| 1. |
- Sikora, M., et al.
(författare)
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The population history of northeastern Siberia since the Pleistocene
- 2019
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 570:7760
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Tidskriftsartikel (refereegranskat)abstract
- Northeastern Siberia has been inhabited by humans for more than 40,000 years but its deep population history remains poorly understood. Here we investigate the late Pleistocene population history of northeastern Siberia through analyses of 34 newly recovered ancient genomes that date to between 31,000 and 600 years ago. We document complex population dynamics during this period, including at least three major migration events: an initial peopling by a previously unknown Palaeolithic population of 'Ancient North Siberians' who are distantly related to early West Eurasian hunter-gatherers; the arrival of East Asian-related peoples, which gave rise to 'Ancient Palaeo-Siberians' who are closely related to contemporary communities from far-northeastern Siberia (such as the Koryaks), as well as Native Americans; and a Holocene migration of other East Asian-related peoples, who we name 'Neo-Siberians', and from whom many contemporary Siberians are descended. Each of these population expansions largely replaced the earlier inhabitants, and ultimately generated the mosaic genetic make-up of contemporary peoples who inhabit a vast area across northern Eurasia and the Americas.
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| 2. |
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| 3. |
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| 4. |
- Jutfelt, Fredrik, 1975, et al.
(författare)
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Translocation of viable Aeromonas salmonicida across the intestine of rainbow trout, Oncorhynchus mykiss (Walbaum)
- 2006
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Ingår i: Journal of Fish Diseases. - : Wiley. - 0140-7775 .- 1365-2761. ; 29:5, s. 255-262
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Tidskriftsartikel (refereegranskat)abstract
- The pathogenic bacterium Aeromonas salmonicida is the causative agent of the destructive disease furunculosis in salmonids. Horizontal transmission in salmonids has been suggested to occur via the skin, gills and/or intestine. Previous reports are contradictory regarding the role of the intestine as a route of infection. The present study therefore investigates the possibility of bacterial translocation across intestinal epithelia using Ussing chamber technology, in vitro. Intestinal segments were exposed for 90 min to fluorescein isothiocyanate-labelled pathogenic A. salmonicida. Sampling from the serosal side of the Ussing chambers showed that bacteria were able to translocate across the intestinal epithelium in both the proximal and distal regions. Plating and subsequent colony counting showed that the bacteria were viable after translocation. During the 90 min exposure to A. salmonicida, the intestinal segments maintained high viability as measured by electrical parameters. The distal region responded to bacterial exposure by increasing the electrical resistance, indicating an increased mucus secretion. This study thus demonstrates translocation of live A. salmonicida through the intestinal epithelium of rainbow trout, suggesting that the intestine is a possible route of infection in salmonids.
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| 5. |
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| 6. |
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| 7. |
- Olsen, R. E., et al.
(författare)
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Acute stress alters intestinal function of rainbow trout, Oncorhynchus mykiss (Walbaum)
- 2005
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486. ; 250:1-2, s. 480-495
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Tidskriftsartikel (refereegranskat)abstract
- Groups of rainbow trout (Oncorhynchus mykiss Walbaum) in feeding (guts filled with digesta) or food-deprived (3 days of diet deprivation) states were subjected to 15 min of acute stress. Blood samples and intestinal tissue were collected and prepared for physiological, chemical and ultrastructural analysis immediately before stress, and at 4 and 48 h post-stress. Haematocrit, plasma cortisol and lactate levels increased following stress, and the response appeared to be more pronounced in food-deprived than in fed fish. Plasma glucose appeared to increase more in fed fish. Stress did not seem to cause massive tissue damage as measured by cellular leakage of transaminase enzymes into the blood. Furthermore, the plasma oxidative stress marker malondialdehyde did not increase markedly following stress. The content of malondialdehyde did not change following stress neither in midgut nor hindgut sections, and nor did membrane lipid class and fatty acid compositions. Ultrastructural studies showed that stress caused significant widening of the tight junctions between enterocytes in the midgut, with little effect seen in the hindgut. Fed fish appeared to experience more damage than food-deprived fish as judged by the ultrastructural analysis. But these changes were to a large extent transient and cellular organization in the midgut had returned to normal values within 2 days. Intestinal paracellular permeability of the midgut increased 4 h post-stress and was further increased 48 h post-stress of food-deprived fish, whereas no effect was seen in fed trout. In hindgut of food-deprived fish, the permeability appeared to increase sometime after 4 h and was still elevated 48 h after stress. No change in permeability occurred in fed fish. The adherent microbial population level and composition in hindgut was significantly reduced following stress, while the level increased in faeces. This suggests that substantial amounts of mucus are peeled off following stress. It is concluded that, under the present experimental conditions, acute stress causes cellular alteration in rainbow trout gastrointestinal tract. Ultrastructural damages are mainly observed in midgut, but most changes appear to be transient returning to normal levels within 48 h. Changes in adherent intestine microbial population level and compositions together with increased intestinal paracellular permeability following acute stress suggest a possible increased susceptibility to bacterial infections after stress and that active feeding may have a protective role. (C) 2005 Elsevier B.V. All rights reserved.
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| 8. |
- Olsen, R.E., et al.
(författare)
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The acute stress response in fed and food deprived Atlantic cod, Gadus morhua L.
- 2008
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486. ; 280:1-4, s. 232-241
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to evaluate the effect of stress and nutritional state (fed vs food deprived) on the generalized stress response and intestinal integrity in Atlantic cod (Gadus morhua L.). Cod in feeding or food deprived states were subjected to 15 min of acute stress (exhaustive exercise). Blood was collected at 9 intervals from before stress (t = 0), to t = 48 h post stress and analysed for blood haematocrit and haemoglobin, and plasma cortisol, lactate, glucose, osmolality, chloride, as well as the tissue damage indicators glutamate oxaloacetate transaminase, glutamate pyruvate transaminase and thiobarbituric acid reactive substances. Intestinal segments were prepared for histology with the same intervals, while assessment of intestinal integrity and microbiology was performed at t = 0, 4 and 48 h post stress. Subjecting cod to exhaustive stress initiated a standard stress response including increased blood Hct and plasma cortisol, glucose, chloride, osmolality and lactate. Food deprived fish did in general have reduced stress resistance compared to fed fish. For many parameters, cod returned slowly to basal levels. Cellular indicators of tissue damage and oxidative stress increased in a biphasic manner following stress. Stress did not affect gut histology but did transiently increase gut permeability. Furthermore, stress had no effect on the adherent bacterial population level in midgut, but did cause a small decrease in hindgut (non-significant) and hindgut chamber (p < 0.05). Isolates belonging to Carnobacterium were predominant but not affected by stress. In conclusion, food deprived cod are less resistant to stress than fed cod. The magnitude of the response is less than in salmonids, but the effects are persistent (including tissue damage indicators and oxidative stress) and may have negative long term consequences. The gut is relatively resistant to stress, there is however a transient increase in the intestinal permeability and alterations in microbiota that may indicate lower protection against invading pathogens.
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| 9. |
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| 10. |
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| 11. |
- Arapoglu, S., et al.
(författare)
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Multi-spin giants
- 2004
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Ingår i: Phys. Rev.. ; D69, s. 106006-
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Tidskriftsartikel (refereegranskat)
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| 12. |
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| 13. |
- Berman, David S., et al.
(författare)
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Holographic Noncommutativity
- 2000
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Ingår i: J. High Energy Phys. ; 05, s. 002-
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Tidskriftsartikel (refereegranskat)
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| 14. |
- Bexell, U., et al.
(författare)
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A ToF-SIMS study of linseed oil bonded to mercapto silane treated aluminium
- 2004
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Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 231-2, s. 362-365
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Tidskriftsartikel (refereegranskat)abstract
- ToF-SIMS has been used to analyse an aluminium surface treated with a vegetable oil using a mercapto silane as a coupling agent between the aluminium substrate and the vegetable oil. The coupling between the vegetable oil and the mercapto silane was obtained through a photoinduced thiol-ene reaction using UV-radiation. The ToF-SIMS results show that the desired thiolene reaction has taken place between the unsaturated parts of the vegetable oil and the thiol groups of the mercapto silane via the thiol-ene reaction forming a surface film.
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| 15. |
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| 16. |
- Bexell, U., et al.
(författare)
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A tribological study of a novel pre-treatment with linseed oil bonded to mercaptosilane treated aluminium
- 2003
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Ingår i: Surface & Coatings Technology. - 0257-8972 .- 1879-3347. ; 166:03-feb, s. 141-152
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Tidskriftsartikel (refereegranskat)abstract
- In sheet metal forming processes, lubricants are necessary in order to prevent galling, i.e. material transfer from the sheet metal to the tool surface and to control friction. Today, dry lubricants are increasingly being used for solving this problem. Among these, multifunctional coatings, often referred to as permanent coatings, normally based on organic resins, are lubricants which have the potential to increase the formability without additional lubrication, give corrosion protection, fingerprint and scratch resistance during handling and transport and finally, serve as a pre-treatment before painting. With increasing concern about the environment and human health it is important to develop new environmentally friendly pre-treatments in the surface engineering of metal substrates. This is mainly due to the toxic and carcinogenic properties of the chromium based surface pre-treatments frequently used in the industry. During the last decade, simple solution-dip silane based pre-treatments have emerged as promising candidates for the replacement of currently used pre-treatments of metals. A silane film can give good corrosion protection properties but is often too thin to prevent galling under a forming operation. A renewed interest for using vegetable oils in surface engineering has appeared lately due to several factors. Vegetable oils are renewable resources, modem technology can produce more well defined and pure oils, and the fatty acid content can be altered with modern crops development techniques. With the proper choice of silane pre-treatment of a metal surface, a vegetable oil can be coupled to the surface and give the desired lubrication properties. In this paper, aluminium sheets have been pre-treated with a mercapto silane after which a vegetable oil has been attached. The coupling between the silane and the oil was obtained through a photoinduced thiol-ene reaction using UV-radiation. The influence of different process parameters on the friction and wear behaviour was evaluated using modified scratch testing. Scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and contact angle measurements were used to characterise the as-deposited surface films and their tribological behaviour, i.e. failure mechanisms. The results obtained show that the unsaturated vegetable oil has reacted with the thiol groups via the thiol-ene reaction forming a surface film. Also, the results show that the thickness of the films is of importance for the tribological characteristics, i.e. a too thin layer (less than 25 A in the present work) results in high friction and severe adhesive wear. However, a thicker layer with enhanced load carrying capacity can be produced with a proper heat treatment of the deposited vegetable oil. Finally, the results show that thick (more than 200 Angstrom in the present work) silane films are sensitive to brittle fracture when exposed to a sliding contact.
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| 17. |
- Bexell, Ulf, et al.
(författare)
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Bonding of vegetable oils to mercapto silane treated metal surfaces : Surface engineering on the nano scale
- 2006
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Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 515:2, s. 838-841
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Tidskriftsartikel (refereegranskat)abstract
- In this paper the bonding of thin vegetable oil films on mercapto silane treated aluminium surfaces has been studied. The silane molecules are attached to the surface by metal-oxygen-silicon bonds. The coupling between the unsaturated bonds of the vegetable oil and the thiol functionalised surface was obtained through a photoinduced thiol-ene reaction. The surfaces were characterised by X-ray photoelectron spectroscopy (XPS). Vegetable oil contains both saturated and unsaturated carbon chains. For the reactions investigated in this study it is the unsaturated carbon chains that can react by a thiol-ene reaction and the results indicate that it is possible to attach a vegetable oil to a metal surface pre-treated with a thiol functionalised silane.
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| 18. |
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| 19. |
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| 20. |
- Brijs, J., et al.
(författare)
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Humane slaughter of African sharptooth catfish (Clarias gariepinus): Effects of various stunning methods on brain function
- 2021
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486 .- 1873-5622. ; 531
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Tidskriftsartikel (refereegranskat)abstract
- © 2020 The Authors Common slaughter procedures for African sharptooth catfish (Clarias gariepinus) include asphyxiation, ice chilling and exsanguination, which may all cause substantial suffering over prolonged periods of time before death. Therefore, comprehensive evaluations of potentially more humane slaughter procedures for this species are urgently needed. Here, we use a non-invasive electroencephalographic (EEG) method to assess the state of sensibility in African sharptooth catfish in response to various stunning methods (e.g. ice chilling, electrical stunning, electrical stunning followed by exsanguination, percussive stunning, and immersion in isoeugenol). Based on the abolition of visually evoked responses (VERs) on the EEG, ice slurry immersion induced insensibility between 2.6 and 7.6 min, during which catfish exhibited aversive behaviours. Once VERs were lost, they remained absent so long as catfish remained immersed in the ice slurry. Electrical stunning (i.e. exposure to ~1.7 A dm−2 at a water conductivity of ~997 μS cm−1) induced insensibility immediately but not irreversibly. Depending on the duration of the stun (i.e. from 1 to 10 s), catfish either regained VERs immediately or within 4.9 min after the completion of the electrical insult. However, when a 10 s electrical stun was immediately followed by exsanguination and immersion in an ice slurry, the duration of insensibility was sufficient to humanely kill catfish. When administered correctly, manual percussive stunning with a fish priest induced insensibility immediately and irreversibly. However, 36% of catfish regained VERs, which is likely explained by the difficulty associated with administering an accurate manual percussive stun of sufficient force on a live and struggling catfish. Catfish appeared to be sedated following immersion in isoeugenol (i.e. catfish were calm and easy to handle), yet VERs remained present at doses exceeding that recommended for euthanasia in salmonids, which indicates that this substance may not be suitable for stunning catfish. However, the potential for using isoeugenol as a pre-stunning sedative for improving handleability and reducing handling stress of this species warrants further investigation. In conclusion, this study clearly demonstrates that when singularly administered, none of the abovementioned stunning methods could reliably induce insensibility immediately and/or irreversibly without welfare implications. Yet, our findings indicate that these shortcomings can be resolved by using a combination of methods. This could include an electrical or percussive stun to immediately induce insensibility that should be immediately followed by exsanguination and immersion in an ice slurry to maintain insensibility until death.
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| 21. |
- Cederwall, Martin, 1961, et al.
(författare)
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An action for the superfive-brane in D=11 supergravity
- 1997
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Ingår i: J. High Energy Phys. 9804:007,1998.
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Tidskriftsartikel (refereegranskat)abstract
- An alternative path is taken for deriving an action for the supersymmetric 5-brane in 11 dimensions. Selfduality does not follow from the action, but is consistent with the equations of motion for arbitrary supergravity backgrounds. The action involves a 2-form as well as a 5-form world-volume potential; inclusion of the latter makes the action, as well as the non-linear selfduality relation for the 3-form field strength, polynomial. The requirement of invariance under kappa-transformations determines the form of the selfduality relation, as well as the action. The formulation is shown to be equivalent to earlier formulations of 5-brane dynamics.
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| 22. |
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| 23. |
- Clark, M. S., et al.
(författare)
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Deciphering mollusc shell production: the roles of genetic mechanisms through to ecology, aquaculture and biomimetics
- 2020
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Ingår i: Biological Reviews. - : Wiley. - 1464-7931 .- 1469-185X. ; 95:6, s. 1812-37
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Tidskriftsartikel (refereegranskat)abstract
- Most molluscs possess shells, constructed from a vast array of microstructures and architectures. The fully formed shell is composed of calcite or aragonite. These CaCO(3)crystals form complex biocomposites with proteins, which although typically less than 5% of total shell mass, play significant roles in determining shell microstructure. Despite much research effort, large knowledge gaps remain in how molluscs construct and maintain their shells, and how they produce such a great diversity of forms. Here we synthesize results on how shell shape, microstructure, composition and organic content vary among, and within, species in response to numerous biotic and abiotic factors. At the local level, temperature, food supply and predation cues significantly affect shell morphology, whilst salinity has a much stronger influence across latitudes. Moreover, we emphasize how advances in genomic technologies [e.g. restriction site-associated DNA sequencing (RAD-Seq) and epigenetics] allow detailed examinations of whether morphological changes result from phenotypic plasticity or genetic adaptation, or a combination of these. RAD-Seq has already identified single nucleotide polymorphisms associated with temperature and aquaculture practices, whilst epigenetic processes have been shown significantly to modify shell construction to local conditions in, for example, Antarctica and New Zealand. We also synthesize results on the costs of shell construction and explore how these affect energetic trade-offs in animal metabolism. The cellular costs are still debated, with CaCO(3)precipitation estimates ranging from 1-2 J/mg to 17-55 J/mg depending on experimental and environmental conditions. However, organic components are more expensive (similar to 29 J/mg) and recent data indicate transmembrane calcium ion transporters can involve considerable costs. This review emphasizes the role that molecular analyses have played in demonstrating multiple evolutionary origins of biomineralization genes. Although these are characterized by lineage-specific proteins and unique combinations of co-opted genes, a small set of protein domains have been identified as a conserved biomineralization tool box. We further highlight the use of sequence data sets in providing candidate genes forin situlocalization and protein function studies. The former has elucidated gene expression modularity in mantle tissue, improving understanding of the diversity of shell morphology synthesis. RNA interference (RNAi) and clustered regularly interspersed short palindromic repeats - CRISPR-associated protein 9 (CRISPR-Cas9) experiments have provided proof of concept for use in the functional investigation of mollusc gene sequences, showing for example that Pif (aragonite-binding) protein plays a significant role in structured nacre crystal growth and that theLsdia1gene sets shell chirality inLymnaea stagnalis. Much research has focused on the impacts of ocean acidification on molluscs. Initial studies were predominantly pessimistic for future molluscan biodiversity. However, more sophisticated experiments incorporating selective breeding and multiple generations are identifying subtle effects and that variability within mollusc genomes has potential for adaption to future conditions. Furthermore, we highlight recent historical studies based on museum collections that demonstrate a greater resilience of molluscs to climate change compared with experimental data. The future of mollusc research lies not solely with ecological investigations into biodiversity, and this review synthesizes knowledge across disciplines to understand biomineralization. It spans research ranging from evolution and development, through predictions of biodiversity prospects and future-proofing of aquaculture to identifying new biomimetic opportunities and societal benefits from recycling shell products.
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| 24. |
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| 25. |
- Gilles, Stefanie, et al.
(författare)
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Pollen exposure weakens innate defense against respiratory viruses.
- 2020
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Ingår i: Allergy. - : Wiley. - 1398-9995 .- 0105-4538. ; 75:3, s. 576-587
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Tidskriftsartikel (refereegranskat)abstract
- Hundreds of plant species release their pollen into the air every year during early spring. During that period, pollen allergic as well as non-allergic patients frequently present to doctors with severe respiratory tract infections.To assess whether pollen may interfere with antiviral immunity.We combined data from real life human exposure cohorts, a mouse model and human cell culture to test our hypothesis.Pollen significantly diminished interferon-λ and pro-inflammatory chemokine responses of airway epithelia to rhinovirus and viral mimics and decreased nuclear translocation of interferon regulatory factors. In mice infected with respiratory syncytial virus, co-exposure to pollen caused attenuated antiviral gene expression and increased pulmonary viral titers. In non-allergic human volunteers, nasal symptoms were positively correlated with airborne birch pollen abundance, and nasal birch pollen challenge led to down-regulation of type I and -III interferons in nasal mucosa. In a large patient cohort, numbers of rhinovirus-positive cases were correlated with airborne birch pollen concentrations.The ability of pollen to suppress innate antiviral immunity, independent of allergy, suggests that high-risk population groups should avoid extensive outdoor activities when pollen and respiratory virus seasons coincide.
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| 26. |
- Hjelmstedt, P., et al.
(författare)
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Assessing the effectiveness of percussive and electrical stunning in rainbow trout: Does an epileptic-like seizure imply brain failure?
- 2022
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486 .- 1873-5622. ; 552
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Tidskriftsartikel (refereegranskat)abstract
- Both percussive and electrical stunning have been highlighted as methods that can be used to quickly render fish unconscious before being killed. However, accurately assessing unconsciousness in animals following stunning remains challenging, and thus methods for reliable interpretation and validation of different stunning methods are urgently needed. Here, we used a non-invasive technique to continuously record electroencephalograms (EEG) of rainbow trout (Oncorhynchus mykiss) enabling us to compare the effects of both percussive stunning, using a captive bolt gun, and various combinations of electrical stun parameters delivered in water. The EEG signals were assessed for the absence or presence of an epileptic-like seizure and for visually evoked responses (VERs). No epileptic-like seizures or VERs were observed after captive bolt stunning. We found that it is possible to reliably induce an epileptic-like seizure and an immediate, but short lasting, loss of VERs following a 1 s exposure to an electrical field strength of at least 2.8 VRMS cm−1 and current density of 0.22 ARMS dm−2 in water of conductivity of ~1000 μS cm−1 using a 50 Hz AC current. However, to avoid recovery of VERs shortly after the stun, it was necessary to increase the duration of the stun application (≥30 s), the electrical field strength (10.2 VRMS cm−1) and the current density (0.84 ARMS dm−2 respectively). We found no clear relationship between presence and absence of ventilation and VERs following electrical stunning in rainbow trout, highlighting that loss of ventilation may not be a good indicator of brain failure in rainbow trout. Our results clearly show that the presence of an epileptic-like seizure following an electrical stun does not guarantee a prolonged period where the fish is unresponsive to visual stimulation (i.e. absence of VERs). It was further found that VERs can return before the end of the seizure. As both presence of a seizure and absence of VERs have been used independently as indicators of unconsciousness in fish, we emphasize the necessity to carefully consider and evaluate the reliability of neurophysiological indicators of unconsciousness when validating methods to stun fish. © 2022
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| 27. |
- Jafarzadeh, Shadi, et al.
(författare)
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UV-curable acrylate-based nanocomposites : Effect of polyaniline additives on the curing performance
- 2013
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Ingår i: Polymers for Advanced Technologies. - : Wiley. - 1042-7147 .- 1099-1581. ; 24:7, s. 668-678
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Tidskriftsartikel (refereegranskat)abstract
- Composites of nanostructured polyaniline (PANI) conducting polymer in a polyester acrylate (PEA) formulation were made to provide conductive organic coatings. The effect of the presence and amount of PANI on the photocuring performance of the ultraviolet (UV)-curable acrylate system has been investigated employing real-time Fourier transform infrared spectroscopy as the main technique. Longer initial retardation of the radical polymerization and lower rates of cross-linking reactions were observed for dispersions containing PANI of higher than 3wt.%. The PEA/PANI samples were more affected than the neat PEA resin by the changes in UV light intensity and oxygen accessibility during UV curing. Samples with higher PANI content, of up to 10wt.%, were tested and could be partially cured even at UV light intensities as low as 2mW cm-2 when the oxygen replenishment into the system was inhibited. Thermal analysis revealed that the presence of PANI did not induce any significant change in Tg of the cured system, meaning that early decrease in mobility and vitrification is not the reason for lower ultimate conversion of the dispersions with higher PANI content compared with the neat PEA resin. Curing under strong UV lamps, of 1.5W cm-2 intensity, made it possible to reach high degrees of conversion on films with similar mechanical properties independent of the PANI content.
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| 28. |
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| 29. |
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| 30. |
- Jutfelt, Fredrik, 1975, et al.
(författare)
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Parr-smolt transformation and dietary vegetable lipids affect intestinal nutrient uptake, barrier function and plasma cortisol levels in Atlantic salmon
- 2007
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486. ; 273:2-3, s. 298-311
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Tidskriftsartikel (refereegranskat)abstract
- For Atlantic salmon, the gastrointestinal tract is the site of food digestion and nutrient uptake, a regulatory site for ion and water balance as well as a barrier against invading pathogens. During the parr–smolt transformation and subsequent seawater (SW) transfer, major changes occur in the intestine. A global shortage of fish oils (FO) for feed production is estimated to appear within a few years, and vegetable oils (VO) are being considered as alternatives for FO in fish feed production. However, VO influences the fatty acid composition of the polar lipids of cell membranes in the intestine which can disturb intestinal functions. A VO-based diet during the parr–smolt transformation, which is a sensitive developmental period, may cause adverse effects. Therefore, Atlantic salmon parr were fed either sunflower oil (SO) or FO as the major lipid source during out-of-season light controlled parr–smolt transformation. At three time points gill Na+,K+-ATPase activity and plasma levels of cortisol and growth hormone were assessed. Intestinal epithelia were sampled for assessment of nutrient absorption and bacterial translocation using an Ussing chamber in vitro system. While both dietary groups showed plasma hormone profiles indicative of successful parr–smolt transformation, the SO-fed fish had consistently increased cortisol levels compared to the FO-fed fish. Translocation of pathogenic bacteria increased, probably due to disturbed barrier functions, during the parr–smolt transformation. However, the fish fed the SO-diet maintained a higher barrier function compared to FO-fed fish, an effect that may be beneficial to these fish. Nutrient uptake was less affected by smoltification. Fish fed the SO-diet had higher uptake rates of amino acids and free fatty acids during mid-smoltification than fish fed the FO-diet. The combined effects of barrier function and nutrient uptake may suggest a positive effect of including vegetable lipids in the diet during the parr–smolt transformation. However, the vegetable lipid diet also seemed to act as a stressor and elevated the basal cortisol levels, which may be of concern in the context of general fish health and welfare.
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| 31. |
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| 32. |
- Lundborg, C. S., et al.
(författare)
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Pharmacoepidemiology at Nordic School of Public Health NHV: Examples from 1999 to 2014
- 2015
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Ingår i: Scandinavian Journal of Public Health. - : SAGE Publications. - 1403-4948 .- 1651-1905. ; 43:16 Suppl, s. 73-80
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Tidskriftsartikel (refereegranskat)abstract
- Background: Pharmacoepidemiology is a branch of public health and had a place at the Nordic School of Public Health. Courses, Master's theses and Doctorates of Public Health (DrPH) in Pharmacoepidemiology were a relatively minor, but still important part of the school's activities. Methods: This paper gives a short background, followed by some snapshots of the activities at NHV, and then some illustrative case-studies. These case-studies list their own responsible co-authors and have separate reference lists. Results: In the Nordic context, NHV was a unique provider of training and research in pharmacoepidemiology, with single courses to complete DrPH training, as well as implementation of externally-funded research projects. Conclusions: With the closure of NHV at the end of 2014, it is unclear if such a comprehensive approach towards pharmacoepidemiology will be found elsewhere in the Nordic countries.
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| 33. |
- Nameer, Samer, et al.
(författare)
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Bio-based multifunctional fatty acid methyl esters as reactive diluents in coil coatings
- 2019
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Ingår i: Progress in organic coatings. - : Elsevier. - 0300-9440 .- 1873-331X. ; 136
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Tidskriftsartikel (refereegranskat)abstract
- The increased environmental awareness has driven academia and industry to utilize environmentally benign sources. An industrially available process that is effective in the coatings industry is the coil-coating process where sheet steel can be pre-coated. During this process volatile organic compounds (VOCs) are generated and incinerated for energy recovery. One way to minimize VOCs is to use a reactive diluent i.e. a molecule that acts both as a solvent as well as chemically react into the final coating upon curing. Fatty acid methyl esters obtained from renewable resources such as vegetable oils are suitable candidates as reactive diluents. In this paper epoxidized fatty acid methyl esters (e-FAMEs) obtained from epoxidized linseed oil where compared with fatty acid methyl esters (FAMEs) obtained from rapeseed oil as reactive diluents in coil-coating formulations. Coil-coating formulations were followed by real-time Fourier transform infrared spectroscopy (RT-FTIR) in order to evaluate the e-FAMEs or the FAMEs reactivity in the coating system. In addition, coil-coating formulation containing e-FAME or FAME where cured in a pilot scale simulated coil-coating process. Moreover, thermal properties of the final coatings were evaluated by differential scanning calorimetry (DSC).
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| 34. |
- Niklasson, Lars, et al.
(författare)
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Effects of Cortisol on the Intestinal Mucosal Immune Response during Cohabitant Challenge with IPNV in Atlantic Salmon (Salmo salar)
- 2014
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 9:5
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Tidskriftsartikel (refereegranskat)abstract
- Infectious pancreatic necrosis virus (IPNV) causes high incidence of disease in salmonids during the first period after SW transfer. During this period as well as during periods of stress, cortisol levels increase and indications of a relationship between IPNV susceptibility and cortisol have been suggested. The intestine is an entry route and a target tissue for IPNV displaying severe enteritis and sloughing of the mucosa in infected fish. The mechanisms behind effects of the virus on the intestinal tissue and the impact of cortisol on the effect remain unclear. In the present study, Atlantic salmon post smolts treated with or without slow release cortisol implants were subjected to a cohabitant IPNV challenge. Analysis of genes and proteins related to the innate and acquired immune responses against virus was performed 6 days post-challenge using qPCR and immunohistochemistry. An increased mRNA expression of anti-viral cytokine interferon type I was observed in the proximal intestine and head kidney as a response to the viral challenge and this effect was suppressed by cortisol. No effect was seen in the distal intestine. T-cell marker CD3 as well as MHC-I in both intestinal regions and in the head kidney was down regulated at the mRNA level. Number of CD8 alpha lymphocytes decreased in the proximal intestine in response to cortisol. On the other hand, mRNA expression of Mx and IL-1 beta increased in the proximal intestine and head kidney in IPNV challenged fish in the presence of cortisol suggesting that the immune activation shifts in timing and response pathway during simulated stress. The present study clearly demonstrates that IPNV infection results in a differentiated epithelial immune response in the different intestinal regions of the Atlantic salmon. It also reveals that the epithelial immune response differs from the systemic, but that both are modulated by the stress hormone cortisol.
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| 35. |
- Nilsen, Tom Ole, et al.
(författare)
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EFFECTS OF ANDROGENS AND CORTISOL ON GILL ION TRANSPORTERS AND OMSMOREGULATORY CAPACITY IN ATLANTIC SALMON (SALMO SALAR)
- 2014
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Ingår i: ICBF 2014, Edinburgh.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Sex steroids have been reported to compromise ion homeostasis in teleosts, yet there is limited and somewhat contradicting knowledge about the mechanisms through which androgens impact osmoregulatory capacity in salmonids. Immature Atlantic salmon post-smolts in seawater (SW) were injected with 11-ketoandrostenedione (OA; 25 µg/g BW), cortisol (F; 25 µg/g BW), F+OA (25 µg/g BW) and sham control (CON). After 8 days treatment, androgen treated fishdemonstrated a striking transcriptional increase in freshwater (FW)-type of ion transporters (NKA α1a ) , concurrent with no apparent ion perturbations, or down regulation of SW gill ion-transporters (NKA α1b). F treated post-smolts displayed increased gill NKA α1a transcription, with an additive effect of F+OA.. Moreover, F also resulted in decreased transcription of NKA α1b whilst fish treated with combinations of F and OA experienced severe ion perturbations and mortalities in SW, while no mortality occurred when only F was administered. Our findings suggests that androgens have, either directly or indirectly, a role in remodelling the gill epithelia for FW entry, rather than leading to osmoregulatory dysfunction in SW acclimated post-smolts. Moreover, maturing post-smolts may be sensitive to stress since combinations of elevated androgens and cortisol levels may have detrimental effects on homeostasis and fish welfare.
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| 36. |
- Olsen, R.E., et al.
(författare)
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Acute stress alters the intestinal lining of Atlantic salmon, Salmo salar L.: An electron microscopical study
- 2002
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Ingår i: Fish Physiology and Biochemistry. ; 26, s. 211-221
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Tidskriftsartikel (refereegranskat)abstract
- Groups of Atlantic salmon (Salmo salar L.) in feeding (guts filled with faeces) or fasted (three days of diet deprivation) states were subjected to 15 minutes of acute stress. Blood samples and intestinal tissue were collected and prepared for chemical and ultrastructural analyses at intervals post stress until 53 h of recovery. Subjecting fish to acute stress led to significant alterations of the ultrastructure of the enterocytes lining the gastrointestinal tract (GI tract). The most notable effect was substantial damage to the intercellular junctional complexes in midgut regions. These effects appeared within the first hour after stress, were maintained for at least 12 h and were more pronounced in fed than fasted fish. In contrast, hindgut was influenced less by stress and damage was rarely observed. Stress also influenced fish intestinal microbiota. Adherent bacteria decreased in both midgut and hindgut of stressed fish, and this was accompanied by a significant increase in the bacterial contents of faeces. It is suggested that this was due to the sloughing off of mucus eliminating existing microflora and allowing remaining bacteria (also pathogenic) in the gut lumen to colonize the surface of the enterocytes. Although blood haematocrit and plasma cortisol increased following stress, the response appeared to be greater in fasted fish. There were also significant differences in carbohydrate metabolism. While liver glycogen stores were depleted in fasted fish following the mobilization of glucose into plasma, liver glycogen was never depleted in fed fish. As a consequence, plasma glucose levels remained high for more than 12 h of recovery. In fed fish, plasma lactate was also higher than in fasted salmon, and the clearance rate appeared slower. Acute stress induced oxidative stress, as measured through plasma malondialdehyde, but the effect was marginal and nonsignificant.
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| 37. |
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| 38. |
- Olsson, Tina M., et al.
(författare)
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Adapted, Adopted, and Novel Interventions : A Whole-Population Meta-Analytic Replication of Intervention Effects
- 2023
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Ingår i: Research on social work practice. - : Sage Publications. - 1049-7315 .- 1552-7581.
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Tidskriftsartikel (refereegranskat)abstract
- Background: A challenge to implementation is management of the adaptation-fidelity dilemma or the balance between adopting an intervention with fidelity while assuring fit when transferred between contexts. A prior meta-analysis found that adapted interventions produce larger effects than novel and adopted interventions. This study attempts to replicate and expand previous findings. Methods: Meta-analysis was used to compare effects across a whole-population of Swedish outcome studies. Main and subcategories are explored. Results: The 523 studies included adapted (22%), adopted (33%), and novel (45%) interventions. The largest effect was found for adapted followed by novel and adopted interventions. Interventions in the mental health setting showed the highest effects, followed by somatic healthcare and social services. Conclusions: These results replicate and expand earlier findings. Results were stable across settings with the exception of social services. Consistent with a growing body of evidence results suggest that context is important when transferring interventions across settings.
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| 39. |
- Oxley, A., et al.
(författare)
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Sn-2-monoaglycerol, not glycerol, is preferentially utilized for triacylglycerols and phosphatidylcholine biosynthesis in Atlantic salmon (Salmo salar L.) intestine.
- 2006
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Ingår i: Comparative Biochemistry and Physiology. Part B: Biochemistry & Molecular Biology. - : Elsevier BV. - 1096-4959. ; 146:1, s. 115-123
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Tidskriftsartikel (refereegranskat)abstract
- Pathways of lipid resynthesis in the intestine of fish are relatively unknown. Various reports have suggested the existence of both sn-1,3-specific (pancreatic) and non-specific (bile salt-activated) lipase activity operating on dietary triacylglycerol (TAG) in the intestinal lumen of fish during digestion. Thus, sn-2-monoacylglycerol (2-MAG) and glycerol, respective hydrolytic products of each lipase, are absorbed and utilised for glycerolipid synthesis in enterocytes via two alternative routes: monoacylglycerol (MAG) and glycerol-3-phosphate (G3P) pathways. Despite different precursors, both pathways converge at the production of sn-1,2-diacylglycerol (1,2-DAG) where TAG or phosphatidylcholine (PC) synthesis can occur. To elucidate the relative activities of MAG and G3P pathways in Atlantic salmon enterocytes, intestinal segments were mounted in Ussing chambers where equimolar mixtures of sn-2-oleoyl-[1,2,3-3H]glycerol (2-MAG) and [14C(U)]glycerol, plus unlabelled 16:0 and 18:2n-6 as exogenous fatty acid sources, were delivered in bile salt-containing Ringer solution to the mucosa. The MAG pathway predominated, over the G3P pathway, synthesizing ca. 95% of total TAG and ca. 80% of total PC after a 3 h incubation period at 10 °C. Further, the 1,2-DAG branch point into TAG or PC was polarised towards TAG synthesis (6:1) via the MAG pathway but more evenly distributed between TAG and PC (1:1) via the G3P pathway. Effect of long-chain saturated, monounsaturated and polyunsaturated fatty acids on the synthesized TAG/PC ratio was assessed by individually exchanging 16:0, 18:1n-9 or 18:2n-6, for 16:0 + 18:2n-6, in mucosal solutions. TAG synthesis was influenced considerably more than PC synthesis, via either pathway, by exogenous fatty acids utilised. 18:1n-9 significantly stimulated TAG synthesis via the MAG pathway yielding a TAG/PC ratio of 12:1. Alternatively, 18:2n-6 stimulated TAG synthesis the most via the G3P pathway (TAG/PC = 4:1). 16:0 significantly attenuated TAG synthesis via either pathway. Micellar fatty acid species also significantly affected intestinal active transport mechanisms as shown by decreasing transepithelial potential (TEP) and short-circuit current (SSC) with increasing fatty acid unsaturation. The epithelial integrity was, however, not compromised after 3 h of exposure to any of the fatty acids. The implications of these findings on dietary fatty acid composition and enterocytic lipid droplet accumulation are discussed.
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| 40. |
- Persson, Daniel, et al.
(författare)
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Depth-resolved FTIR focal plane array (FPA) spectroscopic imaging of the loss of melamine functionality of polyester melamine coating after accelerated and natural weathering
- 2020
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Ingår i: Polymer testing. - : Elsevier Ltd. - 0142-9418 .- 1873-2348. ; 86
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Tidskriftsartikel (refereegranskat)abstract
- FTIR-ATR (Focal Plane Array) FPA spectroscopic imaging was used to obtain depth resolved information about degradation of a polyester melamine coating by performing measurements on drilled conical holes. The results of the FTIR-FPA imaging show that combined effect of UV and moisture resulted in larger degradation effects in the outermost parts of the coatings but loss of melamine functionality was detected to the depth of approximately 8–10 μm after 2163 h weathering in QUVA accelerated test and after 4 years exposure in a marine environment. Longer periods of accelerated weathering, up to 4000 h, resulted in degradation through the whole coating outer layer.
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| 41. |
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| 42. |
- Ringø, Einar, et al.
(författare)
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Damaging effect of the fish pathogen Aeromonas salmonicida ssp salmonicida on intestinal enterocytes of Atlantic salmon (Salmo salar L.)
- 2004
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Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 318:2, s. 305-312
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Tidskriftsartikel (refereegranskat)abstract
- In fish, bacterial pathogens can enter the host by one or more of three different routes: (a) skin, (b) gills and (c) gastrointestinal tract. Bacteria can cross the gastrointestinal lining in three different ways. In undamaged tissue, bacteria can translocate by transcellular or paracellular routes. Alternatively, bacteria can damage the intestinal lining with extracellular enzymes or toxins before entering. Using an in vitro (Ussing chamber) model, this paper describes intestinal cell damage in Atlantic salmon (Salmo salar L.) caused by the fish pathogen Aeromonas salmonicida ssp. salmonicida, the causative agent of furunculosis. The in vitro method clearly demonstrated substantial detachment of enterocytes from anterior region of the intestine (foregut) upon exposure to the pathogen. In the hindgut (posterior part of the intestine), little detachment was observed but cellular damage involved microvilli, desmosomes and tight junctions. Based on these findings, we suggest that A. salmonicida may obtain entry to the fish by seriously damaging the intestinal lining. Translocation of bacteria through the foregut (rather than the hindgut) is a more likely infection route for A. salmonicida infections in Atlantic salmon.
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| 43. |
- Rosengren, Malin, 1982, et al.
(författare)
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Born to be wild: effects of rearing density and environmental enrichment on stress, welfare, and smolt migration in hatchery-reared Atlantic salmon
- 2017
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Ingår i: Canadian Journal of Fisheries and Aquatic Sciences. - : Canadian Science Publishing. - 0706-652X .- 1205-7533. ; 74:3, s. 396-405
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Tidskriftsartikel (refereegranskat)abstract
- Hatchery-reared salmonids released into the wild generally have poor survivability compared with wild conspecifics. To assess potential hatchery rearing improvements, behavioral and physiological effects of reducing animal density and adding in-tank shelter were investigated. Atlantic salmon (Salmo salar) parr were placed in barren or shelter-enriched tanks at high or low density up until release as smolts. Lowered density rendered positive effects on growth and intestinal barrier function, and both lowered density and shelter decreased conspecific aggression, as inferred by fin damage. Furthermore, while the presence of shelter decreased stress hormone levels following human disturbance, it also decreased growth and smolt migration success, an effect particularly pronounced at high densities. Therefore, we suggest that this type of structural enrichment should be avoided for Atlantic salmon smolts held at high densities and conclude that a lowered animal density with or without shelter has the highest potential in producing a more resilient smolt for stocking.
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| 44. |
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| 45. |
- Samuelsson, Johan, et al.
(författare)
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Synthesis and polymerization of a radiation curable hyperbranched resin based on epoxy functional fatty acids
- 2004
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Ingår i: Progress in organic coatings. - : Elsevier BV. - 0300-9440 .- 1873-331X. ; 50:3, s. 193-198
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Tidskriftsartikel (refereegranskat)abstract
- A radiation curable resin has been synthesized from a hydroxy functional hyperbranched polyether onto which an epoxy functional fatty acid, vernolic acid, has been attached. The resin was cationically polymerized in presence of different amounts of vernolic acid methyl ester as a reactive diluent. The coating mixtures contained up to 30 wt.% methyl ester and all formulations polymerized readily and formed crosslinked films with T-g's between 16 and -18degreesC, where the addition of the reactive diluent lowered the T-g with approximately 10degreesC for each 10 wt.% diluent added. The viscosities of the coating mixtures were also heavily influenced by the presence of the reactive diluent, from the pare hyperbranched epoxy functionalized polymer with a viscosity of 4 100 mPa s to the formulation containing 30 wt.% methyl ester with a viscosity of 460 mPa s. The viscosities of the mixtures and the hardness of the films were also compared with a model oil based on trimethylol propane, i.e. a structurally similar resin without a polyether core. The model oil was found to have a lower viscosity than the other mixtures and produced a soft film with a low T-g (-21degreesC) after polymerization.
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| 46. |
- Sandberg, Kenneth, 1945, et al.
(författare)
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Fetal nicotine exposure increases airway responsiveness and alters airway wall composition in young lambs.
- 2011
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Ingår i: Respiratory physiology & neurobiology. - : Elsevier BV. - 1878-1519 .- 1569-9048. ; 176:1-2, s. 57-67
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Tidskriftsartikel (refereegranskat)abstract
- To test the hypotheses that fetal nicotine exposure alters airway wall composition and enhances the airway response to inhaled methacholine (MCh), lambs were exposed during the last fetal trimester to (1) a low dose (LN) (n=13, 0.5mg/kg/d (maternal weight) of free base nicotine, (2) a moderate dose (MN) (n=10, 1.5mg/kg/d) or (3) saline (n=14). Studies were performed at postnatal days 12, 26 and 52. Prenatal nicotine exposure induced a dose- and age-related hyper-responsiveness to MCh in the proximal airways. Moment analysis of nitrogen decay curves showed no nicotine or MCh effects on ventilation homogeneity or gas-mixing efficiency in the distal airways during MCh inhalations suggesting a bimodal response. Fetal nicotine exposure increased epithelial mucosubstance volume in central (LN, MN) and distal bronchi (LN), increased smooth muscle volume in distal bronchi and bronchioles (LN) and decreased bronchiolar diameter (MN). In conclusion, third trimester nicotine exposure causes hyperreactive proximal airways and alters proximal airway wall composition associated with airflow limitation.
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| 47. |
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| 48. |
- Sezgin, E., et al.
(författare)
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An exact solution of 4D higher-spin gauge theory
- 2007
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Ingår i: Nuclear Physics B. - : Elsevier BV. - 0550-3213 .- 1873-1562. ; 762:1-2, s. 1-37
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Tidskriftsartikel (refereegranskat)abstract
- We give a one-parameter family of exact solutions to 4D higher-spin gauge theory invariant under a deformed higher-spin extension of SO(3,1) and parameterized by a zero-form invariant. All higher-spin gauge fields vanish, while the metric interpolates between two asymptotically AdS4 regions via two dS3-foliated domain walls and two H3-foliated Robertson–Walker spacetimes—one in the future and one in the past—with the scalar field playing the role of foliation parameter. All Weyl tensors vanish, including that of spin two. We furthermore discuss methods for constructing solutions, including deformation of solutions to pure AdS gravity, the gauge-function approach, the perturbative treatment of (pseudo-)singular initial data describing isometric or otherwise projected solutions, and zero-form invariants.
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| 49. |
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| 50. |
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