A Test of the Biogenicity Criteria Established for Microfossils And
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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. -
Confocal Raman Microscope Mapping As a Tool to Describe Different
Biogeosciences, 8, 3761–3769, 2011 www.biogeosciences.net/8/3761/2011/ Biogeosciences doi:10.5194/bg-8-3761-2011 © Author(s) 2011. CC Attribution 3.0 License. Confocal Raman microscope mapping as a tool to describe different mineral and organic phases at high spatial resolution within marine biogenic carbonates: case study on Nerita undata (Gastropoda, Neritopsina) G. Nehrke1 and J. Nouet2 1Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany 2University Paris Sud, IDES UMR 8148, batimentˆ 504, campus universitaire, 91405 Orsay cedex, France Received: 20 May 2011 – Published in Biogeosciences Discuss.: 9 June 2011 Revised: 10 November 2011 – Accepted: 7 December 2011 – Published: 20 December 2011 Abstract. Marine biogenic carbonates formed by inverte- 1 Introduction brates (e.g. corals and mollusks) represent complex compos- ites of one or more mineral phases and organic molecules. Calcium carbonates formed by marine calcifying organisms This complexity ranges from the macroscopic structures ob- (e.g. corals and mollusks) received much attention in the field served with the naked eye down to sub micrometric struc- of biogeosciences during the last decades. On the one hand tures only revealed by micro analytical techniques. Under- they represent important proxy archives (e.g. oxygen isotopic standing to what extent and how organisms can control the composition can be used for temperature reconstruction (Mc- formation of these structures requires that the mineral and Crea, 1950; Urey et al., 1951)) and on the other hand they are organic phases can be identified and their spatial distribution affected by the increasing acidification of the ocean due to related. -
Paleoceanographical Proxies Based on Deep-Sea Benthic Foraminiferal Assemblage Characteristics
CHAPTER SEVEN Paleoceanographical Proxies Based on Deep-Sea Benthic Foraminiferal Assemblage Characteristics Frans J. JorissenÃ, Christophe Fontanier and Ellen Thomas Contents 1. Introduction 263 1.1. General introduction 263 1.2. Historical overview of the use of benthic foraminiferal assemblages 266 1.3. Recent advances in benthic foraminiferal ecology 267 2. Benthic Foraminiferal Proxies: A State of the Art 271 2.1. Overview of proxy methods based on benthic foraminiferal assemblage data 271 2.2. Proxies of bottom water oxygenation 273 2.3. Paleoproductivity proxies 285 2.4. The water mass concept 301 2.5. Benthic foraminiferal faunas as indicators of current velocity 304 3. Conclusions 306 Acknowledgements 308 4. Appendix 1 308 References 313 1. Introduction 1.1. General Introduction The most popular proxies based on microfossil assemblage data produce a quanti- tative estimate of a physico-chemical target parameter, usually by applying a transfer function, calibrated on the basis of a large dataset of recent or core-top samples. Examples are planktonic foraminiferal estimates of sea surface temperature (Imbrie & Kipp, 1971) and reconstructions of sea ice coverage based on radiolarian (Lozano & Hays, 1976) or diatom assemblages (Crosta, Pichon, & Burckle, 1998). These à Corresponding author. Developments in Marine Geology, Volume 1 r 2007 Elsevier B.V. ISSN 1572-5480, DOI 10.1016/S1572-5480(07)01012-3 All rights reserved. 263 264 Frans J. Jorissen et al. methods are easy to use, apply empirical relationships that do not require a precise knowledge of the ecology of the organisms, and produce quantitative estimates that can be directly applied to reconstruct paleo-environments, and to test and tune global climate models. -
Polymorphic Protective Dps–DNA Co-Crystals by Cryo Electron Tomography and Small Angle X-Ray Scattering
biomolecules Article Polymorphic Protective Dps–DNA Co-Crystals by Cryo Electron Tomography and Small Angle X-Ray Scattering Roman Kamyshinsky 1,2,3,* , Yury Chesnokov 1,2 , Liubov Dadinova 2, Andrey Mozhaev 2,4, Ivan Orlov 2, Maxim Petoukhov 2,5 , Anton Orekhov 1,2,3, Eleonora Shtykova 2 and Alexander Vasiliev 1,2,3 1 National Research Center “Kurchatov Institute”, Akademika Kurchatova pl., 1, 123182 Moscow, Russia; [email protected] (Y.C.); [email protected] (A.O.); [email protected] (A.V.) 2 Shubnikov Institute of Crystallography of Federal Scientific Research Centre “Crystallography and Photonics” of Russian Academy of Sciences, Leninskiy prospect, 59, 119333 Moscow, Russia; [email protected] (L.D.); [email protected] (A.M.); [email protected] (I.O.); [email protected] (M.P.); [email protected] (E.S.) 3 Moscow Institute of Physics and Technology, Institutsky lane 9, 141700 Dolgoprudny, Moscow Region, Russia 4 Shemyakin-Ovchinnikov Institute of bioorganic chemistry of Russian Academy of Sciences, Miklukho-Maklaya, 16/10, 117997 Moscow, Russia 5 Frumkin Institute of Physical Chemistry and Electrochemistry of Russian Academy of Sciences, Leninsky prospect, 31, 119071 Moscow, Russia * Correspondence: [email protected]; Tel.: +7-916-356-3963 Received: 6 November 2019; Accepted: 22 December 2019; Published: 26 December 2019 Abstract: Rapid increase of intracellular synthesis of specific histone-like Dps protein that binds DNA to protect the genome against deleterious factors leads to in cellulo crystallization—one of the most curious processes in the area of life science at the moment. However, the actual structure of the Dps–DNA co-crystals remained uncertain in the details for more than two decades. -
PROGRAMME ABSTRACTS AGM Papers
The Palaeontological Association 63rd Annual Meeting 15th–21st December 2019 University of Valencia, Spain PROGRAMME ABSTRACTS AGM papers Palaeontological Association 6 ANNUAL MEETING ANNUAL MEETING Palaeontological Association 1 The Palaeontological Association 63rd Annual Meeting 15th–21st December 2019 University of Valencia The programme and abstracts for the 63rd Annual Meeting of the Palaeontological Association are provided after the following information and summary of the meeting. An easy-to-navigate pocket guide to the Meeting is also available to delegates. Venue The Annual Meeting will take place in the faculties of Philosophy and Philology on the Blasco Ibañez Campus of the University of Valencia. The Symposium will take place in the Salon Actos Manuel Sanchis Guarner in the Faculty of Philology. The main meeting will take place in this and a nearby lecture theatre (Salon Actos, Faculty of Philosophy). There is a Metro stop just a few metres from the campus that connects with the centre of the city in 5-10 minutes (Line 3-Facultats). Alternatively, the campus is a 20-25 minute walk from the ‘old town’. Registration Registration will be possible before and during the Symposium at the entrance to the Salon Actos in the Faculty of Philosophy. During the main meeting the registration desk will continue to be available in the Faculty of Philosophy. Oral Presentations All speakers (apart from the symposium speakers) have been allocated 15 minutes. It is therefore expected that you prepare to speak for no more than 12 minutes to allow time for questions and switching between presenters. We have a number of parallel sessions in nearby lecture theatres so timing will be especially important. -
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. -
Magnesium Silicate on Chloroquine Phosphate, Against Plasmodium Berghei
Ajuvant effect of a Synthetic Aluminium – Magnesium Silicate on chloroquine phosphate, against Plasmodium berghei. * Ezeibe Maduike, Elendu – Eleke Nnenna, Okoroafor Obianuju and Ngene Augustine Department of Veterinary Medicine, University of Nigeria, Nsukka. *Corresponding authur [email protected] Abstract Effect of a synthetic Aluminium – Magnesium Silicate (AMS) on antiplasmodial activity of chloroquine was tested.Plasmodium berghei infected mice were treated with 7 mg/ kg, 5 mg / kg and 3 mg / kg chloroquine, respectively.Subgroups in each experiment were treated with chloroquine alone and with chloroquine in AMS.Parasitaemia (%) of the group treated with 7 mg / kg was higher than that of the control.At 5 mg / kg, chloroquine treatment reduced parasitaemia from 3.60 to 2.46 (P = ).Incorporating chloroquine in AMS improved its ability to reduce P.berghei parasitaemia at 5 mg /kg and at 3 mg / kg, from 2.46 0.21 to 1.57 0.25 (P = ) and from 3.82 0.06 to 2.12 0.08 (P = ). It also increased mortality of mice treated at 7 mg / kg from 20 to 80 % (P = ). Key words: Antiplasmodial resistance, chloroquine toxicity, Aluminium – Magnesium Silicate, chloroquine phosphate. Background. Nature Precedings : hdl:10101/npre.2012.6749.1 Posted 2 Jan 2012 Protozoan parasites of the genus plasmodium are causative agents of malaria1, 2. Malaria is a zoonotic disease , affecting man, zoo primates, avian species and rodents3,4. It has also been reported that when species of plasmodium which infect animals were passaged in human volunteers they produced malaria in man5. In humans, malaria is cause of between one to three million deaths in sub saharan Africa every year 6.Malaria is not only an effect of poverty it is also a cause of poverty7.To combat malaria, most countries in Africa spend upto 40 % of their public health budget on the disease annually8. -
Biomineralization of Carbonates in Modern Microbial Sediments and Its Implications for CO₂ Sequestration
Scholars' Mine Doctoral Dissertations Student Theses and Dissertations Spring 2014 Biomineralization of carbonates in modern microbial sediments and its implications for CO₂ sequestration Varun Gnanaprian Paul Follow this and additional works at: https://scholarsmine.mst.edu/doctoral_dissertations Part of the Geology Commons, and the Geophysics and Seismology Commons Department: Geosciences and Geological and Petroleum Engineering Recommended Citation Paul, Varun Gnanaprian, "Biomineralization of carbonates in modern microbial sediments and its implications for CO₂ sequestration" (2014). Doctoral Dissertations. 2138. https://scholarsmine.mst.edu/doctoral_dissertations/2138 This thesis is brought to you by Scholars' Mine, a service of the Missouri S&T Library and Learning Resources. This work is protected by U. S. Copyright Law. Unauthorized use including reproduction for redistribution requires the permission of the copyright holder. For more information, please contact [email protected]. BIOMINERALIZATION OF CARBONATES IN MODERN MICROBIAL SEDIMENTS AND ITS IMPLICATIONS FOR CO2 SEQUESTRATION by VARUN GNANAPRIAN PAUL A DISSERTATION Presented to the Faculty of the Graduate School of the MISSOURI UNIVERSITY OF SCIENCE AND TECHNOLOGY In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY in GEOLOGY AND GEOPHYSICS 2014 Approved by: David J. Wronkiewicz, Advisor Melanie R. Mormile, Co-Advisor Francisca Oboh-Ikuenobe Wan Yang Jamie S. Foster © 2014 Varun Gnanaprian Paul All Rights Reserved iii PUBLICATION DISSERTATION OPTION This dissertation is organized into four main sections. Section 1 (pages 1 to 17) introduces the two main research projects undertaken and states the hypotheses and objectives. Section 2 (pages 18 to 35) describes the sites, materials used and the experimental methodology that has been employed in all the projects. -
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. -
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 -
Microorganisms
microorganisms Article Comparative Proteomics Analysis Reveals New Features of the Oxidative Stress Response in the Polyextremophilic Bacterium Deinococcus radiodurans Lihua Gao, Zhengfu Zhou, Xiaonan Chen, Wei Zhang, Min Lin and Ming Chen * Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; [email protected] (L.G.); [email protected] (Z.Z.); [email protected] (X.C.); [email protected] (W.Z.); [email protected] (M.L.) * Correspondence: [email protected] Received: 20 February 2020; Accepted: 19 March 2020; Published: 23 March 2020 Abstract: Deinococcus radiodurans is known for its extreme resistance to ionizing radiation, oxidative stress, and other DNA-damaging agents. The robustness of this bacterium primarily originates from its strong oxidative resistance mechanisms. Hundreds of genes have been demonstrated to contribute to oxidative resistance in D. radiodurans; however, the antioxidant mechanisms have not been fully characterized. In this study, comparative proteomics analysis of D. radiodurans grown under normal and oxidative stress conditions was conducted using label-free quantitative proteomics. The abundances of 852 of 1700 proteins were found to significantly differ between the two groups. These differential proteins are mainly associated with translation, DNA repair and recombination, response to stresses, transcription, and cell wall organization. Highly upregulated expression was observed for ribosomal proteins such as RplB, Rpsl, RpsR, DNA damage response proteins (DdrA, DdrB), DNA repair proteins (RecN, RecA), and transcriptional regulators (members of TetR, AsnC, and GntR families, DdrI). The functional analysis of proteins in response to oxidative stress is discussed in detail. This study reveals the global protein expression profile of D. radiodurans in response to oxidative stress and provides new insights into the regulatory mechanism of oxidative resistance in D. -
Microbial Lithification in Marine Stromatolites and Hypersaline Mats
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by RERO DOC Digital Library Published in Trends in Microbiology 13,9 : 429-438, 2005, 1 which should be used for any reference to this work Microbial lithification in marine stromatolites and hypersaline mats Christophe Dupraz1 and Pieter T. Visscher2 1Institut de Ge´ ologie, Universite´ de Neuchaˆ tel, Rue Emile-Argand 11, CP 2, CH-2007 Neuchaˆ tel, Switzerland 2Center for Integrative Geosciences, Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Road, Groton, Connecticut, 06340, USA Lithification in microbial ecosystems occurs when pre- crucial role in regulating sedimentation and global bio- cipitation of minerals outweighs dissolution. Although geochemical cycles. the formation of various minerals can result from After the decline of stromatolites in the late Proterozoic microbial metabolism, carbonate precipitation is pos- (ca. 543 million years before present), microbially induced sibly the most important process that impacts global and/or controlled precipitation continued throughout the carbon cycling. Recent investigations have produced geological record as an active and essential player in most models for stromatolite formation in open marine aquatic ecosystems [9,10]. Although less abundant than in environments and lithification in shallow hypersaline the Precambrian, microbial precipitation is observed in a lakes, which could be highly relevant for interpreting the multitude of semi-confined (physically or chemically)