| 1. |
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| 2. |
- Andersson, Sofia E M, 1979, et al.
(författare)
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Moderate- to high intensity aerobic and resistance exercise reduces peripheral blood regulatory cell populations in older adults with rheumatoid arthritis
- 2020
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Ingår i: Immunity & Ageing. - : Springer Science and Business Media LLC. - 1742-4933. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- Objective Exercise can improve immune health and is beneficial for physical function in patients with rheumatoid arthritis (RA), but the immunological mechanisms are largely unknown. We evaluated the effect of moderate- to high intensity exercise with person-centred guidance on cells of the immune system, with focus on regulatory cell populations, in older adults with RA. Methods Older adults (>= 65 years) with RA were randomized to either 20-weeks of moderate - to high intensity aerobic and resistance exercise (n = 24) or to an active control group performing home-based exercise of light intensity (n = 25). Aerobic capacity, muscle strength, DAS28 and CRP were evaluated. Blood samples were collected at baseline and after 20 weeks. The frequency of immune cells defined as adaptive regulatory populations, CD4 + Foxp3 + CD25 + CD127- T regulatory cells (Tregs) and CD19 + CD24hiCD38hi B regulatory cells (Bregs) as well as HLA-DR-/lowCD33 + CD11b + myeloid derived suppressor cells (MDSCs), were assessed using flow cytometry. Results After 20 weeks of moderate- to high intensity exercise, aerobic capacity and muscle strength were significantly improved but there were no significant changes in Disease Activity Score 28 (DAS28) or CRP. The frequency of Tregs and Bregs decreased significantly in the intervention group, but not in the active control group. The exercise intervention had no effect on MDSCs. The reduction in regulatory T cells in the intervention group was most pronounced in the female patients. Conclusion Moderate- to high intensity exercise in older adults with RA led to a decreased proportion of Tregs and Bregs, but that was not associated with increased disease activity or increased inflammation.
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| 3. |
- Andrésen, Cecilia, et al.
(författare)
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Critical biophysical properties in the Pseudomonas aeruginosa efflux gene regulator MexR are targeted by mutations conferring multidrug resistance
- 2010
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Ingår i: Protein Science. - : Cold Spring Harbor Laboratory Press. - 0961-8368 .- 1469-896X. ; 19:4, s. 680-692
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Tidskriftsartikel (refereegranskat)abstract
- The self-assembling MexA-MexB-OprM efflux pump system, encoded by the mexO operon, contributes to facile resistance of Pseudomonas aeruginosa by actively extruding multiple antimicrobials. MexR negatively regulates the mexO operon, comprising two adjacent MexR binding sites, and is as such highly targeted by mutations that confer multidrug resistance (MDR). To understand how MDR mutations impair MexR function, we studied MexR-wt as well as a selected set of MDR single mutants distant from the proposed DNA-binding helix. Although DNA affinity and MexA-MexB-OprM repression were both drastically impaired in the selected MexR-MDR mutants, MexR-wt bound its two binding sites in the mexO with high affinity as a dimer. In the MexR-MDR mutants, secondary structure content and oligomerization properties were very similar to MexR-wt despite their lack of DNA binding. Despite this, the MexR-MDR mutants showed highly varying stabilities compared with MexR-wt, suggesting disturbed critical interdomain contacts, because mutations in the DNA-binding domains affected the stability of the dimer region and vice versa. Furthermore, significant ANS binding to MexR-wt in both free and DNA-bound states, together with increased ANS binding in all studied mutants, suggest that a hydrophobic cavity in the dimer region already shown to be involved in regulatory binding is enlarged by MDR mutations. Taken together, we propose that the biophysical MexR properties that are targeted by MDR mutations stability, domain interactions, and internal hydrophobic surfaces are also critical for the regulation of MexR DNA binding.
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| 4. |
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| 5. |
- Argento, Daniela, et al.
(författare)
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Integrating sustainability in higher education : a Swedish case
- 2020
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Ingår i: International Journal of Sustainability in Higher Education. - : Emerald Group Publishing Limited. - 1467-6370 .- 1758-6739. ; 21:6, s. 1131-1150
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Tidskriftsartikel (refereegranskat)abstract
- Purpose – This paper aims to unveil how sustainability is integrated into the courses/programmes ofhigher education institutions. The research question addressed is: how do academics representing differentdisciplines cooperate and engage in the work of integrating sustainability into their teaching programmes.Design/methodology/approach – This paper draws upon the notions of practise variation andinstitutional work from institutional theory and empirically focusses on the case of Kristianstad University(Sweden). This case is based on an autoethnographic approach and illustrates the experiences shared by sixcolleagues, representing different disciplines, engaged in implementing sustainability in their courses/programmes.Findings – The findings highlight how academics representing different disciplines, with specific traditionsand characteristics, face the sustainability challenge. Despite being bound by similar sustainable developmentgoals, differences across disciplines need to be acknowledged and used as an asset if trans-disciplinarity is theultimate goal.Research limitations/implications – Although the intrinsic motivation of individuals to work withsustainability might be a strong driver, the implementation of sustainability within courses/programmes andacross disciplines requires joint efforts and collective institutional work.Practical implications – By highlighting how academics engage in the work of integratingsustainability, this study emphasizes that managers of higher education institutions need to account for thetime and additional resources needed to ensure that academics effectively cope with sustainability. Intrinsicmotivation may not last if organizational structures and leadership are not supportive on a practical level andin the long run.
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| 6. |
- Argento, Daniela, et al.
(författare)
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Integrating sustainability in higher education : a Swedish case
- 2020
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Ingår i: International Journal of Sustainability in Higher Education. - : Emerald Group Publishing Ltd.. - 1467-6370. ; 21:6, s. 1131-1150
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose – This paper aims to unveil how sustainability is integrated into the courses/programmes ofhigher education institutions. The research question addressed is: how do academics representing differentdisciplines cooperate and engage in the work of integrating sustainability into their teaching programmes.Design/methodology/approach – This paper draws upon the notions of practise variation andinstitutional work from institutional theory and empirically focusses on the case of Kristianstad University(Sweden). This case is based on an autoethnographic approach and illustrates the experiences shared by sixcolleagues, representing different disciplines, engaged in implementing sustainability in their courses/programmes.Findings – The findings highlight how academics representing different disciplines, with specific traditionsand characteristics, face the sustainability challenge. Despite being bound by similar sustainable developmentgoals, differences across disciplines need to be acknowledged and used as an asset if trans-disciplinarity is theultimate goal.Research limitations/implications – Although the intrinsic motivation of individuals to work withsustainability might be a strong driver, the implementation of sustainability within courses/programmes andacross disciplines requires joint efforts and collective institutional work.Practical implications – By highlighting how academics engage in the work of integratingsustainability, this study emphasizes that managers of higher education institutions need to account for thetime and additional resources needed to ensure that academics effectively cope with sustainability. Intrinsicmotivation may not last if organizational structures and leadership are not supportive on a practical level andin the long run.
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| 7. |
- Aydin-Schmidt, Berit, et al.
(författare)
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Field Evaluation of a High Throughput Loop Mediated Isothermal Amplification Test for the Detection of Asymptomatic Plasmodium Infections in Zanzibar
- 2017
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Background New field applicable diagnostic tools are needed for highly sensitive detection of residual malaria infections in pre-elimination settings. Field performance of a high throughput DNA extraction system for loop mediated isothermal amplification (HTP-LAMP) was therefore evaluated for detecting malaria parasites among asymptomatic individuals in Zanzibar. Methods HTP-LAMP performance was evaluated against real-time PCR on 3008 paired blood samples collected on filter papers in a community-based survey in 2015. Results The PCR and HTP-LAMP determined malaria prevalences were 1.6% (95% CI 1.3-2.4) and 0.7% (95% CI 0.4-1.1), respectively. The sensitivity of HTP-LAMP compared to PCR was 40.8% (CI95% 27.0-55.8) and the specificity was 99.9% (CI95% 99.8-100). For the PCR positive samples, there was no statistically significant difference between the geometric mean parasite densities among the HTP-LAMP positive (2.5 p/mu L, range 0.2-770) and HTP-LAMP negative (1.4 p/mu L, range 0.1-7) samples (p = 0.088). Two lab technicians analysed up to 282 samples per day and the HTP-LAMP method was experienced as user friendly. Conclusions Although field applicable, this high throughput format of LAMP as used here was not sensitive enough to be recommended for detection of asymptomatic low-density infections in areas like Zanzibar, approaching malaria elimination.
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| 8. |
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| 9. |
- Carnerud, Daniel, 1983-, et al.
(författare)
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On the inclusion of sustainability and digitalisation in quality management : an overview from past to present
- 2020
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Ingår i: Total Quality Management and Business Excellence. - : Taylor & Francis. - 1478-3363 .- 1478-3371. ; , s. 1-23
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study is to explore whether trends in sustainability and digitalisation from the 1980s until today have left any significant practical or epistemological footprints on the quality management paradigm. The study design consists of a mixed-methods approach that applies a data-mining methodology and content analysis to the digital archives of eight scientific journals: six within the quality management (QM) domain and two with a focus on operations management (OM). The data set contains an unbroken time series of over 12,000 research paper abstracts, the first of them published in 1980, giving the study a coverage of almost 40 years. The findings show that sustainability came onto the scholarly scene in 1996 and has since become an increasingly popular research area. In regard to digitalisation, the story is quite different, as the concept is currently absent from the scholarly QM and OM literatures. However, a search for information technology (IT) and information systems (IS) revealed that these topics have been gaining attention since the 1980s. However, it was found that QM research only addresses one part of digitalisation, omitting several interesting dimensions. One example is that the QM and OM literatures address IS mainly in relation to standardised guidelines and business processes within organisations. At the same time, we found a handful of studies combining QM and topics related to modern digitisation, like social media.
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| 10. |
- Dartora, Caroline, et al.
(författare)
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A deep learning model for brain age prediction using minimally preprocessed T1w images as input
- 2023
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: In the last few years, several models trying to calculate the biological brain age have been proposed based on structural magnetic resonance imaging scans (T1-weighted MRIs, T1w) using multivariate methods and machine learning. We developed and validated a convolutional neural network (CNN)-based biological brain age prediction model that uses one T1w MRI preprocessing step when applying the model to external datasets to simplify implementation and increase accessibility in research settings. Our model only requires rigid image registration to the MNI space, which is an advantage compared to previous methods that require more preprocessing steps, such as feature extraction. Methods: We used a multicohort dataset of cognitively healthy individuals (age range = 32.0–95.7 years) comprising 17,296 MRIs for training and evaluation. We compared our model using hold-out (CNN1) and cross-validation (CNN2–4) approaches. To verify generalisability, we used two external datasets with different populations and MRI scan characteristics to evaluate the model. To demonstrate its usability, we included the external dataset’s images in the cross-validation training (CNN3). To ensure that our model used only the brain signal on the image, we also predicted brain age using skull-stripped images (CNN4). Results: The trained models achieved a mean absolute error of 2.99, 2.67, 2.67, and 3.08 years for CNN1–4, respectively. The model’s performance in the external dataset was in the typical range of mean absolute error (MAE) found in the literature for testing sets. Adding the external dataset to the training set (CNN3), overall, MAE is unaffected, but individual cohort MAE improves (5.63–2.25 years). Salience maps of predictions reveal that periventricular, temporal, and insular regions are the most important for age prediction. Discussion: We provide indicators for using biological (predicted) brain age as a metric for age correction in neuroimaging studies as an alternative to the traditional chronological age. In conclusion, using different approaches, our CNN-based model showed good performance using one T1w brain MRI preprocessing step. The proposed CNN model is made publicly available for the research community to be easily implemented and used to study ageing and age-related disorders.
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| 11. |
- Eisfeldt, Jesper, et al.
(författare)
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Discovery of Novel Sequences in 1,000 Swedish Genomes
- 2020
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Ingår i: Molecular biology and evolution. - : OXFORD UNIV PRESS. - 0737-4038 .- 1537-1719. ; 37:1, s. 18-30
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Tidskriftsartikel (refereegranskat)abstract
- Novel sequences (NSs), not present in the human reference genome, are abundant and remain largely unexplored. Here, we utilize de novo assembly to study NS in 1,000 Swedish individuals first sequenced as part of the SweGen project revealing a total of 46 Mb in 61,044 distinct contigs of sequences not present in GRCh38. The contigs were aligned to recently published catalogs of Icelandic and Pan-African NSs, as well as the chimpanzee genome, revealing a great diversity of shared sequences. Analyzing the positioning of NS across the chimpanzee genome, we find that 2,807 NS align confidently within 143 chimpanzee orthologs of human genes. Aligning the whole genome sequencing data to the chimpanzee genome, we discover ancestral NS common throughout the Swedish population. The NSs were searched for repeats and repeat elements: revealing a majority of repetitive sequence (56%), and enrichment of simple repeats (28%) and satellites (15%). Lastly, we align the unmappable reads of a subset of the thousand genomes data to our collection of NS, as well as the previously published Pan-African NS: revealing that both the Swedish and Pan-African NS are widespread, and that the Swedish NSs are largely a subset of the Pan-African NS. Overall, these results highlight the importance of creating a more diverse reference genome and illustrate that significant amounts of the NS may be of ancestral origin.
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| 12. |
- Guath, Mona, et al.
(författare)
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Pupil dilation during negative prediction errors is related to brain choline concentration and depressive symptoms in adolescents
- 2023
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Ingår i: Behavioural Brain Research. - : Elsevier BV. - 0166-4328 .- 1872-7549. ; 436
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Tidskriftsartikel (refereegranskat)abstract
- Depressive symptoms are associated with altered pupillary responses during learning and reward prediction as well as with changes in neurometabolite levels, including brain concentrations of choline, glutamate and gamma-aminobutyric acid (GABA). However, the full link between depressive symptoms, reward-learning-related pupillary responses and neurometabolites is yet to be established as these constructs have not been assessed in the same individuals. The present pilot study, investigated these relations in a sample of 24 adolescents aged 13 years. Participants completed the Revised Child Anxiety and Depression Scale (RCADS) and underwent a reward learning task while measuring pupil dilation and a single voxel dorsal anterior cingulate cortex (dACC) MEGA-PRESS magnetic resonance spectroscopy scan assessing choline, glutamate and GABA concentrations. Pupil dilation was related to prediction errors (PE) during learning, which was captured by a prediction error-weighted pupil dilation response index (PE-PDR) for each individual. Higher PE-PDR scores, indicating larger pupil dilations to negative prediction errors, were related to lower depressive symptoms and lower dACC choline concentrations. Dorsal ACC choline was positively associated with depressive symptoms, whereas glutamate and GABA were not related to PE-PDR or depressive symptoms. The findings support notions of cholinergic involvement in depressive symptoms and cholinergic influence on reward-related pupillary response, suggesting that pupillary responses to negative prediction errors may hold promise as a biomarker of depressive states.
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| 13. |
- Honfi, Daniel, et al.
(författare)
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Modelling of bending creep of low- and high-temperature-dried spruce timber
- 2013
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Ingår i: Wood Science and Technology. - : Springer Science and Business Media LLC. - 1432-5225 .- 0043-7719.
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Tidskriftsartikel (refereegranskat)abstract
- In the current project, a finite element model is developed to analyse the long-term behaviour of timber beams. The time-dependent response of wood subjected to bending and moisture changes is investigated in terms of strains and stresses. A rheological model is implemented to capture the effects of creep, mechano-sorption and hygroexpansion. The model is validated against test results from Bengtsson and Kliger (Holzforschung 57:95–100, 2003). The results of the analysis showed that the mechano-sorptive creep of low- (LT) and high-temperature-dried (HT) timber beams can be sufficiently modelled with a spring and a single Kelvin body. The different mechano-sorptive behaviour of LT- and HT-dried specimens is considered with different mechano-sorptive and shrinkage–swelling parameters. The presented model could be used to derive general mechano-sorptive parameters: (1) for better prediction of creep over the service life and (2) to provide a basis of time-dependent probabilistic calculations for structural-sized timber in serviceability limit state.
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| 14. |
- Honfi, Daniel, et al.
(författare)
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Reliability of beams according to Eurocodes in serviceability limit state
- 2012
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Ingår i: Engineering Structures. - : Elsevier BV. - 1873-7323 .- 0141-0296. ; 35, s. 48-54
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Tidskriftsartikel (refereegranskat)abstract
- To achieve a relatively consistent probability of failure for structural elements, most design codes apply reliability based code calibration process. Such approaches commonly focus on the strength of the structural members, which is related to the ultimate limit state (ULS). However in the design of beams the performance of the structural elements is often limited by the serviceability requirements, which are related to the serviceability limit state (SLS) using different load combinations than applied in the ultimate limit state. The current study aims to investigate the reliability for serviceability design for flexural members made of different materials (steel, concrete and timber) according to the specifications of the Eurocodes. Second-order reliability method (SORM) is applied to determine the reliability index for different design situations for beams subjected to bending. The probabilistic models of basic variables for time invariant analysis have been taken from the JCSS Probabilistic Model Code. The characteristic, the frequent and the quasi-permanent combination of actions are investigated and compared. The differences in service reliability for different materials are discussed. The results show that there are differences between the achieved reliability indices in the serviceability state between different materials and that for the given load combinations in the Eurocode the reliability index is often below the one given in the code. (C) 2011 Elsevier Ltd. All rights reserved.
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| 15. |
- Honfi, Daniel, et al.
(författare)
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Reliability of steel flexural members according to EC in serviceability limit state
- 2009
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Ingår i: Proceedings of 11th Nordic Steel Construction Conference. - 9171270582 ; , s. 446-453
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Konferensbidrag (refereegranskat)abstract
- To achieve a relatively consistent probability of failure for structural elements, most design codes apply reliability based code calibration process. Such approaches commonly focus on the ultimate strength of the structural members, which is related to the ultimate limit state (ULS). In the design of steel beams the performance of the structural elements is often limited by the serviceability requirements, which are related to the serviceability limit state (SLS) using different load combinations than those applied in the ultimate limit state. The current study aims to investigate the reliability for serviceability design for flexural steel members according to the specifications of the Eurocode. Second-order reliability method (SORM) is applied to determine the reliability index for different load ratios.
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| 16. |
- Honfi, Daniel, et al.
(författare)
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Structural reliability according to Eurocodes in serviceability limit state
- 2011
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Ingår i: IABSE-IASS 2011 London Symposium Report. - 9780707971223
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Konferensbidrag (refereegranskat)abstract
- The current study aims to investigate the reliability for serviceability design for flexural members made of different materials (steel, concrete and timber) according to the specifications of the current versions of Eurocodes. Second-order reliability method is applied to determine the reliability index for different design situations for simply supported beams subjected to bending. The characteristic, the frequent and the quasi-permanent combination of actions has been investigated and compared. The differences in service reliability for different materials have been discussed.
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| 17. |
- Hossain, Mosharraf, 1984-, et al.
(författare)
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Integrated Modeling and Application of Standardized Data Schema
- 2012
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Ingår i: Proceedings of the 5th Swedish Production Symposium (SPS 12). - Linköping : The Swedish Production Academy. - 9789175197524 ; , s. 473-478
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Konferensbidrag (refereegranskat)abstract
- Application of discrete event simulation has been widely accepted in the manufacturing industry forshop floor capacity and flow analysis. Often the models are made to analyse a limited aspects ofthe system behaviour that abstract only few factors for the sake of simplicity in the expense ofmodel accuracy. One of the prohibitive reasons for a detailed and multi objective model is thecollection and management of the input output simulation data.In this work an integrated and detailed simulation model of a machining line has been built for thepurpose of a multi objective analysis and optimization with application of thestandard simulation data schema for data management. The model incorporates detailed capacityand flow related factors as well as sustainability factors (energy usage in machine tools), Theabstraction level of the model is sufficiently low to capture the effect of operators’ movements inthe shop floor and setup procedures. To support modeling of such a detailed model enhancemodel reusability, the Core Manufacturing Simulation Data standard XML schema was used. Thisneutral format of data will also help to build model with less effort, reuse the information, andcommunicate with different application tools. A case study is carried out to illustrate the methodsand run a multi objective optimization. The results of the optimization work are reported in anotherpaper.
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| 18. |
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| 19. |
- Johansson, Daniel, et al.
(författare)
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Small scale testing of PCD and WC-Co tooling in rock cutting using longitudinal turning
- 2019
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Ingår i: Wear. - : Elsevier BV. - 0043-1648. ; 426-427:Part B, s. 1515-1522
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Tidskriftsartikel (refereegranskat)abstract
- Rock cutting and crushing stands for a considerable part of the world use of Cemented Carbide (CC). CC is preferred due to its hardness while maintaining high fracture toughness. However, new cutting tool materials are developed allowing increased efficiency whilst minimizing the use of critical raw material such as tungsten and cobalt. One material showing promising capabilities is Polycrystalline Diamond (PCD). Field testing of new wear resistant tool materials are known to be notoriously difficult due to issues controlling the test environment. To further support the development of new and more wear resistant tool materials there is a need for an improved methodology of laboratory testing of rock cutting. In this work a test rig was developed and testing methodology was validated, when using cutting tool inserts with standard shapes, such as round double sided general purpose insert RNGN and dome shaped buttons while machining and crushing bars of red granite by longitudinal turning using a standard lathe. Optical microscopy, 3D data of Volume Difference Measurements and SEM were used for analyzing tool wear. Different grades of CC showed similar wear mechanisms irrespectively of tool geometry. The PCD grade did not show similar wear mechanisms, but did outperform CC grade in regard to wear resistance.
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| 20. |
- Johansson, Karolina, et al.
(författare)
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Dietitian visits were a safe and cost-effective form of follow-up care for children with celiac disease
- 2019
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Ingår i: Acta Paediatrica, International Journal of Paediatrics. - : Wiley. - 0803-5253. ; 108:4, s. 676-680
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Tidskriftsartikel (refereegranskat)abstract
- Aim: This study compared follow-up protocols for paediatric celiac disease (CD) led by either paediatricians or dietitians at Swedish university hospitals. Methods: We followed 363 CD patients under 18 years at the university hospitals in Malmö (n = 140) and Lund (n = 79) between 2011 and 2013 and after they merged to become Skåne (n = 144) between 2014 and 2016. Both Lund and Malmö provided regular paediatrician follow-up visits, whereas Skåne provided mainly dietitian-led visits. Results: Children at Lund were followed for a mean of 1.0 ± 0.5 visits per year, compared to 0.7 ± 0.6 at Malmö (p < 0.0001) and 0.9 ± 0.6 at Skåne (p = 0.11). The ratio of annual paediatrician to dietitian annual visits was 1.4:1.0 at Lund, which was higher than Malmö (0.9:1.0; p = 0.0017) and Skåne (0.6:1.0; p < 0.0001). There was no difference in the prevalence of non-compliant patients between the clinics (p = 0.26, Malmö 13.6%, Lund 10.1%, Skåne 7.6%). Tissue transglutaminase autoantibody levels reversed equally over time at all three clinics after the subjects started a gluten-free diet (r = -0.55, p < 0.0001). The total mean annual cost per patient was lowest at Malmö and highest at Lund (p < 0.0001). Conclusion: Dietary compliance was similar regardless of whether care was provided by a dietitian or paediatrician. Dietitian-led follow-up visits may provide lower long-term costs.
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| 21. |
- Kallesoe, Christian, et al.
(författare)
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Integration, gap formation, and sharpening of III-V heterostructure nanowires by selective etching
- 2010
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Ingår i: Journal of Vacuum Science and Technology B. - : American Vacuum Society. - 1520-8567. ; 28:1, s. 21-26
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Tidskriftsartikel (refereegranskat)abstract
- Epitaxial growth of heterostructure nanowires allows for the definition of narrow sections with specific semiconductor composition. The authors demonstrate how postgrowth engineering of III-V heterostructure nanowires using selective etching can form gaps, sharpening of tips, and thin sections simultaneously on multiple nanowires. They investigate the potential of combining nanostencil deposition of catalyst, epitaxial III-V heterostructure nanowire growth, and selective etching, as a road toward wafer scale integration and engineering of nanowires with existing silicon technology. Nanostencil lithography is used for deposition of catalyst particles on trench sidewalls and the lateral growth of III-V nanowires is achieved from such catalysts. The selectivity of a bromine-based etch on gallium arsenide segments in gallium phosphide nanowires is examined, using a hydrochloride etch to remove the III-V native oxides. Depending on the etching conditions, a variety of gap topologies and tiplike structures are observed, offering postgrowth engineering of material composition and morphology.
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| 22. |
- Kuehn, Danilo, et al.
(författare)
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Directional sub-femtosecond charge transfer dynamics and the dimensionality of 1T-TaS2
- 2019
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Ingår i: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- For the layered transition metal dichalcogenide 1T-TaS2, we establish through a unique experimental approach and density functional theory, how ultrafast charge transfer in 1T-TaS2 takes on isotropic three-dimensional character or anisotropic two-dimensional character, depending on the commensurability of the charge density wave phases of 1T-TaS2. The X-ray spectroscopic core-hole-clock method prepares selectively in-and out-of-plane polarized sulfur 3p orbital occupation with respect to the 1T-TaS2 planes and monitors sub-femtosecond wave packet delocalization. Despite being a prototypical two-dimensional material, isotropic three-dimensional charge transfer is found in the commensurate charge density wave phase (CCDW), indicating strong coupling between layers. In contrast, anisotropic two-dimensional charge transfer occurs for the nearly commensurate phase (NCDW). In direct comparison, theory shows that interlayer interaction in the CCDW phase - not layer stacking variations - causes isotropic three-dimensional charge transfer. This is presumably a general mechanism for phase transitions and tailored properties of dichalcogenides with charge density waves.
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| 23. |
- Lennquist, Anna, 1978, et al.
(författare)
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Colour and melanophore function in rainbow trout after long term exposure to the new antifoulant medetomidine
- 2010
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 80:9, s. 1050-1055
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Tidskriftsartikel (refereegranskat)abstract
- Medetomidine is a new antifouling agent, and its effects in non-target aquatic organisms have been investigated. Earlier short-term studies in fish have shown a skin lightening response to medetomidine, but effects after chronic exposure have not been studied. In fish, the dark pigment melanin is contained within specialized cells, melanophores. Medetomidine binds to the melanophore α2-adrenoceptor, which stimulates pigment aggregation resulting in the light appearance. In the present study, rainbow trout (Oncorhynchus mykiss) was long-term exposed to 0.5 and 5.0 nM of medetomidine via water for 54 d. The fish were then photographed for paleness quantification and the images were analyzed using ImageJ analysis software. Additionally, scales were removed and used for in vitro function studies of the melanophores, monitoring the response to melanophore stimulating hormone (MSH) and subsequent medetomidine addition. The number of melanophores was also investigated. As a result of the medetomidine exposure, fish from the 5 nM treatment were significantly paler than control fish and the melanophores from these fishes were also more aggregated. Melanophores from all the treatments were functional, responding to MSH by dispersion and to subsequent medetomidine by aggregation. However, the results indicate a difference in sensitivity among treatments. The number of melanophores in the scales did not change significantly after long term exposure to medetomidine. These results suggest that the observed paleness may be reversible, even after chronic exposure.
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| 24. |
- Ljungqvist, Oskar, 1990-
(författare)
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On motion planning and control for truck and trailer systems
- 2019
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- During the last decades, improved sensor and hardware technologies as well as new methods and algorithms have made self-driving vehicles a realistic possibility in the near future. Thanks to this technology enhancement, many leading automotive and technology companies have turned their attention towards developing advanced driver assistance systems (ADAS) and self-driving vehicles. Autonomous vehicles are expected to have their first big impact in closed areas, such as mines, harbors and loading/offloading sites. In such areas, the legal requirements are less restrictive and the surrounding environment is more controlled and predictable compared to urban areas. Expected positive outcomes include increased productivity and safety, reduced emissions and the possibility to relieve the human from performing complex or dangerous tasks. Within these sites, different truck and trailer systems are used to transport materials. These systems are composed of several interconnected modules, and are thus large and highly unstable while reversing. This thesis addresses the problem of designing efficient motion planning and feedback control frameworks for such systems.First, a cascade controller for a reversing truck with a dolly-steered trailer is presented. The unstable modes of the system is stabilized around circular equilibrium configurations using a gain-scheduled linear quadratic (LQ) controller together with a higher-level pure pursuit controller to enable path following of piecewise linear reference paths. The cascade controller is then used within a rapidly-exploring random tree (RRT) framework and the complete motion planning and control framework is demonstrated on a small-scale test vehicle.Second, a path following controller for a reversing truck with a dolly-steered trailer is proposed for the case when the obtained motion plan is kinematically feasible. The control errors of the system are modeled in terms of their deviation from the nominal path and a stabilizing LQ controller with feedforward action is designed based on the linearization of the control error model. Stability of the closed-loop system is proven by combining global optimization, theory from linear differential inclusions and linear matrix inequality techniques.Third, a systematic framework is presented for analyzing stability of the closed-loop system consisting of a controlled vehicle and a feedback controller, executing a motion plan computed by a lattice planner. When this motion planner is considered, it is shown that the closed-loop system can be modeled as a nonlinear hybrid system. Based on this, a novel method is presented for analyzing the behavior of the tracking error, how to design the feedback controller and how to potentially impose constraints on the motion planner in order to guarantee that the tracking error is bounded and decays towards zero.Fourth, a complete motion planning and control solution for a truck with a dolly-steered trailer is presented. A lattice-based motion planner is proposed, where a novel parametrization of the vehicle’s state-space is proposed to improve online planning time. A time-symmetry result is established that enhance the numerical stability of the numerical optimal control solver used for generating the motion primitives. Moreover, a nonlinear observer for state estimation is developed which only utilizes information from sensors that are mounted on the truck, making the system independent of additional trailer sensors. The proposed framework is implemented on a full-scale truck with a dolly-steered trailer and results from a series of field experiments are presented.
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| 25. |
- Maliakkal, Carina B., et al.
(författare)
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Independent Control of Nucleation and Layer Growth in Nanowires
- 2020
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 14:4, s. 3868-3875
-
Tidskriftsartikel (refereegranskat)abstract
- Control of the crystallization process is central to developing nanomaterials with atomic precision to meet the demands of electronic and quantum technology applications. Semiconductor nanowires grown by the vapor-liquid-solid process are a promising material system in which the ability to form components with structure and composition not achievable in bulk is well-established. Here, we use in situ TEM imaging of Au-catalyzed GaAs nanowire growth to understand the processes by which the growth dynamics are connected to the experimental parameters. We find that two sequential steps in the crystallization process - nucleation and layer growth - can occur on similar time scales and can be controlled independently using different growth parameters. Importantly, the layer growth process contributes significantly to the growth time for all conditions and will play a major role in determining material properties such as compositional uniformity, dopant density, and impurity incorporation. The results are understood through theoretical simulations correlating the growth dynamics, liquid droplet, and experimental parameters. The key insights discussed here are not restricted to Au-catalyzed GaAs nanowire growth but can be extended to most compound nanowire growths in which the different growth species has very different solubility in the catalyst particle.
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| 26. |
- Marnauza, Mikelis, et al.
(författare)
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In situ observations of size effects in GaAs nanowire growth
- 2022
-
Ingår i: Nanoscale Horizons. - : Royal Society of Chemistry (RSC). - 2055-6756 .- 2055-6764. ; 8:2, s. 291-296
-
Tidskriftsartikel (refereegranskat)abstract
- Lateral dimensions of III-V nanowires are known to affect the growth dynamics and crystal structure. Investigations into size effects have in the past relied on theoretical models and post growth observations, which only give a limited insight into the growth dynamics. Here we show the first experimental investigation into how nanowire diameter affects the growth dynamics by growing Au-seeded GaAs nanowires in an environmental transmission electron microscope. This was done by recording videos of nanowires during growth and analysing the Ga-limited incubation time and As-limited step-flow time. Our data show that the incubation time is stable across the investigated diameter range aside from a sharp increase for the smallest diameter, whereas the step-flow time is observed to steadily increase across the diameter range. We show using a simple model that this can be explained by the increasing vapour pressure in the droplet. In addition to the existing understanding of nanowire growth at small dimensions being limited by nucleation this work provides experimental evidence that growth is also limited by the inability to finish the step-flow process.
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| 27. |
- McGrath, Sarah, et al.
(författare)
-
Correlation of Professional Antigen-Presenting Tbet+CD11c+ B Cells With Bone Destruction in Untreated Rheumatoid Arthritis
- 2024
-
Ingår i: Arthritis & Rheumatology. - : John Wiley & Sons. - 2326-5191 .- 2326-5205.
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Subsets of CD21−/low memory B cells (MBCs), including double-negative (DN, CD27−IgD−) and Tbet+CD11c+ cells, are expanded in chronic inflammatory diseases. In rheumatoid arthritis (RA), CD21−/low MBCs correlate with joint destruction. However, whether this is due to the Tbet+CD11c+ subset, its function and pathogenic contribution to RA are unknown. This study aims to investigate the association between CD21−/lowTbet+CD11c+ MBCs and joint destruction as well as other clinical parameters and to elucidate their functional properties in patients with untreated RA (uRA). Methods: Clinical observations were combined with flow cytometry (n = 36) and single-cell RNA sequencing (scRNA-seq) and V(D)J sequencing (n = 4) of peripheral blood (PB) MBCs from patients with uRA. The transcriptome of circulating Tbet+CD11c+ MBCs was compared with scRNA-seq data of synovial B cells. In vitro coculture of Tbet+CD11c+ B cells with T cells was used to assess costimulatory capacity. Results: CD21−/lowTbet+CD11c+ MBCs in PB correlated with bone destruction but no other clinical parameters analyzed. The Tbet+CD11c+ MBCs have undergone clonal expansion and express somatically mutated V genes. Gene expression analysis of these cells identified a unique signature of more than 150 up-regulated genes associated with antigen presentation functions, including B cell receptor activation and clathrin-mediated antigen internalization; regulation of actin filaments, endosomes, and lysosomes; antigen processing, loading, presentation, and costimulation; a transcriptome mirrored in their synovial tissue counterparts. In vitro, Tbet+CD11c+ B cells induced retinoic acid receptor–related orphan nuclear receptor γT expression in CD4+ T cells, thereby polarizing to Th17 cells, a T cell subset critical for osteoclastogenesis and associated with bone destruction. Conclusion: This study suggests that Tbet+CD11c+ MBCs contribute to the pathogenesis of RA by promoting bone destruction through antigen presentation, T cell activation, and Th17 polarization. (Figure presented.).
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| 28. |
- Mårtensson, Gustav, et al.
(författare)
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AVRA : Automatic visual ratings of atrophy from MRI images using recurrent convolutional neural networks
- 2019
-
Ingår i: NeuroImage. - : ELSEVIER SCI LTD. - 2213-1582. ; 23
-
Tidskriftsartikel (refereegranskat)abstract
- Quantifying the degree of atrophy is done clinically by neuroradiologists following established visual rating scales. For these assessments to be reliable the rater requires substantial training and experience, and even then the rating agreement between two radiologists is not perfect. We have developed a model we call AVRA (Automatic Visual Ratings of Atrophy) based on machine learning methods and trained on 2350 visual ratings made by an experienced neuroradiologist. It provides fast and automatic ratings for Scheltens' scale of medial temporal atrophy (MTA), the frontal subscale of Pasquier's Global Cortical Atrophy (GCA-F) scale, and Koedam's scale of Posterior Atrophy (PA). We demonstrate substantial inter-rater agreement between AVRA's and a neuroradiologist ratings with Cohen's weighted kappa values of kappa(w) = 0.74/0.72 (MTA left/right), kappa(w) = 0.62 (GCA-F) and kappa(w) = 0.74 (PA). We conclude that automatic visual ratings of atrophy can potentially have great scientific value, and aim to present AVRA as a freely available toolbox.
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| 29. |
- Mårtensson, Stefan, et al.
(författare)
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Snowmobiling in Sweden 2014 : trends, attitudes to risk and knowledge about avalanches
- 2014
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Konferensbidrag (refereegranskat)abstract
- In spring 2014 a web survey aimed towards Swedish snowmobilers were conducted. The aim was to identify riding habits, attitudes to risk, knowledge of avalanches and the use of safety equip- ment. In total 2917 snowmobilers responded. The results provide new and important knowledge about behavior and attitudes to risk and general knowledge about avalanches and avalanche awareness. 34 % of the snowmobilers state that they are sometimes or often in contact with avalanche terrain. Of those, 19 % has been involved in at least on avalanche related incident. In the same group, only 14 % are regularly equipped with avalanche transmitter and probe. Among those who are using avalanche safety equipment, 33 % states that they rarely or never practice to use it.In Sweden the use of snowmobile has greatly increased the past 20 years and so has the popularity re- garding freeriding with snowmobiles in steep terrain. The total number of snowmobiles is now more than 280,000. Between 2005 and 2014, 102 snowmobilers in Sweden where killed in snowmobile related acci- dents in total but very few accidents during this period has officially been avalanche related which is surprisingly. Do Swedish snowmobilers uses the terrain differently than in North America and in Norway where there is much more accidents recorded or is there a difference in their attitudes to risk, or is the relatively few ava- lanche accidents just a coincidence? Is the relatively few accidents connected with the development of stronger and faster snowmobiles? Will Sweden also see a growing number of accidents with more vic- tims? Are there other factors? The final results will be used in the Swedish Mountain Safety Councils efforts to develop future avalanche education programs for snowmobilers and as a way to support research and development in the area.
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| 30. |
- Mårtensson, T., et al.
(författare)
-
Efficient and effective exploratory testing of large-scale software systems
- 2021
-
Ingår i: Journal of Systems and Software. - : Elsevier BV. - 0164-1212 .- 1873-1228. ; 174
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Tidskriftsartikel (refereegranskat)abstract
- Context: Exploratory testing plays an important role in the continuous integration and delivery pipelines of large-scale software systems, but a holistic and structured approach is needed to realize efficient and effective exploratory testing. Objective: This paper seeks to address the need for a structured and reliable approach by providing a tangible model, supporting practitioners in the industry to optimize exploratory testing in each individual case. Method: The reported study includes interviews, group interviews and workshops with representatives from six companies, all multi-national organizations with more than 2,000 employees. Results: The ExET model (Excellence in Exploratory Testing) is presented. It is shown that the ExET model allows companies to identify and visualize strengths and improvement areas. The model is based on a set of key factors that have been shown to enable efficient and effective exploratory testing of large-scale software systems, grouped into four themes: “The testers’ knowledge, experience and personality”, “Purpose and scope”, “Ways of working” and “Recording and reporting”. Conclusions: The validation of the ExET model showed that the model is novel, actionable and useful in practice, showing companies what they should prioritize in order to enable efficient and effective exploratory testing in their organization.
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| 31. |
- Mårtensson, Torvald, et al.
(författare)
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Enable more frequent integration of software in industry projects
- 2018
-
Ingår i: Journal of Systems and Software. - : Elsevier BV. - 0164-1212. ; 142, s. 223-236
-
Tidskriftsartikel (refereegranskat)abstract
- Based on interviews with 20 developers from two case study companies that develop large-scale software-intensive embedded systems, this paper presents twelve factors that affect how often developers commit software to the mainline. The twelve factors are grouped into four themes: "Activity planning and execution", "System thinking", "Speed" and "Confidence through test activities". Based on the interview results and a literature study we present the EMFIS model, which allows companies to explicate a representation of the organization's current situation regarding continuous integration impediments, and visualizes what the organization must focus on in order to enable more frequent integration of software. The model is used to perform an assessment of the twelve factors, where the ratings from participants representing the developers are summarized separately from ratings from participants representing the enablers (responsible for processes, development tools, test environments etc.). The EMFIS model has been validated in workshops and interviews, which in total included 46 individuals in five case study companies. The model was well received during the validation, and was appreciated for its simplicity and its ability to show differences in rating between developers and enablers.
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| 32. |
- Mårtensson, Torvald, et al.
(författare)
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Test environments for large-scale software systems-An industrial study of intrinsic and extrinsic success factors
- 2023
-
Ingår i: Software testing, verification & reliability. - : WILEY. - 0960-0833 .- 1099-1689. ; 33:3
-
Tidskriftsartikel (refereegranskat)abstract
- The characteristics of the test environment are of vital importance to its ability to support the organizations testing objectives. This paper seeks to address the need for a structured and reliable approach, which can be used by companies and other organizations to optimize their test environments in each individual case. The reported study included a series of interviews with 30 individuals, a series of focus groups with in total 31 individuals and a cross-company workshop with 30 participants from five large-scale companies, operating in different industry segments. The study resulted in a list of success factors, including not only characteristics and capabilities existing within a test environment (intrinsic success factors) but also properties not inherent to the test environment, but still vital for a successfully implemented test environment (extrinsic success factors). This distinction is important, as the root causes differ and as addressing them requires distinct approaches-not only of technology but also of organization, communication and collaboration. We find that successful implementations of test environments for large-scale software systems depend primarily on how they support the companys business strategy, test organization and product testability (extrinsic success factors). Based on this, test environments can then be optimized to improve test environment capabilities, usability and stability (intrinsic success factors). The list of intrinsic and extrinsic success factors was well received by all five companies included in the study, supporting that the intrinsic and extrinsic success factors for test environments can be applied to a large segment of the software industry.
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| 33. |
- Ngasala, Billy E., et al.
(författare)
-
Effectiveness of artemether-lumefantrine provided by community health workers in under-five children with uncomplicated malaria in rural Tanzania : an open label prospective study
- 2011
-
Ingår i: Malaria Journal. - : Springer Science and Business Media LLC. - 1475-2875. ; 10, s. 64-
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Home-management of malaria (HMM) strategy improves early access of anti-malarial medicines to high-risk groups in remote areas of sub-Saharan Africa. However, limited data are available on the effectiveness of using artemisinin-based combination therapy (ACT) within the HMM strategy. The aim of this study was to assess the effectiveness of artemether-lumefantrine (AL), presently the most favoured ACT in Africa, in under-five children with uncomplicated Plasmodium falciparum malaria in Tanzania, when provided by community health workers (CHWs) and administered unsupervised by parents or guardians at home. Methods: An open label, single arm prospective study was conducted in two rural villages with high malaria transmission in Kibaha District, Tanzania. Children presenting to CHWs with uncomplicated fever and a positive rapid malaria diagnostic test (RDT) were provisionally enrolled and provided AL for unsupervised treatment at home. Patients with microscopy confirmed P. falciparum parasitaemia were definitely enrolled and reviewed weekly by the CHWs during 42 days. Primary outcome measure was PCR corrected parasitological cure rate by day 42, as estimated by Kaplan-Meier survival analysis. This trial is registered with ClinicalTrials.gov, number NCT00454961. Results: A total of 244 febrile children were enrolled between March-August 2007. Two patients were lost to follow up on day 14, and one patient withdrew consent on day 21. Some 141/241 (58.5%) patients had recurrent infection during follow-up, of whom 14 had recrudescence. The PCR corrected cure rate by day 42 was 93.0% (95% CI 88.3%-95.9%). The median lumefantrine concentration was statistically significantly lower in patients with recrudescence (97 ng/mL [IQR 0-234]; n = 10) compared with reinfections (205 ng/mL [114-390]; n = 92), or no parasite reappearance (217 [121-374] ng/mL; n = 70; p <= 0.046). Conclusions: Provision of AL by CHWs for unsupervised malaria treatment at home was highly effective, which provides evidence base for scaling-up implementation of HMM with AL in Tanzania.
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| 34. |
- Ngasala, Billy E., et al.
(författare)
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Efficacy and Effectiveness of Artemether-Lumefantrine after Initial and Repeated Treatment in Children < 5 Years of Age with Acute Uncomplicated Plasmodium falciparum Malaria in Rural Tanzania : A Randomized Trial
- 2011
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Ingår i: Clinical Infectious Diseases. - : Oxford University Press (OUP). - 1058-4838 .- 1537-6591. ; 52:7, s. 873-882
-
Tidskriftsartikel (refereegranskat)abstract
- Background. We assessed the efficacy, effectiveness and safety of artemether-lumefantrine, which is the most widely used artemisinin-based combination therapy in Africa, against Plasmodium falciparum malaria during an extended follow-up period after initial and repeated treatment. Methods. We performed an open-label randomized trial of artemether-lumefantrine with supervised (n 5 180) and unsupervised intake (n = 179) in children <5 years of age with uncomplicated falciparum malaria in rural Tanzania. Recurrent infections between day 14 and day 56 were retreated within the same study arm. Main end points were polymerase chain reaction (PCR)-corrected cure rates by day 56 and day 42 after initial and repeated treatment, respectively, as estimated by survival analysis. Results. The PCR-corrected cure rate after initial treatment was 98.1% (95% confidence interval [CI], 94.2%-99.4%) after supervised and 95.1% (95% CI, 90.7%-98.1%) after unsupervised intake (P = .29). After retreatment of recurrent infections, the cure rates were 92.9% (95% CI, 81.8%-97.3%) and 97.6% (95% CI, 89.3%-98.8%), respectively (P = .58). Reinfections occurred in 46.9% (82 of 175) versus 50.9 % of the patients (relative risk [RR], 0.92 [95% CI, 0.74-1.14]; P 5.46) after initial therapy and 32.4% (24 of 74) versus 39.0% (32 of 82) (RR, 0.83 [95% CI, 0.54-1.27]; P 5.39) after retreatment. Median blood lumefantrine concentrations in supervised and unsupervised patients on day 7 were 304 versus 194 ng/ mL (P <.001) after initial treatment and 253 versus 164 ng/ mL (P 5.001) after retreatment. Vomiting was the most commonly reported drug-related adverse event (in 1% of patients) after both initial and repeated treatment. Conclusions. Artemether-lumefantrine was highly efficacious even after unsupervised administration, despite significantly lower lumefantrine concentrations, compared with concentration achieved with supervised intake, and was well-tolerated and safe after initial and repeated treatment.
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| 35. |
- Nilsson, Daniel, et al.
(författare)
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Characterization of Self-Assembled Monolayers of Oligo(phenyleneethynylene) Derivatives of Varying Shapes on Gold : Effect of Laterally Extended ∏-Systems
- 2007
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Ingår i: Langmuir. - : American Chemical Society. - 0743-7463 .- 1520-5827. ; 23:11, s. 6170-6181
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Tidskriftsartikel (refereegranskat)abstract
- Fully conjugated organic molecules, such as the oligo(phenyleneethynylene) (OPE) systems, are of growing interest within the field of molecular electronics, as is the self-assembly of well-defined molecular thin films with predefined functions. The structure and function of such films are intimately related and governed by the structures of their molecular constituents, through the intermolecular interactions and the interactions between the molecules and the substrate, onto which the film is assembled. Here we report on the synthesis of a series of three OPE derivatives, with the general structure phenylethynylene−aryl−ethynylenephenylene−headgroup, and the structural investigation of the self-assembled monolayers (SAMs) formed from them on Au(111) surfaces. The SAMs were characterized by infrared reflection−absorption spectroscopy, spectroscopic ellipsometry, high-resolution X-ray photoemission spectroscopy, and near-edge X-ray absorption fine structure spectroscopy. The effective thickness of the SAMs was observed to decrease as the π-system of the aryl moiety of the OPE adsorbate was extended perpendicular to its molecular long axis. Changing the aryl moiety from benzene to naphthalene to anthracene resulted in lower molecular surface densities and larger molecular inclination. The average tilt angles for the benzene, naphthalene, and anthracene SAMs were found to be about 30°, 40°, and 42° from the surface normal, respectively. For the largest adsorbate, the anthracene derivative, there is spectroscopic evidence suggesting the existence of nonequivalent binding sites. The differences observed between the SAMs are rationalized in terms of the shape of the adsorbates and the strength of the π−π interactions between them
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| 36. |
- Pereira, Goncalo Collares
(författare)
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Adaptive Lateral Model Predictive Control for Autonomous Driving of Heavy-Duty Vehicles
- 2023
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Autonomous Vehicle (AV) technology promises safer, greener, and more efficient means of transportation for everyone. AVs are expected to have their first big impact in closed environments, such as mining areas, ports, and construction sites, where Heavy-Duty Vehicles (HDVs) operate. This thesis addresses lateral motion control for autonomous HDVs using Model Predictive Control (MPC). Lateral control for HDVs still has many open questions to be addressed, in particular, precise path tracking while ensuring a smooth, comfortable, and stable ride, coping with both external and internal disturbances, and adapting to different vehicles and conditions.To address these challenges, a comprehensive control module architecture is designed to adapt seamlessly to different vehicle types and interface with various planning and localization modules. Furthermore, it is designed to address system delays, maintain certain error bounds, and respect actuation constraints.This thesis presents the Reference Aware MPC (RA-MPC) for autonomous vehicles. This controller is iteratively improved throughout the thesis. The RA-MPC introduces a method to systematically handle references generated by motion planners which can consider different algorithms and vehicle models from the controller. The controller uses the linear time-varying MPC framework and considers control input rate and acceleration constraints to account for steering limitations. Furthermore, multiple models and control inputs are considered throughout the thesis. Ultimately, curvature acceleration is used as the control input, which together with stability ingredients, allows for stability guarantees under certain conditions via Lyapunov techniques.MPC is highly dependent on the prediction model used. This thesis proposes and compares different models. First, an offline-fitted, vehicle-specific nonlinear curvature response function is proposed and integrated into the kinematic bicycle model. The curvature response function is modeled as two Gaussian functions. To enhance the model's versatility and applicability to a fleet of vehicles the nonlinear curvature response table kinematic model is presented. This model replaces the function with a table, which is estimated online by means of Kalman filtering, adapting to the current vehicle and operating conditions.All controllers and models are simulated and experimentally validated on Scania HDVs and iteratively compared to the previous state-of-the-art. The RA-MPC with the nonlinear curvature response table kinematic model is shown to be the best for the problems and conditions considered. The robustness and adaptiveness of the proposed approach are highlighted by testing different vehicle configurations (a haulage truck, a mining truck, and a bus), operating conditions, and scenarios. The model allows all vehicles to accomplish the scenarios with very similar performance. Overall, the results show an average absolute lateral error to path no bigger than 7 cm, and a worst-case deviation no bigger than 25 cm. These results demonstrate the controller's ability to handle a fleet of HDVs, without the need for vehicle-specific tuning or intervention from expert engineers.
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| 37. |
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| 38. |
- Salmen, Lennart, et al.
(författare)
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Enzymatic chip treatment for TMP - Prospects
- 2014
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Ingår i: International Mechanical Pulping Conference, IMPC 2014, part of PulPaper 2014 Conference. - : PI.
-
Konferensbidrag (refereegranskat)abstract
- In order to evaluate enzyme pre-treatments of chips as means of lowering the energy demand in mechanical pulping, impregnation and refining trials were performed. Wing refining showed that property development was similar to that of reference pulps in the case of pectinase and xylanase while for chips treated with mannanase a less favourable development of the tensile index was noted. Considering the highly increased possibility for enzymatic interactions reached with greater disintegration of chips it could well be that the possibilities for enzymes to attack desired fibre wall structures may have been too few even in the case of Impressafiner treated material used here.
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| 39. |
- Stepniewska, Kasia, et al.
(författare)
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Safety of single-dose primaquine as a Plasmodium falciparum gametocytocide : a systematic review and meta-analysis of individual patient data
- 2022
-
Ingår i: BMC Medicine. - : Springer Nature. - 1741-7015. ; 20:1
-
Forskningsöversikt (refereegranskat)abstract
- BackgroundIn 2012, the World Health Organization (WHO) recommended single low-dose (SLD, 0.25 mg/kg) primaquine to be added as a Plasmodium (P.) falciparum gametocytocide to artemisinin-based combination therapy (ACT) without glucose-6-phosphate dehydrogenase (G6PD) testing, to accelerate malaria elimination efforts and avoid the spread of artemisinin resistance. Uptake of this recommendation has been relatively slow primarily due to safety concerns.MethodsA systematic review and individual patient data (IPD) meta-analysis of single-dose (SD) primaquine studies for P. falciparum malaria were performed. Absolute and fractional changes in haemoglobin concentration within a week and adverse effects within 28 days of treatment initiation were characterised and compared between primaquine and no primaquine arms using random intercept models.ResultsData comprised 20 studies that enrolled 6406 participants, of whom 5129 (80.1%) had received a single target dose of primaquine ranging between 0.0625 and 0.75 mg/kg. There was no effect of primaquine in G6PD-normal participants on haemoglobin concentrations. However, among 194 G6PD-deficient African participants, a 0.25 mg/kg primaquine target dose resulted in an additional 0.53 g/dL (95% CI 0.17-0.89) reduction in haemoglobin concentration by day 7, with a 0.27 (95% CI 0.19-0.34) g/dL haemoglobin drop estimated for every 0.1 mg/kg increase in primaquine dose. Baseline haemoglobin, young age, and hyperparasitaemia were the main determinants of becoming anaemic (Hb < 10 g/dL), with the nadir observed on ACT day 2 or 3, regardless of G6PD status and exposure to primaquine. Time to recovery from anaemia took longer in young children and those with baseline anaemia or hyperparasitaemia. Serious adverse haematological events after primaquine were few (9/3, 113, 0.3%) and transitory. One blood transfusion was reported in the primaquine arms, and there were no primaquine-related deaths. In controlled studies, the proportions with either haematological or any serious adverse event were similar between primaquine and no primaquine arms.ConclusionsOur results support the WHO recommendation to use 0.25 mg/kg of primaquine as a P. falciparum gametocytocide, including in G6PD-deficient individuals. Although primaquine is associated with a transient reduction in haemoglobin levels in G6PD-deficient individuals, haemoglobin levels at clinical presentation are the major determinants of anaemia in these patients.
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| 40. |
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| 41. |
- Svärd, Daniel, et al.
(författare)
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Cognitive interference processing in adult survivors of childhood acute lymphoblastic leukemia using functional magnetic resonance imaging
- 2022
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Ingår i: Acta Oncologica. - 1651-226X. ; 61:3, s. 333-340
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Tidskriftsartikel (refereegranskat)abstract
- Background: Childhood acute lymphoblastic leukemia (ALL) is associated with cognitive impairment in adulthood. Cognitive interference processing and its correlated functional magnetic resonance imaging (fMRI) activity in the brain have not yet been studied in this patient group.Material: Twenty-six adult childhood ALL survivors (median [interquartile range {IQR}] age, 40.0 [37.0-42.3] years) were investigated at median age (IQR), 35.0 (32.0-37.0) years after treatment with intrathecal and intravenous chemotherapy as well as cranial radiotherapy (24 Gy) and compared with 26 matched controls (median [IQR] age, 37.5 [33.0-41.5] years).Methods: Cognitive interference processing was investigated in terms of behavioral performance (response times [ms] and accuracy performance [%]) and fMRI activity in the cingulo-fronto-parietal (CFP) attention network as well as other parts of the brain using the multisource interference task (MSIT).Results: ALL survivors had longer response times and reduced accuracy performance during cognitive interference processing (median [IQR] interference effect, 371.9 [314.7-453.3] ms and 6.7 [4.2-14.7]%, respectively) comparedwith controls (303.7 [275.0-376.7] ms and 2.3 [1.6-4.3]%, respectively), but did not exhibit altered fMRI activity in the CFP attention network or elsewhere in the brain.Conclusion: Adult childhood ALL survivors demonstrated impaired behavioral performance but no altered fMRI activity when performing cognitive interference processing when compared with controls. The results can be used to better characterize this patient group and to optimize follow-up care and support for these individuals.
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| 42. |
- Svärd, Daniel, et al.
(författare)
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Cognitive interference processing in adults with childhood craniopharyngioma using functional magnetic resonance imaging
- 2021
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Ingår i: Endocrine. - : Springer Science and Business Media LLC. - 1355-008X .- 1559-0100. ; 74:3, s. 714-722
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To assess cognitive interference processing in adults with childhood craniopharyngioma (CP), with and without hypothalamic injury, respectively, in terms of behavioral performance and functional magnetic resonance imaging (fMRI) activity, using the multi-source interference task (MSIT).METHODS: Twenty-eight CP patients (median age 34.5 [29.0-39.5] years) were investigated at median 20.5 (16.3-28.8) years after treatment with surgical resection and in some cases additional radiotherapy (n = 10) and compared to 29 matched controls (median age 37.0 [32.5-42.0] years). The subjects performed the MSIT during fMRI acquisition and behavioral performance in terms of response times (ms) and accuracy performance (%) were recorded.RESULTS: The MSIT activated the cingulo-fronto-parietal (CFP) attention network in both CP patients and controls. No differences were found in behavioral performance nor fMRI activity between CP patients (interference effect 333.9 [287.3-367.1] ms and 3.1 [1.6-5.6]%, respectively) and controls (309.1 [276.4-361.0] ms and 2.6 [1.6-4.9]%). No differences were found in behavioral performance nor fMRI activity between the two subgroups with (332.0 [283.6-353.4] ms and 4.2 [2.3-5.7]%, respectively) and without hypothalamic injury (355.7 [293.7-388.7] ms and 2.1 [1.0-5.2]%, respectively), respectively, and controls.CONCLUSION: Adults with childhood CP performed cognitive interference processing equally well as controls and demonstrated no compensatory fMRI activity in the CFP attention network compared to controls. This was also true for the two subgroups with and without hypothalamic injury. The results can be useful to better characterize this condition, and to optimize treatment and support for these individuals.
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| 44. |
- Watcharinyanon, Somsakul, 1978-, et al.
(författare)
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A spectroscopic study of self-assembled monolayer of porphyrin-functionalized oligo(phenyleneethynylene)s on gold : the influence of the anchor moiety
- 2008
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - London : RSC Publishing. - 1463-9076 .- 1463-9084. ; 10:34, s. 5264-5275
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Tidskriftsartikel (refereegranskat)abstract
- Porphyrin-functionalized oligo(phenyleneethynylene)s (OPE) are promising molecules for molecular electronics applications. Three such molecules (1-3) with the common structure P-OPE-AG (P and AG are a porphyrin and anchor group, respectively) and different anchor groups, viz. an acetyl protected thiol, -S-COCH3 (1), an acetyl protected thiol with methylene linker, -CH2-S-COCH3 (2), and a trimethylsilylethynyl group, -C(triple bond)C-Si(CH3)3 (3) have been synthesized and the corresponding self-assembled monolayers (SAMs) on Au(111) substrates have been prepared. The integrity and structural properties of these films were studied by X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure spectroscopy. The results suggest that the films formed from 1 have a high orientational order with an almost upright orientation and dense packing of the molecular constituents, i.e. represent a high quality SAM. In contrast, molecule 2 formed disordered molecular layers on Au, even though the molecule-surface bonding (thiolate) is the same as in the case of molecule 1. This suggests that the methylene linker in molecule 2 has a strong impact on the quality of the resulting film, so that a well-ordered SAM cannot be formed. The silane system, 3, is also able to bind to the gold surface but the resulting SAM has a poor quality, being significantly disordered and/or comprised of strongly inclined molecules. The above results suggest that the nature of the anchor group along with a possible linker is an important parameter which, to a high extent, predetermines the entire quality of OPE-based molecular layers
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| 46. |
- Wiberg, Joanna, 1980, et al.
(författare)
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Charge recombination versus charge separation in donor-bridge-acceptor systems
- 2007
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 129:1, s. 155-163
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Tidskriftsartikel (refereegranskat)abstract
- Optimizing the ratio of the rates for charge separation (CS) over charge recombination (CR) is crucial to create long-lived charge-separated states. Mastering the factors that govern the electron transfer (ET) rates is essential when trying to achieve molecular-scale electronics, artificial photosynthesis, and also for the further development of solar cells. Much work has been put into the question of how the donor-acceptor distances and donor-bridge energy gaps affect the electronic coupling, V DA , and thus the rates of ET. We present here a unique comparison on how these factors differently influence the rates for CS and CR in a porphyrin-based donor-bridge-acceptor model system. Our system contains three series, each of which focuses on a separate charge-transfer rate-determining factor, the donor-acceptor distance, the donor-bridge energy gap, and last, the influence of the electron acceptor on the rate for charge transfer. In these three series both CS and CR are governed by superexchange interactions which make a CR/CS comparative study ideal. We show here that the exponential distance dependence increases slightly for CR compared to that for CS as a result of the increased tunneling barrier height for this reaction, in accordance with the McConnell superexchange model. We also show that the dependence on the tunneling barrier height is different for CS and CR. This difference is highly dependent on the electron acceptor and thus cannot solely be explained by the differences in the frontier orbitals of the electron donor in these porphyrin systems. © 2007 American Chemical Society.
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| 47. |
- Wikberg, Per-Olov, et al.
(författare)
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Changes in Attitudes To Risk and Knowledge About Avalanches Among Swedish Skiers After The Introduction of a National Avalanche Safety Program
- 2018
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Konferensbidrag (refereegranskat)abstract
- In 2013, a web survey was conducted together with Freeride.se, aimed towards Swedish off-piste skiers in order to identify the target group's knowledge, experience and attitudes towards off-piste skiing and avalanches. 1047 skiers participated. The results of the survey gave new important knowledge about different target groups prior to the start of the Swedish avalanche forecast program and also more knowledge regarding the level of avalanche awareness among skiers in general. In 2016 Sweden launched the first national avalanche forecasting program and the same year, a revised avalanche education program was developed and presented. Both constitute important tools for prevention of future avalanche accidents among Swedish skiers. In April 2017, a repetition of the first survey was initiated, with nearly the same questionnaire, to see if there had been any change in behavior, attitudes to risk and knowledge about avalanche awareness among Swedish skiers since 2013. With 1028 participants, the results of the new survey showed some interesting changes that probably could be seen as early effects of the introduction of a new public avalanche forecasting service together with the revised avalanche education program.
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| 48. |
- Zhan, Shaoqi, et al.
(författare)
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Capturing the Role of Explicit Solvent in the Dimerization of Ru-V(bda) Water Oxidation Catalysts
- 2017
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Ingår i: Angewandte Chemie International Edition. - : Wiley-VCH Verlagsgesellschaft. - 1433-7851 .- 1521-3773. ; 56:24, s. 6962-6965
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Tidskriftsartikel (refereegranskat)abstract
- A ground-breaking empirical valence bond study for a soluble transition-metal complex is presented. The full reaction of catalyst monomers approaching and reacting in the Ru-V oxidation state were studied. Analysis of the solvation shell in the reactant and along the reaction coordinate revealed that the oxo itself is hydrophobic, which adds a significant driving force to form the dimer. The effect of the solvent on the reaction between the prereactive dimer and the product was small. The solvent seems to lower the barrier for the isoquinoline (isoq) complex while it is increased for pyridines. By comparing the reaction in the gas phase and solution, the proposed p-stacking interaction of the isoq ligands is found to be entirely driven by the water medium.
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