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Sökning: LAR1:hig > Umeå universitet > Engelska > Sveriges Lantbruksuniversitet

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1.
  • Berg, Björn, et al. (författare)
  • Late stage pine litter decomposition : Relationship to litter N, Mn, and acid unhydrolyzable residue (AUR) concentrations and climatic factors
  • 2015
  • Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 358, s. 41-47
  • Tidskriftsartikel (refereegranskat)abstract
    • The aim of this paper is to evaluate relationships between decomposition rates of Scots pine (Pinus sylvestris) and lodgepole pine (Pinus contorta var. contorta) needle litter in the late stage of decomposition (>30% accumulated mass loss), and the progressively changing concentrations of manganese (Mn), nitrogen (N), and acid unhydrolyzable residue (AUR), as well as mean annual temperature (MAT) and mean annual precipitation (MAP). Using available long-term decomposition studies on pine needle litter in a climate gradient in Sweden, we calculated annual mass loss and related to concentrations of Mn, N, and AUR at the start of each one-year period as well as to MAT and MAP. We investigated these relationships for (i) all data on annual mass loss combined and (ii) annual mass loss for five different decomposition categories as defined by accumulated mass loss. We found highly significant, negative, and dominant relationships between annual mass loss and N (R2=0.39) and AUR (R2=0.39), a slight but significant positive relationship to Mn (R2=0.08) and a significant negative relationship to MAT (R2=0.06). The relationships were dynamic, and changed with accumulated mass loss. The rate-dampening effect of N decreased to be a rate-enhancing effect at c. 60-80% accumulated mass loss. A similar trend was found for AUR, becoming rate-enhancing at 70-80% accumulated mass loss. For Scots pine needle litter the effect of MAT on mass loss decreased with increasing accumulated mass loss and changed to a rate-dampening effect at c. 50-70% accumulated mass loss. Mn showed a stimulating effect on mass loss rate in all categories whereas MAP showed no effect in this mainly boreal climatic gradient. The current approach indicates a method for detailed studies of rate-regulating factors for litter decomposition. 
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2.
  • Berg, Björn, et al. (författare)
  • Manganese in the litter fall-forest floor continuum of boreal and temperate pine and spruce forest ecosystems : a review
  • 2015
  • Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 358, s. 248-260
  • Forskningsöversikt (refereegranskat)abstract
    • We have reviewed the literature on the role of manganese (Mn) in the litter fall-to-humus subsystem. Available data gives a focus on North European coniferous forests. Manganese concentrations in pine (Pinus spp.) foliar litter are highly variable both spatially and temporally within the same litter species and for the genus Pinus we found a range from 0.03 to 3.7mgg-1. Concentrations were related negatively to site mean annual temperature (MAT) and annual actual evapotranspiration (AET) for pine species litter but not for that of Norway spruce (Picea abies) as a single species. Combined data for several species showed a highly significant relationship to MAT.Manganese peroxidase is an Mn-dependent enzyme, found in white-rot fungi, essential for the degradation of lignin and ligninlike compounds. The decomposition rates of lignified litter tissue (late phase) is positively related to the litter’s Mn concentration. Further, the Mn concentration is positively related to the limit value for decomposition - the higher the Mn concentration the smaller the stable litter fraction. Manganese release from decomposing litter appears at least in part to be species related. Thus was release from pine needle litter significantly faster (p<. 0.001) than that from the Mn-richer litter of Norway spruce. Over Northern Europe concentrations of total Mn in mor humus as well as extractable Mn in the mineral soil increase with decreasing MAT and over a climatic gradient the Mn concentrations in Norway spruce mor increase more with decreasing MAT than in a gradient with Scots pine. Higher Mn concentrations in humus appear to decrease its stability and result in a higher release of carbon dioxide (CO2) and dissolved organic carbon (DOC). We conclude that this may explain (i) the lower amount of carbon (C) in mor layers under Norway spruce as compared to Scots pine as well as the higher amount of C in mineral soil under spruce. The increase in nitrogen (N) concentration in humus, following N fertilization resulted in a decrease in that of Mn. We have found four cases - empirical - with negative interaction between Mn and N; (i) in pine foliar litter fall concentrations of Mn decrease with site MAT whereas those of N increase, (ii) in decomposing late-stage litter with N retarding and Mn stimulating decomposition, (iii) for the stable phase, limit values are related negatively to N and positively to Mn, and (iv) Mn concentrations in humus decrease with MAT whereas those of N increase.
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3.
  • Dantoft, Thomas M., et al. (författare)
  • Gene expression profiling in persons with multiple chemical sensitivity before and after a controlled n-butanol exposure session
  • 2017
  • Ingår i: BMJ Open. - : BMJ. - 2044-6055. ; 7:2
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVES: To investigate the pathophysiological pathways leading to symptoms elicitation in multiple chemical sensitivity (MCS) by comparing gene expression in MCS participants and healthy controls before and after a chemical exposure optimised to cause symptoms among MCS participants.The first hypothesis was that unexposed and symptom-free MCS participants have similar gene expression patterns to controls and a second hypothesis that MCS participants can be separated from controls based on differential gene expression upon a controlled n-butanol exposure.DESIGN: Participants were exposed to 3.7 ppm n-butanol while seated in a windowed exposure chamber for 60 min. A total of 26 genes involved in biochemical pathways found in the literature have been proposed to play a role in the pathogenesis of MCS and other functional somatic syndromes were selected. Expression levels were compared between MCS and controls before, within 15 min after being exposed to and 4 hours after the exposure.SETTINGS: Participants suffering from MCS and healthy controls were recruited through advertisement at public places and in a local newspaper.PARTICIPANTS: 36 participants who considered themselves sensitive were prescreened for eligibility. 18 sensitive persons fulfilling the criteria for MCS were enrolled together with 18 healthy controls.OUTCOME MEASURES: 17 genes showed sufficient transcriptional level for analysis. Group comparisons were conducted for each gene at the 3 times points and for the computed area under the curve (AUC) expression levels.RESULTS: MCS participants and controls displayed similar gene expression levels both at baseline and after the exposure and the computed AUC values were likewise comparable between the 2 groups. The intragroup variation in expression levels among MCS participants was noticeably greater than the controls.CONCLUSIONS: MCS participants and controls have similar gene expression levels at baseline and it was not possible to separate MCS participants from controls based on gene expression measured after the exposure.
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4.
  • Essner, Ann, Medicine Doktor, PhD, et al. (författare)
  • Investigating the Probability of Response Bias in Owner-Perceived Pain Assessment in Dogs With Osteoarthritis
  • 2020
  • Ingår i: Topics in Companion Animal Medicine. - : Elsevier. - 1938-9736 .- 1946-9837. ; 39
  • Tidskriftsartikel (refereegranskat)abstract
    • Owners’ ability to recognize signs of chronic pain in dogs undergoing pharmacologic and nonpharmacologic pain interventions during a period of physical rehabilitation is not known. This study aimed to compare dogs with and without chronic pain, and to assess the relationship between explanatory factors, including the probability of owners’ response bias induced by pharmacologic and nonpharmacologic pain intervention, and chronic pain in dogs with osteoarthritis (OA). Seventy-one dogs with OA were included in this observational study. Owner-perceived pain interference was measured by Canine Brief Pain Inventory (CBPI) and owner-perceived pain behavior was assessed using Helsinki Chronic Pain Index. A dichotomous variable of Helsinki Chronic Pain Index was used in regression analysis to investigate the association between chronic pain and explanatory factors (body condition, anti-inflammatory medication, animal physiotherapy consultation once or more and owners’ perception of pain interfering). Seventy-five percent of the dogs had ongoing anti-inflammatory medication, 51% of were overweight and 45% had a physiotherapy consultation. Higher levels of overt pain behaviors were reported in items addressing activities. Body condition, physiotherapy consultation and medication were not associated with chronic pain. Odds ratio (OR) and 95% confidence intervals of OR for the CBPI were 1.74 (1.23-2.47) and significantly associated with chronic pain. The adjusted OR of the CBPI did not differ from the crude OR. Owner-perceived pain behavior was not confounded by the dogs’ medication. Results indicated that CBPI was not mediated by the medication. The CBPI pain interference score was not associated with response bias and may be used as clinical outcome measure of chronic pain and pain-related disability in dogs with OA along a period of physical rehabilitation comprising pharmacologic and nonpharmacologic pain interventions.
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5.
  • Essner, Ann, et al. (författare)
  • Psychometric evaluation of the canine brief pain inventory in a Swedish sample of dogs with pain related to osteoarthritis
  • 2017
  • Ingår i: Acta Veterinaria Scandinavica. - : Springer Science and Business Media LLC. - 0044-605X .- 1751-0147. ; 59:1
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: To evaluate intervention, implement evidence-based practice and enhance the welfare of dogs with naturally occurring osteoarthritis (OA), access to valid, reliable and clinically relevant outcome measures is crucial for researchers, veterinarians and rehabilitation practitioners. The objectives of the present study were to translate and evaluate psychometric properties, in terms of internal consistency and construct validity, of the owner-reported measure canine brief pain inventory (CBPI) in a Swedish sample of dogs with pain related to OA.RESULTS: Twenty-one owners of clinically sound dogs and 58 owners of dogs with pain related to OA were included in this observational and cross-sectional study. After being translated according to the guidelines for patient-reported outcome measures, the CBPI was completed by the canine owners. Construct validity was assessed by confirmatory factor analysis, by repeating the principal component analysis and by assessing for differences between clinically sound dogs and dogs with pain related to OA. Internal consistency was estimated by Cronbach's α. Confirmatory factor analysis was not able to confirm the factor-structure models tested in our sample. Principal component analysis showed a two-component structure, pain severity and pain interference of function. Two components accounted for 76.8% of the total variance, suggesting an acceptable fit of a two-component structure. The ratings from the clinically sound dogs differed from OA dogs and showed significantly lower CBPI total sum. Cronbach's α was 0.94 for the total CBPI, 0.91 for the pain severity and 0.91 for the pain interference of function.CONCLUSIONS: The results indicate that the translated version of the CBPI is valid for use in the Swedish language. The findings suggest satisfying psychometric properties in terms of high internal consistencies and ability to discriminate clinically sound dogs from OA dogs. However, based on the confirmatory factor analysis, the original factor structure in the CBPI is not ideally suited to measure pain related to OA in our sample and the hypothesis of the presented two-factor structure was rejected. Further research needs to be conducted to determine whether the original psychometric results from CBPI can be replicated across different target groups and particularly with larger sample size.
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6.
  • Lind, Nina, 1989-, et al. (författare)
  • Comorbidity and multimorbidity of asthma and allergy and intolerance to chemicals and certain buildings
  • 2017
  • Ingår i: Journal of Occupational and Environmental Medicine. - 1076-2752 .- 1536-5948. ; 59:1, s. 80-84
  • Tidskriftsartikel (refereegranskat)abstract
    • Objectives: We tested the hypothesis of high comorbidity between asthma/allergy and chemical intolerance (CI) and between asthma/allergy and building intolerance (BI), and high multimorbidity between asthma/allergy, CI, and BI.Methods: Population-based questionnaire data were used from 530 participants with asthma/allergy (allergic asthma, nonallergic asthma, allergic rhinitis, and/or atopic dermatitis), 414 with self-reported and 112 with physician-diagnosed CI, and 165 with self-reported and 47 with physician-diagnosed BI. Separate reference groups were formed for each of the five case groups.Results: Adjusted odds ratios varied from 4.6 to 13.1 for comorbidity, and from 6.6 to 46.4 for multimorbidity.Conclusion: The large comorbidity and multimorbidity between asthma/allergy, CI, and BI evokes the question as to whether there are similarities in underlying mechanisms between these conditions.
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