A previous experiment (Doise, Mugny and Perret-Clermont, 1975)

In this paper we introduce a new paradigm for nanowire growth that explains the unwanted appearance of parasitic nonvertical nanowires. With a crystal structure polarization analysis of the initial stages of GaAs nanowire growth on Si substrates, we demonstrate that secondary seeds form due to a three-dimensional twinning phenomenon. We derive the geometrical rules that underlie the multiple growth directions observed experimentally. These rules help optimizing nanowire array devices such as solar or water splitting cells or of more complex hierarchical branched nanowire devices.

A bstraci This paper presents two experiments to support the general hypothesis that the coordination of actions between individuals promotesHow do the cognitive operations controlling the interaction between the individual and his environment develop? The two research studies which we present here suggest that social psychology can help in answering this question. These operations do not develop only when the individual interacts with the objects of his physical environment. We present the hypothesis that the development of cognitive operations is facilitated when several individuals are required to coordinate their actions on the environment. This thesis lies at the crossroads of several lines of thought and research, the most useful for our purposes being the 'theoretical' approach of Piaget and the more 'practical' approach of certain educational psychologists.Piaget often underlines the importances of social factors in the child's cognitive development. 'Human intelligence develops in the individual in terms of qocial interactions too often disregarded' (Piaget, 1971, pp. 224-225). Indeed, according to Piaget, '. . . cooperation is the first of a series of forms of behaviour which are important for the constitution and development of logic ' (Piaget, 1950, In his Etudes sociologiques, Piaget constructs a model which demonstrates that Eur.

Five studies examined the hypothesis that heterosexual men, but not heterosexual women, endorse negative attitudes toward homosexuality (i.e., sexual prejudice) in order to maintain a positive gender-related identity that is unambiguously different from a homosexual identity. Studies 1 and 2 showed that men's (but not women's) gender self-esteem (but not personal self-esteem) was positively related to sexual prejudice: The more positive heterosexual men's gender self-esteem, the more negative their attitude toward homosexuality. Studies 3 and 4 showed that this link appears specifically among men motivated to maintain psychological distance from gay men. Study 5 experimentally manipulated the perceived biological differences between homosexual and heterosexual men. The previously observed link between men's gender self-esteem and sexual prejudice appeared in the control and no-differences conditions but disappeared in the differences condition. These findings are discussed in terms of men's attitudes as a defensive function against threat to masculinity.

No abstract