Ana Cristina Silva

Why do winners keep winning? Androgen mediation of winner but not loser effects in cichlid fish

Animal conflicts are influenced by social experience such that a previous winning experience increases the probability of winning the next agonistic interaction, whereas a previous losing experience has the opposite effect. Since androgens respond to social interactions, increasing in winners and decreasing in losers, we hypothesized that socially induced transient changes in androgen levels could be a causal mediator of winner/loser effects. To test this hypothesis, we staged fights between dyads of size-matched males of the Mozambique tilapia (Oreochromis mossambicus). After the first contest, winners were treated with the anti-androgen cyproterone acetate and losers were supplemented with 11-ketotestosterone. Two hours after the end of the first fight, two contests were staged simultaneously between the winner of the first fight and a naive male and between the loser of first fight and another naive male. The majority (88%) of control winners also won the second interaction, whereas the majority of control losers (87%) lost their second fight, thus confirming the presence of winner/loser effects in this species. As predicted, the success of anti-androgen-treated winners in the second fight decreased significantly to chance levels (44%), but the success of androgenized losers (19%) did not show a significant increase. In summary, the treatment with anti-androgen blocks the winner effect, whereas androgen administration fails to reverse the loser effect, suggesting an involvement of androgens on the winner but not on the loser effect.

Escritas inventadas em crianças de idade pré-escolar: necessidade de um modelo integrativo das abordagens fonológica, construtivista e da aprendizagem estatística

This article focus on invented spelling in pre-school children and its aim is to describe three perspectives in the study of spelling development: phonological, constructivist and the statistical learning perspectives These theories differ not only on the perspectives about the phases of early spelling but most of all diverge on the mechanisms behind the evolution. The two first approaches present the progression on invented spelling through a stage models while the third approach does not, because, according to their point of view the same basic mechanism underlies spelling acquisition throughout development. The authors discuss several critics that can be point out to each model and defend the importance of integrating the contributions of each theory in order to build up a clear picture of children’s development. They also describe several investigations that try to accomplish that purpose.

Luis A. Carneiro

Our colleague Lu s Carneiro died, struck by lightning, during a birdwatching expedition to Georgia and Turkey on the afternoon of 12 September 2002. He was together with Jos Pedro Tavares (RSPB) and another Portuguese friend in the mountains of Georgia when they were caught by a storm and sought shelter in a mountain refuge hut. There was another group of locals already there and the conversation had started. As usual Luis was talking over everybody describing all the new bird species he had just added to his beloved tick list. And then it happened... So, apparently Luis died having a good time and doing something he loved. Lu s was finishing his PhD thesis on the role of AVT in the expression of alternative reproductive tactics in blenniid fish and he had collaborated in a number of other projects going on in the laboratory. As a graduate student he had already co-authored over ten refereed papers (including one in Nature) and given several talks in international meetings. He had recently been elected Secretary of the Portuguese Ethological Society, and was a student member of other scientific societies including the Association for the Study of Animal Behaviour, the Society for Behavioral Neuroendocrinology, the Society for Neuroscience and the International Society for Behavioral Ecology. But more than a PhD student with a promising career, Lu s was a beloved friend and his humor and attitude towards life made him the soul of our laboratory. The laboratory (and in fact nothing) will ever be the same without him around. But we believe that for those of you that ever met him he will stay in our hearts (neocortex Lu s would point out) as an example of how intensively life can and should be lived. Lu s leaves a wife (Patricia) and a 2.5-year-old daughter (Constan a). As Buzz Lightyear (a Space Ranger from Toy Story that is the favourite hero of my 3-year-old daughter) says “To infinity and beyond”; See you there Luis! From a mourning laboratory.