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- Andersson, Agneta, et al.
(author)
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DNA-streckkodning av marina växtplankton : Ett nytt verktyg i miljöövervakningen
- 2024
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Reports (other academic/artistic)abstract
- Växtplankton utgör grunden i den marina näringsväven och används världen över för att bestämma miljöstatus i hav och sjöar. De ingår exempelvis som en kvalitetsfaktor i EU:s vattendirektiv och havsmiljödirektiv. Det finns långa tidsserier av växtplanktonövervakning där analyserna utförts med mikroskopi. Det sker nu en snabb internationell utveckling av DNA-metoder för att övervaka växtplankton. Målsättningen med detta projekt var att utveckla en praktisk och robust DNA analysmetod som kan implementeras i svensk marin miljöövervakning. Vårt tillvägagångssätt var att följa med på ordinarie marina miljöövervakningsexpeditioner under ett års tid (2019–2020) och ta parallella havsvattenprov för så kallad DNA-streckkodning av växtplankton. Sammanlagt tog vi prov vid 19 övervakningsstationer som var spridda från Bottenviken i norr till Skagerrak i söder. Provtagningsfrekvensen var cirka 1 gång per månad. Praktiska metoder utarbetades för fältprovtagning, DNA-extraktion, sekvensering, bioinformatisk analys och taxonomisk annotering. Vi har även tagit fram system för datahantering hos nationell datavärd och gett förslag på en ny datatyp för nationellt datavärdskap för marinbiologi och oceanografi vid Svenskt Oceanografiskt Datacentrum (https://sharkweb. smhi.se/hamta-data/). En viktig del har varit att jämföra resultaten av DNA-streckkodning och mikroskopi. Resultaten visar att DNA-streckkodning ger ungefär dubbelt så högt biodiversitetsmått än mikroskopering, även om det skiljer sig åt mellan olika grupper av växtplankton. För att undersöka om DNA-streckkodning kan användas för kvantitativ analys tillsatte vi en intern standard till proverna bestående av syntetiskt DNA, men eftersom resultatet varierade så behöver man arbeta vidare med detta. Den relativa fördelningen av vanliga eukaryota växtplanktongrupper visade sig ha relativt bra överensstämmelse mellan DNA-streckkodning och mikroskopimåttet kolbiomassa, medan biovolym och abundans skiljde sig åt mer. DNA-streckkodning visade sig ge detaljerade utbredningsmönster av skadliga alger, till exempel för släktet Prymnesium bland häftalgerna (Coccolithophyceae). Vi har inom projektet kunnat utvärdera ekologiska drivkrafter för växtplanktonsamhällets diversitet och artsammansättning, genom att miljöövervakningen mäter många fysikalisk-kemiska parametrar. Både salthalt och närsalter visade sig ha stor inverkan på växtplanktonsamhällets sammansättning och diversitet. Sammanfattningsvis ser vi att den framtagna DNA-streckkodningsmetoden skulle vara ett bra komplement till den etablerade växtplanktonövervakningen.
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| 2. |
- Berglund, Anders
(author)
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Process control and production strategies in the sawmill industry
- 2013
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Licentiate thesis (other academic/artistic)abstract
- The sawmill process itself is not complicated. What makes it complex is thediversity of the raw material, the logs that are processed in the sawmill, and thedivergent production with many different end products. In the sawmill variousnumber of measurement and scanning equipments are installed. These are usedfor controlling the various processes and for measuring how well they are carriedthrough.The main objective of this thesis is to build knowledge of how we can makethe sawing process, one of the main steps within the sawmill process, more efficientwith respect to both volume yield and value recovery by new equipmentand new production strategies. The intention has been that the conclusions inthis thesis can contribute to a knowledge base that can be of assistance in decisionsregarding control process parameters and production strategies for a sawmill.There is a possible economic saving by increased volume yield for the sawmillsif the saw kerf width can be reduced, but there is a fear that the presence andmagnitude of saw mismatch will be affected by this. Saw mismatch occurs on thesawn boards due to displacement in axial direction of the saw blades in doublearbor saw machines as a consequence of wear, heat or mechanical disturbance. Itis shown in this thesis that it was possible to measure saw mismatch automaticallyduring sawmill operation by laser triangulation and that the measurements werecomparable to manual measurements. It is also suggested how the presence andmagnitude of saw mismatch can be evaluated when measurements are carriedout in a sawmill.Another study addressed in the thesis is the consideration of applying analternative log rotation for each log than the in Scandinavia industrial praxis ofhorns down (log crook faced upwards). This possibility for a greater profit returncomes in question since the development of an industrial computed tomographyscanner makes the internal knot structure of the log available.Log breakdown simulations of about 600 Scots pine (Pinus sylvestris [L.])logs and 800 Norway spruce (Picea abies [L.] Karst.) logs mainly from differentgeographic locations in Sweden showed that there is a potential value increasewhen rotating each log for greatest profit return. The potential value increase wasdependent of the rotational error of the sawing machine and the price differencesbetween quality grades. For the 600 Scots pine logs and the 800 Norway sprucelogs in the study an increased average value increase of 13% was obtained ifapplying the rotation that maximizes the value of each log instead of the horns down position. An introduced rotational error of the sawing machine reducedthe value potential to 6%. There was a weak correlation between the log rotationthat maximizes the value of each log and the outer shape of the logs. This meansthat the outer shape can not be used as an indicator of how the log should berotated for greatest profit return.One subject of discussion in the thesis is also the importance of representativeinput data in order to make as general conclusions as possible. The Swedishstem bank has been an important factor in many studies made in the field ofwood technology. It is a well-documented data set and computed tomographyscanning of logs has made it possible to represent internal wood features in logbreakdown software. Since computed tomography scanning of logs is a time consuming process the number of scanned logs are relatively small. Now thatan industrial computed tomography scanner operating at production speed isentering the market this opens up new possibilities. Hopefully simulation studiesthat are performed on larger industrial data sets coming from logs processed inthe sawmills at a daily basis is not too far away.
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| 3. |
- Johansson, Carl-Johan, et al.
(author)
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Sågverksnytt nr 1
- 2013
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Reports (other academic/artistic)
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| 4. |
- Latz, Meike, et al.
(author)
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A comprehensive dataset on spatiotemporal variation of microbial plankton communities in the Baltic Sea
- 2024
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In: Scientific Data. - : Springer Nature. - 2052-4463. ; 11:1
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Journal article (peer-reviewed)abstract
- The Baltic Sea is one of the largest brackish water environments on earth and is characterised by pronounced physicochemical gradients and seasonal dynamics. Although the Baltic Sea has a long history of microscopy-based plankton monitoring, DNA-based metabarcoding has so far mainly been limited to individual transect cruises or time-series of single stations. Here we report a dataset covering spatiotemporal variation in prokaryotic and eukaryotic microbial communities and physicochemical parameters. Within 13-months between January 2019 and February 2020, 341 water samples were collected at 22 stations during monthly cruises along the salinity gradient. Both salinity and seasonality are strongly reflected in the data. Since the dataset was generated with both metabarcoding and microscopy-based methods, it provides unique opportunities for both technical and ecological analyses, and is a valuable biodiversity reference for future studies, in the prospect of climate change.
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| 9. |
- Funk, Peter, et al.
(author)
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Värde- eller volymoptimering av sidobräder
- 2022
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Reports (other academic/artistic)abstract
- With the help of the saw simulation program Saw2010, and the Swedish stem bank, a simulated sawing of 1288 logs has been performed, after which planks and boards have been quality-determined according to Nordic Wood (the Blue Book) and evaluated. After a large number of simulations on boards and planks of pine and spruce, it can be stated that value optimization gives a higher value yield than volume optimization in all three realistic price situations tested. The total value varies between price ranges and types of wood but is stably better on all runs with value optimization compared with volume optimization. The result is described as the total value increase in percent for all products in each run. A total of three runs were made in pine and three in spruce with respectively low, intermediate, and high prize level. The highest increase in value for edging with value optimization, compared with volume optimization, is found in both pine and spruce in the lowest price level, 5.1% and 5.0%, respectively. At the intermediate price level, the increase in value is 4.2% for pine and 3.3% for spruce. The highest price level gave a value increase of 3.0% for pine and 1.8% for spruce in value optimization compared with volume optimization. Simulations with changed quality parameters were also performed. One simulation was performed with a smaller permitted wane and one with larger permitted knots on the flat face compared to Nordic Wood. Also, these simulations showed clearly increased value in value optimization compared with volume optimization.
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