bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Mount Pinatubo volcanic ash on the mechanical properties of styrene–butadiene rubber vulcanizates
Authors: Bedia Elinor L. , Kasai Yutaka , Ikeda Yuko , Kohjiya Shinzo 
Published: November 2004

AbstractMt. Pinatubo volcanic ash, collected from Porac, Pampanga, was screened at 32 mesh screen, wet‐ground in a pot mill for 3, 5, and 7 days, and dried. The volcanic ash was characterized and compounded with styrene–butadiene rubber (SBR) vulcanizates. Mineralogical investigation of the volcanic ash showed the presence of feldspar, homblende, quartz, mica, and magnetite. The particle size of the volcanic ash ground for 3, 5, and 7 days ranged from 1440 to 4, 720 to 2, and 640 to 2 μm, respectively. The addition of volcanic ash did not significantly influence the mechanical strength of the SBR vulcanizates. Stress–strain curves of the volcanic ash–filled SBR vulcanizates showed a slight increase from that of the pure gum. As the particle size of the volcanic ash decreased, the tensile strength and elongation at break points increased. Crosslinking sites also increased with the addition of rubber. Furthermore, it was noted that the addition of diethylene glycol hastened the curing reaction without affecting the mechanical properties of SBR vulcanizates. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 68–73, 2005
Chemical modification of polydienes in latex medium: Study of epoxidation and ring opening of oxiranes
Authors: Derouet Daniel , Mulder‐Houdayer Stéphanie , Brosse Jean‐Claude 
Published: November 2004

AbstractReferring to previous work carried out in organic solvents, a study of the action of nucleophilic reagents on epoxidized units of 1,4‐epoxidized polyisoprene (synthetic polyisoprene or natural rubber) was performed in latex medium. Among the considered reagents, dialkylphosphate and ammonium diethyldithiophosphate demonstrated the ability to add under these reaction conditions on epoxidized units according to a SN2 substitution with an oxirane ring‐opening mechanism. A systematic study was performed with dibutylphosphate that was shown to be very reactive. Grafting of phosphorated groups along polyisoprene chains was carried out via reaction of the acidic function (P‐OH) of the phosphate with oxirane rings previously created on a 1,4‐polyisoprene backbone. The prominent role of latex pH on the reaction was shown. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 39–52, 2005
Differential expression of estrogen receptors (ERα/ERβ) in testis of mature and immature pigs
Authors: Rago Vittoria , Maggiolini Marcello , Vivacqua Adele , Palma Antonio , Carpino Amalia 
Published: November 2004

AbstractHigh affinity estrogen receptors (ERs) mediate estrogen action in male reproductive tissues. The objective of the present study was the immunolocalization of estrogen receptor α and estrogen receptor β in immature and mature testes of pig, a species in which the role of estrogens on gonadal function is scarcely known. Testes from 3 and 18 month‐old pigs were investigated. Immunohistochemistry was performed on paraffin embedded‐tissues using both mouse anti‐human monoclonal IgG ERα and IgG ERβ 1 isoform. Western blot analysis demonstrated antibody specificity. ERα staining was not observed in immature testes, but it was detected in spermatogonia, spermatocytes and in the most Leydig cells of mature testes. ERβ immunoreactivity was observed in spermatogonia and Leydig cells of immature gonads, while it was clearly detected in spermatogonia and in spermatocytes of adult pig testes. The differential ERα/ERβ expression in germ and somatic cells of the gonads suggest a role of estrogens in function and in development of pig testis. © 2004 Wiley‐Liss, Inc.
Scholarly use of internet‐based electronic resources
Authors: Zhang Yin 
Published: November 2004

AbstractThis research examines the use of Internet‐based electronic resources (e‐sources) by a group of library and information science (LIS) scholars. It focuses particularly on how scholars use, cite, and evaluate e‐sources during the research process. This research also explores the problems scholars encounter and concerns they have when using e‐sources for research. The following approaches were used to collect data for the investigation: (a) a longitudinal analysis of e‐source citations in eight LIS journals from 1991 through 1998; (b) a survey of editors of the eight journals; and (c) a survey of 201 authors with articles to be published in the eight journals. The longitudinal analysis of e‐source citations shows that there has been a notable increase in the number and proportion of authors who cite e‐sources in their research articles over the 8‐year period, although at the time of this study, e‐sources were still cited much less frequently than print sources. This result provides empirical evidence that e‐sources are increasingly used among scholars. Complementing the citation data, the results from the author survey show that e‐sources are becoming an important component in scholars' research, and are serving a wide range of purposes and functions. The number of access points and self‐perceived overall ability to use the Internet are identified as the two significant variables affecting frequency of e‐source use. The results of this study also suggest that a limited number of criteria can be implemented in practice for scholars to evaluate electronic sources and systems. When citing e‐sources, scholars consider some factors that are unique to e‐sources, in addition to the factors they consider for print sources. Although the advantages of e‐sources promote citing, some drawbacks of e‐sources at this stage serve as a barrier. The survey of editors also reveals a lack of clearly stated editorial policies regarding citing e‐sources. The major problems and concerns reported by scholars regarding using e‐sources are summarized, and both the theoretical implications and practical applications of the findings are discussed.
FEATURES: Real‐time adaptive feature and document learning for web search
Authors: Chen Zhixiang , Meng Xiannong , Fowler Richard H. , Zhu Binhai 
Published: November 2004

AbstractIn this article we report our research on building FEATURES—an intelligent web search engine that is able to perform real‐time adaptive feature (i.e., keyword) and document learning. Not only does FEATURES learn from the user's document relevance feedback, but it also automatically extracts and suggests indexing keywords relevant to a search query and learns from the user's keyword relevance feedback so that it is able to speed up its search process and to enhance its search performance. We design two efficient and mutual‐benefiting learning algorithms that work concurrently, one for feature learning and the other for document learning. FEATURES employs these algorithms together with an internal index database and a real‐time meta‐searcher to perform adaptive real‐time learning to find desired documents with as little relevance feedback from the user as possible. The architecture and performance of FEATURES are also discussed.
Analysis of publications and citations from a geophysics research institute
Authors: Frohlich Cliff , Resler Lynn 
Published: November 2004

AbstractWe here perform an analysis of all 1128 publications produced by scientists during their employment at the University of Texas Institute for Geophysics, a geophysical research laboratory founded in 1972 that currently employs 23 Ph.D.‐level scientists. We thus assess research performance using as bibliometric indicators such statistics as publications per year, citations per paper, and cited half‐lives. To characterize the research style of individual scientists and to obtain insight into the origin of certain publication‐counting discrepancies, we classified the 1128 publications into four categories that differed significantly with respect to statistics such as lifetime citation rates, fraction of papers never‐cited after 10 years, and cited half‐life. The categories were: mainstream (prestige journal) publications—32.6 lifetime cit/pap, 2.4% never cited, and 6.9 year half‐life; archival (other refereed)—12.0 lifetime cit/pap. 21.5% never cited, and 9.5 years half‐life; articles published as proceedings of conferences—5.4 lifetime cit/pap, 26.6% never cited, and 5.4 years half‐life; and “other” publications (news articles, book reviews, etc.)—4.2 lifetime cit/pap, 57.1% never cited, and 1.9 years half‐life. Because determining cited half‐lives is highly similar to a well‐studied phenomenon in earthquake seismology, which was familiar to us, we thoroughly evaluate five different methods for determining the cited half‐life and discuss the robustness and limitations of the various methods. Unfortunately, even when data are numerous the various methods often obtain very different values for the half‐life. Our preferred method determines half‐life from the ratio of citations appearing in back‐to‐back 5‐year periods. We also evaluate the reliability of the citation count data used for these kinds of analysis and conclude that citation count data are often imprecise. All observations suggest that reported differences in cited half‐lives must be quite large to be significant.
Google's web page ranking applied to different topological web graph structures
Authors: Meghabghab George 
Published: November 2004

AbstractThis research is part of the ongoing study to better understand web page ranking on the web. It looks at a web page as a graph structure or a web graph, and tries to classify different web graphs in the new coordinate space: (out‐degree, in‐degree). The out‐degree coordinate od is defined as the number of outgoing web pages from a given web page. The in‐degree id coordinate is the number of web pages that point to a given web page. In this new coordinate space a metric is built to classify how close or far different web graphs are. Google's web ranking algorithm (Brin & Page, 1998) on ranking web pages is applied in this new coordinate space. The results of the algorithm has been modified to fit different topological web graph structures. Also the algorithm was not successful in the case of general web graphs and new ranking web algorithms have to be considered. This study does not look at enhancing web ranking by adding any contextual information. It only considers web links as a source to web page ranking. The author believes that understanding the underlying web page as a graph will help design better ranking web algorithms, enhance retrieval and web performance, and recommends using graphs as a part of visual aid for browsing engine designers.
Totality and representation: A history of knowledge management through European documentation, critical modernity, and post‐Fordism
Authors: Day Ronald E. 
Published: November 2004

AbstractThis article presents European documentalist, critical modernist, and Autonomous Marxist influenced post‐Fordist views regarding the management of knowledge in mid‐ and late twentieth century Western modernity and postmodernity, and the complex theoretical and ideological debates, especially concerning issues of language and community. The introduction and use for corporate, governmental, and social purposes of powerful information and communication technologies created conceptual and political tensions and theoretical debates. In this article, knowledge management, including the specific recent approach known as “Knowledge Management,” is discussed as a social, cultural, political, and organizational issue, including the problematic feasibility of capturing and representing knowledge that is “tacit,” “invisible,” and is imperfectly representable. “Social capital” and “affective labor” are discussed as elements of “tacit” knowledge. Views of writers in the European documentalist, critical modernist, and Italian Autonomous Marxist influenced post‐Fordist traditions, such as Otlet, Briet, Heidegger, Benjamin, Marazzi, and Negri, are discussed.1
Toward automatic Chinese temporal information extraction
Authors: Li Wenjie , Wong Kam‐Fai , Yuan Chunfa 
Published: November 2004

AbstractOver the past few years, temporal information processing and temporal database management have increasingly become hot topics. Nevertheless, only a few researchers have investigated these areas in the Chinese language. This lays down the objective of our research: to exploit Chinese language processing techniques for temporal information extraction and concept reasoning. In this article, we first study the mechanism for expressing time in Chinese. On the basis of the study, we then design a general frame structure for maintaining the extracted temporal concepts and propose a system for extracting time‐dependent information from Hong Kong financial news. In the system, temporal knowledge is represented by different types of temporal concepts (TTC) and different temporal relations, including absolute and relative relations, which are used to correlate between action times and reference times. In analyzing a sentence, the algorithm first determines the situation related to the verb. This in turn will identify the type of temporal concept associated with the verb. After that, the relevant temporal information is extracted and the temporal relations are derived. These relations link relevant concept frames together in chronological order, which in turn provide the knowledge to fulfill users' queries, e.g., for question‐answering (i.e., Q&A) applications.
Information discovery from complementary literatures: Categorizing viruses as potential weapons
Authors: Swanson Don R. , Smalheiser Neil R. , Bookstein A. 
Published: November 2004

AbstractUsing novel informatics techniques to process the output of Medline searches, we have generated a list of viruses that may have the potential for development as weapons. Our findings are intended as a guide to the virus literature to support further studies that might then lead to appropriate defense and public health measures. This article stresses methods that are more generally relevant to information science. Initial Medline searches identified two kinds of virus literatures—the first concerning the genetic aspects of virulence, and the second concerning the transmission of viral diseases. Both literatures taken together are of central importance in identifying research relevant to the development of biological weapons. Yet, the two literatures had very few articles in common. We downloaded the Medline records for each of the two literatures and used a computer to extract all virus terms common to both. The fact that the resulting virus list includes most of an earlier independently published list of viruses considered by military experts to have the highest threat as potential biological weapons served as a test of the method; the test outcome showed a high degree of statistical significance, thus supporting an inference that the new viruses on the list share certain important characteristics with viruses of known biological warfare interest.
A unified maximum likelihood approach to document retrieval
Authors: Bodoff David , Enache Daniel , Kambil Ajit , Simon Gary , Yukhimets Alex 
Published: November 2004

AbstractEmpirical work shows significant benefits from using relevance feedback data to improve information retrieval (IR) performance. Still, one fundamental difficulty has limited the ability to fully exploit this valuable data. The problem is that it is not clear whether the relevance feedback data should be used to train the system about what the users really mean, or about what the documents really mean. In this paper, we resolve the question using a maximum likelihood framework. We show how all the available data can be used to simultaneously estimate both documents and queries in proportions that are optimal in a maximum likelihood sense. The resulting algorithm is directly applicable to many approaches to IR, and the unified framework can help explain previously reported results as well as guide the search for new methods that utilize feedback data in IR.
Content based image retrieval and information theory: A general approach
Authors: Zachary John , Iyengar S. S. , Barhen Jacob 
Published: November 2004

AbstractA fundamental aspect of content‐based image retrieval (CBIR) is the extraction and the representation of a visual feature that is an effective discriminant between pairs of images. Among the many visual features that have been studied, the distribution of color pixels in an image is the most common visual feature studied. The standard representation of color for content‐based indexing in image databases is the color histogram. Vector‐based distance functions are used to compute the similarity between two images as the distance between points in the color histogram space. This paper proposes an alternative real valued representation of color based on the information theoretic concept of entropy. A theoretical presentation of image entropy is accompanied by a practical description of the merits and limitations of image entropy compared to color histograms. Specifically, the L1norm for color histograms is shown to provide an upper bound on the difference between image entropy values. Our initial results suggest that image entropy is a promising approach to image description and representation.
Information theoretic similarity measures for content based image retrieval
Authors: Zachary John , Iyengar S. S. 
Published: November 2004

AbstractContent‐based image retrieval is based on the idea of extracting visual features from image and using them to index images in a database. The comparisons that determine similarity between images depend on the representations of the features and the definition of appropriate distance function. Most of the research literature uses vectors as the predominate representation given the rich theory of vector spaces. While vectors are an extremely useful representation, their use in large databases may be prohibitive given their usually large dimensions and similarity functions. In this paper, we propose similarity measures and an indexing algorithm based on information theory that permits an image to be represented as a single number. When use in conjunction with vectors, our method displays improved efficiency when querying large databases.
Flow injection chemiluminescence determination of dihydralazine sulphate based on permanganate oxidation sensitized by rhodamine B
Authors: Yang Xiao‐Feng , Wu Dong‐Bing , Li Hua 
Published: November 2004

AbstractA novel ﬂow injection chemiluminescence (CL) method for the determination of dihydralazine sulphate (DHZS) is described. The method is based on the CL produced during the oxidation of DHZS by acidic permanganate solution in the presence of rhodamine B. Rhodamine B is suggested as a ﬂuorescing compound for the energy‐transferred excitation. The CL emission allows quantitation of DHZS concentration in the range 5–800 ng/mL, with a detection limit of 1.9 ng/mL (3σ). The experimental conditions for the CL reaction are optimized and the possible reaction mechanism is discussed. The method has been applied to the determination of DHZS in pharmaceutical preparations and compares well with the high performance liquid chromatography (HPLC) method. Copyright © 2004 John Wiley & Sons, Ltd.
Effect of Silver Nanoparticles on the Electron Transfer Reactivity and the Catalytic Activity of Myoglobin
Authors: Gan Xin , Liu Tao , Zhong Jun , Liu Xinjian , Li Genxi 
Published: November 2004

AbstractSilver nanoparticles (11±1.5 nm) could greatly enhance the electron‐transfer reactivity of myoglobin (Mb) and its catalytic ability toward hydrogen peroxide (H2O2). Direct fast electron transfer between Mb and a pyrolytic graphite (PG) electrode was achieved, and a pair of well‐defined, quasireversible redox peaks was obtained. The cathodic and anodic peaks were located at −329 and −281 mV, respectively. Meanwhile, the catalytic ability of the protein toward the reduction of H2O2 was also studied, and a H2O2 biosensor was subsequently fabricated. Its detection limit was 1.0×10−6 M with a sensitivity of 0.0205 μA per μM of H2O2. The apparent Michaelis–Menten constant was calculated to be 1303 μM. Flocculation assay showed that the protein maintained plasmon layers surrounding the surface of silver nanoparticles and avoided silver‐nanoparticle aggregation. On the other hand, UV‐visible spectroscopy studies revealed that silver nanoparticles could induce a small change of the heme‐group environment of the protein; this contributed to the enhancement of the electron‐transfer reactivity and the catalytic activity.
Peroxidase Activity of Cationic Metalloporphyrin‐Antibody Complexes
Authors: Yamaguchi Hiroyasu , Tsubouchi Kaori , Kawaguchi Kazuhide , Horita Eri , Harada Akira 
Published: November 2004

AbstractPeroxidase activity of a complex of water‐soluble cationic metalloporphyrin with anti‐cationic porphyrin antibody is reported. Antibody 12E11G, which was prepared by immunization with a conjugate of 5‐(4‐carboxyphenyl)‐10,15,20‐tris(4‐methylpyridyl)porphine iodide (3MPy1C), bound to tetramethylpyridylporphyrin iron complex (FeIII–TMPyP) with the dissociation constant of 2.6×10−7 M. The complex of antibody 12E11G with FeIII–TMPyP catalyzed oxidation of pyrogallol, catechol, and guaiacol. A Lineweaver–Burk plot for the oxidation of pyrogallol catalyzed by the FeIII–TMPyP–antibody complex showed Km=8.6 mM and kcat=680 min−1. Under the same conditions, Km and kcat for horseradish peroxidase (HRP) were 0.8 mM and 1750 min−1, respectively. Although the binding interaction of the antibody to the substrates was one order lower than that of native HRP, the peroxidase activity of this system was in the same order of magnitude as that of HRP.
Intramolecular γ‐Hydroxylations of Nonactivated CH Bonds with Copper Complexes and Molecular Oxygen
Authors: Schönecker Bruno , Zheldakova Tatjana , Lange Corinna , Günther Wolfgang , Görls Helmar , Bohl Martin 
Published: November 2004

AbstractCopper(I) complexes incorporating the isomeric bidentate ligands IMPY (iminomethyl‐2‐pyridines) or AMPY (aminomethylene‐2‐pyridines) are quite unusual in their ability to bind and activate molecular oxygen. Using these complexes, hydroxylations of nonactivated CH, CH2, or CH3 groups in the γ‐position in relation to the imino‐nitrogen atom, and with a specific orientation of one H atom with respect to the binuclear CuO species, can be achieved in synthetically useful yields. Through mechanistic studies employing conformationally well‐defined molecules (for example, cyclic isoprenoids), coupled with solid‐state X‐ray structure analyses and force‐field calculations, we postulate a seven‐membered transition state for this reaction in which six atoms lie approximately in a plane. This plane is defined by the positions of the lone pairs on the nitrogen atoms, as well as the copper and the oxygen atoms. For a successful hydroxylation, one hydrogen atom should be located close to this plane. Prediction of the stereochemical course of these reactions is possible based on a simple geometrical criterion. The convenient introduction of IMPY and AMPY groups as auxiliaries into oxo and primary amino compounds and the simple hydrolysis after the hydroxylation procedure has allowed the synthesis of 3‐hydroxy‐1‐oxo and 3‐hydroxy‐1‐amino compounds. If desired, the 3‐hydroxy‐1‐IMPY and ‐1‐AMPY compounds can be reduced with NaBH4 to obtain 3‐hydroxy‐1‐aminomethylpyridines. For a successful hydroxylation procedure, the method employed for the synthesis of the CuI complexes is very important. Starting either from CuI salts or from CuII salts with a subsequent reduction with benzoin/triethylamine may turn out to be the better way, depending on the ligand and the molecular structure.