Search

Your search keyword '"Pearson, Ann"' showing total 577 results
Start Over Author "Pearson, Ann"
577 results on '"Pearson, Ann"'

3. Fundamentally different global marine nitrogen cycling in response to severe ocean deoxygenation

Author

Naafs, B David A, Monteiro, Fanny M, Pearson, Ann, Higgins, Meytal B, Pancost, Richard D, and Ridgwell, Andy

Subjects
Earth Sciences, Biological Sciences, Ecology, Life Below Water, nitrogen, ocean, OAE, Cretaceous, anthropogenic
Abstract

The present-day marine nitrogen (N) cycle is strongly regulated by biology. Deficiencies in the availability of fixed and readily bioavailable nitrogen relative to phosphate (P) in the surface ocean are largely corrected by the activity of diazotrophs. This feedback system, termed the "nitrostat," is thought to have provided close regulation of fixed-N speciation and inventory relative to P since the Proterozoic. In contrast, during intervals of intense deoxygenation such as Cretaceous ocean anoxic event (OAE) 2, a few regional sedimentary δ15N records hint at the existence of a different mode of marine N cycling in which ammonium plays a major role in regulating export production. However, the global-scale dynamics during this time remain unknown. Here, using an Earth System model and taking the example of OAE 2, we provide insights into the global marine nitrogen cycle under severe ocean deoxygenation. Specifically, we find that the ocean can exhibit fundamental transitions in the species of nitrogen dominating the fixed-N inventory--from nitrate (NO3 -) to ammonium (NH4 +)--and that as this transition occurs, the inventory can partially collapse relative to P due to progressive spatial decoupling between the loci of NH4 + oxidation, NO3 - reduction, and nitrogen fixation. This finding is relatively independent of the specific state of ocean circulation and is consistent with nitrogen isotope and redox proxy data. The substantive reduction in the ocean fixed-N inventory at an intermediate state of deoxygenation may represent a biogeochemical vulnerability with potential implications for past and future (warmer) oceans.

Published
2019

8. Interlaboratory Comparison of Branched GDGT Temperature and pH Proxies Using Soils and Lipid Extracts

Author

De Jonge, Cindy, Peterse, Francien, Nierop, Klaas G.J., Blattmann, Thomas M., Alexandre, Marcelo, Ansanay-Alex, Salome, Austin, Thomas, Babin, Mathieu, Bard, Edouard, Bauersachs, Thorsten, Blewett, Jerome, Boehman, Brenna, Castañeda, Isla S., Chen, Junhui, Conti, Martina L.G., Contreras, Sergio, Cordes, Julia, Davtian, Nina, van Dongen, Bart, Duncan, Bella, Elling, Felix J., Galy, Valier, Gao, Shaopeng, Hefter, Jens, Hinrichs, Kai Uwe, Helling, Mitchell R., Hoorweg, Mariska, Hopmans, Ellen, Hou, Juzhi, Huang, Yongsong, Huguet, Arnaud, Jia, Guodong, Karger, Cornelia, Keely, Brendan J., Kusch, Stephanie, Li, Hui, Liang, Jie, Lipp, Julius S., Liu, Weiguo, Lu, Hongxuan, Mangelsdorf, Kai, Manners, Hayley, Martinez Garcia, Alfredo, Menot, Guillemette, Mollenhauer, Gesine, Naafs, B. David A., Naeher, Sebastian, O'Connor, Lauren K., Pearce, Ethan M., Pearson, Ann, Rao, Zhiguo, Rodrigo-Gámiz, Marta, Rosendahl, Chris, Rostek, Frauke, Bao, Rui, Sanyal, Prasanta, Schubotz, Florence, Scott, Wesley, Sen, Rahul, Sluijs, Appy, Smittenberg, Rienk, Stefanescu, Ioana, Sun, Jia, Sutton, Paul, Tierney, Jess, Tejos, Eduardo, Villanueva, Joan, Wang, Huanye, Werne, Josef, Yamamoto, Masanobu, Yang, Huan, Zhou, Aifeng, De Jonge, Cindy, Peterse, Francien, Nierop, Klaas G.J., Blattmann, Thomas M., Alexandre, Marcelo, Ansanay-Alex, Salome, Austin, Thomas, Babin, Mathieu, Bard, Edouard, Bauersachs, Thorsten, Blewett, Jerome, Boehman, Brenna, Castañeda, Isla S., Chen, Junhui, Conti, Martina L.G., Contreras, Sergio, Cordes, Julia, Davtian, Nina, van Dongen, Bart, Duncan, Bella, Elling, Felix J., Galy, Valier, Gao, Shaopeng, Hefter, Jens, Hinrichs, Kai Uwe, Helling, Mitchell R., Hoorweg, Mariska, Hopmans, Ellen, Hou, Juzhi, Huang, Yongsong, Huguet, Arnaud, Jia, Guodong, Karger, Cornelia, Keely, Brendan J., Kusch, Stephanie, Li, Hui, Liang, Jie, Lipp, Julius S., Liu, Weiguo, Lu, Hongxuan, Mangelsdorf, Kai, Manners, Hayley, Martinez Garcia, Alfredo, Menot, Guillemette, Mollenhauer, Gesine, Naafs, B. David A., Naeher, Sebastian, O'Connor, Lauren K., Pearce, Ethan M., Pearson, Ann, Rao, Zhiguo, Rodrigo-Gámiz, Marta, Rosendahl, Chris, Rostek, Frauke, Bao, Rui, Sanyal, Prasanta, Schubotz, Florence, Scott, Wesley, Sen, Rahul, Sluijs, Appy, Smittenberg, Rienk, Stefanescu, Ioana, Sun, Jia, Sutton, Paul, Tierney, Jess, Tejos, Eduardo, Villanueva, Joan, Wang, Huanye, Werne, Josef, Yamamoto, Masanobu, Yang, Huan, and Zhou, Aifeng

Abstract

Ratios of glycerol dialkyl glycerol tetraethers (GDGT), which are membrane lipids of bacteria and archaea, are at the base of several paleoenvironmental proxies. They are frequently applied to soils as well as lake- and marine sediments to generate records of past temperature and soil pH. To derive meaningful environmental information from these reconstructions, high analytical reproducibility is required. Based on submitted results by 39 laboratories from across the world, which employ a diverse range of analytical and quantification methods, we explored the reproducibility of brGDGT-based proxies (MBT′5ME, IR, and #ringstetra) measured on four soil samples and four soil lipid extracts. Correct identification and integration of 5- and 6-methyl brGDGTs is a prerequisite for the robust calculation of proxy values, but this can be challenging as indicated by the large inter-interlaboratory variation. The exclusion of statistical outliers improves the reproducibility, where the remaining uncertainty translates into a temperature offset from median proxy values of 0.3–0.9°C and a pH offset of 0.05–0.3. There is no apparent systematic impact of the extraction method and sample preparation steps on the brGDGT ratios. Although reported GDGT concentrations are generally consistent within laboratories, they vary greatly between laboratories. This large variability in brGDGT quantification may relate to variations in ionization efficiency or specific mass spectrometer settings possibly impacting the response of brGDGTs masses relative to that of the internal standard used. While ratio values of GDGT are generally comparable, quantities can currently not be compared between laboratories.

Published
2024

10. Influence of ammonia oxidation rate on thaumarchaeal lipid composition and the TEX86 temperature proxy.

Author

Hurley, Sarah, Elling, Felix, Könneke, Martin, Buchwald, Carolyn, Wankel, Scott, Santoro, Alyson, Lipp, Julius, Hinrichs, Kai-Uwe, and Pearson, Ann

Subjects
GDGT, TEX86, Thaumarchaeota, continuous culture, nitrification, Ammonia, Archaea, Culture Techniques, Energy Metabolism, Glyceryl Ethers, Lipid Metabolism, Oceans and Seas, Oxidation-Reduction, Paleontology, Temperature
Abstract

Archaeal membrane lipids known as glycerol dibiphytanyl glycerol tetraethers (GDGTs) are the basis of the TEX86 paleotemperature proxy. Because GDGTs preserved in marine sediments are thought to originate mainly from planktonic, ammonia-oxidizing Thaumarchaeota, the basis of the correlation between TEX86 and sea surface temperature (SST) remains unresolved: How does TEX86 predict surface temperatures, when maximum thaumarchaeal activity occurs below the surface mixed layer and TEX86 does not covary with in situ growth temperatures? Here we used isothermal studies of the model thaumarchaeon Nitrosopumilus maritimus SCM1 to investigate how GDGT composition changes in response to ammonia oxidation rate. We used continuous culture methods to avoid potential confounding variables that can be associated with experiments in batch cultures. The results show that the ring index scales inversely (R(2) = 0.82) with ammonia oxidation rate (ϕ), indicating that GDGT cyclization depends on available reducing power. Correspondingly, the TEX86 ratio decreases by an equivalent of 5.4 °C of calculated temperature over a 5.5 fmol·cell(-1)·d(-1) increase in ϕ. This finding reconciles other recent experiments that have identified growth stage and oxygen availability as variables affecting TEX86 Depth profiles from the marine water column show minimum TEX86 values at the depth of maximum nitrification rates, consistent with our chemostat results. Our findings suggest that the TEX86 signal exported from the water column is influenced by the dynamics of ammonia oxidation. Thus, the global TEX86-SST calibration potentially represents a composite of regional correlations based on nutrient dynamics and global correlations based on archaeal community composition and temperature.

Published
2016

11. Carbon and Sulfur Cycling below the Chemocline in a Meromictic Lake and the Identification of a Novel Taxonomic Lineage in the FCB Superphylum, Candidatus Aegiribacteria

Author

Hamilton, Trinity L, Bovee, Roderick J, Sattin, Sarah R, Mohr, Wiebke, Gilhooly, William P, Lyons, Timothy W, Pearson, Ann, and Macalady, Jennifer L

Subjects
Microbiology, Biological Sciences, Ecology, Genetics, Human Genome, meromictic, euxinia, DSR, Clostridia, sulfate reducing bacteria, Deltaproteobacteria, sulfide, sulfate, Environmental Science and Management, Soil Sciences, Medical microbiology
Abstract

Mahoney Lake in British Columbia is an extreme meromictic system with unusually high levels of sulfate and sulfide present in the water column. As is common in strongly stratified lakes, Mahoney Lake hosts a dense, sulfide-oxidizing phototrophic microbial community where light reaches the chemocline. Below this "plate," the euxinic hypolimnion is anoxic, eutrophic, saline, and rich in sulfide, polysulfides, elemental sulfur, and other sulfur intermediates. While much is known regarding microbial communities in sunlit portions of euxinic systems, the composition and genetic potential of organisms living at aphotic depths have rarely been studied. Metagenomic sequencing of samples from the hypolimnion and the underlying sediments of Mahoney Lake indicate that multiple taxa contribute to sulfate reduction below the chemocline and that the hypolimnion and sediments each support distinct populations of sulfate reducing bacteria (SRB) that differ from the SRB populations observed in the chemocline. After assembling and binning the metagenomic datasets, we recovered near-complete genomes of dominant populations including two Deltaproteobacteria. One of the deltaproteobacterial genomes encoded a 16S rRNA sequence that was most closely related to the sulfur-disproportionating genus Dissulfuribacter and the other encoded a 16S rRNA sequence that was most closely related to the fatty acid- and aromatic acid-degrading genus Syntrophus. We also recovered two near-complete genomes of Firmicutes species. Analysis of concatenated ribosomal protein trees suggests these genomes are most closely related to extremely alkaliphilic genera Alkaliphilus and Dethiobacter. Our metagenomic data indicate that these Firmicutes contribute to carbon cycling below the chemocline. Lastly, we recovered a nearly complete genome from the sediment metagenome which represents a new genus within the FCB (Fibrobacteres, Chlorobi, Bacteroidetes) superphylum. Consistent with the geochemical data, we found little or no evidence for organisms capable of sulfide oxidation in the aphotic zone below the chemocline. Instead, comparison of functional genes below the chemocline are consistent with recovery of multiple populations capable of reducing oxidized sulfur. Our data support previous observations that at least some of the sulfide necessary to support the dense population of phototrophs in the chemocline is supplied from sulfate reduction in the hypolimnion and sediments. These studies provide key insights regarding the taxonomic and functional diversity within a euxinic environment and highlight the complexity of biogeochemical carbon and sulfur cycling necessary to maintain euxinia.

Published
2016

14. Lipids (Bacteria and Archaea)

Author

Pearson, Ann, White, William M., editor, Casey, William H., Associate Editor, Marty, Bernhard, Associate Editor, and Yurimoto, Hisayoshi, Associate Editor

Published
2018
Full Text
View/download PDF

19. Spatial and Temporal Patterns in Petrogenic Organic Carbon Mobilisation during the Paleocene-Eocene Thermal Maximum

Author

Hollingsworth, Emily H, primary, Elling, Felix J, additional, Badger, Marcus Peter Sebastian, additional, Pancost, Richard, additional, Dickson, Alexander, additional, Rees-Owen, Rhian L., additional, Papadomanolaki, Nina Maria, additional, Pearson, Ann, additional, Sluijs, Appy, additional, Freeman, Katherine H, additional, Baczynski, Allison A, additional, Foster, Gavin L, additional, Whiteside, Jessica, additional, and Inglis, Gordon N., additional

Published
2023
Full Text
View/download PDF

33. Nitrifying Microorganisms Linked to Biotransformation of Perfluoroalkyl Sulfonamido Precursors from Legacy Aqueous Film-Forming Foams

Author

Ruyle, Bridger J., primary, Schultes, Lara, additional, Akob, Denise M., additional, Harris, Cassandra R., additional, Lorah, Michelle M., additional, Vojta, Simon, additional, Becanova, Jitka, additional, McCann, Shelley, additional, Pickard, Heidi M., additional, Pearson, Ann, additional, Lohmann, Rainer, additional, Vecitis, Chad D., additional, and Sunderland, Elsie M., additional

Published
2023
Full Text
View/download PDF

34. Toward a Cenozoic history of atmospheric CO 2

Author

Hönisch, Bärbel, Royer, Dana L., Breecker, Daniel O., Polissar, Pratigya J., Bowen, Gabriel J., Henehan, Michael J., Cui, Ying, Steinthorsdottir, Margret, McElwain, Jennifer C., Kohn, Matthew J., Pearson, Ann, Phelps, Samuel R., Uno, Kevin T., Ridgwell, Andy, Anagnostou, Eleni, Austermann, Jacqueline, Badger, Marcus P. S., Barclay, Richard S., Bijl, Peter K., Chalk, Thomas B., Scotese, Christopher R., de la Vega, Elwyn, DeConto, Robert M., Dyez, Kelsey A., Ferrini, Vicki, Franks, Peter J., Giulivi, Claudia F., Gutjahr, Marcus, Harper, Dustin T., Haynes, Laura L., Huber, Matthew, Snell, Kathryn E., Keisling, Benjamin A., Konrad, Wilfried, Lowenstein, Tim K., Malinverno, Alberto, Guillermic, Maxence, Mejía, Luz María, Milligan, Joseph N., Morton, John J., Nordt, Lee, Whiteford, Ross, Roth-Nebelsick, Anita, Rugenstein, Jeremy K. C., Schaller, Morgan F., Sheldon, Nathan D., Sosdian, Sindia, Wilkes, Elise B., Witkowski, Caitlyn R., Zhang, Yi Ge, Anderson, Lloyd, Beerling, David J., Bolton, Clara, Cerling, Thure E., Cotton, Jennifer M., Da, Jiawei, Ekart, Douglas D., Foster, Gavin L., Greenwood, David R., Hyland, Ethan G., Jagniecki, Elliot A., Jasper, John P., Kowalczyk, Jennifer B., Kunzmann, Lutz, Kürschner, Wolfram M., Lawrence, Charles E., Lear, Caroline H., Martínez-Botí, Miguel A., Maxbauer, Daniel P., Montagna, Paolo, Naafs, B. David A., Rae, James W. B., Raitzsch, Markus, Retallack, Gregory J., Ring, Simon J., Seki, Osamu, Sepúlveda, Julio, Sinha, Ashish, Tesfamichael, Tekie F., Tripati, Aradhna, van der Burgh, Johan, Yu, Jimin, Zachos, James C., Zhang, Laiming, Hönisch, Bärbel, Royer, Dana L., Breecker, Daniel O., Polissar, Pratigya J., Bowen, Gabriel J., Henehan, Michael J., Cui, Ying, Steinthorsdottir, Margret, McElwain, Jennifer C., Kohn, Matthew J., Pearson, Ann, Phelps, Samuel R., Uno, Kevin T., Ridgwell, Andy, Anagnostou, Eleni, Austermann, Jacqueline, Badger, Marcus P. S., Barclay, Richard S., Bijl, Peter K., Chalk, Thomas B., Scotese, Christopher R., de la Vega, Elwyn, DeConto, Robert M., Dyez, Kelsey A., Ferrini, Vicki, Franks, Peter J., Giulivi, Claudia F., Gutjahr, Marcus, Harper, Dustin T., Haynes, Laura L., Huber, Matthew, Snell, Kathryn E., Keisling, Benjamin A., Konrad, Wilfried, Lowenstein, Tim K., Malinverno, Alberto, Guillermic, Maxence, Mejía, Luz María, Milligan, Joseph N., Morton, John J., Nordt, Lee, Whiteford, Ross, Roth-Nebelsick, Anita, Rugenstein, Jeremy K. C., Schaller, Morgan F., Sheldon, Nathan D., Sosdian, Sindia, Wilkes, Elise B., Witkowski, Caitlyn R., Zhang, Yi Ge, Anderson, Lloyd, Beerling, David J., Bolton, Clara, Cerling, Thure E., Cotton, Jennifer M., Da, Jiawei, Ekart, Douglas D., Foster, Gavin L., Greenwood, David R., Hyland, Ethan G., Jagniecki, Elliot A., Jasper, John P., Kowalczyk, Jennifer B., Kunzmann, Lutz, Kürschner, Wolfram M., Lawrence, Charles E., Lear, Caroline H., Martínez-Botí, Miguel A., Maxbauer, Daniel P., Montagna, Paolo, Naafs, B. David A., Rae, James W. B., Raitzsch, Markus, Retallack, Gregory J., Ring, Simon J., Seki, Osamu, Sepúlveda, Julio, Sinha, Ashish, Tesfamichael, Tekie F., Tripati, Aradhna, van der Burgh, Johan, Yu, Jimin, Zachos, James C., and Zhang, Laiming

Abstract

The geological record encodes the relationship between climate and atmospheric carbon dioxide (CO 2 ) over long and short timescales, as well as potential drivers of evolutionary transitions. However, reconstructing CO 2 beyond direct measurements requires the use of paleoproxies and herein lies the challenge, as proxies differ in their assumptions, degree of understanding, and even reconstructed values. In this study, we critically evaluated, categorized, and integrated available proxies to create a high-fidelity and transparently constructed atmospheric CO 2 record spanning the past 66 million years. This newly constructed record provides clearer evidence for higher Earth system sensitivity in the past and for the role of CO 2 thresholds in biological and cryosphere evolution. Editor’s summary The concentration of atmospheric carbon dioxide is a fundamental driver of climate, but its value is difficult to determine for times older than the roughly 800,000 years for which ice core records are available. The Cenozoic Carbon dioxide Proxy Integration Project (CenCO2PIP) Consortium assessed a comprehensive collection of proxy determinations to define the atmospheric carbon dioxide record for the past 66 million years. This synthesis provides the most complete record yet available and will help to better establish the role of carbon dioxide in climate, biological, and cryosphere evolution. — H. Jesse Smith

Published
2023
Full Text
View/download PDF

35. Nitrifying Microorganisms Linked to Biotransformation of Perfluoroalkyl Sulfonamido Precursors from Legacy Aqueous Film-Forming Foams

Author

Ruyle, Bridger J., Schultes, Lara, Akob, Denise A., Harris, Cassandra R., Lorah, Michelle M., Votja, Simon, Becanova, Jitka, McCann, Shelley, Pickard, Heidi M., Pearson, Ann, Lohmann, Rainer, Vecitis, Chad D., Sunderland, Elsie M., Ruyle, Bridger J., Schultes, Lara, Akob, Denise A., Harris, Cassandra R., Lorah, Michelle M., Votja, Simon, Becanova, Jitka, McCann, Shelley, Pickard, Heidi M., Pearson, Ann, Lohmann, Rainer, Vecitis, Chad D., and Sunderland, Elsie M.

Abstract

Drinking water supplies across the United States have been contaminated by firefighting and fire-training activities that use aqueous film-forming foams (AFFF) containing per- and polyfluoroalkyl substances (PFAS). Much of the AFFF is manufactured using electrochemical fluorination by 3M. Precursors with six perfluorinated carbons (C6) and non-fluorinated amine substituents make up approximately one-third of the PFAS in 3M AFFF. C6 precursors can be transformed through nitrification (microbial oxidation) of amine moieties into perfluorohexane sulfonate (PFHxS), a compound of regulatory concern. Here, we report biotransformation of the most abundant C6 sulfonamido precursors in 3M AFFF with available commercial standards (FHxSA, PFHxSAm, and PFHxSAmS) in microcosms representative of the groundwater/surface water boundary. Results show rapid (<1 day) biosorption to living cells by precursors but slow biotransformation into PFHxS (1–100 pM day–1). The transformation pathway includes one or two nitrification steps and is supported by the detection of key intermediates using high-resolution mass spectrometry. Increasing nitrate concentrations and total abundance of nitrifying taxa occur in parallel with precursor biotransformation. Together, these data provide multiple lines of evidence supporting microbially limited biotransformation of C6 sulfonamido precursors involving ammonia-oxidizing archaea (Nitrososphaeria) and nitrite-oxidizing bacteria (Nitrospina). Further elucidation of interrelationships between precursor biotransformation and nitrogen cycling in ecosystems would help inform site remediation efforts.

Published
2023

36. A new and improved protocol for extraction of intact polar membrane lipids from archaea

Author

Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Evans, Thomas W, Elling, Felix J, Li, Yongli, Pearson, Ann, Summons, Roger E, Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Evans, Thomas W, Elling, Felix J, Li, Yongli, Pearson, Ann, and Summons, Roger E

Published
2023

Catalog

Books, media, physical & digital resources
See catalog results