A characterization of scientometric distributions based on harmonic means

The traditional stochastic approach to scientometric and bibliometric phenomena is based on measuring the absolute number of objects (e.g., publications, topics, citations). These measures reflect underlying rules such as the cumulative advantage principle and lead to classical statistical functions such as arithmetic mean and standard deviation. An alternative measure based on the contribution share of an individual object in the entirety of related objects reveals more about the coherence in the analyzed structure. This approach is connected with (conditional) harmonic means. The analysis of the properties of these statistical functions leads to a special urn-model distribution which has an analogous behaviour to that of the Waring distribution in connection with conditional arithmetic means. The new distribution combines specific properties (long tail, flexibility of the distribution shape) of the two scientometric favourites, the Waring and the negative binomial distribution. Five methods of parameter estimation are presented. The fit and the properties of this special urn-model distribution are illustrated by three scientometric examples, particularly, by two citation rate distributions with different shapes and one publication activity distribution with lacking zero frequencies.     

Patents cited in the scientific literature: An exploratory study of 'reverse' citation relations

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 new classification scheme of science fields and subfields designed for scientometric evaluation purposes

A two-level hierarchic system of fields and subfields of the sciences, social sciences and arts and humanities is proposed. The system was specifically designed for scientometric (evaluation) purposes with the ultimate goal of classifying every single document into a well-defined category. This goal was achieved using a three-step iterative process. The basic concepts and some preliminary results are presented. This revised version was published online in August 2006 with corrections to the Cover Date.     

Effects of adrenalectomy on serotonin-, somatostatin-, and gastrin-immunoreactive cells in rat gastrointestinal tract

The effects of bilateral adrenalectomy on the serotonin-, somatostatin-, and gastrin-immunoreactive cells in the rat gastrointestinal tract were studied four weeks after surgery. Body weight was reduced and the small intestine shorter in adrenalectomized animals compared with controls, while no changes were found in the histology of the mucosa. In the adrenalectomized animals the number of serotonin-immunoreactive cells was increased in the cecum and large intestine, while the somatostatin-immunoreactive cells were decreased in number in the antrum and increased in the corpus, cecum, and large intestine. The gastrin-immunoreactive cells in the antrum were not affected in number, but their nuclear size was enlarged, possibly indicating increased cellular activity.     

Influenza vaccination in the elderly

Interleukin 1 beta-converting enzyme (ICE)-like proteases (caspases) play an important role in programmed cell death (apoptosis), and elucidating the consequences of their proteolytic activity is central to our understanding of the molecular mechanisms of cell death. Diverse structural and regulatory proteins and enzymes, including protein kinase C delta, the retinoblastoma protein (a protein involved in cell survival), the DNA repair enzyme DNA-dependent protein kinase and the nuclear lamins, undergo specific and limited endoproteolytic cleavage by various caspases during apoptosis. Since individual caspases can cleave multiple substrates, the consequences of cleavage of only a single substrate are still poorly understood. Nevertheless, proteolytic activation of protein kinase C delta may be an important early step in the cell death pathway, and cleavage of the retinoblastoma protein could suppress its cell survival function, whereas proteolytic inactivation of DNA repair enzymes might compromise the ability of the cell to reverse DNA fragmentation. On the other hand, cleavages of nuclear and cytoplasmic structural proteins (e.g. the lamins and Gas2) appear to be required for or contribute to the dramatic rearrangements in cellular architecture that are necessary for the completion of the cell death process. An emerging theme is that parallel and sequential proteolytic activation and inactivation of key protein substrates occurs during the multiple steps of apoptosis.