Minimum effective dose of folic acid for food fortification to prevent neural-tube defects

BACKGROUND: Although a daily supplement of 400 micrograms folic acid has been shown to prevent neural-tube defects (NTD), most women do not take the recommended supplement. Thus, food fortification is to be introduced in the USA and is being considered in the UK. Because of safety concerns, the USA has chosen a level of fortification that will increase the average woman's intake by only 100 micrograms. Such an increase, although safe, may be ineffective; but a trial to assess its efficacy would be unethical. Because women with red-cell folate concentrations above 400 micrograms/L have a very low risk of NTD, we undertook a randomised trial of several folic acid doses to find out how much is needed to reach this protective concentration. METHODS: We screened 323 women. 172 with red-cell folate between 150 micrograms/L and 400 micrograms/L were invited to take part in the trial. 121 women were randomly assigned placebo or 100 micrograms, 200 micrograms, or 400 micrograms daily of additional folic acid. Compliance was monitored by having the women sign a dated sheet when taking the tablet. 95 women completed the 6-month study. FINDINGS: There were significant increases in red-cell folate in all folic acid groups. The placebo group showed no significant change. The median incremental changes and median post-treatment concentrations were 67 micrograms/L (95% CI 43-120) and 375 micrograms/L (354-444) in the 100 micrograms/day group, 130 micrograms/L (108-184) and 475 micrograms/L (432-503) in the 200 micrograms/day group, and 200 micrograms/L (125-312) and 571 micrograms/L (481-654) in the 400 micrograms/day group. INTERPRETATION: A fortification programme that delivered 400 micrograms folic acid daily to women would protect against NTD, but at the expense of unnecessarily high exposure for many people. Delivery of 200 micrograms daily is also effective against NTD and safer for the general population. Based on projections from the positive folate balance in the group that received 100 micrograms daily, this dose taken continually, as it will be in fortified food, will also produce an important decrease in NTD.     

Mutations affecting induction of glycolytic and fermentative genes during germination and environmental stresses in Arabidopsis

Expression of the alcohol dehydrogenase gene (ADH) of Arabidopsis is known to be induced by environmental stresses and regulated developmentally. We used a negative-selection approach to isolate mutants that were defective in regulating the expression of the ADH gene during seed germination; we then characterized three recessive mutants, aar1-1, aar1-2, and aar2-1, which belong to two complementation groups. In addition to their defects during seed germination, mutations in the AAR1 and AAR2 genes also affected anoxic and hypoxic induction of ADH and other glycolytic genes in mature plants. The aar1 and aar2 mutants were also defective in responding to cold and osmotic stress. The two allelic mutants aar1-1and aar1-2 exhibited different phenotypes under cold and osmotic stresses. Based on our results we propose that these mutants are defective in a late step of the signaling pathways that lead to increased expression of the ADH gene and glycolytic genes.     

Epilogue: A legal and cultural commentary on the psychology of jury instructions.

This essay comments on each of the contributions to this special issue. The principal thesis of the review is that the more we learn about the complex effects of jury instructions, the less confident we become about our ability to advocate for specific reforms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social attributions and conversation style in trial testimony.

83 undergraduates and 43 law students heard either a male or a female witness in a taped reenactment of criminal trial testimony. The testimony was presented either in a "fragmented" style, with brief answers by the witness to many questions by the lawyer, or in a "narrative" style, with long answers to few questions. Consideration of adversary court norms and sex stereotypes led to the prediction that Ss would attribute favorable evaluation of the witness by the lawyer in the female witness–narrative style condition and unfavorable evaluation of the witness by the lawyer in the male witness–fragmented style condition. The prediction with respect to the female witness was confirmed only with law students; the prediction with respect to the male witness was confirmed only with undergraduates. Ss' own evaluations of the witness showed the same pattern of effects. Implications for social perception and social psychology of law are discussed. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)