| 1. |
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| 2. |
- Nordenskjöld, A., et al.
(författare)
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Copy number variants suggest different molecular pathways for the pathogenesis of bladder exstrophy
- 2023
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Ingår i: American Journal of Medical Genetics, Part A. - : Wiley. - 1552-4825 .- 1552-4833. ; 191:2, s. 378-390
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Tidskriftsartikel (refereegranskat)abstract
- Bladder exstrophy is a rare congenital malformation leaving the urinary bladder open in the midline of the abdomen at birth. There is a clear genetic background with chromosome aberrations, but so far, no consistent findings apart from 22q11-duplications detected in about 2%–3% of all patients. Some genes are implicated like the LZTR1, ISL1, CELSR3, and the WNT3 genes, but most are not explained molecularly. We have performed chromosomal microarray analysis on a cohort of 140 persons born with bladder exstrophy to look for submicroscopic chromosomal deletions and duplications. Pathogenic or possibly pathogenic microdeletions or duplications were found in 16 patients (11.4%) and further 9 with unknown significance. Two findings were in regions linked to known syndromes, two findings involved the same gene (MCC), and all other findings were unique. A closer analysis suggests a few gene networks that are involved in the pathogenesis of bladder exstrophy; the WNT-signaling pathway, the chromosome 22q11 region, the RIT2 and POU families, and involvement of the Golgi apparatus. Bladder exstrophy is a rare malformation and is reported to be associated with several chromosome aberrations. Our data suggest involvement of some specific molecular pathways.
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| 7. |
- Pettersen, I., et al.
(författare)
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Expression of TWEAK/Fn14 in neuroblastoma: Implications in tumorigenesis
- 2013
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Ingår i: International Journal of Oncology. - : Spandidos Publications. - 1019-6439 .- 1791-2423. ; 42:4, s. 1239-1248
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Tidskriftsartikel (refereegranskat)abstract
- Tumor necrosis factor-like weak inducer of apoptosis (TWEAK), a member of the tumor necrosis factor (TNF) family of cytokines, acts on responsive cells via binding to a cell surface receptor called Fn14. TWEAK binding to an Fn14 receptor or constitutive Fn14 overexpression has been shown to activate nuclear factor κB signaling which is important in tumorigenesis and cancer therapy resistance. In the present study, we demonstrate that TWEAK and Fn14 are expressed in neuroblastoma cell lines and primary tumors, and both are observed at increased levels in high-stage tumors. The treatment of neuroblastoma cell lines with recombinant TWEAK in vitro causes increased survival, and this effect is partially due to the activation of NF-κB signaling. Moreover, TWEAK induces the release of matrix metalloprotease-9 (MMP-9) in neuroblastoma cells, suggesting that TWEAK may play a role in the invasive phase of neuroblastoma tumorigenesis. TWEAK-induced cell survival was significantly reduced by silencing the TWEAK and Fn14 gene functions by siRNA. Thus, the expression of TWEAK and Fn14 in neuroblastoma suggests that TWEAK functions as an important regulator of primary neuroblastoma growth, invasion and survival and that the therapeutic intervention of the TWEAK/Fn14 pathway may be an important clinical strategy in neuroblastoma therapy.
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| 8. |
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| 11. |
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| 12. |
- Abbey-Lee, Robin N., et al.
(författare)
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The Influence of Rearing on Behavior, Brain Monoamines, and Gene Expression in Three-Spined Sticklebacks
- 2018
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Ingår i: Brain, behavior, and evolution. - Basel : S. Karger AG. - 0006-8977 .- 1421-9743. ; 91:4, s. 201-213
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Tidskriftsartikel (refereegranskat)abstract
- The causes of individual variation in behavior are often not well understood, and potential underlying mechanisms include both intrinsic and extrinsic factors, such as early environmental, physiological, and genetic differences. In an exploratory laboratory study, we raised three-spined sticklebacks (Gasterosteus aculeatus) under 4 different environmental conditions (simulated predator environment, complex environment, variable social environment, and control). We investigated how these manipulations related to behavior, brain physiology, and gene expression later in life, with focus on brain dopamine and serotonin levels, turnover rates, and gene expression. The different rearing environments influenced behavior and gene expression, but did not alter monoamine levels or metabolites. Specifically, compared to control fish, fish exposed to a simulated predator environment tended to be less aggressive, more exploratory, and more neophobic; and fish raised in both complex and variable social environments tended to be less neophobic. Exposure to a simulated predator environment tended to lower expression of dopamine receptor DRD4A, a complex environment increased expression of dopamine receptor DRD1B, while a variable social environment tended to increase serotonin receptor 5-HTR2B and serotonin transporter SLC6A4A expression. Despite both behavior and gene expression varying with early environment, there was no evidence that gene expression mediated the relationship between early environment and behavior. Our results confirm that environmental conditions early in life can affect phenotypic variation. However, the mechanistic pathway of the monoaminergic systems translating early environmental variation into observed behavioral responses was not detected.
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| 13. |
- Balkenius, Christian, et al.
(författare)
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Cognitive modeling with context sensitive reinforcement learning
- 2004
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Ingår i: Proceedings of AILS 04 ( Report / Lund Institute of Technology, Lund University ; 151). - 1650-1276. ; , s. 10-19
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Konferensbidrag (refereegranskat)abstract
- We describe how a standard reinforcement learning algorithm can be changed to include a second contextual input that is used to modulate the learning in the original algorithm. The new algorithm takes the context into account during relearning when the previously learned actions are no longer valid. The algorithm was tested on a number of cognitive experiment and shown to reproduce the learning in both a task switching test and in the Wisconsin Card Sorting Test. In addition, the algorithm was able to learn a context sensitive categorization of objects in the Labov experiment.
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| 19. |
- Basic, D., et al.
(författare)
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Context-dependent responses to novelty in Rainbow trout (Oncorhynchus mykiss), selected for high and low post-stress cortisol responsiveness
- 2012
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Ingår i: Physiology and Behavior. - : Elsevier BV. - 0031-9384 .- 1873-507X. ; 105:5, s. 1175-1181
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies in a rainbow trout model, selectively bred for high (HR) and low (LR) post stress plasma cortisol levels, have yielded data that are indicative of contrasting stress coping styles. Fish from the HR line have been suggested to display a more diverse behavioral repertoire in challenging situations than the LR counterpart. The present study addressed whether such variation in behavioral flexibility traits was evident in different experimental settings using these selection lines. The fish were subjected to three sets of challenges (novel object test, resident-intruder test and confinement stressor test), all which were repeated a week later. Introducing a novel object evoked a divergent behavioral response in association with feeding: fish from the LR line displayed consistently suppressed feed intake while the HR fish remained unaffected. This observation was found to be repeatable along with attack latency and movement activity from the resident-intruder and confinement stressor tests. These results indicate that the behavioral responses in this animal model are context-dependent and shed new light on the expression of behavioral flexibility.
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| 20. |
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| 21. |
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| 22. |
- Borg, Farhana, 1967-
(författare)
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Caring for people and the planet : preschool children’s knowledge and practices of sustainability
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Children across the globe today are continuously being exposed to and affected by various kinds of real-world complexities and challenges; however, research on their knowledge and practices in terms of sustainability is limited, in particular with regards to how preschool- and home-related factors are associated with their learning for sustainability. Since 1998, different types of eco-certification have been awarded by the Swedish National Agency for Education and Keep Sweden Tidy Foundation to promote education for sustainability (EfS) in all areas of education and learning. Despite certificates having been granted in Sweden since 1998, no studies have been conducted at the national level to investigate whether eco-certification has any role to play in children’s learning for environmental and sustainability issues. This knowledge is important to develop pedagogical activities to engage young children meaningfully in learning for sustainability at preschool. This study was undertaken so as to address this research gap in a Swedish context.The overall aim of this study was to enhance the existing knowledge about preschool children’s learning for sustainability in Sweden. The objectives of this study have been to investigate and compare the knowledge and self-reported practices of sustainability among children attending eco-certified and non-eco-certified preschools, respectively, and to explore the extent to which preschool- and home-related factors are associated with children’s knowledge and practices of sustainability. Further, this study explored children’s perceived sources of such knowledge. The term ‘knowledge’ in this text refers to the descriptions of children’s ideas and thoughts. Similarly, eco-certified preschool refers to a school that work explicitly with EfS.The study was designed from a "child’s perspective": this means that it was designed by adults to understand children’s perceptions and actions. Bandura’s (1977) social learning theory and Bruner’s (1961) iconic (image-based) modes of representation were applied in various stages of the study. A conceptual framework was developed within the three-interlocking-circles model of sustainability that illustrates how environmental, social and economic dimensions are interconnected. The concept of sustainability was operationalized in four themes: economic equality, resource sharing, recycling and transport use.With the use of illustrations and semi-structured questions, final-year preschool children (n=53), aged five to six years, and the directors (n=7) at six eco-certified and six non-eco-certified preschools were interviewed, while guardians (n=89) and teachers (n=74) filled out questionnaires. Qualitative and quantitative data were analyzed using content analysis and Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA), respectively. The quality and complexity of children’s responses were assessed and classified using the SOLO Taxonomy (Biggs & Collis, 1982).The results showed that by the time the children completed preschool, many had acquired some knowledge about how to use money, about the sorting of different recyclable items at home and at preschool, and about the impact of different modes of transport on the environment and people’s lives. They also had ideas about the lives of other children in the world and what it can mean to share resources with other people. There was a positive relationship between children’s declarative (understanding) and functional (practice) knowledge of sustainability issues and the involvement of teachers and guardians in sustainability-related discussions and activities. No statistically significant differences between eco-certified and non-eco-certified preschools in terms of children’s declarative and functional knowledge were found. Parents were reported to be the main sources of children’s knowledge along with the children themselves, teachers and media.The findings offer support for integrating environmental, social and economic dimensions of sustainability into the daily pedagogical activities of preschools and for giving children opportunities to participate in discussions and practical activities that concern their lives. Further studies are needed to investigate the extent to which different educational activities contribute to developing children’s understanding and behavior when it comes to a sustainable society.
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| 23. |
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| 24. |
- Cakir, B., et al.
(författare)
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IGF1, serum glucose, and retinopathy of prematurity in extremely preterm infants
- 2020
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Ingår i: Jci Insight. - : American Society for Clinical Investigation. - 2379-3708. ; 5:19
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND. Hyperglycemia, insulin insensitivity, and low IGF1 levels in extremely preterm infants are associated with an increased risk of retinopathy of prematurity (ROP), but the interactions are incompletely understood. METHODS. In 117 extremely preterm infants, serum glucose levels and parenteral glucose intake were recoded daily in the first postnatal week. Serum IGF1 levels were measured weekly. Mice with oxygen-induced retinopathy alone versus oxygen-induced retinopathy plus streptozotocin-induced hyperglycemia/hypoinsulinemia were assessed for glucose, insulin, IGF1, IGFBP1, and IGFBP3 in blood and liver. Recombinant human IGF1 was injected to assess the effect on glucose and retinopathy. RESULTS. The highest mean plasma glucose tertile of infants positively correlated with parenteral glucose intake [r (39) = 0.67, P < 0.0001]. IGF1 plasma levels were lower in the high tertile compared with those in low and intermediate tertiles at day 28 (P = 0.038 and P = 0.03). In high versus lower glucose tertiles, ROP was more prevalent (34 of 39 versus 19 of 39) and more severe (ROP stage 3 or higher; 71% versus 32%). In oxygen-induced retinopathy, hyperglycemia/hypoinsulinemia decreased liver IGF1 expression (P < 0.0001); rh-IGF1 treatment improved normal vascular regrowth (P = 0.027) and reduced neovascularization (P < 0.0001). CONCLUSION. In extremely preterm infants, high early postnatal plasma glucose levels and signs of insulin insensitivity were associated with lower IGF1 levels and increased ROP severity. In a hyperglycemia retinopathy mouse model, decreased insulin signaling suppressed liver IGF1 production, lowered serum IGF1 levels, and increased neovascularization. IGF1 supplementation improved retinal revascularization and decreased pathological neovascularization. The data support IGF1 as a potential treatment for prevention of ROP.
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| 25. |
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| 26. |
- Cocco, Arianna
(författare)
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The γ-aminobutyric acid and proton signaling systems in the zebrafish brain : Characterization and effect of stress
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The central nervous system of vertebrates is continuously processing sensory information relayed from the periphery, integrating it and producing outputs transmitted to efferents. In the brain, neurons employ an array of messenger molecules to filter afferent information and finely regulate synaptic transmission. The γ-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the adult vertebrate central nervous system, synthesized from α, L-glutamate by the glutamate decarboxylases (GADs). GABA promotes fast hyperpolarization of target cells mediated by the ionotropic, chloride-conducting type A GABA (GABAA) receptors. Those channels are homo- or heteropentamers and, in the zebrafish, at least twenty-three genes encode for putative GABAA receptor subunits.The present PhD thesis presents the expression levels of the almost complete panel of the GABA signaling machinery in the adult zebrafish brain and retinas. The results point toward GABA signaling modalities in zebrafish strikingly similar to those observed in mammals. The most common GABAA receptor subunit combinations in the whole brain were proposed to be α1β2γ2 and α1β2δ, and region-specific GABAA channels were also inferred. Those included telencephalic α2bβ3γ2, α2bβ3δ, α5β2γ2, α5β3γ2 and cerebellar α4β2γ2 and α4β2δ. A tissue specific expression was documented for the paralogues α6a and α6b; the former was abundantly transcribed in the retinas, the latter in the cerebellum. Proposed retinal GABAA receptors were α1βxγ2, α1βxδ, α6aβxγ2 and α6aβxδ, with either β2 or β3.Focus was also placed on functional aspects of the GABA signaling system in the adult zebrafish brain, and specifically on the effects of stress on GABAA receptor subunits expression. Treated animals experienced social isolation and repeated confinement, and depicted increased mRNA levels of several GABAA receptor monomers. It was deduced that a higher number of extrasynaptic, tonic-current-mediating GABAA channels was synthesized in the brain following stress. As synaptic transmission promotes extracellular acidification, interest was also placed on the acid-sensing ion channel (ASIC) subunits. The overall results presented in this PhD thesis point toward GABA and proton signaling systems in the zebrafish brain that have many common points with those of mammals. Thus, fundamental signaling pathways appear to be conserved across vertebrates.
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| 27. |
- Cvetkovic, Vladimir, et al.
(författare)
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Sorbing tracer experiments in a crystalline rock fracture at Aspo (Sweden) : 2. Transport model and effective parameter estimation
- 2007
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Ingår i: Water resources research. - : American Geophysical Union (AGU). - 0043-1397 .- 1944-7973. ; 43:11
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Tidskriftsartikel (refereegranskat)abstract
- [1] Transport and retention of sorbing tracers in a single, altered crystalline rock fracture on a 5 m scale is investigated. We evaluate the results of a comprehensive field study ( referred to as Tracer Retention Understanding Experiments, first phase ( TRUE- 1)), at a 400 m depth of the Aspo Hard Rock Laboratory ( Sweden). A total of 16 breakthrough curves are analyzed, from three test configurations using six radioactive tracers with a broad range of sorption properties. A transport- retention model is proposed, and its applicability is assessed based on available data. We find that the conventional model with an asymptotic power law slope of - 3/ 2 ( one- dimensional diffusion into an unlimited rock matrix) is a reasonable approximation for the conditions of the TRUE- 1 tests. Retention in the altered rock of the rim zone appears to be significantly stronger than implied by retention properties inferred from generic ( unaltered) rock samples. The effective physical parameters which control retention ( matrix porosity and retention aperture) are comparable for all three test configurations. The most plausible in situ ( rim zone) porosity is in the range 1% - 2%, which constrains the effective retention aperture to the range 0.2 - 0.7 mm. For all sorbing tracers the estimated in situ sorption coefficient appears to be larger by at least a factor of 10, compared to the value inferred from through- diffusion tests using unaltered rock samples.
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| 28. |
- Cvetkovic, Vladimir, et al.
(författare)
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Transport and retention from single to multiple fractures in crystalline rock at Aspo (Sweden) : 1. Evaluation of tracer test results and sensitivity analysis
- 2010
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Ingår i: Water resources research. - 0043-1397 .- 1944-7973. ; 46, s. W05505-
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Tidskriftsartikel (refereegranskat)abstract
- We evaluate the breakthrough curves obtained within a comprehensive experimental program for investigating the retention properties of crystalline rock, referred to as Tracer Retention Understanding Experiments (TRUE). The tracer tests were conducted at the Aspo Hard Rock Laboratory (Sweden) in two phases jointly referred to as TRUE Block Scale (TBS); the TBS tests comprise a total of 17 breakthrough curves with nonsorbing and a range of sorbing tracers. The Euclidian length scales are between 10 and 30 m, compared to 5 m for the earlier tests TRUE-1. The unlimited diffusion model is consistent with measured breakthrough curves and is adopted here for evaluation. The model has four independent parameters, two of which are related to advection and dispersion, one which is related to diffusion-sorption, and one which is related to surface sorption; the individual retention parameters or properties cannot be inferred from breakthrough curves alone and require additional constraints. The mean water residence times for the TBS tests are in the range 15-250 h, whereas the coefficient of variation of the water residence times is in the range 0.4-0.6. A consistent trend is found in the calibrated retention parameters with the sorption affinities of the tracers involved. Using Bode sensitivity functions, it is shown that sensitivity increases for the retention parameter with increasing sorption affinity; for nonsorbing tracers, diffusion and hydrodynamic dispersion are shown to "compete," exhibiting similar effects; hence, their estimates are uncertain. The analysis presented here exposes a few fundamental limitations and sensitivities when evaluating diffusion-controlled retention in the subsurface; it is general and applicable to any site with comparable tracer test data. In part 2, it will be shown how discrete fracture network simulations based on the hydrostructural information available can be used for further constraining individual retention parameters, in particular, the active specific surface area (s(f)) and the rock matrix porosity (theta).
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| 29. |
- de Abreu, Murilo S., et al.
(författare)
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Dopamine and serotonin mediate the impact of stress on cleaner fish cooperative behavior
- 2020
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Ingår i: Hormones and Behavior. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0018-506X .- 1095-6867. ; 125
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Tidskriftsartikel (refereegranskat)abstract
- Stress is known to modulate behavioral responses and rapid decision-making processes, especially under challenging contexts which often occur in social and cooperative interactions. Here, we evaluated the effects of acute stress on cooperative behavior of the Indo-Pacific cleaner wrasse (Labroides dimidiatus) and the implications of pre-treatment with monoaminergic compounds: the selective serotonin reuptake inhibitor - fluoxetine, the 5-HT1A receptor antagonist - WAY-100,635, the D-1 receptor agonist - SKF-38393, and the D-1 receptor antagonist - SCH-23390. We demonstrated that stress decreased the predisposal to interact and increased cortisol levels in cleaners, which are alleviated by fluoxetine and the dopaminergic D-1 antagonist. Overall, our findings highlight the crucial influence of stress on cooperative behavior.
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| 30. |
- De Sitter, K, et al.
(författare)
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Silica filled poly(1-trimethylsilyl-1-propyne) nanocomposite membranes: Relation between the transport of gases and structural characteristics
- 2006
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Ingår i: Journal of Membrane Science. - : Elsevier BV. - 0376-7388. ; 278:1-2, s. 83-91
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Tidskriftsartikel (refereegranskat)abstract
- The performance of poly(1-trimethylsilyl-1-propyne) (PTMSP)/silica nanocomposites was studied for membranes with a filler content between 0 and 50 wt%. An increase in permeability and a decrease in vapor selectivity was measured with increasing filler content. The free volume sizes and interstitial mesopore sizes of the composites were determined by use of positron annihilation lifetime spectroscopy (PALS). In addition to an increase in large free volume size with increasing filler content, interstitial mesopores were observed in all PTMSP/silica nanocomposites. The size of these interstitial cavities, located between the particles of a silica agglomerate, was increasing with increasing filler concentration. The presence of these agglomerates was visualized by TEM. The existence of the cavities was confirmed by nitrogen adsorption measurements. The hydrogen, nitrogen and propane permeability was clearly correlated with the size of the interstitial mesopores. (c) 2005 Elsevier B.V. All rights reserved.
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| 31. |
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| 32. |
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| 33. |
- Höglund, Erik, et al.
(författare)
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Suppression of aggressive behaviour in juvenile Atlantic cod (Gadus morhua) by L-tryptophan supplementation
- 2005
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Ingår i: AQUACULTURE. ; 249:1-4, s. 525-531
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Tidskriftsartikel (refereegranskat)abstract
- Aggressive interactions and cannibalism of juvenile Atlantic cod may cause substantial production losses under conditions of intensive rearing. In other teleosts, chronically increased brain concentrations and turnover of the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT) are associated with suppressed aggression. Further, dietary supplementation with the serotonin precursor, L-tryptophan (TRP) suppresses aggression in juvenile rainbow trout (Onchorhyncus mykiss) and reduces cannibalism in juvenile grouper (Epinephelus coioides). In the present study, the behavioural effect of dietary TRP supplementation was observed in pairs of juvenile Atlantic cod subjected to repeated encounters for 10 days. After 3 days, one group was given TRP-supplemented feed (28 g/kg). A significant (P < 0.01) decrease in aggressive acts (from 40 +/- 2.7/ 10 min to 17 +/- 2.0/10 min, mean +/- standard error of mean) was seen after changing to TRP-supplemented feed. The mean number of aggressive acts was also significantly (P<0.05) lower in the TRP-treated group (17 +/- 2.0/10 min) compared to a control group not receiving TRP treatment (29 3.3/10 min). A second experiment examined the effect of TRP-supplemented feed (28 g/kg) on the activity of central 5-HT, quantified as the concentration ratio between the 5-HT metabolite, 5-hydroxyindoleacetic acid (5-HIAA), and 5-HT. In this experiment, the TRP-treated group ([5-HIAA]/[5-HT]=0.56 +/- 0.04) showed elevated values (P<0.038) compared with the control group ([5-HIAA]/[5-HT]=0.43 +/- 0.03). In conclusion, this study shows that juvenile Atlantic cod are highly aggressive and that supplementing the feed with TRP affects central 5-HT signalling systems and reduces this behaviour. (c) 2005 Elsevier B.V. All rights reserved.
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| 34. |
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| 35. |
- Isaguliants, MG, et al.
(författare)
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DNA-encoding enzymatically active HIV-1 reverse transcriptase, but not the inactive mutant, confers resistance to experimental HIV-1 challenge
- 2000
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Ingår i: Intervirology. - : S. Karger AG. - 0300-5526 .- 1423-0100. ; 43:4-6, s. 288-293
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Tidskriftsartikel (refereegranskat)abstract
- The present study was undertaken to examine the immunogenicity of a single plasmid DNA representing the reverse transcriptase (RT) of HIV-1. Plasmids containing the enzymatically active RT as well as a mutated nonenzymatically active RT with nucleotide (nt)-binding motifs of YMDD and YMLL, respectively, were used to immunize mice. Both constructs induced similar good antibody and T cell responses, with a tendency towards antibody directed to peptides representing the active and mutated sites. Immunized mice were challenged with a murine pseudotype HIV-1/MuLV infected spleen cells. Seven out of 10 mice immunized with RT had no recoverable HIV-1, while 10 individuals immunized with the RT mutant and all the 18 controls had high levels of recoverable HIV-1. This indicates that mutation of RT reduces the desired immunogenicity.
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| 36. |
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| 37. |
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| 38. |
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| 39. |
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| 40. |
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| 41. |
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| 42. |
- Kotrschal, Alexander, et al.
(författare)
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Artificial Selection on Relative Brain Size Reveals a Positive Genetic Correlation Between Brain Size and Proactive Personality in the Guppy
- 2014
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Ingår i: Evolution. - : Wiley. - 0014-3820 .- 1558-5646. ; 68:4, s. 1139-1149
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Tidskriftsartikel (refereegranskat)abstract
- Animal personalities range from individuals that are shy, cautious, and easily stressed (a "reactive" personality type) to individuals that are bold, innovative, and quick to learn novel tasks, but also prone to routine formation (a "proactive" personality type). Although personality differences should have important consequences for fitness, their underlying mechanisms remain poorly understood. Here, we investigated how genetic variation in brain size affects personality. We put selection lines of large- and small-brained guppies (Poecilia reticulata), with known differences in cognitive ability, through three standard personality assays. First, we found that large-brained animals were faster to habituate to, and more exploratory in, open field tests. Large-brained females were also bolder. Second, large-brained animals excreted less cortisol in a stressful situation (confinement). Third, large-brained animals were slower to feed from a novel food source, which we interpret as being caused by reduced behavioral flexibility rather than lack of innovation in the large-brained lines. Overall, the results point toward a more proactive personality type in large-brained animals. Thus, this study provides the first experimental evidence linking brain size and personality, an interaction that may affect important fitness-related aspects of ecology such as dispersal and niche exploration.
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| 43. |
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| 44. |
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| 45. |
- 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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| 46. |
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| 47. |
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| 48. |
- Meager, Justin J., et al.
(författare)
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Multidimensionality of behavioural phenotypes in Atlantic cod, Gadus morhua
- 2012
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Ingår i: Physiology and Behavior. - : Elsevier BV. - 0031-9384 .- 1873-507X. ; 106:4, s. 462-470
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Tidskriftsartikel (refereegranskat)abstract
- Much of the inter-individual variation observed in animal behaviour is now attributed to the existence of behavioural phenotypes or animal personalities. Such phenotypes may be fundamental to fisheries and aquaculture, yet there have been few detailed studies of this phenomenon in exploited marine animals. We investigated the behavioural and neuroendocrine responses of Atlantic cod (Gad us morhua L), to situations reflecting critical ecological challenges: predator attacks and territorial challenges. Both hatchery-reared and wild fish were tested and behavioural profiles were compared with baseline conditions. We then used an objective, multivariate approach, rather than assigning individuals along one-dimensional behavioural axes, to examine whether distinct behavioural phenotypes were present. Our results indicate that two distinct behavioural phenotypes were evident in fish from each background. In hatchery-reared fish, phenotypes displayed divergent locomotor activity, sheltering, brain monoamine concentrations and responses to competitive challenges. In wild fish, phenotypes were distinguished primarily by locomotor activity, sheltering and responsiveness to predator stimuli. Hatcheries presumably represent a more stressful social environment, and social behaviour and neuroendocrine responses were important in discerning behavioural phenotypes in hatchery fish, whereas antipredator responses were important in discerning phenotypes in wild fish that have previously encountered predators. In both fish types, behavioural and physiological traits that classified individuals into phenotypes were not the same as those that were correlated across situations These results highlight the multidimensionality of animal personalities, and that the processes that regulate one suite of behavioural traits may be very different to the processes that regulate other behaviours.
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| 49. |
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| 50. |
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