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.
Analyses the age of references cited in source papers of the theoretical population genetics speciality at different phases
of its development. Discusses the characteristics of specialities in terms of obsolescence measures such as half-life and
immediacy index. Explores the applicability of different theoretical probability functions in the age densities of references
cited. Concludes that age of references cited is best modelled according to lognormal distribution.
Authors:Giulia Rivellini, Ester Rizzi, and Susanna Zaccarin
The scientific community organises its relationships
into network patterns, where the nodes are individuals (scientists) and the
links are acquaintance and common work, usually presented at workshops and
conferences and/or published in books and scientific journals. A references
review on Population Studies by Italian scientists is delivered every two years
by the Demography Section of the Italian Statistical Society; the review is
exhaustive for academic demographers. In this paper, the properties of the demographers'
network in 1998-1999 are evaluated, with the aim of identifying factors which
may influence collaborative relations among actors. The probability of
cooperation between couples (dyads) of demographers is modelled, conditionally
on observed characteristics of the dyad (sex, academic position, university
affiliation). Main results suggest that “closeness”, defined in a wider sense
and not simply as geographical proximity, plays a major role in determining
A mathematical model consisting of a system of two ordinary differential equations is formulated to represent the interrelationship
between healthy and radiated cells at a given cite. Three different modes of radiation are considered: constant, decaying,
and periodic radiation. For the constant case, precise criteria for persistence and extinction are obtained. In the decaying
case, it is shown that the radiated cells always become extinct. Finally in the periodic case, criteria are obtained for a
perturbed positive periodic solution.
Recently scientists have investigated what statistical distributions can be used to describe the distribution of the number
of authors per article.Ajiferuke has undertaken the most comprehensive study of this problem. He has found that by and large the Inverse Gaussian-Poisson
distribution could describe most properly the observed authorship distributions. However, it is well known that this distribution
is rather intricate, soRousseau tried to fit some simple one-parameter distributions to the number of authors of LIS articles. He has found that the geometric
and the truncated Poisson distribution adequately describe these authorship data sets. The main purpose of the present paper
is to continue these investigations and to analyse and test the viability of simple statistical distributions. As to (sub)fields
where the single author dominates the results ofRousseau were corroborated: the truncated Poisson and the geometric distribution give often adequate fits to describe the number of
authors. The Lotka distribution should be rejected. The truncated binomial distribution and the truncated negative binomial
were investigated as well. However, it is not clear whether they are acceptable candidates.
Like in other areas of the society there have been significant changes in the demography of the population related to sciences in the last decades. Historically these demographic changes since about 1975 can be
Authors:Carolina Cañibano, F. Javier Otamendi, and Francisco Solís
and network building. The access to an electronic CV database covering the entire public research system of a region allows us to analyze a much larger sample than in previous studies and one that is representative of a specific researcher population
Authors:Vincent Larivière, Etienne Vignola-Gagné, Christian Villeneuve, Pascal Gélinas, and Yves Gingras
et al. 2008 ; Simonton 2004 ) and the population pyramids of men and women are different (see Fig. 1b ), the data presented here are also broken down according to the researchers’ ages. Furthermore, we analyze trends in each of the three broad
The use of surnames in human population biology dates back to 1875, when George Darwin used frequency of occurrence of the same surname in married couples to study the amount of in-breeding Darwin 1875 . Surnames