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Peters RL, Steppe K, Pappas C, Zweifel R, Babst F, Dietrich L, von Arx G, Poyatos R, Fonti M, Fonti P, Grossiord C, Gharun M, Buchmann N, Steger DN, Kahmen A. Daytime stomatal regulation in mature temperate trees prioritizes stem rehydration at night. New Phytol 2023. [PMID: 37235688 DOI: 10.1111/nph.18964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 04/16/2023] [Indexed: 05/28/2023]
Abstract
Trees remain sufficiently hydrated during drought by closing stomata and reducing canopy conductance (Gc ) in response to variations in atmospheric water demand and soil water availability. Thresholds that control the reduction of Gc are proposed to optimize hydraulic safety against carbon assimilation efficiency. However, the link between Gc and the ability of stem tissues to rehydrate at night remains unclear. We investigated whether species-specific Gc responses aim to prevent branch embolisms, or enable night-time stem rehydration, which is critical for turgor-dependent growth. For this, we used a unique combination of concurrent dendrometer, sap flow and leaf water potential measurements and collected branch-vulnerability curves of six common European tree species. Species-specific Gc reduction was weakly related to the water potentials at which 50% of branch xylem conductivity is lost (P50 ). Instead, we found a stronger relationship with stem rehydration. Species with a stronger Gc control were less effective at refilling stem-water storage as the soil dries, which appeared related to their xylem architecture. Our findings highlight the importance of stem rehydration for water-use regulation in mature trees, which likely relates to the maintenance of adequate stem turgor. We thus conclude that stem rehydration must complement the widely accepted safety-efficiency stomatal control paradigm.
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Affiliation(s)
- Richard L Peters
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000, Ghent, Belgium
- Forest Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
- Forest is Life, TERRA Teaching and Research Centre, Gembloux Agro Bio-Tech, University of Liège, Passage des Déportés 2, 5030, Gembloux, Belgium
| | - Kathy Steppe
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000, Ghent, Belgium
| | - Christoforos Pappas
- Department of Civil Engineering, University of Patras, Rio, Patras, 26504, Greece
| | - Roman Zweifel
- Forest Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
| | - Flurin Babst
- School of Natural Resources and the Environment, University of Arizona, East Lowell Street 1064, Tucson, AZ, 85721, USA
- Laboratory of Tree-Ring Research, University of Arizona, East Lowell Street 1215, Tucson, AZ, 857121, USA
| | - Lars Dietrich
- Department of Environmental Sciences - Botany, University of Basel, Schönbeinstrasse 6, CH-4056, Basel, Switzerland
| | - Georg von Arx
- Forest Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
- Oeschger Centre for Climate Change Research, University of Bern, 3012, Bern, Switzerland
| | - Rafael Poyatos
- CREAF, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
- Universitat Autònoma de Barcelona, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
| | - Marina Fonti
- Forest Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
| | - Patrick Fonti
- Forest Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
| | - Charlotte Grossiord
- Plant Ecology Research Laboratory PERL, School for Architecture, Civil and Environmental Engineering, EPFL, CH-1015, Lausanna, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape WSL, CH-1015, Lausanne, Switzerland
| | - Mana Gharun
- Department of Environmental Systems Science, ETH Zurich, Universitatstrasse 2, CH-8092, Zurich, Switzerland
- Department of Geosciences, University of Münster, Heisenbergstrasse 2, 48149, Münster, Germany
| | - Nina Buchmann
- Department of Environmental Systems Science, ETH Zurich, Universitatstrasse 2, CH-8092, Zurich, Switzerland
| | - David N Steger
- Department of Environmental Sciences - Botany, University of Basel, Schönbeinstrasse 6, CH-4056, Basel, Switzerland
| | - Ansgar Kahmen
- Department of Environmental Sciences - Botany, University of Basel, Schönbeinstrasse 6, CH-4056, Basel, Switzerland
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Zweifel R, Pappas C, Peters RL, Babst F, Balanzategui D, Basler D, Bastos A, Beloiu M, Buchmann N, Bose AK, Braun S, Damm A, D'Odorico P, Eitel JUH, Etzold S, Fonti P, Rouholahnejad Freund E, Gessler A, Haeni M, Hoch G, Kahmen A, Körner C, Krejza J, Krumm F, Leuchner M, Leuschner C, Lukovic M, Martínez-Vilalta J, Matula R, Meesenburg H, Meir P, Plichta R, Poyatos R, Rohner B, Ruehr N, Salomón RL, Scharnweber T, Schaub M, Steger DN, Steppe K, Still C, Stojanović M, Trotsiuk V, Vitasse Y, von Arx G, Wilmking M, Zahnd C, Sterck F. Networking the forest infrastructure towards near real-time monitoring - A white paper. Sci Total Environ 2023; 872:162167. [PMID: 36775147 DOI: 10.1016/j.scitotenv.2023.162167] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Forests account for nearly 90 % of the world's terrestrial biomass in the form of carbon and they support 80 % of the global biodiversity. To understand the underlying forest dynamics, we need a long-term but also relatively high-frequency, networked monitoring system, as traditionally used in meteorology or hydrology. While there are numerous existing forest monitoring sites, particularly in temperate regions, the resulting data streams are rarely connected and do not provide information promptly, which hampers real-time assessments of forest responses to extreme climate events. The technology to build a better global forest monitoring network now exists. This white paper addresses the key structural components needed to achieve a novel meta-network. We propose to complement - rather than replace or unify - the existing heterogeneous infrastructure with standardized, quality-assured linking methods and interacting data processing centers to create an integrated forest monitoring network. These automated (research topic-dependent) linking methods in atmosphere, biosphere, and pedosphere play a key role in scaling site-specific results and processing them in a timely manner. To ensure broad participation from existing monitoring sites and to establish new sites, these linking methods must be as informative, reliable, affordable, and maintainable as possible, and should be supplemented by near real-time remote sensing data. The proposed novel meta-network will enable the detection of emergent patterns that would not be visible from isolated analyses of individual sites. In addition, the near real-time availability of data will facilitate predictions of current forest conditions (nowcasts), which are urgently needed for research and decision making in the face of rapid climate change. We call for international and interdisciplinary efforts in this direction.
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Affiliation(s)
- Roman Zweifel
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland.
| | - Christoforos Pappas
- Department of Civil Engineering, University of Patras, Rio, Patras 26504, Greece.
| | - Richard L Peters
- Department of Environmental Sciences, Institute of Botany, University of Basel, Schönbeinstrasse 6, 4056 Basel, Switzerland.
| | - Flurin Babst
- School of Natural Resources and the Environment, University of Arizona, 1064 E Lowell St, Tucson, AZ 85721, USA; Laboratory of Tree-Ring Research, University of Arizona, 1215 E Lowell St, Tucson, AZ 85721, USA.
| | - Daniel Balanzategui
- GFZ German Research Centre for Geosciences, Wissenschaftpark "Albert Einstein", Telegrafenberg, Potsdam, Germany; Geography Department, Humboldt University of Berlin, Rudower Ch 16, 12489 Berlin, DE, USA.
| | - David Basler
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland; Department of Environmental Sciences, Institute of Botany, University of Basel, Schönbeinstrasse 6, 4056 Basel, Switzerland.
| | - Ana Bastos
- Max Planck Institute for Biogeochemistry, Dept. of Biogeochemical Integration, Hans Knöll Str. 10, 07745 Jena, Germany.
| | - Mirela Beloiu
- Institute of Terrestrial Ecosystems, ETH Zurich, Zurich, Switzerland.
| | - Nina Buchmann
- Department of Environmental Systems Science, ETH Zurich, Universitätstr. 2, LFW C56, 8092 Zurich, Switzerland.
| | - Arun K Bose
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland; Forestry and Wood Technology Discipline, Khulna University, Khulna 9208, Bangladesh.
| | - Sabine Braun
- Institute for Applied Plant Biology, Benkenstrasse 254A, 4108 Witterswil, Switzerland.
| | - Alexander Damm
- Department of Geography, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland; Eawag, Swiss Federal Institute of Aquatic Science & Technology, Surface Waters - Research and Management, Ueberlandstrasse 133, 8600 Duebendorf, Switzerland.
| | - Petra D'Odorico
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland.
| | - Jan U H Eitel
- Department of Natural Resource and Society, University of Idaho, 1800 University Lane, 83638 McCall, ID, USA.
| | - Sophia Etzold
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland.
| | - Patrick Fonti
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland.
| | | | - Arthur Gessler
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland.
| | - Matthias Haeni
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland.
| | - Günter Hoch
- Department of Environmental Sciences, Institute of Botany, University of Basel, Schönbeinstrasse 6, 4056 Basel, Switzerland.
| | - Ansgar Kahmen
- Department of Environmental Sciences, Institute of Botany, University of Basel, Schönbeinstrasse 6, 4056 Basel, Switzerland.
| | - Christian Körner
- Department of Environmental Sciences, Institute of Botany, University of Basel, Schönbeinstrasse 6, 4056 Basel, Switzerland.
| | - Jan Krejza
- Global Change Research Institute of the Czech Academy of Sciences, Bělidla 4a, 603 00 Brno, Czech Republic.
| | - Frank Krumm
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland.
| | - Michael Leuchner
- Department of Physical Geography and Climatology, Institute of Geography, RWTH Aachen University, 52056 Aachen, Germany.
| | - Christoph Leuschner
- Plant Ecology, University of Göttingen, Untere Karspüle 2, 37073 Göttingen, Germany.
| | - Mirko Lukovic
- Swiss Federal Laboratories for Materials Science and Technology (Empa), Dübendorf 8600, Switzerland.
| | - Jordi Martínez-Vilalta
- CREAF, Bellaterra (Cerdanyola del Valles), Catalonia E08193, Spain; Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Valles), Catalonia E08193, Spain.
| | - Radim Matula
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha 6, Suchdol 16521, Czech Republic.
| | - Henning Meesenburg
- Northwest German Forest Research Institute, Grätzelstr. 2, D-37079 Göttingen, Germany.
| | - Patrick Meir
- School of Geosciences, University of Edinburgh, Alexander Crum Brown Road, Edinburgh EH93FF, UK.
| | - Roman Plichta
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemedelska 1, 61300 Brno, Czech Republic.
| | - Rafael Poyatos
- CREAF, Bellaterra (Cerdanyola del Valles), Catalonia E08193, Spain; Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Valles), Catalonia E08193, Spain.
| | - Brigitte Rohner
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland.
| | - Nadine Ruehr
- Institute of Meteorology and Climate Research - Atmospheric Environmental Research, Karlsruhe Institute of Technology KIT, Garmisch-Partenkirchen 82467, Germany.
| | - Roberto L Salomón
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, 28040 Madrid, Spain.
| | - Tobias Scharnweber
- DendroGreif, University Greifswald, Soldmannstrasse 15, D-17487 Greifswald, Germany.
| | - Marcus Schaub
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland.
| | - David N Steger
- Department of Environmental Sciences, Institute of Botany, University of Basel, Schönbeinstrasse 6, 4056 Basel, Switzerland.
| | - Kathy Steppe
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Gent, Belgium.
| | - Christopher Still
- Forest Ecosystems and Society Department, Oregon State University, Corvallis, OR 97331, USA.
| | - Marko Stojanović
- Global Change Research Institute of the Czech Academy of Sciences, Bělidla 4a, 603 00 Brno, Czech Republic.
| | - Volodymyr Trotsiuk
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland.
| | - Yann Vitasse
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland.
| | - Georg von Arx
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, 3012 Bern, Switzerland.
| | - Martin Wilmking
- DendroGreif, University Greifswald, Soldmannstrasse 15, D-17487 Greifswald, Germany.
| | - Cedric Zahnd
- Department of Environmental Sciences, Institute of Botany, University of Basel, Schönbeinstrasse 6, 4056 Basel, Switzerland.
| | - Frank Sterck
- Forest Ecology and Forest Management Group, Wageningen University and Research, P.O. Box 47, 6700 AA Wageningen, the Netherlands.
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Cabon A, Kannenberg SA, Arain A, Babst F, Baldocchi D, Belmecheri S, Delpierre N, Guerrieri R, Maxwell JT, McKenzie S, Meinzer FC, Moore DJP, Pappas C, Rocha AV, Szejner P, Ueyama M, Ulrich D, Vincke C, Voelker SL, Wei J, Woodruff D, Anderegg WRL. Cross-biome synthesis of source versus sink limits to tree growth. Science 2022; 376:758-761. [PMID: 35549405 DOI: 10.1126/science.abm4875] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Uncertainties surrounding tree carbon allocation to growth are a major limitation to projections of forest carbon sequestration and response to climate change. The prevalence and extent to which carbon assimilation (source) or cambial activity (sink) mediate wood production are fundamentally important and remain elusive. We quantified source-sink relations across biomes by combining eddy-covariance gross primary production with extensive on-site and regional tree ring observations. We found widespread temporal decoupling between carbon assimilation and tree growth, underpinned by contrasting climatic sensitivities of these two processes. Substantial differences in assimilation-growth decoupling between angiosperms and gymnosperms were determined, as well as stronger decoupling with canopy closure, aridity, and decreasing temperatures. Our results reveal pervasive sink control over tree growth that is likely to be increasingly prominent under global climate change.
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Affiliation(s)
- Antoine Cabon
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
| | | | - Altaf Arain
- McMaster Centre for Climate Change, McMaster University, Hamilton, Ontario L8S 4K1, Canada.,School of Earth, Environment and Society, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Flurin Babst
- School of Natural Resources and the Environment, University of Arizona, Tucson, AZ, USA.,Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ, USA
| | - Dennis Baldocchi
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA, USA
| | - Soumaya Belmecheri
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ, USA
| | - Nicolas Delpierre
- Université Paris-Saclay, CNRS, AgroParisTech, Ecologie Systématique et Evolution, 91405 Orsay, France.,Institut Universitaire de France, 75231 Paris Cedex 05, France
| | | | - Justin T Maxwell
- Department of Geography, Indiana University, Bloomington, IN, USA
| | - Shawn McKenzie
- McMaster Centre for Climate Change, McMaster University, Hamilton, Ontario L8S 4K1, Canada.,School of Earth, Environment and Society, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | | | - David J P Moore
- School of Natural Resources and the Environment, University of Arizona, Tucson, AZ, USA
| | - Christoforos Pappas
- Centre d'étude de la forêt, Université du Québec à Montréal, C.P. 8888, Succursale Centre-ville, Montréal, Quebec H3C 3P8, Canada.,Département Science et Technologie, Téluq, Université du Québec, Bureau 1105, Montréal, Quebec H2S 3L5, Canada
| | - Adrian V Rocha
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Paul Szejner
- Geology Institute, National Autonomous University of Mexico, Coyoacán, CDMX, Mexico
| | - Masahito Ueyama
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai 599-8531, Japan
| | - Danielle Ulrich
- Department of Ecology, Montana State University, Bozeman, MT, USA
| | - Caroline Vincke
- Earth and Life Institute, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Steven L Voelker
- College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI, USA
| | - Jingshu Wei
- Department of Ecology, W. Szafer Institute of Botany, Polish Academy of Sciences, 31-512 Kraków, Poland
| | - David Woodruff
- USDA Forest Service, Pacific Northwest Research Station, Corvallis, OR, USA
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Hurley AG, Peters RL, Pappas C, Steger DN, Heinrich I. Addressing the need for interactive, efficient, and reproducible data processing in ecology with the datacleanr R package. PLoS One 2022; 17:e0268426. [PMID: 35551557 PMCID: PMC9098071 DOI: 10.1371/journal.pone.0268426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/29/2022] [Indexed: 11/18/2022] Open
Abstract
Ecological research, just as all Earth System Sciences, is becoming increasingly data-rich. Tools for processing of “big data” are continuously developed to meet corresponding technical and logistical challenges. However, even at smaller scales, data sets may be challenging when best practices in data exploration, quality control and reproducibility are to be met. This can occur when conventional methods, such as generating and assessing diagnostic visualizations or tables, become unfeasible due to time and practicality constraints. Interactive processing can alleviate this issue, and is increasingly utilized to ensure that large data sets are diligently handled. However, recent interactive tools rarely enable data manipulation, may not generate reproducible outputs, or are typically data/domain-specific. We developed datacleanr, an interactive tool that facilitates best practices in data exploration, quality control (e.g., outlier assessment) and flexible processing for multiple tabular data types, including time series and georeferenced data. The package is open-source, and based on the R programming language. A key functionality of datacleanr is the “reproducible recipe”—a translation of all interactive actions into R code, which can be integrated into existing analyses pipelines. This enables researchers experienced with script-based workflows to utilize the strengths of interactive processing without sacrificing their usual work style or functionalities from other (R) packages. We demonstrate the package’s utility by addressing two common issues during data analyses, namely 1) identifying problematic structures and artefacts in hierarchically nested data, and 2) preventing excessive loss of data from ‘coarse,’ code-based filtering of time series. Ultimately, with datacleanr we aim to improve researchers’ workflows and increase confidence in and reproducibility of their results.
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Affiliation(s)
- Alexander G. Hurley
- Climate Dynamics and Landscape Evolution, GFZ German Research Centre for Geosciences, Potsdam, Germany
- * E-mail:
| | - Richard L. Peters
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
- Department of Environmental Sciences, University of Basel, Basel, Switzerland
| | - Christoforos Pappas
- Centre d’étude de la forêt, Université du Québec à Montréal, Montréal, Canada
- Département Science et Technologie, Téluq, Université du Québec, Montréal, Canada
- Department of Civil Engineering, University of Patras, Rio Patras, Greece
| | - David N. Steger
- Climate Dynamics and Landscape Evolution, GFZ German Research Centre for Geosciences, Potsdam, Germany
- Humboldt-Universität zu Berlin, Berlin, Germany
- Natural Sciences Unit, German Archaeological Institute DAI, Berlin, Germany
| | - Ingo Heinrich
- Climate Dynamics and Landscape Evolution, GFZ German Research Centre for Geosciences, Potsdam, Germany
- Humboldt-Universität zu Berlin, Berlin, Germany
- Natural Sciences Unit, German Archaeological Institute DAI, Berlin, Germany
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Martin N, Bannenberg LJ, Deutsch M, Pappas C, Chaboussant G, Cubitt R, Mirebeau I. Field-induced vortex-like textures as a probe of the critical line in reentrant spin glasses. Sci Rep 2021; 11:20753. [PMID: 34675354 PMCID: PMC8531314 DOI: 10.1038/s41598-021-99860-2] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 09/29/2021] [Indexed: 11/09/2022] Open
Abstract
We study the evolution of the low-temperature field-induced magnetic defects observed under an applied magnetic field in a series of frustrated amorphous ferromagnets (Fe\documentclass[12pt]{minimal}
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\begin{document}$$x_{\mathrm{C}} \approx 0.36$$\end{document}xC≈0.36 which separates the RSG and “true” spin glass (SG) within the low temperature part of the magnetic phase diagram of a-Fe1−xMnx. These textures systematically decrease in size with increasing magnetic field or decreasing the average exchange interaction, and they finally disappear in the SG sample (\documentclass[12pt]{minimal}
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\begin{document}$$x = 0.41$$\end{document}x=0.41), being replaced by field-induced correlations over finite length scales. We argue that the study of these nanoscopic defects could be used to probe the critical line between the RSG and SG phases.
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Affiliation(s)
- N Martin
- Université Paris-Saclay, CNRS, CEA, Laboratoire Léon Brillouin, 91191, Gif-sur-Yvette, France.
| | - L J Bannenberg
- Faculty of Applied Science, Delft University of Technology, 2629 JB, Delft, The Netherlands
| | - M Deutsch
- CNRS, CRM2, Université de Lorraine, Nancy, France
| | - C Pappas
- Faculty of Applied Science, Delft University of Technology, 2629 JB, Delft, The Netherlands
| | - G Chaboussant
- Université Paris-Saclay, CNRS, CEA, Laboratoire Léon Brillouin, 91191, Gif-sur-Yvette, France
| | - R Cubitt
- Institut Laue Langevin, BP156, 38042, Grenoble, France
| | - I Mirebeau
- Université Paris-Saclay, CNRS, CEA, Laboratoire Léon Brillouin, 91191, Gif-sur-Yvette, France
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Fatichi S, Peleg N, Mastrotheodoros T, Pappas C, Manoli G. An ecohydrological journey of 4500 years reveals a stable but threatened precipitation-groundwater recharge relation around Jerusalem. Sci Adv 2021; 7:eabe6303. [PMID: 34516766 PMCID: PMC8442904 DOI: 10.1126/sciadv.abe6303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 07/21/2021] [Indexed: 06/13/2023]
Abstract
Groundwater is a key water resource in semiarid and seasonally dry regions around the world, which is replenished by intermittent precipitation events and mediated by vegetation, soil, and regolith properties. Here, a climate reconstruction of 4500 years for the Jerusalem region was used to determine the relation between climate, vegetation, and groundwater recharge. Despite changes in air temperature and vegetation characteristics, simulated recharge remained linearly related to precipitation over the entire analyzed period, with drier decades having lower rates of recharge for a given annual precipitation due to soil memory effects. We show that in recent decades, the lack of changes in the precipitation–groundwater recharge relation results from the compensating responses of vegetation to increasing CO2, i.e., increased leaf area and reduced stomatal conductance. This multicentury relation is expected to be modified by climate change, with changes up to −20% in recharge for unchanged precipitation, potentially jeopardizing water resource availability.
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Affiliation(s)
- Simone Fatichi
- Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, 117576 Singapore, Singapore
| | - Nadav Peleg
- Institute of Environmental Engineering, ETH Zurich, Stefano-Franscini-Platz 5, 8093 Zurich, Switzerland
- Institute of Earth Surface Dynamics, University of Lausanne, Géopolis, 1015 Lausanne, Switzerland
| | - Theodoros Mastrotheodoros
- Institute of Environmental Engineering, ETH Zurich, Stefano-Franscini-Platz 5, 8093 Zurich, Switzerland
| | - Christoforos Pappas
- Centre d’étude de la forêt, Université du Québec à Montréal, C.P. 8888, Succursale Centre-ville, Montréal, QC H3C 3P8, Canada
- Département Science et Technologie, Téluq, Université du Québec, 5800 rue Saint-Denis, Bureau 1105, Montréal, QC H2S 3L5, Canada
| | - Gabriele Manoli
- Department of Civil, Environmental and Geomatic Engineering, University College London, Gower Street, WC1E 6BT London, UK
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7
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Navarro-López A, Ioannidou C, van der Wal EM, Arechabaleta Z, van den Oever R, Verleg MN, Dalgliesh RM, Sykora J, Akeroyd FA, Geerlofs N, Sietsma J, Pappas C, van Well AA, Offerman SE. Furnace for in situ and simultaneous studies of nano-precipitates and phase transformations in steels by SANS and neutron diffraction. Rev Sci Instrum 2020; 91:123903. [PMID: 33379987 DOI: 10.1063/5.0022507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 11/13/2020] [Indexed: 06/12/2023]
Abstract
Interphase precipitation occurring during solid-state phase transformations in micro-alloyed steels is generally studied through transmission electron microscopy, atom probe tomography, and ex situ measurements of Small-Angle Neutron Scattering (SANS). The advantage of SANS over the other two characterization techniques is that SANS allows for the quantitative determination of size distribution, volume fraction, and number density of a statistically significant number of precipitates within the resulting matrix at room temperature. However, the performance of ex situ SANS measurements alone does not provide information regarding the probable correlation between interphase precipitation and phase transformations. This limitation makes it necessary to perform in situ and simultaneous studies on precipitation and phase transformations in order to gain an in-depth understanding of the nucleation and growth of precipitates in relation to the evolution of austenite decomposition at high temperatures. A furnace is, thus, designed and developed for such in situ studies in which SANS measurements can be simultaneously performed with neutron diffraction measurements during the application of high-temperature thermal treatments. The furnace is capable of carrying out thermal treatments involving fast heating and cooling as well as high operation temperatures (up to 1200 °C) for a long period of time with accurate temperature control in a protective atmosphere and in a magnetic field of up to 1.5 T. The characteristics of this furnace give the possibility of developing new research studies for better insight of the relationship between phase transformations and precipitation kinetics in steels and also in other types of materials containing nano-scale microstructural features.
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Affiliation(s)
- A Navarro-López
- Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands
| | - C Ioannidou
- Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands
| | - E M van der Wal
- Department of Radiation Science and Technology, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands
| | - Z Arechabaleta
- Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands
| | - R van den Oever
- Department of Radiation Science and Technology, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands
| | - M N Verleg
- Department of Radiation Science and Technology, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands
| | - R M Dalgliesh
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Oxfordshire OX11 0QX, United Kingdom
| | - J Sykora
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Oxfordshire OX11 0QX, United Kingdom
| | - F A Akeroyd
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Oxfordshire OX11 0QX, United Kingdom
| | - N Geerlofs
- Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands
| | - J Sietsma
- Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands
| | - C Pappas
- Department of Radiation Science and Technology, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands
| | - A A van Well
- Department of Radiation Science and Technology, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands
| | - S E Offerman
- Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands
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8
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Pulit-Penaloza J, Brock N, Pappas C, Sun X, Belser J, Zeng H, Tumpey T, Maines T. Virulence and transmissibility of highly pathogenic avian influenza H5N6 viruses in the ferret model. Int J Infect Dis 2020. [DOI: 10.1016/j.ijid.2020.09.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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9
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Peters RL, Pappas C, Hurley AG, Poyatos R, Flo V, Zweifel R, Goossens W, Steppe K. Assimilate, process and analyse thermal dissipation sap flow data using the TREX
r
package. Methods Ecol Evol 2020. [DOI: 10.1111/2041-210x.13524] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Richard L. Peters
- Laboratory of Plant Ecology Department of Plants and Crops Faculty of Bioscience Engineering Ghent University Ghent Belgium
- Forest Dynamics Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL) Birmensdorf Switzerland
| | - Christoforos Pappas
- Département de géographie Université de Montréal Montreal QC Canada
- Centre d’étude de la forêtUniversité du Québec à Montréal Montreal QC Canada
- Département Science et Technologie Téluq Université du Québec Montreal QC Canada
| | - Alexander G. Hurley
- GFZ German Research Centre for GeosciencesSection 4.3 Climate Dynamics and Landscape Evolution Potsdam Germany
- School of Geography, Earth and Environmental Sciences University of Birmingham Birmingham UK
| | - Rafael Poyatos
- CREAFE08193 Bellaterra (Cerdanyola del Vallès) Catalonia Spain
- Universitat Autònoma de BarcelonaE08193 Bellaterra (Cerdanyola del Vallès) Catalonia Spain
| | - Victor Flo
- School of Geography, Earth and Environmental Sciences University of Birmingham Birmingham UK
| | - Roman Zweifel
- Forest Dynamics Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL) Birmensdorf Switzerland
| | - Willem Goossens
- Laboratory of Plant Ecology Department of Plants and Crops Faculty of Bioscience Engineering Ghent University Ghent Belgium
| | - Kathy Steppe
- Laboratory of Plant Ecology Department of Plants and Crops Faculty of Bioscience Engineering Ghent University Ghent Belgium
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Lianos I, Sfantou D, Pappas C, Revela I, Triantafyllidi H, Alexopoulos D. P2551A randomized, pharmacodynamic comparison of low dose ticagrelor (60mg bid) to low dose prasugrel (5mg od) in patients with prior myocardial infarction: the ALTIC-2 study. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz748.0879] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Background
In patients with prior myocardial infarction (MI) and features of high ischemic and low bleeding risk, extending dual antiplatelet therapy beyond 1 year or reinitiating treatment is reasonable. A lower than the standard dose, namely ticagrelor 60mg bid instead of 90mg bid and prasugrel 5mg od instead of 10mg od, may be associated with reduced bleeding risk. In the Patients with Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin–Thrombolysis in Myocardial Infarction 54 (PEGASUS-TIMI 54) trial, ticagrelor 60mg bid reduced the ischemic events, at the cost of increased bleeding events. There is no data on the pharmacodynamic efficacy of ticagrelor 60mg bid over low dose prasugrel (5mg od).
Purpose
To compare platelet reactivity (PR) between prasugrel 5mg od and ticagrelor 60 mg bid in the chronic phase of stable post-MI patients.
Methods
The ALTIC-2 was a prospective, single-center, randomized, crossover study involving patients on aspirin 100mg od and PEGASUS-TIMI 54 characteristics: >50 years old with MI 1–3 years earlier and at least one high risk feature (age >65 years, diabetes mellitus, a second MI, multivessel disease, or renal dysfunction). After a 14-day washout period–if on P2Y12 receptor antagonist therapy-, patients were randomized to either ticagrelor 60mg bid or prasugrel 5mg od for 14 days, with a crossover directly to the alternate treatment for another 14 days. PR was assessed by the VerifyNow P2Y12 reaction assay in PRU at baseline, pre and post-crossover, 2 hours post last study-drug dose. Statistical analysis was performed with STATA13.0.
Results
We recruited 20 eligible patients (80% men, 40% diabetics, 65% smokers, 70% multivessel disease, with a mean age of 64.8±6.3 years) for participation in the study (10 in each treatment sequence). During pre-crossover period, in the group allocated first in prasugrel PR levels (mean ± standard deviation) decreased from 238.4±50 to 128±47 (p<0.0001), while in the group allocated first in ticagrelor levels of PR decreased from 259.6±36 to 30.8±29 (p<0.0001). At the end of the 2 treatments, PR levels decreased to 33±26 in the group allocated first in prasugrel (p=0.0001), while in the group allocated first in ticagrelor levels of PR increased to 136±61 (p=0.0001). Analysis of combined data of PR levels (pre- and post-crossover, primary endpoint) adjusted for baseline values and age showed a difference of PR levels (β: −103, 95% CI: −120 to −85) in favor of ticagrelor. A non-significant period effect was observed and no carry effect was found. The secondary endpoint of high PR (>208 PRU) rate was 0% for ticagrelor and 5.0% for prasugrel. No patient exhibited a major bleeding event at either treatment group.
Conclusions
In patients with previous MI and at least one other high-risk feature, low dose of ticagrelor results in a significantly lower PR compared to prasugrel 5mg od.
Acknowledgement/Funding
National and Kapodistrian University of Athens
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Affiliation(s)
- I Lianos
- Attikon University Hospital, Athens, Greece
| | - D Sfantou
- Attikon University Hospital, Athens, Greece
| | - C Pappas
- Attikon University Hospital, Athens, Greece
| | - I Revela
- Attikon University Hospital, Athens, Greece
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11
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Markopoulou A, Karchristos C, Kozyrakis E, Gouliaros N, Antonopoulos N, Dimitriadis I, Pappas C, Tsantiridis C, Rampiadou C, Kounti G, Chloros A. CHYLOTHORAX AND CHYLOPERICARDIUM WITH SUPERIMPOSED INFECTION IN A PATIENT WITH LYMPHADENOPATHY. Chest 2019. [DOI: 10.1016/j.chest.2019.04.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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12
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Peters RL, Speich M, Pappas C, Kahmen A, von Arx G, Graf Pannatier E, Steppe K, Treydte K, Stritih A, Fonti P. Contrasting stomatal sensitivity to temperature and soil drought in mature alpine conifers. Plant Cell Environ 2019; 42:1674-1689. [PMID: 30536787 DOI: 10.1111/pce.13500] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [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: 07/23/2018] [Revised: 12/03/2018] [Accepted: 12/06/2018] [Indexed: 06/09/2023]
Abstract
Conifers growing at high elevations need to optimize their stomatal conductance (gs ) for maximizing photosynthetic yield while minimizing water loss under less favourable thermal conditions. Yet the ability of high-elevation conifers to adjust their gs sensitivity to environmental drivers remains largely unexplored. We used 4 years of sap flow measurements to elucidate intraspecific and interspecific variability of gs in Larix decidua Mill. and Picea abies (L.) Karst along an elevational gradient and contrasting soil moisture conditions. Site- and species-specific gs response to main environmental drivers were examined, including vapour pressure deficit, air temperature, solar irradiance, and soil water potential. Our results indicate that maximum gs of L. decidua is >2 times higher, shows a more plastic response to temperature, and down-regulates gs stronger during atmospheric drought compared to P. abies. These differences allow L. decidua to exert more efficient water use, adjust to site-specific thermal conditions, and reduce water loss during drought episodes. The stronger plasticity of gs sensitivity to temperature and higher conductance of L. decidua compared to P. abies provide new insights into species-specific water use strategies, which affect species' performance and should be considered when predicting terrestrial water dynamics under future climatic change.
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Affiliation(s)
- Richard L Peters
- Forest Dynamics, Landscape Dynamics and Forest Soils and Biogeochemistry, Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
- Department of Environmental Sciences-Botany, Basel University, Basel, CH-4056, Switzerland
| | - Matthias Speich
- Forest Dynamics, Landscape Dynamics and Forest Soils and Biogeochemistry, Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
- Department of Environmental Systems Science, ETH Zurich, Zurich, CH-8092, Switzerland
| | - Christoforos Pappas
- Département de géographie and Centre d'études nordiques, Université de Montréal, Montréal, Quebec, Canada
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Ansgar Kahmen
- Department of Environmental Sciences-Botany, Basel University, Basel, CH-4056, Switzerland
| | - Georg von Arx
- Forest Dynamics, Landscape Dynamics and Forest Soils and Biogeochemistry, Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
| | - Elisabeth Graf Pannatier
- Forest Dynamics, Landscape Dynamics and Forest Soils and Biogeochemistry, Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
| | - Kathy Steppe
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, B-9000, Belgium
| | - Kerstin Treydte
- Forest Dynamics, Landscape Dynamics and Forest Soils and Biogeochemistry, Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
| | - Ana Stritih
- Institute for Landscape and Spatial Development, Planning of Landscape and Urban Systems (PLUS), ETH Zurich, Zürich, CH-8093, Switzerland
| | - Patrick Fonti
- Forest Dynamics, Landscape Dynamics and Forest Soils and Biogeochemistry, Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
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13
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Fatichi S, Pappas C, Zscheischler J, Leuzinger S. Modelling carbon sources and sinks in terrestrial vegetation. New Phytol 2019; 221:652-668. [PMID: 30339280 DOI: 10.1111/nph.15451] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [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: 01/16/2018] [Accepted: 08/12/2018] [Indexed: 05/06/2023]
Abstract
Contents Summary 652 I. Introduction 652 II. Discrepancy in predicting the effects of rising [CO2 ] on the terrestrial C sink 655 III. Carbon and nutrient storage in plants and its modelling 656 IV. Modelling the source and the sink: a plant perspective 657 V. Plant-scale water and Carbon flux models 660 VI. Challenges for the future 662 Acknowledgements 663 Authors contributions 663 References 663 SUMMARY: The increase in atmospheric CO2 in the future is one of the most certain projections in environmental sciences. Understanding whether vegetation carbon assimilation, growth, and changes in vegetation carbon stocks are affected by higher atmospheric CO2 and translating this understanding in mechanistic vegetation models is of utmost importance. This is highlighted by inconsistencies between global-scale studies that attribute terrestrial carbon sinks to CO2 stimulation of gross and net primary production on the one hand, and forest inventories, tree-scale studies, and plant physiological evidence showing a much less pronounced CO2 fertilization effect on the other hand. Here, we review how plant carbon sources and sinks are currently described in terrestrial biosphere models. We highlight an uneven representation of complexity between the modelling of photosynthesis and other processes, such as plant respiration, direct carbon sinks, and carbon allocation, largely driven by available observations. Despite a general lack of data on carbon sink dynamics to drive model improvements, ways forward toward a mechanistic representation of plant carbon sinks are discussed, leveraging on results obtained from plant-scale models and on observations geared toward model developments.
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Affiliation(s)
- Simone Fatichi
- Institute of Environmental Engineering, ETH Zurich, Stefano Franscini Platz 5, 8093, Zurich, Switzerland
| | - Christoforos Pappas
- Département de géographie and Centre d'études nordiques, Université de Montréal, Montreal, QC, H2V 2B8, Canada
| | - Jakob Zscheischler
- Institute for Atmospheric and Climate Science, ETH Zurich, Universitätstrasse 16, 8092, Zurich, Switzerland
| | - Sebastian Leuzinger
- Institute for Applied Ecology New Zealand, School of Science, Auckland University of Technology, Wakefield Street 46, 1142, Auckland, New Zealand
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14
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Basalekou M, Pappas C, Tarantilis P, Kyraleou M, Cotea V, Kallithraka S. Astringency estimation of wines maturing in different types of containers. BIO Web Conf 2019. [DOI: 10.1051/bioconf/20191502014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Astringency is a parameter of great importance for wine quality. During wine maturation in wooden barrels it can be enhanced by tannins extracted by the wood. However, their concentration is not directly correlated with astringency. Mean Degree of Polymerization (mDP) is often employed to characterize the structural characteristics of tannins in wines, providing also information on their proanthocyanidin content. The prodelphinidin content (%P), as well as the percentage of epigallocatechin (EGC) in extension and terminal units, have been negatively linked with astringency. Since the intensity of astringency is a decisive factor for the quality of a barrel-aged wine in this experiment, the structural characteristics of wine proanthocyanidins were determined in four different Greek wines, two white (Vilana and Dafni) and two red (Kotsifali and Mandilari). All wines matured for nine months in different types of containers (stainless steel tanks and barrels made of different woods). The prodelphinidin (terminal or extension) content was determined by means of phloroglucinolysis, followed by HPLC-UV-MS analysis, while astringency was assessed by a panel of trained tasters. Multivariate analysis showed that only white wines that matured in Acacia barrels contained high %P values independently of the variety used and were characterized as less astringent by the panel. Moreover, the determination of %extension and terminal EGC units revealed that the tannins of the wines maturing in Acacia barrels, contain higher amounts of EGC as terminal units. These findings could be used by winemakers in order to select the appropriate type of barrel according to the type of wine.
Keywords: Astringency, proanthocyanidin, tannin, barrel
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15
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Peters RL, Fonti P, Frank DC, Poyatos R, Pappas C, Kahmen A, Carraro V, Prendin AL, Schneider L, Baltzer JL, Baron-Gafford GA, Dietrich L, Heinrich I, Minor RL, Sonnentag O, Matheny AM, Wightman MG, Steppe K. Quantification of uncertainties in conifer sap flow measured with the thermal dissipation method. New Phytol 2018; 219:1283-1299. [PMID: 29862531 DOI: 10.1111/nph.15241] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [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: 01/30/2018] [Accepted: 04/24/2018] [Indexed: 06/08/2023]
Abstract
Trees play a key role in the global hydrological cycle and measurements performed with the thermal dissipation method (TDM) have been crucial in providing whole-tree water-use estimates. Yet, different data processing to calculate whole-tree water use encapsulates uncertainties that have not been systematically assessed. We quantified uncertainties in conifer sap flux density (Fd ) and stand water use caused by commonly applied methods for deriving zero-flow conditions, dampening and sensor calibration. Their contribution has been assessed using a stem segment calibration experiment and 4 yr of TDM measurements in Picea abies and Larix decidua growing in contrasting environments. Uncertainties were then projected on TDM data from different conifers across the northern hemisphere. Commonly applied methods mostly underestimated absolute Fd . Lacking a site- and species-specific calibrations reduced our stand water-use measurements by 37% and induced uncertainty in northern hemisphere Fd . Additionally, although the interdaily variability was maintained, disregarding dampening and/or applying zero-flow conditions that ignored night-time water use reduced the correlation between environment and Fd . The presented ensemble of calibration curves and proposed dampening correction, together with the systematic quantification of data-processing uncertainties, provide crucial steps in improving whole-tree water-use estimates across spatial and temporal scales.
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Affiliation(s)
- Richard L Peters
- Landscape Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
- Department of Environmental Sciences - Botany, Basel University, Schönbeinstrasse 6, CH-4056, Basel, Switzerland
| | - Patrick Fonti
- Landscape Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
| | - David C Frank
- Landscape Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
- Laboratory of Tree-Ring Research, 1215 E. Lowell Street, Tucson, AZ, 8572, USA
- Oeschger Centre for Climate Change Research, Falkenplatz 16, CH-3012, Bern, Switzerland
| | - Rafael Poyatos
- CREAF, E08193, Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
- Faculty of Bioscience Engineering, Department of Plants and Crops, Laboratory of Plant Ecology, Ghent University, Coupure links 653, B-9000, Ghent, Belgium
| | - Christoforos Pappas
- Département de géographie and Centre d'études nordiques, Université de Montréal, Montréal, QC, H2V 2B8, Canada
| | - Ansgar Kahmen
- Department of Environmental Sciences - Botany, Basel University, Schönbeinstrasse 6, CH-4056, Basel, Switzerland
| | - Vinicio Carraro
- Department TeSAF Territorio e Sistemi Agro-Forestali, Università degli Studi di Padova, Viale dell'Università 16, I-35020, Legnaro, PD, Italy
| | - Angela Luisa Prendin
- Department TeSAF Territorio e Sistemi Agro-Forestali, Università degli Studi di Padova, Viale dell'Università 16, I-35020, Legnaro, PD, Italy
- Department of Bioscience, Ecoinformatic & Biodiversity, Aarhus University, Ny Munkegade 116, Building 1540, DK-8000, Aarhus C, Denmark
| | - Loïc Schneider
- Landscape Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
| | - Jennifer L Baltzer
- Biology Department, Wilfrid Laurier University, 75 University Ave. W, Waterloo, ON, N2L 3C5, Canada
| | - Greg A Baron-Gafford
- School of Geography and Development, University of Arizona, 1064 E Lowell St, Tucson, AZ, 85719, USA
| | - Lars Dietrich
- Department of Environmental Sciences - Botany, Basel University, Schönbeinstrasse 6, CH-4056, Basel, Switzerland
| | - Ingo Heinrich
- Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Climate Dynamics and Landscape Evolution, Telegrafenberg, 14473, Potsdam, Germany
| | - Rebecca L Minor
- School of Geography and Development, University of Arizona, 1064 E Lowell St, Tucson, AZ, 85719, USA
| | - Oliver Sonnentag
- Département de géographie and Centre d'études nordiques, Université de Montréal, Montréal, QC, H2V 2B8, Canada
| | - Ashley M Matheny
- Department of Geological Sciences, Jackson School of Geosciences, 2305 Speedway Stop, C1160, Austin, TX, USA
| | - Maxwell G Wightman
- College of Forestry, Oregon State University, 1500 SW Jefferson St, Corvallis, OR, 97331, USA
| | - Kathy Steppe
- Faculty of Bioscience Engineering, Department of Plants and Crops, Laboratory of Plant Ecology, Ghent University, Coupure links 653, B-9000, Ghent, Belgium
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16
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Pappas C, Matheny AM, Baltzer JL, Barr AG, Black TA, Bohrer G, Detto M, Maillet J, Roy A, Sonnentag O, Stephens J. Boreal tree hydrodynamics: asynchronous, diverging, yet complementary. Tree Physiol 2018; 38:953-964. [PMID: 29741658 DOI: 10.1093/treephys/tpy043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 04/17/2018] [Indexed: 06/08/2023]
Abstract
Water stress has been identified as a key mechanism of the contemporary increase in tree mortality rates in northwestern North America. However, a detailed analysis of boreal tree hydrodynamics and their interspecific differences is still lacking. Here we examine the hydraulic behaviour of co-occurring larch (Larix laricina) and black spruce (Picea mariana), two characteristic boreal tree species, near the southern limit of the boreal ecozone in central Canada. Sap flux density (Js), concurrently recorded stem radius fluctuations and meteorological conditions are used to quantify tree hydraulic functioning and to scrutinize tree water-use strategies. Our analysis revealed asynchrony in the diel hydrodynamics of the two species with the initial rise in Js occurring 2 h earlier in larch than in black spruce. Interspecific differences in larch and black spruce crown architecture explained the observed asynchrony in their hydraulic functioning. Furthermore, the two species exhibited diverging stomatal regulation strategies with larch and black spruce employing relatively isohydric and anisohydric behaviour, respectively. Such asynchronous and diverging tree-level hydrodynamics provide new insights into the ecosystem-level complementarity in tree form and function, with implications for understanding boreal forests' water and carbon dynamics and their resilience to environmental stress.
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Affiliation(s)
- Christoforos Pappas
- Département de géographie and Centre d'études nordiques, Université de Montréal, Montréal, QC, Canada
| | - Ashley M Matheny
- Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, TX, USA
- Department of Civil, Environmental, and Geodetic Engineering, Ohio State University, Columbus, OH, USA
| | | | - Alan G Barr
- Climate Research Division, Environment Canada and Global Institute for Water Security, University of Saskatchewan, Saskatoon, SK, Canada
| | - T Andrew Black
- Faculty of Land and Food Systems, Biometeorology and Soil Physics Group, University of British Columbia, Vancouver, BC, Canada
| | - Gil Bohrer
- Department of Civil, Environmental, and Geodetic Engineering, Ohio State University, Columbus, OH, USA
| | - Matteo Detto
- Center for Tropical Forest Science-Forest Global Earth Observatory, Smithsonian Tropical Research Institute, Panamà, Republic of Panamà
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Jason Maillet
- School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK, Canada
| | - Alexandre Roy
- Département de géographie and Centre d'études nordiques, Université de Montréal, Montréal, QC, Canada
| | - Oliver Sonnentag
- Département de géographie and Centre d'études nordiques, Université de Montréal, Montréal, QC, Canada
| | - Jilmarie Stephens
- Faculty of Land and Food Systems, Biometeorology and Soil Physics Group, University of British Columbia, Vancouver, BC, Canada
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Mavromatis A, Maglaveras N, Tsikotis A, Pangalos G, Ambrosiadou V, Pappas C. Cardiological Database Management System as a Mediator to Clinical Decision Support. Methods Inf Med 2018. [DOI: 10.1055/s-0038-1634632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
AbstractAn object-oriented medical database management system is presented for a typical cardiologic center, facilitating epidemiological trials. Object-oriented analysis and design were used for the system design, offering advantages for the integrity and extendibility of medical information systems. The system was developed using object-oriented design and programming methodology, the C++ language and the Borland Paradox Relational Data Base Management System on an MS-Windows NT environment. Particular attention was paid to system compatibility, portability, the ease of use, and the suitable design of the patient record so as to support the decisions of medical personnel in cardiovascular centers. The system was designed to accept complex, heterogeneous, distributed data in various formats and from different kinds of examinations such as Holter, Doppler and electrocardiography.
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18
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Basalekou M, Pappas C, Kotseridis Y, Tarantilis PA, Kontaxakis E, Kallithraka S. Red Wine Age Estimation by the Alteration of Its Color Parameters: Fourier Transform Infrared Spectroscopy as a Tool to Monitor Wine Maturation Time. J Anal Methods Chem 2017; 2017:5767613. [PMID: 29225994 PMCID: PMC5687142 DOI: 10.1155/2017/5767613] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 09/12/2017] [Accepted: 09/26/2017] [Indexed: 06/02/2023]
Abstract
Color, phenolic content, and chemical age values of red wines made from Cretan grape varieties (Kotsifali, Mandilari) were evaluated over nine months of maturation in different containers for two vintages. The wines differed greatly on their anthocyanin profiles. Mid-IR spectra were also recorded with the use of a Fourier Transform Infrared Spectrophotometer in ZnSe disk mode. Analysis of Variance was used to explore the parameter's dependency on time. Determination models were developed for the chemical age indexes using Partial Least Squares (PLS) (TQ Analyst software) considering the spectral region 1830-1500 cm-1. The correlation coefficients (r) for chemical age index i were 0.86 for Kotsifali (Root Mean Square Error of Calibration (RMSEC) = 0.067, Root Mean Square Error of Prediction (RMSEP) = 0,115, and Root Mean Square Error of Validation (RMSECV) = 0.164) and 0.90 for Mandilari (RMSEC = 0.050, RMSEP = 0.040, and RMSECV = 0.089). For chemical age index ii the correlation coefficients (r) were 0.86 and 0.97 for Kotsifali (RMSEC 0.044, RMSEP = 0.087, and RMSECV = 0.214) and Mandilari (RMSEC = 0.024, RMSEP = 0.033, and RMSECV = 0.078), respectively. The proposed method is simpler, less time consuming, and more economical and does not require chemical reagents.
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Affiliation(s)
- M. Basalekou
- Laboratory of Oenology, Department of Food Science & Human Nutrition, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece
| | - C. Pappas
- Laboratory of Chemistry, Department of Food Science & Human Nutrition, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece
| | - Y. Kotseridis
- Laboratory of Oenology, Department of Food Science & Human Nutrition, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece
| | - P. A. Tarantilis
- Laboratory of Chemistry, Department of Food Science & Human Nutrition, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece
| | - E. Kontaxakis
- Department of Agriculture, School of Agriculture, Food and Nutrition, Technological Educational Institute of Crete, Estavromenos, 71004 Heraklion, Greece
| | - S. Kallithraka
- Laboratory of Oenology, Department of Food Science & Human Nutrition, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece
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19
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Pappas C, Mahecha MD, Frank DC, Babst F, Koutsoyiannis D. Ecosystem functioning is enveloped by hydrometeorological variability. Nat Ecol Evol 2017; 1:1263-1270. [PMID: 29046560 DOI: 10.1038/s41559-017-0277-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 06/23/2017] [Indexed: 12/22/2022]
Abstract
Terrestrial ecosystem processes, and the associated vegetation carbon dynamics, respond differently to hydrometeorological variability across timescales, and so does our scientific understanding of the underlying mechanisms. Long-term variability of the terrestrial carbon cycle is not yet well constrained and the resulting climate-biosphere feedbacks are highly uncertain. Here we present a comprehensive overview of hydrometeorological and ecosystem variability from hourly to decadal timescales integrating multiple in situ and remote-sensing datasets characterizing extra-tropical forest sites. We find that ecosystem variability at all sites is confined within a hydrometeorological envelope across sites and timescales. Furthermore, ecosystem variability demonstrates long-term persistence, highlighting ecological memory and slow ecosystem recovery rates after disturbances. However, simulation results with state-of-the-art process-based models do not reflect this long-term persistent behaviour in ecosystem functioning. Accordingly, we develop a cross-time-scale stochastic framework that captures hydrometeorological and ecosystem variability. Our analysis offers a perspective for terrestrial ecosystem modelling and paves the way for new model-data integration opportunities in Earth system sciences.
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Affiliation(s)
- Christoforos Pappas
- Département de Géographie and Centre d'Études Nordiques, Université de Montréal, Montréal, QC, H2V 2B8, Canada.
| | - Miguel D Mahecha
- Max Planck Institute for Biogeochemistry, 07745, Jena, Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103, Leipzig, Germany
| | - David C Frank
- Swiss Federal Research Institute, WSL, 8903, Birmensdorf, Switzerland.,Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona, 85721-0045, USA
| | - Flurin Babst
- Swiss Federal Research Institute, WSL, 8903, Birmensdorf, Switzerland.,W. Szafer Institute of Botany, Polish Academy of Sciences, 31-512, Krakow, Poland
| | - Demetris Koutsoyiannis
- Department of Water Resources and Environmental Engineering, School of Civil Engineering, National Technical University of Athens, 15780, Athens, Greece
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20
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Pappas C, Bannenberg LJ, Lelièvre-Berna E, Qian F, Dewhurst CD, Dalgliesh RM, Schlagel DL, Lograsso TA, Falus P. Magnetic Fluctuations, Precursor Phenomena, and Phase Transition in MnSi under a Magnetic Field. Phys Rev Lett 2017; 119:047203. [PMID: 29341765 DOI: 10.1103/physrevlett.119.047203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Indexed: 06/07/2023]
Abstract
The reference chiral helimagnet MnSi is the first system where Skyrmion lattice correlations have been reported. At a zero magnetic field the transition at T_{C} to the helimagnetic state is of first order. Above T_{C}, in a region dominated by precursor phenomena, neutron scattering shows the buildup of strong chiral fluctuating correlations over the surface of a sphere with radius 2π/ℓ, where ℓ is the pitch of the helix. It has been suggested that these fluctuating correlations drive the helical transition to first order following a scenario proposed by Brazovskii for liquid crystals. We present a comprehensive neutron scattering study under magnetic fields, which provides evidence that this is not the case. The sharp first order transition persists for magnetic fields up to 0.4 T whereas the fluctuating correlations weaken and start to concentrate along the field direction already above 0.2 T. Our results thus disconnect the first order nature of the transition from the precursor fluctuating correlations. They also show no indication for a tricritical point, where the first order transition crosses over to second order with increasing magnetic field. In this light, the nature of the first order helical transition and the precursor phenomena above T_{C}, both of general relevance to chiral magnetism, remain an open question.
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Affiliation(s)
- C Pappas
- Delft University of Technology, Mekelweg 15, 2629 JB Delft, Netherlands
| | - L J Bannenberg
- Delft University of Technology, Mekelweg 15, 2629 JB Delft, Netherlands
| | - E Lelièvre-Berna
- Institut Laue-Langevin, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - F Qian
- Delft University of Technology, Mekelweg 15, 2629 JB Delft, Netherlands
| | - C D Dewhurst
- Institut Laue-Langevin, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - R M Dalgliesh
- STFC, ISIS, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - D L Schlagel
- Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | - T A Lograsso
- Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | - P Falus
- Institut Laue-Langevin, 71 Avenue des Martyrs, 38000 Grenoble, France
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21
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van Eijck L, Cussen LD, Sykora GJ, Schooneveld EM, Rhodes NJ, van Well AA, Pappas C. Design and performance of a novel neutron powder diffractometer: PEARL at TU Delft. J Appl Crystallogr 2016. [DOI: 10.1107/s160057671601089x] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The performance of the new neutron powder diffraction instrument PEARL that is installed at the research reactor of Delft University of Technology is reported. It is based on the optimization concepts developed by Cussen [Nucl. Instrum. Methods Phys. Res. Sect. A (2007), 583, 394–406], which lead to high performance competing with existing constant-wavelength neutron powder diffractometers, despite the relatively low source brightness of the 2 MW reactor of Delft University of Technology.
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22
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Pappas C, Fatichi S, Burlando P. Modeling terrestrial carbon and water dynamics across climatic gradients: does plant trait diversity matter? New Phytol 2016; 209:137-51. [PMID: 26389742 DOI: 10.1111/nph.13590] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [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: 04/28/2015] [Accepted: 07/04/2015] [Indexed: 05/22/2023]
Abstract
Plant trait diversity in many vegetation models is crudely represented using a discrete classification of a handful of 'plant types' (named plant functional types; PFTs). The parameterization of PFTs reflects mean properties of observed plant traits over broad categories ignoring most of the inter- and intraspecific plant trait variability. Taking advantage of a multivariate leaf-trait distribution (leaf economics spectrum), as well as documented plant drought strategies, we generate an ensemble of hypothetical species with coordinated attributes, rather than using few PFTs. The behavior of these proxy species is tested using a mechanistic ecohydrological model that translates plant traits into plant performance. Simulations are carried out for a range of climates representative of different elevations and wetness conditions in the European Alps. Using this framework we investigate the sensitivity of ecosystem response to plant trait diversity and compare it with the sensitivity to climate variability. Plant trait diversity leads to highly divergent vegetation carbon dynamics (fluxes and pools) and to a lesser extent water fluxes (transpiration). Abiotic variables, such as soil water content and evaporation, are only marginally affected. These results highlight the need for revising the representation of plant attributes in vegetation models. Probabilistic approaches, based on observed multivariate whole-plant trait distributions, provide a viable alternative.
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Affiliation(s)
- Christoforos Pappas
- Institute of Environmental Engineering, ETH Zürich, Stefano Franscini-Platz 5, Zurich, Switzerland
| | - Simone Fatichi
- Institute of Environmental Engineering, ETH Zürich, Stefano Franscini-Platz 5, Zurich, Switzerland
| | - Paolo Burlando
- Institute of Environmental Engineering, ETH Zürich, Stefano Franscini-Platz 5, Zurich, Switzerland
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23
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Dounousi E, Mitsis M, Naka KK, Pappas C, Lakkas L, Harisis C, Pappas K, Koutlas V, Tzalavra I, Spanos G, Michalis LK, Siamopoulos KC. Differences in cardiac structure assessed by echocardiography between renal transplant recipients and chronic kidney disease patients. Transplant Proc 2015; 46:3194-8. [PMID: 25420857 DOI: 10.1016/j.transproceed.2014.10.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Cardiovascular disease (CVD) is the leading cause of death in predialysis chronic kidney disease (CKD) and dialysis patients as well as in renal transplant recipients (RTRs). Left ventricular hypertrophy (LVH) starts early during the course of CKD and is a strong predictor of CVD in this population. Regression of LVH after a successful renal transplantation remains a debatable issue among investigators, whereas there is little data comparing echocardiographic measurements between patients with predialysis CKD and RTRs. AIM The aim of this study was to compare echocardiographic measurements of LV structure and function between predialysis CKD patients and RTRs of similar renal function level. PATIENTS AND METHODS We conducted a case control study with individual (1:2) matching from the Renal Transplant and the predialysis CKD Outpatient Clinic. For each of the 36 RTRs, two matched for gender, age and estimated glomerular filtration rate (eGFR) predialysis CKD outpatients (72 patients) were included. All patients underwent transthoracic echocardiography and LV mass, LV mass index [LVM and LVMI = LVM/BSA g/m(2)] and indices of systolic function were measured. In a subgroup of 12 RTRs we retrospectively assessed and compared the LVMI measurements at three different time points, during predialysis, dialysis and post transplant period. RESULTS The prevalence of LVH was 33% in RTRs and 52% in CKD patients (ns). RTRs had significantly lower LVM and LVMI levels compared with predialysis CKD patients (P = .006 and P = .008) while the other echocardiographic indices did not differ. In the subgroup of 12 RTRs, post-transplant LVMI levels (105 ± 25 g/m(2)) were significantly lower in comparison with predialysis (147 ± 57 g/m(2)) and dialysis LVMI levels (169 ± 72 g/m(2)) (P = .01, P = .01, respectively). CONCLUSION RTRs had significantly lower LVMI compared with predialysis CKD patients of similar age, renal function, hemoglobin and blood pressure level.
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Affiliation(s)
- E Dounousi
- Renal Transplant Unit, University Hospital of Ioannina, Ioannina, Greece
| | - M Mitsis
- Renal Transplant Unit, University Hospital of Ioannina, Ioannina, Greece
| | - K K Naka
- Cardiology Department, University Hospital of Ioannina, Ioannina, Greece
| | - C Pappas
- Renal Transplant Unit, University Hospital of Ioannina, Ioannina, Greece
| | - L Lakkas
- Cardiology Department, University Hospital of Ioannina, Ioannina, Greece
| | - C Harisis
- Renal Transplant Unit, University Hospital of Ioannina, Ioannina, Greece
| | - K Pappas
- Cardiology Department, University Hospital of Ioannina, Ioannina, Greece
| | - V Koutlas
- Renal Transplant Unit, University Hospital of Ioannina, Ioannina, Greece
| | - I Tzalavra
- Renal Transplant Unit, University Hospital of Ioannina, Ioannina, Greece
| | - G Spanos
- Renal Transplant Unit, University Hospital of Ioannina, Ioannina, Greece
| | - L K Michalis
- Cardiology Department, University Hospital of Ioannina, Ioannina, Greece
| | - K C Siamopoulos
- Renal Transplant Unit, University Hospital of Ioannina, Ioannina, Greece.
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Kusmin A, van Eijck L, Pappas C, Zolnierczuk P, Arend N, Ohl M, van Well A. Quasielastic neutron scattering experiment on water using TOFLAR (Time Of Flight and LARmor precession) technique at SNS. EPJ Web of Conferences 2015. [DOI: 10.1051/epjconf/20158303009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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25
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Steier C, Madur A, Bailey B, Berg K, Biocca A, Black A, Casey P, Colomb D, Gunion B, Li N, Marks S, Nishimura H, Pappas C, Petermann K, Portmann G, Prestemon S, Rawlins A, Robin D, Rossi S, Scarvie T, Schlueter R, Sun C, Tarawneh H, Wan W, Williams E, Yin L, Zhou Q, Jin J, Zhang J, Chen C, Wen Y, Wu J. Completion of the Brightness Upgrade of the ALS. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/1742-6596/493/1/012030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Andrikopoulos G, Tzeis S, Nikas N, Richter D, Pipilis A, Gotsis A, Tsaknakis T, Kartalis A, Kitsiou A, Toli K, Mantas I, Olympios C, Pras A, Lampropoulos S, Oikonomou K, Pappas C, Kranidis A, Anastasiou-Nana M, Triposkiadis F, Goudevenos I, Theodorakis G, Vardas P. Short-term outcome and attainment of secondary prevention goals in patients with acute coronary syndrome—Results from the countrywide TARGET study. Int J Cardiol 2013. [DOI: 10.1016/j.ijcard.2012.10.049] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Jasaityte R, Claus P, Pappas C, Jurcut R, Desmet W, Bogaert J, Rademakers F, D'Hooge J. Stretch strain relationship for the discrimination of ischemic substrates after acute myocardial infarction. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht310.p5562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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28
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Chatziparasidou A, Moissidou M, Oraiopoulou C, Ioakeimidou C, Pappas C, Nijs M, Christoforidis N. P-11 The use of PGD in vitrified oocytes and embryos after repeat ovarian stimulation cycles in poor responder patients. Reprod Biomed Online 2013. [DOI: 10.1016/s1472-6483(13)60074-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Dounousi E, Mitsis M, Spanos G, Pappas C, Koutlas V, Tzalavra I, Xarisis C, Glantzounis G, Fatouros M, Siamopoulos KC. Assessment of nonimmunologic factors in kidney transplant recipients according to Kidney Disease Improving Global Outcomes. Transplant Proc 2012; 44:2709-11. [PMID: 23146500 DOI: 10.1016/j.transproceed.2012.09.010] [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] [Indexed: 10/27/2022]
Abstract
INTRODUCTION Cardiovascular disease is the primary cause of death among kidney transplant recipients (KTRs), whereas chronic allograft nephropathy (CAN) is the main reason leading to end-stage chronic kidney disease. The etiologies of both entities include immunologic and nonimmunologic factors. The management of modifiable nonimmunologic parameters has recently been identified by the Kidney Disease Improving Global Outcomes (KDIGO) guidelines. The aim of our study was to assess the implementation of these guidelines in the outpatient kidney transplantation clinic of our hospital. PATIENT AND METHODS We retrospectively monitored the records of 48 transplanted KTRs including 32 males of overall mean age 45.1 ± 10.7 years regarding control of anemia, dyslipidemia, mineral bone disorder (MBD), and blood pressure (BP) levels. Data were recorded every 6 months for 2 years, starting 1 year after renal transplantation. RESULTS The estimated glomerular filtration rate of patients at baseline was 60.3 ± 18.8 mL/min/1.73 m(2) with no significant change during 2 years of follow-up. The control of anemia was satisfactory in 42 patients (88%) with hemoglobin values ≥ 11 g/dL during the follow-up. Regarding dyslipidemia management, the aggregate of patients showed fasting triglycerides ≤500 mg/dL in all measurements. The percentage of KTRs with LDL ≤100 mg/dL tended to improve from baseline versus the end of the study period (20.8% vs 41.7%). Serum calcium was satisfactorily controlled in 77% of patients, serum phosphorus in all patients, whereas parathyroid hormone (PTH) was abnormal in 60% of KTRs with chronic kidney disease stages 3-5. Finally, the BP goal of <130/80 mm Hg was achieved in approximately half of the patients. CONCLUSION Control of nonimmunologic factors was satisfactory in terms of renal anemia and MBD, whereas dyslipidemia and BP levels were inadequately controlled. There is a clear need for better integration into clinical practice of KDIGO guidelines with regard to modifiable nonimmunologic factors.
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Affiliation(s)
- E Dounousi
- Renal Transplant Unit, University Hospital of Ioannina, Ioannina, Greece.
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Lithari C, Klados M, Pappas C, Albani M, Kapoukranidou D, Kovatsi L, Fragou D, Papadelis C, Bamidis P. The effect of inebriation on human brain functional connectivity. Int J Psychophysiol 2012. [DOI: 10.1016/j.ijpsycho.2012.07.071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Lithari C, Klados M, Papadelis C, Pappas C, Albani M, Bamidis P. How does the metric choice affect brain functional connectivity networks? Biomed Signal Process Control 2012. [DOI: 10.1016/j.bspc.2011.05.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Perpati G, Moraitou H, Armeniakou E, Mavrommati A, Pappas C, Makarona M, Kanavaki S, Pouliou E, Papamichalopoulos A. Incidence of different pathogens and sensitivity to antimicrobials in an adult CF center in Greece during 2002–2009. J Cyst Fibros 2010. [DOI: 10.1016/s1569-1993(10)60094-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Dubois CL, Pappas C, Belmans A, Erven K, Adriaenssens T, Sinnaeve P, Coosemans M, Kayaert P, Weltens C, Desmet W. Clinical outcome of coronary stenting after thoracic radiotherapy: a case-control study. Heart 2010; 96:678-82. [DOI: 10.1136/hrt.2009.183129] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Billis AS, Konstantinidis EI, Mouzakidis C, Tsolaki MN, Pappas C, Bamidis PD. A Game-Like Interface for Training Seniors’ Dynamic Balance and Coordination. XII Mediterranean Conference on Medical and Biological Engineering and Computing 2010 2010. [DOI: 10.1007/978-3-642-13039-7_174] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Anastasaki E, Kanakis C, Pappas C, Maggi L, del Campo CP, Carmona M, Alonso GL, Polissiou MG. Differentiation of saffron from four countries by mid-infrared spectroscopy and multivariate analysis. Eur Food Res Technol 2009. [DOI: 10.1007/s00217-009-1197-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Kanakis C, Tarantilis P, Pappas C, Bariyanga J, Tajmir-Riahi H, Polissiou M. An overview of structural features of DNA and RNA complexes with saffron compounds: Models and antioxidant activity. Journal of Photochemistry and Photobiology B: Biology 2009; 95:204-12. [DOI: 10.1016/j.jphotobiol.2009.03.006] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Revised: 03/13/2009] [Accepted: 03/20/2009] [Indexed: 11/30/2022]
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Pappas C, Turnage A, Frazier KS, Liu Q, Brown P. LX1032: A potential new therapy for carcinoid syndrome (CS). J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.e14555] [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] [Indexed: 11/20/2022] Open
Abstract
e14555 Background: Patients with metastatic CS experience a variety of symptoms due to increased serotonin (5-HT) produced by metastatic GI tumor cells. The enzyme tryptophan hydroxylase (TPH) catalyzes the rate-limiting step in the synthesis of 5-HT. Reducing 5-HT synthesis by TPH inhibition represents a new mechanism for potentially managing symptoms associated with CS. LX1032 is a novel, orally bioavailable TPH inhibitor designed to afford systemic exposure without affecting 5-HT synthesis in the CNS. Preclinical studies of LX1032 in multiple species confirmed systemic inhibition of 5-HT synthesis without changes in brain 5-HT levels. Methods: Single (n=47 subjects) and multiple (n=40 subjects) ascending dose studies with LX1032 were completed in normal volunteers; 24-hr urinary 5-HIAA and blood 5-HT were measured as biomarkers of 5-HT metabolism. Results: LX1032 produced a significant dose-dependent reduction in urinary 5-HIAA and blood 5-HT levels, with maximal reductions observed at doses at or above 500 mg, once daily, in the 14 day multiple ascending dose (MAD) study; the mean change from baseline in blood 5-HT was -30% for the 1500 mg (500 mg TID) dose group. Single doses up to 500 mg were well tolerated with no evidence of dose limiting toxicity or tolerability; GI related adverse events (nausea, emesis, and diarrhea) started to emerge at the 1,000 mg dose level and became dose-limiting at the 1,500 mg single dose level. Multiple doses were well tolerated at all dose levels up to 1.500 mg (500 mg TID). Adverse events (AEs) were mild to moderate and no serious AEs occurred; a dose-dependent, mild increase in hepatic transaminase levels was observed in the MAD study. Conclusions: Inhibiting TPH, and thereby reducing peripheral 5-HT production, represents a potential new approach for managing symptoms in CS patients. LX1032 is a novel, orally bioavailable TPH inhibitor that significantly reduced 5-HT production at well tolerated dose levels. The favorable safety profile and observed decrease in urinary 5-HIAA and blood 5-HT levels indicate that LX1032 could be used to lower 5-HT as a potential new approach for managing hyperserotoninemia-related complications of CS, and support studies of the compound in CS patients. [Table: see text]
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Affiliation(s)
- C. Pappas
- Lexicon Pharmaceuticals, Inc., The Woodlands, TX
| | - A. Turnage
- Lexicon Pharmaceuticals, Inc., The Woodlands, TX
| | | | - Q. Liu
- Lexicon Pharmaceuticals, Inc., The Woodlands, TX
| | - P. Brown
- Lexicon Pharmaceuticals, Inc., The Woodlands, TX
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Katz JM, Veguilla V, Belser JA, Maines TR, Van Hoeven N, Pappas C, Hancock K, Tumpey TM. The public health impact of avian influenza viruses. Poult Sci 2009; 88:872-9. [PMID: 19276438 DOI: 10.3382/ps.2008-00465] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [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] Open
Abstract
Influenza viruses with novel hemagglutinin and 1 or more accompanying genes derived from avian influenza viruses sporadically emerge in humans and have the potential to result in a pandemic if the virus causes disease and spreads efficiently in a population that lacks immunity to the novel hemagglutinin. Since 1997, multiple avian influenza virus subtypes have been transmitted directly from domestic poultry to humans and have caused a spectrum of human disease, from asymptomatic to severe and fatal. To assess the pandemic risk that avian influenza viruses pose, we have used multiple strategies to better understand the capacity of avian viruses to infect, cause disease, and transmit among mammals, including humans. Seroepidemiologic studies that evaluate the frequency and risk of human infection with avian influenza viruses in populations with exposure to domestic or wild birds can provide a better understanding of the pandemic potential of avian influenza subtypes. Investigations conducted in Hong Kong following the first H5N1 outbreak in humans in 1997 determined that exposure to poultry in live bird markets was a key risk factor for human disease. Among poultry workers, butchering and exposure to sick poultry were risk factors for antibody to H5 virus, which provided evidence for infection. A second risk assessment tool, the ferret, can be used to evaluate the level of virulence and potential for host-to-host transmission of avian influenza viruses in this naturally susceptible host. Avian viruses isolated from humans exhibit a level of virulence and transmissibility in ferrets that generally reflects that seen in humans. The ferret model thus provides a means to monitor emerging avian influenza viruses for pandemic risk, as well as to evaluate laboratory-generated reassortants and mutants to better understand the molecular basis of influenza virus transmissibility. Taken together, such studies provide valuable information with which we can assess the public health risk of avian influenza viruses.
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Affiliation(s)
- J M Katz
- Immunology and Pathogenesis Branch, Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
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Pappas C, Lelièvre-Berna E, Falus P, Bentley PM, Moskvin E, Grigoriev S, Fouquet P, Farago B. Chiral paramagnetic skyrmion-like phase in MnSi. Phys Rev Lett 2009; 102:197202. [PMID: 19518992 DOI: 10.1103/physrevlett.102.197202] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Indexed: 05/27/2023]
Abstract
We present a comprehensive study of chiral fluctuations in the reference helimagnet MnSi by polarized neutron scattering and neutron spin echo spectroscopy, which reveals the existence of a completely left-handed and dynamically disordered phase. This phase may be identified as a spontaneous Skyrmion phase: it appears in a limited temperature range just above the helical transition T_{C} and coexists with the helical phase at T_{C}.
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Affiliation(s)
- C Pappas
- Helmholtz Zentrum Berlin für Materialien und Energie, Glienickerstrasse 100, 14109 Berlin, Germany.
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Abstract
Spin relaxation close to the glass temperature of CuMn and AuFe spin glasses is shown, by neutron spin echo, to follow a generalized exponential function which explicitly introduces hierarchically constrained dynamics and macroscopic interactions. The interaction parameter is directly related to the normalized Tsallis nonextensive entropy parameter q and exhibits universal scaling with reduced temperature. At the glass temperature q=5/3 corresponding, within Tsallis' q statistics, to a mathematically defined critical value for the onset of strong disorder and nonlinear dynamics.
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Affiliation(s)
- R M Pickup
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
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Pappas C, Lelievre-Berna E, Bentley P, Moskvin E, Farago B, Falus P, Grigoriev S, Dyadkin V. Polarimetric neutron spin echo spectroscopy. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308093963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Dragusin O, Bosmans H, Pappas C, Desmet W. An investigation of flat panel equipment variables on image quality with a dedicated cardiac phantom. Phys Med Biol 2008; 53:4927-40. [PMID: 18711249 DOI: 10.1088/0031-9155/53/18/005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Image quality (IQ) evaluation plays a key role in the process of optimization of new x-ray systems. Ideally, this process should be supported by real clinical images, but ethical issues and differences in anatomy and pathology of patients make it impossible. Phantom studies might overcome these issues. This paper presents the IQ evaluation of 30 cineangiographic films acquired with a cardiac flat panel system. The phantom used simulates the anatomy of the heart and allows the circulation of contrast agent boluses through coronary arteries. Variables investigated with influence on IQ and radiation dose are: tube potential, detector dose, added Copper filters, dynamic density optimization (DDO) and viewing angle. The IQ evaluation consisted of scoring 4 simulated calcified lesions located on different coronary artery segments in terms of degree of visualization. Eight cardiologists rated the lesions using a five-point scale ((1) lesion not visible to (5) very good visibility). Radiation doses associated to the angiograms are expressed in terms of incident air kerma (IAK) and effective dose that has been calculated with PCXMX software (STUK, Finland) from the exposure settings assuming a standard sized patient of 70 Kg. Mean IQ scores ranged from 1.68 to 4.88. The highest IQ scores were obtained for the angiograms acquired with tube potential 80 kVp, no added Cu filters, DDO 60%, RAO and LAO views and the highest entrance detector dose that has been used in the present study, namely 0.17 microGy/im. Radiation doses (IAK approximately 40 mGy and effective dose of 1 mSv) were estimated for angiograms acquired at 15 frames s(-1), detector field-of-view 20 cm, and a length of 5 s. The following parameters improved the IQ factor significantly: a change in tube potential from 96 to 80 kVp, detector dose from 0.10 microGy/im to 0.17 microGy/im, the absence of Copper filtration. DDO variable which is a post-processing parameter should be carefully evaluated because it alters the quality of the images independently of radiation exposure settings. The SAM anthropomorphic phantom has the advantage of visualization of stenotic lesions during the injection of a contrast agent and using an anatomical background. In the future, this phantom could potentially bridge the gap between physics tests and the clinical reality in the catheterization laboratory.
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Affiliation(s)
- O Dragusin
- Department of Radiology, University Hospital Gasthuisberg, 49, Herestraat, 3000-Leuven, Belgium.
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44
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Bamidis PD, Konstantinidis S, Papadelis CL, Perantoni E, Styliadis C, Kourtidou-Papadeli C, Kourtidou-Papadeli C, Pappas C. An e-learning platform for aerospace medicine. Hippokratia 2008; 12 Suppl 1:15-22. [PMID: 19048088 PMCID: PMC2577394] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The appeal of online education and distance learning as an educational alternative is ever increasing. To support and accommodate the over-specialized knowledge available by different experts, information technology can be employed to develop virtual distributed pools of autonomous specialized educational modules and provide the mechanisms for retrieving and sharing them. New educational standards such as SCORM and Healthcare LOM enhance this process of sharing by offering qualities like interoperability, accessibility, and reusability, so that learning material remains credible, up-to-date and tracks changes and developments of medical techniques and standards through time. Given that only a few e-learning courses exist in aerospace medicine the material of which may be exchanged among teachers, the aim of this paper is to illustrate the procedure of creating a SCORM compliant course that incorporates notions of recent advances in social web technologies. The course is in accordance with main educational and technological details and is specific to pulmonary disorders in aerospace medicine. As new educational trends place much emphasis in continuing medical education, the expansion of a general practitioner's knowledge in topics such as aviation and aerospace pulmonary disorders for crew and passengers becomes a societal requirement.
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Affiliation(s)
- P D Bamidis
- Lab of Medical Informatics, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
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Crist MA, Matthews NS, Oberle NL, Pappas C. Effect of 1- and 10-day administration of tepoxalin on minimum alveolar concentration of isoflurane and sevoflurane in dogs. Vet Ther 2007; 8:107-12. [PMID: 17616945] [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: 05/16/2023]
Abstract
Analgesics given preoperatively have the potential to decrease the amount of inhalant anesthetics required intraoperatively (i.e., to decrease the minimum alveolar concentration, or MAC, for the inhalant). Tepoxalin is an NSAID approved for the treatment of arthritis in dogs in the United States and, hence, could be administered to patients undergoing anesthesia. In this study, administration of a single dose or a 10-day course of tepoxalin did not affect the MAC for isoflurane or sevoflurane.
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Affiliation(s)
- M A Crist
- Department of Small Animal Clinical Sciences, Texas A & M University, College Station, TX 77843-4474, USA
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Zimprich F, Ronen GM, Stögmann W, Baumgartner C, Stögmann E, Rett B, Pappas C, Leppert M, Singh N, Anderson VE. Andreas Rett and benign familial neonatal convulsions revisited. Neurology 2006; 67:864-6. [PMID: 16966552 DOI: 10.1212/01.wnl.0000234066.46806.90] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [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: 11/15/2022] Open
Abstract
In 1964 Andreas Rett published the first account of a family with benign familial neonatal convulsions (BFNC). The authors retraced Rett's family and report that the clinical and genetic features of this original family fit the currently accepted definitions of BFNC. They also consider the career of Dr. Rett, a researcher and social reformer as well as an advocate for the rights of children with developmental disabilities.
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Affiliation(s)
- F Zimprich
- Department of Clinical Neurology, Medical University of Vienna, Austria.
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47
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Mountricha A, Platsouka E, Pappas C, Vourli S, Velonakis E, Hadjiconstantinou V, Vatopoulos A, Paniara O. S. aureus nasal carriage among hemodialysis (HD) patients. Clin Nephrol 2006; 65:229-30. [PMID: 16550758 DOI: 10.5414/cnp65229] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Monkenbusch M, Ohl M, Richter D, Pappas C, Zsigmond G, Lieutenant K, Mezei F. Aspects of Neutron Spin-echo Spectrometer Operation on a Pulsed Source. Journal of Neutron Research 2005. [DOI: 10.1080/10238160412331299555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Zervou EK, Georgiadou S, Tzilianos M, Georgitsi P, Pournara V, Nousis S, Pappas C, Daskalou L, Vrettou A, Karabini F, Dalekos GN. Human T-lymphotropic virus type I/II infections in volunteer blood donors from Northern and Western Greece: increased prevalence in one blood bank unit. Eur J Intern Med 2004; 15:422-427. [PMID: 15581745 DOI: 10.1016/j.ejim.2004.06.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2003] [Revised: 05/24/2004] [Accepted: 06/07/2004] [Indexed: 11/18/2022]
Abstract
BACKGROUND: Blood donors are routinely screened for antibodies to human T-cell lymphotropic viruses type I and II (HTLV-I and HTLV-II) in the United States, Canada, Japan, and some European countries. Previous reports from our group in relatively small numbers of donors have shown a zero prevalence of HTLV-I/II markers in our region. In this study, seven blood banks in the north and west of Greece participated in order to determine whether mandatory screening of blood donations for HTLV-I/II infection should be established. METHODS: Sera from 51,714 consecutive donors were investigated for anti-HTLV-I/II using two commercially available enzyme immunoassays (EIAs). Reactive samples in one or both EIAs were repeatedly evaluated further by Western blot, which is specific for both confirmation and differentiation of HTLV-I and HTLV-II seroreactivities. Investigation for HTLV DNA was also done in all EIA-reactive donors, irrespective of the WB result, using a combination assay based on the polymerase chain reaction (PCR) and a DNA EIA. RESULTS: A total of 115 donors (0.222%; 95% CI 0.018-0.26%) were initially considered reactive for anti-HTLV-I/II by EIAs. However, only 7 of the 115 were confirmed as positive by WB (five HTLV-I and two HTLV-I/II). Thus, the prevalence of anti-HTLV-I/II in donors from northern and western Greece was 0.013% (95% CI 0.003-0.023%). Interestingly, the majority of WB-confirmed anti-HTLV-positive individuals were detected in the blood bank of Corfu (5/7, all anti-HTLV-I). This prevalence (5/15383; 0.032%; 95% CI 0.004-0.061%) was six times the prevalence found at the other blood banks combined (2/36331; 0.0055%; 95% CI 0-0.013%), but it was not statistically significant. None of the EIA-reactive donors had detectable HTLV DNA. CONCLUSIONS: The very low prevalence of confirmed anti-HTLV-I/II infection markers in northern and western Greek blood donors, together with the negative PCR results in EIA-reactive subjects, indicates that anti-HTLV-I/I routine screening is not really justified in this area of our country. However, the increased prevalence of WB-confirmed anti-HTLV-I-positive donors in the Corfu blood bank calls for further prospective and careful investigation in order to address whether this finding represents a real cluster phenomenon of HTLV infection.
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Affiliation(s)
- E K Zervou
- Blood Bank at the University Hospital of Ioannina, Greece
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Chouvarda I, Maglaveras N, Pappas C, VAN Capelle FJL, DeBakker J. Estimation of Distance Between a Unipolar Recording Electrode and a Myocardial Bundle Based on Signal Characteristics. Ann Biomed Eng 2004; 32:1336-47. [PMID: 15535052 DOI: 10.1114/b:abme.0000042222.90548.00] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [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: 11/24/2022]
Abstract
The aim of the present paper, is the estimation of the distance between an electrode used as a recording site of the extracellular potential field and a surviving myocardial bundle. The importance of the reliable solution of this problem lies among others in controlling ablation. For our purposes one-dimensional propagation is considered and current sources are activated along a cable simulating the propagating waves with constant velocity. Different models of current sources are explored. By use of these models, the corresponding functions expressing extracellular potentials are calculated, using the volume conductor equation. This way, extracellular potentials are modeled as parametric functions of longitudinal distance, while perpendicular distance, current source strength, and other factors related to the propagated wave are parameters of the functions. Simulated annealing is applied for model parameter estimation and appropriate Time Domain and Wavelet Domain cost functions are investigated. Different combinations of model and cost function are evaluated regarding the accuracy of distance estimation. A continuous source model function with a wavelet cost function was found to be the most accurate combination. The accuracy of distance estimation is related to the selected source model and to the actual distance of recording in a nonmonotonic way.
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Affiliation(s)
- I Chouvarda
- Lab of Medical Informatics, Medical School, Aristotelian University of Thessaloniki, Macedonia, Greece
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