| 1. |
- Abrahamsson, Markus, et al.
(författare)
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Saproxylic beetle assemblages in artificially created high-stumps of spruce (Picea abies) and birch (Betula pendula/pubescens) – does the surrounding landscape matter?
- 2009
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Ingår i: Insect Conservation and Diversity. - : Wiley. - 1752-458X .- 1752-4598. ; 2, s. 284-294
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Tidskriftsartikel (refereegranskat)abstract
- Abstract. 1. To create high-stumps (snags) is a common conservation action during final felling in Swedish production forests. However, many wood-living beetle species are only found in certain areas with higher overall biodiversity, so called hotspots. It has been argued that it is efficient to concentrate conservation efforts to hotspots. 2. The saproxylic beetle fauna was sampled on ten clearcuts inside hotspots and ten clearcuts outside the hotspots. They were collected with window traps mounted on 2- and 4-year-old spruce and birch high-stumps. We also used environmental data (e.g. tree species composition) to confirm differences between the surroundings of two, the clearcut types. 3. High-stumps on the hotspot clearcuts did not attract more saproxylic beetle species, or red-listed species, than high-stumps outside the hotspots. The environmental data showed that the clearcuts differed in several important aspects, for instance, were there a higher proportion of broadleaved trees around the hotspot compared with the clearcuts outside the hotspots. In a Canonical Correspondence Analysis, the proportion of coniferous and broadleaved forest was an important explanatory variables. The hotspot variable did contribute significantly in explaining the beetle composition on the birch high-stumps, but not on the spruce high-stumps. 4. In general, the study suggests that concentrating high-stumps to hotspot areas will not benefit more species. However, the result indicates birch high-stumps could be prioritised in a biologically rich landscape. The hotspot effect may be more noticeable in the future as the high-stumps decay and their importance for late successional species increase
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| 2. |
- Dion, Claude, et al.
(författare)
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Controllable 3D atomic Brownian motor in optical lattices
- 2008
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Ingår i: The European Physical Journal - Special Topics. - : Springer Science and Business Media LLC. - 1951-6355 .- 1951-6401. ; 159:1, s. 11-17
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Tidskriftsartikel (refereegranskat)abstract
- We study a Brownian motor, based on cold atoms in optical lattices, where atomic motion can be induced in a controlled manner in an arbitrary direction, by rectification of isotropic random fluctuations. In contrast with ratchet mechanisms, our Brownian motor operates in a potential that is spatially and temporally symmetric, in apparent contradiction to the Curie principle. Simulations, based on the Fokker-Planck equation, allow us to gain knowledge on the qualitative behaviour of our Brownian motor. Studies of Brownian motors, and in particular ones with unique control properties, are of fundamental interest because of the role they play in protein motors and their potential applications in nanotechnology. In particular, our system opens the way to the study of quantum Brownian motors.
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| 3. |
- Jansson, Nicklas, 1967-, et al.
(författare)
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An indicator system for identification of sites of high conservation value for saproxylic oak (Quercus spp.) beetles in southern Sweden
- 2009
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Ingår i: Journal of Insect Conservation. - : Springer Science and Business Media LLC. - 1366-638X .- 1572-9753. ; 13:4, s. 399-412
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Tidskriftsartikel (refereegranskat)abstract
- The saproxylic beetle fauna on old oaks was sampled in four regions of southern Sweden using two methods: window and pitfall trapping. The aim was to test a way of finding indicator species which can be used to identify sites with high species number or that scored high on a conservation priority species index, based on occurrence of red-listed species. From 92 sites surveyed, in total 164 species of saproxylic beetles were identified. Different sets of indicator species were selected based upon 22 sites from a centrally located region. Predictions of species number and the index for 30 other sites from the same province were made. The correlation between observed and predicted species number and the index increased with increasing number of indicators. When comparing different treatment of species indata, the explanatory power of predictions was strongest for presence/absence data. Indicator sets of species effectively caught with pitfall traps gave overall the best predictions of both species number and the index. Predictions of species number and the index worked well within the same regions but gave varied result for the three other regions which shows that transferability of indicators between regions may be doubtful.
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| 4. |
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| 5. |
- Jonsell, Svante, et al.
(författare)
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A nonadiabatic semi-classical method for dynamics of atoms in optical lattices
- 2006
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Ingår i: European Physical Journal D. - Les Ulis : EDP Sciences. - 1434-6060 .- 1434-6079. ; 39:1, s. 67-74
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Tidskriftsartikel (refereegranskat)abstract
- We develop a semi-classical method to simulate the motion of atoms in a dissipative optical lattice. Our method treats the internal states of the atom quantum mechanically, including all nonadiabatic couplings, while position and momentum are treated as classical variables. We test our method in the one-dimensional case. Excellent agreement with fully quantum mechanical simulations is found. Our results are much more accurate than those of earlier semi-classical methods based on the adiabatic approximation.
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| 6. |
- Jonsell, Svante, et al.
(författare)
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Raglande atomer nyktrar till
- 2006
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Ingår i: Fysikaktuellt. - 0283-9148. ; :2, s. 10-
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 7. |
- Sjölund, Peder, et al.
(författare)
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Demonstration of a controllable three-dimensional Brownian motor in symmetric potentials
- 2006
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Ingår i: Physical Review Letters. - New York : American Physical Society. - 0031-9007 .- 1079-7114. ; 96:19, s. 190602-
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate a Brownian motor, based on cold atoms in optical lattices, where isotropic random fluctuations are rectified in order to induce controlled atomic motion in arbitrary directions. In contrast to earlier demonstrations of ratchet effects, our Brownian motor operates in potentials that are spatially and temporally symmetric, but where spatiotemporal symmetry is broken by a phase shift between the potentials and asymmetric transfer rates between them. The Brownian motor is demonstrated in three dimensions and the noise-induced drift is controllable in our system.
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| 8. |
- Thulin, Mats, et al.
(författare)
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The status of “Frangula dodonei” (Rhamnaceae)
- 2009
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Ingår i: Taxon. - 0040-0262 .- 1996-8175. ; 58:3, s. 991-992
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Tidskriftsartikel (refereegranskat)abstract
- The widely used name Frangula alnus (syn. Rhamnus frangula) has in recent years been threatened by F. dodonei, an allegedly older name said to be published in a rare work by Pietro Arduino. However, from the context of Arduino's paper it is clear that “F. dodonei” is not a binomial; it just happens to look like one, and has no nomenclatural status.
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