Present-day sedimentation rates on the southern and southeastern Australian continental margins

<div><p>The Australian continental margin presents highly contrasted settings depending on (1) the presence or absence of a fluvial sediment supply, (2) the distance from the Australian mainland, and (3) the local hydrological setting. Despite the importance in surface area of the continental margin around the Australian mainland, so far only a few studies have dealt with sedimentation, most of them focusing on the northeastern Australian Shelf. This work presents the first large-scale investigation of modern sedimentation along the southern margin of Australia in the SE Indian Ocean, and the western margin of the Tasman Sea. Sedimentation intensity was assessed on a century timescale using a multi-tracer approach (²³⁴Th, ²¹⁰Pb, ²³²Th) on interface cores around the 1000 m water depth contour. ²³⁴Th (half-life: 24.1 days) in excess was detected in all surface samples, testifying to the occurrence of freshly deposited particles. Sedimentation and mass accumulation rates based on sedimentary ²¹⁰Pb excess profiles (CF:CS model) range between 0.027 and 0.280 cm y^–1 and between 14 and 222 mg cm^–2 y^–1, respectively. Whereas sedimentation rates are low and associated with carbonates on the western margin, sediments are more influenced by the detrital fraction and organic carbon on the eastern side of the continent. In comparison with northern continental margins (e.g. Timor Sea, Gulf of Papua), the southern Australian margin receives little sediment today, as it is rarely linked to a river system that would otherwise deliver large amounts of sediment, and also because of the presence of the extended shelf south of Australia.</p></div

Historical Records of Mercury, Lead, and Polycyclic Aromatic Hydrocarbons Depositions in a Dated Sediment Core from the Eastern Mediterranean

Depth profiles of mercury, lead and its stable isotopes, and polycyclic aromatic hydrocarbons were determined in a dated sediment core from the Levantine basin. Sedimentary records show that preindustrial fluxes and levels of Hg, Pb, and PAHs remained generally constant in the region before 1850. An almost concurrent uniform increase of both metals and PAHs deposition occurring at the beginning of the Industrial Revolution suggests coal combustion as a main source of these contaminants in the Levantine basin after the 1850s. However, none of the contaminant profiles indicates a decline after 1950–60, the characteristic period of coal use reduction. The modern fluxes of Hg and Pb reveal a 3- to 5-fold increase over preindustrial loads, while the contemporaneous flux of PAHs rises by 4–7 times. On the whole, records in the Eastern Mediterranean suggest atmospheric inputs from relatively distant sources, likely from Central and Eastern Europe

Authors' reply to Page and Rafi.

Authors' reply to Page and Rafi

Evidence-based neonatal unit practices and determinants of Postnatal corticosteroid-use in preterm births below 30 weeks ga in Europe. A population-based cohort study

Background: Postnatal corticosteroids (PNC) were widely used to treat and prevent bronchopulmonary dysplasia in preterm infants until studies showed increased risk of cerebral palsy and neurodevelopmental impairment. We aimed to describe PNC use in Europe and evaluate the determinants of their use, including neonatal characteristics and adherence to evidencebased practices in neonatal intensive care units (NICUs). Methods: 3917/4096 (95,6%) infants born between 24 and 29 weeks gestational age in 19 regions of 11 European countries of the EPICE cohort we included. We examined neonatal characteristics associated with PNC use. The cohort was divided by tertiles of probability of PNC use determined by logistic regression analysis. We also evaluated the impact of the neonatal unit's reported adherence to European recommendations for respiratory management and a stated policy of reduced PNC use. Results: PNC were prescribed for 545/3917 (13.9%) infants (regional range 3.1-49.4%) and for 29.7% of infants in the highest risk tertile (regional range 5.4-72.4%). After adjustment, independent predictors of PNC use were a low gestational age, small for gestational age, male sex, mechanical ventilation, use of non-steroidal anti-inflammatory drugs to treat persistent ductus arteriosus and region. A stated NICU policy reduced PNC use (odds ratio 0.29 [95% CI 0.17; 0.50]). Conclusion: PNC are frequently used in Europe, but with wide regional variation that was unexplained by neonatal characteristics. Even for infants at highest risk for PNC use, some regions only rarely prescribed PNC. A stated policy of reduced PNC use was associated with observed practice and is recommended