| 1. |
- Bergh, Jan-Erik, et al.
(author)
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Insect DNA Exposed to Two Insecticides
- 2007
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In: International Conference Directions in Preventive Conservation Sibiu. - Sibiu, Rumänien.
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Conference paper (other academic/artistic)abstract
- Analyses of DNA is now a standard method in exploring taxonomical relationships between taxa or when studying intraspecific genetic variation. For these purposes museum specimen are often used. During their “museum history”, biological collections often have been treated with various insecticides to avoid museum pest attacks. There is a risk that some insecticides have more or less destroyed the specimen DNA, and thus it is important to know to what extent this happens to be able to estimate if old collection are useful for DNA screening and also to avoid future mistakes. Kigawa et al. (2003) showed that methyl bromide, methyl bromide/ethylene oxide (mixed), ethylene oxide, propylene oxide and methyl iodide all caused degradation of DNA in samples of mushroom and chicken muscle. We have tested possible negative effects on insect DNA from exposure of paradichlorobenzene and diclorvos. Species used were Schistocerca gregaria (Orthoptera), Musca domestica (Diptera), Dermestes hemeroidalis (Coleoptera), Periplaneta americana (Blattodea). The specimens were cut into two parts before completely dried in silica gel in closed containers for about 2 weeks. Three serials were set up in sealed, small glass containers for each species: (1) paradichlorobenzene (0.5g ±0.02g, representing saturated concentration); (2) diclorvos (0.5g ±0.02g, representing saturated concentration); and (3) no chemicals (blank). Each serial was sampled after 1 and 4 weeks. Immediately after sampling, the insect tissues were exposed to clean air for 8 hours in order to eliminate chemicals from the tissue before subsequent treatment. Together with the blank samples, the exposed tissues were stored in deep freezers before extracted for DNA after the last tissue sampling. After extraction, a 658 bp (base pair) COI gene fragment of the DNA was amplified using the forward and reverse primers HCO2198 (TAA ACT TCA GGG TGA CCA AAA AAT CA) and HCOout (CCA GGT AAA ATT AAA ATA TAA ACT TC), respectively. Electrophoresis of the PCR products was run for about 2h and presence or absence of the amplified COI gene fragment showed as band or absence of band in UV light. The gel was photographed for documentation of the results. For S. gregaria we did not obtain any clear results, probably because the primer did not work for the COI gene of this species. For the other three species no effect could be seen from the exposure of paradichlorobenzene, while dichlorvos destroyed the COI gene fragment after 28 days. For M. domestica a band was present after one week exposure. Our conclusion is that dichlorvos has a deteriorating effect on DNA. A more extensive experimental series on M. domestica has been started at the Swedish Museum of Natural History. Reference: Kigawa, R., Nochide, H., Kimura, H. and Miura, S., Effects of various fumigants, thermal methods and carbon dioxide treatment on DNA extraction and amplification: A case study on freeze-dried mushroom and free-dried muscle specimens. Collection Forum 2003, 18 (1-2): 74-89.
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| 3. |
- Goloboff, P., Farris, S., Källersjö, M., Oxelman. B., Ramirez, M. J., Szumik, C. A.
(author)
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Improvements to resampling measures of group support
- 2003
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In: Cladistics. ; 19, s. 324-332
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Journal article (peer-reviewed)
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| 4. |
- Anderberg, A. A., et al.
(author)
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Maesaceae, a new primuloid family in the order Ericales s.l.
- 2000
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In: Taxon. - Vienna, Austria : IAPT. - 0040-0262 .- 1996-8175. ; 49:2, s. 183-187
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Journal article (peer-reviewed)abstract
- Evidence from morphology and molecular sequence data from three chloroplast genes, rbcL, ndhF, and atpB, have shown that the genus Maesa constitutes an evolutionary lineage separate from the other three primuloid families, Theophrastaceae, Myrsinaceae, and Primulaceae. The new family Maesaceae is here formally recognised, its taxonomic status being changed from a subfamily of Myrsinaceae. The new family comprises a single genus, Maesa Forssk., with some 100 species of trees or shrubs; it is diagnosed by characters such as flower pedicels with two bracteoles, a semi-inferior ovary, and indehiscent fruits with many seeds. A key to the major groups of primuloid taxa is presented.
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| 5. |
- Bremer, B., K, Bremer, N. Heidari, P. Erixon, R. G. Olmstead, A. A. Anderberg, M. Källersjö, & E. Borkhardarian
(author)
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Phylogenetics of asterids based on 3 coding and 3 non-coding chloroplast DNA markers and the utility of non-coding DNA at higher taxonomic level
- 2002
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In: Molecular Phylogenetics and Evolution. ; 24, s. 273-300.
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Journal article (peer-reviewed)
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| 6. |
- Dehghani, Reihaneh, et al.
(author)
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Phylogeography of the white-tailed mongoose (Herpestidae, Carnivora, Mammalia) based on partial sequences of the mtDNA control region (p 385-393)
- 2008
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In: Journal of Zoology. ; :276, s. 385-393
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Journal article (peer-reviewed)abstract
- The phylogeography of the white-tailed mongoose Ichneumia albicauda is examined using phylogenetic analyses based on partial sequences of the mitochondrial control region. The phylogeny is used to: (1) Analyse the phylogeographic pattern of I. albicauda; (2) discuss the existing delimitation of subspecies; (3) test if the coloration of the tail tip, generally white but occasionally black in West African specimens, is a species polymorphism or if it has phylogenetic significance. Our results suggest a north–south division within white-tailed mongoose populations, and within the northern clade, we observe an east–west subdivision. This phylogenetic pattern is partly in concordance with the traditional division into six subspecies. The white-tailed mongoose probably originated in southern Africa, from where it dispersed northwards and colonized eastern and western parts of Africa, as well as the Arabian Peninsula. Colour polymorphism observed in Western populations reflects variation at the individual level.
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| 7. |
- Erséus, Christer, 1951, et al.
(author)
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18S rDNA phylogeny of Clitellata (Annelida).
- 2004
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In: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 33:2, s. 187-196
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Journal article (peer-reviewed)abstract
- The phylogeny of Clitellata was analysed using 18S rDNA sequences of a selection of species representing Hirudinida, Acanthobdellida, Branchiobdellida and 10 oligochaetous families. Eleven new 18S sequences of Capilloventridae (one), Haplotaxidae (one), Propappidae (one), Enchytraeidae (two), Lumbricidae (one), Almidae (one), Megascolecidae (two), Lumbriculidae (one), and Phreodrilidae (one) are reported and aligned together with corresponding sequences of 28 previously studied clitellate taxa. Twelve polychaete species were used as an outgroup. The analysis supports an earlier hypothesis based on morphological features that Capilloventridae represents a basal clade of Clitellata; in the 18S tree it shows a sister-group relationship to all other clitellates. The remaining clitellate taxa form a basal dichotomy, one clade containing Tubificidae (including the former ‘Naididae’), Phreodrilidae, Haplotaxidae, and Propappidae, the other clade with two subgroups: (1) Lumbriculidae together with all leech-like taxa (Acanthobdellida, Branchiobdellida and Hirudinida), and (2) Enchytraeidae together with a monophyletic group of all earthworms included in the study (Lumbricidae, Almidae and Megascolecidae). These earthworms are members of the taxon Crassiclitellata, the monophyly of which is thus supported by the data. The tree also shows support for the hypothesis that the first clitellates were aquatic. The position of the single species representing Haplotaxidae is not as basal as could have been expected from earlier morphology-based conclusions about the ancestral status of this family. However, if Haplotaxidae is indeed a paraphyletic assemblage of relict taxa, a higher number of representatives will be needed to resolve its exact relationships with the other clitellates.
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| 10. |
- Hartman, Henrik, et al.
(author)
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First storage of ion beams in the Double Electrostatic Ion-Ring Experiment : DESIREE
- 2013
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In: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 84:5
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Journal article (peer-reviewed)abstract
- We report on the first storage of ion beams in the Double ElectroStatic Ion Ring ExpEriment, DESIREE, at Stockholm University. We have produced beams of atomic carbon anions and small carbon anion molecules (Cn-, n = 1, 2, 3, 4) in a sputter ion source. The ion beams were accelerated to 10 keV kinetic energy and stored in an electrostatic ion storage ring enclosed in a vacuum chamber at 13 K. For 10 keV C2- molecular anions we measure the residual-gas limited beam storage lifetime to be 448 s +/- 18 s with two independent detector systems. Using the measured storage lifetimes we estimate that the residual gas pressure is in the 10-14 mbar range. When high current ion beams are injected, the number of stored particles does not follow a single exponential decay law as would be expected for stored particles lost solely due to electron detachment in collision with the residual-gas. Instead, we observe a faster initial decay rate, which we ascribe to the effect of the space charge of the ion beam on the storage capacity.
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