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Sökning: WFRF:(Ekström Nils)

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  • Ekström, Hanna, et al. (författare)
  • Barking up the wrong tree? : A guide to forest owner typology methods
  • 2024
  • Ingår i: Forest Policy and Economics. - : Elsevier. - 1389-9341 .- 1872-7050. ; 163
  • Tidskriftsartikel (refereegranskat)abstract
    • Creating typologies of forest owners is a common approach for analyzing and understanding heterogeneity in responses to forest policies and management practice uptake. While many forest owner typologies have been developed, only a few quantitative methods dominate the field with little information on how methodological choice affects outcomes. In this study we compare five methods for quantitative typology formation and ask what type of information each method provides, and to which degree the methods complement each other. Empirically we use data from a survey conducted in 2014–2015 about Swedish forest owner's objectives, attitudes, and factors of decision-making. The results show that individual forest owners are assigned to different clusters by the compared methods, and how each method highlights different aspects of forest owner characteristics. The study shows the importance of method selection as it influences how we can describe and interpret forest owners in connection to policy adoption, uptake of practices, and environmental awareness. We conclude by providing basis for a methodological guidance on how to make judgments when selecting method(s) to typology formation based on research purpose and approach. 
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  • Ekström, Hanna, et al. (författare)
  • Barking up the wrong tree? : A guide to forest owner typology methods
  • 2024
  • Ingår i: Forest Policy and Economics. - 1389-9341. ; 163
  • Tidskriftsartikel (refereegranskat)abstract
    • Creating typologies of forest owners is a common approach for analyzing and understanding heterogeneity in responses to forest policies and management practice uptake. While many forest owner typologies have been developed, only a few quantitative methods dominate the field with little information on how methodological choice affects outcomes. In this study we compare five methods for quantitative typology formation and ask what type of information each method provides, and to which degree the methods complement each other. Empirically we use data from a survey conducted in 2014–2015 about Swedish forest owner's objectives, attitudes, and factors of decision-making. The results show that individual forest owners are assigned to different clusters by the compared methods, and how each method highlights different aspects of forest owner characteristics. The study shows the importance of method selection as it influences how we can describe and interpret forest owners in connection to policy adoption, uptake of practices, and environmental awareness. We conclude by providing basis for a methodological guidance on how to make judgments when selecting method(s) to typology formation based on research purpose and approach.
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  • Ekström, Hanna, et al. (författare)
  • Modelling forests as social-ecological systems : A systematic comparison of agent-based approaches
  • 2024
  • Ingår i: Environmental Modelling and Software. - 1364-8152 .- 1873-6726. ; 175
  • Forskningsöversikt (refereegranskat)abstract
    • The multifunctionality of forest systems calls for appropriately complex modelling approaches to capture social and ecosystem dynamics. Using a social-ecological systems framework, we review the functionality of 31 existing agent-based models applied to managed forests. Several applications include advanced cognitive and emotional decision-making, crucial for understanding complex sustainability challenges. However, far from all demonstrate representation of key elements in a social-ecological system like direct interactions, and dynamic representations of social and ecological processes. We conclude that agent-based approaches are adequately complex for simulating both social and ecological subsystems, but highlight three main avenues for further development: i) robust methodological standards for calibration and validation of agent-based approaches; ii) modelling of agent learning, adaptive governance and feedback loops; iii) coupling to ecological models such as dynamic vegetation models or species distribution models. We round-off by providing a set of questions to support social-ecological systems modelling choices.
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  • Ekström, Joakim, 1980-, et al. (författare)
  • Simulation based optimisation of toll levels in urban road traffic networks
  • 2014
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • There has recently been a growing interest in analysing road pricing schemes in urban areas using dynamic traffic assignment (DTA) tools. The motivation behind this development is the problem for static transportation models to accurately predict travel time savings, from introducing road pricing, in networks with severe congestion. Finding optimal toll levels and locations in urban road traffic networks has so far mainly been studied using either derivative-free heuristics (e.g. genetic algorithms and simulated annealing) or ascent methods. Both approaches rely on fast computations of the road users response (traffic flows, travel times and demands), given the road pricing scheme, and for the case of ascent methods, the methods also rely on fast computations (or rather approximation) of derivatives. Using DTA tools for evaluating the road users’ response to a pricing scheme is, however, very computationally expensive. Previously developed methods are therefore not suitable to use together with DTA.Surrogate models, e.g. in terms of response surfaces, are commonly used for optimisation problems with expensive-to-evaluate objective functions. The surrogate model is used for approximating the expensive-to-evaluate objective function, and the optimisation is then done on the surrogate model instead. The performances of optimisation methods based on surrogate models are, however, dependent on experimental design, infill strategy and choice of surrogate model itself. The experimental design will give the initial set of toll levels, for which the DTA needs to be evaluated, the infill strategy determined additional toll levels to be evaluated by the DTA, and the choice of surrogate model will give the functional form to be fitted to the sampled toll levels.We apply a surrogate model framework for optimising toll levels in a multiple cordon pricing scheme. In the first stage we evaluate the experimental design, infill strategy and choice of surrogate model, using a static macroscopic traffic model.  This allows a large number of experiments to be carried out, which would not be possible with a DTA tool. It also allows us to compare the performance of the surrogate modelling approach with other global optimisation methods. In the second stage, the insight which has been gained from the experiments with the static model is used when applying the surrogate modelling approach to a DTA model of Stockholm.Computational results are presented for a Stockholm network with three cordons, each with differentiated toll level in both directions, resulting in a total of six toll level variables. Surrogate models in the form of Radial Basis Functions and Kriging models are evaluated with a static model of Stockholm, for different initial experimental designs, infill strategies and choice of surrogate models. In comparison with previously developed derivative based methods for static models, our results show that the surrogate based optimisation approach performs better, since it allows for metaheuristic methods to search for global optimal solutions efficiently.
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  • Ekström, Joakim, 1980-, et al. (författare)
  • Surrogatbaserad optimering av avgiftsnivåer i trängselavgiftssystem
  • 2015
  • Rapport (övrigt vetenskapligt/konstnärligt)abstract
    • Trängselskatt finns idag i både Stockholm och Göteborg, och det är troligt att utformningen av dessa trängselskattesystem kommer att justeras framöver med avseende på avgiftsnivå, placering och tidpunkt. För Stockholm finns beslut om ändring från januari 2016 och i Göteborg ändrades avgiftsnivåerna i januari 2015. I detta projekt utvecklas metoder som ska kunna ge stöd vid justering av avigiftsnivåer, så att en så stor samhällsekonomisk nytta som är möjligt uppnås med trängselskattesystemet.För storstadsområden, där det under rusningstrafik är trängsel i delar av nätverket, är trängselskatt främst intressant att analysera med dynamiska transportmodeller. Tidigare utveckling av metoder för optimal avgiftssättning har dock främst fokuserat på statiska modeller, exempelvis Emme, som har kända problem med att korrekt uppskatta förändring i restider när det är trängsel i delar av trafiknätverket. I detta projekt har vi därför tillämpat surrogat-baserad optimering, som är en metodansats som ställer få krav på vilken transportmodell som används. Den dynamiska transportmodellen Regent/VisumDUE finns sedan tidigare implementerad för Stockholmsregionen, och har därför även använts i detta projekt. VisumDUE är en makroskopisk nätutläggningsmodell med dynamiskt ruttval, och Regent är en efterfrågemodell som innehåller resgenerering, färdmedelsval och destinationsval för arbetsresor[1].Surrogat-baserad optimering erbjuder ett ramverk för optimering av problem med beräkningsmässigt kostsamma målfunktioner. Genom att approximera en funktionsyta till samplade punkter från den kostsamma målfunktionen, kan optimeringen istället göras över den approximerade funktionsytan. För Regent/VisumDUE tar utvärderingen av ett givet trängselskattescenario ca tio timmar, och det är denna beräkningstid som gör målfunktionen kostsam. Givet ett antal samplade punkter, görs ytterligare sampling utifrån en given strategi för att förbättra approximationen, så kallad iterativ sampling. Inom ramverket finns dock en mängd möjligheter för hur de olika komponenterna designas. Därför är det svårt att utvärdera surrogat-baserad optimering med endast Regent/VisumDUE. En statisk transportmodell har därför använts för att utvärdera ett antal kombinationer av samplingsstrategi och funktionsyta. Den mest lovande kombinationen har sedan även utvärderats med Regent/VisumDUE. För att vara praktiskt tillämpbart i framtiden har fokus i projektet varit att utvärdera hur metodansatsen fungerar när antalet möjliga tulluppsättningar är kraftigt begränsat (20-40 stycken).Det scenario som har använts som grund i projektet är trängselskatt i Stockholm på nuvarande tullring, på Essingeleden samt på innerstadsbroarna. Skatten är differentierad med avseende på riktning, vilket ger sex olika skattenivåer att optimera. Optimeringen har gjorts för trängselskattenivå under maxtimmen. I det dynamiska fallet har trängselskattens nivå utanför maxtimme funnits med som indata, men samma tidsprofil som på nuvarande tullring har antagits i alla scenarier (avgiftstrappa 50%, 75%, 100%, 75%, 50%). Utvärderingen med den statiska transportmodellen visar att lösningar nära globalt optimum kan uppnås med endast 40 utvärderade trängselskattenivåer, och en tydlig förbättring av den samhällsekonomiska nyttan uppnås redan vid 20 utvärderade trängselskattenivåer.Även med ett kraftigt begränsat antal utvärderingar av den kostsamma målfunktionen i Regent/VisumDUE, har vi visat att det är möjligt att använda metodansatsen. En tydlig förbättring av den samhällsekonomiska nyttan uppnås med endast 22 utvärderade trängselskattenivåer. Ytterligare experiment skulle dock behövas för att undersöka hur stor denna förbättring är i förhållande till vad som skulle kunna uppnås.
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  • Ekström, Joakim, 1980-, et al. (författare)
  • Surrogate-based optimisation of toll levels in congestion pricing schemes
  • 2014
  • Ingår i: Transportation Infrastructure. - Hong Kong : Hong Kong Society of Transportation Studies Limited. - 9789881581433 ; , s. 209-216
  • Konferensbidrag (refereegranskat)abstract
    • There has recently been a growing interest in analysing road pricing schemes in urban areas using dynamic traffic assignment (DTA) tools. Finding optimal toll levels in cordon based road pricing schemes has so far mainly been studied using either derivative-free heuristics or ascent methods. For future use of DTA tools such methods are not suitable and in this paper we investigate how a surrogate modelling framework can be used instead. We focus on cases when the number of costly objective function evaluations is limited to between 20 and 40. In order to allow a large number of different configurations of the surrogate modelling framework to be evaluated, a static user equilibrium model is used for simulating the road users’ response to a given pricing scheme. The results show that for a realistic scenario, valuable information on close to optimal toll levels can be achieved with only 20 costly function evaluations.
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  • Ekström, Joakim, et al. (författare)
  • Surrogate-based optimization of cordon toll levels in congested traffic networks
  • 2016
  • Ingår i: Journal of Advanced Transportation. - : John Wiley & Sons. - 0197-6729 .- 2042-3195. ; 50:6, s. 1008-1033
  • Tidskriftsartikel (refereegranskat)abstract
    • The benefit, in terms of social surplus, from introducing congestion charging schemes in urban networks is depending on the design of the charging scheme. The literature on optimal design of congestion pricing schemes is to a large extent based on static traffic assignment, which is known for its deficiency in correctly predict travel times in networks with severe congestion. Dynamic traffic assignment can better predict travel times in a road network, but are more computational expensive. Thus, previously developed methods for the static case cannot be applied straightforward. Surrogate-based optimization is commonly used for optimization problems with expensive-to-evaluate objective functions. In this paper, we evaluate the performance of a surrogate-based optimization method, when the number of pricing schemes, which we can afford to evaluate (because of the computational time), are limited to between 20 and 40. A static traffic assignment model of Stockholm is used for evaluating a large number of different configurations of the surrogate-based optimization method. Final evaluation is performed with the dynamic traffic assignment tool VisumDUE, coupled with the demand model Regent, for a Stockholm network including 1240 demand zones and 17 000 links. Our results show that the surrogate-based optimization method can indeed be used for designing a congestion charging scheme, which return a high social surplus.
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  • Ekström, Nils, et al. (författare)
  • Aspirin treatment and risk of first incident cardiovascular diseases in patients with type 2 diabetes : an observational study from the Swedish National Diabetes Register
  • 2013
  • Ingår i: BMJ Open. - : BMJ Publishing Group. - 2044-6055. ; 3:4, s. e002688-
  • Tidskriftsartikel (refereegranskat)abstract
    • Objectives To investigate the benefits and risks associated with aspirin treatment in patients with type 2 diabetes and no previous cardiovascular disease (CVD) in clinical practice. Design Population-based cohort study between 2005 and 2009, mean follow-up 3.9years. Setting Hospital outpatient clinics and primary care in Sweden. Participants Men and women with type 2 diabetes, free from CVD, including atrial fibrillation and congestive heart failure, at baseline, registered in the Swedish National Diabetes Register, with continuous low-dose aspirin treatment (n=4608) or no aspirin treatment (n=14038). Main outcome measures Risks of CVD, coronary heart disease (CHD), stroke, mortality and bleedings, associated with aspirin compared with no aspirin, were analysed in all patients and in subgroups by gender and estimated cardiovascular risk. Propensity scores were used to adjust for several baseline risk factors and characteristics at Cox regression, and the effect of unknown covariates was evaluated in a sensitivity analysis. Results There was no association between aspirin use and beneficial effects on risks of CVD or death. Rather, there was an increased risk of non-fatal/fatal CHD associated with aspirin; HR 1.19 (95% CI 1.01 to 1.41), p=0.04. The increased risk of cardiovascular outcomes associated with aspirin was seen when analysing women separately; HR 1.41 (95% CI 1.07 to 1.87), p=0.02, and HR 1.28 (95% CI 1.01 to 1.61), p=0.04, for CHD and CVD, respectively, but not for men separately. There was a trend towards increased risk of a composite of bleedings associated with aspirin, n=157; HR 1.41 (95% CI 0.99 to 1.99). Conclusions The results support the trend towards more restrictive use of aspirin in patients with type 2 diabetes and no previous CVD. More research is needed to explore the differences in aspirin's effects in women and men.
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  • Ekström, Nils, et al. (författare)
  • Cardiovascular safety of glucose-lowering agents as add-on medication to metformin treatment in type 2 diabetes: report from the Swedish National Diabetes Register
  • 2016
  • Ingår i: Diabetes Obesity & Metabolism. - : Wiley. - 1462-8902 .- 1463-1326. ; 18:10, s. 990-998
  • Tidskriftsartikel (refereegranskat)abstract
    • Aim: To investigate the relative safety of various glucose-lowering agents as add-on medication to metformin in type 2 diabetes in an observational study linking five national health registers. Research design and methods: Patients with type 2 diabetes who had been on metformin monotherapy and started another agent in addition to metformin were eligible for inclusion. The study period was 2005-2012. Adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) of mortality, cardiovascular disease (CVD), coronary heart disease (CHD), stroke and congestive heart failure (CHF) were estimated using Cox proportional hazards models, weighted for a propensity score. Results: Of the 20 422 patients included in the study, 43% started on second-line treatment with sulphonylurea (SU), 21% basal insulin, 12% thiazolidinedione (TZD), 11% meglitinide, 10% dipeptidyl peptidase-4 (DPP-4) inhibitor, 1% glucagon-like peptide-1 (GLP-1) receptor agonist and 1% acarbose. At the index date, the mean patient age was similar to 60 years for all groups except the GLP-1 receptor agonist (56.0 years) and SU (62.9 years) groups. Diabetes duration and glycated haemoglobin levels were similar in all groups. When compared with SU, basal insulin was associated with an 18% higher risk and TZD with a 24% lower risk of mortality [HR 1.18 (95% CI 1.03-1.36) and 0.76 (95% CI 0.62-0.94)], respectively. DPP-4 inhibitor treatment was associated with significantly lower risks of CVD, fatal CVD, CHD, fatal CHD and CHF. Conclusions: This nationwide observational study showed that second-line treatment with TZD and DPP-4 inhibitor as add-on medication to metformin were associated with significantly lower risks of mortality and cardiovascular events compared with SU, whereas basal insulin was associated with a higher risk of mortality.
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  • Ekström, Nils, et al. (författare)
  • Glucose-lowering treatment and clinical results in 163 121 patients with type 2 diabetes: an observational study from the Swedish national diabetes register
  • 2012
  • Ingår i: Diabetes Obesity & Metabolism. - : Wiley. - 1462-8902 .- 1463-1326. ; 14:8, s. 717-726
  • Tidskriftsartikel (refereegranskat)abstract
    • Aims: To analyse clinical characteristics and treatment results in unselected type 2 diabetes mellitus (T2DM) patients, with non-pharmacological treatment as well as the most commonly used pharmacological glucose-lowering treatment regimens, in everyday clinical practice. Methods: In this population-based cross-sectional study, information was linked from the Swedish National Diabetes Register, Prescribed Drug Register and Patient Register. T2DM patients with non-pharmacological treatment and T2DM patients continuously using the 12 most common pharmacological treatment regimens were included in the study (n = 163121). Results: There were statistically significant differences in clinical characteristics between the groups. Patients with insulin-based treatment regimens had the longest duration of diabetes and more cardiovascular risk factors than the T2DM-population in general. The proportion of patients reaching HbA1c =7% varied between 70.1% (metformin) and 25.0% [premixed insulin (PMI) + SU) in patients with pharmacological treatment. 84.8% of the patients with non-pharmacological treatment reached target. Compared to patients on metformin, patients on other pharmacological treatments had a lower likelihood, with hazard ratios ranging from 0.58; 95% confidence interval (CI), 0.540.63 to 0.97;0.940.99, of having HbA1c =7% (adjusted for covariates). Patients on insulin-based treatments had the lowest likelihood, while non-pharmacological treatment was associated with an increased likelihood of having HbA1c =7%. Conclusion: This nation-wide study shows insufficiently reached treatment goals for haemoglobin A1c (HbA1c) in all treatment groups. Patients on insulin-based treatment regimens had the longest duration of diabetes, more cardiovascular risk factors and the highest proportions of patients not reaching HbA1c target.
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  • Fridén, Alexia, et al. (författare)
  • Mapping two centuries of forest governance in Nordic countries : An open access database
  • 2024
  • Ingår i: Forest Policy and Economics. - 1389-9341. ; 160
  • Tidskriftsartikel (refereegranskat)abstract
    • Forest ecosystems play a crucial role in the production and protection of economic, social, and environmental values. To understand current challenges and trajectories shaping future strategies within the Nordic forest sector, it is important to map and trace past and present policy and governance developments. The core contribution of this short communication is to present an open-access database that compiles key forest-related public national policies, legislative documents, and private governance initiatives in Denmark, Finland, Sweden, and Norway from the 19th century to the present day. To showcase the potential use of the database, we conducted a comparative appraisal of forest governance trends across Nordic countries, outlining differences and shared characteristics. We identify a shift from a highly regulated and rationalized forest management regime in the 19th and early 20th centuries towards more flexible forms of contemporary governance. This transformation comes with the growing importance of sectorial freedom with responsibility principles, but also increasing calls for forest multifunctionality. Demands for recreation, climate change mitigation, and biodiversity conservation have intensified pressures on forest owners to provide public goods. However, the production and processing of marketable forest resources remains important to meet circular bioeconomy strategy goals. We conclude by briefly discussing the implications for strategic multifunctional use and polycentric governance of forests.
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  • Hansen, Lea B.S., et al. (författare)
  • A low-gluten diet induces changes in the intestinal microbiome of healthy Danish adults
  • 2018
  • Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 9:1
  • Tidskriftsartikel (refereegranskat)abstract
    • © 2018, The Author(s). Adherence to a low-gluten diet has become increasingly common in parts of the general population. However, the effects of reducing gluten-rich food items including wheat, barley and rye cereals in healthy adults are unclear. Here, we undertook a randomised, controlled, cross-over trial involving 60 middle-aged Danish adults without known disorders with two 8-week interventions comparing a low-gluten diet (2 g gluten per day) and a high-gluten diet (18 g gluten per day), separated by a washout period of at least six weeks with habitual diet (12 g gluten per day). We find that, in comparison with a high-gluten diet, a low-gluten diet induces moderate changes in the intestinal microbiome, reduces fasting and postprandial hydrogen exhalation, and leads to improvements in self-reported bloating. These observations suggest that most of the effects of a low-gluten diet in non-coeliac adults may be driven by qualitative changes in dietary fibres.
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  • Hofmann, Robin, et al. (författare)
  • Oxygen therapy in suspected acute myocardial infarction
  • 2017
  • Ingår i: New England Journal of Medicine. - : MASSACHUSETTS MEDICAL SOC. - 0028-4793 .- 1533-4406. ; 377:13, s. 1240-1249
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: The clinical effect of routine oxygen therapy in patients with suspected acute myocardial infarction who do not have hypoxemia at baseline is uncertain. METHODS: In this registry-based randomized clinical trial, we used nationwide Swedish registries for patient enrollment and data collection. Patients with suspected myocardial infarction and an oxygen saturation of 90% or higher were randomly assigned to receive either supplemental oxygen (6 liters per minute for 6 to 12 hours, delivered through an open face mask) or ambient air. RESULTS: A total of 6629 patients were enrolled. The median duration of oxygen therapy was 11.6 hours, and the median oxygen saturation at the end of the treatment period was 99% among patients assigned to oxygen and 97% among patients assigned to ambient air. Hypoxemia developed in 62 patients (1.9%) in the oxygen group, as compared with 254 patients (7.7%) in the ambient-air group. The median of the highest troponin level during hospitalization was 946.5 ng per liter in the oxygen group and 983.0 ng per liter in the ambient-air group. The primary end point of death from any cause within 1 year after randomization occurred in 5.0% of patients (166 of 3311) assigned to oxygen and in 5.1% of patients (168 of 3318) assigned to ambient air (hazard ratio, 0.97; 95% confidence interval [CI], 0.79 to 1.21; P=0.80). Rehospitalization with myocardial infarction within 1 year occurred in 126 patients (3.8%) assigned to oxygen and in 111 patients (3.3%) assigned to ambient air (hazard ratio, 1.13; 95% CI, 0.88 to 1.46; P=0.33). The results were consistent across all predefined subgroups. CONCLUSIONS: Routine use of supplemental oxygen in patients with suspected myocardial infarction who did not have hypoxemia was not found to reduce 1-year all-cause mortality. (Funded by the Swedish Heart–Lung Foundation and others; DETO2X-AMI ClinicalTrials.gov number, NCT01787110.)
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  • Häll, Carl Henrik, 1978-, et al. (författare)
  • Adjustments of public transit operations planning process for the use of electric buses
  • 2019
  • Ingår i: Journal of Intelligent Transportation Systems / Taylor & Francis. - : Taylor & Francis. - 1547-2450 .- 1547-2442. ; 23:3, s. 216-230
  • Tidskriftsartikel (refereegranskat)abstract
    • This work investigates and discusses how the introduction of electric buses (EB), both battery and plug-in hybrid EB, will and should change the operations planning of a public transit system. It is shown that some changes are required in the design of a transit route network, and in the timetabling and vehicle scheduling processes. Other changes are not required, but are advisable, using this opportunity upon the introduction of EB. The work covers the main characteristics of different types of EB with a short description, including the most popular charging technologies, and it presents the generally accepted transit operations planning process. Likewise, it describes and analytically formulates new challenges that arise when introducing EB. The outcome of the analyses shows that multiple new considerations must take place. It is also shown that the different charging techniques will influence the operations planning process in different ways and to a varying extent. With overnight, quick and continuous charging, the main challenges are in the network route design step, given the possibility of altering the existing network of routes, with efficient and optimal changes of the timetabling and vehicle scheduling components. An illustrative example, based on four bus lines in Norrköping, Sweden, is formulized and introduced using three problem instances of 48, 82, and 116 bus trips. The main results exhibit the minimum number of vehicles required using different scenarios of charging stations.
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  • Häll, Carl Henrik, 1978-, et al. (författare)
  • Adjustments of Public Transit Operations Planning Process for the Use of Electric Buses
  • 2017
  • Ingår i: TRB Annual Meeting Online, 2017. - : Transportation Research Board.
  • Konferensbidrag (refereegranskat)abstract
    • This work investigates and discusses how the introduction of electric buses (EB), both battery and plug-in hybrid EB, will and should change the operations planning of a public transit system. It is shown that some changes are required in the design of a transit route network, and in the timetabling and vehicle scheduling processes. Other changes are not required, but are advisable, using this opportunity upon the introduction of EB. The work covers the main characteristics of different types of EB with a short description, including the most popular charging technologies, and it presents the generally accepted transit operations planning process. Likewise, it describes and analytically formulates new challenges that arise when introducing EB. The outcome of the analyses shows that multiple new considerations must take place. It is also shown that the different charging techniques will influence the operations planning process in different ways and to a varying extent. With overnight, quick and continuous charging, the main challenges are in the network route design step, given the possibility of altering the existing network of routes, with efficient and optimal changes of the timetabling and vehicle scheduling components.
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  • Karlsson, Richard, et al. (författare)
  • Establishment of Prostate Tumor Growth and Metastasis Is Supported by Bone Marrow Cells and Is Mediated by PIP5K1α Lipid Kinase
  • 2020
  • Ingår i: Cancers. - : MDPI. - 2072-6694. ; 12:9
  • Tidskriftsartikel (refereegranskat)abstract
    • Cancer cells facilitate growth and metastasis by using multiple signals from the cancer-associated microenvironment. However, it remains poorly understood whether prostate cancer (PCa) cells may recruit and utilize bone marrow cells for their growth and survival. Furthermore, the regulatory mechanisms underlying interactions between PCa cells and bone marrow cells are obscure. In this study, we isolated bone marrow cells that mainly constituted populations that were positive for CD11b and Gr1 antigens from xenograft PC-3 tumor tissues from athymic nu/nu mice. We found that the tumor-infiltrated cells alone were unable to form tumor spheroids, even with increased amounts and time. By contrast, the tumor-infiltrated cells together with PCa cells formed large numbers of tumor spheroids compared with PCa cells alone. We further utilized xenograft athymic nu/nu mice bearing bone metastatic lesions. We demonstrated that PCa cells were unable to survive and give rise to colony-forming units (CFUs) in media that were used for hematopoietic cell colony-formation unit (CFU) assays. By contrast, PC-3M cells survived when bone marrow cells were present and gave rise to CFUs. Our results showed that PCa cells required bone marrow cells to support their growth and survival and establish bone metastasis in the host environment. We showed that PCa cells that were treated with either siRNA for PIP5K1α or its specific inhibitor, ISA-2011B, were unable to survive and produce tumor spheroids, together with bone marrow cells. Given that the elevated expression of PIP5K1α was specific for PCa cells and was associated with the induced expression of VEGF receptor 2 in PCa cells, our findings suggest that cancer cells may utilize PIP5K1α-mediated receptor signaling to recruit growth factors and ligands from the bone marrow-derived cells. Taken together, our study suggests a new mechanism that enables PCa cells to gain proliferative and invasive advantages within their associated host microenvironment. Therapeutic interventions using PIP5K1α inhibitors may not only inhibit tumor invasion and metastasis but also enhance the host immune system.
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  • Kaspersson, A., et al. (författare)
  • Microbial dynamics in barley grain stored under controlled atmosphere
  • 1988
  • Ingår i: Animal Feed Science and Technology. - : Elsevier BV. - 0377-8401 .- 1873-2216. ; 19:4, s. 299-312
  • Tidskriftsartikel (refereegranskat)abstract
    • Barley of 2 moisture contents, 20-23% and 26-28%, was stored airtight for 2 separate seasons in 2 full-scale silos, and for 3 separate seasons in 12-16 pilot silos (1.25 m3). The microbial dynamics were studied, using colony-forming units (CFU) of microorganisms, the proportion of internally-invaded kernels and ATP content. The ATP content was a good measure of the microbial activity, which decreased after loading and was very low during the winter period. Field-associated moulds and yeasts decreased in numbers of CFU and in the amount of invaded kernels. Fusarium species survived more satisfactorily than most field fungi. The temperature rise in spring caused an increase in ATP content, as a result of extensive growth of yeast of the genera Hansenula and Candida. This activity started earlier in the high-moisture grain (March). In May, a significant increase in CFU of Penicillium was observed and, during May to July, in many silos, all kernels were invaded, mostly by P. roqueforti. In an attempt to increase the time of safe storage, some technical improvements and gaseous and liquid chemical additives were tested. Attachment of "lungs" to the silos, and addition of organic acids or gases (CO2, N2, NH3) to the grain, increased the safe storage time by one to several months. The aerobic storage stability of rolled barley taken in July from the full-scale silos was tested. The rapid deterioration following unloading limited the aerobic storage stability to a few days. © 1988.
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34.
  • Lundberg, Martin, et al. (författare)
  • Multiplexed Homogeneous Proximity Ligation Assays for High-throughput Protein Biomarker Research in Serological Material
  • 2011
  • Ingår i: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 10:4, s. M110.004978-
  • Tidskriftsartikel (refereegranskat)abstract
    • A high throughput protein biomarker discovery tool has been developed based on multiplexed proximity ligation assays in a homogeneous format in the sense of no washing steps. The platform consists of four 24-plex panels profiling 74 putative biomarkers with sub-pM sensitivity each consuming only 1 mu l of human plasma sample. The system uses either matched monoclonal antibody pairs or the more readily available single batches of affinity purified polyclonal antibodies to generate the target specific reagents by covalently linking with unique nucleic acid sequences. These paired sequences are united by DNA ligation upon simultaneous target binding forming a PCR amplicon. Multiplex proximity ligation assays thereby converts multiple target analytes into real-time PCR amplicons that are individually quantified using microfluidic high capacity qPCR in nano liter volumes. The assay shows excellent specificity, even in multiplex, by its dual recognition feature, its proximity requirement, and most importantly by using unique sequence specific reporter fragments on both antibody-based probes. To illustrate the potential of this protein detection technology, a pilot biomarker research project was performed using biobanked plasma samples for the detection of colorectal cancer using a multivariate signature.
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35.
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36.
  • Nebasifu, Ayonghe A., et al. (författare)
  • Forest policy in Nordic countries : Expert opinions on future needs, uncertainties, and recommendations
  • 2024
  • Ingår i: Trees, Forests and People. - 2666-7193. ; 16
  • Tidskriftsartikel (refereegranskat)abstract
    • There are broad calls in national and international forest policy processes for basing decision-making on the best obtainable scientific knowledge. Simultaneously, there is also a need to accommodate plural values and objectives people and society in general have associated with forests. An essential step for building an evidence base that accommodates pluralistic understandings is to capture informant views on forest policies and the alternatives they offer to better prepare for future scenarios. This article draws on research experts’ views in Finland, Sweden, Norway, and Denmark, gathered from interviews between February and May 2023. An existing gap to bridge is understanding to what extent such views differ or correlate across the study countries. By systematizing on the similarities and differences in opinions, we develop a synopsis of future needs and uncertainties in policies across the studied countries, concluding with recommendations for determining the use of Nordic forests. Despite divergence in personal views and uncertainties about the future, most respondents saw a need for inclusive policymaking, policy coherence and integration, and changes in forest management. We find that strengthening evidence-basis, stakeholder participation, adaptive governance, and integrative forest management are challenges for future policy making.
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37.
  • Pomp, Stephan, et al. (författare)
  • The New Uppsala Neutron Beam Facility
  • 2004
  • Ingår i: Proc. Int. Conf. on Nuclear Data for Science and Technology.
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)
  •  
38.
  • Quttineh, Nils-Hassan, 1979-, et al. (författare)
  • Combined Timetabling and Vehicle Scheduling for Electric Buses
  • 2017
  • Ingår i: Proceedings of the 22nd International Conference of Hong Kong Society for Transportation Studies (HKSTS), December 9-11, 2017, Hong Kong, China. - Hong Kong : HKSTS.
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • In this paper we present a novel mathematical model, integrating the timetabling and vehicle schedulingproblems for electric buses. The objective is to minimize the number of buses while satisfying constraintsconcerning routing and charging, including design choices of where to install charging equipment. Weillustrate the different effects of tackling the timetabling and vehicle scheduling of electric buses as separateproblems or as a joint problem, both for fixed and variable headways. To do so, tests are performed with: (i) given timetable, i.e. solving only the vehicle scheduling problem, (ii) fixed headways for each line, (iii) variable headways. For these tests, a small case based on four bidirectional bus lines is used.
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39.
  • Quttineh, Nils-Hassan, et al. (författare)
  • Integrated solution for electric bus timetabling and vehicle scheduling combined with choices of charging locations
  • 2023
  • Ingår i: Journal of Public Transportation. - : ELSEVIER. - 1077-291X. ; 25
  • Tidskriftsartikel (refereegranskat)abstract
    • This paper presents a novel mathematical model, integrating timetabling and vehicle scheduling problems for electric buses. The objective is to minimize the number of buses while satisfying constraints concerning routing and charging, including design choices for where to install charging stations. The aim of the paper is to illustrate and discuss the effects of solving the timetabling and vehicle scheduling of electric buses (including where to install charging infrastructure) separately, compared to solving them jointly in one single step. For that purpose, we perform tests with: i) given timetable, that is, solving only the vehicle scheduling problem, ii) fixed headways for each line, and iii) variable headways. A small test case based on actual bus lines from Va center dot stra Fro center dot lunda, Gothenburg, Sweden, is used. From the numerical experiments, we verify that combining the two planning steps can significantly reduce the number of vehicles needed.
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40.
  • Ström, Kristoffer, et al. (författare)
  • N1-methylnicotinamide is a signalling molecule produced in skeletal muscle coordinating energy metabolism
  • 2018
  • Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Obesity is a major health problem, and although caloric restriction and exercise are successful strategies to lose adipose tissue in obese individuals, a simultaneous decrease in skeletal muscle mass, negatively effects metabolism and muscle function. To deeper understand molecular events occurring in muscle during weight-loss, we measured the expressional change in human skeletal muscle following a combination of severe caloric restriction and exercise over 4 days in 15 Swedish men. Key metabolic genes were regulated after the intervention, indicating a shift from carbohydrate to fat metabolism. Nicotinamide N-methyltransferase (NNMT) was the most consistently upregulated gene following the energy-deficit exercise. Circulating levels of N1-methylnicotinamide (MNA), the product of NNMT activity, were doubled after the intervention. The fasting-fed state was an important determinant of plasma MNA levels, peaking at ~18 h of fasting and being lowest ~3 h after a meal. In culture, MNA was secreted by isolated human myotubes and stimulated lipolysis directly, with no effect on glucagon or insulin secretion. We propose that MNA is a novel myokine that enhances the utilization of energy stores in response to low muscle energy availability. Future research should focus on applying MNA as a biomarker to identify individuals with metabolic disturbances at an early stage. 
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41.
  • Söderqvist, Anita, et al. (författare)
  • Prediction of mortality in elderly patients with hip fractures : a two-year prospective study of 1,944 patients
  • 2009
  • Ingår i: Gerontology. - : S. Karger AG. - 0304-324X .- 1423-0003. ; 55:5, s. 496-504
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Hip fracture patients are reported to have an increased mortality rate compared to the general population. In order to be able to reduce the morbidity and mortality after a hip fracture, our efforts to identify the patients at risk already upon admission to the hospital need to be increased. For such a risk assessment, robust, validated, and reproducible criteria are mandatory. OBJECTIVE: To determine preoperative factors associated with mortality and to evaluate the combined use of the American Society of Anesthesiologists (ASA) and the Short Portable Mental Status Questionnaire (SPMSQ) to identify patients with an increased mortality rate and to create a predictive model to assess the mortality risk after hip fracture surgery. METHODS: A total of 1,944 consecutive patients aged 66 years or older admitted for a hip fracture were included in a prospective cohort study with a 24-month follow-up. The patients were assessed with regard to gender, age, type of hip fracture, smoking habits, comorbidities, general physical health according to the ASA classification, and cognitive function according to the SPMSQ. A higher ASA score indicates an increasingly severe systemic disease and a lower SPMSQ score indicates an increasingly severe cognitive dysfunction. We used Cox proportional hazard models and classification trees to identify the factors associated with mortality. The predictive model was created based on factors that were significantly associated with death and all readily accessible upon admission. RESULTS: The mortality rate during the acute hospitalization period was 4%, at 4 months 16%, and at 24 months 38%. The most prominent factors associated with mortality were high ASA scores, low SPMSQ scores, high age and male gender. The SPMSQ score provided additional information about the survival time, compared to when the ASA score was used alone. CONCLUSION: The combined use of the ASA classification for assessing physical health and the SPMSQ for assessing cognitive function effectively identified hip fracture patients with an increased mortality rate. We present a predictive model including age, gender, ASA, and SPMSQ that can be used to assess the mortality risk after hip fracture surgery.
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42.
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