1
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LaBute B, Fong J, Ziaee F, Gombar R, Stover M, Beaudin T, Badalova M, Geng Q, Corchis-Scott R, Podadera A, Lago K, Xu Z, Lim F, Chiu F, Fu M, Nie X, Wu Y, Quan C, Hamm C, McKay RM, Ng K, Porter LA, Tong Y. Evaluating and optimizing Acid-pH and Direct Lysis RNA extraction for SARS-CoV-2 RNA detection in whole saliva. Sci Rep 2024; 14:7017. [PMID: 38527999 DOI: 10.1038/s41598-024-54183-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 02/09/2024] [Indexed: 03/27/2024] Open
Abstract
COVID-19 has been a global public health and economic challenge. Screening for the SARS-CoV-2 virus has been a key part of disease mitigation while the world continues to move forward, and lessons learned will benefit disease detection beyond COVID-19. Saliva specimen collection offers a less invasive, time- and cost-effective alternative to standard nasopharyngeal swabs. We optimized two different methods of saliva sample processing for RT-qPCR testing. Two methods were optimized to provide two cost-efficient ways to do testing for a minimum of four samples by pooling in a 2.0 mL tube and decrease the need for more highly trained personnel. Acid-pH-based RNA extraction method can be done without the need for expensive kits. Direct Lysis is a quick one-step reaction that can be applied quickly. Our optimized Acid-pH and Direct Lysis protocols are reliable and reproducible, detecting the beta-2 microglobulin (B2M) mRNA in saliva as an internal control from 97 to 96.7% of samples, respectively. The cycle threshold (Ct) values for B2M were significantly higher in the Direct Lysis protocol than in the Acid-pH protocol. The limit of detection for N1 gene was higher in Direct Lysis at ≤ 5 copies/μL than Acid-pH. Saliva samples collected over the course of several days from two COVID-positive individuals demonstrated Ct values for N1 that were consistently higher from Direct Lysis compared to Acid-pH. Collectively, this work supports that each of these techniques can be used to screen for SARS-CoV-2 in saliva for a cost-effective screening platform.
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Affiliation(s)
- Brayden LaBute
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, Canada
| | - Jackie Fong
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, Canada
- WE-SPARK Health Institute, University of Windsor, Windsor, ON, Canada
| | - Farinaz Ziaee
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, Canada
| | - Robert Gombar
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, Canada
| | - Mathew Stover
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, Canada
| | - Terry Beaudin
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, Canada
| | - Maria Badalova
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, Canada
| | - Qiudi Geng
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada
| | - Ryland Corchis-Scott
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada
| | - Ana Podadera
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, Canada
| | - Kyle Lago
- WE-SPARK Health Institute, University of Windsor, Windsor, ON, Canada
| | - ZhenHuan Xu
- Aumintec Research Inc., Richmond Hill, ON, Canada
| | - Fievel Lim
- Aumintec Research Inc., Richmond Hill, ON, Canada
| | - Felix Chiu
- Aumintec Research Inc., Richmond Hill, ON, Canada
| | - Minghua Fu
- Aumintec Research Inc., Richmond Hill, ON, Canada
| | - Xiaofeng Nie
- Aumintec Research Inc., Richmond Hill, ON, Canada
| | - Yuanmin Wu
- Aumintec Research Inc., Richmond Hill, ON, Canada
| | | | - Caroline Hamm
- WE-SPARK Health Institute, University of Windsor, Windsor, ON, Canada
- Windsor Regional Hospital, Windsor, ON, Canada
| | - R Michael McKay
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada
| | - Kenneth Ng
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, Canada
- WE-SPARK Health Institute, University of Windsor, Windsor, ON, Canada
| | - Lisa A Porter
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, Canada.
- WE-SPARK Health Institute, University of Windsor, Windsor, ON, Canada.
| | - Yufeng Tong
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, Canada.
- WE-SPARK Health Institute, University of Windsor, Windsor, ON, Canada.
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2
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Wong CH, Zhang Z, Eid W, Plaza-Diaz J, Kabir P, Wan S, Jia JJ, Mercier E, Thakali O, Pisharody L, Hegazy N, Stephenson SE, Fang W, Nguyen TB, Ramsay NT, McKay RM, Corchis-Scott R, MacKenzie AE, Graber TE, D' Aoust PM, Delatolla R. Rapidly developed, optimized, and applied wastewater surveillance system for real-time monitoring of low-incidence, high-impact MPOX outbreak. J Water Health 2023; 21:1264-1276. [PMID: 37756194 PMCID: wh_2023_145 DOI: 10.2166/wh.2023.145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
Recent MPOX viral resurgences have mobilized public health agencies around the world. Recognizing the significant risk of MPOX outbreaks, large-scale human testing, and immunization campaigns have been initiated by local, national, and global public health authorities. Recently, traditional clinical surveillance campaigns for MPOX have been complemented with wastewater surveillance (WWS), building on the effectiveness of existing wastewater programs that were built to monitor SARS-CoV-2 and recently expanded to include influenza and respiratory syncytial virus surveillance in wastewaters. In the present study, we demonstrate and further support the finding that MPOX viral fragments agglomerate in the wastewater solids fraction. Furthermore, this study demonstrates that the current, most commonly used MPOX assays are equally effective at detecting low titers of MPOX viral signal in wastewaters. Finally, MPOX WWS is shown to be more effective at passively tracking outbreaks and/or resurgences of the disease than clinical testing alone in smaller communities with low human clinical case counts of MPOX.
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Affiliation(s)
- Chandler H Wong
- Department of Civil Engineering, University of Ottawa, Ottawa K1N 6N5, Canada E-mail:
| | - Zhihao Zhang
- Department of Civil Engineering, University of Ottawa, Ottawa K1N 6N5, Canada
| | - Walaa Eid
- Children's Hospital of Eastern Ontario Research Institute, Ottawa K1H 8L1, Canada
| | - Julio Plaza-Diaz
- Children's Hospital of Eastern Ontario Research Institute, Ottawa K1H 8L1, Canada
| | - Pervez Kabir
- Department of Civil Engineering, University of Ottawa, Ottawa K1N 6N5, Canada
| | - Shen Wan
- Department of Civil Engineering, University of Ottawa, Ottawa K1N 6N5, Canada
| | - Jian-Jun Jia
- Department of Civil Engineering, University of Ottawa, Ottawa K1N 6N5, Canada
| | - Elisabeth Mercier
- Department of Civil Engineering, University of Ottawa, Ottawa K1N 6N5, Canada
| | - Ocean Thakali
- Department of Civil Engineering, University of Ottawa, Ottawa K1N 6N5, Canada
| | - Lakshmi Pisharody
- Department of Civil Engineering, University of Ottawa, Ottawa K1N 6N5, Canada
| | - Nada Hegazy
- Department of Civil Engineering, University of Ottawa, Ottawa K1N 6N5, Canada
| | - Sean E Stephenson
- Children's Hospital of Eastern Ontario Research Institute, Ottawa K1H 8L1, Canada
| | - Wanting Fang
- Department of Civil Engineering, University of Ottawa, Ottawa K1N 6N5, Canada
| | - Tram B Nguyen
- Department of Civil Engineering, University of Ottawa, Ottawa K1N 6N5, Canada
| | - Nathan T Ramsay
- Department of Civil Engineering, University of Ottawa, Ottawa K1N 6N5, Canada
| | - R Michael McKay
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Ryland Corchis-Scott
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Alex E MacKenzie
- Children's Hospital of Eastern Ontario Research Institute, Ottawa K1H 8L1, Canada
| | - Tyson E Graber
- Children's Hospital of Eastern Ontario Research Institute, Ottawa K1H 8L1, Canada
| | - Patrick M D' Aoust
- Department of Civil Engineering, University of Ottawa, Ottawa K1N 6N5, Canada
| | - Robert Delatolla
- Department of Civil Engineering, University of Ottawa, Ottawa K1N 6N5, Canada
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3
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Corchis-Scott R, Geng Q, Al Riahi AM, Labak A, Podadera A, Ng KKS, Porter LA, Tong Y, Dixon JC, Menard SL, Seth R, McKay RM. Actionable wastewater surveillance: application to a university residence hall during the transition between Delta and Omicron resurgences of COVID-19. Front Public Health 2023; 11:1139423. [PMID: 37265515 PMCID: PMC10230041 DOI: 10.3389/fpubh.2023.1139423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Accepted: 04/28/2023] [Indexed: 06/03/2023] Open
Abstract
Wastewater surveillance has gained traction during the COVID-19 pandemic as an effective and non-biased means to track community infection. While most surveillance relies on samples collected at municipal wastewater treatment plants, surveillance is more actionable when samples are collected "upstream" where mitigation of transmission is tractable. This report describes the results of wastewater surveillance for SARS-CoV-2 at residence halls on a university campus aimed at preventing outbreak escalation by mitigating community spread. Another goal was to estimate fecal shedding rates of SARS-CoV-2 in a non-clinical setting. Passive sampling devices were deployed in sewer laterals originating from residence halls at a frequency of twice weekly during fall 2021 as the Delta variant of concern continued to circulate across North America. A positive detection as part of routine sampling in late November 2021 triggered daily monitoring and further isolated the signal to a single wing of one residence hall. Detection of SARS-CoV-2 within the wastewater over a period of 3 consecutive days led to a coordinated rapid antigen testing campaign targeting the residence hall occupants and the identification and isolation of infected individuals. With knowledge of the number of individuals testing positive for COVID-19, fecal shedding rates were estimated to range from 3.70 log10 gc ‧ g feces-1 to 5.94 log10 gc ‧ g feces-1. These results reinforce the efficacy of wastewater surveillance as an early indicator of infection in congregate living settings. Detections can trigger public health measures ranging from enhanced communications to targeted coordinated testing and quarantine.
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Affiliation(s)
- Ryland Corchis-Scott
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada
| | - Qiudi Geng
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada
| | - Abdul Monem Al Riahi
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada
| | - Amr Labak
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada
| | - Ana Podadera
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, Canada
| | - Kenneth K. S. Ng
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, Canada
| | - Lisa A. Porter
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, Canada
| | - Yufeng Tong
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, Canada
| | - Jess C. Dixon
- Department of Kinesiology, University of Windsor, Windsor, ON, Canada
| | | | - Rajesh Seth
- Civil and Environmental Engineering, University of Windsor, Windsor, ON, Canada
| | - R. Michael McKay
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada
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4
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Abstract
Planktothrix agardhii is a filamentous cyanobacterial species that dominates harmful algal blooms in Sandusky Bay, Lake Erie and other freshwater basins across the world. P. agardhii isolates were obtained from early (June) blooms via single filament isolation; eight have been characterized from 2016, and 12 additional isolates have been characterized from 2018 for a total of 20 new cultures. These novel isolates were processed for genomic sequencing, where reads were used to generate scaffolds and contigs which were annotated with DIAMOND BLAST hit, Pfam, and GO. Analyses include whole genome alignment to generate phylogenetic trees and comparison of genetic rearrangements between isolates. Nitrogen acquisition and metabolism was compared across isolates. Secondary metabolite production was genetically explored including microcystins, two types of aeruginosin clusters, anabaenopeptins, cyanopeptolins, microviridins, and prenylagaramides. Two common and 4 unique CRISPR-cas islands were analyzed for similar sequences across all isolates and against the known Planktothrix-specific cyanophage, PaV-LD. Overall, the uniqueness of each genome from Planktothrix blooms sampled from the same site and at similar times belies the unexplored diversity of this genus.
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Affiliation(s)
- Katelyn M. McKindles
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, United States of America
| | - R. Michael McKay
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada
- Great Lakes Center for Fresh Waters and Human Health, Bowling Green State University, Bowling Green, OH, United States of America
| | - George S. Bullerjahn
- Great Lakes Center for Fresh Waters and Human Health, Bowling Green State University, Bowling Green, OH, United States of America
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH, United States of America
- * E-mail:
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5
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McKindles KM, Manes MA, McKay RM, Davis TW, Bullerjahn GS. Environmental factors affecting chytrid (Chytridiomycota) infection rates on Planktothrix agardhii. J Plankton Res 2021; 43:658-672. [PMID: 34588922 PMCID: PMC8461644 DOI: 10.1093/plankt/fbab058] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 08/17/2021] [Indexed: 05/05/2023]
Abstract
Planktothrix agardhii dominates the cyanobacterial harmful algal bloom biomass in Sandusky Bay, Lake Erie (USA) from May until September. This filamentous cyanobacterium known parasites including the chytrid fungal species Rhizophydium sp. C02, which was previously isolated from this region. The purpose of our work has been to establish how parasitic interactions affect Planktothrix population dynamics during a bloom event. Samples analyzed from the 2015 to 2019 bloom seasons using quantitative PCR investigate the spatial and temporal prevalence of chytrid infections. Abiotic factors examined in lab include manipulating temperature (17-31°C), conductivity (0.226-1.225 mS/cm) and turbulence. Planktothrix-specific chytrids are present throughout the bloom period and are occasionally at high enough densities to exert parasitic pressure on their hosts. Temperatures above 27.1°C in lab can inhibit chytrid infection, indicating the presence of a possible upper thermal refuge for the host. Data suggest that chytrids can survive conductivity spikes in lab at levels three-fold above Sandusky Bay waters if given sufficient time (7-12 days), whereas increased turbulence in lab severely inhibits chytrid infections, perhaps due to disruption of chemical signaling. Overall, these data provide insights into the environmental conditions that inhibit chytrid infections during Planktothrix-dominated blooms in temperate waters.
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Affiliation(s)
- Katelyn M McKindles
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403, USA
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Makayla A Manes
- Department of Biological Sciences, The Ohio State University, Columbus, OH, USA
| | - R Michael McKay
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403, USA
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Timothy W Davis
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403, USA
- Great Lakes Center for Fresh Waters and Human Health, Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403, USA
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6
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Chaffin JD, Bratton JF, Verhamme EM, Bair HB, Beecher AA, Binding CE, Birbeck JA, Bridgeman TB, Chang X, Crossman J, Currie WJS, Davis TW, Dick GJ, Drouillard KG, Errera RM, Frenken T, MacIsaac HJ, McClure A, McKay RM, Reitz LA, Domingo JWS, Stanislawczyk K, Stumpf RP, Swan ZD, Snyder BK, Westrick JA, Xue P, Yancey CE, Zastepa A, Zhou X. The Lake Erie HABs Grab: A binational collaboration to characterize the western basin cyanobacterial harmful algal blooms at an unprecedented high-resolution spatial scale. Harmful Algae 2021; 108:102080. [PMID: 34588116 PMCID: PMC8682807 DOI: 10.1016/j.hal.2021.102080] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 06/29/2021] [Accepted: 06/30/2021] [Indexed: 05/12/2023]
Abstract
Monitoring of cyanobacterial bloom biomass in large lakes at high resolution is made possible by remote sensing. However, monitoring cyanobacterial toxins is only feasible with grab samples, which, with only sporadic sampling, results in uncertainties in the spatial distribution of toxins. To address this issue, we conducted two intensive "HABs Grabs" of microcystin (MC)-producing Microcystis blooms in the western basin of Lake Erie. These were one-day sampling events during August of 2018 and 2019 in which 100 and 172 grab samples were collected, respectively, within a six-hour window covering up to 2,270 km2 and analyzed using consistent methods to estimate the total mass of MC. The samples were analyzed for 57 parameters, including toxins, nutrients, chlorophyll, and genomics. There were an estimated 11,513 kg and 30,691 kg of MCs in the western basin during the 2018 and 2019 HABs Grabs, respectively. The bloom boundary poses substantial issues for spatial assessments because MC concentration varied by nearly two orders of magnitude over very short distances. The MC to chlorophyll ratio (MC:chl) varied by a factor up to 5.3 throughout the basin, which creates challenges for using MC:chl to predict MC concentrations. Many of the biomass metrics strongly correlated (r > 0.70) with each other except chlorophyll fluorescence and phycocyanin concentration. While MC and chlorophyll correlated well with total phosphorus and nitrogen concentrations, MC:chl correlated with dissolved inorganic nitrogen. More frequent MC data collection can overcome these issues, and models need to account for the MC:chl spatial heterogeneity when forecasting MCs.
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Affiliation(s)
- Justin D Chaffin
- F.T. Stone Laboratory and Ohio Sea Grant, The Ohio State University, 878 Bayview Ave. P.O. Box 119, Put-In-Bay, OH 43456, USA.
| | | | | | - Halli B Bair
- F.T. Stone Laboratory and Ohio Sea Grant, The Ohio State University, 878 Bayview Ave. P.O. Box 119, Put-In-Bay, OH 43456, USA
| | - Amber A Beecher
- Lake Erie Center, University of Toledo, 6200 Bayshore Rd., Oregon, OH 43616, USA
| | - Caren E Binding
- Environment and Climate Change Canada, Canada Centre for Inland Waters, 867 Lakeshore Road, Burlington, Ontario L7S1A1, Canada
| | - Johnna A Birbeck
- Lumigen Instrument Center, Wayne State University, 5101Cass Ave., Detroit, MI 48202, USA
| | - Thomas B Bridgeman
- Lake Erie Center, University of Toledo, 6200 Bayshore Rd., Oregon, OH 43616, USA
| | - Xuexiu Chang
- Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Ave., Windsor, Ontario N9B 3P4, Canada; School of Ecology and Environmental Sciences, Yunnan University, Kunming 650091, PR China
| | - Jill Crossman
- School of the Environment, University of Windsor, 401 Sunset Avenue, Windsor, Ontario N9B 3P4, Canada
| | - Warren J S Currie
- Fisheries and Oceans Canada, Canada Centre for Inland Waters, 867 Lakeshore Rd., Burlington, Ontario L7S 1A1, Canada
| | - Timothy W Davis
- Biological Sciences, Bowling Green State University, Life Sciences Building, Bowling Green, OH 43402, United States
| | - Gregory J Dick
- Department of Earth and Environmental Sciences, University of Michigan, 2534 North University Building, 1100 North University Avenue, Ann Arbor, MI 48109-1005, USA
| | - Kenneth G Drouillard
- Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Ave., Windsor, Ontario N9B 3P4, Canada
| | - Reagan M Errera
- Great Lakes Environmental Research Laboratory, National Oceanic and Atmospheric Administration, Ann Arbor, MI 48108, USA
| | - Thijs Frenken
- Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Ave., Windsor, Ontario N9B 3P4, Canada
| | - Hugh J MacIsaac
- Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Ave., Windsor, Ontario N9B 3P4, Canada
| | - Andrew McClure
- Division of Water Treatment, City of Toledo, Toledo, OH 43605, USA
| | - R Michael McKay
- Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Ave., Windsor, Ontario N9B 3P4, Canada
| | - Laura A Reitz
- Biological Sciences, Bowling Green State University, Life Sciences Building, Bowling Green, OH 43402, United States
| | | | - Keara Stanislawczyk
- F.T. Stone Laboratory and Ohio Sea Grant, The Ohio State University, 878 Bayview Ave. P.O. Box 119, Put-In-Bay, OH 43456, USA
| | - Richard P Stumpf
- National Ocean Service, National Oceanic and Atmospheric Administration, 1305 East West Highway, Silver Spring, MD 20910, USA
| | - Zachary D Swan
- Lake Erie Center, University of Toledo, 6200 Bayshore Rd., Oregon, OH 43616, USA
| | - Brenda K Snyder
- Lake Erie Center, University of Toledo, 6200 Bayshore Rd., Oregon, OH 43616, USA
| | - Judy A Westrick
- Lumigen Instrument Center, Wayne State University, 5101Cass Ave., Detroit, MI 48202, USA
| | - Pengfei Xue
- Civil and Environmental Engineering, Michigan Technological University, 1400 Townsend Dr., Houghton, MI 49931, USA
| | - Colleen E Yancey
- Department of Earth and Environmental Sciences, University of Michigan, 2534 North University Building, 1100 North University Avenue, Ann Arbor, MI 48109-1005, USA
| | - Arthur Zastepa
- Environment and Climate Change Canada, Canada Centre for Inland Waters, 867 Lakeshore Road, Burlington, Ontario L7S1A1, Canada
| | - Xing Zhou
- Civil and Environmental Engineering, Michigan Technological University, 1400 Townsend Dr., Houghton, MI 49931, USA
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7
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McKindles KM, Manes MA, DeMarco JR, McClure A, McKay RM, Davis TW, Bullerjahn GS. Dissolved Microcystin Release Coincident with Lysis of a Bloom Dominated by Microcystis spp. in Western Lake Erie Attributed to a Novel Cyanophage. Appl Environ Microbiol 2020; 86:e01397-20. [PMID: 32859600 PMCID: PMC7642080 DOI: 10.1128/aem.01397-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/25/2020] [Indexed: 11/20/2022] Open
Abstract
Western Lake Erie (Laurentian Great Lakes) is prone to annual cyanobacterial harmful algal blooms (cHABs) dominated by Microcystis spp. that often yield microcystin toxin concentrations exceeding the federal EPA recreational contact advisory of 8 μg liter-1 In August 2014, microcystin levels were detected in finished drinking water above the World Health Organization 1.0 μg liter-1 threshold for consumption, leading to a 2-day disruption in the supply of drinking water for >400,000 residents of Toledo, Ohio (USA). Subsequent metatranscriptomic analysis of the 2014 bloom event provided evidence that release of toxin into the water supply was likely caused by cyanophage lysis that transformed a portion of the intracellular microcystin pool into the dissolved fraction, rendering it more difficult to eliminate during treatment. In August 2019, a similar increase in dissolved microcystins at the Toledo water intake was coincident with a viral lytic event caused by a phage consortium different in composition from what was detected following the 2014 Toledo water crisis. The most abundant viral sequence in metagenomic data sets was a scaffold from a putative member of the Siphoviridae, distinct from the Ma-LMM01-like Myoviridae that are typically documented to occur in western Lake Erie. This study provides further evidence that viral activity in western Lake Erie plays a significant role in transformation of microcystins from the particulate to the dissolved fraction and therefore requires monitoring efforts from local water treatment plants. Additionally, identification of multiple lytic cyanophages will enable the development of a quantitative PCR toolbox to assess viral activity during cHABs.IMPORTANCE Viral attack on cHABs may contribute to changes in community composition during blooms, as well as bloom decline, yet loss of bloom biomass does not eliminate the threat of cHAB toxicity. Rather, it may increase risks to the public by delivering a pool of dissolved toxin directly into water treatment utilities when the dominating Microcystis spp. are capable of producing microcystins. Detecting, characterizing, and quantifying the major cyanophages involved in lytic events will assist water treatment plant operators in making rapid decisions regarding the pool of microcystins entering the plant and the corresponding best practices to neutralize the toxin.
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Affiliation(s)
- Katelyn M McKindles
- Department of Biological Sciences and Great Lakes Center for Fresh Waters and Human Health, Bowling Green State University, Bowling Green, Ohio, USA
| | - Makayla A Manes
- Department of Biological Sciences and Great Lakes Center for Fresh Waters and Human Health, Bowling Green State University, Bowling Green, Ohio, USA
| | - Jonathan R DeMarco
- Department of Biological Sciences and Great Lakes Center for Fresh Waters and Human Health, Bowling Green State University, Bowling Green, Ohio, USA
| | - Andrew McClure
- Division of Water Treatment for the City of Toledo, Toledo, Ohio, USA
| | - R Michael McKay
- Department of Biological Sciences and Great Lakes Center for Fresh Waters and Human Health, Bowling Green State University, Bowling Green, Ohio, USA
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario, Canada
| | - Timothy W Davis
- Department of Biological Sciences and Great Lakes Center for Fresh Waters and Human Health, Bowling Green State University, Bowling Green, Ohio, USA
- Center for Great Lakes and Watershed Studies, Bowling Green State University, Bowling Green, Ohio, USA
| | - George S Bullerjahn
- Department of Biological Sciences and Great Lakes Center for Fresh Waters and Human Health, Bowling Green State University, Bowling Green, Ohio, USA
- Center for Great Lakes and Watershed Studies, Bowling Green State University, Bowling Green, Ohio, USA
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8
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McKay RM, Frenken T, Diep N, Cody WR, Crevecoeur S, Dove A, Drouillard KG, Ortiz X, Wintermute J, Zastepa A. Bloom announcement: An early autumn cyanobacterial bloom co-dominated by Aphanizomenon flos- aquae and Planktothrix agardhii in an agriculturally-influenced Great Lakes tributary (Thames River, Ontario, Canada). Data Brief 2020; 30:105585. [PMID: 32373689 PMCID: PMC7195512 DOI: 10.1016/j.dib.2020.105585] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/26/2020] [Accepted: 04/09/2020] [Indexed: 12/03/2022] Open
Affiliation(s)
- R. Michael McKay
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada
- Great Lakes Center for Fresh Waters and Human Health, Bowling Green State University, Bowling Green, OH, United States
| | - Thijs Frenken
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada
| | - Ngan Diep
- Ontario Ministry of the Environment, Conservation and Parks, Toronto, ON, Canada
| | | | - Sophie Crevecoeur
- Environment and Climate Change Canada, Canada Centre for Inland Waters, Burlington, ON, Canada
| | - Alice Dove
- Environment and Climate Change Canada, Canada Centre for Inland Waters, Burlington, ON, Canada
| | - Kenneth G. Drouillard
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada
| | - Xavier Ortiz
- Ontario Ministry of the Environment, Conservation and Parks, Toronto, ON, Canada
| | | | - Arthur Zastepa
- Environment and Climate Change Canada, Canada Centre for Inland Waters, Burlington, ON, Canada
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Grant GR, Naish TR, Dunbar GB, Stocchi P, Kominz MA, Kamp PJJ, Tapia CA, McKay RM, Levy RH, Patterson MO. The amplitude and origin of sea-level variability during the Pliocene epoch. Nature 2019; 574:237-241. [PMID: 31578526 DOI: 10.1038/s41586-019-1619-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 07/16/2019] [Indexed: 11/09/2022]
Abstract
Earth is heading towards a climate that last existed more than three million years ago (Ma) during the 'mid-Pliocene warm period'1, when atmospheric carbon dioxide concentrations were about 400 parts per million, global sea level oscillated in response to orbital forcing2,3 and peak global-mean sea level (GMSL) may have reached about 20 metres above the present-day value4,5. For sea-level rise of this magnitude, extensive retreat or collapse of the Greenland, West Antarctic and marine-based sectors of the East Antarctic ice sheets is required. Yet the relative amplitude of sea-level variations within glacial-interglacial cycles remains poorly constrained. To address this, we calibrate a theoretical relationship between modern sediment transport by waves and water depth, and then apply the technique to grain size in a continuous 800-metre-thick Pliocene sequence of shallow-marine sediments from Whanganui Basin, New Zealand. Water-depth variations obtained in this way, after corrections for tectonic subsidence, yield cyclic relative sea-level (RSL) variations. Here we show that sea level varied on average by 13 ± 5 metres over glacial-interglacial cycles during the middle-to-late Pliocene (about 3.3-2.5 Ma). The resulting record is independent of the global ice volume proxy3 (as derived from the deep-ocean oxygen isotope record) and sea-level cycles are in phase with 20-thousand-year (kyr) periodic changes in insolation over Antarctica, paced by eccentricity-modulated orbital precession6 between 3.3 and 2.7 Ma. Thereafter, sea-level fluctuations are paced by the 41-kyr period of cycles in Earth's axial tilt as ice sheets stabilize on Antarctica and intensify in the Northern Hemisphere3,6. Strictly, we provide the amplitude of RSL change, rather than absolute GMSL change. However, simulations of RSL change based on glacio-isostatic adjustment show that our record approximates eustatic sea level, defined here as GMSL unregistered to the centre of the Earth. Nonetheless, under conservative assumptions, our estimates limit maximum Pliocene sea-level rise to less than 25 metres and provide new constraints on polar ice-volume variability under the climate conditions predicted for this century.
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Affiliation(s)
- G R Grant
- Antarctic Research Centre, Victoria University of Wellington, Wellington, New Zealand. .,GNS Science, Lower Hutt, New Zealand.
| | - T R Naish
- Antarctic Research Centre, Victoria University of Wellington, Wellington, New Zealand
| | - G B Dunbar
- Antarctic Research Centre, Victoria University of Wellington, Wellington, New Zealand
| | - P Stocchi
- Coastal Systems Department, Royal Netherlands Institute for Sea Research, and Utrecht University, Den Burg, The Netherlands
| | - M A Kominz
- Department of Geological and Environmental Sciences, Western Michigan University, Kalamazoo, MI, USA
| | - P J J Kamp
- School of Science, University of Waikato, Hamilton, New Zealand
| | - C A Tapia
- Departamento de Obras Civiles y Geologia, Facultad de Ingenieria, Universidad Catolica de Temuco, Temuco, Chile
| | - R M McKay
- Antarctic Research Centre, Victoria University of Wellington, Wellington, New Zealand
| | - R H Levy
- Antarctic Research Centre, Victoria University of Wellington, Wellington, New Zealand.,GNS Science, Lower Hutt, New Zealand
| | - M O Patterson
- Binghamton University, State University of New York, Binghamton, NY, USA
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McKay RM, Barrett PJ, Levy RS, Naish TR, Golledge NR, Pyne A. Antarctic Cenozoic climate history from sedimentary records: ANDRILL and beyond. Philos Trans A Math Phys Eng Sci 2016; 374:rsta.2014.0301. [PMID: 26667911 DOI: 10.1098/rsta.2014.0301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/20/2015] [Indexed: 06/05/2023]
Abstract
Mounting evidence from models and geological data implies that the Antarctic Ice Sheet may behave in an unstable manner and retreat rapidly in response to a warming climate, which is a key factor motivating efforts to improve estimates of Antarctic ice volume contributions to future sea-level rise. Here, we review Antarctic cooling history since peak temperatures of the Middle Eocene Climatic Optimum (approx. 50 Ma) to provide a framework for future initiatives to recover sediment cores from subglacial lakes and sedimentary basins in Antarctica's continental interior. While the existing inventory of cores has yielded important insights into the biotic and climatic evolution of Antarctica, strata have numerous and often lengthy time breaks, providing a framework of 'snapshots' through time. Further cores, and more work on existing cores, are needed to reconcile Antarctic records with the more continuous 'far-field' records documenting the evolution of global ice volume and deep-sea temperature. To achieve this, we argue for an integrated portfolio of drilling and coring missions that encompasses existing methodologies using ship- and sea-ice-/ice-shelf-based drilling platforms as well as recently developed seafloor-based drilling and subglacial access systems. We conclude by reviewing key technological issues that will need to be overcome.
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Affiliation(s)
- R M McKay
- Antarctic Research Centre, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
| | - P J Barrett
- Antarctic Research Centre, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
| | - R S Levy
- GNS Science, PO Box 30-368, Lower Hutt 5040, New Zealand
| | - T R Naish
- Antarctic Research Centre, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand GNS Science, PO Box 30-368, Lower Hutt 5040, New Zealand
| | - N R Golledge
- Antarctic Research Centre, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand GNS Science, PO Box 30-368, Lower Hutt 5040, New Zealand
| | - A Pyne
- Antarctic Research Centre, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
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Triscott JAC, Dobbs BM, McKay RM, Babenko O, Triscott E. Prevalence and Types of Anemia and Associations with Functional Decline in Geriatric Inpatients. J Frailty Aging 2015; 4:7-12. [PMID: 27031910 DOI: 10.14283/jfa.2015.35] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND The prevalence of anemia in hospitalized seniors has been linked to poor functional outcomes, increased mortality, and longer hospital stays, and has been associated with advancing age, male sex, and cognitive impairment. Despite the potential for complications, anemia often is undiagnosed and/or untreated in seniors. OBJECTIVES Examine (a) the distribution of anemia diagnosis and treatment in patients in a rehabilitation hospital, and (b) patients' cognitive and functional outcomes. DESIGN Retrospective chart review of medical records of 132 patients. MEASUREMENTS The presence and type of anemia were determined based on the World Health Organization criteria for adults and Smith's algorithm, respectively. The Mini-Mental State Exam (MMSE) was used to measure cognitive status. Functional impairment was assessed using the Functional Independence Measure (FIM). RESULTS The mean age of the sample was 82.20 years, with 68% being female, the mean MMSE and FIM scores were 23.95 (SD = 4.3) and 82.82 (SD = 15.63), respectively. In total, 67% of males and 46% of females were anemic (P < 0.05). The majority of anemias were caused by nutritional deficiencies. The percent of anemic females receiving treatment for anemia was higher (71%) than the percent of anemic males (46%) (P < 0.05). The majority of the patients improved functionally regardless of anemia status. CONCLUSIONS Results indicated that a substantial number of patients in a geriatric hospital were anemic, with significant percentage going untreated. The overall improvement in patients' functional abilities suggests that remedial rehabilitation of frail seniors has an impact on recovery during their hospital stay.
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Affiliation(s)
- J A C Triscott
- Dr. Jean A.C. Triscott, Division of Care of the Elderly, Department of Family Medicine, University of Alberta, 205, 8215 - 112 Street, Edmonton, AB, Canada, T6G 2C8, Phone 780-735-8826, Fax 780-735-8846,
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12
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Speechley WJ, Murray CB, McKay RM, Munz MT, Ngan ETC. A failure of conflict to modulate dual-stream processing may underlie the formation and maintenance of delusions. Eur Psychiatry 2009; 25:80-6. [PMID: 19699616 DOI: 10.1016/j.eurpsy.2009.05.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Revised: 05/20/2009] [Accepted: 05/29/2009] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Dual-stream information processing proposes that reasoning is composed of two interacting processes: a fast, intuitive system (Stream 1) and a slower, more logical process (Stream 2). In non-patient controls, divergence of these streams may result in the experience of conflict, modulating decision-making towards Stream 2, and initiating a more thorough examination of the available evidence. In delusional schizophrenia patients, a failure of conflict to modulate decision-making towards Stream 2 may reduce the influence of contradictory evidence, resulting in a failure to correct erroneous beliefs. METHOD Delusional schizophrenia patients and non-patient controls completed a deductive reasoning task requiring logical validity judgments of two-part conditional statements. Half of the statements were characterized by a conflict between logical validity (Stream 2) and content believability (Stream 1). RESULTS Patients were significantly worse than controls in determining the logical validity of both conflict and non-conflict conditional statements. This between groups difference was significantly greater for the conflict condition. CONCLUSIONS The results are consistent with the hypothesis that delusional schizophrenia patients fail to use conflict to modulate towards Stream 2 when the two streams of reasoning arrive at incompatible judgments. This finding provides encouraging preliminary support for the Dual-Stream Modulation Failure model of delusion formation and maintenance.
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Affiliation(s)
- W J Speechley
- Department of Psychiatry, The University of British Columbia, Vancouver B.C., Canada
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Piunova V, Berger D, Neckers DC, Bullerjahn GS, McKay RM, Fedorov AV. Biocidal performance of acrylated glyphosate in a model photopolymerizable coating formulation. Photochem Photobiol Sci 2008; 7:1565-9. [PMID: 19037510 DOI: 10.1039/b809659g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Accepted: 07/21/2008] [Indexed: 12/16/2023]
Abstract
Acrylated glyphosate was blended into a model polyolacrylate formulation and copolymerized. The resulting copolymer retains herbicidal activity similar to that of the monomer as indicated by the results of biological tests. No release of biocide from the coating was observed. The potential value of these biologically active acrylic formulations as biofouling compositions has been demonstrated by field trials.
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Affiliation(s)
- Victoria Piunova
- Center for Photochemical Sciences, Bowling Green State University, Bowling Green, OH 43403, USA
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14
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Abstract
Wnt signals play important roles in development and oncogenesis and are transduced through at least two pathways: a canonical beta-catenin-dependent and a beta-catenin-independent cascade. Casein kinase I (CKI) is required in both invertebrates and vertebrates to transduce canonical Wnt signals. However, its role in the beta-catenin-independent pathway was unknown. During vertebrate embryogenesis, the beta-catenin-independent cascade is thought to control cell movements and has been postulated to be analogous to the Drosophila planar cell polarity pathway, which signals through the JNK cascade. Here, we report that blocking CKI function inhibits embryonic morphogenesis and activates JNK in cell lines. These studies suggest that CKI might also act in the beta-catenin-independent pathway and indicate a role for CKI during convergence extension in early vertebrate development.
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Affiliation(s)
- R M McKay
- Center for Developmental Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9133, USA
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15
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Abstract
The canonical Wnt-signaling pathway is critical for many aspects of development, and mutations in components of the Wnt pathway are carcinogenic. Recently, sufficiency tests identified casein kinase Iepsilon (CKIepsilon) as a positive component of the canonical Wnt/beta-catenin pathway, and necessity tests showed that CKIepsilon is required in vertebrates to transduce Wnt signals. In addition to CKIepsilon, the CKI family includes several other isoforms (alpha, beta, gamma, and delta) and their role in Wnt sufficiency tests had not yet been clarified. However, in Caenorhabditis elegans studies, loss-of-function of a CKI isoform most similar to alpha produced the mom phenotype, indicative of loss-of-Wnt signaling. In this report, we examine the ability of the various CKI isoforms to activate Wnt signaling and find that all the wild-type CKI isoforms do so. Dishevelled (Dsh), another positive component of the Wnt pathway, becomes phosphorylated in response to Wnt signals. All the CKI isoforms, with the exception of gamma, increase the phosphorylation of Dsh in vivo. In addition, CKI directly phosphorylates Dsh in vitro. Finally, we find that CKI is required in vivo for the Wnt-dependent phosphorylation of Dsh. These studies advance our understanding of the mechanism of Wnt action and suggest that more than one CKI isoform is capable of transducing Wnt signals in vivo.
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Affiliation(s)
- R M McKay
- Center for Developmental Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9133, USA
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Boyd PW, Watson AJ, Law CS, Abraham ER, Trull T, Murdoch R, Bakker DC, Bowie AR, Buesseler KO, Chang H, Charette M, Croot P, Downing K, Frew R, Gall M, Hadfield M, Hall J, Harvey M, Jameson G, LaRoche J, Liddicoat M, Ling R, Maldonado MT, McKay RM, Nodder S, Pickmere S, Pridmore R, Rintoul S, Safi K, Sutton P, Strzepek R, Tanneberger K, Turner S, Waite A, Zeldis J. A mesoscale phytoplankton bloom in the polar Southern Ocean stimulated by iron fertilization. Nature 2000; 407:695-702. [PMID: 11048709 DOI: 10.1038/35037500] [Citation(s) in RCA: 319] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Changes in iron supply to oceanic plankton are thought to have a significant effect on concentrations of atmospheric carbon dioxide by altering rates of carbon sequestration, a theory known as the 'iron hypothesis'. For this reason, it is important to understand the response of pelagic biota to increased iron supply. Here we report the results of a mesoscale iron fertilization experiment in the polar Southern Ocean, where the potential to sequester iron-elevated algal carbon is probably greatest. Increased iron supply led to elevated phytoplankton biomass and rates of photosynthesis in surface waters, causing a large drawdown of carbon dioxide and macronutrients, and elevated dimethyl sulphide levels after 13 days. This drawdown was mostly due to the proliferation of diatom stocks. But downward export of biogenic carbon was not increased. Moreover, satellite observations of this massive bloom 30 days later, suggest that a sufficient proportion of the added iron was retained in surface waters. Our findings demonstrate that iron supply controls phytoplankton growth and community composition during summer in these polar Southern Ocean waters, but the fate of algal carbon remains unknown and depends on the interplay between the processes controlling export, remineralisation and timescales of water mass subduction.
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Affiliation(s)
- P W Boyd
- National Institute of Water and Atmosphere, Centre for Chemical and Physical Oceanography, Department of Chemistry, University of Otago, Dunedin, New Zealand.
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Abstract
The Wnt signalling cascade is essential for the development of both invertebrates and vertebrates, and is altered during tumorigenesis. Although a general framework for Wnt signalling has been elucidated, not all of the components have been identified. Here we describe a serine kinase, casein kinase I (CKI), which was isolated by expression cloning in Xenopus embryos. CKI reproduces several properties of Wnt signals, including generation of complete dorsal axes, stabilization of beta-catenin and induction of genes that are direct targets of Wnt signals. Dominant-negative forms of CKI and a pharmacological blocker of CKI inhibited Wnt signals in Xenopus. Inhibiting CKI in Caenorhabditis elegans generated worms with a mom phenotype, indicative of a loss of Wnt signals. In addition, CKI bound to and increased the phosphorylation of dishevelled, a known component of the Wnt pathway. These data indicate that CKI may be a conserved component of the Wnt pathway.
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Affiliation(s)
- J M Peters
- Center for Developmental Biology, Department of Molecular Biology, UT Southwestern Medical Center, Dallas, Texas 75235-9133, USA.
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18
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Abstract
Individual pig growth curves were derived on 445 Yorkshire, 323 Hampshire, and 316 Landrace boars and gilts. The range in age was from 1 to 35 d and these growth curves were linear. The regression parameters (x- and y-intercepts, and slopes) were different among the three breeds, and differences between boars and gilts were found in the Yorkshire breed for the y-intercept and slope and in the Landrace breed for the y-intercept and slope and in the Landrace breed for the y-intercept. An additional 130 Yorkshire, 126 Hampshire, and 96 Landrace boars and gilts were used to evaluate the effectiveness of adjustments that were additive, multiplicative, additive-multiplicative, or based on the x- and y-intercepts. Effectiveness was evaluated in terms of accuracy, equality of variance, and practical application. The multiplicative adjustments were the most effective in the Hampshire breed and the average of the additive and multiplicative adjustments was the most effective in the Yorkshire breed. In the Landrace breed none of the four methods evaluated produced a credible adjusted 21-d weight. From an industry standpoint this study suggests the need for breed-specific specific adjustments, and in some breeds this may have to be extended to sex-specific adjustments.
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Affiliation(s)
- R M McKay
- Agriculture Canada Research Station, Brandon, Manitoba
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McKay RM, Gibbs SP. Phycoerythrin is absent from the pyrenoid of Porphyridium cruentum: photosynthetic implications. Planta 1990; 180:249-256. [PMID: 24201953 DOI: 10.1007/bf00194004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/09/1989] [Indexed: 06/02/2023]
Abstract
The thylakoid lamellae which traverse the pyrenoid of the unicellular red alga Porphyridium cruentum (Agardh) Nägeli appear to lack phycobilisomes. We have confirmed by immuno-electron microscopy that phycoerythrin (PE), an important structural component of the phycobilisomes of red algae, is absent from the pyrenoid. To characterize pyrenoid thylakoids further, electron-microscopic cytochemical methods were employed to detect photosystem activity. Photosystem (PS) I activity was demonstrated in both stromal and pyrenoid thylakoids by the photooxidation of 3,3'-diaminobenzidine. In contrast, the localization of photoreduced distyryl nitroblue tetrazolium demonstrated that PSII activity was restricted to stromal thylakoids. The observed partitioning of PE and PSII activity within the plastid may be related to another observation, that being the localization of nearly all ribulose-1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39) within the pyrenoid of this alga. It is possible that the pyrenoid of P. cruentum functions as a specific metabolic compartment where CO2 fixation is enhanced by the absence of photosynthetic O2 evolution.
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Affiliation(s)
- R M McKay
- Department of Biology, McGill University, H3A 1B1, Montreal, P.Q., Canada
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20
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McKay RM. Vesiculo-bullous disorders in adulthood. Can Fam Physician 1987; 33:2797-2800. [PMID: 20469479 PMCID: PMC2218251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
In this third and final article in the series on vesiculo-bullous disorders, I shall review some of the blistering diseases seen among adults. Many of the disorders are not common, but a delayed diagnosis can put the patient at risk. I shall mention some key aspects of the disease or its diagnosis, but for further detail, I refer the reader to the references cited.
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McKay RM. Vesiculo-bullous disorders in childhood. Can Fam Physician 1987; 33:2593-2597. [PMID: 21264002 PMCID: PMC2218675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This is the second of three articles outlining the diagnoses to be considered when vesiculo-bullous lesions are identified in the neonate, children, and adults. This paper deals with a number of blistering disorders which can arise throughout infancy and childhood. Both inherited and acquired diseases are considered, and general guidelines for diagnosis and management are discussed.
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McKay RM. Vesiculo-bullous disorders of the neonate. Can Fam Physician 1987; 33:2297-2301. [PMID: 21263952 PMCID: PMC2218535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This is the first of three articles which outline the diagnoses to be considered when vesiculo-bullous lesions are identified in the neonate, children, and adults. This paper presents a brief sketch of blistering disorders which may occur during the first few weeks of life. Vesiculo-bullous lesions in the neonate may represent benign, infectious, genetic, or life-threatening disorders. Early recognition, appropriate diagnostic procedures, and specific therapeutic interventions can be vital in reducing potential morbidity and mortality. General guidelines for diagnostic procedures and therapeutic interventions are discussed, along with some of the newer etiologic and epidemiologic concepts.
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Abstract
Data from 153 foster groups, each consisting of a dam and a nurse, were analyzed separately for breed (Lacombe, Yorkshire) parity (first, second), and sex of piglet (boar, gilt) to estimate prenatal, postnatal and prenatal X postnatal influences on growth and fat measurements. Significant differences were not observed between breeds, parity and sex of piglets; the estimates were pooled over these traits. Prenatal effects were the major contributing factor in the determination of preweaning growth rate, weaning weight, postweaning average daily gain and allometric growth coefficient, rib and loin fat deposition coefficients. Postnatal influence was of minor importance and the prenatal X postnatal interaction was of negligible consequence. These observations indicated that crossfostering of piglets between parities and breeds without regard for the sex of the piglet would not seriously bias subsequent performance testing results. Heritability estimates for weaning weight, postweaning growth rate and backfat thickness differed from published values.
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Abstract
Data from 11 generations of a selection study were analyzed to estimate genetic correlations between boars and gilts, boars and barrows, and gilts and barrows for carcass traits in the Lacombe and Yorkshire breeds of swine. Genetic correlations were estimated to determine if genotype X sex interactions existed and to assess the need for separate genetic parameters for boars and gilts in selection response equations. Genotype X sex interactions were found for total carcass fat/kg of cold carcass weight, area of lean in the ham face/kg of cold carcass weight and percent lean in the ham face/kg of cold carcass weight. Carcass length, longissimus muscle area/kg of cold carcass weight percent ham of side and percent lean in the ham face did not have genotype X sex interactions. Selection based on pooled genetic parameters over sex were favored over selection based on separate genetic parameters regardless of the presence or absence of genotype X sex interactions.
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Grinwich DL, McKay RM. Effects of reduced suckling on days to estrus, conception during lactation and embryo survival in sows. Theriogenology 1985; 23:449-59. [PMID: 16726015 DOI: 10.1016/0093-691x(85)90017-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/1984] [Accepted: 11/29/1984] [Indexed: 10/26/2022]
Abstract
Trials to investigate the effects of limited suckling on sow reproduction and piglet growth were conducted using 41 first parity and 32 second parity Yorkshire sows. Separation of sows from their litters (22 hrs/day, days 21-35 postpartum) induced estrus in 60% of primiparous and 72% of second parity sows during lactation. Compared to control group animals, primiparous sows had higher weaning weights and second parity sows higher rates of embryo survival on day 30 of gestation. Piglets subjected to suckling restriction had weights, at 2 weeks after weaning, equal to those weaned after 5 weeks of unrestricted suckling. We conclude that suckling restriction can provide the dual benefits of an extended piglet nursing period and a decreased breeding to breeding interval in sows.
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Affiliation(s)
- D L Grinwich
- Agriculture Canada Research Station, Box 610 Brandon, Manitoba, Canada R7A 5Z7
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