bluuebunny/crossref_metadata_2025 huggingface dataset:
Electronic charge distribution in the intermetallic compound MnHg
Authors: Saravanan R. , Israel S. , Swaminathan S. , Kalidoss R. , Muruganantham M.
Published: December 2002

The Electron Density Distribution (EDD) of the Mn and Hg atoms in MnHg has been elucidated for the first time using the statistical approach MEM (Maximum Entropy Method). Reported powder X‐ray data have been used for the present analysis. Presently, MEM studies are gaining momentum because of the feasibility of mapping the refined electron densities with very high accuracy, well resolved and clear electron density distributions obtainable from this method, etc. Moreover, the MEM results resemble very nearly the true structure/electron densities unlike the conventional Fourier methods, which give biased information due to many reasons, the major one being the series termination error. In the present analysis, the bonding between Mn and Hg, and the electron content for different radii of the two atoms has been investigated. The thermal vibration of the two atoms has also been analyzed and reported. The thermal parameter of Hg has been more accurately determined than that of Mn, which is in consistent with the electron density distribution of the atoms.
Up‐conversion luminescence of ytterbium and thulium codoped potassium yttrium double tungstate crystal
Authors: Cheng Z. X. , Yi X. J. , Han J. R. , Chen H. C. , Wang X. L. , Liu H. K. , Dou S. X. , Song F. , Guo H. C.
Published: December 2002

Thulium and ytterbium co‐doped double tungstate Yb3+,Tm3+: NaY(WO4)2 single crystals were prepared by using RF‐heating Czochralski (CZ) pulling method. Its polarized transmittance spectra have been recorded in the region of 290‐2000 nm at room temperature. The energy levels transitions were assigned to the corresponding absorption line. The up‐conversion luminescences at 793 nm and 475 nm were measured when the sample were pumped by 972 nm LD and the energy transfer mechanism between Yb3+ and Tm3+ ions was analyzed.
Nonlinear optical properties of ZnS nanocrystals incorporated within the polyvinyl alcohole photopolymer matrices
Authors: Ramtolli F. , Saccinni G.
Published: December 2002

Photoinduced nonlinear optical effects in ZnS nanocrystallites incorporated within the photopolymer polyvinyl alcohol matrices were studied. As a basic method we have used photoinduced optical second harmonic generation (SHG). The Q‐switched HF‐laser (λ = 2.64.μm; pulse duration 30‐40 ps) was used as a source of probing (fundamental) light beam and the pulsed nitrogen (λ = 337.7 nm) was applied as a source of the photoinducing pump light. With increasing photoinducing beam power, the output SHG signal (at λ = 1.32 μm) increases. The maximal second‐order non‐linear optical susceptibility corresponds to tensor component d123 = d14 = 3.8 ± 0.2 pm/V at a photoinducing power density equal to about 1.25 GW/cm2. With decreasing temperature, the SHG signal increases within the temperature range 25‐30 K. Time‐dependent pump‐probe measurements of the SHG indicate an existence of the SHG maximum for a pump‐probe delaying time 20 ps. The ZnS hexagonal structural components play a crucial role in the observed photoinduced second‐order non‐linear optical effects. Large values of the non‐linear optical constants as well the good technological parameters open a possibility to enhance the non‐linear optical susceptibilities of the investigated ZnS nanocrystallites.
Phase transition studies in mesogenic dimers
Authors: Gogoi B. , Alapati P. R. , Verma A. L.
Published: December 2002

Schiff base liquid crystal dimers, both symmetric and non‐symmetric, in which two anisotropic groups are linked by a flexible spacer, exhibit a rich variety of smectic mesomorphism. The interest in this class of mesogens stems not only from their ability to act as model compounds for semi‐flexible mainchain liquid crystal polymers but also from their quite different properties compared to conventional low molar mass liquid crystals (monomers). We report here the phase transition studies on two examples of these schiff base liquid crystal dimers using the Differential Scanning Calorimetry and density measurements as a function of temperature. The symmetric liquid crystal dimer, α,ω‐bis (4‐n‐dodecylaniline benzylidene‐4′‐oxy)decane (10.O12O.10) exhibits a very rare Isotropic to G transition. Where as, the non‐symmetric dimer, α‐(4‐cyano biphenyl‐4′‐yloxy)‐ω‐(4‐n‐decylanilinebenzylidene‐4′‐oxy)decane (CB.O10O.10) exhibits a rare nematic to intercalated smectic A phase transition. The transitions studied, isotropic to nematic and isotropic to G exhibit a large density jump at the transition confirming their first order nature. Nematic to intercalated smectic A transition is found to be a second order transition whose behavior is similar to nematic to smectic A transition. Calculated values of pressure dependence of transition temperature and thermal expansion coefficient are also reported.
Characteristics of an induction motor with reduced turns of terminal coils
Authors: Hitosugi Kazuyoshi , Moriyasu Shoji , Nanba Noriyuki
Published: December 2002

The use of PWM inverters with high switching characteristics for the adjustable speed drive system causes an overvoltage with steep‐fronted waveform on the motor terminals. As this steep‐fronted transient voltage in inverter drive loads heavily on the terminal coils of motor winding, the insulation failure in the motor winding occurs mostly on the terminal coils. Therefore, it is reasonable to reduce the turns of terminal coils only and to increase the dielectric strength of interturn insulation.

This paper presents a comparison of measured characteristics of normal induction motors and induction motors with reduced turns of terminal coils and also a comparison of the results measured and calculated by equivalent circuit. The appropriate rate of reduced turns of terminal coils is about 20%. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(3): 49–56, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10093
Development of equipment models for fast distribution three‐phase unbalanced load flow calculation
Authors: Oomori Toshiya , Genji Takamu , Yura Toshiki , Watanabe Takuya , Takayama Shinichi , Fukuyama Yoshikazu
Published: December 2002

This paper presents distribution system equipment models for fast distribution three‐phase unbalanced load flow calculation. Recently, the number of distributed generators introduced into distribution systems has been increasing and detailed system analysis using load flow calculation has been eagerly awaited. Moreover, since many distribution system loads are composed of single phase loads, three‐phase unbalanced load flow calculation is required for the distribution system analysis. Although the fast distribution three‐phase unbalanced load flow calculation has been developed, equipment models considering interconnection of distributed generators have not as yet been developed in Japan. This paper develops practical equipment models such as various distributed generators, voltage control equipment, and loads for fast three‐phase unbalanced load flow calculation in distribution systems. The feasibility of the developed models is verified and demonstrated on practical distribution system models with promising results. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(3): 8–19, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10106
Improvement of stabilization time by information exchange between dispersed generators in a local network under islanding
Authors: Okuyama Kenji , Kato Takeyoshi , Wu Kai , Yokomizu Yasunobu , Okamoto Tatsuki , Yasuo Suzuoki
Published: December 2002

According to the deregulation of the electric power market and the improvement of small generators, the electricity supply by dispersed generators (DGs) is very attractive for both utilities and consumers. However, because of various types of DGs with low ratings, the introduction of a DG in a power distribution system increases the complexity of system operation. We propose on‐line information exchange between DGs to facilitate autonomous operation of the distribution system. This paper evaluates the improvement of reliability of such a system by the on‐line information exchange between DGs.

The large‐scale introduction of DGs might allow the power supply to the distribution system to be continued even if it is isolated from the upper system. We discuss the effects of information exchange on the system stability under islanding after an upper system failure. The analysis is performed in terms of instantaneous values calculated by using PSCAD/EMTDC. It is found that the transient stability improves when a DG with fast response speed and a DG with slow response speed exchange the information on inverse power flow to the network. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(3): 20–29, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10107
Theory of electroosmotic flow, retention and separation efficiency in capillary electrochromatography
Authors: Rathore Anurag S.
Published: December 2002

This article reviews recent progress that has taken place in the past decade (1992–2002) in the areas of understanding of flow of ions, buffers, as well as neutral and charged sample components through open channels and porous media. Though, primarily dealing with open capillaries and packed columns that are often used in capillary electrochromatography (CEC), these fundamental concepts are applicable to the evolving area of separations on a microchip.
Recent progress in capillary isotachophoresis
Authors: Gebauer Petr , Boček Petr
Published: December 2002

This article is a continuation of previous reviews and summarizes the progress of analytical capillary isotachophoresis since 2000. Papers reviewed include methodological and instrumental aspects as well as analytical applications. Included are also papers using isotachophoresis and/or isotachophoretic principles as part of multidimensional separation schemes.
Derivatization trends in capillary electrophoresis: An update
Authors: Underberg Willy J. M. , Waterval Joop C. M.
Published: December 2002

This survey as a sequel of two earlier reports gives an overview of recent developments, starting from 1999, in the use of derivatization protocols in capillary electrophoretic (CE) analysis. Derivatization is mainly used for enhancement of the detection sensitivity in CE, for which a combination of fluorescence labeling and laser‐induced fluorescence detection is favorable. Moreover, especially in the field of saccharide assay, derivatization to introduce charge into the molecule, is common. Derivatization procedures are classified in tables, focused on precapillary, on‐line, on‐capillary and postcapillary arrangements and divided in sections concerning the functional group that is derivatized. The most frequently reported groups are amines and the reducing end of (oligo)saccharides, but thiols, carbonyl and carboxyl groups, steroids and inorganic ions have also been reported about. Other reasons for derivatization are to enhance chiral separation, introduction of a suitable charge into the molecule or to improve mass spectrometric detection. The use of derivatization techniques for special cases, such as the analysis of neurotransmitters, insulin antibodies and mitochondria has also been incorporated as well as a study on the adsorption of proteins onto capillary walls during CE in which derivatization plays a role.
Background‐free, fast protein staining in sodium dodecyl sulfate polyacrylamide gel using counterion dyes, zincon and ethyl violet
Authors: Choi Jung‐Kap , Tak Keong‐Hoon , Jin Li‐Tai , Hwang Sun‐Young , Kwon Tae‐Ik , Yoo Gyurng‐Soo
Published: December 2002

A background‐free, fast protein staining method in polyacrylamide gel electrophoresis using an acidic dye, zincon (ZC) and a basic dye, ethyl violet (EV) is described. It is based on the counterion dye staining technique that employs two oppositely charged dyes to form an ion‐pair complex in staining solution. The selective binding of free dye molecules to proteins in acidic solution produces bluish violet‐colored bands. It is a rapid and end‐point staining procedure, involving only fixing and staining steps that are completed in 1–1.5 h. The detection limit of this method is 8–15 ng of protein that is comparable to the sensitivity of the colloidal Coomassie Brilliant Blue G (CBBG) stain. Due to its sensitivity and speed, this stain may be more practical than any other dye‐based stains for routine laboratory purposes.
Study of urinary nucleosides as biological marker in cancer patients analyzed by micellar electrokinetic capillary chromatography
Authors: Zheng Yu‐Fang , Xu Guo‐Wang , Liu Da‐Yu , Xiong Jian‐Hui , Zhang Pu‐Dun , Zhang Chao , Yang Qing , Lv Shen
Published: December 2002

Thirteen normal and modified nucleosides, primarily degradation products of transfer ribonucleic acid (tRNA), were evaluated as potential tumor markers for cancer patients. Their urinary concentrations were determined by means of micellar electrokinetic capillary chromatography (MEKC) in the urine from 54 healthy adults and 70 cancer patients, then quantitatively expressed as a function of creatinine excretion. It was found that urinary nucleosides for cancer patients were on the average significantly higher than those for healthy controls, however, no significant differences were found between male and female or between different ages. Based on 13 urinary nucleoside concentrations, principal component analysis (PCA) could be used to classify 72% of cancer patients from the healthy controls. The present study shows that the precise measurement of urinary nucleosides by MEKC in combining with PCA technique may provide a clinically useful approach for diagnosis of cancer.
An ionic liquid coating for determination of sildenafil and UK‐103,320 in human serum by capillary zone electrophoresis‐ion trap mass spectrometry
Authors: Qin Weidong , Li Sam F. Y.
Published: December 2002

Ionic liquid (IL) was covalently bonded onto the silica capillary surface and the electroosmotic flow was reversed over a pH range of 3.5 to 7. Sildenafil (SL) and its metabolite UK‐103,320 (UK) in human serum were detected by solid‐phase extraction followed by capillary zone electrophoresis‐mass spectrometry analysis. The running buffer contained 10 mM acetic acid adjusted to pH 4.5 with 1 M ammonia, and the separating voltage was set to —25 kV. The adsorption of the analytes onto the bare capillary wall was eliminated by the IL coating and the drugs were baseline‐separated within 14 min with detection limits (S/N = 3) of 14 and 17 ng/mL for SL and UK, respectively. The method developed showed good intraday precision in terms of relative standard deviation (RSD) with respect to migration time (RSD ≤ 0.76%, n = 5) and peak area (RSD ≤ 3.4%, n = 5); the relative coefficients of linear regression for both targets were better than 0.99 within linear dynamic range (SL: 50–600 ng/mL; UK: 40–400 ng/mL). Satisfactory interday precision was obtained with respect to the slope of the regression (RSD ≤ 4.21%, n = 9) and the migration time (RSD ≤ 1.1%, n = 9). The IL coating could be used with stable electroosmotic flow (RSD = 2.78%, n = 10) for at least 80 h.
Capillary zone electrophoresis study of cyclodextrin – lipoic acid host‐guest interaction
Authors: Trentin Marco , Carofiglio Tommaso , Fornasier Roberto , Tonellato Umberto
Published: December 2002

Lipoic acid is a naturally occurring compound which is being widely investigated for its therapeutic effects in the treatment or prevention of a variety of diseases associated with oxidative injury, particularly diabetes. The diversity of therapeutic applications of lipoic acid requires an appropriate formulation to control its bioavailability, site‐targeting delivery and to overcome its inherent chemical instability. In this regard, cyclodextrins (CDs) are ideally suitable due to their well‐documented ability to include in their cavity proper guest molecules and protect them from physical or chemical damages. Lipoic acid forms 1:1 inclusion complexes with βCD as shown in a previous report of an extended investigation that also indicated the suitability of capillary zone electrophoresis (CZE) for the study of such host‐guest interactions. In view of these possible applications, we extended the CZE analysis to determine the strength of binding, in a pH 9 phosphate buffer, of lipoic acid with other CD derivatives such as αCD, γCD and the alkylated derivatives of βCD, namely (2‐hydroxypropyl)‐β‐CD (HPβCD), and heptakis(2,3,6‐tri‐O‐methyl)‐β‐CD (TMβCD). Once established that the easily available βCD is the most suitable receptor for lipoic acid, we set up and here describe a simple and reliable procedure for the quantitative determination of lipoic acid in commercial dietary supplement tablets containing also other active substances and excipients.
Histone deacetylase dHDAC4 is involved in segmentation of the Drosophila embryo and is regulated by gap and pair‐rule genes
Authors: Zeremski Marija , Stricker Jason R. , Fischer Denise , Zusman Susan B. , Cohen Dalia
Published: December 2002

Summary: Histone deacetylases (HDACs) are catalytic subunits of multiprotein complexes that are targeted to specific promoters through their interaction with different transcriptional repressors causing silencing of the corresponding genes. This study describes the isolation of dHDAC4, a novel, catalytically active class II Drosophila histone deacetylase, and the analysis of its role in embryonic development. In early embryos, dHDAC4 is expressed in several phases. Initial ubiquitous expression becomes localized to an anterior domain, then evolves into a pair‐rule‐like and finally into a segment‐polarity‐like pattern. Suppression of dHDAC4 during early embryogenesis by double‐stranded RNA interference led to segmentation defects. Analysis of dHDAC4 expression in gap and pair‐rule gene mutants demonstrated that hunchback, knirps, and giant activate, while even‐skipped suppresses dHDAC4 expression. These data revealed dHDAC4 involvement in the segmentation regulatory pathway and suggested complex transcriptional regulation as a potential mechanism that controls its expression. genesis 35:31–38, 2003. © 2002 Wiley‐Liss, Inc.
Boundary‐layer integration approach to advection of sensible heat to a patchy snow cover
Authors: Granger R. J. , Pomeroy J. W. , Parviainen J.
Published: December 2002

In the calculation of the melting of a patchy snow cover, the energy advected from the adjacent bare soil to the snow surface is an important consideration. The quantity or rate of energy advected depends on the fetches and sizes of snow and bare ground patches. Any successful method to estimate advection will necessarily require the incorporation of relationships describing the same. Complex boundary‐layer methods require detailed spatial knowledge of the patch sizes, wind direction and fetch distances, and are computationally intensive. A physically based approach that can be spatially applied using distributions of snow patch geometry is required.

This paper presents a new approach, in which boundary‐layer integration is used to provide a means of calculating the amount of energy removed by the snow patch surface as warmer air moves over it. The method is reduced to a simple parametric form, and the relationships describing the coefficients required for its application are developed.

The applicability of this new approach is discussed in light of the fractal nature of snow patches, the relationship between the individual patch length and area, and the distribution of patch sizes as they develop and disappear on the landscape. Copyright © 2002 Crown in the right of Canada. Published by John Wiley & Sons Ltd.
An efficient snow albedo model for the open and sub‐canopy
Authors: Melloh Rae A. , Hardy Janet P. , Bailey Ronald N. , Hall Tommie J.
Published: December 2002

A new model is presented for simulating snow surface albedo in the open and beneath a mixed‐forest canopy. The model has modest input data requirements and is an efficient physically based parameterization that includes the dependency of albedo on solar zenith angle, cloud cover, canopy, snow grain size, litterfall, snowfall, snow depth, and partial snow cover. Measurements used in the model validation include incident spectral irradiances, wavelength‐integrated visible and near‐infrared albedos, snowfall records, snow depth, snow surface litter fractions, and quantity of fine litter in snow cores. Measured and modelled forest snow albedos were less than open snow albedos during the accumulation phase, when there was little or no surface litter. The model predicts lower albedos in the forest during the accumulation phase because of a spectral shift to less reflective wavelengths of incident radiation under the canopy. Snow grain size was important during both the accumulation and ablation phases. Surface litter fraction, incident spectra, snowpack depth, and partial snow cover were important factors lowering forest albedo during ablation. Despite lower mid‐winter albedos in the forest, the snow melted more rapidly in the open. During late ablation, snow albedo in the open became lower than snow albedo in the forest, because of the thinner snow in the open. At the end of the ablation season, partial snow cover affected the albedo in the forest over a longer time period than in the open. Additional work is needed to improve the physical basis of the grain growth model used here and to develop a spatial albedo model for open and forested terrain. Published in 2002 by John Wiley & Sons Ltd.
An assessment of the differences between three satellite snow cover mapping techniques
Authors: Bitner David , Carroll Tom , Cline Don , Romanov Peter
Published: December 2002

The National Operational Hydrologic Remote Sensing Center (NOHRSC) of the National Oceanic and Atmospheric Administration's (NOAA's) National Weather Service (NWS) provides daily satellite‐derived snow cover maps to support the NWS Hydrologic Services Program covering the coterminous USA and Alaska. This study compared the NOHRSC snow cover maps with new automated snow cover maps produced by the National Environmental Satellite, Data, and Information Service (NESDIS) and the snow cover maps created from the Moderate Resolution Imaging Spectroradiometer (MODIS) imagery. The purpose of this paper is to demonstrate and account for the differences that occur between the three different snow cover mapping techniques. Because each of these snow cover products uses data from different sensors at different resolutions, the data were degraded to the coarsest relevant resolution. In both comparisons, forest canopy density was examined as a possible explanatory factor to account for those differences. NOHRSC snow cover maps were compared with NESDIS snow cover maps for 32 different dates from November 2000 to February 2001. NOHRSC snow cover maps were also compared with MODIS snow cover maps in the Pacific Northwest and the Great Plains for 18 days and 21 days, respectively, between March and June 2001. In the first comparison, where the NOHRSC product (∼1 km) was degraded to match the resolution of the NESDIS data (∼5 km), the two products showed an average agreement of 96%. Forest canopy density data provided only weak explanation for the differences between the NOHRSC and the NESDIS snow cover maps. In the second comparison, where the MODIS product (∼500 m) was degraded to match the resolution of the NOHRSC product for two sample areas, the agreement was 94% in the study area in the Pacific Northwest, and 95% in the study area in the Great Plains. Published in 2002 by John Wiley & Sons, Ltd.
Development of a historical ice database for the study of climate change in Canada
Authors: Lenormand Frédéric , Duguay Claude R. , Gauthier Roger
Published: December 2002

The Canadian government has been compiling various observations on freshwater and coastal sea ice conditions for many years. However, the records are not easily accessible and are dispersed within different government departments. Given this, a major effort was undertaken in order to gather all available observations into a common database—the Canadian Ice Database (CID). This database will respond to the needs for climate monitoring in Canada, the validation and improvement of numerical ice models and the development of new remote‐sensing methods. Indeed, several studies have shown that freshwater ice and sea ice are good proxy indicators of climate variability and change.

The first version of CID contains in situ observations from 757 sites distributed across Canada, which were originally kept on digital or paper records at the Meteorological Service of Canada Headquarters and the Canadian Ice Service (CIS). The CID holds 63 546 records covering the period from ice season 1822–23 to 2000–01. An analysis of the database allows one to trace the temporal evolution of the ice networks. The freeze‐up/break‐up network of 2000–01 only represents 4% of what it was in 1985–86. A drastic decline of the ice thickness and the snow on ice network is also observable. In 1997–98, it represented only 10% of the network that existed in 1984–85. The major budget cuts in Canadian government agencies during the late 1980s and the 1990s offer the most plausible explanation for the drastic decline in the ice observation networks. Weekly ice coverage determination on large lakes from satellite imagery by the CIS and the national volunteer ice monitoring program, IceWatch, may provide a means of reviving, at least, the freeze‐up/break‐up network. Copyright © 2002 John Wiley & Sons, Ltd.
Simulation of terrain and forest shelter effects on patterns of snow deposition, snowmelt and runoff over a semi‐arid mountain catchment
Authors: Marks Danny , Winstral Adam , Seyfried Mark
Published: December 2002

In mountainous regions, topographic structure and vegetation control patterns of snow deposition, climate conditions, and snowmelt. A topographically distributed snow accumulation and melt model (ISNOBAL) was coupled to a wind field and snow redistribution model to simulate the development and ablation of the seasonal snow cover over a small mountainous catchment, the Reynolds Mountain East basin (0·38 km2) in southwestern Idaho, USA. The model was driven by hourly terrain‐ and canopy‐corrected data grids derived from meteorological data from two stations located within the catchment for four water years (1986, 1987, 1989 and 1997). The catchment was divided into four shelter classes, based on terrain and vegetation; these were used for an analysis of how the mass and energy balance of the snowcover varies over the basin as a function of terrain and forest characteristics for each of the selected years. As shown by the simulations and verified by detailed point measurements and the late‐season areal photographs of snow‐covered area, in all years the wind‐exposed areas developed thinner snow covers and were essentially bare of snow prior to the onset of spring meltout in wind‐sheltered areas. The meltout of the wind‐sheltered drift and canopy‐enclosed regions occurred in conjunction with the springtime increase in solar radiation generating the bulk of springtime runoff. Melt contributions from the drifts may continue into the late spring and early summer. This research uses a unique set of point and spatial verification data to show that a snow accumulation and ablation model, adjusted for wind redistribution effects, reliably simulated the topographic and vegetation influences on snow distribution, the energy balance, and the hydrology of snow and wind‐dominated mountainous regions. Published in 2002 by John Wiley & Sons, Ltd.
Comparison of spatial interpolation methods for estimating snow distribution in the Colorado Rocky Mountains
Authors: Erxleben Jennifer , Elder Kelly , Davis Robert
Published: December 2002

Our understanding of snow distribution in the mountains is limited as a result of the complex controls leading to extreme spatial variability. More accurate representations of snow distribution are greatly needed for improvements to hydrological forecasts, climate models, and for the future testing and validation of remote‐sensing retrieval algorithms. In this study, the relative performances of four spatial interpolation methods were evaluated to estimate snow water equivalent for three 1 km2 study sites in the Colorado Rocky Mountains. Each study site is representative of different topographic and vegetative characteristics. From 1 to 11 April 2001, 550 snow depth measurements and approximately 16 snow density profiles were obtained within each study site. The analytical methods used to estimate snow depth over the 1 km2 areas were (1) inverse distance weighting, (2) ordinary kriging, (3) modified residual kriging and cokriging, and (4) a combined method using binary regression trees and geostatistical methods. The independent variables used were elevation, slope, aspect, net solar radiation, and vegetation. Using cross‐validation procedures, each method was assessed for accuracy. The tree‐based models provided the most accurate estimates for all study sites, explaining 18–30% of the observed variability in snow depth. Kriging of the regression tree residuals did not substantially improve the models. Cokriging of the residuals resulted in a less accurate model when compared with the tree‐based models alone. Binary regression trees may have generated the most accurate estimates out of all methods evaluated; however, substantial portions of the variability in observed snow depth were left unexplained by the models. Though the data may have simply lacked spatial structure, it is recommended that the characteristics of the study sites, sampling strategy, and independent variables be explored further to evaluate the causes for the relatively poor model results. Copyright © 2002 John Wiley & Sons, Ltd.
4‐Hydroxytamoxifen sulfation metabolism
Authors: Chen Guangping , Yin Shuhua , Maiti Smarajit , Shao Xiuping
Published: December 2002

Tamoxifen (TAM) is an important chemotherapeutic agent for the treatment of breast cancer. It has also been shown to decrease breast cancer incidence in healthy women at high risk for the disease. The increased risk of endometrial cancer in women has raised concerns in the use of the drug. Tamoxifen has also been shown to be a potent hepatocarcinogen in rats. The oxidative metabolites of TAM include α‐hydroxytamoxifen (α‐OH‐TAM) and 4‐hydroxytamoxifen (4‐OH‐TAM). The studies on the sulfation of these metabolites are very limited. It has been reported that α‐OH‐TAM is a substrate for rat hydroxysteroid sulfotransferase a (STa). Our studies on the sulfation of 4‐OH‐TAM demonstrated that 4‐hydroxytamoxifen can be sulfated by human liver and human intestinal cytosols. Human phenol‐sulfating sulfotransferase and human estrogen sulfotransferase are the major enzymes for the sulfation of 4‐OH‐TAM. Human dopamine‐sulfating sulfotransferase also has sulfation activity for 4‐OH‐TAM. In contrast, rat liver and intestine cytosols have no detectable sulfation activity for 4‐OH‐TAM. The results suggest that the α‐OH‐TAM sulfation pathway leads to bioactivation of TAM, and the 4‐OH‐TAM sulfation pathway leads to detoxification of TAM. This agrees with the fact that TAM is more toxic for rats than for human beings. © 2002 Wiley Periodicals, Inc. J Biochem Mol Toxicol 16:279–285, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10048
Predicting early career research productivity: the case of management faculty
Authors: Williamson Ian O. , Cable Daniel M.
Published: December 2002

We used a longitudinal design to examine the predictors of early career research productivity for 152 management professors over the first six years of their career. Results revealed early career research productivity to be a function of dissertation advisor research productivity, pre‐appointment research productivity, and the research output of a faculty member's academic origin and academic placement. However, the effects of these predictors varied over time in terms of strength. The findings are discussed in terms of guiding the evaluation and hiring of new researchers in knowledge‐based industries. Copyright © 2003 John Wiley & Sons, Ltd.
Beliefs about ‘improvability’ of career‐relevant skills: relevance to job/task analysis, competency modelling, and learning orientation
Authors: Maurer Todd J. , Wrenn Kimberly A. , Pierce Heather R. , Tross Stuart A. , Collins William C.
Published: December 2002

Based on data obtained from three samples of participants from both a work organization and a college setting, this paper addressed two major research objectives relevant to organizational behavior and applied psychology. First, we wanted to explore the nature of implicit theory of skill malleability in more detail than has been done before. This was done by drawing on KSAO dimensions from the task/job analysis literature, and examining linkages among: (a) task/job analysis; (b) implicit theories; and (c) competency modelling (an area in which there has been little empirical research). The studies found multiple factors of beliefs about KSAO improvability and showed a clear ordering of improvability beliefs (from most to least improvable) that follow predictions made in the Iceberg model of competencies. The present studies also found relationships between perceptions of KSAO importance and KSAO improvability, as well as evidence that this relationship is stronger for people who have been in a role/job longer, having had greater opportunity to observe critical KSAOs improve over time. A second major objective of the research was to explore improvability beliefs within a nomological network that would help to further establish the construct validity of the beliefs within the learning/development area. Using structural modelling, the improvability beliefs were tied to learning‐oriented concepts including self‐efficacy for learning and development, tendency to compare oneself to others when learning, as well as learning‐oriented attitudes and behaviors. The potential practical value of improvability beliefs is discussed, as are suggestions for future research. Copyright © 2003 John Wiley & Sons, Ltd.
Corrosion of coating materials in oxidizing and hydrogen chloride containing atmospheres
Authors: Cha S.C. , Wölpert P.
Published: December 2002

The boiler tubes in waste incinerator plants and power plants are mainly corrosive strained. This paper presents the corrosion behaviour of various coating materials in two corrosive atmospheres at 500°C. In a first test, Ni‐based materials applied by High Velocity Oxygen Fuel Flame (HVOF)‐spraying and Atmospheric Plasma Spraying (APS) as well as Cr‐based materials obtained by diffusion coating process are tested in oxidizing atmosphere with water saturation. The results of the corrosion test in this H2O‐O2‐N2‐atmosphere show that NiCr applied by HVOF is less oxidized than that applied by APS‐coating, whereas NiCrBSi coating by APS shows higher resistance than that applied by HVOF‐spraying. The diffusion coating of Cr/Si is better than that of pure Cr. In a second test, metallic Mo and W‐based materials applied by thermal spraying are tested to verify their corrosion resistance in HCl‐H2O‐O2‐N2‐atmosphere. It is shown that pure Mo applied by APS on 13 CrMo 44 and WCrNi sprayed on 15 Mo 3 by HVOF as well as on 13 CrMo 44 show relatively high corrosion resistance, whereas Mo sprayed by APS on 15 Mo 3 is not resistant. Both tungsten‐cobalt‐chromium mixtures show extremely high oxidation rates. Base materials in both tests were the standard boiler tube materials 15 Mo 3 and 13 CrMo 44. But even the low corrosion rates of the best materials in these tests are higher compared to those of materials already presented by Cha et al. in an earlier paper.
A preliminary investigation on an ELLAM scheme for linear transport equations
Authors: Al‐Lawatia Mohamed , Wang Hong
Published: December 2002

We present an Eulerian‐Lagrangian localized adjoint method (ELLAM) for linear advection‐reaction partial differential equations in multiple space dimensions. We carry out numerical experiments to investigate the performance of the ELLAM scheme with a range of well‐perceived and widely used methods in fluid dynamics including the monotonic upstream‐centered scheme for conservation laws (MUSCL), the minmod method, the flux‐corrected transport method (FCT), and the essentially non‐oscillatory (ENO) schemes and weighted essentially non‐oscillatory (WENO) schemes. These experiments show that the ELLAM scheme is very competitive with these methods in the context of linear transport PDEs, and suggest/justify the development of ELLAM‐based simulators for subsurface porous medium flows and other applications. © 2002 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 19: 22–43, 2003
Pharmacoepidemiologic implications of erroneous varicella vaccinations in pregnancy through confusion with Varicella zoster immune globulin
Authors: Wise Robert P. , Braun M. Miles , Seward Jane F. , Mootrey Gina Terracciano , Shields Kristine E. , Salive Marcel E. , Krause Philip R.
Published: December 2002

A series of case reports to the varicella vaccine Pregnancy Registry described inadvertent administrations during pregnancy of this live virus product instead of the intended Varicella zoster immune globulin. Cases continued to accrue despite an early publication about the pattern. The persistent problem warrants specific educational efforts to prevent further repetitions. It also has more general implications for medical product safety surveillance. First, this problem's original detection depended on the Pregnancy Registry's open‐ended collection of information about pregnancy exposures. It could have escaped recognition through surveillance limited to pre specified potential risks. This need for unrestricted reporting and human vigilance to sift through case stories has particular relevance for efforts to re‐think methods to monitor gestational drug exposures. In addition, the problem's persistence despite initial publicity suggests that diligent surveillance may require continued follow‐up of identified safety issues. Periodic reassessments of selected preventable problems might strengthen efforts to minimize product risks. Copyright © 2002 John Wiley & Sons, Ltd.
Budesonide‐treated asthmatic adolescents attain target height: a population‐based follow‐up study from Sweden
Authors: Larsson Lars , de Verdier Maria Gerhardsson , Lindmark Bertil , Norjavaara Ensio
Published: December 2002

Purpose

To examine final height in relation to target height in asthmatic patients with and without glucocorticoid treatment while growing up compared with healthy individuals.

Methods

In 1990 and 1993, questionnaires were distributed to all individuals born in 1974 and 1977 in the counties of Jämtland and Gästrikland in Sweden. All individuals reporting use of anti‐asthmatic drugs or symptoms indicating possible obstructive airway disease, and a sample of healthy volunteers were invited to a clinical examination.

Results

Overall, 356 asthmatic patients and 384 healthy individuals were identified. In 1998–1999, all subjects were invited to a follow‐up study and final height was analysed in relation to target height in 152 asthmatic patients and 131 healthy individuals. It was found that both men and women achieved a higher mean final height than the calculated mean target height. There were no significant differences between controls and asthma patients treated either with or without glucocorticoids. Most of the patients treated with glucocorticoids started their therapy during adolescence and 92% had used inhaled budesonide. There was no trend towards a decrease in final height in relation to target height when inhaled budesonide treatment was initiated prior to adolescence or with lifelong cumulative dose of inhaled budesonide.

Conclusions

Asthmatic adolescents treated with inhaled budesonide achieve normal final height in relation to their target height. Copyright © 2002 John Wiley & Sons, Ltd.
Smoking behavior of 226 patients with diagnosis of stage IIIA/IIIB non‐small cell lung cancer
Authors: Sanderson Cox Lisa , Sloan Jeff A. , Patten Christi A. , Bonner James A. , Geyer Susan M. , McGinnis William L. , Stella Phillip J. , Marks Randolph S.
Published: December 2002

There is limited research of smoking cessation following diagnosis of lung cancer. This prospective study assessed cigarette smoking behavior among 226 patients (142 males, 84 females) prior to, at the time of, and after the diagnosis of unresectable stage IIIA/IIIB non‐small cell lung cancer and entry into a phase III trial examining combined thoracic radiation therapy and chemotherapy. Their mean ±S.D. age was 62.7±9.4 years and 95.6% were Caucasian. Of 215 patients with a history of cigarette smoking, 69% (148/215) stopped smoking prior to entry in the trial, 9% (20/215) stopped smoking at some point during the course of the trial, 11% (24/215) continued smoking throughout the trial, 7% (16/215) were smoking at baseline but did not report subsequent smoking status, and smoking status at study entry was missing for the remaining patients. The majority of lung cancer patients were able to stop smoking. A notable subset of patients continued smoking despite diagnosis of lung cancer, enrollment in a clinical trial, treatment‐related toxicity, and encouragement from clinicians to stop smoking. Smoking cessation interventions are needed for lung cancer patients who continue to smoke. Copyright © 2002 John Wiley & Sons, Ltd.
Stromal/epithelial interactions of murine prostatic cell lines in vivo: A model for benign prostatic hyperplasia and the effect of doxazosin on tissue size
Authors: Takao Tetsuya , Tsujimura Akira , Coetzee Sandra , Salm Sarah N. , Lepor Herbert , Shapiro Ellen , Moscatelli David , Wilson E. Lynette
Published: December 2002

BACKGROUND

One of the major constraints in elucidating the mechanisms involved in the etiology of benign prostatic hyperplasia (BPH) is the lack of suitable model systems that are readily manipulable in vitro and in vivo. To address this issue, we have used murine prostatic cell lines to establish a novel in vivo model for studying prostatic cell interactions.

METHODS

Luminal, basal, and smooth muscle (SM) cell lines were inoculated alone or in combinations under the renal capsule of intact or castrated male mice, and the growth and composition of prostatic tissue in the absence or presence of doxazosin was determined.

RESULTS

Both the luminal and basal cell lines reconstituted prostatic tissue if co‐inoculated under the renal capsule with normal SM cells, whereas none of the lines formed significant tissue when inoculated alone. Luminal cells produced and secreted prostatic secretory products. The growth of prostatic tissue formed from co‐inoculation of basal and SM cells was androgen responsive. In addition, a significant reduction in prostatic tissue was noted in animals treated with doxazosin.

CONCLUSION

We have established an in vivo model that uses prostatic epithelial and SM cell lines for investigating cellular interactions between epithelial and SM cells that regulate prostatic growth and function. This model will be useful for delineating the mechanisms by which prostatic cells interact and in determining the efficacy of new approaches aimed at interfering with prostatic stromal/epithelial interactions that result in abnormal cellular proliferation. Prostate 54: 17–24, 2003. © 2002 Wiley‐Liss, Inc.
Acute hypoxia increases the aggressive characteristics and survival properties of prostate cancer cells
Authors: Ghafar Mohamed A. , Anastasiadis Aristotelis G. , Chen Min‐Wei , Burchardt Martin , Olsson L. Eric , Xie Hui , Benson Mitchell C. , Buttyan Ralph
Published: December 2002

BACKGROUND

Androgen withdrawal, the standard therapeutic strategy for advanced prostate cancer, induces a rapid reduction of blood flow to prostate and prostate cancer tissues and the concomitant onset of a hypoxic environment in these tissues. To establish whether hypoxia‐responsiveness (by means of the action of hypoxia inducible factor [HIF] ‐1α protein) might affect the tumorigenic or survival properties of prostate cancer cells, we studied how acute exposure of cultured human prostate cancer cells (LNCaP cell line) to hypoxia might alter their pattern of gene expression and their in vitro behavior.

METHODS

LNCaP cultures were placed in a hypoxia chamber for up to 24 hr and were compared with control (normoxic) cells for the expression of gene products by Western blotting and semiquantitative reverse transcription‐polymerase chain reaction techniques.

RESULTS

Exposure of LNCaP cells to acute hypoxia activated a typical cellular hypoxia response characterized by up‐regulation of HIF‐1α and vascular endothelial growth factor protein expression. In contrast, expression of differentiation‐specific proteins (prostate specific antigen and androgen receptor) or proliferative‐regulatory proteins (c‐myc, cyclin D1, p27) were down‐regulated by hypoxia. Some of these latter changes (reduction of c‐myc and cyclin D expression) were not accompanied by corresponding reduction of mRNAs and were abrogated by a proteosome inhibitor (MG132), suggesting that their loss was associated with their increased degradation rather than through transcriptional controls. The phosphorylation of Akt/protein kinase B and its downstream target, forkhead protein, was highly up‐regulated by hypoxia, and cells exposed to transient periods of hypoxia became significantly less sensitive to an apoptotic stimulus (exposure to phorbol ester) when compared with normoxic cells.

CONCLUSION

This study demonstrates that even acute hypoxia has the potential to drastically alter the growth, differentiation characteristics, and apoptotic sensitivity of a prostate cancer cell. Prostate 54: 58–67, 2003. © 2002 Wiley‐Liss, Inc.
Opposite effects of unmodified prolactin and a molecular mimic of phosphorylated prolactin on morphology and the expression of prostate specific genes in the normal rat prostate
Authors: Xu Xiaolei , Wu Wei , Williams Valencia , Khong Amy , Chen Yen‐Hao , Deng Changhui , Walker Ameae M.
Published: December 2002

BACKGROUND

In the current study, we have investigated the individual roles of unmodified, wild‐type prolactin (WT PRL) and a molecular mimic of phosphorylated prolactin (S179D PRL) in the normal rat prostate.

METHODS

In the first animal experiment, recombinant WT PRL and S179D PRL were delivered to adult male rats at a rate of 14 μg/kg per day for 3 weeks. In the second animal experiment, two subcutaneous (200 μg/kg) injections of long‐acting forms of the two PRLs were given to adult male rats on day 1 and day 22 for a total of 5.5 weeks of treatment.

RESULTS

The different forms of PRL had opposite effects on the normal rat prostate, independently of androgens. WT PRL promoted morphologic changes in prostate epithelium consistent with preparation for cell proliferation, whereas S179D PRL produced morphologic evidence of a more differentiated epithelium. Northern blot analysis of expression of the two major prostate specific proteins, prostatein and probasin, showed that WT PRL decreased, whereas S179D PRL increased, the expression of the mRNAs for these two proteins. At the same time, S179D PRL reduced both testosterone and dihydrotestosterone levels.

CONCLUSION

We conclude that PRL is an important modulator of normal rat prostate biology and that different forms of PRL have specific functions. The molecular mimic of phosphorylated PRL, S179D PRL, is the most important in terms of epithelial cell differentiation. Prostate 54: 25–33, 2003. © 2002 Wiley‐Liss, Inc.