The paper is divided in two parts. Part I deals with the novel use of the concept ofentropy H (measured in nepers) of the ageT of references cited in the literature of a specialty, and the derived parameterS=exp(H) (measured in years). We have proposed to useS (orH) as a measure of the obsolescence of the literature. The concept of entropy comes from the Theory of Information (Shannon) where its mathematical properties have been widely studied and are thus available.H andS have been calculated for the log-normal probability density functions (which model the empirical distributions ofT) of some IEEE journals and for the 58-year collection of an electronics journal, and then they have been compared to the total utility function, this latter defined in the literature. Part II recalls and discusses the mean residual life,M(T), and the expected lifeE(T), of a reference of ageT (concepts borrowed from lifetime data analysis). Besides their intrinsic applications, another possible application of these concepts may be in defining quantitatively the age of historical papers. Examples taken from the literatures of the XX and XIX centuries have been reported.
The beginning and early spread of the world-wide epidemic of acquired immunodeficiency syndrome (AIDS) has been paralleled closely by a rapidly expanding literature concerned with many aspects of the disease. In order to assess the growth of the AIDS literature, a quantitative analysis was conducted focusing on the number of articles, the number of journals contributing, the number of languages used, and the number of countries of origin of publications over time (a bibliometric study). The growth of the popular literature was also studied. Three online databases — MEDLINE, Magazine Index, and the National Newspaper Index — were examined from 24 September 1982 (the date the Centers for Disease Control first adopted the name acquired immunodeficiency syndrome) through the end of 1986 for the popular literature and through the end of 1987 for MEDLINE. A survey of the MEDLINE file showed that by the end of 1987, twenty-five languages were represented in articles from fifty-four countries published in 1170 different journal titles.
Authors:C. Macias-Chapula, Irma Rodea-Castro, and Nora Narvaez-Berthelemot
This work reports on the preliminary results of a bibliometric analysis of AIDS literature, as produced in or about Latin
America and the Caribbean for the period 1980–1996. Two international and two regional secondary sources were used in order
to obtain comparative analyses regarding for example, comprehensiveness of AIDS literature coverage and local/main frame visibility.
Less than 1000 records were retrieved from each of the databases searched. Leading countries in AIDSLINE were Haiti, Brasil,
Mexico and Puerto Rico. The distribution by year of publication showed a decrease in Haiti records, from 54 in 1983, to 4
in 1995. The rest of the countries either increased or maintained an average production throughout the years. Regional secondary
information sources were less current and comprehensive in the field. Further lines of research are described by the authors.
Authors:Claude Robert, Concepción Wilson, Jean-François Gaudy, and Charles-Daniel Arreto
During the 1974–2004 period, the sleep literature had quadrupled (2384 publications in 1974, and 9721 in 2004) while overall
scientific productivity had only doubled. The set of the seven most productive countries (USA, Japan, United Kingdom, Germany,
France, Canada and Italy) in sleep research, and the geographical region distribution remained stable over the three decades.
On the other hand several indicators appeared in the sleep research literature during the 1990s: the increasing productivity
of sleep researchers; the growing number of countries publishing on sleep; the continuous creation of sleep-focused journals;
the scattering of sleep publication among increasingly more scientific journals; the turnover among the leading journals;
and the emergence of new entities such as China, Turkey, and the European Union.
An attempt has been made to trace and compare the trends in growth of Food Science and Technology (FST) literature (periodical
articles, patents, standards, theses and dissertations) produced by CFTRI scientists, by food scientists in India and by food
scientsts of the world, covering a period between 1950 and 1990; to identify the best fitting growth models for actual and
cumulative growth of data through regression analysis; and αt and α2t analysis; and to compute and compare the growth rates of FST documnets.
Different approaches are introduced for studying the growth of scientific knowledge, as reflected through publications and authors. Selected growth models are applied to the cumulated growth of publications and authors in theoretical population genetics from 1907 to 1980. The criteria are studied on which growth models are to be selected for their possible application in the growth of literature. It is concluded that the power model is observed to be the only model among the models studied which best explains the cumulative growth of publication and author counts in the theoretical population genetics.
Authors:C. Macias-Chapula, G. Sotolongo-Aguilar, B. Magde, and J. Solorio-Lagunas
The purpose of this paper is to present the preliminary results of a research in progress regarding the subject content analysis
of AIDS literature, as produced in or about the Latin American and Caribbean (LAC) region. An AIDSLINE/OVID literature search
was conducted to obtain only the Medical Subject Headings (MeSH)-geographic-terms related to the LAC region. The period of
study was from 1982 to June, 1998.
Indicators regarding the distribution of records throughout the years of study, as well as the subject, check tags, and subject/subheadings
distribution patterns were analysed. This was done through the application of a modular bibliometric information system, as
well as the applications of Biblio-Link for Windows, Version 1.2 1994–1997, Research Information Systems; Pro-Cite for Windows,
Version 4.0.1 1995–1998, Research Information Systems; and Microsoft EXCEL 97, of 1985–1998, Microsoft Corporation.
A total of 4124 records were obtained and analysed. In descending order, Brazil, Mexico, Haiti, Argentina and Puerto Rico,
generated the highest number of citations. Highly ranked MeSH subject headings wereRisk Factors; Acquired Immunodeficiency Syndrome; Sex Behavior, Support, Non U.S. Govt.; HIV Infections; andDeveloping Countries.
Results demonstrate that major research concerns centred on the epidemiological aspects and transmission of AIDS; and more
recently, on the prevention and control of the disease. A swith of the studies from male to female, and from middle age to
adolescence was also observed. The authors provide further lines of research.
This paper reports on a new approach to study the linkage between science and technology. Unlike most contributions to this area we do not trace citations of scientific literature in patents but explore citations of patents in scientific literature. Our analysis is based on papers recorded in the 1996-2000 annual volumes of the CD-Edition of Science Citation Index (SCI) of the Institute for Scientific Information (ISI) and patent data provided by the US Patent and Trademark Office. Almost 30,000 US patents were cited by scientific research papers. We analysed the citation links by scientific fields and technological sectors. Chemistry-related subfields tended to cite patents more than other scientific area. Among technological sectors, chemical clearly dominates followed by drugs and medical patents as the most frequently cited categories. Further analyses included a country-ranking based on inventor-addresses of the cited patents, a more detailed inspection of the ten most cited patents, and an analysis of class-field transfers. The paper concludes with the suggestions for future research. One of them is to compare our 'reverse' citation data with 'regular' patent citation data within the same classification system to see whether citations occur, irrespectively of their directionality, in the same fields of science and technology. Another question is as to how one should interpret reverse citation linkages.
A total of 2192 articles published in the international literature with UNAM (National University of Mexico) first author affiliation and registered by the CICH (Centro de Iformación Científica y Humanística) BIBLAT database from 1978-mid-1987 were included in our analysis. Distribution of articles according to the main subject areas of the 692 different journal titles used was as follows: Physics 24.1%, Medicine 19.7%, Biology 19.4%, Chemistry 9.7%, Engineering 8.9%, Exact Sciences 7.3%, Geosciences 4.7%, Psychology 0.96%, Agrosciences 0.27%. Thirty-seven percent of articles were published in journals with a known impact factor for 1987 of 1, 46.1% (920) in journals within the range of >1–3 average citations/article and only 16.4% (327) in those titles with a factor >3. Fifty-four percent (1082) of studies appeared in journals whose total citation count for 1987 was 5000; 7.3% (146) in journals cited >50,000 times in that same year. UNAM scientists therefore as a group tend to publish in journals whose articles are not frequently cited in subsequent publications thus limiting their impact and visibility in the international scientific literature.
1460 items of literature in English on alcohol fuel, both technical and non-technical between 1901 and 1980 (only first quarter) collected and published as a bibliography by NAFIC, SERI (USA) were analysed. It was found that the growth pattern is befitting qualitatively with the epidemic growth model. Of the 1460 items, 828 are scattered in 288 journals. The pattern of scatter has been fitted in an empirical formula, a linear equation of the formR(r)=ar-b, whereR(r) is the Mean Relative Scatter (MRS) of the articles over a class of ranked journals in increasing productivity andr is the rank of the class,a andb are the arbitary constants. The formula, if deductively established, can serve as an effective alternative to Bradford's law.