| 1. |
- Koeck, Barbara, et al.
(författare)
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Angling selects against active and stress-resilient phenotypes in rainbow trout
- 2019
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Ingår i: Canadian Journal of Fisheries and Aquatic Sciences. - : Canadian Science Publishing. - 0706-652X .- 1205-7533. ; 76:2, s. 320-333
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Tidskriftsartikel (refereegranskat)abstract
- Selection induced by human harvest can lead to different patterns of phenotypic change than selection induced by natural predation and could be a major driving force of evolution of wild populations. The vulnerability of individuals to angling depends on the individual decision to ingest the bait, possibly mediated by their neuroendocrine response towards the associated stimulus. To investigate the mechanisms behind individual vulnerability to angling, we conducted angling experiments in replicated ponds and quantified individual behavioral traits and neuroendocrine stress responsiveness in two salmonid species, rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta). We discovered a phenotypic syndrome in rainbow trout, but not in brown trout, where lower serotonergic and dopaminergic brain activity and cortisol levels (i.e., lower stress responsiveness) in response to a standardized experimental stressor were associated with higher activity, forming a proactive phenotype that showed increased vulnerability to angling. Our results show that angling targets the most stress-resilient and active phenotypes of rainbow trout, supporting the suggestion that fishing-induced phenotypic selection may lead to an increased representation of stress-responsive and low-activity phenotypes in harvested populations.
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| 2. |
- Larsen, M. H., et al.
(författare)
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Effects of Emergence Time and Early Social Rearing Environment on Behaviour of Atlantic Salmon: Consequences for Juvenile Fitness and Smolt Migration
- 2015
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 10:3
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Tidskriftsartikel (refereegranskat)abstract
- Consistent individual differences in behaviour have been well documented in a variety of animal taxa, but surprisingly little is known about the fitness and life-history consequences of such individual variation. In wild salmonids, the timing of fry emergence from gravel spawning nests has been suggested to be coupled with individual behavioural traits. Here, we further investigate the link between timing of spawning nest emergence and behaviour of Atlantic salmon (Salmo salar), test effects of social rearing environment on behavioural traits in fish with different emergence times, and assess whether behavioural traits measured in the laboratory predict growth, survival, and migration status in the wild. Atlantic salmon fry were sorted with respect to emergence time from artificial spawning nest into three groups: early, intermediate, and late. These emergence groups were hatchery-reared separately or in co-culture for four months to test effects of social rearing environment on behavioural traits. Twenty fish from each of the six treatment groups were then subjected to three individual-based behavioural tests: basal locomotor activity, boldness, and escape response. Following behavioural characterization, the fish were released into a near-natural experimental stream. Results showed differences in escape behaviour between emergence groups in a net restraining test, but the social rearing environment did not affect individual behavioural expression. Emergence time and social environment had no significant effects on survival, growth, and migration status in the stream, although migration propensity was 1.4 to 1.9 times higher for early emerging individuals that were reared separately. In addition, despite individuals showing considerable variation in behaviour across treatment groups, this was not translated into differences in growth, survival, and migration status. Hence, our study adds to the view that fitness (i.e., growth and survival) and life-history predictions from laboratory measures of behaviour should be made with caution and ideally tested in nature.
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| 3. |
- Rosengren, Malin, 1982, et al.
(författare)
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High risk no gain-metabolic performance of hatchery reared Atlantic salmon smolts, effects of nest emergence time, hypoxia avoidance behaviour and size
- 2017
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Ingår i: Physiology & Behavior. - : Elsevier BV. - 0031-9384 .- 1873-507X. ; 175, s. 104-112
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Tidskriftsartikel (refereegranskat)abstract
- When animals are reared for conservational releases it is paramount to avoid reducing genetic and phenotypic variation over time. This requires an understanding of how diverging behavioural and physiological traits affect performance both in captivity and after release. In Atlantic salmon, emergence time from the spawning gravel has been linked to certain behavioural and physiological characteristics and to the concept of stress coping styles. Early emerging fry has for example been shown to be bolder and more aggressive and to have higher standard metabolic rates compared to late emerging fry. The first aim was therefore to examine if emergence latency affect the behavioural stress coping response also beyond the fry and parr stage. This was done using a hypoxia avoidance test, where an active behavioural avoidance response can be related to higher risk taking. No behavioural differences were found between the two emergence fractions either at the parr or pre-smolt stage, instead smaller individuals were more prone to express an "active" hypoxia avoidance response. Further, an individual expressing a "passive" response as parr were also more prone to express this behaviour at the pre-smolt stage. While there are some previous studies showing that early emerging individuals with a bolder personality may be favored within a hatchery setting it is not known to what extent these early differences persist to affect performance after release. The second aim was therefore to compare the physiological performance at the time of release as smolts using the two subgroups; 1) early emerging fish showing active hypoxia avoidance (Early + Bold) and 2) late emerging fish showing a passive hypoxia response (Late + Shy). The Early + Bold group showed a higher red blood cell swelling, suggesting a higher adrenergic output during stress, whereas there was no difference in post-stress plasma cortisol or physiological smolt status. While there was no difference in standard metabolic rate between the groups, the Early + Bold group exhibited a lower maximum metabolic rate and aerobic scope following strenuous swimming. In captivity this may have no clear negative effects, but in the wild, a more risk prone behavioural profile linked to a lower aerobic capacity to escape from e.g. a predator attack, could clearly be disadvantageous.
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| 4. |
- Rustas, Bengt-Ove, et al.
(författare)
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Effect of stage of maturity of whole-crop barley on intake and liveweight gain by dairy steers differing in initial live weight
- 2009
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Ingår i: Grass and Forage Science. - : Wiley. - 0142-5242 .- 1365-2494. ; 64, s. 227-235
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Tidskriftsartikel (refereegranskat)abstract
- The effect of maturity at harvest of whole-crop barley for ensiling on intake and liveweight gain of dairy steers differing in initial live weight (LW) was evaluated in an experiment over two years. Light (104-120 kg) and heavy (402-419 kg) dairy steers were fed diets containing predominantly whole-crop barley silage harvested at the milk stage [dry matter (DM) content of 284 g kg(-1) and neutral-detergent fibre (NDF) concentration of 526 g kg(-1) DM] or the dough stage of maturity (DM content of 328 g kg(-1) and NDF concentration of 445 g kg(-1) DM) and supplemented with up to 1 kg of concentrate. Dry matter intake (g kg(-1) LW) was higher for whole-crop barley harvested at the dough stage than at the milk stage of maturity and the difference was greater in heavy than in light steers (P < 0 center dot 001). Liveweight gain was higher and feed conversion ratio was lower for dough-stage compared with milk-stage silage (P < 0 center dot 05) but there was no interaction with size of steer. Whole-crop barley harvested at the dough stage of maturity promoted higher liveweight gains in dairy steers compared with whole-crop barley harvested at the milk stage due to a higher DM intake.
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| 5. |
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| 6. |
- Sundell, David, et al.
(författare)
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AspWood : High-Spatial-Resolution Transcriptome Profiles Reveal Uncharacterized Modularity of Wood Formation in Populus tremula
- 2017
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Ingår i: The Plant Cell. - : Oxford University Press (OUP). - 1040-4651 .- 1532-298X. ; 29:7, s. 1585-1604
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Tidskriftsartikel (refereegranskat)abstract
- Trees represent the largest terrestrial carbon sink and a renewable source of ligno-cellulose. There is significant scope for yield and quality improvement in these largely undomesticated species, and efforts to engineer elite varieties will benefit from improved understanding of the transcriptional network underlying cambial growth and wood formation. We generated high-spatial-resolution RNA sequencing data spanning the secondary phloem, vascular cambium, and wood-forming tissues of Populus tremula. The transcriptome comprised 28,294 expressed, annotated genes, 78 novel protein-coding genes, and 567 putative long intergenic noncoding RNAs. Most paralogs originating from the Salicaceae whole-genome duplication had diverged expression, with the exception of those highly expressed during secondary cell wall deposition. Coexpression network analyses revealed that regulation of the transcriptome underlying cambial growth and wood formation comprises numerous modules forming a continuum of active processes across the tissues. A comparative analysis revealed that a majority of these modules are conserved in Picea abies. The high spatial resolution of our data enabled identification of novel roles for characterized genes involved in xylan and cellulose biosynthesis, regulators of xylem vessel and fiber differentiation and lignification. An associated web resource (AspWood, http://aspwood.popgenie.org) provides interactive tools for exploring the expression profiles and coexpression network.
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| 7. |
- Sundell, David, et al.
(författare)
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High-spatial-resolution transcriptome profiling reveals uncharacterized regulatory complexity underlying cambial growth and wood formation in Populus tremula
- 2016
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Trees represent the largest terrestrial carbon sink and a renewable source of ligno-cellulose. There is significant scope for yield and quality improvement in these largely undomesticated species, however, efforts to engineer new, elite varieties are constrained by the lack of a comprehensive understanding of the transcriptional network underlying cambial growth and wood formation. We generated RNA Sequencing transcriptome data for four mature, wild-growing aspens (Populus tremula) from high-spatial-resolution tangential cryosection series spanning the secondary phloem, vascular cambium, expanding and secondary cell wall forming xylem cells, cell death zone and the previous years annual ring. The transcriptome comprised 28,294 expressed, previously annotated protein-coding genes, 78 novel protein-coding genes and 567 long intergenic non-coding RNAs. Most paralogs originating from the Salicaceae whole genome duplication had diverged expression, with the notable exception of those with high expression during secondary cell wall deposition. We performed co-expression network analysis to identify central transcriptional modules and associated several of these with known biological processes. This revealed previously uncharacterized complexity underlying the regulation of cambial growth and wood formation, with modules forming a continuum of activated processes across the tissues. The high spatial resolution suggested novel roles for known genes involved in xylan and cellulose biosynthesis, regulators of xylem vessel and fiber differentiation and components of lignification. The associated web resource (AspWood, http://aspwood.popgenie.org) integrates the data within a set of interactive tools for exploring the co-expression network of cambial growth and wood formation.
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| 8. |
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| 9. |
- Ung, Kjell-Arne, 1951, et al.
(författare)
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Covered and uncovered self-expandable metallic Hanarostents are equally efficacious in the drainage of extrahepatic malignant strictures. Results of a double-blind randomized study.
- 2013
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Ingår i: Scandinavian journal of gastroenterology. - : Informa UK Limited. - 1502-7708 .- 0036-5521. ; 48:4, s. 459-65
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Background. Self-expandable metallic stents (SEMS) placement is a standard treatment for inoperable malignant bile duct strictures. Covered SEMS have been introduced to avoid stent occlusion by tumor ingrowth. The aims were to compare covered and uncovered stents in terms of patency, efficacy and complication rate. Material and methods. Consecutive patients with inoperable malignant distal biliary strictures were included in the study and randomized to receive a covered (n = 34) or uncovered (n = 34) Hanaro SEMS. Follow-up was performed by nurses after 18 h, 48 h, 2 weeks and thereafter every month until stent dysfunction or the patient died. Outcomes were measured as follows: the patients reported urine and stool color, presence of fever and abdominal pain. Liver function tests and CRP were analyzed each time. The procedure time and complications were monitored. The follow-up was blinded to stent type. Results. The median patient age was 79 years (IQR: 66-83, R: 54-92), 59% were female and 85% had the gallbladder in situ. There was no difference between covered and uncovered stents in terms of procedure time (median: 30 min (20-38, R: 12-90) vs. 30 min (IQR: 20-42, R: 12-70)), stent patency (median: 153 days (IQR: 65-217; R: 20-609) vs. median of 127 days (IQR: 70-196; R: 18-486)) or patient survival (median: 154 days (IQR: 65-217; R: 21-609) vs 157 days (IQR: 70-273, R: 20-690)). Eighty-seven percent died with a patent covered and 83% with an uncovered stent (n.s.). Two early complications occurred (sepsis; pancreatitis), both with covered stents. Conclusion. There is no clinical difference between covered and uncovered biliary Hanaro SEMS. Both types are easily inserted with low complication rate and have long-term patency.
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