Longitudinal Associations between Gender and Ethnic-Racial Identity Felt Pressure from Family and Peers and Self-Esteem among African American and Latino/a Youth.

Gender identity felt pressure is negatively associated with adjustment indices, including self-esteem, among children and early adolescents, and both gender and ethnic-racial identity felt pressure are negatively associated with self-esteem among young adults. This study explored the longitudinal associations between gender identity and ethnic-racial identity felt pressure from family and peers to behave in either gender or race/ethnic-accordant ways, and self-esteem among a sample of 750 (49.2% female) African American (n = 194) and Latino/a youth (n = 556) (M = 12.10 years, SD = .97 years). For African Americans, the results revealed significant negative longitudinal associations between (a) ethnic-racial identity felt pressure from family at Time 1 and self-esteem at Time 2 and (b) ethnic-racial identity felt pressure from peers at Time 1 and self-esteem at Time 2, controlling for self-esteem at Time 1. These associations were not found among Latinos/as, nor were associations found between gender identity felt pressure from peers or family and self-esteem. The findings are discussed by drawing on the gender identity and ethnic-racial identity literatures.

Molecular and catalytic properties of 2,4'-dihydroxyacetophenone dioxygenase from Burkholderia sp. AZ11.

The gene dad encoding 2,4'-dihydroxyacetophenone (DHAP) dioxygenase was cloned from Burkholderia sp. AZ11. The initiation codon GTG was converted to ATG for high-level expression of the enzyme in Escherichia coli. The enzyme was moderately thermostable, and the recombinant enzyme was briefly purified. The enzyme (M(r)=90 kDa) was a homotetramer with a subunit M(r) of 23 kDa. It contained 1.69 mol of non-heme iron, and had a dark gray color. On anaerobic incubation of it with DHAP, the absorption at around 400 nm increased due to the formation of an enzyme-DHAP complex. Multiple sequence alignment suggested that His77, His79, His115, and Glu96 in the cupin fold were possible metal ligands. The apparent K(m) for DHAP and the apparent V(max) were estimated to be 1.60 µM and 6.28 µmol/min/mg respectively. 2-Hydroxyacetophenone was a poor substrate. CuCl(2) and HgCl(2) strongly inhibited the enzyme, while FeSO(4) weakly activated it.