81. |
- Svensson, Olof, et al.
(author)
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Associations Between Conduct Disorder, Neurodevelopmental Problems and Psychopathic Personality Traits in a Swedish Twin Youth Population
- 2018
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In: Journal of Psychopathology and Behavioral Assessment. - : Springer Science and Business Media LLC. - 0882-2689 .- 1573-3505. ; 40:4, s. 586-592
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Journal article (peer-reviewed)abstract
- Previous research has found a complex relationship between psychopathic traits, neurodevelopmental problems (NDPs), and conduct disorder (CD) in children. This study explores associations between psychopathic traits, assessed with the Child Problematic Traits Inventory—Short Version (CPTI-SV), and CD in children with and without coexisting NDPs (i.e., attention deficit/hyperactivity disorder [ADHD] and autism spectrum disorder [ASD]) in a community-based sample of Swedish twins (n = 8762). Findings indicate weak to moderately strong correlations between psychopathic traits and CD, ADHD, and ASD, respectively. Furthermore, in univariable analyses, both psychopathic traits and NDPs displayed significant positive associations with being screened positive for CD, though only the grandiose-deceitful dimension of CPTI-SV and the ADHD domain concentration and attention deficits remained significantly associated with CD in a multivariable regression model. The results are relevant to screening and assessment in child and youth psychiatry, as a grandiose and deceitful interpersonal style may also be a valid sign of children at risk of developing CD.
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82. |
- Svensson, Pia, et al.
(author)
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A meta-analysis and systematic literature review of factors associated with sexual risk-taking during international travel
- 2018
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In: Travel Medicine and Infectious Disease. - : Elsevier BV. - 1477-8939 .- 1873-0442. ; 24, s. 65-88
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Journal article (peer-reviewed)abstract
- Background: International travel facilitates global spread of sexually transmitted infections (STI). Travellers could contribute to onward transmission of pathogens rarely encountered at home and export new strains to the destination. The aim was to systematically examine evidence regarding determinants of travel-related sexual risk-taking and identify knowledge gaps and areas for targeted interventions. Method: Articles published in peer-reviewed journals from 2000 to 2017 were screened in 6 databases and assessed for relevance against criteria. Data was extracted for factors associated with travel-related STI or proxies. Meta-analyses estimated pooled prevalence of casual sex and non-condom use. Adjusted odds ratios of predictors were pooled to generate a combined estimate. Result: Forty-nine articles qualified for inclusion. A heterogeneity test indicated variation across studies. The pooled prevalence of casual travel sex was 35% and prevalence of non-condom use 17%. Expectations of casual sex strongly predicted sex with a new partner when travelling abroad. Planning to have sex indicated condom use. Conclusion: The studies largely represented sub-groups of risk-taking populations from a European context, indicating substantial knowledge gaps. Studies investigating migrants travelling to visit friends and relatives, older travellers, and female travelers are needed. Post–travel harm reduction activities may serve as a focus for future interventions.
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83. |
- Svensson, Urban, et al.
(author)
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Grains, grids and mineral surfaces : approaches to grain-scale matrix modeling based on X-ray micro-computed tomography data
- 2019
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In: SN Applied Sciences. - : Springer Nature. - 2523-3963 .- 2523-3971. ; 1:10
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Journal article (peer-reviewed)abstract
- X-ray micro-computed tomography (X-μCT) generates 3D mineral distribution maps currently with a resolution of about 10 μm. For tight crystalline rocks, this implies that the mineral grains are well resolved, while micro-fractures, having apertures of less than 10 μm, are not resolved. In this study, we propose a method to analyze the properties (size, volume, surface area) of the mineral grains based on X-μCT data. The numerical approach uses a resolution similar to that of the X-μCT data and hence shares the same limitations. For example, it is clear that a large fraction of the mineral surface area is due to so-called roughness, with scales below 10 μm. In the second part of the study, methods to generate the diffusion-available pore space are discussed. The inter-granular space (distance between grains) is often smaller than 10 μm, and we need to design methods to be able to perform diffusion simulations in the matrix. Three methods, all based on X-μCT, are discussed, and it is demonstrated that models with realistic global properties (mean porosity and effective diffusion coefficient) can be developed based on the suggested techniques.
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84. |
- Svensson, Urban, et al.
(author)
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Modelling the diffusion-available pore space of an unaltered granitic rock matrix using a micro-DFN approach
- 2018
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In: Journal of Hydrology. - : Elsevier BV. - 0022-1694 .- 1879-2707. ; 559, s. 182-191
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Journal article (peer-reviewed)abstract
- In sparsely fractured rock, the ubiquitous heterogeneity of the matrix, which has been observed in different laboratory and in situ experiments, has been shown to have a significant influence on retardation mechanisms that are of importance for the safety of deep geological repositories for nuclear waste. Here, we propose a conceptualisation of a typical heterogeneous granitic rock matrix based on micro-Discrete Fracture Networks (micro-DFN). Different sets of fractures are used to represent grain-boundary pores as well as micro fractures that transect different mineral grains. The micro-DFN model offers a great flexibility in the way inter- and intra-granular space is represented as the different parameters that characterise each fracture set can be fine tuned to represent samples of different characteristics. Here, the parameters of the model have been calibrated against experimental observations from granitic rock samples taken at Forsmark (Sweden) and different variant cases have been used to illustrate how the model can be tied to rock samples with different attributes. Numerical through-diffusion simulations have been carried out to infer the bulk properties of the model as well as to compare the computed mass flux with the experimental data from an analogous laboratory experiment. The general good agreement between the model results and the experimental observations shows that the model presented here is a reliable tool for the understanding of retardation mechanisms occurring at the mm-scale in the matrix.
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85. |
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86. |
- Tirtashi, M. Reza Safari, et al.
(author)
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Dynamic and static analysis of the shunt capacitors control effect on the long-term voltage instability
- 2016
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In: 2016 IEEE Power and Energy Society General Meeting, PESGM 2016. - 9781509041688 ; 2016-November
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Conference paper (peer-reviewed)abstract
- This paper concerns the dynamic and static analysis of the effect of shunt capacitor control strategies on the long-term voltage instability. For this purpose a simplified test system called N3area, reflecting the key voltage instability characteristics of NORDIC32 is considered. Two different control strategies for shunt capacitors including the local and neighboring schemes are applied to improve the voltage control in the system. First the dynamic simulation results for a specified long-term voltage instability scenario are explained and discussed then the static investigation is conducted based on the PV curves and it is shown that the neighboring scheme injects more reactive power to the system. Afterward, based on the modal analysis technique and V-Q sensitivity analysis, it is demonstrated that the possibility of involving the most critical buses from voltage stability perspective in the capacitors connection decisions are much higher in the neighboring scheme compared to the local one. The two strategies are explained and compared in both dynamic and static analysis and it is shown that control using the voltage at neighboring buses gives better performance.
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87. |
- Tirtashi, M. Reza Safari, et al.
(author)
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VSC-HVDC application to improve the long-term voltage stability
- 2017
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In: 2017 IEEE Manchester PowerTech, Powertech 2017. - 9781509042371
-
Conference paper (peer-reviewed)abstract
- This paper concerns the VSC-HVDC application to improve the long-term voltage stability. For this purpose the NORDIC32 test system is considered. All necessary dynamics to study the long-term voltage stability are included in the test system. An appropriate control strategy for VSC-HVDC is proposed in the paper. The goal is to reach the best condition from long-term voltage stability perspective with respect to system configuration and also the VSC-HVDC capability curve. To show the capability of the proposed control methodology, two long-term voltage instability scenarios are considered. For the first scenario, VSC-HVDC can lead to a stable condition with its initial active-reactive power set points. In the second voltage instability scenario which is more severe, the proper power flow change in the system using VSC-HVDC is needed to avoid the voltage collapse. Otherwise the VSC-HVDC could buy some time and lead to later collapse which is still important. The simulation results are explained and thoroughly discussed. It is demonstrated that with the proper control of VSC-HVDC, long-term voltage stability could improve dramatically.
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88. |
- Wallin, Anders, 1950, et al.
(author)
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Cognitive medicine - a new approach in health care science.
- 2018
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In: BMC psychiatry. - : Springer Science and Business Media LLC. - 1471-244X. ; 18:1
-
Journal article (peer-reviewed)abstract
- The challenges of today's society call for more knowledge about how to maintain all aspects of cognitive health, such as speed/attention, memory/learning, visuospatial ability, language, executive capacity and social cognition during the life course.Medical advances have improved treatments of numerous diseases, but the cognitive implications have not been sufficiently addressed. Disability induced by cognitive dysfunction is also a major issue in groups of patients not suffering from Alzheimer's disease or related disorders. Recent studies indicate that several negative lifestyle factors can contribute to the development of cognitive impairment, but intervention and prevention strategies have not been implemented. Disability due to cognitive failure among the workforce has become a major challenge. Globally, the changing aging pyramid results in increased prevalence of cognitive disorders, and the diversity of cultures influences the expression, manifestation and consequences of cognitive dysfunction.Major tasks in the field of cognitive medicine are basic neuroscience research to uncover diverse disease mechanisms, determinations of the prevalence of cognitive dysfunction, health-economical evaluations, and intervention studies. Raising awareness for cognitive medicine as a clinical topic would also highlight the importance of specialized health care units for an integrative approach to the treatment of cognitive dysfunctions.
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89. |
- Westin, Olof, et al.
(author)
-
Cost-effectiveness analysis of surgical versus non-surgical management of acute Achilles tendon ruptures.
- 2018
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In: Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA. - : Springer Science and Business Media LLC. - 1433-7347. ; 26:10, s. 3074-3082
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Journal article (peer-reviewed)abstract
- An Achilles tendon rupture is a common injury that typically affects people in the middle of their working lives. The injury has a negative impact in terms of both morbidity for the individual and the risk of substantial sick leave. The aim of this study was to investigate the cost-effectiveness of surgical compared with non-surgical management in patients with an acute Achilles tendon rupture.One hundred patients (86 men, 14 women; mean age, 40years) with an acute Achilles tendon rupture were randomised (1:1) to either surgical treatment or non-surgical treatment, both with an accelerated rehabilitation protocol (surgical n=49, non-surgical n=51). One of the surgical patients was excluded due to a partial re-rupture and five surgical patients were lost to the 1-year economic follow-up. One patient was excluded due to incorrect inclusion and one was lost to the 1-year follow-up in the non-surgical group. The cost was divided into direct and indirect costs. The direct cost is the actual cost of health care, whereas the indirect cost is the production loss related to the impact of the patient's injury in terms of lost ability to work. The health benefits were assessed using quality-adjusted life years (QALYs). Sampling uncertainty was assessed by means of non-parametric boot-strapping.Pre-injury, the groups were comparable in terms of demographic data and health-related quality of life (HRQoL). The mean cost of surgical management was €7332 compared with €6008 for non-surgical management (p=0.024). The mean number of QALYs during the 1-year time period was 0.89 and 0.86 in the surgical and non-surgical groups respectively. The (incremental) cost-effectiveness ratio was €45,855. Based on bootstrapping, the cost-effectiveness acceptability curve shows that the surgical treatment is 57% likely to be cost-effective at a threshold value of €50,000 per QALY.Surgical treatment was more expensive compared with non-surgical management. The cost-effectiveness results give a weak support (57% likelihood) for the surgical treatment to be cost-effective at a willingness to pay per QALY threshold of €50,000. This is support for surgical treatment; however, additionally cost-effectiveness studies alongside RCTs are important to clarify which treatment option is preferred from a cost-effectiveness perspective.I.
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90. |
- Wärmefjord, Kristina, 1976, et al.
(author)
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Welding of non-nominal geometries : physical tests
- 2016
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In: Procedia CIRP. - : Elsevier BV. - 2212-8271 .- 2212-8271. ; 43, s. 136-141
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Journal article (peer-reviewed)abstract
- The geometrical quality of a welded assembly is to some extent depending part positions before welding. Here, a design of experiment is set up in order to investigate this relation using physical tests in a controlled environment. Based on the experimental results it can be concluded that the influence of part position before welding is significant for geometrical deviation after welding. Furthermore, a working procedure for a completely virtual geometry assurance process for welded assemblies is outlined. In this process, part variations, assembly fixture variations and welding induced variations are important inputs when predicting the capability of the final assembly.
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