Efficient injection of gas tracers into rivers: A tool to study Surface water-Groundwater interactions.

Surface water (SW) - groundwater (GW) interactions exhibit complex spatial and temporal patterns often studied using tracers. However, most natural and artificial tracers have limitations in studying SW-GW interactions, particularly if no significant contrasts in concentrations between SW and GW exist or can be maintained for long durations. In such context, (noble) gases have emerged as promising alternatives to add to the available tracer methods, especially with the recent development of portable mass spectrometers, which enable continuous monitoring of dissolved gas concentrations directly in the field.

Double-vs single-balloon catheter for induction of labor: Systematic review and individual participant data meta-analysis.

Introduction: Evidence comparing double-balloon vs single-balloon catheter for induction of labor is divided. We aim to compare the efficacy and safety of double-vs single-balloon catheters using individual participant data.

Material And Methods: A search of Ovid MEDLINE, Embase, Ovid Emcare, CINAHL Plus, Scopus, and clinicaltrials.

Exploring the reliability of Rn as a tracer of groundwater age in alluvial aquifers: Insights from the explicit simulation of variable Rn production.

Knowledge of groundwater residence times (GRT; the time elapsed since surface water infiltration) between losing rivers and pumping wells is crucial for management of water resources in alluvial aquifers. The radioactive noble gas radon-222 (Rn) has been used for decades as a natural indicator of surface water infiltration, as it can provide quantitative information on GRT. However, models using Rn as a tracer of GRT are often based on a set of highly simplifying assumptions, including spatially homogenous Rn production and exclusively advective mass transport within the aquifer.