Insights on molecular modeling and supramolecular arrangement of bilastine polymorphs.

CONTEXT: The advancement in the development of second-generation drugs in the field of antihistamines represents a significant milestone in the management of allergic diseases, targeting the effects of histamine. The efficacy of bilastine in treating allergic disorders has sparked interest in investigating its polymorphism, a crucial property that impacts quality, safety, and effectiveness as per regulatory guidelines. This study examines the polymorphism of bilastine, focusing on two crystalline forms labeled as Form I and Form II. Utilizing advanced analytical techniques, the research explores the structural characteristics and molecular interactions within these forms. Geometric parameters, such as bond lengths, bond angles, and torsion angles, are examined to comprehend molecular conformations and crystal packing arrangements. Hydrogen bonding, covalent bonds, and van der Waals forces contribute to the unique supramolecular arrangements in these forms. This study provides a significant contribution to understanding bilastine's polymorphism, offering critical insights to researchers and regulatory bodies to ensure the quality, efficacy, and safety of antihistamine products. METHODS: The molecular conformation of two bilastine forms was obtained through DFT with the exchange-correlation functional M06-2X and the 6-311 + + G(d,p) basis set, and the results were compared with the experimental X-ray. The atomic coordinates were obtained directly from the crystalline structures, and charge transfer was also investigated using frontier molecular orbitals (HOMO and LUMO), and MEP map in order to evaluate the energies associated with charge transfers and regions of high electron affinity. The geometric and topological parameters and intermolecular interactions in the crystals were analyzed using Hirshfeld Surface.

Integrating AI in Lipedema Management: Assessing the Efficacy of GPT-4 as a Consultation Assistant.

The role of artificial intelligence (AI) in healthcare is evolving, offering promising avenues for enhancing clinical decision making and patient management. Limited knowledge about lipedema often leads to patients being frequently misdiagnosed with conditions like lymphedema or obesity rather than correctly identifying lipedema. Furthermore, patients with lipedema often present with intricate and extensive medical histories, resulting in significant time consumption during consultations. AI could, therefore, improve the management of these patients. This research investigates the utilization of OpenAI's Generative Pre-Trained Transformer 4 (GPT-4), a sophisticated large language model (LLM), as an assistant in consultations for lipedema patients. Six simulated scenarios were designed to mirror typical patient consultations commonly encountered in a lipedema clinic. GPT-4 was tasked with conducting patient interviews to gather medical histories, presenting its findings, making preliminary diagnoses, and recommending further diagnostic and therapeutic actions. Advanced prompt engineering techniques were employed to refine the efficacy, relevance, and accuracy of GPT-4's responses. A panel of experts in lipedema treatment, using a Likert Scale, evaluated GPT-4's responses across six key criteria. Scoring ranged from 1 (lowest) to 5 (highest), with GPT-4 achieving an average score of 4.24, indicating good reliability and applicability in a clinical setting. This study is one of the initial forays into applying large language models like GPT-4 in specific clinical scenarios, such as lipedema consultations. It demonstrates the potential of AI in supporting clinical practices and emphasizes the continuing importance of human expertise in the medical field, despite ongoing technological advancements.

Assessment of thermohydraulic performance and entropy generation in an evacuated tube solar collector employing pure water and nanofluids as working fluids.

This study conducts a numerical comparison of the thermal performance of three distinct working fluids (pure water, TiO2, and SiO2 water-based nanofluids) within an evacuated tube solar collector using Computational Fluid Dynamics. The study evaluates thermohydraulic performance alongside global and local entropy generation rates, while considering variations in solar radiation values and inlet mass flow rates. Results indicate that nanofluids demonstrate superior performance under low solar radiation, exhibiting higher outlet temperatures, velocities, thermal efficiency, and exergy efficiency compared to pure water. However, at the higher solar radiation level, the efficiency of SiO2 water-based nanofluid diminishes due to its impact on specific heat. Furthermore, the entropy generation analysis reveals significant reductions with TiO2 water-based nanofluid in all the phenomena considered (up to 79 %). The SiO2 nanofluid performance aligns closely with pure water under high radiation value. This investigation offers valuable insights into the utilization of nanofluids in solar collectors across diverse operating conditions, emphasizing their pivotal role in enhancing overall performance.

Impact of trainees involvement on surgical outcomes of abdominal and laparoscopic myomectomy.

BACKGROUND: To determine the association of trainees involvement with surgical outcomes of abdominal and laparoscopic myomectomy including operative time, rate of transfusion, and complications. METHODS: A retrospective cohort study of 1145 patients who underwent an abdominal or laparoscopic myomectomy from 2008-2012 using the American College of Surgeons National Surgical Quality Improvement Program database (Canadian Task Force Classification II-2). RESULTS: Overall, 64% of myomectomies involved trainees. Trainees involvement was associated with a longer operative time for abdominal myomectomies (mean difference 20.17 minutes, 95% Confidence Interval (CI) [11.37,28.97], p < 0.01) overall and when stratified by fibroid burden. For laparoscopic myomectomy, there was no difference in operative time between trainees vs no trainees involvement (mean difference 4.64 minutes, 95% CI [-18.07,27.35], p = 0.67). There was a higher rate of transfusion with trainees involvement for abdominal myomectomies (10% vs 2%, p < 0.01; Odds Ratio (OR) 5.62, 95% CI [2.53,12.51], p < 0.01). Trainees involvement was not found to be associated with rate of transfusion for laparoscopic myomectomy (4% vs 5%, p = 0.86; OR 0.82, 95% CI [0.16,4.14], p = 0.81). For abdominal myomectomy, there was a higher rate of overall complications (15% vs 5%, p < 0.01; OR 2.96, 95% CI [1.77,4.93], p < 0.01) and minor complications (14% vs 4%, p < 0.01; OR 3.71, 95% CI [2.09,6.57], p < 0.01) with no difference in major complications (3% vs 2%, p = 0.23). For laparoscopic myomectomy, there was no difference in overall (6% vs 10% p = 0.41; OR 0.59, 95% CI [0.18,2.01], p = 0.40), major (2% vs 0%, p = 0.38), or minor (5% vs 10%, p = 0.32; OR 0.52, 95% CI [0.15,1.79], p = 0.30) complications. CONCLUSION: Trainees involvement was associated with increased operative time, rate of transfusion, and complications for abdominal myomectomy, however, did not impact surgical outcomes for laparoscopic myomectomy.

TITLE: Trainees Involvement in MyomectomyThe goal of our study was to determine the association of trainees involvement with surgical outcomes of fibroid excision surgery or myomectomy. We conducted a study of abdominal and laparoscopic myomectomies using an international surgical database. We found that trainees involvement in myomectomy was associated with increased operative time, rate of transfusion, and complications for abdominal myomectomy. However, trainees involvement did not impact surgical outcomes for laparoscopic myomectomy.

Association between Donor Age and Osteogenic Potential of Human Adipose Stem Cells in Bone Tissue Engineering.

Adipose stem cells (ASCs) have multilineage differentiation capacity and hold great potential for regenerative medicine. Compared to bone marrow-derived mesenchymal stem cells (bmMSCs), ASCs are easier to isolate from abundant sources with significantly higher yields. It is generally accepted that bmMSCs show age-related changes in their proliferation and differentiation potentials, whereas this aspect is still controversial in the case of ASCs. In this review, we evaluated the existing data on the effect of donor age on the osteogenic potential of human ASCs. Overall, a poor agreement has been achieved because of inconsistent findings in the previous studies. Finally, we attempted to delineate the possible reasons behind the lack of agreements reported in the literature. ASCs represent a heterogeneous cell population, and the osteogenic potential of ASCs can be influenced by donor-related factors such as age, but also gender, lifestyle, and the underlying health and metabolic state of donors. Furthermore, future studies should consider experimental factors in in vitro conditions, including passaging, cryopreservation, culture conditions, variations in differentiation protocols, and readout methods.

Changes in vascular function and correlation with cardiotoxicity in women with newly diagnosed breast cancer undergoing HER2-directed therapy with and without anthracycline/cyclophosphamide.

Aims: The objective of this study was to assess the effect of HER2-directed therapy (HER2-Tx) on peripheral vasoreactivity and its correlation with cardiac function changes and the additive effects of anthracycline/cyclophosphamide (AC) therapy and baseline cardiovascular risk. Methods and results: Single-centre, prospective cohort study of women with newly diagnosed stage 1-3 HER2-positive breast cancer undergoing HER2-Tx +/- AC. All participants underwent baseline and 3-monthly evaluations with Endo-Peripheral Arterial Tonometry (Endo-PAT), vascular biomarkers [C-type natriuretic peptide (CNP) and neuregulin-1 beta (NRG-1ß)], and echocardiography. Cardiotoxicity was defined as a decrease in the left ventricular ejection fraction (LVEF) of >10% to a value <53%. Of the 47 patients enrolled, 20 (43%) received AC in addition to HER2-Tx. Deterioration of reactive hyperaemia index (RHI) on Endo-PAT by ≥20% was more common in patients receiving HER-Tx plus AC than HER2-Tx alone (65% vs. 22%; P = 0.003). A decrease in CNP and log NRG-1ß levels by 1 standard deviation did not differ significantly between the AC and non-AC groups (CNP: 20.0% vs. 7.4%; P = 0.20 and NRG-1ß: 15% vs. 11%; P = 0.69) nor did GLS (35% vs. 37%; P = 0.89). Patients treated with AC had a significantly lower 3D LVEF than non-AC recipients as early as 3 months after exposure (mean 59.3% (SD 3) vs. 63.8% (SD 4); P = 0.02). Reactive hyperaemia index and GLS were the only parameters correlating with LVEF change. Conclusion: Combination therapy with AC, but not HER2-Tx alone, leads to a decline in peripheral vascular and cardiac function. Larger studies will need to define more precisely the causal correlation between vascular and cardiac function changes in cancer patients.

Gel Biopolymer Electrolytes Based on Saline Water and Seaweed to Support the Large-Scale Production of Sustainable Supercapacitors.

Climate change and the demand for clean energy have challenged scientists worldwide to produce/store more energy to reduce carbon emissions. This work proposes a conductive gel biopolymer electrolyte to support the sustainable development of high-power aqueous supercapacitors. The gel uses saline water and seaweed as sustainable resources. Herein, a biopolymer agar-agar, extracted from red algae, is modified to increase gel viscosity up to 17-fold. This occurs due to alkaline treatment and an increase in the concentration of the agar-agar biopolymer, resulting in a strengthened gel with cohesive superfibres. The thermal degradation and agar modification mechanisms are explored. The electrolyte is applied to manufacture sustainable and flexible supercapacitors with satisfactory energy density (0.764 Wh kg-1 ) and power density (230 W kg-1 ). As an electrolyte, the aqueous gel promotes a long device cycle life (3500 cycles) for 1 A g-1 , showing good transport properties and low cost of acquisition and enabling the supercapacitor to be manufactured outside a glove box. These features decrease the cost of production and favor scale-up. To this end, this work provides eco-friendly electrolytes for the next generation of flexible energy storage devices.

Immune mechanisms shape the clonal landscape during early progression of prostate cancer.

Understanding the role of the immune microenvironment in modulating intratumor heterogeneity is essential for effective cancer therapies. Using multicolor lineage tracing in genetically engineered mouse models and single-cell transcriptomics, we show that slowly progressing tumors contain a multiclonal landscape of relatively homogeneous subpopulations within a well-organized tumor microenvironment. In more advanced and aggressive tumors, however, the multiclonal landscape develops into competing dominant and minor clones accompanied by a disordered microenvironment. We demonstrate that this dominant/minor landscape is associated with differential immunoediting, in which minor clones are marked by an increased expression of IFNγ-response genes and the T cell-activating chemokines Cxcl9 and Cxcl11. Furthermore, immunomodulation of the IFNγ pathway can rescue minor clones from elimination. Notably, the immune-specific gene signature of minor clones exhibits a prognostic value for biochemical recurrence-free survival in human prostate cancer. These findings suggest new immunotherapy approaches for modulating clonal fitness and tumor progression in prostate cancer.

Understanding sustainable purchase intention of smartphone users interface: Evidence from China.

In recent decades, the fast development of smartphones has resulted in an enormous mass of e-waste besides a carbon footprint increase. In the face of serious environmental concerns, the manufacture and disposal of smartphones have become a primary customer concern. Environmental concerns are becoming a decisive factor when it comes to purchasing a product. Manufacturers have shifted their focus to product design with sustainable requirements in response to these new customer requirements. With all of the affordable technology manufacturers now may consider customer-sustainable requirements. This research aims to examine the relationship between traditional customer requirements, sustainable customer requirements, and sustainable purchase intention for smartphones in China, as well as the mediation effect of sustainable perceived value and the moderation effect of price sensitivity. Customers' preferences are determined by using an online questionnaire. This research proposed an advanced sustainable purchase intention model by conducting an empirical analysis of the data gathered from 379 questionnaires. To gain a competitive advantage, companies should concentrate on meeting traditional and sustainable requirements more than the product price, according to the findings of the research. And contributes to the segmentation of the eco-friendly smartphone market.

A luminal intermediate cell state maintains long-term prostate homeostasis and contributes to tumorigenesis.

Cellular heterogeneity poses tremendous challenges for developing cell-targeted therapies and biomarkers of clinically significant prostate cancer. The origins of this heterogeneity within normal adult and aging tissue remain unknown, leaving cellular states and transcriptional programs that allow expansions of malignant clones unidentified. To define cell states that contribute to early cancer development, we performed clonal analyses and single cell transcriptomics of normal prostate from genetically-engineered mouse models. We uncovered a luminal transcriptional state with a unique "basal-like" Wnt/p63 signaling ( luminal intermediate , LumI) which contributes to the maintenance of long-term prostate homeostasis. Moreover, LumI cells greatly expand during early stages of tumorigenesis in several mouse models of prostate cancer. Genetic ablation of p63 in vivo in luminal cells reduced the formation of aggressive clones in mouse prostate tumor models. Finally, the LumI cells and Wnt signaling appear to significantly increase in human aging prostate and prostate cancer samples, highlighting the importance of this hybrid cell state for human pathologies with potential translational impact.

Polycyclic aromatic hydrocarbons (PAHs): Updated aspects of their determination, kinetics in the human body, and toxicity.

Polycyclic aromatic hydrocarbons (PAHs) are legacy pollutants of considerable public health concern. Polycyclic aromatic hydrocarbons arise from natural and anthropogenic sources and are ubiquitously present in the environment. Several PAHs are highly toxic to humans with associated carcinogenic and mutagenic properties. Further, more severe harmful effects on human- and environmental health have been attributed to the presence of high molecular weight (HMW) PAHs, that is PAHs with molecular mass greater than 300 Da. However, more research has been conducted using low molecular weight (LMW) PAHs). In addition, no HMW PAHs are on the priority pollutants list of the United States Environmental Protection Agency (US EPA), which is limited to only 16 PAHs. However, limited analytical methodologies for separating and determining HMW PAHs and their potential isomers and lack of readily available commercial standards make research with these compounds challenging. Since most of the PAH kinetic data originate from animal studies, our understanding of the effects of PAHs on humans is still minimal. In addition, current knowledge of toxic effects after exposure to PAHs may be underrepresented since most investigations focused on exposure to a single PAH. Currently, information on PAH mixtures is limited. Thus, this review aims to critically assess the current knowledge of PAH chemical properties, their kinetic disposition, and toxicity to humans. Further, future research needs to improve and provide the missing information and minimize PAH exposure to humans.

Inflammation and Treatment-Resistant Depression from Clinical to Animal Study: A Possible Link?

The aim of this study was to investigate the relationship between treatment-resistant depression (TRD) and inflammation in humans and experimental models. For the human study, a retrospective cohort study was conducted with 206 participants; half were on antidepressants for major depressive disorder. The patients were divided into healthy and depressed groups. Inflammation was assessed based on the values of the main inflammatory biomarkers (CRP, WBC and ESR). For the animal experiments, 35 adult male Wistar rats were assigned to stressed and non-stressed groups. Inflammation and stress were induced using lipopolysaccharide and chronic unpredictable mild stress. A 10 mg/kg intraperitoneal injection of fluoxetine (FLX), a known antidepressant, was simultaneously administered daily for 4 weeks. Behavioral tests were performed. The plasma levels of inflammatory and stress biomarkers were measured and were significantly higher in the stressed and non-responsive groups in both studies. This study provides evidence of the link between inflammation and TRD. We further observed a possible link via the Phosphorylated Janus Kinase 2 and Phosphorylated Signal Transducer and Activator of Transcription 3 (P-JAK2/P-STAT3) signaling pathway and found that chronic stress and high inflammation hinder the antidepressant effects of FLX. Thus, non-response to antidepressants could be mitigated by treating inflammation to improve the antidepressant effect in patients with TRD.

Forty Years of Rape Myth Acceptance Interventions: A Systematic Review of What Works in Naturalistic Institutional Settings and How this can be Applied to Educational Guidance for Jurors.

A systematic review of research assessing rape myth acceptance (RMA) interventions within institutional settings was conducted. The aim of this review was to inform the development of an educational intervention for jurors in rape trials that addresses rape myths, given previous evidence that RMA can affect decision-making and verdicts (Dinos et al., 2015; Gravelin et al., 2019; Leverick, 2020). 12 databases were searched, filtered to return peer-reviewed journals, published from 1980 to 2020, written in English. After removing duplicates from the 5,093 search results returned, 2,676 studies were screened for inclusion. Research studies were included in the review if they assessed the impact of a naturalistic intervention on RMA within an institutional setting. Studies that did not compare an experimental condition to a control condition or did not randomly allocate participants to conditions were excluded. Studies were also excluded if they used a non-validated, or adapted, RMA measure. 20 Research studies were included within the review and were critically appraised according to an author-created critical appraisal tool. It was concluded that RMA interventions can have a short-term impact upon individuals' RMA. Intervention types that were effective in reducing RMA included those that presented RM information; those that contained an empathy component; and bystander programmes. With regards to duration and format, short interventions led to reductions in RMA, and most successful interventions were presented via videos. Implications for policy and practice, and recommendations for future research, are discussed.

Preoperative Hematocrit Level and Associated Risk of Transfusion for Myomectomy Based on Myoma Burden and Surgical Route.

STUDY OBJECTIVE: To determine the association between preoperative hematocrit level and risk of blood transfusion for laparotomic and laparoscopic myomectomy based on myoma burden and surgical route. DESIGN: A cohort study of prospectively collected data. SETTING: American College of Surgeons National Surgical Quality Improvement Program participating institutions. PATIENTS: A total of 26 229 women who underwent a laparotomic or laparoscopic myomectomy from 2010 to 2020. INTERVENTIONS: The primary outcome assessed was the risk of transfusion based on preoperative hematocrit level. This was evaluated with respect to myoma burden and surgical route. MEASUREMENTS AND MAIN RESULTS: There were 26 229 women who underwent a myomectomy during the study interval, 2345 women (9%) of whom required a blood transfusion. Compared with patients who did not require transfusion, those who did had lower median preoperative hematocrit levels (34.7 vs 38.2). Patients were stratified by surgical approach (laparotomic vs laparoscopic) and myoma burden (1-4 myomas/weight ≤250 g or ≥5 myomas/weight >250 g) using Current Procedural Terminology codes (58140, 58146, 58545, 58546). In all categories, there was an inverse relationship between blood transfusion and preoperative hematocrit level with increasing risk depending on preoperative hematocrit range. The odds ratios comparing hematocrit level of 29% with 39% were 6.16 (95% confidence interval [CI], 5.15-7.36), 4.92 (95% CI, 4.19-5.78), 4.85 (95% CI, 3.72-6.33), and 5.2 (95% CI, 3.63-7.43) for patients with laparotomic (1-4 myomas/≤250 g, ≥5 myomas/>250 g) and laparoscopic myomectomy (1-4 myomas/≤250 g, 5 myomas/>250 g), respectively. CONCLUSION: Incremental increases in hematocrit result in a significantly decreased risk of blood transfusion at the time of myomectomy.

Predicting the probability of pT3 or higher pathological stage at radical prostatectomy: COVID19-specific considerations.

Background: We tested whether a model identifying prostate cancer (PCa) patients at risk of pT3-4/pN1 can be developed for use during COVID19 pandemic, in order to guarantee appropriate treatment to patients harboring advanced disease patients without compromising sustainability of care delivery. Methods: Within the Surveillance, Epidemiology and End Results database 2010-2016, we identified 27,529 patients with localized PCa and treated with radical prostatectomy. A multivariable logistic regression model predicting presence of pT3-4/pN1 disease was fitted within a development cohort (n=13,977, 50.8%). Subsequently, external validation (n=13,552, 49.2%) and head-to-head comparison with NCCN risk group stratification was performed. Results: In model development, age, PSA, biopsy Gleason Grade Group (GGG) and percentage of positive biopsy cores were independent predictors of pT3-4/pN1 stage. In external validation, prediction of pT3-4/pN1 with novel nomogram was 74% accurate versus 68% for NCCN risk group stratification. Nomogram achieved better calibration and showed net-benefit over NCCN risk group stratification in decision curve analyses. The use of nomogram cut-off of 49% resulted in pT3-4/pN1 rate of 65%, instead of the average 35%. Conclusion: The newly developed, externally validated nomogram predicts presence of pT3-4/pN1 better than NCCN risk group stratification and allows to focus radical prostatectomy treatment on individuals at highest risk of pT3-4/pN1.

Characterization of myocardial mechanics and its prognostic significance in patients with severe aortic stenosis undergoing aortic valve replacement.

Aims: Aortic stenosis (AS) induces characteristic changes in left ventricular (LV) mechanics that can be reversed after aortic valve replacement (AVR). We aimed to comprehensively characterize LV mechanics before and after AVR in patients with severe AS and identify predictors of short-term functional recovery and long-term survival. Methods and results: We prospectively performed comprehensive strain analysis by 2D speckle-tracking echocardiography in 88 patients with severe AS and LV ejection fraction ≥50% (mean age 71 ± 12 years, 42% female) prior to and within 7 days after AVR. Patients were followed for up to 5.2 years until death from any cause or last encounter. Within days after AVR, we observed an absolute increase in global longitudinal strain (GLS) (-16.0 ± 2.0% vs. -18.5 ± 2.1%, P<0.0001) and a decrease in apical rotation (10.5 ± 4.0° vs. 8.3 ± 2.8°, P = 0.0002) and peak systolic twist (18.2 ± 5.0° vs. 15.5 ± 3.8°, P = 0.0008). A baseline GLS is less negative than -16.2% was 90% sensitive and 67% specific in predicting a ≥ 20% relative increase in GLS. During a median follow-up of 3.8 years, a global circumferential systolic strain rate (GCSRs) less negative than -1.9% independently predicted lower survival. Conclusion: In patients with severe AS, a reversal in GLS, apical rotation, and peak systolic twist abnormalities towards normal occurs within days of AVR. Baseline GLS is the strongest predictor of GLS recovery but neither was associated with long-term survival. In contrast, abnormal baseline GCSRs are associated with worse outcomes.

Ancient marine sediment DNA reveals diatom transition in Antarctica.

Antarctica is one of the most vulnerable regions to climate change on Earth and studying the past and present responses of this polar marine ecosystem to environmental change is a matter of urgency. Sedimentary ancient DNA (sedaDNA) analysis can provide such insights into past ecosystem-wide changes. Here we present authenticated (through extensive contamination control and sedaDNA damage analysis) metagenomic marine eukaryote sedaDNA from the Scotia Sea region acquired during IODP Expedition 382. We also provide a marine eukaryote sedaDNA record of ~1 Mio. years and diatom and chlorophyte sedaDNA dating back to ~540 ka (using taxonomic marker genes SSU, LSU, psbO). We find evidence of warm phases being associated with high relative diatom abundance, and a marked transition from diatoms comprising <10% of all eukaryotes prior to ~14.5 ka, to ~50% after this time, i.e., following Meltwater Pulse 1A, alongside a composition change from sea-ice to open-ocean species. Our study demonstrates that sedaDNA tools can be expanded to hundreds of thousands of years, opening the pathway to the study of ecosystem-wide marine shifts and paleo-productivity phases throughout multiple glacial-interglacial cycles.

Episodes of Early Pleistocene West Antarctic Ice Sheet Retreat Recorded by Iceberg Alley Sediments.

Ice loss in the Southern Hemisphere has been greatest over the past 30 years in West Antarctica. The high sensitivity of this region to climate change has motivated geologists to examine marine sedimentary records for evidence of past episodes of West Antarctic Ice Sheet (WAIS) instability. Sediments accumulating in the Scotia Sea are useful to examine for this purpose because they receive iceberg-rafted debris (IBRD) sourced from the Pacific- and Atlantic-facing sectors of West Antarctica. Here we report on the sedimentology and provenance of the oldest of three cm-scale coarse-grained layers recovered from this sea at International Ocean Discovery Program Site U1538. These layers are preserved in opal-rich sediments deposited ∼1.2 Ma during a relatively warm regional climate. Our microCT-based analysis of the layer's in-situ fabric confirms its ice-rafted origin. We further infer that it is the product of an intense but short-lived episode of IBRD deposition. Based on the petrography of its sand fraction and the Phanerozoic 40Ar/39Ar ages of hornblende and mica it contains, we conclude that the IBRD it contains was likely sourced from the Weddell Sea and/or Amundsen Sea embayment(s) of West Antarctica. We attribute the high concentrations of IBRD in these layers to "dirty" icebergs calved from the WAIS following its retreat inland from its modern grounding line. These layers also sit at the top of a ∼366-m thick Pliocene and early Pleistocene sequence that is much more dropstone-rich than its overlying sediments. We speculate this fact may reflect that WAIS mass-balance was highly dynamic during the ∼41-kyr (inter)glacial world.

Antiphased dust deposition and productivity in the Antarctic Zone over 1.5 million years.

The Southern Ocean paleoceanography provides key insights into how iron fertilization and oceanic productivity developed through Pleistocene ice-ages and their role in influencing the carbon cycle. We report a high-resolution record of dust deposition and ocean productivity for the Antarctic Zone, close to the main dust source, Patagonia. Our deep-ocean records cover the last 1.5 Ma, thus doubling that from Antarctic ice-cores. We find a 5 to 15-fold increase in dust deposition during glacials and a 2 to 5-fold increase in biogenic silica deposition, reflecting higher ocean productivity during interglacials. This antiphasing persisted throughout the last 25 glacial cycles. Dust deposition became more pronounced across the Mid-Pleistocene Transition (MPT) in the Southern Hemisphere, with an abrupt shift suggesting more severe glaciations since ~0.9 Ma. Productivity was intermediate pre-MPT, lowest during the MPT and highest since 0.4 Ma. Generally, glacials experienced extended sea-ice cover, reduced bottom-water export and Weddell Gyre dynamics, which helped lower atmospheric CO2 levels.