Nucleation-induced transition to collective motion in active systems

While the existence of polar ordered states in active systems is well established, the dynamics of the self-assembly processes are still elusive. We study a lattice gas model of self-propelled elongated particles interacting through excluded volume and alignment interactions, which shows a phase transition from an isotropic to a polar ordered state. By analyzing the ordering process we find that the transition is driven by the formation of a critical nucleation cluster and a subsequent coarsening process. Moreover, the time to establish a polar ordered state shows a power-law divergence

230Th Normalization: New Insights on an Essential Tool for Quantifying Sedimentary Fluxes in the Modern and Quaternary Ocean

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 (\u3e1,000 m water depth)

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

\u3csup\u3e230\u3c/sup\u3eTh Normalization: New Insights on an Essential Tool for Quantifying Sedimentary Fluxes in the Modern and Quaternary Ocean

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 (\u3e1,000 m water depth)

Phase 2 safety and antiviral activity of SAB-185, a novel polyclonal antibody therapy for non-hospitalized adults with COVID-19

SAB-185, a novel fully-human IgG polyclonal immunoglobulin product, underwent phase 2 evaluation for non-hospitalized adults with mild-moderate COVID-19.Participants received intravenous SAB-185 3,840 units/kg (low-dose) or placebo, or 10,240 units/kg (high-dose) or placebo. Primary outcome measures were nasopharyngeal SARS-CoV-2 RNA <lower limit of quantification (LLoQ) at study days 3, 7, and 14, time to symptomatic improvement, and safety through day 28.Two-hundred thirteen participants received low-dose SAB-185/placebo (n=107/106) and 215 high-dose SAB-185/placebo (n=110/105). The proportions with SARS-CoV-2 RNA <LLoQ were higher for SAB-185 versus placebo at days 3 and 7 and similar at day 14, and significantly higher at day 7 for high-dose SAB versus placebo only, relative risk (95% CI) 1.23 (1.01, 1.49). At day 3, SARS-CoV-2 RNA levels were lower with low-dose and high-dose SAB-185 versus placebo, differences in medians of -0.78 log10copies/mL (p=0.08) and -0.71 log10copies/mL (p=0.10), respectively. No difference was observed in time to symptom improvement: median 11/10 days (p=0.24) for low-dose SAB-185/placebo and 8/10 days (p=0.50) for high-dose SAB-185/placebo. Grade ≥3 adverse events occurred in 5%/13% of low-dose SAB-185/placebo and 9%/12% of high-dose SAB-185/placebo.SAB-185 was safe and generally well tolerated and demonstrated modest antiviral activity in predominantly low-risk non-hospitalized adults with COVID-19

Interview mit Heiko Beyer über seinen Vortrag "Irland" bei der 6. MUNDOlogia

#Sendedatum: 05.02.2009 ##Dauer: 03:37min Was ist es, das den Reiz und die Faszination dieser Insel ganz im Westen Europas ausmacht? Sind es die Landschaften, die sanft geschwungenen Hügel, deren Grün intensiver zu leuchten scheint als irgendwo anders? Oder verzaubert die Mystik der Geschichte, die den Reisenden in uralten Steinzeitgräbern, keltischen Burgen oder klösterlichen Stadtbefestigungen in ihren Bann zieht? Heiko Beyer und Markus Friedrich sind nach Jahren des Reisens in Irland zu dem Schluß gekommen: Es ist alles zusammen – und noch viel mehr

Interview mit Olaf Krüger über seinen Vortrag "Island" bei der 5. MUNDOlogia

#Sendedatum: Januar 2008 ##Dauer: 03:03min Olaf Krüger hat sich der Nordmeerinsel mit vielen Fragen genähert und sie zwischen 2004 und 2006 fünfmal bereist; zu allen Jahreszeiten und mit wachsender Begeisterung. Von Beginn an faszinierte ihn die Wirkung der Urlandschaften Islands auf die Menschen. Vulkane, Gletscher, Krater, Steinwüsten, Fjorde, Nordlichter, Geysire und dröhnende Wasserfälle – seit der Besiedlung Islands vor über 1100 Jahren hat die grandiose, manchmal auch bedrohliche Natur die Phantasie der Isländer beflügelt

Interview mit Sebastian Burger über seinen Newcomer-Vortrag "Abenteuer Tandem" bei der 5. MUNDOlogia

#Sendedatum: Februar 2008 ##Dauer: 05:22min An eigene Grenzen heranzugehen und über diese hinaus ist die Triebfeder von Sebastian Burger zu seinen Reisen. Damit man die Erfahrungen in fremden Ländern mit anderen Menschen unter Outdoorbedingungen teilen kann, bietet sich seiner Ansicht nach am besten ein Tandem an. Von Deutschland mit dem Tandem nach China oder mit binden Mitfahrern sind nur einige der Touren die Burger bisher unternommen hat. Für den Studenten der Fotografie an der Kunsthochschule Bremen ist es nur logisch, dass er seine Reisen im Bild festhält und dokumentiert. Als Newcomer auf der Mundologia lässt er erstmals andere Menschen an seinen Reisen teilhaben

Interview mit Romano Schenk über seinen Vortrag "Kanada" bei der 6. MUNDOlogia

#Sendedatum: Januar 2009 ##Dauer: 05:34mi