1
|
Monteux S, Blume-Werry G, Gavazov K, Kirchhoff L, Krab EJ, Lett S, Pedersen EP, Väisänen M. Controlling biases in targeted plant removal experiments. New Phytol 2024; 242:1835-1845. [PMID: 38044568 DOI: 10.1111/nph.19386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 10/19/2023] [Indexed: 12/05/2023]
Abstract
Targeted removal experiments are a powerful tool to assess the effects of plant species or (functional) groups on ecosystem functions. However, removing plant biomass in itself can bias the observed responses. This bias is commonly addressed by waiting until ecosystem recovery, but this is inherently based on unverified proxies or anecdotal evidence. Statistical control methods are efficient, but restricted in scope by underlying assumptions. We propose accounting for such biases within the experimental design, using a gradient of biomass removal controls. We demonstrate the relevance of this design by presenting (1) conceptual examples of suspected biases and (2) how to observe and control for these biases. Using data from a mycorrhizal association-based removal experiment, we show that ignoring biomass removal biases (including by assuming ecosystem recovery) can lead to incorrect, or even contrary conclusions (e.g. false positive and false negative). Our gradient design can prevent such incorrect interpretations, regardless of whether aboveground biomass has fully recovered. Our approach provides more objective and quantitative insights, independently assessed for each variable, than using a proxy to assume ecosystem recovery. Our approach circumvents the strict statistical assumptions of, for example, ANCOVA and thus offers greater flexibility in data analysis.
Collapse
Affiliation(s)
- Sylvain Monteux
- Department of Environmental Science, Stockholm University, SE-10691, Stockholm, Sweden
- Bolin Centre for Climate Research, Stockholm University, SE-10691, Stockholm, Sweden
- UiT The Arctic University Museum of Norway, NO-9006, Tromsø, Norway
| | - Gesche Blume-Werry
- Department of Ecology and Environmental Sciences, Climate Impacts Research Centre, Umeå University, SE-98107, Abisko, Sweden
| | - Konstantin Gavazov
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, CH-8903, Birmensdorf, Switzerland
| | - Leah Kirchhoff
- Department of Ecology and Environmental Sciences, Climate Impacts Research Centre, Umeå University, SE-98107, Abisko, Sweden
| | - Eveline J Krab
- Department of Soil and Environment, Swedish University for Agricultural Sciences SLU, SE-75651, Uppsala, Sweden
| | - Signe Lett
- Department of Biology, University of Copenhagen, DK-1165, Copenhagen, Denmark
| | - Emily P Pedersen
- Department of Ecology and Environmental Sciences, Climate Impacts Research Centre, Umeå University, SE-98107, Abisko, Sweden
- Swedish Polar Research Secretariat, Abisko Scientific Research Station, SE-98107, Abisko, Sweden
| | - Maria Väisänen
- Ecology and Genetics Research Unit, University of Oulu, FI-90014, Oulu, Finland
| |
Collapse
|
2
|
Hiltunen TA, Stien A, Väisänen M, Ropstad E, Aspi JO, Welker JM. Svalbard reindeer winter diets: Long-term dietary shifts to graminoids in response to a changing climate. Glob Chang Biol 2022; 28:7009-7022. [PMID: 36071549 PMCID: PMC9826046 DOI: 10.1111/gcb.16420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 08/29/2022] [Accepted: 08/29/2022] [Indexed: 06/15/2023]
Abstract
Arctic ecosystems are changing dramatically with warmer and wetter conditions resulting in complex interactions between herbivores and their forage. We investigated how Svalbard reindeer (Rangifer tarandus platyrhynchus) modify their late winter diets in response to long-term trends and interannual variation in forage availability and accessibility. By reconstructing their diets and foraging niches over a 17-year period (1995-2012) using serum δ13 C and δ15 N values, we found strong support for a temporal increase in the proportions of graminoids in the diets with a concurrent decline in the contributions of mosses. This dietary shift corresponds with graminoid abundance increases in the region and was associated with increases in population density, warmer summer temperatures and more frequent rain-on-snow (ROS) in winter. In addition, the variance in isotopic niche positions, breadths, and overlaps also supported a temporal shift in the foraging niche and a dietary response to extreme ROS events. Our long-term study highlights the mechanisms by which winter and summer climate changes cascade through vegetation shifts and herbivore population dynamics to alter the foraging niche of Svalbard reindeer. Although it has been anticipated that climate changes in the Svalbard region of the Arctic would be detrimental to this unique ungulate, our study suggests that environmental change is in a phase where conditions are improving for this subspecies at the northernmost edge of the Rangifer distribution.
Collapse
Affiliation(s)
| | - Audun Stien
- Department of Arctic and Marine Biology, Fram CentreThe Arctic University of NorwayTromsøNorway
| | - Maria Väisänen
- Ecology and Genetics Research UnitUniversity of OuluOuluFinland
- Arctic CentreUniversity of LaplandRovaniemiFinland
| | - Erik Ropstad
- Department of Production Animal Clinical SciencesNorwegian University of Life SciencesÅsNorway
| | - Jouni O. Aspi
- Ecology and Genetics Research UnitUniversity of OuluOuluFinland
| | - Jeffery M. Welker
- Ecology and Genetics Research UnitUniversity of OuluOuluFinland
- UArcticRovaniemiFinland
- Department of Biological SciencesUniversity of Alaska AnchorageAnchorageAlaskaUSA
| |
Collapse
|
3
|
Jespersen RG, Leffler AJ, Väisänen M, Welker JM. Resistance and change in a High Arctic ecosystem, NW Greenland: Differential sensitivity of ecosystem metrics to 15 years of experimental warming and wetting. Glob Chang Biol 2022; 28:1853-1869. [PMID: 34870887 DOI: 10.1111/gcb.16027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 03/16/2021] [Revised: 09/23/2021] [Accepted: 11/11/2021] [Indexed: 06/13/2023]
Abstract
Dramatic increases in air temperature and precipitation are occurring in the High Arctic (>70°N), yet few studies have characterized the long-term responses of High Arctic ecosystems to the interactive effects of experimental warming and increased rain. Beginning in 2003, we applied a factorial summer warming and wetting experiment to a polar semidesert in northwest Greenland. In summer 2018, we assessed several metrics of ecosystem structure and function, including plant cover, greenness, ecosystem CO2 exchange, aboveground (leaf, stem) and belowground (litter, root, soil) carbon (C) and nitrogen (N) concentrations (%) and pools, as well as leaf and soil stable isotopes (δ13 C and δ15 N). Wetting induced the most pronounced changes in ecosystem structure, accelerating the expansion of Salix arctica cover by 370% and increasing aboveground C, N, and biomass pools by 94%-101% and root C, N, and biomass pools by 60%-122%, increases which coincided with enhanced net ecosystem CO2 uptake. Further, wetting combined with warming enhanced plot-level greenness, whereas in isolation neither wetting nor warming had an effect. At the plant level, the effects of warming and wetting differed among species and included warming-linked decreases in leaf N and δ15 N in S. arctica, whereas leaf N and δ15 N in Dryas integrifolia did not respond to the climate treatments. Finally, neither plant- nor plot-level C and N allocation patterns nor soil C, N, δ13 C, or δ15 N concentrations changed in response to our manipulations, indicating that these ecosystem metrics may resist climate change, even in the longer term. In sum, our results highlight the importance of summer precipitation in regulating ecosystem structure and function in arid parts of the High Arctic, but they do not completely refute previous findings of resistance in some High Arctic ecosystem properties to climate change.
Collapse
Affiliation(s)
- Robert Gus Jespersen
- Department of Biological Sciences, University of Alaska-Anchorage, Anchorage, Alaska, USA
| | - Alan Joshua Leffler
- Department of Natural Resource Management, South Dakota State University, Brookings, South Dakota, USA
| | - Maria Väisänen
- Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland
- Arctic Centre, University of Lapland, Rovaniemi, Finland
| | - Jeffrey M Welker
- UArctic Research Chair, Department of Arctic Ecology & Biogeochemistry, University of Oulu, Oulu, Finland
- University of Alaska-Anchorage, Anchorage, Alaska, USA
| |
Collapse
|
4
|
Ahonen SHK, Ylänne H, Väisänen M, Ruotsalainen AL, Männistö MK, Markkola A, Stark S. Reindeer grazing history determines the responses of subarctic soil fungal communities to warming and fertilization. New Phytol 2021; 232:788-801. [PMID: 34270800 DOI: 10.1111/nph.17623] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 03/26/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
Composition and functioning of arctic soil fungal communities may alter rapidly due to the ongoing trends of warmer temperatures, shifts in nutrient availability, and shrub encroachment. In addition, the communities may also be intrinsically shaped by heavy grazing, which may locally induce an ecosystem change that couples with increased soil temperature and nutrients and where shrub encroachment is less likely to occur than in lightly grazed conditions. We tested how 4 yr of experimental warming and fertilization affected organic soil fungal communities in sites with decadal history of either heavy or light reindeer grazing using high-throughput sequencing of the internal transcribed spacer 2 ribosomal DNA region. Grazing history largely overrode the impacts of short-term warming and fertilization in determining the composition of fungal communities. The less diverse fungal communities under light grazing showed more pronounced responses to experimental treatments when compared with the communities under heavy grazing. Yet, ordination approaches revealed distinct treatment responses under both grazing intensities. If grazing shifts the fungal communities in Arctic ecosystems to a different and more diverse state, this shift may dictate ecosystem responses to further abiotic changes. This indicates that the intensity of grazing cannot be left out when predicting future changes in fungi-driven processes in the tundra.
Collapse
Affiliation(s)
- Saija H K Ahonen
- Ecology and Genetics Research Unit, University of Oulu, PO Box 3000, Oulu, FI-90014, Finland
| | - Henni Ylänne
- Centre for Environmental and Climate Research (CEC), Lund University, Ekologihuset, Sölvegatan 37, Lund, 223 62, Sweden
| | - Maria Väisänen
- Ecology and Genetics Research Unit, University of Oulu, PO Box 3000, Oulu, FI-90014, Finland
- Arctic Center, University of Lapland, PO Box 122, Rovaniemi, FI-96101, Finland
| | - Anna Liisa Ruotsalainen
- Ecology and Genetics Research Unit, University of Oulu, PO Box 3000, Oulu, FI-90014, Finland
| | - Minna K Männistö
- Natural Resources Institute Finland (Luke), Ounasjoentie 6, Rovaniemi, FI-96100, Finland
| | - Annamari Markkola
- Ecology and Genetics Research Unit, University of Oulu, PO Box 3000, Oulu, FI-90014, Finland
| | - Sari Stark
- Arctic Center, University of Lapland, PO Box 122, Rovaniemi, FI-96101, Finland
| |
Collapse
|
5
|
Väisänen M, Tuomi M, Bailey H, Welker JM. Plant and soil nitrogen in oligotrophic boreal forest habitats with varying moss depths: does exclusion of large grazers matter? Oecologia 2021; 196:839-849. [PMID: 34080051 PMCID: PMC8292301 DOI: 10.1007/s00442-021-04957-0] [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] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 05/28/2021] [Indexed: 11/25/2022]
Abstract
The boreal forest consists of drier sunlit and moister-shaded habitats with varying moss abundance. Mosses control vascular plant-soil interactions, yet they all can also be altered by grazers. We determined how 2 decades of reindeer (Rangifer tarandus) exclusion affect feather moss (Pleurozium schreberi) depth, and the accompanying soil N dynamics (total and dissolvable inorganic N, δ15N), plant foliar N, and stable isotopes (δ15N, δ13C) in two contrasting habitats of an oligotrophic Scots pine forest. The study species were pine seedling (Pinus sylvestris L.), bilberry (Vaccinium myrtillus L.), lingonberry (V. vitis-idaea L.), and feather moss. Moss carpet was deeper in shaded than sunlit habitats and increased with grazer exclusion. Humus N content increased in the shade as did humus δ15N, which also increased due to exclusion in the sunlit habitats. Exclusion increased inorganic N concentration in the mineral soil. These soil responses were correlated with moss depth. Foliar chemistry varied due to habitat depending on species identity. Pine seedlings showed higher foliar N content and lower foliar δ15N in the shaded than in the sunlit habitats, while bilberry had both higher foliar N and δ15N in the shade. Thus, foliar δ15N values of co-existing species diverged in the shade indicating enhanced N partitioning. We conclude that despite strong grazing-induced shifts in mosses and subtler shifts in soil N, the N dynamics of vascular vegetation remain unchanged. These indicate that plant-soil interactions are resistant to shifts in grazing intensity, a pattern that appears to be common across boreal oligotrophic forests.
Collapse
Affiliation(s)
- Maria Väisänen
- Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland. .,Arctic Centre, University of Lapland, Rovaniemi, Finland.
| | - Maria Tuomi
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Hannah Bailey
- Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland
| | - Jeffrey M Welker
- Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland.,Department of Biological Science, University of Alaska Anchorage, Anchorage, AK, USA.,UArctic, Rovaniemi, Finland
| |
Collapse
|
6
|
Tuomi M, Väisänen M, Ylänne H, Brearley FQ, Barrio IC, Anne Bråthen K, Eischeid I, Forbes BC, Jónsdóttir IS, Kolstad AL, Macek P, Petit Bon M, Speed JDM, Stark S, Svavarsdóttir K, Thórsson J, Bueno CG. Stomping in silence: Conceptualizing trampling effects on soils in polar tundra. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13719] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Maria Tuomi
- Section of Ecology Department of Biology University of Turku Turku Finland
- Department of Arctic and Marine Biology Faculty of Biosciences, Fisheries, and Economics The Arctic University of Norway Tromsø Norway
| | - Maria Väisänen
- Ecology and Genetics Research Unit University of Oulu Oulu Finland
- Arctic Centre University of Lapland Rovaniemi Finland
| | - Henni Ylänne
- Ecology and Genetics Research Unit University of Oulu Oulu Finland
- Centre for Environmental and Climate Research Lund University Lund Sweden
| | - Francis Q. Brearley
- Department of Natural Sciences Manchester Metropolitan University Manchester UK
| | - Isabel C. Barrio
- Agricultural University of Iceland Reykjavík Iceland
- Institute of Life and Environmental Sciences University of Iceland Reykjavík Iceland
| | - Kari Anne Bråthen
- Department of Arctic and Marine Biology Faculty of Biosciences, Fisheries, and Economics The Arctic University of Norway Tromsø Norway
| | - Isabell Eischeid
- Department of Arctic and Marine Biology Faculty of Biosciences, Fisheries, and Economics The Arctic University of Norway Tromsø Norway
- Norwegian Polar InstituteFRAM – High North Research Centre for Climate and the Environment Tromsø Norway
| | | | - Ingibjörg S. Jónsdóttir
- Agricultural University of Iceland Reykjavík Iceland
- University Centre in Svalbard (UNIS) Longyearbyen Norway
| | - Anders L. Kolstad
- Department of Natural History NTNU University MuseumNorwegian University of Science and Technology Trondheim Norway
| | - Petr Macek
- Centre for Polar Ecology Faculty of Science University of South Bohemia Ceske Budejovice Czech Republic
- Biology Centre ASCRInstitute of Soil Biology Ceske Budejovice Czech Republic
| | - Matteo Petit Bon
- Department of Arctic and Marine Biology Faculty of Biosciences, Fisheries, and Economics The Arctic University of Norway Tromsø Norway
- University Centre in Svalbard (UNIS) Longyearbyen Norway
| | - James D. M. Speed
- Department of Natural History NTNU University MuseumNorwegian University of Science and Technology Trondheim Norway
| | - Sari Stark
- Arctic Centre University of Lapland Rovaniemi Finland
| | | | | | - C. Guillermo Bueno
- Institute of Ecology and Earth Sciences Department of Botany University of Tartu Tartu Estonia
| |
Collapse
|
7
|
Ylänne H, Kaarlejärvi E, Väisänen M, Männistö MK, Ahonen SHK, Olofsson J, Stark S. Removal of grazers alters the response of tundra soil carbon to warming and enhanced nitrogen availability. ECOL MONOGR 2019. [DOI: 10.1002/ecm.1396] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Henni Ylänne
- Arctic Center University of Lapland P.O. Box 122 Rovaniemi FI‐96101 Finland
- Department of Ecology and Genetics University of Oulu P.O. Box 3000 Oulu FI‐90100 Finland
| | - Elina Kaarlejärvi
- Department of Ecology and Environmental Sciences Umeå University Umeå SE‐90187 Sweden
- Department of Biology Vrije Universiteit Brussel (VUB) Pleinlaan 2 Brussel B‐1050 Belgium
| | - Maria Väisänen
- Arctic Center University of Lapland P.O. Box 122 Rovaniemi FI‐96101 Finland
| | - Minna K. Männistö
- Natural Resources Institute Finland (Luke) Eteläranta 55 Rovaniemi FI‐96300 Finland
| | - Saija H. K. Ahonen
- Department of Ecology and Genetics University of Oulu P.O. Box 3000 Oulu FI‐90100 Finland
| | - Johan Olofsson
- Department of Ecology and Environmental Sciences Umeå University Umeå SE‐90187 Sweden
| | - Sari Stark
- Arctic Center University of Lapland P.O. Box 122 Rovaniemi FI‐96101 Finland
| |
Collapse
|
8
|
Väisänen M, Gavazov K, Krab EJ, Dorrepaal E. The Legacy Effects of Winter Climate on Microbial Functioning After Snowmelt in a Subarctic Tundra. Microb Ecol 2019; 77:186-190. [PMID: 29948015 DOI: 10.1007/s00248-018-1213-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 05/28/2018] [Indexed: 06/08/2023]
Abstract
Warming-induced increases in microbial CO2 release in northern tundra may positively feedback to climate change. However, shifts in microbial extracellular enzyme activities (EEAs) may alter the impacts of warming over the longer term. We investigated the in situ effects of 3 years of winter warming in combination with the in vitro effects of a rapid warming (6 days) on microbial CO2 release and EEAs in a subarctic tundra heath after snowmelt in spring. Winter warming did not change microbial CO2 release at ambient (10 °C) or at rapidly increased temperatures, i.e., a warm spell (18 °C) but induced changes (P < 0.1) in the Q10 of microbial respiration and an oxidative EEA. Thus, although warmer winters may induce legacy effects in microbial temperature acclimation, we found no evidence for changes in potential carbon mineralization after spring thaw.
Collapse
Affiliation(s)
- Maria Väisänen
- Climate Impacts Research Center, EMG, Umeå University, Vetenskapensväg 38, SE-981 07, Abisko, Sweden.
- Arctic Centre, University of Lapland, P. O. Box 122, FI-96 101, Rovaniemi, Finland.
| | - Konstantin Gavazov
- Climate Impacts Research Center, EMG, Umeå University, Vetenskapensväg 38, SE-981 07, Abisko, Sweden
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Case postale 96, 1015, Lausanne, Switzerland
| | - Eveline J Krab
- Climate Impacts Research Center, EMG, Umeå University, Vetenskapensväg 38, SE-981 07, Abisko, Sweden
- Department of Soil and Environment, Swedish University of Agricultural Sciences, Lennart Hjelms väg 9, SE-750 07, Uppsala, Sweden
| | - Ellen Dorrepaal
- Climate Impacts Research Center, EMG, Umeå University, Vetenskapensväg 38, SE-981 07, Abisko, Sweden
| |
Collapse
|
9
|
Stark S, Väisänen M, Ylänne H, Julkunen-Tiitto R, Martz F. Decreased phenolic defence in dwarf birch (Betula nana) after warming in subarctic tundra. Polar Biol 2015. [DOI: 10.1007/s00300-015-1758-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
10
|
Järnström J, Väisänen M, Lehto R, Jäsberg A, Timonen J, Peltonen J. Effect of latex on surface structure and wetting of pigment coatings. Colloids Surf A Physicochem Eng Asp 2010. [DOI: 10.1016/j.colsurfa.2009.11.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
11
|
Väisänen M, Oksanen H, Vainio O. Postoperative signs in 96 dogs undergoing soft tissue surgery. Vet Rec 2004; 155:729-33. [PMID: 15623085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
The signs shown by 96 dogs recovering at home after day-case soft tissue operations were assessed by their owners for three days. On the day of the operation there were behavioural changes in all the animals, but by two days after the operation changes in behaviour were detected in only 85 per cent of them. The most common changes were in the dogs' demeanour and their way of moving; there were decreases in overall activity and playfulness, and increases in contact seeking. The dogs also showed signs of pain: the highest ratings were observed on the day of the operation, when the median value on a visual analogue scale from 0 to 100 mm was 43 mm, with a range from 0 to 95 mm. The type of operation significantly affected the signs observed.
Collapse
Affiliation(s)
- M Väisänen
- Department of Clinical Veterinary Sciences, Faculty of Veterinary Medicine, University of Helsinki, PO Box 57, 00014 Helsinki, Finland
| | | | | |
Collapse
|
12
|
Kuusela E, Raekallio M, Väisänen M, Mykkänen K, Ropponen H, Vainio O. Comparison of medetomidine and dexmedetomidine as premedicants in dogs undergoing propofol-isoflurane anesthesia. Am J Vet Res 2001; 62:1073-80. [PMID: 11453483 DOI: 10.2460/ajvr.2001.62.1073] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare 3 dose levels of medetomidine and dexmedetomidine for use as premedicants in dogs undergoing propofol-isoflurane anesthesia. ANIMALS 6 healthy Beagles. PROCEDURE Dogs received medetomidine or dexmedetomidine intravenously at the following dose levels: 0.4 microg of medetomidine or 0.2 microg of dexmedetomidine/kg of body weight (M0.4/D0.2), 4.0 microg of medetomidine or 2.0 microg of dexmedetomidine/kg (M4/D2), and 40 microg of medetomidine or 20 microg of dexmedetomidine/kg (M40/D20). Sedation and analgesia were scored before induction. Anesthesia was induced with propofol and maintained with isoflurane. End-tidal isoflurane concentration, heart rate, and arterial blood pressures and gases were measured. RESULTS Degrees of sedation and analgesia were significantly affected by dose level but not drug. Combined mean end-tidal isoflurane concentration for all dose levels was higher in dogs that received medetomidine, compared with dexmedetomidine. Recovery time was significantly prolonged in dogs treated at the M40/D20 dose level, compared with the other dose levels. After induction, blood pressure decreased below reference range and heart rate increased in dogs treated at the M0.4/D0.2 dose level, whereas blood pressure was preserved in dogs treated at the M40/D20 dose level. However, dogs in these latter groups developed profound bradycardia and mild metabolic acidosis during anesthesia. Treatment at the M4/D2 dose level resulted in more stable cardiovascular effects, compared with the other dose levels. In addition, PaCO2 was similar among dose levels. CONCLUSIONS AND CLINICAL RELEVANCE Dexmedetomidine is at least as safe and effective as medetomidine for use as a premedicant in dogs undergoing propofol-isoflurane anesthesia.
Collapse
Affiliation(s)
- E Kuusela
- Department of Clinical Veterinary Sciences, Faculty of Veterinary Medicine, University of Helsinki, Finland
| | | | | | | | | | | |
Collapse
|
13
|
Olsson KS, Väisänen M, Konar J, Bruce A. The effect of withdrawal of food iron fortification in Sweden as studied with phlebotomy in subjects with genetic hemochromatosis. Eur J Clin Nutr 1997; 51:782-6. [PMID: 9368814 DOI: 10.1038/sj.ejcn.1600488] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [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: 02/05/2023]
Abstract
OBJECTIVES The iron fortification of food in Sweden, the highest in the world, was withdrawn 1st January 1995, because the effect upon target groups was considered to be uncertain. We wanted to study the effect of such a dietary experiment. DESIGN Comparative cross over study. SETTING Out patient service and Blood Bank. SUBJECTS Sixteen men aged 24-73 y on maintenance phlebotomy after treatment for iron overload. One was excluded because of inflammatory disease. INTERVENTIONS Quantitative phlebotomy with serial measurements of Hb conc., % transferrin saturation and serum ferritin concentration. MAIN OUTCOME MEASURES Iron absorption was measured by phlebotomy during two periods, with and without iron fortification. 1 g Hb = 3.4 mg Fe. RESULTS Iron absorption was significantly reduced (P < 0.001) when iron fortification was withdrawn from a mean of 4.27 +/- 1.2 to 3.63 +/- 1.1 mg/d. The difference of 0.65 mg/d (95% c.i. 0.32-0.97) corresponds to the fraction of iron derived from fortification. Intervals between donations had to be extended from 59 +/- 15 to 69 +/- 17 d (P < 0.01) to avoid induction of iron deficiency anemia. The iron content of the fortified diet averaged 15.4 mg/d, of which the fortified fraction constituted 4.1 mg/d (27%). The relative bioavailability of carbonyl iron used as fortificant was 38%. CONCLUSIONS The relative bioavailability of carbonyl iron used as fortificant was higher than previously reported. Target groups such as menstruating females will probably be affected by a higher prevalence of iron deficiency when food is no longer fortified. People with genetic hemochromatosis will accelerate into clinical disease at a slower rate.
Collapse
Affiliation(s)
- K S Olsson
- Department of Medicine, Mölndal Hospital, Sweden
| | | | | | | |
Collapse
|
14
|
Savolainen K, Viitala A, Puhakainen E, Väisänen M. Problems with the use of whole blood as a sample material in novel direct glucose analysers. Scand J Clin Lab Invest 1990; 50:221-3. [PMID: 2339284 DOI: 10.1080/00365519009089158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [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: 12/31/2022]
Abstract
We report a marked shift in whole-blood glucose measurements when a widely available glucose analyser is used. We compared a conventional glucose dehydrogenase (GDHG) method after protein precipitation and a direct polarographic method in conjunction with immobilized glucose oxidase. The polarographic method gave mean whole blood glucose levels from 79% to 95% of those measured by the GDHG method. No such difference was found in either plasma or serum samples or in water-based control samples. The stability of glucose in fluoride oxalate tubes appears to be poorer than is usually assumed. We observed a 5-10% decrease in whole-blood glucose concentrations during the first hour after sampling under routine conditions.
Collapse
Affiliation(s)
- K Savolainen
- Department of Clinical Chemistry, Kuopio University Central Hospital, Finland
| | | | | | | |
Collapse
|
15
|
Hänninen O, Lindström-Seppä P, Koivusaari U, Väisänen M, Julkunen A, Juvonen R. Glucuronidation and glucosidation reactions in aquatic species in boreal regions. Biochem Soc Trans 1984; 12:13-7. [PMID: 6231203 DOI: 10.1042/bst0120013] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
16
|
Mackenzie PI, Väisänen M, Hänninen O. Differential induction of UDP glucuronosyltransferase activities towards various substrates after polycyclic aromatic hydrocarbon administration to rats. Toxicol Lett 1982; 12:259-63. [PMID: 6182644 DOI: 10.1016/0378-4274(82)90249-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Administration of the carcinogens, benzo[a]pyrene and 1,2-benzanthracene, increased UDP glucuronosyltransferase activities towards 4-nitrophenol, 3-hydroxybenzo[a]pyrene, 7-hydroxycoumarin and 1-naphthol to a greater extent than did pretreatment with the noncarcinogens, anthracene and phenanthrene. However, the activity towards morphine was preferentially increased by the noncarcinogens. Activities towards testosterone and oestrone were only slightly increased by the four hydrocarbons. The results suggest that even within a single class of inducer various compounds are capable of causing a differential stimulation of UDP glucuronosyltransferase activities towards certain substrates.
Collapse
|