Paleoceanographical Proxies Based on Deep-Sea Benthic Foraminiferal Assemblage Characteristics
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Evaluating the Biological Pump Efficiency of the Last Glacial Maximum Ocean Using Δ13c Anne L
Evaluating the Biological Pump Efficiency of the Last Glacial Maximum Ocean using δ13C Anne L. Morée1, Jörg Schwinger2, Ulysses S. Ninnemann3, Aurich Jeltsch-Thömmes4, Ingo Bethke1, Christoph Heinze1 5 1Geophysical Institute, University of Bergen and Bjerknes Centre for Climate Research, Bergen, 5007, Norway 2NORCE Norwegian Research Centre and Bjerknes Centre for Climate Research, Bergen, 5838, Norway 3Department of Earth Science, University of Bergen and Bjerknes Centre for Climate Research, Bergen, 5007, Norway 4Climate and Environmental Physics, Physics Institute and Oeschger Centre for Climate Change Research, 10 University of Bern, Bern, Switzerland Correspondence to: Anne L. Morée ([email protected]) Abstract. Although both physical and biological marine changes are required to explain the 100 ppm lower atmospheric pCO2 of the Last Glacial Maximum (LGM, ~21 ka) as compared to pre-industrial (PI) times, their exact contributions are debated. Proxies of past marine carbon cycling (such as δ13C) document these changes, and 15 thus provide constraints for quantifying the drivers of long-term carbon cycle variability. This modelling study explores the relative rolespresents a realization of the of physical and biological changes in the ocean needed to simulate an LGM ocean in satisfactory agreement with proxy data, and here especially δ13C. We prepared a PI and LGM equilibrium simulation using the ocean model state (NorESM-OC) with full biogeochemistry (including the carbon isotopes δ13C and radiocarbon) and dynamic sea ice. The modelled LGM-PI differences are evaluated 20 against a wide range of physical and biogeochemical proxy data, and show agreement for key aspects of the physical ocean state within the data uncertainties. -
Soares, R. Et Al
Original Article DOI: 10.7860/JCDR/2017/23594.9758 Assessment of Enamel Remineralisation After Treatment with Four Different Dentistry Section Remineralising Agents: A Scanning Electron Microscopy (SEM) Study RENITA SOARES1, IDA DE NORONHA DE ATAIDE2, MARINA FERNANDES3, RAJAN LAMBOR4 ABSTRACT these groups were remineralised using the four remineralising Introduction: Decades of research has helped to increase our agents. The treated groups were subjected to pH cycling over a knowledge of dental caries and reduce its prevalence. However, period of 30 days. This was followed by assessment of surface according to World Oral Health report, dental caries still remains microhardness and SEM for qualitative evaluation of surface a major dental disease. Fluoride therapy has been utilised in changes. The results were analysed by One-Way Analysis Of a big way to halt caries progression, but has been met with Variance (ANOVA). Multiple comparisons between groups were limitations. This has paved the way for the development of performed by paired t-test and post-hoc Tukey test. newer preventive agents that can function as an adjunct to Results: The results of the study revealed that remineralisation of fluoride or independent of it. enamel was the highest in samples of Group E (Self assembling Aim: The purpose of the present study was to evaluate the ability peptide P11-4) followed by Group B (CPP-ACPF), Group C (BAG) of Casein Phosphopeptide-Amorphous Calcium Phosphate and Group D (fluoride enhanced HA gel). There was a significant Fluoride (CPP ACPF), Bioactive Glass (BAG), fluoride enhanced difference (p<0.05) in the remineralising ability between the self assembling peptide P -4 group and BAG and fluoride Hydroxyapatite (HA) gel and self-assembling peptide P11-4 to 11 remineralise artificial carious lesions in enamel in vitro using enhanced HA gel group. -
Latest Pliocene Northern Hemisphere Glaciation Amplified by Intensified Atlantic Meridional Overturning Circulation
ARTICLE https://doi.org/10.1038/s43247-020-00023-4 OPEN Latest Pliocene Northern Hemisphere glaciation amplified by intensified Atlantic meridional overturning circulation ✉ Tatsuya Hayashi 1 , Toshiro Yamanaka 2, Yuki Hikasa3, Masahiko Sato4, Yoshihiro Kuwahara1 & Masao Ohno1 1234567890():,; The global climate has been dominated by glacial–interglacial variations since the intensifi- cation of Northern Hemisphere glaciation 2.7 million years ago. Although the Atlantic mer- idional overturning circulation has exerted strong influence on recent climatic changes, there is controversy over its influence on Northern Hemisphere glaciation because its deep limb, North Atlantic Deep Water, was thought to have weakened. Here we show that Northern Hemisphere glaciation was amplified by the intensified Atlantic meridional overturning cir- culation, based on multi-proxy records from the subpolar North Atlantic. We found that the Iceland–Scotland Overflow Water, contributing North Atlantic Deep Water, significantly increased after 2.7 million years ago and was actively maintained even in early stages of individual glacials, in contrast with late stages when it drastically decreased because of iceberg melting. Probably, the active Nordic Seas overturning during the early stages of glacials facilitated the efficient growth of ice sheets and amplified glacial oscillations. 1 Division of Environmental Changes, Faculty of Social and Cultural Studies, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan. 2 School of Marine Resources and Environment, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Tokyo 108-8477, Japan. 3 Department of Earth Sciences, Graduate School of Natural Science and Technology, Okayama University, 1-1, Naka 3-chome, Tsushima, Okayama 700-8530, Japan. 4 Department of Earth ✉ and Planetary Science, The University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan. -
An Updated Synthesis of the Impacts of Ocean Acidification on Marine Biodiversity 2 3 ACKNOWLEDGEMENTS
P a g e | 1 DRAFT FOR CBD PEER-REVIEW ONLY; NOT TO QUOTE; NOT TO CIRCULATE 1 An updated synthesis of the impacts of ocean acidification on marine biodiversity 2 3 ACKNOWLEDGEMENTS ....................................................................................................... 3 4 5 EXECUTIVE SUMMARY ....................................................................................................... 4 6 7 1. Background and introduction ............................................................................................... 8 8 1.1. Mandate of this review .......................................................................................................... 8 9 1.2. What is ocean acidification? ........................................................................................ 9 10 1.3. Re-visiting key knowledge gaps identified in the previous CBD review ................... 14 11 12 2. Scientific and policy framework ........................................................................................ 17 13 2.1. Steps towards global recognition and international science collaboration ................. 17 14 2.2. Intergovernmental interest in ocean acidification and actions to date ........................ 19 15 16 3. Global status and future trends of ocean acidification ....................................................... 23 17 3.1. Variability .................................................................................................................. 23 18 3.2. Modelled simulations of future ocean -
20. Shell Horizons in Cenozoic Upwelling-Facies Sediments Off Peru: Distribution and Mollusk Fauna in Cores from Leg 1121
Suess, E., von Huene, R., et al., 1990 Proceedings of the Ocean Drilling Program, Scientific Results, Vol. 112 20. SHELL HORIZONS IN CENOZOIC UPWELLING-FACIES SEDIMENTS OFF PERU: DISTRIBUTION AND MOLLUSK FAUNA IN CORES FROM LEG 1121 Ralph Schneider2 and Gerold Wefer2 ABSTRACT Shell layers in cores extracted from the continental margin off Peru during Leg 112 of the Ocean Drilling Program (ODP) show the spatial and temporal distribution of mollusks. In addition, the faunal composition of the mollusks in these layers was investigated. Individual shell layers have been combined to form shell horizons whose origin has been traced to periods of increased molluscan growth. It seems that the limiting factor for the growth of mollusks in upwelling regions near the coast of Peru is primarily the oxygen content of the bottom water. Optimal living conditions for mollusks are found at the upper boundary of the oxygen-minimum layer (OML). This OML in the modern sea ranges in depths from 100 to 500 m. Fluctuations in the OML boundary control the spatial and temporal distribution of shell horizons on the outer shelf and upper continental slope. The distribution of mollusks depends further on tectonic events and bottom current effects in the study area. In the range of outer shelf and upper slope, these shell horizons were developed during times of lowered sea level, from the late Miocene through the Quaternary, especially during glacial episodes in the late Quaternary. INTRODUCTION comprehensive reviews of the bivalve and gastropod taxon• omy of the equatorial East Pacific faunal province, but con• Ten holes were drilled using the drill ship JOIDES Reso• tained little information about the ecology of the genera lution during Leg 112, in November and December 1986, on described. -
Biotribology Recent Progresses and Future Perspectives
HOSTED BY Available online at www.sciencedirect.com Biosurface and Biotribology ] (]]]]) ]]]–]]] www.elsevier.com/locate/bsbt Biotribology: Recent progresses and future perspectives Z.R. Zhoua,n, Z.M. Jinb,c aSchool of Mechanical Engineering, Southwest Jiaotong University, Chengdu, China bSchool of Mechanical Engineering, Xian Jiaotong University, Xi'an, China cSchool of Mechanical Engineering, University of Leeds, Leeds, UK Received 6 January 2015; received in revised form 3 March 2015; accepted 3 March 2015 Abstract Biotribology deals with all aspects of tribology concerned with biological systems. It is one of the most exciting and rapidly growing areas of tribology. It is recognised as one of the most important considerations in many biological systems as to the understanding of how our natural systems work as well as how diseases are developed and how medical interventions should be applied. Tribological studies associated with biological systems are reviewed in this paper. A brief history, classification as well as current focuses on biotribology research are analysed according to typical papers from selected journals and presentations from a number of important conferences in this area. Progress in joint tribology, skin tribology and oral tribology as well as other representative biological systems is presented. Some remarks are drawn and prospects are discussed. & 2015 Southwest Jiaotong University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Keywords: Biotribology; Biosurface; Joint; Skin; Dental Contents 1. Introduction ...................................................................................2 2. Classifications and focuses of current research. ..........................................................3 3. Joint tribology .................................................................................4 3.1. -
Climate Change and Ocean Acidification Impacts on Lower
EGU Journal Logos (RGB) Open Access Open Access Open Access Advances in Annales Nonlinear Processes Geosciences Geophysicae in Geophysics Open Access Open Access Natural Hazards Natural Hazards and Earth System and Earth System Sciences Sciences Discussions Open Access Open Access Atmospheric Atmospheric Chemistry Chemistry and Physics and Physics Discussions Open Access Open Access Atmospheric Atmospheric Measurement Measurement Techniques Techniques Discussions Open Access Biogeosciences, 10, 5831–5854, 2013 Open Access www.biogeosciences.net/10/5831/2013/ Biogeosciences doi:10.5194/bg-10-5831-2013 Biogeosciences Discussions © Author(s) 2013. CC Attribution 3.0 License. Open Access Open Access Climate Climate of the Past of the Past Discussions Climate change and ocean acidification impacts on lower trophic Open Access Open Access levels and the export of organic carbon to the deepEarth ocean System Earth System Dynamics 1 1 1 2 1 Dynamics A. Yool , E. E. Popova , A. C. Coward , D. Bernie , and T. R. Anderson Discussions 1National Oceanography Centre, University of Southampton Waterfront Campus, European Way, Southampton SO14 3ZH, UK Open Access Open Access 2Met Office Hadley Centre, FitzRoy Road, Exeter EX1 3PB, UK Geoscientific Geoscientific Instrumentation Instrumentation Correspondence to: A. Yool ([email protected]) Methods and Methods and Received: 29 January 2013 – Published in Biogeosciences Discuss.: 25 February 2013 Data Systems Data Systems Revised: 18 July 2013 – Accepted: 19 July 2013 – Published: 5 September 2013 Discussions -
Understanding the Ocean's Biological Carbon Pump in the Past: Do We Have the Right Tools?
Manuscript prepared for Earth-Science Reviews Date: 3 March 2017 Understanding the ocean’s biological carbon pump in the past: Do we have the right tools? Dominik Hülse1, Sandra Arndt1, Jamie D. Wilson1, Guy Munhoven2, and Andy Ridgwell1, 3 1School of Geographical Sciences, University of Bristol, Clifton, Bristol BS8 1SS, UK 2Institute of Astrophysics and Geophysics, University of Liège, B-4000 Liège, Belgium 3Department of Earth Sciences, University of California, Riverside, CA 92521, USA Correspondence to: D. Hülse ([email protected]) Keywords: Biological carbon pump; Earth system models; Ocean biogeochemistry; Marine sedi- ments; Paleoceanography Abstract. The ocean is the biggest carbon reservoir in the surficial carbon cycle and, thus, plays a crucial role in regulating atmospheric CO2 concentrations. Arguably, the most important single com- 5 ponent of the oceanic carbon cycle is the biologically driven sequestration of carbon in both organic and inorganic form- the so-called biological carbon pump. Over the geological past, the intensity of the biological carbon pump has experienced important variability linked to extreme climate events and perturbations of the global carbon cycle. Over the past decades, significant progress has been made in understanding the complex process interplay that controls the intensity of the biological 10 carbon pump. In addition, a number of different paleoclimate modelling tools have been developed and applied to quantitatively explore the biological carbon pump during past climate perturbations and its possible feedbacks on the evolution of the global climate over geological timescales. Here we provide the first, comprehensive overview of the description of the biological carbon pumpin these paleoclimate models with the aim of critically evaluating their ability to represent past marine 15 carbon cycle dynamics. -
Author's Tracked Changes
Toward a global calibration for quantifying past oxygenation in oxygen minimum zones using benthic Foraminifera Martin Tetard1, Laetitia Licari1, Ekaterina Ovsepyan2, Kazuyo Tachikawa1, and Luc Beaufort1 1Aix Marseille Univ, CNRS, IRD, Coll France, INRAE, CEREGE, Aix-en-Provence, France. 2Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia. Correspondence: M. Tetard ([email protected]) Abstract. Oxygen Minimum Zones (OMZs) are oceanic areas largely depleted in dissolved oxygen, nowadays considered in expansion in the face of global warming. To investigate the relationship between OMZ expansion and global climate changes during the late Quaternary, quantitative oxygen reconstructions are needed, but are still in their early development. 5 Here, past bottom water oxygenation (BWO) was quantitatively assessed through a new, fast, semi-automated, and taxon-free :::::::::::::::taxon-independent morphometric analysis of benthic foraminiferal tests, developed and calibrated using Eastern North Pacific(ENP ::::WNP::::::::(Western::::::North:::::::Pacific, ::::::::including:::its ::::::::marginal :::::seas), ::::ENP::::::::(Eastern :::::North:::::::Pacific) and the ESP:::::(Eastern South Pa- cific(ESP) OMZs samples. This new approach is based on an average size and circularity index for each sample. This method, as well as two already published micropalaeontological approaches techniques:::::::::based on benthic foraminiferal assemblages 10 variability and porosity investigation of a single species, were here calibrated based on availability of new data from 23 45:: -1 core tops recovered along an oxygen gradient (from 0.03 to 1.79 2.88::::mL.L ) from the ENP, ESP, :::::WNP, ::::ENP,::::EEP::::::::(Eastern ::::::::Equatorial::::::::Pacific), ::::ESP,::::::::SWACM::::::(South:::::West :::::::African ::::::::::Continental :::::::Margin),:AS (Arabian Sea) and WNP (Western North Pacific, including its marginal seas) OMZs. -
Combining Marine Macroecology and Palaeoecology in Understanding Biodiversity: Microfossils As a Model
Biol. Rev. (2015), pp. 000–000. 1 doi: 10.1111/brv.12223 Combining marine macroecology and palaeoecology in understanding biodiversity: microfossils as a model Moriaki Yasuhara1,2,3,∗, Derek P. Tittensor4,5, Helmut Hillebrand6 and Boris Worm4 1School of Biological Sciences, The University of Hong Kong, Pok Fu Lam Road, Hong Kong SAR, China 2Swire Institute of Marine Science, The University of Hong Kong, Cape d’Aguilar Road, Shek O, Hong Kong SAR, China 3Department of Earth Sciences, The University of Hong Kong, Pok Fu Lam Road, Hong Kong SAR, China 4Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, Nova Scotia, B3H 4R2, Canada 5United Nations Environment Programme World Conservation Monitoring Centre, 219 Huntingdon Road, Cambridge, CB3 0DL, UK 6Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl-von-Ossietzky University of Oldenburg, Schleusenstrasse 1, 26382 Wilhelmshaven, Germany ABSTRACT There is growing interest in the integration of macroecology and palaeoecology towards a better understanding of past, present, and anticipated future biodiversity dynamics. However, the empirical basis for this integration has thus far been limited. Here we review prospects for a macroecology–palaeoecology integration in biodiversity analyses with a focus on marine microfossils [i.e. small (or small parts of) organisms with high fossilization potential, such as foraminifera, ostracodes, diatoms, radiolaria, coccolithophores, dinoflagellates, and ichthyoliths]. Marine microfossils represent a useful model -
Synthese Nutriscope: Arbeiten Von Agroscope Auf Dem Gebiet Der Ernährung 2008 Bis 2010
Synthese NutriScope: Arbeiten von Agroscope auf dem Gebiet der Ernährung 2008 bis 2010 Pascale Mühlemann Mühlemann Nutrition GmbH März 2011 Synthese Ernährung Impressum Autorin Mühlemann Nutrition GmbH Pascale Mühlemann www.muehlemann-nutrition.ch Auftraggeberin Forschungsanstalt Agroscope Liebefeld-Posieux ALP www.agroscope.admin.ch Bemerkungen Die vorliegende Synthese basiert ausschliesslich auf Arbeiten von Agroscope auf dem Ge- biet der Ernährung, die in irgendeiner Art und Weise öffentlich gemacht wurden. Die beige- zogenen Arbeiten wurden in den Jahren 2008 bis 2010 durchgeführt, wobei auch relevante Arbeiten aus den Vorjahren und einige aktuelle Publikationen aus dem Jahr 2011 einge- schlossen wurden. Das Literaturverzeichnis umfasst insofern ausschliesslich an Agroscope durchgeführte Arbeiten; die darin aufgeführten Originalarbeiten sind im Literaturverzeichnis nicht genannt. Da Agroscope-eigene Arbeiten gegenüber reinen Literaturarbeiten im Vordergrund stehen, sind Erstere in der vorliegenden Synthese in einen Rahmen gesetzt. 9. März 2011 - 2 - Synthese Ernährung Inhaltsverzeichnis Impressum .............................................................................................................................. 2 Abkürzungsverzeichnis ......................................................................................................... 5 Zusammenfassung ................................................................................................................. 6 1. Milch und Milchprodukte ............................................................................................. -
Resolving Ecological Feedbacks on the Ocean Carbon Sink in Earth System Models” by Armstrong Mckay Et Al
Review of “Resolving ecological feedbacks on the ocean carbon sink in Earth system models” by Armstrong McKay et al. Armstrong McKay et al., have put a lot of of effort into revising the manuscript and responding to the reviewer comments, especially given the varied pressures of working during a pandemic. Overall, I think the manuscript is improved with the addition of adequate details about the experimental set up, new analysis of results and improved general presentation. The overall concept and findings are interesting to the Earth system community and are currently very relevant to a wider discussion of resolving plankton ecosystems in Earth system models. Unfortunately I think there are still some outstanding issues with the experimental set-up and analysis that need to be resolved before I can recommend the manuscript for publication. Overall, I think the problems described in the comment by Kvale et al., combined with my own comments highlight a broader issue: can a common baseline be defined for different models and does this limit the level of quantitative analysis? This seems like a tricky issue to resolve but I have tried to outline two ways in which I think it could be achieved below as I think this is worth pursuing. I have also included a more detailed criticism of the recalibration process now that the process has been fully described, but this forms a part of the broader issue. Experimental Set-up Based on the previous reviewer comments and the clarifications in the revised manuscript, I think there is a fundamental issue in trying to define a common baseline for all the experiments.