| 1. |
- Blomqvist, Maria, et al.
(författare)
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Chlamydophila psittaci in birds of prey, Sweden
- 2012
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Ingår i: Infection Ecology & Epidemiology. - : Informa UK Limited. - 2000-8686. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chlamydia psittaci is an intracellular bacterium primarily causing respiratory diseases in birds but may also be transmitted to other animals, including humans. The prevalence of the pathogen in wild birds in Sweden is largely unknown.Methods: DNA was extracted from cloacae swabs and screened for C. psittaci by using a 23S rRNA gene PCR assay. Partial 16S rRNA and ompA gene fragments were sequence determined and phylogenies were analysed by the neighbour-joining method.Results and conclusion: The C. psittaci prevalence was 1.3% in 319 Peregrine Falcons and White-tailed Sea Eagles, vulnerable top-predators in Sweden. 16S rRNA and ompA gene analysis showed that novel Chlamydia species, as well as novel C. psittaci strains, are to be found among wild birds.
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| 2. |
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| 3. |
- Gunnarsson, Gunnar, et al.
(författare)
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Zero Prevalence of Influenza A Virus in Two Raptor Species by Standard Screening
- 2010
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Ingår i: Vector-borne and zoonotic diseases. - : Mary Ann Liebert Inc. - 1530-3667 .- 1557-7759. ; 10:4, s. 387-390
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Tidskriftsartikel (refereegranskat)abstract
- Disease can have sever impact on animal populations, especially in rare species. Baseline data for atypical host species are missing for a range of infectious diseases, although such hosts are potentially more affected than the normal vectors and reservoir species. If highly pathogenic avian influenza strikes rare birds of prey, this may have crucial impact on the predator species itself, but also on the food web in which it interacts. Here we present the first large-scale screening of raptors that regularly consume birds belonging to the natural reservoir of influenza A viruses. Influenza A virus prevalence was studied in two rare raptors, the white-tailed sea eagle (Haliaetus albicilla) and the peregrine falcon (Falco peregrinus). Nestlings were screened for active (181 white-tailed sea eagles and 168 peregrine falcons) and past (123 white-tailed sea eagles and 6 peregrine falcons) infection in 2006-2007, and an additional 20 succumbed adult white-tailed sea eagles were sampled in 2003-2006. Neither high- nor low-pathogenic influnza infections were found in our sample, but this does not rule out that the former may have major impact on rare raptors and their food webs.
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| 4. |
- Gustafsson, Fredrik, et al.
(författare)
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Radio Access Network (UTRAN) Modeling for Heterogenous Network Simulations, A Brief Description
- 2003
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Ingår i: Proceedings of the 1st Swedish National Computer Networking Workshop. - Linköping : Linköping University Electronic Press.
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Konferensbidrag (refereegranskat)abstract
- The vision of mobile Internet comprises heterogeneous networks with both wired and wireless infrastructures. The network parts are typically radio access network, core network, service network, Internet, etc. Due to the multitude of nodes and users in such networks and the complicated nature of layered communications protocols, performance analysis through simulations is crucial. The open source network simulation tool, ns-2, is widely used for simulating the behavior of wired, routed networks. This work adds modules to model radio access network nodes that emulate typical behavior of UTRAN (UMTS Terrestrial Radio Access Network) - the 3G standard opted for in Europe and Japan. Furthermore, data communication examples illustrate typical behavior of such a heterogenous network.
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| 5. |
- Lundgren, Anders, 1978, et al.
(författare)
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Affinity Purification and Single-Molecule Analysis of Integral Membrane Proteins from Crude Cell-Membrane Preparations
- 2018
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 18:1, s. 381-385
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Tidskriftsartikel (refereegranskat)abstract
- The function of integral membrane proteins is critically dependent on their naturally surrounding lipid membrane. Detergent-solubilized and purified membrane proteins are therefore often reconstituted into cell-membrane mimics and analyzed for their function with single-molecule microscopy. Expansion of this approach toward a broad range of pharmaceutically interesting drug targets and biomarkers however remains hampered by the fact that these proteins have low expression levels, and that detergent solubilization and reconstitution often cause protein conformational changes and loss of membrane-specific cofactors, which may impair protein function. To overcome this limitation, we here demonstrate how antibody-modified nanoparticles can be used to achieve affinity purification and enrichment of selected integral membrane proteins directly from cell membrane preparations. Nanoparticles were first bound to the ectodomain of β-secretase 1 (BACE1) contained in cell-derived membrane vesicles. In a subsequent step, these were merged into a continuous supported membrane in a microfluidic channel. Through the extended nanoparticle tag, a weak (∼fN) hydrodynamic force could be applied, inducing directed in-membrane movement of targeted BACE1 exclusively. This enabled selective thousand-fold enrichment of the targeted membrane protein while preserving a natural lipid environment. In addition, nanoparticle-targeting also enabled simultaneous tracking analysis of each individual manipulated protein, revealing how their mobility changed when moved from one lipid environment to another. We therefore believe this approach will be particularly useful for separation in-line with single-molecule analysis, eventually opening up for membrane-protein sorting devices analogous to fluorescence-activated cell sorting.
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| 6. |
- Agnarsson, Björn, 1977, et al.
(författare)
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Evanescent Light-Scattering Microscopy for Label-Free Interfacial Imaging: From Single Sub-100 nm Vesicles to Live Cells
- 2015
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-086X .- 1936-0851. ; 9:12, s. 11849-11862
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Tidskriftsartikel (refereegranskat)abstract
- Advancement in the understanding of biomolecular interactions has benefited greatly from the development of surface-sensitive bioanalytical sensors. To further increase their broad impact, significant efforts are presently being made to enable label-free and specific biomolecule detection with high sensitivity, allowing for quantitative interpretation and general applicability at low cost. In this work, we have addressed this challenge by developing a waveguide chip consisting of a flat silica core embedded in a symmetric organic cladding with a refractive index matching that of water. This is shown to reduce stray light (background) scattering and thereby allow for label-free detection of faint objects, such as individual sub-20 rim gold nanoparticles as well as sub-100 nm lipid vesicles. Measurements and theoretical analysis revealed that light-scattering signals originating from single surface-bound lipid vesicles enable characterization of their sizes without employing fluorescent lipids as labels. The concept is also demonstrated for label-free measurements of protein binding to and enzymatic (phospholipase A2) digestion of individual lipid vesicles, enabling an analysis of the influence on the measured kinetics of the dye-labeling of lipids required in previous assays. Further, diffraction-limited imaging of cells (platelets) binding to a silica surface showed that distinct subcellular features could be visualized and temporally resolved during attachment, activation, and spreading. Taken together, these results underscore the versatility and general applicability of the method, which due to its simplicity and compatibility with conventional microscopy setups may reach a widespread in life science and beyond.
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| 7. |
- Agnarsson, Björn, 1977, et al.
(författare)
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Waveguide structure
- 2018
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Patent (övrigt vetenskapligt/konstnärligt)abstract
- A waveguide structure for evanescent wave microscopy and/or spectroscopy, comprising an optically transparent core layer, a lower dielectric cladding layer and an upper dielectric cladding layer arranged on opposite sides of the core layer. The core layer has a refractive index higher than the refractive indices of the cladding layers. The upper cladding layer is made of an organic material. A sample well is arranged on an upper surface of the core layer formed by a cavity in the upper cladding layer, the sample well being adapted to contain a sample medium with one or more sample objects. The core layer is made of a first dielectric inorganic material, and the upper cladding layer has a refractive index which closely matches the refractive index of the sample medium. A method for manufacturing such waveguide structure, and a measurement system comprising the waveguide structure are also disclosed.
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| 8. |
- Ahlström, Gerd, et al.
(författare)
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A comprehensive rehabilitation programme tailored to the needs of adults with muscular dystrophy.
- 2006
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Ingår i: Clinical Rehabilitation. - : SAGE Publications. - 0269-2155 .- 1477-0873. ; 20:2, s. 132-141
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To assess if activities of daily living (ADL), coping and quality of life could be improved in adults with muscular dystrophy through a comprehensive rehabilitation programme. DESIGN: Quasi-experimental, controlled clinical study comparing patients with similar age and disease aspects. SETTING: Two different counties in Sweden, being either study or control setting. SUBJECTS: The study group comprised 37 adults (21 women, 16 men; mean age 50 years), while the control group comprised 39 people (25 women, 14 men; mean age 46 years). INTERVENTIONS: Four rehabilitation sessions tailored to different medical, physical and psychosocial needs of the patients, comprising a total of 10 days over a period of 18 months. MAIN MEASURES: ADL, the Mental Adjustment to Cancer Scale measuring coping strategies, the Sickness Impact Profile measuring health-related quality of life, the Hospital Anxiety and Depression Scale, and the Psychosocial Well-being Questionnaire. RESULTS: No significant differences were found between groups with regard to the outcome measures. There was increased dependence on others in ADL after 18 months in both groups, but it was more pronounced in the control group. Furthermore, a clear trend was observed in the data with regard to coping patterns, the control group using more coping strategies such as 'Helplessness/hopelessness' (P= 0.057), 'Anxious preoccupation' (P = 0.085) and 'Fatalistic' (P= 0.073) when being compared to the study group. CONCLUSIONS: No apparent effects on ADL were found from the rehabilitation programme, although there was a tendency of reduction of maladaptive coping patterns in the study group. This initial study may provide the rationale and basis for a randomized controlled trial.
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| 9. |
- Arnason, T., et al.
(författare)
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Impact of temperature and growth hormone on growth physiology of juvenile Atlantic wolffish (Anarhichas lupus)
- 2019
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486. ; 504, s. 404-413
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Tidskriftsartikel (refereegranskat)abstract
- The effects of temperature and growth hormone (GH) implantation on growth of juvenile Atlantic wolffish (Anarhichas lupus) were investigated. The year-long study had three sequential experimental phases (EP) termed EP1, EP2 and EP3, lasting for 6, 9 and 37 weeks, respectively. The experimental fish were divided into four groups and reared at different target temperatures (3, 7, 11 and 15 degrees C) during EP1 and EP2, but at a constant temperature of 7 degrees C during EP3. At the beginning of EP2, half of the fish from each group was implanted with formulation of recombinant bovine GH (Posilac (R)), while the other half was sham-implanted with vehicle. The optimal temperature for growth (T-opt.G) of early juveniles (geometric mean weight 7.5 g) was determined as 12.1 degrees C during EP1, while the upper critical temperature (Tc) was concluded to be very close to 15 degrees C, as fish at that temperature had stunted growth, increased mortality and showed external signs of skeletal deformities. Thus, the species was found to be relatively stenothermic during the early juvenile stages and therefore vulnerable to relatively modest increases in environmental temperature above T-opt.G At 15 degrees C, GH implantation had no effects on growth rate. This indicates that the high allostatic load at this temperature leaves no scope for increased growth. In contrast, at lower rearing temperatures, the GH implantation had substantial, long-term effects on growth rate and induced remarkably similar relative growth stimulation at 3, 7 and 11 degrees C, suggesting a temperature-independent mechanism for the growth-promoting effects of GH.
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| 10. |
- Arnason, T., et al.
(författare)
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Long-term rearing of Arctic charr Salvelinus alpinus under different salinity regimes at constant temperature
- 2014
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Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112. ; 85:4, s. 1145-1162
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Tidskriftsartikel (refereegranskat)abstract
- Arctic charr Salvelinus alpinus of the Holar strain (mean+/- s. e. body mass= 152.1+/-3.1g) were reared at four different salinity regimes at a constant temperature of 7.4 degrees C. Two groups were given a three-month acclimation in salinity 18 before the salinity was increased to either 25 or 29 (groups called A25 and A29), and two groups were reared in salinities 25 or 29 over the full experimental period of 409 days (groups called F25 and F29). In the first 3months, the A25 and A29 groups had the highest growth rates. By October 2011, there were no significant differences (two-way nested ANOVA, P> 0.05) in the mean body masses among A25, F25 and F29 (c. 1450 g), whereas A29 had a lower mean mass (1282 g). The growth in the last period from October 2011 to January 2012 was reduced by sexual maturation in the highest salinity regimes (A29 and F29), whereas fish in groups A25 and F25 showed high growth throughout the study. Males in all salinity groups had higher growth rates than females for the most part of the study, but the divergence between the sexes was most pronounced in the highest salinity regimes. All salinity groups showed distinct changes in Na+, K+-ATPase activity, with high activity in spring and summer, and lower activity in the autumn. Plasma sodium (Na+) levels were stable indicating that none of the experimental groups had problems in maintaining hydromineral balance during the study. While plasma leptin levels were not affected by salinity regimes, it was noted that these levels were 13-30% higher in fish with empty guts compared with those having food in their gut at the time of sampling. This suggests a link between leptin levels and food intake, indicating that this hormone may play a role in food intake and energy allocation in fishes.
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