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Oxygen isotopes (δ18O) are the most commonly utilized speleothem proxy and have provided many foundational records of paleoclimate. Thus, understanding processes affecting speleothem δ18O is crucial. Yet, prior calcite precipitation (PCP), a process driven by local hydrology, is a widely ignored control of speleothem δ18O. Here we investigate the effects of PCP on a stalagmite δ18O record from central Vietnam, spanning 45 – 4 ka. We employ a geochemical model that utilizes speleothem Mg/Ca and cave monitoring data to correct the δ18O record for PCP effects. The resulting record exhibits improved agreement with regional speleothem δ18O records and climate model simulations, suggesting that the corrected record more accurately reflects precipitation δ18O (δ18Op). Without considering PCP, our interpretations of the δ18O record would have been misleading. To avoid misinterpretations of speleothem δ18O, our results emphasize the necessity of considering PCP as a significant driver of speleothem δ18O. This study finds that in-cave processes affect speleothem oxygen isotope records. Correcting for these processes improves agreement with other regional records and climate models, providing a more accurate reflection of past hydroclimate change. [ABSTRACT FROM AUTHOR]

Oxygen isotopes (δ 18 O) are the most commonly utilized speleothem proxy and have provided many foundational records of paleoclimate. Thus, understanding processes affecting speleothem δ 18 O is crucial. Yet, prior calcite precipitation (PCP), a process driven by local hydrology, is a widely ignored control of speleothem δ 18 O. Here we investigate the effects of PCP on a stalagmite δ 18 O record from central Vietnam, spanning 45 - 4 ka. We employ a geochemical model that utilizes speleothem Mg/Ca and cave monitoring data to correct the δ 18 O record for PCP effects. The resulting record exhibits improved agreement with regional speleothem δ 18 O records and climate model simulations, suggesting that the corrected record more accurately reflects precipitation δ 18 O (δ 18 O p ). Without considering PCP, our interpretations of the δ 18 O record would have been misleading. To avoid misinterpretations of speleothem δ 18 O, our results emphasize the necessity of considering PCP as a significant driver of speleothem δ 18 O., (© 2024. The Author(s).)

Background: Anorexia nervosa (AN) is associated with abnormalities that may increase the risk of future cardiovascular disease. This study assessed the cardiovascular health of individuals who recovered from AN during adolescence by conducting wave power analysis., Methods: Former AN patients discharged from the Royal Children's and Monash Children's Hospitals (N = 17) in Melbourne, Australia underwent ultrasound imaging of the right carotid artery. Wave power analysis was conducted to assess biomechanical interactions of the cardiovascular system. Patient measures were compared to healthy controls (N = 51)., Results: Eighty-eight percent of the former AN patients and controls were female, aged approximately 25 years, with a healthy body mass index. Mean carotid flow and pulsatility index were not different between groups. Carotid arterial strain and distensibility were lower, and the wave speed and beta stiffness index higher in the former AN patients. Characteristic impedance was not different nor were the forward and backward wave amplitudes. However, wave reflection indices (ratios of backward-to-forward compression wave area, and wave-related effect on pressure and hydraulic power) were 12-18% lower in the former AN patients (p < 0.05)., Conclusions: Increased carotid artery stiffness and reduced wave reflection are evident in young adults who recovered from adolescent AN. This may relate to an adaptive process that helps to maintain or restore flow and characteristic impedance despite increased vessel stiffness, with this warranting future investigation., (© 2024. The Author(s).)