Variations du taux en composés sulfhydrilés acidosolubles de tissus cultivés in vitro

Variations of the Level of the Nitrogen and Thiol Groups in Tissues Culture.—Distribution of nitrogen and thiol compounds was analysed in the fragments of carrot roots cultivated in vitro. A typical gradient of –SH groups was observed: high level in the callus, low level in the base of the fragment (in contact with the medium). In discontinuous light, callus—which have a great amount of chlorophylls—contain less sulfhydric compounds than in continuous dark. With increasing age of the tissues, the concentration of the endogenous –SH groups was decreasing. The probable biochemical relations between –SH level, auxin content and auxin-oxidase activity are discussed.     

Men's voice pitch influences women's trusting behavior

Women tend to trust men with low-pitched voices as political leaders but trust men with high-pitched voices in mating scenarios. To elucidate the role of pitch in perceptions of trust, we used a one-decision variant of the trust game in which female participants were given the choice to trust males to divide the money, or to end the game, taking a smaller than equal sum. Male receivers were simulated using pitch-manipulated voice recordings. Women trusted raised pitch voices more than lowered pitch voices. These results suggest that although people with masculine voices are entrusted to lead our governments, people with masculine voices are not trusted to divide up financial resources equitably on a personal level.     

Women's evaluations of other women's natural body odor depend on target's fertility status

A large research literature indicates that men perceive women as more attractive when they are at high fertility than at low fertility within the ovulatory cycle. However, it remains unclear whether women also perceive women as more attractive at high fertility. This study examined women's ratings of samples of natural body odor collected from naturally-cycling women at high and low fertility within the cycle and from hormonal contraceptive-using women at mid-cycle. Like men, women rated naturally-cycling women's high-fertility scent samples as more attractive than their low-fertility samples. Women rated hormonal contraceptive (HC) users' scent samples as more attractive than naturally-cycling women's high- and low-fertility samples, though the difference between HC and high-fertility samples was statistically significant only when raters were treated as the unit of analysis. These findings reveal a potentially important role for scent communication in women's perceptions of other women and are consistent with the notion that the ovulatory cycle could influence women's interactions with one another. The findings also highlight the need for rigorous investigations of the possible impacts of hormonal contraception on women's attractiveness and social relationships with other women.