| 1. |
- Berg, Björn, et al.
(författare)
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Late stage pine litter decomposition : Relationship to litter N, Mn, and acid unhydrolyzable residue (AUR) concentrations and climatic factors
- 2015
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 358, s. 41-47
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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. |
- Gerdle, Björn, et al.
(författare)
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The importance of emotional distress, cognitive behavioural factors and pain for life impact at baseline and for outcomes after rehabilitation - a SQRP study of more than 20,000 chronic pain patients
- 2019
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Ingår i: Scandinavian Journal of Pain. - : Walter de Gruyter GmbH. - 1877-8860 .- 1877-8879. ; 19:4, s. 693-711
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Tidskriftsartikel (refereegranskat)abstract
- Background and aims Although literature concerning chronic pain patients indicates that cognitive behavioural variables, specifically acceptance and fear of movement/(re)injury, are related to life impact, the relative roles of these factors in relation to pain characteristics (e.g. intensity and spreading) and emotional distress are unclear. Moreover, how these variables affect rehabilitation outcomes in different subgroups is insufficiently understood. This study has two aims: (1) to investigate how pain, cognitive behavioural, and emotional distress variables intercorrelate and whether these variables can regress aspects of life impact and (2) to analyse whether these variables can be used to identify clinically meaningful subgroups at baseline and which subgroups benefit most from multimodal rehabilitation programs (MMRP) immediately after and at 12-month follow-up. Methods Pain aspects, background variables, psychological distress, cognitive behavioural variables, and two life impact variables were obtained from the Swedish Quality Registry for Pain Rehabilitation (SQRP) for chronic pain patients. These data were analysed mainly using advanced multivariate methods. Results The study includes 22,406 chronic pain patients. Many variables, including acceptance variables, showed important contributions to the variation in clinical presentations and in life impacts. Based on the statistically important variables considering the clinical presentation, three clusters/subgroups of patients were identified at baseline; from the worst clinical situation to the relatively good situation. These clusters showed significant differences in outcomes after participating in MMRP; the subgroup with the worst situation at baseline showed the most significant improvements. Conclusions Pain intensity/severity, emotional distress, acceptance, and life impacts were important for the clinical presentation and were used to identify three clusters with marked differences at baseline (i.e. before MMRP). Life impacts showed complex relationships with acceptance, pain intensity/severity, and emotional distress. The most significant improvements after MMRP were seen in the subgroup with the lowest level of functioning before treatment, indicating that patients with complex problems should be offered MMRP. Implications This study emphasizes the need to adopt a biopsychosocial perspective when assessing patients with chronic pain. Patients with chronic pain referred to specialist clinics are not homogenous in their clinical presentation. Instead we identified three distinct subgroups of patients. The outcomes of MMRP appears to be related to the clinical presentation. Thus, patients with the most severe clinical presentation show the most prominent improvements. However, even though this group of patients improve they still after MMRP show a complex situation and there is thus a need for optimizing the content of MMRP for these patients. The subgroup of patients with a relatively good situation with respect to pain, psychological distress, coping and life impact only showed minor improvements after MMRP. Hence, there is a need to develop other complex interventions for them.
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| 3. |
- Gerdle, Björn, et al.
(författare)
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Who benefits from multimodal rehabilitation - an exploration of pain, psychological distress, and life impacts in over 35,000 chronic pain patients identified in the Swedish Quality Registry for Pain Rehabilitation
- 2019
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Ingår i: Journal of Pain Research. - : DOVE Medical Press Ltd.. - 1178-7090. ; 12, s. 891-908
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chronic pain patients frequently suffer from psychological symptoms. There is no consensus concerning the prevalence of severe anxiety and depressive symptoms and the strength of the associations between pain intensity and psychological distress. Although an important aspect of the clinical picture is understanding how the pain condition impacts life, little is known about the relative importance of pain and psychological symptoms for individual's life impact. The aims of this study were to identify subgroups of pain patients; to analyze if pain, psychological distress, and life impact variables influence subgrouping; and to investigate how patients in the subgroups benefit from treatments.Methods: Background variables, pain aspects (intensity/severity and spreading), psychological distress (depressive and anxiety symptoms), and two life impact variables (pain interference and perceived life control) were obtained from the Swedish Quality Registry for Pain Rehabilitation for chronic pain patients and analyzed mainly using advanced multivariate methods.Results: Based on >35,000 patients, 35%-40% had severe anxiety or depressive symptoms. Severe psychological distress was associated with being born outside Europe (21%-24% vs 6%-8% in the category without psychological distress) and low education level (20.7%-20.8% vs 26%-27% in the category without psychological distress). Dose relationships existed between the two psychological distress variables and pain aspects, but the explained variances were generally low. Pain intensity/severity and the two psychological distress variables were significantly associated (R2=0.40-0.48; P>0.001) with the two life impact variables (pain interference and life control). Two subgroups of patients were identified at baseline (subgroup 1: n=15,901-16,119; subgroup 2: n=20,690-20,981) and the subgroup with the worst situation regarding all variables participated less in an MMRP (51% vs 58%, P<0.001) but showed the largest improvements in outcomes.Conclusion: The results emphasize the need to assess both pain and psychological distress and not take for granted that pain involves high psychological stress in the individual case. Not all patients benefit from MMRP. A better matching between common clinical pictures and the content of MMRPs may help improve results. We only partly found support for treatment resistance in patients with psychological distress burden.
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| 4. |
- Berg, Björn, 1943-, et al.
(författare)
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Magnesium dynamics in decomposing foliar litter - a synthesis
- 2021
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Ingår i: Geoderma. - : Elsevier. - 0016-7061 .- 1872-6259. ; 382
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Tidskriftsartikel (refereegranskat)abstract
- We synthesized available data for magnesium (Mg) dynamics in newly shed and decomposing foliar litter of mainly pine (Pinus) species, Norway spruce (Picea abies), and birch (Betula) species. Using original, measured data from 40 stands organized in climatic gradients we intended to determine patterns of Mg concentration and net release vs accumulated mass loss of the litter. This synthesis is likely the first synthesis of Mg dynamics in decomposing litter.In paired stands, litter of both Norway spruce and lodgepole pine (Pinus contorta) had higher Mg concentrations than Scots pine (Pinus silvestris), with concentrations in Norway spruce litter even twice as high.In decomposing litter, Mg concentrations followed a quadratic (X2-X) function vs accumulated mass loss and consequently had minima, different for Norway spruce and Scots pine litter. Out of 68 decomposition studies 53 gave minimum concentration. The Mg minimum concentration during decomposition was positively related to initial Mg concentration for Scots pine and Scots pine plus lodgepole pine but not for Norway spruce. The increase in concentration suggests that after the minimum Mg was temporarily limiting.For Norway spruce litter there was a relationship between minimum concentration of Mg and the limit value. There was no such relationship for Scots pine and not for the combined pine data.Magnesium net release started directly after the incubation and was linear to accumulated mass loss of litter, giving a slope coefficient (release rate) for each study. The net release rate was linear to initial Mg concentration and all studies combined gave a negative linear relationship.
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| 5. |
- Funa, Nina, et al.
(författare)
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Interdependent fibroblast growth factor and activin A signaling promotes the expression of endodermal genes in differentiating mouse embryonic stem cells expressing Src Homology 2-domain inactive Shb
- 2008
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Ingår i: Differentiation. - : Elsevier BV. - 0301-4681 .- 1432-0436. ; 76:5, s. 443-453
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Tidskriftsartikel (refereegranskat)abstract
- The mechanisms controlling endodermal development during stem cell differentiation have been only partly elucidated, although previous studies have suggested the participation of fibroblast growth factor (FGF) and activin A in these processes. Shb is a Src homology 2 (SH2) domain-containing adapter protein that has been implicated in FGF receptor 1 (FGFR1) signaling. To study the putative crosstalk between activin A and Shb-dependent FGF signaling in the differentiation of endoderm from embryonic stem (ES) cells, embryoid bodies (EBs) derived from mouse ES cells overexpressing wild-type Shb or Shb with a mutated SH2 domain (R522K-Shb) were cultured in the presence of activin A. We show that expression of R522K-Shb results in up-regulation of FGFR1 and FGF2 in EBs. Addition of activin A to the cultures enhances the expression of endodermal genes primarily in EBs expressing mutant Shb. Inhibition of FGF signaling by the addition of the FGFR1 inhibitor SU5402 completely counteracts the synergistic effects of R522K-Shb and activin A. In conclusion, the present results suggest that expression of R522K-Shb enhances certain signaling pathways downstream of FGF and that an interplay between FGF and activin A participates in ES cell differentiation to endoderm.
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| 6. |
- Funa, Nina S, et al.
(författare)
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Dysfunctional microvasculature as a consequence of shb gene inactivation causes impaired tumor growth
- 2009
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 69:5, s. 2141-2148
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Tidskriftsartikel (refereegranskat)abstract
- Shb (Src homology 2 protein B) is an adapter protein downstream of the vascular endothelial growth factor receptor receptor-2 (VEGFR-2). Previous experiments have suggested a role for Shb in endothelial cell function. Recently, the Shb gene was inactivated and Shb null mice were obtained on a mixed genetic background, but not on C57Bl6 mice. The present study was performed to address endothelial function in the Shb knockout mouse and its relevance for tumor angiogenesis. Tumor growth was retarded in Shb mutant mice, and this correlated with decreased angiogenesis both in tumors and in Matrigel plugs. Shb null mice display an abnormal endothelial ultrastructure in liver sinusoids and heart capillaries with cytoplasmic extensions projecting toward the lumen. Shb null heart VE-cadherin staining was less distinct than that of control heart, exhibiting in the former case a wavy and punctuate pattern. Experiments on isolated endothelial cells suggest that these changes could partly reflect cytoskeletal abnormalities. Vascular permeability was increased in Shb null mice in heart, kidney, and skin, whereas VEGF-stimulated vascular permeability was reduced in Shb null mice. It is concluded that Shb plays an important role in maintaining a functional vasculature in adult mice, and that interference with Shb signaling may provide novel means to regulate tumor angiogenesis.
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| 7. |
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| 8. |
- Jonsson, Sofi, et al.
(författare)
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Terrestrial discharges mediate trophic shifts and enhance methylmercury accumulation in estuarine biota
- 2017
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Ingår i: Science Advances. - : American association for the advancement of science. - 2375-2548. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- The input of mercury (Hg) to ecosystems is estimated to have increased two- to fivefold during the industrial era, and Hg accumulates in aquatic biota as neurotoxic methylmercury (MeHg). Escalating anthropogenic land use and climate change are expected to alter the input rates of terrestrial natural organic matter (NOM) and nutrients to aquatic ecosystems. For example, climate change has been projected to induce 10 to 50% runoff increases for large coastal regions globally. A major knowledge gap is the potential effects on MeHg exposure to biota following these ecosystem changes. We monitored the fate of five enriched Hg isotope tracers added to mesocosm scale estuarine model ecosystems subjected to varying loading rates of nutrients and terrestrial NOM. We demonstrate that increased terrestrial NOM input to the pelagic zone can enhance the MeHg bioaccumulation factor in zooplankton by a factor of 2 to 7 by inducing a shift in the pelagic food web from autotrophic to heterotrophic. The terrestrial NOM input also enhanced the retention of MeHg in the water column by up to a factor of 2, resulting in further increased MeHg exposure to pelagic biota. Using mercury mass balance calculations, we predict that MeHg concentration in zooplankton can increase by a factor of 3 to 6 in coastal areas following scenarios with 15 to 30% increased terrestrial runoff. The results demonstrate the importance of incorporating the impact of climate-induced changes in food web structure on MeHg bioaccumulation in future biogeochemical cycling models and risk assessments of Hg.
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| 9. |
- Mokhtari, Dariush, et al.
(författare)
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Increased Hsp70 expression attenuates cytokine-induced cell death in islets of Langerhans from Shb knockout mice
- 2009
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 387:3, s. 553-557
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Tidskriftsartikel (refereegranskat)abstract
- Type 1 diabetes may depend on cytokine-induced beta-cell death and therefore the current investigation was performed in order to elucidate this response in Shb-deficient islets. A combination of interleukin-1beta and interferon-gamma caused a diminished beta-cell death response in Shb null islets. Furthermore, the induction of an unfolded protein response (UPR) by adding cyclopiazonic acid did not increase cell death in Shb-deficient islets, despite simultaneous expression of UPR markers. The heat-shock protein Hsp70 was more efficiently induced in Shb knockout islets, providing an explanation for the decreased susceptibility of Shb-deficient islets to cytokines. It is concluded that islets deficient in the Shb protein are less susceptible to cytotoxic conditions, and that this partly depends on their increased ability to induce Hsp70 under such circumstances. Interference with Shb signaling may provide means to improve beta-cell viability under conditions of beta-cell stress.
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| 10. |
- Wang, Baolin, et al.
(författare)
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Biogeochemical influences on net methylmercury formation proxies along a peatland chronosequence
- 2021
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Ingår i: Geochimica et Cosmochimica Acta. - : Elsevier. - 0016-7037 .- 1872-9533 .- 0046-564X. ; 308, s. 188-203
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Tidskriftsartikel (refereegranskat)abstract
- A geographically constrained chronosequence of peatlands divided into three age classes (young, intermediate and old) was used to explore the role of biogeochemical influences, including electron donors and acceptors as well as chemical speciation of inorganic mercury (Hg(II)), on net formation of methylmercury (MeHg) as approximated by the fraction of MeHg to total mercury (THg) in the peat soil. We hypothesized that removing vascular plants would reduce availability of electron donors and thus net MeHg formation. However, we found no effect of the vascular plant removal. The sum of the potential electron donors (acetate, lactate, propionate and oxalate), the electron donation proxy organic C/Organic N, and the potential electron acceptors (Fe(III), Mn and sulfate) in porewater all showed significant correlations with the net MeHg formation proxies in peat soil (MeHg concentration and %MeHg of THg). Thus differences in both electron donor and acceptor availability may be contributing to the pattern of net MeHg formation along the chronosequence. In contrast, Hg(II) concentrations in peat porewater showed small differences along the gradient. A chemical speciation model successfully predicted the solubility of Hg and MeHg in the porewater. The modeling pointed to an enhanced concentration of Hg-polysulfide species in the younger peatlands as a potential factor behind increased Hg(II) solubility and methylation in the more nutrient-rich peatlands. This work contributes to the understanding of Hg and MeHg cycling in peatlands which can help guide mitigation measures to reduce aquatic MeHg biomagnification in peatland dominated landscapes.
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