  Gender differences in collaborative research have received little attention
when compared with the growing importance that women hold in academia and
research. Unsurprisingly, most of bibliometric databases have a strong lack of
directly available information by gender. Although empirical-based network
approaches are often used in the study of research collaboration, the studies
about the influence of gender dissimilarities on the resulting topological
outcomes are still scarce. Here, networks of scientific subjects are used to
characterize patterns that might be associated to five categories of
authorships which were built based on gender. We find enough evidence that
gender imbalance in scientific authorships brings a peculiar trait to the
networks induced from papers published in Web of Science (WoS) indexed journals
of Economics over the period 2010-2015 and having at least one author
affiliated to a Portuguese institution. Our results show the emergence of a
specific pattern when the network of co-occurring subjects is induced from a
set of papers exclusively authored by men. Such a male-exclusive authorship
condition is found to be the solely responsible for the emergence that
particular shape in the network structure. This peculiar trait might facilitate
future network analyses of research collaboration and interdisciplinarity.
