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- Erlandsson, Johan
(författare)
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Do reproductive strategy and breeding season influence the presence of mate recognition in the intertidal snail Littorina?
- 2002
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Ingår i: Invertebrate Reproduction & Development. - 0168-8170. ; 41:1-3, s. 53-60
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Tidskriftsartikel (refereegranskat)abstract
- To test the assumption that littorinid snails do not discriminate between mates prior to copulation, I studied mate recognition behaviour in two species of Littorina on Swedish rocky shores: L. littorea (which has pelagic development and a distinct reproductive season) and L. saxatilis (non-pelagic development; reproduces throughout the year). Copulating pairs were sampled in five populations of each species to determine the occurrence of maladaptive (male-male or male-juvenile) matings, To complement the field sampling I did laboratory experiments on mucous-trail following, to reveal possible discriminating behaviour among potential mates when following mucous trails. In L. littorea about 5% of copulating pairs were between males, while in L. saxatilis, 33-38% were male-male or male-juvenile pairs. In contrast to L. littorea, this study showed that males of L. saxatilis did not discriminate between sexes from mucous trails, but followed any mucous trail (irrespective of sex of marker snail) for longer than females did. Thus, mate recognition behaviour by trail following can explain the difference in the proportion of maladaptive mating pairs between the two species studied. Among the 19 recognized species of the snail Littorina, nine show pelagic larval development, while 10 have direct, non-pelagic development. From the literature a clear relationship between reproductive strategy and the presence or absence of breeding season in Littorina snails was found. Species with pelagic development always have a distinct reproductive season, while species with nonpelagic development either reproduce throughout the year, or show variation between regions in seasonal or non-seasonal reproduction. The hypothesis that reproductive strategy and breeding season may influence the presence of mate recognition in Littorina snails is discussed.
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- Persson, Per, et al.
(författare)
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Determination of the detection limit of Ni-59 at the Lund AMS facility by using characteristic projectile X-rays
- 2000
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 160:4, s. 510-514
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Tidskriftsartikel (refereegranskat)abstract
- Accelerator mass spectrometry (AMS) is an ultra-sensitive method for counting atoms, both radionuclides and stable nuclides. When using small tandem accelerators to measure heavy isotopes, interfering isobars are often troublesome. One way to reduce this interference is to combine AMS with the detection of characteristic X-rays of the projectile. After analysis in the AMS system it is possible to identify ions of different atomic number by their characteristic X-rays, by slowing down the ions in a suitable target. In this paper, the detection limit of Ni-59 at the Land AMS facility is reported. A method for the chemical extraction of nickel from stainless steel, combined with a purification step to reduce the cobalt content in the sample by several orders of magnitude, is also described. (C) 2000 Elsevier Science B.V. All rights reserved.
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