The grand tour of the Ruby-East Humboldt metamorphic core complex, northeastern Nevada: Part 1 - Introduction & road log

Abstract

1. Analysis of the secular trend for the last two decades of the 20th century revealed no acceleration in pubertal development of girls. A reduction in environmentally-dependent differences in menarcheal age (urban vs. rural residence) was observed. 2. Marked influence of the environment (family and school factors) on the age at menarche was evidenced. 3. At the age of first menstruation, biophysical parameters (height, body mass, sex features, concentrations of hormones) revealed specific patterns but subtle individual differences remain.