AMBAR: A midwifery-led training program to improve obstetric and neonatal practices among low-risk births in Mexico.

Background: Birth care in Mexican health institutions is highly medicalized and of poor quality because of the prevalence of outdated and dangerous practices. AMBAR-a training program for health care providers on the use of evidence-based midwifery practices-was implemented during 2016-2018 and evaluated to assess the impact of training on key practices.

Methods: For this mixed-methods study, we evaluated the effects of a training program implemented in three public hospital networks in Mexico.

Improved online hydrogen isotope analysis of halite aqueous inclusions.

We demonstrate an improved method based on continuous-flow elemental analyser pyrolysis isotopic ratio mass spectrometry (CF-EA-PY-IRMS) to measure the H/ H ratios of water trapped in halite crystals. Two challenges to overcome are the low hydrogen concentration of samples (10-50 μmol H ·g ) and the high chloride concentration released when reacting halite in an elemental analyser. We describe an optimization procedure for determining the H/ H ratio of this trapped water with an acceptable accuracy.

Simultaneous N, C, S stable isotope analyses using a new purge and trap elemental analyzer and an isotope ratio mass spectrometer.

Rationale: The evolution of stable isotope applications has demonstrated the increasing need for the determination of more than one isotopic signature from the same sample. Simultaneous determinations of (13)C/(12)C and (15)N/(14)N have become a widespread technique but up to now very few fully automated systems have offered the possibility of also measuring (34)S/(32)S from the same sample aliquot. This could be critical when sample amounts are limited, but it could also represent a significant gain of analytical time or cost.