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- Althoff, Karin, 1974, et al.
(författare)
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Combined segmentation and tracking of neural stem-cells
- 2005
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Ingår i: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics). - 1611-3349 .- 0302-9743. ; 3540, s. 282-291
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we analyze neural stem/progenitor cells in an time-lapse image sequence. By using information about the previous positions of the cells, we are able to make a. better selection of possible cells out of a collection of blob-like objects. As a blob detector we use Laplacian of Gaussian (LoG) filters at multiple scales, and the cell contours of the selected cells are segmented using dynamic programming. After the segmentation process the cells are tracked in the sequence using a. combined nearest-neighbor and correlation matching technique. An evaluation of the system show that 95% of the cells were correctly segmented and tracked between consecutive frames.
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| 2. |
- Andersson, J., et al.
(författare)
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Echogenecity of the carotid intima-media complex is related to cardiovascular risk factors, dyslipidemia, oxidative stress and inflammation The Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study
- 2009
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Ingår i: Atherosclerosis. - : Elsevier BV. - 1879-1484 .- 0021-9150. ; 204:2, s. 612-618
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Tidskriftsartikel (refereegranskat)abstract
- Background: Increased carotid artery intima-media thickness (IMT), measured by ultrasound, is related to an increased risk of cardiovascular disease. Since presence of echolucent plaques increases the risk further, we investigated if echogenecity of the carotid intima-media complex is related to markers of cardiovascular risk. Our aim was therefore to investigate if intima-media echogenecity is related to cardiovascular risk factors, or to markers of inflammation and oxidation in an exploratory investigation. Methods: The PIVUS cohort study is an observational study of 1016 (509 women and 507 men) randomly chosen individuals aged 70 living in Uppsala, Sweden. Carotid artery ultrasound measurements were performed. IMT and the grey scale median (GSM) value were calculated in the intima-media complex (IM-GSM) in the far wall of the common carotid artery. Traditional risk factors were evaluated together with indices of oxidative stress and inflammation. Results: In the multiple regression analysis, HDL-cholesterol, body mass index, conjugated diens, glutathione, e-selectin and TNF alfa were significantly related to IM-GSM. IMT was independently related to blood pressure, smoking and body mass index. Conclusion: The echolucency of the carotid intima-media was related to several cardiovascular risk factors not related to IMT, such as dyslipidemia, oxidative stress and inflammation. Since the echogenecity of the carotid intima-media complex was related to different risk factors compared to carotid IMT, it is worthwhile to further explore the usefulness of this new marker of the vascular wall. (C) 2009 Published by Elsevier Ireland Ltd.
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| 3. |
- Andersson, J., et al.
(författare)
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The Carotid Artery Plaque Size and Echogenicity are Related to Different Cardiovascular Risk Factors in the Elderly
- 2009
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Ingår i: Lipids. - : Wiley. - 0024-4201 .- 1558-9307. ; 44:5, s. 397-403
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Tidskriftsartikel (refereegranskat)abstract
- Carotid plaques can be characterised by ultrasound by size and echogenicity. Both size and echogenicity are predictors of cardiovascular events. The aim of this study was to examine whether traditional risk factors and markers of inflammation and oxidation were associated with plaque size and echogenicity. Computerised analysis of carotid plaque size and echogenicity (grey scale median, GSM) were performed by ultrasound in a population-based health survey in 1,016 subjects aged 70 years (PIVUS study). Information on cardiovascular risk factors was collected, together with markers of inflammation and oxidation. Increased Framingham risk score, systolic blood pressure, higher BMI and decreased HDL, lower glutathione levels were related to echolucent plaques. Previous or present smoking was common with significantly more pack-years related to the echorich plaques. Plaque size was associated with increased Framingham risk score, systolic blood pressure, blood glucose levels, smoking, ApoB/A1 ratio, OxLDL, TNF alpha, HOMA insulin resistance, leucocyte count, decreased BCD-LDL and low levels of l-selectin. Low HDL, increased BMI and decreased glutathione levels were associated with the echolucency of carotid plaques, implying metabolic factors to play a role for plaque composition. Markers of inflammation were related to plaque size alone, implying inflammation to be predominantly associated with the amount of atherosclerosis. These results suggest that plaque size and echogenicity are influenced by different risk factors.
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| 7. |
- Degerman, Johan, 1976, et al.
(författare)
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An automatic system for in vitro cell migration studies
- 2009
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Ingår i: Journal of Microscopy. - : Wiley. - 0022-2720 .- 1365-2818. ; 233:1, s. 178-191
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes a system for in vitro cell migration analysis. Adult neural stem/progenitor cells are studied using time-lapse bright-field microscopy and thereafter stained immunohistochemically to find and distinguish undifferentiated glial progenitor cells and cells having differentiated into type-1 or type-2 astrocytes. The cells are automatically segmented and tracked through the time-lapse sequence. An extension to the Chan-Vese Level Set segmentation algorithm, including two new terms for specialized growing and pruning, made it possible to resolve clustered cells, and reduced the tracking error by 65%. We used a custom-built manual correction module to form a ground truth used as a reference for tracked cells that could be identified from the fluorescence staining. On average, the tracks were correct 95% of the time, using our new segmentation. The tracking, or association of segmented cells, was performed using a 2-state Hidden Markov Model describing the random behaviour of the cells. By re-estimating the motion model to conform with the segmented data we managed to reduce the number of tracking parameters to essentially only one. Upon characterization of the cell migration by the HMM state occupation function, it was found that glial progenitor cells were moving randomly 2/3 of the time, while the type-2 astrocytes showed a directed movement 2/3 of the time. This finding indicates possibilities for cell-type specific identification and cell sorting of live cells based on specific movement patterns in individual cell populations, which would have valuable applications in neurobiological research.
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| 9. |
- Gustavsson, Per M., et al.
(författare)
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Service Oriented Simulations Concept
- 2005
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Ingår i: Proceedings of the 10th Simulation conference and exhibition. ; , s. 533-538
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In the effort to provide simulation support to the future Network Based Defence (NBD) that are currently being applied by the Swedish Armed Forces (SwAF), and the similair work within US and NATO, the authors opinion is that simulation should be treated as any other services, existing in the operational systems. Meaning that architecture should be conformant between the operational and simulated systems, for a start use the same infrastructure. The choice so far for simulation is the High Level Architecture (HLA). During the author’s participation in ongoing work supporting NBD, questions have gradually been raised if HLA is the simulation path to walk. In the Core Enterprise Services (CES) and Swedish Armed Force Enterprise Architecture (FMA) Services IT-Kernel, core services are specified and HLA do address a lot of non-simulation specific services giving unwanted redundancy. However, the services already defined may with some enhancements deliver the same services addressed within FMA Services ITKernel. The Next Generation HLA could be more than just a simulation standard if it utilizes the FMA ideas. In this paper the authors present the ongoing work, as it stands today, with Service Oriented Simulations, that is an outlook for simulation using the architectural structuring, services, components and infrastructures concepts evolving in FMA and Global Information Grid (GIG). The focus of the work is to enable interoperable simulation support for the whole system lifecycle – Acquisition, Development, Training, Planning, In-the-Field decision support, System removal – within NBD, entailing that the architecture for simulation is uniform regardless of its application and giving end-users the capability to focus on what to simulate instead of how to simulate.
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| 10. |
- Gustavsson, Tomas
(författare)
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AGILE - konsten att slutföra projekt
- 2007
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Bok (refereegranskat)abstract
- Boken har utsetts till Årets Projektledarbok 2008 av Svenskt Projektforum!Motiveringen från juryn var följande: "Författaren - Tomas Gustavsson - har hittat ett intressant ämne som han beskriver på ett enkelt och lättbegripligt sätt. Detta är inte en "frälsningsbok" utan en mycket nyanserad beskrivning av begreppet "agila metoder", dvs projekt med föränderliga både krav och mål." Agile är engelska och betyder smidig eller vig. I projektledningssammanhang har ordet översatts till lättrörlig för att peka på förändringsmöjligheterna med detta synsätt. Men det finns andra fördelar med Agile. Den, i mitt tycke, största fördelen består i möjligheten i att kunna slutföra projekt. Att slutföra projekt är en konstart som många eftersträvar men få behärskar.De agila teknikernas lösning för att hantera denna konst är att delleverera små resultat ofta. Genom att planera, genomföra och leverera en mindre del av projektet får vi möjlighet att uppleva en del av slutresultatet tidigt och kan därefter ställa konkretare krav på resten av projektet. Vi kan dessutom stanna upp, utvärdera och enkelt förändra projektet under vägen. Metoderna (med namn såsom Scrum, XP, DSDM) härstammar från IT-projekt men går att appliceras på många projekt oavsett bransch eller miljöDetta är en praktiskt bok! Med praktisk bok menas att den innehåller de checklistor, mallar och verktyg som krävs för att med boken som stöd kunna börja arbeta agilt.
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