Measuring collective action intention toward gender equality across cultures

Collective action is a powerful tool for social change and is fundamental to women and girls’ empowerment on a societal level. Collective action towards gender equality could be understood as intentional and conscious civic behaviors focused on social transformation, questioning power relations, and promoting gender equality through collective efforts. Various instruments to measure collective action intentions have been developed, but to our knowledge none of the published measures were subject to invariance testing. We introduce the gender equality collective action intention (GECAI) scale and examine its psychometric isomorphism and measurement invariance, using data from 60 countries (N = 31,686). Our findings indicate that partial scalar measurement invariance of the GECAI scale permits conditional comparisons of latent mean GECAI scores across countries. Moreover, this metric psychometric isomorphism of the GECAI means we can interpret scores at the country-level (i.e., as a group attribute) conceptually similar to individual attributes. Therefore, our findings add to the growing body of literature on gender based collective action by introducing a methodologically sound tool to measure collective action intentions towards gender equality across cultures

Characterization of l-arginine uptake by plasma membrane vesicles isolated from cultured pulmonary artery endothelial cells

AbstractWe investigated the mechanisms of [3H]-l-arginine transport via System y+ using plasma membrane vesicles derived from cultured pulmonary artery endothelial cells. [3H]-l-arginine uptake into plasma membrane vesicles was Na-independent, sensitive to trans-stimulation, unaffected by proton-conducting ionophores, and selectively inhibited by cationic amino acids. Kinetic experiments performed over a wide range of substrate concentrations revealed only one population of l-arginine transporters with Km = 130 μM. To elucidate the driving force for l-arginine transport, we measured [3H]-l-arginine uptake by plasma membrane vesicles at different transmembrane ion gradients. Plasma membrane vesicles accumulated [3H]-l-arginine only when a membrane potential was imposed across the vesicles, and the velocity of uptake was linearly related to the magnitude of the created membrane potential. The presence of potassium ions inside the vesicles was not essential for uptake of l-arginine into vesicles, but it was essential for trans-stimulation of l-arginine transport. [3H]-l-arginine accumulated in plasma membrane vesicles can be released by agents that dissipate transmembrane potassium gradients (e.g. saponin, gramicidin, and nigericin). Diazoxide and pinacidil, activators of K+-channels, had no significant effect on [3H]-l-arginine uptake, whereas tetraethylammonium chloride, 4-aminopyridine, and glibenclamide, inhibitors of K+-channels, caused decreases in [3H]-l-arginine transport by plasma membrane vesicles. This study demonstrates for the first time a specific role for potassium ions in the mechanism of l-arginine transport, particularly in the phenomenon of trans-stimulation