| 1. |
- Stalhandske, Per, et al.
(författare)
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Homogeneous assay for real-time and simultaneous detection of thymidine kinase 1 and deoxycytidine kinase activities
- 2013
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Ingår i: Analytical Biochemistry. - : Elsevier BV. - 0003-2697 .- 1096-0309. ; 432:2, s. 155-164
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Tidskriftsartikel (refereegranskat)abstract
- Measurement of thymidine kinase-1 (TK1) and deoxycytidine kinase (dCK) activity may be useful in cancer disease management. Therefore, a one-step homogeneous assay for real-time determination of TK1 and dCK was developed by combining enzyme complementation with fluorescent signal generation using primer extension and a quenched probe oligodeoxyribonucleotide system at 37 degrees C. Complementation, for producing dCTP and TIP from nucleoside substrates, was carried out by dTMP kinase and/or UMP/CMP kinase and nucleoside diphosphate kinase. dNTP was continuously incorporated into a fixed oligodeoxyribonucleotide primer, template, and probe system, and the fluorescent signal was generated by using the combined actions of primer extension and 5' exonuclease activity of Thermophilus aquaticus (Taq) DNA polymerase for specific relief of fluorescent quenching. Fluorescence was captured at 1-min intervals using a real-time polymerase chain reaction (PCR) instrument. A horizontal threshold line, crossing all sample relative fluorescent units (RFU) values at the level of the RFU of the blank sample at the end of the assay (i.e., 90 min), was drawn, obtaining RFU measurement data in minutes for each sample. Duplex proof of principle was demonstrated by the independent determination of different amounts of dCK and TK1 in combination. R-2 values of 0.90 were demonstrated with Prolifigen TK-REA U/L reference values obtained from pathological canine and human serum samples.
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| 2. |
- Andersson, Håkan S., 1967-, et al.
(författare)
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The toxicity of ribbon worms: alpha-nemertides or tetrodotoxin, or both?
- 2016
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Ingår i: Planta Medica. - : Georg Thieme Verlag KG. - 0032-0943 .- 1439-0221. ; 82:Supplement 1
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The marine ribbon worms (nemerteans) are predators which capture their prey by everting a proboscis carrying a mixture of toxins which brings on rapid paralysis [1]. Moreover, ribbon worms have a thick layer of epidermal mucus of similar constitution. Tetrodotoxin (TTX) has been identified as one of these toxins [2]. The extreme toxicity of TTX (lethal by ingestion of 0.5-2 mg) is due to its ability to block voltage-gated sodium channels. Although several bacterial species (among these Vibrio sp.) have been linked to its synthesis, the biogenic origin and biosynthesis is unclear. One hypothesis is that TTX production occurs in a symbiotic relationship with its host, in this case the ribbon worm [3]. We have made significant effort to identify TTX in a setup for production through the cultivation of Vibrio alginolyticus in nutrient broth infused with mucus from the ribbon worm Lineus longissimus. Toxicity was demonstrated by fraction injections into shore crabs, but no TTX was found, and it could be shown conclusively that toxicity was unrelated to TTX and the Vibrio culture itself, and rather a constituent of the ribbon worm mucus [4]. The following studies led us to the discovery of a new class of peptides, the alpha-nemertides, in the mucus of the ribbon worms, which could be directly linked to the toxic effects. A literature review of the available evidence for TTX in ribbon worms show that the evidence in most cases are indirect, although notable exceptions exist. This points to the necessity to further investigate the presence and roles of TTX and alpha-nemertides in ribbon worms.
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| 3. |
- Blanck, Hans, 1950, et al.
(författare)
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A retrospective analysis of contamination and periphyton PICT patterns for the antifoulant irgarol 1051, around a small marina on the Swedish west coast
- 2009
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Ingår i: Marine Pollution Bulletin. - : Elsevier BV. - 0025-326X .- 1879-3363. ; 58:2, s. 230-237
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Tidskriftsartikel (refereegranskat)abstract
- Irgarol is a triazine photosystem II (PSII) inhibitor that has been used in Sweden as an antifouling ingredient since the 1990´s. Early microcosm studies indicated that periphyton was sensitive to irgarol at concentrations regularly found in harbours and marinas. However, field studies of irgarol effects on the Swedish west coast in 1994, using the Pollution-Induced Community Tolerance (PICT) approach, failed to detect any effects of the toxicant in the field. A PICT study involves sampling of replicate communities in a gradient of contamination, and a comparison of their community tolerance levels, with an increase being an indication that sensitive species have been eliminated and replaced by more tolerant ones. Typically, short-term assays are used to quantify the community tolerance levels. Later PICT studies in the same area over a 10 year period demonstrate that irgarol tolerance levels have increased, although the contamination pattern has been stable. Our results support the hypothesis that that the PICT potential was low initially, due to a small differential sensitivity between the community members, and that a persistent selection pressure was required to favour and enrich irgarol tolerant species or genotypes.
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| 4. |
- Buratovic, Sonja, 1986-, et al.
(författare)
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Effects on adult cognitive function after neonatal exposure to clinically relevant doses of ionising radiation and ketamine in mice
- 2018
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Ingår i: British Journal of Anaesthesia. - : ELSEVIER SCI LTD. - 0007-0912 .- 1471-6771. ; 120:3, s. 546-554
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Tidskriftsartikel (refereegranskat)abstract
- Background: Radiological methods for screening, diagnostics and therapy are frequently used in healthcare. In infants and children, anaesthesia/sedation is often used in these situations to relieve the patients' perception of stress or pain. Both ionising radiation (IR) and ketamine have been shown to induce developmental neurotoxic effects and this study aimed to identify the combined effects of these in a murine model. Methods: Male mice were exposed to a single dose of ketamine (7.5 mg kg(-1) body weight) s.c. on postnatal day 10. One hour after ketamine exposure, mice were whole body irradiated with 50-200 mGy gamma radiation (Cs-137). Behavioural observations were performed at 2, 4 and 5 months of age. At 6 months of age, cerebral cortex and hippocampus tissue were analysed for neuroprotein levels. Results: Animals co-exposed to IR and ketamine displayed significant (P <= 0.01) lack of habituation in the spontaneous behaviour test, when compared with controls and single agent exposed mice. In the Morris Water Maze test, co-exposed animals showed significant (P <= 0.05) impaired learning and memory capacity in both the spatial acquisition task and the relearning test compared with controls and single agent exposed mice. Furthermore, in co-exposed mice a significantly (P <= 0.05) elevated level of tau protein in cerebral cortex was observed. Single agent exposure did not cause any significant effects on the investigated endpoints. Conclusion: Co-exposure to IR and ketamine can aggravate developmental neurotoxic effects at doses where the single agent exposure does not impact on the measured variables. These findings show that estimation of risk after paediatric low-dose IR exposure, based upon radiation dose alone, may underestimate the consequences for this vulnerable population.
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| 5. |
- Buratovic, Sonja, et al.
(författare)
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Neonatal exposure to a moderate dose of ionizing radiation causes behavioural defects and altered levels of tau protein in mice
- 2014
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Ingår i: Neurotoxicology. - : Elsevier BV. - 0161-813X .- 1872-9711. ; 45, s. 48-55
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Tidskriftsartikel (refereegranskat)abstract
- Medical use of ionizing radiation (IR) has great benefits for treatment and diagnostic imaging, butprocedures as computerized tomography (CT) may deliver a significant radiation dose to the patient.Recently, awareness has been raised about possible non-cancer consequences from low dose exposure toIR during critical phases of perinatal and/or neonatal brain development.In the present study neonatal NMRI mice were whole body irradiated with a single dose of gammaradiation (0; 350 and 500 mGy) on postnatal day 10 (PND 10). At 2 and 4 months of age, mice of bothsexes were observed for spontaneous behaviour in a novel home environment. The neuroproteinsCaMKII, GAP-43, synaptophysin and total tau in male mouse cerebral cortex and hippocampus wereanalysed 24 h post-irradiation and in adults at 6 months of age exposed to 0 or 500 mGy on PND 10.A significantly dose-response related deranged spontaneous behaviour in 2- and 4-month-old micewas observed, where both males and females displayed a modified habituation, indicating reducedcognitive function. The dose of 350 mGy seems to be a tentative threshold. Six-month-old male miceshowed a significantly increased level of total tau in cerebral cortex after irradiation to 500 mGy compared to controls. This demonstrates that a single moderate dose of IR, given during a defined criticalperiod of brain development, is sufficient to cause persistently reduced cognitive function. Moreover, anelevation of tau protein was observed in male mice displaying reduced cognitive function.
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| 6. |
- Callaghan, Terry, et al.
(författare)
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Multi-Decadal Changes in Tundra Environments and Ecosystems : Synthesis of the International Polar Year-Back to the Future Project (IPY-BTF)
- 2011
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Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 40:6, s. 705-716
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the responses of tundra systemsto global change has global implications. Most tundraregions lack sustained environmental monitoring and oneof the only ways to document multi-decadal change is toresample historic research sites. The International PolarYear (IPY) provided a unique opportunity for such researchthrough the Back to the Future (BTF) project (IPY project#512). This article synthesizes the results from 13 paperswithin this Ambio Special Issue. Abiotic changes includeglacial recession in the Altai Mountains, Russia; increasedsnow depth and hardness, permafrost warming, andincreased growing season length in sub-arctic Sweden;drying of ponds in Greenland; increased nutrient availabilityin Alaskan tundra ponds, and warming at mostlocations studied. Biotic changes ranged from relativelyminor plant community change at two sites in Greenland tomoderate change in the Yukon, and to dramatic increasesin shrub and tree density on Herschel Island, and in subarcticSweden. The population of geese tripled at one sitein northeast Greenland where biomass in non-grazed plotsdoubled. A model parameterized using results from a BTFstudy forecasts substantial declines in all snowbeds andincreases in shrub tundra on Niwot Ridge, Colorado overthe next century. In general, results support and provideimproved capacities for validating experimental manipulation,remote sensing, and modeling studies.
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| 7. |
- Ding, Jihua, et al.
(författare)
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GIGANTEA-like genes control seasonal growth cessation in Populus
- 2018
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Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 218:4, s. 1491-1503
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Tidskriftsartikel (refereegranskat)abstract
- Survival of trees growing in temperate zones requires cycling between active growth and dormancy. This involves growth cessation in the autumn triggered by a photoperiod shorter than the critical day length. Variations in GIGANTEA (GI)-like genes have been associated with phenology in a range of different tree species, but characterization of the functions of these genes in the process is still lacking. We describe the identification of the Populus orthologs of GI and their critical role in short-day-induced growth cessation. Using ectopic expression and silencing, gene expression analysis, protein interaction and chromatin immunoprecipitation experiments, we show that PttGIs are likely to act in a complex with PttFKF1s (FLAVIN-BINDING, KELCH REPEAT, F-BOX 1) and PttCDFs (CYCLING DOF FACTOR) to control the expression of PttFT2, the key gene regulating short-day-induced growth cessation in Populus. In contrast to Arabidopsis, in which the GI-CONSTANS (CO)-FLOWERING LOCUS T (FT) regulon is a crucial day-length sensor for flowering time, our study suggests that, in Populus, PttCO-independent regulation of PttFT2 by PttGI is more important in the photoperiodic control of growth cessation and bud set.
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| 8. |
- Eklöf, Johan S., 1978-, et al.
(författare)
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Effects of seasonal spawning closures on pike (Esox lucius L.) and perch (Perca fluviatilis L.) catches and coastal food webs in the western Baltic Sea
- 2023
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Ingår i: Fisheries Research. - : Elsevier BV. - 0165-7836 .- 1872-6763. ; 263
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Tidskriftsartikel (refereegranskat)abstract
- Marine protected areas have become one of the main tools in the battle to curb marine biodiversity loss and habitat degradation. Yet, implementation of permanent fishery closures has often generated resource user conflicts that ultimately undermine conservation goals. Here we assessed the influence of an alternative and often more accepted measure – seasonal fish spawning closures – on large predatory fish and coastal food webs in the western Baltic Sea (Sweden). In spring 2017, we conducted a multivariable field survey in 11 seasonal closures and 11 paired references areas open to fishing. In each area, pike was sampled through angling, and perch and mesopredators through gillnet surveys. To assess trophic cascades, we measured zooplankton abundance and loss of tethered gammarids from predation. Catches per unit effort of northern pike (Esox lucius) – the main target species in recreational fisheries – were ca. 2.5 times higher per unit effort in closures than reference areas; an effect that may be caused by higher abundance and/or higher catchability of pike in the absence of fishing. Catch and weight per unit effort of the more common predator European perch (Perca fluviatilus), and the mesopredators roach (Rutilus rutilus) and three-spined stickleback (Gasterosteus aculeatus) in survey nets were, however, unaffected by closures. Moreover, a previously hypothesized trophic cascade from perch to zooplankton via three-spined stickleback was supported by the analyses, but appeared independent of closures. Yet, predation risk for tethered gammarid amphipods (a prey of stickleback and an important grazer on macroalgae) was three times higher in fished areas than in closures; a cascading closure effect that may potentially be caused by small predatory fish being less active in protected areas to avoid pike predation. Overall, our results suggest that spawning closures impact pike abundance and/or behavior and could help limit the effects of fishing, but that more research is needed to disentangle i) what mechanism(s) that underlie the protection effect on pike catches, ii) the apparently weaker closure impacts on other fish species, as well as iii) the potential for cascading effects on lower trophic levels. Therefore, new seasonal spawning closures should be implemented in addition to (and not instead of) much-needed permanent closures, which have well-known effects on the wider ecosystem.
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| 9. |
- Fransson, Johan E.S., et al.
(författare)
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Estimation of Forest Stem Volume using ALOS-2 PALSAR-2 Satellite Images
- 2016
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Ingår i: Proceedings of 36th IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2016; Beijing; China; 10-15 July 2016. - 9781509033324 ; 2016-November, s. Art no 7730388, Pages 5327-5330
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Konferensbidrag (refereegranskat)abstract
- © 2016 IEEE. A first evaluation of ALOS-2 PALSAR-2 data for forest stem volume estimation has been performed at a coniferous dominated test site in southern Sweden. Both the Fine Beam Dual (FBD) polarization and the Quad-polarimetric mode were investigated. Forest plots with stem volume reaching up to a maximum of about 620 m 3 ha -1 (corresponding to 370 tons ha -1 ) were analyzed by relating backscatter intensity to field data using an exponential model derived from the Water Cloud Model. The estimation accuracy of stem volume at plot level (0.5 ha) was calculated in terms of Root Mean Square Error (RMSE). For the best case investigated an RMSE of 39.8% was obtained using one of the FBD HV-polarized images. The corresponding RMSE for the FBD HH-polarized images was 43.9%. In the Quad-polarimetric mode the lowest RMSE at HV- and HH-polarization was found to be 43.1% and 66.1%, respectively.
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| 10. |
- Gudmannsson, Petur, et al.
(författare)
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A Unique Fatal Moose Attack Mimicking Homicide
- 2018
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Ingår i: Journal of Forensic Sciences. - : John Wiley & Sons. - 0022-1198 .- 1556-4029. ; 63:2, s. 622-625
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Tidskriftsartikel (refereegranskat)abstract
- Fatalities caused by animal attacks are rare, but have the potential to mimic homicide. We present a case in which a moose attacked and killed a woman who was walking her dog in a forest. Autopsy showed widespread blunt trauma with a large laceration on one leg in which blades of grass were embedded. Flail chest was the cause of death. The case was initially conceived as homicide by means of a riding lawn mower. A review of the case by moose experts and analyses of biological trace material that proved to originate from moose, established the true source of injury. The dog probably provoked a moose, which, in response, stomped and gored the victim to death. The injuries resembled those previously reported from attacks by cattle and water buffalo. Fatal moose attacks constitute an extremely rare threat in boreal areas, but can be considered in traumatic deaths of unknown cause.
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