Near collapse of the meridional SST gradient in the eastern equatorial Pacific during Heinrich Stadial 1

Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 28 (2013): 663–674, doi:10.1002/2013PA002499.Sea surface temperatures (SST) and inorganic continental input over the last 25,000 years (25 ka) are reconstructed in the far eastern equatorial Pacific (EEP) based on three cores stretching from the equatorial front (~0.01°N, ME0005-24JC) into the cold tongue region (~3.6°S; TR163-31P and V19-30). We revisit previously published alkenone-derived SST records for these sites and present a revised chronology for V19-30. Inorganic continental input is quantified at all three sites based on 230Th-normalized fluxes of the long-lived continental isotope thorium-232 and interpreted to be largely dust. Our data show a very weak meridional (cross-equatorial) SST gradient during Heinrich Stadial 1 (HS1, 18–15 ka B.P.) and high dust input along with peak export production at and north of the equator. These findings are corroborated by an Earth system model experiment for HS1 that simulates intensified northeasterly trade winds in the EEP, stronger equatorial upwelling, and surface cooling. Furthermore, the related southward shift of the Intertropical Convergence Zone (ITCZ) during HS1 is also indicative of drier conditions in the typical source regions for dust.This work was supported by grants from the Canadian Foundation for Climate and Atmospheric Sciences (CFCAS), the Canadian Institute for Advanced Research (CIFAR), the Natural Sciences and Engineering Research Council (NSERC), Canada and the National Science Foundation (NSF), USA. A. Timmermann and T. Friedrich were supported by NSF grant 1010869.2014-05-2

Spontaneous settlements in Turkey and Bangladesh: Preconditions of emergence and environmental quality of Gecekondu settlements and bustees

Spontaneous settlements are common phenomena in many third world countries. Although the different geographical locations, along with morphological factors, play an important role in shaping up different physical settings, dynamic social factors have similar consequences in such settlements. Ankara's gecekondu and Dhaka's bustees are in continuous change and adaptation into the structure of the cities in which they exist. Both remain as popular housing in the respective capitals of Turkey and Bangladesh. The aim of this paper is to find similarities and dissimilarities among gecekondu and bustees, giving an emphasis to five fundamental issues. Those are location of the settlement within the city, appropriation of land and ownership patterns, economic possibilities of the inhabitants, cultural and local dynamics of formation and uses of space, and last, the transformation of the settlements. Despite all physical and social dissimilarities, ownership patterns are perhaps the key factor in the development of such settlements both in Ankara and in Dhaka. The main commonality is that those settlements provide not only shelter but also possibilities to satisfy other needs for their inhabitants. © 2001 Elsevier Science Ltd. All rights reserved

Thorium-230 normalized particle flux and sediment focusing in the Panama Basin region during the last 30,000 years

Application of the ²³⁰Th normalization method to estimate sediment burial fluxes in six cores from the eastern equatorial Pacific (EEP) reveals that bulk sediment and organic carbon fluxes display a coherent regional pattern during the Holocene that is consistent with modern oceanographic conditions, in contrast with estimates of bulk mass accumulation rates (MARs) derived from core chronologies. Two nearby sites (less than 10 km apart), which have different MARs, show nearly identical ²³⁰Th-normalized bulk fluxes. Focusing factors derived from the ²³⁰Th data at the foot of the Carnegie Ridge in the Panama Basin are >2 in the Holocene, implying that lateral sediment addition is significant in this part of the basin. New geochemical data and existing literature provide evidence for a hydrothermal source of sediment in the southern part of the Panama Basin and for downslope transport from the top of the Carnegie Ridge. The compilation of core records suggests that sediment focusing is spatially and temporally variable in the EEP. During oxygen isotope stage 2 (OIS 2, from 13–27 ka BP), focusing appears even higher compared to the Holocene at most sites, similar to earlier findings in the eastern and central equatorial Pacific. The magnitude of the glacial increase in focusing factors, however, is strongly dependent on the accuracy of age models. We offer two possible explanations for the increase in glacial focusing compared to the Holocene. The first one is that the apparent increase in lateral sediment redistribution is partly or even largely an artifact of insufficient age control in the EEP, while the second explanation, which assumes that the observed increase is real, involves enhanced deep sea tidal current flow during periods of low sea level stand

Near collapse of the meridional SST gradient in the eastern equatorial Pacific during Heinrich Stadial 1

Sea surface temperatures (SST) and inorganic continental input over the last 25,000 years (25 ka) are reconstructed in the far eastern equatorial Pacific (EEP) based on three cores stretching from the equatorial front (~0.01°N, ME0005-24JC) into the cold tongue region (~3.6°S; TR163-31P and V19-30). We revisit previously published alkenone-derived SST records for these sites and present a revised chronology for V19-30. Inorganic continental input is quantified at all three sites based on ²³⁰Th-normalized fluxes of the long-lived continental isotope thorium-232 and interpreted to be largely dust. Our data show a very weak meridional (cross-equatorial) SST gradient during Heinrich Stadial 1 (HS1, 18–15 ka B.P.) and high dust input along with peak export production at and north of the equator. These findings are corroborated by an Earth system model experiment for HS1 that simulates intensified northeasterly trade winds in the EEP, stronger equatorial upwelling, and surface cooling. Furthermore, the related southward shift of the Intertropical Convergence Zone (ITCZ) during HS1 is also indicative of drier conditions in the typical source regions for dust.Keywords: Heinrich Stadial 1, Meridional SST gradient, Eastern equatorial Pacifi

FHIR-DHP: A standardized clinical data harmonisation pipeline for scalable AI application deployment

Background Increasing digitalisation in the medical domain gives rise to large amounts of healthcare data which has the potential to expand clinical knowledge and transform patient care if leveraged through artificial intelligence (AI). Yet, big data and AI oftentimes cannot unlock their full potential at scale, owing to non-standardised data formats, lack of technical and semantic data interoperability, and limited cooperation between stakeholders in the healthcare system. Despite the existence of standardised data formats for the medical domain, such as Fast Healthcare Interoperability Resources (FHIR), their prevalence and usability for AI remains limited.Objective We developed a data harmonisation pipeline (DHP) for clinical data sets relying on the common FHIR data standard.Methods We validated the performance and usability of our FHIR-DHP with data from the MIMIC IV database including > 40,000 patients admitted to an intensive care unit.Results We present the FHIR-DHP workflow in respect of transformation of “raw” hospital records into a harmonised, AI-friendly data representation. The pipeline consists of five key preprocessing steps: querying of data from hospital database, FHIR mapping, syntactic validation, transfer of harmonised data into the patient-model database and export of data in an AI-friendly format for further medical applications. A detailed example of FHIR-DHP execution was presented for clinical diagnoses records.Conclusions Our approach enables scalable and needs-driven data modelling of large and heterogenous clinical data sets. The FHIR-DHP is a pivotal step towards increasing cooperation, interoperability and quality of patient care in the clinical routine and for medical research

On the sedimentological origin of down-core variations of bulk sedimentary nitrogen isotope ratios

Author Posting. © American Geophysical Union, 2005. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 20 (2005): PA2009, doi:10.1029/2004PA001081.The bulk sedimentary nitrogen isotopic composition of two cores from nearby sites on the northern slope of the South China Sea (Site 17940 and Ocean Drilling Program (ODP) Site 1144) differs by up to >2‰ during the last glacial period. Given their close proximity, both core sites are located in the same biogeographic zone and nutrient regime, and it is thus unlikely that this offset is due to a true gradient in surface ocean conditions. In an attempt to resolve this offset, we have investigated the possible effects of two sedimentological parameters that can affect bulk sedimentary δ15N, namely, the variable contribution of inorganic N to bulk N in the sediment and the grain-size dependence of bulk δ15N. We find that neither effect, singly or in combination, is sufficient to explain the significant δ15N offset between the two down-core records. By elimination the most likely explanation for the observed discrepancy is a different origin of both the organic and inorganic nitrogen at each site. This study adds to the growing body of evidence highlighting the complex nature and origin of the sedimentary components in sediment drifts, such as ODP Site 1144.Funding from NSERC Canada (to S.E.C. and M.K.) and NSF (OCE-0214365 and OCE-0318371 to M.J.H. and OCE-0327405 to T.I.E.) is gratefully acknowledged, as well as Woods Hole Oceanographic Institution Postdoctoral Fellowships (M.K. and G.M.), the Camille and Henry Dreyfus Postdoctoral Program in Environmental Chemistry (M.J.H.), and a Geological Society of America student research grant (M.K.)

230 Th normalization: new insights on an essential tool for quantifying sedimentary fluxes in the modern and quaternary ocean

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Costa, K. M., Hayes, C. T., Anderson, R. F., Pavia, F. J., Bausch, A., Deng, F., Dutay, J., Geibert, W., Heinze, C., Henderson, G., Hillaire-Marcel, C., Hoffmann, S., Jaccard, S. L., Jacobel, A. W., Kienast, S. S., Kipp, L., Lerner, P., Lippold, J., Lund, D., Marcantonio, F., McGee, D., McManus, J. F., Mekik, F., Middleton, J. L., Missiaen, L., Not, C., Pichat, S., Robinson, L. F., Rowland, G. H., Roy-Barman, M., Alessandro, Torfstein, A., Winckler, G., & Zhou, Y. 230 Th normalization: new insights on an essential tool for quantifying sedimentary fluxes in the modern and quaternary ocean. Paleoceanography and Paleoclimatology, 35(2), (2020): e2019PA003820, doi:10.1029/2019PA003820.230Th normalization is a valuable paleoceanographic tool for reconstructing high‐resolution sediment fluxes during the late Pleistocene (last ~500,000 years). As its application has expanded to ever more diverse marine environments, the nuances of 230Th systematics, with regard to particle type, particle size, lateral advective/diffusive redistribution, and other processes, have emerged. We synthesized over 1000 sedimentary records of 230Th from across the global ocean at two time slices, the late Holocene (0–5,000 years ago, or 0–5 ka) and the Last Glacial Maximum (18.5–23.5 ka), and investigated the spatial structure of 230Th‐normalized mass fluxes. On a global scale, sedimentary mass fluxes were significantly higher during the Last Glacial Maximum (1.79–2.17 g/cm2kyr, 95% confidence) relative to the Holocene (1.48–1.68 g/cm2kyr, 95% confidence). We then examined the potential confounding influences of boundary scavenging, nepheloid layers, hydrothermal scavenging, size‐dependent sediment fractionation, and carbonate dissolution on the efficacy of 230Th as a constant flux proxy. Anomalous 230Th behavior is sometimes observed proximal to hydrothermal ridges and in continental margins where high particle fluxes and steep continental slopes can lead to the combined effects of boundary scavenging and nepheloid interference. Notwithstanding these limitations, we found that 230Th normalization is a robust tool for determining sediment mass accumulation rates in the majority of pelagic marine settings (>1,000 m water depth).We thank Zanna Chase and one anonymous reviewer for valuable feedback. K. M. C. was supported by a Postdoctoral Scholarship at WHOI. L. M. acknowledges funding from the Australian Research Council grant DP180100048. The contribution of C. T. H., J. F. M., and R. F. A. were supported in part by the U.S. National Science Foundation (US‐NSF). G. H. R. was supported by the Natural Environment Research Council (grant NE/L002434/1). S. L. J. acknowledges support from the Swiss National Science Foundation (grants PP002P2_144811 and PP00P2_172915). This study was supported by the Past Global Changes (PAGES) project, which in turn received support from the Swiss Academy of Sciences and the US‐NSF. This work grew out of a 2018 workshop in Aix‐Marseille, France, funded by PAGES, GEOTRACES, SCOR, US‐NSF, Aix‐Marseille Université, and John Cantle Scientific. All data are publicly available as supporting information to this document and on the National Center for Environmental Information (NCEI) at https://www.ncdc.noaa.gov/paleo/study/28791