Historical Research Approaches to the Analysis of Internationalisation

Historical research methods and approaches can improve understanding of the most appropriate techniques to confront data and test theories in internationalisation research. A critical analysis of all “texts” (sources), time series analyses, comparative methods across time periods and space, counterfactual analysis and the examination of outliers are shown to have the potential to improve research practices. Examples and applications are shown in these key areas of research with special reference to internationalisation processes. Examination of these methods allows us to see internationalisation processes as a sequenced set of decisions in time and space, path dependent to some extent but subject to managerial discretion. Internationalisation process research can benefit from the use of historical research methods in analysis of sources, production of time-lines, using comparative evidence across time and space and in the examination of feasible alternative choices

Mitochondrial DNA modifies cognition in interaction with the nuclear genome and age in mice.

International audienceSeveral lines of evidence indicate an association between mitochondrial DNA (mtDNA) and the functioning of the nervous system. As neuronal development(1,2) and structure(3-5) as well as axonal and synaptic activity(6,7) involve mitochondrial genes, it is not surprising that most mtDNA diseases are associated with brain disorders(8,9). Only one study has suggested an association between mtDNA and cognition(10), however. Here we provide direct evidence of mtDNA involvement in cognitive functioning. Total substitution of mtDNA was achieved by 20 repeated backcrosses in NZB/BINJ (N) and CBA/H (H) mice with different mtDNA origins. All 13 mitochondrial genes were expressed in the brains of the congenic quartet. In interaction with nuclear DNA (nDNA), mtDNA modified learning, exploration, sensory development and the anatomy of the brain. The effects of mtDNA substitution persisted with age, increasing in magnitude as the mice got older. We observed different effects with input of mtDNA from N versus H mice, varying according to the phenotypes. Exchanges of mtDNA may produce phenotypes outside the range of scores observed in the original mitochondrial and nuclear combinations. These findings show that mitochondrial polymorphisms are not as neutral as was previously believed