| 1. |
- Asghar, Naveed, et al.
(författare)
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Deep sequencing analysis of tick-borne encephalitis virus from questing ticks at natural foci reveals similarities between quasispecies pools of the virus
- 2017
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Ingår i: Journal of General Virology. - : The Microbiology Society. - 0022-1317 .- 1465-2099. ; 98:3, s. 413-421
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Tidskriftsartikel (refereegranskat)abstract
- Every year, tick-borne encephalitis virus (TBEV) causes severe central nervous system infection in 10 000 to 15 000 people in Europe and Asia. TBEV is maintained in the environment by an enzootic cycle that requires a tick vector and a vertebrate host, and the adaptation of TBEV to vertebrate and invertebrate environments is essential for TBEV persistence in nature. This adaptation is facilitated by the error-prone nature of the virus's RNA-dependent RNA polymerase, which generates genetically distinct virus variants called quasispecies. TBEV shows a focal geographical distribution pattern where each focus represents a TBEV hotspot. Here, we sequenced and characterized two TBEV genomes, JP-296 and JP-554, from questing Ixodes ricinus ticks at a TBEV focus in central Sweden. Phylogenetic analysis showed geographical clustering among the newly sequenced strains and three previously sequenced Scandinavian strains, Toro-2003, Saringe-2009 and Mandal-2009, which originated from the same ancestor. Among these five Scandinavian TBEV strains, only Mandal-2009 showed a large deletion within the 3' non-coding region (NCR), similar to the highly virulent TBEV strain Hypr. Deep sequencing of JP-296, JP-554 and Mandal-2009 revealed significantly high quasispecies diversity for JP-296 and JP-554, with intact 3' NCRs, compared to the low diversity in Mandal-2009, with a truncated 3' NCR. Single-nucleotide polymorphism analysis showed that 40% of the single-nucleotide polymorphisms were common between quasispecies populations of JP-296 and JP-554, indicating a putative mechanism for how TBEV persists and is maintained within its natural foci.
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| 2. |
- Bertrand, Yann, et al.
(författare)
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First Dating of a Recombination Event in Mammalian Tick-borne Flaviviruses
- 2012
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Ingår i: PLoS ONE. - San Francisco : Public Library of Science (PLoS). - 1932-6203. ; 7:2
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Tidskriftsartikel (refereegranskat)abstract
- The mammalian tick-borne flavivirus group (MTBFG) contains viruses associated with important human and animal diseases such as encephalitis and hemorrhagic fever. In contrast to mosquito-borne flaviviruses where recombination events are frequent, the evolutionary dynamic within the MTBFG was believed to be essentially clonal. This assumption was challenged with the recent report of several homologous recombinations within the Tick-borne encephalitis virus (TBEV). We performed a thorough analysis of publicly available genomes in this group and found no compelling evidence for the previously identified recombinations. However, our results show for the first time that demonstrable recombination (i.e., with large statistical support and strong phylogenetic evidences) has occurred in the MTBFG, more specifically within the Louping ill virus lineage. Putative parents, recombinant strains and breakpoints were further tested for statistical significance using phylogenetic methods. We investigated the time of divergence between the recombinant and parental strains in a Bayesian framework. The recombination was estimated to have occurred during a window of 282 to 76 years before the present. By unravelling the temporal setting of the event, we adduce hypotheses about the ecological conditions that could account for the observed recombination.
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| 3. |
- de Moor, Joost, et al.
(författare)
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Country reports: Sweden
- 2019
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Ingår i: Protest for a future. - Bryssel : Confederation Syndicat European Trade Union. ; , s. 19-31, s. 96-111
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 4. |
- Hamsten, C., et al.
(författare)
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Identification of galactose-α-1,3-galactose in the gastrointestinal tract of the tick Ixodes ricinus; possible relationship with red meat allergy
- 2013
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Ingår i: Allergy. European Journal of Allergy and Clinical Immunology. - West Sussex, United Kingdom : Wiley-Blackwell Publishing Inc.. - 0105-4538 .- 1398-9995. ; 68:4, s. 549-552
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Tidskriftsartikel (refereegranskat)abstract
- Patients with IgE antibodies against the carbohydrate epitope galactose-α-1,3-galactose (α-Gal) have reported severe allergic reactions after consumption of red meat. Investigations have revealed associations between IgE to α-Gal and tick bites. We provide the first direct evidence that α-Gal is present within ticks thus potentially explaining the relationship between tick exposure and sensitization to α-Gal, with development of red meat allergy as a secondary phenomena. Serum from Swedish patients with delayed severe reactions to red meat was included in the study. A dose-dependent inhibition of IgE responses to α-Gal by the tick Ixodes ricinus is demonstrated. Furthermore, using cryostat-cut sections of I. ricinus, we show that both a monoclonal and a polyclonal antibody against α-Gal stains the gastrointestinal tract of the tick. The same pattern is seen when staining with patient sera IgE positive to α-Gal. These results confirm that the α-Gal epitope is present in I. ricinus and imply host exposure to α-Gal during a tick bite. This provides further evidence that tick bites are associated with IgE responses to α-Gal and red meat allergy.
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| 5. |
- Johansson, J, et al.
(författare)
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Conformation-dependent antibacterial activity of the naturally occurring human peptide LL-37
- 1998
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Ingår i: Journal of Biological Chemistry. - : Elsevier BV. - 0021-9258 .- 1083-351X. ; 273:6, s. 3718-3724
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Tidskriftsartikel (refereegranskat)abstract
- The influence of ion composition, pH, and peptide concentration on the conformation and activity of the 37-residue human antibacterial peptide LL-37 has been studied. At micromolar concentration in water, LL-37 exhibits a circular dichroism spectrum consistent with a disordered structure. The addition of 15 mM HCO3-, SO42-, or CF3CO2- causes the peptide to adopt a helical structure, with approximately equal efficiency, while 160 mM Cl- is less efficient, A cooperative transition from disordered to helical structure is observed as the peptide concentration is increased, consistent with formation of an oligomer, The extent of alpha-helicity correlates with the antibacterial activity of LL-37 against both Gram-positive and Gram-negative bacteria. Two homologous peptides, FF-33 and SK-29, containing 4 and 8 residue deletions at the N terminus, respectively, require higher concentrations of anions for helix formation and are less active than LL 37 against Escherichia coli D21. Below pH 5, the helical content of LL-37 gradually decreases, and at pH 2 it is entirely disordered, In contrast, the helical structure is retained at pH over 13. The minimal inhibitory concentration of LL-37 against E. coli is 5 mu M, and at 13-25 mu M the peptide is cytotoxic against several eukaryotic cells, In solutions containing the ion compositions of plasma, intracellular fluid, or interstitial fluid, LL-37 is helical, and hence it could pose a danger to human cells upon release. However, in the presence of human serum, the antibacterial and the cytotoxic activities of LL-37 are inhibited.
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| 6. |
- Johansson, Johanna, 1983-, et al.
(författare)
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Coordinating and implementing multiple systems for forest management : implications of the regulatory framework for sustainable forestry in Sweden
- 2014
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Ingår i: Journal of Natural Resources Policy Research. - : Taylor & Francis. - 1939-0459 .- 1939-0467. ; 6:2-3, s. 117-133
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Tidskriftsartikel (refereegranskat)abstract
- The complexity of multi-level governance is well illustrated by forest management in one of Europe’s large forested states, Sweden. Deregulated government policies emphasise “freedom with responsibility,” largely expecting the forest sector to determine ways in which policy goals and legal requirements are reached. In relation to this, Sweden has become one of the countries with the largest share of forests certified by third-party organisations, such as the Forest Stewardship Council (FSC), in accordance with specific environmental and social criteria. This multi-level case study draws on official documents and semi-structured interviews to analyse Swedish forest governance; specifically, the impact of multiplicity and complexity of environmental considerations on agreement over goal coordination, implementation, and evaluation for feedback and accountability. This contributes to previous research by analysing interactions between state regulation and certification at multiple levels.
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| 7. |
- Keskitalo, E. Carina H., 1974-, et al.
(författare)
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Local consequences of applying international norms : differences in the application of forest certification in northern Sweden, northern Finland, and northwest Russia
- 2009
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Ingår i: Ecology and Society. - : Resilience Alliance Publications. - 1708-3087. ; 14:2, s. 1-
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Tidskriftsartikel (refereegranskat)abstract
- Forest certification, developed in the early 1990s, is a process in which independent assessors grant use of the certification label to producers who meet certain environmental and social criteria set for their forest products. This label was quickly seen to offer a market advantage and to signal corporate social and environmental responsibility. This paper focuses on international norms pertaining to environmental and indigenous rights, as manifested in cases of Forest Stewardship Council (FSC)- and Programme for the Endorsement of Forest Certification (PEFC)-compatible certification, and how these norms have been applied domestically and perceived locally in different states. Case studies are drawn from northern Sweden, northern Finland, and three regions in northwest Russia. The studies illustrate that the choice and implementation of certification type depend considerably on national infrastructure and market characteristics and result in substantial differences in the impact that international norms have at the local level.
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| 8. |
- Mårald, Erland, 1970-, et al.
(författare)
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Forest governance and management across time : developing a new forest social contract
- 2017
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Bok (refereegranskat)abstract
- The influence of the past, and of the future on current-time tradeoffs in the forest arena are particularly relevant given the long-term successions in forest landscapes and the hundred years' rotations in forestry. Historically established path dependencies and conflicts determine our present situation and delimit what is possible to achieve. Similarly, future trends and desires have a large influence on decision making. Nevertheless, decisions about forest governance and management are always made in the present – in the present-time appraisal of the developed situation, future alternatives and in negotiation between different perspectives, interests, and actors.This book explores historic and future outlooks as well as current tradeoffs and methods in forest governance and management. It emphasizes the generality and complexity with empirical data from Sweden and internationally. It first investigates, from a historical perspective, how previous forest policies and discourses have influenced current forest governance and management. Second, it considers methods to explore alternative forest futures and how the results from such investigations may influence the present. Third, it examines current methods of balancing tradeoffs in decision-making among ecosystem services. Based on the findings the authors develop an integrated approach – Reflexive Forestry – to support exchange of knowledge and understandings to enable capacity building and the establishment of common ground. Such societal agreements, or what the authors elaborate as forest social contracts, are sets of relational commitment between involved actors that may generate mutual action and a common directionality to meet contemporary challenges.
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| 9. |
- Olsson, Karin H., 1979, et al.
(författare)
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Dark eyes in female sand gobies indicate readiness to spawn
- 2017
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 12:6
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Tidskriftsartikel (refereegranskat)abstract
- In animals, colorful and conspicuous ornaments enhance individual attractiveness to potential mates, but are typically tempered by natural selection for crypsis and predator protection. In species where males compete for females, this can lead to highly ornamented males competing for mating opportunities with choosy females, and vice versa. However, even where males compete for mating opportunities, females may exhibit conspicuous displays. These female displays are often poorly understood and it may be unclear whether they declare mating intent, signal intrasexual aggression or form a target for male mate preference. We examined the function of the conspicuous dark eyes that female sand gobies temporarily display during courtship by experimentally testing if males preferred to associate with females with artificially darkened eyes and if dark eyes are displayed during female aggression. By observing interactions between a male and two females freely associating in an aquarium we also investigated in which context females naturally displayed dark eyes. We found that dark eyes were more likely to be displayed by more gravid females than less gravid females and possibly ahead of spawning, but that males did not respond behaviorally to dark eyes or prefer dark-eyed females. Females behaving aggressively did not display dark eyes. We suggest that dark eyes are not a signal per se but may be an aspect of female mate choice, possibly related to vision.
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| 10. |
- Sagemark, Johan, et al.
(författare)
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Redox properties and evolution of human glutaredoxins
- 2007
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Ingår i: Proteins. - : Wiley. - 0887-3585 .- 1097-0134. ; 68:4, s. 879-892
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Tidskriftsartikel (refereegranskat)abstract
- Glutaredoxins (Grxs) are glutathione-dependent oxidoreductases that belong to the thioredoxin superfamily catalyzing thiol-disulfide exchange reactions via active site cysteine residues. Focusing on the human dithiol glutaredoxins having a C-X-Y-C active site sequence motif, the redox potentials of hGrxl and hGrx2 were determined to be -232 and -221 mV, respectively, using a combination of redox buffers, protein-protein equilibrium and thermodynamic linkage. In addition, a nonactive site disulfide was identified between Cys28 and Cys.113 in hGrx2 using redox buffers and chemical digestion. This disulfide confers nearly five kcal mol-1 additional stability by linking the C-terminal helix to the bulk of the protein. The redox potential of this nonactive site disulfide was determined to be -317 mVand is thus expected to be present in all but the most reducing conditions in vivo. As all human glutaredoxins contain additional nonactive site cysteine residues, a full phylogenetic analysis was performed to help elucidate their structural and functional roles. Three distinct groups were found: Grx1, Grx2, and Grx5, the latter representing a highly conserved group of monothiol glutaredoxins having a C-G-F-S active site sequence, with clear homologs from bacteria to human. Grx1 and Grx2 diverged from a common ancestor before the origin vertebrates, possibly even earlier in animal evolution. The highly stabilizing nonactive site disulfide observed in hGrx2 is found to be a conserved feature within the deuterostomes and appears to be the only additional conserved intramolecular disulfide within the glutaredoxins.
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