lnu.sePublications
Change search
Refine search result
78910111213 451 - 500 of 899
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 451.
    Kraus, Robert H. S.
    et al.
    Wageningen University, The Netherlands.
    van Hooft, Pim
    Wageningen University, The Netherlands.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Latorre-Margalef, Neus
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Ydenberg, Ronald C.
    Wageningen University, The Netherlands ; Simon Fraser University, Canada.
    Prins, Herbert H. T.
    Wageningen University, The Netherlands.
    Avian influenza surveillance with FTA cards: field methods, biosafety, and transportation issues solved2011In: Journal of Visualized Experiments, ISSN 1940-087X, E-ISSN 1940-087X, no 54, article id 2832Article in journal (Refereed)
    Abstract [en]

    Avian Influenza Viruses (AIVs) infect many mammals, including humans(1). These AIVs are diverse in their natural hosts, harboring almost all possible viral subtypes(2). Human pandemics of flu originally stem from AIVs(3). Many fatal human cases during the H5N1 outbreaks in recent years were reported. Lately, a new AIV related strain swept through the human population, causing the 'swine flu epidemic'(4). Although human trading and transportation activity seems to be responsible for the spread of highly pathogenic strains(5), dispersal can also partly be attributed to wild birds(6, 7). However, the actual reservoir of all AIV strains is wild birds. In reaction to this and in face of severe commercial losses in the poultry industry, large surveillance programs have been implemented globally to collect information on the ecology of AIVs, and to install early warning systems to detect certain highly pathogenic strains(8-12). Traditional virological methods require viruses to be intact and cultivated before analysis. This necessitates strict cold chains with deep freezers and heavy biosafety procedures to be in place during transport. Long-term surveillance is therefore usually restricted to a few field stations close to well equipped laboratories. Remote areas cannot be sampled unless logistically cumbersome procedures are implemented. These problems have been recognised(13, 14) and the use of alternative storage and transport strategies investigated (alcohols or guanidine)(15-17). Recently, Kraus et al.(18) introduced a method to collect, store and transport AIV samples, based on a special filter paper. FTA cards(19) preserve RNA on a dry storage basis(20) and render pathogens inactive upon contact(21). This study showed that FTA cards can be used to detect AIV RNA in reverse-transcription PCR and that the resulting cDNA could be sequenced and virus genes and determined. In the study of Kraus et al.(18) a laboratory isolate of AIV was used, and samples were handled individually. In the extension presented here, faecal samples from wild birds from the duck trap at the Ottenby Bird Observatory (SE Sweden) were tested directly to illustrate the usefulness of the methods under field conditions. Catching of ducks and sample collection by cloacal swabs is demonstrated. The current protocol includes up-scaling of the work flow from single tube handling to a 96-well design. Although less sensitive than the traditional methods, the method of FTA cards provides an excellent supplement to large surveillance schemes. It allows collection and analysis of samples from anywhere in the world, without the need to maintaining a cool chain or safety regulations with respect to shipping of hazardous reagents, such as alcohol or guanidine.

  • 452.
    Kristiansson, Håkan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    The Effect of Optical Defocus on the Peripheral Resolution Acuity in Old Healthy Emmetropes2011Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 453.
    Kristiansson, Håkan
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Baskaran, Karthikeyan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Lewis, Peter
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Rosén, Robert
    Biomedical and X-Ray Physics.
    Unsbo, Peter
    Biomedical and X-Ray Physics.
    Gustafsson, Jörgen
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Effect of Optical Defocus on Peripheral Resolution Acuity in Old Healthy Emmetropes2011Conference paper (Refereed)
    Abstract [en]

    Background:

    A recent study by Rosén et al found peripheral low contrast resolution acuity, but not high contrast acuity, to be affected by defocus in young healthy eyes. Since aging causes considerable degradation in peripheral optics even in healthy subjects we wanted to see if, older subjects were also sensitive to defocus in low contrast acuity.

     

    Purpose:

    The aim of this study was to evaluate the effect of optical defocus on high and low contrast resolution acuity in the peripheral visual field of healthy older emmetropes.

     

    Subjects:

    High- and low-contrast resolution acuity was evaluated under spherical defocus in the 20° nasal visual field of four healthy older emmetropic subjects. The off-axis refractive error at the 20° nasal visual field was measured by a COAS-HD VR aberrometer and was corrected accordingly for each subject.

     

    Methods:

    Resolution thresholds for visual acuity (VA) were obtained using stimuli consisting of high- (100%) and low- (10%) contrast gratings that were presented on a CRT monitor situated 1.0 meter from the subject. Stimuli, 3° in diameter were presented for 300 ms using a 2AFC paradigm. Two repeated measurements, for both high and low contrast, were obtained for each point of defocus in 1.0 D steps up to ±4 D at 45mm vertex distance. The results are corrected to effective defocus at the corneal plane.

     

    Results:

    Defocus had no visible effect on high contrast VA, although there was a slight decrease in VA with higher amounts of positive defocus. However, defocus was found to have a significant effect on low contrast VA. Moreover, low contrast resolution was more sensitive to positive defocus than the negative defocus.

     

    Conclusions:

    Defocus has an impact on low contrast resolution whereas no such effect was found for high contrast resolution. These results are similar to those obtained by Rosén et al1 in young eyes. These results suggest that low contrast optotypes could possibly be used for determining subjective refraction in low vision subjects.

  • 454.
    Krona, Liselotte
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Omregleringen av apoteksmarknaden : Aspekter på receptfria läkemedel i dagligvaruhandeln2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Från den 1 nov 2009 är det i Sverige tillåtet att sälja ett stort urval av receptfria läkemedel i dagligvaruhandeln. Motivet därtill är att skapa en ökad tillgänglighet för konsumenterna, en prispress samt en fortsatt säker och ändamålsenlig läkemedelsanvändning. Syftet med denna uppsats är att redovisa och diskutera hur berörda intressenter på den svenska apoteksmarknaden ser på att receptfria läkemedel nu får försäljas utanför apotek. Uppsatsen belyser de aspekter som låg till grund för liberaliseringen av marknaden för receptfria läkemedel. För studien har en kvalitativ metod med strukturerade intervjuer använts. Sammanlagt intervjuades 18 personer som kunde tänkas ha intressen i och åsikter om de utvalda aspekterna. De intervjuade pekade på att utfallet av avregleringen blivit en ökad tillgänglighet speciellt i tätbebyggda områden och för frekvent använda läkemedel. Trots ökad konkurrens har ingen prispress på receptfria läkemedel ännu skett. För att uppnå en säker och ändamålsenlig läkemedelsanvändning är det viktigt att läkemedlen exponeras på lämpligt sätt så att ingen självbetjäning förekommer samt att det finns en åldersgräns för inköp. Krävs rådgivning ska den lämnas av personer med farmaceutisk kompetens. Slutsats: Den ökade tillgängligheten av de vanligast förekommande receptfria läkemedel får konsumenterna betala för genom oförändrade eller högre priser, och minskade ekonomiska möjligheter för apoteken att ge rådgivning.

  • 455. Kruse, Robert
    et al.
    Säve, Susanne
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Persson, Katarina
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Adenosine Triphosphate Induced P2Y(2) Receptor Activation Induces Proinflammatory Cytokine Release in Uroepithelial Cells.2012In: Journal of Urology, ISSN 0022-5347, E-ISSN 1527-3792, Vol. 188, no 6, p. 2419-2425Article in journal (Refereed)
    Abstract [en]

    PURPOSE: We characterized and identified the uroepithelial P2 receptor responsible for adenosine triphosphate mediated release of the cytokines interleukin-8 and 6.

    MATERIALS AND METHODS: The human renal epithelial cell line A498 (ATCC™) was cultured and stimulated with different purinergic agonists with or without prior inhibition with different antagonists or signaling pathway inhibitors. Supernatant was analyzed for interleukin-8 and 6 by enzyme-linked immunosorbent assay. P2 receptor mRNA expression was assessed by real-time reverse transcriptase-polymerase chain reaction. The candidate receptor was knocked down with siRNA technology. Interleukin-8 and 6 responses were measured after purinergic stimulation of knocked down cells.

    RESULTS: ATP and ATP-γ-S (Roche Diagnostics, Mannheim, Germany) were equipotent as inducers of interleukin-8 and 6 release. Agonist profile experiments using different P2 receptor agonists indicated that P2Y(2) was the main contributor to this release, although P2Y(11) and P2X(7) activation could not be excluded. Signaling pathway experiments showed that interleukin-8 release involved phospholipase C and inositol trisphosphate mediated signaling, indicating a P2Y receptor subtype. Antagonist experiments indicated P2Y(2) as the responsible receptor. Gene expression analysis of P2 receptors showed that strong expression of P2Y(2) receptor and subsequent knockdown of P2Y(2) receptor mRNA for 72 and 96 hours abrogated interleukin-8 and 6 release after purinergic stimulation with adenosine triphosphate-γ-S.

    CONCLUSIONS: Interleukin-8 and 6 release after purinergic stimulation in uroepithelial A498 cells is mediated through P2Y(2) receptor activation.

  • 456.
    Kull, Sara
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Attityder till val av fordonsbränsle2010Independent thesis Advanced level (degree of Master (One Year)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Fossil fuels are amongst the largest contributors to the climate changes currently happening. Through an increased use of alternative fossil-free fuel it is possible to achieve a significant reduction of carbon dioxide emissions to the atmosphere. One such fuel is biogas, which is considered as one of the cleanest fuels available today. Biogas is produced from various types of waste materials, and replacing fossil fuel with biogas results in an overall reduction of green-house gas emissions.

    The Kalmar County has set a target to become a completely fossil fuel-free region by the year 2030. Through an increased use of biogas in the transport sector, such types of national targets can be achieved. The Municipality of Västervik, a part of the Kalmar County, has since 2008 been producing biogas locally, which meant that a fuelling station could be built in 2009 and through this, the Municipality has taken a major step towards an increased use of biogas. With supply secured, it is up to individuals and companies to use it for vehicle fuel. This choice requires a change in human habits. The motivations for making changes vary among individuals and theirs attitudes.

    The aim of this study was to examine which factors affect the choice of vehicular fuel among individuals and companies. This was achieved through a survey for individuals and a questionnaire for companies. Individuals and companies could then be compared to. The study was made for the Municipality of Västervik, and the study subjects were both local and non-local residents. 612 people replied to the survey, 336 users of gas and 276 users of fossil fuels. Totally five local companies were included in the survey and three local Car Dealers.

    In this study, a number of interesting patterns regarding attitudes and affecting factors have been observed. Users of fossil considered the economic aspect as the most important factor for their choice. Users of gas have adopted environmentally friendly habits through the use of gas, where the strongest argument was the environmentally friendly approach. It was also found that biogas must be part of a coherent system in order to increase use; some biogas users pointed on shortcomings in the current system. The economic aspects and the environmental conscience were also important for companies for theirs choice of vehicles. The reduced benefit value was an important factor for investment of biogas vehicles. This was also something that Car Dealers pointed out; it is after all the own wallet that govern elections. Biogas is an environmentally friendly fuel in the current situation and previous research has also shown that there is good potential for significant improvements in the future.

  • 457.
    Kumar, Eva
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Rosenlund, JoacimLinnaeus University, Faculty of Science and Engineering, School of Natural Sciences.Kaczala, FabioLinnaeus University, Faculty of Science and Engineering, School of Natural Sciences.Hogland, WilliamLinnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Linnaeus Eco-Tech 2012 proceedings: Eighth International Conference on the Establishment of Cooperation Between Companies and Institutions in the Nordic Countries, the Baltic Sea Region, and the World. Conference on Natural Sciences and Environmental Technologies for Waste and Wastewater Treatment, Remediation, Emissions Related to Climate, Environmental and Economic Effects2012Conference proceedings (editor) (Other academic)
  • 458.
    Kumar, Saroj
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    ten Siethoff, Lasse
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Persson, Malin
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Lard, Mercy
    Lund University.
    Kronnie, Geertruy Te
    University of Padua, Italy.
    Linke, Heiner
    Lund University.
    Månsson, Alf
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Antibodies Covalently Immobilized on Actin Filaments for Fast Myosin Driven Analyte Transport2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 10, article id e46298Article in journal (Refereed)
    Abstract [en]

    Biosensors would benefit from further miniaturization, increased detection rate and independence from external pumps and other bulky equipment. Whereas transportation systems built around molecular motors and cytoskeletal filaments hold significant promise in the latter regard, recent proof-of-principle devices based on the microtubule-kinesin motor system have not matched the speed of existing methods. An attractive solution to overcome this limitation would be the use of myosin driven propulsion of actin filaments which offers motility one order of magnitude faster than the kinesin-microtubule system. Here, we realized a necessary requirement for the use of the actomyosin system in biosensing devices, namely covalent attachment of antibodies to actin filaments using heterobifunctional cross-linkers. We also demonstrated consistent and rapid myosin II driven transport where velocity and the fraction of motile actin filaments was negligibly affected by the presence of antibody-antigen complexes at rather high density (>20 mu m(-1)). The results, however, also demonstrated that it was challenging to consistently achieve high density of functional antibodies along the actin filament, and optimization of the covalent coupling procedure to increase labeling density should be a major focus for future work. Despite the remaining challenges, the reported advances are important steps towards considerably faster nanoseparation than shown for previous molecular motor based devices, and enhanced miniaturization because of high bending flexibility of actin filaments.

  • 459.
    Kuneš, Petr
    et al.
    Department of Geoscience, Aarhus University, Høegh-Guldbergs Gade 2, DK-8000 Århus C, Denmark.
    Odgaard, Bent Vad
    Department of Geoscience, Aarhus University, Høegh-Guldbergs Gade 2, DK-8000 Århus C, Denmark.
    Gaillard, Marie-José
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Soil phosphorous as a control of productivity and openness in temperate interglacial forest ecosystems.2011In: Journal of Biogeography, ISSN 0305-0270, E-ISSN 1365-2699, Vol. 38, no 11, p. 2150-2164Article in journal (Refereed)
    Abstract [en]

    Aim  Observations of long chronosequences in forest ecosystems show that, after some millennia of build-up, biomass declines in relation to the slow depletion of soil phosphorus. Plants that dominate during this period of soil impoverishment have specialized strategies for P acquisition, including ectomycorrhiza or root clusters. We use quantitative, pollen-based reconstructions of regional vegetation in four Quaternary warm stages (Holocene, Eemian, Holsteinian, Harreskovian) to test whether inferred forest cover and productivity changes are consistent with long-term modification of soil nutrient pools.

    Location  Southern Scandinavia (Denmark, southern Sweden).

    Methods  The REVEALS model was used to estimate regional vegetation abundances of 25 pollen-type-equivalent taxa from pollen records of large sedimentary basins in southernmost Scandinavia. Based on the estimated regional vegetation, we then calculated time-series of Ellenberg indicator values for L (light), R (soil reaction) and N (a productivity proxy). We classified the vegetation records into distinct phases and compared these phases and the samples using hierarchical clustering and ordination.

    Results  All three interglacials developed coniferous or mixed forests. However, pure deciduous forests were never reached during the Holsteinian, while pure coniferous forests never developed in the Holocene. Above-ground productivity was inferred to be low initially, peaking in the first third of the warm stages and then slowly declining (except during the Holocene). Dominant trees of the post-peak phases all had ectomycorrhiza as a strategy for P acquisition, indicating that easily accessible P pools had become depleted. Increases in fire regimes may have amplified the inferred final drop in productivity. Mid/late Holocene productivity changes were much influenced by agricultural activities.

    Main conclusions  REVEALS vegetation estimates combined with Ellenberg indicator values suggest a consistent pattern in warm stages of initially rising productivity, followed by a long and slow decline. The P-acquisition strategies of dominant trees indicate that the decline reflects increasing P depletion of soils.

  • 460.
    Kyhlberg, Anna
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Analys av fluorexponering i Kalmar Län2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Föreliggande examensarbete utgörs av en exponeringsbedömning för att undersöka intaget av fluor hos 4-åriga barn i hushåll med egen brunn i Kalmar län. Anledningen är att fluor är ett grundämne som kan ha negativa effekter på hälsan, och som samtidigt kan förekomma naturligt i höga halter i berggrund, jord och vatten. I ett nationellt perspektiv utmärker sig Kalmar län, där höga fluorhalter är vanliga. De exponeringsvägar som undersöktes i examensarbetet var intag via: brunnsvatten, konsumtion av jord, tandvårdsprodukter (tandkräm), inandning av damm och intag via livsmedel. Exponering genom dermalt upptag och via konsumtion av hemodlade grönsaker exkluderades ur studien då dessa bedömdes vara försumbara efter genomgång i litteraturen.

    Metod: Data för respektive exponeringsväg söktes i vetenskapliga artiklar och publikationer och valdes ut så att de skulle motsvara svenska förhållanden i modellen. Befintliga analyser av ca 4800 privata brunnar i Kalmar län fick representera koncentrationer av fluor i dricksvatten. Fluorhalter i jord uppskattades genom jämförelse med områden med liknande berggrund som provtagits och beskrivits. Intag av fluor via livsmedel representerades med ett intervall, från en exponeringsstudie på barn i samma åldersgrupp, vilket väl återspeglade svenska barns exponering via livsmedel. Detta visades genom att data över fluorhalter i olika livsmedel från Livsmedelsverket kombinerades med information om mängder av respektive livsmedel som intas av 4-åriga barn ur underökningen "Riksmaten 2003". Information om koncentrationer av fluor i tandkräm i Sverige inhämtades från Läkemedelsverket och data över mängder av tandkräm som nedsväljs i samband med tandborstning av barn återfanns i rapporter från SBU och WHO. En beräkningsmodell för generell exponering för fluor hos ett 4-årigt barn skapades i programmet RAMAS Risk Calc. Beräkningar gjordes både deterministiskt och probabilistiskt för att få fram möjliga värden som beskriver intervallet från minimal till maximal exponering.

    Resultat: Resultatet visade att hela den studerade populationen från och med första percentilen riskerade att drabbas av mild dental fluoros. 95 % av de exponerade 4-åringarna löpte dessutom risk för dental fluoros med gropar i tänderna. Akut toxisk och letal dos överskreds ej enligt resultaten från denna exponeringsbedömning. Resultaten från detta examensarbete är viktiga eftersom de belyser hur små marginalerna är mellan beräknade doser vid exponering och de doser som kan ge negativa effekter till följd av intag av fluor, även under svenska förhållanden. Vid en översyn av riktvärden för fluor av Livsmedelsverket och Socialstyrelsen samt vid undersökning av faktisk påverkan på tänder hos barn till följd av fluorintag kan resultaten från detta examensarbete vara av värde.

  • 461. Kängsepp, P
    et al.
    Mathiasson, Lennart
    Hogland, William
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Design of a pilot plan for treatment of an industrial leachate (abs)2005In: 2nd updated edition, Proceedings of Kalmar Eco-Tech'05 Waste to Energy, Bioremediation and Leachate Treatment; The 2nd Baltic Symposium on Environmental Chemistry; The 1st Kalmar Nanotechnology Workshop, the 5th International conference on the establishment of cooperation between companies/institutions in the Nordic countries and countries in the Baltic Sea region. RVF's Utvecklingssatsning Deponering Report n2 / [ed] Hogland, W., Broby, T., Kalmar, Sweden, 2005, p. 609-Conference paper (Other academic)
  • 462.
    Ladekrans, Thereze
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Beräkning av massbalanser för metaller i vatten samt miljöriskbedömning av Nerån vid Österbyverken i Östhammars kommun2011Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Österbyverken is an industrial estate in Östhammars municipality in Uppland, Sweden. Many different activities have taken place on the estate the last 600 years. During the last 15 years both health and environmental studies have been made by different companies. At the most recent study a great increase of metals in Nerån, a river that runs partly through and partly next to the estate, was identified with mass balances. The purpose of this thesis is to accomplish a deepened study about the reasons for the increase of metals in Nerån. The aim is to identify knowledge gaps in the mass balances and try to complete these. From the outcome an environmental risk assessment will be attempted for Nerån and its outlet in the lake Filmsjön. The method went through steps and started with data analyses after which calculations for new mass balances were made. Beginning by acknowledge the increase of metals from the groundwater, both through measured results and through calculated confidence intervals. In addition, among other methods, calculations of theoretical leakage data from Kd-values were made. Surface water concentrations were also compared with levels of metals in sediments to see whether any connection existed between them. Additional mass balances were calculated to take suspended solids in the surface water under consideration. From the results an environmental risk assessment was made using guidelines from Netherland and Canada and the state division from the Swedish Environmental Protection Agency. The results of the study show that the differences of metal content between surface water and groundwater and between surface water and sediments might be smaller than first revealed, but there is still a great increase caused by another, unknown source. The environmental risk assessment shows that there are hazards for both Nerån and Filmsjön because of the leakage of metals from Österbyverken. For the surface water in Nerån it is mainly cobalt, copper and zinc that contributes with risks, for the sediment in Nerån it is mainly barium, cobalt, copper, chromium and nickel and for the sediments in Filmsjön it is mainly lead, cobalt, copper, chromium, nickel and zinc. Reasons for the differences between metal contents and medias might be from surface water outlet from the Österbyverken or because of differences in methods of taking specimens in surface and groundwater. Conclusions that have been drawn of the study is that further studies of the knowledge gaps needs to be done, particularly regarding the metals cobalt, copper, chromium, nickel and zinc. Further, the biodiversity in Nerån and Filmsjön is at risk, partly because several metals in the sediments reaches such high concentrations, partly because high concentrations of several metals in one area may increase risks.

  • 463.
    Landström, Jens
    et al.
    Stockholm Univ, Dept Organ Chem, Arrhenius Lab, S-10691 Stockholm.
    Bergström, Maria
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Hamark, Christoffer
    Stockholm Univ, Dept Organ Chem, Arrhenius Lab, S-10691 Stockholm.
    Ohlson, Sten
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Widmalm, Göran
    Stockholm Univ, Dept Organ Chem, Arrhenius Lab, S-10691 Stockholm.
    Combining weak affinity chromatography, NMR spectroscopy and molecular simulations in carbohydrate-lysozyme interaction studies.2012In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 10, no 15, p. 3019-3032Article in journal (Refereed)
    Abstract [en]

    By examining the interactions between the protein hen egg-white lysozyme (HEWL) and commercially available and chemically synthesized carbohydrate ligands using a combination of weak affinity chromatography (WAC), NMR spectroscopy and molecular simulations, we report on new affinity data as well as a detailed binding model for the HEWL protein. The equilibrium dissociation constants of the ligands were obtained by WAC but also by NMR spectroscopy, which agreed well. The structures of two HEWL-disaccharide complexes in solution were deduced by NMR spectroscopy using (1)H saturation transfer difference (STD) effects and transferred (1)H,(1)H-NOESY experiments, relaxation-matrix calculations, molecular docking and molecular dynamics simulations. In solution the two disaccharides β-d-Galp-(1→4)-β-D-GlcpNAc-OMe and β-D-GlcpNAc-(1→4)-β-D-GlcpNAc-OMe bind to the B and C sites of HEWL in a syn-conformation at the glycosidic linkage between the two sugar residues. Intermolecular hydrogen bonding and CH/π-interactions form the basis of the protein-ligand complexes in a way characteristic of carbohydrate-protein interactions. Molecular dynamics simulations with explicit water molecules of both the apo-form of the protein and a ligand-protein complex showed structural change compared to a crystal structure of the protein. The flexibility of HEWL as indicated by a residue-based root-mean-square deviation analysis indicated similarities overall, with some residue specific differences, inter alia, for Arg61 that is situated prior to a flexible loop. The Arg61 flexibility was notably larger in the ligand-complexed form of HEWL. N,N'-Diacetylchitobiose has previously been observed to bind to HEWL at the B and C sites in water solution based on (1)H NMR chemical shift changes in the protein whereas the disaccharide binds at either the B and C sites or the C and D sites in different crystal complexes. The present study thus highlights that protein-ligand complexes may vary notably between the solution and solid states, underscoring the importance of targeting the pertinent binding site(s) for inhibition of protein activity and the advantages of combining different techniques in a screening process.

  • 464.
    Laohaprapanon, Sawanya
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    de Sa Salomao, Andre Luis
    Department of Sanitary and Environmental Engineering, Rio de Janeiro State University (UERJ).
    Marques, Marcia
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Hogland, William
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Toxicity evaluation in wastewater treatment process2012Conference paper (Other academic)
  • 465.
    Laohaprapanon, Sawanya
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Kaczala, Fabio
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Salomon, Paulo
    Deapartment of Marine Biology , Federal University of Rio de Janeiro (UFRJ).
    Marques, Marcia
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Hogland, William
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Toxicity on the Microalgae Desmodesmus subspicatus: Wastewater Generated during washing procedures in a Wood-floor industry2012Conference paper (Other academic)
  • 466.
    Laohaprapanon, Sawanya
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Kaczala, Fabio
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Salomon, Paulo
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Department of Marine Biology , Institute of Biology, Federal University of Rio de Janeiro (UFRJ) , Rio de Janeiro , Brazil.
    Marques, Marcia
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Hogland, William
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Wastewater generated during cleaning/washing procedures in a wood-floor industry: toxicity on the microalgae Desmodesmus subspicatus2012In: Environmental technology, ISSN 0959-3330, E-ISSN 1479-487X, Vol. 33, no 21, p. 2439-2446Article in journal (Refereed)
    Abstract [en]

    In industries based on dry processes, such as wood floor and wood furniture manufacture, wastewater is mainly generated after cleaning of surfaces, storage tanks and machinery. Owing to the small volumes, onsite treatment options and potential environmental risks posed to aquatic ecosystems due to discharge of these wastewaters are seldom investigated. In the present study, the effects of cleaning wastewater streams generated at two wood floor production lines on Desmodesmus subspicatus were investigated. The microalgae was exposed to different wastewater concentrations (100, 50, 25, 12.5 and 6.25% v:v) and the algae growth evaluation was based on in vivo chlorophyll fluorescence, cell density, cell size (number of cells/colony) and cell ratio (length/width). Inhibitory effects of the tested wastewaters on the microalgae were positively related to concentration and negatively related to exposure time. The EC50,24 h of blade cleaning wastewater (BCW) and floor cleaning wastewater (FCW) were 3.36 and 5.87% (v:v), respectively. No negative effect on cell colony formation was caused by BCW, whereas an increase of 90% unicellular cells was observed in FCW concentrations below 50% (v:v). At the lowest concentration (3.13% v:v) where no growth inhibition was observed, both wastewater streams caused changes in cell dimensions by increasing cell length and width. To conclude, wastewaters generated during cleaning procedures in the wood floor industries can have severe environmental impacts on aquatic organisms, even after high dilution. Therefore, these wastewaters must be treated before being discharged into water bodies.

  • 467.
    Laohaprapanon, Sawanya
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Marques, Marcia
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Hogland, William
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Removal of Organic Pollutants from Wastewater Using Wood Fly Ash as a Low-Cost Sorbent2010In: CLEAN - Soil, Air, Water, ISSN 1863-0650, E-ISSN 1863-0669, Vol. 38, no 11, p. 1055-1061Article in journal (Refereed)
    Abstract [en]

    In this study untreated and treated wood fly ash (WA) was used as a low cost sorbent in batch sorption tests to investigate the removal of organic pollutants from a real wastewater generated by cleaning/washing of machinery in a wood laminate floor industry in Sweden The experiments focused on the effect of the WA dosage and particle size on the removal efficiency for organic compounds With a WA dosage of 160 g L-1 and a particle size less thin 1 mm the reductions of chemical oxygen demand (COD) biologic oxygen demand and total organic carbon were 37 +/- 0 4 24 +/- 0 4 and 30 +/- 0 3% respectively Pre treatment of WA with hot water improved the COD removal efficiency by absorption from 37 +/- 0 4 to 42 +/- 1 6% when the same dosage (160 g L-1) was applied Sorption isotherm and sorption kinetics for COD using untreated WA can be explained by Freundlich isotherm and pseudo-second-order kinetic models Intra particle diffusion model indicates that pore diffusion is not the rate limiting step for COD removal Based on the experimental data WA could be used as an alternative low cost sorption media/filter for removal of organic compounds from real industrial wastewater.

  • 468. Laohaprapanon, Sawanya
    et al.
    Marques, Marcia
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Hogland, William
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Studies on treatment of urea-formaldehyde based wastewater using anaerobic baffled reactor (ABR): COD and formaldehyde removal2012Conference paper (Other academic)
  • 469.
    Larson, Malin
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Visusskillnad med Air Optix® och Air Optix® for Astigmatism vid låg astigmatism2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna studie var att kontrollera om och i så fall hur mycketvisus förbättras med toriska linser jämfört med sfäriska linser vid astigmatism -0,50 D - -1,00 D.

    I studien ingick tolv försökspersoner, fördelat på nio kvinnor och tre män, medcylinder mellan -0,50 D och -1,00 D på ett eller båda ögonen korrigerades först medAir Optix® (sfärisk) beräknad på sfärisk ekvivalent och sedan med Air Optix forAstigmatism®(torisk) med styrkor baserade på refraktionen. Högkontrastvisus ochlågkontrastvisus mättes både monokulärt och binokulärt.

    I studien framkom att i både monokulärt och binokulärt finns en statistisktsignifikant förbättring med den toriska linsen jämfört med den sfäriska. Ävenlågkontrastvisus visar en förbättring både monokulärt och binokulärt med den toriskalinsen, denna skillnad är inte statistiskt signifikant. Även vid 0,50 D cylinder finnsäven här en förbättring med den toriska linsen men denna är inte heller statistisktsignifikant, varken för hög eller lågkontrastvisus. För 1,00 D cylinder är förbättringensignifikant vid högkontrast men inte vid lågkontrastS. I likhet med tidigare studier har denna studie visat att även lågastigmatism drar fördel av korrigeras med toriska linser.

  • 470.
    Larsson, Mats
    et al.
    Linnaeus University, Faculty of Humanities and Social Sciences, School of Cultural Sciences.
    Lemdahl, Geoffrey
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Lidén, Kerstin
    Stockholms universitet.
    Mot en ny värld: Yngre stenålder i Sverige 4000-1700 f.KR2012 (ed. 1)Book (Other academic)
    Abstract [sv]

    Denna bok tar avstamp i den omvälvning som skedde för 6000 år sedan när människor övergick från att huvudsakligen ha varit jägare och fiskare till att bli bönder. I boken belyses och dsikuteras denna utveckling i ett långtidsperspektiv som sträcker sig från ca 4000 f.Kr. till ca 1700 f.Kr. Två kapitel i boken behandlar också natruvetenskapliga undersökningar och hur dessa på många avgörande sätt bidrar till förståelsen för hur månniksor levde och dog för många tusen år sedan.

  • 471.
    Leberfinger, Karolina
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Revealing the role of shredders and detritus in open-canopy, intermittent streams2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Many streams run through naturally-unforested, agricultural, and residential landscapes and thus do not have closed riparian canopies. Little is known of food web dynamics and ecosystem function in such open-canopy streams. Similarly, our knowledge of ecosystem processes in intermittent streams and effects of drought on stream ecosystem function are limited, despite that predictions of climate change effects include increased frequency and duration of droughts in freshwaters. The aim of my thesis was to increase our knowledge of invertebrate shredder assemblages and ecosystem function in open-canopy intermittent streams and to reveal the role of terrestrial organic matter in open-canopy streams. Invertebrate shredders, as primary consumers of detritus, significantly contribute to the ecosystem function decomposition of organic matter. Thereby, shredders are important vectors for transferring detrital energy into stream food webs.

    I found high-density and species-rich shredder assemblages in three open-canopy intermittent streams on the island of Öland in the southern Baltic Sea, Sweden. My results showed that terrestrially derived organic matter was the shredder’s main food source and the amount of high-quality CPOM potentially limited shredder production. However, through supplementing their feeding with algae, a high shredder production, similar to production estimates in forested permanent streams, could be maintained in these open-canopy intermittent streams. Instead, my results indicate that the primary physical factor constraining shredder production in intermittent streams is the length of the summer drought period. Furthermore, drying simulated as decreasing water levels in an experiment, decreased invertebrate shredder feeding activity and consequently, the breakdown rate of organic matter. Drying also altered a caddisfly shredders’ life cycle phenology and such evident induction of earlier pupation due to drying has not been shown for aquatic insects earlier.

    Food webs and ecosystem function and processes in open-canopy and intermittent streams deserve further attention, especially as these types of streams are very common worldwide. My findings indicate that the energy base in open-canopy streams may be terrestrially derived organic matter, as in forested streams, but constraints imposed by habitat traits and differences in organic matter input size may have significant consequences on stream productivity. My results may be important for increased understanding of potential effects of land use changes (i.e. forestry, agriculture, urbanization) and environmental changes (i.e. climate change) on stream ecosystems.

  • 472.
    Leberfinger, Karolina
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Bohman, Irene
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Grass, mosses, algae or leaves? Food preference among shredders from open-canopy streams2010In: Aquatic Ecology, ISSN 1386-2588, E-ISSN 1573-5125, Vol. 44, no 1, p. 195-203Article in journal (Refereed)
    Abstract [en]

    Shredder feeding is a vital process in making decomposition products available to biota in streams. To investigate which food sources shredders in open-canopy streams exploit, we conducted a feeding preference experiment with the invertebrate detritivores Limnephilus bipunctatus and Nemoura sp., which are commonly found in open-canopy streams on the Swedish island of A-land in the southern Baltic Sea. Leaves of birch, Swedish whitebeam, and shrubby cinquefoil; dead and fresh grass; water moss; and algae were offered to the shredders in multi- and single treatments. We hypothesized that food with high nutritional value would be preferred. Both taxa preferred leaves of shrubby cinquefoil, a bush common in the riparian zone of A-land streams; additionally Nemoura sp. also chose algae. Dead grass, the most abundant food source in the streams during the whole year, was the least consumed food type. The fresh food types had highest nutritional value, measured as carbon to nitrogen content. Therefore, food quality could not alone explain the preference of shrubby cinquefoil. However, among the detritus type offered, shrubby cinquefoil had the highest nutritional value. Shrubby cinquefoil may constitute one important energy source to these open-canopy stream ecosystems and may be essential in maintaining an abundant shredder community in these streams. Thus, the results of this study indicate that detrital resources are indeed important in open-canopy stream systems.

  • 473.
    Leberfinger, Karolina
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Bohman, Irene
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Herrmann, Jan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Drought impact on stream detritivores - experimental effects on leaf litter breakdown and life cycles2010In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 652, no 1, p. 247-254Article in journal (Refereed)
    Abstract [en]

    Predictions of effects of global climate change include decreased runoff for many parts of the world, which will result in drying of streams. Information of the effects of drought on aquatic ecosystems is limited and little is known of the effects on ecosystem functions. Our main objective was to measure the direct effects of drought on leaf litter breakdown by invertebrate shredders in a controlled laboratory experiment. We hypothesized a decreased breakdown at high drought level. Single-species and multi-species treatments with three shredder species (Asellus aquaticus, Limnephilus bipunctatus, and L. flavicornis) were set up in an experiment with three drought level treatments, control, medium, and high drought (6 cm water level, 1 cm water level, and water level below sediment surface, respectively). Breakdown measured as leaf litter loss was significantly lower in both medium and high drought treatments compared to the control. Previously, decreased breakdown due to drying has been reported, but attributed to low densities of invertebrate shredders. We show that even when shredders are present, drought decreases the breakdown. Drought treatments also induced earlier pupation for the caddisfly L. flavicornis. Shifts in species phenology due to drought, e.g., earlier emergence, may affect species ability to adult survival and reproduction. Shifts in timing of emergence may also affect terrestrial food webs, where emerging aquatic insects may constitute an important food subsidy. Our knowledge of the complex effects of droughts in aquatic systems is limited with an urgent need of extended knowledge of the ecological effects of droughts on freshwater ecosystem functioning.

  • 474.
    Leberfinger, Karolina
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Bohman, Irene
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Herrmann, Jan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    The importance of terrestrial resource subsidies for shredders in open-canopy streams revealed by stable isotope analysis2011In: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 56, no 3, p. 470-480Article in journal (Refereed)
    Abstract [en]

    1. Allochthonous detritus is the major source of energy in forested streams, but less is known of the importance of terrestrial subsidies to open-canopy streams. Here, we used stable isotope analysis to assess the importance of allochthonous versus autochthonous energy sources to invertebrate shredders in four open-canopy streams in Sweden. Shredders and potential food sources were analysed at both open sites and those with deciduous trees in the riparian zone.2. Mixing models showed that allochthonous coarse particulate organic matter was the most important energy source to shredders at both the open and wooded sites, suggesting that terrestrial subsidies may be an important process in open-canopy streams, just as they are in forested streams.3. However, shredders at open sites had a larger proportion of biofilm in their diet than at wooded sites, indicating an ability of shredders to adjust their diet with food availability.4. We also used the carbon and nitrogen stable isotope signatures to assess the size of the feeding niche of shredders. Feeding on both allochthonous and autochthonous sources at open sites was reflected in a larger feeding niche than at wooded sites for one of the three species analysed. There was substantial overlap of the feeding niche among shredder species, indicating a high functional redundancy within this guild.

  • 475.
    Leberfinger, Karolina
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Herrmann, Jan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Secondary production of invertebrate shredders in open-canopy, intermittent streams on the island of Öland, SE Sweden2010In: Journal of The North American Benthological Society, ISSN 0887-3593, E-ISSN 1937-237X, Vol. 29, p. 934-944Article in journal (Refereed)
    Abstract [en]

    Knowledge of functional aspects of communities in intermittent streams currently is lacking, and the role of terrestrial detritus as a resource in open-canopy streams is uncertain. Our main objective was to characterize and quantify the macroinvertebrate shredder assemblages in 3 intermittent open-canopy streams on the island of Öland in the Baltic Sea, Sweden, by estimating secondary production. Estimates of annual shredder secondary production ranged from 0.005 to 13.6 g ash-free dry mass (AFDM) m−2 y−1 among sites. Shredder production and amount of organic matter were positively related, but shredder production was more strongly influenced by the duration of the summer dry period. Production decreased with increase in the length of the summer dry period, but shredder production was still high at sites with long dry phases and was comparable to estimates of shredder production in permanent forested streams, results suggesting that terrestrial organic matter might be an important energy resource in open-canopy streams. Shredder species richness decreased with increase in length of the summer dry phase, and shredder species composition at sites with a long dry period was dominated by drought-tolerant taxa. Our results suggest that ecosystem functions might shift from being sustained by many taxa to being sustained by fewer taxa as stream ecosystems experience moderate droughts of similar length (2–4 mo).

  • 476.
    Leberfinger, Karolina
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Herrmann, Jan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Spatial and temporal distribution of shredders in leaf-limited intermittent streams2010In: Verhandlungen Internat. Verein. Limnol 30, Stuttgart: E. Schweizerbart'sche Verlagsbuchhandlung, 2010, p. 1342-1344Conference paper (Refereed)
  • 477.
    Leberfinger, Karolina
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Herrmann, Jan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Hoover, Trent M.
    University of British Columbia.
    Bohman, Irene
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Richardson, John S.
    University of British Columbia.
    Modelling climatic change effects of decomposition processes in small streamsManuscript (preprint) (Other academic)
  • 478.
    Legrand, Catherine
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Casotti, Raffaella
    Stazione Zoologica Anton Dohrn, Napoli, Italy.
    Climate-induced changes and Harmful Algal Blooms in the Mediterranean Sea: Perspectives on future scenarios2009In: CIESM workshop monograph series : Phytoplankton responses to Mediterranean environmental changes, Tunis (Tunisia) 7-10 October 2009, ISSN 1726-5886, no 40, p. 63-66Article, review/survey (Refereed)
  • 479.
    Legrand, Catherine
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Olofsson, Martin
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Growing algae in Scandinavia: utopia or opportunity?2011In: Algae: The sustainable biomass for the future.: Perspectives from the submariner project algae cooperation event Trelleborg, Sweden - September 28-29, 2011., Berlin, Germany: s.Pro sustainable projects GmbH , 2011, p. 16-17Conference paper (Other (popular science, discussion, etc.))
  • 480. Legrand, Sacha
    et al.
    Heikkinen, Harri
    Nicholls, Ian A.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Root, Andrew
    Svenson, Johan
    Unelius, C. Rikard
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Preparation, characterization and application of a stationary chromatographic phase from a new (+)-tartaric acid derivative2010In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 51, no 17, p. 2258-2261Article in journal (Refereed)
    Abstract [en]

    The preparation, characterization and application of a new stationary phase derived from 1,4-cyclohexanedione and diethyl (+)-tartrate are described. A suitable TADDOL for immobilization has been synthesized and grafted to a gamma-mercaptopropylsilylated silica gel. The resulting modified stationary phase has been characterized and its ability to separate enantiomers has been studied. While the free TADDOL in solution was able to resolve a range of enantiomers, the resolving properties were lost on immobilization. Solid state C-13 CPMAS NMR of the new stationary phase was used to explain the lack of stereoselective recognition. (C) 2010 Elsevier Ltd. All rights reserved.

  • 481.
    Lemdahl, Geoffrey
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Beetle remains from the refuse layer of the bog site Ageröd V1983In: Acta Archaeologica, ISSN 0065-101X, E-ISSN 1600-0390, Vol. 12, p. 169-172Article in journal (Refereed)
  • 482.
    Lemdahl, Geoffrey
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Gustavsson, Gunnar
    Olsson, Fredrik
    Gaillard, Marie-José
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Fossil insects may provide unique information on structures and disturbances in past forest ecosystems – examples from Holocene studies in southern Sweden.2010In: Geophysical Research Abstracts Vol. 12, EGU2010-5140, 2010, 2010Conference paper (Other academic)
  • 483.
    Lengstrand, Anna
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Molecular Characterizing of Starch and Starch Based Materials in Food Packaging2010Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
  • 484.
    Lennartsson, Hanna
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Framtagning av ett nytt recept för clear-coat batter av pommes frites: En teknisk och sensorisk utvärdering2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The requirements of good quality and appetizing fast food increases continuously as a consequence of a community where food is always available. The crispiness of French fries is an issue that must be considered in this context, since it tends to decrease and give the fries a soft surface not appreciated by the consumer. To prolong the crispiness, the fries can be coated by a batter, a mix of starches. The batters used often consists of modified starches, e.g. cross-linked, acetylated and dextrinizated to increase and prolong crispiness, flour to stabilize the batter and sodium bicarbonate to make the batter “rise”.

    The cross-linked starch keeps the granules in a swelled state and prevents them from breaking when exposed to heat or processing: therefore, it delays the gelatinization and decreases the stickiness of the batter. The acetylated starch delays the retrogradation since it prevents amylose from packing when retrograded. It also stabilizes the batter. The dextrin added consists of heat and acid processed starch and decreases the gelatinization temperature of the batter. It also gives an appetizing color to the French fries.

    The aim of this project is to give further understanding of the ingredients´ functions, and to find alternative ingredients in a recipe already used, since the price of some ingredients has increased rapidly during the last few years. By studying an existing recipe and by doing a literary research some of the ideas were applied in the laboratory, followed by sensory and technical evaluations where color, appearance, crispiness, hardness and, to some degree, taste were evaluated. The viscosity of the starch solutions was measured since it indicates the pick-up (the amount of batter attached to the French fries). Pick-up and texture were also analyzed.

    Experiments confirmed the hypothesis that the acetylated starch was unnecessary and could be replaced by cross-linked starch. A high degree of cross-linking seemed to decrease the crispiness, which may depend on the prevented granule swelling. Replacing the cross-linked starch with native potato starch did not work since the batter became way too sticky. The flour could, to some degree, be replaced by native potato starch since the crispiness was very distinct. Too high concentrations of native starch made all batters very sticky, though, probably because of the early granule “explosion” caused by processing and high frying temperatures. Maize flour was an alternative to the flour currently used, since the color, appearance and crispiness of the French fries were very good according to the sensory evaluations. Although the difference between the batters seemed evident when evaluated sensory, statistics made sure that it was not significant.

    More research and tests needs to be done to assure the results of this project. It is also necessary to verify that the laboratory results are identical to those in industry. However, the study gave further understanding of the function of the ingredients and confirmed that there are several ways of improving an already good concept.

  • 485.
    Lewis, Peter
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Baskaran, Karthikeyan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Rosén, Robert
    Biomedical & X-Ray Physics.
    Unsbo, Peter
    Biomedical & X-Ray Physics.
    Gustafsson, Jörgen
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Clinical Impact of Objectively Determined Peripheral Refractive Error Correction on Low-Contrast Resolution AcuityManuscript (preprint) (Other academic)
  • 486.
    Lewis, Peter
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Baskaran, Karthikeyan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Rosén, Robert
    KTH, Royal Institute of Technology, Stockholm, Sweden.
    Unsbo, Peter
    KTH, Royal Institute of Technology, Stockholm, Sweden.
    Gustafsson, Jörgen
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    The Effect of Refractive-Correction on Peripheral Low-Contrast Resolution Acuity2012Conference paper (Other academic)
    Abstract [en]

    Purpose: High-contrast resolution acuity in the peripheral retina has been shown to be sampling-limited, however, a recent study indicates that peripheral low-contrast resolution acuity (PLCRA) is degraded by imposition of optical defocus. On the other hand, it has not been investigated whether refractive errors present in the peripheral field of normal, emmetropic eyes are sufficient to degrade PLCRA. The aim of this study was to evaluate the effect of peripheral refractive-correction on PLCRA in young emmetropes.Methods: Low-contrast (10 %) resolution acuity was measured off-axis (20° nasal visual field) on the right eyes of 10 emmetropic subjects (age 22 ± 2 years), both with and without peripheral refractive correction. Central and peripheral refractive errors were acquired using an open-field COAS-HD VR aberrometer. Stimuli, consisting of low-contrast Gabor patches with a visible diameter of 2°, were presented on a CRT monitor situated 3.0 meters from the subjects. Resolution thresholds were determined using a 2-alternative forced-choice Bayesian algorithm.Results: All the subjects had off-axis astigmatism (against-the-rule) at 20° in the nasal visual field ranging from -1.00 DC to -2.00 DC; of which four had -1.00 DC, three had -1.25 DC, one had -1.50 DC and the remaining two had -2.00 DC. Two of the subjects with -1.25 DC had -0.50 DS to -0.75 DS spherical errors; the rest had purely cylindrical errors. The mean uncorrected and corrected low-contrast resolution acuities for all subjects were 0.92 logMAR and 0.86 logMAR respectively. This shows an improvement in resolution acuity of 0.06 logMAR (p = 0.028) after correction of off-axis refractive errors. However when grouped according to the amount of astigmatism, the -1.00 DC group showed no difference in acuity with correction, the -1.25 DC, -1.50 DC and -2.00 DC groups improved on average by 0.05, 0.14 and 0.16 logMAR respectively.Conclusions: Correction of off-axis refractive errors had a positive effect on low-contrast resolution thresholds in the peripheral visual field on the emmetropic subjects in this study. Moreover, the effects become appreciable only for those subjects having larger degrees of astigmatism. This suggests that optical factors influence peripheral visual tasks involving low-contrast. There may be benefits in correcting even moderate amounts of off-axis refractive errors, especially for people who rely on optimal peripheral visual function.

  • 487.
    Lewis, Peter
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Rosén, Robert
    KTH, Royal Institute of Technology, Stockholm, Sweden.
    Gustafsson, Jörgen
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Carius, Staffan
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Unsbo, Peter
    KTH, Royal Institute of Technology, Stockholm, Sweden.
    Dynamic Visual Acuity in the Peripheral Visual Field Using Gabor Patches2010Conference paper (Refereed)
    Abstract [en]

    Purpose:To evaluate dynamic visual acuity (DVA) in the peripheral visual field. This ability is important within the areas of sports, traffic safety, as well as for people with low vision; specifically those with central visual field loss. In this study we investigated both static- and dynamic visual acuity in the periphery of normally sighted observers using Gabor patches.

    Methods:DVA and static visual acuity (SVA) was measured on the right eye of normally sighted emmetropes. Stimuli consisted of high-contrast Gabor patches; sine wave gratings multiplied by a Gaussian hull with a diameter of 2º, with the sine gratings drifting at 1, 2, and 4 degrees per second. Stimuli were presented, using MATLAB and Psychophysics Toolbox, on one of seven CRT monitors at the following retinal eccentricities: 10, 20 and 30 degrees, nasally and temporally as well as in the fovea. Subjects were informed to maintain fixation on a central fixation object during measurements at eccentric locations. An Adaptive Bayesian algorithm was employed to determine resolution thresholds at each eccentricity.

    Results:The results show a trend towards both better static- and dynamic visual acuities for the temporal visual field at retinal eccentricities 20° and 30° compared to nasally. There appears to be a more rapid decrease in both static- and dynamic visual acuity with increasing eccentricity for the nasal visual field. In addition, we did not find any difference in DVA and SVA in the peripheral visual field for the velocities used in this study.

    Conclusions:Results of these first preliminary measurements suggest that dynamic visual acuity measured with drifting Gabor patches is greater in the temporal visual field for eccentricities 20 degrees or larger. To confirm these results more measurements need to be performed on a lager sample of subjects.

  • 488.
    Lewis, Peter
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Rosén, Robert
    KTH, Royal Institute of Technology, Stockholm, Sweden.
    Unsbo, Peter
    KTH, Royal Institute of Technology, Stockholm, Sweden.
    Gustafsson, Jörgen
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Naso-temporal Asymmetry of Peripheral Static and Dynamic Visual Acuity2011Conference paper (Refereed)
    Abstract [en]

    Summary

    Static and dynamic visual acuity was evaluated in the peripheral visual field on normally sighted emmetropes. The results show a significant asymmetry for both static and dynamic visual acuity between the nasal and temporal visual fields.

     

    Introduction

    It is well known that visual performance thresholds decrease rapidly with increasing retinal eccentricity1. This reduction in performance can be attributed to both optical factors and reduced neural sampling2-3; the latter being the predominant limiting factor in the peripheral retina3.  Previous studies have shown that slowly moving stimuli are more easily resolved than stationary stimuli in the peripheral retina4. There is little evidence published regarding resolution thresholds for moving stimuli in more than a few limited directions in the visual field.     

    In this study, static visual acuity (SVA) and dynamic visual acuity (DVA) thresholds were measured at 10° intervals both nasally and temporally on healthy, young emmetropes. DVA was measured at angular velocities of 1 °/s and 2 °/s using drifting Gabor patches.  

     

    Discussion

    Static and dynamic visual acuity was measured on the right eye of emmetropic subjects. Results for SVA showed significantly better resolution in the temporal visual field compared with the nasal visual field at eccentricities 20° and beyond. The mean difference in acuity at 20° was approximately 0.2 LogMAR and at 30°, 0.3 LogMAR. The difference between the thresholds for DVA showed a similar naso-temporal asymmetry; the reduction in DVA paralleling the decrease in SVA for eccentricities 10° and beyond.  No significant differences were observed between averaged results of SVA and DVA for the eccentricities tested in this study.

     

    Conclusions

    The results of this study confirm previous research conducted by Frisén (1987) showing better resolution for static stimuli presented in the temporal visual field compared to the nasal visual field. We have found that this is also true for DVA.

  • 489.
    Lewis, Peter
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Rosén, Robert
    KTH, Royal Institute of Technology, Stockholm, Sweden.
    Unsbo, Peter
    KTH, Royal Institute of Technology, Stockholm, Sweden.
    Gustafsson, Jörgen
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Resolution of static and dynamic stimuli in the peripheral visual field.2011In: Vision Research, ISSN 0042-6989, E-ISSN 1878-5646, Vol. 51, no 16, p. 1829-1834Article in journal (Refereed)
    Abstract [en]

    In a clinical setting, emphasis is given to foveal visual function, and tests generally only utilize static stimuli. In this study, we measured static (SVA) and dynamic visual acuity (DVA) in the central and peripheral visual field on healthy, young emmetropic subjects using stationary and drifting Gabor patches. There were no differences between SVA and DVA in the peripheral visual field; however, SVA was superior to DVA in the fovea for both velocities tested. In addition, there was a clear naso-temporal asymmetry for both SVA and DVA for isoeccentric locations in the visual field beyond 10° eccentricity. The lack of difference in visual acuity between static and dynamic stimuli found in this study may reflect the use of drift-motion as opposed to displacement motion used in previous studies.

  • 490.
    Lideberg, Josefine
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Keratitbehandling, antibiotika versus corneal collagen crosslinking (CXL) genom riboflavin och UVA2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syfte: Syftet med denna studie var att jämföra antibiotikabehandling med corneal collagen crosslinking (CXL)-behandling genom fotoaktivering av riboflavin vid bakteriell keratit. Att experimentellt undersöka om en viss stam av Pseudomonas aeruginosa kunde infektera cornealt epitel var också en del av studien.

    Metod: Litteraturstudie samt ett experiment med Pseudomonas aeruginosa och grisögon in vitro.

    Resultat: Dagens behandling av keratit är initial med antibiotika. I experimentella studier har CXL använts både i kombination med antibiotika och som enskild behandling. Positiva resultat från studier med CXL som behandling mot keratit har rapporterats.

    Resultatet av det experimentella försöket pekar på att den stam av Pseudomonas aeruginosa som användes i experimentet inte kan penetrera ett intakt epitel.

    Slutsats: CXL kan bli en viktig och användbar behandlingsform vid keratit, särskilt med tanke på den ökade antibiotikaresistensutvecklingen. Ytterligare forskning på området krävs dock innan metoden kan bli fullt vedertagen.

    För att kunna fastställa om stammen av Pseudomonas aeruginosa i det aktuella experimentet har virulensfaktorer för att ta sig in i ett oskadat epitel eller inte krävs fler försök.

  • 491.
    Lidén, Maja
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Synfältsundersökningen vid synprövning för körkort hos optiker2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syfte: Syftet var att ta reda på vilken metod som är lämpligast att använda för synfältsundersökning vid ett körkortstest hos optiker samt vilken metod det är vanligast att optiker i Sverige använder idag. Dessutom var syftet att utreda varför optiker inte får använda konfrontationstest då det är den metod läkare ska använda för synfältsundersökning enligt körkortsföreskrifterna.

    Metod: En enkätundersökning med 275 deltagande optiker gjordes. De fick besvara ett fåtal frågor kring vilken metod de använder när de undersöker synfältet vid ett körkortstest samt deras kunskap och inställning till bestämmelserna kring vilken metod som skall användas utav optiker och läkare. Enkätundersökningen publicerades med web-enkätprogrammet Easy Survey.

    Resultat: Enkätundersökningen visade att endast 58,5 % av optiker i Sverige använder sig av den speciellt avsedda apparaturen. 34,9 % av deltagarna svarade att de använde sig av Donders konfrontationstest. Undersökningen visade på att många optiker i Sverige inte vet vilken metod de enligt föreskriften från 2008 ska använda. Dessutom visar resultaten att en klar majoritet av dem inte förstår varför inte optiker får använda samma metod som läkare för synfältsundersökning vid ett körkortstest.

    Slutsats: Studien visar att en majoritet av optiker i Sverige använder den av myndigheten rekommenderade metoden men att många också använder Donders. Ett konfrontationstest borde vara mer lämpligt att använda för att undersöka synfältet vid en synprövning för körkort hos optiker än en synfältsapparat. Optiker har tillräckligt stor kunskap för att klara av att använda Donders konfrontationstest och när det utförs korrekt verkar det vara mer tillförlitligt än en apparatur så som Campitestet, då det undersöker synfältet mer utförligt.

  • 492.
    Liew, Josefine
    et al.
    Swedish University of Agricultural Sciences, Department of Crop Production Ecology.
    Andersson, Lars
    Swedish University of Agricultural Sciences, Department of Crop Production Ecology.
    Boström, Ullalena
    Swedish University of Agricultural Sciences, Department of Crop Production Ecology.
    Forkman, Johannes
    Swedish University of Agricultural Sciences, Department of Crop Production Ecology.
    Hakman, Inger
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Magnuski, Ewa
    Swedish University of Agricultural Sciences, Department of Crop Production Ecology.
    Influence of temperature and photoperiod on sprouting capacity of Cirsium arvense and Sonchus arvensis root buds2012In: Weed research (Print), ISSN 0043-1737, E-ISSN 1365-3180, Vol. 52, no 5, p. 449-457Article in journal (Refereed)
    Abstract [en]

    Influence of temperature and photoperiod on sprouting capacity of Cirsium arvense and Sonchus arvensis root buds. Weed Research.52, 449-457. Summary Timing of treatment is a key to successful and sustainable weed management. For perennial weeds, highly energy-demanding, repeated stubble cultivation or tillage is a common strategy in organic agriculture. The fragmentation of underground material stimulates root buds to grow and, if repeated, significantly reduces the energy and nutrient resources of the roots. However, the effect might differ depending on variation in sprouting over the season and among species. Here, we studied the impact of different photoperiods and temperatures on sprouting capacity of root buds of Cirsium arvense and Sonchus arvensis in a climate chamber experiment. Two populations of each species, collected in northern and southern Sweden, were used. Plants were exposed to long (18 h), short (12 h) or decreasing (from 18 to 8 h) photoperiods in combinations with high (18/12 degrees C for 16/8 h), low (12/6 degrees C), decreasing (from 21 to 5 degrees C in 4 weeks) or constant high (16 degrees C) temperatures. Sprouting capacity was evaluated based on the proportion of sprouting buds from short root fragments. Neither temperature nor photoperiod affected root bud sprouting in C. arvense, while in S. arvensis, photoperiod seemed to regulate sprouting capacity. The proportion of sprouted buds decreased in short photoperiods, especially if combined with high temperature. In northern conditions, this suggests that weeding strategies based on fragmentation of the root system of S. arvensis will have low efficiency if the autumns are warm.

  • 493.
    Liew, Josefine
    et al.
    Swedish University of Agricultural Sciences, Department of Crop Production Ecology.
    Andersson, Lars
    Swedish University of Agricultural Sciences, Department of Crop Production Ecology.
    Boström, Ullalena
    Swedish University of Agricultural Sciences, Department of Crop Production Ecology.
    Forkman, Johannes
    Swedish University of Agricultural Sciences, Department of Crop Production Ecology.
    Hakman, Inger
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Magnuski, Ewa
    Swedish University of Agricultural Sciences, Department of Crop Production Ecology.
    Seasonal variation and control of sprouting capacity of Cirsium arvense and Sonchus arvensis root buds2011In: NJF Report Vol 7 No 9 2011. (Sem 446) Risk assessment/risk management, forecasting pests and diseases of field crops in a changing climate, 2011Conference paper (Refereed)
  • 494.
    Liew, Josefine
    et al.
    Swedish University of Agricultural Sciences, Department of Crop Production Ecology.
    Andersson, Lars
    Swedish University of Agricultural Sciences, Department of Crop Production Ecology.
    Boström, Ullalena
    Swedish University of Agricultural Sciences, Department of Crop Production Ecology.
    Hakman, Inger
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Magnuski, Ewa
    Swedish University of Agricultural Sciences, Department of Crop Production Ecology.
    Milberg, Per
    Seasonal variation in sprouting capacity from underground root buds of Cirsium arvense and Sonchus arvensis2010In: Proceedings 15th European Weed Research Society Symposium, Kaposvár, 2010, p. 52-Conference paper (Refereed)
  • 495.
    Liljenberg, Anna
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Antioxidanter förhindrar AMD: Sanning eller myt?2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syfte: Att undersöka ifall ett ökat intag av antioxidanter via kost eller supplement kan förhindra uppkomst och progression av åldersrelaterad makuladegeneration, AMD.

    Metod: Granskning och sammanställning av publicerade forskningsresultat inom området.

    Resultat: Av 7 granskade studier visade 5 på en skyddande effekt mot uppkomst eller progression av AMD vid ett ökat intag av antioxidanter. Resterande 2 studier kunde inte finna något signifikant samband. Resultatet varierar för specifika antioxidativa ämnen i olika studier.

    Slutsats: Forskningen tyder på att ett ökat intag av antioxidanter, antingen via kosten eller supplement, skulle kunna förebygga och bromsa de skador som uppkommer vid AMD. Man bör dock ytterligare utreda eventuella negativa bieffekter vid höga doser av bland annat β-karoten och E-vitamin. Det behövs fler långtidsstudier för att fullt ut förstå samspelet mellan hur olika livsmedel och specifika antioxidanter tas upp och metaboliseras och hur dessa kan påverka uppkomst och progression av AMD.

  • 496. Liljeqvist, Maria
    et al.
    Valdes, Jorge
    Holmes, David S
    Dopson, Mark
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Department of Molecular Biology, Umeå University.
    Draft genome of the psychrotolerant acidophile Acidithiobacillus ferrivorans SS3.2011In: Journal of Bacteriology, ISSN 0021-9193, E-ISSN 1098-5530, Vol. 193, no 16, p. 4304-4305Article in journal (Refereed)
    Abstract [en]

    Acidithiobacillus ferrivorans SS3 is a psychrotolerant acidophile capable of growth in the range of 5° to 30°C (optimum, ≈25°C). It gains energy from the oxidation of ferrous iron and inorganic sulfur compounds and obtains organic carbon from carbon dioxide. Here, we present the draft genome sequence of A. ferrivorans SS3 that will permit investigation of genes involved in growth in acidic environments at low temperatures.

  • 497.
    Lindahl, Mats
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Book review: Alister Jones, Anne Kim and Michael Reiss (Eds.) (2010). Ethics in the Science and Technology Classroom: A New Approach to Teaching and Learning,2011In: Science & Education, ISSN 0926-7220, E-ISSN 1573-1901, Vol. 20, no 9, p. 927-929Article, book review (Other academic)
  • 498.
    Lindahl, Mats
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Of pigs and men - Understanding students' reasoning about the use of pigs as donors for xenotransplantation2010In: Science & Education, ISSN 0926-7220, E-ISSN 1573-1901, Vol. 19, no 9, p. 867-894Article in journal (Refereed)
    Abstract [en]

    Education has a role in society to provide students with knowledge for their democratic participation in society as well as for a future profession. In science education, students encounter values that may be in conflict with their worldview. Such conflicts may for example lead to constructive reflections as well as rejection of scientific knowledge and technology. Students' ways of reasoning are important starting points for discussing problematic issues and may be crucial for constructive dialogues in the classroom. This study investigates students' reasoning about conflicting values concerning the human-animal relationship exemplified with the use of genetically modified pigs as organ donors for xenotransplantation. Students’ reasoning is analyzed using Giddens’ concepts of disembedded and embedded practices in parallel with moral philosophical theories in a framework based on human-animal relationships. Thirteen students were interviewed and their stances categorized. Kantian deontological and classical utilitarian ethics were found within the patronage and the partnership models. These students appreciated expert knowledge but those using the partnership model could not accept xenotransplantation if pigs were to be killed. Students using care ethics did not appreciate expert knowledge since it threatened naturalness. The results suggest that stances against the use of scientific knowledge are more problematic than knowledge per se, and that conflicting stances have similarities that present opportunities for understanding and development of students’ argumentation skills for future participation in societal discourse on utilizing expert knowledge. Furthermore it is suggested that science education could benefit from a higher awareness of the presence of different morals.

  • 499.
    Lindahl, Mats
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Folkesson, Anne-Mari
    Linnaeus University, Faculty of Health, Social Work and Behavioural Sciences, School of Education, Psychology and Sport Science.
    Can we let computers change practice? Educators’ interpretations of preschool tradition2012In: Computers in human behavior, ISSN 0747-5632, E-ISSN 1873-7692, Vol. 28, no 5, p. 1728-1737Article in journal (Refereed)
    Abstract [en]

    The introduction of ICT into preschool practice is generally lagging. However, there is a variation regarding use of new technology. Hence, the aim of this study is to analyze which are the possibilities and difficulties to embed computers into preschool practice. Data consists of naturalistic texts from 31 preschool teacher students revealing their experiences from trying to embed computers into practice. Analysis of data was guided by a framework adapted from Giddens’ structuration theory, focussing on students’ drawing on tradition and on knowledge claims when justifying their stances. Results show ambivalence to computer use. However, two groups of students emerged. One group embraced the new technology, whereas the other group conceived new technology as a threat to tradition. Depending on how activities are interpreted to fit into preschool tradition, using computers can or cannot be justified. Understanding tradition, as partially values and partially routines, provides possibilities to modify preschool practice to include computer activities. Knowledge claims, for example pertaining to developmental stimulation, can also be used as justifications for embedding computers into preschool practice. If, however, values appear to be threatened, tradition as well as knowledge claims can be used to justify protection against using computers in preschool practice.

  • 500.
    Lindahl, Mats
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Folkesson, Anne-Mari
    Linnaeus University, Faculty of Health, Social Work and Behavioural Sciences, School of Education, Psychology and Sport Science.
    ICT in preschool: friendor foe? The significance of norms in a changing practice2012In: International Journal of Early Years Education, ISSN 0966-9760, E-ISSN 1469-8463, Vol. 20, no 4, p. 422-436Article in journal (Refereed)
    Abstract [en]

    Societal change and prescriptions in curricula demand a change in educationalpractice. This can create conflicts between practitioners’ usual practices (norms)and those prescribed by curricula. One example is the introduction of Informationand Communication Technology (ICT) into preschool practice. Hence, our aim isto analyse how norms are used as arguments for or against using computers inpreschool practice. Data consist of naturalistic texts from 31 preschool teacherstudents revealing their experiences in attempting to embed computers intopractice. Results show ambivalence to computer use. Two lines of argumentsemerged: one embracing the new technology, the other rejecting this newtechnology. The following arguments were made to justify ICT in preschool: thechild as a citizen, the competent child and the active child. Concern wasexpressed between the teacher’s need for control and the child’s need forindependence and guidance.

78910111213 451 - 500 of 899
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf