Adverse drug reactions to tocolytic treatment for preterm labour: prospective cohort study

Objective To evaluate the incidence of serious maternal complications after the use of various tocolytic drugs for the treatment of preterm labour in routine clinical situations

Dynamic anoxic ferruginous conditions during the end-Permian mass extinction and recovery

The end-Permian mass extinction, ~252 million years ago, is notable for a complex recovery period of ~5 Myr. Widespread euxinic (anoxic and sulfidic) oceanic conditions have been proposed as both extinction mechanism and explanation for the protracted recovery period, yet the vertical distribution of anoxia in the water column and its temporal dynamics through this time period are poorly constrained. Here we utilize Fe–S–C systematics integrated with palaeontological observations to reconstruct a complete ocean redox history for the Late Permian to Early Triassic, using multiple sections across a shelf-to-basin transect on the Arabian Margin (Neo-Tethyan Ocean). In contrast to elsewhere, we show that anoxic non-sulfidic (ferruginous), rather than euxinic, conditions were prevalent in the Neo-Tethys. The Arabian Margin record demonstrates the repeated expansion of ferruginous conditions with the distal slope being the focus of anoxia at these times, as well as short-lived episodes of oxia that supported diverse biota

Permian-Triassic boundary microbialites (PTBMs) in soutwest China: implications for paleoenvironment reconstruction

Permian–Triassic boundary microbialites (PTBMs) are commonly interpreted to be a sedimentary response to upwelling of anoxic alkaline seawater and indicate a harsh marine environment in the Permian–Triassic transition. However, recent studies propose that PTBMs may instead be developed in an oxic environment, therefore necessitating the need to reassess the paleoenvironment of formation of PTBMs. This paper is an integrated study of the PTBM sequence at Yudongzi, northwest Sichuan Basin, which is one of the thickest units of PTBMs in south China. Analysis of conodont biostratigraphy, mega- to microscopic microbialite structures, stratigraphic variations in abundance and size of metazoan fossils, and total organic carbon (TOC) and total sulfur (TS) contents within the PTBM reveals the following results: (1) the microbialites occur mainly in the Hindeodus parvus Zone but may cross the Permian–Triassic boundary, and are comprised of, from bottom to top: lamellar thrombolites, dendritic thrombolites and lamellar-reticular thrombolites; (2) most metazoan fossils of the microbialite succession increase in abundance upsection, so does the sizes of bivalve and brachiopod fossils; (3) TOC and TS values of microbialites account respectively for 0.07 and 0.31 wt% on average, both of which are very low. The combination of increase in abundance and size of metazoan fossils upsection, together with the low TOC and TS contents, is evidence that the Yudongzi PTBMs developed in oxic seawater. We thus dispute the previous view, at least for the Chinese sequences, of low-oxygen seawater for microbialite growth, and question whether it is now appropriate to associate PTBMs with anoxic, harsh environments associated with the end-Permian extinction. Instead, we interpret those conditions as fully oxygenated.13th Five-Year Plan National Scientific and Technology Major Project (2016ZX05004002-001); National Natural Science Foundation of China (41602166)

Catastrophic soil loss associated with end-Triassic deforestation

Soils are a crucial link between the atmosphere, biosphere, and geosphere. Any disturbance to the health of soils will severely impact plants as well as a multitude of organisms living in or on soils, such as fungi, bacteria, and insects. Catastrophic soil loss is thought to have played a pivotal role during mass-extinction events as a result of major deforestation, but the exact feedbacks remain elusive. Here, we assess the role of soil loss during the end-Triassic mass-extinction event based on proxy data obtained from four sediment sections recovered from France, Germany, and Denmark. Clay mineral and palynological data indicate a strong increase in erosion during the latest Rhaetian with the influx of kaolinite and abundantly reworked Palaeozoic and Neoproterozoic organic matter. Based on a new timeline, these changes were coeval with intense volcanic activity in the Central Atlantic Magmatic Province (CAMP). In addition to vegetation dieback, repeated forest fires, as well as widespread seismic activity related to CAMP emplacement led to landscape destruction triggering removal of soils. The biological degradation of fern spore walls by fungi and bacteria, a process coupled to organic matter decay in soils, strongly decreased across the T/J boundary. We interpret this counter-intuitive result as evidence for rapid and widespread removal of soils. Taken together, CAMP induced environmental changes led to profound changes in erosion and removal of soils, while soil resilience during the Hettangian appears to have proceeded hand in hand with recovery in Jurassic seas

Catastrophic soil loss associated with end-Triassic deforestation

Soils are a crucial link between the atmosphere, biosphere, and geosphere. Any disturbance to the health of soils will severely impact plants as well as a multitude of organisms living in or on soils, such as fungi, bacteria, and insects. Catastrophic soil loss is thought to have played a pivotal role during mass-extinction events as a result of major deforestation, but the exact feedbacks remain elusive. Here, we assess the role of soil loss during the end-Triassic mass-extinction event based on proxy data obtained from four sediment sections recovered from France, Germany, and Denmark. Clay mineral and palynological data indicate a strong increase in erosion during the latest Rhaetian with the influx of kaolinite and abundantly reworked Palaeozoic and Neoproterozoic organic matter. Based on a new timeline, these changes were coeval with intense volcanic activity in the Central Atlantic Magmatic Province (CAMP). In addition to vegetation dieback, repeated forest fires, as well as widespread seismic activity related to CAMP emplacement led to landscape destruction triggering removal of soils. The biological degradation of fern spore walls by fungi and bacteria, a process coupled to organic matter decay in soils, strongly decreased across the T/J boundary. We interpret this counter-intuitive result as evidence for rapid and widespread removal of soils. Taken together, CAMP induced environmental changes led to profound changes in erosion and removal of soils, while soil resilience during the Hettangian appears to have proceeded hand in hand with recovery in Jurassic seas