| 1. |
- Persson, Jan, 1962, et al.
(author)
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Fully covered stents are similar to semi-covered stents with regard to migration in palliative treatment of malignant strictures of the esophagus and gastric cardia : results of a randomized controlled trial.
- 2017
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In: Surgical Endoscopy. - : Springer Science and Business Media LLC. - 0930-2794 .- 1432-2218. ; 31:10, s. 4025-4033
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Journal article (peer-reviewed)abstract
- INTRODUCTION: Stent migration is a significant clinical problem in palliation of malignant strictures in the esophagus and gastro-esophageal junction (GEJ). We have compared a newer design of a fully-covered stent to a widely used semi-covered stent using migration >20 mm as the primary outcome variable. Effects on dysphagia, quality of life (QoL) and re-intervention frequency were also investigated.METHODS: Patients with dysphagia due to non-curable esophagus/GEJ cancer were randomized to receive either a more recent design of a fully-covered stent (n = 48) or a conventional semi-covered stent (n = 47). Chest x-ray, dysphagia and QoL were studied at baseline, one week, four weeks and three months thereafter.RESULTS: There were no significant differences either in stent migration distance or in the migration frequency. Stent migration during the total study period occurred in 37.2 % in the semi-covered group compared to 20.0 % for the fully-covered group. Dysphagia was measured with Watson and Ogilvie scores and with the dysphagia module in the QoL scale (QLQ-OG25). On average, there was a tendency to better dysphagia relief for the fully-covered design as scored with the two latter dysphagia instruments (p= 0.081 and p= 0.067) at three months and towards more re-interventions in the semi-covered group (p= 0.083).CONCLUSION: In spite of its somewhat lower intrinsic radial force, the fully-covered stent was comparable to the conventional semi-covered stent with regard to stent migration. The data further suggest a potential benefit of the fully-covered stent in improving dysphagia in patients with longer life expectancy.
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| 2. |
- Johnsson, Helena, et al.
(author)
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En pedagogisk idé för ingenjörsutbildningarna vid Luleå tekniska universitet
- 2009
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Conference paper (peer-reviewed)abstract
- Utmärkande för Luleå tekniska universitet (LTU) har länge varit närheten mellan studenterna och lärarna vilket har manifesterats genom klassrumsundervisning, lärartillgänglighet, mindre studiegrupper, koncentrerade campus etc. Undervisningsformerna har dock ändrats till att idag omfatta dels klassiska föreläsningar i stora studentgrupper, men också projektarbete i team där totalt sett 1/3 av all undervisning vid Luleå tekniska universitet sker i projektform. En fråga har ställts: Har Luleå tekniska universitet idag en gemensam pedagogisk idé för ingenjörsutbildningarna? I så fall är ytterligare en fråga hur denna pedagogiska idé tar sig uttryck i organisationen?Intervjuer med 40 aktiva lärare vid Luleå tekniska universitet har genomförts av projektgruppen (tillika författarna) varpå svaren har grupperats och analyserats i fjorton olika teman. Från dessa teman har sedan fyra hörnstenar i en definition av en pedagogisk idé aggregerats. Formuleringen av den pedagogiska idén lyder: Ett aktivt lärande för yrkeslivet – i branschnära projekt och med god vetenskaplig grund tränas förmågan att arbeta som ingenjör genom coachning från lärare i ett nära och öppet klimat. Idén har antagits av den tekniska fakultetsnämnden vid Luleå tekniska universitet och verifierats på institutionerna. Exempel på implementering och hur den pedagogiska idén aktivt verkar presenteras i artikeln.
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| 3. |
- Johnsson, Kerstin, et al.
(author)
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What is a “unimodal” cell population? Using statistical tests as criteria for unimodality in automated gating and quality control
- 2017
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In: Cytometry Part A. - : Wiley. - 1552-4922. ; 91:9, s. 908-916
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Journal article (peer-reviewed)abstract
- Many automated gating algorithms for flow cytometry data are based on the concept of unimodal cell populations. However, in this article, we show that criteria previously used to make decisions on unimodality cannot adequately distinguish unimodal from bimodal densities. We show that dip and bandwidth tests for unimodality, taken from the statistics literature, can do this with consistent and low error rates. These tests also have the possibility to adjust the significance level to handle the trade-off between failing to detect a second mode and seeing a second mode when there is none. The differences between the dip and bandwidth tests are elucidated using real data from the FlowCAP I challenge, also guidelines for flow cytometry data preprocessing are given.
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| 4. |
- Nyholm, Tufve, et al.
(author)
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A national approach for automated collection of standardized and population-based radiation therapy data in Sweden
- 2016
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In: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 119:2, s. 344-350
-
Journal article (peer-reviewed)abstract
- Purpose: To develop an infrastructure for structured and automated collection of interoperable radiation therapy (RT) data into a national clinical quality registry. Materials and methods: The present study was initiated in 2012 with the participation of seven of the 15 hospital departments delivering RT in Sweden. A national RT nomenclature and a database for structured unified storage of RT data at each site (Medical Information Quality Archive, MIQA) have been developed. Aggregated data from the MIQA databases are sent to a national RT registry located on the same IT platform (INCA) as the national clinical cancer registries. Results: The suggested naming convention has to date been integrated into the clinical workflow at 12 of 15 sites, and MIQA is installed at six of these. Involvement of the remaining 3/15 RT departments is ongoing, and they are expected to be part of the infrastructure by 2016. RT data collection from ARIA (R), Mosaiq (R), Eclipse (TM), and Oncentra (R) is supported. Manual curation of RT-structure information is needed for approximately 10% of target volumes, but rarely for normal tissue structures, demonstrating a good compliance to the RT nomenclature. Aggregated dose/volume descriptors are calculated based on the information in MIQA and sent to INCA using a dedicated service (MIQA2INCA). Correct linkage of data for each patient to the clinical cancer registries on the INCA platform is assured by the unique Swedish personal identity number. Conclusions: An infrastructure for structured and automated prospective collection of syntactically inter operable RT data into a national clinical quality registry for RT data is under implementation. Future developments include adapting MIQA to other treatment modalities (e.g. proton therapy and brachytherapy) and finding strategies to harmonize structure delineations. How the RT registry should comply with domain-specific ontologies such as the Radiation Oncology Ontology (ROO) is under discussion.
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| 5. |
- Andersson, Lennart, et al.
(author)
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Praktikfall i reglerteknik - Råspritbränneriet i Nöbbelöv
- 1998
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Reports (other academic/artistic)abstract
- During spring 1998 the course Industrial Case Studies in Control was given at the Department of Automatic Control in Lund. The course consisted of a project at an industry with control applications. This report considers a project at the crude alcohol distillery in Nöbbelöv, where the base product for the liquor Absolut Vodka is produced. The distillery had problems with fluctuations in the concentration of ethanol in the crude alcohol. The purpose of the project was to analyze the cause of the fluctuations, and if possibly eliminate it. The fluctuations were cause by an output limiter on a controller, and were relatively easily eliminated. To examine if control performance could be further improved, a series of experiments was carried out on the plant. The result of the experiments were then used to derive a simple process model, and a suggestion for new controller parameters.
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| 6. |
- Andersson, Magnus, et al.
(author)
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Efficient multi-view ray tracing using edge detection and shader reuse
- 2011
-
In: The Visual Computer. - : Springer Science and Business Media LLC. - 0178-2789 .- 1432-2315. ; 27:6-8, s. 665-676
-
Conference paper (peer-reviewed)abstract
- Stereoscopic rendering and 3D stereo displays are quickly becoming mainstream. The natural extension is autostereoscopic multi-view displays, which by the use of parallax barriers or lenticular lenses, can accommodate many simultaneous viewers without the need for active or passive glasses. As these displays, for the foreseeable future, will support only a rather limited number of views, there is a need for high-quality interperspective antialiasing. We present a specialized algorithm for efficient multi-view image generation from a camera line using ray tracing, which builds on previous methods for multi-dimensional adaptive sampling and reconstruction of light elds. We introduce multi-view silhouette edges to detect sharp geometrical discontinuities in the radiance function. These are used to significantly improve the quality of the reconstruction. In addition, we exploit shader coherence by computing analytical visibility between shading points and the camera line, and by sharing shading computations over the camera line.
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| 7. |
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| 8. |
- Arvidsson, Jonathan, 1986, et al.
(author)
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Automated estimation of in-plane nodule shape in chest tomosynthesis images
- 2015
-
In: International Federation for Medical and Biological Engineering Proceedings. - Cham : Springer International Publishing. - 1680-0737. - 9783319129679 ; 48, s. 20-23
-
Conference paper (peer-reviewed)abstract
- The purpose of this study was to develop an automated segmentation method for lung nodules in chest tomo-synthesis images. A number of simulated nodules of different sizes and shapes were created and inserted in two different locations into clinical chest tomosynthesis projections. The tomosynthesis volumes were then reconstructed using standard cone beam filtered back projection, with 1 mm slice interval. For the in-plane segmentation, the central plane of each nodule was selected. The segmentation method was formulated as an optimization problem where the nodule boundary corresponds to the minimum of the cost function, which is found by dynamic programming. The cost function was composed of terms related to pixel intensities, edge strength, edge direction and a smoothness constraint. The segmentation results were evaluated using an overlap measure (Dice index) of nodule regions and a distance measure (Hausdorff distance) between true and segmented nodule. On clinical images, the nodule segmentation method achieved a mean Dice index of 0.96 ± 0.01, and a mean Hausdorff distance of 0.5 ± 0.2 mm for isolated nodules and for nodules close to other lung structures a mean Dice index of 0.95 ± 0.02 and a mean Hausdorff distance of 0.5 ± 0.2 mm. The method achieved an acceptable accuracy and may be useful for area estimation of lung nodules.
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| 9. |
- Arvidsson, Jonathan, et al.
(author)
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Image Fusion of Reconstructed Digital Tomosynthesis Volumes From a Frontal and a Lateral Acquisition
- 2016
-
In: Radiation protection dosimetry. - : Oxford University Press (OUP). - 1742-3406 .- 0144-8420. ; 169:1-4, s. 410-415
-
Journal article (peer-reviewed)abstract
- Digital tomosynthesis (DTS) has been used in chest imaging as a low radiation dose alternative to computed tomography (CT). Traditional DTS shows limitations in the spatial resolution in the out-of-plane dimension. As a first indication of whether a dual-plane dual-view (DPDV) DTS data acquisition can yield a fair resolution in all three spatial dimensions, a manual registration between a frontal and a lateral image volume was performed. An anthropomorphic chest phantom was scanned frontally and laterally using a linear DTS acquisition, at 120 kVp. The reconstructed image volumes were resampled and manually co-registered. Expert radiologist delineations of the mediastinal soft tissues enabled calculation of similarity metrics in regard to delineations in a reference CT volume. The fused volume produced the highest total overlap, implying that the fused volume was a more isotropic 3D representation of the examined object than the traditional chest DTS volumes.
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| 10. |
- Ásgeirsdóttir, Helga, et al.
(author)
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Depiction of anatomic structures of relevance for scoring of cystic fibrosis changes by chest tomosynthesis and computed tomography
- 2014
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In: Journal of Cystic Fibrosis. 37th European Cystic Fibrosis Conference, 11-14 June 2014, Gothenburg, Sweden. ; 13:Suppl. 2
-
Conference paper (other academic/artistic)abstract
- Introduction: Chest radiography (CR) and computed tomography (CT) are commonly used for imaging of patients with cystic fibrosis, and scoring is applied to assess disease severity. Chest tomosynthesis (CTS) is a new imaging modality providing better anatomic visualization than CR at radiation doses and costs lower than CT. Objective: To compare visibility and size of anatomic structures of relevance for scoring in CTS and CT images. Methods: 21 adult patients with cystic fibrosis were examined both with CTS (VolumeRAD; GE Healthcare) and volumetric CT (LightSpeed Pro 16, LightSpeed VCT, Discovery CT750HD; GE healthcare and Somatom Definition, Siemens Medical Solutions). The average effective dose for a standard patient was 0.13 and 4.5 mSv for CTS and CT, respectively. Comparison of visibility and manual measurements of diameters of the central and peripheral bronchi and their accompanying artery, as well as bronchial wall thickness (BWT), were performed in a non-blinded fashion. Results: All central structures could be evaluated. Mean difference in diameter of central bronchi, accompanying artery and BWT between CTS and CT was −0.6 (SD 0.6), −0.7 (SD 0.7) and −0.4 (SD 0.2) mm, respectively. Peripheral structures were more difficult to assess by CTS. Peripheral bronchial diameter, BWT and diameter of accompanying artery could be assessed by CTS in 20, 15 and 4 cases, respectively and mean difference between measurements was −0.5 (SD 0.5), −0.3 (SD 0.3) and −0.4 (SD 0.4) mm, respectively. Conclusion: This study indicates that peripheral structures are more difficult to evaluate by CTS and that CTS slightly underestimate size of structures in comparison to CT
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| 11. |
- Aspeborg, Henrik, 1970-, et al.
(author)
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Vegetabile material, plants and a method of producing a plant having altered lignin properties
- 2008
-
Patent (pop. science, debate, etc.)abstract
- The present invention is related to a set of genes, which when modified in plants gives altered lignin properties. The invention provides DNA construct such as a vector useful in the method of the invention. Further, the invention relates to a plant cell or plant progeny of the plants and wood produced by the plants according to the invention Lower lignin levels will result in improved saccharification for bio-refining and ethanol production and improved pulp and paper. Increased lignin levels will utilise lignin properties for energy production. The genes and DNA constructs may be used for the identification of plants having altered lignin characteristics as compared to the wild-type. According to the invention genes and DNA constructs may also be used as candidate genes in marker assisted breeding.
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| 12. |
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| 13. |
- Asplund, Sara, 1976, et al.
(author)
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Extended analysis of the effect of learning with feedback on the detectability of pulmonary nodules in chest tomosynthesis
- 2011
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In: Progress in Biomedical Optics and Imaging - Proceedings of SPIE. - : SPIE. - 1605-7422. ; 7966
-
Journal article (other academic/artistic)abstract
- In chest tomosynthesis, low-dose projections collected over a limited angular range are used for reconstruction of section images of the chest, resulting in a reduction of disturbing anatomy at a moderate increase in radiation dose compared to chest radiography. In a previous study, we investigated the effects of learning with feedback on the detection of pulmonary nodules in chest tomosynthesis. Six observers with varying degrees of experience of chest tomosynthesis analyzed tomosynthesis cases for presence of pulmonary nodules. The cases were analyzed before and after learning with feedback. Multidetector computed tomography (MDCT) was used as reference. The differences in performance between the two readings were calculated using the jackknife alternative free-response receiver operating characteristics (JAFROC-2) as primary measure of detectability. Significant differences between the readings were found only for observers inexperienced in chest tomosynthesis. The purpose of the present study was to extend the statistical analysis of the results of the previous study, including JAFROC-1 analysis and FROC curves in the analysis. The results are consistent with the results of the previous study and, furthermore, JAFROC-1 gave lower p-values than JAFROC-2 for the observers who improved their performance after learning with feedback. © 2011 SPIE.
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| 14. |
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| 15. |
- Asplund, Sara, 1976, et al.
(author)
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Learning aspects and potential pitfalls regarding detection of pulmonary nodules in chest tomosynthesis and proposed related quality criteria.
- 2011
-
In: Acta radiologica. - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 52:5, s. 503-512
-
Journal article (peer-reviewed)abstract
- Background In chest tomosynthesis, low-dose projections collected over a limited angular range are used for reconstruction of an arbitrary number of section images of the chest, resulting in a moderately increased radiation dose compared to chest radiography. Purpose To investigate the effects of learning with feedback on the detection of pulmonary nodules for observers with varying experience of chest tomosynthesis, to identify pitfalls regarding detection of pulmonary nodules, and present suggestions for how to avoid them, and to adapt the European quality criteria for chest radiography and computed tomography (CT) to chest tomosynthesis. Material and Methods Six observers analyzed tomosynthesis cases for presence of nodules in a jackknife alternative free-response receiver-operating characteristics (JAFROC) study. CT was used as reference. The same tomosynthesis cases were analyzed before and after learning with feedback, which included a collective learning session. The difference in performance between the two readings was calculated using the JAFROC figure of merit as principal measure of detectability. Results Significant improvement in performance after learning with feedback was found only for observers inexperienced in tomosynthesis. At the collective learning session, localization of pleural and subpleural nodules or structures was identified as the main difficulty in analyzing tomosynthesis images. Conclusion The results indicate that inexperienced observers can reach a high level of performance regarding nodule detection in tomosynthesis after learning with feedback and that the main problem with chest tomosynthesis is related to the limited depth resolution.
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| 16. |
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| 17. |
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| 18. |
- Balkenius, Christian, et al.
(author)
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Explorations in Cognitive Robotics
- 2007
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In: Proceedings of SAIS 2007. ; , s. 189-192
-
Conference paper (other academic/artistic)abstract
- We describe a number of research projects at Lund Univer- sity Cognitive Science. The first project focuses on visual attention. The second area is haptic perceptions by robots. The third area is anticipation in groups of robots. The final research area concerns building computa- tional tools that can be used to design large-scale cognitive models which will ultimately allow results from the different project areas to be merged into a single cognitive architecture.
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| 19. |
- Balkenius, Christian, et al.
(author)
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Ikaros: Building Cognitive Models for Robots
- 2010
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In: Advanced Engineering Informatics. - : Elsevier BV. - 1873-5320 .- 1474-0346. ; 24:1, s. 40-48
-
Journal article (peer-reviewed)abstract
- The Ikaros project started in 2001 with the aim of developing an open infrastructure for system-level brain modeling. The system has developed into a general tool for cognitive modeling as well as robot control. Here we describe the main parts of the Ikaros system and how it has been used to implement various cognitive systems and to control a number of different robots ranging from robot arms and hands to active vision systems and mobile robots. (C) 2009 Elsevier Ltd. All rights reserved.
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| 20. |
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| 21. |
- Bergquist, Henrik, 1969, et al.
(author)
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Combined stent insertion and single high-dose brachytherapy in patients with advanced esophageal cancer - results of a prospective safety study.
- 2011
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In: Diseases of the esophagus. - : Oxford University Press (OUP). - 1442-2050 .- 1120-8694. ; Early View
-
Journal article (peer-reviewed)abstract
- Previous randomized studies comparing the two commonly used palliative treatments for incurable esophageal cancer, i.e. stent insertion and intraluminal brachytherapy, have revealed the pros and cons of each therapy. While stent treatment offers a more prompt effect, brachytherapy results in more long-lasting relief of dysphagia and a better health-related quality of life (HRQL) in those living longer. This prospective pilot study aimed to explore the feasibility and safety of combining these two regimes and incorporating a single high dose of internal radiation. Patients with newly diagnosed, incurable cancer of the esophagus and dysphagia were eligible for inclusion, and stent insertion followed by a single dose (12Gy) of brachytherapy was performed as a two-stage procedure. Clinical parameters including HRQL and adverse events were registered at inclusion, and 1, 2, 3, 6, and 12 months later. Twelve patients (nine males) with a median age of 73 years (range 54-85) were included. Stent insertion followed by a single dose of brachytherapy was successfully performed in all but one patient who was treated with stent only. Relief of dysphagia was achieved in the majority of cases (10/11, P < 0.05), but HRQL did not improve except for dysphagia-related items. Only minor adverse events, including chest pain, reflux, and restenosis, were reported. The median survival time after inclusion was 6.6 months. Our conclusion is that the combination of stent insertion and single high-dose brachytherapy seems to be a feasible and safe palliative regime in patients with advanced esophageal cancer. Randomized trials comparing the efficacy of this strategy to stent insertion or brachytherapy alone are warranted.
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| 22. |
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| 23. |
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| 24. |
- Buckley, Patrick G, et al.
(author)
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A full-coverage, high-resolution human chromosome 22 genomic microarrayfor clinical and research applications
- 2002
-
In: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 11:25, s. 3221-3229
-
Journal article (peer-reviewed)abstract
- We have constructed the first comprehensive microarray representing a human chromosome for analysis of DNA copy number variation. This chromosome 22 array covers 34.7 Mb, representing 1.1% of the genome, with an average resolution of 75 kb. To demonstrate the utility of the array, we have applied it to profile acral melanoma, dermatofibrosarcoma, DiGeorge syndrome and neurofibromatosis 2. We accurately diagnosed homozygous/heterozygous deletions, amplifications/gains, IGLV/IGLC locus instability, and breakpoints of an imbalanced translocation. We further identified the 14-3-3 eta isoform as a candidate tumor suppressor in glioblastoma. Two significant methodological advances in array construction were also developed and validated. These include a strictly sequence defined, repeat-free, and non-redundant strategy for array preparation. This approach allows an increase in array resolution and analysis of any locus; disregarding common repeats, genomic clone availability and sequence redundancy. In addition, we report that the application of phi29 DNA polymerase is advantageous in microarray preparation. A broad spectrum of issues in medical research and diagnostics can be approached using the array. This well annotated and gene-rich autosome contains numerous uncharacterized disease genes. It is therefore crucial to associate these genes to specific 22q-related conditions and this array will be instrumental towards this goal. Furthermore, comprehensive epigenetic profiling of 22q-located genes and high-resolution analysis of replication timing across the entire chromosome can be studied using our array.
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| 25. |
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| 26. |
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| 27. |
- Buonamente, Miriam, et al.
(author)
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Discriminating and Simulating Actions with the Associative Self-Organizing Map
- 2015
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In: Connection Science. - : Informa UK Limited. - 0954-0091 .- 1360-0494. ; 27:2, s. 118-136
-
Journal article (peer-reviewed)abstract
- Abstract in UndeterminedWe propose a system able to represent others' actions as well as to internally simulate their likely continuation from a partial observation. The approach presented here is the first step towards a more ambitious goal of endowing an artificial agent with the ability to recognise and predict others' intentions. Our approach is based on the associative self-organising map, a variant of the self-organising map capable of learning to associate its activity with different inputs over time, where inputs are processed observations of others' actions. We have evaluated our system in two different experimental scenarios obtaining promising results: the system demonstrated an ability to learn discriminable representations of actions, to recognise novel input, and to simulate the likely continuation of partially seen actions.
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| 28. |
- Buonamente, Miriam, et al.
(author)
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Hierarchies of Self-Organizing Maps for Action Recognition
- 2016
-
In: Cognitive Systems Research. - : Elsevier BV. - 1389-0417.
-
Journal article (peer-reviewed)abstract
- We propose a hierarchical neural architecture able to recognise observed human actions. Each layer in the architecture represents increasingly complex human activity features. The first layer consists of a SOM which performs dimensionality reduction and clustering of the feature space. It represents the dynamics of the stream of posture frames in action sequences as activity trajectories over time. The second layer in the hierarchy consists of another SOM which clusters the activity trajectories of the first-layer SOM and learns to represent action prototypes. The third - and last - layer of the hierarchy consists of a neural network that learns to label action prototypes of the second-layer SOM and is independent - to certain extent - of the camera’s angle and relative distance to the actor. The experiments were carried out with encouraging results with action movies taken from the INRIA 4D repository. In terms of representational accuracy, measured as the recognition rate over the training set, the architecture exhibits 100% accuracy indicating that actions with overlapping patterns of activity can be correctly discriminated. On the other hand, the architecture exhibits 53% recognition rate when presented with the same actions interpreted and performed by a different actor. Experiments on actions captured from different view points revealed a robustness of our system to camera rotation. Indeed, recognition accuracy was comparable to the single viewpoint case. To further assess the performance of the system we have also devised a behavioral experiments in which humans were asked to recognize the same set of actions, captured from different points of view. Results form such a behavioral study let us argue that our architecture is a good candidate as cognitive model of human action recognition, as architectural results are comparable to those observed in humans.
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| 29. |
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| 30. |
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| 31. |
- Båth, Magnus, 1974, et al.
(author)
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Chest tomosynthesis
- 2014
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In: Tomosynthesis Imaging. Ed. Stephen Glick. - Boca Raton : CRC Press/Taylor & Francis. - 9781439878705 ; , s. 189-197
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Book chapter (other academic/artistic)
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| 32. |
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| 33. |
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| 34. |
- Cardeña, Etzel, et al.
(author)
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Posttraumatiska störningar hos flyktingar
- 2009
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In: Mänskliga möten över gränser : vård och social omsorg i det mångkulturella samhället. - 9789147084678 ; , s. 61-80
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Book chapter (other academic/artistic)
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| 35. |
- Chodorowski, Artur, 1959, et al.
(author)
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An attempt to estimate out-of-plane lung nodule elongation in tomosynthesis images
- 2015
-
In: Medical Imaging 2015: Physics of Medical Imaging (SPIE Proceedings). Conference on Medical Imaging - Physics of Medical Imaging. February 22-25, 2015, Orlando, Florida, USA.. - : SPIE. - 0277-786X .- 1605-7422. - 9781628415025
-
Conference paper (peer-reviewed)abstract
- In chest tomosynthesis (TS) the most commonly used reconstruction methods are based on Filtered Back Projection (FBP) algorithms. Due to the limited angular range of x-ray projections, FBP reconstructed data is typically associated with a low spatial resolution in the out-of-plane dimension. Lung nodule measures that depend on depth information such as 3D shape and volume are therefore difficult to estimate. In this paper the relation between features from FBP reconstructed lung nodules and the true out-of-plane nodule elongation is investigated and a method for estimating the out-of-plane nodule elongation is proposed. In order to study these relations a number of steps that include simulation of spheroidal-shaped nodules, insertion into synthetic data volumes, construction of TS-projections and FBP-reconstruction were performed. In addition, the same procedure was used to simulate nodules and insert them into clinical chest TS projection data. The reconstructed nodule data was then investigated with respect to in-plane diameter, out-of-plane elongation, and attenuation coefficient. It was found that the voxel value in each nodule increased linearly with nodule elongation, for nodules with a constant attenuation coefficient. Similarly, the voxel value increased linearly with in-plane diameter. These observations indicate the possibility to predict the nodule elongation from the reconstructed voxel intensity values. Such a method would represent a quantitative approach to chest tomosynthesis that may be useful in future work on volume and growth rate estimation of lung nodules.
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| 36. |
- Consiglio, Camila, et al.
(author)
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Immune system adaptation during gender-affirming testosterone treatment
- 2023
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In: Journal of Reproductive Immunology. - : Elsevier. - 0165-0378 .- 1872-7603. ; 159, s. 29-30
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Journal article (other academic/artistic)abstract
- Biological sex impacts human immune responses, modulating susceptibility and severity to immune-related diseases. Female generally mount more robust immune responses than males, resulting in lower infection severity and greater autoimmunity incidence. Here, we addressed the contribution of testosterone to human immune function by analyzing a cohort of subjects undergoing gender-affirming testosterone treatment. We performed systems-level immunomonitoring through mass cytometry, scRNA and scA-TAC-Sequencing, and proteome profiling of blood samples at baseline and following 3 and 12 months of treatment. Testosterone treatment was associated with a low-grade inflammatory profile, evidenced by upregulation of proinflammatory plasma proteome (e.g., EN-RAGE, OSM, TNF), and induction of an inflammatory transcriptional program associated with NFkB signaling, and TNF signaling. Following testosterone treatment, higher NFkB activity was revealed in CD4 T, CD8 T, and NK cells in scATACseq analyses. Further, testosterone increased monocytic inflammatory responses upon bacterial stimulation in vitro. Although testosterone was associated with this inflammatory profile, it also exerted negative effects on antiviral immunity. Firstly, the percentage of plasmacytoid dendritic cells (pDC) decreased over transition, with pDC also displaying phenotypic changes associated with lower IFN responses. Secondly, bulk transcriptomics analyses show an overall reduction of IFNa responses. Thirdly, testosterone treatment led to reduced IFNa production upon PBMCs stimulation with a viral agonist. Our results show that testosterone has broad effects on the human immune system, and significantly modulates important players in antiviral immunity and inflammatory response. Identifying pathways involved in immune sexual dimorphism will help define novel targets for effective prevention and treatment of immune-mediated diseases.
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| 37. |
- Deverell, Edward, et al.
(author)
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Understanding Public Agency Communication : the case of the Swedish Armed Forces
- 2015
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In: Journal of Public Affairs. - : Wiley. - 1472-3891 .- 1479-1854. ; 15:4, s. 387-396
-
Journal article (peer-reviewed)abstract
- This article suggests a diagnostic framework of public communication intended to capture new communication strategies used by Armed Forces across Europe to legitimize new tasks and recruit new personnel. Three distinct communicative models that impact differently on democratic values and public support are suggested: an Old Public Administration (OPA) model influenced by bureaucratic values, a New Public Management (NPM) model fuelled by market values and a deliberative model labelled ‘New Public Service’ (NPS) that is largely influenced by proponents of ‘e-democracy’. A case study of the communication of the Swedish Armed Forces identifies a lingering bureaucratic (OPA) ideal. The market ideal (NPM) however clearly dominates. The article concludes that communication along market purposes, principles and practices risks distancing Armed Forces further from society. Yet, an embryonic deliberative ideal (NPS)—much fuelled by the use of social media such as blogs—was also identified. This growing ideal holds the potential of infusing deliberative vigor into the organization and presumably facilitates the bridging of the gap to society.
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| 38. |
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| 39. |
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| 40. |
- Eyjolfsson, Atli, et al.
(author)
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Cardiorespiratory effects of venous lipid micro embolization in an experimental model of mediastinal shed blood reinfusion.
- 2009
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In: Journal of Cardiothoracic Surgery. - : Springer Science and Business Media LLC. - 1749-8090. ; 4:48
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Journal article (peer-reviewed)abstract
- BACKGROUND: Retransfusion of the patient's own blood during surgery is used to reduce the need for allogenic blood transfusion. It has however been found that this blood contains lipid particles, which form emboli in different organs if the blood is retransfused on the arterial side. In this study, we tested whether retransfusion of blood containing lipid micro-particles on the venous side in a porcine model will give hemodynamic effects. METHODS: Seven adult pigs were used. A shed blood surrogate containing 400 ml diluted blood and 5 ml radioactive triolein was produced to generate a lipid embolic load. The shed blood surrogate was rapidly (<2 minutes) retransfused from a transfusion bag to the right atrium under general anesthesia. The animals' arterial, pulmonary, right and left atrial pressure were monitored, together with cardiac output and deadspace. At the end of the experiment, an increase in cardiac output and pulmonary pressure was pharmacologically induced to try to flush out lipid particles from the lungs. RESULTS: A more than 30-fold increase in pulmonary vascular resistance was observed, with subsequent increase in pulmonary artery pressure, and decrease in cardiac output and arterial pressure. This response was transient, but was followed by a smaller, persistent increase in pulmonary vascular resistance. Only a small portion of the infused triolein passed the lungs, and only a small fraction could be recirculated by increasing cardiac output and pulmonary pressure. CONCLUSION: Infusion of blood containing lipid micro-emboli on the venous side leads to acute, severe hemodynamic responses that can be life threatening. Lipid particles will be trapped in the lungs, leading to persistent effects on the pulmonary vascular resistance.
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| 41. |
- Eyjolfsson, Atli, et al.
(author)
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Lipid emboli distribution in cardiac surgery is dependent on the state of emulsification
- 2012
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In: Scandinavian Cardiovascular Journal. - : Informa UK Limited. - 1651-2006 .- 1401-7431. ; 46:1, s. 51-56
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Journal article (peer-reviewed)abstract
- Objective. Lipid embolizations from retransfused shed blood during cardiac surgery have been shown to enter the circulation and end up in different organs. The purpose of this investigation was to evaluate differences in the kinetics and deposition between emulsified and non-emulsified lipid emboli in a porcine model. Design. Twelve animals were anesthetized and put on cardiopulmonary bypass. A shed-blood phantom (6 animals given emulsified and 6 given non-emulsified lipids) was produced from arterial blood, saline, and tritium-labeled triolein. The phantom was infused into the cardiopulmonary bypass circuit. Arterial and venous blood samples were taken at short intervals. Tissue samples were taken post-mortem from examined organs and prepared for scintillation counting. Levels of radioactivity were used to measure lipid emboli content in blood and tissue. Results. Emulsified lipid emboli generated a 5-fold higher embolic load in the arterial and a 12-fold higher in the venous circulation, compared with non-emulsified lipid emboli. Emulsified lipid micro emboli resulted in a 2-15-fold higher tissue deposition in investigated organs compared with non-emulsified lipid micro emboli. Conclusions. This study shows that the state of emulsion significantly alter the kinetics and tissue deposition of lipid emboli. Emulsified lipid emboli give higher embolic load in the arterial and venous circulation, and higher tissue deposition versus non-emulsified lipid emboli. In both groups, the embolic load was higher in the arterial circulation than on the venous side.
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| 42. |
- Fisichella, Valeria A, 1974, et al.
(author)
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Evaluation of image quality and lesion perception by human readers on 3D CT colonography: comparison of standard and low radiation dose
- 2010
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In: European Radiology. - 1432-1084. ; 20:3, s. 630-9
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Journal article (peer-reviewed)abstract
- AIMS: We compared the prevalence of noise-related artefacts and lesion perception on three-dimensional (3D) CT colonography (CTC) at standard and low radiation doses. METHODS: Forty-eight patients underwent CTC (64 x 0.625 mm collimation; tube rotation time 0.5 s; automatic tube current modulation: standard dose 40-160 mA, low dose 10-50 mA). Low- and standard-dose acquisitions were performed in the supine position, one after the other. The presence of artefacts (cobblestone and snow artefacts, irregularly delineated folds) and the presence of polyps were evaluated by five radiologists on 3D images at standard dose, the original low dose and a modified low dose, i.e. after manipulation of opacity on 3D. RESULTS: The mean effective dose was 3.9 +/- 1.3 mSv at standard dose and 1.03 +/- 0.4 mSv at low dose. The number of images showing cobblestone artefacts and irregularly delineated folds at original and modified low doses was significantly higher than at standard dose (P < 0.0001). Most of the artefacts on modified low-dose images were mild. No significant difference in sensitivity between the dose levels was found for polyps >/=6 mm. CONCLUSIONS: Reduction of the effective dose to 1 mSv significantly affects image quality on 3D CTC, but the perception of >/=6 mm lesions is not significantly impaired.
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| 43. |
- Gharaee, Zahra, et al.
(author)
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Action Recognition Online with Hierarchical Self-Organizing Maps
- 2016
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In: 12th International Conference on Signal Image Technology & Internet-Based Systems : SITIS 2016. Proceedings. - SITIS 2016. Proceedings.. - 9781509056989 ; , s. 538-544
-
Conference paper (peer-reviewed)abstract
- We present a hierarchical self-organizing map based system for online recognition of human actions. We have made a first evaluation of our system by training it on two different sets of recorded human actions, one set containing manner actions and one set containing result actions, and then tested it by letting a human performer carry out the actions online in real time in front of the system’s 3D-camera. The system successfully recognized more than 94% of the manner actions and most of the result actions carried out by the human performer.
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| 44. |
- Gharaee, Zahra, et al.
(author)
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First and Second Order Dynamics in a Hierarchical SOM system for Action Recognition
- 2017
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In: Applied Soft Computing. - : Elsevier BV. - 1568-4946. ; 59, s. 574-585
-
Journal article (peer-reviewed)abstract
- Human recognition of the actions of other humans is very efficient and is based on patterns of movements. Our theoretical starting point is that the dynamics of the joint movements is important to action categorization. On the basis of this theory, we present a novel action recognition system that employs a hierarchy of Self-Organizing Maps together with a custom supervised neural network that learns to categorize actions. The system preprocesses the input from a Kinect like 3D camera to exploit the information not only about joint positions, but also their first and second order dynamics. We evaluate our system in two experiments with publicly available datasets, and compare its performance to the performance with less sophisticated preprocessing of the input. The results show that including the dynamics of the actions improves the performance. We also apply an attention mechanism that focuses on the parts of the body that are the most involved in performing the actions.
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| 45. |
- Gharaee, Zahra, et al.
(author)
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Hierarchical Self-Organizing Maps System for Action Classification
- 2017
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In: Proceedings of the 9th International Conference on Agents and Artificial Intelligence (ICAART 2017). - : SCITEPRESS - Science and Technology Publications. - 9789897582202 ; , s. 583-590
-
Conference paper (peer-reviewed)abstract
- We present a novel action recognition system that is able to learn how to recognize and classify actions. Our system employs a three-layered hierarchy of Self-Organizing Maps together with a supervised neural network for labelling the actions. We have evaluated our system in an experiments consisting of ten different actions from a publicly available data set. The results are encouraging with 83% correctly classified actions based on the actor’s spatial trajectory.
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| 46. |
- Gharaee, Zahra, et al.
(author)
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Online Recognition of Actions Involving Objects
- 2017
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In: Biologically Inspired Cognitive Architectures. - : Elsevier BV. - 2212-6848 .- 2212-683X. ; 22, s. 10-19
-
Journal article (peer-reviewed)abstract
- We present an online system for real time recognition of actions involving objects working in online mode. The system merges two streams of information pro- cessing running in parallel. One is carried out by a hierarchical self-organizing map (SOM) system that recognizes the performed actions by analysing the spa- tial trajectories of the agent’s movements. It consists of two layers of SOMs and a custom made supervised neural network. The activation sequences in the first layer SOM represent the sequences of significant postures of the agent during the performance of actions. These activation sequences are subsequently recoded and clustered in the second layer SOM, and then labeled by the ac- tivity in the third layer custom made supervised neural network. The second information processing stream is carried out by a second system that determines which object among several in the agent’s vicinity the action is applied to. This is achieved by applying a proximity measure. The presented method combines the two information processing streams to determine what action the agent per- formed and on what object. The action recognition system has been tested with excellent performance.
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| 47. |
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| 48. |
- Gil, David, et al.
(author)
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Application of artificial neural networks in the diagnosis of urological dysfunctions
- 2009
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In: Expert Systems with Applications. - : Elsevier BV. - 0957-4174. ; 36:3, s. 5754-5760
-
Research review (peer-reviewed)abstract
- In this article, we evaluate the work out of some artificial neural network models as tools for support in the medical diagnosis of urological dysfunctions. We develop two types of unsupervised and one supervised neural network. This scheme is meant to help the urologists in obtaining a diagnosis for complex multi-variable diseases and to reduce painful and costly medical treatments since neurological dysfunctions are difficult to diagnose. The clinical study has been carried out using medical registers of patients with urological dysfunctions. The proposal is able to distinguish and classify between ill and healthy patients. (C) 2008 Elsevier Ltd. All rights reserved.
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| 49. |
- Gil, D., et al.
(author)
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Architecture Based on Machine Learning Techniques and Data Mining for Prediction of Indicators in the Diagnosis and Intervention of Autistic Spectrum Disorder
- 2021
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In: Research and Innovation Forum 2021. - : Springer. - 9783030843106 - 9783030843113 ; , s. 133-140
-
Conference paper (peer-reviewed)abstract
- In the complex study to obtain indicators in the autism spectrum disorder it is very common to perform many and very complex tasks. Often, these tasks require the completion of a series of forms and surveys that are even more complex and tedious, which means that the accuracy of the reports is not always satisfactory. In this paper, we propose a general architecture based on machine learning techniques and data mining for prediction of the main indicators in the diagnosis and intervention of the autistic spectrum disorder. The main idea of this approach is to replace those print documents by mobile tests, tablet or smartphones tests through games, store them in databases and analyse them. Furthermore, very often these last two steps are not undertaken with the lack of quantitative and qualitative analysis that could be generated. Finally, the presented architecture is oriented to data collection with the objective of the creation of large specialized datasets. © 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG.
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