The validity of three methods (last menstrual period [LPM], Ballard and Dubowitz scores) for assessment of gestational age for premature infants in a low-resource setting was assessed, using antenatal ultrasound as the gold standard. It was hypothesized that LMP and other methods would perform similarly in determining postnatal gestational age. Concordance analysis was applied to data on 355 ne...

BACKGROUND Accurate assessment of gestational age at birth is critical to the identification of neonates at high risk. In resource-poor settings, postnatal techniques are commonly used but may be difficult to apply and have not been well validated against ultrasound in community studies. The aim of this study was to evaluate postnatal assessment of gestational age in rural Africa using the exte...

The Rock Cycle is a useful pedagogical device. Science-fiction novelist James G. Ballard published a colorful description of a nameless fictional world in 1957 that has an artificially closed Rock Cycle. Were such an anthropogenic cycle instigated for Earth, it would be consistent with James Hutton’s viewpoint on the Earth as a self-repairing machine without an endogenetic end to planetary Geol...