| 1. |
- Barbulescu, Andrei, et al.
(author)
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Oral metronidazole use and risk of acute pancreatitis : a population-based case-control study.
- 2018
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In: Clinical Epidemiology. - 1179-1349 .- 1179-1349. ; 10, s. 1573-1581
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Journal article (peer-reviewed)abstract
- OBJECTIVE: Oral metronidazole used in combined regimens for Helicobacter pylori eradication has been associated with an increased risk of acute pancreatitis; however, it is less clear whether a similar association exists for single-regimen metronidazole. We, therefore, examined the association of single and combined regimens of oral metronidazole with risk of acute pancreatitis.METHODS: In this population-based case-control study, all individuals in Sweden (aged 40-84 years) hospitalized with acute pancreatitis between January 2006 and December 2008 were identified from a national hospital register (n=5,996). Controls, matched for calendar year, age, and sex, were randomly sampled from a national population register (n=60,681). Data on oral metronidazole and covariates were extracted from national health and prescription registers. Odds ratios (ORs) of acute pancreatitis, according to timing of the latest metronidazole prescription before hospitalization, were estimated using logistic regression models. Confounding by indication was examined by contrasting the main results with the association when amoxicillin was used as exposure. The robustness of results was examined by calculating incidence rate ratios using a self-controlled case series approach.RESULTS: After adjustment for potential confounders, there was a substantially increased risk of acute pancreatitis within 30 days of oral metronidazole exposure, both for single (OR: 4.06; 95% confidence interval [CI]: 1.90-8.64) and combined (OR: 11.80; 95% CI: 6.86-20.28) regimens, compared to nonexposure. In contrast, the adjusted OR was 1.79 (95% CI: 1.25-2.54) for current use of amoxicillin compared to nonexposure. These results were supported by the self-controlled cases series analysis (incidence rate ratio: 3.30; 95% CI: 2.69-4.06, for single and combined regimens of oral metronidazole pooled). There was no strong association between oral metronidazole and acute pancreatitis more than 30 days after exposure.CONCLUSION: There was an increased risk of acute pancreatitis within 30 days of exposure to single and combined regimens of oral metronidazole. While reverse causality and confounding by indication cannot be entirely excluded, they are unlikely to fully explain the association. These results warrant an increased awareness among physicians.
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| 2. |
- Berglund, Fanny, et al.
(author)
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Dietary habits among snus users : a population-based cross-sectional study
- 2023
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In: Food & Nutrition Research. - : SNF Swedish Nutrition Foundation. - 1654-6628 .- 1654-661X. ; 67
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Journal article (peer-reviewed)abstract
- Background: The dietary habits among snus users are largely unknown and have not been accounted for in observational studies on the health effects of snus use.Aim: To examine whether snus users eat unhealthier than never tobacco users.Methods: A total of 3,397 male participants, examined between 1994 and 2014 in the Northern Sweden Monitoring of Trends and Determinants in Cardiovascular Disease (MONICA) study, were included. Snus use and dietary habits were self-reported using questionnaires, from which intakes of different food groups, macronutrients, and a healthy diet score (HDS) were calculated (the latter as a proxy for overall diet quality). The association between snus use and dietary habits was examined by quantile regression models.Results: In the multivariable-adjusted model, current snus users had a lower HDS (median difference: -0.86 [95% confidence interval: -1.32, -0.40]) than never tobacco users. Snus users also consumed fewer weekly servings of fruits and berries (median difference: -1.03 [-1.65, -0.40]), and their estimated percentage of energy intake con -sisted of less carbohydrates (median difference: -1.43 [-2.12, -0.74]) and of more total fat (median difference: 0.99 [0.30, 1.67]), saturated fat (median difference: 0.67 [0.29, 1.05]), monounsaturated fat (median difference: 0.44 [0.20, 0.68]), trans fat (median difference: 0.03 [0.01, 0.06]), and alcohol (median difference: 0.21 [0.02, 0.40]).Conclusion: We observed that snus users had an unhealthier diet than never tobacco users. Future studies on the association between snus use and health outcomes should, therefore, consider diet as a potential confounder.
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| 3. |
- Byhamre, Marja Lisa, et al.
(author)
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Association between snus use and lipid status in Swedish men
- 2023
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In: Scandinavian Journal of Clinical and Laboratory Investigation. - : Taylor & Francis. - 0036-5513 .- 1502-7686. ; 83:4, s. 241-250
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Journal article (peer-reviewed)abstract
- Snus is a common tobacco product in Sweden, but the cardiovascular risk profile for snus users is less known than for cigarette smokers. We examined the association of snus use with lipid status, particularly in comparison to non-tobacco use and cigarette smoking, using data from 5930 men in the Northern Sweden MONICA study. Tobacco use was self-reported in 1986 to 2014 (24.4% used snus) and blood samples were collected at the same time. Harmonized analyses on non-high-density lipoprotein (non-HDL) cholesterol, HDL cholesterol, and triglycerides were conducted in 2016 to 2018. Three hundred eighty-one snus users had also been examined more than once, allowing us to study the effect of discontinued use (achieved by 21.0%). In multivariable linear regression models, snus use was associated with higher HDL cholesterol and triglyceride concentrations compared to non-tobacco use (p values ≤ 0.04), and it was associated with higher HDL cholesterol concentrations and lower triglyceride concentrations compared to cigarette smoking (p values ≤ 0.02). Snus use was not associated with non-HDL cholesterol concentrations, irrespective of the comparison group (p values ≥ 0.07). There was no indication that higher intensity of snus use led to a worse lipid profile, given that high-consumers had higher HDL cholesterol concentrations than low-consumers (p value = 0.02), or that discontinuation of snus use led to a better lipid profile, given that continued users had lower triglyceride concentrations than discontinued users (p value = 0.03). Further studies are needed to confirm or refute our findings.
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| 4. |
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| 5. |
- Dahl, Viktor, 1979-
(author)
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Breaking the law : adolescents' involvement in illegal political activitiy
- 2014
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Doctoral thesis (other academic/artistic)abstract
- Illegal political activity has always been part of a democratic society. Despite this, not much is known about young people’s involvement in these political activities. Research portrays political influence attempts of this kind in different terms; as troublesome for the democratic political system, as expressions of conscious decisions vital for humanity’s future, and yet other times as illustrations of a coming-of-age rebellion. Overall there is a lack of collective knowledge on illegal political activity, and especially in adolescence – the age period when these political activities seem to peak.The aim of this dissertation is therefore to enhance knowledge of involvement in illegal political activity in adolescence. This dissertation addresses this task in four empirical studies. Results show that mostly boys engage politically with illegal political means. Adolescents involved are also interested in politics, believe in their own abilities to take part in political activities, have long-term political goals, and approve of violent political tactics. In addition, these activities also seem to associate with a challenge of authority. This could be seen in how political dissatisfaction was translated into illegal political activity, and in the way these activities seemed to be reactions to a non legitimized parental authority. Besides authority challenges, these activities are likely the result of important peer relations; influences from peers with experiences of illegal political activity seem to be a most probable answer to why adolescents adopt these political means. Taken together, the results of this dissertation show that adolescents involved in illegal political activity are well-equipped for political involvement, challenge authorities in most contexts of their lives, and are likely to adopt these political means from already involved peers.
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| 6. |
- Larsson, Malte, et al.
(author)
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Efficient Time-of-Arrival Self-Calibration using Source Implicitization
- 2023
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In: 31st European Signal Processing Conference, EUSIPCO 2023 - Proceedings. - 2219-5491. - 9789464593600 ; , s. 1644-1648
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Conference paper (peer-reviewed)abstract
- In this paper we revisit the Time-of-Arrival self-calibration problem. In particular we focus on imbalanced problem instances where there are significantly more sources compared to the number of receivers, which is a common configuration in real applications. Using an implicit representation, we are able to re-parameterize the sensor node self-calibration problem using only the parameters of the receiver positions. Making the source positions implicit, we show that it is possible to linearize the maximum-likelihood error around the measured distances, resulting in a Sampson-like approximation. Given four unknown receiver positions and a large number of unknown sender positions, we show that our formulation leads to algorithms for robust calibration, with significant speed-up compared to running the full optimization over all unknowns. The proposed method is tested on both synthetic and real data.
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| 7. |
- Larsson, Martin, et al.
(author)
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Optimal Trilateration Is an Eigenvalue Problem
- 2019
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In: 2019 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2019 - Proceedings. - 9781479981311 ; 2019-May, s. 5586-5590
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Conference paper (peer-reviewed)abstract
- The problem of estimating receiver or sender node positions from measured receiver-sender distances is a key issue in different applications such as microphone array calibration, radio antenna array calibration, mapping and positioning using UWB or using round-trip-time measurements between mobile phones and WiFi-units. In this paper we address the problem of optimally estimating a receiver position given a number of distance measurements to known sender positions, so called trilateration. We show that this problem can be rephrased as an eigenvalue problem. We also address different error models and the multilateration setting where an additional offset is also unknown, and show that these problems can be modeled using the same framework.
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| 8. |
- Larsson, Viktor, et al.
(author)
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Beyond Gröbner Bases : Basis Selection for Minimal Solvers
- 2018
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In: Proceedings - 2018 IEEE/CVF Conference on Computer Vision and Pattern Recognition, CVPR 2018. - 9781538664209 ; , s. 3945-3954
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Conference paper (peer-reviewed)abstract
- Many computer vision applications require robust estimation of the underlying geometry, in terms of camera motion and 3D structure of the scene. These robust methods often rely on running minimal solvers in a RANSAC framework. In this paper we show how we can make polynomial solvers based on the action matrix method faster, by careful selection of the monomial bases. These monomial bases have traditionally been based on a Grobner basis for the polynomial ideal. Here we describe how we can enumerate all such bases in an efficient way. We also show that going beyond Grobner bases leads to more efficient solvers in many cases. We present a novel basis sampling scheme that we evaluate on a number of problems.
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| 9. |
- Larsson, Viktor, et al.
(author)
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Efficient Solvers for Minimal Problems by Syzygy-based Reduction
- 2017
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In: IEEE Conference on Computer Vision and Pattern Recognition (CVPR), 2017. - 9781538604588 - 9781538604571 ; , s. 2383-2392
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Conference paper (peer-reviewed)abstract
- In this paper we study the problem of automatically generatingpolynomial solvers for minimal problems. The maincontribution is a new method for finding small eliminationtemplates by making use of the syzygies (i.e. the polynomialrelations) that exist between the original equations. Usingthese syzygies we can essentially parameterize the setof possible elimination templates.We evaluate our method on a wide variety of problemsfrom geometric computer vision and show improvementcompared to both handcrafted and automatically generatedsolvers. Furthermore we apply our method on two previouslyunsolved relative orientation problems.
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| 10. |
- Larsson, Viktor, et al.
(author)
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Orthographic-Perspective Epipolar Geometry
- 2021
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In: Proceedings - 2021 IEEE/CVF International Conference on Computer Vision, ICCV 2021. - 1550-5499. - 9781665428125 ; , s. 5550-5558
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Conference paper (peer-reviewed)abstract
- In this paper we consider the epipolar geometry between orthographic and perspective cameras. We generalize many of the classical results for the perspective essential matrix to this setting and derive novel minimal solvers, not only for the calibrated case, but also for partially calibrated and non-central camera setups. While orthographic cameras might seem exotic, they occur naturally in many applications. They can e.g. model 2D maps (such as floor plans), aerial/satellite photography and even approximate narrow field-of-view cameras (e.g. from telephoto lenses). In our experiments we highlight various applications of the developed theory and solvers, including Radar-Camera calibration and aligning Structure-from-Motion models to aerial or satellite images.
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