| 1. |
- Andersson, Agneta, et al.
(författare)
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Projected future climate change and Baltic Sea ecosystem management
- 2015
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Ingår i: Ambio. - : Springer. - 0044-7447 .- 1654-7209. ; 44:Supplement 3, s. S345-S356
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is likely to have large effects on the Baltic Sea ecosystem. Simulations indicate 2-4 degrees C warming and 50-80 % decrease in ice cover by 2100. Precipitation may increase similar to 30 % in the north, causing increased land runoff of allochthonous organic matter (AOM) and organic pollutants and decreased salinity. Coupled physical-biogeochemical models indicate that, in the south, bottom-water anoxia may spread, reducing cod recruitment and increasing sediment phosphorus release, thus promoting cyanobacterial blooms. In the north, heterotrophic bacteria will be favored by AOM, while phytoplankton production may be reduced. Extra trophic levels in the food web may increase energy losses and consequently reduce fish production. Future management of the Baltic Sea must consider the effects of climate change on the ecosystem dynamics and functions, as well as the effects of anthropogenic nutrient and pollutant load. Monitoring should have a holistic approach, encompassing both autotrophic (phytoplankton) and heterotrophic (e.g., bacterial) processes.
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| 2. |
- Andersson, Patrik, et al.
(författare)
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The internal barriers of rotation for the 209 polychlorinated biphenyls
- 1997
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Ingår i: Environmental Science and Pollution Research. - 0944-1344 .- 1614-7499. ; 4:2, s. 75-81
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Tidskriftsartikel (refereegranskat)abstract
- The internal barrier of rotation (Erot) was calculated for all 209 polychlorinated biphenyls (PCBs) by using a semi-empirical method, viz. the Austin Model 1 (AM1) Hamiltonian. The difference in total energy between a forced planar state and an optimised twisted structure was defined as Erot. The Erot values were in the range of 8.33 to 483 kJ/mol, and were significantly influenced by the number of chlorine atoms in ortho position. An additional structural characteristic of the PCBs influencing Erot of ortho substituted congeners was substitution by chlorine atoms in vicinal meta positions, which is assumed to prevent outward bending of ortho substituents. This so-called buttressing effect contributed with 4 to 31 kJ/mol per added chlorine atom. In conclusion, the internal barrier of rotation, calculated for all 209 PCBs, provides an important structure dependent physico-chemical parameter for multivariate modelling of future quantitative structure-activity and structure-property relationships (QSARs/QSPRs).
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| 3. |
- Andersson, Patrik, et al.
(författare)
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Ultraviolet absorption characteristics and calculated semi-empirical parameters as chemical descriptors in multivariate modelling of polychlorinated biphenyls
- 1996
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Ingår i: Journal of Chemometrics. - 0886-9383 .- 1099-128X. ; 10:2, s. 171-185
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Tidskriftsartikel (refereegranskat)abstract
- The structural variation within the polychlorinated biphenyls (PCBs) was characterized by using principal component analysis (PCA). A multivariate model was evolved from 52 physicochemical descriptors including measured ultraviolet (UV) absorption spectra, calculated semiempirical parameters (AM1) and properties captured from the literature. Parameters calculated by using the AM1-Hamiltonian were e.g. heat of formation, dipole moments, ionization potential and the barrier of internal rotation. The UV spectra were measured and digitized in the range 200-300 nm. The multivariate model revealed that most of the information within the set of physicochemical parameters was related to molecular size. Descriptors depending on size were e.g. GC retention times, partition coefficients and a subset of semiempirically derived energy terms. Important also were parameters reflecting differences in substitution patterns and related to electronic and steric properties, such as UV absorption in the wavelength region 245-300 nm, the barrier of internal rotation and the ionization potential. The developed model describes the large variation in physicochemical characteristics within the PCBs. The importance of a broad chemical characterization is illustrated by a quantitative structure-activity relationship (QSAR) for the potency of inhibition of intercellular communication for 27 structurally diverse tetra- to heptachlorinated PCBs.
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| 4. |
- Andersson, Patrik, et al.
(författare)
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Ultraviolet absorption spectra of all 209 polychlorinated biphenyls evaluated by principal component analysis
- 1997
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Ingår i: Fresenius' Journal of Analytical Chemistry. - : Springer Science and Business Media LLC. - 0937-0633 .- 1432-1130. ; 357:8, s. 1088-1092
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Tidskriftsartikel (refereegranskat)abstract
- The ultraviolet absorption spectra of all 209 polychlorinated biphenyls (PCBs) were recorded in the range 200-300 nm and displayed two important absorption maxima, viz., the main-band, lambda(max) 200-225 nm, and the kappa-band, lambda(max) 245-265 nm. By utilising principal component analysis, substitution related spectral characteristics of the PCBs, underlying the main patterns of the spectra, were examined. Captured in the multivariate evaluation were e.g., the importance of chlorine atoms in ortho positions, determining the intensity and existence of the kappa-band, chlorine substitution in para-para position, and the total number of chlorine atoms. The measured UV-spectra of all 209 polychlorinated biphenyls provide important physico-chemical descriptors for use in future quantitative structure-activity and structure-property relationship (QSAR/QSPR) studies.
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| 5. |
- Asghar, Naveed, et al.
(författare)
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Tick-borne encephalitis virus sequenced directly from questing and blood-feeding ticks reveals quasispecies variance.
- 2014
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Ingår i: PLOS ONE. - San Francisco, USA : Public Library of Science (PLoS). - 1932-6203. ; 9:7
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Tidskriftsartikel (refereegranskat)abstract
- The increased distribution of the tick-borne encephalitis virus (TBEV) in Scandinavia highlights the importance of characterizing novel sequences within the natural foci. In this study, two TBEV strains: the Norwegian Mandal 2009 (questing nymphs pool) and the Swedish Saringe 2009 (blood-fed nymph) were sequenced and phylogenetically characterized. Interestingly, the sequence of Mandal 2009 revealed the shorter form of the TBEV genome, similar to the highly virulent Hypr strain, within the 3' non-coding region (3'NCR). A different genomic structure was found in the 3'NCR of Saringe 2009, as in-depth analysis demonstrated TBEV variants with different lengths within the poly(A) tract. This shows that TBEV quasispecies exists in nature and indicates a putative shift in the quasispecies pool when the virus switches between invertebrate and vertebrate environments. This prompted us to further sequence and analyze the 3'NCRs of additional Scandinavian TBEV strains and control strains, Hypr and Neudoerfl. Toro 2003 and Habo 2011 contained mainly a short (A)3C(A)6 poly(A) tract. A similar pattern was observed for the human TBEV isolates 1993/783 and 1991/4944; however, one clone of 1991/4944 contained an (A)3C(A)11 poly(A) sequence, demonstrating that quasispecies with longer poly(A) could be present in human isolates. Neudoerfl has previously been reported to contain a poly(A) region, but to our surprise the re-sequenced genome contained two major quasispecies variants, both lacking the poly(A) tract. We speculate that the observed differences are important factors for the understanding of virulence, spread, and control of the TBEV.
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| 6. |
- Berggren, Mats, et al.
(författare)
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Kärnkraftsdebatt ger möjlighet till kritiskt tänkande i högstadiefysiken
- 2019
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Ingår i: Naturvetenskapernas och teknikens didaktik. - Linköping : LiU-Tryck. - 9789176850442 ; , s. 39-48
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- I skolans styrdokument betonas vikten av att elever ges möjlighet att utveckla sitt kritiska tänkande. Detta är inte minst angeläget i dessa tider av tillgång till sociala medier och spridande av så kallade alternativa fakta. Trots sin positiva klang finns det dock ingen etablerad konsensus kring vad kritiskt tänkande egentligen är. Inom ramen för ett skolutvecklingsprojekt i samverkan mellan Uppsala universitet och Tiundaskolan, en 4-9-skola i Uppsala, utforskar vi hur kritiskt tänkande kan uttryckas i undervisningspraktiken i ämnena svenska, historia, matematik och fysik. Som exempel har vi i fysikämnet designat, genomfört och analyserat en undervisningssekvens utifrån kärnkraft som tema, där elever i årskurs 9 gavs möjlighet att anamma olika åsikter och argument i frågan genom rollspel. Eleverna genomförde en debatt, där de representerade olika parter: boende nära Forsmark, miljöorganisationen Grön Fred, och företag som utvecklar kärnkraft, respektive vindkraft. Före och efter debatten skrev eleverna individuella texter där de argumenterade för sin personliga åsikt i frågan: Ska kärnkraften bevaras som den är, läggas ner, eller utvecklas? Vi fann att de genom debatten fick goda möjligheter att utveckla och visa kunskaper motsvarande flera kunskapskrav i kursplanen i fysik som annars sällan berörs i fysikklassrummet, såsom, för betyg A: ”Eleven kan samtala om och diskutera frågor som rör energi, teknik, miljö och samhälle och skiljer då fakta från värderingar och formulerar ställningstaganden med välutvecklade motiveringar samt beskriver några tänkbara konsekvenser.” Som exempel på naturvetenskapligt förankrade argument utnyttjade eleverna genererad energi per utsläppt mängd koldioxid som ett mått vid jämförelser mellan kärnkraft och andra energikällor. I de individuella texterna höll de flesta eleverna fast vid sina åsikter från innan de arbetade med temat även efteråt, men nu med fler och mer nyanserade argument.
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| 7. |
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| 8. |
- Bergknut, Magnus, et al.
(författare)
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Assessment of the availability of polycyclic aromatic hydrocarbons from gasworks soil using different extraction solvents and techniques
- 2004
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Ingår i: Environmental Toxicology and Chemistry. - : Wiley. - 0730-7268 .- 1552-8618. ; 23:8, s. 1861-1866
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Tidskriftsartikel (refereegranskat)abstract
- This study was designed to assess the availability of polycyclic aromatic hydrocarbons (PAHs) present at a gasworks site to different soil remediation techniques. The study examined the effect on PAH availability of using different organic solvents, the degree of pretreatment, and the extraction time. In total, 25 PAHs (with two to six fused rings) and five carbonyl derivatives were measured. The results indicated that the PAHs and their derivatives were bound loosely to the surface of the studied soil and that there were no significant kinetic boundaries associated with the extraction of the PAHs. Furthermore, it was concluded that the studied soil was not suitable for bioremediation, as the concentration of PAHs with low molecular weight were limited. However, pressurized liquid extraction (PLE) with methanol as the solvent extracted 97% of all PAHs and PAH-derivatives, indicating that extraction may be effective as part of a soil remediation technique for old gasworks soils.
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| 9. |
- Bergknut, Magnus, et al.
(författare)
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Characterization and classification of complex PAH samples using GC-qMS and GC-TOFMS
- 2006
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 65:11, s. 2208-2215
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to compare the polycyclic aromatic hydrocarbon (PAH) contents in a number of complex samples, including soil samples from industrial sites, anti-skid sand, urban dust and ash samples from municipal solid waste incinerators. The samples were characterized by routine analysis of PAHs (gas chromatography–quadrupole mass spectrometry) and gas chromatography–time of flight mass spectrometry (GC–TOFMS). Classification of the samples by principal component analysis (PCA) according to their composition of PAHs revealed that samples associated with traffic and the municipal incinerator formed homogeneous clusters, while the PAH-contaminated soils clustered in separate groups. Using spectral data to resolve co-eluting chromatographic peaks, 962 peaks could be identified in the GC–TOFMS analysis of a pooled sample and 123–527 peaks in the individual samples. Many of the studied extracts included a unique set of chemicals, indicating that they had a much more diverse contamination profile than their PAH contents suggested. Compared to routine analysis, GC–TOFMS provided more detailed information about each sample and in this study a large number of alkylated PAHs were found to be associated with the corresponding unsubstituted PAHs. The possibility to filter peaks according to different criteria (e.g. to include only peaks that were detected in the analysis of another sample) was explored and used to identify unique as well as common compounds within samples. This procedure could prove to be valuable for obtaining relevant chemical data for use in conjunction with results from various biological test systems.
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| 10. |
- Bergknut, Magnus, et al.
(författare)
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Comparison of techniques for estimating PAH bioavailability : uptake in Eisenia fetida, passive samplers and leaching using various solvents and additives.
- 2007
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 145:1, s. 154-60
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate different techniques for assessing the availability of polycyclic aromatic hydrocarbons (PAHs) in soil. This was done by comparing the amounts (total and relative) taken up by the earthworm Eisenia fetida with the amounts extracted by solid-phase microextraction (SPME), semi-permeable membrane devices (SPMDs), leaching with various solvent mixtures, leaching using additives, and sequential leaching. Bioconcentration factors of PAHs in the earthworms based on equilibrium partitioning theory resulted in poor correlations to observed values. This was most notable for PAHs with high concentrations in the studied soil. Evaluation by principal component analysis (PCA) showed distinct differences between the evaluated techniques and, generally, there were larger proportions of carcinogenic PAHs (4–6 fused rings) in the earthworms. These results suggest that it may be difficult to develop a chemical method that is capable of mimicking biological uptake, and thus estimating the bioavailability of PAHs. The total and relative amounts of PAHs extracted by abiotic techniques for assessing the bioavailability of PAHs was found to differ from the amounts taken up by Eisenia fetida. Keywords: Bioavailability; Polycyclic aromatic hydrocarbons; Earthworms; Leaching; Hydroxypropyl-β-cyclodextrin; Solid-phase microextraction; Semi-permeable membrane device
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| 11. |
- Bergknut, Magnus, et al.
(författare)
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Identification of potentially toxic compounds in complex extracts of environmental samples using gas chromatography-mass spectrometry and multivariate data analysis
- 2007
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Ingår i: Environmental Toxicology and Chemistry. - New York : Pergamon. - 0730-7268 .- 1552-8618. ; 26:2, s. 208-217
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we examined 31 samples of varying chemical composition, including samples of soils from gasworks, coke production sites, and sites where wood preservatives were heavily used; ash and soot from municipal solid waste incinerators; antiskid sand; and dust from areas with heavy road traffic. The samples were comprehensively chemically characterized, especially their polycyclic aromatic compound contents, using gas chromatography-time-of-flight mass spectrometry, whereas their biological effects were assessed using dehydrogenase activity, root growth (Hordeum vulgare), reproduction of springtails (Folsomia candida), algal growth (Desmodesmus subspicatus), germinability (Sinapis alba), Vibrio fischeri, DR-CALUX, and Ames Salmonella assays. The number of compounds detected in the samples ranged from 123 to 527. Using the multivariate regression technique of partial-least-squares projections to latent structures, it was possible to find individual compounds that exhibited strong correlations with the different biological responses. Some of the results, however, indicate that a broader chemical characterization may be needed to identify all the compounds that may cause the measured biological responses.
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| 12. |
- Bergknut, Magnus, et al.
(författare)
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Identification of potentially toxic compounds in complex extracts of environmental samples using GC-MS and multivariate data analysis
- 2007
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Ingår i: Environmental Toxicology and Chemistry. - 0730-7268 .- 1552-8618. ; 26:2, s. 208-17
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we examined 31 samples of varying chemical composition, including samples of soils from gasworks, coke production sites, and sites where wood preservatives were heavily used; ash and soot from municipal solid waste incinerators; antiskid sand; and dust from areas with heavy road traffic. The samples were comprehensively chemically characterized, especially their polycyclic aromatic compound contents, using gas chromatography–time-of-flight mass spectrometry, whereas their biological effects were assessed using dehydrogenase activity, root growth (Hordeum vulgare), reproduction of springtails (Folsomia candida), algal growth (Desmodesmus subspicatus), germinability (Sinapis alba), Vibrio fischeri, DR-CALUX, and Ames Salmonella assays. The number of compounds detected in the samples ranged from 123 to 527. Using the multivariate regression technique of partial-least-squares projections to latent structures, it was possible to find individual compounds that exhibited strong correlations with the different biological responses. Some of the results, however, indicate that a broader chemical characterization may be needed to identify all the compounds that may cause the measured biological responses.
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| 13. |
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| 14. |
- Berglund, Åsa M. M., 1978-, et al.
(författare)
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Effects on the food-web structure and bioaccumulation patterns of organic contaminants in a climate-altered Bothnian Sea mesocosms
- 2023
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Ingår i: Frontiers in Marine Science. - : Frontiers Media S.A.. - 2296-7745. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is expected to alter global temperature and precipitation patterns resulting in complex environmental impacts. The proposed higher precipitation in northern Scandinavia would increase runoff from land, hence increase the inflow of terrestrial dissolved organic matter (tDOM) in coastal regions. This could promote heterotrophic bacterial production and shift the food web structure, by favoring the microbial food web. The altered climate is also expected to affect transport and availability of organic micropollutants (MPs), with downstream effects on exposure and accumulation in biota. This study aimed to assess climate-induced changes in a Bothnian Sea food web structure as well as bioaccumulation patterns of MPs. We performed a mesocosms-study, focusing on aquatic food webs with fish as top predator. Alongside increased temperature, mesocosm treatments included tDOM and MP addition. The tDOM addition affected nutrient availability and boosted both phytoplankton and heterotrophic bacteria in our fairly shallow mesocosms. The increased tDOM further benefitted flagellates, ciliates and mesozooplankton, while the temperature increase and MP addition had minor effect on those organism groups. Temperature, on the other hand, had a negative impact on fish growth and survival, whereas tDOM and MP addition only had minor impact on fish. Moreover, there were indications that bioaccumulation of MPs in fish either increased with tDOM addition or decreased at higher temperatures. If there was an impact on bioaccumulation, moderately lipophilic MPs (log Kow 3.6 - 4.6) were generally affected by tDOM addition and more lipophilic MPs (log Kow 3.8 to 6.4) were generally affected by increased temperature. This study suggest that both increased temperatures and addition of tDOM likely will affect bioaccumulation patterns of MPs in shallow coastal regions, albeit with counteracting effects.
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| 15. |
- Bidleman, Terry, et al.
(författare)
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Atmospheric pathways of chlorinated pesticides and natural bromoanisoles in the northern Baltic Sea and its catchment
- 2015
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Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 44, s. 472-483
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Tidskriftsartikel (refereegranskat)abstract
- Long-range atmospheric transport is a major pathway for delivering persistent organic pollutants to the oceans. Atmospheric deposition and volatilization of chlorinated pesticides and algae-produced bromoanisoles (BAs) were estimated for Bothnian Bay, northern Baltic Sea, based on air and water concentrations measured in 2011-2012. Pesticide fluxes were estimated using monthly air and water temperatures and assuming 4 months ice cover when no exchange occurs. Fluxes were predicted to increase by about 50 % under a 2069-2099 prediction scenario of higher temperatures and no ice. Total atmospheric loadings to Bothnian Bay and its catchment were derived from air-sea gas exchange and bulk'' (precipitation ? dry particle) deposition, resulting in net gains of 53 and 46 kg year(-1) for endosulfans and hexachlorocyclohexanes, respectively, and net loss of 10 kg year(-1) for chlordanes. Volatilization of BAs releases bromine to the atmosphere and may limit their residence time in Bothnian Bay. This initial study provides baseline information for future investigations of climate change on biogeochemical cycles in the northern Baltic Sea and its catchment.
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| 16. |
- Bidleman, Terry F., et al.
(författare)
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Air-water exchange of brominated anisoles in the northern baltic sea
- 2014
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 48:11, s. 6124-6132
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Tidskriftsartikel (refereegranskat)abstract
- Bromophenols produced by marine algae undergo O-methylation to form bromoanisoles (BAs), which are exchanged between water and air. BAs were determined in surface water of the northern Baltic Sea (Gulf of Bothnia, consisting of Bothnian Bay and Bothnian Sea) during 2011-2013 and on a transect of the entire Baltic in September 2013. The abundance decreased in the following order: 2,4,6-tribromoanisole (2,4,6-TBA) > 2,4-dibromoanisole (2,4-DBA) ≫ 2,6-dibromoanisole (2,6-DBA). Concentrations of 2,4-DBA and 2,4,6-TBA in September were higher in the southern than in the northern Baltic and correlated well with the higher salinity in the south. This suggests south-to-north advection and dilution with fresh riverine water enroute, and/or lower production in the north. The abundance in air over the northern Baltic also decreased in the following order: 2,4,6-TBA > 2,4-DBA. However, 2,6-DBA was estimated as a lower limit due to breakthrough from polyurethane foam traps used for sampling. Water/air fugacity ratios ranged from 3.4 to 7.6 for 2,4-DBA and from 18 to 94 for 2,4,6-TBA, indicating net volatilization. Flux estimates using the two-film model suggested that volatilization removes 980-1360 kg of total BAs from Bothnian Bay (38000 km(2)) between May and September. The release of bromine from outgassing of BAs could be up to 4-6% of bromine fluxes from previously reported volatilization of bromomethanes and bromochloromethanes.
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| 17. |
- Bidleman, Terry F., et al.
(författare)
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Bromoanisoles and Methoxylated Bromodiphenyl Ethers in Macroalgae from Nordic Coastal Regions
- 2019
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Ingår i: Environmental Science. - London : Royal Society of Chemistry. - 2050-7887 .- 2050-7895. ; , s. 881-892
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Tidskriftsartikel (refereegranskat)abstract
- Marine macroalgae are used worldwide for human consumption, animal feed, cosmetics and agriculture. In addition to beneficial nutrients, macroalgae contain halogenated natural products (HNPs), some of which have toxic properties similar to those of well-known anthropogenic contaminants. Sixteen species of red, green and brown macroalgae were collected in 2017–2018 from coastal waters of the northern Baltic Sea, Sweden Atlantic and Norway Atlantic, and analyzed for bromoanisoles (BAs) and methoxylated bromodiphenyl ethers (MeO-BDEs). Target compounds were quantified by gas chromatography-low resolution mass spectrometry (GC-LRMS), with qualitative confirmation in selected species by GC-high resolution mass spectrometry (GC-HRMS). Quantified compounds were 2,4-diBA, 2,4,6-triBA, 2′-MeO-BDE68, 6-MeO-BDE47, and two tribromo-MeO-BDEs and one tetrabromo-MeO-BDE with unknown bromine substituent positions. Semiquantitative results for pentabromo-MeO-BDEs were also obtained for a few species by GC-HRMS. Three extraction methods were compared; soaking in methanol, soaking in methanol–dichloromethane, and blending with mixed solvents. Extraction yields of BAs did not differ significantly (p > 0.05) with the three methods and the two soaking methods gave equivalent yields of MeO-BDEs. Extraction efficiencies of MeO-BDEs were significantly lower using the blend method (p < 0.05). For reasons of simplicity and efficiency, the soaking methods are preferred. Concentrations varied by orders of magnitude among species: ∑2BAs 57 to 57 700 and ∑5MeO-BDEs < 10 to 476 pg g−1 wet weight (ww). Macroalgae standing out with ∑2BAs >1000 pg g−1 ww were Ascophyllum nodosum, Ceramium tenuicorne, Ceramium virgatum, Fucus radicans, Fucus serratus, Fucus vesiculosus, Saccharina latissima, Laminaria digitata, and Acrosiphonia/Spongomorpha sp. Species A. nodosum, C. tenuicorne, Chara virgata, F. radicans and F. vesiculosus (Sweden Atlantic only) had ∑5MeO-BDEs >100 pg g−1ww. Profiles of individual compounds showed distinct differences among species and locations.
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| 18. |
- Bidleman, Terry F., et al.
(författare)
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Sea-air exchange of bromoanisoles and methoxylated bromodiphenylethers in the Northern Baltic
- 2016
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Ingår i: Marine Pollution Bulletin. - : Elsevier. - 0025-326X .- 1879-3363. ; 112:1-2, s. 58-64
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Tidskriftsartikel (refereegranskat)abstract
- Halogenated natural products in biota of the Baltic Sea include bromoanisoles (BAs) and methoxylated bromodiphenyl ethers (MeO-BDEs). We identified biogenic 6-MeO-BDE47 and 2'-MeO-BDE68 in Baltic water and air for the first time using gas chromatography - high resolution mass spectrometry. Partial pressures in air were related to temperature by: log p/Pa=m/T(K)+b. We determined Henry's law constants (HLCs) of 2,4-dibromoanisole (2,4-DiBA) and 2,4,6-tribromoanisole (2,4,6-TriBA) from 5 to 30°C and revised our assessment of gas exchange in the northern Baltic. The new water/air fugacity ratios (FRs) were lower, but still indicated net volatilization in May-June for 2,4-DiBA and May - September for 2,4,6-TriBA. The net flux (negative) of BAs from Bothnian Bay (38,000km2) between May - September was revised from -1319 to -532kg. FRs of MeO-BDEs were >1, suggesting volatilization, although this is tentative due to uncertainties in their HLCs and binding to dissolved organic carbon.
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| 19. |
- Bidleman, Terry F., et al.
(författare)
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Will Climate Change Influence Production and Environmental Pathways of Halogenated Natural Products?
- 2020
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Ingår i: Environmental Science and Technology. - Washington, DC, USA : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 54:11, s. 6468-6485
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Tidskriftsartikel (refereegranskat)abstract
- Thousands of halogenated natural products (HNPs) pervade the terrestrial and marine environment. HNPs are generated by biotic and abiotic processes and range in complexity from low molecular mass natural halocarbons (nHCs, mostly halomethanes and haloethanes) to compounds of higher molecular mass which often contain oxygen and/or nitrogen atoms in addition to halogens (hHNPs). nHCs have a key role in regulating tropospheric and stratospheric ozone, while some hHNPs bioaccumulate and have toxic properties similar those of anthropogenic-persistent organic pollutants (POPs). Both chemical classes have common sources: biosynthesis by marine bacteria, phytoplankton, macroalgae, and some invertebrate animals, and both may be similarly impacted by alteration of production and transport pathways in a changing climate. The nHCs scientific community is advanced in investigating sources, atmospheric and oceanic transport, and forecasting climate change impacts through modeling. By contrast, these activities are nascent or nonexistent for hHNPs. The goals of this paper are to (1) review production, sources, distribution, and transport pathways of nHCs and hHNPs through water and air, pointing out areas of commonality, (2) by analogy to nHCs, argue that climate change may alter these factors for hHNPs, and (3) suggest steps to improve linkage between nHCs and hHNPs science to better understand and predict climate change impacts.
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| 20. |
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| 21. |
- Björlenius, Berndt, et al.
(författare)
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Pharmaceutical residues are widespread in Baltic Sea coastal and offshore waters – Screening for pharmaceuticals and modelling of environmental concentrations of carbamazepine
- 2018
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 633, s. 1496-1509
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Tidskriftsartikel (refereegranskat)abstract
- The consumption of pharmaceuticals worldwide coupled with modest removal efficiencies of sewage treatment plants have resulted in the presence of pharmaceuticals in aquatic systems globally. In this study, we investigated the environmental concentrations of a selection of 93 pharmaceuticals in 43 locations in the Baltic Sea and Skagerrak. The Baltic Sea is vulnerable to anthropogenic activities due to a long turnover time and a sensitive ecosystem in the brackish water. Thirty-nine of 93 pharmaceuticals were detected in at least one sample, with concentrations ranging between 0.01 and 80 ng/L. One of the pharmaceuticals investigated, the anti-epileptic drug carbamazepine, was widespread in coastal and offshore seawaters (present in 37 of 43 samples). In order to predict concentrations of pharmaceuticals in the sub-basins of the Baltic Sea, a mass balance-based grey box model was set up and the persistent, widely used carbamazepine was selected as the model substance. The model was based on hydrological and meteorological sub-basin characteristics, removal data from smaller watersheds and wastewater treatment plants, and statistics relating to population, consumption and excretion rate of carbamazepine in humans. The grey box model predicted average environmental concentrations of carbamazepine in sub-basins with no significant difference from the measured concentrations, amounting to 0.57-3.2 ng/L depending on sub-basin location. In the Baltic Sea, the removal rate of carbamazepine in seawater was estimated to be 6.2 10(-9) s(-1) based on a calculated half-life time of 3.5 years at 10 degrees C, which demonstrates the long response time of the environment to measures phasing out persistent or slowly degradable substances such as carbamazepine. Sampling, analysis and grey box modelling were all valuable in describing the presence and removal of carbamazepine in the Baltic Sea.
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| 22. |
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| 23. |
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| 24. |
- Eimer, Johannes, et al.
(författare)
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Spiroplasma ixodetis Infections in Immunocompetent and Immunosuppressed Patients after Tick Exposure, Sweden
- 2022
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Ingår i: Emerging Infectious Diseases. - : Centers for Disease Control and Prevention (CDC). - 1080-6040 .- 1080-6059. ; 28:8, s. 1681-1685
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Tidskriftsartikel (refereegranskat)abstract
- We report 2 cases of Spiroplasma ixodetis infection in an immunocompetent patient and an immunocompromised patient who had frequent tick exposure. Fever, thrombocytopenia, and increased liver aminotransferase levels raised the suspicion of anaplasmosis, but 16S rRNA PCR and Sanger sequencing yielded a diagnosis of spiroplasmosis. Both patients recovered after doxycycline treatment.
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| 25. |
- Fransson, Marcus, et al.
(författare)
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Case Report : Subtherapeutic Vancomycin and Meropenem Concentrations due to Augmented Renal Clearance in a Patient With Intracranial Infection Caused by Streptococcus intermedius
- 2021
-
Ingår i: Frontiers in Pharmacology. - : Frontiers Media SA. - 1663-9812. ; 12
-
Tidskriftsartikel (refereegranskat)abstract
- Streptococcus intermedius occasionally causes brain abscesses that can be life-threatening, requiring prompt antibiotic and neurosurgical treatment. The source is often dental, and it may spread to the eye or the brain parenchyma. We report the case of a 34-year-old man with signs of apical periodontitis, endophthalmitis, and multiple brain abscesses caused by Streptococcus intermedius. Initial treatment with meropenem and vancomycin was unsuccessful due to subtherapeutic concentrations, despite recommended dosages. Adequate concentrations could be reached only after increasing the dose of meropenem to 16 g/day and vancomycin to 1.5 g x 4. The patient exhibited high creatinine clearance consistent with augmented renal clearance, although iohexol and cystatin C clearances were normal. Plasma free vancomycin clearance followed that of creatinine. A one-day dose of trimethoprim-sulfamethoxazole led to an increase in serum creatinine and a decrease in both creatinine and urea clearances. These results indicate that increased tubular secretion of the drugs was the cause of suboptimal antibiotic treatment. The patient eventually recovered, but his left eye needed enucleation. Our case illustrates that augmented renal clearance can jeopardize the treatment of serious bacterial infections and that high doses of antibiotics are needed to achieve therapeutic concentrations in such cases. The mechanisms for regulation of kidney tubular transporters of creatinine, urea, vancomycin, and meropenem in critically ill patients are discussed.
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| 26. |
- Förlin, Lars, 1950, et al.
(författare)
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mRNA Expression and Biomarker Responses in Perch at a Biomonitoring Site in the Baltic Sea - Possible Influence of Natural Brominated Chemicals
- 2019
-
Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 6
-
Tidskriftsartikel (refereegranskat)abstract
- Perch (Perca fluviatilis) has been used in biological effect monitoring in a program for integrated coastal fish monitoring at the reference site Kvadofjarden along the Swedish east coast, which is a site characterized by no or minor local anthropogenic influences. Using a set of physiological and biochemical endpoints (i.e., biomarkers), clear time trends for "early warning" signs of impaired health were noted in the perch from this site, possibly as a result of increased baseline pollution. The data sets also showed relatively large variations among years. To identify additional temporal variation in biological parameters, global mRNA expression studies using RNA sequencing was performed. Perch collected in 2010 and 2014 were selected, as they showed variations in several biomarkers, such as the activity of the detoxification enzyme CYP1A (EROD), the plasma levels of vitellogenin, markers for oxidative stress, white blood cells count and gonad sizes. The RNA sequencing study identified approximately 4800 genes with a significantly difference in mRNA expression levels. A gene ontology enrichment analysis showed that these differentially expressed genes were involved in biological processes such as complement activation, iron ion homeostasis and cholesterol biosynthetic process. In addition, differences in immune system parameters and responses to the exposure of toxic substances have now been verified in two different biological levels (mRNA and protein) in perch collected in 2010 and 2014. Markedly higher mRNA expression of the membrane transporter (MATE) and the detoxification enzyme COMT, together with higher concentrations of bioactive naturally produced brominated compounds, such as brominated indoles and carbazoles, seem to indicate that the perch collected in 2014 had been exposed to macro- and microalga blooming to a higher degree than did perch from 2010. These results and the differential mRNA expression between the 2 years in genes related to immune and oxidative stress parameters suggest that attention must be given to algae blooming when elucidating the well-being of the perch at Kvadofjarden and other Baltic coastal sites.
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| 27. |
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| 28. |
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| 29. |
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| 30. |
- Günther, Göran, et al.
(författare)
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Ticke-borne encephalitis is associated with low levels of interleukin-10 in cerebrospinal fluid
- 2011
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Ingår i: Infection Ecology & Epidemiology. - : Informa UK Limited. - 2000-8686. ; 1, s. 6029-
-
Tidskriftsartikel (refereegranskat)abstract
- Tick-borne encephalitis (TBE) is associated with higher morbidity and induces a stronger intrathecal immune activation than most other viral induced meningo-encephalitis. The aim of this study was to investigate cytokine concentrations in cerebrospinal fluid (CSF) and serum in relation to aetiology and clinical course. Cytokines were analysed by Enzyme-linked Immuno Assay (ELISA) from 44 patients with TBE and from 36 patients with aseptic meningo-encephalitis of other aetiology (non-TBE). Significantly increased CSF levels of Interferon-γ (IFN-γ), Interleukin-10 (IL-10), Interleukin-6 (IL-6), Interleukin-1 receptor antagonist (IL- 1ra), and soluble CD8 receptor (sCD8) were detected in both cohorts. Tumour necrosis factor-α (TNF-α showed low levels or was not detected in CSF in any group in the acute stage. However, the CSF levels of IL- 10 were significantly lower in TBE than in non-TBE cases 06 days after onset of encephalitis. The TBE patients with encephalitis had significantly lower IL-10 CSF levels later in the clinical course (day 718) than TBE patients with meningeal disease. Increased IFN-γ production, but low IL-10 secretion, may be of pathophysiological significance in TBE.
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| 31. |
- Göthelid, Mats, et al.
(författare)
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Influence of O and Co on the early stages of sintering of Wc-Co : A surface study by AES and STM
- 2000
-
Ingår i: Acta Materialia. - 1359-6454 .- 1873-2453. ; 48:17, s. 4357-4362
-
Tidskriftsartikel (refereegranskat)abstract
- The influence of oxygen on the sintering behavior of WC-Co has been investigated by Auger electron spectroscopy (AES) and scanning tunneling microscopy (STM). Deposition of Co on the WC(0001) surface and subsequent annealing at 650 degreesC results in a 2x2 reconstructed pre-cursor layer on top of which Co grows in weakly bound islands which can be moved on the surface by the STM rip. Annealing at 850 degreesC removes excess Co and leaves only the 2x2 surface. Oxygen exposure of the 2x2 surface results in a clustered cobalt oxide overlayer which on annealing at 750 degreesC breaks up and restores the 2x2 structure as the metallic Co wets the surface.
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| 32. |
- Haglund, B, et al.
(författare)
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Is moist snuff use associated with excess risk of IHD or stroke? A longitudinal follow-up of snuff users in Sweden
- 2007
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Ingår i: Scandinavian journal of public health. - : SAGE Publications. - 1403-4948 .- 1651-1905. ; 35:6, s. 618-622
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Tidskriftsartikel (refereegranskat)abstract
- Background: The potential risks of Swedish moist snuff (snus) are debated and studies have shown diverging results. Aims: The aim of this study is to investigate whether there is any excess risk of ischaemic heart disease (IHD) and stroke from snuff use. Methods: The Swedish Survey of Living Conditions from 1988—89 was record-linked to the Swedish Cause of Death Register and the Swedish Hospital Discharge Register to investigate excess mortality and hospitalization from IHD and stroke. A Poisson regression model was used and incidence rate ratios (IRRs) for snuff and smoking were calculated controlling for age, physical activity, self-reported health, number of longstanding illnesses, residential area, and socioeconomic position. Results: Among snuff users there were no excess risks of mortality or hospitalization from IHD (IRR 0.8; 0.5—1.2,) or stroke (IRR 1.1; 0.7—1.8), but, as expected, clear excess risks were found for smokers (IRR 1.7; 1.4—2.1 for IHD, and IRR 1.4; 1.0—1.9 for stroke). Conclusions: This study has not shown any excess risk among users of snuff for IHD or stroke. If there is a risk associated with snuff it is evidently much lower than those associated with smoking.
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| 33. |
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| 34. |
- Haglund, Mats
(författare)
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Speed Choice : The Driver, the Road and Speed Limits
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Speed choice is one of the more characteristic features of driver behaviour. The speed a driver chooses to travel at determines the degree of difficulty he or she operates under. Higher speeds lead to more accidents, higher accident risk and more severe consequences of an accident. The present thesis examines factors that are associated with drivers’ speed choice. Repeated measures of drivers’ speed showed a reasonably high correlation, but also that stability in speed varied with road layout between measurement sites. Effects of police enforcement were studied on roads with temporary reduced speed limits (from 50 km/h to 30 km/h) during school hours. Lower speeds were found on roads with enforcement and drivers observed on one such road showed a higher perceived probability of detection than did drivers observed on a non-enforced road. However, in a laboratory study higher driving speeds and lower accident risk was associated with enforced roads. Drivers not informed about existing speed limits overestimated the limits to a large extent and chose driving speeds above the limit as did drivers informed about the limits. In an on-the-road survey, fast drivers reported higher driving speed, thought a higher percentage of other drivers were speeding and had a more positive attitude towards speeding than did slower drivers. The results suggest that drivers’ travel speed is influenced by road factors, other road users and enforcement. Furthermore, drivers’ own judgements of what is an appropriate speed are also important for speed choice.
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| 35. |
- Haglund, Mats, et al.
(författare)
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Speed choice in relation to speed limit and influences from other drivers
- 2000
-
Ingår i: Transportation Research Part F: Traffic Psychology and Behaviour. ; 3:1, s. 39-51
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Tidskriftsartikel (refereegranskat)abstract
- Speeding is a general problem in traffic and exploring factors underlying the choice of speed is an important task. In the present paper, based on data from Swedish drivers on 90 km/h roads, drivers' attitudes towards speeding and influences from other ro
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| 36. |
- Haglund, Mats, et al.
(författare)
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Stability in drivers' speed choice
- 2002
-
Ingår i: Transportation Research Part F: Traffic Psychology and Behaviour. ; 5:3, s. 177-188
-
Tidskriftsartikel (refereegranskat)
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| 37. |
- Haglund, Mats
(författare)
-
Tick-borne encephalitis : prognosis, immunization and virus strain characterization
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aims were to investigate the morbidity associated with tick-borne encephalitis (TBE) both in the acute phase and at long-term follow-up, to develop a rapid neutralization test for confirmation of TBEV-specific antibody response and to study the serological response after TBE-vaccination and, finally, to characterize Swedish human TBEV isolates. The morbidity was studied in one retrospective follow-up study of consecutive TBE-patients, treated during a 10-year period (Paper 1) and in one prospective study of TBE-patients with aseptic meningoencephalitis of non-TBE etiology as a reference group (Paper II). The retrospective study with applied neuropsychiatric questionnaire comprised 114/143 individuals followed for 47 months (20-133 months). Two elderly men were dead due to TBE. Of the remaining 112 individuals 40 (36%) were left with residual TBE related symptoms, in 31 classified as moderate or severe. The most common complaints were cognitive/neuropsychiatric symptoms, balance/coordination disturbances, headache and hearing loss/tinnitus. Three patients had permanent paralysis. A vast majority of the TBE patients had contracted the infection during leisure time and were permanent residents or visited endemic regions on regular basis. Half of them were aware of other TBE-cases in their environment. The prospective follow-up study in 85/108 TBE-patients and 64/488 non-TBE patients confirmed the existence of a post-encephalitic syndrome after TBE. 40% of TBE patients and 20% of the non-TBE patients (p=0.006) were left with residual symptoms after one year e.g. various cognitive dysfunctions, ataxia/tremor, dysphasia and headache. Nine TBE patients developed paresis, of which 5 cases persisted after one year (tetraparesis and bilateral shoulder paresis). The TBE patients had longer hospitalization-time and sick-leave, more intense blood-CSF-barrier damage and more pronounced intrathecal IgG-production compared to patients in the reference group. No CSF parameter was found useful as a prognostic marker. A rapid neutralization test (RFFIT) was developed and found sensitive and specific for confirmation of TBEV-specific antibody response (Paper III). The assay had high performance stability and took just one day to perform, in contrast to PRNT which was unstable and time-consuming. The test is useful in seroprevalence studies for confirmation of TBE-specific activity in ELISA reactive samples, for evaluation of TBE immunity and for the diagnosis of TBE patients previously exposed to other flaviviruses. The RFFIT with a Swedish human TBEV-isolate proved to be more sensitive than ELISA or HI to measure the antibody response to TBE-vaccination (FSME-ImmunTM Inject, Baxter) in 535 randomly selected adult persons (Paper IV). The emphasis of the study was laid on long-term follow-up from the 3rd until 3 years after the 5th, dose. At the time of the 3rd dose, 77% of the vaccinees had neutralizing antibody activity and at the time of the 4th-6th doses in 89-95%. The corresponding figures after the 3rd dose was >90%, and after doses 4 and 5 >98%. Based on our data and previous experience of vaccine failures after two doses, a more condensed three-dose primary vaccination schedule may be advantageous. Judging from antibody persistence, it seems justified to initiate studies of antibody persistence after the 4th dose for periods beyond the recommended three-year booster interval. Swedish TBEV strains have previously not been characterized. 17 human strains were studied, isolated from acute phase serum of TBE patients, three from 1958-1966 and 14 from 1991-1994 (Paper V). Serological characterization using a panel of E-specific mouse MAbs and cross-neutralization indicated that the strains belonged to the Western TBEV subtype which includes the Austrian vaccine strain Neudoerfl. Genetic analysis of a partial E-sequence confirmed the close relationship: all Swedish strains belonged to the Western TBEV lineage. When comparing the almost complete sequence of the E-gene of two Swedish strains with the Neudoerfl strain only one conservative amino acid substitution was found. This close similarity and the neutralizing activity to a local strain evoked by the vaccine indicate that the vaccine available in Sweden ought to induce a proper protection. A correlation between the phylogenetic relationships and the geographical origin of the strains was indicated, but genetic data or geographic origin did not correlate to severity of disease.
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| 38. |
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| 39. |
- Haglund, Petter, et al.
(författare)
-
Developing Construction Logistics Services in the Construction Equipment Rental Company-Contractor Dyad
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- PurposeThe understanding of how to develop or expand logistics service offerings to the construction industry has received limited attention in the research community. The purpose of this study is to investigate how construction equipment rental companies (CERCs) can approach the challenge of expanding their service offerings to include construction logistics services.Design/methodology/approachThe study builds on a descriptive case study to analyse how a CERC has approached developing logistics services for construction through the lens of New Service Development literature.FindingsThe study shows that the CERC’s ongoing transition from a construction equipment supplier to a logistics service provider requires both back-end and front-end service development. The New Service Development process extends into sales and delivery of solutions where the company’s established customer-base in the construction industry can be beneficial.Research limitations/implicationsThe study is limited to the Swedish construction context and further studies are needed to generalize the findings. Future studies should investigate how well service offerings match the contractor’s needs.Practical implicationsThe study can be used by contractors and prospective logistics service providers for developing logistics services.Original/valueThe study contributes to construction logistics literature by addressing how construction logistics services can be developed by adopting a New Service Development approach.
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| 40. |
- Haglund, Petter, 1995-, et al.
(författare)
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Organizing construction logistics outsourcing : a logistics strategy perspective
- 2023
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Ingår i: Construction Innovation. - : EMERALD GROUP PUBLISHING LTD. - 1471-4175 .- 1477-0857.
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose The construction industry shows an increased interest in how to manage logistics within construction projects. Often construction logistics is outsourced to a logistics service provider (LSP). However, construction logistics is normally approached either as a strategic decision or as an operational issue and rarely as a tactical concern. The purpose of this study is to explore how to organize the logistics outsourcing decision at strategic, tactical and operational levels.Design/methodology/approach This study is performed as a single-case study within a construction corporation, containing (amongst others) a building contractor (BC) and a construction equipment rental company (CERC) offering logistics services.Findings The study shows that to procure construction logistics service successfully, BCs need logistics capabilities at strategic and tactical levels to maintain an alignment between the use of logistics services and operational characteristics. Simultaneously, CERC’s need to design their service offerings to correspond to the needs of the BC.Research limitations/implications This study builds on a single-case study of a Swedish construction corporation. Further research is needed to better understand current logistics outsourcing and development practices and how these can be improved to foster better logistics management at the project level.Practical implications BCs find suggestions of different logistics organization structures and suitable outsourcing arrangements. CERCs and LSPs can use the findings to understand their customers’ needs and adapt service offerings.Originality/value To the best of the authors’ knowledge, this study is one of the first studies of how two companies within a corporation can work together to develop construction logistics service offerings.
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| 41. |
- Harju, Mikael, et al.
(författare)
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Determination of atropisomeric and planar polychlorinated biphenyls, their enantiomeric fractions and tissue distribution in grey seals using comprehensive 2D gas chromatography
- 2003
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Ingår i: Journal of Chromatography A. - Amsterdam : Elsevier. - 0021-9673 .- 1873-3778. ; 1019:1-2, s. 127-142
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Tidskriftsartikel (refereegranskat)abstract
- High prevalence of uterine occlusions and sterility is found among Baltic ringed and grey seal. Polychlorinated biphenyls (CBs) are suspected to be the main cause. The CB concentrations are higher in affected than in healthy animals, but the natural variation is considerable. Thus, it might be possible to assess the health status of seals by CB analysis. The ratios of chiral compounds (enantiomeric fractions (EFs)) such as atropisomeric CBs are of particular interest, since these may reflect differences in metabolic rates. An analytical procedure was developed and used to determine the levels of atropisomeric CBs, planar-CBs (WHO-PCBs) and total CBs in seals of different health status. Comprehensive 2D gas chromatography (GC×GC) was used to separate the target analytes from other CBs and interferences and a micro electron-capture detector (μECD) was used for detection. EFs of the atropisomeric CBs were difficult to determine as the levels were low and the interferences many. Two column combinations had to be used to avoid biased results—both had a chiral column as first-dimension column. The second-dimension column was coated with either a high-polarity cyanopropyl or a liquid crystal phase. EFs were determined for five atropisomeric CBs, i.e. CBs 91, 95, 132, 149 and 174. The results were verified by GC×GC–time-of-flight mass spectrometry (TOF-MS). Some atropisomeric CBs had EFs that deviated strongly from the racemic-mixture value. The deviations were larger in liver than blubber, which indicates enantioselective metabolism. However, there was no selective passage of the studied atropisomeric CBs across placenta and no selective blood–brain barrier. Similarly, no correlation between EFs and health status was observed, although there was a correlation between the total CB levels and health status.
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| 42. |
- Harju, Mikael, et al.
(författare)
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Multivariate physicochemical characterisation and quantitative structure–property relationship modelling of polybrominated diphenyl ethers
- 2002
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Ingår i: Chemosphere. ; 47:4, s. 375-84
-
Tidskriftsartikel (refereegranskat)abstract
- Levels of polybrominated diphenyl ethers (PBDEs) are increasing in the environment and may cause long-term environmental problems. Developing a model describing the chemical variation among the 209 possible congeners would be a useful step in any systematic approach for assessing the fate and risk posed by the PBDEs. Therefore, 40 physicochemical descriptors were derived for all PBDEs using a semi-empirical method (AM1), molecular mechanics, and empirically estimated parameters. Descriptors included heats of formation, frontier molecular orbital energies, atomic charges, dipole moments, logP values, and molecular surface areas. Principal component analysis (PCA) was used to evaluate the descriptors. The first four PCs, explaining 76% of the variation in the data, described the size, charge distribution and symmetric elements of the congeners. A quantitative structure–activity relationship model was constructed based on data for dioxin-like activity (using the luciferase bioassay) for 17 PBDEs with the partial least squares method. In addition, quantitative structure–property relationship models for gas chromatographic relative retention times on four capillary columns were developed. These models proved suitable to assist in the identification of untested PBDEs. Based on the results of the PCA, a factorial design was applied for selecting 21 representative congeners, PBDEs 11, 13, 17, 32, 35, 47, 53, 77, 85, 99, 119, 135, 153, 155, 156, 169, 176, 181, 190, 192, and 209. The spacing of these congeners in the physicochemical domain maximises the coverage of key factors such as molecular size and substitution pattern. Consideration of the selected congeners should be useful for guiding the synthesis of new compounds for use in future studies of the fate and biological effects of PBDEs.
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| 43. |
- Hashemi, Seyed Ehsan, 1986, et al.
(författare)
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Effect of compositional interlayers on the vertical electrical conductivity of Si-doped AlN/GaN distributed Bragg reflectors grown on SiC''
- 2017
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Ingår i: Applied Physics Express. - 1882-0786 .- 1882-0778. ; 10:5, s. 055501-
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the effect of strain-compensating interlayers on the vertical electrical conductivity of Si-doped AlN/GaN distributed Bragg reflectors (DBRs). Samples with 10.5 mirror pairs were grown through plasma-assisted molecular beam epitaxy on SiC. Room-temperature current–voltage characteristics were measured vertically in mesas through 8 of the 10.5 pairs. The sample with no interlayers yields a mean specific series resistance of 0.044 Ω cm2 at low current densities, while three samples with 5/5-Å-thick, 2/2-nm-thick, and graded interlayers have resistivities between 0.16 and 0.34 Ω cm2. Thus, interlayers impair vertical current transport, and they must be designed carefully when developing conductive DBRs.
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| 44. |
- Hjort, Filip, 1991, et al.
(författare)
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Vertical Electrical Conductivity of ZnO/GaN Multilayers for Application in Distributed Bragg Reflectors
- 2018
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Ingår i: IEEE Journal of Quantum Electronics. - 0018-9197 .- 1558-1713. ; 54:4
-
Tidskriftsartikel (refereegranskat)abstract
- We have demonstrated an electrically conductive ZnO/GaN multilayer structure using hybrid plasma-assisted molecular beam epitaxy. Electrical I-V characteristics were measured through the top three pairs of a six pair ZnO/GaN sample. The total measured resistance was dominated by lateral and contact resistances, setting an upper limit of similar to 10(-4) Omega.cm(2) for the vertical specific series resistance of the stack. A strong contribution to the low resistance is the cancellation of spontaneous and piezoelectric polarization that occurs in the in- plane strained ZnO/GaN sample, as shown by electrical simulations. In addition, the simulations show that the actual vertical resistance of the sample could in fact be three orders of magnitude lower and that ZnO/GaN structures with thicknesses fulfilling the Bragg condition should have similar resistance. Our results suggest that ZnO/GaN distributed Bragg reflectors (DBRs) are a promising alternative to pure III-nitride DBRs in GaN-based vertical-cavity surface-emitting lasers.
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| 45. |
- Holmberg, Linnéa, 1983-
(författare)
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Konsten att producera lärande demokrater
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation builds on the basic question of how individuals are formed and created as citizens in society today, and how individuals construct themselves as citizens in this society. It takes interest in how they are managed to govern themselves through specific constructions of citizenship, and looks at how the exercise of power establishes certain knowledge that affects their view of themselves and generates truths about how they are expected to live their lives. Simultaneously, the dissertation deals with the concept of freedom: what does it mean in contemporary society, how can one be free today, and what dangers might this liberty involve?In a broad sense, the analysis centres on the relationship between education and society; more specifically, it engages with the Swedish education system and its construction and production of desirable citizen subjects. The concrete example deals with the institution called leisure-time centre, with a purpose to investigate and problematise how institutionalised leisure-time is staged and legitimised in Sweden today. The studies take as a common starting point the following research question: how are children and personnel governed discursively in and through leisure-time centres?The first empirical contribution provides historical context for the study. In this, the `problematic leisure-time´ of today is outlined based on education policy documents relevant for children aged 6–13 years. These texts are discussed together with similar texts gathered from two other periods in history in order to give perspective on aspects of the leisure-time centre that may seem obvious in our own time.The first separate article investigates how talk about activities in leisure-time centres is couched in terms of meaningfulness and consists of an analysis of the ideological tension between democracy and authority, which the governmental authority, the Swedish Schools Inspectorate (Skolinspektionen), must address in its discursive work. The second article explores how the production of systematic reporting and documentation by personnel in leisure-time centres works through specific self-technologies in the form of confessional practices and which can be said to be primarily about constructing a free but loyal collective subject.The third article problematises the use of democracy as a method to produce specific citizen subjects in leisure-time centres. Children’s councils are analysed, focusing on how different nuances of influence are staged discursively by participating children and personnel. The article highlights how democracy – through pastoral care and in the name of children’s influence – becomes a governmentalising technology that produces an active, responsible and learning citizen.In summary, this dissertation highlights how leisure-time centres are staged and legitimised in Sweden today. The analysis shows how an administration of children and control of the development of society through the autonomous, competent, and voluntarily active individual is apparent; power operates through a perceived freedom in a way that makes the free choice the `right´ choice. With political ideas about forming a forward-looking mentality, children – and personnel – are constructed as a project of learning and improvement.
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| 46. |
- Isaksson, Sofi, et al.
(författare)
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Detecting EGFR alterations in clinical specimens-pitfalls and necessities.
- 2013
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Ingår i: Virchows Archiv: an international journal of pathology. - : Springer Science and Business Media LLC. - 1432-2307. ; 463:6, s. 755-764
-
Tidskriftsartikel (refereegranskat)abstract
- We investigated the epidermal growth factor receptor (EGFR) status in early stage lung cancer in Southern Sweden, a population for which there are no previous reports on the EGFR mutation frequency. Three hundred fifty small cell lung cancers, adenocarcinomas (AC), squamous cell carcinomas (SqCC), and large cell carcinomas were analyzed using a combination of techniques for the analysis of protein expression, gene copy numbers, and mutations. Immunohistochemical (IHC) staining with antibodies for the EGFR mutations L858R and del E746-A750 revealed intratumoral heterogeneity and several discrepant cases when compared to mutation-specific polymerase chain reaction (PCR)-based analysis. The frequencies of these two mutations, when considering IHC staining with mutation-specific antibodies in a cohort of 298 cases and subsequent confirmation by PCR, were 10 % in AC and <2 % in SqCC. Furthermore, screening by sequencing of EGFR in a cohort of 52 lung AC and squamous carcinomas demonstrated a more diverse mutation spectrum, not covered by the mutation-specific antibodies. High expression of total EGFR protein was correlated to high gene copy numbers but did not reflect the mutational status of the tumors. We believe that the mutation spectra in a Southern Swedish population is too diverse to be covered by the mutation-specific antibodies, and we also raise some other issues regarding the use of the mutation-specific antibodies, for example concerning heterogeneous expression of the mutated protein, optimal antibody dilution, and discrepancies between staining results and PCR.
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| 47. |
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| 48. |
- Jelenik, Zsuzsanna, et al.
(författare)
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Tick-borne encephalitis and golden agers : position paper of the International Scientific Working Group on Tick-borne encephalitis (ISW-TBE)
- 2010
-
Ingår i: Wiener Medizinische Wochenschrift. - : Springer Science and Business Media LLC. - 0043-5341 .- 1563-258X. ; 160:9-10, s. 247-251
-
Tidskriftsartikel (refereegranskat)abstract
- One of the primary goals of the 11th Annual Meeting of the International Scientific Working Group on Tick-borne encephalitis (ISW-TBE) held in 2009 was to develop the first update of the Position Paper on TBE in Golden Agers, summarizing the most essential aspects of the disease in this age group. TBE morbidity has continued to increase in recent years, which is thought to be due to an interplay of social, political, ecological, economic and demographic factors combined with climate changes. Today's golden agers i.e. individuals aged 50 years or above, are healthier and more mobile, lead more active lifestyles and spend more time travelling and performing outdoor leisure activities. This places them at an increased risk of infection. At the same time, increasing age is associated with a quantitative and qualitative decline in innate and adaptive immunity, which is why elderly individuals are more susceptible to infection and severe disease than younger people. Also, their response to vaccination tends to be slower, antibody titres generally reach lower levels and titres tend to decrease earlier than in younger individuals. Evidence is accumulating that this is also the case with TBE vaccination, emphasizing the importance of administering the first TBE booster vaccination no later than 3 years after the completion of primary immunization or at an even shorter interval. Encouragingly, recent data have shown that the field effectiveness of TBE vaccination exceeds 97%, with no significant differences between age groups.
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| 49. |
- Johansson, Christian, et al.
(författare)
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Microwave circuits in multilayer inorganic-organic polymer thin film technology on laminate substrates
- 2003
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Ingår i: IEEE Transactions on Advanced Packaging. - 1521-3323 .- 1557-9980. ; 26:1, s. 81-89
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Tidskriftsartikel (refereegranskat)abstract
- Requirements of higher performance, reduced size, weight and cost of high-frequency (HF) devices has led to the search for new: materials, material combinations, methods, processes and production equipment. Efficient technologies for producing HF-circuits and integral passives are looked for. Also of interest are integrated packaging solutions for high frequency electrical packaging and optical interconnects and packaging. Sequentially build up multi-layers have been deposited on a low cost FR-4 epoxy substrate. The dielectric layers consist of a photo-patternable inorganic-organic hybrid polymer (ORMOCER) and the metallization is Cu. An UV-exposure equipment enabling projection patterning with 5 μm resolution have been used. The produced microstrip lines, ring resonators, vias, stacked capacitors and filters have been characterized at frequencies from 1 to 40 GHz showing the potential of the new dielectric materials and processing technologies for microwave applications.
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- Johansson, Christian, et al.
(författare)
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Microwave circuits in multilayer ORMOCER® thin film
- 2002
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Ingår i: Proceedings IMAPS Nordic 2002. ; , s. 60-63
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A multilayer sequential build-up structure for the integration of passivemicrowave devices is presented. The different devices were processed byusing a photo-patternable polymer ORMOCER together with conducting layersof Cu on top of a FR-4 substrate. Microstrip and stub structures have beencharacterised at frequencies between 1 to 40 GHZ showing the feasibility ofusing this kind of material and build-up technology for microwaveapplications.
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