| 1. |
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- 2019
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Journal article (peer-reviewed)
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| 2. |
- Kehoe, Laura, et al.
(author)
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Make EU trade with Brazil sustainable
- 2019
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In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 364:6438, s. 341-
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Journal article (other academic/artistic)
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| 3. |
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| 4. |
- Nilsson, Christer, et al.
(author)
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How do biota respond to additional physical restoration of restored streams?
- 2017
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In: Ecosystems (New York. Print). - : Springer. - 1432-9840 .- 1435-0629. ; 20:1, s. 144-162
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Journal article (peer-reviewed)abstract
- Restoration of channelized streams by returning coarse sediment from stream edges to the wetted channel has become a common practice in Sweden. Yet, restoration activities do not always result in the return of desired biota. This study evaluated a restoration project in the Vindel River in northern Sweden in which practitioners further increased channel complexity of previously restored stream reaches by placing very large boulders (> 1 m), trees (> 8 m), and salmonid spawning gravel from adjacent upland areas into the channels. One reach restored with basic methods and another with enhanced methods were selected in each of ten different tributaries to the main channel. Geomorphic and hydraulic complexity was enhanced but the chemical composition of riparian soils and the communities of riparian plants and fish did not exhibit any clear responses to the enhanced restoration measures during the first 5 years compared to reaches restored with basic restoration methods. The variation in the collected data was among streams instead of between types of restored reaches. We conclude that restoration is a disturbance in itself, that immigration potential varies across landscapes, and that biotic recovery processes in boreal river systems are slow. We suggest that enhanced restoration has to apply a catchment-scale approach accounting for connectivity and availability of source populations, and that low-intensity monitoring has to be performed over several decades to evaluate restoration outcomes.
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| 5. |
- Rosenfeld, Jordan, et al.
(author)
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Contrasting Landscape Influences on Sediment Supply and Stream Restoration Priorities in Northern Fennoscandia (Sweden and Finland) and Coastal British Columbia
- 2011
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In: Environmental Management. - : Springer Science and Business Media LLC. - 0364-152X .- 1432-1009. ; 47:1, s. 28-39
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Journal article (peer-reviewed)abstract
- Sediment size and supply exert a dominant control on channel structure. We review the role of sediment supply in channel structure, and how regional differences in sediment supply and landuse affect stream restoration priorities. We show how stream restoration goals are best understood within a common fluvial geomorphology framework defined by sediment supply, storage, and transport. Landuse impacts in geologically young landscapes with high sediment yields (e.g., coastal British Columbia) typically result in loss of instream wood and accelerated sediment inputs from bank erosion, logging roads, hillslopes and gullies. In contrast, northern Sweden and Finland are landscapes with naturally low sediment yields caused by low relief, resistant bedrock, and abundant mainstem lakes that act as sediment traps. Landuse impacts involved extensive channel narrowing, removal of obstructions, and bank armouring with boulders to facilitate timber floating, thereby reducing sediment supply from bank erosion while increasing export through higher channel velocities. These contrasting landuse impacts have pushed stream channels in opposite directions (aggradation versus degradation) within a phase-space defined by sediment transport and supply. Restoration in coastal British Columbia has focused on reducing sediment supply (through bank and hillslope stabilization) and restoring wood inputs. In contrast, restoration in northern Fennoscandia (Sweden and Finland) has focused on channel widening and removal of bank-armouring boulders to increase sediment supply and retention. These contrasting restoration priorities illustrate the consequences of divergent regional landuse impacts on sediment supply, and the utility of planning restoration activities within a mechanistic sediment supply-transport framework.
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| 6. |
- Thorlacius, Guðný Ella, et al.
(author)
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Genetic and clinical basis for two distinct subtypes of primary Sjögren's syndrome
- 2021
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In: Rheumatology. - : Oxford University Press. - 1462-0324 .- 1462-0332. ; 60:2, s. 837-848
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Journal article (peer-reviewed)abstract
- ObjectivesClinical presentation of primary Sjögren’s syndrome (pSS) varies considerably. A shortage of evidence-based objective markers hinders efficient drug development and most clinical trials have failed to reach primary endpoints.MethodsWe performed a multicentre study to identify patient subgroups based on clinical, immunological and genetic features. Targeted DNA sequencing of 1853 autoimmune-related loci was performed. After quality control, 918 patients with pSS, 1264 controls and 107 045 single nucleotide variants remained for analysis. Replication was performed in 177 patients with pSS and 7672 controls.ResultsWe found strong signals of association with pSS in the HLA region. Principal component analysis of clinical data distinguished two patient subgroups defined by the presence of SSA/SSB antibodies. We observed an unprecedented high risk of pSS for an association in the HLA-DQA1 locus of odds ratio 6.10 (95% CI: 4.93, 7.54, P=2.2×10−62) in the SSA/SSB-positive subgroup, while absent in the antibody negative group. Three independent signals within the MHC were observed. The two most significant variants in MHC class I and II respectively, identified patients with a higher risk of hypergammaglobulinaemia, leukopenia, anaemia, purpura, major salivary gland swelling and lymphadenopathy. Replication confirmed the association with both MHC class I and II signals confined to SSA/SSB antibody positive pSS.ConclusionTwo subgroups of patients with pSS with distinct clinical manifestations can be defined by the presence or absence of SSA/SSB antibodies and genetic markers in the HLA locus. These subgroups should be considered in clinical follow-up, drug development and trial outcomes, for the benefit of both subgroups.
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| 7. |
- Birkeland, Shanda R., et al.
(author)
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Transcriptome analyses of the Giardia lamblia life cycle
- 2010
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In: Molecular and biochemical parasitology (Print). - : Elsevier BV. - 0166-6851 .- 1872-9428. ; 174:1, s. 62-65
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Journal article (peer-reviewed)abstract
- We quantified mRNA abundance from 10 stages in the Giardia lamblia life cycle in vitro using Serial Analysis of Gene Expression (SAGE). 163 abundant transcripts were expressed constitutively. 71 transcripts were upregulated specifically during excystation and 42 during encystation. Nonetheless, the transcriptomes of cysts and trophozoites showed major differences. SAGE detected co-expressed clusters of 284 transcripts differentially expressed in cysts and excyzoites and 287 transcripts in vegetative trophozoites and encysting cells. All clusters included known genes and pathways as well as proteins unique to Giardia or diplomonads. SAGE analysis of the Giardia life cycle identified a number of kinases, phosphatases, and DNA replication proteins involved in excystation and encystation, which could be important for examining the roles of cell signaling in giardial differentiation. Overall, these data pave the way for directed gene discovery and a better understanding of the biology of G. lamblia.
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| 8. |
- Chio, Iok In Christine, et al.
(author)
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NRF2 Promotes Tumor Maintenance by Modulating mRNA Translation in Pancreatic Cancer
- 2016
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In: Cell. - : Elsevier BV. - 0092-8674 .- 1097-4172. ; 166:4, s. 936-976
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Journal article (peer-reviewed)abstract
- Pancreatic cancer is a deadly malignancy that lacks effective therapeutics. We previously reported that oncogenic Kras induced the redox master regulator Nfe2l2/Nrf2 to stimulate pancreatic and lung cancer initiation. Here, we show that NRF2 is necessary to maintain pancreatic cancer proliferation by regulating mRNA translation. Specifically, loss of NRF2 led to defects in autocrine epidermal growth factor receptor (EGFR) signaling and oxidation of specific translational regulatory proteins, resulting in impaired cap-dependent and cap-independent mRNA translation in pancreatic cancer cells. Combined targeting of the EGFR effector AKT and the glutathione antioxidant pathway mimicked Nrf2 ablation to potently inhibit pancreatic cancer ex vivo and in vivo, representing a promising synthetic lethal strategy for treating the disease.
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| 9. |
- Davids, Barbara J., et al.
(author)
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Polymeric immunoglobulin receptor in intestinal immune defense against the lumen-dwelling protozoan parasite Giardia
- 2006
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In: Journal of Immunology. - 0022-1767 .- 1550-6606. ; 177:9, s. 6281-6290
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Journal article (peer-reviewed)abstract
- The polymeric Ig receptor (pIgR) is conserved in mammals and has an avian homologue, suggesting evolutionarily important functions in vertebrates. It transports multimeric IgA and IgM across polarized epithelia and is highly expressed in the intestine, yet little direct evidence exists for its importance in defense against common enteric pathogens. In this study, we demonstrate that pIgR can play a critical role in intestinal defense against the lumen-dwelling protozoan parasite Giardia, a leading cause of diarrheal disease. The receptor was essential for the eradication of Giardia when high luminal IgA levels were required. Clearance of Giardia muris, in which IgA plays a dominant role, was severely compromised in pIgR-deficient mice despite significant fecal IgA output at 10% of normal levels. In contrast, eradication of the human strain Giardia lamblia GS/M, for which adaptive immunity is less IgA dependent in mice, was unaffected by pIgR deficiency, indicating that pIgR had no physiologic role when lower luminal IgA levels were sufficient for parasite elimination. Immune IgA was greatly increased in the serum of pIgR-deficient mice, conferred passive protection against Giardia, and recognized several conserved giardial Ags, including ornithine carbamoyltransferase, arginine deiminase, alpha-enolase, and alpha- and beta-giardins, that are also detected in human giardiasis. Corroborative observations were made in mice lacking the J chain, which is required for pIgR-dependent transepithelial IgA transport. These results, together with prior data on pIgR-mediated immune neutralization of luminal cholera toxin, suggest that pIgR is essential in intestinal defense against pathogenic microbes with high-level and persistent luminal presence.
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| 10. |
- Dawkins, Elena, et al.
(author)
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The Swedish footprint : A multi-model comparison
- 2019
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In: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 209, s. 1578-1592
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Journal article (peer-reviewed)abstract
- Sweden has a large per capita carbon footprint, particularly compared to the levels recommended for maintaining a stable climate. Much of that footprint falls outside Sweden's territory; emissions occurring abroad are "embodied" in imported goods consumed in Sweden. In this study we calculate the total amount and geographical hotspots of the Swedish footprint produced by different multi-regional input-output (MRIO) models, and compare these results in order to gain a picture of the present state of knowledge of the Swedish global footprint. We also look for insights for future model development that can be gained from such comparisons. We first compare a time series of the Swedish carbon footprint calculated by the Swedish national statistics agency, Statistics Sweden, using a single-region model, with data from the EXIOBASE, GTAP, OECD, Eora, and WIOD MRIO databases. We then examine the MRIO results to investigate the geographical distribution of four types of Swedish footprint: carbon dioxide, greenhouse gas emissions, water use and materials use. We identify the hotspot countries and regions where environmental pressures linked to Swedish consumption are highest. We also consider why the results may differ between calculation methods and types of environmental pressure. As might be expected, given the complexity and modelling assumptions, the MRIO models and Statistics Sweden data provide different (but similar) results for each footprint. The MRIO models have different strengths that can be used to improve the national calculations. However, constructing and maintaining a new MRIO model would be very demanding for one country. It is also clear that for a single country's calculation, there will be better and more precise data available nationally that would not have priority in the construction of an MRIO model. Thus, combining existing MRIO data with national economic and environmental data seems to be a promising method for integrated footprint analysis. Our findings are relevant not just for Sweden but for other countries seeking to improve national consumption-based accounts. Based on our analysis we offer recommendations to guide future research and policy making to this end.
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| 11. |
- Dietze, Michael, et al.
(author)
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A seismic monitoring approach to detect and quantify river sediment mobilization by steelhead redd-building activity
- 2020
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In: Earth Surface Processes and Landforms. - : John Wiley & Sons. - 0197-9337 .- 1096-9837. ; 45:12, s. 2840-2849
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Journal article (peer-reviewed)abstract
- The role of spawning salmonids in altering river bed morphology and sediment transport is significant, yet poorly understood. This is due, in large part, to limitations in monitoring the redd‐building process in a continuous and spatially extended way. A complementary approach may be provided through the use of a small seismic sensor network analysing the ground motion signals generated by the agitation of sediment during the redd‐building process. We successfully tested the viability of this approach by detecting and locating artificially generated redd signals in a reach of the Mashel River, Washington State, USA. We then utilize records of 17 seismic stations, in which we automatically detected seismic events that were subsequently manually checked, yielding a catalogue of 45 potential redd‐building events. Such redd‐building events typically lasted between 1 and 20 min and consisted of a series of clusters of 50–100 short energetic pulses in the 20–60 Hz frequency range. The majority (>90%) of these redd‐building events occurred within 11 days, predominantly during the early morning and late afternoon. The seismically derived locations of the signals were in agreement with independently mapped redds. Improved network geometry and installation conditions are required for more efficient detection, robust location and improved energetic insights into redd‐building processes in larger reaches. The passive and continuous nature of the seismic approach in detecting redds and describing fish behaviour provides a novel tool for fish biologists and fisheries managers, but also for fluvial geomorphologists, interested in quantifying the amount of sediment mobilized by this ecosystem engineer. When complemented with classic approaches, it could allow for a more holistic picture of the kinetics and temporal patterns (at scales from seconds to multiple seasons) of a key phase of salmonid life cycles.
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| 12. |
- Engström, Johanna, 1981-, et al.
(author)
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Large wood restoration in boulder dominated streams
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Other publication (other academic/artistic)abstract
- 1. An important aim of many restoration activities is to improve ecological structures and processes that have a central role for ecosystem functioning. Large wood (LW) is such a component, affecting hydraulics, channel morphology, floodplain dynamics, and ecological communities.2. We studied the effect of in-stream wood restoration, evaluating the difference before and after wood addition using boulder restored sites as controls. We investigated channel dynamics, movement and recruitment of large wood, retention of propagules and fish communities.3. One of three streams experienced a reduced current velocity after LW placement. The width of the channel and the reduced velocity were probably the reasons why this stream trapped most naturally drifting wood. LW sites experienced increased retention of organic matter compared to control sites, but LW proved to be unimportant in controlling brown trout density and biomass.4. Restoring habitat heterogeneity has been widely used to enhance ecological functioning, but during the last years its potential to restore streams and rivers has been questioned. In streams affected by multiple stressors, increased habitat heterogeneity is less important. Our result demonstrates that restoration with wood can enhance the restoration made with only boulders, and as a consequence advance ecological functioning.
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| 13. |
- Ferella, Marcela, et al.
(author)
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Gene expression changes during Giardia-host cell interactions in serum-free medium
- 2014
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In: Molecular and biochemical parasitology (Print). - : Elsevier BV. - 0166-6851 .- 1872-9428. ; 197:1-2, s. 21-23
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Journal article (peer-reviewed)abstract
- Serial Analysis of Gene Expression (SAGE) was used to quantify transcriptional changes in Giardia intestinalis during its interaction with human intestinal epithelial cells (IECs, HT-29) in serum free M199 medium. Transcriptional changes were compared to those in trophozoites alone in M199 and in TYI-S-33 Giardia growth medium. In total, 90 genes were differentially expressed, mainly those involved in cellular redox homeostasis, metabolism and small molecule transport but also cysteine proteases and structural proteins of the giardin family. Only 29 genes changed their expression due to IEC interaction and the rest were due to M199 medium. Although our findings generated a small dataset, it was consistent with our earlier microarray studies performed under different interaction conditions. This study has confined the number of genes in Giardia to a small subset that specifically change their expression due to interaction with IECs.
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| 14. |
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| 15. |
- Franzen, Oscar, et al.
(author)
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Draft genome sequencing of Giardia intestinalis assemblage B isolate GS : is human giardiasis caused by two different species?
- 2009
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In: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 5:8, s. e1000560-
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Journal article (peer-reviewed)abstract
- Giardia intestinalis is a major cause of diarrheal disease worldwide and two major Giardia genotypes, assemblages A and B, infect humans. The genome of assemblage A parasite WB was recently sequenced, and the structurally compact 11.7 Mbp genome contains simplified basic cellular machineries and metabolism. We here performed 454 sequencing to 16 x coverage of the assemblage B isolate GS, the only Giardia isolate successfully used to experimentally infect animals and humans. The two genomes show 77% nucleotide and 78% amino-acid identity in protein coding regions. Comparative analysis identified 28 unique GS and 3 unique WB protein coding genes, and the variable surface protein (VSP) repertoires of the two isolates are completely different. The promoters of several enzymes involved in the synthesis of the cyst-wall lack binding sites for encystation-specific transcription factors in GS. Several synteny-breaks were detected and verified. The tetraploid GS genome shows higher levels of overall allelic sequence polymorphism (0.5 versus <0.01% in WB). The genomic differences between WB and GS may explain some of the observed biological and clinical differences between the two isolates, and it suggests that assemblage A and B Giardia can be two different species.
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| 16. |
- Fursatz, Marian, et al.
(author)
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Functionalization of bacterial cellulose wound dressings with the antimicrobial peptide ε-poly-L-Lysine
- 2018
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In: Biomedical Materials. - : Institute of Physics Publishing (IOPP). - 1748-6041 .- 1748-605X. ; 13
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Journal article (peer-reviewed)abstract
- Wound dressings based on bacterial cellulose (BC) can form a soft and conformable protective layer that can stimulate wound healing while preventing bacteria from entering the wound. Bacteria already present in the wound can, however, thrive in the moist environment created by the BC dressing which can aggravate the healing process. Possibilities to render the BC antimicrobial without affecting the beneficial structural and mechanical properties of the material would hence be highly attractive. Here we present methods for functionalization of BC with ε-Poly-L-Lysine (ε-PLL), a non-toxic biopolymer with broad-spectrum antimicrobial activity. Low molecular weight ε-PLL was cross-linked in pristine BC membranes and to carboxymethyl cellulose (CMC) functionalized BC using carbodiimide chemistry. The functionalization of BC with ε-PLL inhibited growth of S. epidermidis on the membranes but did not affect the cytocompatibility to cultured human fibroblasts as compared to native BC. The functionalization had no significant effects on the nanofibrous structure and mechanical properties of the BC. The possibility to functionalize BC with ε-PLL is a promising, green and versatile approach to improve the performance of BC in wound care and other biomedical applications.
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| 17. |
- Gennemark, Peter, et al.
(author)
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An oral antisense oligonucleotide for PCSK9 inhibition
- 2021
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In: Science Translational Medicine. - : AMER ASSOC ADVANCEMENT SCIENCE. - 1946-6234 .- 1946-6242. ; 13:593
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Journal article (peer-reviewed)abstract
- Inhibitors of proprotein convertase subtilisin/kexin type 9 (PCSK9) reduce low-density lipoprotein (LDL) cholesterol and are used for treatment of dyslipidemia. Current PCSK9 inhibitors are administered via subcutaneous injection. We present a highly potent, chemically modified PCSK9 antisense oligonucleotide (ASO) with potential for oral delivery. Past attempts at oral delivery using earlier-generation ASO chemistries and transient permeation enhancers provided encouraging data, suggesting that improving potency of the ASO could make oral delivery a reality. The constrained ethyl chemistry and liver targeting enabled by N-acetylgalactosamine conjugation make this ASO highly potent. A single subcutaneous dose of 90 mg reduced PCSK9 by >90% in humans with elevated LDL cholesterol and a monthly subcutaneous dose of around 25 mg is predicted to reduce PCSK9 by 80% at steady state. To investigate the feasibility of oral administration, the ASO was coformulated in a tablet with sodium caprate as permeation enhancer. Repeated oral daily dosing in dogs resulted in a bioavailability of 7% in the liver (target organ), about fivefold greater than the plasma bioavailability. Target engagement after oral administration was confirmed by intrajejunal administration of a rat-specific surrogate ASO in solution with the enhancer to rats and by plasma PCSK9 and LDL cholesterol lowering in cynomolgus monkey after tablet administration. On the basis of an assumption of 5% liver bioavailability after oral administration in humans, a daily dose of 15 mg is predicted to reduce circulating PCSK9 by 80% at steady state, supporting the development of the compound for oral administration to treat dyslipidemia.
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| 18. |
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| 19. |
- Gernandt, Otto, et al.
(author)
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Liquidity premia during the industrial breakthrough : evidence from the Stockholm Stock Exchange, 1901-1919
- 2012
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In: European Review of Economic History. - : Oxford University Press (OUP). - 1361-4916 .- 1474-0044. ; 16:3, s. 247-269
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Journal article (peer-reviewed)abstract
- This paper analyzes the importance of liquidity in determining security returns for firms listed on the Stockholm Stock Exchange between 1901 and 1919. Using a new and detailed firm-level data set with matching stock price and balance sheet information, we construct new stock return indices as well as firm-specific liquidity measures for our empirical analysis. Our main finding is that there was a substantial illiquidity effect on returns. Securities in the 25th percentile of the liquidity distribution earned, on average, a 0.59 percent higher monthly return than securities in the 75th percentile. This effect is comparable with estimates from modern stock markets and suggests that the liquidity premium is not solely a modern phenomenon but could be an inherent characteristic of financial markets.
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| 20. |
- Grünwald, Jan, et al.
(author)
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Ecological traits predict population trends of urban birds in Europe
- 2024
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In: Ecological Indicators. - 1470-160X. ; 160
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Journal article (peer-reviewed)abstract
- The population dynamics of urban animals has been so far remarkably understudied. At the same time, urban species’ population trends can provide important information on the consequences of environmental changes in cities. We modelled long-term population trends of 93 bird species breeding in urban areas in 16 European countries as a function of species’ traits, characterising variability in their urbanization and ecology. We found that: (i) earlier colonisers have more negative population trends than recent colonisers; (ii) more urbanized open habitat species had more positive population trends than less urbanized open habitat species; (iii) highly urbanized birds breeding above the ground had more negative trends than highly urbanized ground breeders. These patterns can be explained by several processes occurring in cities as well as outside city borders. Namely, (i) pre-industrial colonisers might struggle to persist in rapidly changing urban areas, limiting their foraging and breeding opportunities of the birds. (ii) Open habitats are under pressure of intensive agricultural exploitation in rural areas, which may negatively affect populations of less urbanized birds. In contrast, urban areas do not experience such pressure keeping the trends of urbanized open habitat species more positive. (iii) Differences in population trends between highly urbanized ground and above-ground breeders suggest that the latter may lose their breeding opportunities in modern buildings that do not provide suitable breeding sites. Our results indicate that even once successful, city dwellers may not keep pace with changes in urban areas, but these areas may also provide suitable habitats for biodiversity.
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| 21. |
- Helfield, James M, et al.
(author)
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Restoration of rivers used for timber floating : Effects on riparian plant diversity
- 2007
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In: Ecological Applications. - : Wiley. - 1051-0761. ; 17:3, s. 840-851
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Journal article (peer-reviewed)abstract
- Fluvial processes such as flooding and sediment deposition play a crucial role in structuring riparian plant communities. In rivers throughout the world, these processes have been altered by channelization and other anthropogenic stresses. Yet despite increasing awareness of the need to restore natural flow regimes for the preservation of riparian biodiversity, few studies have examined the effects of river restoration on riparian ecosystems. In this study, we examined the effects of restoration in the Ume River system, northern Sweden, where tributaries were channelized to facilitate timber floating in the 19th and early 20th centuries. Restoration at these sites involved the use of heavy machinery to replace instream boulders and remove floatway structures that had previously lined stream banks and cut off secondary channels. We compared riparian plant communities along channelized stream reaches with those along reaches that had been restored 3-10 years prior to observation. Species richness and evenness were significantly increased at restored sites, as were floodplain inundation frequencies. These findings demonstrate how river restoration and associated changes in fluvial disturbance regimes can enhance riparian biodiversity. Given that riparian ecosystems tend to support a disproportionate share of regional species pools, these findings have potentially broad implications for biodiversity conservation at regional or landscape scales.
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| 22. |
- Hellström, Gustav, et al.
(author)
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Effects of boulder addition on European grayling (Thymallus thymallus) in a channelized river in Sweden
- 2019
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In: Journal of Freshwater Ecology. - : Informa UK Limited. - 0270-5060 .- 2156-6941. ; 34, s. 559-573
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Journal article (peer-reviewed)abstract
- During the last century, the majority of Swedish rivers were heavily channelized to facilitate timber floating. This dramatically altered in-stream habitat by reducing the structural heterogeneity and increasing water velocity, which in turn had effects on the aquatic fauna. Today, extensive efforts to restore channelized rivers are being made by adding boulders to the streambed. In northern boreal rivers, evaluations of such restorations are often based on the response of trout and salmon populations. Few studies have investigated the effect on European grayling (Thymallus thymallus L), despite it being an important and vulnerable gamefish in both North America and Europe. This 6-year study investigated the effect of streambed restoration on grayling in a channelized, regulated (hydro-peaking) river in northern Sweden open to recreational fisheries. No effects on habitat preference, size, body condition, abundance or survival of grayling could be detected. The results are discussed based on grayling habitat preferences and behaviour, and give perspectives on streambed restoration in river conditions common to many Scandinavian grayling rivers today. The study is one of very few that presents multiyear abundance and survival estimates of grayling in a large boreal river.
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| 23. |
- Hellström, Gustav, et al.
(author)
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Restoring the Vindel River, Sweden for Atlantic Salmon and Brown Trout
- 2019
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In: From Catastrophe to Recovery: Stories of Fishery Management Success. - 9781934874554 ; , s. 125-156
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Book chapter (peer-reviewed)abstract
- The Vindel River (Vindelfilven), Sweden, is 450 km long with a mean annual discharge of 190 m3/s and runs through sparsely populated areas in northern Sweden, joining the Ume River near the Baltic Sea. A severe decline in Atlantic Salmon Salmo salar and Brown Trout S. trutta during the past century was caused by (1) intense timber-floating activities starting in the mid-1800s, which degraded stream habitat; (2) hydropower development in the early 1900s, which limited or blocked upstream migration; and (3) an expanded coastal/ocean fishery after 1950, which overharvested anadromous populations. Restoration efforts during the 1970s and 1980s failed due to low efficacy of stocking programs and insufficient habitat restoration. A legislative reform to unify the fishery right owners (FROs) along the river helped initiate restoration efforts in the late 1990s, focusing on improving fish migration past a hydropower station and restoring degraded habitat. Sweden's membership in the European Union made large funding for restoration projects possible. The number of returning Atlantic Salmon increased significantly after migration conditions improved around the hydropower station and with stricter regulations on the offshore fishery. Successful habitat restoration was based upon gaining trust from landowners and FROs via extensive communication to gain access to their land. Restoration work was adaptive and experiences gained were incorporated into restoration guidelines. Involvement of universities, as a provider of expertise and as an unbiased interpreter of data, provided support to legal processes and when evaluating restoration measures. During the course of the restoration work, managers learned that stocking often did not produce satisfactory results. By studying historical documents from the timber-floating era, managers learned that the scope of modifications of the tributaries had been much greater than previously thought and that habitat restoration needed to be extensive. In many tributaries, the number of juvenile Brown Trout increased significantly after habitat restoration, sometimes dramatically exceeding expectations, which made the managers question the validity of established production estimates for northern boreal streams. The experience and knowledge gained from the Vindel River restoration served as the catalyst for many other major restoration projects in rivers emptying into the Baltic Sea.
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| 24. |
- Ingason, Haukur, et al.
(author)
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The Metro Project : Final report
- 2012
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Reports (other academic/artistic)abstract
- This report compiles the results from the METRO project. The different parts of theproject – design fires, evacuation, integrated fire control, smoke control, extraordinarystrain onconstructions and fire- and rescue operations – are presented separately.The most complicated and expensive part of the project was the performance of thelarge scale fire and explosion tests in the Brunsberg tunnel, where the maximum heatrelease rates measured from the metro wagon was 77 MW.The main results from the project are new recommendations regarding design firesin mass transport systems, identification of key factors for fire and smoke spread in tunnelsand at stations as well as regarding the difficulties for disabled persons to evacuatefrom trains in tunnels, new recommended types of way guiding systems, safer design incase of explosions in trains and evaluation of the fire and rescue services’ possibilitiesand limitations in underground mass transport systems.
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| 25. |
- Ingason, Haukur, et al.
(author)
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The Metro Project: Final Report
- 2012
-
Reports (other academic/artistic)abstract
- The report compiles the results from the METRO-project. The different parts of the project; design fires, evacuation, integrated fire control, smoke control, extraordinary strain on constructions and fire- and rescue operations are presented separately. The most complicated and expensive part of the project was the performance of the large scale fire and explosion tests in the Brunsberg tunnel. The maximum heat release rates measured from the metro carriage was 77 MW. The maximum ceiling gas temperatures was 1118 °C. These values are high, and should be put into a perspective of the situation and the type of carriages used. The project is not recommending the highest values as the design fire, but values reflected in conditions. The egress study confirm that one of the major issues related to fire evacuation in underground transportation systems is that people often are reluctant to initiate an evacuation. New data show that participants moved with an average of 0.9 meters per second in the smoke filled environment (average visibility of 1.5–3.5 meters). A way-finding installation at the emergency exit, which consisted of a loudspeaker, was found to perform particularly well in terms of attracting people to the door. Two smoke control systems were simulated for a single exit metro station. The systems consisted of a pressurizing supply air system and mechanical exhaust ventilation system with and without platform screen doors. The results show that both the pressurizing supply air system and the mechanical exhaust air system provide effective smoke control for one exit metro station. The significance of the platform screen doors was shown to be important in relation to smoke control. Experiments and simulations have provided increased confidence in ability to simulate explosion scenarios to determine the pressure inside and outside a carriage and to be able to study variations of conditions such as carriage geometry and window designs. The explosion test performed show that an explosion with a relatively minor charge can significantly change the conditions for both evacuees and the rescue service. The results show that the conditions for evacuation and rescue operations can change dramatically as a result of a relatively minor explosion. Evaluation of methods and fire and rescue tactics in metros is given. Mapping of IR imaging as a tactical resource at tunnel fires was presented.
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| 26. |
- Jansson, Leif, et al.
(author)
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Pancreatic islet blood flow and its measurement
- 2016
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In: Upsala Journal of Medical Sciences. - : Uppsala Medical Society. - 0300-9734 .- 2000-1967. ; 121:2, s. 81-95
-
Research review (peer-reviewed)abstract
- Pancreatic islets are richly vascularized, and islet blood vessels are uniquely adapted to maintain and support the internal milieu of the islets favoring normal endocrine function. Islet blood flow is normally very high compared with that to the exocrine pancreas and is autonomously regulated through complex interactions between the nervous system, metabolites from insulin secreting beta-cells, endothelium derived mediators, and hormones. The islet blood flow is normally coupled to the needs for insulin release and is usually disturbed during glucose intolerance and overt diabetes. The present review provides a brief background on islet vascular function and especially focuses on available techniques to measure islet blood perfusion. The gold standard for islet blood flow measurements in experimental animals is the microsphere technique, and its advantages and disadvantages will be discussed. In humans there are still no methods to measure islet blood flow selectively, but new developments in radiological techniques hold great hopes for the future.
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| 27. |
- Laettig-Tuennemann, Gisela, et al.
(author)
-
Backbone rigidity and static presentation of guanidinium groups increases cellular uptake of arginine-rich cell-penetrating peptides
- 2011
-
In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 2, s. 453-
-
Journal article (peer-reviewed)abstract
- In addition to endocytosis-mediated cellular uptake, hydrophilic cell-penetrating peptides are able to traverse biological membranes in a non-endocytic mode termed transduction, resulting in immediate bioavailability. Here we analysed structural requirements for the non-endocytic uptake mode of arginine-rich cell-penetrating peptides, by a combination of live-cell microscopy, molecular dynamics simulations and analytical ultracentrifugation. We demonstrate that the transduction efficiency of arginine-rich peptides increases with higher peptide structural rigidity. Consequently, cyclic arginine-rich cell-penetrating peptides showed enhanced cellular uptake kinetics relative to their linear and more flexible counterpart. We propose that guanidinium groups are forced into maximally distant positions by cyclization. This orientation increases membrane contacts leading to enhanced cell penetration.
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| 28. |
- Larsson, Daniel, 1970, et al.
(author)
-
Göteborgs befolkningsutveckling före 1800-talet
- 2021
-
In: Göteborg genom tiderna : nedslag i stadens sociala och politiska historia / under redaktion av Jan Christensen, Per Cornell, Johannes Daun & Martin Linde.. - Göteborg : Daidalos. - 9789171736239 ; , s. 547-580
-
Book chapter (peer-reviewed)
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| 29. |
- Lauwaet, Tineke, et al.
(author)
-
Protein phosphatase 2A plays a crucial role in Giardia lamblia differentiation
- 2007
-
In: Molecular and biochemical parasitology (Print). - : Elsevier BV. - 0166-6851 .- 1872-9428. ; 152:1, s. 80-89
-
Journal article (peer-reviewed)abstract
- The ability of Giardia lamblia to undergo two distinct differentiations in response to physiologic stimuli is central to its pathogenesis. The giardial cytoskeleton changes drastically during encystation and excystation. However, the signal transduction pathways mediating these transformations are poorly understood. We tested the hypothesis that PP2A, a highly conserved serine/threonine protein phosphatase, might be important in giardial differentiation. We found that in vegetatively growing trophozoites, gPP2A-C protein localizes to basal bodies/centrosomes, and to cytoskeletal structures unique to Giardia: the ventral disk, and the dense rods of the anterior, posterior-lateral, and caudal flagella. During encystation, gPP2A-C protein disappears from only the anterior flagellar dense rods. During excystation, gPP2A-C localizes to the cyst wall in excysting cysts but is not found in the wall of cysts with emerging excyzoites. Transcriptome and immunoblot analyses indicated that gPP2A-C mRNA and protein are upregulated in mature cysts and during the early stage of excystation that models passage through the host stomach. Stable expression of gPP2A-C antisense RNA did not affect vegetative growth, but strongly inhibited the formation of encystation secretory vesicles (ESV) and water-resistant cysts. Moreover, the few cysts that formed were highly defective in excystation. Thus, gPP2A-C localizes to universal cytoskeletal structures and to structures unique to Giardia. It is also important for encystation and excystation, crucial giardial transformations that entail entry into and exit from dormancy.
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| 30. |
- Lind, Alexander, et al.
(author)
-
HLA high-resolution typing by next-generation sequencing in Pandemrix-induced narcolepsy
- 2019
-
In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 14:10, s. 1-13
-
Journal article (peer-reviewed)abstract
- The incidence of narcolepsy type 1 (NT1) increased in Sweden following the 2009-2010 mass-vaccination with the influenza Pandemrix-vaccine. NT1 has been associated with Human leukocyte antigen (HLA) DQB1*06:02 but full high-resolution HLA-typing of all loci in vaccine-induced NT1 remains to be done. Therefore, here we performed HLA typing by sequencing HLA-DRB3, DRB4, DRB5, DRB1, DQA1, DQB1, DPA1 and DPB1 in 31 vaccine-associated NT1 patients and 66 of their first-degree relatives (FDR), and compared these data to 636 Swedish general population controls (GP). Previously reported disease-related alleles in the HLA-DRB5*01:01:01-DRB1*15:01:01-DQA1*01:02:01-DQB1*06:02:01 extended haplotype were increased in NT1 patients (34/62 haplotypes, 54.8%) compared to GP (194/1272 haplotypes, 15.3%, p = 6.17E-16). Indeed, this extended haplotype was found in 30/31 patients (96.8%) and 178/636 GP (28.0%). In total, 15 alleles, four extended haplotypes, and six genotypes were found to be increased or decreased in frequency among NT1 patients compared to GP. Among subjects with the HLA-DRB5*01:01:01-DRB1*15:01:01-DQA1*01:02-DQB1*06:02 haplotype, a second DRB4*01:03:01-DRB1*04:01:01-DQA1*03:02//*03:03:01-DQB1*03:01:01 haplotype (p = 2.02E-2), but not homozygosity for DRB1*15:01:01-DQB1*06:02:01 (p = 7.49E-1) conferred association to NT1. Alleles with increased frequency in DQA1*01:02:01 (p = 1.07E-2) and DQA1*03:02//*03:03:01 (p = 3.26E-2), as well as with decreased frequency in DRB3*01:01:02 (p = 8.09E-3), DRB1*03:01:01 (p = 1.40E-2), and DQB1*02:01:01 (p = 1.40E-2) were found among patients compared to their FDR. High-resolution HLA sequencing in Pandemrix-associated NT1 confirmed the strong association with the DQB1*06:02:01-containing haplotype but also revealed an increased association to the not previously reported extended HLA-DRB4*01:03:01-DRB1*04:01:01-DQA1*03:02//*03:03:01-DQB1*03:01:01 haplotype. High-resolution HLA typing should prove useful in dissecting the immunological mechanisms of vaccination-associated NT1.
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| 31. |
- Lind, Alexander, et al.
(author)
-
Screening for autoantibody targets in post-vaccination narcolepsy using proteome arrays
- 2020
-
In: Scandinavian Journal of Immunology. - : Wiley. - 0300-9475 .- 1365-3083. ; 91:4
-
Journal article (peer-reviewed)abstract
- Narcolepsy type 1 (NT1) is a chronic sleep disorder caused by a specific loss of hypocretin‐producing neurons. The incidence of NT1 increased in Sweden, Finland and Norway following Pandemrix®‐vaccination, initiated to prevent the 2009 influenza pandemic. The pathogenesis of NT1 is poorly understood, and causal links to vaccination are yet to be clarified. The strong association with Human leukocyte antigen (HLA) DQB1*06:02 suggests an autoimmune pathogenesis, but proposed autoantigens remain controversial. We used a two‐step approach to identify autoantigens in patients that acquired NT1 after Pandemrix®‐vaccination. Using arrays of more than 9000 full‐length human proteins, we screened the sera of 10 patients and 24 healthy subjects for autoantibodies. Identified candidate antigens were expressed in vitro to enable validation studies with radiobinding assays (RBA). The validation cohort included NT1 patients (n = 39), their first‐degree relatives (FDR) (n = 66), population controls (n = 188), and disease controls representing multiple sclerosis (n = 100) and FDR to type 1 diabetes patients (n = 41). Reactivity towards previously suggested NT1 autoantigen candidates including Tribbles homolog 2, Prostaglandin D2 receptor, Hypocretin receptor 2 and α‐MSH/proopiomelanocortin was not replicated in the protein array screen. By comparing case to control signals, three novel candidate autoantigens were identified in the protein array screen; LOC401464, PARP3 and FAM63B. However, the RBA did not confirm elevated reactivity towards either of these proteins. In summary, three putative autoantigens in NT1 were identified by protein array screening. Autoantibodies against these candidates could not be verified with independent methods. Further studies are warranted to identify hypothetical autoantigens related to the pathogenesis of Pandemrix®‐induced NT1.
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| 32. |
- Losee, James, et al.
(author)
-
Anadromous trout from opposite sides of the globe: biology, ocean ecology, and management of anadromous brown and cutthroat trout
- 2024
-
In: Reviews in Fish Biology and Fisheries. - 0960-3166 .- 1573-5184. ; 34, s. 461-490
-
Journal article (peer-reviewed)abstract
- Anadromous brown trout (Salmo trutta) in the northeastern Atlantic Ocean, and coastal cutthroat trout (Oncorhynchus clarkii clarkii) in the northeastern Pacific Ocean, are analogs in many ways. Both species display similar patterns of complex life histories and behavioral flexibility, are iteroparous and facultatively anadromous and occupy nearshore coastal marine habitats where numerous populations often mix. These characteristics create specific challenges for management and conservation that have been complicated by inadequate scientific attention in some areas. Both species are declining across their native range, and their ecology make them particularly vulnerable to habitat destruction, fishing, and climate change. Here, we review the available literature to compare the biology, ocean ecology, and management practices of these two species. We highlight ecological similarities and differences between the species and identify current knowledge gaps suggesting future research needs and management actions. Using a comparative approach, the review aims to promote and facilitate knowledge exchange between anadromous trout research communities from opposite sides of the globe to improve management and conservation of these species and stimulate the production of management plans specific to anadromous trout.
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| 33. |
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| 34. |
- Luthander, Rasmus, et al.
(author)
-
Photovoltaic self-consumption in buildings : A review
- 2015
-
In: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 142, s. 80-94
-
Research review (peer-reviewed)abstract
- The interest in self-consumption of PV electricity from grid-connected residential systems is increasing among PV system owners and in the scientific community. Self-consumption can be defined as the share of the total PV production directly consumed by the PV system owner. With decreased subsidies for PV electricity in several countries, increased self-consumption could raise the profit of PV systems and lower the stress on the electricity distribution grid. This review paper summarizes existing research on PV self-consumption and options to improve it. Two options for increased self-consumption are included, namely energy storage and load management, also called demand side management (DSM). Most of the papers examine PV-battery systems, sometimes combined with DSM. The results show that it is possible to increase the relative self-consumption by 13-24% points with a battery storage capacity of 0.5-1. kW. h per installed kW PV power and between 2% and 15% points with DSM, both compared to the original rate of self-consumption. The total number of papers is however rather limited and further research and more comparative studies are needed to give a comprehensive view of the technologies and their potential. Behavioral responses to PV self-consumption and the impact on the distribution grid also need to be further studied.
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| 35. |
- Matsubara, Nami, et al.
(author)
-
Cation Distributions and Magnetic Properties of Ferrispinel MgFeMnO4
- 2020
-
In: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 59:24, s. 17970-17980
-
Journal article (peer-reviewed)abstract
- The crystal structure and magnetic properties of the cubic spinel MgFeMnO4 were studied by using a series of in-house techniques along with large-scale neutron diffraction and muon spin rotation spectroscopy in the temperature range between 1.5 and 500 K. The detailed crystal structure is successfully refined by using a cubic spinel structure described by the space group Fd3¯ m. Cations within tetrahedral A and octahedral B sites of the spinel were found to be in a disordered state. The extracted fractional site occupancies confirm the presence of antisite defects, which are of importance for the electrochemical performance of MgFeMnO4 and related battery materials. Neutron diffraction and muon spin spectroscopy reveal a ferrimagnetic order below TC = 394.2 K, having a collinear spin arrangement with antiparallel spins at the A and B sites, respectively. Our findings provide new and improved understanding of the fundamental properties of the ferrispinel materials and of their potential applications within future spintronics and battery devices.
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| 36. |
- Matsubara, Nami, et al.
(author)
-
Magnetism and ion diffusion in honeycomb layered oxide K 2Ni 2TeO 6
- 2020
-
In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 10:1
-
Journal article (peer-reviewed)abstract
- In the quest for developing novel and efficient batteries, a great interest has been raised for sustainable K-based honeycomb layer oxide materials, both for their application in energy devices as well as for their fundamental material properties. A key issue in the realization of efficient batteries based on such compounds, is to understand the K-ion diffusion mechanism. However, investigation of potassium-ion (K+) dynamics in materials using e.g. NMR and related techniques has so far been very challenging, due to its inherently weak nuclear magnetic moment, in contrast to other alkali ions such as lithium and sodium. Spin-polarised muons, having a high gyromagnetic ratio, make the muon spin rotation and relaxation (μ+SR) technique ideal for probing ions dynamics in these types of energy materials. Here we present a study of the low-temperature magnetic properties as well as K+ dynamics in honeycomb layered oxide material K 2Ni 2TeO 6 using mainly the μ+SR technique. Our low-temperature μ+SR results together with complementary magnetic susceptibility measurements find an antiferromagnetic transition at TN≈ 27 K. Further μ+SR studies performed at higher temperatures reveal that potassium ions (K+) become mobile above 200 K and the activation energy for the diffusion process is obtained as Ea= 121 (13) meV. This is the first time that K+ dynamics in potassium-based battery materials has been measured using μ+SR. Assisted by high-resolution neutron diffraction, the temperature dependence of the K-ion self diffusion constant is also extracted. Finally our results also reveal that K-ion diffusion occurs predominantly at the surface of the powder particles. This opens future possibilities for potentially improving ion diffusion as well as K-ion battery device performance using nano-structuring and surface coatings of the particles.
|
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| 37. |
- Matsubara, Nami, et al.
(author)
-
Magnetism and ion diffusion in honeycomb layered oxide K2Ni2TeO6
- 2020
-
In: Scientific Reports. - : Springer Nature. - 2045-2322. ; 10:1
-
Journal article (peer-reviewed)abstract
- In the quest for developing novel and efficient batteries, a great interest has been raised for sustainable K-based honeycomb layer oxide materials, both for their application in energy devices as well as for their fundamental material properties. A key issue in the realization of efficient batteries based on such compounds, is to understand the K-ion diffusion mechanism. However, investigation of potassium-ion (K+) dynamics in materials using e.g. NMR and related techniques has so far been very challenging, due to its inherently weak nuclear magnetic moment, in contrast to other alkali ions such as lithium and sodium. Spin-polarised muons, having a high gyromagnetic ratio, make the muon spin rotation and relaxation (mu+SR) technique ideal for probing ions dynamics in these types of energy materials. Here we present a study of the low-temperature magnetic properties as well as K+ dynamics in honeycomb layered oxide material K2Ni2TeO6 using mainly the mu+SR technique. Our low-temperature mu+SR results together with complementary magnetic susceptibility measurements find an antiferromagnetic transition at T-N approximate to 27 K. Further mu+SR studies performed at higher temperatures reveal that potassium ions (K+) become mobile above 200 K and the activation energy for the diffusion process is obtained as E-a = 121(13) meV. This is the first time that K+ dynamics in potassium-based battery materials has been measured using mu+SR. Assisted by high-resolution neutron diffraction, the temperature dependence of the K-ion self diffusion constant is also extracted. Finally our results also reveal that K-ion diffusion occurs predominantly at the surface of the powder particles. This opens future possibilities for potentially improving ion diffusion as well as K-ion battery device performance using nano-structuring and surface coatings of the particles.
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| 38. |
- Miniotaite, Ugne, et al.
(author)
-
Magnetic Properties of Multifunctional 7 LiFePO 4 under Hydrostatic Pressure
- 2023
-
In: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 2462:1
-
Conference paper (peer-reviewed)abstract
- LiFePO4 (LFPO) is an archetypical and well-known cathode material for rechargeable Li-ion batteries. However, its quasi-one-dimensional (Q1D) structure along with the Fe ions, LFPO also displays interesting low-temperature magnetic properties. Our team has previously utilized the muon spin rotation (μ +SR) technique to investigate both magnetic spin order as well as Li-ion diffusion in LFPO. In this initial study we extend our investigation and make use of high-pressure μ +SR to investigate effects on the low-T magnetic order. Contrary to theoretical predictions we find that the magnetic ordering temperature as well as the ordered magnetic moment increase at high pressure (compressive strain).
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| 39. |
- Miniotaite, Ugne, et al.
(author)
-
Magnetic Properties of Multifunctional (LiFePO4)-Li-7 under Hydrostatic Pressure
- 2023
-
In: Proceedings 15th International Conference on Muon Spin Rotation, Relaxation and Resonance (SR). - : IOP Publishing.
-
Conference paper (peer-reviewed)abstract
- LiFePO4 (LFPO) is an archetypical and well-known cathode material for rechargeable Li-ion batteries. However, its quasi-one-dimensional (Q1D) structure along with the Fe ions, LFPO also displays interesting low-temperature magnetic properties. Our team has previously utilized the muon spin rotation (mu+SR) technique to investigate both magnetic spin order as well as Li-ion diffusion in LFPO. In this initial study we extend our investigation and make use of high-pressure mu+SR to investigate effects on the low-T magnetic order. Contrary to theoretical predictions we find that the magnetic ordering temperature as well as the ordered magnetic moment increase at high pressure (compressive strain).
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| 40. |
- Morrison, Hilary G., et al.
(author)
-
Genomic minimalism in the early diverging intestinal parasite Giardia lamblia
- 2007
-
In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 317:5846, s. 1921-1926
-
Journal article (peer-reviewed)abstract
- The genome of the eukaryotic protist Giardia lamblia, an important human intestinal parasite, is compact in structure and content, contains few introns or mitochondrial relics, and has simplified machinery for DNA replication, transcription, RNA processing, and most metabolic pathways. Protein kinases comprise the single largest protein class and reflect Giardia's requirement for a complex signal transduction network for coordinating differentiation. Lateral gene transfer from bacterial and archaeal donors has shaped Giardia's genome, and previously unknown gene families, for example, cysteine-rich structural proteins, have been discovered. Unexpectedly, the genome shows little evidence of heterozygosity, supporting recent speculations that this organism is sexual. This genome sequence will not only be valuable for investigating the evolution of eukaryotes, but will also be applied to the search for new therapeutics for this parasite.
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| 41. |
- Nilsson, Christer, 1951-, et al.
(author)
-
Forecasting environmental responses to restoration of rivers used as log floatways : an interdisciplinary challenge
- 2005
-
In: Ecosystems (New York. Print). - : Springer Science and Business Media LLC. - 1432-9840 .- 1435-0629. ; 8:7, s. 779-800
-
Journal article (peer-reviewed)abstract
- Log floating in the 19th to mid 20th centuries has profoundly changed the environmental conditions in many northern river systems of the world. Regulation of flow by dams, straightening and narrowing of channels by various piers and wing dams, and homogenization of bed structure are some of the major impacts. As a result, the conditions for many riverine organisms have been altered. Removing physical constructions and returning boulders to the channels can potentially restore conditions for these organisms. Here we describe the history of log driving, review its impact on physical and biological conditions and processes, and predict the responses to restoration. Reviewing the literature on comparable restoration efforts and building upon this knowledge, using boreal Swedish rivers as an example, we address the last point. We hypothesize that restoration measures will make rivers wider and more sinuous, and provide rougher bottoms, thus improving land-water interactions and increasing the retention capacity of water, sediment, organic matter and nutrients. The geomorphic and hydraulic/hydrologic alterations are supposed to favor production, diversity, migration and reproduction of riparian and aquatic organisms. The response rates are likely to vary according to the types of processes and organisms. Some habitat components, such as beds of very large boulders and bedrock outcrops, and availability of sediment and large woody debris are believed to be extremely difficult to restore. Monitoring and evaluation at several scales are needed to test our predictions.
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| 42. |
- Palm, Daniel
(author)
-
Adaptive responses during giardia-host interactions
- 2005
-
Doctoral thesis (other academic/artistic)abstract
- Giardia lamblia is a major cause of water-borne enteric disease. The parasite is a noninvasive, flagellated protozoan that inhabits the upper part of the small intestine of its vertebrate hosts. Differentiation is central to its success as a pathogen since transmission to a new host is dependent on a rapid developmental metamorphosis between the infectious cyst and the disease-causing trophozoite. To investigate this process the genome content throughout the parasite's life cycle was determined. During vegetative growth of the binucleated trophozoites, each nucleus cycle between a diploid (2N) and tetraploid (4N) genome content. Fully differentiated cysts contain four nuclei, each with a ploidy of 4N, resulting in a cyst ploidy of 16N. The newly excysted cell has a ploidy of 16N, but divide twice to form four trophozoites containing two diploid nuclei. The polypIoidy of the cyst is likely to be of importance in infection, since it will de facto increase the infectious dose with a factor of four. During an infection, the trophozoite attaches to the small intestinal cells using a unique cytoskeletal organelle, the adhesive disk. The structure and composition of this organelle was determined throughout the life cycle of the parasite. A new disk protein, SALP-1, was identified. During encystation the levels of the mRNAs of the disk proteins were down regulated but the protein levels were constant. The disk proteins are stored in fragments within the cyst and assembled again during excystation. Transcriptional regulation during differentiation was further studied by characterization of a Myb-related transcription factor found in the Giardia genome. This protein was shown to localize to both nuclei, be upregulated during encystation and bind to a target sequence found in the promoters of genes induced during encystation. The target sequence of the Myb protein was shown to be crucial for stage-specific expression. This implies that this transcription factor is important for gene regulation during differentiation. Taken together, these data show that regulation at both protein and transcriptional level are important during differentiation. Infection is not accompanied by heavy inflammation, although a humoral immune response is triggered that is associated to clearance of the parasite and reduction of symptoms. A large-scale proteomic study to identify what proteins the Immoral immune system targets during infection was undertaken. Sixteen immunoreactive proteins were identified using serum samples from patients with acute giardiasis. Most of the identified proteins were associated with the cytoskeleton (tubulins, alpha- and beta-giardins) or metabolism (ADI, OCT, enolase). The proteins localized to the adhesive disk were also shown to be immunogenic. In addition, the major supernatant proteins after in vitro interaction between Giardia and intestinal epithelial cells were identified. The secreted Giardia proteins were shown to be the immunogenic metabolic enzymes (ADI, OCT and enolase). These proteins are also secreted from other pathogens living on mucosal surfaces. We hypothesize that the identified proteins are essential in the pathogenesis related to Giardia infection.
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| 43. |
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| 44. |
- Palm, Daniel
(author)
-
Discovery and application of insertion-deletion (INDEL) polymorphisms for QTL mapping of early life-history traits in Atlantic salmon
- 2010
-
In: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 11
-
Journal article (peer-reviewed)abstract
- Background: For decades, linkage mapping has been one of the most powerful and widely used approaches for elucidating the genetic architecture of phenotypic traits of medical, agricultural and evolutionary importance. However, successful mapping of Mendelian and quantitative phenotypic traits depends critically on the availability of fast and preferably high-throughput genotyping platforms. Several array-based single nucleotide polymorphism (SNP) genotyping platforms have been developed for genetic model organisms during recent years but most of these methods become prohibitively expensive for screening large numbers of individuals. Therefore, inexpensive, simple and flexible genotyping solutions that enable rapid screening of intermediate numbers of loci (similar to 75-300) in hundreds to thousands of individuals are still needed for QTL mapping applications in a broad range of organisms.Results: Here we describe the discovery of and application of insertion-deletion (INDEL) polymorphisms for cost-efficient medium throughput genotyping that enables analysis of > 75 loci in a single automated sequencer electrophoresis column with standard laboratory equipment. Genotyping of INDELs requires low start-up costs, includes few standard sample handling steps and is applicable to a broad range of species for which expressed sequence tag (EST) collections are available. As a proof of principle, we generated a partial INDEL linkage map in Atlantic salmon (Salmo salar) and rapidly identified a number of quantitative trait loci (QTLs) affecting early life-history traits that are expected to have important fitness consequences in the natural environment.Conclusions: The INDEL genotyping enabled fast coarse-mapping of chromosomal regions containing QTL, thus providing an efficient means for characterization of genetic architecture in multiple crosses and large pedigrees. This enables not only the discovery of larger number of QTLs with relatively smaller phenotypic effect but also provides a cost-effective means for evaluation of the frequency of segregating QTLs in outbred populations which is important for further understanding how genetic variation underlying phenotypic traits is maintained in the wild.
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| 45. |
- Palm, Daniel, et al.
(author)
-
Dispersal of brown trout (Salmo trutta L.) fry in a low gradient stream - implications for egg stocking practices
- 2023
-
In: River Research and Applications. - : Wiley. - 1535-1459 .- 1535-1467. ; 39, s. 790-796
-
Journal article (peer-reviewed)abstract
- Stocking of eggs is a common strategy to support declining or reintroduce extirpated salmonid populations. Data on how juveniles disperse from stocking points is crucial to be able to design efficient stocking programs. Detailed information of dispersal is limited for many salmonids, for example, brown trout. In this study, dispersal distance was measured at the end of the first growing season in a low gradient (0.7%) stream in Sweden where the trout population had been depleted. Eggs from 17 separate sets of parents were stocked as eyed eggs in March. During the following fall fry were sampled throughout the stream. The majority of the fry dispersed downstream and remained within a distance of 200 m from the stocking point with no difference between sizes of fry and the presence of a competing cohort or not. There was no dissimilarity in dispersal distances across offspring originating from different parents indicating absence of genetic influence. Our results suggest that, in streams similar to our study site, stocking points should be separated by approximately 330 m in order to avoid overlap in habitat use of fry from different stocking points and that the presence of competing cohorts, fry size and within population variability in dispersal can be neglected.
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| 46. |
- Palm, Daniel, et al.
(author)
-
Do brown trout (Salmo trutta L.) move streambed substrate?-Implications for durability and maintenance of artificial spawning habitat
- 2021
-
In: River Research and Applications. - : Wiley. - 1535-1459 .- 1535-1467. ; 37, s. 1357-1361
-
Journal article (peer-reviewed)abstract
- Artificial spawning habitat has been used to mitigate for lost habitat and to increase the abundance of salmonids, but the endurance and potential need of maintenance of these habitat improvements have not been well studied. We studied the movement of gravel, attributed to spawning activity of brown trout in a third-order stream in northern Sweden by deploying PIT-tagged grains of gravel on artificially constructed gravel patches. The results suggest that gravel movement was substantial and most prevalent at the central parts of the patches. As 76% of the tagged gravel was mobilized during a single spawning season, maintenance of this habitat improvement may be necessary in order to guarantee its functionality over time. This study provides a first step in guiding managers tasked with identifying factors degrading restored spawning habitat and maintenance needed.
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| 47. |
- Palm, Daniel, et al.
(author)
-
Effects of egg stocking on density, distribution, and size of young-of-year brown trout (Salmo trutta) in a large boreal river in northern Sweden
- 2024
-
In: Fisheries Management and Ecology. - 0969-997X .- 1365-2400. ; 31
-
Journal article (peer-reviewed)abstract
- An understanding of egg densities and juvenile production is critical in salmonid egg stocking projects, but the question is not deeply studied. Given that managers rely on the number of young of the year (YOY) fish to evaluate stocking success, this knowledge gap poses a major challenge. We studied effects of two stocking levels on YOY brown trout at different downstream distances (0-600 m) from the stocking point. Density increased significantly with increasing distance from the stocking point when 60,000 eggs were stocked but not when 30,000 eggs were stocked. Body length was not related to distance from the stocking point and only moderately negatively related to density. We conclude that the results of egg stocking can be difficult to interpret because site-specific density may vary with distance from the stocking point and the number of eggs stocked.
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| 48. |
- Palm, Daniel
(author)
-
Inblandning av kalkgrus i lekbottnar för öring (Salmo trutta L.)
- 2013
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Reports (other academic/artistic)abstract
- Under 2007-2009 konstruerades 30 lekbottnar för öring i anslutning till elfiskelokaler i 30 olika vattendrag i Västerbottens, Västra Götalands och Jönköpings län. I 15 av lekbottnarna blandades 50% kalkgrus in. Ytterligare 17 elfiskelokaler i 17 andra vattendrag valdes ut som kontrollokaler. Alla vattendrag var kalkade, och hade ingen förekomst av surstötar. Uppföljningen av lekbottnarna i Västerbotten 2008-2012 visade att 50 % av det utlagda gruset kvarstod 5 år efter utläggning. Uppföljningen i Västra Götalands och Jönköpings län 2010-2012 visade att 70 % av det utlagda gruset kvarstod 3 år efter utläggning. Provtagning av anlagda lekbottnar i Västerbottens län 2012 (5 år efter anläggning) visade att kalkinblandning orsakade en pH höjning på 0,85 pH enhet i jämförelsen med ytvattnet. I lekbottnar utan kalkgrus var pH 0,10 enheter lägre i jämförelse med ytvattnet. I syfte att utvärdera lösligheten av kalksubstrat och effekten av pålagring placerades individmärkt kalkgrus ut i 10 olika bäckar med olika vattenkemisk karaktär. Efter 24 månaders exponering hade kalkgruset i samtliga vattendrag påverkats negativt i avseende på deras förmåga att höja pH i avjonat vatten på labb samt på bäckvatten. Den avtagande pH- höjande förmågan förklarades delvis av andelen våtmark samt biomassan av skog i avrinningsområdet. Dock orsakade fortfarande kalkgruset en pH höjning med i medeltal 1,16 enheter av bäckvatten efter 24 månaders exponering. Årliga uppföljningar av bottnarna i Västerbotten (2007-2011) och i Västra Götalands och Jönköpings län (2010-2011) visade att lekgropar eller öring observerades på 6-60 respektive 40 % av bottnarna. I syfte att genomföra en ägg till yngelöverlevnadsstudie av nybefruktad öringsrom under 2012-2013 anlades 18 lekbottnar i Kattån i Jönköpings län 2011. Kattån är i likhet med övriga vatten i studien kalkat och utan förekomst av surstötar. I hälften av lekbottnarna blandades kalkgrus in. Resultaten visade att medelöverlevnaden var 66,6 ± 12,4% (SD) respektive 55,6 ± 9,1% i bottnar utan respektive med inblandning av kalkgrus. Skillnaden var ej statistiskt signifikant. I Västerbottens län hade tätheterna av öring (0+) förändrats i medel + 149 %, + 139 % respektive + 108 % på lokaler behandlade med grus, grus + kalkgrus respektive obehandlade kontroller. I Västra Götaland och Jönköpings län hade tätheterna förändrats i medel -29 %, +64 % respektive - 37 % på lokaler behandlade med grus, grus + kalkgrus respektive obehandlade kontroller. Skillnaderna mellan behandlingarna var dock ej statistiskt signifikanta.
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| 49. |
- Palm, Daniel, et al.
(author)
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Influence of European sculpin, Cottus gobio, on Atlantic salmon Salmo salar, recruitment and the effect of gravel size on egg predation - implications for spawning habitat restoration
- 2009
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In: Fisheries Management and Ecology. - : Wiley. - 0969-997X .- 1365-2400. ; 16, s. 501-507
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Journal article (peer-reviewed)abstract
- P>The study examined if recruitment of juvenile Atlantic salmon, Salmo salar L., was influenced by the presence of European sculpin, Cottus gobio L., and if the spawning substrate size used by salmon influences sculpin predation on salmon eggs. A combination of information on spawning site selection by female salmon and associated densities of juvenile salmon indicated that recruitment of juvenile salmon was 10 times lower in areas where sculpin was present than areas without sculpin. Predation rate on salmon eggs was found to be dependent on substrate size in artificial redds created in stream aquaria using four different sizes of substrate (13, 23, 37 and 62 mm). Predation rate averaged 83% in the aquaria with the largest substrate size, whereas a rate of only 2-3% was observed using smaller substrate sizes. Sculpin may thus be an important factor influencing the recruitment of juvenile salmon. Selecting small enough gravel sizes during restoration of salmon spawning habitat could therefore be important to minimise egg predation.
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| 50. |
- Palm, Daniel, et al.
(author)
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Influence of habitat restoration on post-emergence displacement of brown trout (Salmo Trutta L.): a case study in a northern Swedish stream
- 2010
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In: River Research and Applications. - : Wiley. - 1535-1459 .- 1535-1467. ; 26, s. 742-750
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Journal article (peer-reviewed)abstract
- During the 19th and 20th centuries, Swedish streams were channelized to facilitate the commercial transport of timber on water. Stream-dwelling fish were affected by the consequent reduction in habitat quality. To mitigate the effects on salmonids, which sustain important recreational fisheries, many streams have been restored through the replacement of boulders into the channel since the early 1980s. However, the effects of restoration on salmonids remain poorly known. This study assesses the effect of habitat restoration on the post-emergence displacement of brown trout (Salmo trutta L.) fry. Hatchery-raised fry were released in a third-order stream canalized for timber floating in northern Sweden, and the effect of restoration on displacement was assessed. The short-term (24 h) displacement of trout fry was reduced from 10.1 to 2.3% of fry released following restoration. Water velocity accounted for 89.4% of the variation in fry displacement across years and sites. Post-summer recruitment (the proportion of introduced juvenile trout remaining in the study reaches 60 days after the emergence) increased approximately three fold after restoration. These findings suggest that habitat restoration benefit trout populations through substantial reductions of fry displacement and possible contributions to juvenile recruitment. Copyright (C) 2009 John Wiley & Sons, Ltd.
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