| 1. |
- Akselsson, Cecilia, et al.
(författare)
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The influence of N load and harvest intensity on the risk of P limitation in Swedish forest soils
- 2008
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 1879-1026 .- 0048-9697. ; 404, s. 284-289
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Tidskriftsartikel (refereegranskat)abstract
- Nitrogen (N) is often considered to be the major factor limiting tree growth in northern forest ecosystems. An increased N availability, however, increases the demand for other nutrients such as base cations and phosphorous (P) which in turn may change which nutrient is the limiting factor. If P or base cations become limiting, N will start to leach which means a risk of increased eutrophication of surface waters. As many studies focus on base cations, this study instead aims at estimating P budgets on a regional scale for different harvesting scenarios relevant for Swedish conditions. P budget calculations were carried out for 14,550 coniferous sites from the Swedish National Forest Inventory, as weathering+deposition–harvesting–leaching. Three scenarios with different harvest intensities were used: 1) no harvesting, 2) stem harvesting and 3) wholetree harvesting. The input data were derived from measurements and model results. The P budget estimates indicate that harvesting, especially whole-tree harvesting, result in net losses of P in large parts of Sweden. The highest losses were found in southern Sweden due to high growth rate in this area. In the whole-tree harvesting scenario the losses exceeded 1 kg ha−1 y−1 on many sites. N budget calculations on the same sites indicate that N generally accumulates in the whole country and especially in the southern parts. Consequently, the N and P budget calculations indicate that the forests in southern Sweden are in a transition phase from N-to P-limitation to growth. This transition will proceed as long as the accumulation of N continues. These results are important in a sustainable forestry context, as a basis for assessing the risk of future N leaching, and in designing recommendations for abatement strategies of N deposition and for application of wood ash recycling and N fertilization.
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| 2. |
- Alveteg, Mattias, et al.
(författare)
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On the Calculation and Interpretation of Target Load Functions
- 2007
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Ingår i: Water, Air, & Soil Pollution: Focus. - : Springer Science and Business Media LLC. - 1573-2940 .- 1567-7230. ; 7:1-3, s. 385-390
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Tidskriftsartikel (refereegranskat)abstract
- In this study critical load functions and target load functions of nitrogen and sulphur deposition with respect to acidity and minimum base cation to aluminium ratio were calculated with the SAFE model using three different averaging strategies: (1) averaging based on current forest generation, (2) averaging based on next generation and (3) averaging based on the entire simulation period. From the results it is evident that although target load calculation and indeed critical load calculation is straight forward, there is a problem in translating a predicted recovery according to the target load calculation back to a site-specific condition. We conclude that a policy strategy for emission reductions that ensures recovery, according to calculated target load functions, is likely to be beneficial from an ecosystem point of view. However, such a strategy may not be sufficient to achieve actual non-violation of the chemical criteria throughout the seasonal or rotational variations. To address this issue we propose a method for calculating dynamic critical loads which ensures that the chosen criteria is not violated.
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| 3. |
- Benson, Mikael, 1954, et al.
(författare)
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Inverse relation between nasal fluid Clara Cell Protein 16 levels and symptoms and signs of rhinitis in allergen-challenged patients with intermittent allergic rhinitis.
- 2007
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Ingår i: Allergy. - : Wiley. - 0105-4538 .- 1398-9995. ; 62:2, s. 178-83
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Decreased levels of the anti-inflammatory Clara Cell Protein 16 (CC16) are found in intermittent allergic rhinitis (IAR) and asthma. In asthma this decrease has been associated with hyperreactivity and the A38G single nucleotide polymorphism (SNP). The aim of this study was to examine if IAR is associated with signs and symptoms of rhinitis and the A38G SNP. METHODS: Nasal fluid CC16 was analyzed in 20 patients with IAR before allergen challenge and 1 and 6 h after challenge, and from 28 healthy controls. The A38G SNP was analyzed in 80 patients with IAR and 106 controls. Nasal biopsies were obtained from three subjects in each group for immunohistochemical analysis of CC16. RESULTS: In the allergen-challenged patients symptoms and rhinoscopic signs of rhinitis increased after 1 h and normalized after 6 h. In contrast, nasal fluid CC16 decreased 1 h after allergen challenge and returned to baseline after 6 h. Nasal fluid CC16 levels did not differ from controls before and 6 h after challenge. Immunohistochemical investigation showed intense CC16 staining in the nasal epithelium of both patients before season and healthy controls, but weak staining in symptomatic patients during season. No significant association between the A38G SNP and IAR was found. CONCLUSION: There was an inverse relation between nasal fluid CC16 levels and symptoms and signs of rhinitis in allergen-challenged patients with IAR. However, there was no association between IAR and the A38G SNP.
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| 4. |
- Ekman, Anna-Karin, et al.
(författare)
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Nasal Challenge with LPS Stimulates the Release of Macrophage Inflammatory Protein 1 alpha
- 2009
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Ingår i: International Archives of Allergy and Immunology. - : S. Karger AG. - 1423-0097 .- 1018-2438. ; 149:2, s. 154-160
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Tidskriftsartikel (refereegranskat)abstract
- Background: Bacterial infections can cause a variety of airway diseases. Toll-like receptors (TLRs) directly respond to the presence of microbes and partake in the innate immune defense. TLR4 is activated by lipopolysaccharide (LPS), and has been detected in sinonasal tissue, epithelial cells and various inflammatory cells. Macrophage inflammatory protein 1 alpha (MIP-1 alpha) is a chemokine released during the inflammatory process. The present study investigated the potential role and regulation of MIP-1 alpha in LPS-induced nasal inflammation. Methods: Thirty-two healthy individuals were intranasally challenged with LPS or vehicle. Nasal lavage was performed, followed by a nasal biopsy. Inflammatory cells were counted, MIP-1 alpha levels analyzed and expression of MIP-1 alpha mRNA in biopsies quantified. Neutrophils isolated from peripheral blood were treated with LPS and effects on MIP1 alpha release, cell survival, and the involved signal pathways, were investigated. Results: LPS challenge caused an increase of MIP-1 alpha in nasal lavage. No corresponding change in mRNA expression was seen in nasal biopsies, suggesting the increase was not due to epithelial synthesis. Neutrophil numbers increased after LPS provocation. Treatment of isolated neutrophils with LPS delayed neutrophil apoptosis and resulted in a time-and concentration-dependent release of MIP-1 alpha, which was reduced by inhibitors of transcription and of nuclear factor (NF)-kappa B, protein kinase C (PKC) and p38 MAPK pathways. Conclusions: Nasal LPS challenge results in release of MIP-1 alpha. The release most likely originates from recruited neutrophils, via NF-kappa B-, PKC-and p38 MAPK-dependent pathways. LPS stimulation delayed neutrophil apop tosis. MIP-1 alpha may constitute an important mediator in neutrophilic airway disease. Copyright (C) 2009 S. Karger AG, Basel
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| 5. |
- Fransson, J.E.S., et al.
(författare)
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Detection of clear-cuts using ALOS PALSAR satellite images
- 2008
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Ingår i: Proceedings of the European Conference on Synthetic Aperture Radar, EUSAR. - 2197-4403. ; 1-4
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Konferensbidrag (refereegranskat)abstract
- The objective of this study is to make a first evaluation of the possibilities to detect forest clear-cuts using high-resolution ALOS PALSAR FBD (Fine Beam Dual polarization) satellite images. New operational applications for mapping of changes in forest cover are of interest for government authorities in Sweden and in other countries with similar needs. The study was conducted in southern Sweden and included seven old coniferous stands located on flat terrain. Three of the stands were clear-felled and the remaining stands were left untreated for reference. Altogether, six PALSAR FBD images (look angle 34.3°, HH- and HV-polarization) acquired during the summer and fall seasons were analyzed. The difference in backscattering coefficient between the reference and the clear-felled stands was on average 2.4 dB and 2.9 dB for the HH- and HV-polarization, respectively. When comparing the backscattering coefficient before and after clear-felling the drop was found to be 1.7 dB and 2.3 dB for the HH- and HV-polarization, respectively.
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| 6. |
- Fransson, Liisa, et al.
(författare)
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A regional perspective on present and future soil chemistry at 16 Swedish forest sites
- 2005
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Ingår i: Water, Air and Soil Pollution. - : Springer Science and Business Media LLC. - 1573-2932 .- 0049-6979. ; 162:1-4, s. 89-105
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Tidskriftsartikel (refereegranskat)abstract
- Assessing the timescales of recovery, by the use of dynamic models, will be used as input to the policy process to abate acidification. In this study the multilayer dynamic soil chemistry model SAFE was applied to 16 forest sites in Sweden, covering a sulfur deposition gradient of 1.2-11 kg S/ha/yr. Soil samples were collected at all sites and the pH and sulfate concentration dependent isotherm, used for modeling sulfate adsorption in SAFE, was parameterized for every site. A new way of implementing the nutrient uptake distribution in SAFE was developed, which allows the uptake distribution between layers in the rooting zone to vary with time, depending on the availability of base cations in the individual layers. Model output was compared to measurements of base cation concentration, total inorganic Al, pH and Bc/Al both site-by-site and cumulatively for all sites, and the usefulness of these comparisons is discussed from a policy viewpoint. Future projections of recovery show that the overall recovery, expressed as minimum Bc/Al ratio > 1 in the rooting zone, is slow. Assuming full implementation of the UNECE LRTAP Gothenburg Protocol and no further emission reductions thereafter, 44% of the modeled sites still have a Bc/Al ratio below 1 in 2100 in some soil layer within the rooting zone.
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| 7. |
- Fransson, Mattias, et al.
(författare)
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Expression of Toll-like receptor 9 in nose, peripheral blood and bone marrow during symptomatic allergic rhinitis.
- 2007
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Ingår i: Respiratory research. - : Springer Science and Business Media LLC. - 1465-993X .- 1465-9921. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Allergic rhinitis is an inflammatory disease of the upper airway mucosa that also affects leukocytes in bone marrow and peripheral blood. Toll-like receptor 9 (TLR9) is a receptor for unmethylated CpG dinucleotides found in bacterial and viral DNA. The present study was designed to examine the expression of TLR9 in the nasal mucosa and in leukocytes derived from different cellular compartments during symptomatic allergic rhinitis. METHODS: The study was based on 32 patients with seasonal allergic rhinitis and 18 healthy subjects, serving as controls. Nasal biopsies were obtained before and after allergen challenge. Bone marrow, peripheral blood and nasal lavage fluid were sampled outside and during pollen season. The expression of TLR9 in tissues and cells was analyzed using immunohistochemistry and flow cytometry, respectively. RESULTS: TLR9 was found in several cell types in the nasal mucosa and in different leukocyte subpopulations derived from bone marrow, peripheral blood and nasal lavage fluid. The leukocyte expression was generally higher in bone marrow than in peripheral blood, and not affected by symptomatic allergic rhinitis. CONCLUSION: The widespread expression of TLR9 in the nasal mucosa along with its rich representation in leukocytes in different compartments, demonstrate the possibility for cells involved in allergic airway inflammation to directly interact with bacterial and viral DNA.
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| 8. |
- Fransson, Mattias, et al.
(författare)
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Lipopolysaccharide-induced down-regulation of uteroglobin in the human nose.
- 2007
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Ingår i: Acta Oto-Laryngologica. - : Informa UK Limited. - 1651-2251 .- 0001-6489. ; 127:3, s. 285-291
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Tidskriftsartikel (refereegranskat)abstract
- Conclusion. Lipopolysaccharide (LPS) challenge of the human nose has the capacity to reduce the amount of natural anti-inflammatory proteins, such as uteroglobin. Objectives. Nasal challenge with LPS, an activator of innate immunity, has been shown to increase the amount of pro-inflammatory mediators in nasal lavage fluid. Uteroglobin is a newly described anti-inflammatory mediator that is secreted in the nose. This study examined the effect of nasal LPS application on the level of uteroglobin in nasal lavage fluid as well as on the expression of uteroglobin in nasal mucosa. Materials and methods. Thirty-eight volunteers were challenged nasally with either 50 mu g LPS or vehicle; 6 h later, nasal lavage fluid was collected and a nasal biopsy was obtained. Levels of uteroglobin, albumin and the pro-inflammatory mediators interleukin (IL)-6 and IL-8 were analysed in the lavage fluids using enzyme-linked immunosorbent assays (ELISAs). Biopsies were used for either quantification of uteroglobin mRNA by real-time PCR or for localization of the corresponding protein with immunohistochemistry. Results. The uteroglobin level decreased in nasal lavage fluid following LPS challenge, whereas the levels of IL-6 and albumin increased. Uteroglobin was mainly seen in the respiratory epithelium and its mRNA expression decreased as a consequence of the LPS challenge.
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| 9. |
- Fransson, Mattias
(författare)
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Toll-like Receptors in Allergic Rhinitis
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Allergic rhinitis is an inflammatory disorder with the characteristic symptoms itching, sneezing, secretion and blockage upon allergen contact. In addition to the local inflammation in the nose, there is a systemic component that influences peripheral blood, bone marrow and lungs. The immune system is conventionally divided into innate and acquired (adaptive) immunity. The former is important in the early phase of the defense against previously unknown intruders, since there is a delay of 4-7 days for a full function of the adaptive immunity. Repeated encounters with the same antigen will result in a faster and more effective response of the adaptive immunity. Development of allergic airway inflammation is traditionally related to T helper type 2 (Th2) lymphocytes and their production of inflammatory cytokines as a part of the adaptive immunity, but recent data suggest that the innate immunity might also have a role in this process. Toll-like receptors (TLRs) have emerged as key receptors of the innate immune system but information about their role in allergy and airway inflammation is so far limited. The aims of the present study were to investigate the expression of TLR2, TLR3, TLR4 and TLR9 in the nose, peripheral blood and bone marrow, and to find out if pollen encounter affects the local and systemic expression of these proteins. The effects of nasal provocation with lipopolysaccharide (LPS), a ligand to TLR4, were investigated and the functional activity of TLR3 in eosinophils was explored in a series of in vitro experiments. In the six studies included in this thesis, a total of 111 patients with allergic rhinitis and 55 healthy volunteers were investigated. Samples of nasal mucosa, nasal lavage fluid, peripheral blood and bone marrow were examined using enzyme-linked immunosorbent assay (ELISA), real-time polymerase chain reaction (RT-PCR), immunohistochemistry and flow cytometry. TLR2, TLR3, TLR4 and TLR9 were found in the nasal epithelium and in inflammatory cells in the submucosa, and TLR2, TLR4 and TLR9 were expressed in neutrophils in nasal lavage fluid. In bone marrow, TLR2, TLR3, TLR4 and TLR9 were found in neutrophils, eosinophils, monocytes and immature granulocytes. These TLRs also appeared in peripheral blood, except for the absence of TLR3 in neutrophils. In addition, TLR9 was seen in basophils and lymphocytes. Generally, the leukocyte expression of TLRs was higher in nasal lavage fluid compared to bone marrow, where it in turn was higher than in peripheral blood. Stimulation of isolated eosinophils with the TLR3 agonist polyinosinic-polycytidylic acid (poly(I:C)), resulted in an enhanced expression of CD11b and release of interleukin (IL)-8, involving the intracellular pathways of p38 mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-?B). Nasal provocation with the TLR4 ligand LPS resulted in leukocyte recruitment and increase in IL-6 and albumin in nasal lavage fluid after 6 hours. In addition, it caused a reduction in the tissue expression and the nasal lavage fluid levels of the anti-inflammatory mediator uteroglobin. Nasal pollen challenge in allergic patients resulted in an increased amount of neutrophils in nasal lavage fluid after one hour and an increased expression of TLR2, TLR3 and TLR4 in the nasal epithelium after 24 hours. Patients with seasonal allergic rhinitis had an activated expression of TLR4 in neutrophils, eosinophils and monocytes in peripheral blood during pollen season. Similarly, an activated expression of TLR4 was found in immature granulocytes and neutrophils in bone marrow and in neutrophils in nasal lavage fluid. The expression of TLR3 in eosinophils decreased in peripheral blood and bone marrow during pollen season, whereas the expression of TLR9 was not affected by allergen exposure. The present findings that pollen-induced upper airway inflammation affects the expression of TLRs locally and systemically, support the idea of a role for the innate immune system during symptomatic allergic rhinitis.
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| 10. |
- Fransson, Mattias, et al.
(författare)
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Up-regulation of Toll-like receptors 2, 3 and 4 in allergic rhinitis
- 2005
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Ingår i: Respiratory Research. - : Springer Science and Business Media LLC. - 1465-9921 .- 1465-993X. ; 6:100
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Toll-like receptors enable the host to recognize a large number of pathogen-associated molecular patterns such as bacterial lipopolysaccharide, viral RNA, CpG-containing DNA and flagellin. Toll-like receptors have also been shown to play a pivotal role in both innate and adaptive immune responses. The role of Toll-like receptors as a primary part of our microbe defense system has been shown in several studies, but their possible function as mediators in allergy and asthma remains to be established. The present study was designed to examine the expression of Toll-like receptors 2, 3 and 4 in the nasal mucosa of patients with intermittent allergic rhinitis, focusing on changes induced by exposure to pollen. METHODS: 27 healthy controls and 42 patients with seasonal allergic rhinitis volunteered for the study. Nasal biopsies were obtained before and during pollen season as well as before and after allergen challenge. The seasonal material was used for mRNA quantification of Toll-like receptors 2, 3 and 4 with real-time polymerase chain reaction, whereas specimens achieved in conjunction with allergen challenge were used for immunohistochemical localization and quantification of corresponding proteins. RESULTS: mRNA and protein representing Toll-like receptors 2, 3 and 4 could be demonstrated in all specimens. An increase in protein expression for all three receptors could be seen following allergen challenge, whereas a significant increase of mRNA only could be obtained for Toll-like receptor 3 during pollen season. CONCLUSION: The up-regulation of Toll-like receptors 2, 3 and 4 in the nasal mucosa of patients with symptomatic allergic rhinitis supports the idea of a role for Toll-like receptors in allergic airway inflammation.
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| 11. |
- Klintenberg, Mattias, et al.
(författare)
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Evolving properties of two-dimensional materials : from graphene to graphite
- 2009
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Ingår i: Journal of Physics. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 21:33, s. 335502-
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Tidskriftsartikel (refereegranskat)abstract
- We have studied theoretically, using density functional theory, several material properties when going from one C layer in graphene to two and three graphene layers and on to graphite. The properties we have focused on are the elastic constants, electronic structure (energy bands and density of states), and the dielectric properties. For any of the properties we have investigated the modification due to an increase in the number of graphene layers is within a few per cent. Our results are in agreement with the analysis presented recently by Kopelevich and Esquinazi (unpublished).
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| 12. |
- Ragnehed, Mattias, 1976-
(författare)
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Functional Magnetic Resonance Imaging for Clinical Diagnosis : Exploring and Improving the Examination Chain
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Functional Magnetic Resonance Imaging (fMRI) is a relatively new imaging technique, first reported in 1992, which enables mapping of brain functions with high spatial resolution. Functionally active areas are distinguished by a small signal increase mediated by changes in local blood oxygenation in response to neural activity. The ability to non-invasively map brain function and the large number of MRI scanners quickly made the method very popular, and fMRI have had a huge impact on the study of brain function, both in healthy and diseased subjects.The most common clinical application of fMRI is pre-surgical mapping of brain functions in order to optimise surgical interventions. The clinical fMRI examination procedure can be divided into four integrated parts: (1) patient preparation, (2) image acquisition, (3) image analysis and (4) clinical decision. In this thesis, important aspects of all parts of the fMRI examination procedure are explored with the aim to provide recommendations and methods for prosperous clinical usage of the technique.The most important results of the thesis were: (I) administration of low doses of diazepam to reduce anxiety did not invalidate fMRI mapping results of primary motor and language areas, (II) the choice of visual stimuli equipment can have severe impact on the mapping of visual areas, (III) three-dimensional fMRI imaging sequences did not perform better than two-dimensional imaging sequences, (IV) adaptive spatial filtering can improve the fMRI data analysis, (V) clinical decisions should not be based on activation results from a single statistical threshold.
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| 13. |
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| 14. |
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| 15. |
- Sundström, Timmy, 1981-, et al.
(författare)
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Prognostics of electronic systems through power supply current trends
- 2008
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Ingår i: IEEE Internatioanl Conference on Prognostics and Health Management. - Denver, USA : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- As today's avionic systems highly rely on electronic components, the prognostic of electronic systems in the context of avionics has become crucial. This paper presents a prognostic method applicable to electronic components and systems based on the analysis of the power supply current. In this method, the focus is on trends in the measured power supply current of the device under prognostic process. The discussion in this paper reveals that there is a measurable relationship between the supply current and the remaining lifetime of the electronic devices. The presented methodology is supported by circuit simulations performed on a system consisting of reference circuitry. The prognostic method shows great promise due to the ability of being applicable at any prognostic level.
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| 16. |
- Sverdrup, Harald, et al.
(författare)
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Modeling recovery of Swedish ecosystems from acidification
- 2005
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Ingår i: Ambio: a Journal of Human Environment. - 0044-7447. ; 34:1, s. 25-31
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Tidskriftsartikel (refereegranskat)abstract
- Dynamic models complement existing time series of observations and static critical load calculations by simulating past and future development of chemistry in forest and lake ecosystems. They are used for dynamic assessment of the acidification and to produce target load functions, that describe what combinations of nitrogen and sulfur emission reductions are needed to achieve a chemical or biological criterion in a given target year. The Swedish approach has been to apply the dynamic acidification models MAGIC, to 133 lakes unaffected by agriculture and SAFE, to 645 productive forest sites. While the long-term goal is to protect 95% of the area, implementation of the Gothenburg protocol will protect approximately 75% of forest soils in the long term. After 2030, recovery will be very slow and involve only a limited geographical area. If there had been no emission reductions after 1980, 87% of the forest area would have unwanted soil status in the long term. In 1990, approximately 17% of all Swedish lakes unaffected by agriculture received an acidifying deposition above critical load. This fraction will decrease to 10% in 2010 after implementation of the Gothenburg protocol. The acidified lakes of Sweden will recover faster than the soils. According to the MAGIC model the median pre-industrial ANC of 107 mueq L-1 in acid sensitive lakes decreased to about 60 mueq L-1 at the peak of the acidification (1975-1990) and increases to 80 mueq L-1 by 2010. Further increases were small, only 2 mueq L-1 between 2010 and 2040. Protecting 95% of the lakes will require further emission reductions below the Gothenburg protocol levels. More than 7000 lakes are limed regularly in Sweden and it is unlikely that this practice can be discontinued in the near future without adverse effects on lake chemistry and biology.
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| 17. |
- Zhou, Qin, et al.
(författare)
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The C-terminal amidated analogue of the Substance P (SP) fragment SP (1-7) attenuates the expression of naloxone- precipitated withdrawal in morphine dependent rats
- 2009
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Ingår i: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 30:12, s. 2418-2422
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Tidskriftsartikel (refereegranskat)abstract
- We previously demonstrated that intracerebroventricular (i.c.v.) administration of the substance P (SP) aminoterminal fragment SP(1-7) attenuates the expression of morphine withdrawal in the male rat. In this study we have used a synthetic analogue of this peptide, i.e. the SP(1-7) amide showing higher binding potency than the native heptapeptide, in a similar experimental set-up. Thus, Wistar male rats were made tolerant to morphine by daily injections of the opiate during 8 days. Following peptide administration (i.c.v.) and a subsequent naloxone challenge a variety of physical syndromes of withdrawal were recorded. We observed that the SP(1-7) amide potently and dose-dependently reduced several signs of reaction to morphine withdrawal. Interestingly, the effect of the peptide amide was significantly attenuated by the addition of the sigma agonist (+)-SKF-10047. We conclude that the SP(1-7) amide mimics the effect of the native SP fragment and that the mechanisms for its action involve a sigma receptor site.
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