| 1. |
- Allard, Anna, et al.
(författare)
-
Småbiotopsuppföljning i NILS år 2008
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna rapport presenterar resultat för mängden av småbiotoper vid åkermark i det svenska landskapet. Analyserna görs på uppdrag av Jordbruksverket, som underlag för bl.a. utvärderingen av miljökvalitetsmålet Ett rikt odlingslandskap. Särskilda rutiner har tagits fram för att aggregera olika variabler för att välja ut de småbiotoper som uppfyller de krav som Jordbruksverket har ställt upp, ur den befintliga databasen. Urvalet av småbiotoper är anpassat för att överensstämma med det urval av objekt som ingår i det s.k. KULT-stödet (miljöersättning till lantbrukare för skötsel av värdefulla natur- och kulturmiljöer) inom Jordbruksverkets Landsbygdsprogram. Arbetet har utförts vid institutionen för skoglig resurshushållning, Sveriges lantbruks-universitet, Umeå. Resultaten baseras på data från flygbildsinventeringen inom det nationella miljöövervakningsprogrammet NILS (Nationell Inventering av Landskapet i Sverige) vilket följer tillstånd och förändringar i det svenska landskapet och hur dessa påverkar förutsättningarna för den biologiska mångfalden. NILS finansieras av Naturvårdsverket, och ingår där i programområde Landskap. Ett viktigt syfte med programmet är att följa upp de nationella miljökvalitetsmålen för olika naturtyper och fungera som underlag för att se om genomförda policybeslut och miljövårdsåtgärder leder till önskade förbättringar
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| 2. |
- Alsaqal, Salem, et al.
(författare)
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The Combination of MR Elastography and Proton Density Fat Fraction Improves Diagnosis of Nonalcoholic Steatohepatitis.
- 2022
-
Ingår i: Journal of Magnetic Resonance Imaging. - : John Wiley & Sons. - 1053-1807 .- 1522-2586. ; 56:2, s. -379
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is rapidly increasing worldwide. It is subdivided into nonalcoholic fatty liver (NAFL) and the more aggressive form, nonalcoholic steatohepatitis (NASH), which carries a higher risk of developing fibrosis and cirrhosis. There is currently no reliable non-invasive method for differentiating NASH from NAFL.PURPOSE: To investigate the ability of magnetic resonance imaging (MRI)-based imaging biomarkers to diagnose NASH and moderate fibrosis as well as assess their repeatability.STUDY TYPE: Prospective.SUBJECTS: Sixty-eight participants (41% women) with biopsy-proven NAFLD (53 NASH and 15 NAFL). Thirty participants underwent a second MRI in order to assess repeatability.FIELD STRENGTH/SEQUENCE: 3.0 T; MR elastography (MRE) (a spin-echo echo-planar imaging [SE-EPI] sequence with motion-encoding gradients), MR proton density fat fraction (PDFF) and R2* mapping (a multi-echo three-dimensional gradient-echo sequence), T1 mapping (a single-point saturation-recovery technique), and diffusion-weighted imaging (SE-EPI sequence).ASSESSMENT: Quantitative MRI measurements were obtained and assessed alone and in combination with biochemical markers (cytokeratin-18 [CK18] M30, alanine transaminase [ALT], and aspartate transaminase [AST]) using logistic regression models. Models that could differentiate between NASH and NAFL and between moderate to advanced fibrosis (F2-4) and no or mild fibrosis (F0-1), based on the histopathological results, were identified.STATISTICAL TESTS: Independent samples t-test, Pearson's chi-squared test, area under the receiver operating characteristic curve (AUROC), Spearman's correlation, intra-individual coefficient of variation, and intraclass correlation coefficient (ICC). Statistical significance was set at P < 0.05.RESULTS: There was a significant difference between the NASH and NAFL groups with liver stiffness assessed with MRE, CK18 M30, and ALT, with an AUROC of 0.74, 0.76, and 0.70, respectively. Both MRE and PDFF contributed significantly to a bivariate model for diagnosing NASH (AUROC = 0.84). MRE could significantly differentiate between F2-4 and F0-1 (AUROC = 0.74). A model combining MRE with AST improved the diagnosis of F2-4 (AUROC = 0.83). The ICC for repeatability was 0.94 and 0.99 for MRE and PDFF, respectively.DATA CONCLUSION: MRE can potentially diagnose NASH and differentiate between fibrosis stages. Combining MRE with PDFF improves the diagnosis of NASH.LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 2.
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| 3. |
- Langner, Taro, et al.
(författare)
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Fully convolutional networks for automated segmentation of abdominal adipose tissue depots in multicenter water–fat MRI
- 2019
-
Ingår i: Magnetic Resonance in Medicine. - : Wiley. - 0740-3194 .- 1522-2594. ; 81:4, s. 2736-2745
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: An approach for the automated segmentation of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) in multicenter water–fat MRI scans of the abdomen was investigated, using 2 different neural network architectures.Methods: The 2 fully convolutional network architectures U‐Net and V‐Net were trained, evaluated, and compared using the water–fat MRI data. Data of the study Tellus with 90 scans from a single center was used for a 10‐fold cross‐validation in which the most successful configuration for both networks was determined. These configurations were then tested on 20 scans of the multicenter study beta‐cell function in JUvenile Diabetes and Obesity (BetaJudo), which involved a different study population and scanning device.Results: The U‐Net outperformed the used implementation of the V‐Net in both cross‐validation and testing. In cross‐validation, the U‐Net reached average dice scores of 0.988 (VAT) and 0.992 (SAT). The average of the absolute quantification errors amount to 0.67% (VAT) and 0.39% (SAT). On the multicenter test data, the U‐Net performs only slightly worse, with average dice scores of 0.970 (VAT) and 0.987 (SAT) and quantification errors of 2.80% (VAT) and 1.65% (SAT).Conclusion: The segmentations generated by the U‐Net allow for reliable quantification and could therefore be viable for high‐quality automated measurements of VAT and SAT in large‐scale studies with minimal need for human intervention. The high performance on the multicenter test data furthermore shows the robustness of this approach for data of different patient demographics and imaging centers, as long as a consistent imaging protocol is used.
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| 4. |
- Löfgren, N., et al.
(författare)
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Remote sessions and frequency analysis for improved insight into cerebral function during pediatric and neonatal intensive care.
- 2003
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Ingår i: IEEE transactions on information technology in biomedicine. - 1089-7771 .- 1558-0032. ; 7:4, s. 283-90
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Tidskriftsartikel (refereegranskat)abstract
- A project involving recording and analysing EEG together with cardiovascular signals and temperature has been initiated. The aim of this project is to establish difficulties and possibilities involved with implementing a system for remote sessions and analysing EEG in correlation with other physiological signals. One objective is to find indicators of cerebral function during postasphyxia neonatal intensive care and pediatric cardiopulmonary bypass surgery with hypothermia. Remote sessions for joint interpretation have been carried out between pediatricians and clinical neurophysiologists, and EEG has been analyzed using frequency analyzing tools. One result is the discovery of reversible spectral changes coinciding with blood pressure falls, which may indicate loss of autoregulation function. This finding is one outcome from initial use of a system, developed during the project to facilitate communication about, and analysis of the recorded signals. Thus, already from a limited number of remote sessions and the use of basic signal processing techniques, important results have been achieved and better insight has been gained of how cerebral function is affected by cardiopulmonary bypass surgery. In this paper, we present our experiences from introducing a system for remote consultations, and evaluate the use for such a system in the current applications.
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| 5. |
- Ståhl, Göran, et al.
(författare)
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National inventory of landscapes in Sweden (NILS) : scope, design, and experiences from establishing a multi-scale biodiversity monitoring system
- 2011
-
Ingår i: Environmental Monitoring & Assessment. - : Springer Science and Business Media LLC. - 0167-6369 .- 1573-2959. ; 173:1-4, s. 579-595
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Tidskriftsartikel (refereegranskat)abstract
- The landscape-level and multiscale biodiversity monitoring program National Inventory of Landscapes in Sweden (NILS) was launched in 2003. NILS is conducted as a sample-based stratified inventory that acquires data across several spatial scales, which is accomplished by combining aerial photo interpretation with field inventory. A total of 631 sample units are distributed across the land base of Sweden, of which 20% are surveyed each year. By 2007 NILS completed the first 5-year inventory phase. As the reinventory in the second 5-year phase (2008-2012) proceeds, experiences and insights accumulate and reflections are made on the setup and accomplishment of the monitoring scheme. In this article, the emphasis is placed on background, scope, objectives, design, and experiences of the NILS program. The main objective to collect data for and perform analyses of natural landscape changes, degree of anthropogenic impact, prerequisites for natural biological diversity and ecological processes at landscape scale. Different environmental conditions that can have direct or indirect effects on biological diversity are monitored. The program provides data for national and international policy and offers an infrastructure for other monitoring program and research projects. NILS has attracted significant national and international interest during its relatively short time of existence; the number of stakeholders and cooperation partners steadily increases. This is constructive and strengthens the incentive for the multiscale monitoring approach.
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| 6. |
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| 7. |
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| 8. |
- Belichenko, P, et al.
(författare)
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Dendritic morphology in epileptogenic cortex from TRPE patients, revealed by intracellular Lucifer Yellow microinjection and confocal laser scanning microscopy.
- 1994
-
Ingår i: Epilepsy research. - 0920-1211. ; 18:3, s. 233-47
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Tidskriftsartikel (refereegranskat)abstract
- Biopsy material was obtained from cortical epileptogenic zones (eight temporal, one occipital, one parietal and one frontal) of eleven patients aged 1.5-47 years with therapy-resistant partial epilepsy (TRPE) undergoing epilepsy surgery. Control autopsy material (two temporal, two occipital, one parietal and one frontal) was removed from six neurologically healthy cases within 6-10 hours postmortem delay. In each specimen, 100-300 pyramidal and non-pyramidal neurons were visualized by intracellular Lucifer Yellow microinjection. Single neurons were imaged using CLSM generated serial optical sections; 2-D reconstruction of each neuron was made using z-projection of serial optical images, and 3-D reconstructions and rotations were computerized. Neuronal maps from TRPE biopsies, compared to control autopsies, show markedly increased numbers of dendritic abnormalities of single pyramidal and non-pyramidal neurons in layers I, II-III, V-VII, and in the subcortical white matter. The abnormalities include: (1) increased number of non-pyramidal cells in layer I; (2) many pyramidal cells with two or three dendrites originating apically, rather than one single apical dendrite, in layers II-III; (3) atypical orientation of oblique apical and basal dendrites in pyramidal neurons of layers II-VII; (4) increased number of atypical 'dinosaur-like' and fusiform cells in layers V-VII; (5) numerous neurons in the white matter. These abnormalities may be etiological in cases with early onset, and predisposing in cases with late onset.
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| 9. |
- Esseen, Per-Anders, et al.
(författare)
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Factors driving structure of natural and anthropogenic forest edges from temperate to boreal ecosystems
- 2016
-
Ingår i: Journal of Vegetation Science. - : Wiley. - 1100-9233 .- 1654-1103. ; 27:3, s. 482-492
-
Tidskriftsartikel (refereegranskat)abstract
- Questions What factors control broad-scale variation in edge length and three-dimensional boundary structure for a large region extending across two biomes? What is the difference in structure between natural and anthropogenic edges? Location Temperate and boreal forests across all of Sweden, spanning latitudes 55-69 degrees N. MethodsWe sampled more than 2000 forest edges using line intersect sampling in a monitoring programme (National Inventory of Landscapes in Sweden). We compared edge length, ecosystem attributes (width of adjacent ecosystem, canopy cover, canopy height, patch contrast in canopy height, forest type) and boundary attributes (profile, abruptness, shape) of natural edges (lakeshore, wetland) with anthropogenic edges (clear-cut, agricultural, linear disturbance) in five regions. Results Anthropogenic edges were nearly twice as abundant as natural edges. Length of anthropogenic edges was largest in southern regions, while the abundance of natural edges increased towards the north. Edge types displayed unique spectrums of boundary structures, but abrupt edges dominated, constituting 72% of edge length. Anthropogenic edges were more abrupt than natural edges; wetland edges had the most gradual and sinuous boundaries. Canopy cover, canopy height, patch contrast and forest type depended on region, whereas overall boundary abruptness and shape showed no regional pattern. Patch contrast was related to temperature sum (degree days5 degrees C), suggesting that regional variability can be predicted from climate-controlled forest productivity. Boundary abruptness was coupled with the underlying environmental gradient, land use and forest type, with higher variability in deciduous than in conifer forest. Conclusions Edge origin, land use, climate and tree species are main drivers of broad-scale variability in forest edge structure. Our findings have important implications for developing ecological theory that can explain and predict how different factors affect forest edge structure, and help to understand how land use and climate change affect biodiversity at forest edges.
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| 10. |
- Fröberg, Anders, et al.
(författare)
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Controlling Gear Engagement and disengagement on heavy trucks for minimization of fuel consumption
- 2005
-
Ingår i: Proceedings of the 16th IFAC World Congress.
-
Konferensbidrag (refereegranskat)abstract
- There is a potential to save fuel for heavy trucks by storing kineticenergy in the vehicle when driving downhill, because the speed adds kinetic energyto the vehicle which can be used after the downhill slope to propell the vehicle.This behavior can be even more utilized by disengaging the gear to reduce thefriction in the driveline and thus increase the speed even more. Two differentcontrol strategies to choose when to disengage the gear is presented: One schemethat uses instantaneous inclination and one predictive control scheme that useslook ahead information of the road topology. Simulation results show that geardisengagement in downhills can reduce the fuel consumption about 3%.
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| 11. |
- Gillberg, Christopher, 1950, et al.
(författare)
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Autism and epilepsy (and tuberous sclerosis?) in two pre-adolescent boys: neuropsychiatric aspects before and after epilepsy surgery.
- 1996
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Ingår i: Journal of intellectual disability research : JIDR. - 0964-2633. ; 40 ( Pt 1), s. 75-81
-
Tidskriftsartikel (refereegranskat)abstract
- We report on two pre-adolescent boys with a combination of severe seizure disorders and severe-moderate autism who underwent brain surgery for their epilepsy at the ages of 9 and 10 years, respectively. Both boys became seizure-free and initially improved dramatically with regard to autism symptoms. One of the boys continued to improve, but the other had a relapse to his pre-operative state in conjunction with his pubertal growth spurt. Several years after surgery, one of the boys remained much improved with respect to his autism. The other subject showed some improvement with respect to self-injury and aggression, and had slightly lower scores on screens for autism symptoms than in the year preceding epilepsy surgery. The histopathological examination of the brain tissue that was removed at surgery suggested a diagnosis of tuberous sclerosis in both cases.
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| 12. |
- Glimskär, Anders, et al.
(författare)
-
Uppföljning av kvalitetsförändringar i ängs- och betesmark via NILS år 2008
- 2009
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna rapport presenterar resultat för ett antal indikatorer på kvalitet och skötsel i ett stickprov av ängs- och betesmarker i hela Sverige. Inventeringen och analyserna görs varje år från och med 2006 på uppdrag av Jordbruksverket, som underlag för bl.a. utvärderingen av miljökvalitetsmålet Ett rikt odlingslandskap. Som indikatorer har i första hand valts ett antal organismgrupper (fjärilar, humlor, kärlväxter, grova lövträd och epifytlavar), och dessutom beskrivs vegetationens struktur och sammansättning i provytor, som underlag för att ta fram strukturella indikatorer (t.ex. påverkan av gödsling och hävdintensitet/igenväxning). Urvalet bygger på förslag som tagits fram av Naturcentrum AB. De resultat som presenteras i denna rapport kommer från de första tre årens inventering, vilket innefattar tre femtedelar av det totala stickprovet. Efter fem år får man således de mest tillförlitliga mängdskattningarna. Därefter återkommer man till samma objekt med samma intervall, vilket gör att man på ett tillförlitligt sätt kan analysera förändringar baserat på jämförelser mellan femårsperioder. Uppdraget att inventera ängs- och betesmarker samordnas med fältarbetet i NILS (Nationell Inventering av Landskapet i Sverige), och metodiken är till stor del likartad, med en del tilläggsmoment. NILS är ett rikstäckande miljöövervakningsprogram som följer tillstånd och förändringar i det svenska landskapet och hur dessa påverkar förutsättningarna för den biologiska mångfalden. NILS finansieras av Naturvårdsverket och ingår i programområde Landskap. Ett viktigt syfte med NILS är att följa upp de nationella miljökvalitetsmålen för olika naturtyper och fungera som underlag för att till exempel visa om genomförda miljövårdsåtgärder leder till önskade förbättringar på nationell nivå eller landsdelsnivå. Arbetet har utförts vid institutionen för skoglig resurshushållning, Sveriges lantbruksuniversitet, Umeå, i samarbete med inst. för ekologi, SLU och avd. för biologi/IFM, Linköpings universitet. Erik Cronvall och Åsa Gallegos Torell (SLU, inst. för skoglig resurshushållning) har ansvarat för fältkurser och genomförandet av fältinventeringen tillsammans med säsongsanställd fältpersonal, med stöd av bl.a. Kjell Lagerqvist (SLU) och Karl-Olof Bergman (Linköpings universitet). Beräkningarna har utförts av Saskia Sandring och Åsa Eriksson, med stöd av Anna Ringvall (SLU). Sammanställandet av rapporten har utförts av Anders Glimskär och Jörgen Wissman (SLU). NILS programchef Johan Svensson (SLU) har det övergripande ansvaret för uppdraget
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| 13. |
- Glimskär, Anders, et al.
(författare)
-
Uppföljning av kvalitetsändringar i ängs- och betesmark via NILS år 2008
- 2009
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna rapport presenterar resultat för ett antal indikatorer på kvalitet och skötsel i ett stickprov av ängs- och betesmarker i hela Sverige. Inventeringen och analyserna görs varje år från och med 2006 på uppdrag av Jordbruksverket, som underlag för bl.a. utvärderingen av miljökvalitetsmålet Ett rikt odlingslandskap. Som indikatorer har i första hand valts ett antal organismgrupper (fjärilar, humlor, kärlväxter, grova lövträd och epifytlavar), och dessutom beskrivs vegetationens struktur och sammansättning i provytor, som underlag för att ta fram strukturella indikatorer (t.ex. påverkan av gödsling och hävdintensitet/igenväxning). Urvalet bygger på förslag som tagits fram av Naturcentrum AB. De resultat som presenteras i denna rapport kommer från de första tre årens inventering, vilket innefattar tre femtedelar av det totala stickprovet. Efter fem år får man således de mest tillförlitliga mängdskattningarna. Därefter återkommer man till samma objekt med samma intervall, vilket gör att man på ett tillförlitligt sätt kan analysera förändringar baserat på jämförelser mellan femårsperioder. Uppdraget att inventera ängs- och betesmarker samordnas med fältarbetet i NILS (Nationell Inventering av Landskapet i Sverige), och metodiken är till stor del likartad, med en del tilläggsmoment. NILS är ett rikstäckande miljöövervakningsprogram som följer tillstånd och förändringar i det svenska landskapet och hur dessa påverkar förutsättningarna för den biologiska mångfalden. NILS finansieras av Naturvårdsverket och ingår i programområde Landskap. Ett viktigt syfte med NILS är att följa upp de nationella miljökvalitetsmålen för olika naturtyper och fungera som underlag för att till exempel visa om genomförda miljövårdsåtgärder leder till önskade förbättringar på nationell nivå eller landsdelsnivå.
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| 14. |
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| 15. |
- Hedström, Lars, et al.
(författare)
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Key factors in planning a sustainable energy future including hydrogen and fuel cells
- 2006
-
Ingår i: Bulletin of Science, Technology & Society. - : SAGE Publications. - 0270-4676 .- 1552-4183. ; 26:4, s. 264-277
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Tidskriftsartikel (refereegranskat)abstract
- In this article, a number of future energy visions, especiallythose basing the energy systems on hydrogen, are discussed.Some often missing comparisons between alternatives, from asustainability perspective, are identified and then performedfor energy storage, energy transportation, and energy use invehicles. It is shown that it is important to be aware of thelosses implied by production, packaging, distribution, storage,and end-use of hydrogen when suggesting a "hydrogen economy."It is also shown that for stationary electric energy storage,fuel cell electrolyzers could be feasible. Zero-tailpipeemissionvehicles are compared. The battery electric vehicle has thehighest electrical efficiency, but other requirements implythat plug-in hybrids or fuel cell hybrids might be a betteroption in some types of vehicles. Finally, a simplified exampleis applied to the overall results and used to discuss the needsand nature of an energy system based on intermittent energysources.
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| 16. |
- Hedström, Mariann, et al.
(författare)
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Accuracy of assessment of distress, anxiety, and depression by physicians and nurses in adolescents recently diagnosed with cancer
- 2006
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Ingår i: Pediatric Blood & Cancer. - : Wiley. - 1545-5009 .- 1545-5017. ; 46:7, s. 773-9
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Tidskriftsartikel (refereegranskat)abstract
- Background. As staff members prioritize medical resources forpatients, it is imperative to find out whether their assessments ofpatients’ health status agree with patients’ assessments. The degree towhich physicians and nurses can identify the distress, anxiety, anddepression experienced by adolescents recently diagnosed withcancer was examined here. Procedure. Adolescents undergoingchemotherapy (13–19 years, n¼53), physicians (n¼48), and nurses(n¼53) completed a structured telephone interview, 4–8 weeksafter diagnosis or relapse, investigating disease and treatment-relateddistress, anxiety, and depression. Results. The accuracy of staffratings of physical distress could be considered acceptable.However, problems of a psychosocial nature, which were frequentlyoverestimated, were difficult for staff to identify. Staff underestimatedthe distress caused by mucositis and worry about missing schoolmore than they overestimated distress. These aspects were some ofthe most prevalent and overall worst according to the adolescents.Both physicians and nurses overestimated levels of anxiety anddepression. Nurses tended to show higher sensitivity than physiciansfor distress related to psychosocial aspects of distress, whilephysicians tended to show higher accuracy than nurses for physicaldistress. Conclusions. Staff was reasonably accurate at identifyingphysical distress in adolescents recently diagnosed with cancerwhereas psychosocial problems were generally poorly identified.Thus, the use of staff ratings as a ‘‘test’’ to guide specific supportseems problematic. Considering that the accuracy of staff ratingsoutside a research study is probably lower, identification of andaction taken on adolescent problems in relation to cancer diagnosisand treatment need to rely on direct communication.
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| 17. |
- Hedström, Mariann, 1965-
(författare)
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Distress among Adolescents with Cancer
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The primary aim was to investigate the distress perceived by adolescents with cancer treated in paediatric oncology. In Study I, especially distressing events for children/adolescents with cancer were identified by interviews with children/adolescents/parents and nurses. Data were analysed with content analysis. A range of physical and emotional concerns was identified. Physical concerns are of a rather similar nature across age groups. Emotional concerns vary more between age groups. For children 8-12 years, emotional concerns are rather frequent. In Study II distressing and positive aspects related to some care situations for adolescents with cancer were identified by interviews with adolescents and nurses. Data were analysed with content analysis. A range of negative aspects, e.g. fear of alienation, fear of dying, altered appearance and physical concerns, as well as positive aspects, e.g. positive relations to staff and being well cared for were identified. The aspects of distress identified in Studies I and II formed the basis for a structured interview-guide, used in Studies III and IV. Adolescents, recently diagnosed with cancer, physicians and nurses were interviewed by telephone about distress, anxiety, depression and well-being experienced by the adolescents. Adolescent ratings of prevalence, levels and worst aspects of distress do not necessarily agree, however, worry missing school and mucositis are among those rated with the highest prevalence, levels and those perceived as the overall worst. The findings from Study IV demonstrate that physicians and nurses underestimate the distress caused by worry missing school and mucositis. The accuracy of physician and nurse ratings of physical distress is acceptable, however, this is not the case for psychosocial distress. It can be concluded that it is crucial to consider how questions are asked when interpreting the significance of the answers, and that action on adolescent problems in relation to cancer diagnosis and treatment need to rely on direct communication.
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| 18. |
- Hedström, Ragnar, 1952-, et al.
(författare)
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Innovationsupphandling och implementering av komplexa signalsystem : arbetsprocesser och verktyg
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Projektets syfte är att identifiera problem och behov som möjliggör att en beställarorganisation uppnår målen för funktionalitet, tid och budget för innovationsupphandling av signalsystem. En litteraturgenomgång och att antal workshops med efterföljande strukturerad analys har genomförts. Spårburen trafik har någon form av styrsystem och säkerhetskoncept där signalsystemet utgör en väsentlig del av säkerheten. Ur ett systemperspektiv är signalsystem en komplex och tekniskt avancerad infrastruktur som behöver behandlas tvärvetenskapligt. Varje delsystem och varje objekt i trafikstyrningssystemet är vanligtvis inte komplicerat i sig självt. Kombinationen av många delsystem och integrationen med övrig infrastruktur skapar en komplex struktur och blir en abstrakt, icke visuell skapelse. För att hantera komplexiteten och närma sig ett hanterbart sätt att identifiera vilka behov som finns för en effektiv och innovativ utveckling av signalsystem gjordes en analys av signalsystem ur ett processperspektiv. Behoven analyserades sedan ur två teoretiska perspektiv – Integrerad Produktutveckling (IPU) och Systems Engineering (SE) som båda innehåller beskrivningar av hur olika aktörer vid produktutveckling bör involveras med avseende på roller och ansvar. Analyserna och resultatet från workshopen identifierade ett antal problemområden som behöver hanteras för att utveckling av signalsystem ska kunna genomföras på ett bättre sätt i framtiden. Flera problemområden finns identifierade i teoretiska beskrivningar för i IPU och SE men de behöver anpassas till beställarorganisationer.
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| 19. |
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| 20. |
- Johansson, Bengt, et al.
(författare)
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Evaluation of hyaluronan and calcifications in stenotic and regurgitant aortic valves.
- 2011
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Ingår i: European Journal of Cardio-Thoracic Surgery. - : Elsevier. - 1010-7940 .- 1873-734X. ; 39:1, s. 27-32
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Hyaluronan (HA) is a major component of the interstitium and has been observed in normal heart valves. The function of HA in heart valves is unknown but contribution to biomechanical function has been proposed. The purpose of this investigation was to study the distribution of HA in relation to calcifications in diseased human aortic valves. Methods: Human aortic valves were collected at aortic valve replacement, of whom nine patients had regurgitation and 13 stenotic disease. The valves were decalcified and stained for the visualisation of HA. The specimens were macroscopically evaluated for magnitude of calcification using image analysis. The microscopic amount and distribution of HA and calcifications were semiquantitatively evaluated using histochemistry. Results: The overall HA staining showed an inverse relationship against the magnitude of observed valve calcifications (p<0.001) and type of disease (p=0.014). Multiple-group comparison revealed regionally reduced HA staining in diffuse and heavy calcified regions inside the valve (both p<0.001) compared with normal-structured parts of the valve. HA was concentrated on the ventricular side of the valve (p=0.002). Conclusions: The content of HA was reduced in calcified aortic valves and had a heterogeneous distribution, potentially contributing to poor valve function. HA may also be involved in the pathophysiological process in degenerative aortic stenosis.
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| 21. |
- Kullberg, Joel, 1979-, et al.
(författare)
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Automated analysis of liver fat, muscle and adipose tissue distribution from CT suitable for large-scale studies
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Computed Tomography (CT) allows detailed studies of body composition and its association with metabolic and cardiovascular disease. The purpose of this work was to develop and validate automated and manual image processing techniques for detailed and efficient analysis of body composition from CT data. The study comprised 107 subjects examined in the Swedish CArdioPulmonary BioImage Study (SCAPIS) using a 3-slice CT protocol covering liver, abdomen, and thighs. Algorithms were developed for automated assessment of liver attenuation, visceral (VAT) and subcutaneous (SAT) abdominal adipose tissue, thigh muscles, subcutaneous, subfascial (SFAT) and intermuscular adipose tissue. These were validated using manual reference measurements. SFAT was studied in selected subjects were the fascia lata could be visually identified (approx. 5%). In addition, precision of manual measurements of intra-(IPAT) and retroperitoneal adipose tissue (RPAT) and deep-and superficial SAT was evaluated using repeated measurements. Automated measurements correlated strongly to manual reference measurements. The SFAT depot showed the weakest correlation (r = 0.744). Automated VAT and SAT measurements were slightly, but significantly overestimated (<= 4.6%, p <= 0.001). Manual segmentation of abdominal sub-depots showed high repeatability (CV <= 8.1%, r >= 0.930). We conclude that the low dose CT-scanning and automated analysis makes the setup suitable for large-scale studies.
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| 22. |
- Kyllerman, Mårten, 1941, et al.
(författare)
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Clinical and neurophysiological development of Unverricht-Lundborg disease in four Swedish siblings.
- 1991
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Ingår i: Epilepsia. - 0013-9580. ; 32:6, s. 900-9
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Tidskriftsartikel (refereegranskat)abstract
- Four siblings aged 12-18 years with progressive myoclonus epilepsy demonstrated a subclinical stage at the age of 9-11 years, with visual blackouts and polyspike electroencephalographic (EEG) activity on photic stimulation, an early myoclonic stage at the age of 12-15 years, with increasing segmental, stimulus-sensitive myoclonus, occasional nocturnal buildup myoclonic "cascade" seizures, slowing of EEG alpha-activity, episodic 4-6 Hz bilateral sharp waves and polyspikes with myoclonias on photic stimulation, and a disabling myoclonic stage at the age of 16-18 years, with periodic generalized myoclonias, nocturnal myoclonic "cascade" seizures, ataxia, dysarthria, mental changes, intermittent wheelchair dependency, and continuous EEG slow waves with polyspikes and intense myoclonias on photic stimulation. One of the siblings died at the age of 18 years with no apparent cause of death. Treatment with antiepileptic drugs other than valproate may have contributed but none of the siblings were ever treated with phenytoin. Extensive clinical and laboratory investigations revealed no abnormalities and excluded other known possible causes of progressive myoclonus epilepsy. The diagnosis was consistent with Unverricht-Lundborg disease and rested on typical age of onset, clinical signs, EEG, and evoked response abnormalities. Buildup myoclonic seizures are typical in advanced stages of Unverricht-Lundborg disease. We have labeled these myoclonic "cascade" seizures. A typical seizure was studied with video-EEG and cardiorespiratory monitoring. Characteristics revealed were onset with continuous arrhythmic myoclonic jerks followed by intense rhythmic myoclonus with increasing muscle tone that successively reduced the amplitude of the jerks. The EEG during the whole seizure showed intense polyspike activity. Obstructive apnea was seen at the peak of the seizure. There were no cardiac dysrhythmias. Consciousness was normal or only slightly impaired. Postictal drowsiness was not observed. Myoclonic "cascade" seizures are easily confused with generalized tonic-clonic seizures.
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| 23. |
- Lennartson, Anders, 1980, et al.
(författare)
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Diisopropyl(N,N,N ',N '-tetramethylethylenediamine)zinc(II), the first crystal structure of a diisopropylzinc complex
- 2007
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Ingår i: Acta Crystallographica Section E-Structure Reports Online. ; 63
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Tidskriftsartikel (refereegranskat)abstract
- Although diisopropylzinc has attracted considerable interest as a useful organometallic reagent over the past ten years, diisopropylzinc complexes are still absent in the present version of the Cambridge Structural Database. In the title compound, a tmeda (tmeda is N, N, N', N'-tetramethylethylenediamine) adduct, [Zn(C3H7)(2)(C6H16N2)], the Zn II atom, which lies on a crystallographic twofold rotation axis, is in a distorted tetrahedral geometry. The molecules are held together by dispersion forces, without any contacts within the sum of the van der Waals radii.
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| 24. |
- Lennartson, Anders, 1980, et al.
(författare)
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Spontaneous Generation of Chirality in Simple Diaryl Ethers.
- 2015
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Ingår i: Chirality. - : Wiley. - 1520-636X .- 0899-0042. ; 27:7, s. 425-9
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Tidskriftsartikel (refereegranskat)abstract
- We studied the spontaneous formation of chiral crystals of four diaryl ethers, 3-phenoxybenzaldehyde, 1; 1,3-dimethyl-2-phenoxybenzene, 2; di(4-aminophenyl) ether, 3; and di(p-tolyl) ether, 4. Compounds 1, 3, and 4 form conformationally chiral molecules in the solid state, while the chirality of 2 arises from the formation of supramolecular helices. Compound 1 is a liquid at ambient temperature, but 2-4 are crystalline, and solid-state CD-spectroscopy showed that they could be obtained as optically active bulk samples. It should be noted that the optical activity arise upon crystallization, and no optically active precursors were used. Indeed, even commercial samples of 3 and 4 were found to be optically active, giving evidence for the ease at which total spontaneous resolution may occur in certain systems.
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| 25. |
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| 26. |
- Liu, Chang, et al.
(författare)
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Stability and Effects of Subsurface Oxygen in Oxide-Derived Cu Catalyst for CO2 Reduction
- 2017
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 121:45, s. 25010-25017
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Tidskriftsartikel (refereegranskat)abstract
- Oxide-derived copper (OD-Cu) catalysts are promising candidates for the electrochemical CO2 reduction reaction (CO2RR) due to the enhanced selectivity toward ethylene over methane evolution, which has been linked to the presence of subsurface oxygen (O-sb). In this work, O-sb is investigated with theoretical methods. Although O-sb is unstable in slab models, it becomes stabilized within a manually reduced OD-Cu nanocube model which was calculated by self-consistent charge density functional tight binding (SCC-DFTB). The results obtained with SCC-DFTB for the full nanocube were confirmed with subcluster models extracted from the nanocube, calculated with both density functional theory (DFT) and SCC-DFTB. The. higher stability of O-sb in the nanocube is attributed to the disordered structure and greater flexibility. The adsorption strength of CO on Cu(100) is enhanced by O-sb withdrawing electron density from the Cu atom, resulting in reduction of the sigma-repulsion. Hence, the coverage of CO may be increased, facilitating its dimerization.
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| 27. |
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| 28. |
- Malmgren, Kristina, 1952, et al.
(författare)
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Successful epilepsy surgery in a patient with neurosarcoidosis
- 2010
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Ingår i: Epilepsia. - : Wiley. - 1528-1167 .- 0013-9580. ; 51:6, s. 1101-1103
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Tidskriftsartikel (refereegranskat)abstract
- This case concerns a patient with generalized neurosarcoidosis and pharmacoresistant focal epilepsy. Although immunosuppressive therapy resulted in remission of the neurosarcoidosis, seizures continued and were shown to originate from the right temporal lobe (TL). The patient underwent a right anterior temporal lobe resection (TLR) and obtained >90% reduction of seizure frequency.
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| 29. |
- Meyer, Anna C., et al.
(författare)
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Trends in Hip Fracture Incidence, Recurrence, and Survival by Education and Comorbidity : A Swedish Register-based Study
- 2021
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Ingår i: Epidemiology. - 1044-3983 .- 1531-5487. ; 32:3, s. 425-433
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Tidskriftsartikel (refereegranskat)abstract
- Background: Hip fractures are common and severe conditions among older individuals, associated with high mortality, and the Nordic countries have the highest incidence rates globally. With this study, we aim to present a comprehensive picture of trends in hip fracture incidence and survival in the older Swedish population stratified by education, birth country, and comorbidity level.Methods: This study is based on a linkage of several population registers and included the entire population over the age of 60 living in Sweden. We calculated age-standardized incidence rates for first and recurrent hip fractures as well as age-standardized proportions of patients surviving 30 and 365 days through the time period 1998 to 2017. We calculated all outcomes for men and women in the total population and in each population stratum.Results: Altogether, we observed 289,603 first hip fractures during the study period. Age-standardized incidence rates of first and recurrent fractures declined among men and women in the total population and in each educational-, birth country-, and comorbidity group. Declines in incidence were more pronounced for recurrent than for first fractures. Approximately 20% of women and 30% of men died within 1 year of their first hip fracture. Overall, survival proportions remained constant throughout the study period but improved when taking into account comorbidity level.Conclusions: Hip fracture incidence has declined across the Swedish population, but mortality after hip fracture remained high, especially among men. Hip fracture patients constitute a vulnerable population group with increasing comorbidity burden and high mortality risk.
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| 30. |
- Olsson, Ingrid, 1948, et al.
(författare)
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Epilepsy surgery in children with accompanying impairments.
- 2013
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Ingår i: European journal of paediatric neurology : EJPN : official journal of the European Paediatric Neurology Society. - : Elsevier BV. - 1532-2130. ; 17:6, s. 645-650
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to assess seizure outcome 2 years after epilepsy surgery in a consecutive series of paediatric patients, with special focus on children with learning disabilities and other neuroimpairments in addition to the epilepsy. Outcome 2 years after surgery was assessed in 110 of 125 children operated upon for drug resistant epilepsy in Gothenburg 1987-2006. More than half of the children had learning disabilities, 43% motor impairments and 30% a neuropsychiatric diagnosis. Fifty-six per cent of those with an IQ<70 became seizure-free or had a >75% reduction in seizure frequency, and two thirds if the operation was a resection. The corresponding figure in those with more than 100 seizures per month was 15 out of 31, and another seven had a 50-75% reduction in seizure frequency. The message is that learning disability, motor impairment and psychiatric morbidity should not be contraindications for paediatric epilepsy surgery. More than half of the children with learning disabilities had a worthwhile seizure outcome, with even better results after resective surgery. Children with drug resistant epilepsy and additional severe neurological impairments should have the benefit of referral to a tertiary centre for evaluation for epilepsy surgery.
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| 31. |
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| 32. |
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| 33. |
- Persson, Mikael, 1959, et al.
(författare)
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Advances in Neuro Diagnostic based on Microwave Technology, Transcranial Magnetic Stimulation and EEG source localization
- 2011
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Ingår i: Asia Pacific Microwave Conference, (APMC 2011;Melbourne, VIC; 5 - 8 December 2011). - 9780858259744 ; , s. 469-472
-
Konferensbidrag (refereegranskat)abstract
- Advances in neuro diagnostics based on microwave antenna system in terms of a helmet including a set of broad band patch antennas is presented. It is shown that classification algorithms can be used to detect internal bleeding in stroke patients. Transcranial magnetic stimulation has traditionally been used for brain mapping and treatment of depression. In this paper we discuss the use of the method for neuro diagnostics with the help of integrated image guidance. Surgical therapy has become an important therapeutic alternative for some patients with medically intractable epilepsy. Electroencephalography and the associated model based diagnostics as a non-invasive diagnostic tool is also discussed.
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| 34. |
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| 35. |
- Qaiser, Mahmood, 1981, et al.
(författare)
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On the Fully Automatic Construction of a Realistic Head Model for EEG Source Localization
- 2013
-
Ingår i: Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS. Osaka, Japan, 3-7 July 2013. - 1557-170X. - 9781457702167 ; , s. 3331-3334
-
Konferensbidrag (refereegranskat)abstract
- Accurate multi-tissue segmentation of magnetic resonance (MR) images is an essential first step in the construction of a realistic finite element head conductivity model (FEHCM) for electroencephalography (EEG) source localization. All of the segmentation approaches proposed to date for this purpose require manual intervention or correction and are thus laborious, time-consuming, and subjective. In this paper we propose and evaluate a fully automatic method based on a hierarchical segmentation approach (HSA) incorporating Bayesian-based adaptive mean-shift segmentation (BAMS). An evaluation of HSA-BAMS, as well as two reference methods, in terms of both segmentation accuracy and the source localization accuracy of the resulting FEHCM is also presented. The evaluation was performed using (i) synthetic 2D multi-modal MRI head data and synthetic EEG (generated for a prescribed source), and (ii) real 3D T1-weighted MRI head data and real EEG data (with expert determined source localization). Expert manual segmentation served as segmentation ground truth. The results show that HSA-BAMS outperforms the two reference methods and that it can be used as a surrogate for manual segmentation for the construction of a realistic FEHCM for EEG source localization.
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| 36. |
- Rasmuson, Johan, et al.
(författare)
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Cardiopulmonary involvement in Puumala hantavirus infection
- 2013
-
Ingår i: BMC Infectious Diseases. - : BioMed Central. - 1471-2334. ; 13:1, s. 501-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Hantavirus infections cause potentially life-threatening disease in humans world-wide. Infections with American hantaviruses may lead to hantavirus pulmonary syndrome characterised by severe cardiopulmonary distress with high mortality. Pulmonary involvement in European Puumala hantavirus (PUUV) infection has been reported, whereas knowledge of potential cardiac manifestations is limited. We aimed to comprehensively investigate cardiopulmonary involvement in patients with PUUV-infection.METHODS: Twenty-seven hospitalised patients with PUUV-infection were examined with lung function tests, chest high-resolution CT (HRCT), echocardiography including speckle tracking strain rate analysis, ECG and measurements of cardiac biomarkers N-terminal pro-B-type natriuretic peptide (NT-ProBNP) and troponin T. Patients were re-evaluated after 3 months. Twenty-five age and sex-matched volunteers acted as controls for echocardiography data.RESULTS: Two-thirds of the patients experienced respiratory symptoms as dry cough or dyspnoea. Gas diffusing capacity was impaired in most patients, significantly improving at follow-up but still subnormal in 38%. HRCT showed thoracic effusions or pulmonary oedema in 46% of the patients. Compared to controls, the main echocardiographic findings in patients during the acute phase were significantly higher pulmonary vascular resistance, higher systolic pulmonary artery pressure, lower left ventricular ejection fraction and impaired left atrial myocardial motion. Pathological ECG, atrial fibrillation or T-wave changes, was demonstrated in 26% of patients. NT-ProBNP concentrations were markedly increased and were inversely associated with gas diffusing capacity but positively correlated to pulmonary vascular resistance. Furthermore, patients experiencing impaired general condition at follow-up had significantly lower gas diffusing capacity and higher pulmonary vascular resistance, compared to those feeling fully recovered.CONCLUSIONS: In a majority of patients with PUUV-infection, both cardiac and pulmonary involvement was demonstrated with implications on patients' recovery. The results demonstrate vascular leakage in the lungs that most likely is responsible for impaired gas diffusing capacity and increased pulmonary vascular resistance with secondary pulmonary hypertension and right heart distress. Interestingly, NT-ProBNP was markedly elevated even in the absence of overt ventricular heart failure. The method of simultaneous investigations of important cardiac and respiratory measurements improves the interpretation of the underlying pathophysiologic mechanisms.
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| 37. |
- Rejnö-Habte Selassie, Gunilla, 1947, et al.
(författare)
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Speech, language, and cognitive dysfunction in children with focal epileptiform activity : A follow-up study
- 2010
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Ingår i: Epilepsy & Behavior. - : Elsevier BV. - 1525-5050 .- 1525-5069. ; 18:3, s. 267-275
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Tidskriftsartikel (refereegranskat)abstract
- We reviewed the medical history, EEG recordings, and developmental milestones of 19 children with speech and language dysfunction and focal epileptiform activity. Speech, language, and neuropsychological assessments and EEG recordings were performed at follow-up, and prognostic indicators were analyzed. Three patterns of language development were observed: late start and slow development, late start and deterioration/regression, and normal start and later regression/deterioration. No differences in test results among these groups were seen, indicating a spectrum of related conditions including Landau-Kleffner syndrome and epileptic language disorder. More than half of the participants had speech and language dysfunction at follow-up. IQ levels, working memory, and processing speed were also affected. Dysfunction of auditory perception in noise was found in more than half of the participants, and dysfunction of auditory attention in all. Dysfunction of communication, oral motor ability, and stuttering were noted in a few. Family history of seizures and abundant epileptiform activity indicated a worse prognosis.
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| 38. |
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| 39. |
- Sandberg, Camilla, et al.
(författare)
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Home-based interval training increases endurance capacity in adults with complex congenital heart disease
- 2018
-
Ingår i: Congenital Heart Disease. - : Computers, Materials and Continua (Tech Science Press). - 1747-079X .- 1747-0803. ; 13:2, s. 254-262
-
Tidskriftsartikel (refereegranskat)abstract
- ObjectiveThe beneficial effects of exercise training in acquired heart failure and coronary artery disease are well known and have been implemented in current treatment guidelines. Knowledge on appropriate exercise training regimes for adults with congenital heart disease is limited, thus further studies are needed. The aim of this study was to examine the effect of home-based interval exercise training on maximal endurance capacity and peak exercise capacity. MethodsTwenty-six adults with complex congenital heart disease were recruited from specialized units for adult congenital heart disease. Patients were randomized to either an intervention group12 weeks of home-based interval exercise training on a cycle ergometer (n=16), or a control group (n=10). The latter was instructed to maintain their habitual physical activities. An incremental cardiopulmonary exercise test and a constant work rate cardiopulmonary exercise test at 75% of peak workload were performed preintervention and postintervention. ResultsTwenty-three patients completed the protocol and were followed (intervention n=13, control n=10). Postintervention exercise time at constant work rate cardiopulmonary exercise test increased in the intervention group compared to controls (median[range] 12[-4 to 52]min vs 0[-4 to 5]min, P=.001). At incremental cardiopulmonary exercise test, peak VO2 increased 15% within the intervention group (P=.019) compared to 2% within the control group (P=.8). However, in comparison between the groups no difference was found (285[-200 to 535] ml/min vs 17[-380 to 306] ml/min, P=.10). In addition, peak workload at incremental cardiopulmonary exercise test increased in the intervention group compared to controls (20[-10 to 70]W vs 0[-20 to 15]W, P=.003). ConclusionHome-based interval exercise training increased endurance capacity and peak exercise capacity in adults with complex congenital heart disease. Aerobic endurance might be more relevant than peak oxygen uptake with regard to daily activities, and therefore a more clinically relevant measure to evaluate.
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| 40. |
- Shirvany, Yazdan, 1980, et al.
(författare)
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Application of particle swarm optimization in epileptic spike EEG source localization
- 2013
-
Ingår i: Applied Soft Computing Journal. - : Elsevier BV. - 1568-4946. ; 13:5, s. 2515-2525
-
Tidskriftsartikel (refereegranskat)abstract
- Surgical therapy has become an important therapeutic alternative for patients with medically intractable epilepsy. Correct and anatomically precise localization of an epileptic focus is essential to decide if resection of brain tissue is possible. The inverse problem in EEG-based source localization is to determine the location of the brain sources that are responsible for the measured potentials at the scalp electrodes. We propose a new global optimization method based on particle swarm optimization (PSO) to solve the epileptic spike EEG source localization inverse problem. In a forward problem a modified subtraction method is proposed to reduce the computational time. The good accuracy and fast convergence are demonstrated for 2D and 3D cases with realistic head models. The results from the new method are promising for use in the pre-surgical clinic in the future
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| 41. |
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| 42. |
- Shirvany, Yazdan, 1980, et al.
(författare)
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Non-invasive EEG source localization using particle swarm optimization: A clinical experiment
- 2012
-
Ingår i: Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS. - 1557-170X. - 9781424441198 ; , s. 6232-6235
-
Konferensbidrag (refereegranskat)abstract
- One of the most important steps of pre-surgical diagnosis in patients with medically intractable epilepsy is to find the precise location of the epileptogenic foci. An Electroencephalography (EEG) is a non-invasive standard tool used at epilepsy surgery center for pre-surgical diagnosis. In this paper a modified particle swarm optimization (MPSO) method is applied to a real EEG data, i.e., a somatosensory evoked potentials (SEPs) measured from a healthy subject, to solve the EEG source localization problem. A high resolution 1 mm hexahedra finite element volume conductor model of the subject's head was generated using T1-weighted magnetic resonance imaging data. An exhaustive search pattern and the MPSO method were then applied to the peak of the averaged SEPs data. The non-invasive EEG source analysis methods localized the somatosensory cortex area where our clinical expert expected the received SEPs. The proposed inverse problem solver found the global minima with acceptable accuracy and reasonable number of iterations.
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| 43. |
- Shirvany, Yazdan, 1980, et al.
(författare)
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Particle Swarm Optimization Applied to EEG Source Localization of Somatosensory Evoked Potentials
- 2014
-
Ingår i: IEEE Transactions on Neural Systems and Rehabilitation Engineering. - 1558-0210 .- 1534-4320. ; 22:1, s. 11-20
-
Tidskriftsartikel (refereegranskat)abstract
- One of the most important steps in presurgical diagnosis of medically intractable epilepsy is to find the precise location of the epileptogenic foci. Electroencephalography (EEG) is a noninvasive tool commonly used at epilepsy surgery centers for presurgical diagnosis. In this paper, a modified particle swarm optimization (MPSO) method is used to solve the EEG source localization problem. The method is applied to noninvasive EEG recording of somatosensory evoked potentials (SEPs) for a healthy subject. A 1 mm hexahedra finite element volume conductor model of the subject's head was generated using T1-weighted magnetic resonance imaging data. Special consideration was made to accurately model the skull and cerebrospinal fluid. An exhaustive search pattern and the MPSO method were then applied to the peak of the averaged SEP data and both identified the same region of the somatosensory cortex as the location of the SEP source. A clinical expert independently identified the expected source location, further corroborating the source analysis methods. The MPSO converged to the global minima with significantly lower computational complexity compared to the exhaustive search method that required almost 3700 times more evaluations.
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| 44. |
- Steding Ehrenborg, Katarina, et al.
(författare)
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Diastolic Filling in Patients After Heart Transplantation Is Impaired Due to an Altered Geometrical Relationship Between the Left Atrium and Ventricle
-
Ingår i: Journal of the American Heart Association. - 2047-9980.
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundThe geometrical relationship between atrial and ventricular short‐axis cross‐sectional area determines the hydraulic forces acting on intracardiac blood. This is important for diastolic filling. In patients undergoing heart transplantation (HTx), the left atrium is often enlarged as a result of the standard surgical technique. We hypothesized that diastolic filling in HTx patients is affected by the surgery altering the geometrical relationship between atrium and ventricle.Methods and ResultsThis retrospective, cross‐sectional study included 25 HTx patients (median age, 52 [range, 25–70] years), 15 patients with heart failure with reduced ejection fraction (median age, 63 [range, 52–75] years), 15 patients with heart failure with preserved ejection fraction (median age, 74 [range, 56–82] years), and 15 healthy controls (median age, 64 [range, 58–67] years) who underwent cardiac magnetic resonance imaging. Left ventricular, atrial, and total heart volumes (THV) were obtained. Atrioventricular area difference at end diastole and end systole was calculated as the largest ventricular short‐axis area minus the largest atrial short‐axis area. Left atrial minimum volume normalized for THV (LAmin/THV) was larger in HTx patients (median, 0.13 [range, 0.07–0.19]) compared with controls (median, 0.05 [range, 0.03–0.08], P <0.001), whereas left ventricular volume normalized for THV (left ventricular end‐diastolic volume/THV) was similar between HTx and controls (median, 0.19 [range, 0.12–0.24] and median, 0.22 [range, 0.20–0.25], respectively). At end diastole, when atrioventricular area difference reached its largest positive value in controls, 11 HTx patients (44%) had a negative atrioventricular area difference, indicating impaired diastolic filling.ConclusionsDiastolic filling is impaired in HTx patients due to an altered geometrical relationship between the left atrium and ventricle. When performing cardiac transplantation, a surgical technique that creates a smaller left atrium may improve diastolic filling by aiding hydraulic forces.
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| 45. |
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| 46. |
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| 47. |
-
Understanding eParticipation : Contemporary PhD eParticipation Research in Europe
- 2007
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Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- This book presents contemporary European research on eParticipation by means of a 13 chapters each describing a PhD research project as well as analyses of this research. The book both reflects the field and contributes to shaping it by discussing both long-standing and emerging issues. Contributions include three chapters on issues of DEVELOPMENT, including communities of practice, user-centred development, and safety & privacy issues, four chapters on IMPLEMENTATION, including spatial planning, participatory budgeting, and transformation processes, and five chapters on issues of USE, focusing on local government, developing countries, EU, civil society and NGO.
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| 48. |
- Uvebrant, Paul, 1951, et al.
(författare)
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Brain single photon emission computed tomography (SPECT) in neuropediatrics.
- 1991
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Ingår i: Neuropediatrics. - 0174-304X. ; 22:1, s. 3-9
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Tidskriftsartikel (refereegranskat)abstract
- The clinical value in neuropediatrics of [99mTc]HM-PAO brain single photon emission computed tomography was preliminary evaluated by the consecutive investigation of 79 children. Planned epilepsy surgery was the most common indication for the investigation. In 56 children investigated because of epilepsy, SPECT yielded relevant information in 79% of cases examined. The corresponding figures for magnetic resonance imaging and CT were 49% of 35 and 36% of 56 cases, respectively. All 22 children with an epileptic focus, ascertained by freedom from seizures after removal of the area or by consistent neurophysiological and neuroradiological findings, also had abnormal perfusion in the relevant area. Twenty-three children were examined because of neurological signs and symptoms other than epilepsy. SPECT findings were useful for elucidating neonatal brain impairments. Hypoperfused areas in the brain of asphyxiated infants and in posthemorrhagic hydrocephalus corresponded to neuroradiological and autopsy findings. SPECT was found to be an excellent tool when analysing cerebrovascular accidents. In cases with signs and symptoms of a diffuse severe encephalopathy, SPECT did not clarify the etiology but provided information on the distribution of the lesions and probable underlying pathophysiological mechanisms.
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| 49. |
- Vaziri-Sani, Fariba, et al.
(författare)
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Phenotypic expression of factor H mutations in patients with atypical hemolytic uremic syndrome
- 2006
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Ingår i: Kidney International. - : Nature Publishing Group. - 0085-2538 .- 1523-1755. ; 69:6, s. 981-988
-
Tidskriftsartikel (refereegranskat)abstract
- We investigated the phenotypic expression of factor H mutations in two patients with atypical hemolytic uremic syndrome (HUS). Factor H in serum was assayed by rocket immunoelectrophoresis, immunoblotting, and double immunodiffusion and in tissue by immunohistochemistry. Functional activity was analyzed by hemolysis of sheep erythrocytes and binding to endothelial cells. A homozygous mutation in complement control protein (CCP) domain 10 of factor H was identified in an adult man who first developed membranoproliferative glomerulonephritis and later HUS. C3 levels were very low. The patient had undetectable factor H levels in serum and a weak factor H 150 kDa band. Double immunodiffusion showed partial antigenic identity with factor H in normal serum owing to the presence of factor H-like protein 1. Strong specific labeling for factor H was detected in glomerular endothelium, mesangium and in glomerular and tubular epithelium as well as in bone marrow cells. A heterozygous mutation in CCP 20 of factor H was found in a girl with HUS. C3 levels were moderately decreased at onset. Factor H levels were normal and a normal 150 kDa band was present. Double immunodiffusion showed antigenic identity with normal factor H. Factor H labeling was minimal in the renal cortex. Factor H dysfunction was demonstrated by increased sheep erythrocyte hemolysis and decreased binding to endothelial cells. In summary, two different factor H mutations associated with HUS were examined: in one, factor H accumulated in cells, and in the other, membrane binding was reduced.
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| 50. |
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