| 1. |
- Khayyeri, Hanifeh, et al.
(författare)
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A novel semi-automatic hip morphology assessment tool is more accurate than manual radiographic evaluations
- 2020
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Ingår i: Computer Methods in Biomechanics and Biomedical Engineering: Imaging and Visualization. - : Informa UK Limited. - 2168-1163 .- 2168-1171. ; 8:1, s. 76-86
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Tidskriftsartikel (refereegranskat)abstract
- Radiological and pathological characteristics of hip osteoarthritis (OA) is joint-space loss due to degradation of articular cartilage. However, patients with early-stage OA do not yet show any radiological signs, which leaves them without diagnosis and treatment. This study evaluates the potential of a novel tool to identify pre-radiographic OA changes based on hip bone morphology. Two statistical appearance models for femur and pelvis were used to estimate the 3Dmorphology of the hip bones based on planar radiographs from patients. Well-known hip geometrical parameters (n = 22) were computed from patient CT scans (truth), 3D reconstructions (new method) and radiographs (calculated manually). The methods were compared by measuring relative error to truth. The new method was significantly more accurate in calculating hip geometrical parameters than the manual 2D calculations. The proposed approach could also capture rotational parameters like cross-over sign and anterior wall sign (100% correct predictions). The method can successfully reconstruct 3D hip shapes and densities for patients that have not yet developed severe osteoarthritis, and provided higher precision than manual estimations. Thus, it may be used to calculate morphological parameters that are predictors of OA and can become a powerful tool in human hip OA research and diagnostics.
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| 2. |
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| 3. |
- Malmberg, Filip, et al.
(författare)
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SmartPaint : a tool for interactive segmentation of medical volume images
- 2017
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Ingår i: Computer Methods In Biomechanics And Biomedical Engeineering-Imaging And Visualization. - : TAYLOR & FRANCIS LTD. - 2168-1163 .- 2168-1171. ; 5:1, s. 36-44
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Tidskriftsartikel (refereegranskat)abstract
- We present SmartPaint, a general-purpose method and software for interactive segmentation of medical volume images. SmartPaint uses a novel paint-brush interaction paradigm, where the user segments objects in the image by 'sweeping' over them with the mouse cursor. The key feature of SmartPaint is that the painting tools adapt to the image content, selectively sticking to objects of interest while avoiding other structures. This behaviour is achieved by modulating the effect of the tools by both the Euclidean distance and the range distance (difference in image intensity values) from the mouse cursor. We evaluate SmartPaint on three publicly available medical image datasets, covering different image modalities and segmentation targets. The results show that, with a limited user effort, SmartPaint can produce segmentations whose accuracy is comparable to both the state-of-the-art automatic segmentation methods and manual delineations produced by expert users. The SmartPaint software is freely available, and can be downloaded from the authors' web page (http://www.cb.uu.se/similar to filip/SmartPaint/).
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| 4. |
- Svensson, Lennart, et al.
(författare)
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ProViz : a tool for explorative 3-D visualization and template matching in electron tomograms
- 2017
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Ingår i: Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization. - : Taylor & Francis. - 2168-1163 .- 2168-1171. ; 5:6, s. 446-454
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Tidskriftsartikel (refereegranskat)abstract
- Visual understanding is a key aspect when studying electron tomography data-sets, aside quantitative assessments such as registration of high-resolution structures. We here present the free software tool ProViz (Protein Visualization) for visualisation and template matching in electron tomograms of biological samples. The ProViz software contains methods and tools which we have developed, adapted and computationally optimised for easy and intuitive visualisation and analysis of electron tomograms with low signal-to-noise ratio. ProViz complements existing software in the application field and serves as an easy and convenient tool for a first assessment and screening of the tomograms. It provides enhancements in three areas: (1) improved visualisation that makes connections as well as intensity differences between and within objects or structures easier to see and interpret, (2) interactive transfer function editing with direct visual result feedback using both piecewise linear functions and Gaussian function elements, (3) computationally optimised template matching and tools to visually assess and interactively explore the correlation results. The visualisation capabilities and features of ProViz are demonstrated on various biological volume data-sets: bacterial filament structures in vitro, a desmosome and the transmembrane cadherin connections therein in situ, and liposomes filled with doxorubicin in solution. The explorative template matching is demonstrated on a synthetic IgG data-set.
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| 5. |
- Widing, Erik, 1987-, et al.
(författare)
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Tailoring biomechanical model meshes for aero-acoustic simulations
- 2015
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Ingår i: Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization. - : Taylor & Francis Group. - 2168-1171 .- 2168-1163.
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Tidskriftsartikel (refereegranskat)abstract
- To simulate the airflow and acoustic wave propagation associated with voice production, a closed surface mesh representing the vocal tract is needed. Biomechanically, the vocal tract is composed of surfaces from several different anatomical structures. We present a method for assembling a dynamic vocal tract mesh by trimming and stitching surface meshes tracking biomechanical models of relevant structures. Two algorithms, one for trimming and one for stitching, are used to first isolate surface mesh patches that are in contact with the airway and then merge them into a closed surface. The algorithms rely on manually selected boundaries and are able to cover gaps between mesh patches. Test cases are used to illustrate how the algorithms behave in various situations. The algorithms are implemented in the toolkit ArtiSynth where many relevant biomechanical models are already available.
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| 6. |
- Davis, Paul A., et al.
(författare)
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Balancing time for health behaviors : associations of time perspective with physical activity and weight management in older adults
- 2024
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Ingår i: American Journal of Health Promotion. - : Sage Publications. - 0890-1171 .- 2168-6602.
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To examine associations between time perspective and health promotion behaviors of physical activity and weight management.Design: Quantitative cross-sectional.Setting: This study is part of the Betula project on aging, memory, and dementia in Northern Sweden.Subjects: 417 older adults aged between 55 and 85 years.Measures: Swedish-Zimbardo Time Perspective Inventory; Physical Activity in the past year, past week, and in comparison with others of similar age; Weight Management = Body Mass Index (BMI; kg/m2).Results: After controlling for age, sex, and years of education, hierarchical linear regression indicated a Balanced Time Perspective was significantly associated with more physical activity in the past year (P =.04), the past week (P <.001), and in comparison with others (P <.01). Past Negative time perspective was associated with less physical activity in the past year (P =.03), and in comparison with others (P =.03). Present Fatalistic was associated with less physical activity during the past week (P =.03), and in comparison with others (P =.01). Present Hedonistic was associated with more physical activity the past week (P =.03), and in comparison with others (P =.03). Past Negative was associated with higher BMI (P =.02), and Future Negative were associated with lower BMI (P =.01). Taken collectively, greater positivity and flexibility across time perspectives was associated with more physical activity, whereas negative oriented time perspectives related with less physical activity and poorer weight management.Conclusion: Time perspective can be associated with health behaviors in older adults and have implications for health across the lifespan. Health promotion interventions may target older adults’ enjoyment of exercise and weight management in the present, rather than highlight potential negative health outcomes in the future.
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| 7. |
- Hallgren, Mats, et al.
(författare)
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Physical Activity, Sedentary Behavior, and Cardiorespiratory Fitness in Hazardous and Non-Hazardous Alcohol Consumers.
- 2021
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Ingår i: American Journal of Health Promotion. - : Sage Publications. - 0890-1171 .- 2168-6602. ; 35:5, s. 669-678
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To describe physical activity habits, sedentary behavior, and cardiorespiratory fitness levels among alcohol abstainers, hazardous and non-hazardous drinkers.DESIGN: Cross-sectional study with data collected between 2017-19.SETTING: Sweden.SUBJECTS: Adults aged 18-65 years (n = 47,559; 59.4% male).MEASURES: During a routine health assessment, participants answered validated single-item questions regarding: habitual physical activity, structured exercise, and the percentage of time spent sedentary during leisure-time (past 30 days), and completed a 6-minute cycle ergometer test (V02max) to determine cardiorespiratory fitness (CRF). Participants were categorized as alcohol abstainers, non-hazardous drinkers or hazardous drinkers (low/high) based on the Alcohol Use Disorders Identification Test (AUDIT-C) cut-points for men and women.ANALYSIS: Logistic regression models stratified by sex and age.RESULTS: Compared to non-hazardous drinkers, the heaviest drinkers were less physically active (males: OR = 1.38, CI = 1.13-1.67, p = .001; females: OR = 1.41, CI = 1.01-1.97, p = .040) and more sedentary during leisure time (males: OR = 1.94, CI = 1.62-2.32, p = .000; females: OR = 1.62, CI = 1.21-2.16, p = .001). Apart from young females, the heaviest drinkers also did less structured exercise than non-hazardous drinkers (males: OR = 1.22, CI = 1.15-1.51, p = .000; females: OR = 1.43, CI = 1.15-1.78, p = .001). The strongest associations were seen among adults aged 40-65 years (shown here). High-hazardous drinking was associated with low CRF among older males only (OR = 1.19, CI = 1.00-1.41).CONCLUSION: Middle-aged adults with AUDIT-C scores of ≥6 (women) and ≥7 (men) were less physically active and more sedentary during leisure time and may be appropriate targets for physical activity interventions.
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| 8. |
- Pena, R., et al.
(författare)
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Evaluating a peer intervention strategy for the promotion of sexual health-related knowledge and skills in 10- to 14-year-old girls. Findings from the "Entre Amigas" project in Nicaragua
- 2008
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Ingår i: American Journal of Health Promotion. - 0890-1171 .- 2168-6602. ; 22:4, s. 275-281
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Tidskriftsartikel (refereegranskat)abstract
- Purpose. Report effects on knowledge of sexual health and gender from an intervention using peer methodology in Nicaragua. Design. A prepost nonequivalent control group design. Setting. Ciudad Sandino, Managua, Nicaragua. Subjects. A total of 599 girls were surveyed, 60% nonintervened and 40% intervened. Intervention. Peer methodology consisted of (1) meetings in which. girls talked and worked with other girls, (2) mothers taking an active role in the peer groups, and/or (3) girls watching the soap opera "Sexto Sentido." Measures. Indices measuring changes in sexual knowledge and gender vision. Results. Girls participating in the peer groups were twice us likely to have satisfactory sexual health-related self-esteem as those who did not participate. Eleven percent of the girls achieved satisfactory self-esteem as a result of the (peer groups X mothers) interaction and 15% due to the (peer groups X mothers X "Sexto Sentido') interaction. Girls participating in the peer groups were three times as likely to have satisfactory gender visions; if exposed to all three components, they were almost four times as likely to develop satisfactory gender visions. Conclusions. Peer methodology, participation of a female family member, and an educational soap opera seem beneficial in promoting sexual health-related knowledge and gender vision in young girls.
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