| 1. |
- Ahonen-Jonnarth, Ulla, et al.
(författare)
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Organic acids produced by mycorrhizal Pinus sylvestris exposed to elevated aluminium and heavy metals concentrations
- 2000
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Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 146:3, s. 557-567
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Tidskriftsartikel (refereegranskat)abstract
- A cultivation method was developed to enable exposure of ectomycorrhizal plants with intact extramatrical mycelium to solutions containing different concentrations of aluminium or heavy metals. Pinus sylvestris seedlings colonized by Suillus variegatus (two isolates), Rhizopogon roseolus or Paxillus involutus (two isolates) were used. Seedlings were transferred to Petri dishes containing glass beads and exposed to elevated concentrations of Al, Cd, Cu, or Ni in two ways: immediately following transfer; and after allowing mycorrhizal seedlings to develop an extraradical mycelium that colonized the interface between the upper surface of the beads and the metal-containing solution. Production of organic acids in mycorrhizal and non-mycorrhizal systems was measured by withdrawing samples from the solution and analyzing by HPLC. In most experiments, levels of oxalic acid were significantly higher in mycorrhizal treatments than in non-mycorrhizal controls. The measured levels of organic acids were variable, but the results obtained suggest that production of oxalic acid is stimulated by exposure to elevated Al in mycorrhizal seedlings colonized by S. variegatus and R. roseolus. Elevated Al concentrations also increased oxalic acid production by non-mycorrhizal seedlings significantly in two of four Al experiments performed, but the measured concentrations were significantly lower than in corresponding mycorrhizal treatments in both cases. Malonic acid was found in the culture solution of non-mycorrhizal had P. involutus-colonized seedlings, but only trace amounts were found in S. variegatus or R. roseolus-infected seedlings. Citric, shikimic, lactic, acetic, propionic, fumaric, formic, iso-butyric and butyric acid were found in variable concentrations. Production of oxalic acid by seedlings ColoniZed by S. variegatus BL or P. involutus was not stimulated by exposure to 0.44 μM Cd or 17 μM Ni. Exposure to 0.157 mM CU in two separate experiments using P. involutus 87.017 and two strains of S. variegatus (BL and 159) appeared to stimulate production of oxalic acid irrespective of mycorrhizal status or species.
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| 2. |
- Ali, Tara, 1980-, et al.
(författare)
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Liquid extraction of low molecular mass organic acids and hydroxamate siderophores from boreal forest soil
- 2011
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Ingår i: Soil Biology and Biochemistry. - : Elsevier BV. - 0038-0717 .- 1879-3428. ; 43:12, s. 2417-2422
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Tidskriftsartikel (refereegranskat)abstract
- Low molecular mass organic acids (LMMOAs) and hydroxamate siderophores (HS) are molecules secreted by microbes and have previously been found in soil solution and in cultures. Mycorrhizal fungi are suggested to be involved in the nutrient uptake processes of trees and weathering of minerals. In this study soil samples taken from the O and E horizons of a podzol were extracted with 10 mM potassium phosphate buffer at pH 7.2. Variable parameters included addition of methanol to the extraction buffer and the use of ultrasonication or rotary shaking during extraction. LMMOAs and HS content of the soil extracts were determined. Analysis of soil extracts were carried out by liquid chromatography mass spectrometry (LC-MS) and the extraction results compared to results for soil solution samples obtained by centrifugation of the soils sampled. The extraction yields were significantly increased by addition of methanol to the extraction buffer, especially for the O horizon samples. Rotary shaking of the samples for 90 min gave slightly higher yields than ultrasonication for 15 min but the reduction in extraction time makes ultrasonication an attractive option. Of the HSs determined, ferricrocin was found in all samples. Optimal extraction conditions showed citric acid and isocitric acid to be the most abundant organic acids in the O and E horizons, respectively.
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| 3. |
- Ambrosi, Aurelie, et al.
(författare)
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Development of heart block in children of SSA/SSB-autoantibody-positive women is associated with maternal age and displays a season-of-birth pattern
- 2012
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Ingår i: Annals of the Rheumatic Diseases. - London : BMJ Publishing Group. - 0003-4967 .- 1468-2060. ; 71:3, s. 334-340
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Tidskriftsartikel (refereegranskat)abstract
- Objective Congenital heart block may develop in the fetuses of Ro/SSA-positive and La/SSB-positive mothers. Recurrence rates of only 10-20% despite persisting maternal antibodies indicate that additional factors are critical for the establishment of heart block. The authors investigated the influence of other maternal and fetal factors on heart block development in a Swedish population-based cohort. less thanbrgreater than less thanbrgreater thanMethods The influence of fetal gender, maternal age, parity and time of birth on heart block development was analysed in 145 families, including Ro/La-positive (n=190) and Ro/La-negative (n=165) pregnancies. less thanbrgreater than less thanbrgreater thanResults There was a recurrence rate of 12.1% in Ro/La-positive women, and no recurrence in Ro/La-negative women. Fetal gender and parity did not influence the development of heart block in either group. Maternal age in Ro/La-positive pregnancies with a child affected by heart block was, however, significantly higher than in pregnancies resulting in babies without heart block (pandlt;0.05). Seasonal timing of pregnancy influenced the outcome. Gestational susceptibility weeks 18-24 occurring during January-March correlated with a higher proportion of children with heart block and lower vitamin D levels during the same period in a representative sample of Swedish women and a corresponding higher proportion of children with heart block born in the summer (pandlt;0.02). Maternal age or seasonal timing of pregnancy did not affect the outcome in Ro/La-negative pregnancies. less thanbrgreater than less thanbrgreater thanConclusion This study identifies maternal age and seasonal timing of pregnancy as novel risk factors for heart block development in children of Ro/La-positive women. These observations may be useful for counselling when pregnancy is considered.
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| 4. |
- Antonsson, Helena, et al.
(författare)
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Caregivers' reflections on their interactions with adult people with learning disabilities
- 2008
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Ingår i: Journal of Microscopy. - : Wiley. - 0022-2720 .- 1365-2818. ; 15:6, s. 484-91
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Tidskriftsartikel (refereegranskat)abstract
- People with learning disabilities and their professional carers often have difficulty interacting. The aim of this study was to illuminate carers' reflections on their interactions with adult people with learning disabilities. In a previous study, interactions between 16 carers and 11 residents with learning disabilities were recorded on video. In this study, stimulated recall interviews about the interactions were carried out with all the carers. The text was analysed using qualitative content analysis. The findings indicate that the carers reflected on both successful and unsuccessful interaction. Examples of successful interaction included understanding cues, satisfying needs, and managing challenging behaviours, and the carers reflected on the influences that successful interaction had on security, confidence, and satisfaction among the residents. Examples of unsuccessful interaction included failing to understand cues, failing to satisfy needs and failing to manage challenging behaviours, and the carers reflected on the consequences of such interaction, which included irritation, aggression and violence among the residents. Our findings have implications for interventions aimed at strengthening the competence of carers and developing strategies for managing challenging behaviour, in order to ensure high-quality care and a good working climate. © 2008 The Authors.
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| 5. |
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| 6. |
- Antonsson, Helena, et al.
(författare)
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Evaluation of a Web-Based Training Program for Professional Carers Working With People With Learning Disabilities and Challenging Behavior : A Pilot Study with SSED-Design
- 2016
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Ingår i: Issues in Mental Health Nursing. - : Informa UK Limited. - 0161-2840 .- 1096-4673. ; 37:10, s. 734-743
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Tidskriftsartikel (refereegranskat)abstract
- The interaction between people with intellectual disabilities and professional carers is often influenced by communicative difficulties contributing challenging behaviours. The aims of this study were to evaluate to a web-based training program aimed at improving carers' abilities to interact with people with learning disabilities who exhibit challenging behaviours and to explore carers' experiences of participating in such a program. A single-subject experimental design and mixed methods were used to integrate qualitative and quantitative data. Triangulation of questionnaires, interviews with carers, and assessments of one woman's behaviour was performed. The participants were professional carers aged 20 to 55 years. The web-based training program increased carers' abilities to handle challenging behaviours and decreased challenging behaviours in daily care. The program improved the opportunities to offer training to carers who work in community-based accommodations with limited time to receive training.
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| 7. |
- Antonsson, Helena, 1962-
(författare)
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Interaktion i särskilt boende för personer med utvecklingsstörning och utmanande beteende
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Bakgrund: Många personer med utvecklingsstörning har kommunikativa svårigheter och har därför behov av att utveckla olika sätt att kommunicera för att kunna förstå andra och göra sig förstådda. Svårigheter i kommunikationen påverkar interaktionen mellan personer med utvecklingsstörning och deras vårdare. Detta ställer höga krav på vårdare att kunna tolka och förstå den enskilda individens sätt att uttrycka önskningar och behov. På samma sätt riskerar vårdares budskap att missförstås. Om vårdaren misslyckas att förstå den boendes kommunikation och vice versa, kan det leda till situationer med utmanande beteende exempelvis i form av vägran, verbal eller fysisk aggressivitet.Syfte: Det övergripande syftet med avhandlingen är att studera interaktion mellan vuxna personer med utvecklingsstörning och vårdare i gruppbostäder, samt att studera effekter av en utbildningsintervention för vårdare som arbetar i gruppbostäder.Metod: Avhandlingens samtliga delstudier har genomförts i gruppbostäder för personer med utvecklingsstörning bland boende och vårdare i ett län i norra Sverige. I studie I insamlades data kring 556 personer med utvecklingsstörning. I studie II och III deltog 16 vårdare och 11 personer med utvecklingsstörning. I studie IV deltog 7 vårdare. Studie I bygger på personalens skattningar av funktionsnivåer och förekomst av begränsningsåtgärder. I Studie II och III utgörs data av videoobservationer och narrativa intervjuer. I studie IV användes flera datainsamlingsmetoder i en mixed method design med både vårdarnas skattningar, med hjälp av instrument och semi-strukturerade intervjuer. Analys av materialet i studie II, III och IV har gjorts med kvalitativ innehållsanalys och i studie I och IV har data analyserats statistiskt.Resultat: I studie I framkom att av 556 boende hade 99 (18%) varit föremål för fysiska begränsningsåtgärder under den senaste veckan. Av dessa 99 hade nästan alla varit föremål för mer än en typ av begränsningsåtgärd. Den vanligaste begränsningsåtgärden var bälte i stol (74%). Användningen av begränsningsåtgärder var relaterade både till fysiska funktionsnedsättningar och till beteende.I studie II reflekterade vårdare över videoinspelad interaktion där vårdarna medverkat, både framgångsrik och misslyckad interaktion. Exempel på framgångsrik interaktion var att förstå tecken, kunna möta behov och hantera situationer med utmanande beteenden. Vårdarna reflekterade över att framgångsrik interaktion ledde till säkerhet, trygghet och självförtroende hos de boende. Vårdarna reflekterade även över de konsekvenser misslyckad interaktion fick i form av irritation, aggression och våld från de boende.I studie III studerades videoinspelad interaktion mellan 11 personer med utvecklingsstörning och 16 av deras vårdare. Verbal och icke-verbal interaktion identifierades. Fyra inspelade situationer valdes ut för att belysa framgångsrikt samspel. Resultatet visade att framgångsrikt samspel mellan personer med utvecklingsstörning och deras vårdare bland annat bygger på möjligheten att bekräfta varandra, dela vardagshändelser, ge tid och utrymme och på att använda ett kongruent och tydligt språk.I studie IV utvärderades effekterna av en web-baserad utbildningsintervention, vars syfte var att förbättra interaktionen mellan personer med utvecklingsstörning och vårdare samt att därmed reducera förekomsten av situationer med utmanande beteende. Resultatet visade att vårdarna hade förbättrat sin förmåga att hantera situationer med utmanande beteende och att förekomsten av utmanande beteende minskat. Vårdarna beskrev att den web-baserade utbildningen upplevts givande och möjlig att ta del av parallellt med arbetet.Slutsats: Fysiska begränsningsåtgärder förekommer i gruppbostäder för personer med utvecklingsstörning. Användningen av begränsningsåtgärder kan vara relaterade både till fysiska funktionsnedsättningar och till beteenden i samspelet mellan brukare och vårdare. Vårdare upplever användningen av fysiska begränsningsåtgärder svår och tröttande. Brott i kommunikationen mellan personer med utvecklingsstörning och deras vårdare kan leda till försvårad interaktion med risk för situationer med utmanande beteenden. När vårdare är framgångsrika i interaktionen med personer med utvecklingsstörning ger det tillfredsställelse både för de boende och vårdarna. Vårdarna upplever dock ofta hjälplöshet och osäkerhet i relation till hantering av situationer med utmanande beteende och efterfrågar utbildning. Web-baserad utbildning om interaktion med personer med utvecklingsstörning och utmanande beteende har i vår studie visat sig ge lovande effekter och bör vara möjlig att utveckla för både introduktion av nyanställda vårdare och för kompetensutveckling bland mer erfaren personal.
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| 8. |
- Antonsson, Helena, et al.
(författare)
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Skilled interaction among professional carers in special accommodations for adult people with learning disabilities.
- 2013
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Ingår i: Journal of Psychiatric and Mental Health Nursing. - : Wiley. - 1351-0126 .- 1365-2850. ; 20:7, s. 576-583
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Tidskriftsartikel (refereegranskat)abstract
- Communicative difficulties affect interactions between people with learning disabilities and their carers. Despite such difficulties, however, some carers seem to interact successfully with people who have limited ability to communicate verbally and exhibit challenging behaviour. This study aims to illuminate skilled interaction among carers working in special accommodations for people with learning disabilities. Interactions between 16 caregivers and 11 residents with learning disabilities were recorded on video. Verbal and non-verbal interaction skills among the carers were identified. Four caring situations with people with learning disabilities were chosen to illuminate skilled interaction. The transcribed text was subjected to qualitative content analysis and core stories were created. The results show that skilled interaction between the carers and the people with learning disabilities is based upon being confirming, sharing daily life experience, giving time and space, and using congruent and distinct language. In this paper we present examples that offer concrete suggestions of how to promote successful interaction and create meaning in the shared day-to-day life in special accommodations for people with learning disabilities.
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| 9. |
- Bergelin, A., et al.
(författare)
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The acid-base properties of high and low molecular weight organic acids in soil solutions of podzolic soils
- 2000
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Ingår i: Geoderma. - 0016-7061 .- 1872-6259. ; 94:2-4, s. 223-235
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Tidskriftsartikel (refereegranskat)abstract
- The acid properties of the organic acids and identified low molecular weight (LMW) organic acids in soil solutions of podzolic soils were determined using proton affinity spectra, based on EMF titration data, and Gran titrations. The proton affinity spectra showed apparent pKa values of 2.6, 4.1, 5.4 and 6.7 for the dissolved organic material. The LMW organic acids had similar pKa values. The average specific buffer capacity as determined by Gran titrations was 8.8±0.5 μmol H+/mg DOC. The specific buffer capacity for the identified low molecular acids was 40±2 μmol H+/mg DOC.
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| 10. |
- Bylund, Dan, et al.
(författare)
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Analysis of low molecular mass organic acids in natural waters by ion exclusion chromatography tandem mass spectrometry
- 2007
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Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673 .- 1873-3778. ; 1176:1-2, s. 89-93
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Tidskriftsartikel (refereegranskat)abstract
- A sensitive and selective method for the analysis of aliphatic low molecular mass organic acids (LMMOAs) in natural waters is presented. The method is based on separation with ion exclusion chromatography and detection with electrospray ionization tandem mass spectrometry (LC-MS/MS). The extra selectivity gained by applying MS/MS allows for a minimum of sample preparation and the use of a sub-optimal mobile phase regarding chromatographic resolution. Instead the mobile phase, comprising aqueous formic acid With methanol as organic modifier, was mainly optimized for maximum sensitivity and long term MS stability. Detection limits for malonic, fumaric, maleic, succinic, citraconic, glutaric, malic, alpha-ketoglutaric, tartaric, shikimic, trans-aconitic, cis-aconitic, isocitric and citric acid were in the range 1-50 nM, while the detection limits for pyruvic, oxalic and lactic acid were around 250 nM for an injection volume of 100 mu L. Due to their metal-chelating properties, these LMMOAs are all considered to affect the bioavailability of metals and to be involved in soil forming processes. It is thus of interest to be able to monitor their presence in natural waters, and the method developed within this work was successfully applied for the analysis of LMMOAs in soil solution and stream water samples.
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