Suchergebnisse

In two experimental studies, we explored the politicized use of immigrant stereotypes by members of the Portuguese host society. Our goal was to demonstrate that stereotypes strategically vary to support political arguments and mobilize others towards one's political position. In Study 1, the way in which participants described immigrants varied as a function of (a) whether or not they were provided with the opportunity to mobilize an ingroup audience, (b) the direction in which they sought to mobilize that audience, and (c) the instrumentality of particular stereotypical traits in a given argumentative context. Study 2 examined the cognitive processes underlying the strategic expression of stereotypes, by measuring implicit stereotyping and manipulating participants' ability to do cognitive work prior to and during stereotype expression. The findings showed that (a) variability in stereotype expression was matched by a consonant variability in implicit representations of immigrants, and that (b) the ability to do cognitive work was a necessary condition for variability in stereotype expression to emerge. Taken together, these findings suggest that strategic effects in stereotype expression are underpinned by strategic work on intra-psychic representations. We conclude by discussing the complementarity between strategic and cognitive explanations of stereotype expression, as well as by arguing the possibility of a more predictive approach to the politicized use of stereotypes. ; info:eu-repo/semantics/acceptedVersion

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) ; European Union Grant LIFECYCLE ; Norwegian Research Council BIOTEK2021 program ; project SALMOSTERILE ; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) ; Processo FAPESP: 12/00423-6 ; Processo FAPESP: 14/07620-7 ; European Union Grant LIFECYCLE: FP7-222719 ; project SALMOSTERILE: 221648 ; CNPq: 201488/2014-0 ; Fsh-mediated regulation of zebrafish spermatogenesis includes modulating the expression of testicular growth factors. Here, we study if and how two Sertoli cell-derived Fsh-responsive growth factors, anti-Mullerian hormone (Amh; inhibiting steroidogenesis and germ cell differentiation) and insulin-like growth factor 3 (Igf3; stimulating germ cell differentiation), cooperate in regulating spermatogonial development. In dose response and time course experiments with primary testis tissue cultures, Fsh up regulated igf3 transcript levels and down-regulated amh transcript levels; igf3 transcript levels were more rapidly up-regulated and responded to lower Fsh concentrations than were required to decrease amh mRNA levels. Quantification of immunoreactive Amh and Igf3 on testis sections showed that Fsh increased slightly Igf3 staining but decreased clearly Amh staining. Studying the direct interaction of the two growth factors showed that Amh compromised Igf3-stimulated proliferation of type A (both undifferentiated [A(und)] and differentiating [A(diff)]) spermatogonia. Also the proliferation of those Sertoli cells associated with Aund spermatogonia was reduced by Amh. To gain more insight into how Amh inhibits germ cell development, we examined Amh-induced changes in testicular gene expression by RNA sequencing. The majority (69%) of the differentially expressed genes was down-regulated by Amh, including several stimulators of spermatogenesis, such as igf3 and steroidogenesis-related genes. At the same time, Amh increased the expression of inhibitory signals, such as inha and id3, or facilitated prostaglandin E-2 (PGE(2)) signaling. Evaluating one of the potentially inhibitory signals, we indeed found in tissue culture experiments that PGE(2) promoted the accumulation of Aund at the expense of Ada and B spermatogonia. Our data suggest that an important aspect of Fsh bioactivity in stimulating spermatogenesis is implemented by restricting the different inhibitory effects of Amh and by counterbalancing them with stimulatory signals, such as Igf3. (C) 2017 Elsevier B.V. All rights reserved.