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- Damangir, Soheil, et al.
(författare)
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Multispectral MRI segmentation of age related white matter changes using a cascade of support vector machines
- 2012
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Ingår i: Journal of the Neurological Sciences. - : Elsevier BV. - 0022-510X .- 1878-5883. ; 322:1-2, s. 211-216
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Tidskriftsartikel (refereegranskat)abstract
- White matter changes (WMC) are the focus of intensive research and have been linked to cognitive impairment and depression in the elderly. Cumbersome manual outlining procedures make research on WMC labor intensive and prone to subjective bias. We present a fast, fully automated method for WMC segmentation using a cascade of reduced support vector machines (SVMs) with active learning. Data of 102 subjects was used in this study. Two MRI sequences (T1-weighted and FLAIR) and masks of manually outlined WMC from each subject were used for the image analysis. The segmentation framework comprises pre-processing, classification (training and core segmentation) and post-processing. After pre-processing, the model was trained on two subjects and tested on the remaining 100 subjects. The effectiveness and robustness of the classification was assessed using the receiver operating curve technique. The cascade of SVMs segmentation framework outputted accurate results with high sensitivity (90%) and specificity (99.5%) values, with the manually outlined WMC as reference. An algorithm for the segmentation of WMC is proposed. This is a completely competitive and fast automatic segmentation framework, capable of using different input sequences, without changes or restrictions of the image analysis algorithm.
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| 2. |
- Firbank, Michael J, et al.
(författare)
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White matter hyperintensities and depression--preliminary results from the LADIS study.
- 2005
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Ingår i: International journal of geriatric psychiatry. - : Wiley. - 0885-6230 .- 1099-1166. ; 20:7, s. 674-9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: White matter hyperintensities have been associated with the development of depression in older subjects, though the details of this relationship are not fully understood. METHODS: In a pan-European multicentre study of 629 older subjects, we examined the relationship between MRI white matter hyperintensities (WMH), depressive symptoms and self perceived health quality of life (QOL). WMH were rated using a three-point scale. RESULTS: We found depressive symptoms as assessed by the geriatric depression 15-item scale to be associated with WMH rating (Spearman's rho 0.11, p = 0.008) and also with the Euro-QOL health score (Spearman's rho -0.5, p < 0.001). In a ordinal logistic regression model, QOL was found to strongly predict GDS score (p < 0.001) and severe vs mild WMH were associated with increased depression (p = 0.028). The relationship between history of severe depression and WMH score was examined, but there were no differences either between those with and without a history of severe depression, or those with an early vs late onset of depression. CONCLUSIONS: The results suggest that WMH play a role in increasing depressive symptoms, even when perceived quality of life is controlled for as a possible mediating factor.
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| 3. |
- Green, Jonathan M. H., et al.
(författare)
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Research priorities for managing the impacts and dependencies of business upon food, energy, water and the environment
- 2017
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Ingår i: Sustainability Science. - : Springer Science and Business Media LLC. - 1862-4065 .- 1862-4057. ; 12:2, s. 319-331
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Tidskriftsartikel (refereegranskat)abstract
- Delivering access to sufficient food, energy and water resources to ensure human wellbeing is a major concern for governments worldwide. However, it is crucial to account for the 'nexus' of interactions between these natural resources and the consequent implications for human wellbeing. The private sector has a critical role in driving positive change towards more sustainable nexus management and could reap considerable benefits from collaboration with researchers to devise solutions to some of the foremost sustainability challenges of today. Yet opportunities are missed because the private sector is rarely involved in the formulation of deliverable research priorities. We convened senior research scientists and influential business leaders to collaboratively identify the top forty questions that, if answered, would best help companies understand and manage their food-energy-water-environment nexus dependencies and impacts. Codification of the top order nexus themes highlighted research priorities around development of pragmatic yet credible tools that allow businesses to incorporate nexus interactions into their decision-making; demonstration of the business case for more sustainable nexus management; identification of the most effective levers for behaviour change; and understanding incentives or circumstances that allow individuals and businesses to take a leadership stance. Greater investment in the complex but productive relations between the private sector and research community will create deeper and more meaningful collaboration and cooperation.
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| 4. |
- Hamilton, Calum Alexander, et al.
(författare)
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Plasma biomarkers of neurodegeneration in mild cognitive impairment with Lewy bodies
- 2023
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Ingår i: PSYCHOLOGICAL MEDICINE. - 0033-2917 .- 1469-8978. ; 53:16, s. 7865-7873
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Tidskriftsartikel (refereegranskat)abstract
- Background. Blood biomarkers of Alzheimer's disease (AD) may allow for the early detection of AD pathology in mild cognitive impairment (MCI) due to AD (MCI-AD) and as a co-pathology in MCI with Lewy bodies (MCI-LB). However not all cases of MCI-LB will feature AD pathology. Disease-general biomarkers of neurodegeneration, such as glial fibrillary acidic protein (GFAP) or neurofilament light (NfL), may therefore provide a useful supplement to AD biomarkers. We aimed to compare the relative utility of plasma A beta 42/40, p-tau181, GFAP and NfL in differentiating MCI-AD and MCI-LB from cognitively healthy older adults, and from one another.Methods. Plasma samples were analysed for 172 participants (31 healthy controls, 48 MCI-AD, 28 possible MCI-LB and 65 probable MCI-LB) at baseline, and a subset (n = 55) who provided repeated samples after >= 1 year. Samples were analysed with a Simoa 4-plex assay for A beta 42, A beta 40, GFAP and NfL, and incorporated previously-collected p-tau181 from this same cohort.Results. Probable MCI-LB had elevated GFAP (p < 0.001) and NfL (p = 0.012) relative to controls, but not significantly lower A beta 42/40 (p = 0.06). GFAP and p-tau181 were higher in MCI-AD than MCI-LB. GFAP discriminated all MCI subgroups, from controls (AUC of 0.75), but no plasma-based marker effectively differentiated MCI-AD from MCI-LB. NfL correlated with disease severity and increased with MCI progression over time (p = 0.011).Conclusion. Markers of AD and astrocytosis/neurodegeneration are elevated in MCI-LB. GFAP offered similar utility to p-tau181 in distinguishing MCI overall, and its subgroups, from healthy controls.
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