| 1. |
- Arlt, D, et al.
(author)
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Breeding synchrony does not affect extra-pair paternity in great reed warblers
- 2004
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In: Behaviour. - : Brill. - 1568-539X .- 0005-7959. ; 141:7, s. 863-880
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Journal article (peer-reviewed)abstract
- Breeding synchrony is hypothesised to influence the occurrence and frequency of extra-pair fertilisations (EPFs) in birds irrespective of the social mating system. The two proposed hypotheses make opposite predictions. (1) Synchronous breeding leads to a lower frequency of EPFs because males face a trade-off between mate guarding and obtaining additional matings via extra-pair copulations (EPCs) ('guarding constraint' hypothesis). (2) Synchronous breeding promotes EPFs because females are able to compare displaying males simultaneously, which provides them with more reliable cues for extra-pair mate choice ('mate assessment' hypothesis). In a study of great reed warblers (Acrocephalus arundillaceus) from 1987-1998, annual breeding was asynchronous and the frequency of EPFs was rather low (extra-pair young occurring in 6.4% of the broods). Within this population, however, there was no relationship between the frequency of EPFs and breeding synchrony, thus not favouring any of the two hypotheses. Contrary to assumptions of the hypotheses, mate guarding did not seem to constrain males from engaging in EPCs (disfavouring the 'guarding constraint' hypothesis), and females seem to have repeated opportunities to compare males irrespective of breeding synchrony (disfavouring the 'mate assessment' hypothesis). Our results suggest that breeding synchrony is not an important factor influencing patterns of EPFs in great reed warblers. The low frequency of EPFs may instead be explained by the socially polygynous mating system, where females are less constrained in their choice of a social male.
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| 2. |
- Baias, Maria, et al.
(author)
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De Novo Determination of the Crystal Structure of a Large Drug Molecule by Crystal Structure Prediction-Based Powder NMR Crystallography
- 2013
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In: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 135:46, s. 17501-17507
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Journal article (peer-reviewed)abstract
- The crystal structure of form 4 of the drug 4-[4-(2-adamantylcarbamoyl)-5-tert-butyl-pyrazol-1-yl]benzoic acid is determined using a protocol for NMR powder crystallography at natural isotopic abundance combining solid-state H-1 NMR spectroscopy, crystal structure prediction, and density functional theory chemical shift calculations. This is the first example of NMR crystal structure determination for a molecular compound of previously unknown structure, and at 422 g/mol this is the largest compound to which this method has been applied so far.
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| 3. |
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| 4. |
- Hansson, Bengt, et al.
(author)
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Increase of genetic variation over time in a recently founded population of great reed warblers (Acrocephalus arundinaceus) revealed by microsatellites and DNA fingerprinting
- 2000
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In: Molecular Ecology. - : Wiley. - 0962-1083 .- 1365-294X. ; 9:10, s. 1529-1538
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Journal article (peer-reviewed)abstract
- Genetic similarity within pairs of individuals was examined using both 10 polymorphic microsatellite loci and multi-locus DNA fingerprinting profiles in a semi-isolated population of great reed warblers at Lake Kvismaren, south Central Sweden, in 1987-1993. The population was founded by a few individuals in 1978, followed by a gradual increase in numbers until 1988, since when the population has remained relatively stable with about 60 breeding birds. We have previously found that high genetic similarity between pairmates in the population during the early part of the study period reduced egg hatching success, and hence reproductive success. The measures of pairwise genetic similarity, microsatellite allele sharing and DNA fingerprinting band sharing, were highly correlated with pedigree-based relatedness. Both microsatellite and DNA fingerprinting similarities between pair-mates declined significantly over the study period, and the pattern was most pronounced in the DNA fingerprinting data. Analyses restricted to the microsatellite data showed that the average annual microsatellite similarity between pairwise combinations of individuals, as well as individual homozygosity in males, declined significantly over the study period, and that several immigrants carrying novel alleles entered the population during the study. Hence, the temporal decline in genetic similarity of mates in the population is probably a consequence of increased immigration, facilitated by the recent expansion of the species in the region. These results suggest that the population has now recovered genetically, or is in the process of recovering, from a recent founder event.
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| 5. |
- Idström, Alexander, 1983, et al.
(author)
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13C NMR assignments of regenerated cellulose from solid-state 2D NMR spectroscopy
- 2016
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In: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617. ; 151, s. 480-487
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Journal article (peer-reviewed)abstract
- From the assignment of the solid-state 13C NMR signals in the C4 region, distinct types of crystalline cellulose, cellulose at crystalline surfaces, and disordered cellulose can be identified and quantified. For regenerated cellulose, complete 13C assignments of the other carbon regions have not previously been attainable, due to signal overlap. In this study, two-dimensional (2D) NMR correlation methods were used to resolve and assign 13C signals for all carbon atoms in regenerated cellulose. 13C-enriched bacterial nanocellulose was biosynthesized, dissolved, and coagulated as highly crystalline cellulose II. Specifically, four distinct 13C signals were observed corresponding to conformationally different anhydroglucose units: two signals assigned to crystalline moieties and two signals assigned to non-crystalline species. The C1, C4 and C6 regions for cellulose II were fully examined by global spectral deconvolution, which yielded qualitative trends of the relative populations of the different cellulose moieties, as a function of wetting and drying treatments.
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| 6. |
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| 7. |
- Lillandt, B G, et al.
(author)
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Family structure in the Siberian Jay as revealed by microsatellite analyses
- 2003
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In: The Condor: ornithological applications. - 0010-5422. ; 105:3, s. 505-514
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Journal article (peer-reviewed)abstract
- The Siberian Jay (Perisoreus infaustus) lives in resident, territorial family groups outside the breeding season, but does not breed cooperatively. Thereby it offers an opportunity to study the evolution of territorial group living, without confounding effects of reproductive cooperation. During a long-term study in Finland 1974-2000, we observed Siberian Jay group composition in autumn. Using microsatellite analysis based on feather or blood samples we clarified kin relations within the groups. We found that out of 311 groups that included at least one more individual than the territory holders, 74% were nuclear families, including breeding birds and 1-3 retained offspring. However, 26% of the groups were not families, but consisted of pairs accompanied only by individuals that were not their offspring. According to extensive pedigrees we found that 70% of the 82 immatures associated with a nonparent pair were not related to either territory holder. Of these 82 immatures, 91% were associated with pairs that had no offspring on their own, suggesting that they were failed breeders or newly established pairs. The composition of groups was mostly unchanged during the observation period within each season, regardless of kinship. Previous studies have reported apparent nepotism between parents and retained offspring in the Siberian Jay, and a high degree of aggression toward nonoffspring, so we did not expect to find such high frequency and remarkable within-season stability of nonfamily groups. These observations suggest that there are important fitness benefits to gain from territoriality and group living, regardless of kinship.
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| 8. |
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| 9. |
- Naurin, Sara, et al.
(author)
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A microarray for large-scale genomic and transcriptional analyses of the zebra finch (Taeniopygia guttata) and other passerines
- 2008
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In: Molecular Ecology Notes. - : Wiley. - 1471-8278 .- 1755-098X. ; 8:2, s. 275-281
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Journal article (peer-reviewed)abstract
- The microarray technology has revolutionized biological research in the last decade. By monitoring the expression of many genes simultaneously, microarrays can elucidate gene function, as well as scan entire genomes for candidate genes encoding complex traits. However, because of high costs of sequencing and design, microarrays have largely been restricted to a few model species. Cross-species microarray (CSM) analyses, where microarrays are used for other species than the one they were designed for, have had varied success. We have conducted a CSM analysis by hybridizing genomic DNA from the common whitethroat (Sylvia communis) on a newly developed Affymetrix array designed for the zebra finch (Taeniopygia guttata), the Lund-zf array. The results indicate a very high potential for the zebra finch array to act as a CSM utility in other passerine birds. When hybridizing zebra finch genomic DNA, 98% of the gene representatives had higher signal intensities than the background cut-off, and for the common whitethroat, we found the equivalent proportion to be as high as 96%. This was surprising given the fact that finches and warblers diverged 25-50 million years ago, but may be explained by a relatively low sequence divergence between passerines (89-93%). Passerine birds are widely used in studies of ecology and evolution, and a zebra finch array that can be used for many species may have a large impact on future research directions.
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| 10. |
- Schantz, Staffan, et al.
(author)
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Poly(methyl methacrylate-co-ethyl acrylate) latex particles with poly(ethylene glycol) grafts: Structure and film formation
- 2007
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In: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 23:7, s. 3590-3602
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Journal article (peer-reviewed)abstract
- Water-based copolymer dispersions were prepared using methyl methacrylate (MMA), ethyl acrylate (EA) (MMA/EA = 1:2), and a series of nonionic polymerizable surfactants, i.e., "surfmers" based on poly(ethylene glycol)-(meth)acrylates. The latexes were compared with the behavior of a conventionally stabilized (nonionic nonylphenol ethoxylate, NP100 with 84 ethylene oxide units) dispersion with the same MMA-EA composition (PMMAEA). A number of techniques were employed in order to characterize structure, dynamics, and film formation properties: solution/solid-state NMR, dynamic/static light scattering (DLS/SLS), differential scanning calorimetry (DSC), tensile/shear mode dynamic mechanical thermal analysis (DMTA), and atomic force microscopy (AFM). The surfmers were found to be miscible with the MMA-EA copolymer at room temperature, with 46-85 mol % of the reacted surfmer detected at the particle surfaces, and the remaining part buried in the particle bulk. In contrast, the NP100 surfactant formed a separate interphase between the copolymer particles with no mixing detected at room temperature or at 90 degrees C. For a 4.0% dry weight concentration, NP100 phase separated and further crystallized at room temperature over a period of several months. Composition fluctuations related to a limited blockiness on a length scale above similar to 2 nm were detected for PMMAEA particles, whereas the surfmer particles were found to be homogeneous also below this limit. On a particle-particle level, the dispersions tended to form colloidal crystals unless hindered by a broadened particle size distribution or, in the case of PMMAEA, by the action of NP100. Finally, a surface roughness (R-q) master plot was constructed for data above the glass transition temperature (T-g) from T-g + 11 degrees C to T-g + 57 degrees C and compared with the complex shear modulus over 11 frequency decades. Shift factors from the 2 methods obeyed the same Williams-Landel-Ferry (WLF) temperature dependence, thus connecting the long-time surface flattening process to the rheological behavior of the copolymer.
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