| 1. |
- Laikre, Linda, et al.
(författare)
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Potentials for monitoring gene level biodiversity : using Sweden as an example
- 2008
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Ingår i: Biodiversity and Conservation. - : Springer Science and Business Media LLC. - 0960-3115 .- 1572-9710. ; 17:4, s. 893-910
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Tidskriftsartikel (refereegranskat)abstract
- Programs for monitoring biological diversity over time are needed to detect changes that can constitute threats to biological resources. The convention on biological diversity regards effective monitoring as necessary to halt the ongoing erosion of biological variation, and such programs at the ecosystem and species levels are enforced in several countries. However, at the level of genetic biodiversity, little has been accomplished, and monitoring programs need to be developed. We define “conservation genetic monitoring” to imply the systematic, temporal study of genetic variation within particular species/populations with the aim to detect changes that indicate compromise or loss of such diversity. We also (i) identify basic starting points for conservation genetic monitoring, (ii) review the availability of such information using Sweden as an example, (iii) suggest categories of species for pilot monitoring programs, and (iv) identify some scientific and logistic issues that need to be addressed in the context of conservation genetic monitoring. We suggest that such programs are particularly warranted for species subject to large scale enhancement and harvest—operations that are known to potentially alter the genetic composition and reduce the variability of populations.
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| 2. |
- Laikre, Linda, et al.
(författare)
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Release of alien populations in Sweden
- 2006
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Ingår i: Ambio. - 0044-7447 .- 1654-7209. ; 35:5, s. 255-261
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Tidskriftsartikel (refereegranskat)abstract
- Introduction of alien species is a major threat to biological diversity. Although public attention typically focuses on the species level, guidelines from the Convention of Biological Diversity define alien species to include entities below species level. This inclusion recognizes that release of nonlocal populations of native species may also result in negative effects on biodiversity. In practice, little is known about the extent, degree of establishment, or the effects on natural gene pools of such releases. Existing information on the releases in Sweden shows that alien populations are spread to a great extent. The most commonly released species include brown trout, Atlantic salmon, Arctic char, common whitefish, Scots pine, Norway spruce, mallard duck, gray partridge, and pheasant. Although millions of forest trees, fish, and birds are released annually, poor documentation makes the geographic and genetic origin of these populations, as well as the sites where they have been released, largely unclear. We provide recommendations for urgently needed first steps relating to the risks and problems associated with release of alien populations.
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| 3. |
- Schalk, Oliver, et al.
(författare)
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Dissociation kinetics of excited ions : PEPICO measurements of Os-3(CO)(12) - The 7-35 eV single ionization binding energy region
- 2018
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 148:8
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Tidskriftsartikel (refereegranskat)abstract
- In this article, we study the photoinduced dissociation pathways of a metallocarbonyl, Os-3(CO)(12), in particular the consecutive loss of CO groups. To do so, we performed photoelectron-photoion coincidence (PEPICO) measurements in the single ionization binding energy region from 7 to 35 eV using 45-eV photons. Zero-energy ion appearance energies for the dissociation steps were extracted by modeling the PEPICO data using the statistical adiabatic channel model. Upon ionization to the excited ionic states above 13 eV binding energy, non-statistical behaviorwas observed and assigned to prompt CO loss. Double ionization was found to be dominated by the knockout process with an onset of 20.9 similar to 0.4 eV. The oscillator strength is significantly larger for energies above 26.6 similar to 0.4 eV, corresponding to one electron being ejected from the Os3 center and one from the CO ligands. The cross section for double ionization was found to increase linearly up to 35 eV ionization energy, at which 40% of the generated ions are doubly charged.
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| 4. |
- Schalk, Oliver, et al.
(författare)
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Ionization and photofragmentation of Ru-3(CO)(12) and Os-3(CO)(12)
- 2015
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 143:15
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we use a combination of photoelectron spectroscopy, mass spectrometry, and density functional theory calculations to get a detailed understanding of valence single and double ionization and the subsequent dissociation processes. This is exemplified on benchmark systems, trimetallo-dodecacarbonyls M-3(CO)(12) with M = Ru, Os, where the energy remaining in the molecule after photoionization can be retrieved by measuring the degree of fragmentation of the molecular ion. The intensity of different mass peaks can thus be directly related to ionization cross sections obtained by photoelectron spectroscopy. We find that the M-CO dissociation energy rises as the number of CO ligands decreases due to dissociation. Moreover, ionization of the CO ligands has a higher cross section than that of the metal center for both single and double ionization. After advanced fragmentation, a CO bond can break and the carbon atom remains bonded to the metal core. In addition, we found that the valence ionization cross sections of M-3(CO)(12) are maximal at about 40 eV photon energy thus showing a more pronounced shape resonance than Ru and Os-complexes with a single metal atom center. Finally, an np. nd giant resonance absorption causes a significant increase of the ionization cross section above 50 eV for Ru-3(CO)(12).
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