1
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Panwar A, Migliavacca M, Nelson JA, Cortés J, Bastos A, Forkel M, Winkler AJ. Methodological challenges and new perspectives of shifting vegetation phenology in eddy covariance data. Sci Rep 2023; 13:13885. [PMID: 37620417 PMCID: PMC10449856 DOI: 10.1038/s41598-023-41048-x] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 08/18/2023] [Indexed: 08/26/2023] Open
Abstract
While numerous studies report shifts in vegetation phenology, in this regard eddy covariance (EC) data, despite its continuous high-frequency observations, still requires further exploration. Furthermore, there is no general consensus on optimal methodologies for data smoothing and extracting phenological transition dates (PTDs). Here, we revisit existing methodologies and present new prospects to investigate phenological changes in gross primary productivity (GPP) from EC measurements. First, we present a smoothing technique of GPP time series through the derivative of its smoothed annual cumulative sum. Second, we calculate PTDs and their trends from a commonly used threshold method that identifies days with a fixed percentage of the annual maximum GPP. A systematic analysis is performed for various thresholds ranging from 0.1 to 0.7. Lastly, we examine the relation of PTDs trends to trends in GPP across the years on a weekly basis. Results from 47 EC sites with long time series (> 10 years) show that advancing trends in start of season (SOS) are strongest at lower thresholds but for the end of season (EOS) at higher thresholds. Moreover, the trends are variable at different thresholds for individual vegetation types and individual sites, outlining reasonable concerns on using a single threshold value. Relationship of trends in PTDs and weekly GPP reveal association of advanced SOS and delayed EOS to increase in immediate primary productivity, but not to the trends in overall seasonal productivity. Drawing on these analyses, we emphasise on abstaining from subjective choices and investigating relationship of PTDs trend to finer temporal trends of GPP. Our study examines existing methodological challenges and presents approaches that optimize the use of EC data in identifying vegetation phenological changes and their relation to carbon uptake.
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Affiliation(s)
- Annu Panwar
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Hans-Knöll-Straße 10, 07745, Jena, Germany.
| | - Mirco Migliavacca
- European Commission, Joint Research Centre (JRC), Ispra, Lombardia, Italy
| | - Jacob A Nelson
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Hans-Knöll-Straße 10, 07745, Jena, Germany
| | - José Cortés
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Hans-Knöll-Straße 10, 07745, Jena, Germany
| | - Ana Bastos
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Hans-Knöll-Straße 10, 07745, Jena, Germany
| | - Matthias Forkel
- TUD Dresden University of Technology, Faculty of Environmental Sciences, Dresden, Germany
| | - Alexander J Winkler
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Hans-Knöll-Straße 10, 07745, Jena, Germany
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2
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Gomarasca U, Migliavacca M, Kattge J, Nelson JA, Niinemets Ü, Wirth C, Cescatti A, Bahn M, Nair R, Acosta ATR, Arain MA, Beloiu M, Black TA, Bruun HH, Bucher SF, Buchmann N, Byun C, Carrara A, Conte A, da Silva AC, Duveiller G, Fares S, Ibrom A, Knohl A, Komac B, Limousin JM, Lusk CH, Mahecha MD, Martini D, Minden V, Montagnani L, Mori AS, Onoda Y, Peñuelas J, Perez-Priego O, Poschlod P, Powell TL, Reich PB, Šigut L, van Bodegom PM, Walther S, Wohlfahrt G, Wright IJ, Reichstein M. Leaf-level coordination principles propagate to the ecosystem scale. Nat Commun 2023; 14:3948. [PMID: 37402725 DOI: 10.1038/s41467-023-39572-5] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 06/15/2023] [Indexed: 07/06/2023] Open
Abstract
Fundamental axes of variation in plant traits result from trade-offs between costs and benefits of resource-use strategies at the leaf scale. However, it is unclear whether similar trade-offs propagate to the ecosystem level. Here, we test whether trait correlation patterns predicted by three well-known leaf- and plant-level coordination theories - the leaf economics spectrum, the global spectrum of plant form and function, and the least-cost hypothesis - are also observed between community mean traits and ecosystem processes. We combined ecosystem functional properties from FLUXNET sites, vegetation properties, and community mean plant traits into three corresponding principal component analyses. We find that the leaf economics spectrum (90 sites), the global spectrum of plant form and function (89 sites), and the least-cost hypothesis (82 sites) all propagate at the ecosystem level. However, we also find evidence of additional scale-emergent properties. Evaluating the coordination of ecosystem functional properties may aid the development of more realistic global dynamic vegetation models with critical empirical data, reducing the uncertainty of climate change projections.
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Affiliation(s)
- Ulisse Gomarasca
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany.
| | | | - Jens Kattge
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
| | - Jacob A Nelson
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
| | - Ülo Niinemets
- Chair of Plant and Crop Science, Estonian University of Life Sciences, Kreutzwaldi 1, 51006, Tartu, Estonia
| | - Christian Wirth
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
- Institute of Biology, Leipzig University, Leipzig, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena Leipzig, Leipzig, Germany
| | | | - Michael Bahn
- Universität Innsbruck, Institut für Ökologie, Innsbruck, Austria
| | - Richard Nair
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
- Discipline of Botany, School of Natural Sciences Trinity College Dublin, Dublin, Ireland
| | - Alicia T R Acosta
- Dipartimento di Scienze - Università Roma TRE - V.le Marconi 446, 00146, Roma, Italy
| | - M Altaf Arain
- School of Earth, Environment & Society and McMaster Centre for Climate Change, McMaster University, Hamilton, ON, Canada
| | - Mirela Beloiu
- Institute of Terrestrial Ecosystems, ETH Zurich, Zurich, Switzerland
| | - T Andrew Black
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada
| | - Hans Henrik Bruun
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen Ø, Denmark
| | - Solveig Franziska Bucher
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena Leipzig, Leipzig, Germany
- Institute of Ecology and Evolution - Friedrich Schiller University Jena, Philosophenweg 16, 07743, Jena, Germany
| | - Nina Buchmann
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Chaeho Byun
- Department of Biological Sciences, Andong National University, Andong, 36729, Republic of Korea
| | - Arnaud Carrara
- Fundación Centro de Estudios Ambientales del Mediterráneo (CEAM), Paterna, Spain
| | - Adriano Conte
- National Research Council of Italy (CNR), Institute for Sustainable Plant Protection (IPSP), Metaponto, 75012, Italy
| | - Ana C da Silva
- Santa Catarina State University, Agroveterinary Center, Forestry Department, Av Luiz de Camões, 2090, Conta Dinheiro, 88.520-000, Lages, SC, Brazil
| | - Gregory Duveiller
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
| | - Silvano Fares
- National Research Council of Italy (CNR), Institute for Agriculture and Forestry Systems in the Mediterranean (ISAFOM), Naples, 80055, Italy
| | - Andreas Ibrom
- Technical University of Denmark (DTU), Environmental Engineering and Resource Management, Bygningstorvet 115, 2800 Kgs., Lyngby, Denmark
| | - Alexander Knohl
- Bioclimatology, University of Göttingen, Büsgenweg 2, 37077, Göttingen, Germany
| | - Benjamin Komac
- Andorra Research + Innovation; Avinguda Rocafort 21-23, Edifici Molí, 3r pis, AD600, Sant Julià de Lòria, Andorra
| | | | - Christopher H Lusk
- Environmenal Research Institute, University of Waikato, Private Bag, 3105, Hamilton, New Zealand
| | - Miguel D Mahecha
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena Leipzig, Leipzig, Germany
- Remote Sensing Centre for Earth System Research, Leipzig University, 04103, Leipzig, Germany
| | - David Martini
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
| | - Vanessa Minden
- Department of Biology, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussel, Belgium
| | - Leonardo Montagnani
- Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100, Bolzano, Italy
| | - Akira S Mori
- Research Center for Advanced Science and Technology, the University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo, 153-8904, Japan
| | - Yusuke Onoda
- Graduate School of Agriculture, Kyoto University, Oiwake, Kitashirakawa, Kyoto, 606-8502, Japan
| | - Josep Peñuelas
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, Barcelona, 08193, Catalonia, Spain
- CREAF, Cerdanyola del Vallès, Barcelona, 08193, Catalonia, Spain
| | - Oscar Perez-Priego
- Department of Forestry Engineering, University of Córdoba, Edif. Leonardo da Vinci, Campus de Rabanales s/n, 14071, Córdoba, Spain
| | - Peter Poschlod
- Ecology and Conservation Biology, Institute of Plant Sciences - Faculty of Biology and Preclinical Medicine - University of Regensburg, Universitaetsstrasse 31, D-93053, Regensburg, Germany
| | - Thomas L Powell
- The Department of Earth and Environmental Systems, The University of the South, Sewanee, TN, USA
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St. Paul, MN, 55108, USA
- Institute for Global Change Biology, and School for Environment and Sustainability, University of Michigan, Ann Arbor, MI, 48109, USA
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, 2753, Australia
| | - Ladislav Šigut
- Department of Matter and Energy Fluxes, Global Change Research Institute of the Czech Academy of Sciences, Bělidla 986/4a, 603 00, Brno, Czech Republic
| | - Peter M van Bodegom
- Institute of Environmental Sciences, Leiden University, Einsteinweg 2, 2333 CC, Leiden, the Netherlands
| | - Sophia Walther
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
| | - Georg Wohlfahrt
- Universität Innsbruck, Institut für Ökologie, Innsbruck, Austria
| | - Ian J Wright
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, 2753, Australia
- School of Natural Sciences, Macquarie University, Macquarie Park, NSW, 2109, Australia
| | - Markus Reichstein
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena Leipzig, Leipzig, Germany
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3
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Burchard-Levine V, Nieto H, Riaño D, Kustas WP, Migliavacca M, El-Madany TS, Nelson JA, Andreu A, Carrara A, Beringer J, Baldocchi D, Martín MP. A remote sensing-based three-source energy balance model to improve global estimations of evapotranspiration in semi-arid tree-grass ecosystems. Glob Chang Biol 2022; 28:1493-1515. [PMID: 34799950 DOI: 10.1111/gcb.16002] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 11/01/2021] [Indexed: 06/13/2023]
Abstract
It is well documented that energy balance and other remote sensing-based evapotranspiration (ET) models face greater uncertainty over water-limited tree-grass ecosystems (TGEs), representing nearly 1/6th of the global land surface. Their dual vegetation strata, the grass-dominated understory and tree-dominated overstory, make for distinct structural, physiological and phenological characteristics, which challenge models compared to more homogeneous and energy-limited ecosystems. Along with this, the contribution of grasses and trees to total transpiration (T), along with their different climatic drivers, is still largely unknown nor quantified in TGEs. This study proposes a thermal-based three-source energy balance (3SEB) model, accommodating an additional vegetation source within the well-known two-source energy balance (TSEB) model. The model was implemented at both tower and continental scales using eddy-covariance (EC) TGE sites, with variable tree canopy cover and rainfall (P) regimes and Meteosat Second Generation (MSG) images. 3SEB robustly simulated latent heat (LE) and related energy fluxes in all sites (Tower: LE RMSD ~60 W/m2 ; MSG: LE RMSD ~90 W/m2 ), improving over both TSEB and seasonally changing TSEB (TSEB-2S) models. In addition, 3SEB inherently partitions water fluxes between the tree, grass and soil sources. The modelled T correlated well with EC T estimates (r > .76), derived from a machine learning ET partitioning method. The T/ET was found positively related to both P and leaf area index, especially compared to the decomposed grass understory T/ET. However, trees and grasses had contrasting relations with respect to monthly P. These results demonstrate the importance in decomposing total ET into the different vegetation sources, as they have distinct climatic drivers, and hence, different relations to seasonal water availability. These promising results improved ET and energy flux estimations over complex TGEs, which may contribute to enhance global drought monitoring and understanding, and their responses to climate change feedbacks.
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Affiliation(s)
- Vicente Burchard-Levine
- Environmental Remote Sensing and Spectroscopy Laboratory (SpecLab), Spanish National Research Council (CSIC), Madrid, Spain
| | - Héctor Nieto
- Complutum Tecnologías de la Información Geográfica S.L. (COMPLUTIG), Alcalá de Henares, Spain
| | - David Riaño
- Environmental Remote Sensing and Spectroscopy Laboratory (SpecLab), Spanish National Research Council (CSIC), Madrid, Spain
- Center for Spatial Technologies and Remote Sensing (CSTARS), John Muir Institute of the Environment, University of California Davis, Davis, California, USA
| | - Wiliam P Kustas
- Hydrology and Remote Sensing Laboratory, U.S. Department of Agriculture, Agriculture Research Service, Beltsville, Maryland, USA
| | - Mirco Migliavacca
- Department Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Tarek S El-Madany
- Department Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Jacob A Nelson
- Department Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Ana Andreu
- IFAPA - Consejería de Agricultura, Pesca y Desarrollo Rural, Córdoba, Spain
| | - Arnaud Carrara
- Fundación Centro de Estudios Ambientales del Mediterráneo (CEAM), Valencia, Spain
| | - Jason Beringer
- School of Geography and Environmental Science, Monash University, Australia
| | - Dennis Baldocchi
- Ecosystem Sciences Division, Department of Environmental Science, Policy and Management, University of California, Berkeley, Berkeley, California, USA
| | - M Pilar Martín
- Environmental Remote Sensing and Spectroscopy Laboratory (SpecLab), Spanish National Research Council (CSIC), Madrid, Spain
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4
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Migliavacca M, Musavi T, Mahecha MD, Nelson JA, Knauer J, Baldocchi DD, Perez-Priego O, Christiansen R, Peters J, Anderson K, Bahn M, Black TA, Blanken PD, Bonal D, Buchmann N, Caldararu S, Carrara A, Carvalhais N, Cescatti A, Chen J, Cleverly J, Cremonese E, Desai AR, El-Madany TS, Farella MM, Fernández-Martínez M, Filippa G, Forkel M, Galvagno M, Gomarasca U, Gough CM, Göckede M, Ibrom A, Ikawa H, Janssens IA, Jung M, Kattge J, Keenan TF, Knohl A, Kobayashi H, Kraemer G, Law BE, Liddell MJ, Ma X, Mammarella I, Martini D, Macfarlane C, Matteucci G, Montagnani L, Pabon-Moreno DE, Panigada C, Papale D, Pendall E, Penuelas J, Phillips RP, Reich PB, Rossini M, Rotenberg E, Scott RL, Stahl C, Weber U, Wohlfahrt G, Wolf S, Wright IJ, Yakir D, Zaehle S, Reichstein M. The three major axes of terrestrial ecosystem function. Nature 2021; 598:468-472. [PMID: 34552242 PMCID: PMC8528706 DOI: 10.1038/s41586-021-03939-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 08/20/2021] [Indexed: 02/08/2023]
Abstract
The leaf economics spectrum1,2 and the global spectrum of plant forms and functions3 revealed fundamental axes of variation in plant traits, which represent different ecological strategies that are shaped by the evolutionary development of plant species2. Ecosystem functions depend on environmental conditions and the traits of species that comprise the ecological communities4. However, the axes of variation of ecosystem functions are largely unknown, which limits our understanding of how ecosystems respond as a whole to anthropogenic drivers, climate and environmental variability4,5. Here we derive a set of ecosystem functions6 from a dataset of surface gas exchange measurements across major terrestrial biomes. We find that most of the variability within ecosystem functions (71.8%) is captured by three key axes. The first axis reflects maximum ecosystem productivity and is mostly explained by vegetation structure. The second axis reflects ecosystem water-use strategies and is jointly explained by variation in vegetation height and climate. The third axis, which represents ecosystem carbon-use efficiency, features a gradient related to aridity, and is explained primarily by variation in vegetation structure. We show that two state-of-the-art land surface models reproduce the first and most important axis of ecosystem functions. However, the models tend to simulate more strongly correlated functions than those observed, which limits their ability to accurately predict the full range of responses to environmental changes in carbon, water and energy cycling in terrestrial ecosystems7,8.
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Affiliation(s)
- Mirco Migliavacca
- grid.419500.90000 0004 0491 7318Max Planck Institute for Biogeochemistry, Jena, Germany ,grid.9647.c0000 0004 7669 9786German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, Germany ,grid.434554.70000 0004 1758 4137Present Address: European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Talie Musavi
- grid.419500.90000 0004 0491 7318Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Miguel D. Mahecha
- grid.419500.90000 0004 0491 7318Max Planck Institute for Biogeochemistry, Jena, Germany ,grid.9647.c0000 0004 7669 9786German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, Germany ,grid.9647.c0000 0004 7669 9786Remote Sensing Center for Earth System Research, Leipzig University, Leipzig, Germany ,grid.7492.80000 0004 0492 3830Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany
| | - Jacob A. Nelson
- grid.419500.90000 0004 0491 7318Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Jürgen Knauer
- grid.492990.f0000 0004 0402 7163CSIRO Oceans and Atmosphere, Canberra, Australian Capital Territory Australia ,grid.1029.a0000 0000 9939 5719Present Address: Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales Australia
| | - Dennis D. Baldocchi
- grid.47840.3f0000 0001 2181 7878Department of Environmental Science, Policy and Management, University of California, Berkeley, Berkeley, CA USA
| | - Oscar Perez-Priego
- grid.411901.c0000 0001 2183 9102Department of Forest Engineering, ERSAF Research Group, University of Cordoba, Cordoba, Spain
| | - Rune Christiansen
- grid.5254.60000 0001 0674 042XDepartment of Mathematical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jonas Peters
- grid.5254.60000 0001 0674 042XDepartment of Mathematical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Karen Anderson
- grid.8391.30000 0004 1936 8024Environment and Sustainability Institute, University of Exeter, Penryn, UK
| | - Michael Bahn
- grid.5771.40000 0001 2151 8122Department of Ecology, University of Innsbruck, Innsbruck, Austria
| | - T. Andrew Black
- Faculty of Land and Food Systems, Vancouver, British Columbia Canada
| | - Peter D. Blanken
- grid.266190.a0000000096214564Department of Geography, University of Colorado, Boulder, CO USA
| | - Damien Bonal
- grid.29172.3f0000 0001 2194 6418Université de Lorraine, AgroParisTech, INRAE, UMR Silva, Nancy, France
| | - Nina Buchmann
- grid.5801.c0000 0001 2156 2780Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Silvia Caldararu
- grid.419500.90000 0004 0491 7318Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Arnaud Carrara
- grid.17095.3a0000 0000 8717 7992Fundación Centro de Estudios Ambientales del Mediterráneo (CEAM), Paterna, Spain
| | - Nuno Carvalhais
- grid.419500.90000 0004 0491 7318Max Planck Institute for Biogeochemistry, Jena, Germany ,grid.10772.330000000121511713Departamento de Ciências e Engenharia do Ambiente, Universidade Nova de Lisboa, Caparica, Portugal
| | - Alessandro Cescatti
- grid.434554.70000 0004 1758 4137European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Jiquan Chen
- grid.17088.360000 0001 2150 1785Landscape Ecology & Ecosystem Science (LEES) Lab, Center for Global Change and Earth Observations, and Department of Geography, Environmental and Spatial Science, Michigan State University, East Lansing, MI USA
| | - Jamie Cleverly
- grid.117476.20000 0004 1936 7611School of Life Sciences, University of Technology Sydney, Ultimo, New South Wales Australia ,grid.1011.10000 0004 0474 1797Terrestrial Ecosystem Research Network, College of Science and Engineering, James Cook University, Cairns, Queensland Australia
| | - Edoardo Cremonese
- Climate Change Unit, Environmental Protection Agency of Aosta Valley, Aosta, Italy
| | - Ankur R. Desai
- grid.14003.360000 0001 2167 3675Department of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison, Madison, WI USA
| | - Tarek S. El-Madany
- grid.419500.90000 0004 0491 7318Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Martha M. Farella
- grid.411377.70000 0001 0790 959XO’Neill School of Public and Environmental Affairs, Indiana University, Bloomington, IN USA
| | - Marcos Fernández-Martínez
- grid.5284.b0000 0001 0790 3681Research Group Plant and Ecosystems (PLECO), Department of Biology, University of Antwerp, Wilrijk, Belgium
| | - Gianluca Filippa
- Climate Change Unit, Environmental Protection Agency of Aosta Valley, Aosta, Italy
| | - Matthias Forkel
- grid.4488.00000 0001 2111 7257Institute of Photogrammetry and Remote Sensing, TU Dresden, Dresden, Germany
| | - Marta Galvagno
- Climate Change Unit, Environmental Protection Agency of Aosta Valley, Aosta, Italy
| | - Ulisse Gomarasca
- grid.419500.90000 0004 0491 7318Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Christopher M. Gough
- grid.224260.00000 0004 0458 8737Department of Biology, Virginia Commonwealth University, Richmond, VA USA
| | - Mathias Göckede
- grid.419500.90000 0004 0491 7318Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Andreas Ibrom
- grid.5170.30000 0001 2181 8870Department of Environmental Engineering, Technical University of Denmark (DTU), Kongens Lyngby, Denmark
| | - Hiroki Ikawa
- grid.416835.d0000 0001 2222 0432Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Ivan A. Janssens
- grid.5284.b0000 0001 0790 3681Research Group Plant and Ecosystems (PLECO), Department of Biology, University of Antwerp, Wilrijk, Belgium
| | - Martin Jung
- grid.419500.90000 0004 0491 7318Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Jens Kattge
- grid.419500.90000 0004 0491 7318Max Planck Institute for Biogeochemistry, Jena, Germany ,grid.9647.c0000 0004 7669 9786German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, Germany
| | - Trevor F. Keenan
- grid.47840.3f0000 0001 2181 7878Department of Environmental Science, Policy and Management, University of California, Berkeley, Berkeley, CA USA ,grid.184769.50000 0001 2231 4551Earth and Environmental Science Area, Lawrence Berkeley National Laboratory, Berkeley, CA USA
| | - Alexander Knohl
- grid.7450.60000 0001 2364 4210Bioclimatology, Faculty of Forest Sciences and Forest Ecology, University of Goettingen, Goettingen, Germany ,grid.7450.60000 0001 2364 4210Centre of Biodiversity and Sustainable Land Use (CBL), University of Goettingen, Goettingen, Germany
| | - Hideki Kobayashi
- grid.410588.00000 0001 2191 0132Research Institute for Global Change, Institute of Arctic Climate and Environment Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokohama, Japan
| | - Guido Kraemer
- grid.9647.c0000 0004 7669 9786Remote Sensing Center for Earth System Research, Leipzig University, Leipzig, Germany ,grid.5338.d0000 0001 2173 938XImage Processing Laboratory (IPL), Universitat de València, València, Spain
| | - Beverly E. Law
- grid.4391.f0000 0001 2112 1969Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR USA
| | - Michael J. Liddell
- grid.1011.10000 0004 0474 1797Centre for Tropical, Environmental, and Sustainability Sciences, James Cook University, Cairns, Queensland Australia
| | - Xuanlong Ma
- grid.32566.340000 0000 8571 0482College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China
| | - Ivan Mammarella
- grid.7737.40000 0004 0410 2071Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland
| | - David Martini
- grid.419500.90000 0004 0491 7318Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Craig Macfarlane
- grid.469914.70000 0004 0385 5215CSIRO Land and Water, Floreat, Western Australia Australia
| | - Giorgio Matteucci
- grid.5326.20000 0001 1940 4177Consiglio Nazionale delle Ricerche, Istituto per la BioEconomia (CNR – IBE), Sesto Fiorentino, Italy
| | - Leonardo Montagnani
- grid.34988.3e0000 0001 1482 2038Facoltà di Scienze e Tecnologie, Libera Universita’ di Bolzano, Bolzano, Italy ,Forest Services of the Autonomous Province of Bozen-Bolzano, Bolzano, Italy
| | | | - Cinzia Panigada
- grid.7563.70000 0001 2174 1754Department of Earth and Environmental Sciences (DISAT), University of Milano-Bicocca, Milan, Italy
| | - Dario Papale
- grid.12597.380000 0001 2298 9743Department for Innovation in Biological, Agro-Food and Forest Systems (DIBAF), University of Tuscia, Viterbo, Italy
| | - Elise Pendall
- grid.1029.a0000 0000 9939 5719Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales Australia
| | - Josep Penuelas
- grid.4711.30000 0001 2183 4846CSIC, Global Ecology Unit CREAF-CSIC-UAB, Barcelona, Spain ,grid.452388.00000 0001 0722 403XCREAF, Barcelona, Spain
| | - Richard P. Phillips
- grid.411377.70000 0001 0790 959XDepartment of Biology, Indiana University, Bloomington, IN USA
| | - Peter B. Reich
- grid.1029.a0000 0000 9939 5719Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales Australia ,grid.17635.360000000419368657Department of Forest Resources, University of Minnesota, Saint Paul, MN USA ,grid.214458.e0000000086837370Institute for Global Change Biology and School for Environment and Sustainability, University of Michigan, Ann Arbor, MI USA
| | - Micol Rossini
- grid.7563.70000 0001 2174 1754Department of Earth and Environmental Sciences (DISAT), University of Milano-Bicocca, Milan, Italy
| | - Eyal Rotenberg
- grid.13992.300000 0004 0604 7563Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Russell L. Scott
- grid.463419.d0000 0001 0946 3608Southwest Watershed Research Center, USDA Agricultural Research Service, Tucson, AZ USA
| | - Clement Stahl
- INRAE, UMR EcoFoG, CNRS, Cirad, AgroParisTech, Université des Antilles, Université de Guyane, Kourou, France
| | - Ulrich Weber
- grid.419500.90000 0004 0491 7318Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Georg Wohlfahrt
- grid.5771.40000 0001 2151 8122Department of Ecology, University of Innsbruck, Innsbruck, Austria
| | - Sebastian Wolf
- grid.5801.c0000 0001 2156 2780Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Ian J. Wright
- grid.1029.a0000 0000 9939 5719Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales Australia ,grid.1004.50000 0001 2158 5405Department of Biological Sciences, Macquarie University, Sydney, New South Wales Australia
| | - Dan Yakir
- grid.13992.300000 0004 0604 7563Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Sönke Zaehle
- grid.419500.90000 0004 0491 7318Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Markus Reichstein
- grid.419500.90000 0004 0491 7318Max Planck Institute for Biogeochemistry, Jena, Germany ,grid.9647.c0000 0004 7669 9786German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, Germany ,grid.9613.d0000 0001 1939 2794Michael-Stifel-Center Jena for Data-driven and Simulation Science, Friedrich-Schiller-Universität Jena, Jena, Germany
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Oufiero CE, Kraskura K, Bennington R, Nelson JA. Individual Repeatability of Locomotor Kinematics and Swimming Performance in a Gymnotiform Swimmer. Physiol Biochem Zool 2020; 94:22-34. [PMID: 33275536 DOI: 10.1086/712058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractGymnotiform swimming is a specialized form of swimming wherein thrust is produced by the ribbonlike motion of an elongate anal fin, while the body is held relatively stiff. This form of swimming has been extensively examined in relation to the biomechanics of thrust production, the kinematics of the anal fin, and neuromuscular control, whereas few studies have examined whole-animal performance parameters of this swimming mode. The goals of this research were to (1) assess the maximum abilities and repeatability of two swimming performance measures, sprinting and prolonged swimming, which would indicate that these performance measures in a gymnotiform swimmer may be a target for selection, similar to body-caudal fin-swimming fish; (2) examine how a gymnotiform swimmer modulates swimming speed; and (3) determine whether modulatory behavior is consistent across different-sized fish and within individuals across time. Sprinting and prolonged swimming were examined in black ghost knifefish (Apteronotus albifrons; N=15), multiple times on the same day, and were measured again 4 wk later. Sprinting ability was measured by chasing a fish down a photocell-lined racetrack and obtaining the fastest speed between any 8-cm span. Prolonged swimming abilities were measured in a constant acceleration test (Ucat) in a Brett-style swim tunnel by measuring the maximum speed the fish could attain against a steadily increasing water velocity. We determined frequency, wavelength, and amplitude of the anal fin sine wave in fish swimming at different speeds during the Ucat trials. We found repeatable measures of sprint speed and Ucat performance over short (day) and medium (4 wk) time periods for both tests. Neither sprint nor Ucat performance was significantly dependent on size, suggesting that the primary driver of performance variation was individual differences in physiology. Most modulation of swimming speed occurred through changes in the frequency of the wave train processing down the anal fin, with only modest changes to the wavelength and minimal changes to amplitude. Finally, we compare our measures of swimming performance in this gymnotiform swimmer to published values of body-caudal fin swimmers to demonstrate that this form of locomotion results in comparable sprint and constant-acceleration values.
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Nelson JA, Pérez-Priego O, Zhou S, Poyatos R, Zhang Y, Blanken PD, Gimeno TE, Wohlfahrt G, Desai AR, Gioli B, Limousin JM, Bonal D, Paul-Limoges E, Scott RL, Varlagin A, Fuchs K, Montagnani L, Wolf S, Delpierre N, Berveiller D, Gharun M, Belelli Marchesini L, Gianelle D, Šigut L, Mammarella I, Siebicke L, Andrew Black T, Knohl A, Hörtnagl L, Magliulo V, Besnard S, Weber U, Carvalhais N, Migliavacca M, Reichstein M, Jung M. Ecosystem transpiration and evaporation: Insights from three water flux partitioning methods across FLUXNET sites. Glob Chang Biol 2020; 26:6916-6930. [PMID: 33022860 DOI: 10.1111/gcb.15314] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [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: 01/14/2020] [Accepted: 06/24/2020] [Indexed: 06/11/2023]
Abstract
We apply and compare three widely applicable methods for estimating ecosystem transpiration (T) from eddy covariance (EC) data across 251 FLUXNET sites globally. All three methods are based on the coupled water and carbon relationship, but they differ in assumptions and parameterizations. Intercomparison of the three daily T estimates shows high correlation among methods (R between .89 and .94), but a spread in magnitudes of T/ET (evapotranspiration) from 45% to 77%. When compared at six sites with concurrent EC and sap flow measurements, all three EC-based T estimates show higher correlation to sap flow-based T than EC-based ET. The partitioning methods show expected tendencies of T/ET increasing with dryness (vapor pressure deficit and days since rain) and with leaf area index (LAI). Analysis of 140 sites with high-quality estimates for at least two continuous years shows that T/ET variability was 1.6 times higher across sites than across years. Spatial variability of T/ET was primarily driven by vegetation and soil characteristics (e.g., crop or grass designation, minimum annual LAI, soil coarse fragment volume) rather than climatic variables such as mean/standard deviation of temperature or precipitation. Overall, T and T/ET patterns are plausible and qualitatively consistent among the different water flux partitioning methods implying a significant advance made for estimating and understanding T globally, while the magnitudes remain uncertain. Our results represent the first extensive EC data-based estimates of ecosystem T permitting a data-driven perspective on the role of plants' water use for global water and carbon cycling in a changing climate.
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Affiliation(s)
- Jacob A Nelson
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Oscar Pérez-Priego
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Sha Zhou
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
- Earth Institute, Columbia University, New York, NY, USA
- Department of Earth and Environmental Engineering, Columbia University, New York, NY, USA
| | - Rafael Poyatos
- CREAF, Cerdanyola del Vallès, Spain
- Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
| | - Yao Zhang
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
| | - Peter D Blanken
- Department of Geography, University of Colorado, Boulder, CO, USA
| | - Teresa E Gimeno
- Basque Centre for Climate Change, Scientific Campus of the University of the Basque Country, Leioa, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Georg Wohlfahrt
- Department of Ecology, University of Innsbruck, Innsbruck, Austria
| | - Ankur R Desai
- Department of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Beniamino Gioli
- Institute of Bioeconomy (IBE), National Research Council of Italy (CNR), Firenze, Italy
| | - Jean-Marc Limousin
- CEFE, UMR 5175, CNRS, Univ Montpellier, Univ Paul Valéry Montpellier 3, EPHE, IRD, Montpellier, France
| | - Damien Bonal
- Université de Lorraine, AgroParisTech, INRA, UMR Silva, Nancy, France
| | | | - Russell L Scott
- Southwest Watershed Research Center, USDA-ARS, Tucson, AZ, USA
| | - Andrej Varlagin
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
| | - Kathrin Fuchs
- Karlsruhe Institute of Technology (KIT) Institute of Meteorology and Climate Research - Atmospheric Environmental Research, Garmisch-Partenkirchen, Germany
| | | | - Sebastian Wolf
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Nicolas Delpierre
- Ecologie Systématique Evolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, France
| | - Daniel Berveiller
- Ecologie Systématique Evolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, France
| | - Mana Gharun
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Luca Belelli Marchesini
- Department of Sustainable Agro-Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
- Department of Landscape Design and Sustainable Ecosystems, Agrarian-Technological Institute, RUDN University, Moscow, Russia
| | - Damiano Gianelle
- Department of Sustainable Agro-Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Ladislav Šigut
- Department of Matter and Energy Fluxes, Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
| | - Ivan Mammarella
- Institute for Atmospheric and Earth System Research INAR/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland
| | - Lukas Siebicke
- Bioclimatology, University of Goettingen, Göttingen, Germany
| | - T Andrew Black
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada
| | - Alexander Knohl
- Bioclimatology, University of Goettingen, Göttingen, Germany
- Centre of Biodiversity and Sustainable Land Use, University of Goettingen, Goettingen, Germany
| | - Lukas Hörtnagl
- Institute of Agricultural Sciences, ETH Zurich, Zurich, Switzerland
| | - Vincenzo Magliulo
- Institute for Agricultural and Forest Systems in the Mediterranean (ISAFoM), National Research Council of Italy (CNR), Ercolano, Italy
| | - Simon Besnard
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
- Laboratory of Geo-Information Science and Remote Sensing, Wageningen University and Research Center, Wageningen, The Netherlands
| | - Ulrich Weber
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Nuno Carvalhais
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
- Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Mirco Migliavacca
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Markus Reichstein
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
- Michael-Stifel-Center Jena for Data-Driven and Simulation Science, Jena, Germany
| | - Martin Jung
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
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Pfob A, Mehrara BJ, Nelson JA, Wilkins EG, Pusic AL, Sidey-Gibbons C. Towards data-driven decision-making for breast cancer patients undergoing mastectomy and reconstruction: accurate prediction of individual patient-reported outcomes at 2-year follow-up using machine learning. Geburtshilfe Frauenheilkd 2020. [DOI: 10.1055/s-0040-1717866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Affiliation(s)
- A Pfob
- Harvard Medical School & Brigham and Women’s Hospital, PROVE Center
- University Hospital Heidelberg, Department of Obstetrics and Gynecology
| | | | - JA Nelson
- Memorial Sloan Kettering Cancer Center
| | | | - AL Pusic
- Harvard Medical School & Brigham and Women’s Hospital, PROVE Center
| | - C Sidey-Gibbons
- The University of Texas MD Anderson Cancer Center, Department of Symptom Research
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Nelson JA. Oxygen consumption rate v. rate of energy utilization of fishes: a comparison and brief history of the two measurements. J Fish Biol 2016; 88:10-25. [PMID: 26768970 DOI: 10.1111/jfb.12824] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 09/23/2015] [Indexed: 06/05/2023]
Abstract
Accounting for energy use by fishes has been taking place for over 200 years. The original, and continuing gold standard for measuring energy use in terrestrial animals, is to account for the waste heat produced by all reactions of metabolism, a process referred to as direct calorimetry. Direct calorimetry is not easy or convenient in terrestrial animals and is extremely difficult in aquatic animals. Thus, the original and most subsequent measurements of metabolic activity in fishes have been measured via indirect calorimetry. Indirect calorimetry takes advantage of the fact that oxygen is consumed and carbon dioxide is produced during the catabolic conversion of foodstuffs or energy reserves to useful ATP energy. As measuring [CO2 ] in water is more challenging than measuring [O2 ], most indirect calorimetric studies on fishes have used the rate of O2 consumption. To relate measurements of O2 consumption back to actual energy usage requires knowledge of the substrate being oxidized. Many contemporary studies of O2 consumption by fishes do not attempt to relate this measurement back to actual energy usage. Thus, the rate of oxygen consumption (M˙O2 ) has become a measurement in its own right that is not necessarily synonymous with metabolic rate. Because all extant fishes are obligate aerobes (many fishes engage in substantial net anaerobiosis, but all require oxygen to complete their life cycle), this discrepancy does not appear to be of great concern to the fish biology community, and reports of fish oxygen consumption, without being related to energy, have proliferated. Unfortunately, under some circumstances, these measures can be quite different from one another. A review of the methodological history of the two measurements and a look towards the future are included.
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Affiliation(s)
- J A Nelson
- Towson University, Department of Biological Sciences, 8000 York Road, Towson, MD 21252, U.S.A
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Nelson JA, Lipkey GK. Hypoxia tolerance variance between swimming and resting striped bass Morone saxatilis. J Fish Biol 2015; 87:510-518. [PMID: 26184582 DOI: 10.1111/jfb.12735] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 05/28/2015] [Indexed: 06/04/2023]
Abstract
Individual striped bass Morone saxatilis were each exposed in random order to aquatic hypoxia (10% air saturation) either while swimming at 50% of their estimated critical swimming speed (Ucrit ) or while at rest until they lost equilibrium. Individuals were always less tolerant of hypoxia when swimming (P < 0.01); the average fish was over five times more tolerant to the same hypoxia exposure when not swimming. There was no relationship between an individual's rank order of hypoxia tolerance (HT) under the two flow regimes, suggesting that different factors determine an individual's HT when at rest than when swimming.
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Affiliation(s)
- J A Nelson
- Towson University, Department of Biological Sciences, 8000 York Road, Towson, MD, 21252, U.S.A
| | - G K Lipkey
- Towson University, Department of Biological Sciences, 8000 York Road, Towson, MD, 21252, U.S.A
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Chung CU, Nelson JA, Fischer JP, Wink JD, Serletti JM, Kovach SJ. Acute kidney injury after open ventral hernia repair: an analysis of the 2005-2012 ACS-NSQIP datasets. Hernia 2015; 20:131-8. [PMID: 26099501 DOI: 10.1007/s10029-015-1395-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Accepted: 06/06/2015] [Indexed: 12/13/2022]
Abstract
PURPOSE Acute kidney injury (AKI) is a serious postoperative complication, negatively impacting mortality rates, extending length of stay, and raising hospital costs. The purpose of this study was to examine AKI following open ventral hernia repair (OVHR) using a large, heterogeneous database to determine the incidence and identify risk factors for this complication. METHODS Using the 2005-2012 ACS-NSQIP database, patients undergoing open ventral hernia repair were identified by CPT codes. Patients with acute kidney injury within 30 days of surgery were compared to controls by multivariate logistic regression across preoperative and intraoperative characteristics. RESULTS Of 48,629 open ventral hernia repair patients identified in the dataset, AKI developed in 1.4% (681 patients). Multivariate logistic regression determined a number of factors associated with AKI. These include WHO Class III obesity (OR = 2.57, p < 0.001), history of cardiovascular disease (OR = 1.81, p < 0.001), diabetes (OR = 1.29, p = 0.028), hypoalbuminemia (OR = 1.42, p = 0.004), and chronic kidney disease (for a baseline GFR of 60-89 mL/min/1.73 m2, OR = 1.62, p = 0.001; for 30-59 mL/min/1.73 m2, OR = 2.25, p < 0.001; for 15-29 mL/min/1.73 m2, OR = 4.96, p < 0.001). Intraoperative factors include prolonged operative time (for ≥1 SD above the mean, OR = 1.68, p = 0.002; for ≥2SD above the mean, OR = 2.76, p < 0.001) and intraoperative transfusion (OR = 2.44, p < 0.001). CONCLUSIONS Patients with a history of obesity, chronic kidney disease, cardiovascular history, diabetes, and hypoalbuminemia are at increased risk for AKI when undergoing OVHR. Intraoperative variables such as prolonged operative times and blood transfusions may also suggest increased risk. Preoperative identification of patients with these characteristics and perioperative hemodynamic stabilization are important first steps to minimize this complication.
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Affiliation(s)
- C U Chung
- Division of Plastic Surgery, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA, 19104, USA.
| | - J A Nelson
- Division of Plastic Surgery, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA, 19104, USA
| | - J P Fischer
- Division of Plastic Surgery, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA, 19104, USA
| | - J D Wink
- Division of Plastic Surgery, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA, 19104, USA
| | - J M Serletti
- Division of Plastic Surgery, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA, 19104, USA
| | - S J Kovach
- Division of Plastic Surgery, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA, 19104, USA
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Nelson JA, Bugbee B. Economic analysis of greenhouse lighting: light emitting diodes vs. high intensity discharge fixtures. PLoS One 2014; 9:e99010. [PMID: 24905835 PMCID: PMC4048233 DOI: 10.1371/journal.pone.0099010] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 05/08/2014] [Indexed: 11/19/2022] Open
Abstract
Lighting technologies for plant growth are improving rapidly, providing numerous options for supplemental lighting in greenhouses. Here we report the photosynthetic (400–700 nm) photon efficiency and photon distribution pattern of two double-ended HPS fixtures, five mogul-base HPS fixtures, ten LED fixtures, three ceramic metal halide fixtures, and two fluorescent fixtures. The two most efficient LED and the two most efficient double-ended HPS fixtures had nearly identical efficiencies at 1.66 to 1.70 micromoles per joule. These four fixtures represent a dramatic improvement over the 1.02 micromoles per joule efficiency of the mogul-base HPS fixtures that are in common use. The best ceramic metal halide and fluorescent fixtures had efficiencies of 1.46 and 0.95 micromoles per joule, respectively. We also calculated the initial capital cost of fixtures per photon delivered and determined that LED fixtures cost five to ten times more than HPS fixtures. The five-year electric plus fixture cost per mole of photons is thus 2.3 times higher for LED fixtures, due to high capital costs. Compared to electric costs, our analysis indicates that the long-term maintenance costs are small for both technologies. If widely spaced benches are a necessary part of a production system, the unique ability of LED fixtures to efficiently focus photons on specific areas can be used to improve the photon capture by plant canopies. Our analysis demonstrates, however, that the cost per photon delivered is higher in these systems, regardless of fixture category. The lowest lighting system costs are realized when an efficient fixture is coupled with effective canopy photon capture.
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Affiliation(s)
- Jacob A. Nelson
- Crop Physiology Laboratory, Department of Plant Soils and Climate, Utah State University, Logan, Utah, United States of America
| | - Bruce Bugbee
- Crop Physiology Laboratory, Department of Plant Soils and Climate, Utah State University, Logan, Utah, United States of America
- * E-mail:
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Abstract
Several taxonomically disparate groups of fishes have evolved the ability to extract oxygen from the air with elements of their gut. Despite perceived difficulties with balancing digestive and respiratory function, gut air breathing (GAB) has evolved multiple times in fishes and several GAB families are among the most successful fish families in terms of species numbers. When gut segments evolve into an air-breathing organ (ABO), there is generally a specialized region for exchange of gases where the gut wall has diminished, vascularization has increased, capillaries have penetrated into the luminal epithelium and surfactant is produced. This specialized region is generally separated from digestive portions of the gut by sphincters. GAB fishes tend to be facultative air breathers that use air breathing to supplement aquatic respiration in hypoxic waters. Some hindgut breathers may be continuous, but not obligate air breathers (obligate air breathers drown if denied access to air). Gut ABOs are generally used only for oxygen uptake; CO₂ elimination seems to occur via the gills and skin in all GAB fishes studied. Aerial ventilation in GAB fishes is driven primarily by oxygen partial pressure of the water (PO₂) and possibly also by metabolic demand. The effect of aerial ventilation on branchial ventilation and the cardiovascular system is complex and generalizations across taxa or ABO type are not currently possible. Blood from GAB fishes generally has a low blood oxygen partial pressure that half saturates haemoglobin (p50) with a very low erythrocytic nucleoside triphosphate concentration [NTP]. GAB behaviour in nature depends on the social and ecological context of the animal as well as on physiological factors.
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Affiliation(s)
- J A Nelson
- Department of Biological Sciences, Towson University, Towson, MD 21252-0001, U.S.A
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Abstract
Pigeons were trained to respond to two stimuli on the wavelength continuum, 550 nm and 570 nm, each correlated with an independent schedule of reinforcement. The multiple schedule component in effect during 550 nm (S1) was always a variable-interval 1-min. During the 570-nm stimulus (S2) the second component of the schedule was either variable-interval 30-sec, 1-min, 2-min, 5-min, or extinction for different groups of birds. Generalization gradients were obtained after this training, with the following results: (1) response rate to S1 during training was related to the reinforcement frequency associated with S2; the distribution of responding during generalization testing was a function of the schedules of reinforcement used during training and the response rates they produced. Decreases in the relative frequency of reinforcement correlated with S2 resulted in increases in the distribution shift of responses away from S2 during generalization testing.
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Vomaske J, Nelson JA, Streblow DN. Human Cytomegalovirus US28: a functionally selective chemokine binding receptor. Infect Disord Drug Targets 2010; 9:548-56. [PMID: 19594424 DOI: 10.2174/187152609789105696] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2009] [Accepted: 03/06/2009] [Indexed: 11/22/2022]
Abstract
Chemokines are small cytokines that are part of a large family of molecules that bind to G-protein coupled receptors, which, as a family, are the most widely targeted group of molecules in the treatment of disease. Chemokines are critical for recruiting and activating the cells of the immune system during inflammation especially during viral infections. However, a number of viruses including the large herpes virus human cytomegalovirus (HCMV) encode mechanisms to impede the effects of chemokines or has gained the ability to use these molecules to its own advantage. The Human Cytomegalovirus (HCMV)-encoded chemokine receptor US28 is the best characterized of the four unique chemokine receptor-like molecules found in the HCMV genome. US28 has been studied as an important virulence factor for HCMV-mediated vascular disease and, more recently, in models of HCMV-associated malignancy. US28 is a rare multi-chemokine family binding receptor with the ability to bind ligands from two distinct chemokine classes. Ligand binding to US28 activates cell-type and ligand-specific signaling pathways leading to cellular migration, which is an important example of receptor functional selectivity. Additionally, US28 has been demonstrated to constitutively activate phospholipase C (PLC) and NF-kB signaling pathways. Understanding the structure/function relationships between US28, its ligands and intracellular signaling molecules will provide essential clues for effective pharmacological targeting of this multifunctional chemokine receptor.
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Affiliation(s)
- Jennifer Vomaske
- Department of Molecular Microbiology and Immunology and The Vaccine and Gene Therapy Institute, Oregon Health and Sciences University, Portland, OR 97201, USA
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Marras S, Claireaux G, McKenzie DJ, Nelson JA. Individual variation and repeatability in aerobic and anaerobic swimming performance of European sea bass, Dicentrarchus labrax. ACTA ACUST UNITED AC 2010; 213:26-32. [PMID: 20008358 DOI: 10.1242/jeb.032136] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Studies of inter-individual variation in fish swimming performance may provide insight into how selection has influenced diversity in phenotypic traits. We investigated individual variation and short-term repeatability of individual swimming performance by wild European sea bass in a constant acceleration test (CAT). Fish were challenged with four consecutive CATs with 5 min rest between trials. We measured maximum anaerobic speed at exhaustion (U(CAT)), gait transition speed from steady aerobic to unsteady anaerobic swimming (U(gt)), routine metabolic rate (RMR), post-CAT maximum metabolic rate (MMR), aerobic scope and recovery time from the CATs. Fish achieved significantly higher speeds during the first CAT (U(CAT)=170 cm s(-1)), and had much more inter-individual variation in performance (coefficient of variation, CV=18.43%) than in the subsequent three tests (U(CAT)=134 cm s(-1); CV=7.3%), which were very repeatable among individuals. The individual variation in U(CAT) in the first trial could be accounted for almost exclusively by variation in anaerobic burst-and-coast performance beyond U(gt). The U(gt) itself varied substantially between individuals (CV=11.4%), but was significantly repeatable across all four trials. Individual RMR and MMR varied considerably, but the rank order of post-CAT MMR was highly repeatable. Recovery rate from the four CATs was highly variable and correlated positively with the first U(CAT) (longer recovery for higher speeds) but negatively with RMR and aerobic scope (shorter recovery for higher RMR and aerobic scope). This large variation in individual performance coupled with the strong correlations between some of the studied variables may reflect divergent selection favouring alternative strategies for foraging and avoiding predation.
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Affiliation(s)
- S Marras
- Institut des Sciences de l'Evolution de Montpellier, UMR 5554 CNRS-Université de Montpellier 2, Station Méditerranéenne de l'Environnement Littoral, 1 Quai de La Daurade, F-34200 Sète, France.
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Streblow DN, Dumortier J, Moses AV, Orloff SL, Nelson JA. Mechanisms of cytomegalovirus-accelerated vascular disease: induction of paracrine factors that promote angiogenesis and wound healing. Curr Top Microbiol Immunol 2008; 325:397-415. [PMID: 18637518 DOI: 10.1007/978-3-540-77349-8_22] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Human cytomegalovirus (HCMV) is associated with the acceleration of a number of vascular diseases such as atherosclerosis, restenosis, and transplant vascular sclerosis (TVS). All of these diseases are the result of either mechanical or immune-mediated injury followed by inflammation and subsequent smooth muscle cell (SMC) migration from the vessel media to the intima and proliferation that culminates in vessel narrowing. A number of epidemiological and animal studies have demonstrated that CMV significantly accelerates TVS and chronic rejection (CR) in solid organ allografts. In addition, treatment of human recipients and animals alike with the antiviral drug ganciclovir results in prolonged survival of the allograft, indicating that CMV replication is a requirement for acceleration of disease. However, although virus persists in the allograft throughout the course of disease, the number of directly infected cells does not account for the global effects that the virus has on the acceleration of TVS and CR. Recent investigations of up- and downregulated cellular genes in infected allografts in comparison to native heart has demonstrated that rat CMV (RCMV) upregulates genes involved in wound healing (WH) and angiogenesis (AG). Consistent with this result, we have found that supernatants from HCMV-infected cells (HCMV secretome) induce WH and AG using in vitro models. Taken together, these findings suggest that one mechanism for HCMV acceleration of TVS is mediated through induction of secreted cytokines and growth factors from virus-infected cells that promote WH and AG in the allograft, resulting in the acceleration of TVS. We review here the ability of CMV infection to alter the local environment by producing cellular factors that act in a paracrine fashion to enhance WH and AG processes associated with the development of vascular disease, which accelerates chronic allograft rejection.
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Affiliation(s)
- D N Streblow
- Vaccine and Gene Therapy Institute and Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97201, USA.
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Streblow DN, Kreklywich CN, Andoh T, Moses AV, Dumortier J, Smith PP, Defilippis V, Fruh K, Nelson JA, Orloff SL. The role of angiogenic and wound repair factors during CMV-accelerated transplant vascular sclerosis in rat cardiac transplants. Am J Transplant 2008; 8:277-87. [PMID: 18093265 DOI: 10.1111/j.1600-6143.2007.02062.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Human cytomegalovirus (HCMV) accelerates transplant vascular sclerosis (TVS), a consequence of angiogenesis (AG) and wound repair (WR). While HCMV can be localized to TVS lesions, the low number of infected cells suggests a global effect on target tissues. We used microarray analysis followed by real-time-polymerase chain reaction (RT-PCR) in an RCMV-accelerated TVS rat cardiac transplant model to determine whether CMV activates host WR and AG factors. Dysregulated cellular genes in allografts from RCMV-infected recipients were compared to those from uninfected recipients and native hearts. We demonstrated that RCMV upregulates the genes involved in WR and AG, which was highest during the critical time of TVS acceleration (21-28 days). Using a standard in vitro AG assay, virus and serum-free supernatants collected at 48 h postinfection significantly induced endothelial cell (EC) migration, branching and tubule formation compared to supernatants from mock-infected cells. Supernatants from ultraviolet (UV)-inactivated RCMV-infected cells failed to induce AG, indicating that virus replication is required. Upregulation of WR and AG genes occurs during the critical period of CMV-accelerated TVS. Targeting these genes may prevent this process and improve allograft survival.
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Affiliation(s)
- D N Streblow
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Portland, OR, USA
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Affiliation(s)
- A V Moses
- Department of Molecular Microbiology, Oregon Health Sciences University, OR 97201-3098, USA
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Anhang R, Nelson JA, Telerant R, Chiasson MA, Wright TC. Acceptability of self-collection of specimens for HPV DNA testing in an urban population. J Womens Health (Larchmt) 2006; 14:721-8. [PMID: 16232104 DOI: 10.1089/jwh.2005.14.721] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE To assess the acceptability of self-collection of specimens for human papillomavirus (HPV) DNA testing and to explore whether use of self-collected specimens would increase intention to participate in regular screening among low-income, inner-city, minority women. METHODS A written survey was administered to 172 women after they underwent gynecological examination and self-collection of a sample for HPV DNA testing. RESULTS Participants agreed that ease of use (69%), less painful procedure (62%), "could do it myself" (56%), and privacy (52%) were desirable characteristics of the self-sampling procedure they performed. Most of the participants (57%) reported that there was nothing they did not like about self-sampling; however, the majority (68%) preferred the clinician-collected test. Those recruited through a sexually transmitted disease (STD) clinic were significantly more likely than those recruited at a cancer screening clinic (57% vs. 24%), those with some or more college education were significantly more likely than those with less education (43% vs. 26%), and those who were not Hispanic were significantly more likely than those who were Hispanic (49% vs. 28%) to prefer the self-collected test. Although most women (47%) reported that they would be most likely to attend regular screening if tested by a clinician during a pelvic examination, 21% asserted that self-collection at home would increase their likelihood of participation in screening. CONCLUSIONS Although most of the predominantly Hispanic, low-income, uninsured, and recently screened women in the study preferred clinician-collected HPV tests to self-collected sampling, self-sampling is acceptable to the majority and may increase the likelihood of participation in cervical cancer screening programs.
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Affiliation(s)
- R Anhang
- Harvard University, Boston, Massachusetts, USA
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Nelson JA, Dou H, Ellison B, Uberti M, Xiong H, Anderson E, Mellon M, Gelbard HA, Boska M, Gendelman HE. Coregistration of quantitative proton magnetic resonance spectroscopic imaging with neuropathological and neurophysiological analyses defines the extent of neuronal impairments in murine human immunodeficiency virus type-1 encephalitis. J Neurosci Res 2005; 80:562-75. [PMID: 15825192 DOI: 10.1002/jnr.20466] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [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] [Indexed: 11/11/2022]
Abstract
Relatively few immune-activated and virus-infected mononuclear phagocytes (MP; perivascular macrophages and microglia) may affect widespread neuronal dysfunction during human immunodeficiency virus type 1 (HIV-1)-associated dementia (HAD). Indeed, histopathological evidence of neuronal dropout often belies the extent of cognitive impairment. To define relationships between neuronal function and histopathology, proton magnetic resonance spectroscopic imaging (1H MRSI) and hippocampal long-term potentiation (LTP) were compared with neuronal and glial immunohistology in a murine model of HIV-1 encephalitis (HIVE). HIV-1(ADA)-infected human monocyte-derived macrophages (MDM) were stereotactically injected into the subcortex of severe combined immunodeficient (SCID) mice. Sham-operated and unmanipulated mice served as controls. Seven days after cell injection, brain histological analyses revealed a focal giant cell encephalitis, with reactive astrocytes, microgliosis, and neuronal dropout. Strikingly, significant reductions in N-acetyl aspartate concentration ([NAA]) and LTP levels in HIVE mice were in both injected and contralateral hemispheres and in brain subregions, including the hippocampus, where neuropathology was limited or absent. The data support the importance of 1H MRSI as a tool for assessing neuronal function for HAD. The data also demonstrate that a highly focal encephalitis can produce global deficits for neuronal function and metabolism.
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Affiliation(s)
- J A Nelson
- Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska 68198-1045, USA.
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Abstract
BACKGROUND Recent data indicated a potential role for extracellular ubiquitin in hematopoiesis and inflammation. The biological significance and therapeutic potential of these findings in vivo are unknown. Based on its in vitro abilities to inhibit endotoxin-stimulated tumor necrosis factor alpha (TNFalpha) production, we hypothesized that exogenous ubiquitin has salutary effects on sequelae caused by endotoxin in vivo. METHODS Anesthetized and mechanically ventilated swine were infused with endotoxin for 3 hours. Ubiquitin was administered intravenously either 15 minutes before or 45 minutes after the endotoxin infusion was started. Albumin was administered to a control group. An additional control group received only ubiquitin. Ex vivo endotoxin evoked TNFalpha production was measured using a whole blood assay. Ubiquitin and TNFalpha concentrations were determined by enzyme-linked immunosorbent assay. RESULTS Ubiquitin reduced mortality (P <.05), prevented development of pulmonary failure (P <.05), reduced fluid requirements (P <.05), and diminished erythema and edema formation. Ubiquitin pretreatment was more effective than treatment 45 minutes after an endotoxin infusion was started. In vivo ubiquitin administration alone inhibited ex vivo endotoxin-evoked TNFalpha secretion, but had no effect on TNFalpha serum levels after endotoxin infusion. CONCLUSION In vivo ubiquitin administration has salutary actions during lethal endotoxemia and inhibits ex vivo whole blood TNFalpha production upon endotoxin stimulation. The clinical appearance after ubiquitin treatment in endotoxemia indicates the endothelium as another potential target cell population for interactions with ubiquitin. A novel therapeutic approach to a broad variety of diseases, in which endotoxin triggers immune activation, is suggested.
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Boska MD, Welch KM, Barker PB, Nelson JA, Schultz L. Contrasts in cortical magnesium, phospholipid and energy metabolism between migraine syndromes. Headache 2003. [DOI: 10.1046/j.1526-4610.2003.03085_7.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Nelson JA, Gotwalt PS, Reidy SP, Webber DM. Beyond U(crit): matching swimming performance tests to the physiological ecology of the animal, including a new fish 'drag strip'. Comp Biochem Physiol A Mol Integr Physiol 2002; 133:289-302. [PMID: 12208301 DOI: 10.1016/s1095-6433(02)00161-7] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [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: 11/25/2022]
Abstract
Locomotor performance of animals is of considerable interest from management, physiological, ecological and evolutionary perspectives. Yet, despite the extensive commercial exploitation of fishes and interest in the health of various fish stocks, the relationships between performance capacity, natural selection, ecology and physiology are poorly known for fishes. One reason may be the technical challenges faced when trying to measure various locomotor capacities in aquatic species, but we will argue that the slow pace of developing new species-appropriate swim tests is also hindering progress. A technique developed for anadromous salmonids (the U(crit) procedure) has dominated the fish exercise physiology field and, while accounting for major advances in the field, has often been used arbitrarily. Here we propose criteria swimming tests should adhere to and report on several attempts to match swimming tests to the physiological ecology of the animal. Sprint performance measured with a laser diode/photocell timed 'drag strip' is a new method employing new technology and is reported on in some detail. A second new test involves accelerating water past the fish at a constant rate in a traditional swim tunnel/respirometer. These two performance tests were designed to better understand the biology of a bentho-pelagic marine fish, the Atlantic cod (Gadus morhua). Finally, we report on a modified incremental velocity test that was developed to better understand the biology of the blacknose dace (Rhinichthys atratulus), a Nearctic, lotic cyprinid.
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Affiliation(s)
- J A Nelson
- Department of Biological Sciences, Towson University, Towson, MD 21252, USA.
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Boska MD, Welch KMA, Barker PB, Nelson JA, Schultz L. Contrasts in cortical magnesium, phospholipid and energy metabolism between migraine syndromes. Neurology 2002; 58:1227-33. [PMID: 11971091 DOI: 10.1212/wnl.58.8.1227] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [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] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Previous single voxel (31)P MRS pilot studies of migraine patients have suggested that disordered energy metabolism or Mg(2+) deficiencies may be responsible for hyperexcitability of neuronal tissue in migraine patients. These studies were extended to include multiple brain regions and larger numbers of patients by multislice (31)P MR spectroscopic imaging. METHODS Migraine with aura (MWA), migraine without aura (MwoA), and hemiplegic migraine patients were studied between attacks by (31)P MRS imaging using a 3-T scanner. RESULTS Results were compared with those in healthy control subjects without headache. In MwoA, consistent increases in phosphodiester concentration [PDE] were measured in most brain regions, with a trend toward increase in [Mg(2+)] in posterior brain. In MWA, phosphocreatine concentration ([PCr]) was decreased to a minor degree in anterior brain regions and a trend toward decreased [Mg(2+)] was observed in posterior slice 1, but no consistent changes were found in phosphomonoester concentration [PME], [PDE], inorganic phosphate concentration ([Pi]), or pH. In hemiplegic migraine patients, [PCr] had a tendency to be lower, and [Mg(2+)] was significantly lower than in the posterior brain regions of control subjects. Trend analysis showed a significant decrease of brain [Mg(2+)] and [PDE] in posterior brain regions with increasing severity of neurologic symptoms. CONCLUSIONS Overall, the results support no substantial or consistent abnormalities of energy metabolism, but it is hypothesized that disturbances in magnesium ion homeostasis may contribute to brain cortex hyperexcitability and the pathogenesis of migraine syndromes associated with neurologic symptoms. In contrast, migraine patients without a neurologic aura may exhibit compensatory changes in [Mg(2+)] and membrane phospholipids that counteract cortical excitability.
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Affiliation(s)
- M D Boska
- Department of Neurology, Henry Ford Hospital, Detroit, MI, USA
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Wallace MR, Persing DH, McCutchan JA, Magara J, Nelson JA, Heaton RK, Tasker SA, Grant I. Bartonella henselae serostatus is not correlated with neurocognitive decline in HIV infection. Scand J Infect Dis 2002; 33:593-5. [PMID: 11525353 DOI: 10.1080/00365540110026700] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Bartonella henselae has been implicated as a significant cause of HIV-associated dementia. We attempted to confirm this association by utilizing the database of the San Diego HIV Neurobehavioral Research Center, which collects longitudinal neurocognitive and laboratory data on over 500 HIV-infected participants. Utilizing an immunofluorescent assay we found that 11% of 177 subjects, half of whom had documented neurocognitive decline, were seropositive for B. henselae. There was no correlation between B. henselae seropositivity and neurocognitive decline. The role of B. henselae in HIV-associated dementia remains ambiguous.
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Affiliation(s)
- M R Wallace
- Clinical Investigation Department, Naval Medical Center San Diego, California 92134-1005, USA
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Martínez M, Guderley H, Nelson JA, Webber D, Dutil JD. Once a fast cod, always a fast cod: maintenance of performance hierarchies despite changing food availability in cod (Gadus morhua). Physiol Biochem Zool 2002; 75:90-100. [PMID: 11880982 DOI: 10.1086/339213] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [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: 11/03/2022]
Abstract
To examine whether Atlantic cod maintain constant hierarchies of sprint speeds and muscle metabolic capacities under different feeding regimes, the physiological capacities of individual cod were followed through a starvation-feeding-starvation cycle. We examined sprint speeds and maximal enzyme activities in white-muscle biopsies at each period. We measured the glycolytic enzymes, phosphofructokinase (PFK) and lactate dehydrogenase (LDH), the mitochondrial enzyme, cytochrome C oxidase (CCO), and the biosynthetic enzyme, nucleotide diphosphate kinase (NDPK). Sprint speeds were measured in a laser diode/photocell-timed raceway. As expected, the feeding regime had a marked impact on the physiological capacities of cod, but the responses differed for sprint-swimming and muscle metabolic capacities. The different enzyme activities as well the condition index generally decreased during the first starvation, improved with feeding, and fell again during the second starvation. In contrast, sprint performance improved after feeding but did not fall with the second starvation. Although both the enzyme activities and the sprint speeds showed considerable interindividual variation, sprint speeds were not significantly correlated with the enzyme activities. The hierarchy of sprint performance of the cod was maintained, regardless of the preceding feeding regime, whereas those of muscle metabolic capacities were not.
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Affiliation(s)
- M Martínez
- Département de Biologie, Université Laval, Québec, Québec G1K 7P4, Canada.
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Bentler RA, Nelson JA. Effect of spectral shaping and content on loudness discomfort. J Am Acad Audiol 2001; 12:462-70. [PMID: 11699817] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
The purpose of this investigation was to study the impact of spectral shape and content on thresholds of discomfort (TD) for listeners with normal hearing and listeners with hearing loss. Secondary to that purpose was to quantify binaural summation at high intensities across complex stimulus conditions for both groups of listeners. Forty subjects (20 with normal hearing, 20 with hearing loss) participated. Complex acoustic stimuli (multitone and continuous discourse) were filtered to have four spectral shapes: (1) flat spectrum, (2) long-term average speech spectrum, (3) reverse long-term average speech spectrum, and (4) the TD contour derived for each subject from pure-tone TD obtained with eight pure tones from 250 to 4000 Hz. The results suggest that (1) TD for complex stimuli are lower for subjects with hearing loss compared with those with normal hearing, suggesting increased loudness summation with this population; (2) binaural summation of approximately 6 dB (independent of stimulus type, filter shape, or spectral content), indicating that a correction of similar magnitude for bilateral hearing aid fittings is appropriate; and (3) TD obtained at 750, 1500, and 3000 Hz accounted for approximately 60 percent of the variance in the complex TD measures, suggesting that TD at these frequencies be used to set the output obtained from a hearing aid with a 90-dB pure-tone sweep as the input stimulus.
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Affiliation(s)
- R A Bentler
- Department of Speech Pathology and Audiology, The University of Iowa, Iowa City 52242, USA
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Abstract
Infection with the pathogens human cytomegalovirus (HCMV) or Chlamydia pneumonia (CP) is linked to the development of vascular disease, including atherosclerosis. The role of pathogens in vasculopathies has been controversial. However, animal models have demonstrated a direct link between infection with CP and herpesviruses and the development of vascular disease. Clinical studies have shown a direct association of HCMV and CP with the acceleration of vascular disease. This article will review the evidence supporting the role for CP and HCMV in the development of vascular disease and will suggest a potential mechanism for HCMV acceleration of the disease process. Vascular diseases are the result of either mechanical or immune-related injury followed by inflammation and subsequent smooth muscle cell (SMC) proliferation and/or migration from the vessel media to the intima, which culminates in vessel narrowing. A number of in vitro and in vivo models have provided potential mechanisms involved in pathogen-mediated vascular disease. Recently, we have demonstrated that HCMV infection of arterial but not venous SMC results in significant cellular migration in vitro. Migration was dependent on expression of the HCMV-encoded chemokine receptors, US28, and the presence of the chemokines, RANTES or MCP-1. Migration involved chemotaxis and provided the first evidence that viruses may induce migration of SMC toward sites of chemokine production through the expression of a virally encoded chemokine receptor in infected SMC. Because SMC migration into the neointimal space is the hallmark of vascular disease, these observations provide a molecular link between HCMV and the development of vascular disease.
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Affiliation(s)
- D N Streblow
- Department of Molecular Microbiology and Immunology and The Vaccine and Gene Therapy Institute, Oregon Health Sciences University, Portland OR 97201, USA
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Abstract
The human cytomegalovirus (HCMV) has been implicated in the acceleration of vascular disease for some time. The development of vascular disease involves a chronic inflammatory process with many contributing factors, and of these, chemokines and their receptors have recently been identified as key mediators. Interestingly, HCMV encodes four potential chemokine receptors (US27, US28, UL33 and UL78). Of these virally-encoded chemokine receptors, US28 has been the most widely characterized. US28 binds many of the CC-chemokines, and this class of chemokines contributes to the development of vascular disease. Importantly, HCMV infection mediates in vitro SMC migration, which is dependent upon expression of US28 and CC-chemokine binding. US28 and the US28 functional homologues that are capable of inducing the migration of SMC represent potential targets in the treatment of CMV-accelerated vascular disease such as atherosclerosis, restenosis, and transplant vascular sclerosis.
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Affiliation(s)
- D N Streblow
- Department of Molecular Microbiology and Immunology, Vaccine and Gene Therapy Institute, Oregon Health Sciences University, Portland, OR 97201, USA
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Söderberg-Nauclér C, Streblow DN, Fish KN, Allan-Yorke J, Smith PP, Nelson JA. Reactivation of latent human cytomegalovirus in CD14(+) monocytes is differentiation dependent. J Virol 2001; 75:7543-54. [PMID: 11462026 PMCID: PMC114989 DOI: 10.1128/jvi.75.16.7543-7554.2001] [Citation(s) in RCA: 174] [Impact Index Per Article: 7.6] [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: 01/29/2001] [Accepted: 05/04/2001] [Indexed: 01/04/2023] Open
Abstract
We have previously demonstrated reactivation of latent human cytomegalovirus (HCMV) in myeloid lineage cells obtained from healthy donors. Virus was obtained from allogenically stimulated monocyte-derived macrophages (Allo-MDM), but not from macrophages differentiated by mitogenic stimulation (ConA-MDM). In the present study, the cellular and cytokine components essential for HCMV replication and reactivation were examined in Allo-MDM. The importance of both CD4(+) and CD8(+) T cells in the generation of HCMV-permissive Allo-MDM was demonstrated by negative selection or blocking experiments using antibodies directed against both HLA class I and HLA class II molecules. Interestingly, contact of monocytes with CD4 or CD8 T cells was not essential for reactivation of HCMV, since virus was observed in macrophages derived from CD14(+) monocytes stimulated by supernatants produced by allogeneic stimulation of peripheral blood mononuclear cells. Examination of the cytokines produced in Allo-MDM and ConA-MDM cultures indicated a significant difference in the kinetics of production and quantity of these factors. Further examination of the cytokines essential for the generation of HCMV-permissive Allo-MDM identified gamma interferon (IFN-gamma) but not interleukin-1 or -2, tumor necrosis factor alpha, or granulocyte-macrophage colony-stimulating factor as critical components in the generation of these macrophages. In addition, although IFN-gamma was crucial for reactivation of latent HCMV, addition of IFN-gamma to unstimulated macrophage cultures was insufficient to reactivate virus. Thus, this study characterizes two distinct monocyte-derived cell types which can be distinguished by their ability to reactivate and support HCMV replication and identifies the critical importance of IFN-gamma in the reactivation of HCMV.
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Abstract
Human immunodeficiency virus type 1 (HIV-1) only recently established an epidemic world-wide infection in the human population. The virus persists in the human host through active replication and is able to avoid clearance by the immune system. Active replication is an important component of the rapid evolutionary potential of HIV-1, a potential which manifests itself in the evolution of immune escape variants, drug resistant variants, and variants with the ability to use different cell surface coreceptors in conjunction with CD4. Multiple zoonotic introductions, compartmentalization of virus replication in the body, and genetic bottlenecks associated with sampling during transmission, antiretroviral therapy, and geographic and/or host population isolation further contribute to the range of sequences present in extant viruses. The sum of the history of all of these phenomena is reflected in HIV-1 sequence variability, and most of these phenomena are ongoing today. Here we review the use of HIV-1 sequence variability to explore its underlying biology.
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Affiliation(s)
- K M McGrath
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, 22-062 Lineberger Cancer Center, CB# 7295, Chapel Hill, NC 27599-7295, USA
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Wallace MR, Nelson JA, McCutchan JA, Wolfson T, Grant I. Symptomatic HIV seroconverting illness is associated with more rapid neurological impairment. Sex Transm Infect 2001; 77:199-201. [PMID: 11402229 PMCID: PMC1744314 DOI: 10.1136/sti.77.3.199] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [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] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVES To establish whether symptomatic seroconverting illness in HIV infected people is associated with more rapid development of neurological impairment. METHODS 166 HIV infected subjects with a known date of HIV infection enrolled in a longitudinal study of neurocognitive function were stratified by whether or not they had experienced a symptomatic serconverting illness. RESULTS 29 of 166 (17.5%) dated HIV seroconverters had a history of symptomatic seroconverting illness. Though baseline neurocognitive function was similar, subjects with a symptomatic seroconverting illness developed clinical neurocognitive impairment significantly more rapidly than their asymptomatic counterparts in a survival analysis model (636 v 1075 days till impaired). CONCLUSION Symptomatic seroconverting illness predisposes to more rapid neurocognitive impairment.
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Affiliation(s)
- M R Wallace
- Naval Medical Center San Diego, CA, USA University of California at San Diego, CA, USA.
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Freel SA, Williams JM, Nelson JA, Patton LL, Fiscus SA, Swanstrom R, Shugars DC. Characterization of human immunodeficiency virus type 1 in saliva and blood plasma by V3-specific heteroduplex tracking assay and genotype analyses. J Virol 2001; 75:4936-40. [PMID: 11312368 PMCID: PMC114251 DOI: 10.1128/jvi.75.10.4936-4940.2001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [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] [Indexed: 11/20/2022] Open
Abstract
The gp120 V3-encoding region of human immunodeficiency virus type 1 (HIV-1) RNA derived from the saliva and blood plasma of 11 individuals was characterized by heteroduplex tracking assay and sequence analyses. R5-like viral variants were identified in both fluids of all subjects. X4-like variants were detected in the plasma and/or saliva of three subjects, indicating that X4-like variants are not excluded from the saliva compartment. Viral subpopulations were similar in both fluids of most subjects, suggesting that HIV-1 in oral fluids and blood may stem from a common source. These findings raise the possibility of using saliva as a noninvasive fluid for evaluating and monitoring viral evolution in infected persons.
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Affiliation(s)
- S A Freel
- School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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Abstract
We report that single-bubble sonoluminescence (SBSL) at low light intensities produces emission bands similar to multibubble sonoluminescence (MBSL) for pure noble gas bubbles. A smooth crossover between SBSL and MBSL behavior can be induced by varying the acoustic pressure amplitude and thereby the intensity of the light emitted. The relative intensity of the band emission depends both on the molecular weight of the noble gas and the water temperature. Our results provide a connection between the mechanisms SBSL and MBSL and show that molecular emission plays a role in SBSL.
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Affiliation(s)
- J B Young
- James Franck Institute and Department of Physics, University of Chicago, 5640 S. Ellis Avenue, Chicago, Illinois 60637, USA
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Abstract
OBJECTIVES Dietary guidelines for athletes emphasize complex carbohydrates. This study examined dietary intakes of elite figure skaters relative to current recommendations in sports nutrition. PARTICIPANTS Subjects were male (n=80) and female (n=81) figure skaters taking part in a series of training camps held in Colorado between 1988 and 1995. Mean age was 18 years for men and 16 years for women. DESIGN Measures of height, weight, and skinfold thickness were used to calculate body mass index and percent body fat. Blood samples were drawn for analysis of nutritional status. Energy and nutrient intakes were based on 3-day food records. STATISTICAL ANALYSES Multivariate regression model and correlation analyses used the SPSS for Windows program. RESULTS Values of body mass index and percent body fat were similar to those obtained for elite athletes in other studies. Plasma chemistries were in the normal range. Energy intakes (2,329 kcal/day for men and 1,545 kcal/day for women) were below recommended values for sex and age. The skaters derived approximately 50% of their daily energy from sugars and fat. Sugars alone accounted for 25% of daily energy intakes--the skaters consumed between 100 g (women) and 142 g of sugars per day. Sugar and fat intakes, when expressed as percent of daily energy, were inversely linked, providing evidence of a fat-sugar seesaw. Higher-energy diets were higher in fat but lower in carbohydrate and protein. APPLICATIONS High consumption of sugars and fat by elite athletes was not associated with overweight or excess body fat. Although recommended diets are usually built around complex carbohydrates, dietetics professionals can address the increased energy needs of elite athletes by recommending energy-dense foods. Sugars and fats are efficient sources of energy per unit volume.
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Affiliation(s)
- P Ziegler
- Nutrition and Regulatory Division, Gerber Products Co, Summit, NJ, USA
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De La Melena VT, Kreklywich CN, Streblow DN, Yin Q, Cook JW, Soderberg-Naucler C, Bruggeman CA, Nelson JA, Orloff SL. Kinetics and development of CMV-accelerated transplant vascular sclerosis in rat cardiac allografts is linked to early increase in chemokine expression and presence of virus. Transplant Proc 2001; 33:1822-3. [PMID: 11267529 DOI: 10.1016/s0041-1345(00)02729-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- V T De La Melena
- Department of Surgery, Oregon Health Sciences University, VA Medical Center, Portland, Oregon, USA
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41
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Endris RG, Reuter VE, Nelson J, Nelson JA. Efficacy of a topical spot-on containing 65% permethrin against the dog louse, Trichodectes canis (Mallophaga:Trichodectidae). Vet Ther 2001; 2:135-139. [PMID: 19753706] [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] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The efficacy of a 65% permethrin spot-on formulation (Defend EXspot, Schering-Plough Animal Health Corp., Union, NJ) against the dog louse, Trichodectes canis de Greer 1778, was studied. Fourteen dogs naturally infested with T. canis were evenly and randomly allocated to treatment with 65% permethrin administered at the label dose rate of 1 or 2 ml per dog or to an untreated control group. Louse counts were performed for each dog by gently back-combing the hair at six designated anatomic sites (head, tail, belly, each side, and an 8-cm strip the length of the body on the back), and lice were counted without removal on Days 0 (pretreatment), 7, 14, 21, and 28. Lice were eliminated from all dogs treated with the 65% permethrin spot-on within 7 days after treatment, and no subsequent reinfestations due to hatching of eggs were observed during the 28-day evaluation period. Untreated control dogs were subsequently treated with the 65% permethrin spot-on after the initial phase was completed and lice populations were evaluated as previously described. All lice were cleared from these dogs by Day 7, and there were no signs of reinfestation. No adverse reactions to treatment were noted during the study.
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Affiliation(s)
- R G Endris
- Schering-Plough Animal Health Corp., 995 Morris Avenue Union, NJ 07093, USA
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42
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Ping LH, Cohen MS, Hoffman I, Vernazza P, Seillier-Moiseiwitsch F, Chakraborty H, Kazembe P, Zimba D, Maida M, Fiscus SA, Eron JJ, Swanstrom R, Nelson JA. Effects of genital tract inflammation on human immunodeficiency virus type 1 V3 populations in blood and semen. J Virol 2000; 74:8946-52. [PMID: 10982338 PMCID: PMC102090 DOI: 10.1128/jvi.74.19.8946-8952.2000] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [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] [Indexed: 11/20/2022] Open
Abstract
We have examined cell-free viral populations in the blood plasma and seminal plasma compartments of men infected with subtype C human immunodeficiency virus type 1 (HIV-1) using the V3-specific heteroduplex tracking assay (V3-HTA). We studied two cohorts of subjects who had visited either a sexually transmitted disease (STD) clinic for genital tract inflammation in the form of urethritis (n = 43) or a dermatology clinic (controls, n = 14) in Malawi. We have previously shown that the presence of urethritis is associated with an eightfold increase in virus load in the seminal plasma compartment (M. S. Cohen et al., Lancet 349:1868-1873, 1997). The purpose of this study was to determine whether genital tract inflammation and its treatment caused genetic instability in cell-free HIV-1 populations. In a cross-sectional analysis at study entry, three-fourths of the STD and control subjects had multiple V3 populations in their blood while 60% of the STD subjects and 79% of the control subjects had multiple V3 populations in their semen. Overall, one-fourth of all of the subjects showed discordance between results with blood and semen specimens when samples were compared for the presence and absence of subpopulations. When differences in the relative levels of abundance of bands were also taken into account, two-fifths of all of the subjects showed discordance between the compartments. Among the subset of subjects in whom multiple virus populations could be detected, half showed discordance between the compartments. There were no differences between STD and control cohorts for these comparisons of the compartments in this cross-sectional analysis at study entry. Longitudinal analysis of the viral populations from two separate clinic visits over 1 to 4 weeks showed that the complexity of each V3 population as measured by Shannon entropy was different in blood and semen at the two time points, indicating that the blood and semen constitute different compartments for HIV-1. The seminal plasma compartment was more dynamic than the blood plasma compartment for the STD subjects who were treated for urethritis, with changes being noted in the presence or absence of V3-HTA bands in the semen of 29% of these subjects but in the blood of only 9% of these subjects. However, the changes were generally small. Overall, our results suggest that 40% of male subjects show discordance between seminal and blood viral populations and that the complexity of each V3 population was different between the two compartments. Both of these results point to the partial independence of the seminal compartment as a viral niche within the body.
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Affiliation(s)
- L H Ping
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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Welmaker GS, Nelson JA, Sabalski JE, Sabb AL, Potoski JR, Graziano D, Kagan M, Coupet J, Dunlop J, Mazandarani H, Rosenzweig-Lipson S, Sukoff S, Zhang Y. Synthesis and 5-hydroxytryptamine (5-HT) activity of 2,3,4,4a-tetrahydro-1H-pyrazino[1,2-a]quinoxalin-5-(6H)ones and 2,3,4,4a,5,6-hexahydro-1H-pyrazino[1,2-a]quinoxalines. Bioorg Med Chem Lett 2000; 10:1991-4. [PMID: 10987434 DOI: 10.1016/s0960-894x(00)00400-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [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: 11/25/2022]
Abstract
A series of 2,3,4,4a-tetrahydro-1H-pyrazino[1,2-a]quinoxalin-5-(6H)ones and 2,3,4,4a,5,6-hexahydro-1H-pyrazino[1,2-a]quinoxalines was shown to exhibit 5-HT2C agonist binding and functional activity. Compound 21R inhibited food intake over 2 h in fasted, male Sprague Dawley rats with ED50 values of 2 mg/kg (i.p.) and 10 mg/kg (p.o.).
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Affiliation(s)
- G S Welmaker
- Medicinal Chemistry, Chemical Sciences, Wyeth-Ayerst Research, Princeton, NJ 08543, USA.
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Abstract
We have used a V3-specific heteroduplex tracking assay (V3-HTA) with probes from two different human immunodeficiency virus type 1 (HIV-1) subtypes to examine the extent and pace of HIV-1 evolution late in infection. Twenty-four subjects with advanced HIV-1 infection (CD4(+) T-cell count, <100/microl) and stable viral loads were studied using blood plasma samples collected over a study period of approximately 9 months, during which time most of the subjects were treated with reverse transcriptase inhibitors. The V3-HTA patterns from the first and last time points were evaluated initially to determine the amounts of change in V3 sequence populations, which were primarily changes in abundance in preexisting sequence populations. Three of the 24 subjects had major changes (greater than 50% total change in the relative abundance of the sequence populations), 11 subjects had intermediate changes (10 to 50% total change), and 10 subjects had minimal changes (less than 10% total change). The average total amount of change was between two- and threefold greater in subjects with X4-like variants, although there was no correlation between average viral load and the presence of X4-like variants. V3-HTA patterns in monthly samples from 11 of the subjects were also compared. In two subjects, the amount of change exceeded 40% in a 1-month period. Overall, the pace of change in V3 populations varied between subjects and was not constant within a subject over time. Sequence analysis of the V3 variants showed that R5-like variants (not containing any X4-associated substitutions) continued to be maintained in three subjects in the presence of X4-like variants, indicating that X4 variants do not always outgrow R5 variants. The coreceptor usage of the V3 sequences from two subjects was determined using a cell fusion assay. One subject had an X4 variant that was maintained at a low level for at least 9 months, during which time the predominant variants were R5X4 (dualtropic), while in the second subject the reverse situation was observed. One of the dualtropic variants had a novel sequence motif in V3, suggesting another evolutionary pathway to altered tropism. These studies begin to probe the complexities and pace of V3 evolution in vivo, revealing dynamic patterns of change among multiple V3 sequence variants in a subset of subjects.
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Affiliation(s)
- J A Nelson
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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Murphy EA, Streblow DN, Nelson JA, Stinski MF. The human cytomegalovirus IE86 protein can block cell cycle progression after inducing transition into the S phase of permissive cells. J Virol 2000; 74:7108-18. [PMID: 10888651 PMCID: PMC112229 DOI: 10.1128/jvi.74.15.7108-7118.2000] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.8] [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] [Indexed: 11/20/2022] Open
Abstract
Human cytomegalovirus (HCMV) infection of permissive cells has been reported to induce a cell cycle halt. One or more viral proteins may be involved in halting progression at different stages of the cell cycle. We investigated how HCMV infection, and specifically IE86 protein expression, affects the cell cycles of permissive and nonpermissive cells. We used a recombinant virus that expresses the green fluorescent protein (GFP) to determine the effects of HCMV on the cell cycle of permissive cells. Fluorescence by GFP allowed us to select for only productively infected cells. Replication-defective adenovirus vectors expressing the IE72 or IE86 protein were also used to efficiently transduce 95% or more of the cells. The adenovirus-expressed IE86 protein was determined to be functional by demonstrating negative autoregulation of the major immediate-early promoter and activation of an early viral promoter in the context of the viral genome. To eliminate adenovirus protein effects, plasmids expressing GFP for fluorescent selection of only transfected cells and wild-type IE86 protein or a mutant IE86 protein were tested in permissive and nonpermissive cells. HCMV infection induced the entry of U373 cells into the S phase. All permissive cells infected with HCMV were blocked in cell cycle progression and could not divide. After either transduction or transfection and IE86 protein expression, the number of all permissive or nonpermissive cell types in the S phase increased significantly, but the cells could no longer divide. The IE72 protein did not have a significant effect on the S phase. Since IE86 protein inhibits cell cycle progression, the IE2 gene in a human fibroblast IE86 protein-expressing cell line was sequenced. The IE86 protein in these retrovirus-transduced cells has mutations in a critical region of the viral protein. The locations of the mutations and the function of the IE86 protein in controlling cell cycle progression are discussed.
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Affiliation(s)
- E A Murphy
- Molecular Biology Program, College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA
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Abstract
The mammalian kidney eliminates toxic substances from the body, in part via secretion by the organic cation transporters (OCT) or organic anion transporters. Nucleosides are nitrogenous heterocycles that are often secreted by human and other animal kidneys. Previous experiments have shown that 2'-deoxytubercidin (7-deazadeoxyadenosine, dTub) is secreted by the mouse kidney via a cimetidine-sensitive OCT (Nelson et al., Biochem Pharmacol 32: 2323-2327, 1983). Experiments reported herein demonstrated that the cloned rat kidney rOCT1 transports dTub, cytosine arabinoside, 2-chlorodeoxyadenosine, and azidothymidine when expressed in the Xenopus laevis oocyte translation system. Although rOCT2 is 67% identical with rOCT1 in its amino acid sequence, rOCT2 does not mediate the uptake of these nucleosides. Uptake of dTub mediated by rOCT1 was pH-dependent in a manner suggesting that the positive charged moiety of dTub may be the true substrate. Protons acted as competitive inhibitors for the rOCT1-mediated uptake of dTub or tetraethylammonium (TEA), with K(i) values corresponding to a pH of about 6.1. TEA and dTub mutually inhibited the uptake of one another by rOCT1, competitively, with K(i) values approximately the same as their respective K(m) values. These findings suggest that protons, dTub, and TEA act at a common site on rOCT1, and that rOCT1 participates in the renal secretion of dTub and other nucleosides.
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Affiliation(s)
- R Chen
- Division of Pediatrics and The Graduate School of Biomedical Sciences, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA
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Bonk RT, Schmiedl UP, Yuan C, Nelson JA, Black CD, Ladd DL. Time-of-flight MR angiography with Gd-DTPA hexamethylene diamine co-polymer blood pool contrast agent: comparison of enhanced MRA and conventional angiography for arterial stenosis induced in rabbits. J Magn Reson Imaging 2000; 11:638-46. [PMID: 10862063 DOI: 10.1002/1522-2586(200006)11:6<638::aid-jmri10>3.0.co;2-g] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [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: 11/08/2022] Open
Abstract
Vascular stenoses were induced in the external iliac arteries of New Zealand white rabbits by a combination of hypercholesterolemic diet and repeat balloon injury. Two-dimensional (2D) and three-dimensional (3D) time-of-flight (TOF) magnetic resonance angiography (MRA) was performed with a specifically designed phased array coil in a 1.5 T system. Enhancement with gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) hexamethylene diamine co-polymer (Nycomed: NC 22181), a blood pool MR contrast agent, was measured after contrast administration and compared with pre-contrast images at the same levels. Vessel diameter measurements were obtained at multiple levels and compared with comparable levels on conventional angiograms of the same animals. Stable enhancement, averaging 227% above baseline, was observed with the 3D TOF MRA over the 40 minutes of this study. Enhancement was not observed with the 2D TOF technique. Measurement of the smallest vessels in this study with 3D TOF MRA was slightly improved following contrast enhancement, although both pre- and post-contrast diameter measurements tended to underestimate the assumed true vessel diameter. Thus, Gd-DTPA hexamethylene diamine co-polymer (Nycomed: NC 22181), a blood pool MR contrast agent, produces significant, stable enhancement with the 3D TOF technique and may improve MRA measurement of small vessels.
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Affiliation(s)
- R T Bonk
- Department of Radiology, University of Washington Medical Center, Seattle, Washington, 98195, USA
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Jean F, Thomas L, Molloy SS, Liu G, Jarvis MA, Nelson JA, Thomas G. A protein-based therapeutic for human cytomegalovirus infection. Proc Natl Acad Sci U S A 2000; 97:2864-9. [PMID: 10681468 PMCID: PMC16021 DOI: 10.1073/pnas.050504297] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [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] [Indexed: 12/16/2022] Open
Abstract
Current antiviral strategies target viral gene products. Although initially successful, their severe toxicity and susceptibility to circumvention by the generation of drug-resistant variants limit their usefulness. By contrast, the central role of the host cell serine endoprotease furin in the proteolytic activation of numerous pathogens points to the endoprotease as a strategic target for therapeutics. Herein, we show that the production of infectious human cytomegalovirus is dramatically reduced by exogenous addition of a bioengineered serpin, alpha(1)-PDX. This protein is a potent and selective furin inhibitor (K(i) = 0.6 nM) and is 10-fold more effective than currently used antiherpetic agents in cell-culture models. The requirement of furin for the processing of envelope glycoproteins from many pathogenic viruses and for the activation of several bacterial toxins suggests that selective inhibitors of furin have potential as broad-based anti-pathogens.
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Affiliation(s)
- F Jean
- Vollum Institute, and Department of Molecular Microbiology and Immunology, Oregon Health Sciences University, 3181 Southwest Sam Jackson Park Road, Portland, OR 97201, USA
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McLane ML, Nelson JA, Lenner KA, Hejal R, Kotaru C, Skowronski M, Coreno A, Lane E, McFadden ER. Integrated response of the upper and lower respiratory tract of asthmatic subjects to frigid air. J Appl Physiol (1985) 2000; 88:1043-50. [PMID: 10710402 DOI: 10.1152/jappl.2000.88.3.1043] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [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] [Indexed: 11/22/2022] Open
Abstract
To evaluate the influence of cold air hyperpnea on integrated upper and lower airway behavior, 22 asthmatic volunteers hyperventilated through their mouths (OHV) and noses (NHV) while pulmonary and nasal function were determined individually and in combination. In the isolated studies, OHV at a minute ventilation of 65 +/- 3 l/min lowered the 1-s forced expiratory volume (FEV(1)) 24 +/- 2% (P < 0. 001) and NHV (40 l/min) induced a 31 +/- 9% (P < 0.001) increase in nasal resistance (NR). In the combined studies, oral hyperpnea reduced the FEV(1) (DeltaFEV(1) 26 +/- 2%, P < 0.001) and evoked a significant rise in NR (DeltaNR 26 +/- 9%, P = 0.01). In contrast, NHV only affected the upper airway. NR rose 33 +/- 9% (P = 0.01), but airway caliber did not change (DeltaFEV(1) 2%, P = 0.27). The results of this investigation demonstrate that increasing the transfer of heat and water in the lower respiratory tract alters bronchial and nasal function in a linked fashion. Forcing the nose to augment its heat-exchanging activity, however, reduces nasal caliber but has no effect on the intrathoracic airways.
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Affiliation(s)
- M L McLane
- Division of Pulmonary and Critical Care Medicine, University Hospitals of Cleveland, Cleveland, Ohio 44106, USA
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Abstract
Individual Atlantic cod (Gadus morhua) were exercised using three different measures of swimming performance. (1) An endurance test (critical swimming speed, U(crit), protocol) designed to assess predominantly aerobic endurance swimming (duration hours). (2) An acceleration test (U(burst)), in which the fish were required to swim against a rapidly increasing current until exhausted (duration minutes). This test was designed to assess predominantly glycolytic-based swimming capacity. (3) A sprint test that examined the animals' ability to swim away from a sudden stimulus (duration seconds). Rates of oxygen consumption (mdot (O2)) during the endurance test and various morphological variables of the individual fish were also measured. Both aerobic and anaerobic swimming performance of individual cod were found to be significantly repeatable over a 3 month period. mdot (O2) during the U(crit) protocol was also significantly repeatable at intermediate to high swimming speeds, but not at low speeds. Our results support extrapolation from metabolic rates at incremented swimming speeds to zero activity as the best way to measure standard metabolic rate in cod. While performance in the U(crit) test and the sprint test were positively correlated, there was a negative correlation between performance in the U(crit) test and performance in the U(burst) test. This implies a potential trade-off in individual cod between stamina and the ability to use glycolytic-based locomotion. Inter-individual variation in swimming performance during these protocols, while substantial, was not correlated with individual variation in fin surface areas, age or morphology. However, U(burst) performance was dependent upon the sex of the animals, while performance during the U(crit) protocol was significantly correlated with their aerobic scope for activity.
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Affiliation(s)
- S P Reidy
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4J1
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