| 1. |
- Degerman, E, et al.
(författare)
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Are fish populations in temperate streams affected by crayfish? - A field survey and prospects
- 2007
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Ingår i: Environmental Biology of Fishes. - : Springer Science and Business Media LLC. - 0378-1909 .- 1573-5133. ; 78:3, s. 231-239
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Tidskriftsartikel (refereegranskat)abstract
- Fish populations may be affected by predation and competition from various types of organisms, among which crayfish have been suggested as important actors. We here present results from stream surveys, suggesting that neither native noble, Astacus astacus, nor introduced signal crayfish, Pacifastacus leniusculus, necessarily affect fish population densities in temperate stream communities. Comparisons of fish densities within stream sites between years with absence and presence of crayfish showed no effect of either crayfish species. A further analysis of changes in fish densities between periods without and with crayfish in low, intermediate and high densities revealed that crayfish density did neither have an effect on fish densities. Our study is one of exceptionally few that consider the above aspects in long-term perspectives in natural systems, and we discuss that previously reported divergent results of cray. sh effects on. sh may be highly dependent on specific species and methods used, and that the effects of cray. sh on. sh populations deserve further attention to enable reliable predictions of community processes in streams.
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| 2. |
- Sha, Yongcui, et al.
(författare)
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Diel vertical migration of copepods and its environmental drivers in subtropical Bahamian blue holes
- 2021
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Ingår i: Aquatic Ecology. - : Springer. - 1386-2588 .- 1573-5125. ; 55:4, s. 1157-1169
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Tidskriftsartikel (refereegranskat)abstract
- Diel vertical migration (DVM) is the most common behavioral phenomenon in zooplankton, and numerous studies have evaluated DVM under strong seasonality at higher latitudes. Yet, our understanding of the environmental drivers of DVM at low latitudes, where seasonal variation is less pronounced, remains limited. Therefore, we here examined patterns of vertical distribution in copepods in six subtropical Bahamian blue holes with different food web structure and tested the role of several key environmental variables potentially affecting this behavior. Day and night samplings showed that copepods generally performed DVM, characterized by downward migration to deeper depths during the day and upward migration to surface waters at night. Across all blue holes, the daytime vertical depth distribution of calanoid copepods correlated positively with both predation risk and depth of food resources (Chlorophyll a), but was less affected by ultraviolet radiation (UVR). A potential explanation is that since UVR is a continuous threat across seasons, zooplankton have established photoprotective pigmentation making them less vulnerable to this threat. The copepods also showed a size-structured depth segregation, where larger individuals were found at deeper depths during the day, which further strengthens the suggestion that predation is a major driver of DVM in these systems. Hence, in contrast to studies performed at higher latitudes, we show that despite the constant exposure to UVR, predator avoidance and food availability are the most pronounced drivers of copepod DVM at those low latitudes, suggesting that the main driver of DVM may vary among systems, but also systematically by latitude.
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| 3. |
- Svensson, Mattias, 1982, et al.
(författare)
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Fms-like tyrosine kinase 3 ligand controls formation of regulatory T cells in autoimmune arthritis.
- 2013
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Fms-like tyrosine kinase 3 ligand (Flt3L) is known as the primary differentiation and survival factor for dendritic cells (DCs). Furthermore, Flt3L is involved in the homeostatic feedback loop between DCs and regulatory T cell (Treg). We have previously shown that Flt3L accumulates in the synovial fluid in rheumatoid arthritis (RA) and that local exposure to Flt3L aggravates arthritis in mice, suggesting a possible involvement in RA pathogenesis. In the present study we investigated the role of Flt3L on DC populations, Tregs as well as inflammatory responses in experimental antigen-induced arthritis. Arthritis was induced in mBSA-immunized mice by local knee injection of mBSA and Flt3L was provided by daily intraperitoneal injections. Flow cytometry analysis of spleen and lymph nodes revealed an increased formation of DCs and subsequently Tregs in mice treated with Flt3L. Flt3L-treatment was also associated with a reduced production of mBSA specific antibodies and reduced levels of the pro-inflammatory cytokines IL-6 and TNF-α. Morphological evaluation of mBSA injected joints revealed reduced joint destruction in Flt3L treated mice. The role of DCs in mBSA arthritis was further challenged in an adoptive transfer experiment. Transfer of DCs in combination with T-cells from mBSA immunized mice, predisposed naïve recipients for arthritis and production of mBSA specific antibodies. We provide experimental evidence that Flt3L has potent immunoregulatory properties. Flt3L facilitates formation of Treg cells and by this mechanism reduces severity of antigen-induced arthritis in mice. We suggest that high systemic levels of Flt3L have potential to modulate autoreactivity and autoimmunity.
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| 4. |
- Almered Olsson, Gunilla, 1951, et al.
(författare)
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City–Region Food Systems: Scenarios to re-establish urban-rural links through sustainable food provisioning
- 2018
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Ingår i: Tomorrow’s Food Travel (TFT) conference, Centre for Tourism – University of Gothenburg, 8–10 October 2018, Gothenburg, Sweden.
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Konferensbidrag (refereegranskat)abstract
- City–Region Food Systems (CRFS) is a cutting-edge concept and an emerging field of research. As a new analytical lens, it offers an integrated and multi-dimensional perspective on food’s origins, how it is grown and the path it follows to our plates and beyond. Building on this concept, this presentation reflects a prospective research project which seeks to explore opportunities for innovative and sustainable food systems in the Gothenburg region of Sweden by focusing on how rural and urban regions, food production and market can be integrated to promote regional food security. The project intends to: 1) develop scenarios with stakeholders for local food production in the region; 2) analyze the consequences of the scenarios on landscape change and biodiversity; 3) explore socio-economic consequences for producers and local communities; and 4) evaluate the sustainability and feasibility of scenarios with stakeholders. Five municipalities in Western Sweden (Gothenburg, Kungälv, Lerum, Alingsås and Essunga) will serve as study areas for the project, selected to reflect different kinds of potential for local food production in terms of dissimilar environmental conditions, prerequisites for farming and economic histories. The project responds to expressed interests and knowledge needs in the region and will be developed and implemented in direct cooperation with local and regional actors such as Västarvet, the Västra Götaland Region, the municipalities and various producer organizations. In sum, there are premises suggesting that recent urban food strategies and plans with sustainability ambitions are embracing several Sustainable Development Goals in the environmental, social, economic, and equity dimensions. This, in turn, is a characteristic of the Transition Movements pathway, in which the utility of food strategies in the work with sustainability transitions seems inevitable. The results are therefore likely to be transferable to other regions.
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| 5. |
- Anter, Karin Fridell, et al.
(författare)
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SYN-TES INTERDISCIPLINARY RESEARCH ON COLOUR AND LIGHT
- 2012
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Ingår i: Proceedings for Interim Meeting of the International Colour Association (AIC); AIC 2012 “In Color We Live: Color and Environment”, 22 – 25 September 2012, Taipei, Taiwan. - : The International Colour Association. ; , s. 80-83, s. 80-83
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Konferensbidrag (refereegranskat)abstract
- Colour and light have largely been considered as belonging to two different fields of knowledge, having disparate theoretical, terminological and methodological traditions. This creates a ground for misunderstandings and obstructs a fruitful interdisciplinary and interprofessional collaboration. A survey over international research literature from 2006 -2011 shows that there has been only little research on the spatial interaction between colour and light, but that the interest for this area has recently increased. The interdisciplinary Nordic research project SYN-TES: Human colour and light synthesis. Towards a coherent field of knowledge was carried out during 2010-11. Colour and light experts from Nordic universities and companies investigated different aspects of the spatial interaction between colour and light and its importance for human beings. This paper deals with the general learnings from the process. Specific results are presented in other papers at this conference.
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| 6. |
- Björnerås, Caroline, et al.
(författare)
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Inland blue holes of The Bahamas - chemistry and biology in a unique aquatic environment
- 2020
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Ingår i: Fundamental and Applied Limnology. - : Schweizerbart science publishers. - 1863-9135. ; 194:2, s. 95-106
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Tidskriftsartikel (refereegranskat)abstract
- While lake systems in temperate regions have been extensively studied, tropical and subtropical systems have received less attention. Here, we describe the water chemistry and biota of ten inland blue holes on Andros Island, The Bahamas, representative of the morphological, abiotic, and biotic variation among Androsian inland blue holes. The majority of the studied blue holes were vertically stratified with oxic freshwater overlying anoxic saline groundwater of marine origin. Water chemistry (e.g. total phosphorus and nitrogen) in shallow waters was similar among blue holes, while turbidity and water color varied. Presence of hydrogen sulfide and reduced iron in and below the halocline indicate reducing conditions in all stratified blue holes. The biota above the halocline was also similar among blue holes with a few taxa dominating the phytoplankton community, and the zooplankton community consisting of copepods and rotifers. The Bahamas mosquitofish (Gambusia hubbsi) was present in all investigated blue holes, often accompanied by other small planktivorous fish, while the piscivorous bigmouth sleeper (Gobiomorus donnitor) was only present in some of the blue holes. Our field study reinforces that inland blue holes are highly interesting for biogeochemical research, and provide naturally replicated systems for evolutionary studies.
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| 10. |
- Corcoll, Natàlia, 1981, et al.
(författare)
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Linking pesticide pollution with periphyton quality in agricultural streams: a fatty-acids approach
- 2018
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Ingår i: SETAC Europe 28th Annual Meeting 13−17 May 2018 | Rome, Italy. Abstract Book.. - 2309-8031.
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Konferensbidrag (refereegranskat)abstract
- Although the environmental risks associated with pesticide pollution in agricultural streams are quite well documented, little is know about its potential effects on periphyton quality. Periphyton provides many of the essential polyunsaturated fatty acids (PUFA) that are needed for organisms at higher trophic levels in river food webs. This study aims to assess the effects of pesticide mixtures on periphyton quality in situ. Three streams (Höje å, Skivarpsån and M42) located in the agriculturally dominated region of Skåne (SE Sweden) were sampled in September and October 2016. The effects of pesticide pollution were assessed by passive field sampling coupled with laboratory ecotoxicity tests, by mixture toxicity modelling to predict which chemical stressors were potentially driving the toxicity, and by examining the fatty acid profiles, pigment content and algal diversity of periphyton communities. Results from water chemical analyses clearly showed higher levels of nutrients and pesticide pollution in Skivarpsån and M42 than in Höje å. Ecotoxicity tests using the passive sampler extracts demonstrated that the pesticide mixtures ocurring at Skivarpsån and M42 were toxic for periphyton communities from Höje å, causing an inhibition of the photosynthetic activity up to 63% and 53%, respectively. Cluster and principal component analyses based on pigments content, algal diversity and fatty acid profiles, clearly separated the periphyton from the three river sites studied. Algal biomass from periphyton of pesticide polluted streams (Skivarpsån and M42) was higher than in Höje å. The nutritive quality of the periphyton differed among streams, and fatty acids considered high-quality such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were also more abundant in pesticide polluted streams (Skivarpsån and M42). Overal, even though results from the lab show that the mixture of pesticides pollution in the studied streams might be toxic for periphyton (i.e. inhibiting the photosynthetic activity), being herbicides the driving chemical stressors. Results from the field, indicate that when the levels of pesticide pollution are low and co-occur with high levels of nutrients pollution, nutrients migh mask pesticides effects on periphyton quantity and quality because compensatory effects from nutrients
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