| 1. |
- Crespo, Ana, et al.
(författare)
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Phylogenetic generic classification of parmelioid lichens (Parmeliaceae,Ascomycota) based on molecular, morphological and chemical evidence.
- 2010
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Ingår i: Taxon. - : John Wiley & Sons. - 0040-0262 .- 1996-8175. ; 59:6, s. 1735-1753
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Tidskriftsartikel (refereegranskat)abstract
- Parmelioid lichens are a diverse and ubiquitous group of foliose lichens. Generic delimitation in parmelioid lichens has been in a state of flux since the late 1960s with the segregation of the large, heterogeneous genus Parmelia into numerous smaller genera. Recent molecular phylogenetic studies have demonstrated that some of these new genera were monophyletic, some were not, and others, previously believed to be unrelated, fell within single monophyletic groups, indicating the need for a revision of the generic delimitations. This study aims to give an overview of current knowledge of the major clades of all parmelioid lichens. For this, we assembled a dataset of 762 specimens, including 31 of 33 currently accepted parmelioid genera (and 63 of 84 accepted genera of Parmeliaceae). We performed maximum likelihood and Bayesian analyses of combined datasets including two, three and four loci. Based on these phylogenies and the correlation of morphological and chemical characters that characterize monophyletic groups, we accept 27 genera within nine main clades. We re-circumscribe several genera and reduce Parmelaria to synonymy with Parmotrema. Emodomelanelia Divakar & A. Crespo is described as a new genus (type: E. masonii). Nipponoparmelia (Kurok.) K.H. Moon, Y. Ohmura & Kashiw. ex A. Crespo & al. is elevated to generic rank and 15 new combinations are proposed (in the genera Flavoparmelia, Parmotrema, Myelochroa, Melanelixia and Nipponoparmelia). A short discussion of the accepted genera is provided and remaining challenges and areas requiring additional taxon sampling are identified.
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| 2. |
- Fridman, Jonas, et al.
(författare)
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Education and advice contribute to increased density of broadleaved conservation trees, but not saplings, in young forest in Sweden
- 2009
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Ingår i: Journal of Environmental Management. - : Elsevier BV. - 0301-4797 .- 1095-8630. ; 90, s. 1081–1088-
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Tidskriftsartikel (refereegranskat)abstract
- The effectiveness of different conservation policies is debated, but the policies are rarely evaluated quantitatively. A voluntary or ‘soft’ policy based mainly on education provides information about ecosystems and effects of land use, to encourage conservation action. Swedish forestry relies mainly on soft policy, with substantial resources for education and advice to more than 200,000 forest owners, while legal regulation is weak. Increased retention of broadleaved trees at clear-cutting, with environmental benefits in the conifer-dominated forestry, is important in the policy. We used the Swedish National Forest Inventory to analyse this policy for young forests in southern Sweden. Between 1983–1987 and 1998–2002 the policy had no positive effect on saplings (1.3 m tall to 4.9 cm dbh) of birch, oak, beech and other species that mostly decreased in density, due to planting of conifers and browsing by ungulates. However, broadleaved conservation trees (??15 cm dbh) increased in density, e.g. to about one oak and six birches per ha in young coniferous forest in 1998–2002. The relative increase in density was higher for large (??20 cm dbh) than for small trees (15–20 cm dbh). The density of conservation trees was higher on forestland of high than of low productivity. Thus, the soft conservation policy did not influence regeneration of saplings in this type of forestry system, but large broadleaved trees were increasingly saved at ‘clear-cuttings’. Advice and educational programmes probably contributed to this result. A continued increase in conservation trees at harvest may require economical support to forest owners
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| 3. |
- Helldin, Jan Olof, et al.
(författare)
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Viltet i samhället
- 2010
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Ingår i: Vilt, människa, samhälle. - 9789147094189 ; , s. 135-168
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Bokkapitel (populärvet., debatt m.m.)
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| 4. |
- Vasur, Jonas, et al.
(författare)
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Synthesis of cyclic β-glucan using Laminarinase 16A glycosynthase mutant from the basidiomycete Phanerochaete chrysosporium
- 2010
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society. - 0002-7863 .- 1520-5126. ; 132:5, s. 1724-1730
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Tidskriftsartikel (refereegranskat)abstract
- Glycosynthases are precise molecular instruments for making specifically linked oligosaccharides. X-ray crystallography screening of ligands bound to the 1,3(4)-β-d-glucanase nucleophile mutant E115S of Phanerochaete chrysosporium Laminarinase 16A (Lam16A) showed that laminariheptaose (L7) bound in an arch with the reducing and nonreducing ends occupying either side of the catalytic cleft of the enzyme. The X-ray structure of Lam16A E115S in complex with α-laminariheptaosyl fluoride (αL7F) revealed how αL7F could make a nucleophilic attack upon itself. Indeed, when Lam16A E115S was allowed to react with αL7F the major product was a cyclic β-1,3-heptaglucan, as shown by mass spectrometry. NMR confirmed uniquely β-1,3-linkages and no reducing end. Molecular dynamics simulations indicate that the cyclic laminariheptaose molecule is not completely planar and that torsion angles at the glycosidic linkages fluctuate between two energy minima. This is the first report of a glycosynthase that joins the reducing and nonreducing ends of a single oligosaccharide and the first reported synthesis of cyclic β-glucan.
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