Procedures are described for the use of high-performance liquid chromatography and gas chromatography with a chemiluminescence detector in the analysis of N-nitrosoamino acids, N-nitrosothiazolidine-4-carboxylic acid, N-nitroso-oxazolidine-4-carboxylic acids and N-nitroso dipeptides N-terminal in N-nitrosoproline in cured meat products. The detection limit is around 5-10 micrograms/kg. Evidence is presented for the presence of all these species except the N-nitrosated dipeptides.

Several studies have suggested that women in science are less productive than men, and that this gap contributes to their under-representation in the ranks of senior researchers. However, few studies have examined the role of mentoring, and in particular mentor gender, on the productivity of female scientists early in their careers. Such efforts are limited by the difficulties of unambiguously linking mentees to their mentors and measuring the research productivity resulting from those relationships. Here we use our novel author disambiguation solution to investigate the role of self-identified gender in mentorship of 12,932 trainees who either successfully or unsuccessfully applied to the National Institutes of Health for research fellowships between fiscal years 2011 and 2017, applying a multi-dimensional framework to assess productivity. We found that, after normalizing for the funding level of mentors, the productivity of female and male mentees is indistinguishable; it is also independent of the gender of the mentor, other than in measures of clinical impact, where women mentored by women outperform other mentee-mentor dyads.

The problem of discrimination reversal has recently been given a good deal of attention by various experimenters. The present experiment is designed to study the effect of problem difficulty on ease of discrimination reversal. The following specific question is asked: Will a discrimination reversal problem involving stimuli which fall near each other on the generalization gradient be more difficult than one using relatively dissimilar stimuli? METHOD SubjectsThe iS' s were 20 naive albino rats, approximately 00 days old, from the colony of the Psychology Department of Michigan Stale University. A pparalus:\ two-window Lashley-type jumping stand was employed. A feeding platform was behind (he windows, and a canvas net into which the iS' s fell after an incorrect response was attached below the windows. The apparatus was painted flat black. The stimulus cards used were as follows: Card 1 was a light gray similar to Munsell no. N 9/0 (6); Card 2, a slightly darker gray than Card 1, was similar to Munsell no. N" 8/0; and Card 3, a slightly darker gray than Card 2, was similar to Munsell no. M 7/0.