| 1. |
- Chen, X., et al.
(författare)
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A genome-wide association study of IgM antibody against phosphorylcholine: shared genetics and phenotypic relationship to chronic lymphocytic leukemia
- 2018
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 27:10, s. 1809-1818
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Tidskriftsartikel (refereegranskat)abstract
- Phosphorylcholine (PC) is an epitope on oxidized low-density lipoprotein (oxLDL), apoptotic cells and several pathogens like Streptococcus pneumoniae. Immunoglobulin M against PC (IgM anti-PC) has the ability to inhibit uptake of oxLDL by macrophages and increase clearance of apoptotic cells. From our genome-wide association studies (GWASs) in four European-ancestry cohorts, six single nucleotide polymorphisms (SNPs) in 11q24.1 were discovered (in 3002 individuals) and replicated (in 646 individuals) to be associated with serum level of IgM anti-PC (the leading SNP rs35923643-G, combined beta = 0.19, 95% confidence interval 0.13-0.24, P = 4.3 x 10-11). The haplotype tagged by rs35923643-G (or its proxy SNP rs735665-A) is also known as the top risk allele for chronic lymphocytic leukemia (CLL), and a main increasing allele for general IgM. By using summary GWAS results of IgM anti-PC and CLL in the polygenic risk score (PRS) analysis, PRS on the basis of IgM anti-PC risk alleles positively associated with CLL risk (explained 0.6% of CLL variance, P = 1.2 x 10-15). Functional prediction suggested that rs35923643-G might impede the binding of Runt-related transcription factor 3, a tumor suppressor playing a central role in the immune regulation of cancers. Contrary to the expectations from the shared genetics between IgM anti-PC and CLL, an inverse relationship at the phenotypic level was found in a nested case-control study (30 CLL cases with 90 age- and sex-matched controls), potentially reflecting reverse causation. The suggested function of the top variant as well as the phenotypic association between IgM anti-PC and CLL risk needs replication and motivates further studies.
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| 2. |
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| 3. |
- Geretovszky, Zsolt, et al.
(författare)
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Aerosol phase generation of In-Se nanoparticles
- 2006
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Ingår i: Journal of Nanoscience and Nanotechnology. - : American Scientific Publishers. - 1533-4880. ; 6:3, s. 600-611
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Tidskriftsartikel (refereegranskat)abstract
- Results on the generation and heat treatment of In-Se nanoparticles, made by heterogeneous condensation of selenium on indium nanoparticles synthesised via the evaporation/condensation route are reported. In-situ aerosol measurements are complemented with ex-situ analysis, to provide structural, morphological, and compositional information on the In-Se nanoparticles. Our results indicate that prior to heat treatment In-Se nanoparticles have a shape in the aerosol phase, similar to an asymmetric dumbbell. The bigger particle of the dumbbell structure is made up of amorphous Se, while the overall composition of the polycrystalline smaller particle is around InSe. The smaller particle has an intrinsic structure, and consists of different InSe-compounds, with a decreasing In content towards the shell. The shape of the In-Se nanoparticles is different in the aerosol phase and on the surface of the samples. The observed variety of particle sizes and shapes on the sample surface is shown to be partly due to the agglomeration of the aerosol phase binaries (i.e., dumbbells) via coalescence on the surface of the sample and wetting of the sample surface by the Se nanoparticles. These processes make the bigger particle of the dumbbell structure appear almost perfectly hemispherical on the sample surfaces. During heat treatment at lower temperatures mainly the evaporative removal of the big Se particle of the dumbbell structure will take place. Annealing of the smaller particles starts to dominate at temperatures above 240 degrees C and makes the composition of the small particles closer to that of the thermodynamically most favoured In2Se3.
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| 4. |
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| 5. |
- Karlsson, Martin, et al.
(författare)
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Size- and compostition-controlled Au-Ga aerosol nanoparticles
- 2004
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Ingår i: Aerosol Science and Technology. - : Informa UK Limited. - 1521-7388 .- 0278-6826. ; 38:9, s. 948-954
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Tidskriftsartikel (refereegranskat)abstract
- A simple gas-phase method has been developed for producing size- and composition-controlled nanoparticles of binary alloys. The process includes the formation and classification of aerosol nanoparticles of one material and the subsequent condensation of a controlled shell of another. The shell thickness is controlled by the evaporation temperature of the second material. Here we study the Au-Ga system with particle compositions ranging from pure Au to 50 atomic percent Ga. Transmission electron microscopy was used to study the morphology, composition, and structure of the generated particles.
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| 6. |
- Karlsson, Martin, et al.
(författare)
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Size-controlled nanoparticles by thermal cracking of iron pentacarbonyl
- 2005
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Ingår i: Applied Physics A: Materials Science & Processing. - : Springer Science and Business Media LLC. - 1432-0630. ; 80:7, s. 1579-1583
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Tidskriftsartikel (refereegranskat)abstract
- A gas-phase method has been developed for producing size-controlled nanoparticles by thermal cracking of iron pentacarbonyl. The method includes the formation of iron particles from vapor emanating from the cracking of the volatile compound and subsequent compacting of the selected particles. Different temperature steps were involved in the process, and their effects on the particle production were investigated. On-line differential mobility measurements and off-line transmission electron microscopy (TEM) were used to study the morphology, composition and structure of the generated particles. The aim of the study was to produce nanoparticles of pure iron. After transportation in air, the composition of the particles was analyzed by TEM and found to be magnetite, Fe3O4. The oxidation may be attributed to the exposure to air and humidity during the transport. The phase of the uncontaminated particles could not be determined. Tests for growth of silicon nanowhiskers using nanoparticles produced with this method were successful.
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| 7. |
- Karlsson, Tove, et al.
(författare)
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The school lighting innovation dilemma
- 2022
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Ingår i: IOP Conference Series: Earth and Environmental Science, Volume 1099. - : Institute of Physics Publishing (IOPP). - 1755-1307 .- 1755-1315.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a qualitative descriptive case study that aims to build awareness about the need for improvement of the indoor environment in classrooms and to exemplify how renewal-oriented processes can be initiated. The study focuses on innovation processes that have resulted in both completely new designs and further spread of innovative solutions. The reason for the need to improve is that too many pupils and students have problems with concentration, relaxation and recuperation. The number of diagnoses such as Autism and ADHD is growing. One factor which significantly influences the pupil's mental well-being is the daily physical environment. The single aspect which may be improved in reasonable time, at a reasonable cost, is the lighting design of classrooms. An underlying reason for the habit to continue installing insipid uniform static "light-carpets" is the lack of awareness about how lighting affects wellbeing and health. As with innovation in other industries, it is an innovation dilemma that the vast majority of the people who sell and procure classroom lighting tend to prefer the established solutions that they are used to. The article describes how Malmö's early investment in Human Centric Lighting and the unique indoor environment of the Study hall in the Centre for Economic Sciences at Uppsala University are used as role models for lighting design in classrooms. The case study combines the authors' own observations and earlier interviews with users. Malmö's temporal light variation and parts of the Study hall's lighting design are used in more than 30 classrooms, in Malmö, Stockholm Business School and Iggesund. The article concludes with suggestions on how today's lighting design knowledge and technology can be combined to provide more advanced adaptations to the varying lighting needs of pupils, students and teachers.
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| 8. |
- Lundström, Karl, et al.
(författare)
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Understanding the diet composition of marine mammals : grey seals (Halichoerus grypus) in the Baltic Sea
- 2010
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Ingår i: ICES Journal of Marine Science. - : Oxford University Press (OUP). - 1054-3139 .- 1095-9289. ; 67:6, s. 1230-1239
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Tidskriftsartikel (refereegranskat)abstract
- Dietary studies are important in understanding the ecological role of marine mammals and in formulating appropriate management plans in terms of their interactions with fisheries. The validity of such studies has, however, often been compromised by unrepresentative sampling procedures, resulting in false weight being given to external factors seeming to influence diet composition. The bias caused by non-random sampling was examined, using canonical correspondence analysis to assess how the prey species composition in digestive tract samples of Baltic grey seals (Halichoerus grypus) was related to spatial, temporal, and demographic factors and to whether the samples were collected in association with fishing gear or not (“sampling condition”). Geographic region explained the largest fraction of the observed variation, followed by sampling condition, age group, and year. Season and gender were not statistically significant. Segregation of the two age categories “pups” and “juveniles–adults”, and the two geographic categories “Baltic proper” and “Gulf of Bothnia” are proposed to estimate the diet and fish consumption of the Baltic grey seal population as a whole. Atlantic herring was the most commonly recovered prey item in all areas and age groups, followed by European sprat in the south, and common whitefish in the north. Pups had eaten relatively more small non-commercial species than older seals.
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| 9. |
- Olsson, Gunnel, et al.
(författare)
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Kinetics of coal desulphurization by Acidianus brierleyi
- 1993
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Ingår i: Chemical Engineering & Technology. - : Wiley. - 1521-4125 .- 0930-7516. ; 16:3, s. 180-185
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Tidskriftsartikel (refereegranskat)abstract
- Acidianus brierleyi was demonstrated to remove pyritic sulphur from coal. A. brierleyi was also found capable of catalyzing the removal of what is normally reported as organic sulphur from coal 171US34. A kinetic analysis was performed by assuming a first order reaction. The first order kinetics allowed a comparison with literature data for Thiobacillus ferrooxidans. Also, formation of jarosite was taken into account in the analysis. The simple first order kinetics was observed to fit the data on removal of sulphur satisfactorily.
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| 10. |
- Abou-Hachem, Maher, et al.
(författare)
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Calcium binding and thermostability of carbohydrate binding module CBM4-2 of Xyn10A from Rhodothermus marinus.
- 2002
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Ingår i: Biochemistry. - : American Chemical Society (ACS). - 0006-2960 .- 1520-4995. ; 41:18, s. 5720-5729
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Tidskriftsartikel (refereegranskat)abstract
- Calcium binding to carbohydrate binding module CBM4-2 of xylanase 10A (Xyn10A) from Rhodothermus marinus was explored using calorimetry, NMR, fluorescence, and absorbance spectroscopy. CBM4-2 binds two calcium ions, one with moderate affinity and one with extremely high affinity. The moderate-affinity site has an association constant of (1.3 +/- 0.3) x 10(5) M(-1) and a binding enthalpy DeltaH(a) of -9.3 +/- 0.4 kJ x mol(-1), while the high-affinity site has an association constant of approximately 10(10) M(-1) and a binding enthalpy DeltaH(a) of -40.5 +/- 0.5 kJ x mol(-1). The locations of the binding sites have been identified by NMR and structural homology, and were verified by site-directed mutagenesis. The high-affinity site consists of the side chains of E11 and D160 and backbone carbonyls of E52 and K55, while the moderate-affinity site comprises the side chain of D29 and backbone carbonyls of L21, A22, V25, and W28. The high-affinity site is in a position analogous to the calcium site in CBM4 structures and in a recent CBM22 structure. Binding of calcium increases the unfolding temperature of the protein (T(m)) by approximately 23 degrees C at pH 7.5. No correlation between binding affinity and T(m) change was noted, as each of the two calcium ions contributes almost equally to the increase in unfolding temperature.
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| 11. |
- Abou Hachem, Maher, et al.
(författare)
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Carbohydrate-binding modules from a thermostable Rhodothermus marinus xylanase : Cloning, expression and binding studies
- 2000
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Ingår i: Biochemical Journal. - : Portland Press Ltd.. - 0264-6021. ; 345:1, s. 53-60
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Tidskriftsartikel (refereegranskat)abstract
- The two N-terminally repeated carbohydrate-binding modules (CBM4-1 and CBM4-2) encoded by xyn10A from Rhodothermus marinus were produced in Escherichia coli and purified by affinity chromatography. Binding assays to insoluble polysaccharides showed binding to insoluble xylan and to phosphoric-acid-swollen cellulose but not to Avicel or crystalline cellulose. Binding to insoluble substrates was significantly enhanced by the presence of Na+ and Ca2+ ions. The binding affinities for soluble polysaccharides were tested by affinity electrophoresis; strong binding occurred with different xylans and β-glucan. CBM4-2 displayed a somewhat higher binding affinity than CBM4-1 for both soluble and insoluble substrates but both had similar specificities. Binding to short oligosaccharides was measured by NMR; both modules bound with similar affinities. The binding of the modules was shown to be dominated by enthalpic forces. The binding modules did not contribute with any significant synergistic effects on xylan hydrolysis when incubated with a Xyn10A catalytic module. This is the first report of family 4 CBMs with affinity for both insoluble xylan and amorphous cellulose.
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| 12. |
- Abou-Hachem, Maher, et al.
(författare)
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The modular organisation and stability of a thermostable family 10 xylanase
- 2003
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Ingår i: Biocatalysis and Biotransformation. - : Informa UK Limited. - 1024-2422 .- 1029-2446. ; 21:5-6, s. 253-260
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Tidskriftsartikel (refereegranskat)abstract
- The thermophilic marine bacterium Rhodothermus marinus produces a modular family 10 xylanase (Xyn10A). It consists of two N-terminal family 4 carbohydrate binding modules (CBMs) followed by a domain of unknown function (D3), and a catalytic module (CM) flanked by a small fifth domain (D5) at its C-terminus. Several truncated mutants of the enzyme have been produced and characterised with respect to biochemical properties and stability. Multiple calcium binding sites are shown to be present in the two N-terminal CBMs and recent evidence suggests that the third domain of the enzyme also has the ability to bind the same metal ligand. The specific binding of Ca2+ was demonstrated to have a pronounced effect on thermostability as shown by differential scanning calorimetry and thermal inactivation studies. Furthermore, deletion mutants of the enzyme were less stable than the full-length enzyme suggesting that module interactions contributed to the stability of the enzyme. Finally, recent evidence indicates that the fifth domain of Xyn10A is a novel type of module mediating cell-attachment.
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| 13. |
- Aguilar, Helena, et al.
(författare)
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VAV3 mediates resistance to breast cancer endocrine therapy
- 2014
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Ingår i: Breast Cancer Research. - : BioMed Central. - 1465-5411 .- 1465-542X. ; 16:3, s. R53-
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Endocrine therapies targeting cell proliferation and survival mediated by estrogen receptor alpha (ERalpha) are among the most effective systemic treatments for ERalpha-positive breast cancer. However, most tumors initially responsive to these therapies acquire resistance through mechanisms that involve ERalpha transcriptional regulatory plasticity. Here, we identify VAV3 as a critical component in this process.METHODS: A cell-based chemical compound screen was carried out to identify therapeutic strategies against resistance to endocrine therapy. Binding to ERalpha was evaluated by molecular docking analyses, an agonist fluoligand assay, and short-hairpin (sh) RNA-mediated protein depletion. Microarray analyses were performed to identify altered gene expression. Western blot of signaling and proliferation markers and shRNA-mediated protein depletion in viability and clonogenic assays were performed to delineate the role of VAV3. Genetic variation in VAV3 was assessed for association with the response to tamoxifen. Immunohistochemical analyses of VAV3 were carried out to determine the association with therapy response and different tumor markers. An analysis of gene expression association with drug sensitivity was carried out to identify a potential therapeutic approach based on differential VAV3 expression.RESULTS: The compound YC-1 was found to comparatively reduce the viability of cell models of acquired resistance. This effect was probably not due to activation of its canonical target (soluble guanylyl cyclase) but instead a result of binding to ERalpha. VAV3 was selectively reduced upon exposure to YC-1 or ERalpha depletion and, accordingly, VAV3 depletion comparatively reduced the viability of cell models of acquired resistance. In the clinical scenario, germline variation in VAV3 was associated with response to tamoxifen in Japanese breast cancer patients (rs10494071 combined P value = 8.4 x 10-4). The allele association combined with gene expression analyses indicated that low VAV3 expression predicts better clinical outcome. Conversely, high nuclear VAV3 expression in tumor cells was associated with poorer endocrine therapy response. Based on VAV3 expression levels and the response to erlotinib in cancer cell lines, targeting EGFR signaling may be a promising therapeutic strategy.CONCLUSIONS: This study proposes VAV3 as a biomarker and rationale signaling target to prevent and/or overcome resistance to endocrine therapy in breast cancer.
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| 14. |
- Ahlgren, Kerstin M., et al.
(författare)
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Increased IL-17A secretion in response to Candida albicans in autoimmune polyendocrine syndrome type 1 and its animal model
- 2011
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Ingår i: European Journal of Immunology. - : Wiley. - 0014-2980 .- 1521-4141. ; 41:1, s. 235-245
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Tidskriftsartikel (refereegranskat)abstract
- Autoimmune polyendocrine syndrome type 1 (APS-1) is a multiorgan autoimmune disease caused by mutations in the autoimmune regulator (AIRE) gene. Chronic mucocutaneous candidiasis, hypoparathyroidism and adrenal failure are hallmarks of the disease. The critical mechanisms causing chronic mucocutaneous candidiasis in APS-1 patients have not been identified although autoantibodies to cytokines are implicated in the pathogenesis. To investigate whether the Th reactivity to Candida albicans (C. albicans) and other stimuli was altered, we isolated PBMC from APS-1 patients and matched healthy controls. The Th17 pathway was upregulated in response to C. albicans in APS-1 patients, whereas the IL-22 secretion was reduced. Autoantibodies against IL-22, IL-17A and IL-17F were detected in sera from APS-1 patients by immunoprecipitation. In addition, Aire-deficient (Aire(0/0) ) mice were much more susceptible than Aire(+/+) mice to mucosal candidiasis and C. albicans-induced Th17- and Th1-cell responses were increased in Aire(0/0) mice. Thus an excessive IL-17A reactivity towards C. albicans was observed in APS-1 patients and Aire(0/0) mice.
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| 15. |
- Ahnström Waltersson, Marie, 1976-, et al.
(författare)
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miR-206 expression is downregulated in cyclin D1 amplified breast tumours
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Amplification in the 11q13 region has been found in around 15% of all breast cancers and is strongly correlated with oestrogen receptor (ER) positive tumours. We have previously found that amplification of at least one of the genes PAK1 or CCND1 is associated with decreased recurrencefree survival among ER+ patients. Other genes in the amplicon might also contribute to this effect and situated close to CCND1 are the FGF-3, -4 and - 19 genes. The FGF-4 protein has been shown to inhibit the expression of the ERα regulator miR-206 in chicken embryo. In this study we analysed 23 tumours with and 27 tumours without previously detected 11q13 amplification to explore if 11q13 amplification is associated with decreased levels of miR-206 and if miR-206 is associated with ER expression. Using real-time PCR, we found that miR-206 expression was inversely correlated to CCND1 and 11q13 amplification (P=0.016 and P=0.022 respectively). Tumours with low miR-206 expression had higher levels of ERα than tumours with intermediate and high expression (P=0.043). We conclude that miR-206 might be an important regulator of the ERα. Our finding that low mir-206 is associated with CCND1 amplification and thereby also FGF-4 amplification points towards the possibility of a miR-206 regulator, FGF-4 or another FGF, present in the amplicon.
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| 16. |
- Akselsson, Cecilia, et al.
(författare)
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För Värmlands läns Luftvårdsförbund Övervakning av luftföroreningar i Värmlands län Resultat till och med september 1999
- 2000
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- På uppdrag av Värmlands läns Luftvårdsförbund har IVL mätt nedfall av luftföroreningar, markvattnets kvalitet och lufthalter på sju lokaler i Värmlands län. Syftet är att beskriva nedfallets storlek och markvattnets sammansättning i skogsytorna, men även visa skillnader mellan olika delar av regionen och hur förhållandena ändras med tiden. Vissa av provytorna ligger i Skogsvårdsorganisationens observationsytor, vilket gör att Luftvårdsförbundets data kan jämföras med skogens hälsa. Depositionen av svavel och kväve är störst i de sydvästra delarna av Sverige och avtar mot nordost. Denna gradient återfinns även i Värmlands län, där nästan 6 kg svavel deponerades per hektar i den sydligaste skogsytan Södra Averstad, medan omkring 2 kg/ha deponerades i Båtstad och Transtrandsberget i norr. De fyra ytor för vilka det finns en nioårig mätserie visar en markant minskning av svaveldeposition till skogsmark. Medelvärdet har minskat från omkring 7 kg/ha i början av 1990-talet till knappt 4 kg/ha, framför allt beroende på minskad torrdeposition. För kväve saknas motsvarande trend, medeldepositionen på öppet fält har varierat mellan 5 och 7 kg/ha. Prognoser visar att nedfallet år 2010 kommer att vara 2,5 kg svavel och 4 kg kväve per hektar i Svealand om beslutade utsläppsbegränsande åtgärder genomförs i Europa. Det minskade nedfallet av syror ska leda till en minskning av markvattnets försurningsgrad enligt modellberäkningar. Andra faktorer, som episoder av naturligt nedfall av havssalter, kan under kortare eller längre perioder dölja återhämtningen. Därför krävs det långa mätserier för att beskriva om markvattnets kvalitet verkligen förbättras. Markvattnets pH-värde har liksom tidigare år varit omkring 5, förutom ytan på Blåbärskullen centralt i Värmland, där förhållandena varit avsevärt bättre ur försurningsssynpunkt. Säsongsmedelhalten av marknära ozon, O3, var högre än året innan på grund av den fina sommaren 1999. Halterna har sannolikt varit skadliga för vegetationen. Däremot har luftens innehåll av svavel- och kvävedioxid varit betydligt under svenska miljökvalitetsnormer.
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| 17. |
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| 18. |
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| 19. |
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| 20. |
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| 21. |
- Azeem, Muhammad, et al.
(författare)
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A fungal metabolite masks the host plant odor for the pine weevil (Hylobius abietis)
- 2015
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Ingår i: Fungal ecology. - : Elsevier BV. - 1754-5048 .- 1878-0083. ; 13, s. 103-111
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Tidskriftsartikel (refereegranskat)abstract
- The pine weevil is one of the most important pest insects of conifer reforestation areas in Europe. Female pine weevils cover their eggs with chewed bark and feces (frass) resulting in avoidance behavior of feeding conspecifics towards egg laying sites. It has been suggested that microorganisms present in the frass may be responsible for producing deterrent compounds for the pine weevil. The fungi Ophiostoma canum, O. pluriannulatum, and yeast Debaryomyces hansenii were isolated from aseptically collected pine-weevil frass. The isolated fungi were cultured on weevil frass broth and their volatiles were collected by SPME and identified by GC MS. D. hansenii produced methyl salicylate (MeS) as a major compound, whereas, in addition, O. canum and O. pluriannulatum produced 6-protoilludene. In a multi-choice lab bioassay, MeS strongly reduced pine weevil's attraction to the Pinus sylvestris volatiles. Thus, a fungal metabolite was found that strongly affects the pine weevil host-odor search. (C) 2014 Elsevier Ltd and The British Mycological Society. All rights reserved.
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| 22. |
- Balmes, Olivier, et al.
(författare)
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Cryo-TEM observation of 3-dimensionally ordered aggregates of 5-nm gold particles in organic solvents
- 2004
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Ingår i: Journal of Nanoparticle Research. - : Springer Science and Business Media LLC. - 1572-896X .- 1388-0764. ; 6:6, s. 569-576
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Tidskriftsartikel (refereegranskat)abstract
- In this article, we show evidence for the assembly of ordered 3-dimensional aggregates of 5-nm gold particles in toluene, 1-octanol, n-decane, and chloroform. The use of plunge-freezing allows to freeze the solution containing the aggregates at a rate which does not allow reorganisation of the particles during sample preparation. The samples were then observed using cryo-transmission electron microscopy (cryo-TEM) showing that most of the particles were part of ordered aggregates, thus proving that organisation already exists in solution. In some cases, the stability of the sample under the electron beam made it possible to record several pictures of the same aggregate at different angles and build animated tilt series.
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| 23. |
- Balmes, Olivier, et al.
(författare)
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Imaging atomic structure in metal nanoparticles using high-resolution cryo-TEM
- 2006
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Ingår i: Microscopy and Microanalysis. - 1435-8115. ; 12:2, s. 145-150
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Tidskriftsartikel (refereegranskat)abstract
- It has been shown, by imaging gold (200) planes, that it is possible to achieve better than 0.20-nm structural resolution in cryo-transmission electron microscopy (cryo-TEM). This has been done using commercially available cryo equipment and using a 300-kV field emission gun (FEG) TEM. The images of 15-nm gold particles embedded in amorphous frozen water clearly show the (111) planes (separated by 0.235 nm) in gold. Fourier transform demonstrates the presence of (200) planes in the image, proving a resolution of better than 0.20 nm. The experimental results are Supported by image simulations using the multislice method. These simulations suggest that it should be possible to achieve the same resolution even in smaller particles and particles of lighter elements. The crucial experimental problem to overcome is keeping the thickness of the amorphous film low and to work at low electron dose conditions.
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| 24. |
- Barreto Henriksson, Helena, et al.
(författare)
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Identification of Cell Proliferation Zones, Progenitor Cells and a Potential Stem Cell Niche in the Intervertebral Disc Region: A Study in Four Species.
- 2009
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Ingår i: SPINE. - 0362-2436. ; 34:21, s. 2278-2287
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN.: Descriptive experimental study in 4 different mammals. OBJECTIVE.: To investigate cell proliferation/regeneration and localize stem cells/progenitor cells within the intervertebral disc (IVD). SUMMARY OF BACKGROUND DATA.: Disc degeneration (DD) is believed to play a major role in patients with chronic lumbar pain. Lately, biologic treatment options for DD have gained increasing interest. Normal regeneration processes within the IVD and have previously been sparsely described and therefore it is of great interest to increase the knowledge about these processes. METHODS.: Detection of cell proliferations zones and label-retaining cells were done by in vivo 5-bromo-2-deoxyuridine (BrdU) labeling in 18 rabbits, killed after 4, 6, 10, 14, 28, or 56 days. Results were visualized with immunohistochemistry and fluorescence/confocal microscopy. Localization of progenitor cell were further investigated by immunohistochemistry using antibodies towards Notch1, Delta4, Jagged1, C-KIT, KI67, and Stro-1 in normal IVD from rabbits (n = 3), rats (n = 2), minipigs (n = 2), and in human degenerated IVD (n = 4). Further, flowcytometry analysis using progenitor markers were performed on additional human IVD cells (n = 3). RESULTS.: BrdU positive cells were found in comparable numbers at early and late time points in most regions of the anulus fibrosus (AF) and nucleus pulposus demonstrating slow ongoing cell proliferation. In the AF border to ligament zone (AFo) and the perichondriumregion (P) a stem cell niche-like pattern was determined (a high number of BrdU positive cells at early time points vs. only a few label retaining cells at later time points). In normal and DD tissue from the 4 investigated species progenitor cell markers were detected. CONCLUSION.: The IVD is a tissue with ongoing slow cell proliferation both in the AF and the nucleus pulposus. The stem cell niche pattern detected in AFo and P can be suggested to play a role for IVD morphology and function. These findings may be of importance for the development of biologic treatment strategies. PMID: 19755937 [PubMed - as supplied by publisher]
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| 25. |
- Bellander, M, et al.
(författare)
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Preliminary evidence that allelic variation in the LMX1A gene influences training-related working memory improvement
- 2011
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Ingår i: NEUROPSYCHOLOGIA. - : Elsevier BV. - 0028-3932 .- 1873-3514. ; 49:7, s. 1938-1942
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Tidskriftsartikel (refereegranskat)abstract
- LMX1A is a transcription factor involved in the development of dopamine (DA)-producing neurons in midbrain. Previous research has shown that allelic variations in three LMX1A single nucleotide polymorphisms (SNPs) were related to risk of Parkinson's disease (PD), suggesting that these SNPs may influence the number of mesencephalic DA neurons. Prompted by the established link between striatal DA functions and working memory (WM) performance, we examined two of these SNPs in relation to the ability to benefit from 4 weeks of WM training. One SNP (rs4657412) was strongly associated with the magnitude of training-related gains in verbal WM. The allele linked to larger gains has previously been suggested to be associated with higher dopaminergic nerve cell density. No differential gains of either SNP were observed for spatial WM, and the genotype groups were also indistinguishable in tests of attention, interference control, episodic memory, perceptual speed, and reasoning for both SNPs. This pattern of data is in agreement with previous findings from our group, suggesting that cognitive effects of DA-related genes may be more easily detected in a training context than for single-assessment performance scores.
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| 26. |
- Berglund, David, et al.
(författare)
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Imaging the in vivo fate of human T cells following transplantation in immunoincompetent mice - Implications for clinical cell therapy trials
- 2013
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Ingår i: Transplant Immunology. - : Elsevier BV. - 0966-3274 .- 1878-5492. ; 29:1-4, s. 105-108
-
Tidskriftsartikel (refereegranskat)abstract
- Many forms of adoptive T cell therapy are on the verge of being translated to the clinic. To gain further insight in their immunomodulating functions and to optimize future clinical trials it is essential to develop techniques to study their homing capacity. CD4+ T cells were labeled using [In-111]oxine, and the radioactive uptake was determined in vitro before intravenous injection in immunodeficient mice. In vivo biodistribution of [In-111] oxine-labeled cells or tracer alone was subsequently measured by mu SPECT/CT and organ distribution. CD4+ T cells incorporated [In-111]oxine with higher labeling yield using Ringer-Acetate compared to 0.9% NaCl. Cellular viability after labeling with [In-111]oxine was not compromised using less than 0.4 MBq/million cells. After intravenous infusion CD4+ T cells preferentially homed to the liver (p < 0.01) and spleen (p < 0.05). This study presents a protocol for labeling of T cells by [In-111]oxine with preserved viability and in vivo tracking by SPECT for up to 8 days, which can easily be translated to clinical cell therapy trials.
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| 27. |
- Berglund, David, et al.
(författare)
-
Obtaining regulatory T cells from uraemic patients awaiting kidney transplantation for use in clinical trials
- 2013
-
Ingår i: Clinical and Experimental Immunology. - : Oxford University Press (OUP). - 0009-9104 .- 1365-2249. ; 173:2, s. 310-322
-
Tidskriftsartikel (refereegranskat)abstract
- Adoptive transfer of regulatory T cells (Tregs) has been proposed for use as a cellular therapy to induce transplantation tolerance. Preclinical data are encouraging, and clinical trials with Treg therapy are anticipated. In this study, we investigate different strategies for the isolation and expansion of CD4+CD25highCD127low Tregs from uraemic patients. We use allogeneic dendritic cells (DCs) as feeder cells for the expansion and compare Treg preparations isolated by either fluorescence activated cell sorting (FACS) or magnetic activated cell sorting (MACS) that have been expanded subsequently with either mature or tolerogenic DCs. Expanded Treg preparations have been characterized by their purity, cytokine production and in-vitro suppressive ability. The results show that Treg preparations can be isolated from uraemic patients by both FACS and MACS. Also, the type of feeder cells used in the expansion affects both the purity and the functional properties of the Treg preparations. In particular, FACS-sorted Treg preparations expanded with mature DCs secrete more interleukin (IL)-10 and granzyme B than FACS-sorted Treg preparations expanded with tolerogenic DCs. This is a direct comparison between different isolation techniques and expansion protocols with Tregs from uraemic patients that may guide future efforts to produce clinical-grade Tregs for use in kidney transplantation.
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| 28. |
- Bergström, Marcus, et al.
(författare)
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Comparing the Effects of the mTOR Inhibitors Azithromycin and Rapamycin on In Vitro Expanded Regulatory T Cells
- 2019
-
Ingår i: Cell Transplantation. - : SAGE PUBLICATIONS INC. - 0963-6897 .- 1555-3892. ; 28:12, s. 1603-1613
-
Tidskriftsartikel (refereegranskat)abstract
- Adoptive transfer of autologous polyclonal regulatory T cells (Tregs) is a promising option for reducing graft rejection in allogeneic transplantation. To gain therapeutic levels of Tregs there is a need to expand obtained cells ex vivo, usually in the presence of the mTOR inhibitor Rapamycin due to its ability to suppress proliferation of non-Treg T cells, thus promoting a purer Treg yield. Azithromycin is a bacteriostatic macrolide with mTOR inhibitory activity that has been shown to exert immunomodulatory effects on several types of immune cells. In this study we investigated the effects of Azithromycin, compared with Rapamycin, on Treg phenotype, growth, and function when expanding bulk, naive, and memory Tregs. Furthermore, the intracellular concentration of Rapamycin in CD4+ T cells as well as in the culture medium was measured for up to 48 h after supplemented. Treg phenotype was assessed by flow cytometry and Treg function was measured as inhibition of responder T-cell expansion in a suppression assay. The concentration of Rapamycin was quantified with liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Azithromycin and Rapamycin both promoted a FoxP3-positive Treg phenotype in bulk Tregs, while Rapamycin also increased FoxP3 and FoxP3+Helios positivity in naive and memory Tregs. Furthermore, Rapamycin inhibited the expansion of naive Tregs, but also increased their suppressive effect. Rapamycin was quickly degraded in 37 degrees C medium, yet was retained intracellularly. While both compounds may benefit expansion of FoxP3+ Tregs in vitro, further studies elucidating the effects of Azithromycin treatment on Tregs are needed to determine its potential use.
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| 29. |
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| 30. |
- Bianchi, Matteo, et al.
(författare)
-
Whole-genome genotyping and resequencing reveal the association of a deletion in the complex interferon alpha gene cluster with hypothyroidism in dogs
- 2020
-
Ingår i: BMC Genomics. - : BMC. - 1471-2164. ; 21
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Hypothyroidism is a common complex endocrinopathy that typically has an autoimmune etiology, and it affects both humans and dogs. Genetic and environmental factors are both known to play important roles in the disease development. In this study, we sought to identify the genetic risk factors potentially involved in the susceptibility to the disease in the high-risk Giant Schnauzer dog breed.Results: By employing genome-wide association followed by fine-mapping (top variant p-value=5.7x10(-6)), integrated with whole-genome resequencing and copy number variation analysis, we detected a similar to 8.9 kbp deletion strongly associated (p-value=0.0001) with protection against development of hypothyroidism. The deletion is located between two predicted Interferon alpha (IFNA) genes and it may eliminate functional elements potentially involved in the transcriptional regulation of these genes. Remarkably, type I IFNs have been extensively associated to human autoimmune hypothyroidism and general autoimmunity. Nonetheless, the extreme genomic complexity of the associated region on CFA11 warrants further long-read sequencing and annotation efforts in order to ascribe functions to the identified deletion and to characterize the canine IFNA gene cluster in more detail.Conclusions: Our results expand the current knowledge on genetic determinants of canine hypothyroidism by revealing a significant link with the human counterpart disease, potentially translating into better diagnostic tools across species, and may contribute to improved canine breeding strategies.
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| 31. |
- Blücher, Anna, et al.
(författare)
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Substrate-dependent production and some properties of a thermostable, α-galactosidase from Rhodothermus marinus
- 2000
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Ingår i: Biotechnology Letters. - 0141-5492. ; 22:8, s. 663-669
-
Tidskriftsartikel (refereegranskat)abstract
- α-Galactosidase activity in Rhodothermus marinus is dependent on the composition of the growth media. A maximum of 46 μU g-1 cell dry weight was obtained using minimal medium with galactooligo- or polysaccharides as single carbon source. An enzyme hydrolysing both high and low molecular weight galacto-saccharides was partly purified from the cell fractions. The molecular weight was 200 kDa (native) and 50 kDa (monomer). It was optimally active at 85°C, with a half-life of 2 h at 75°C, and had a broad pH range (4-8).
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| 32. |
- Bojmar, Linda, et al.
(författare)
-
miR-18a is regulated between progressive compartments of cancers, and incorporated in exosomes with the potential of creating premetastatic niches and predict cancer outcome
- 2015
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The ultimate cause of death for many cancer patients is the spread of the cancer via metastasis. Even so, there are still a lack of knowledge regarding the metastasis process. This study was performed to investigate the role of metastamirs in exosomes and their metastatic patterns. We used the well-established isogeneic murine cancer model of low metastatic 67NR cells, mimicking luminal/basal breast tumors, and highly metastatic 4T1 cells with characteristics of basal breast tumors. We studied the exosomal properties and pre-metastatic effects in this metastasis model and compared human materials and exosomes of several other tumor types. Our data clearly demonstrated that exosomes from the highly metastatic cells home to the metastatic organs of their parental cells whereas exosomes from cells with low metastatic potential mostly located to lymph nodes. The exosome protein cargos also resembled their parental cells and potentially affects their target organs, and cells, differently. Furthermore, the exosomes from the highly metastatic cells had a more pronounced effect on tumor growth and pre-metastatic changes than the low metastatic exosomes. The microRNA-18a, a predictor of metastasis, was present to a higher extent in metastatic exosomes as compared to low metastatic exosomes, and altered the tumor progressive properties. Our findings support the role of exomirs as important players in the metastatic process, the value as biomarkers and potential therapeutic targets.
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| 33. |
- Bojmar, Linda, et al.
(författare)
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The Role of MicroRNA-200 in Progression of Human Colorectal and Breast Cancer
- 2013
-
Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 8:12, s. 84815-
-
Tidskriftsartikel (refereegranskat)abstract
- The role of the epithelial-mesenchymal transition (EMT) in cancer has been studied extensively in vitro, but involvement of the EMT in tumorigenesis in vivo is largely unknown. We investigated the potential of microRNAs as clinical markers and analyzed participation of the EMT-associated microRNA-200 ZEB E-cadherin pathway in cancer progression. Expression of the microRNA-200 family was quantified by real-time RT-PCR analysis of fresh-frozen and microdissected formalin-fixed paraffin-embedded primary colorectal tumors, normal colon mucosa, and matched liver metastases. MicroRNA expression was validated by in situ hybridization and after in vitro culture of the malignant cells. To assess EMT as a predictive marker, factors considered relevant in colorectal cancer were investigated in 98 primary breast tumors from a treatment-randomized study. Associations between the studied EMTmarkers were found in primary breast tumors and in colorectal liver metastases. MicroRNA-200 expression in epithelial cells was lower in malignant mucosa than in normal mucosa, and was also decreased in metastatic compared to non-metastatic colorectal cancer. Low microRNA-200 expression in colorectal liver metastases was associated with bad prognosis. In breast cancer, low levels of microRNA-200 were related to reduced survival and high expression of microRNA-200 was predictive of benefit from radiotheraphy. MicroRNA-200 was associated with ER positive status, and inversely correlated to HER2 and overactivation of the PI3K/AKT pathway, that was associated with high ZEB1 mRNA expression. Our findings suggest that the stability of microRNAs makes them suitable as clinical markers and that the EMT-related microRNA-200 - ZEB - E-cadherin signaling pathway is connected to established clinical characteristics and can give useful prognostic and treatment-predictive information in progressive breast and colorectal cancers.
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| 34. |
- Bostner, Josefine, et al.
(författare)
-
Activation of Akt, mTOR, and the estrogen receptor as a signature to predict tamoxifen treatment benefit
- 2013
-
Ingår i: Breast Cancer Research and Treatment. - : Springer Verlag (Germany). - 0167-6806 .- 1573-7217. ; 137:2, s. 397-406
-
Tidskriftsartikel (refereegranskat)abstract
- The frequent alterations of the PI3K/Akt/mTOR-growth signaling pathway are proposed mechanisms for resistance to endocrine therapy in breast cancer, partly through regulation of estrogen receptor alpha (ER) activity. Reliable biomarkers for treatment prediction are required for improved individualized treatment. We performed a retrospective immunohistochemical analysis of primary tumors from 912 postmenopausal patients with node-negative breast cancer, randomized to either tamoxifen or no adjuvant treatment. Phosphorylated (p) Akt-serine (s) 473, p-mTOR-s2448, and ER phosphorylations-s167 and -s305 were evaluated as potential biomarkers of prognosis and tamoxifen treatment efficacy. High expression of p-mTOR indicated a reduced response to tamoxifen, most pronounced in the ER+/progesterone receptor (PgR) + subgroup (tamoxifen vs. no tamoxifen: hazard ratio (HR), 0.86; 95 % confidence interval (CI), 0.31-2.38; P = 0.78), whereas low p-mTOR expression predicted tamoxifen benefit (HR, 0.29; 95 % CI, 0.18-0.49; P = 0.000002). In addition, nuclear p-Akt-s473 as well as p-ER at -s167 and/or -s305 showed interaction with tamoxifen efficacy with borderline statistical significance. A combination score of positive pathway markers including p-Akt, p-mTOR, and p-ER showed significant association with tamoxifen benefit (test for interaction; P = 0.029). Cross-talk between growth signaling pathways and ER-signaling has been proposed to affect tamoxifen response in hormone receptor-positive breast cancer. The results support this hypothesis, as an overactive pathway was significantly associated with reduced response to tamoxifen. A clinical pre-treatment test for cross-talk markers would be a step toward individualized adjuvant endocrine treatment with or without the addition of PI3K/Akt/mTOR pathway inhibitors.
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| 35. |
- Bostner, Josefine, et al.
(författare)
-
S6 kinase signaling and tamoxifen response in breast cancer cells and in two randomized breast cancer cohorts
- 2013
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Detecting signals in the mammalian target of rapamycin (mTOR), and the estrogen receptor (ER) pathways for prediction of treatment response may be a future clinical tool in primary breast cancer. Here, we investigated the validity and value of the mTOR targets p70-S6 kinase (S6K) 1 and 2 as biomarkers for tamoxifen sensitivity in vitro and in two independent tamoxifen randomized postmenopausal breast cancer cohorts. In addition, the prognostic value of the S6Ks was evaluated. A simultaneous knockdown of the S6Ks in ER-positive breast cancer cells resulted in G1 arrest, and tamoxifen-induced G1 arrest was in part S6K1+S6K2 dependent, suggesting separate roles in proliferation and in tamoxifen response. We found S6K1 to correlate with HER2 and cytoplasmic Akt activity, whereas S6K2 and phosphorylated S6K were closer connected with ER positivity, low proliferation and nucleic p-Akt. Treatment prediction and prognosis were evaluated by immunohistochemical staining. Nuclear accumulation of S6K1 was indicative of a reduced tamoxifen treatment effect, compared with a significant benefit from tamoxifen treatment in patients without tumor S6K1 nuclear accumulation. Patients with a combination of S6K1 nuclear accumulation and S6K2 cytoplasmic accumulation in the tumor cells had no tamoxifen benefit. Also, S6K1 and S6K2 activation, indicated by p-S6K-t389 expression, was associated with low benefit from tamoxifen compared with untreated patients. In addition, high protein expression of S6K1, independent of localization, predicted worse prognosis. This was not evident for variations in S6K2 or p-S6K-t389 expression.In conclusion, the mTOR targeted kinases S6K1 and S6K2 interfere with proliferation and response to tamoxifen. Monitoring their activity andintracellular localization may provide biomarkers for breast cancer treatment, allowing for identification of a group of patients less likely tobenefit from tamoxifen and thus in need of an alternative or additional treatment.
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| 36. |
- Bostner, Josefine, et al.
(författare)
-
S6 kinase signaling: tamoxifen response and prognostic indication in two breast cancer cohorts
- 2015
-
Ingår i: Endocrine-Related Cancer. - : BioScientifica. - 1351-0088 .- 1479-6821. ; 22:3, s. 331-343
-
Tidskriftsartikel (refereegranskat)abstract
- Detection of signals in the mammalian target of rapamycin (mTOR) and the estrogen receptor (ER) pathways may be a future clinical tool for the prediction of adjuvant treatment response in primary breast cancer. Using immunohistological staining, we investigated the value of the mTOR targets p70-S6 kinase (S6K) 1 and 2 as biomarkers for tamoxifen benefit in two independent clinical trials comparing adjuvant tamoxifen with no tamoxifen or 5 years versus 2 years of tamoxifen treatment. In addition, the prognostic value of the S6Ks was evaluated. We found that S6K1 correlated with proliferation, HER2 status, and cytoplasmic AKT activity, whereas high protein expression levels of S6K2 and phosphorylated (p) S6K were more common in ER-positive, and low-proliferative tumors with pAKT-s473 localized to the nucelus. Nuclear accumulation of S6K1 was indicative of a reduced tamoxifen effect (hazard ratio (HR): 1.07, 95% CI: 0.53-2.81, P=0.84), compared with a significant benefit from tamoxifen treatment in patients without tumor S6K1 nuclear accumulation (HR: 0.42, 95% CI: 0.29-0.62, Pless than0.00001). Also S6K1 and S6K2 activation, indicated by pS6K-t389 expression, was associated with low benefit from tamoxifen (HR: 0.97, 95% CI: 0.50-1.87, P=0.92). In addition, high protein expression of S6K1, independent of localization, predicted worse prognosis in a multivariate analysis, P=0.00041 (cytoplasm), P=0.016 (nucleus). In conclusion, the mTOR-activated kinases S6K1 and S6K2 interfere with proliferation and response to tamoxifen. Monitoring their activity and intracellular localization may provide biomarkers for breast cancer treatment, allowing the identification of a group of patients less likely to benefit from tamoxifen and thus in need of an alternative or additional targeted treatment.
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| 37. |
- Brault, Emily K., et al.
(författare)
-
Trophic position and foraging ecology of Ross, Weddell, and crabeater seals revealed by compound-specific isotope analysis
- 2019
-
Ingår i: Marine Ecology Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 611, s. 1-18
-
Tidskriftsartikel (refereegranskat)abstract
- © The authors 2019. Ross seals Ommatophoca rossii are one of the least studied marine mammals, with little known about their foraging ecology. Research to date using bulk stable isotope analysis suggests that Ross seals have a trophic position intermediate between that of Weddell Leptonychotes weddellii and crabeater Lobodon carcinophaga seals. However, consumer bulk stable isotope values not only reflect trophic dynamics, but also variations in baseline isotope values, which can be substantial. We used compound-specific isotope analysis of amino acids (CSI-AA) to separate isotopic effects of a shifting baseline versus trophic structure on the foraging ecology of these ecologically important Antarctic pinnipeds. We found that Ross seals forage in an open ocean food web, while crabeater and Weddell seals forage within similar food webs closer to shore. However, isotopic evidence suggests that crabeater seals are likely following sea ice, while Weddell seals target productive areas of the continental shelf of West Antarctica. Our CSI-AA data indicate that Ross seals have a high trophic position equivalent to that of Weddell seals, contrary to prior conclusions from nitrogen isotope results on bulk tissues. CSI-AA indicates that crabeater seals are at a trophic position lower than that of Ross and Weddell seals, consistent with a krill-dominated diet. Our results redefine the view of the trophic dynamics and foraging ecology of the Ross seal, and also highlight the importance of quantifying baseline isotope variations in foraging studies.
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| 38. |
- Bredberg, Katarina, et al.
(författare)
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Reduction of vanadium(V) with Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans
- 2004
-
Ingår i: Bioresource Technology. - : Elsevier BV. - 1873-2976 .- 0960-8524. ; 92:1, s. 93-96
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Tidskriftsartikel (refereegranskat)abstract
- Biotechnological leaching has been proposed as a suitable method for extraction of vanadium from spent catalysts and oil ash. In the biological leaching process, the vanadium(V) can be reduced to vanadium(IV), which is a less toxic and more soluble form of the vanadium. The present investigation showed that Acidithiobacillus ferrooxidans efficiently reduced vanadium(V) in the form of vanadium pentaoxide, to vanadyl(IV) ions, and tolerated high concentrations of vanadium(IV) and vanadium(V). A. ferrooxidans was compared with Acidithiobacillus thiooxidans, which has previously been utilized for vanadium leaching and reduction. Vanadium pentaoxide and sodium vanadate were used as model compounds. The results of this study indicate possibilities to develop an economical and technically feasible process for biotechnological vanadium recovery. (C) 2003 Elsevier Ltd. All rights reserved.
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| 39. |
- Bro-Jørgensen, Maiken Hemme, 1990-
(författare)
-
Ancient genomics of Baltic seals : Insights on the past Baltic grey seal and harp seal populations
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis aims to study and describe the ancient populations of grey and harp seals in the Baltic Sea, and to present new methodological approaches for general use in ancient DNA studies.The dissertation is comprised of five studies: a review of the use of paleogenetics in studying ancient human-marine mammal interactions; a method paper investigating patterns of DNA preservation in ancient pinniped samples; a method paper presenting a genetic sex identification method for ancient pinnipeds; a population genomic study of the Baltic grey seal; and a population genomic study of the now extinct Baltic harp seal.Guidelines for ancient DNA sample selections were deduced from broad-scale statistical modelling of factors influencing DNA preservation in pinniped bones, the most significant of which included type of bone element, collagen content, and whether the bone derive from a cave context. Modern ringed seal samples with known sex were used to test an alternative pinniped sex identification method using the annotated dog genome as a reference for quantification of the relative representation of X chromosome reads. Reliable sex identification was shown to require a minimum of 5,000 total reads mapped to the reference genome. A total of 69 mitochondrial control regions were generated for Baltic grey seals, which revealed that the Mesolithic data largely represent extinct haplotypes, the main of which continued until the Early Neolithic. A population replacement prior to the early Bronze Age introduced mitochondrial variation resembling that of modern Baltic greys seals. The level of genetic differentiation between the Baltic harp seal population and the three contemporary breeding populations, suggests that the White Sea population is the most likely ancestor of the Baltic harp seal breeding population. An increase in genetic diversity, following a hiatus with no Baltic harp seals, combined with the measures of genetic differentiation from this period, further suggests that a second colonization likely occurred from the White Sea during the early Bronze Age.
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| 40. |
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| 41. |
- Bäcklin, Britt-Marie, 1957-, et al.
(författare)
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Sälpopulationer och sälhälsa
- 2016
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Ingår i: HAVET 2015/2016. - : Havsmiljöinstitutet. - 9789198229134 - 9789187967122 ; , s. 116-118
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 42. |
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| 43. |
- Calles, Olle, et al.
(författare)
-
Downstream passage of diadromous fish in Swedish rivers
- 2009
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Konferensbidrag (refereegranskat)abstract
- Downstream passage problems for diadromous fish are rarely addressed in regulated rivers in northern Europe. Some attempts to decrease the mortality among downstream moving fish are now tested in southern Sweden, ranging from the use of trash gates totesting of low-sloped fine-spaced racks. This presentation describes the efficiency of twosuch measures at hydroelectric facilities in the River Ätran. The targeted species were Atlantic salmon, anadromous brown trout and European eel. Smolt (N=66, 2007), kelt (N=20, 2007) and silver eels (N=170, 2007-2008) were radio-tagged and tracked inpassing the facilities.An open trash gate proved to have a very low efficiency for smolt (7%) and most individuals passed through the racks and turbines. The efficiency was intermediate for kelt (40%) and several individuals died on the trash racks or remained upstream until theend of the study. The route seeking time was limited for smolts, but substantial for kelts. Since no control groups were used the extent of the delays could not be quantified. The overall passage success was 50% for kelts and 85% for smolts, illustrating the need for a more efficient measure for kelts in particular.The passage for silvers eels of the two lower most hydroelectric plants (HEPs) in the River Ätran revealed a 28% passage success at HEP 2 (N=50), with a 23,5 m head and Francis turbines. The corresponding success for the control group released downstream ofthe HEP was 92% (N=50). The following year the old rack (20 mm / 43°) was replaced by a new rack (18 mm / 35°) with exits at the surface. With the new rack in place 80% of the eels released upstream were successfully diverted and caught, resulting in a totalsuccess of 90% (compared to 28% with the old rack). The success at HEP 1 was 76% (N=58), but no individuals entered the open trash gate. The success rate was somewhat uncertain because of the short distance to sea and the possibility for injured (but not dead) individuals to reach sea but not surviving in the long run
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| 44. |
- Calles, Olle, 1974-, et al.
(författare)
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Evaluating technical improvements for downstream migrating diadromous fish at a hydroelectric plant
- 2012
-
Ingår i: Ecological Engineering - The Journal of Ecosystem Restoration. - : Elsevier. - 0925-8574. ; 48, s. 30-37
-
Tidskriftsartikel (refereegranskat)abstract
- Technical improvements to ameliorate downstream passage for diadromous fish have rarely been eval-uated in regulated rivers in northern Europe. The current study evaluated rehabilitative measures for downstream migrating Atlantic salmon, brown trout and European eel at a hydroelectric plant in south-ern Sweden. Smolts (N= 66), kelts (N= 20) and silver eels (N= 55) were caught, radio-tagged and tracked whilst passing the facilities in spring (salmonids) and fall (eels) of 2007. A surface gate in combination with a 90 mm-spaced turbine intake rack had a fish guidance efficiency ranging from no effect for eels and trout smolts to 50% for trout kelts. A siphon discharging water from the bottom of the same 90 mm rack did not bypass any tagged fish, and only a few untagged eels. The poor function of the measures was attributed to the failure of the rack to stop smolts and eels from entering the turbines. The kelts, on the other hand, could not pass through the rack, and instead took a long time to locate the surface bypass entrance. The conditions for downstream migrating fish have improved at the hydroelectric plant, but the total losses remain quite high for the studied groups (10–67%), and there is a need for a new rehabilitative measure that effectively allows all fish to bypass the turbines.
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| 45. |
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| 46. |
- Calles, Olle, 1974-, et al.
(författare)
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Success of a low-sloping rack for improving downstream passage of silver eels at a hydroelectric plant
- 2013
-
Ingår i: Freshwater Biology. - : John Wiley & Sons. - 0046-5070 .- 1365-2427. ; 58, s. 2168-2179
-
Tidskriftsartikel (refereegranskat)abstract
- 1. The European eel (Anguilla anguilla) is a critically endangered species, and one major threat is thesurvival of silver eels migrating downstream towards the sea from lake and river rearing areas. Duringthis migration, many eels are impinged and die on intake racks, or are injured or killed whenpassing through turbines.2. Intake racks at a hydroelectric plant were modified to avoid impingement and to collect eels withoutinjury; high mortality on both racks and in turbines was previously documented. Modificationsconsisted of reducing the rack gap width from 20 to 18 mm, decreasing the rack slope from 63 to 35degrees, increasing the rack surface area by 58% and installing six openings in the rack leading totraps.3. Downstream passage conditions for silver eels at the hydroelectric plant were significantlyimproved, reducing mortality from >70% at the old steep 20 mm racks to <10% at the modified18 mm rack collection facility. No tagged eels were impinged and killed on the racks, and 80%entered the collection facility.4. Survival can probably be improved even more, as the individuals that passed the facility mostlikely escaped through holes in the traps. Moreover, injured untagged eels were still encountered atthe modified racks, illustrating the need for rehabilitative measures to be implemented at all obstaclesbetween the main eel rearing areas and the sea.
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| 47. |
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| 48. |
- Carlson, Annelie, 1969-, et al.
(författare)
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Energy use due to traffic and pavement maintenance : the cost effectiveness of reducing rolling resistance
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- There is a potential to reduce energy use of traffic by performing maintenance measures that lower the rolling resistance. However, the overall aim should be to decrease the total energy use in a life cycle perspective, including energy for both traffic and maintenance. When choosing maintenance alternative, it is also of importance to consider the costs involved. Pavement management is focused on keeping wide spread road networks in acceptable condition given certain budget constraints. Therefore, the economic constraints need to be addressed and in the case of choosing a maintenance alternative that reduces total energy, it also has to be cost-efficient in order for it to be performed. The main scope of the research presented in this report is to investigate how road management should act to reduce total energy use of roads, including traffic and maintenance induced energy use, while also taking cost efficiency and the aspect of uncertainty into consideration. The purpose is to enable a better consideration of the total energy used and maintenance cost when managing the road network. The objective is to derive a meaningful instrument for decision making situations such as when selecting and designing maintenance treatments, in which total energy use and maintenance cost is considered. A general method is developed and presented. A criterion, CR, has been identified for how to choose a pavement maintenance strategy in regards to cost and energy efficiency. A cost benefit analysis approach using Benefit to Cost Ratio, BCR, has been adopted. The study indicates that it is difficult to establish a simple rule of thumb. However, the CR-value may be a useful criterion in some circumstances and it is important to have guidelines as decision support where assessments are made of the road surface characteristics, total energy use and maintenance cost and where the different aspects are valued. This is especially important on an object level.
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| 49. |
- Chen, Tingjie, et al.
(författare)
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Effect of Refining on Physical Properties and Paper Strength of Pinus massoniana and China Fir Cellulose Fibers
- 2016
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Ingår i: BioResources. - : BioResources. - 1930-2126. ; 11:3, s. 7839-7848
-
Tidskriftsartikel (refereegranskat)abstract
- To obtain a suitable refining process for Pinus massoniana cellulose fibers (PMCF) and China fir cellulose fibers (CFCF), the effects of the beating gap and the pulp consistency on the physical properties and the morphology of the two cellulose fibers were investigated. The results showed that the physical properties of the PMCF and the CFCF were well affected by the beating gap and the pulp consistency. The CFCF showed a smaller weight-average length and width than that of the PMCF. The CFCF exhibited smaller weight-average length, width, and kink index than the PMCF. It is easy to get the high beating degree, indicating it is more easily to be refined. Additionally, the tensile index and burst index of PMCFP and CFCFP increased with increasing beating degree, while the tear index decreased. Compared to the CFCF, the paper made from PMCF had superior strength properties. Consequently, the PMCF was suitable for refining with a high pulp consistency and a medium beating gap, whereas the CFCF had a medium pulp consistency and a big beating gap.
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| 50. |
- Chen, Tingjie, et al.
(författare)
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Improving the Mechanical Properties of Ultra-Low Density Plant Fiber Composite (ULD_PFC) by Refining Treatment
- 2016
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Ingår i: BioResources. - : BioResources. - 1930-2126. ; 11:4, s. 8558-8569
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Tidskriftsartikel (refereegranskat)abstract
- To improve the mechanical properties of ultra-low density plant fiber composite (ULD_PFC), a suitable beating process to improve the fibrillation of cellulose fibers and maintain their length was investigated. The physical properties of cellulose fibers and papers, surface chemical bonds, and internal bond strength (IB) of ULD_PFCs were analyzed. The results showed that the beating degrees, degree of fibrillation, and fiber fines increased with the decreasing of beating gap, except for the fiber weight-average length, width, kink index, and curl index. The tensile index and burst index of paper showed an increasing trend with an increase in beating degree, while the tear index showed a decreasing trend. FTIR results showed that intermolecular and intramolecular hydrogen bonds in ULDF were broken. A suitable beating gap of 30 μm with a beating degree of 35 °SR was obtained. The corresponding IB was 50.9 kPa, which represented an increase of 73.1% over fibers with a beating degree of 13 °SR.
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