| 1. |
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| 2. |
- Ahlberg, Ernst, et al.
(författare)
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Using conformal prediction to prioritize compound synthesis in drug discovery
- 2017
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Ingår i: Proceedings of Machine Learning Research. - Stockholm : Machine Learning Research. ; , s. 174-184
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Konferensbidrag (refereegranskat)abstract
- The choice of how much money and resources to spend to understand certain problems is of high interest in many areas. This work illustrates how computational models can be more tightly coupled with experiments to generate decision data at lower cost without reducing the quality of the decision. Several different strategies are explored to illustrate the trade off between lowering costs and quality in decisions.AUC is used as a performance metric and the number of objects that can be learnt from is constrained. Some of the strategies described reach AUC values over 0.9 and outperforms strategies that are more random. The strategies that use conformal predictor p-values show varying results, although some are top performing.The application studied is taken from the drug discovery process. In the early stages of this process compounds, that potentially could become marketed drugs, are being routinely tested in experimental assays to understand the distribution and interactions in humans.
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| 3. |
- Albrektsson, Joakim, 1981-
(författare)
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Durability of fire exposed concrete : Experimental Studies Focusing on Sti„ffness & Transport Properties
- 2015
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Road and rail tunnels are important parts of the modern infrastructure. High strength concrete (HSC) is commonly used for tunnels and other civil engineering structures, since it allows high load carrying capacity and long service life. In general, Swedish road and rail tunnels should be designed for a service life of 120 years. However, HSC has shown to be sensitive to severe fires in the moist tunnel environment, i.e., fire spalling may occur. Extensive research shows that addition of polypropylene (PP) fibres in the fresh concrete mix significantly reduces the risk of fire spalling. The durability of a concrete structure is mainly governed by the transport properties. Further, experimental studies aimed at understanding the protective mechanism of PP fibres indicate that fluid transport increases in connection with the melting temperature of such fibres. This might reduce the durability of fire exposed concrete with addition of PP fibres. This study aims to investigate whether the use of PP fibres has any significant effect on the durability of moderate fire exposed concrete structures.The experimental study focused on transport properties related to durability and stiffness reduction of fire exposed civil engineering concrete with and without addition of PP fibres. The study consists of three parts; (i) unilateral fire exposure in accordance with the standard time-temperature curve (Std) and a slow heating curve (SH), (ii) uniformly heating of non-restrained samples to 250oC, and (iii) moderate unilateral fire exposure, 350oC, of restrained samples. Changes in material properties caused by the fire exposure were studied by means of ultrasonic pulse velocity, full field-strain measurements during uniaxial compression core tests, polarization and fluorescence microscopy (PFM), water absorption and non-steady state chloride migration.The study shows that fire exposure influences different properties of importance for load carrying capacity and durability. To get a clear image of the fire damage one has to combine different test methods during damage assessments. Transport properties of concrete both with and without addition of PP fibres were considerably affected even at moderate fire exposure. Hence, the service life might be reduced. All series with addition of PP fibres exhibited higher water absorption compared to the series without PP fibres. The practical importance of this might, however, be small since also the water absorption of concrete without PP fibres was considerably affected for the fire scenarios considered in this study. Behind the fire exposed surface, i.e., between 30 and 60 mm, no change in water absorption was observed for concrete without PP fibres. However, higher water absorption of the series with addition of PP fibres was observed.Indicative fire tests aimed to evaluate the resistance to fire spalling during a subsequent severe fire was also conducted. The concretes with addition of PP fibres showed no signs of fire spalling, while progressive spalling was observed for the concrete without PP fibres.
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| 4. |
- Anderson, Johan, et al.
(författare)
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Applying uncertainty quantification in modelling of a steel beam exposed to fire
- 2016
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Ingår i: Structures in Fire. - 9781605953205 ; , s. 925-932
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Modelling of structures exposed to fires is prone to be heavily influenced by uncertainties in geometrical parameters, thermal material data as well as uncertainties in the boundary conditions. Assessing the effects and influences in variations of all the uncertain parameters is often cumbersome and traditional methods are impractical thus modelling of the total uncertainty is needed. Uncertainty Quantification with deterministic sampling is one possible way ahead to accommodate and evaluating the effects of uncertainties with as few repeated simulations as possible. In this paper the uncertainties stemming from error in the input data and boundary conditions on one example of a steel beam under four point bending exposed to fire is evaluated.
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| 5. |
- Anderson, Johan, et al.
(författare)
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EUROPEAN APPROACH TO ASSESS THE FIRE PERFORMANCE OF FAÇADES
- 2019
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Ingår i: Interflam 2019, proceedings. - : Interscience Communications. ; , s. 213-
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Konferensbidrag (refereegranskat)abstract
- Several attempts have been made in the past to develop a European harmonized testing and assessment method for façades before the European commission decided to publish a call for tender on the topic. A project consortium from five countries (Sweden, UK, France, Germany and Hungary) applied to the call for tender and was contracted to develop a European approach to assess the fire performance of façades. 24 sub-contractors and 14 stakeholder entities were part of the project.The objective of the European project was to address a request from the Standing Committee of Construction (SCC) to provide EC Member States regulators with a means to regulate the fire performance of façade systems based on a European approach agreed by SCC. In addressing this objective, the project team was asked to consider a number of issues which are presented and discussed.The initial stages of this project were focused on:establishing a register of the regulatory requirements in all Member States in relation to the fire performance of façade systems, andto identify those Member States who have regulatory requirements for the fire performance façade systems which go beyond the current EN 13501 (reaction to fire and fire resistance) classification systems and to collate the details of these additional requirements. [6]After having confirmed the regulatory needs the following steps were discussed:a testing and classification methodology based on BS 8414 - Fire performance of external cladding systems series and DIN 4102-20 - Fire behaviour of building materials and building components - Part 20: Complementary verification for the assessment of the fire behaviour of external wall claddings to address the identified key performance and classification characteristics [4] [5]a verification and validation proposal, in the form of a round robin programme to support the development of the proposed testing and classification methodologies.an alternative test method which was developed on the basis of the comments from stakeholders during the projectSeveral hundreds of comments were received during the project and were implemented in the development.This paper is a short overview of results the two-year development work, which Final Report published by the European Commission in 2018 [1].
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| 6. |
- Anderson, Johan, et al.
(författare)
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European approach to assess the fire performance of façades
- 2020
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Ingår i: Fire and Materials. - : John Wiley and Sons Ltd. - 0308-0501 .- 1099-1018.
-
Tidskriftsartikel (refereegranskat)abstract
- Several attempts have been made in the past to develop a European harmonized testing and assessment method for façades before the European commission decided to publish a call for tender on the topic. A project consortium from five countries (Sweden, UK, France, Germany and Hungary) applied to the call for tender and was contracted to develop a European approach to assess the fire performance of façades. 24 sub-contractors and 14 stakeholder entities were part of the project. The objective of the European project was to address a request from the Standing Committee of Construction (SCC) to provide EC Member States regulators with a means to regulate the fire performance of façade systems based on a European approach agreed by SCC. The initial stages of this project were focused on establishing a register of the regulatory requirements in all Member States in relation to the fire performance of façade systems, and to identify those Member States who have regulatory requirements for the fire performance façade systems which go beyond the current EN 13501 (reaction to fire and fire resistance) classification systems and to collate the details of these additional requirements. After having confirmed the regulatory needs a testing and classification methodology based on BS 8414 and DIN 4102-20 was developed to address the identified key performance and classification characteristics. This paper is a short overview of results the two-year development work, which Final Report published by the European Commission in 2018. © 2020 The Authors. Fire and Materials published by John Wiley & Sons Ltd.
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| 7. |
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| 8. |
- Anderson, Johan, et al.
(författare)
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Experimental comparisons in façade fire testing considering SP Fire 105 and the BS 8414‐1
- 2018
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Ingår i: Fire and Materials. - : Wiley. - 0308-0501 .- 1099-1018. ; 42:5
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Tidskriftsartikel (refereegranskat)abstract
- A comparison between full‐scale façade fire tests where SP Fire 105 and BS 8414‐1 were used regarding repeatability and the use of modeling to discern changes in the setups is presented. Two test series according to BS 8414‐1 were repeated outside using the same façade systems on 2 different days, whereas for the SP Fire 105 a set of common façade systems in Sweden were tested indoors. In particular, the results show that the wind around the test setup may have a significant impact on the tests and that the heat exposure to the façade surface will depend on the thickness of the test specimen where an increased temperature in front of the façade, and a decreased temperature on the façade 2.1 m above the fire room, is observed experimentally. The heat exposure to the test specimen varies to a more limited extent when an uncontrollable free burning fire source is used (in this study heptane and wood, respectively) and that this variation increases when wind is present.
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| 9. |
- Anderson, Johan, et al.
(författare)
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Fire dynamics in Façade fire tests : Measurement, modeling and repeatability
- 2015
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Ingår i: Applications of Structural Fire Engineering. - : Czech Technical University in Prague. - 2336-7318. - 9788001061947
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Konferensbidrag (refereegranskat)abstract
- Presented is a comparison between full-scale façade tests where SP Fire 105 and BS 8414-1 were used regarding repeatability and the use of modelling to discern changes in the set-ups. Results show that the air movements around the test set-up (the wind) may have a significant impact on the tests and that the heat exposure to the façade surface will among other depend on the thickness of the test specimen. Also demonstrated was that good results could be obtained by modelling of the façade fire tests giving us the opportunity to use these methods to determine the effect of a change in the experimental setup.
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| 10. |
- Anderson, Johan, 1973-, et al.
(författare)
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Fire Safety of Façades
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Façade fires do not occur often (in comparison to other major structure fires) but in recent years there have been a number of spectacular façade fires in high rise building such as the recent fire in Grenfell Tower, London.Under-ventilated compartment fires may cause flames to spill out of window openings impinging the façade, thus devastating façade fires may start on one floor leap-frogging to adjacent floors. It is therefore necessary to limit or delay fire spread to higher floors. Requirements built on large scale fire testing may decrease the risk of these types of fires provided that the building is constructed according to the specifications provided by the manufacturer. Different countries have different regulations and tests for façades. New materials and façade systems are continuously introduced which might call for an update of these tests and regulations.This report summarizes experimental and modelling efforts in characterizing the fire safety of façades using the Swedish SP Fire 105 and the British BS 8414 methods. Recent experimental results and modelling is presented exploring the variations in the fire exposure, fire load and the fuel used. The fire source and the heat exposure to the façade are characterized by additional temperatures measured by plate thermometers while some other aspects are only treated in the numerical study such as a change in fuel. It is found that the results from the BS 8414 are largely affected by wind and climate since the experimental test was performed outdoors, moreover fire spread on wooden façades is also briefly discussed.In order to obtain a deeper understanding of the test methods and the results CFD (Computational Fluid Dynamics) Modelling in FDS was used. The models were based on measured input parameters including uncertainties and an assessment of the impact of said uncertainties. The models could often reproduce the experimentally found temperatures qualitatively and quantitatively. A detailed discussion on the regulations and the tests that lead to the SP Fire 105 test method is also presented. Summaries of the façade testing methods and conditions in other European countries are presented in the appendices.Finally possible ways forward in updating the façade testing and regulations are discussed.
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| 11. |
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| 12. |
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| 13. |
- Anderson, Johan, et al.
(författare)
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Modelling of fire exposure in facade fire testing
- 2017
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Ingår i: Fire and Materials. - : John Wiley & Sons. - 0308-0501 .- 1099-1018. ; 42:5, s. 475-483
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, a comparative simulation study on 3 large‐scale facade testing methods, namely,the SP Fire 105, BS 8414‐1, and the ISO 13785‐2 methods, is presented. Generally goodcorrespondence between simulations and experimental data has been found, provided thatthermal properties of the facade material and heat release rates are known; however, thecorrespondence deviates in close proximity of the fire source. Furthermore, a statistical ensemblefor evaluating the effects stemming from uncertainty in input data is used. Here, it wasfound using this statistical ensemble that the variability was smaller in the ISO 13785‐2compared to the BS 8414‐1 method. The heat release rates (HRR) used in the simulations wereadopted from measurements except for the ISO method where the information in the standardwas used to approximate the HRR. A quantitative similarity between the HRR in the ISOmethod and the British method was found.
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| 14. |
- Anderson, Johan, et al.
(författare)
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Uncertainties in façade fire tests - Measurements and modeling
- 2016
-
Ingår i: MATEC Web of Conferences. - : EDP Sciences.
-
Konferensbidrag (refereegranskat)abstract
- In this paper a comparison between test and modelling results are performed for two large-scale façade fire testing methods, namely SP Fire 105 and BS 8414-1. In order to be able to compare tests and modelling the uncertainties have to be quantified both in the test and the modelling. Here we present a methodology based on deterministic sampling to quantify uncertainties in the modelling input. We find, in general good agreement between the models and the test results. Moreover, temperatures estimated by plate thermometers is indicated to be less sensitive to small variations in model input and is thus suitable for these kind of comparisons.
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| 15. |
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| 16. |
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| 17. |
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| 18. |
- Andersson, Lars, et al.
(författare)
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Sprouting capacity from intact root systems of Cirsium arvense and Sonchus arvensis decrease in autumn
- 2013
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Ingår i: Weed research (Print). - : Wiley. - 0043-1737 .- 1365-3180. ; 53:3, s. 183-191
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Tidskriftsartikel (refereegranskat)abstract
- Perennial weeds are often controlled by mechanical means, which aim at stimulating axillary and adventitious buds to sprout. This happens when the apical dominance of the main shoot is removed by defoliation or when the underground system is fragmented. By repeating the measures, the result is a depletion of storage compounds, which weakens the plants and reduces their capacity to grow and reproduce. However, timing is critical. Earlier research has indicated that emergence from fragments of Sonchus arvensis cease during a period in autumn, while the seasonal pattern of sprouting in Cirsium arvense appears to be inconsistent. We studied the emergence pattern of defoliated plants with undisturbed root systems, from late summer to early spring. Potted plants grown outdoors were exhumed at regular intervals, put under forcing conditions for 4weeks, after which shoots above and below soil level were counted and weighed together with the remaining root systems. In both species, the number and weight of emerged shoots decreased during a period in the autumn. In C.arvense, underground shoots were constantly produced during the same period, while fewer underground shoots were present in S.arvensis. For the latter species, apical dominance does not fully explain the effect; thus, endodormancy might be involved. Root weight increased until withering and did not explain the lack of emergence. Our results suggest an impaired sprouting capacity of undisturbed root systems of C.arvense and S.arvensis during SeptemberOctober, which has implications for the timing and method of control of these species.
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| 19. |
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| 20. |
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| 21. |
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| 22. |
- Antonsson, Ann-Beth, et al.
(författare)
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Soffan och miljön. En översiktlig studie av hur en soffa kan påverka miljön,från tillverkningen av de olika materialen i den, tills den blivit avfall. Ett exempel på en livstidsanalys.
- 1990
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Det är alltmer uppenbart att påverkan på miljön inte enbart beror på utsläppen från enskilda industrier. Miljön påverkas i hela kedjan från utvinning av råvaror, produktion och konsumtion av en vara, fram tills varan blir avfall. Även transporter, energiförbrukning och effekter på arbetsmiljön är viktiga faktorer i bedömningen av den totala påverkan på miljön. I framtiden kommer bedömningen att innefatta allt fler av dessa steg. Det är enbart mot bakgrund av sådana totalbedömningar, som det går att jämföra mijöeffekter, t ex av olika varor eller olika produktionsmetoder. En beskrivning av miljöpåverkan från olika delar av varans livstid, gör det också möjligt att prioritera åtgärderna, så att de sätts in där de gör störst nytta. Som ett enkelt exempel på vad som kan innefattas i en livstidsanalys, har IVL på uppdrag av Miljödepartementet, gjort en översiktlig livstidsanalys av en soffa som exempel på hur en vardagsvara kan påverka miljön, från vaggan till graven.
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| 23. |
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| 24. |
- Asker, Lars, et al.
(författare)
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Identifying Factors for the Effectiveness of Treatment of Heart Failure : A Registry Study
- 2016
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Ingår i: IEEE 29th International Symposiumon Computer-Based Medical Systems. - : IEEE Computer Society. - 9781467390361
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Konferensbidrag (refereegranskat)abstract
- An administrative health register containing health care data for over 2 million patients will be used to search for factors that can affect the treatment of heart failure. In the study, we will measure the effects of employed treatment for various groups of heart failure patients, using different measures of effectiveness. Significant deviations in effectiveness of treatments of the various patient groups will be reported and factors that may help explaining the effect of treatment will be analyzed. Identification of the most important factors that may help explain the observed deviations between the different groups will be derived through generation of predictive models, for which variable importance can be calculated. The findings may affect recommended treatments as well as high-lighting deviations from national guidelines.
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| 25. |
- Asker, Lars, et al.
(författare)
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Learning from Swedish Healthcare Data
- 2016
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Ingår i: Proceedings of the 9th ACM International Conference on PErvasive Technologies Related to Assistive Environments. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450343374
-
Konferensbidrag (refereegranskat)abstract
- We present two ongoing projects aimed at learning from health care records. The first project, DADEL, is focusing on high-performance data mining for detrecting adverse drug events in healthcare, and uses electronic patient records covering seven years of patient record data from the Stockholm region in Sweden. The second project is focusing on heart failure and on understanding the differences in treatment between various groups of patients. It uses a Swedish administrative health register containing health care data for over two million patients.
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| 26. |
- Asker, Lars, et al.
(författare)
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Mining Candidates for Adverse Drug Interactions in Electronic Patient Records
- 2014
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Ingår i: PETRA '14 Proceedings of the 7th International Conference on Pervasive Technologies Related to Assistive Environments, PETRA’14. - New York : ACM Press. - 9781450327466
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Konferensbidrag (refereegranskat)abstract
- Electronic patient records provide a valuable source of information for detecting adverse drug events. In this paper, we explore two different but complementary approaches to extracting useful information from electronic patient records with the goal of identifying candidate drugs, or combinations of drugs, to be further investigated for suspected adverse drug events. We propose a novel filter-and-refine approach that combines sequential pattern mining and disproportionality analysis. The proposed method is expected to identify groups of possibly interacting drugs suspected for causing certain adverse drug events. We perform an empirical investigation of the proposed method using a subset of the Stockholm electronic patient record corpus. The data used in this study consists of all diagnoses and medications for a group of patients diagnoses with at least one heart related diagnosis during the period 2008--2010. The study shows that the method indeed is able to detect combinations of drugs that occur more frequently for patients with cardiovascular diseases than for patients in a control group, providing opportunities for finding candidate drugs that cause adverse drug effects through interaction.
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| 27. |
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| 28. |
- Boström, Anders E, 1951, et al.
(författare)
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Scattering of acoustic waves by a circular disc in the interface between two fluids
- 1991
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Ingår i: Journal of the Acoustical Society of America. - 1520-8524 .- 0001-4966. ; 90, s. 3338-3343
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Tidskriftsartikel (refereegranskat)abstract
- The scattering of acoustic waves by a sound-hard circular disc situated in the planar interface between two different fluids is considered. The incident wave is taken as a plane wave and a Hankel transform representation of the scattered field is used. After some manipulations using the boundary conditions, this leads to an integral equation over the disc for the potential jump across the disc. This jump is expanded in a series of Legendre functions which fulfill the correct edge condition and the integral equation is projected on the same set of Legendre functions. The far fields are calculated and the implications of energy conservation are explored and used as a numerical check. A few numerical computations showing the disc-scattered far field amplitude and the total scattering cross section are given and are shown to compare favorably with the expectations from simple ray theory at higher frequencies.
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| 29. |
- Boström, Anne-Marie, et al.
(författare)
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Barriers to research utilization and research use among registered nurses working in the care of older people. Does the BARRIERS Scale discriminate between research users and non-research uses on perception of barriers?
- 2008
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Ingår i: Implementation Science. - : Springer Science and Business Media LLC. - 1748-5908. ; 3:24
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundOne strategy to enhance research use and change current practice is to identify barriers and then implement tailored interventions to reduce these barriers. In nursing, the BARRIERS scale has been frequently used to identify nurses' perceptions of barriers to research utilization. However, this scale has not been applied to care of older people, and only one study has investigated how identified barriers link to research utilization. Therefore, the purpose of this study was twofold: to describe RNs' perceptions of barriers to and facilitators of research utilization and to examine the validity of the BARRIERS scale in relation to research use.MethodsA cross-sectional survey design was used and registered nurses (RNs) working in the care of older people participated (response rate 67%, n = 140/210). Two questionnaires, the BARRIERS scale and the Research Utilization Questionnaire (RUQ), were used. Data were analyzed using descriptive and bivariate inferential statistics.ResultsCharacteristics of the organization and the presentation of research findings were rated as the most prominent barriers. The three items most frequently reported as barriers were: the nurse is isolated from knowledgeable colleagues with whom to discuss the research (89%); the facilities are inadequate for implementation (88%); and, the relevant literature is not compiled in one place (81%). Surveyed RNs suggested more support from unit managers and better availability of user-friendly reports in Swedish to enhance research use.The RNs reported a modest use of research. A weak but significant correlation was found between the Research Use index in RUQ and the Presentation subscale in the BARRIERS scale (r = -0.289, p < 0.01), suggesting that the RNs reporting more research use were less likely to perceive presentation of research as a barrier. Dividing the sample into research users (n = 29) and non-research users (n = 105), the research users rated significantly lower on the subscales Presentation, Nurse and Research in the BARRIERS scale.ConclusionThe BARRIERS scale revealed differences in the perception of barriers between research users and non-research users. Thus, methodologically the scale appears useful in identifying some types of barriers to research utilization but not organizational barriers. The identified barriers, however, are general and wide-ranging, making it difficult to design useful specific interventions.
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| 30. |
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| 31. |
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| 32. |
- Boström, Anne-Marie, et al.
(författare)
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Registered nurses' application of evidence based practice : a national survey
- 2009
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Ingår i: Journal of Evaluation In Clinical Practice. - : Wiley - Blackwell. - 1356-1294 .- 1365-2753. ; 15:6, s. 1159-1163
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Tidskriftsartikel (refereegranskat)abstract
- Background. Evidence-based practice (EBP) is a worldwide approach to improving health care. There is, however, a shortage of studies examining whether or not newly graduated health care professionals are actually applying EBP in their daily work.Objectives. To examine the application of EBP in clinical practice by registered nurses (RNs) 2 years post graduation and to explore whether the application of EBP differed with regard to the clinical settings where RNs were working.Method. A cross-sectional design using a national sample. Data were collected in 2007 from 987 RNs (response rate 76%). Six items measuring respondents' self-reported extent of applying EBP were used.Results. Of the 987 RNs, 19% formulated questions and performed searches in data bases, 56% used other information sources, 31% appraised the literature, 30% participated in practice development and 34% participated in evaluating clinical practice. A greater proportion of the RNs working in elder care applied EBP compared with the RNs working in hospitals, psychiatric care and primary care.Conclusions. The RNs applied the components of EBP to a rather low extent 2 years post graduation despite EBP being an important objective in Swedish health care and educational programmes since the 1990s. These findings support other studies reporting the implementation of EBP in organizations as a complex and often slow process. The differences in the RNs extent of applying EBP in relation to their workplace indicate that contextual factors and the role of the RN in the organization are of importance for getting EBP into practice.
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| 33. |
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| 34. |
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| 35. |
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| 36. |
- Boström, Fredrik, et al.
(författare)
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Cerebrospinal fluid total tau is associated with shorter survival in dementia with Lewy bodies.
- 2009
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Ingår i: Dementia and geriatric cognitive disorders. - : S. Karger AG. - 1421-9824 .- 1420-8008. ; 28:4, s. 314-9
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Tidskriftsartikel (refereegranskat)abstract
- A pathology typical of dementia with Lewy bodies (DLB) has been demonstrated to increase mortality to a greater extent than the pathology of Alzheimer's disease (AD). However, mortality in DLB has also been shown to increase with concomitant AD pathology. Furthermore, in a recent publication, we showed that there is a robust and specific increase in CSF calcium and magnesium in DLB patients compared to both AD patients and controls. Thus, in order to explore the influence of CSF AD markers and trace element concentrations on mortality in DLB, we undertook a longitudinal prospective study of 47 clinically diagnosed DLB patients and 157 AD patients as well as 49 healthy volunteers. Both AD and DLB patients showed an increased mortality compared to the healthy controls (relative risk: 10 and 8, respectively; p < 0.001). Increased levels of CSF total tau were associated with increased mortality among the DLB patients (p < 0.05), but not among the AD patients or controls. Gender, age, MMSE score, Abeta42 concentration and phosphorylated tau, and CSF trace element concentrations did not influence survival in the obtained models.
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| 37. |
- Boström, Fredrik, et al.
(författare)
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CSF Mg and Ca as diagnostic markers for dementia with Lewy bodies.
- 2008
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Ingår i: Neurobiology of aging. - : Elsevier BV. - 1558-1497 .- 0197-4580. ; 30:8, s. 1265-1271
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Tidskriftsartikel (refereegranskat)abstract
- Accumulating evidence implicates a role for altered metal homeostasis in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease (AD). However, few investigations have addressed this issue in dementia with Lewy bodies (DLB). The aim of the present study was to investigate metal concentrations in cerebrospinal fluid (CSF) and plasma from patients with DLB and other neurodegenerative disorders. To that end, CSF and plasma samples were collected from 29 patients with DLB, 174 patients with AD, 90 patients with AD with minor vascular components, and 51 healthy volunteers. Total concentrations of Mg, Ca, Mn, Fe, Cu, Zn, Rb, Sr, and Cs were determined using mass spectrometry. Patients with DLB had elevated Ca and Mg levels in CSF and Mg levels in plasma as compared to all other groups (p<0.001). Furthermore, a combination of CSF-Mg and CSF-Ca could distinguish DLB from AD with a sensitivity of 93% and a specificity of 85%. Cu levels in both CSF and plasma tended to be higher in DLB compared to the other groups, but these trends failed to reach significance after correction for multiple comparisons. Mn, Fe, Zn, Rb, and Sr concentration in CSF or plasma were similar in all groups. The observed elevations of CSF-Mg, CSF-Ca and CSF-Cu may contribute to or be associated with the neurodegenerative process in DLB. Furthermore, determination of CSF-Mg and CSF-Ca concentration may be a valuable tool in distinguishing DLB from AD.
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| 38. |
- Boström, Gert-Olof, et al.
(författare)
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Growth ambitions and internationalization among newly started small Swedish firms
- 2017
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Ingår i: Motivating SMEs to cooperate and internationalize. - New York : Routledge. - 9781315412603 - 9781138220577 ; , s. 191-203
-
Bokkapitel (refereegranskat)abstract
- Small firms are essential for any national economy due to their aggregate number of employees, their role in technological change and productivity growth, and essentially in economic development (Boter and Lundström 2005; Glower 1999; Eurostat 2016). Whereas much research takes departure in the broader SME category, an explicit delimitation to the smaller firms means that we will find many self-employed and enterprises where the main intention is to secure a livelihood for the owner/manager rather than to expand business operations. Nevertheless, small firms hold important roles for employment and income generation not least in local and regional settings. The smallest category of firms naturally also contains many new ventures, firms which have not yet proven if they will survive or fail in the long run. As such, they constitute crucial components in development and change on a societal level: New ventures are needed for a dynamic and developing economy. Such processes could relate to the development of new technologies, new forms of organization and marketing, and to various ways to approach sustainable development, not least by the use of new business models (e.g. Bocken et al. 2014).
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| 39. |
- Boström, Gert-Olof, et al.
(författare)
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Sweden : Bank of Year Recognition & Performance
- 2015
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Ingår i: Services Marketing Quarterly. - : Informa UK Limited. - 1533-2969 .- 1533-2977. ; 36:1, s. 1-21
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Tidskriftsartikel (refereegranskat)abstract
- Swedish banking has been recognized for financial prudence, innovations and service provision. Bank of the Year winners are characterized in terms of their prize-winning performance. It details and then generalizes items that led to awards and quantifies the financial rewards that come from providing superior performance. In most cases, growth slowed, but winners still tended to attain above average performance. It would appear that 1.) service really is the foundation for recognition; 2.) more recently, sound management, innovation and financial performance have come into play, and 3.) it is easier to be recognized if the organization is small.
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| 40. |
- Boström, Henrik, et al.
(författare)
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Conformal prediction using random survival forests
- 2017
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Ingår i: Proceedings - 16th IEEE International Conference on Machine Learning and Applications, ICMLA 2017. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781538614174 ; , s. 812-817, s. 812-817
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Konferensbidrag (refereegranskat)abstract
- Random survival forests constitute a robust approach to survival modeling, i.e., predicting the probability that an event will occur before or on a given point in time. Similar to most standard predictive models, no guarantee for the prediction error is provided for this model, which instead typically is empirically evaluated. Conformal prediction is a rather recent framework, which allows the error of a model to be determined by a user specified confidence level, something which is achieved by considering set rather than point predictions. The framework, which has been applied to some of the most popular classification and regression techniques, is here for the first time applied to survival modeling, through random survival forests. An empirical investigation is presented where the technique is evaluated on datasets from two real-world applications; predicting component failure in trucks using operational data and predicting survival and treatment of heart failure patients from administrative healthcare data. The experimental results show that the error levels indeed are very close to the provided confidence levels, as guaranteed by the conformal prediction framework, and that the error for predicting each outcome, i.e., event or no-event, can be controlled separately. The latter may, however, lead to less informative predictions, i.e., larger prediction sets, in case the class distribution is heavily imbalanced.
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| 41. |
- Boström, Henrik, et al.
(författare)
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On the Definition of Information Fusion as a Field of Research
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A more precise definition of the field of information fusion can be of benefit to researchers within the field, who may use uch a definition when motivating their own work and evaluating the contribution of others. Moreover, it can enable researchers and practitioners outside the field to more easily relate their own work to the field and more easily understand the scope of the techniques and methods developed in the field. Previous definitions of information fusion are reviewed from that perspective, including definitions of data and sensor fusion, and their appropriateness as definitions for the entire research field are discussed. Based on strengths and weaknesses of existing definitions, a novel definition is proposed, which is argued to effectively fulfill the requirements that can be put on a definition of information fusion as a field of research.
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| 42. |
- Boström, Kurt, et al.
(författare)
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Biological matter as a source of authigenic matter in pelagic sediments
- 1978
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Ingår i: Chemical Geology. - : Elsevier BV. - 0009-2541 .- 1872-6836. ; 23:1-4, s. 11-20
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Tidskriftsartikel (refereegranskat)abstract
- Pelagic sediments are rich in components that appear to have formed from seawater, so-called authigenic deposits. Such authigenic components are commonly well oxidized and are rich in many metals such as Cu, Co and Ni. On the other hand, most of these metals have restricted solubilities and very short residence times in seawater. True authigenesis can therefore only account for little of the "authigenic"-looking matter in the deep sea.Conservative mixing models, using average terrigenous matter, average marine biological matter, average volcanic matter (East Pacific Rise-emanation) and average basaltic matter, produce model sediments that are strikingly similar to real sediments.In the model sediments several of the trace-element abundances for instance those for Cu, Ni and Ba can only be explained by a large admixture of biological matter. Several of these elements are enriched in the authigenic phases in deep-sea sediments. This implies that most components that generally have been considered as authigenic are rearranged decay products of biological material.
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| 43. |
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| 44. |
- Boström, Kurt, et al.
(författare)
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Geochemistry and origin of ferromanganese concretions in the Gulf of Bothnia
- 1982
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Ingår i: Marine Geology. - : Elsevier BV. - 0025-3227 .- 1872-6151. ; 50:1-2, s. 1-24
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Tidskriftsartikel (refereegranskat)abstract
- Ferromanganese concretions cover large areas of the Gulf of Bothnia. They are flat to well-rounded, the rounded ones being richer in oxyhydroxides of iron and manganese. Rounded and ellipsoidal nodules, particularly those in the northern Gulf of Bothnia, are richest in Mn, Ni, Ba and Cu, which probably coexist in a Mn oxyhydroxide phase. Flat nodules are enriched in Fe, P, rare earths and As, probably associated with an Fe oxy-hydroxide component. Aluminum, V, Cr and Ti occur in still another phase. The sediments of the gulf generally consist of a 10-50 mm-thick layer of oxidized surface sediment, enriched in Mn, Ba, P and Ni lying on top of reduced sediments which are diagenetically depleted in these elements. The remobilized elements have redeposited in the nodules, but this process cannot explain the origin of all the nodular material. Some released Mn, Ba and Ni furthermore enter into suspended phases, which eventually leave the Baltic Sea. The economic value of the nodules in the Gulf of Bothnia is probably limited at present.
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