| 1. |
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| 2. |
- Carlson, Annika, et al.
(författare)
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Kinetic parameters in anion-exchange membrane fuel cells
- 2019
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Ingår i: ECS Transactions. - : Electrochemical Society Inc.. - 1938-6737 .- 1938-5862. - 9781607685395 ; , s. 649-659
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Konferensbidrag (refereegranskat)abstract
- Understanding limitations in an operating AEMFC is essential to .enhance the technology. Here the electrode processes are studied experimentally as well as by two physics-based models taking the porosity of the electrodes into account. The aim is to use the models to determine kinetic parameters specific for in-situ operation. The models can also be used to explain the experimental .behavior. From the impedance model of a symmetric H2/H2 cell it is shown that the hydrogen oxidation reaction (HOR) proceeds through the Tafel-Volmer reaction pathway, with the hydrogen adsorption as the slower reaction step. Based on the HOR model a •steady-state model of an O2/H2 cell is used to evaluate data from 14 experimental I-V curves, obtained for different gas partial pressures and catalyst loadings, in order to study the effects of the oxygen reduction reaction and overall cell limitations. The results show that the oxygen reduction reaction kinetics limit the cell performance for low current densities. However, at higher currents the uneven current distribution and locally low hydrogen adsorption at the anode increasingly affect the overall performance. Uneven current distribution is also observed at the cathode and likely caused by insufficient effective ionomer conductivity.
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| 3. |
- Carlson, Annika, et al.
(författare)
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The Hydrogen Electrode Reaction in the Anion Exchange Membrane Fuel Cell
- 2021
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Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 0013-4651 .- 1945-7111. ; 168:3
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Tidskriftsartikel (refereegranskat)abstract
- The hydrogen electrode in the anion-exchange membrane fuel cell needs further attention to understand the overall cell limitations. In this study, electrochemical impedance spectroscopy and galvanodynamic measurements in combination with a physics-based model are used to determine the kinetic parameters of the hydrogen oxidation reaction and hydrogen evolution reaction on Pt/C porous gas-diffusion electrodes in an AEMFC. Two semicircles are observed in the Nyquist plot of a symmetrical AEM hydrogen cell, indicating a two-step reaction pathway. The fit of the model shows that the Tafel-Volmer pathway describes the kinetics better than the Heyrovsky-Volmer pathway. The reaction rates of the adsorption and charge transfer steps are similar in magnitude implying that both need consideration during modeling and evaluation of the hydrogen electrode. Furthermore, the performance is limited also by the ionic conductivity in the electrode. Comparison of the impedance of the HOR and a hydrogen/oxygen AEMFC indicates that the low-frequency semicircle is mainly associated with the oxygen reduction reaction and the cathode, while the high-frequency semicircle is likely related to a combination of the anode and the cathode. Based on this work, a platform for further studies of losses and total impedance of operating AEMFC has been created.
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| 4. |
- Ekman, Inger, 1952, et al.
(författare)
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The person-centred approach to an ageing society
- 2013
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Ingår i: European Journal for Person Centered Healthcare. - : University of Buckingham Press. - 2052-5656 .- 2052-5648. ; 1:1, s. 132-137
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Tidskriftsartikel (refereegranskat)abstract
- Modern care is often based on investigations such as laboratory markers and imaging - for example, x-ray or ultrasound. The results contribute to a diagnosis and, if judged necessary, treatment is initiated. This diseased-oriented approach is the prevailing mode of management in modern medicine. In contrast, person-centered care (PCC) takes the point of departure from each person´s subjective experience of illness and its impact on daily life. A patient is considered as a person with emotions and feelings. PCC is considered present within clinical care according to a definition articulated by the Centre for Person Centred Care at the University of Gothenburg (GPCC) when three core components are present: elicitation of a detailed patient narrative; formulated partnership between caregiver and patient and documentation of the partnership in the patient record. Accordingly, when there is an illness requiring care and the person is attended using these components, PCC is being applied. In most situations today, PCC is not applied as the narrative is not fully elicited or the partnership and/or the documentation are not included. It is proposed that the challenge to Society arising from changing demographics can be addressed by implementing PCC and creating an alternative to existing healthcare. The importance and benefits of such an approach on a wider scale is not yet clear as research has been limited to date. Studies in selected patient populations (heart failure and hip fractures), however, have shown promising results. As the population ages, there will be a dramatic increase in healthcare consumption. Even with technological developments, there will be a need for tremendous resources to be dedicated to care. A new organization and attitude from healthcare policymakers and providers above and beyond the present model appears required in order to respond to this demand. As part of such change, person-centred care, with the interaction between healthcare providers and the person of the patient, can facilitate, compensate and develop more effective healthcare services for the future.
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| 5. |
- Eriksson, Björn, et al.
(författare)
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Quantifying water transport in anion exchange membrane fuel cells
- 2019
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Ingår i: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 44:10, s. 4930-4939
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Tidskriftsartikel (refereegranskat)abstract
- Sufficient water transport through the membrane is necessary for a well-performing anion exchange membrane fuel cell (AEMFC). In this study, the water flux through a membrane electrode assembly (MEA), using a Tokuyama A201 membrane, is quantified using humidity sensors at the in- and outlet on both sides of the MEA. Experiments performed in humidified inert gas at both sides of the MEA or with liquid water at one side shows that the aggregation state of water has a large impact on the transport properties. The water fluxes are shown to be approximately three times larger for a membrane in contact with liquid water compared to vaporous. Further, the flux during fuel cell operation is investigated and shows that the transport rate of water in the membrane is affected by an applied current. The water vapor content increases on both the anode and cathode side of the AEMFC for all investigated current densities. Through modeling, an apparent water drag coefficient is determined to −0.64, indicating that the current-induced transport of water occurs in the opposite direction to the transport of hydroxide ions. These results implicate that flooding, on one or both electrodes, is a larger concern than dry-out in an AEMFC.
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| 6. |
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| 7. |
- Grimler, Henrik, et al.
(författare)
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Determination of Kinetic Parameters for the Oxygen Reduction Reaction on Platinum in an AEMFC
- 2021
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Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 0013-4651 .- 1945-7111. ; 168:12, s. 124501-
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Tidskriftsartikel (refereegranskat)abstract
- To promote the development of anion exchange membrane fuel cells (AEMFC), an understanding of the oxygen reduction reaction (ORR) kinetics in porous gas diffusion electrodes is essential. In this work, experimental polarisation curves for electrodes with different platinum catalyst loadings and oxygen partial pressures at the cathode are fitted to a physics-based porous electrode model in the voltage range from open circuit voltage (OCV) to 0.7 V. Polarisation curves measured with different anode catalyst loadings, and hydrogen partial pressures, were used to verify the model. The reactions are described using a two-step Tafel-Volmer pathway at the anode and concentration-dependent Butler-Volmer kinetics at the cathode. A good fit to experimental data in the kinetic region is obtained with an exchange current density of 1.0.10(-8)Acm(-2), a first order dependency on oxygen partial pressure, and a charge transfer coefficient of 0.8 for the ORR. For lower oxygen partial pressure, hydrogen crossover is needed to explain the downward shift of the polarisation curves in the kinetic region. In the experimental data, the polarisation curves show an apparent limiting current density at lower hydrogen partial pressures, explained by the lower rate of the Tafel step at these conditions.
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| 8. |
- Grimler, Henrik, et al.
(författare)
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Modelling electrode and membrane processes in an anion-exchange membrane fuel cell
- 2017
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Ingår i: EFC 2017 - Proceedings of the 7th European Fuel Cell Piero Lunghi Conference. - : ENEA. ; , s. 127-128
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Konferensbidrag (refereegranskat)abstract
- To better understand which processes that limits the performance in an anion-exchange membrane fuel cell (AEMFC), a physical performance model has been developed. The model considers a tertiary current distribution and is validated against experimental results. The results show that both the anode and the cathode contributes to significant polarisation in the system.
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| 9. |
- Grimler, Henrik, et al.
(författare)
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Water diffusion, drag and absorption in an anion-exchange membrane fuel cell
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Water is a key factor in anion-exchange membrane fuel cells, since it is botha product, reactant, and humidifies the membrane and ionomer phase. Toenable anion-exchange membrane fuel cells, knowledge about the water trans-port properties is needed, so that operating conditions can be optimised toprevent cathode dry-out or anode flooding. In this work, the water trans-port across an AemionTM membrane is quantified for different applied waterpartial pressure differences and current densities, with the help of humiditysensors. Two membrane thicknesses, 25 and 50 μm, are studied, as well astwo gas diffusion layers of different hydrophobicity: Sigracet 25BC which hasbeen PTFE treated to make it more hydrophobic, and Freudenberg H23C2which has not been PTFE treated, and is hence more hydrophilic. The re-sults show that having a hydrophilic GDL on the cathode and a hydrophobicGDL on the anode gives both the highest electrochemical performance, andthe highest water transport, while a hydrophilic GDL on both sides give thelowest electrochemical performance and the lowest water transport. A wa-ter transport model considering absorption/desorption resistance, electroos-motic drag and diffusion was deployed. The best fit was obtained with adrag coefficient close to two and 30 % increased absorption/desorption ratefor a hydrophobic GDL compared to a hydrophilic one.
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| 10. |
- Herbertsson, Lina, et al.
(författare)
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Bees increase seed set of wild plants while the proportion of arable land has a variable effect on pollination in European agricultural landscapes
- 2021
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Ingår i: Plant Ecology and Evolution. - : Societe Royale de Botanique de Belgique. - 2032-3913 .- 2032-3921. ; 154:3, s. 341-350
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Tidskriftsartikel (refereegranskat)abstract
- Background and aims: Agricultural intensification and loss of farmland heterogeneity have contributed to population declines of wild bees and other pollinators, which may have caused subsequent declines in insect-pollinated wild plants.Material and methods: Using data from 37 studies on 22 pollinator-dependent wild plant species across Europe, we investigated whether flower visitation and seed set of insect-pollinated plants decline with an increasing proportion of arable land within 1 km.Key results: Seed set increased with increasing flower visitation by bees, most of which were wild bees, but not with increasing flower visitation by other insects. Increasing proportion of arable land had a strongly variable effect on seed set and flower visitation by bees across studies.Conclusion:Factors such as landscape configuration, local habitat quality, and temporally changing resource availability (e.g. due to mass-flowering crops or honey bee hives) could have modified the effect of arable land on pollination. While our results highlight that the persistence of wild bees is crucial to maintain plant diversity, we also show that pollen limitation due to declining bee populations in homogenized agricultural landscapes is not a universal driver causing parallel losses of bees and insect-pollinated plants.
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| 11. |
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| 12. |
- Lundgren, Henrik, et al.
(författare)
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Thermal Management of Large-Format Prismatic Lithium-Ion Battery in PHEV Application
- 2016
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Ingår i: Journal of the Electrochemical Society. - : Electrochemical Society. - 0013-4651 .- 1945-7111. ; 163:2, s. A309-A317
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Tidskriftsartikel (refereegranskat)abstract
- Thermal effects are linked to all main barriers to the widespread commercialization of lithium-ion battery powered vehicles. This paper presents a coupled 2D electrochemical - 3D thermal model of a large-format prismatic lithium-ion battery, including a thermal management system with a heat sink connected to the surface opposite the terminals, undergoing the dynamic current behavior of a plug-in hybrid electric (PHEV) vehicle using a load cycle with a maximum current of 8 C, validated using potential and temperature data. The model fits the data well, with small deviations at the most demanding parts of the cycle. The maximum temperature increase and temperature difference of the jellyroll is found to be 9.7 degrees C and 3.6 degrees C, respectively. The electrolyte is found to limit the performance during the high-current pulses, as the concentration reaches extreme values, leading to a very uneven current distribution. Two other thermal management strategies, short side and long side surfaces cooling, are evaluated but are found to have only minor effects on the temperature of the jellyroll, with maximum jellyroll temperatures increases of 9.4 degrees C and 8.1 degrees C, respectively, and maximum temperature differences of 3.7 degrees C and 5.0 degrees C, respectively.
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| 13. |
- Moberg, Christina, et al.
(författare)
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De unga gör helt rätt när de stämmer staten
- 2022
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Ingår i: Aftonbladet. - 1103-9000.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
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| 14. |
- Nystrup, Peter, et al.
(författare)
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Dynamic Allocation or Diversification : A Regime-Based Approach to Multiple Assets
- 2017
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Ingår i: Journal of Portfolio Management. - : Pageant Media US. - 0095-4918 .- 2168-8656. ; 44:2, s. 62-73
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Tidskriftsartikel (refereegranskat)abstract
- This article investigates whether regime-based asset allocation can effectively respond to changes in financial regimes at the portfolio level in an effort to provide better long-term results when compared to a static 60/40 benchmark. The potential benefit from taking large positions in a few assets at a time comes at the cost of reduced diversification. The authors analyze this trade-off in a multi-asset universe with great potential for static diversification. The regime-based approach is centered around a regime-switching model with time-varying parameters that can match financial markets’ behavior and a new, more intuitive way of inferring the hidden market regimes. The empirical results show that regime-based asset allocation is profitable, even when compared to a diversified benchmark portfolio. The results are robust because they are based on available market data with no assumptions about forecasting skills.
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| 15. |
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| 16. |
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| 17. |
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| 18. |
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| 19. |
- Ahlford, Marianne, et al.
(författare)
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Uppsala Underdogs - A Robot Soccer Project
- 2006
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Rapport (populärvet., debatt m.m.)abstract
- In this paper, we describe the four-legged soccer team Uppsala Underdogs developed by a group of 4th year computer science students at Uppsala University during the fall of 2004. The project is based on the experience from two similar previous projects. This year the emphasis of the project has been on distribution of data and on support for evaluation and reconfiguration of strategies. To support data distribution, a middleware has been developed, which implements a replication algorithm and provides a clean interface for the other software modules (or behaviors). To enable easy reconfiguration of strategies, an automata-based graphical description language has been developed, which can be compiled into code that uses the database and the lower level modules, such as tactics and positioning, to make decisions and control the robot. In addition, a graphical simulator has been developed in which the strategies can be evaluated.
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| 20. |
- Allen-Perkins, Alfonso, et al.
(författare)
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CropPol : a dynamic, open and global database on crop pollination
- 2022
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Ingår i: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 103:3
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Tidskriftsartikel (refereegranskat)abstract
- Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open and global database on crop pollination. It contains measurements recorded from 202 crop studies, covering 3,394 field observations, 2,552 yield measurements (i.e. berry weight, number of fruits and kg per hectare, among others), and 47,752 insect records from 48 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (32 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (34.22% counts), bumblebees (19.19%), flies other than Syrphidae and Bombyliidae (13.18%), other wild bees (13.13%), beetles (10.97%), Syrphidae (4.87%), and Bombyliidae (0.05%). Locations comprise 34 countries distributed among Europe (76 studies), Northern America (60), Latin America and the Caribbean (29), Asia (20), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-05 (21 studies), 2006-10 (40), 2011-15 (88), and 2016-20 (50). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date, and we encourage researchers to add more datasets to this database in the future. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY-NC-SA). This article is protected by copyright. All rights reserved.
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| 21. |
- Andersson, G., et al.
(författare)
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Arthropod populations in a sub-arctic environment facing climate change over a half-century: variability but no general trend
- 2022
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Ingår i: Insect Conservation and Diversity. - : Wiley. - 1752-458X .- 1752-4598. ; 15:5, s. 534-542
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Tidskriftsartikel (refereegranskat)abstract
- Dramatic declines of some arthropod populations have recently received a lot of attention. Identified declines have mainly been attributed to changes in agriculture, climate, pathogen prevalence and light pollution, as well as cross-regional effects of, e.g., drifting pesticides. However, the overall picture is complex and debated, and there is a need for systematically collected long-term data, not least from areas relatively unaffected by humans. We monitored the abundance of arthropods (mainly insects) in subalpine birch forest in Swedish Lapland over a period of 53 years (1968-2020), in an area comparatively unaffected by human activities. Arthropod abundance was assessed by yearly systematic counts on 24,000 birch shoots, in the second half of June. Animals were categorised into 17 different groups directly upon counting, dependent on taxonomy and life stage (imago, larva). Overall, there was no significant change in arthropod numbers. Nor did estimates of the total biomass of arthropods (using group-specific indices of the mass of individuals) show any significant trend. Accordingly, there are no signs that the arthropod abundance or biomass on birch in this subarctic study site has gone through the same declines as have been reported from sites in other habitats. The reason may be that the impact of factors identified worldwide as drivers of arthropod declines so far are small or non-existent because of the low human population density in this area.
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| 22. |
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| 23. |
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| 24. |
- Bakx, Tristan, et al.
(författare)
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Areas of high conservation value support specialist forest birds
- 2023
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Ingår i: Ecosphere. - 2150-8925. ; 14:6
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Tidskriftsartikel (refereegranskat)abstract
- Scientists have deemed existing protected areas in European forests insufficient to halt and reverse biodiversity loss resulting from ongoing intensification of management. In Sweden, protected areas are therefore complemented with the so-called areas of high conservation value (AHCVs), that is, landscapes encompassing both protected and assumed biodiversity-valuable areas as well as surrounding land, where managers should pay increased attention to biodiversity. However, it is not known whether AHCVs are chosen so that the species they are intended to benefit inhabit such AHCVs to a higher degree. We investigated whether the occurrence and abundance of bird species that may be particularly vulnerable to intense forest management were higher in Swedish forest landscapes proposed as AHCVs compared with other forest landscapes. To this end, we fitted a joint species distribution model to bird count data for 70 forest bird species from a standardized Swedish bird monitoring scheme. Twelve of the 20 forest specialists (60%) were detected to occur more often inside AHCVs than outside, whereas no forest specialist was less likely to occur inside AHCVs. For forest generalists, the corresponding figures were 28% and 18%, respectively. Six of 15 red-listed species (40%) were detectably more likely to occur inside AHCVs. The relationship between AHCV status of landscapes and the abundance of individual species was not as consistently negative or positive. The higher occurrence of specialists and threatened species inside AHCVs than outside of them suggests that if managed correctly, AHCVs are important habitat for a considerable part of the specialized forest avifauna in Sweden. We conclude that AHCVs represent an opportunity for designing green infrastructure benefitting Swedish forest biodiversity.
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| 25. |
- Bakx, Tristan R.M., et al.
(författare)
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Farmland birds occupying forest clear-cuts respond to both local and landscape features
- 2020
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127. ; 478
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Tidskriftsartikel (refereegranskat)abstract
- Agricultural landscapes have changed fast in Europe, which has led to steep declines in farmland biodiversity. While this has differentially impacted “farmland species”, some of these seem to be able to use alternative man-made open habitats in forests, such as forest clear-cuts and powerline rights-of-way. We investigated the use of clear-cuts by two historically declining farmland birds, the Yellowhammer (Emberiza citrinella) and the Red-backed Shrike (Lanius collurio), to determine both local and landscape habitat characteristics of clear-cuts used for breeding. Among 101 clear-cuts visited in Scania, southern Sweden, 27% were occupied by Yellowhammers and 12% by Red-backed Shrikes. Yellowhammer occurrence in clear-cuts was positively related to local spruce cover (the planted tree species). There was also an interaction between clear-cut size and the proportion of farmland in the landscape, such that the positive effect of the proportion of farmland nearby was stronger for larger clear-cuts. Red-backed Shrike occurrence was positively related to clear-cut size and the local presence of piles of forest residues (tops and branches). The relation between occurrence and the proportion of clear-cuts in the landscape was positive for small clear-cuts and negative for larger ones. Yellowhammers and Red-backed shrikes are affected by both the local habitat structure in the clearcut and on the composition of the surrounding landscape, most likely because they use the clear-cut for nesting and the surroundings as complementary feeding habitat. To what extent clear-cuts as complementary breeding habitat to farmland may contribute to the conservation of Yellowhammers and Red-backed shrikes, as well as other farmland birds, is a promising path for future investigations.
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| 26. |
- Blasi, Maria, et al.
(författare)
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Evaluating predictive performance of statistical models explaining wild bee abundance in a mass-flowering crop
- 2021
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Ingår i: Ecography. - : Wiley. - 0906-7590 .- 1600-0587. ; 44:4, s. 525-536
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Tidskriftsartikel (refereegranskat)abstract
- Wild bee populations are threatened by current agricultural practices in many parts of the world, which may put pollination services and crop yields at risk. Loss of pollination services can potentially be predicted by models that link bee abundances with landscape-scale land-use, but there is little knowledge on the degree to which these statistical models are transferable across time and space. This study assesses the transferability of models for wild bee abundance in a mass-flowering crop across space (from one region to another) and across time (from one year to another). The models used existing data on bumblebee and solitary bee abundance in winter oilseed rape fields, together with high-resolution land-use crop-cover and semi-natural habitats data, from studies conducted in five different regions located in four countries (Sweden, Germany, Netherlands and the UK), in three different years (2011, 2012, 2013). We developed a hierarchical model combining all studies and evaluated the transferability using cross-validation. We found that both the landscape-scale cover of mass-flowering crops and permanent semi-natural habitats, including grasslands and forests, are important drivers of wild bee abundance in all regions. However, while the negative effect of increasing mass-flowering crops on the density of the pollinators is consistent between studies, the direction of the effect of semi-natural habitat is variable between studies. The transferability of these statistical models is limited, especially across regions, but also across time. Our study demonstrates the limits of using statistical models in conjunction with widely available land-use crop-cover classes for extrapolating pollinator density across years and regions, likely in part because input variables such as cover of semi-natural habitats poorly capture variability in pollinator resources between regions and years.
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| 27. |
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| 28. |
- Christensson, Anders, et al.
(författare)
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Serum cystatin C is a more sensitive and more accurate marker of glomerular filtration rate than enzymatic measurements of creatinine in renal transplantation.
- 2003
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Ingår i: Nephron Physiology. - : S. Karger AG. - 1660-2137. ; 94:2, s. 19-27
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Tidskriftsartikel (refereegranskat)abstract
- <i>Background/Aims:</i> Serum creatinine has several drawbacks as marker of glomerular filtration rate (GFR), and therefore serum cystatin C has been proposed as a more optimal GFR marker. Previous reports have suggested benefits of serum cystatin C measurements in patients with renal transplants. The purpose of the present study was to evaluate the diagnostic accuracy of cystatin C measurements compared with enzymatic creatinine measurements as serum markers of GFR (established from plasma clearance of iohexol) in a large cohort of stable renal transplant recipients and in the early postoperative phase. <i>Methods:</i> Renal transplant patients (n = 125) with stable graft function were evaluated from reciprocals of serum creatinine and cystatin C compared with iohexol clearance. Fourteen patients were examined immediately after the onset of renal function. Cystatin C was measured by a particle-enhanced turbidimetric method and creatinine by an enzymatic method. <i>Results:</i> In stable renal transplant recipients, serum cystatin C showed a significantly (p = 0.033) closer correlation (r = 0.89 or 79% co-variance) with iohexol clearance than did serum creatinine (r = 0.81 or 66% co-variance). Using the χ<sup>2</sup> test and a cut-off at 60 ml/min/1.73 m<sup>2</sup>, serum cystatin C levels demonstrated significantly higher sensitivity for early GFR impairment (p = 0.0045) compared with serum creatinine measurements. On the first day after transplantation, serum cystatin C fell more rapidly than serum creatinine. <i>Conclusion:</i> Serum cystatin C levels correlate significantly closer to accurate measurements of GFR and are significantly more sensitive to detect early GFR impairment than enzymatic measurements of creatinine in serum.
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| 29. |
- Danielsson, Henrik, Professor, 1974-
(författare)
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Randomiserade kontrollerade studier av interventionsprogram för elever med tidiga läs- och matematiksvårigheter
- 2023
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Ingår i: Resultatdialog 2023. - : Vetenskapsrådet. - 9789189845107 ; , s. 15-18
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Forskningens syfte var att utveckla och utvärdera två interventioner för elever med tidiga lässvårigheter eller tidiga mattesvårigheter. Resultaten visade att bägge interventionerna hade en medelstor till stor effekt på förbättring för interventionsgrupperna direkt efter interventionerna. Ett år efter interventionerna hade de flesta av de positiva effekterna minskat till ungefär hälften.
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| 30. |
- de Rojas, I., et al.
(författare)
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Common variants in Alzheimer’s disease and risk stratification by polygenic risk scores
- 2021
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Genetic discoveries of Alzheimer’s disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery n = 409,435 and validation size n = 58,190). Here, we add six variants associated with Alzheimer’s disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimer’s disease patients in APOE ɛ4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimer’s disease. © 2021, The Author(s).
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| 31. |
- Dänhardt, Juliana, et al.
(författare)
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Ekosystemtjänster i det skånska jordbrukslandskapet
- 2013
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Rapport (populärvet., debatt m.m.)abstract
- Jordbrukslandskapet tillhandahåller ekosystemtjänster som utgör förutsättningen för en uthållig jordbruksproduktion och är till nytta för samhället i stort. Bakom dessa finns ekologiska processer som beror av samspel mellan en mångfald av organismer. Skånes jordbruk har genomgått betydande förändringar som förändrat landskapet och livsmiljön för många av dessa. För att bevara och förvalta ekosystemtjänsterna krävs en förståelse för sambanden mellan jordbruk, landskap och ekosystemprocesser. Rapporten beskriver ekologiska processer som ligger till grund för några viktiga ekosystemtjänster i Skånes jordbrukslandskap och visar betydelsen av biologisk mångfald för deras funktion. Där så är möjligt beskrivs hur de kan värderas. Slutligen redovisas praktiska åtgärder som gynnar dem. Rapporten visar att ekosystemtjänster inte enkelt går att ersätta med teknologiska lösningar, utan att förvaltning av dessa tjänster lönar sig. Detta kräver ökad ekologisk kunskap och anpassade styrmedel vilket kräver ökat samråd och regelbunden återkoppling mellan lantbrukare, myndigheter och forskare. Förhoppningen är att rapporten, framtagen av Lunds universitet och Region Skåne, inspirerar till detta!
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| 32. |
- Dänhardt, Juliana, et al.
(författare)
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Farmland as stopover habitat for migrating birds - effects of organic farming and landscape structure
- 2010
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Ingår i: Oikos. - : Wiley. - 1600-0706 .- 0030-1299. ; 119:7, s. 1114-1125
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Tidskriftsartikel (refereegranskat)abstract
- Agricultural intensification in Europe has affected farmland bird populations negatively, both during summer and winter. Although the migratory period poses separate challenges on birds than breeding and wintering, the consequences of farming practices for birds during migration remain poorly investigated. We monitored abundance and species richness of migratory birds in autumn at matched pairs of organic and conventional farms situated either in intensively farmed open plains (homogeneous landscapes) or in small-scale farming landscapes (heterogeneous landscapes) in southern Sweden. Total bird density did not differ between landscape types but was marginally higher on organic compared to conventional farms. When including taxonomic status in the model (passerines vs non-passerines), we found significantly more birds on organic farms, and more non-passerines in the homogeneous landscapes. The effect of farming practice and landscape type on density differed between functional groups. Omnivore density was higher in the homogeneous landscapes, and invertebrate feeders were marginally more abundant on organic farms. The effects of farming practice on the overall species richness and on the density of granivorous birds were landscape dependent. In the homogeneous landscapes, organic farms held a higher number of species and density of granivorous birds than conventional farms, but there was no such difference in the heterogeneous landscapes. Thus, organic farming can enhance abundance and species richness of farmland birds during migration, but the effect differs between landscape types and species. The effectiveness of organic farming was highest in the homogeneous landscape making it important to promote organic farming there. However, for some species during migration, increased heterogeneity in homogeneous landscapes may have negative effects. We propose that migratory bird diversity in homogeneous landscapes may be best preserved by keeping the landscape open, but that a reduced agricultural intensity, such as organic farming, should be encouraged.
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| 33. |
- Enquist, Per-Anders, et al.
(författare)
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Derivatives of 8-hydroxyquinoline-antibacterial agents that target intra- and extracellular Gram-negative pathogens
- 2012
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Ingår i: Bioorganic & Medicinal Chemistry Letters. - : Elsevier. - 0960-894X .- 1464-3405. ; 22:10, s. 3550-3553
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Tidskriftsartikel (refereegranskat)abstract
- Small molecule screening identified 5-nitro-7-((4-phenylpiperazine-1-yl-)methyl)quinolin-8-ol INP1750 as a putative inhibitor of type III secretion (T3S) in the Gram-negative pathogen Yersinia pseudotuberculosis. In this study we report structure-activity relationships for inhibition of T3S and show that the most potent compounds target both the extracellular bacterium Y. pseudotuberculosis and the intracellular pathogen Chlamydia trachomatis in cell-based infection models.
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| 34. |
- Erlström, Mikael, et al.
(författare)
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Stratigraphy and geothermal assessment of Mesozoic sandstone reservoirs in the Öresund Basin - exemplified by well data and seismic profiles
- 2018
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Ingår i: Bulletin of the Geological Society of Denmark. - 0011-6297. ; 66, s. 123-149
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Tidskriftsartikel (refereegranskat)abstract
- The Øresund Basin in the transnational area between Sweden and Denmark forms a marginal part of the Danish Basin. The structural outline and stratigraphy of the Mesozoic succession is described, and a novel interpretation and description of the subsurface geology and geothermal potential in the North Sjælland Half-graben is presented. The subsurface bedrock in the basin includes several Mesozoic intervals with potential geothermal sandstone reservoirs. Parts of the succession fulfill specific geological requirements about distribution, composition and quality of the sandstones. A characterisation of these is presently of great interest in the attempt to identify geothermal reservoirs suitable for district heating purposes. The results presented in this paper include for the first time a comprehensive description of the stratigraphic intervals as well as the characteristics of the potential Mesozoic geothermal reservoirs in the Øresund region, including their distribution, composition and physical properties. This is illustrated by seismic cross-sections and well sections. In addition, results from analyses and evaluations of porosity, permeability, formation fluids and temperature are presented. Six potential geothermal reservoirs in the Mesozoic succession are described and assessed. Primary focus is placed on the characteristics of the reservoirs in the Lower Triassic and Rhaetian–Lower Jurassic succession. The study shows that the Mesozoic reservoir sandstones vary considerably with respect to porosity and permeability. Values range between 5–25% for the pre-Rhaetian Triassic sandstones, but are commonly > 25% for the Rhaetian–Lower Jurassic and Lower Cretaceous sandstones. The corresponding permeability rarely reaches above 500 mD for the pre-Rhaetian Triassic reservoirs, but often reach >1 Darcy for the Rhaetian–Lower Jurassic and the Lower Cretaceous sandstones. The interpreted formation temperatures for the reservoirs in the Øresund Basin are: 45–50°C at 1500 m, 60–70°C at 2000 m and 70–90°C at 2500 m depth . The combined results provide a geological framework for making site specific predictions regarding appraisal of viable geothermal projects for district heating purposes in the region as well as reducing the risk of unsuccessful wells
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| 35. |
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| 36. |
- Fredholm, Hanna, et al.
(författare)
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Long-term outcome in young women with breast cancer : a population-based study
- 2016
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Ingår i: Breast Cancer Research and Treatment. - : Springer Science and Business Media LLC. - 0167-6806 .- 1573-7217. ; 160:1, s. 131-143
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Tidskriftsartikel (refereegranskat)abstract
- Whether young age at diagnosis of breast cancer is an independent risk factor for death remains controversial, and the question whether young age should be considered in treatment decisions is still to be answered. From a population-based cohort of 22,017 women with breast cancer, all women < 35 years (n = 471) were compared to a random sample of 700 women aged 35-69 years from the same cohort. Information on patient and tumor characteristics, treatment, and follow-up was collected from the medical records. Tissue microarrays were produced for analysis of classical biomarkers. Breast cancer-specific survival (BCSS), distant disease-free survival (DDFS), and locoregional recurrence-free survival (LRFS) by age were compared using women 50-69 years as reference. At 10 years follow-up, women < 35 years and 35-39 years had a worse BCSS [age < 35 years 69 % (HR 2.75, 95 % CI 1.93-3.94), age 35-39 years 76 % (HR 2.33, 95 % CI 1.54-3.52), age 40-49 years 84 % (HR 1.53, 95 % CI 0.97-2.39), and age 50-69 years 89 % (reference)]. The worse BCSS was statistically significant in stages I-IIa and Luminal B tumors. At multivariate analysis age < 35 years and 35-39 years confined a risk in LRFS (HR 2.13, 95 % CI 1.21-3.76 and HR 1.97, 95 % CI 1.06-3.68) but not in DDFS and BCSS. In the subgroup of women < 40 years with luminal tumors stage I-IIa, low age remained an independent risk factor also in DDFS (HR 1.87, 95 % CI 1.03-3.44). Young women have a high risk of systemic disease even when diagnosed in an early stage. The excess risk of relapse is most pronounced in Luminal B tumors, where low age is an independent prognostic factor of DDFS and LRFS.
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| 37. |
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| 38. |
- Giordano, Giuseppe Nicola, et al.
(författare)
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Social capital and health-Purely a question of context?
- 2011
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Ingår i: Health and Place. - : Elsevier BV. - 1873-2054 .- 1353-8292. ; 17, s. 946-953
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Tidskriftsartikel (refereegranskat)abstract
- Debate still surrounds which level of analysis (individual vs. contextual) is most appropriate to investigate the effects of social capital on health. Applying multilevel ecometric analyses to British Household Panel Survey data, we estimated fixed and random effects between five individual-, household- and small area-level social capital indicators and general health. We further compared the variance in health attributable to each level using intraclass correlations. Our results demonstrate that association between social capital and health depends on indicator type and level investigated, with one quarter of total individual-level health variance found at the household level. However, individual-level social capital variables and other health determinants appear to influence contextual-level variance the most.
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| 39. |
- Giordano, Giuseppe Nicola, et al.
(författare)
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Testing the association between social capital and health over time: a family-based design.
- 2013
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Ingår i: BMC Public Health. - : Springer Science and Business Media LLC. - 1471-2458. ; 13:Jul,17
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Tidskriftsartikel (refereegranskat)abstract
- The past decade has seen a vast increase in empirical research investigating associations between social capital and health outcomes. Literature reviews reveal 'generalized trust' and 'social participation' to be the most robust of the commonly used social capital proxies, both showing positive association with health outcomes. However, this association could be confounded by unmeasured factors, such as the shared environment. Currently, there is a distinct lack of social capital research that takes into account such residual confounding.
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| 40. |
- Grimler, Henrik
(författare)
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Limiting processes in anion-exchange membrane fuel cells
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Fuel cells allow for converting chemical energy stored in hydrogen into electrical energy, with only heat and water as by-products. In a sustainable energy society, hydrogen may play an important role due to its ability to act both as an energy carrier and as a valuable chemical in the process industry. The main remaining obstacles for widely available commercial fuel cells are durability and cost. One way to potentially decrease the cost is to change the fuel cell environment to an alternative chemistry by replacing the proton-exchange membrane (PEM) with an anion-exchange membrane (AEM). This thesis studies the anode reaction, the cathode reaction and water transport in an anion-exchange membrane fuel cell (AEMFC), to investigate where its performance limitations lies in the system. Electrochemical characterisation techniques together with physics-based modelling have been utilised.The results from the study of the anode, shows that the hydrogen reaction proceeds through the Tafel-Volmer pathway, with the Tafel step starting to limit the reaction as the anode overpotential increases. Combining the anode model with a Butler-Volmer expression for the cathode reaction made it possible to model a H2:O2 fuel cell. Comparing the losses from the different processes in the fuel cell shows that the cathode is still the main contributor, but that the anode contribution cannot be neglected when predicting the fuel cell performance. Low ionic conductivity in the electrode was also identified as responsible for part of the overall resistances, leading to uneven current distribution in the catalyst layers and bad utilisation of the catalytic material.Investigating the water transport properties of AEMs showed that not only electroosmotic drag and diffusion, but also an absorption/desorption step between gas phase and membrane phase, are necessary to get a model that can explain the experimental observations. The choice of gas diffusion layers (GDLs) used on the anode and cathode was found to be of similar importance on the water transport as doubling the membrane thickness, showing that not only the membrane is important for water transport. Under most realistic conditions, the risk of local dry-out in a cell was found to be low, as water readily diffuses from the high humidity side of the membrane to the low humidity side.
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| 41. |
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| 42. |
- Gunnarsson, Frida, et al.
(författare)
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Comagotchi - a social toy
- 2001
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Ingår i: Reprints from the PCC Summer School.
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Konferensbidrag (refereegranskat)
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| 43. |
- Gutting, Alicia, 1986-
(författare)
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The Nuclear Rhine : Conflict and Cooperation in a Transnational River Basin
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The water and nuclear energy sectors are intricately and interdependently entwined. In this thesis, the relationship between water and nuclear energy is being examined specifically in the Rhine River basin from the 1950s to the contemporary period. Through a series of four research articles, this work scrutinises the complex interaction between nuclear development and water management, emphasising the critical yet often undervalued role of water in the nuclear energy sector. This investigation gains particular relevance in the context of climate change, which heightens the environmental impact of nuclear power as well as the vulnerability of nuclear power plants to extreme weather events, such as heatwaves.A central thesis argument is the contemporary societal undervaluation of water for nuclear energy, contrasted with its more recognised value in the mid-20th century. This shift in perception is especially pertinent as extreme weather conditions underscore the need to reassess water's worth. Employing a transnational and interconnected approach, this research challenges conventional national narratives and underscores the significance of cooperative and shared resource management along the Rhine. This paradigm serves as a blueprint for future transnational collaborations, particularly within the European sphere.The analysis explores various facets of water-nuclear-interactions, including the selection of riverine sites for nuclear power plants, the challenges and conflicts arising from these decisions, and specific case studies on risk perception, water diplomacy, and the sustainability of nuclear power in the age of climate change. These discussions are not only rooted in historical analysis but also engage with contemporary debates about the environmental sustainability of nuclear energy and its role in a future marked by increasing climatic uncertainties.In summary, this thesis offers a novel perspective on the dynamic relationship between water and nuclear energy, advocating for a renewed appreciation of water as a crucial but limited resource. It highlights the necessity for sustainable, forward-thinking approaches to nuclear energy development. As we confront the challenges of climate change, the insights from this research present valuable lessons on the importance of transnational cooperation, comprehensive risk assessment, and the meticulous consideration of environmental impacts in shaping future energy policy. Thus, this work illuminates the past while providing guidance for navigating the complex interdependencies between water and nuclear energy in the future.
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| 44. |
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| 45. |
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| 46. |
- Hansson, L-A, et al.
(författare)
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A synthesis of animal movement across scales
- 2014
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Ingår i: Animal Movement Across Scales. - : Oxford University Press. - 9780199677184 ; , s. 259-267
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Bokkapitel (refereegranskat)abstract
- This chapter aims at synthesizing the knowledge presented in the chapters of the book’s three sections by addressing evolutionary compromises, dispersal, gene flow, and assisted movements. How climate change and other environmental changes at different scales may affect animal movement, migration, and dispersal in the future are also summarized here. Moreover, how the different senses are utilized for navigation and orientation and how these may lead to different movement and migration patterns are also discussed. Finally, how the recent technical revolution has affected animal movement research is addressed and the view on future perspectives of animal movement research is also provided.
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| 47. |
- Herbertsson, Lina, et al.
(författare)
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Competition between managed honeybees and wild bumblebees depends on landscape context
- 2016
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Ingår i: Basic and Applied Ecology. - : Elsevier BV. - 1439-1791 .- 1618-0089. ; 17:7, s. 609-616
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Tidskriftsartikel (refereegranskat)abstract
- Honeybees might outcompete wild bees by depleting common resources, possibly more so in simplified landscapes where flower-rich habitats have been lost. We tested this by experimentally adding honeybee hives to nine sites while ensuring that ten additional sites were free from hives. The landscape surrounding each geographically separated site either held low (homogeneous landscape) or high (heterogeneous landscape) proportions of semi-natural grassland. Adding honeybees suppressed bumblebee densities in field borders and road verges in homogeneous landscapes whereas no such effect was detected in heterogeneous landscapes. The proportional abundance of bumblebee species with small foraging ranges was lower at honeybee sites than at control sites in heterogeneous landscapes, whereas bumblebee communities in homogeneous landscapes were dominated by a single species with long foraging range irrespective of if honeybees were added or not. We conclude that honeybees can impact bumblebee densities, but that landscape heterogeneity modified this effect.
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| 48. |
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| 49. |
- Holmøy, Trygve, et al.
(författare)
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Vitamin D supplementation and neurofilament light chain in multiple sclerosis.
- 2019
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Ingår i: Acta neurologica Scandinavica. - : Hindawi Limited. - 1600-0404 .- 0001-6314. ; 139:2, s. 172-176
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Tidskriftsartikel (refereegranskat)abstract
- The effect of vitamin D supplementation on the disease course of multiple sclerosis (MS) is not established. Neurofilament light chain (NFL) is a sensitive marker of axonal degeneration. The aim of this study was to establish whether high-dose vitamin D supplementation reduces serum levels of NFL.We have performed a 96weeks placebo-controlled randomized study of weekly supplementation with 20000IU vitamin D3 in 71 patients with relapsing remitting MS (RRMS). Serum levels of NFL were measured at baseline, week 48 and week 96 with a single molecule (Simoa) assay in 69 of these patients.Serum levels of 25-hydroxyvitamin D more than doubled in the vitamin D group. Compared to placebo, vitamin D supplementation had no overall effect on the change in serum levels of NFL from baseline (P=0.93 at week 48 and P=0.56 at week 96). In the subgroup of patients not receiving disease-modifying therapy, NFL decreased by 30.9% to week 48% and 32.6% to week 96 from baseline in the vitamin D group as compared to the placebo group (P=0.06 for both time points).With a possible exception for patients not treated with disease-modifying drugs, weekly supplementation with 20000IU vitamin D3 did not affect NFL levels in these RRMS patients.
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| 50. |
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