No abstract

While current conceptualisations of the inextricable connection between language and culture in English language education are largely informed by complex sociocultural theories that view culture as constructed in and through social practices among people, classroom practices continue to be influenced by mainstream discourses of culture that simplistically construct essentialised cultural/racialised identities. This article will present data excerpts from a case study of a Canadian university -based English as a second language (ESL) programme that specifically emphasised in its pedagogical and curricular design the significance of learning language through culture and a process of cultural analysis. In various classrooms observed, however, the programme's dialogic approach to culture most often manifested as cross/intercultural comparisons of cultural difference. The potential danger of this pedagogical approach to culture in the ESL classroom, however, arises with a contextualisation of the English language in broader identity politics -namely, the equating of the English language with Whiteness -where discourses of 'culture' can become a proxy for 'race'. Seemingly innocuous everyday common-sense discussions of 'culture' in second language education may thus construct identities in problematic ways. It is therefore imperative for us to critically reflect on how our pedagogies may be 'doing race' through 'doing culture' in the ESL classroom.

Polybrominated diphenyl ethers (PBDE) are a class of brominated flame retardants that are recognized as global environmental contaminants with potential adverse effects on human health. This study examined the effects of prenatal exposure to PBDE on reproductive organs, neuronal development, and levels of thyroid hormones. Pregnant rats were exposed to the vehicle or deca-bromodiphenyl ether (BDE) (BDE-209; 5, 40, or 320 mg/kg body weight/d) during gestation days (GD) 6-18. There was a significant decrease in body weight gain in F1 male offspring exposed to high-dose (320 mg/kg) BDE-209. Significant increases in thyroid weight and a decrease in adrenal weight were observed in high-dose BDE-209. Thyroxine (T4) concentrations were significantly lower in F1 female offspring exposed to BDE-209 at postnatal day (PND) 42. This reduction was more pronounced in the group exposed to higher doses. A low dose (5 mg/kg) of BDE-209 significantly reduced serum estradiol concentration in female offspring but did not affect testosterone levels in males. There was no significant effect on hippocampal neurogenesis in BDE-209 treatment groups. In conclusion, there was no apparent association between thyroid hormone concentrations and low birth weight in F1 rats after gestational exposure to BDE-209.

This study compared the effects of di(n-butyl) phthalate (DBP) on the oxidative damage and antioxidant enzymes activity in testes of hyperthyroid rats. Hyperthyroidism was induced in pubertal male rats by intraperitoneal injection of triiodothyronine (T3, 10 microg/kg body weight) for 30 days. An oral dose of DBP (750 mg/kg) was administered simultaneously to normal or hyperthyroid (T3) rats over a 30-day period. No changes in body weight were observed in the hyperthyroid groups (T3, T3 + DBP) compared with controls. There were significantly higher serum T3 levels observed in the hyperthyroid rats than in the control, but the serum thyroid stimulating hormone levels were markedly lower in the hyperthyroid rats. DBP significantly decreased the weight of the testes in the normal (DBP) and hyperthyroid (T3 + DBP) groups. The serum testosterone concentrations were significantly lower in only DBP group. DBP significantly increased the 8-hydroxy-2-deoxyguanosine (8-OHdG) level in the testes, whereas the DBP-induced 8-OHdG levels were slightly higher in T3 + DBP group. Superoxide dismutase and glutathione peroxidase activities were significantly higher in the testes of the DBP or T3 + DBP groups. Catalase (CAT) activity was significantly higher in the DBP treatment group, but the T3 + DBP group showed slightly lower DBP-induced CAT activity. The testicular expression of thyroid hormone receptor alpha-1 (TRalpha-1) was significantly higher in the DBP groups, and androgen receptor (AR) expression was not detected in the DBP treatment group. In addition, DBP significantly increased the peroxisome proliferator-activated receptor-r (PPAR-r) levels in the testis. These results suggest that hyperthyroidism can cause a change in the expression level of PPAR-r in testes, and may increase the levels of oxidative damage induced by the metabolic activation of DBP.

This study examined the levels of polybrominated diphenyl ethers (PBDE) in the umbilical cord blood of infants, and investigated the relationship between PBDE concentration and thyroid hormone levels. The concentration of PBDE were measured in the cord blood samples of 108 infants collected in Cheil Woman's Hospital, Seoul, Korea, in 2007. Of 108 pregnant woman reported, the average age was 31.9 +/- 3.54 yr (range 20-42 yr). The mean body weight of the infants was 3.15 +/- 0.57 kg (1.89-4.43 kg), and no birth defects were documented. The concentrations of the total PBDEs (7 congeners) found in the umbilical cord blood averaged 8.377 +/- 6.381 ng/g lipid, ranging from not determined (ND) to 29.407 ng/g lipid. Of the seven congeners detected, BDE-47 (4.571 +/- 2.903 ng/g lipid) accounted for the majority (38% of total PBDE) of total PBDE, followed in descending order by BDE-153 (3.080 +/- 2.231 ng/g lipid) and BDE-183 (2.933 +/- 2.386). There was no apparent correlation between the serum PBDE levels and thyroid hormone concentrations. Similarly, there was no apparent relationship between the infant thyroxine (T4) levels and four prevalent PBDE congener concentrations. Data suggest that the concentration of PBDE in umbilical cord blood of Korean infants is similar to or lower than concentrations reported from North America. In addition, PBDE readily crossed the blood placenta barrier. Therefore, further study on the relationship between the maternal and fetal blood concentrations of PBDE is recommended for a more comprehensive exposure assessment of PBDE in Koreans.