| 1. |
- Ahlström, Christoffer, et al.
(författare)
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Optimus Pråm - Semi-submersible wind farm installation vessel for Blekinge Offshore
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In Sweden the government is investing lots of resources in order to meet the energy need with clean and renewable alternatives. Since wind is an unlimited source of energy the exploitations of wind farms is of great interest. This report describes a conceptual design of an innovative offshore wind turbine installation vessel for inland sea conditions, with highest possible energy efficiency and environmental friendly performance in every detail. The customer, Blekinge Offshore, main requirement is to receive a concept with an as low installation cost as possible.The final concept Optimus Pråm includes one installation vessel, which is a semi-submersible barge, and one support vessel that supply the installation vessel with power and propulsion. The power is distributed from the support vessel to the installation vessel through a power cable. The installation vessel will be self-propelled during the installation phase using electrical motors and thrusters.The installation vessel shall be able to handle gravity foundations and fully assembled wind turbines, transported vertically to the installation site. Foundations and windmills will be fully assembled in Karlshamn port before transit to site. During transit the installation and support vessel are connected to each other in all motions except pitch. This almost total fixed connection makes the two vessels acts like one, which gives the joint vessel excellent manoeuvrability. When installing foundations, the installation vessel and the support vessel disconnect. The installation vessel places the foundation at the planned location by ballasting until the foundation has reached the seabed. After de-ballasting the installation vessel and support vessel connects again and transit back to the harbour. When installing wind turbines the two vessels are kept connected and makes highly accurate positioning for the installation possible
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| 2. |
- Berglund, Mikael, 1965-, et al.
(författare)
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Post-glacial fault scarps in Jämtland, central Sweden
- 2015
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Ingår i: GFF. - : Informa UK Limited. - 1103-5897 .- 2000-0863. ; 137:4, s. 339-343
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Tidskriftsartikel (refereegranskat)abstract
- Analysis of a light detection and ranging-derived digital elevation model has revealed previously unknown fault scarps in central Jämtland, Sweden. These are interpreted to have been formed by earthquakes at the time of deglaciation, c. 10 ka BP, in an area with current low-magnitude seismicity. The dating is based upon morphology and comparison with similar features at other locations in Sweden but not supported by independent dating. Observed scarps are 0.4–6 km long, 2–8 m high, trending SSW–NNE to WSW–ENE, the northern and western sides uplifted. The dimensions of the scarps suggest an approximate moment magnitude M 7 of the strongest corresponding earthquakes.
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| 3. |
- Bomfim, I L, et al.
(författare)
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The immunogenetics of narcolepsy associated with A(H1N1)pdm09 vaccination (Pandemrix) supports a potent gene-environment interaction.
- 2017
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Ingår i: Genes and immunity. - : Springer Science and Business Media LLC. - 1476-5470 .- 1466-4879. ; 18, s. 75-81
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Tidskriftsartikel (refereegranskat)abstract
- The influenza A(H1N1)pdm09 vaccination campaign from 2009 to 2010 was associated with a sudden increase in the incidence of narcolepsy in several countries. Narcolepsy with cataplexy is strongly associated with the human leukocyte antigen (HLA) class II DQB1*06:02 allele, and protective associations with the DQB1*06:03 allele have been reported. Several non-HLA gene loci are also associated, such as common variants of the T-cell receptor-α (TRA), the purinergic receptor P2RY11, cathepsin H (CTSH) and TNFSF4/OX40L/CD252. In this retrospective multicenter study, we investigated if these predisposing gene loci were also involved in vaccination-associated narcolepsy. We compared HLA- along with single-nucleotide polymorphism genotypes for non-HLA regions between 42 Pandemrix-vaccinated narcolepsy cases and 1990 population-based controls. The class II gene loci associations supported previous findings. Nominal association (P-value<0.05) with TRA as well as suggestive (P-value<0.1) associations with P2RY11 and CTSH were found. These associations suggest a very strong gene-environment interaction, in which the influenza A(H1N1)pdm09 strain or Pandemrix vaccine can act as potent environmental triggers.Genes and Immunity advance online publication, 23 March 2017; doi:10.1038/gene.2017.1.
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| 4. |
- Dahlström, Niklas
(författare)
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Function and dynamics of woody debris in boreal forest streams
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The work in this thesis deals with (1) the effects of woody debris on stream channel morphology and retention of organic material, and (2) the dynamics of woody debris and its relation to riparian forest history and composition. The studied stream reaches are situated in mature, productive forests in the boreal zone of Sweden.Wood variables were important predictors of the frequency of debris dams, pool area, the proportion of pools formed by wood, and variation in the bankfull channel width. Pools formed by woody debris were mainly created by damming and had larger surface areas and residual depths than pools formed by other agents. Stream reaches intersecting old-growth forest (with minor influence of forest management) had coarser and longer woody debris pieces, greater amounts of wood, more debris dams, and wood-formed pools compared to streams surrounded by forests influenced by selective logging.The influence of past forest management on the quality and quantity of woody debris in streams were analyzed by using dendrochrnological methods. Selective loggings and absence of forest fires after 1831 resulted in lower input rates and a gradual replacement of pine by sruce over time. Residence times in stream channels of woody debris (>10 cm in basal diameter) were long and the oldest dated pieces of pine and spruce were over 300 and 100 years, respectively.Dynamics of woody debris were explored by comparing wood volumes and characteristics between stream channels and their riparianforests and between old growth and managed sites. Wood volumes recorded in the stream channels exceeded, but were related to, the volumes found in the riparian forests. Limited input of woody debris by bank cutting and absence of slope processes suggest that recruitment processes of woody debri to stream channels are similar as in riparian forests and slow decay in channels results in greater volumes.The retentiveness of organic material in stream channels was examined by using release and capture experiments in multiple reaces during varying discharges using different sizes of leaf mimics. Sixty eight percent of the variation in retention was explained by a multiple regression model including discharge and leaf mimic siz. Between 44 and 80% of the variation in retention among reaches was explained by channel constraint, gravel coverage, and woody debris variables as the most important. Estimates from a partial least squares (PLS) model suggest an increase in mean transport distances by 22 to 53% in managed forest streams compared to old growth conditions and in a low wood scenario, mean transport distances increased by 38 to 99% with larger increases for higher discharges and larger particle sizes.To regain more pristine conditions of stream channels, management and restoration are needed to increase the amount of woody debris that recreates lost channel structures and increaes the retention of organic material.
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| 5. |
- Dahlström, Niklas, et al.
(författare)
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Influence of Woody Debris on Channel Structure in Old Growth and Managed Forest Streams in Central Sweden
- 2004
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Ingår i: Environmental Management. - : Springer Science and Business Media LLC. - 0364-152X .- 1432-1009. ; 33:3, s. 376-384
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Tidskriftsartikel (refereegranskat)abstract
- Anecdotal information suggests that woody debris have had an important channel-forming role in Swedish streams and rivers, but there are few data to support this view. We identified 10 streams within near-natural and 10 streams within managed forest landscapes in central Sweden, and quantified their channel characteristics and content of woody debris. All pieces of woody debris greater than 0.5 m in length and greater than 0.05 m in base diameter were included. The near-natural forests were situated in reserves protected from forest cutting, whereas the managed forests had previously faced intensive logging in the area adjacent to the stream, The two sets of streams did not differ in general abiotic characteristics such as width, slope, or boulder cover, but the number of wood pieces was twice as high and the wood volume almost four times as high in the near-natural streams. This difference resulted in a higher frequency of debris dams in the near-natural streams. Although the total pool area did not differ between the two sets of streams, the wood-formed pools were larger and deeper, and potentially ecologically more important than other pools. In contrast to what has been believed so far, woody debris can be a channel-forming agent also in steeper streams with boulder beds. In a step-wise multiple regression analysis, pool area was positively and most strongly related to the quantity of woody debris, whereas channel gradient and wood volume were negatively related. The frequency of debris dams increased with the number of pieces of woody debris, but was not affected by other variables. The management implications of this study are that the wood quantity in streams in managed forests would need to be increased if management of streams will target more pristine conditions.
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| 6. |
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| 7. |
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| 8. |
- Dahlström, Niklas, et al.
(författare)
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Kvicksilver i insjöfisk i Skåne år 2000
- 2001
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Frysta fiskprover från tio sjöar i norra Skåne har analyserats med avseende på kvicksilver. Materialet ingår i en studie vars syfte är dels att klarlägga kvicksilverhalterna i länets sjöar, dels att utröna om mörten kan användas som indikatororganism där andra fiskar saknas.
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| 9. |
- Dahlström, Niklas, et al.
(författare)
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Long-term dynamics of large woody debris in a managed boreal forest stream.
- 2005
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 210:1-3, s. 363-373
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Tidskriftsartikel (refereegranskat)abstract
- Little is known about how past forest management in Sweden influenced the quantity and quality of large woody debris (LWD) in streams. The present study provides information of the long-term dynamics of LWD in a reach of a boreal stream intersecting a managed forest. Dendrochronological methods were used to reconstruct mortality years of the pieces of LWD and the general history of fire and cuttings of the surrounding riparian forest. Today, spruce dominates among the living trees, whereas the LWD is dominated by birch in the forest and by pine in the stream. Fire frequency prior to active fire suppression was similar to values reported from boreal forests. Pine trees were more abundant in the riparian forest before selective logging operations and active fire suppression began in the 1800s. Many of the pieces of LWD found in the stream today died more than 200 years ago and derived from a cohort of pines that generated in the early 1600s. Pine LWD in stream channels is highly resistant to decomposition and can reside for more than 300 years. A substantial amount of the LWD found today in managed forest streams in boreal Sweden most likely derives from the time before extensive human influence and is likely to decrease further in the future. Management of riparian forests to ascertain future supply of long-lived LWD in streams should target to increase the proportion of pine trees.
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| 10. |
- Dahlström, Niklas, et al.
(författare)
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The dynamics of coarse woody debris in boreal Swedish forests are similar between stream channels and adjacent riparian forests
- 2006
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Ingår i: Canadian Journal of Forest Research. - 0045-5067 .- 1208-6037. ; 36:5, s. 1139-1148
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Tidskriftsartikel (refereegranskat)abstract
- Although numerous studies have focused on the dynamics of coarse woody debris (CWD) in boreal Fennoscandian forests, information on CWD in streams remains limited. To achieve a better understanding of CWD dynamics in streams we compared amounts and characteristics of CWD between streams and adjacent riparian forests in old-growth and managed forest sites, respectively. We also identified distances to the sources of CWD and evaluated these in relation to the lateral zonation of riparian trees. CWD volumes found in the stream channels were related to, but exceeded, the volumes found in the adjacent forest. In-channel volumes separated by species were better correlated with terrestrial volumes of CWD than with volumes of living trees. Tree species appeared to be zoned across the riparian zone, with slightly higher abundances of deciduous trees and lower abundances of Scots pine trees close to the stream. Similar to upland forests, riparian forests were dominated by coniferous tree species, mainly Norway spruce (Picea abies (L.) Karst.). These findings suggest large similarities in CWD input between streams and riparian forests and substantially slower decomposition rates in stream channels compared with those in riparian forest. The results provide an improved basis for creating reliable models of CWD supply and maintenance in streams based on knowledge of forest development and CWD dynamics in the terrestrial environment. Site productivity could potentially be used to predict CWD volumes in stream channels under pristine conditions.
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