bluuebunny/crossref_metadata_2025_split huggingface dataset:
The utility of multivariate design in PLS modeling
Authors: Wold Svante , Josefson Mats , Gottfries Johan , Linusson Anna 
Published: July 2004

AbstractWe discuss the use of multivariate design to ensure representativity and balance of the training set data for PLS multivariate modeling. Three application areas are used to illustrate the discussion, namely multivariate calibration in process analytical chemistry, quantitative structure activity relationships (QSAR) in medicinal and pharmaceutical chemistry, and data mining. In both QSAR and data mining, the multivariate design is also useful for the balanced sampling of data from a large, complex, and unbalanced data repository. Copyright © 2004 John Wiley & Sons, Ltd.
Bridge–PLS regression: two‐block bilinear regression without deflation
Authors: Gidskehaug Lars , Stødkilde‐Jørgensen Hans , Martens Magni , Martens Harald 
Published: July 2004

AbstractFunctional MRI (fMRI) represents experiments with experimental design in the time domain, and yields a very high number of response variables. In this paper an fMRI data set is analyzed for temporal response delays relative to the design, and for spatial response patterns. Two families of two‐block PLS are compared, namely PLS Regression (PLSR) and a method developed by F.L. Bookstein, here called Bookstein PLS (BPLS). In BPLS, all components are found simultaneously, making the deflation of X and/or y superfluous. When reformulated as a regression method y = f(X), the BPLS performs badly compared with PLSR in the case of only one dependent variable, y, because only one component can be calculated. Contrary to the asymmetrical PLSR, the symmetrical BPLS lacks a predictive direction from X to y, and is therefore difficult to assess, e.g. by cross‐validation. A new PLS method, here called bridge–PLS regression, is presented. It combines elements from both PLSR (predictive asymmetry) and BPLS (all components determined by one single eigen‐decomposition). Copyright © 2004 John Wiley & Sons, Ltd.
The Nenitzescu reaction: an initial screening of experimental conditions for improvment of the yield of a model reaction
Authors: Katkevica Daze , Trapencieris Peteris , Boman Arne , Kalvins Ivars , Lundstedt Torbjörn 
Published: July 2004

AbstractThis paper describes the synthesis of the biologically important indole scaffold by using the Nenitzescu reaction. The scope and limitation of the reaction is investigated by multivariate methods where concentration, ratio of substrate and reactant, solvent, temperature and time are varied in a systematic way. The present investigation is the first reported systematic study of the impact of the experimental settings in the Nenitzescu reaction and is part of a more thorough project in which this reaction will be explored in more detail. Copyright © 2004 John Wiley & Sons, Ltd.
Persistent area socioeconomic disparities in U.S. incidence of cervical cancer, mortality, stage, and survival, 1975–2000
Authors: Singh Gopal K. , Miller Barry A. , Hankey Benjamin F. , Edwards Brenda K. 
Published: July 2004

AbstractBACKGROUNDTemporal cervical cancer incidence and mortality patterns and ethnic disparities in patient survival and stage at diagnosis in relation to socioeconomic deprivation measures have not been well studied in the United States. The current article analyzed temporal area socioeconomic inequalities in U.S. cervical cancer incidence, mortality, stage, and survival.METHODSCounty and census tract poverty and education variables from the 1990 census were linked to U.S. mortality and Surveillance, Epidemiology, and End Results cancer incidence data from 1975 to 2000. Age‐adjusted incidence and mortality rates and 5‐year cause‐specific survival rates were calculated for each socioeconomic group and differences in rates were tested for statistical significance at the 0.05 level.RESULTSSubstantial area socioeconomic gradients in both incidence and mortality were observed, with inequalities in cervical cancer persisting against a backdrop of declining rates. Cervical cancer incidence and mortality rates increased with increasing poverty and decreasing education levels for the total population as well as for non‐Hispanic white, black, American Indian, Asian/Pacific Islander, and Hispanic women. Patients in lower socioeconomic census tracts had significantly higher rates of late‐stage cancer diagnosis and lower rates of cancer survival. Even after controlling for stage, significant differences in survival remained. The 5‐year survival rate among women diagnosed with distant‐stage cervical cancer was approximately 30% lower in low than in high socioeconomic census tracts.CONCLUSIONSCensus‐based socioeconomic measures such as area poverty and education levels could serve as important surveillance tools for monitoring temporal trends in cancer‐related health inequalities and targeting interventions. Cancer 2004. Published 2004 by the American Cancer Society.
Quality of life and survival prediction in terminal cancer patients
Authors: Vigano Antonio , Donaldson Nora , Higginson Irene J. , Bruera Eduardo , Mahmud Salaheddin , Suarez‐Almazor Maria 
Published: July 2004

AbstractBACKGROUNDIt remains unclear whether health‐related quality of life (HRQoL) measurements from patients and staff can be combined with medical data to predict survival in patients with terminal cancer.METHODSThe correlations between survival and potential health‐related quality‐of‐life (HRQoL) prognostic variables were explored in 2 independent cohorts of patients with terminal cancer (248 patients in Cohort 1 and 756 patients in Cohort 2) after adjusting for clinical and demographics variables using Cox regression models.RESULTSAt the onset of the terminal phase (Cohort 1), the hazards of dying increased by 28% in the presence of dyspnea and by 68% in the presence of nausea/emesis; however, the most important predictors of worse survival were the presence of liver metastases (hazard ratio [HR], 2.5; 95% confidence interval [95% CI], 1.8–3.8), lung tumor (HR, 2.4; 95% CI, 1.7–3.4), and tumor burden (HR, 2.0; 95% CI, 1.4–2.7). In contrast, for patients who were seen in later stages of their terminal disease (Cohort 2), dyspnea (HR, 1.5; 95% CI, 1.1–1.9) and the coexistence of weakness with a diagnosis of digestive tumors (HR, 5.2; 95% CI, 1.2–21.8), breast tumors (HR, 3.1; 95% CI, 1.6–6.2), and genitourinary tumors (HR, 3.5; 95% CI, 1.6–7.8) were more predictive of survival than the type of tumor primary. Emotional functioning along with anxiety, spiritual distress, and lack of insight were not associated consistently with survival in both cohorts.CONCLUSIONSHealth care professionals should focus on physical HRQoL indicators, such as nausea and emesis, dyspnea, and weakness, to gather prognostic clues in patients with terminal cancer. These symptoms may reflect consequences of cancer cachexia and the progress of patients toward this terminal syndrome. Psychosocial distress did not appear to be associated consistently with survival; however, future studies should clarify further the prognostic significance of “positive attitudes”, such as hope and optimism, in patients with advanced cancer. Cancer 2004. © 2004 American Cancer Society.
Moses Harris's The Natural System of Colours and its later representations
Authors: Spillmann Werner 
Published: July 2004

AbstractIn this article the only complete copy of the very rare Natural System of Colours by Moses Harris (ca. 1770) is reproduced. The color plates of the two hue circles are compared to those in the second edition of Harris's work (1811) as well as the so‐called facsimile edition by Faber Birren of 1963. Comparisons are also made against later reproductions and modifications of these circles, including those by Mérimée and Varley. The small number of authentic representations are identified. Four versions of the central triangles of the “prismatic” color circle are compared, including that by the painter J. M. W. Turner. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 333–341, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20041
Estimation of fuzzy sets for computational colour categorization
Authors: Benavente Robert , Vanrell Maria , Baldrich Ramon 
Published: July 2004

AbstractColour is an important visual cue for computer vision applications. However, until recently, the automatic assignment of names to image regions has not been widely used due to the nonexistence of a general computational model for colour categorization. In this article we present a model for colour naming based on fuzzy‐set theory, in which each of the 11 basic colour terms defined by Berlin and Kay1is modeled as a fuzzy set with a characteristic function that assigns a membership value to the category to any colour sample. The model is based on combining two well‐known functions, a sigmoid and a Gaussian, to define a membership function for colour categories. It is denoted here as the sigmoid–Gaussian function and it fulfills a set of properties that make it adequate to this purpose. The characteristic functions for each colour category have been fitted to data obtained from a psychophysical experiment and the model has been tested on the Munsell colour array to show its validity. The results obtained indicate that our approach can be very useful as a first step to expand the use of colour‐naming information in computer vision applications. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 342–353, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20042
Theoretical analysis of subtractive color mixture characteristics II—General colorants and single tristimulus dimension
Authors: Matsushiro Nobuhito , Ohta Noboru 
Published: July 2004

AbstractTo further understand the characteristics of the stimulus values in colors obtained via subtractive color mixture, new theorems are provided. The theorems aim to establish bounds on mixtures of colorants given stimulus measurements of the constituent single‐colorant samples and the illuminant. Previously we only proved theorems for the ideal color. In the present article, new theorems related to the removal of the restriction of the ideal color are provided and establish bounds for all cases of spectral transmittances. The results of this article contributes to a systematization of subtractive color mixture. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 354–359, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20043
Colour matching using LEDs as primaries
Authors: Borbély Ákos , Schanda János 
Published: July 2004

AbstractIn our metameric experiment, the colour of a filtered incandescent lamp was matched with the additive mixture of three LEDs in a Lummer–Brodhun‐type visual photometer. Two sets of primaries were used, one had their dominant wavelengths at 467, 533, and 600 nm; the other set had dominant wavelengths at 478, 552, and 635 nm. These values correspond approximately to the characteristic wavelengths of the Prime and Non‐Prime Colour spectral regions defined by W. A. Thornton.1 Both the light of the incandescent lamp and that of the LED clusters were seen monocularly in a centrally divided bipartite field at a visual angle of 2°. The luminance of the matching fields was in the order of 20 cd/m2 to provide sufficient gamut for the LED mixture. Ten young observers with normal colour vision participated in the experiment. The emission spectra of the viewing fields were measured with an array‐type spectroradiometer, and two sets of colour‐matching functions were used to calculate the chromaticity of the matching stimuli: the CIE 1931 standard colorimetric observer and the Judd–Vos modification of the colour‐matching functions.We found that the Judd–Vos modification of the CIE 1931 standard observer represents more accurately the real observers in the evaluation of our results. No systematic differences between the use of the two sets of LEDs were detected in contradiction to Thornton's findings. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 360–364, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20044
Evaluation of the crispening effect using CRT‐displayed colour samples
Authors: Xin J. H. , Lam C. C. , Luo M. R. 
Published: July 2004

AbstractIn this study, the crispening effect was clearly observed when 38 neutral‐coloured sample pairs with only lightness differences were assessed under 5 neutral backgrounds of different lightness values. The sample pairs are CRT‐based colours, and they are selected along the CIELAB L* axis from 0 to 100. The magnitude of colour difference of each pair is 5.0 CIELAB units. The visual assessment results showed that there is a very large crispening effect. The colour differences of the same pair assessed under different backgrounds could differ by a factor of up to 8 for a sample pair with low lightness. The perceived colour difference was enlarged when the lightness of a sample pair was similar to that of the background. The extent of crispening effect and its quantification are discussed in this investigation. The performances of five colour‐difference equations were also tested, including the newly developed CIEDE2000. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 374–380, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20045
Colorimetric characterization of a computer‐controlled liquid crystal display
Authors: Day Ellen A. , Taplin Lawrence , Berns Roy S. 
Published: July 2004

AbstractA new method was used to characterize computer‐controlled liquid crystal displays (LCDs). The characterization, which was performed to enable colorimetric image display, included channel independence, spatial independence, screen uniformity, and colorimetry. The colorimetric model consisted of three one‐dimensional look‐up tables (LUTs) describing each channel's optoelectronic transfer function and a 3 × 4 matrix transformation that included black‐level flare. The matrix coefficients were estimated statistically by minimizing the average CIEDE2000 color difference for a data set sampling the display's colorimetric gamut. The LUTs were recreated dynamically throughout the optimization of the matrix coefficients. The characterization was implemented with three different instruments to evaluate the robustness of the method with respect to measurement uncertainty. The average performance ranged between 0.1 and 0.4 ΔE00 and was well correlated with instrument precision. The optimization approach improved performance by a factor of two compared with direct measurements. Despite differences in instrument design, the chromaticities of each primary following optimization and black‐level flare compensation were very similar. This excellent performance was a result of the display's optoelectronic properties well matching the model assumptions. The technique was also used to characterize three additional LCD displays ranging in their matching of the model assumptions. In this case, performance worsened. For one display, more complex models would be required for colorimetric characterization. Finally, a colorimetric characterization based on measurements at the center of the display and perpendicular to the face was used to predict measurements at the edges and at different angles. The results indicated that characterizations would be required at multiple positions and angles in order to achieve sufficient accuracy. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 365–373, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20046
A study of colour emotion and colour preference. Part III: Colour preference modeling
Authors: Ou Li‐Chen , Luo M. Ronnier , Woodcock Andrée , Wright Angela 
Published: July 2004

AbstractIn this study three colour preference models for single colours were developed. The first model was developed on the basis of the colour emotions, clean–dirty, tense–relaxed, and heavy–light. In this model colour preference was found affected most by the emotional feeling “clean.” The second model was developed on the basis of the three colour‐emotion factors identified in Part I, colour activity, colour weight, and colour heat. By combining this model with the colour‐science‐based formulae of these three factors, which have been developed in Part I, one can predict colour preference of a test colour from its colour‐appearance attributes. The third colour preference model was directly developed from colour‐appearance attributes. In this model colour preference is determined by the colour difference between a test colour and the reference colour (L*, a*, b*) = (50, −8, 30). The above approaches to modeling single‐colour preference were also adopted in modeling colour preference for colour combinations. The results show that it was difficult to predict colour‐combination preference by colour emotions only. This study also clarifies the relationship between colour preference and colour harmony. The results show that although colour preference is strongly correlated with colour harmony, there are still colours of which the two scales disagree with each other. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 381–389, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20047
Prediction of optical efficacy of vital tooth bleaching using regression analysis
Authors: Ishikawa‐Nagai Shigemi , Terui Takayuki , Ishibashi Kanji , Weber Hans‐Peter , Ferguson Michael 
Published: July 2004

AbstractEstablishing a colorimetric guideline to predict the effectiveness of tooth bleaching could produce a more reliable dental treatment. The purpose of this study was to evaluate the effectiveness of tooth bleaching and to test the predictability of tooth color changes. A 10% carbamide peroxide bleaching system was used in studies at Harvard University and at Iwate Medical University in Japan. L*, a*, and b* values (CIELAB) for pre‐ and postbleaching were obtained and color differences (ΔE) were calculated. The b* and L* values of the original tooth color indicated a relatively strong to moderate correlation with ΔE values, whereas a* showed a weak correlation. The multiple‐regression equation obtained from the color data of Harvard subjects performed better than the predictive model. The predicted ΔE correlated strongly with the observed ΔE (r = 0.78). The validation of this equation on data collected from Iwate confirmed the strong correlation (r = 0.74). © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 390–394, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20048
Elliptic equations with BMO coefficients in Reifenberg domains
Authors: Byun Sun‐Sig , Wang Lihe 
Published: July 2004

AbstractThe inhomogeneous Dirichlet problems concerning divergence form elliptic equations are studied. Optimal regularity requirements on the coefficients and domains for the W1,p theory, 1 < p < ∞, are obtained. The principal coefficients are supposed to be in the John‐Nirenberg space with small BMO seminorms. The domain is a Reifenberg domain. These conditions for the W1,p theory not only weaken the requirements on the coefficients but also lead to a more general geometric condition on the domains. In fact, these domains might have fractal dimensions. © 2004 Wiley Periodicals, Inc.
Global existence, singular solutions, and ill‐posedness for the Muskat problem
Authors: Siegel Michael , Caflisch Russel E. , Howison Sam 
Published: July 2004

AbstractThe Muskat, or Muskat‐Leibenzon, problem describes the evolution of the interface between two immiscible fluids in a porous medium or Hele‐Shaw cell under applied pressure gradients or fluid injection/extraction. In contrast to the Hele‐Shaw problem (the one‐phase version of the Muskat problem), there are few nontrivial exact solutions or analytic results for the Muskat problem. For the stable, forward Muskat problem, in which the higher‐viscosity fluid expands into the lower‐viscosity fluid, we show global‐in‐time existence for initial data that is a small perturbation of a flat interface. The initial data in this result may contain weak (e.g., curvature) singularities. For the unstable, backward problem, in which the higher‐viscosity fluid contracts, we construct singular solutions that start off with smooth initial data but develop a point of infinite curvature at finite time. © 2004 Wiley Periodicals, Inc.
Infinite Prandtl number limit of Rayleigh‐Bénard convection
Authors: Wang Xiaoming 
Published: July 2004

AbstractWe rigorously justify the infinite Prandtl number model of convection as the limit of the Boussinesq approximation to the Rayleigh‐Bénard convection as the Prandtl number approaches infinity. This is a singular limit problem involving an initial layer. © 2003 Wiley Periodicals, Inc.
Effect of inducible costimulator blockade on the pathological and protective immune responses induced by the gastrointestinal helminth Trichinella spiralis
Authors: Scales Hannah E. , Ierna Michelle X. , Gutierrez‐Ramos Jose‐Carlos , Coyle Anthony J. , Garside Paul , Lawrence Catherine E. 
Published: August 2004

AbstractInfections with gastrointestinal helminths elicit potent Th2 responses, which ultimately result in their expulsion. However, during expulsion of Trichinella spiralis this Th2 response also induces a severe enteropathy characterized by villus atrophy and crypt hyperplasia. Inducible costimulator (ICOS), a homologue of CD28, interacts with B7‐related protein 1, and has been shown to be important in T‐B cell interactions and antibody class switching. Significantly, ICOS appears to be involved in the induction of both Th1 and Th2 responses, but may be of heightened importance in Th2 responses. Here we employed a blocking antibody against ICOS to investigate the contribution of ICOS costimulation to the development of the protective and pathological immune responses induced during infection with T. spiralis. We show that, although blocking ICOS resulted in a decrease in TNF‐α and the Th2 cytokines IL‐4 and IL‐5 and serum levels of total IgE, it did not affect the expulsion of the adult parasites. Surprisingly, levels of IL‐9, IL‐13 and IL‐10 were elevated and protection against the larval muscle stage of the parasite was enhanced. Importantly, these findings may relate to the fact that ICOS blockade significantly ameliorated the enteropathy that usually accompanies expulsion of the adult parasite.
Primary induction of CD4 T cell responses in nasal associated lymphoid tissue during group A streptococcal infection
Authors: Park Hae‐Sun , Costalonga Massimo , Reinhardt R. Lee , Dombek Priscilla E. , Jenkins Marc K. , Cleary P. Patrick 
Published: August 2004

AbstractCD4 T cells are important for development of long‐term immunity to bacterial infections. Here we describe construction of a group A streptococcus (GAS) strain that expresses the model ovalbumin epitope (OVA) on its surface, and the use of this strain in adoptive transfer experiments to study CD4 T cell response to bacterial infection in nasal‐associated lymphoid tissue (NALT), which was previously shown to be a specific target for GAS colonization. The OVA+ GAS, but not the wild‐type strain was shown to activate CD4 T cells in an antigen‐specific manner both in vitro and in vivo. After intranasal infection of mice with this strain, OVA‐specific CD4 T cells were first activated in NALT, which is functionally equivalent to human tonsils, rather than in the cervical lymph nodes. During localized infection, OVA+ GAS induced rapid and prolonged activation of CD4 T cells at higher magnitudes in the NALT than in draining lymph nodes and spleen, where CD4 T cells underwent little or no activation. In contrast, systemic infection induced significantly higher activation of CD4 T cells in both lymph nodes and spleens, compared to when the infection was localized in NALT. Further investigation of cellular immune responses in NALT during GAS infection using adoptive T cell transfer, combined with the model antigen on the pathogen may ultimately shed light on mechanisms for failure of children to develop protective immune responses following streptococcal tonsillitis.