| 1. |
- Jönsson, K. Ingemar, 1959-, et al.
(författare)
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Sexual patterns of prebreeding energy reserves in the common frog Rana temporaria along a latitudinal gradient
- 2009
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Ingår i: Ecography. - : Wiley-Blackwell. - 0906-7590 .- 1600-0587. ; 32:5, s. 831-839
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Tidskriftsartikel (refereegranskat)abstract
- The ability to store energy is an important life history trait for organisms facing long periods without energy income, and in particular for capital breeders such as temperate zone amphibians, which rely on stored energy during reproduction. However, large scale comparative studies of energy stores in populations with different environmental constraints on energy allocation are scarce. We investigated energy storage patterns in spring (after hibernation and before reproduction) in eight common frog (Rana temporaria) populations exposed to different environmental conditions along a 1600 km latitudinal gradient across Scandinavia (range of annual activity period 3-7 months). Analyses of lean body weight (eviscerated body mass), weight of fat bodies, liver weight, and liver fat content, showed that (i) post-hibernation/pre-breeding energy stores increased with increasing latitude in both sexes, (ii) males generally had larger energy reserves than females and (iii) the difference in energy stores between sexes decreased towards the north. Larger energy reserves towards the north can serve as a buffer against less predictable and/or less benign weather conditions during the short activity period, and may also represent a risk-averse tactic connected with a more pronounced iteroparous life history. In females, the continuous and overlapping vitellogenic activity in the north may also demand more reserves in early spring. The general sexual difference could be a consequence of the fact that, at the time of our sampling, females had already invested their energy into reproduction in the given year (i.e. their eggs were already ovulated), while the males' main reproductive activities (e.g. calling, mate searching, sexual competition) occurred later in the season.
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| 2. |
- Nilsson, Fredrik, et al.
(författare)
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Efterord
- 2017
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Ingår i: Kulturhistoria. En etnologisk metodbok.. - 2001-7529. ; 13
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 3. |
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| 4. |
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| 5. |
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| 6. |
- Bornehag, Carl-Gustaf, 1957-, et al.
(författare)
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The SELMA study : a birth cohort study in Sweden following more than 2000 mother-child pairs
- 2012
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Ingår i: Paediatric and Perinatal Epidemiology. - Hoboken, USA : Wiley-Blackwell. - 0269-5022 .- 1365-3016. ; 26:5, s. 456-467
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Tidskriftsartikel (refereegranskat)abstract
- Background: This paper describes the background, aim and study design for the Swedish SELMA study that aimed to investigate the importance of early life exposure during pregnancy and infancy to environmental factors with a major focus on endocrine disrupting chemicals for multiple chronic diseases/disorders in offspring.Methods: The cohort was established by recruiting women in the 10th week of pregnancy. Blood and urine from the pregnant women and the child and air and dust from home environment from pregnancy and infancy period have been collected. Questionnaires were used to collect information on life styles, socio-economic status, living conditions, diet and medical history.Results: Of the 8394 reported pregnant women, 6658 were invited to participate in the study. Among the invited women, 2582 (39%) agreed to participate. Of the 4076 (61%) non-participants, 2091 women were invited to a non-respondent questionnaire in order to examine possible selection bias. We found a self-selection bias in the established cohort when compared with the non-participant group, e.g. participating families did smoke less (14% vs. 19%), had more frequent asthma and allergy symptoms in the family (58% vs. 38%), as well as higher education among the mothers (51% vs. 36%) and more often lived in single-family houses (67% vs. 60%).Conclusions: These findings indicate that the participating families do not fully represent the study population and thus, the exposure in this population. However, there is no obvious reason that this selection bias will have an impact on identification of environmental risk factors.
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| 7. |
- Hansén Nord, Karolin, et al.
(författare)
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Frequent deletion of the CDKN2A locus in chordoma: analysis of chromosomal imbalances using array comparative genomic hybridisation.
- 2008
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 1532-1827 .- 0007-0920. ; 98:2, s. 434-442
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Tidskriftsartikel (refereegranskat)abstract
- The initiating somatic genetic events in chordoma development have not yet been identified. Most cytogenetically investigated chordomas have displayed near-diploid or moderately hypodiploid karyotypes, with several numerical and structural rearrangements. However, no consistent structural chromosome aberration has been reported. This is the first array-based study characterising DNA copy number changes in chordoma. Array comparative genomic hybridisation (aCGH) identified copy number alterations in all samples and imbalances affecting 5 or more out of the 21 investigated tumours were seen on all chromosomes. In general, deletions were more common than gains and no high-level amplification was found, supporting previous findings of primarily losses of large chromosomal regions as an important mechanism in chordoma development. Although small imbalances were commonly found, the vast majority of these were detected in single cases; no small deletion affecting all tumours could be discerned. However, the CDKN2A and CDKN2B loci in 9p21 were homo- or heterozygously lost in 70% of the tumours, a finding corroborated by fluorescence in situ hybridisation, suggesting that inactivation of these genes constitute an important step in chordoma development.British Journal of Cancer (2008) 98, 434-442. doi:10.1038/sj.bjc.6604130 www.bjcancer.com Published online 11 December 2007.
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| 8. |
- Jönsson, K. Ingemar, 1959-, et al.
(författare)
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Ekologisk kompensation som styrmedel i kommunal planering
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Projektet har undersökt erfarenheter av och förutsättningar för att tillämpa ekologisk kompensation inom ramen för den kommunala planeringen. Inom olika delstudier har projektet undersökt ekologisk kompensation som styrmedel, tillämpningen av skadelindringshierarkin, utformningen av kompensationsmodeller och rutiner, användningen av olika modeller för beräkning av förluster och vinster inom kompensationsprojekt, samt allmänhetens preferenser för olika kompensationsalternativ. Projektet har genomförts i nära samarbete med Helsingborgs och Lomma kommun, och Kommunförbundet Skåne har varit projektets kommunikationspartner och arrangör av flera större möten och workshopar med tjänstemän från många kommuner i Skåne. ...
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| 9. |
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| 10. |
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| 11. |
- Al-Saadi, Munir, et al.
(författare)
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A study of the static recrystallization behaviour of cast Alloy 825 after hot-compressions
- 2019
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596.
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Konferensbidrag (refereegranskat)abstract
- The static recrystallization behaviour of a columnar and equiaxed Alloy 825 material was studied on a Gleeble-3800 thermo-simulator by single-hit compression experiments. Deformation temperatures of 1000-1200 °C, a strain of up to 0.8, a strain rate of 1s-1, and relaxation times of 30, 180, and 300 s were selected as the deformation conditions to investigate the effects of the deformation parameters on the SRX behaviour. Furthermore, the influences of the initial grain structures on the SRX behaviors were studied. The microstructural evolution was studied using optical microscopy and EBSD. The EBSD measurements showed a relaxation time of 95 % for fractional recrystallization grains, ?95, in both structures, was less than 30 seconds at the deformation temperatures 1100 °C and 1200 °C. However, fewer than 95% of recrystallized grains recrystallized when the deformation temperature was lowered to 1000 °C. From the grain-boundary misorientation distribution in statically recrystallized samples, the fraction of high-angle grain boundaries decreased with an increasing deformation temperature from 1000 °C to 1200 °C for a given relaxation time. This was attributed to grain coarsening
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| 12. |
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| 13. |
- Al-Saadi, Munir, et al.
(författare)
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Effect of Trace Magnesium Additions on the Dynamic Recrystallization in Cast Alloy 825 after One-Hit Hot-Deformation
- 2021
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Ingår i: Metals. - : MDPI AG. - 2075-4701. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Alloy 825 is widely used in several industries, but its useful service life is limited by both mechanical properties and corrosion resistance. The current work explores the effect of the addition of magnesium on the recrystallization and mechanical behavior of alloy 825 under hot compression. Compression tests were performed under conditions representative of typical forming processes: temperatures between 1100 and 1250 °C and at strain rates of 0.1–10 s−1 to a true strain of 0.7. Microstructural evolution was characterized by electron backscattered diffraction. Dynamic recrystallization was found to be more prevalent under all test conditions in samples containing magnesium, but not in all cases of conventional alloy 825. The texture direction ⟨101⟩ was the dominant orientation parallel to the longitudinal direction of casting (also the direction in which the samples were compressed) in samples that contained magnesium under all test conditions, but not in any sample that did not contain magnesium. For all deformation conditions, the peak stress was approximately 10% lower in material with the addition of magnesium. Furthermore, the differences in the peak strain between different temperatures are approximately 85% smaller if magnesium is present. The average activation energy for hot deformation was calculated to be 430 kJ mol−1 with the addition of magnesium and 450 kJ mol−1 without magnesium. The average size of dynamically recrystallized grains in both alloys showed a power law relation with the Zener–Hollomon parameter, DD~Z−n, and the exponent of value, n, is found to be 0.12. These results can be used to design optimized compositions and thermomechanical treatments of alloy 825 to maximize the useful service life under current service conditions. No experiments were conducted to investigate the effects of such changes on the service life and such experiments should now be performed.
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| 14. |
- Al-Saadi, Munir, et al.
(författare)
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Hot Deformation Behaviour and Processing Map of Cast Alloy 825
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Alloy 825 is a nickel-based alloy that is commonly used in applications where both high strength and corrosion resistance are required. Applications include tanks in the chemical, food and petrochemical industries and oil and gas pipelines. Components made from Alloy 825 are often manufactured using hot deformation. However, there is no systematic study to optimise the processing conditions reported in literature. In this study, a processing map for as-cast Alloy 825 is established to maximise the power dissipation efficiency of hot deformation and correlate the processing conditions to final materials properties. The hot deformation behaviour of equiaxed Alloy 825 is characterized on the basis of the dynamic materials model and compression data in the temperature range of 950 °C to 1250 °C at an interval of 50°C and strain rate range of 0.01 s-1 to 10 s-1 to a true strain of 0.7 using a Gleeble-3500 thermomechanical simulator. Flow stress is modelled by the constitutive equation based on a hyperbolic sine function. The deformed material is characterized using Vickers hardness, optical microscopy and scanning electron microscopy, including electron backscattered diffraction. The true stress-true strain curves exhibit peak stresses followed by softening due to occurrence of dynamic recrystallization. The value of stress exponent in the hyperbolic sine-based constitutive equation, n=5.0. This suggests that the rate-limiting mechanism of deformation is climb (diffusion)-mediated dislocation glide. The activation energy for plastic flow in the temperature range tested is about 450 kJ mole-1, and the relationship between flow stress and temperature-compensated strain rate (via the Zener-Hollomon parameter) was found to be valid across this temperature range. The maximum power dissipation efficiency is over 35%. The highest efficiency is observed over temperature range of 1100 °C – 1250 °C and a strain rate of 0.01 s-1 – 0.1s-1. These are the optimum conditions for hot working. The optimum processing parameters for good strain hardening are obtained in the temperature range of between 950 °C and 1100 °C with a strain rate between 0.3/s and 10.0/s.
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| 15. |
- Al-Saadi, Munir, et al.
(författare)
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Hot Deformation Behaviour and Processing Map of Cast Alloy 825
- 2021
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Ingår i: Journal of materials engineering and performance (Print). - : Springer Nature. - 1059-9495 .- 1544-1024.
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Tidskriftsartikel (refereegranskat)abstract
- Alloy 825 is a nickel-based alloy that is commonly used in applications where both high strength and corrosion resistance are required, such as tanks in the chemical, food and petrochemical industries and oil and gas pipelines. Components made from Alloy 825 are often manufactured using hot deformation. However, there is no systematic study to optimise the processing conditions reported in literature. In this study, a processing map for as-cast Alloy 825 is established to maximise the power dissipation efficiency of hot deformation in the temperature range of 950 to 1250 °C at an interval of 50 °C and strain rate range of 0.01s−1 to 10.0s−1 to a true strain of 0.7 using a Gleeble-3500 thermomechanical simulator. The processing conditions are also correlated to the Vickers hardness of the final material, which is also characterised using optical microscopy and scanning electron microscopy, including electron backscattered diffraction. The true stress-true strain curves exhibit peak stresses followed by softening due to occurrence of dynamic recrystallization. The activation energy for plastic flow in the temperature range tested is approximately 450 kJ mol−1, and the value of the stress exponent in the (hyperbolic sine-based) constitutive equation, n=5.0, suggests that the rate-limiting mechanism of deformation is dislocation climb. Increasing deformation temperature led to a lower Vickers hardness in the deformed material, due to increased dynamic recrystallization. Raising the strain rate led to an increase in Vickers hardness in the deformed material due to increased work hardening. The maximum power dissipation efficiency is over 35%, obtained for deformation in the temperature range 1100-1250 °C and a strain rate of 0.01s−1-0.1s−1. These are the optimum conditions for hot working.
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| 16. |
- Al-Saadi, Munir, et al.
(författare)
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Influence of Strain Magnitude on Microstructure, Texture and Mechanical Properties of Alloy 825 during hot-forging
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Alloy 825 is a nickel-base alloy that is common in applications with high stresses and corrosive environments. It is commonly processed by hot forging, but there are few data about how hot forging affects the microstructure, which is critical for both mechanical and corrosion performance. Here, the alloy was hot forged in a commercial thermomechanical process to three industrially-relevant strains and the microscture was examined using scanning electron microscopy and EBSD. The tensile properties were also measured after thermomechanical treatment. Dynamic recrystallization was prevalent during the process, so increasing the forging strain leads to smaller grains and also higher dislocation density. Data were combined to allow the 0.2% proof stress to be calculated as a function of forging strain. All forging strains were sufficient to meet the criteria of the relevant industrial standard for this material. The maximum yield strength and ultimate tensile strength were obtained after forging to a true strain of 0.9 were 413 MPa and 622 MPa, respecitvely, with a ductlity of 40%. This may be used to tailor thermomechanical treatments to achieve precise mechanical properties and serve as a basis for future studies into the corrosion performance of this alloy as a function of forging strain.
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| 17. |
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| 18. |
- Al-Saadi, Munir, et al.
(författare)
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Modelling of strengthening mechanisms in wrought nickel-based 825 alloy subjected to solution annealing
- 2021
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Ingår i: Metals. - Basel, Switzerland. : MDPI AG. - 2075-4701. ; 11:5, s. 771-20
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Tidskriftsartikel (refereegranskat)abstract
- Wrought nickel‐based Alloy 825 is widely used in the oil and gas industries, attributed toits high strength at temperatures up to 540 °C. However, differences in mechanical properties arisein finished components due to variations in both grain size and dislocation density. Numerous ex‐perimental studies of the strengthening mechanisms have been reported and many models havebeen developed to predict strengthening under thermomechanical processing. However, there aredebates surrounding some fundamental issues in modeling and the interpretation of experimentalobservations. Therefore, it is important to understand the evolution of strain within the materialduring the hot‐forging process. In addition, there is a lack of research around the behavior duringhot deformation and subsequent stabilization of Alloy 825. This article investigates the origin of thisstrength and considers a variety of strengthening mechanisms, resulting in a quantitative predictionof the contribution of each mechanism. The alloy is processed with a total forging strain of 0.45, 0.65,or 0.9, and subsequent annealing at a temperature of 950 °C, reflecting commercial practice. Themicrostructure after annealing is similar to that before annealing, suggesting that static recovery isdominant at this temperature. The maximum yield strength and ultimate tensile strength were348 MPa and 618 MPa, respectively, obtained after forging to a true strain of 0.9, with a ductility of40%. The majority of strengthening was attributed to grain refinement, the dislocation densities thatarise due to the large forging strain deformation, and solid solution strengthening. Precipitatestrengthening was also quantified using the Brown and Ham modification of the Orowan bowingmodel. The results of yield strength calculations are in excellent agreement with experimental data,with less than 1% difference. The interfacial energy of Ti(C,N) in the face‐centered cubic matrix of. These results can bethe current alloy has been assessed for the first time, with a value of 0.8 mJm−2used by future researchers and industry to predict the strength of Alloy 825 and similar alloys, es‐pecially after hot‐forging.
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| 19. |
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| 20. |
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| 21. |
- Alho, Jussi S., et al.
(författare)
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Increasing melanism along a latitudinal gradient in a widespread amphibian : local adaptation, ontogenic or environmental plasticity?
- 2010
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Ingår i: BMC Evolutionary Biology. - 1471-2148 .- 1471-2148. ; 10, s. 317-
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThe thermal benefits of melanism in ectothermic animals are widely recognized, but relatively little is known about population differentiation in the degree of melanism along thermal gradients, and the relative contributions of genetic vs. environmental components into the level of melanism expressed. We investigated variation in the degree of melanism in the common frog (Rana temporaria; an active heliotherm thermoregulator) by comparing the degree of melanism (i) among twelve populations spanning over 1500 km long latitudinal gradient across the Scandinavian Peninsula and (ii) between two populations from latitudinal extremes subjected to larval temperature treatments in a common garden experiment.ResultsWe found that the degree of melanism increased steeply in the wild as a function of latitude. Comparison of the degree of population differentiation in melanism (PST) and neutral marker loci (FST) revealed that the PST > FST, indicating that the differences cannot be explained by random genetic drift alone. However, the latitudinal trend observed in the wild was not present in the common garden data, suggesting that the cline in nature is not attributable to direct genetic differences.ConclusionsAs straightforward local adaptation can be ruled out, the observed trend is likely to result from environment-driven phenotypic plasticity or ontogenetic plasticity coupled with population differences in age structure. In general, our results provide an example how phenotypic plasticity or even plain ontogeny can drive latitudinal clines and result in patterns perfectly matching the genetic differences expected under adaptive hypotheses.
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| 22. |
- Alho, Jussi S., et al.
(författare)
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Increasing melanism along a latitudinal gradient in a widespread amphibian : local adaptation, ontogenic or environmental plasticity?
- 2010
-
Ingår i: BMC Evolutionary Biology. - : Springer Science and Business Media LLC. - 1471-2148. ; 10:1, s. 317-
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The thermal benefits of melanism in ectothermic animals are widely recognized, but relatively little is known about population differentiation in the degree of melanism along thermal gradients, and the relative contributions of genetic vs. environmental components into the level of melanism expressed. We investigated variation in the degree of melanism in the common frog (Rana temporaria; an active heliotherm thermoregulator) by comparing the degree of melanism (i) among twelve populations spanning over 1500 km long latitudinal gradient across the Scandinavian Peninsula and (ii) between two populations from latitudinal extremes subjected to larval temperature treatments in a common garden experiment. Results: We found that the degree of melanism increased steeply in the wild as a function of latitude. Comparison of the degree of population differentiation in melanism (P-ST) and neutral marker loci (F-ST) revealed that the P-ST >F-ST, indicating that the differences cannot be explained by random genetic drift alone. However, the latitudinal trend observed in the wild was not present in the common garden data, suggesting that the cline in nature is not attributable to direct genetic differences. Conclusions: As straightforward local adaptation can be ruled out, the observed trend is likely to result from environment-driven phenotypic plasticity or ontogenetic plasticity coupled with population differences in age structure. In general, our results provide an example how phenotypic plasticity or even plain ontogeny can drive latitudinal clines and result in patterns perfectly matching the genetic differences expected under adaptive hypotheses.
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| 23. |
- Amer, Eynas, et al.
(författare)
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Evaluation of Shock Tube Retrofitted with Fast-Opening Valve for Dynamic Pressure Calibration
- 2021
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Ingår i: Sensors. - : MDPI. - 1424-8220. ; 21:13
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Tidskriftsartikel (refereegranskat)abstract
- Accurate dynamic pressure measurements are increasingly important. While traceability is lacking, several National Metrology Institutes (NMIs) and calibration laboratories are currently establishing calibration capacities. Shock tubes generating pressure steps with rise times below 1 µs are highly suitable as standards for dynamic pressures in gas. In this work, we present the results from applying a fast-opening valve (FOV) to a shock tube designed for dynamic pressure measurements. We compare the performance of the shock tube when operated with conventional single and double diaphragms and when operated using an FOV. Different aspects are addressed: shock-wave formation, repeatability in amplitude of the realized pressure steps, the assessment of the required driver pressure for realizing nominal pressure steps, and economy. The results show that using the FOV has many advantages compared to the diaphragm: better repeatability, eight times faster to operate, and enables automation of the test sequences.
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| 24. |
- Amer, Eynas, et al.
(författare)
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Towards traceable dynamic pressure calibration using a shock tube with an optical probe for accurate phase determination
- 2022
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Ingår i: Metrologia. - : IOP Publishing. - 0026-1394 .- 1681-7575. ; 59:3
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we introduce a robust method for dynamic characterization of pressure measuring systems used in time-varying pressure applications. The dynamic response of the pressure measuring systems in terms of sensitivity and phase as a function of frequency at various amplitudes of the measurand can be provided. The shock tube which is the candidate primary standard for dynamic pressure calibration at the National Laboratory for pressure, Sweden, was used to realize the dynamic pressure. The shock tube setup used in this study can realize reference pressure with amplitudes up to 1.7 MPa in the frequency range from below a kilohertz up to a megahertz. The amplitude of the realized step pressure was calculated using the Rankine–Hugoniot step relations. In addition, the accurate time of arrival of the generated shock at the device under test (DUT) was measured using an optical probe based on shadowgraphy. The optical detector has a response time in nanosecond time scale which is several orders of magnitude faster than the response time of any pressure measuring system. Hereby, the latency between physical stimuli and response of the DUT can be measured. By the knowledge of the amplitude and the accurate time of arrival of the reference step pressure, the transfer function of the DUT can be calculated and presented in Bode diagrams of sensitivity and phase response versus frequency. The uncertainty in sensitivity and phase measurements was estimated. The information provided by this work is useful for developing reliable models of dynamic pressure measuring system and provide accurate information about their dynamic response. That in turn will contribute to establish a traceability chain for dynamic pressure calibration.
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| 25. |
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| 26. |
- Arshamian, Artin, 1979-, et al.
(författare)
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Sniff Your Way to Clarity : The Case of Olfactory Imagery
- 2008
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Ingår i: CHEMOSENSORY PERCEPTION. - : Springer Science and Business Media LLC. - 1936-5802 .- 1936-5810. ; 1:4, s. 242-246
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Tidskriftsartikel (refereegranskat)abstract
- This study addressed the effects of blocking spontaneous sniffing during olfactory imagery. A group of subjects (n=40) who scored high in olfactory focus and imagery ability rated the vividness in olfactory and visual imagery content under conditions of blocked sniffing, blocked vision, and a nonblocked control. The imagery stimuli consisted of 90 common words that could represent either an odor or a visual object. Blocked sniffing was expected to impair olfactory imagery vividness, but since visual imagery entails eye movements, which was not affected by the ""blocked vision"" manipulation, visual imagery ratings were effectively used as a placebo control. Confirming our hypotheses, the results showed that preventing sniffing resulted in a selectively poorer olfactory but not visual vividness, whereas blocked vision showed no effect on either the visual or olfactory vividness ratings. These observations confirm that sensorimotor activity is an important aspect for the quality of evoked olfactory images.
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| 27. |
- Berggren, Fredrik, et al.
(författare)
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Dynamic Spectrum Access, Phase 1 Scenarios and research challenges
- 2004
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The currently used mechanisms for spectrum management are a contributing factor to the long lead times from innovation to market in wireless technologies andsystems. This has in turn been a major contributing factor to the dominance of the large telecom companies in the European and World markets, whereas very few innovative enterprises have exhibited consistent growth, although the technicalcompetence in Sweden is very high in this area. Alternative spectrum management regimes, such as the introduction of "unlicensed bands" have proven very effective in lowering entry thresholds for smaller companies (e.g the WLAN business). In addition, experts claim that the spectrum requirements for communication purposes will increase by as much as 200-300 % up to 2010. At the same time the actual usage of the electromagnetic spectrum is very inefficient.The project aims at studying new more, flexible, spectrum allocation regimeswhich, in combination with new technologies, such as multi-radio access, novelbroadband access techniques, software defined radio and spatial techniques (e.g.smart antennas, multi-hop schemes) have the potential of lowering the entry thresholds for new actors and provide radical improvement to the efficiency ofspectrum usage. Further the aim is to investigate the economic and regulatory consequences of such Dynamic Spectrum Access technologies and managementregimes. The results will provide input to future policies in spectrum management. The project has been divided into a first, pre-study phase and a second, research phase. The first phase was launched in Dec of 2004 and the second phase is planned to start in Jan 2005. The first phase of the project, reported here, has the aim toprovide a qualitative assessment of the potential benefits of dynamic spectrum access regimes. The analysis in the report and other studies in the area, indeed indicate there is a potential to both lower the entry thresholds for new actors as well as provide radical improvement to the efficiency of spectrum usage. The area isdefinitely of significant issues and the project should be continued studying the DSA concepts in more detail.Further, using a systematic procedure, a number of critical areas and bottleneck problems were identified. Our conclusion is that more research is needed in theseareas to achieve the above mentioned benefits. As `side effect' in this procedure, a number of novel and interesting spectrum management concepts were derived, e.g.the `real-time spectrum trading' and `use rights' concepts. Out of this gross list ofinterest problems, a number of highly important problems were selected, matching the competence of the project team. These problems are proposed to be the focus ofthe next phase in the project.Finally, the report provides an overview of the most important ongoing research and policy-making activities in the DSA-area.
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| 28. |
- Bergh, Jonas, et al.
(författare)
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FACT : An Open-Label Randomized Phase III Study of Fulvestrant and Anastrozole in Combination Compared With Anastrozole Alone as First-Line Therapy for Patients With Receptor-Positive Postmenopausal Breast Cancer
- 2012
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Ingår i: Journal of Clinical Oncology. - Alexandria, VA : American Society of Clinical Oncology. - 0732-183X .- 1527-7755. ; 30:16, s. 1919-1925
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To compare the effect of therapy with anastrozole versus a combination of fulvestrant and anastrozole in women in first relapse of endocrine-responsive breast cancer. Patients and Methods: Postmenopausal women, or premenopausal women receiving a gonadotropin-releasing hormone agonist, with estrogen receptor– and/or progesterone receptor–positive disease at first relapse after primary treatment of localized disease were open-label randomly assigned to a fulvestrant loading dose (LD) regimen followed by monthly injection plus 1 mg of anastrozole daily or to 1 mg of anastrozole daily alone. The primary end point was time to progression (TTP). Results: In all, 514 women were randomly assigned to fulvestrant plus anastrozole (experimental arm; n = 258) or anastrozole (standard arm; n = 256). Approximately two thirds had received adjuvant antiestrogens, but only eight individuals had received an aromatase inhibitor. Median TTP was 10.8 and 10.2 months in the experimental versus standard arm, respectively (hazard ratio [HR] = 0.99; 95% CI, 0.81 to 1.20; P = .91); median overall survival was 37.8 and 38.2 months, respectively (HR = 1.0; 95% CI, 0.76 to 1.32; P = 1.00). Incidences of prespecified adverse events (AEs) were similar. Hot flashes were more common in the experimental arm: 63 patients (24.6%) versus 35 patients (13.8%) in the standard arm (P = .0023). Death owing to AEs was reported in 11 (4.3%) and five patients (2.0%) in the experimental versus standard arm, respectively. Conclusion: Fulvestrant (250 mg + LD regimen) in combination with anastrozole offered no clinical efficacy advantage over anastrozole monotherapy in this population of individuals with a relatively high proportion of previous adjuvant antiestrogen exposure.
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| 29. |
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| 30. |
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| 31. |
- Bergkvist, John, et al.
(författare)
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Modelling managed forest ecosystems in Sweden : An evaluation from the stand to the regional scale
- 2023
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Ingår i: Ecological Modelling. - : Elsevier BV. - 0304-3800. ; 477
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Tidskriftsartikel (refereegranskat)abstract
- Incorporation of a forest management module in the dynamic vegetation model LPJ-GUESS has allowed the study and predictions of management treatment effects on the carbon cycle and on forest ecosystem structure. In this study, LPJ-GUESS is evaluated at the regional scale against observational data from the Swedish National Forest Inventory. Simulated standing volume is compared against observations for the four most common forest types in the country. Furthermore, eddy-covariance flux measurements from the Integrated Carbon Observation System (ICOS) are used to evaluate model predictions of net ecosystem exchange (NEE), gross primary productivity (GPP) and ecosystem respiration (Reco) at the site scale. The model results suggest an adequate representation of standing volume in monocultures of Norway spruce and Scots pine for regional simulations in southern and central Sweden, after an updated parameterization of the species. For northern Sweden, the standing volume in Norway spruce monocultures was overestimated with the updated parameter values. At the stand scale, the model produced mixed results for carbon fluxes when evaluated against eddy-covariance data for two sites, one in central and one in southern Sweden. The interannual variation of GPP was well captured for the central Swedish site, but the modelled average GPP for the period 2015–2019 was overestimated by 9%. For the southern Swedish site, GPP was underestimated by 15% for the corresponding period and the simulated interannual variation was half of the observed. The seasonal estimates of modelled net ecosystem exchange (NEE) deviated from observations and the simulated standing volume was underestimated by 25% for both sites. The results highlight further potential to perform species-specific calibration to capture latitudinal gradients in key ecosystem properties, and to incorporate additional characteristics of site quality which could benefit model accuracy at the scale of individual forest stands, both regarding simulated carbon fluxes and forest stand variables.
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| 32. |
- Bergkvist, John, et al.
(författare)
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Modelling managed forest ecosystems in Sweden : Poster presentation
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this work, the forestry-enabled dynamic vegetation model LPJ-GUESS was used to simulate forest standing volume for the three main regions of Sweden. At the regional scale, the model results were evaluated against observational data from the Swedish National Forest Inventory. Carbon fluxes of net ecosystem exchange (NEE), gross primary productivity (GPP), and ecosystem respiration (Reco) were simulated at the local scale on a daily time step for two sites in Sweden and results were evaluated against data from the Integrated Carbon Observation System (ICOS). The model produced adequate results of standing volume in monocultures of Norway spruce and Scots pine for southern and central Sweden, after an updated parameterization of the species. Stand-scale simulations of carbon fluxes produced mixed results after an evaluation against EC data from ICOS.
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| 33. |
- Bina, Pavel, et al.
(författare)
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Awareness, views and experiences of Citizen Science among Swedish researchers — two surveys
- 2021
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Ingår i: JCOM - Journal of Science Communication. - : Sissa Medialab Srl. - 1824-2049. ; 20:06
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Tidskriftsartikel (refereegranskat)abstract
- In 2021 Sweden’s first national portal for citizen science will be launched to help researchers practice sustainable and responsible citizen science with different societal stakeholders. This paper present findings from two surveys on attitudes and experiences of citizen science among researchers at Swedish universities. Both surveys provided input to the development of the national portal, for which researchers are a key stakeholder group. The first survey (n=636) was exclusively focused on citizen science and involved researchers and other personnel at Swedish University of Agricultural Science (SLU). 63% of respondents at SLU had heard about citizen science (CS) prior to the survey; however a majority of these (61%) had not been involved in any CS initiative themselves. Dominant reasons for researchers choosing a CS approach in projects were to enable collection of large amounts of data (68%), improving the knowledge base (59%), improving data quality (25%), promote participants’ understanding in research (21%) and promote collaboration between the university and society (20%). The other survey (n=3 699) was on the broader topic of communication and open science, including questions on CS, and was distributed to researchers from all Swedish universities. 61% of respondents had not been engaged in any research projects where volunteers were involved in the process. A minority of the researchers had participated in projects were volunteers had collected data (18%), been involved in internal or external communication (16%), contributed project ideas (14%) and/or formulated research questions (11%). Nearly four out of ten respondents (37%) had heard about CS prior to the survey. The researchers were more positive towards having parts of the research process open to citizen observation, rather than open to citizen influence/participation. Our results show that CS is a far from well-known concept among Swedish researchers. And while those who have heard about CS are generally positive towards it, researchers overall are hesitant to invite citizens to take part in the research process.
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| 34. |
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| 35. |
- Blennow, Kristina, et al.
(författare)
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Implementing storm damage in a dynamic vegetation model for regional applications in Sweden
- 2012
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Ingår i: Ecological Modelling. - : Elsevier BV. - 0304-3800 .- 1872-7026. ; 247, s. 71-82
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Tidskriftsartikel (refereegranskat)abstract
- Wind is the dominant agent of damage in forests in Western Europe. Traditional wind-damage models calculate a probability for damage or a critical wind speed at which damage occurs. However, in a dynamic vegetation model actual damage to stands and individual trees is needed to get a dynamical progression of the vegetation. We present a prototype for a new approach to modelling forest wind damage at the regional scale, which we incorporate within a dynamic vegetation model. The approach is based on knowledge from both empirical and mechanical models and calculates the damaged fraction of a cohort based on wind load and a sensitivity that depends on the current physical state and history of the cohort in relation to the ecosystem. The modelling concept has been developed, calibrated and evaluated for Swedish conditions but can be applicable to other similar areas with minor modification. Because of the stochastic nature of local wind load and the difficulty of describing the stand-level exposure, the ability to explain observed damage at stand level was low. Regional level variation in damage, which more depends on the wind load, was however explained reasonably well (R-2 = 0.43). We suggest that this is a useful concept for evaluating alternatives of forest management under different climate scenarios in the process of adaptation to future storm-damage risks. (C) 2012 Elsevier B.V. All rights reserved.
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| 36. |
- Borch, Kurt, 1944-, et al.
(författare)
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Prevalence of coeliac disease and relations to Helicobacter pylori infection and duodenitis in a Swedish adult population sample : A histomorphological and serological survey
- 2000
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Ingår i: InflammoPharmacology. - : Springer Science and Business Media LLC. - 0925-4692 .- 1568-5608. ; 8:4, s. 341-350
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Tidskriftsartikel (refereegranskat)abstract
- Aim: The aim of this study was to determine the prevalence of coeliac disease and its relation to duodenitis, H. pylori infection and gastritis in a sample of the adult general population. Methods: A Swedish population sample of 482 subjects (aged 35 to 85 years) were examined with gastro-duodenoscopy with multiple biopsies taken. Circulating antibodies to endomycium, gliadin, and H. pylori were also determined. Results: Based on histomorphological findings, coeliac disease was evident in 9 of 482 subjects giving a prevalence of 1.9 [1.0-4.0, 95% confidence interval] percent. The prevalence of gastritis with or without H. pylori infection did not differ between subjects with and without coeliac disease. Considering subjects without coeliac disease, there was no difference in the serum levels of gliadin antibodies between those with and without duodenitis. However, subjects with positive H. pylori status had significantly higher levels of gliadin antibodies than those with negative H. pylori status. Conclusions: This study confirms that there is a relatively high prevalence of undiagnosed coeliac disease in Swedish adults. There was no association between coeliac disease and H. pylori infection or gastritis, although serum gliadin antibody levels were slightly increased in subjects with positive H. pylori status.
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| 37. |
- Borch, Kurt, 1944-, et al.
(författare)
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Prevalence of gastroduodenitis and Helicobacter priori infection in a general population sample : relations to symptomatology and life-style
- 2000
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Ingår i: Digestive Diseases and Sciences. - 0163-2116 .- 1573-2568. ; 45:7, s. 1322-1329
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Tidskriftsartikel (refereegranskat)abstract
- Some benign and malignant diseases develop on the background of chronic gastritis or duodenitis. The present study was performed in order to determine the magnitude of these background changes with relations to symptomatology and life style in the general population. Examinations were performed in 501 volunteers (age 35–85 years). Fifty percent had gastritis; this was associated with H. pylori in 87%. H. pylori-negative gastritis was associated with regular use of NSAIDs [odds ratio 3.8 (1.6–9.9)]. Duodenitis, observed in 32%, was associated with H. pylori infection [odds ratio 2.3 (1.3–4.6)], previous cholecystectomy [odds ratio 3.6 (1.1–16.1)], and regular use of NSAIDs [odds ratio 3.0 (1.4–7.1)]. Neither gastritis nor duodenitis was associated with smoking or alcohol consumption. The rate of digestive symptoms did not differ between subjects with and without uncomplicated gastritis or duodenitis. In conclusion, half of this adult population had gastritis strongly associated with H. pylori infection. Gastritis without H. pylori infection was frequently associated with regular NSAID intake. One third had duodenitis, which was associated with H. pylori infection as well as with regular use of NSAIDs and previous cholecystectomy. Digestive symptoms were not overrepresented in uncomplicated gastritis or duodenitis.
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| 38. |
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| 39. |
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| 40. |
- Bornehag, Carl-Gustaf, 1957-, et al.
(författare)
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Prenatal Phthalate Exposures and Anogenital Distance in Swedish Boys
- 2015
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Ingår i: Journal of Environmental Health Perspectives. - : Environmental Health Perspectives. - 0091-6765 .- 1552-9924. ; 123:1, s. 101-107
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Phthalates are used as plasticizers in soft polyvinyl chloride (PVC) and in a large number of consumer products. Because of reported health risks, diisononyl phthalate (DiNP) has been introduced as a replacement for di(2-ethylhexyl) phthalate (DEHP) in soft PVC. This raises concerns because animal data suggest that DiNP may have antiandrogenic properties similar to those of DEHP. The anogenital distance (AGD)-the distance from the anus to the genitals-has been used to assess reproductive toxicity. OBJECTIVE: The objective of this study was to examine the associations between prenatal phthalate exposure and AGD in Swedish infants. METHODS: AGD was measured in 196 boys at 21 months of age, and first-trimester urine was analyzed for 10 phthalate metabolites of DEP (diethyl phthalate), DBP (dibutyl phthalate), DEHP, BBzP (benzylbutyl phthalate), as well as DiNP and creatinine. Data on covariates were collected by questionnaires. RESULTS: The most significant associations were found between the shorter of two AGD measures (anoscrotal distance; AGDas) and DiNP metabolites and strongest for oh-MMeOP [mono(4-methyl-7-hydroxyloctyl) phthalate] and oxo-MMeOP [mono-(2-ethyl-5-oxohexyl) phthalate]. However, the AGDas reduction was small (4%) in relation to more than an interquartile range increase in DiNP exposure. CONCLUSIONS: These findings call into question the safety of substituting DiNP for DEHP in soft PVC, particularly because a shorter male AGD has been shown to relate to male genital birth defects in children and impaired reproductive function in adult males and the fact that human levels of DiNP are increasing globally.
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| 41. |
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| 42. |
- Bornehag, Carl-Gustaf, et al.
(författare)
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Response to Risotto et al.
- 2013
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Ingår i: Indoor Air. ; 23, s. 87-88
-
Tidskriftsartikel (refereegranskat)
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| 43. |
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| 44. |
- Cato, Ville, et al.
(författare)
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Association between benzodiazepines and suicide risk : a matched case-control study
- 2019
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Ingår i: BMC Psychiatry. - : BMC. - 1471-244X. ; 19:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: It is unclear whether benzodiazepines increase the risk of suicide. The aim of this study was to test the hypothesis that benzodiazepines are associated with an increased risk of suicide, by comparing psychopharmacological interventions between psychiatric patients who committed suicide and a group of matched controls.Methods: The case group comprised 154 psychiatric patients (101 men, 53 women; age range: 13-96 years) who had committed suicide in orebro County, Sweden. Control psychiatric patients matched by age, sex, and main psychiatric diagnosis were selected for each case. Binary logistic regression was used to calculate odds ratios in unadjusted and adjusted models.Results: Benzodiazepine prescriptions were more common among cases than controls (65/154 [42.2%] versus 43/154 [27.9%], p = 0.009, odds ratio: 1.89 [95% CI: 1.17-3.03]). This association remained significant in a model adjusted for previous suicide attempts and somatic hospitalizations (odds ratio: 1.83 [95% CI: 1.06-3.14]). No statistically significant differences were seen between the groups in the use of any other subtype of psychopharmaceutical agent.Conclusions: These data indicate that benzodiazepine use may increase the risk of suicide. However, this study is limited by the potential for indication bias.
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| 45. |
- Chen, Eric, et al.
(författare)
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Computer Constructions of Good Codes
- 2021
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- error control coding is a standard method to improve reliabability in data stroage and data communications. in this presentation, computer construtions of good linear codes are discussed.
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| 46. |
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| 47. |
- Chen, Eric, et al.
(författare)
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New good quasi-cyclic codes and codes with improved minimum distance
- 2023
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Ingår i: Journal of Algebra Combinatorics Discrete Structures and Applications. - : Jacodesmath Institute. - 2148-838X. ; 10:1, s. 39-44
-
Tidskriftsartikel (refereegranskat)abstract
- One of the most important and challenging problems in coding theory is to construct codes with optimal parameters. As a generalization of cyclic codes, quasi-cyclic (QC) codes as well as quasi-twisted (QT) codes have been shown to contain record-breaking codes. In this paper, various computer algorithms have been used to search for good QC codes. A lot of good new QC codes have been found and they have been used to construct new linear codes. A total 11 new codes that improve the bound on the minimum distance are presented.
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| 48. |
- Chen, Eric, et al.
(författare)
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New results and bounds on codes over GF (17)
- 2023
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Ingår i: Journal of Algebra Combinatorics Discrete Structures and Applications. - : Jacodesmath Institute. - 2148-838X. ; 11:1, s. 27-39
-
Tidskriftsartikel (refereegranskat)abstract
- Determining the best possible values of the parameters of a linear code is one of the most fundamental and challenging problems in coding theory. There exist databases of best-known linear codes (BKLC) over small finite fields. In this work, we establish a database of BKLCs over the field GF (17) together with upper bounds on the minimum distances for lengths up to 150 and dimensions up to 6. In the process, we have found many new linear codes over GF (17).
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| 49. |
- Chen, Eric, et al.
(författare)
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New Two-Weight Code Construction Using CPlex
- 2023
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- two-weight codes are interesting, since they can be used to construct strongly regular graphs, secret sharing schemes, etc. In this presenation, computer construction using optimization software CPlex is discussed and new two-weight codes are presented.
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| 50. |
- Chukharkin Leonidovich, Maxim, 1980, et al.
(författare)
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Improvement of Ultra-Low Field Magnetic Resonance Recordings With a Multilayer Flux-Transformer-Based High-T-C SQUID Magnetometer
- 2013
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Ingår i: Ieee Transactions on Applied Superconductivity. - : Institute of Electrical and Electronics Engineers (IEEE). - 1051-8223 .- 1558-2515. ; 23:3
-
Tidskriftsartikel (refereegranskat)abstract
- We have developed a multilayer flux-transformer-based high-T-C SQUID (flip-chip) magnetometer that improves signal-to-noise-ratios (SNR) in ultra-low field magnetic resonance (ulf-MR) recordings of protons in water. Direct ulf-MR-based benchmarking of the flip-chip versus a standard planar high-T-C SQUID magnetometer resulted in improvement of the SNR by a factor of 2. This gain is attributable to the improved transformation coefficient (1.9 vs 5.3 nT/Phi(0)) that increased the signal available to the flip-chip sensor and to the lower noise at the measurement frequency (15 vs 25 fT/Hz(1/2) at 4 kHz). The improved SNR can lead to better spectroscopic resolution, lower imaging times, and higher resolution in ulf-MR imaging systems based on high-T-C SQUID technology. The experimental details of the sensors, calibration, and ulf-MR benchmarking are presented in this report.
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