| 1. |
- Aanaes, H, et al.
(författare)
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Robust factorization
- 2002
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Ingår i: IEEE Transactions on Pattern Analysis and Machine Intelligence. - 1939-3539. ; 24:9, s. 1215-1225
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Tidskriftsartikel (refereegranskat)abstract
- Factorization algorithms for recovering structure and motion from an image stream have many advantages, but they usually require a set of well-tracked features. Such a set is in generally not available in practical applications. There is thus a need for making factorization algorithms deal effectively with errors in the tracked features. We propose a new and computationally efficient algorithm for applying an arbitrary errorfunction in the factorization scheme. This algorithm enables the use of robust statistical techniques and arbitrary noise models for the individual features. These techniques and models enable the factorization scheme to deal effectively with mismatched features, missing features, and noise on the individual features. The proposed approach further includes a new method for Euclidean reconstruction that significantly improves convergence of the factorization algorithms. The proposed algorithm has been implemented as a modification of the Christy-Horaud factorization scheme, which yields a perspective reconstruction. Based on this implementation, a considerable increase in error tolerance is demonstrated on real and synthetic data. The proposed scheme can, however, be applied to most other factorization algorithms.
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| 2. |
- Diness, Birgitte R., et al.
(författare)
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Effect of high-dose vitamin A supplementation on the immune response to Bacille Calmette-Guerin vaccines
- 2007
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Ingår i: American Journal of Clinical Nutrition. - 1938-3207. ; 86:4, s. 1152-1159
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Tidskriftsartikel (refereegranskat)abstract
- Background: Vitamin A supplementation (VAS) at birth has been associated with decreased mortality in Asia. Bacille Calmette-Guerin (BCG) vaccine is given at birth in tuberculosis-endemic countries. Previous studies suggest that VAS may influence the immune response to vaccines. Objective: Our objective was to examine whether VAS influences the immune response to simultaneously administered BCG vaccine. Design: Within a randomized trial of 50 000 IU vitamin A or placebo Given with BCG vaccine at birth in Guinea-Bissau, 27 10 infants were examined for BCG scar formation and delayed-type hypersensitivity (DTH) to purified protein derivative of Mycobacterium tuberculosis (PPD) at 2 and 6 mo of age. The ex vivo cytokine response to PPD was measured in 607 infants. Results: At 2 mo of age, 39% (43% of the boys and 34% of the girls) responded to PPD. The prevalence ratio of a measurable PPD reaction for VAS compared with placebo recipients was 0.90 (95% CI: 0.80, 1.02) for all infants. 0.81 (95% CI: 0.69, 0.95) for boys, and 1.04 (95% CI: 0.86, 1.26) for girls. At 6 mo of age, 42% of the infants responded to PPD. No difference was observed between VAS and placebo recipients. The prevalence of BCG scar was not affected by VAS. The ex vivo interferon-gamma response to PPD was increased by VAS (means ratio: 1.40: 95% CI: 1.03, 1.91). Conclusions: VAS with BCG vaccination does not appear to interfere with the long-term immune response to BCG. However, VAS temporarily altered the DTH reaction to PPD in boys at 2 mo of age, suggesting sex differences in the immunologic response to VAS Given with BCG. This trial was registered at www.clinicaltrials.gov as #NCT00168597.
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| 3. |
- Grankvist, J, et al.
(författare)
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MRI and PET/CT of patients with bone metastases from breast carcinoma
- 2012
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Ingår i: European Journal of Radiology. - : Elsevier BV. - 0720-048X .- 1872-7727. ; 81:1, s. e13-e18
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Tidskriftsartikel (refereegranskat)abstract
- 3.0Tesla magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) was compared with combined 18F-fluorodeoxyglucose positron emission tomography and computed tomography (PET/CT) in patients with suspected bone metastases from breast cancer. A prospective clinical study was performed in 13 female breast cancer patients (mean age 61years; range 45-85 years). The spine was imaged in the sagittal plane with T1-weighted (T1), short tau inversion recovery (STIR), and T2-weighted fat-saturated (T2) sequences. The pelvis was imaged similarly in the coronal plane. Axial DWI was performed from the skull base to the mid-thigh. MRI and PET/CT were performed in all patients at a maximum interval of 10 working days and at least 14 days after chemotherapy. MRI was reviewed by two radiologists, and their consensus on potential metastases in 27 predefined locations was recorded. The predefined locations were the vertebral bodies (24), the left (1) and right (1) pelvic bones, and the sacral bone (1). The PET/CT was reviewed by a radiologists and a nuclear medicine physician. MRI detected 59 of the 60 active metastases found with our gold standard modality PET/CT. T1 had the highest sensitivity (98%) but rather low specificity (77%), but with the addition of STIR and DWI, the specificity increased to 95%. The additional metastases detected with MRI most likely represented postherapeutic residual scars without active tumour. In conclusion, 3.0Tesla MRI with T1, STIR, and DWI is useful for the clinical evaluation of bone metastases from breast cancer and compares well to PET/CT.
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