The Antarctic Circumpolar Current (ACC) exerts substantial control on the physical, chemical, and biological properties of the Southern Ocean, playing a key role in modulating the global carbon cycle and climate. However, the orbital-scale forcing and future changes in the strength and position of the ACC remain elusive. Here, we reconstruct the history of ACC extending back to the Last Interglacial (LIG; 128-113 ka) using sediment cores from the Scotia Sea. Based on high-resolution measurements of sortable silt mean grain size, we find that bottom current speed is synchronized with eccentricity, superimposed by precession. During the LIG when both eccentricity and precession reached their maxima, current speed peaked in the region south of the Southern ACC front, suggesting that the Polar Front shifted ~5° southward. We propose that the low-frequency ACC frontal migration is primarily controlled by eccentricity-driven shifts in the Southern Hemisphere Westerlies, while precession-driven shifts contribute to high-frequency migration. Our findings imply under future orbital-scale scenarios, the ACC position is likely to shift north.

Warm and saline Mediterranean overflow today is an important driver of thermohaline circulation in the North Atlantic. In the latest Miocene, Mediterranean salinity varied dramatically as the Messinian salt giant formed. The precipitation of a ~1.5 km thick evaporite layer across the Mediterranean seafloor requires substantial changes both to the geometry of the Atlantic-Mediterranean gateway and the nature of exchange between the two basins. This salinity crisis was the consequence of on-going Africa-Eurasia collision, which formed, narrowed, and ultimately closed the two ancestral marine connections that pre-date the Gibraltar Strait. One of these connections is now preserved on land in southern Spain, the other in northern Morocco. Both the initiation of Mediterranean overflow, variations in its size and salinity, and the establishment of the present-day overflow pattern in the early Pliocene are likely to have impacted thermohaline circulation, climatic change and deep water sedimentation during the late Miocene and Pliocene. IMMAGE (Investigating Miocene Mediterranean-Atlantic Gateway Exchange) is a land-2-sea drilling project designed to recover a complete record of Late Miocene-Pliocene exchange (8-4Ma) offshore with International Ocean Discovery Program (IODP) in both the Atlantic and Mediterranean and onshore with International Continental Scientific Drilling Program (ICDP) in Morocco and Spain. IODP Expedition 401 is the first element of the land-2-sea drilling to take place. At the time of abstract submission, Expedition 401 is at sea (December 2023-February 2024) in the process of recovering these critical records. We propose to present an overview of the sediments recovered during the expedition and initial shipboard analytical results.

Salt giant formation is dependent on the dimensions of the connection linking the marginal basin to the open ocean and the nature of exchange between then. However, records from these connecting straits are rare, making it difficult to test connectivity scenarios. As part of the IMMAGE Land-2-Sea project, Integrated Ocean Discovery Program Expedition 401 drilled a new site, U1611, in the Alborán Sea. This basin is thought to have been part of the corridor that linked the Mediterranean with the Atlantic during the formation of the late Miocene salt giant. More than 600 m of sediments were recovered from Site U1611 spanning the early Messinian to early Pliocene. Here we present preliminary results and consider their implications for the origin and evolution of the Messinian Salinity Crisis.

We report semiquantitative elemental data from X-ray fluorescence (XRF) scanning of Site U1558 sediment cores drilled during International Ocean Discovery Program Expeditions 390C and 393.These expeditions, together with Expeditions 395E and 390, form the South Atlantic Transect, which collected sediment and basement cores from the western flank of the southern Mid-Atlantic Ridge.XRF scanning of the continuous splice of Site U1558, using Holes U1558A and U1558F, was conducted at three acceleration voltages to capture a range of major, minor, and trace elements.At Site U1558, positive correlations exist between terrigenous-sourced elements (Al, Si, Ti, and Fe) and a negative correlation exists between the terrigenous-sourced elements and Ca.XRF geochemistry is correlated with lithologic changes, most notably at the boundary of Lithologic Units I and II, where Unit I is brown and reddish brown nannofossil-rich clay and Unit II is pink, pinkish white, pinkish gray, and light brown nannofossil ooze and chalk with varying amounts of clay and foraminifera.Peaks in XRF data align with the boundaries of Lithologic Subunits IIA and IIB and Subunits IIB and IIC.

Background: Current guidelines recommend initial monotherapy for pulmonary arterial hypertension (PAH) with cardiopulmonary comorbidities, despite limited available evidence to guide management. Research Question: Do left heart disease (LHD) risk factors have an impact on treatment response and influence applicability of risk assessment in a real-world cohort of patients with PAH? Study Design and Methods: The Ambrisentan and Tadalafil in Patients with Pulmonary Arterial Hypertension (AMBITION) trial criteria was used to define the phenotype of patients with PAH with risk factors for LHD. Treatment strategy, functional outcome, long-term survival, and risk discrimination were compared with a reference PAH cohort using the Pulmonary Hypertension Society of Australia and New Zealand Registry. Results: A total of 487 incident patients with PAH diagnosed between 2011 and 2020 were included. Of these, 103 (21.1%) fulfilled the definition of PAH with LHD risk factors, with 384 (78.9%) remaining as the reference group. Patients in the PAH with LHD risk factors group were older (66 +/- 13 vs 58 +/- 19 years; P < .001), had lower pulmonary vascular resistance (393 +/- 266 vs 708 +/- 391 dyn.s/cm(5); P = .031), and had worse 6-min walk distance (286 +/- 130 vs 327 +/- 136 m; P = .005) at diagnosis. The PAH with LHD risk factors group was less likely to receive initial combination therapy (27% vs 44%; P = .02). Changes in 6-min walk distance at 12 months were similar in both groups (43 +/- 77 m in the PAH with LHD risk factors group and 50 +/- 90 m in the reference group; P = .50), including when stratified by initial treatment strategy (PAH with LHD risk factors group vs reference PAH group: monotherapy: 40 +/- 81 vs 38 +/- 95 m, P = .87; combination therapy: 53 +/- 78 vs 64 +/- 106 m, P = .511). Functional class improvements were also similar in both groups. REVEAL Registry 2.0 risk score effectively discriminated risk in both populations (C statistic = 0.756 for the PAH with LHD risk factors group and C statistic = 0.750 for the reference PAH group). There was no difference in survival between the two groups (log-rank test, P = .29). Interpretation: In a real-world cohort, patients with PAH with LHD risk factors were less likely to be exposed to initial combination therapy. Nevertheless, selected patients with PAH with LHD risk factors who were treated with initial combination therapy derived similar functional response compared with the reference group. Further studies are needed to phenotype patients with PAH with cardiopulmonary comorbidities who may benefit from initial combination therapy.

We present a simple, quick, and high-resolution (approx.10 cm) method for calculating almost continuous calcium carbonate (CaCO3) proxy records in deep-marine sediment cores based on the well-known dependence of NGR (natural gamma ray) on sediment clay content. The method used in this study is based on the assumption that sediment composition along the SAT (South Atlantic Transect) consists of two components: carbonate and clay. This assumption is reasonably accurate for the region under investigation. At carbonate-rich Site U1583 (66-97 wt% CaCO3), calculated CaCO(3 )wt% contents are within 4.18% at 1 standard deviation (6) of geochemical analyses of the CaCO3 wt% contents of discrete samples (measured using a coulometer), while at the more lithologically variable Site U1557 (0.1-92 wt% CaCO3), they are within 15.6% at 16. Results indicate good to excellent correlations between the NGR- and coulometry-derived data- sets, supporting the use of this method for carbonate stratigraphy, paleoceanography, and paleoclimate reconstructions. We provide an equation to derive CaCO3 wt% from NGR based on the SAT datasets. The procedure described below can be used to construct the higher resolution proxy CaCO3 records at other sites worldwide compared to discrete CaCO3 values. This method can assist with shipboard lithology determination and can guide core sampling.

Logging data are measurements of physical properties of the formation surrounding a borehole, acquired in situ after completion of coring (wireline logging) or during drilling (Logging-While-Drilling, LWD). The range of data (resistivity, gamma radiation, velocity, density, borehole images,…) in any hole depends on the scientific objectives and operational constraints.

The western South Atlantic Ocean is a relatively understudied area of the world's ocean, in part because of the lack of scientific ocean drilling and complete sedimentary sequences.During 2020-2022, a series of International Ocean Discovery Program Expeditions (390C, 395E, 390, and 393; South Atlantic Transect) sailed to this area, recovering material from the western flank of the Mid-Atlantic Ridge at a latitude of ~31°S.Here, we used X-ray fluorescence scanning of the sediment cores recovered and combined the data with shipboard magnetic susceptibility and natural gamma radiation to generate long-term geochemical records at Site U1561.These records enable us to document climatic and environmental perturbations on varying timescales and explore the paleoclimatic and paleoceanographic history of the western South Atlantic Ocean during the Cenozoic.

Chronic thromboembolic pulmonary disease (CTEPD) with or without pulmonary hypertension (PH) is an important potential consequence of venous thromboembolic disease. Untreated CTEPD with pulmonary hypertension (CTEPH) is associated with high rates of morbidity and mortality. Several treatment options are now available for patients with CTEPD and CTEPH, including pulmonary endarterectomy (PEA), balloon pulmonary angioplasty, medical therapy or a combination of therapies. Choice of treatment depends on the location of the thromboembolic disease burden, presence and severity of PH and patient factors, including frailty, parenchymal lung disease and other comorbidities. PEA is a complex surgery that can result in excellent outcomes and resolution of disease, but also comes with the risk of serious perioperative complications. This manuscript examines the history of PEA and its place in Australasia, and reports on outcomes from the main Australasian CTEPH expert centre. It provides a summary of up-to-date guidance on how PEA should be utilised in the overall management of these patients and describes opportunities and challenges for the future diagnosis and management of this disease, particularly in the Australasian setting.

During International Ocean Discovery Program (IODP) Expeditions 390C, 395E, 390, and 393, deepwater sediments were recovered from the western flank of the southern Mid-Atlantic Ridge along a crustal flow line at ~31°S.This multidisciplinary experiment allowed the recovery of data fundamental to reconstructing past climate changes as well as variations in ocean circulation, productivity, and chemistry (i.e., fluctuations in the carbonate compensation depth) in the South Atlantic Ocean.Here, we report semiquantitative elemental results from X-ray fluorescence (XRF) scanning of the sediment package cored at IODP Site U1559 in the South Atlantic Ocean.Located at 15°02.0941′W,Site U1559 is the easternmost site of the South Atlantic Transect and the closest to the Mid-Atlantic Ridge, located on ~6.6.Ma ocean crust.The XRF data are also compared with magnetic susceptibility and natural gamma radiation measured on the R/V JOIDES Resolution to assess correlations with the different lithologic units/subunits.At Site U1559, sediments are predominantly nannofossil ooze with varying amounts of foraminifera, which is reflected by the dominant Ca counts.Trends in elemental counts reflect the slight variations in siliciclastic materials within the Pleistocene.Major shifts in elemental counts were observed at the sharp contact between Pliocene-Pleistocene Subunits IC and ID, as well as the Miocene-Pliocene transition.

Logging data are measurements of physical properties of the formation surrounding a borehole, acquired in situ after completion of coring (wireline logging) or during drilling (Logging-While-Drilling, LWD). The range of data (resistivity, gamma radiation, velocity, density, borehole images,…) in any hole depends on the scientific objectives and operational constraints.

The western South Atlantic Ocean has not been drilled since the end of the Deep Sea Drilling Program, leading to a dearth of sedimentary sequences available from this sector of the Atlantic Ocean.In 2020-2022, a transect of new sites was drilled during International Ocean Discovery Program Expeditions 390C, 395E, 390, and 393 at 31°S and spanning from 28.8°W to 15.2°W.Here, we use X-ray fluorescence data, combined with shipboard magnetic susceptibility and natural gamma radiation, to characterize the sediments below the oligotrophic South Atlantic Gyre at Site U1583.These geochemical data add to the otherwise understudied southwest Atlantic Ocean.

Site U1557 is the deepest and one of the oldest sites drilled during International Ocean Discovery Program Expeditions 390C, 395E, 390, and 393 on the South Atlantic Transect.It differs from the nearby Site U1556, which also sits on early Paleocene crust, by its stratigraphically expanded Paleocene-Eocene section.Here, we present the results of programmatic X-ray fluorescence (XRF) core scanning of the entire thickness of the sedimentary section at Site U1557.We find a major shift in XRF geochemistry at the boundary between Lithologic Units I and II, coincident with a shift in spectral gamma ray and magnetic susceptibility, as well as a shift from alternating pelagic carbonate and pelagic clay in Unit I to pelagic carbonate in Unit II.Within Unit I, shifts in major elemental composition of core material track alternations between carbonate-rich and clayrich intervals.

Pulmonary arterial hypertension (PAH) is a rare condition for which a remarkable change has been witnessed in the epidemiology, assessment and treatment landscape over the last three decades. Well-established registries from the Western world have not only highlighted the shift in the epidemiology to an older, more comorbid cohort but have also identified markers of prognosis that have been validated as part of risk stratification scores in multiple cohorts. The emphasis on early identification through a systematic assessment pathway and the option of upfront combination therapy with serial risk stratification assessment has laid the foundation for the standard of care and improved prognosis. This review provides an update on the assessment and newer therapies for PAH.

Glacial-marine sediments from the Antarctic continental margin provide a record of depositional environment, oceanographic variability and ice dynamics that is tapped with scientific ocean drilling. This study focuses on Ocean Drilling Program Core 693A-2R, a 9.7 m sediment core retrieved from near the continental margin of the Archean Grunehogna Craton in Dronning Maud Land (DML), East Antarctica. The results contribute to a better understanding of ice-shelf behavior in DML during the mid-Pleistocene transition (MPT), a well-known transition from 40-kyr to 100-kyr cycle periods. The age model, constructed based on Sr isotope stratigraphy and geomagnetic reversals, indicates that the core spans 1.20 to 0.65 Ma. The dynamic behavior of DML ice shelves with periodic iceberg calving is revealed by the glacial-interglacial variation in sedimentation patterns, with interglacials characterized by higher concentrations of ice-rafted debris (IRD) associated with enhanced paleoproductivity than glacial intervals. The responses of DML ice shelves to warm climates are represented by a prolonged interglacial period at 1.0-1.1 Ma (MIS 31-27) and significant interglacial expressions during MIS 19 and 17. The 40Ar/39Ar ages of individual ice-rafted hornblende grains are compared with the on-land geology of DML and neighboring regions to determine the provenances of IRD. Specifically, 40Ar/39Ar results record primarily late Neoproterozoic to Cambrian ages (600-400 Ma) with a predominant peak of 520-480 Ma. This PanAfrican/Ross orogeny signature is very common in East Antarctica but is not found in the most proximal margin of the Grunehogna Craton, and is instead associated with the region of DML several hundred kilometers east of the deposition site. This indicates that significant discharges of icebergs occurred in the remote DML, which were then transported by the westward-flowing Antarctic Coastal Current to deposit IRD at the studied site during the MPT. This study establishes a confirmed MPT sedimentary sequence off DML, against which future MPT proxy records from the Weddell Sea embayment and other sectors in Antarctica can be compared and correlated, and provides a basis for more detailed analyses of the response of DML ice sheet to Pleistocene climate variations.