bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of the effect of branch content of octene‐based linear low‐density polyethylene on its melt miscibility with high‐density polyethylene by inverse gas chromatography
Authors: Zhao Liyan , Choi Phillip 
Published: December 2003

AbstractInverse gas chromatography was used to measure Flory–Huggins interaction parameters (χ23) for five binary blends consisting of high‐density polyethylene (HDPE) and octene‐based linear low‐density polyethylene (LLDPE) with different compositions at four elevated temperatures. The branch content of the LLDPE used in each pair of the blends ranged from 2 to 87 branches per 1000 backbone carbons. To obtain solvent‐independent χ23, the data analysis approach recently proposed by Zhao and Choi (Polymer 2001, 42, 1075) was used. The results indicate that the higher the branch content of LLDPE, the higher the measured χ23, signifying that HDPE/LLDPE blends with low branch content LLDPEs are relatively more miscible than those with high branch contents. In particular, when the branch content of LLDPE is higher than 50 branches per 1000 backbone carbons, phase separation may occur. This result is in good agreement with other researchers' results obtained from different techniques. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1927–1931, 2004
Kinetic features of the nonisothermal oxidative degradation of ethylene vinyl acetate copolymers
Authors: Ruban L. V. , Sychugova O. V. , Kolesnikova N. N. , Zaikov G. E. 
Published: December 2003

AbstractThermogravimetric analysis was used for a comparative investigation of the thermooxidative decomposition of ethylene vinyl acetate (EVA) copolymers with different vinyl acetate (VA) group contents. There were two stages of mass loss in this process. It was revealed that the apparent activation energies were correlated with the content of VA groups in the EVA copolymers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1958–1961, 2004
Effect of poly(vinylidene fluoride) interface layer on charge storage and residual potential in amorphous selenium films
Authors: Chand S. , Sharma G. D. , Dwivedi S. , Chandra R. 
Published: December 2003

AbstractThermally stimulated discharge current and the potential decay behavior of amorphous selenium (a‐Se) films (∼ 100 μm thick) were studied as a function of the thickness of a poly(vinylidene fluoride) (PVDF) interface barrier layer in the range 2000–8000 Å. The incorporation of a PVDF layer into an a‐Se film resulted in (1) a considerable reduction in its charge storage capacity, (2) a considerable increase in its initial surface potential, and (3) a considerable reduction in its residual potential and the enhancement of its X‐ray sensitivity. These effects were attributed to the blocking and field‐enhanced mobility role of the PVDF interface barrier layer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1962–1966, 2004
Instantaneous elastic recovery of poly(trimethylene terephthalate) filament
Authors: Chen Kequan , Tang Xiaozhen 
Published: December 2003

AbstractThe instantaneous elastic recoveries of poly(trimethylene terephthalate) (PTT), PET, and PBT filaments were comparatively analyzed by a tensile testing machine. The conditions of the measurement were studied and the mechanism of instantaneous elastic recovery of these three aromatic polyester filaments is discussed. The instantaneous elastic recovery of PTT filaments was significantly higher than those of PBT and PET filaments. Moreover, PTT filaments had a high instantaneous elastic recovery even at a high elongation of 20%. The outstanding instantaneous elastic recovery of PTT filaments resulted from its helical conformation in crystal lattice, which responded immediately to the applied stress and deformed as though it was a coiled spring; we suggest it was a quasispring elastic recovery mechanism. When we measured the instantaneous elastic recovery of, PTT filaments with the tensile testing machine, it was appropriate to set up the crosshead speed at 500 mm/min with an elongation of 20% and a load of 0.5 cN/tex. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1967–1975, 2004
Methyl methacrylate/N‐(o‐/m‐/p‐chlorophenyl) itaconimide copolymers: Microstructure determination by NMR spectroscopy
Authors: Anand Vishal , Kumar Rajeev , Choudhary Veena 
Published: December 2003

AbstractHomopolymerization and copolymerization of N‐(o‐/m‐/p‐chlorophenyl) itaconimide with methyl methacrylate was carried out by taking varying mole fractions (0.1 to 0.5) of N‐aryl substituted itaconimide monomers in the initial feed using azobisisobutyronitrile as an initiator and tetrahydrofuran as the solvent. The copolymer composition was determined by 1H‐NMR spectroscopy using the ratio of proton resonance signal intensity attributed to OCH3 of MMA (δ = 3.5–3.8 ppm) and the aromatic protons (δ = 7.0–7.5 ppm) of N‐(o‐/m‐/p‐chlorophenyl) itaconimide. The comonomer reactivity ratios were determined using Kelen–Tüdos and nonlinear error in variable methods. The reactivity ratios obtained by nonlinear error in variable methods were r1 (PI) = 1.26/r2 (MMA) = 0.35; r1 (MI) = 1.21/r2 (MMA) = 0.34; and r1 (OI) = 0.78/r2 (MMA) = 0.34. The carbonyl carbon signals of MMA (M) as well as N‐aryl itaconimide (I) copolymers were used for the determination of the sequence distribution of M‐ and I‐centered triads. The sequence distribution of M‐ and I‐centered triads determined from 13C{1H}‐NMR spectra of the copolymers are in good agreement with the triad concentrations calculated using the Alfrey–Mayo statistical model and Monte Carlo simulation method. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2016–2027, 2004
Mapping information policy frames: The politics of the digital millennium copyright act
Authors: Maxwell Terrence A. 
Published: December 2003

AbstractPassage of the Digital Millennium Copyright Act (DMCA) was a significant milestone in congressional information policy legislation. However, the results were widely criticized in some circles as providing too much power to certain stakeholder groups. This paper uses computer‐based content analysis and a theoretical taxonomy of information policy values to analyze congressional hearing testimony. The results of document coding were then analyzed using a variety of statistical tools to map how different stakeholders framed issues in the debate and determine if congressional value statements about the legislation conformed more closely to certain stakeholders. Results of the analysis indicate that significant differences in the use of information policy terms occurred across stakeholders, and showed varying degrees of convergence between congressional or other stakeholders when framing information policy issues.
Localization in Modern Standard Arabic
Authors: Abdelali Ahmed 
Published: December 2003

AbstractModern Standard Arabic (MSA) is the official language used in all Arabic countries. In this paper we describe an investigation of the uniformity of MSA across different countries. Many studies have been carried out locally or regionally on Arabic and its dialects. Here we look on a more global scale by studying language variations between countries. The source material used in this investigation was derived from national newspapers available on the Web, which provided samples of common media usage in each country. This corpus has been used to investigate the lexical characteristics of Modern Standard Arabic as found in 10 different Arabic speaking countries. We describe our collection methods, the types of lexical analysis performed, and the results of our investigations. With respect to newspaper articles, MSA seems to be very uniform across all the countries included in the study, but we have detected various types of differences, with implications for computational processing of MSA.
Spatialization of Web sites using a weighted frequency model of navigation data
Authors: Reitsma René F. , Thabane Lehana , MacLeod J. Michael B. 
Published: December 2003

AbstractA common problem in the spatialization of information systems is the determination of geometry; i.e., dimensionality and metric. Such geometry is either chosen a priori or is inferred a posteriori from secondary data. Recent work emphasizes the use of geometric information latent in a system's navigational record. Resolving this information from its noisy background, however, requires an unambiguous criterion of selection. In this paper we use a previously published, statistical method for resolving a Web‐based information system's geometry from navigational data. However, because of the method's (theoretical) sensitivity to data selection, a weighted frequency correction based on empirical probability distributions is applied. The effect of this correction on the Web‐space geometry is investigated. Results indicate that the inferred geometry is robust; i.e., it does not significantly change under this probabilistic correction.
Catalogers' common ground and shared knowledge
Authors: Šauperl Alenka 
Published: December 2003

AbstractThe problem of multiple interpretations of meaning in the indexing process has been mostly avoided by information scientists. Among the few who have addressed this question are Clare Beghtol and Jens Erik Mai. Their findings and findings of other researchers in the area of information science, social psychology, and psycholinguistics indicate that the source of the problem might lie in the background and culture of each indexer or cataloger. Are the catalogers aware of the problem? A general model of the indexing process was developed from observations and interviews of 12 catalogers in three American academic libraries. The model is illustrated with a hypothetical cataloger's process. The study with catalogers revealed that catalogers are aware of the author's, the user's, and their own meaning, but do not try to accommodate them all. On the other hand, they make every effort to build common ground with catalog users by studying documents related to the document being cataloged, and by considering catalog records and subject headings related to the subject identified in the document being cataloged. They try to build common ground with other catalogers by using cataloging tools and by inferring unstated rules of cataloging from examples in the catalogs.
The real stakes of virtual publishing: The transformation of E‐Biomed into PubMed central
Authors: Kling Rob , Spector Lisa B. , Fortuna Joanna 
Published: December 2003

AbstractIn May 1999, National Institutes of Health (NIH) Director Harold Varmus proposed an electronic repository for biomedical research literature server called “E‐biomed.” E‐biomed reflected the visions of scholarly electronic publishing advocates: It would be fully searchable, be free to readers, and contain full‐text versions of both preprint and postpublication biomedical research articles. However, within 4 months, the E‐biomed proposal was radically transformed: The preprint section was eliminated, delays were instituted between article publication and posting to the archive, and the name was changed to “PubMed Central.” This case study examines the remarkable transformation of the E‐biomed proposal to PubMed Central by analyzing comments about the proposal that were posted to an online E‐biomed forum created by the NIH, and discussions that took place in other face‐to‐face forums where E‐biomed deliberations took place. We find that the transformation of the E‐biomed proposal into PubMed Central was the result of highly visible and highly influential position statements made by scientific societies against the proposal. The literature about scholarly electronic publishing usually emphasizes a binary conflict between (trade) publishers and scholars/scientists. We conclude that: (1) scientific societies and the individual scientists they represent do not always have identical interests in regard to scientific e‐publishing; (2) stakeholder politics and personal interests reign supreme in e‐publishing debates, even in a supposedly status‐free online forum; and (3) multiple communication forums must be considered in examinations of e‐publishing deliberations.
Non‐word identification or spell checking without a dictionary
Authors: Comeau Donald C. , Wilbur W. John 
Published: December 2003

AbstractMEDLINE® is a collection of more than 12 million references and abstracts covering recent life science literature. With its continued growth and cutting‐edge terminology, spell‐checking with a traditional lexicon based approach requires significant additional manual follow‐up. In this work, an internal corpus based context quality rating α, frequency, and simple misspelling transformations are used to rank words from most likely to be misspellings to least likely. Eleven‐point average precisions of 0.891 have been achieved within a class of 42,340 all alphabetic words having an α score less than 10. Our models predict that 16,274 or 38% of these words are misspellings. Based on test data, this result has a recall of 79% and a precision of 86%. In other words, spell checking can be done by statistics instead of with a dictionary. As an application we examine the time history of low α words in MEDLINE® titles and abstracts.
Do the Web sites of higher rated scholars have significantly more online impact?
Authors: Thelwall Mike , Harries Gareth 
Published: December 2003

AbstractThe quality and impact of academic Web sites is of interest to many audiences, including the scholars who use them and Web educators who need to identify best practice. Several large‐scale European Union research projects have been funded to build new indicators for online scientific activity, reflecting recognition of the importance of the Web for scholarly communication. In this paper we address the key question of whether higher rated scholars produce higher impact Web sites, using the United Kingdom as a case study and measuring scholars' quality in terms of university‐wide average research ratings. Methodological issues concerning the measurement of the online impact are discussed, leading to the adoption of counts of links to a university's constituent single domain Web sites from an aggregated counting metric. The findings suggest that universities with higher rated scholars produce significantly more Web content but with a similar average online impact. Higher rated scholars therefore attract more total links from their peers, but only by being more prolific, refuting earlier suggestions. It can be surmised that general Web publications are very different from scholarly journal articles and conference papers, for which scholarly quality does associate with citation impact. This has important implications for the construction of new Web indicators, for example that online impact should not be used to assess the quality of small groups of scholars, even within a single discipline.
An experiment using coordinate title word searches
Authors: Kilgour Frederick G. 
Published: December 2003

AbstractThis study, the fourth and last of a series designed to produce new information to improve retrievability of books in libraries, explores the effectiveness of retrieving a known‐item book using words from titles only. From daily printouts of circulation records at the Walter Royal Davis Library of the University of North Carolina at Chapel Hill, 749 titles were taken and then searched on the 4‐million entry catalog at the library of the University of Michigan. The principal finding was that searches produced titles having personal authors 81.4% of the time and anonymous titles 91.5% of the time; these figures are 15 and 5%, respectively, lower than the lowest findings presented in the previous three articles of this series (Kilgour,1995;1997;2001).
Topically applied minoxidil may cause fetal malformation: A case report
Authors: Smorlesi Carlo , Caldarella Adele , Caramelli Laura , Di Lollo Simonetta , Moroni Flavio 
Published: December 2003

AbstractBACKGROUNDMinoxidil is a K+ channel opener able to cause relaxation of vascular smooth muscles and modify cell growth and cell fate or migration. It is now widely used for its hair growth promoting effects. When locally applied, it is absorbed through the skin and may have systemic pharmacological effects.CASEA 28‐year‐old white pregnant woman daily applied minoxidil 2% to her scalp because of hair loss. At the 22nd gestational week, after a routine ultrasound test showing significant brain, heart, and vascular malformations of the fetus, pregnancy was interrupted. The placenta had numerous ischemic areas and a discrepancy between gestational age and villi maturation. In the villi, capillaries were increased in number, significantly enlarged, and excessively marginalized. The fetus' heart was increased in volume and had a globose shape, the aorta had a distal stenosis. The sigmoid colon was significantly increased in length and a mesentery commune was present. The brain had enlarged ventricles and abundant hemorrhages. Histological examination showed areas of demyelinization with gliosis, signs of excessive and inappropriate angiogenesis, and capillary rearrangement.CONCLUSIONSFurther knowledge on minoxidil‐induced fetal toxicity would be beneficial before allowing its use in pregnant women. Birth Defects Research (Part A), 2003. © 2003 Wiley‐Liss, Inc.
New case of non‐mosaic tetrasomy 9p in a severely polymalformed newborn girl
Authors: De Azevedo Moreira Lília Maria , Freitas Lucy Magalhães , Gusmão Fábio Alexandre Ferreira , Riegel Mariluce 
Published: December 2003

AbstractBACKGROUNDThe phenotypic expression of an additional chromosome 9 causes a very broad clinical spectrum of anomalies. The prognosis for infants with non‐mosaic tetrasomy 9p is poor, and they usually die at a very early age.CASEIn this article we present a new case of complete tetrasomy 9p in a newborn girl with multiple dysmorphologic features. Cytogenetic studies were carried out by CBG, GTG, and QFQ chromosome bandings, as well as by fluorescence in situ hybridization (FISH). The cytogenetic findings for the newborn girl showed an extra chromosome interpreted as an isochromosome 9p. The karyotype was characterized as 47,XX,+mar.ish i(9)(p10)(wcp9+). The parental chromosomes were normal.CONCLUSIONSThe karyotype and clinical features of the newborn girl (e.g., typical craniofacial dysmorphism, severe skeletal anomalies, and visceral and genito‐urinary malformations), compared with cases reported in the literature, give additional support to a clinical definition of this chromosomal syndrome. Birth Defects Research (Part A), 2003. © 2003 Wiley‐Liss, Inc.
Method of weighted proportion of reproductive‐aged women taking folic acid supplements to predict a neural tube defect rate decline
Authors: Yang Quanhe , Atkinson Michael , Erickson J. David 
Published: December 2003

AbstractBACKGROUNDNeural tube defect (NTD) rates can be lowered by increased consumption of folic acid (FA) by women before and during early pregnancy. The crude proportion of reproductive‐aged women taking FA supplements has been used to predict a decline of the NTD rate in the general population. In this study we examine the potential error in using the crude proportion to predict NTD risk reduction, and offer an alternative method.METHODSThe crude proportion measures the number of women taking FA. It ignores the substantial variability by maternal age in the probability of giving birth. Age‐specific fertility rates (ASFRs) reflect the probability that a woman in a specific age group will give birth in a given year. In this study, we show how to calculate a proportion weighted by ASFRs to predict a decline in the NTD rate, and to assess the effectiveness of FA consumption in preventing NTDs.RESULTSOur results show that a crude proportion of 50% of women (15–49 years old) taking FA is associated with a range of 24–77% in weighted proportions. Assuming a 40% risk reduction from taking 400 μg of FA daily, the expected NTD rate decline could vary from 9.6% to 30.6%, depending on the age distribution of women taking FA.CONCLUSIONSThe ASFR‐weighted proportion estimates the proportion of babies born to women taking FA, as opposed to the crude proportion of women taking FA. We recommend using the ASFR‐weighted proportion to predict an NTD rate decline and measure the success of FA education campaigns. We found that when women in high‐fertility age groups increased their FA consumption, the decline in the NTD rate was greater than when women in low‐fertility age groups did so. Our findings suggest that the more efficient approach to NTD prevention is to focus on women with a higher probability of giving birth. For example, by focusing on <50% of women of childbearing age (20–34 years), as much as 76% of the maximum NTD rate reduction can be achieved. Birth Defects Research (Part A), 2003. Published 2003 Wiley‐Liss, Inc.
Differential risks to males and females for congenital malformations among 2.5 million California births, 1989–1997
Authors: Shaw Gary M. , Carmichael Suzan L. , Kaidarova Zhanna , Harris John A. 
Published: December 2003

AbstractBACKGROUNDAlthough many studies have observed variations in the prevalence of specific malformations by sex, there is a lack of population‐based data on potential malformation prevalence differences by sex at birth.METHODSOur objective was to explore differences in the prevalence of structural congenital malformation phenotypes between sexes in a California population of 2.5 million live‐ and stillbirths, using data from a population‐based active surveillance system. Ascertainment was performed among offspring of California women who delivered in nonmilitary hospitals during the period of 1989–1997. Malformations were grouped according to the four‐digit malformation codes of the British Pediatric Association.RESULTSOverall, 32,619 males and 21,835 females were considered to have structural congenital malformations, with prevalences of 2.52% and 1.76%, respectively. Thus, males demonstrated a malformation prevalence that was 22% higher than that in females. Using a criterion of a 40% increase or decrease in the relative risk for males, increased risks for 15 and decreased risks for 17 specific malformation categories were observed. Increased risks were associated with most organ systems, with the notable exception of the nervous system (increased risks for nervous system malformations were observed among female births). Risks were not substantially influenced by adjusting for maternal age, race/ethnicity, parity, or education.CONCLUSIONSOur observations extend the relatively few studies that have investigated differential prevalences of a large number of specific structural malformations between male and female births. Birth Defects Research (Part A) 67:000–000, 2003. © 2003 Wiley‐Liss, Inc.