| 1. |
|
|
| 2. |
- Larsson, Jenny H., 1973-
(författare)
-
Ta inte listan på orden!
- 2015
-
Ingår i: Språktidningen. - 1654-5028. ; :oktober
-
Tidskriftsartikel (populärvet., debatt m.m.)
|
|
| 3. |
- Lundow, Per-Håkan
(författare)
-
Boundary effects on finite-size scaling for the 5-dimensional Ising model
- 2021
-
Ingår i: Nuclear Physics B. - : Elsevier. - 0550-3213 .- 1873-1562. ; 967
-
Tidskriftsartikel (refereegranskat)abstract
- High-dimensional (d≥5) Ising systems have mean-field critical exponents. However, at the critical temperature the finite-size scaling of the susceptibility χ depends on the boundary conditions. A system with periodic boundary conditions then has χ ∝ L5/2. Deleting the 5L4 boundary edges we receive a system with free boundary conditions and now χ ∝ L2. In the present work we find that deleting the L4 boundary edges along just one direction is enough to have the scaling χ ∝ L2. It also appears that deleting L3 boundary edges results in an intermediate scaling, here estimated to χ ∝ L2.275. We also study how the energy and magnetisation distributions change when deleting boundary edges.
|
|
| 4. |
- Lundow, P. H., et al.
(författare)
-
Non-vanishing boundary effects and quasi-first-order phase transitions in high dimensional Ising models
- 2011
-
Ingår i: Nuclear Physics B. - Amsterdam : Elsevier. - 0550-3213 .- 1873-1562. ; 845:1, s. 120-139
-
Tidskriftsartikel (refereegranskat)abstract
- In order to gain a better understanding of the Ising model in higher dimensions we have made a comparative study of how the boundary, open versus cyclic, of a d-dimensional simple lattice, for d = 1,...,5, affects the behaviour of the specific heat C and its microcanonical relative, the entropy derivative -partial derivative(2)S/partial derivative U(2). In dimensions 4 and 5 the boundary has a strong effect on the critical region of the model and for cyclic boundaries in dimension 5 we find that the model displays a quasi-first-order phase transition with a bimodal energy distribution. The latent heat decreases with increasing systems size but for all system sizes used in earlier papers the effect is clearly visible once a wide enough range of values for K is considered. Relations to recent rigorous results for high dimensional percolation and previous debates on simulation of Ising models and gauge fields are discussed. (C) 2010 Elsevier B.V. All rights reserved.
|
|
| 5. |
|
|
| 6. |
- Mesmar, Fahmi, et al.
(författare)
-
Clinical candidate and genistein analogue AXP107-11 has chemoenhancing functions in pancreatic adenocarcinoma through G protein-coupled estrogen receptor signaling
- 2019
-
Ingår i: Cancer Medicine. - : Wiley. - 2045-7634. ; 8:18, s. 7705-7719
-
Tidskriftsartikel (refereegranskat)abstract
- Despite advances in cancer therapeutics, pancreatic cancer remains difficult to treat and often develops resistance to chemotherapies. We have evaluated a bioavailable genistein analogue, AXP107-11 which has completed phase Ib clinical trial, as an approach to sensitize tumor cells to chemotherapy. Using organotypic cultures of 14 patient-derived xenografts (PDX) of pancreatic ductal adenocarcinoma, we found that addition of AXP107-11 indeed sensitized 57% of cases to gemcitabine treatment. Results were validated using PDX models in vivo. Further, RNA-Seq from responsive and unresponsive tumors proposed a 41-gene treatment-predictive signature. Functional and molecular assays were performed in cell lines and demonstrated that the effect was synergistic. Transcriptome analysis indicated activation of G-protein-coupled estrogen receptor (GPER1) as the main underlying mechanism of action, which was corroborated using GPER1-selective agonists and antagonists. GPER1 expression in pancreatic tumors was indicative of survival, and our study proposes that activation of GPER1 may constitute a new avenue for pancreatic cancer therapeutics.
|
|
| 7. |
|
|
| 8. |
- Grandin, Ingemar, 1956-
(författare)
-
Music as message
- 1993
-
Ingår i: Himal. - 1012-9804. ; 6:6, s. 24-24
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
|
|
| 9. |
- Galkin, Nikolai, 1992-
(författare)
-
Model-Integrated Engineering of Smart Energy Distribution Systems
- 2023
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Model-Based Systems Engineering (MBSE) is a formal method that is used to support analysis, design, independent verification, and validation inherent in the development of software and hardware systems. MBSE applications are present in many areas of our daily lives, including manufacturing, robotics, healthcare, automation, etc. However, despite their rapid and sustainable growth during the last few years, the MBSE methods themselves are quite far away from perfect. There are some current problems, which resist more rapid penetration of MBSE systems in their development. One of them is that currently the majority of MBSE systems are vendor dependent and, as a result, they have poor compatibility with each other. Furthermore, currently, there is a gap between the design of a digital model and a control model of an engineering system. Currently, this problem is usually solved by involving two or more groups of engineers, where each of these groups works on their own problems. All this costs companies additional engineering time and, as a result, development costs. Therefore new, and more sophisticated approaches for the generation of MBSEs are needed in order to overwhelm the challenges highlighted above.In order to narrow the field of study and better concentrate on specific problems, smart power distribution systems have been chosen as the main research object for this dissertation. Thus, in this work, the author introduces Model-Integrated Systems Engineering (MISE), as the MBSE sub-discipline. Here and later in this paper, the author will refer to MISE as the main area of interest. Also, the author uses the term DigitalTwin to refer to the multilayered structure of a complex distributed automation system consisting of three layers, namely:– the static machine-readable information about the infrastructure of the smart energy system,– the simulation model layer,– the distributed control layer for the investigated smart energy system.In general, two new transformation approaches for automatic MISE generation are discussed in the scope of this dissertation, namely:1. Transformation of the System Configuration Design (SCD) files of an electric system(presented in IEC 61850) into the corresponding SIMULINK model.2. Transformation of specification files of electronic components into corresponding OPC UA information model.All discussed approaches are implemented in the form of a program code that is publicly available on the Internet.The IEC 61850 and OPC UA standards are considered key components of the current dissertation. IEC 61850 is an international standard covering different sides of smart energy distribution systems including communication protocols for diverse equipment in a substation, including protection, control, and measurement equipment, as well as intelligent electronic devices (IEDs). Information Modeling OPC UA is a platform-independent service-oriented architecture that combines the concepts of semantic modeling.First, the structure of the IEC 61850 standard is discussed, as well as its potential benefits for the MISE of smart power distribution systems in terms of the automatic transformation of the information model.Next, the architecture of the electrical system (the SCD file) of the electrical vehicle (EV) charging station (CS) is proposed as an example. The aim is to design a mechanism for the automatic transformation of MISE in two domains, namely:- Physical model of the electrical system itself,- Automatically build a communication channel between the digital replica (the model) of the electrical system and the virtual energy management system (EMS).Thus, this work aims to contribute to the design and virtual commissioning of Digital Twin systems, as well as to improve the interoperability between IEC 61850 compliant systems and electric vehicle charging stations (paper C explains that in more detail).Finally, by narrowing down the scope of the investigation to one specific electrical device, a new approach for converting integrated circuit (IC) specification files of an electric system into an OPC UA information model is discussed. The designed transformation algorithm is based on the directed graphs theory (paper D explains that in more detail). The purpose of this work is to highlight and contribute to the problems of the MISE analysis solutions. In summary, the work presented in this dissertation raises questions about interoperability between different standards, the problems of converting the IEC 61850 information model into MISE, verification of the generated MISE compared to the original IEC 61850 information model, and the problems of forming an information model OPC UA.
|
|
| 10. |
|
|
| 11. |
- Svensson, Jonas
(författare)
-
Contrast-enhanced magnetic resonance angiography.
- 2003
-
Ingår i: Acta Radiologica. - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 44:S429, s. 7-7
-
Forskningsöversikt (refereegranskat)abstract
- Contrast-enhanced magnetic resonance angiography (CE-MRA) is a diagnostic method for imaging of vascular structures based on nuclear magnetic resonance. Vascular enhancement is achieved by injection of a contrast medium (CM). Studies were performed using two different types of CM: conventional paramagnetic CM, and a new type of CM based on hyperpolarized (HP) nuclei. The effects of varying CM concentration with time during image acquisition were studied by means of computer simulations using two different models. It was shown that a rapid concentration variation during encoding of the central parts of k-space could result in signal loss and severe image artifacts. The results were confirmed qualitatively with phantom experiments. A postprocessing method was developed to address problems with simultaneous enhancement of arteries and veins in CE-MRA of the lower extremities. The method was based on the difference in flow-induced phase in the two vessel types. Evaluation of the method was performed with flow phantom measurements and with CE-MRA in two volunteers using standard pulse sequences. The flow-induced phase in the vessels of interest was sufficient to distinguish arteries from veins in the superior-inferior direction. Using this method, the venous enhancement could be extinguished. The possibility of using HP nuclei as CM for CE-MRA was evaluated. Signal expressions for a flow of HP CM imaged with a gradient echo sequence were derived. These signal expressions were confirmed in phantom experiments using HP 129Xe dissolved in ethanol. Studies were also performed with a new CM based on HP 13C. The CM had very long relaxation times (T1,in vivo/T2,in vivo≈ 38/1.3 s). The long relaxation times were utilized in imaging with a fully balanced steady-state free precession pulse sequence (trueFISP), where the optimal flip angle was found to be 180°. CE-MRA with the 13C-based CM in rats resulted in images with high vascular SNR (~500). CE-MRA is a useful clinical tool for diagnosing vascular disease. With the development of new contrast media, based on hyperpolarized nuclei for example, there is a potential for further improvement in the signal levels that can be achieved, enabling a standard of imaging of vessels that is not possible today.
|
|
| 12. |
- Grandin, Ingemar, 1956-
(författare)
-
Kons fest vid dödsrikets portar
- 1992
-
Ingår i: Sju sjungande folk: musik i fest och rit. - Stockholm : SMS Musikmuseet. ; , s. 28-31
-
Bokkapitel (populärvet., debatt m.m.)abstract
|
|
| 13. |
- Kleist, David, 1974
(författare)
-
NSFR Seminar 2014 – National Report for Sweden
- 2014
-
Ingår i: Nordic Tax Journal. - 2246-1809. ; 2014:2, s. 215-227
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The article, which is based on a national report written for the 2014 seminar of the Nordic Tax Research Council, aims to give an overview of the rules concerning taxation of companies in Sweden and of trends in the taxation of companies that have been evident in the last few years. It focuses in particular on issues that are connected with the so-called BEPS discussion, for instance interest deduction limitations, CFC rules, general anti-avoidance rules and other rules intended to protect the national tax base. It also sets out to describe other important features of the Swedish tax legislation in regard to companies, such as the rules on taxation of inbound and outbound dividends, interest and royalty.
|
|
| 14. |
- Esquivel, A., et al.
(författare)
-
Hydrodynamical interaction of stellar and planetary winds : effects of charge exchange and radiation pressure on the observed Ly alpha absorption
- 2019
-
Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 487:4, s. 5788-5798
-
Tidskriftsartikel (refereegranskat)abstract
- Lyman alpha observations of the transiting exoplanet HD209458b enable the study of exoplanet exospheres exposed to stellar extreme ultraviolet (EUV) fluxes, as well as the interacting stellar wind properties. In this study we present 3D hydrodynamical models for the stellar-planetary wind interaction including radiation pressure and charge exchange, together with photoionization, recombination, and collisional ionization processes. Our models explore the contribution of the radiation pressure and charge exchange to the Ly alpha absorption profile in a hydrodynamical framework, and for a single set of stellar wind parameters appropriate for HD209458. We find that most of the absorption is produced by the material from the planet, with a secondary contribution of neutralized stellar ions by charge exchange. At the same time, the hydrodynamic shock heats up the planetary material, resulting in a broad thermal profile. Meanwhile, the radiation pressure yields a small velocity shift of the absorbing material. While neither charge exchange nor radiation pressure provides enough neutrals at the velocity needed to explain the observations at -100kms(-1) individually, we find that the two effects combined with the broad thermal profile are able to explain the observations.
|
|
| 15. |
|
|
| 16. |
|
|
| 17. |
|
|
| 18. |
|
|
| 19. |
|
|
| 20. |
- Qvarsell, Birgitta
(författare)
-
Vad skapar mening i skolan?
- 2004
-
Ingår i: Pedagogiska Magasinet. - Stockholm. - 1401-3320. ; :2, s. 38-43
-
Tidskriftsartikel (refereegranskat)
|
|
| 21. |
|
|
| 22. |
|
|
| 23. |
- Sandström, Linda, 1973-, et al.
(författare)
-
Speech intelligibility in Parkinson's disease patients with zona incerta deep brain stimulation
- 2015
-
Ingår i: Brain and Behavior. - : John Wiley & Sons. - 2162-3279 .- 2162-3279. ; 5:10
-
Tidskriftsartikel (refereegranskat)abstract
- ObjectivesTo investigate the effects of l-dopa (Levodopa) and cZi-DBS (deep brain stimulation in caudal zona incerta) on spontaneous speech intelligibility in patients with PD (Parkinson's disease).Materials and MethodsSpontaneous utterances were extracted from anechoic recordings from 11 patients with PD preoperatively (off and on l-dopa medication) and 6 and 12 months post bilateral cZi-DBS operation (off and on stimulation, with simultaneous l-dopa medication). Background noise with an amplitude corresponding to a clinical setting was added to the recordings. Intelligibility was assessed through a transcription task performed by 41 listeners in a randomized and blinded procedure.ResultsA group-level worsening in spontaneous speech intelligibility was observed on cZi stimulation compared to off 6 months postoperatively (8 adverse, 1 positive, 2 no change). Twelve months postoperatively, adverse effects of cZi-DBS were not frequently observed (2 positive, 3 adverse, 6 no change). l-dopa administered preoperatively as part of the evaluation for DBS operation provided the overall best treatment outcome (1 adverse, 4 positive, 6 no change).ConclusionscZi-DBS was shown to have smaller negative effects when evaluated from spontaneous speech compared to speech effects reported previously. The previously reported reduction in word-level intelligibility 12 months postoperatively was not transferred to spontaneous speech for most patients. Reduced intelligibility due to cZi stimulation was much more prominent 6 months postoperatively than at 12 months.
|
|
| 24. |
- Westerström, Göran, et al.
(författare)
-
Utbildning och forskning i världsklass vid LTU : Skandinaviens nordligaste tekniska universitet
- 2004
-
Ingår i: V-byggaren : väg- och vattenbyggaren. - 0283-5363. ; :2, s. 42-45
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Luleå tekniska universitet startade 1971 som Tekniska högskolan i Luleå. Målet var att ge regionen tillväxt genom högre teknisk utbildning och forskning. Många i de södra delarna av landet var skeptiska och vanföreställningar som att akademiker inte kan förmås att bo så långt norrut frodades
|
|
| 25. |
- Weidow, Jonas, 1960, et al.
(författare)
-
Abnormal motion of the medial femoral condyle in lateral knee osteoarthritis
- 2007
-
Ingår i: Clin Orthop Relat Res. - 0009-921X. ; 454, s. 27-34
-
Tidskriftsartikel (refereegranskat)abstract
- The pattern of knee motion in patients with lateral osteoarthritis may be associated with the pathogenesis of this disease. Based on previous findings of decreased anteroposterior femoral condylar translation in knees with medial knee osteoarthritis, we asked whether a similar pattern of knee kinematics in lateral osteoarthritis could be related to the wear pattern on the tibial plateau. We used sequential radiostereometric images to study kinematics during active weightbearing extension in five knees with lateral osteoarthritis and 11 control knees. At 45 degrees of flexion, the posterior circular center of the lateral femoral condyle displaced posteriorly at 45 degrees and moved anteriorly during extension in both groups. There was also a proximal displacement with extension, but from a more distal position in the osteoarthritis group. We could only partly relate the kinematics of knees with lateral osteoarthritis to the wear pattern on the tibial plateau. Contrary to our hypothesis of normal anterior displacement of the medial and increased posterior displacement of the lateral femoral condyle, we observed no change of anterior-posterior displacements of the lateral condyle.
|
|
| 26. |
- Grahn, Markus, 1978
(författare)
-
Model-Based Diesel Engine Management System Optimization - A Strategy for Transient Engine Operation
- 2013
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- To meet increasingly strict emission legislation and stronger demands on fuel consumption, typical passenger car diesel engines become increasingly complex with more and more controllable systems added. These added systems open up for the possibility to operate the engine at more efficient conditions, but it also becomes more challenging to optimize the settings in the engine management system. Methods to optimize settings in an engine management system based on steady-state engine operation are well developed and described in the literature, and also used in practice. Methods to handle transient engine operation are not as well developed, and typically various compensations are added in an engine management system to account for effects during transient engine operation. Calibration of these compensations is currently a manual process and is largely performed to meet regulations rather than to optimize the system.This thesis consists of papers that describe the introduction of a novel method to optimize settings in a diesel engine management system with an aim to minimize fuel consumption for a given dynamic vehicle driving cycle while keeping accumulated engine-out emissions below given limits. The strategy is based on existing methods for steady-state engine operation, but extended to account for transient effects in the engine caused by dynamics in the gas exchange system in a systematic manner. The strategy has been evaluated using a simulation model of a complete diesel engine vehicle system. The optimization strategy has been shown to decrease fuel consumption for a diesel engine vehicle compared to existing methods based only on steady-state engine operation. Using the simulation model, the strategy has been shown to decrease fuel consumption for a vehicle driving according to the New European Driving Cycle with 0.56%, compared to a strategy based only on steady-state engine operation.This thesis also consists of papers that describe the complete diesel engine vehicle system simulation model. The model can perform a simulation of a vehicle driving according to a predefined dynamic driving cycle, and it estimates fuel consumption together with NOx and soot emissions throughout the simulation depending on settings in the engine management system. The model accounts for transient effects on fuel consumption and emissions caused by dynamics in the engine gas exchange system. The simulation model is implemented in the \textsc{Matlab} Simulink environment, and the simulation time is in the range of 10 to 20 times faster than real-time.
|
|
| 27. |
|
|
| 28. |
- Wärneryd, Karl
(författare)
-
Informational Aspects of Conflict
- 2012
-
Ingår i: The Oxford Handbook of the Economics of Peace and Conflict. - New York : Oxford University Press. - 9780195392777 ; , s. 23-42
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This article analyzes informational issues that emerge in a contest model of conflict, a model in which the outcome of open conflict depends on the relative military capabilities of the adversaries using a traditional Bayesian game-theoretic approach. It provides an introduction to the topic along with insights into how conflict can emerge in settings with informational asymmetries. The article deals with issues of asymmetric information about players' utility from winning; their costs of producing effort; abilities; and what private information about aggressive potential implies for the probability of outbreak of outright conflict instead of peaceful settlement.
|
|
| 29. |
- Drobyshev, Igor
(författare)
-
Attribution of the role of climate change in the forest fires in Sweden 2018
- 2021
-
Ingår i: Natural Hazards and Earth System Sciences. - : Copernicus GmbH. - 1561-8633 .- 1684-9981. ; 21, s. 2169-2179
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, we analyse the role of climate change in the forest fires that raged through large parts of Sweden in the summer of 2018 from a meteorological perspective. This is done by studying the Canadian Fire Weather Index (FWI) based on sub-daily data, both in reanalysis data sets (ERA-Interim, ERA5, the Japanese 55 year Reanalysis, JRA-55, and Modern-Era Retrospective analysis for Research and Applications version 2, MERRA-2) and three large-ensemble climate models (EC-Earth, weather@home, W@H, and Community Earth System Model, CESM) simulations. The FWI, based on reanalysis, correlates well with the observed burnt area in summer (r = 0.6 to 0.8). We find that the maximum FWI in July 2018 had return times of similar to 24 years (90% CI, confidence interval, > 10 years) for southern and northern Sweden. Furthermore, we find a negative trend of the FWI for southern Sweden over the 1979 to 2017 time period in the reanalyses, yielding a non-significant reduced probability of such an event. However, the short observational record, large uncertainty between the reanalysis products and large natural variability of the FWI give a large confidence interval around this number that easily includes no change, so we cannot draw robust conclusions from reanalysis data.The three large-ensembles with climate models point to a roughly 1.1 (0.9 to 1.4) times increased probability (non-significant) for such events in the current climate relative to preindustrial climate. For a future climate (2 degrees C warming), we find a roughly 2 (1.5 to 3) times increased probability for such events relative to the preindustrial climate. The increased fire weather risk is mainly attributed to the increase in temperature. The other main factor, i.e. precipitation during summer months, is projected to increase for northern Sweden and decrease for southern Sweden. We, however, do not find a clear change in prolonged dry periods in summer months that could explain the increased fire weather risk in the climate models.In summary, we find a (non-significant) reduced probability of such events based on reanalyses, a small (nonsignificant) increased probability due to global warming up to now and a more robust (significant) increase in the risk for such events in the future based on the climate models.
|
|
| 30. |
- Ranhagen, Ulf
(författare)
-
Arbetsområden i Örebro
- 1979
-
Ingår i: Arkitektur. - 0004-2021. ; 79:6, s. 33-34
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
| 31. |
|
|
| 32. |
- Skåmedal, Jo, 1965-
(författare)
-
Telecommuting's implications on travel and travel patterns
- 2004
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The subject field is within technology and social change, with focus particularly on telecommuting and the possible changes that arises in the travel patterns as a result of the telecommuting situation. When a person starts working from home once or twice a week instead of commuting back and forth to the main work place, a number of changes in the telecommuters' distribution of travel can and most probably will arise. The commute trip is often excluded, which leads to the so-called substitution effect. Non-work related trips might be generated and the mix of different types of trips as well as the trips temporal and modal choices is affected. On the aggregate. urban congestion may be reduced and the work form may contribute to the urban sprawl, which may lead to an increase in vehicle kilometres travelled. These and some other travel pattern changes due to telecommuting are the topics studied in the thesis. The comprehensive purpose is to: "Describe how telecommuting affects telecommuters' travel and travel patterns by exploring the work form's travel implications. their mutual interaction and explaining the consequent travel outcome".The thesis has confirmed the work forms net travel reducing effect. Commute trips obviously decreases when working from home, but telecommuting is also expected to lead to an increase in non-commute trips, which it does too, but the work form even reduces a number of non-commute trips, with the probable total outcome of a net travel reduction even for the non-commute trips. A discovery that makes the travel reduction less than initially believed however is the substantial amount of telecommuters frequently practising half-day telecommuting. Half-day telecommuting does in turn stimulate travel mode changes. with increased car usage for commuting in preference of public transportation. For non-commutes, the travel mode tends to shift from cars to non-motorised travel means, such as bicycles and walks instead.A conceptual model is constructed in order to increase the understanding of the underlying causes for the interrelations between telecommuting and travel and the accordingly travel effects. Further, the relations and connections between telecommuting and long distance telecommuting is contextually discussed with regards to how rural telecommutcrs travel pattern potentially differentiates from urban telecommuters. The discussion resulted in 18 hypothetical differences between urban and rural telecommuters' travel patterns, which provide a foundation on which to develop future studies.
|
|
| 33. |
|
|
| 34. |
|
|
| 35. |
|
|
| 36. |
- Ahrné, Karin, et al.
(författare)
-
Dagfjärilar i naturbetesmarker, kraftledningsgator, på hyggen och skogsbilvägar : betydelse för miljöövervakning
- 2011
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Ett förändrat och intensifierat jordbruk har bland annat lett till att naturbetesmarker och andra gräsmarksbiotoper minskat i odlingslandskapet. Detta har fått till följd att många arter knutna till öppna gräsmarker minskat, däribland fåglar, växter och dagfjärilar. Dagfjärilar svarar snabbt på förändringar både i miljön och klimatet och kan därför vara viktiga indikatorarter för miljöövervakning. I år startar en nationell övervakning av dagfjärilar med hjälp av volontärer och de senaste fem åren har dagfjärilar inventerats i ängs- och betesmarker inom den nationella inventeringen av landskapet (NILS). För att få en rättvisande bild av hur situationen ser ut för dagfjärilar i Sverige kan det vara viktigt att systematiskt inventera olika typer av miljöer, inte enbart ängs- och betesmarker eller känt artrika platser. I den här studien jämför vi artrikedom, individantal och artsammansättning av dagfjärilar (Rophalocera) och bastardsvärmare (Zyganidaea) i naturbetesmarker och tre typer av öppna biotoper i skogslandskapet; hyggen, kraftledningsgator och skogsbilvägar. Vi delar också in fjärilarna efter val av värdväxt och flygtid på säsongen för att se om det finns några skillnader mellan biotoperna vad gäller art- och individrikedom inom dessa grupper. Vi undersöker hur mängden skog och betesmark inom det omgivande landskapet påverkar dagfjärilsfaunan på de olika platserna och hur många inventeringstillfällen (3, 5 eller 7) som krävs för att få tillförlitliga data på artrikedomen på en plats. Våra resultat visar att artsammansättningen av fjärilar skiljer sig mellan biotoperna och att alla bidrar med unika arter och således kompletterar varandra. Kraftledningsgatorhade både fler fjärilsarter och individer än de övriga biotoperna och hyggen och skogsbilvägar var lika art- och individrika som betesmarkerna. Det är därför viktigt att övervaka flera typer av miljöer och även skogsbiotoper inom framtida dagfjärilsövervakning. Eftersom alla tre skogsbiotoperna hyser en stor mångfald av fjärilar kan det vara värt att anpassa skötseln av dessa miljöer för att gynna fjärilar. I kraftledningsgator och skogsbilvägar som är relativt beständiga miljöer och som redan idag sköts med ett visst intervall är detta fullt möjligt. Betydelsen av antal inventeringstillfällen beror på vilken frågeställning man har. Vill man jämföra artrikedomen i olika miljöer eller studera förändring i artrikedom mellan år kan det kanske räcka med tre besök, men vill man ha en mer heltäckande bild av artrikedomen på en plats kan det sju eller fler besök spridda över säsongen
|
|
| 37. |
- Hederström, Veronica, et al.
(författare)
-
Pollinator-mediated effects of landscape-scale land use on grassland plant community composition and ecosystem functioning – seven hypotheses
- 2024
-
Ingår i: Biological Reviews. - 1464-7931. ; 99:3, s. 675-698
-
Tidskriftsartikel (refereegranskat)abstract
- Environmental change is disrupting mutualisms between organisms worldwide. Reported declines in insect populations and changes in pollinator community compositions in response to land use and other environmental drivers have put the spotlight on the need to conserve pollinators. While this is often motivated by their role in supporting crop yields, the role of pollinators for reproduction and resulting taxonomic and functional assembly in wild plant communities has received less attention. Recent findings suggest that observed and experimental gradients in pollinator availability can affect plant community composition, but we know little about when such shifts are to be expected, or the impact they have on ecosystem functioning. Correlations between plant traits related to pollination and plant traits related to other important ecosystem functions, such as productivity, nitrogen uptake or palatability to herbivores, lead us to expect non-random shifts in ecosystem functioning in response to changes in pollinator communities. At the same time, ecological and evolutionary processes may counteract these effects of pollinator declines, limiting changes in plant community composition, and in ecosystem functioning. Despite calls to investigate community- and ecosystem-level impacts of reduced pollination, the study of pollinator effects on plants has largely been confined to impacts on plant individuals or single-species populations. With this review we aim to break new ground by bringing together aspects of landscape ecology, ecological and evolutionary plant–insect interactions, and biodiversity–ecosystem functioning research, to generate new ideas and hypotheses about the ecosystem-level consequences of pollinator declines in response to land-use change, using grasslands as a focal system. Based on an integrated set of seven hypotheses, we call for more research investigating the putative pollinator-mediated links between landscape-scale land use and ecosystem functioning. In particular, future research should use combinations of experimental and observational approaches to assess the effects of changes in pollinator communities over multiple years and across species on plant communities and on trait distributions both within and among species.
|
|
| 38. |
- Hederström, Veronica, et al.
(författare)
-
White clover pollinators and seed set in relation to local management and landscape context
- 2024
-
Ingår i: Agriculture, Ecosystems and Environment. - 0167-8809. ; 365
-
Tidskriftsartikel (refereegranskat)abstract
- Bees are declining, which is worrisome since they both have intrinsic conservation value and play a major role as pollinators in both natural and managed ecosystems. Land use change and lack of suitable habitats are often suggested as driving forces of bee decline. To propose mitigation measures to halt bee decline, it is important to understand how land use relates to bee abundance and diversity, and to explore consequences for their provision of pollination services. White clover, Trifolium repens, is an outcrossing mass-flowering crop, which could serve as an abundant, although ephemeral, food resource for bees. We investigated how the bee community in 39 fields of white clover grown for seed, related to local field management (organic, conventional without insecticides and conventional with insecticides) and landscape context (proportion semi-natural land), and how this pollinator community related to white clover seed set. The honey bee, Apis mellifera, was the most commonly observed bee species, and two generalist bumble bee species, Bombus terrestris and B. lapidarius, were the subsequently most common. We observed fewer non-Apis bees, and a lower bee species richness in organic white clover seed fields compared to conventional fields independent of insecticide treatment. Bee species richness in both conventional and organic fields were positively related to the proportion of semi-natural land in the landscape, likely because of a larger species pool in such landscapes. Initial seed set in immature inflorescences was positively related to bee abundance, whereas final seed set in mature inflorescences was unrelated to bee abundance, possibly as a consequence of seed-eating weevils consuming a large proportion of the seeds. We conclude that both bee visitation and seed set in white clover benefit from conventional management and that landscapes rich in semi-natural habitats will make future crop production more resilient. The observed positive relationship between bee abundance and initial seed set suggests that if we can mitigate pest impacts and increase bee abundance in clover seed fields, the final seed yield can be increased. Thus, bee decline should be considered and mitigated both to maintain biodiversity in general and for crop seed production specifically.
|
|
| 39. |
|
|
| 40. |
- Sandström, Olof, et al.
(författare)
-
Ludlow (Silurian) stromatoporoid biostromes from Gotland, Sweden: facies, depositional models and modern analogues
- 2002
-
Ingår i: Sedimentology. - : Wiley. - 0037-0746 .- 1365-3091. ; 49:3, s. 379-395
-
Tidskriftsartikel (refereegranskat)abstract
- Stacked stromatoporoid-dominated biostromes of the Ludlow-age Hemse Group (Silurian) in eastern Gotland, Sweden, are 0.5-5 m thick and a few tens of metres to >1 km in lateral extent. They form one of the world's richest Palaeozoic stromatoporoid deposits. This study compiles published and new data to provide an overall facies model for these biostromes, which is assessed in relation to possible modern analogues. Some biostromes have predominantly in-place fossils and are regarded as reefs, but lack rigid frameworks because of abundant low-profile non-framebuilding stromatoporoids; other biostromes consist of stromatoporoid-rich rudstones interpreted here as storm deposits. Variation between these two 'end-members' occurs both between interlayered biostromes and also vertically and laterally within individual biostromes. Such variation produces problems of applying established reef classification terms and demonstrates the need for the development of terminology that recognizes taphonomic destruction of reef fabrics. An approach to such terminology is found in all four categories of a recent biostrome classification scheme that are easily recognized in the Hemse biostrome facies: autobiostromes (>60% in place); autoparabiostromes (a mixture of in-place and overturned reef-building organisms, 20-60% in place); parabiostromes (builders are overturned and damaged, <20% in place); and allobiostromes (transported and detrital reef material, nothing in place). These categories provide a broad taphofacies scheme for the Hemse biostromes, which are mostly autoparabiostrome to allobiostrome. The biostromes developed on crinoidal grainstone sheets and expanded laterally across relatively flat substrates in a marine setting of low siliciclastic input. Planar erosion surfaces commonly terminate biostrome tops. Three broadly similar modern analogues are identified, each of which has elements in common with the Hemse biostromes, but none of which is an exact equivalent: (a) laterally expanded and coalesced back-barrier patch reefs behind the Belize barrier, an area influenced by limited accommodation space; (b) a hurricane-influenced shelf, interpreted for Grand Cayman, where reef cores consist of rubble and lack substantial framework; the wide distribution of rounded pebbles and cobbles of stromatoporoids in the Hemse biostromes most probably resulted from hurricanes; (c) coral carpets in 5-15 m water depth of the northern Red Sea, where lateral expansion of low-diversity frames dominated by Porites coral has produced low-profile biostromes up to 8 m thick and several km long. Such carpets accumulated large amounts of carbonate, with little export, as in the Hemse biostromes, although the latter did not build frameworks because of the nature of growth of the stromatoporoids. The notable lack of algae in the Hemse biostrome facies is also a feature of Red Sea coral carpets; nevertheless, coral carpets are ecologically different. Hemse biostromes lack evidence of a barrier reef system, although this may not be exposed; the facies assemblage is consistent with either a storm/hurricane-influenced mid- to upper ramp or back-barrier system.
|
|
| 41. |
- Sjölin, Mikael, et al.
(författare)
-
Purification and retention of sucrose in sugar beet molasses by utilizing ceramic nanofiltration membranes
- 2019
-
Ingår i: ; , s. 102-102
-
Konferensbidrag (refereegranskat)abstract
- Biorefineries are rapid growing branches in the world of sustainable chemical engineering, and one aspect that becomes more and more important is the reuse and valorization of different by-products. In sugar mills, molasses is a low value by-product mainly used for animal feed. However, a large part of the molasses contains the main product of the sugar mill: sucrose. By using membrane filtration, it is possible to purify the sucrose in the molasses. The sucrose could then either be recirculated back to the main stream of the sugar mill or be used for other various processes, for instance, biotechnological conversion of sugar to high value bio-based polymers. A small scale tubular ceramic nanofiltration membrane with a molecular weight cut-off of 200 Da has been investigated for purification of sucrose in sugar beet molasses. This membrane can not just purify the sucrose by removing salts and other small molecules, but can also concentrate the sucrose. The trials were conducted in a crossflow setup at 60 ˚C. In order to pump around the molasses in the crossflow system, the molasses required to be diluted first. Two dilutions were investigated: 0.5 % and 10 % molasses in distilled water. For each dilution, two different types of tests were conducted: a process parameter study and a concentration study. The impact on the filtration fluxes was monitored for different pressures and crossflow velocities. The fouling degree and filter cleaning efficiency was also studied, where the effect of different cleaning agents was investigated. The retention of various compounds was evaluated using refractive index, conductivity and turbidity. The results indicate that it is possible to retain sugar with the ceramic nanofiltration membrane, and at the same time achieve high filtration fluxes (up to 270 L/(m2 h), during the 0.5 % molasses concentration test). It is also possible to clean the ceramic membrane efficiently and recover the filtration capacities back to original levels, even after being heavily fouled.
|
|
| 42. |
- Sjölin, Martin, 1987-, et al.
(författare)
-
Relative calibration of energy thresholds on multi-bin spectral x-ray detectors
- 2016
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 840, s. 1-4
-
Tidskriftsartikel (refereegranskat)abstract
- Accurate and reliable energy calibration of spectral x-ray detectors used in medical imaging is essential for avoiding ring artifacts in the reconstructed images (computed tomography) and for performing accurate material basis decomposition. A simple and accurate method for relative calibration of the energy thresholds on a multi-bin spectral x-ray detector is presented. The method obtains the linear relations between all energy thresholds in a channel by scanning the thresholds with respect to each other during x-ray illumination. The method does not rely on a model of the detector's response function and does not require any identifiable features in the x-ray spectrum. Applying the same method, the offset between the thresholds can be determined also without external stimuli by utilizing the electronic noise as a source. The simplicity and accuracy of the method makes it suitable for implementation in clinical multi-bin spectral x-ray imaging systems.
|
|
| 43. |
- Sjölin, Mette
(författare)
-
Shakespeare and Immigration
- 2016
-
Ingår i: English Studies. - 1744-4217. ; 97:4, s. 443-444
-
Recension (refereegranskat)
|
|
| 44. |
|
|
| 45. |
- Sjölin, Per, et al.
(författare)
-
A note on multiparameter maximal operators of Schrödinger type
- 2010
-
Ingår i: Revista Matemática Complutense. - : Springer Science and Business Media LLC. - 1139-1138 .- 1988-2807. ; 23:1, s. 261-265
-
Tidskriftsartikel (refereegranskat)abstract
- In recent years, new features about the boundedness properties of maximal operators related to the solutions of the Schrodinger equation have evolved by considering different time values for each variable. In this paper, a multiparameter maximal estimate is studied for operators of Schrodinger type. Sharp results are obtained.
|
|
| 46. |
- Sjölin, Per, et al.
(författare)
-
Analysis of Schrödinger means
- 2021
-
Ingår i: Annales Fennici Mathematici. - : Finnish Mathematical Society. - 2737-0690 .- 2737-114X. ; 46:1, s. 389-394
-
Tidskriftsartikel (refereegranskat)abstract
- We study integral estimates of maximal functions for Schrödinger means.
|
|
| 47. |
- Sjölin, Per
(författare)
-
Estimates of averages of Fourier transforms with respect to general measures
- 2003
-
Ingår i: Proceedings of the Royal Society of Edinburgh. Section A Mathematics. - 0308-2105 .- 1473-7124. ; 133, s. 943-950
-
Tidskriftsartikel (refereegranskat)abstract
- We study a connection between the L-2 average decay of the Fourier transform of functions with respect to a given measure and the Hausdorff behaviour of that measure.
|
|
| 48. |
- Sjölin, Per
(författare)
-
Nonlocalization of operators of schrödinger type
- 2013
-
Ingår i: Annales Academiae Scientiarum Fennicae Mathematica. - : Finnish Academy of Science and Letters. - 1239-629X .- 1798-2383. ; 38:1, s. 141-147
-
Tidskriftsartikel (refereegranskat)abstract
- Localization properties are studied for operators of Schrodinger type.
|
|
| 49. |
- Sjölin, Per
(författare)
-
Some remarks on localization of Schrodinger means
- 2012
-
Ingår i: Bulletin des Sciences Mathématiques. - : Elsevier BV. - 0007-4497 .- 1952-4773. ; 136:6, s. 638-647
-
Tidskriftsartikel (refereegranskat)abstract
- We study localization and localization almost everywhere of Schrodinger means of functions in Sobolev spaces.
|
|
| 50. |
|
|
