a model in which the L cones comprise a center mechanism and both M and L cones a weaker inhibitory surround. Dark adaptation eliminates only the M component of the surround.
Color notation conversion by neural networks
Authors: Tominaga Shoji
Published: June 2007

This article describes a new method for color‐notation conversion between the Munsell and CIE color systems by means of neural networks. A multilayer feedforward network is regarded as a nonlinear transformer which is trained to learn a mapping between the two color spaces. We adopt the backpropagation learning rule for the training. The mapping is then realized in a simple network architecture in which nonlinear units are linked in parallel and in layers. The tables of data by Newhall, Nickerson, and Judd are used in computer simulations of training and testing phases. We determine an effective network structure and training strategy based on experiments under different conditions. The conversion accuracy is demonstrated in both directions, Munsell‐to‐CIE and CIE‐to‐Munsell. In the neural network method, it is not necessary to use a special database. The knowledge of the mapping is stored in a small set of weighting parameters in the network. We point out that the proposed method for color‐notation conversion provides several potential advantages over the conventional approach based on interpolation of the data tables.
CRT colorimetry. Part II: Metrology
Authors: Berns Roy S. , Gorzynski Mark E. , Motta Ricardo J.
Published: June 2007

The colorimetric characterization of computer‐controlled CRT displays require radiometric measurements with high precision and accuracy in order to achieve acceptable colorimetric accuracy in defining stimuli generated with this type of imaging modality. Precision and accuracy requirements for photometers, colorimeters, and spectroradiometers were evaluated. When models are used to relate digital counts defining a stimulus and resulting spectral radiant exitance, displays are assumed to exhibit channel and spatial independence. A variety of tests and the results of evaluating four imaging systems are described. From these analyses, measurement accuracy is mainly limited by wavelength scale in the case of spectro‐radiometers and filter fit in the case of colorimeters. Measurement precision is limited by the number of significant figures for fixed‐range devices and signal‐to‐noise limitations for low‐luminance stimuli. Display accuracy is limited by a lack of channel and spatial independence. Display precision is mainly limited by the electronic design of the display and the stability and load independence of the gun amplifiers. © 1993 John Wiley & Sons, Inc.
Rod contribution to large‐field color matching
Authors: Shapiro Arthur G. , Pokorny Joel , Smith Vivianne C.
Published: June 2007

The linear algebraic features of foveal colorimetry do not apply to 10° degree colorimetric fields. A light presented as a foveal 2° field stimulates the three classes of cone photoreceptors, and a light presented as a 10° field stimulates the cone and rod photoreceptors. While no more than three primary lights are required to match either of these lights, large‐field color matches with three primaries do not obey Grassmann's laws of linearity because the relative contribution of the rod signal to a color match changes with retinal illuminance. A three‐primary set of color‐matching functions (CMFs) affected by rodintrusion, therefore, cannot serve as the basis for colorimetry. Stiles and Burch removed the effects of rod activity from their 10° color‐matching data to create a set of CMFs that have the same linear algebraic features as foveal, 2° colorimetry. They did this by selecting the primaries appropriately, making the matches at high retinal illuminance levels, and removing the small residual effects with numerical techniques. the resulting CMFs formed the major portion of the CIE 1964 10° Standard Observer. These CMFs describe color matches at the level of the cone‐photoreceptor and, therefore, can be generalized to predict color matches with any set of primaries, but they cannot account for the effects of rod activity in the matching sample. If two colorimetric fields differ in the amount of rod activity they produce, calculations with the 1964 Standard Observer may predict their metamerism inaccurately. This article summarizes Stiles and Burch's methods for removing the effect of rods, gives examples of the implications for colorimetry, and suggests procedures for preventing the adverse effects of rod activity in applied situations. It also shows that three recently published sets of 10° CMFs may be influenced by the effects of rod activity. © 1994 John Wiley & Sons. Inc.
A comparative study of color measurement lntstrumentation
Authors: Rodgers James , Wolf Kaye , Willis Norm , Hamilton Don , Ledbetter Ralph , Stewart Curtis
Published: June 2007

A multiplant Quality Improvement Team [QIT] was firmed to develop and implement an evaluation program for various color measurement .systems as potential replacements for the then‐current aging systems. The emphasis qf this article is the analytical methodology utilized to evaluate the various color systems. The evaluation program consisted cf two phases. Phase I was a general overview/review of several systems, while Phase II was an extensive internal comparative evaluation measurement systems. These were Milton‐Roy's ColorMate HDS, HunterLab's Ultrascan, Datacolor's CS‐5, and BYK‐Gardner's The Color Sphere [TCS]. The main comparison criteria were interinstrument agreement [agreement between two instruments ofthe same system], user‐friendly software and computer interface capability, vendor amenability to a long‐term logistical and maintenance relationship, and price. All systems were evaluated by duplicate measurements on various color tiles, yarns, and polymer flakes‐over 1600 measurements on each system. The systems were compared with an instrument matrix, a decision matrix, and a product matrix. The instrument matrix was a comparison qfinstrument parameters, software/math treatments, and economics. The decision matrix was a forced ranking of each system by each criteria category [1–4 scale, with 1 representing the best and 4 representing the worst]. The product matrix accentuated the relative importance ofone criterion category over another by multiplying the forced ranking by the criticality of the category. The criticality of a given category wus determined by consensus within the QIT. Thr combination qf the three matrices allowed the evaluator[.s] t o select the color rneasuremmt system that best satixfied the color measurement needs and requirements of their facility and their products. For this evaluation, all ofthe evaluated systems were superior to the then‐current agingsystems. As a result of this methodology, one instrument emerged as clearly superior. © 1994 John Wrley & Sons, Inc.
Color Matching in Paints Using a Method of Linear Programming
Authors: Bai Fengxiang , Zeng Hua , Yi Jidong , Liao Ningfang , Guo Lurong
Published: June 2007

This note is based on 2‐constant Kubelka‐Munk theory and the first‐order approximat ion ofspectrum, presenting a method of linear programming to compute the recipes and to get the basic database quickly. A lot of experimental results in paints have shown that matching precision may be achieved by following this practice. © 1994 John Wiley & Sons. Inc.
Match prediction of highly fluorescent colors
Authors: Simon Frederick T. , Funk Robert A. , Laidlaw Ann Campbell
Published: June 2007

Color formulation of fluorescent materials is not feasible with the usual methods used for nonfluorescent colors. Realizing the need for certain textiles that are dyed with fluorescent colorants, a technique was developed based on using certain dual‐monochromator measurements of the spectra of fluorescent colorants. to accomplish this formulation, a new spectral quantity independent of illuminant was developed for all fluorescent colorants. This is termed RELEX, which describes the relative excitation of the colorant. When this quantity is weighted by the spectral power distribution for a specific illuminant and factored for absorption by all ingredients in a mixture of colorants, the proper fluorescent emission is obtained, which can be added to the spectral reflected radiance factor, βs, for that mixture. Consequently, match prediction can be done for spectral radiance factor, βT, curves of fluorescent materials using an iterative estimation algorithm.
The calibration of instruments for the measurement of paper whiteness
Authors: Bristow J. Anthony
Published: June 2007

The pulp and paper industry traditionally measures a property called ISO‐brightness based on a filter function with an effective wavelength of 457 nm, but this is not a satisfactory measure of the appearance of the material. Currently there is a growing interest in determining a whiteness value based on the CIE‐whiteness equation with respect both to an indoor illumination and to the standardized D65 illuminant. This is not, however, merely a question of using the relevant mathematical functions. Many papers contain fluorescent whitening agents and this means that reproducible values can be obtained only if the instruments used are adjusted so that the relative UV‐content in the illumination falling on the sample is controlled to correspond to the chosen illuminant. the paper industry employs instruments with a well‐defined d/0° geometry, and the relevant ISO‐Standards also define a hierarchical calibration system, which enables all instruments to be calibrated with traceability to the perfect reflecting diffuser through a reference instrument. This calibration service has now been extended to include fluorescent standards assigned whiteness [D65/10°] values. This article describes the development of this calibration routine based on the absolute two‐monochromator instrument at BAM, Berlin.
Objective evaluation of color design. III
Authors: Kawamoto Naoki
Published: June 2007

A psychological test was performed by using computergenerated color patterns, which were composed of ordered repeats of random color arrangements, and the effects of the repeat number were investigated. the results were analyzed in terms of power spectra of the Fourier transform of the color patterns, and it was clearly found that the psychological evaluation depended strongly not only on the amount but also on the degree of concentration (or scatter) of the power spectrum. Furthermore, in order to predict the psychological values of the color patterns, multiple regression analyses were done by using three models with 13, 14, and 15 specified variables that were obtained from the Fourier transform. It was found that the multiple correlation coefficient increased considerably by introducing the second‐order term of a variable that indicates the degree of concentration of the dynamic components, especially for the evaluation of beautifulugly or interesting‐boring. © 1995 John Wiley & Sons, Inc.
Assessment of the influence of paper formation on the fluorescence contribution to brightness
Authors: Kulikova Yana Y. , Schaepe Michael K. , Robbins Wayne B.
Published: June 2007

Paper was produced under controlled conditions with a range of resultant formation and a constant level of fluorescent dye. Brightness and CIE‐Whiteness and the fluorescent contribution to brightness or whiteness were measured by directional and diffuse illuminations. Brightness, whiteness, and fluorescence variability were evaluated as the illuminated sample aperture diameter was varied from a maximum of 12.7 mm to a minimum of 6.0 mm over a broad range of paper formation. an increase in the variance of CIE‐Whiteness both including and excluding fluorescence is observed as formation degrades. the variance of the fluorescent contribution also increased, but not in a manner to suggest it is independent of the whiteness including or excluding fluorescence measurements. A higher level of instrument noise prevented a similar definitive concl usion for the fluorescent contribution to directional brightness, even though similar trends were observed. an increase in variance was observed for all whiteness and brightness measurements as viewing aperture size diminished. This suggests an opportunity to understand subjective appearance as a function of viewing aperture size. © 1995 John Wiley & Sons, Inc.
Testing colour‐appearance models: Guidelines for coordinated research
Authors: Fairchild Mark D.
Published: June 2007

These guidelines provide an overview of the many issues involved in generating visual data that can be used to evaluate the performance of colour‐appearance models. the three main sections of these guidelines outline the parameters that must be evaluated and controlled in experimental setups for colour‐appearance experiments, suggested psychophysical techniques for gathering the data, and some suggested techniques for data analysis. Experimental parameters addressed include models to be tested, illumination conditions, background and surround conditions, types of stimuli to be used, and issues relating to viewing technique. the psychophysical techniques of magnitude estimation, matching, and direct model testing (paired comparison) are described. Data analysis techniques for the evaluation of colour‐appearance scales, corresponding‐colours data, and model performance scales are suggested.
Considering the surround in device‐independent color imaging
Authors: Fairchild Mark D.
Published: June 2007

When viewing images, the relative luminance of the surround has a profound impact on the apparent contrast of the image. For this reason, photographic transparencies intended for projection in a darkened room are produced with an objective contrast substantially higher than that necessary for optimum reproduction as prints viewed in an illuminated surround. the dark surround causes the image elements to appear lighter and this effect is stronger for darker colors resulting in a loss in perceived contrast. This effect is also of great importance in deviceindependent color imaging since resultant images might be observed in a wide variety of media and viewing conditions. Research on psychophysical scaling of brightness and lightness and the effects of background and surround relative luminance on lightness and chroma is reviewed. the importance of this research for device‐independent color imaging systems is described along with the prediction of these effects using the RLAB color‐appearance model. Finally, experiments testing the use of RLAB and other color‐appearance models in cross‐media color reproduction applications are described.
Inducible gene expression with the Tet‐on system in CD4+ T cells and thymocytes of mice
Authors: Huai Jisen , Firat Elke , Niedermann Gabriele
Published: June 2007

CD4+ T cells with their growing list of effector and regulatory subpopulations have vital functions within the immunohematopoietic system. We report here on the first mouse lines that allow temporally and quantitatively controlled expression of transgenes specifically in CD4+ thymocytes and T cells. These were constructed using the Tet‐on system. The rtTA2S‐M2 version of the reverse tetracycline‐dependent transactivator was placed under control of all known CD4 regulatory elements. Reporter transgene expression in mice expressing these constructs is highly specific for CD4+ cells, is strictly dependent on the tetracycline derivative doxycycline, and can be regulated by up to five logs depending on the doxycycline concentration. Moreover, we demonstrate that these mice can be used for noninvasive in vivo imaging of a coexpressed luciferase reporter. These new mouse lines should be highly valuable for studying and manipulating numerous aspects of CD4+ T cell development, biology, and function. genesis 45:427–431, 2007. © 2007 Wiley‐Liss, Inc.
Taxation of fertilizers, pesticides and energy use for agricultural production in selected EU countries
Authors: Nam Chang Woon , Parsche Rüdiger , Radulescu Doina Maria , Schöpe Manfred
Published: June 2007

This study examines the differences in taxation of specific means of agricultural production such as fertilizers, pesticides, mineral oil products, gas and electricity in selected EU nations. Apart from the description of relevant tax rules prevailing in these countries, an international comparison of tax burden on profit, which is caused by the combination of the individual tax regulations, is made based on a model entity. Such a comparison identifies the distortion led by the taxation on agricultural firms' business performance and their competitiveness. Copyright © 2007 John Wiley & Sons, Ltd.
Stereospecific Synthesis, Structural Characterisation and Resolution of 2‐Phospha[3]ferrocenophane Derivatives – a New Chiral Scaffold
Authors: Fleury‐Brégeot Nicolas , Panossian Armen , Chiaroni Angèle , Marinetti Angela
Published: June 2007

The first 2‐phospha[3]ferrocenophanes containing stereogenic carbon atoms in the three‐atom bridge have been synthesised from phenylphosphane by stereospecific ring‐closing phosphanation reactions. Either α‐substituted 1,1′‐bis(hydroxymethyl)ferrocenes or the corresponding 2‐oxa‐[3]ferrocenophanes have been used as diastereomerically pure starting materials. The resolution of 1,2,3‐triphenyl[2]phosphaferrocenophane has been achieved by chromatographic separation of the diastereomeric adducts of a chiral cyclopalladate complex. The X‐ray crystal structures of two 2‐phospha[3]ferrocenophane‐borane complexes are also reported. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Enantioselective analysis of pheniramine in urine by charged CD‐mediated CZE provided with a fiber‐based DAD and an on‐line sample pretreatment by capillary ITP
Authors: Marák Jozef , Mikuš Peter , Maráková Katarína , Kaniansky Dušan , Valášková Iva , Havránek Emil
Published: June 2007

Application potentialities of CZE on‐line coupled with capillary ITP and DAD to the identification and determination of trace concentration levels (μg/L) of pheniramine (PHM) enantiomers and their metabolites present in complex ionic matrices of biological origin (urine) are shown. An enhanced (enantio)selectivity of the CZE separation system obtained by the addition of carboxyethyl‐β‐CD (CE‐β‐CD) to the carrier electrolyte provided CZE conditions for a reliable identification of similar/identical DAD spectra of structurally related compounds (PHM enantiomers and their metabolites) in clinical urine samples differing in qualitative and quantitative composition of sample matrix constituents. A high sample loadability (a 30 μL sample injection volume), partial sample clean‐up (removing macroconstituents from the sample), and preconcentration of the analytes in ITP stage resulted in the decrease of concentration LOD for PHM enantiomers in urine to 5.2 and 6.8 μg/L (2.2×10−8 and 2.8×10−8 mol/L), without using any sample pretreatment technique. The background correction and smoothing procedure applied to the raw DAD spectra provided analytically relevant DAD spectra of PHM enantiomers and their metabolites also when they were present in urine sample (30 μL injection volumes of ten‐times diluted urine sample) at a 9×10−8 mol/L concentration. DAD spectra of PHM enantiomers present in urine samples matched their reference spectra with reasonable certainties. DAD spectra of PHM metabolites were compared with the reference spectra of PHM enantiomers and a good match was found which indicates the similarities in the structures of enantiomers and their metabolites detected in the urine samples. This fact allows performing the quantitative analyses of PHM metabolites in the urine samples by applying the calibration parameters of PHM enantiomers also for PHM metabolites and the results show the possibilities of using the ITP–CZE–DAD combination for the direct analysis of PHM enantiomers and/or their metabolites in urine without any sample pretreatment. ITP–CZE–DAD method with oppositely charged selector is suggested to use in clinical research as it provides favorable performance parameters including sensitivity, linearity, precision, recovery, and robustness with minimal demands on sample preparation.
XRCC1 down‐regulation in human cells leads to DNA‐damaging agent hypersensitivity, elevated sister chromatid exchange, and reduced survival of BRCA2 mutant cells
Authors: Fan Jinshui , Wilson Paul F. , Wong Heng‐Kuan , Urbin Salustra S. , Thompson Larry H. , Wilson David M.
Published: June 2007

Previous studies using rodent cells indicate that a deficiency in XRCC1 results in reduced single‐strand break repair, increased sensitivity to DNA‐damaging agents, and elevated levels of sister chromatid exchange (SCE). Epidemiological studies have suggested an association of certain human XRCC1 polymorphisms with genetic instability and cancer susceptibility. However, investigations on the molecular functions of XRCC1 in human cells are limited. To determine the contributions of this nonenzymatic scaffold protein, we suppressed XRCC1 levels in several human cell lines using small interfering RNA (siRNA) technology. We report that XRCC1 down‐regulation in HeLa cells leads to a concomitant decrease in the DNA ligase 3 protein level and an impaired nick ligation capacity. In addition, depletion of XRCC1 resulted in a significantly increased sensitivity to the alkylating agent methyl methanesulfonate and the thymidine base analog 5‐hydroxymethyl‐2′‐deoxyuridine, a slightly increased sensitivity to ethyl methanesulfonate and 1,3‐bis(2‐chloroethyl)‐1‐nitrosourea, and no change in the response to camptothecin. We also discovered that a 70–80% reduction in XRCC1 protein leads to an elevated level of SCE in both HeLa cells and normal human fibroblasts, but does not affect chromosome aberrations in the diploid fibroblasts. Last, XRCC1 siRNA transfection led to an ∼40% decrease in the survival of BRCA2‐deficient cells, supporting a model whereby the accumulation of unrepaired SSBs leads to the accumulation of cytotoxic DNA double strand breaks following replication fork collapse in cells defective in homologous recombination. Environ. Mol. Mutagen., 2007. Published 2007 Wiley‐Liss, Inc.
Turnover of resident retinal microglia in the normal adult mouse
Authors: Xu Heping , Chen Mei , Mayer Eric J. , Forrester John V. , Dick Andrew D.
Published: June 2007

The retina contains two distinct populations of monocyte‐derived cells: perivascular cells (macrophages) and parenchymal cells (microglia), important in homeostasis, neuroinflammation, degeneration, and injury. The turnover of these cells in the retina and their repopulation in normal physiological conditions have not been clarified. Bone marrow (BM) cells from EGFP‐transgenic mice were adoptively transferred into lethally irradiated normal adult C57BL/6 mice. Eight, 14, and 26 weeks later mice were sacrificed and retinal flatmounts were prepared. Retinal microglia were identified by F4/80, CD45, and Iba‐1 immunostaining. BrdU was injected into normal mice for 3–14 days and cell proliferation was examined by confocal microscopy of retinal flatmounts. Few (6.15 ± 2.02 cells/retina) BrdU+ cells were detected and of these some coexpressed CD11b (1.67 ± 0.62 cells/retina) or F4/80 (0.57 ± 0.30 cells/retina). BM‐derived EGFP+ cells were detected by 8‐weeks post‐transplantation. By 6 months, all retinal myeloid cells were EGFP+. Consecutively, donor BM‐EGFP+ cells were demonstrated within the: (1) peripheral and juxtapapillary retina, (2) ganglion cell layer, (3) inner and outer plexiform layers, and (4) photoreceptor layer. EGFP+ cells within the ganglion layer were amoeboid in shape and F4/80highCD45highIba‐1high, whereas cells in the inner and outer plexiform layers were ramified and F4/80low CD45lowIba‐1low. Perivascular macrophages expressed less F4/80, CD45, and Iba‐1 compared with parenchymal microglia. Our results suggest that BM‐derived monocyte precursor cells are able to migrate across the BRB and replace retinal microglia/macrophages. The complete replacement of retinal microglia/macrophages takes about 6 months. In situ proliferation was predominantly of nonhemopoetic retinal cells. © 2007 Wiley‐Liss, Inc.
A randomised double‐blind placebo‐controlled trial of folic acid supplementation of cholinesterase inhibitors in Alzheimer's disease
Authors: Connelly Peter J. , Prentice Neil P. , Cousland Gary , Bonham Jim
Published: June 2007

Objectives

(1) to assess the effect of 1 mg folic acid supplementation of cholinesterase inhibitors (ChI) in a 6 month double‐blind placebo‐controlled study of patients with Alzheimer's Disease (AD) and (2) to assess whether outcome measures were affected by changes in homocysteine levels.

Method

Fifty‐seven consecutive outpatients with probable AD were treated concurrently with a ChI and either folic acid or placebo. None had conditions or medication known to interfere with folate metabolism. Fasting folate and homocysteine levels were measured prior to commencing ChI and 6 months later. Response was categorised using criteria of the National Institute of Clinical Excellence (NICE).

Results

Twelve males and 29 females completed treatment (mean age 76.27 SD 6.23 years, Mini‐Mental State Examination (MMSE) 23.49 SD 3.53, baseline homocysteine 18.39 SD 4.62 micromoles per litre). 23 received folic acid and 18 placebo. There were no significant baseline differences or use of individual ChI between the two arms. After 6 months a significant difference was seen in the change from baseline in combined Instrumental Activities of Daily Living and Social Behaviour scores between arms (folate + 1.50 (SD 5.32) vs placebo −2.29 (SD 6.16) (p = 0.03) but not change in MMSE scores. Sixteen of 23 subjects receiving folic acid and 7/18 placebo subjects were classified as NICE responders (p = 0.05).

Conclusion

This pilot double blind study suggests that response to ChI in patients with AD may be improved by the use of folic acid. The relationship between any change in homocysteine levels and response to treatment is discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Hippocampal involvement in contextual modulation of fear extinction
Authors: Ji Jinzhao , Maren Stephen
Published: June 2007

Extinction of fear conditioning in animals is an excellent model for the study of fear inhibition in humans. Substantial evidence has shown that extinction is a new learning process that is highly context‐dependent. Several recovery effects (renewal, spontaneous recovery, and reinstatement) after extinction suggest that the contextual modulation of extinction is a critical behavioral mechanism underlying fear extinction. In addition, recent studies demonstrate a critical role for hippocampus in the context control of extinction. A growing body of evidence suggests that the hippocampus not only plays a role in contextual encoding and retrieval of fear extinction memories, but also interacts with other brain structures to regulate context‐specificity of fear extinction. In this article, the authors will first discuss the fundamental behavioral features of the context effects of extinction and its underlying behavioral mechanisms. In the second part, the review will focus on the brain mechanisms for the contextual control of extinction. © 2007 Wiley‐Liss, Inc.
Estimation of root zone salinity, using SaltMod, in the arid region of Turkey
Authors: Bahçeci̇ İdri̇s , Nacar A. Suat
Published: June 2007

Soil salinity and waterlogging are the two most common problems limiting crop production in irrigated agriculture in southeastern Turkey. Poor water management and irrigation water leakage from the irrigation canals have caused the groundwater table to rise over approximately 35 000 ha of land. There is a need to predict drainage for salinity control in the Harran plain that has been under irrigation since 1995. The objective of this study was to establish the effects of current irrigation/drainage practices on root zone salinity, using SaltMod. Several scenarios like the changes in irrigation depth, water quality, varying drain spacing and drain depth effects on root zone salinity and groundwater table depth were tested. Experimental values showed that the initial average root zone salinity was 9.03 dS m−1 and decreased to 3.03 dS m−1 at the end of three years of irrigation seasons. These values were very close to those predicted by the SaltMod model. The measured drain discharge rates in the three test years were 0.099, 0.067 and 0.084 m/season. SaltMod revealed that when the drain depth became 1.40 m, there was no change in root zone salinity for the next 10 years. Copyright © 2007 John Wiley & Sons, Ltd.
Inhibition of carrier‐mediated uptake of epirubicin reduces cytotoxicity in primary culture of rat hepatocytes
Authors: Iwakiri Tomomi , Okumura Manabu , Hidaka Muneaki , Kumagai Yuki , Ichihara Emi , Kawano Yohei , Arimori Kazuhiko
Published: June 2007

Epirubicin, an antineoplastic drug, is considered to be taken up by tumor cells via a common carrier by facilitated diffusion and is then pumped out in an energy‐dependent manner because epirubicin is a substrate for P‐glycoprotein (P‐gp). However, this study investigated the details of the influx mechanism of epirubicin and demonstrated that epirubicin uptake was mediated by active carrier systems in addition to facilitated diffusion in the primary culture of rat hepatocytes. The uptake of epirubicin gradually increased in a saturated manner when the concentrations were between 1 × 10−7mand 1 × 10−6m. In contrast, the uptake increased progressively in a linear manner when the concentration was high (greater than 1 × 10−6m). The uptake of epirubicin at a clinical concentration (7.5 × 10−7m) was significantly reduced at 4 °C and significantly inhibited when pretreated with metabolic inhibitors (carbonyl cyanide p‐trifluoromethoxyphenylhydrazone (FCCP), rotenone and sodium azide) by nearly 25%. Furthermore, an organic anion transporter inhibitor, namely, 4,4′‐diisothiocyanato‐stilbene‐2,2′‐disulfonic acid (DIDS); organic anion transport substrates, namely, para‐aminohippurate (PAH), taurocholic acid and estradiol 17‐β‐d‐glucuronide; and organic cation transporter inhibitors, namely, verapamil and tetraethylammonium significantly reduced the uptake of epirubicin. Furthermore, pretreatment with verapamil and PAH significantly prevented epirubicin‐induced reduction of proliferative activity in rat hepatocytes. These results indicated that the uptake of epirubicin was induced, at least in part, by the active transport protein in rat hepatocytes; the inhibition of the probable transport protein protected the intact normal cells from the injury induced by the cytotoxicity of epirubicin. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis and characterization of fluorocarbon chain end‐capped poly(carbonate urethane)s as biomaterials: A novel bilayered surface structure
Authors: Xie Xingyi , Tan Hong , Li Jiehua , Zhong Yinping
Published: June 2007

Poly(carbonate urethane)s (PCUs) are usually considered as biostable elastomers for long‐term implantation. However, their hydrolytic stability is still questionable. The biodegradation appears to be initiated by oxidative and hydrolytic substances released by inflammatory cells. Therefore, the biostability of polyurethane might be improved with control of surface structure to reduce inflammatory response. A new type of PCUs end‐capped with perfluoro chains was synthesized to explore a new avenue. A fluorinated alcohol, 2,2,3,3,4,4,5,5,6,6,7,7,8,8,8‐pentadecafluoro‐1‐octanol (PDFOL), was end‐capped to the backbones of PCUs by reaction of the OH in PDFOL with the NCO end groups in PCU backbones. Contact angle measurement, X‐ray photoelectron spectroscopy, atomic force microscopy, and attenuated total reflectance‐Fourier transform infrared spectroscopy were used to examine their surface structure and properties. Elemental analysis, gel permeation chromatography, differential scanning calorimetry, and tensile testing were used to assess bulk chemistry and properties. The fluorocarbon end‐capped poly (carbonate urethane)s (FPCUs) maintained the high mechanical properties (about 40 MPa tensile strength) and typical microphase separation structure of polyurethane elastomers. Results from surface analyses revealed the presence of a double‐layered structure at the surfaces of the FPCUs. The first one was composed of fluorocarbon tails rising up on the uppermost layer and the second one made up of hard‐segments. This novel bilayered surface structure could protect the weak carbonate linkages in soft segments, and consequently, may potentially increase the biostability of this kind of polyurethanes. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Fluorine doping into diamond‐like carbon coatings inhibits protein adsorption and platelet activation
Authors: Hasebe Terumitsu , Yohena Satoshi , Kamijo Aki , Okazaki Yuko , Hotta Atsushi , Takahashi Koki , Suzuki Tetsuya
Published: June 2007

The first major event when a medical device comes in contact with blood is the adsorption of plasma proteins. Protein adsorption on the material surface leads to the activation of the blood coagulation cascade and the inflammatory process, which impair the lifetime of the material. Various efforts have been made to minimize protein adsorption and platelet adhesion. Recently, diamond‐like carbon (DLC) has received much attention because of their antithrombogenicity. We recently reported that coating silicon substrates with fluorine‐doped diamond‐like carbon (F‐DLC) drastically suppresses platelet adhesion and activation. Here, we evaluated the protein adsorption on the material surfaces and clarified the relationship between protein adsorption and platelet behaviors, using polycarbonate and DLC‐ or F‐DLC‐coated polycarbonate. The adsorption of albumin and fibrinogen were assessed using a colorimetric protein assay, and platelet adhesion and activation were examined using a differential interference contrast microscope. A higher ratio of albumin to fibrinogen adsorption was observed on F‐DLC than on DLC and polycarbonate films, indicating that the F‐DLC film should prevent thrombus formation. Platelet adhesion and activation on the F‐DLC films were more strongly suppressed as the amount of fluorine doping was increased. These results show that the F‐DLC coating may be useful for blood‐contacting devices. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Spatial distribution of mineralized bone matrix produced by marrow mesenchymal stem cells in self‐assembling peptide hydrogel scaffold
Authors: Hamada Kazunori , Hirose Motohiro , Yamashita Toshihiko , Ohgushi Hajime
Published: June 2007

We evaluated the osteogenic differentiation of mesenchymal stem cells (MSCs) using a new class of synthetic self‐assembling peptide hydrogels, RADA 16, as a scaffold for three‐dimensional culture. MSCs derived from rat bone marrow were culture‐expanded and seeded into the hydrogel and further cultured in osteogenic medium containing β‐glycerophosphate, ascorbic acid, and dexamethasone for 2–4 weeks. High alkaline phosphatase activity and osteocalcin (OC) contents were detected at both the protein and gene expression levels during the culture periods. Both calcium and the OC contents increased over time, indicating the growth of a mineralized extracellular matrix within the hydrogel. Moreover, the process of the growth of the mineralized matrix determined by three‐dimensional microarchitecture images was obtained by confocal laser scanning microscopy. The findings show that MSCs can differentiate into mature osteoblasts to form mineralized matrices within the hydrogel scaffold. Importantly, the differentiation can occur three dimensionally within the hydrogel, indicating that RADA 16 can be considered attractive synthetic biomaterial for use in bone tissue engineering. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Conducting psychotherapy around the globe: Orientation and introduction
Authors: Rehm Lynn P.
Published: June 2007

Psychology has become a worldwide science and profession. A number of international associations sponsor meetings and draw together psychologists from around the globe. Psychology and psychotherapy also vary considerably from country to country. Educational systems, licensing patterns, and practice parameters differ in different health service delivery systems depending on the history and policies of the particular country. This issue contains invited articles by psychologists, from a wide sample of countries, who describe the nature of psychotherapy practice in their respective countries and its application to the hypothetical case of Mrs. A. The authors place the case in the cultural context Mrs. A might encounter in their country. © 2007 Wiley Periodicals, Inc. J Clin Psychol: In Session 63: 707–711, 2007.