Discovering, recovering, and covering-up Canada: Tracing historical citizenship discourses in K–12 and adult immigrant citizenship education

In Canada, cultural diversity has always been a contested cornerstone of citizenship and of citizenship education. In the last decade, a number of provinces, including Alberta and Ontario, have published citizenship and character education documents and social studies curricula in which ideas of cultural diversity are central and shape dominant understandings of nationhood. Meanwhile, the federal government produced its own citizenship education text: a study handbook for adult immigrants taking the citizenship test. Recognizing an interesting opportunity to compare how citizenship and diversity are presented to youth and to adult immigrants, we offer a critical analysis of the extent to which current discourses reflect, revise, or reassert those that were prominent in the past. We find that within educational curricula, liberal social justice discourses are taking a background to those that promote social cohesion and a narrow vision of Canadian identity and history and that de-emphasize progressive ideals of engaging with difference and committing to social action policies. At the provincial K–12 level, a neoliberal understanding of individual development and economic rationales is dominant, while at the federal level, there is also a shift toward neoconservatism that recovers the imperial roots of Canadian citizenship ideals while covering up the strong history of equity, diversity, and civic action

Effect of DMPS and DMSA on the Placental and Fetal Disposition of Methylmercury

a b s t r a c t Methylmercury (CH 3 Hg þ ) is a serious environmental toxicant. Exposure to this metal during pregnancy can cause serious neurological and developmental defects in a developing fetus. Surprisingly, little is known about the mechanisms by which mercuric ions are transported across the placenta. Although it has been shown that 2,3-dimercaptopropane-1-sulfonate (DMPS) and 2,3-dimercaptosuccinic acid (DMSA) are capable of extracting mercuric ions from various organs and cells, there is no evidence that they are able to extract mercury from placental or fetal tissues following maternal exposure to CH 3 Hg þ . Therefore, the purpose of the current study was to evaluate the ability of DMPS and DMSA to extract mercuric ions from placental and fetal tissues following maternal exposure to CH 3 Hg þ . Pregnant Wistar rats were exposed to CH 3 HgCl, containing [ 203 Hg], on day 11 or day 17 of pregnancy and treated 24 h later with saline, DMPS or DMSA. Maternal organs, fetuses, and placentas were harvested 48 h after exposure to CH 3 HgCl. The disposition of mercuric ions in maternal organs and tissues was similar to that reported previously by our laboratory. The disposition of mercuric ions in placentas and fetuses appeared to be dependent upon the gestational age of the fetus. The fetal and placental burden of mercury increased as fetal age increased and was reduced by DMPS and DMSA, with DMPS being more effective. The disposition of mercury was examined in liver, total renal mass, and brain of fetuses harvested on gestational day 19. On a per gram tissue basis, the greatest amount of mercury was detected in the total renal mass of the fetus, followed by brain and liver. DMPS and DMSA reduced the burden of mercury in liver and brain while only DMPS was effective in the total renal mass. The results of the current study are the first to show that DMPS and DMSA are capable of extracting mercuric ions, not only from maternal tissues, but also from placental and fetal tissues following maternal exposure to CH 3 Hg þ

Transport and Toxicity of Methylmercury-Cysteine in Cultured BeWo Cells

Mercury is a heavy metal toxicant that is prevalent throughout the environment. Organic forms of mercury, such as methylmercury (MeHg), can cross the placenta and can lead to lasting detrimental effects in the fetus. The toxicological effects of MeHg on the placenta itself have not been clearly defined. Therefore, the purpose of the current study was to assess the transport of MeHg into placental syncytiotrophoblasts and to characterize the mechanisms by which MeHg exerts its toxic effects. Cultured placental syncytiotrophoblasts (BeWo) were used for these studies. The transport of radioactive MeHg was measured to identify potential mechanisms involved in the uptake of this compound. The toxicological effects of MeHg on BeWo cells were determined by assessing visible pathological change, autophagy, mitochondrial viability, and oxidative stress. The findings of this study suggest that MeHg compounds are transported into BeWo cells primarily by sodium-independent amino acid carriers and organic anion transporters. The MeHg altered mitochondrial function and viability, decreased mitophagy and autophagy, and increased oxidative stress. Exposure to higher concentrations of MeHg inhibited the ability of cells to protect against MeHg-induced injury. The findings show that MeHg is directly toxic to syncytiotrophoblasts and may lead to disruptions in the fetal/maternal transfer of nutrients and wastes