| 1. |
- Hansson, Lars Anders, et al.
(författare)
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Instantaneous threat escape and differentiated refuge demand among zooplankton taxa
- 2016
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Ingår i: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 97:2, s. 279-285
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Tidskriftsartikel (refereegranskat)abstract
- Most animals, including aquatic crustacean zooplankton, perform strong avoidance movements when exposed to a threat, such as ultraviolet radiation (UVR). We here show that the genera Daphnia and Bosmina instantly adjust their vertical position in the water in accordance with the present UVR threat, i.e., seek refuge in deeper waters, whereas other taxa show less response to the threat. Moreover, Daphnia repeatedly respond to UVR pulses, suggesting that they spend more energy on movement than more stationary taxa, for example, during days with fluctuating cloud cover, illustrating nonlethal effects in avoiding UVR threat. Accordingly, we also show that the taxa with the most contrasting behavioral responses differ considerably in photoprotection, suggesting different morphological and behavioral strategies in handling the UVR threat. In a broader context, our studies on individual and taxa specific responses to UVR provide insights into observed spatial and temporal distribution in natural ecosystems.
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| 2. |
- Hylander, Samuel, et al.
(författare)
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Induced tolerance expressed as relaxed behavioural threat response in millimetre-sized aquatic organisms
- 2014
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 281:1788, s. Article ID: 20140364-
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Tidskriftsartikel (refereegranskat)abstract
- Natural selection shapes behaviour in all organisms, but this is difficult to study in small, millimetre-sized, organisms. With novel labelling and tracking techniques, based on nanotechnology, we here show how behaviour in zooplankton (Daphnia magna) is affected by size, morphology and previous exposure to detrimental ultraviolet radiation (UVR). All individuals responded with immediate downward swimming to UVR exposure, but when released from the threat they rapidly returned to the surface. Large individuals swam faster and generally travelled longer distances than small individuals. Interestingly, individuals previously exposed to UVR (during several generations) showed a more relaxed response to UVR and travelled shorter total distances than those that were naive to UVR, suggesting induced tolerance to the threat. In addition, animals previously exposed to UVR also had smaller eyes than the naive ones, whereas UVR-protective melanin pigmentation of the animals was similar between populations. Finally, we show that smaller individuals have lower capacity to avoid UVR which could explain patterns in natural systems of lower migration amplitudes in small individuals. The ability to change behavioural patterns in response to a threat, in this case UVR, adds to our understanding of how organisms navigate in the ‘landscape of fear’, and this has important implications for individual fitness and for interaction strengths in biotic interactions.
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| 3. |
- Bengtsson, Göran, et al.
(författare)
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Spatial uncoupling of biodegradation, soil respiration, and PAH concentration in a creosote contaminated soil.
- 2010
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491. ; 158:9, s. 2865-2871
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Tidskriftsartikel (refereegranskat)abstract
- Hotspots and coldspots of concentration and biodegradation of polycyclic aromatic hydrocarbons (PAHs) marginally overlapped at the 0.5-100 m scale in a creosote contaminated soil in southern Sweden, suggesting that concentration and biodegradation had little spatial co-variation. Biodegradation was substantial and its spatial variability considerable and highly irregular, but it had no spatial autocorrelation. The soil concentration of PAHs explained only 20-30% of the variance of their biodegradation. Soil respiration was spatially autocorrelated. The spatial uncoupling between biodegradation and soil respiration seemed to be governed by the aging of PAHs in the soil, since biodegradation of added (13)C phenanthrene covaried with both soil respiration and microbial biomass. The latter two were also correlated with high concentrations of phospholipid fatty acids (PLFAs) that are common in gram-negative bacteria. However, several of the hotspots of biodegradation coincided with hotspots for the distribution of a PLFA indicative of fungal biomass.
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| 4. |
- Törneman, Niklas, et al.
(författare)
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Spatial covariation of microbial community composition and polycyclic aromatic hydrocarbon concentration in a creosote-polluted soil
- 2008
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Ingår i: Environmental Toxicology and Chemistry. - : Wiley. - 0730-7268 .- 1552-8618. ; 27:5, s. 1039-1046
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Tidskriftsartikel (refereegranskat)abstract
- Little is known about the spatial connection between soil microbial community composition and polycyclic aromatic hydrocarbon (PAH) concentration. A spatially explicit survey at a creosote-contaminated site demonstrated that microbial biomass (total concentration of phospholipid fatty acids [PLFAs]) and microbial community composition (PLFA fingerprints) were spatially autocorrelated, mostly within a distance of 25 m, and covaried with PAH concentrations. The concentration of PLFAs indicative of gram-negative bacteria (16:1 omega 7c, 16:1 omega 7t, 18:1 omega 7, cy17:0, and cy19:0) increased in the PAH hot spots, whereas PLFAs representing fungi and gram-positive bacteria (including actinomycetes) were negatively correlated to PAH concentrations. Most PLFAs were spatially autocorrelated, with distances varying between 4 and 25 m. Those PLFAs that increased in PAH-contaminated soil had autocorrelation ranges between 4 and 16 m, whereas the fungal indicator PLEA 18:2 omega 6,9 had the largest autocorrelation range (25 in). Bacterial strains isolated using a spray-plate technique and with the same PLFA composition as that in contaminated soil samples were capable of degrading phenanthrene, fluoranthene, and pyrene, indicating that the main PAH degraders could be isolated.
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| 5. |
- Yun, Junxian, et al.
(författare)
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Chromatographic adsorption of serum albumin and antibody proteins in cryogels with benzyl-quaternary amine ligands.
- 2015
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Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673. ; 1381, s. 173-183
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Tidskriftsartikel (refereegranskat)abstract
- The preparation and characterization of mixed-mode adsorbents for a typical separation purpose are of great importance in bioseparation areas. In this work, we prepared a new monolithic cryogel with a combination of ion-exchange and hydrophobic functions by employing benzyl-quaternary amine groups. The fundamental cryogel properties, protein equilibrium adsorption isotherm and chromatographic adsorption in the cryogel were measured experimentally. The results showed that, by using bovine serum album as the model protein, the dual functional cryogel has protein binding capability even in salt solution and the buffer with pH close or below the protein isoelectric point due to both the electrostatic and hydrophobic interactions. A capillary-based adsorption model was developed, which provided satisfied insights of the microstructure, axial dispersion, mass transfer as well as protein adsorption characteristics within the cryogel bed. The chromatographic isolation of bioactive proteins from rabbit blood serum was carried out by the cryogel. Immunoglobulin G antibody with a purity of 98.2% and albumin with a purity of 96.8% were obtained, indicating that the cryogel could be an interesting and promising adsorbent in bioseparation areas.
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