| 1. |
- Berginström, Nils, 1984-
(författare)
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Fatigue after traumatic brain injury : exploring novel methods for diagnosis and treatment
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Traumatic brain injury (TBI) is one of the most common causes of disability and mortality. While some patients recover quickly, especially at the mild side of the injury severity continuum, many will experience symptoms for years to come. In this chronic phase, patients report a wide array of symptoms, where fatigue is one the most common. This fatigue makes huge impact in several areas of these patients’ lives. Despite the prevalence of fatigue after TBI, the underlying mechanisms are unclear. Further, there are no standardized way for assessment and diagnosis, and there are no treatments with satisfying empirical support. The aim of this thesis was to examine the effects of the novel compound OSU6162 on fatigue in patients with TBI, and to explore functional and structural brain imaging correlates of fatigue after TBI.Methods: Studies I and III were based on a placebo-controlled, double-blinded clinical trial examining the effects of the monoaminergic stabilizer OSU6162 on fatigue in patients in the chronic phase of traumatic brain injury. In study I, self-assessment scales of fatigue and neuropsychological tests were used as outcomes, while functional magnetic resonance imaging (fMRI) blood-oxygen-level dependent (BOLD) signal was the primary outcome in study III. Studies II and IV used cross-sectional designs, comparing patients with TBI with age- and gender matched healthy controls. Study II examined whether fMRI BOLD signal could be used to detect and diagnose fatigue in patients with TBI, and study IV whether white matter hyperintensities (WMH) contribute to lower cognitive functioning and presence of fatigue after TBI.Results: Study I revealed no effects of OSU6162 during 28 days of treatment at maximum doses of 15 mg twice daily on measures of fatigue or any other outcome. The results from study II indicated that fatigue after TBI is linked to alterations in striato-thalamic-cortical loops, and suggested that fMRI could be a promising technique to use in the diagnosis of fatigue after TBI. In study III the results revealed effects of treatment in the right occipitotemporal and orbitofrontal cortex. In these areas, the BOLD response was normalized in the OSU6162 group as compared to healthy controls, while the placebo group showed a steady low activity in these areas. The regional effects were located outside the network shown to be linked to fatigue in study II, which might explain why there were no effects on fatigue after treatment with OSU6162 in study I. Study IV showed that WMH lesions increased with increased TBI severity, but the presence and extent of lesions did not explain lower neuropsychological functioning or fatigue in subjects with previous TBI.Conclusions: In summary, although no effects on fatigue after treatment with OSU6162 were seen, the results provide support to the theory that fatigue after TBI is linked to alterations in striato-thalamic-cortical loops, and on how fatigue after TBI could be assessed or diagnosed using fMRI. Structural damage within white matter was however not related to fatigue.
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| 2. |
- Gardulf, A., et al.
(författare)
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The Nurse Professional Competence (NPC) Scale: Self-reported competence among nursing students on the point of graduation
- 2016
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Ingår i: Nurse Education Today. - : Elsevier BV. - 0260-6917 .- 1532-2793. ; 36, s. 165-171
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Tidskriftsartikel (refereegranskat)abstract
- Background: International organisations, e.g. WHO, stress the importance of competent registered nurses (RN) for the safety and quality of healthcare systems. Low competence among RNs has been shown to increase the morbidity and mortality of inpatients. Objectives: To investigate self-reported competence among nursing students on the point of graduation (NSPGs), using the Nurse Professional Competence (NPC) Scale, and to relate the findings to background factors. Methods and participants; The NPC Scale consists of 88 items within eight competence areas (CAs) and two overarching themes. Questions about socio-economic background and perceived overall quality of the degree programme were added. In total, 1086 NSPGs (mean age, 28.1[20-56] years, 87.3% women) from 11 universities/university colleges participated. Results: NSPGs reported significantly higher scores for Theme I "Patient-Related Nursing" than for Theme II "Organisation and Development of Nursing Care". Younger NSPGs (20-27 years) reported significantly higher scores for the CAs "Medical and Technical Care" and "Documentation and Information Technology". Female NSPGs scored significantly higher for "Value-Based Nursing". Those who had taken the nursing care programme at upper secondary school before the Bachelor of Science in Nursing (BSN) programme scored significantly higher on "Nursing Care", "Medical and Technical Care", "Teaching/Learning and Support", "Legislation in Nursing and Safety Planning" and on Theme I. Working extra paid hours in healthcare alongside the BSN programme contributed to significantly higher self-reported scores for four CAs and both themes. Clinical courses within the BSN programme contributed to perceived competence to a significantly higher degree than theoretical courses (932% vs 875% of NSPGs). Summary and conclusion: Mean scores reported by NSPGs were highest for the four CAs connected with patient-related nursing and lowest for CAs relating to organisation and development of nursing care. We conclude that the NPC Scale can be used to identify and measure aspects of self-reported competence among NSPGs. (C) 2015 Elsevier Ltd. All rights reserved.
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| 3. |
- Nilsson, Jan, et al.
(författare)
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Disaster nursing: Self-reported competence of nursing students and registered nurses, with focus on their readiness to manage violence, serious events and disasters
- 2016
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Ingår i: Nurse Education in Practice. - : Elsevier BV. - 1471-5953 .- 1873-5223. ; 17, s. 102-108
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Tidskriftsartikel (refereegranskat)abstract
- The World Health Organization and the International Council of Nurses recognises the importance of nurses' involvement in disaster preparedness and response. The aim of this study was to describe and compare self reported disaster nursing competence (DNC) among nursing students (NSs) and among registered nurses (RNs) with professional experience. Further to investigate possible associations between self-reported DNC and background factors. A cross-sectional study was conducted of 569 NSs and 227 RNs. All respondents completed the 88-item Nurse Professional Competence Scale, including three items assessing DNC. Significant differences were found among the NSs depending on which University/University College they had attended. RNs reported significantly higher overall DNC and better ability to handle situations involving violence, and to apply principles of disaster medicine during serious events. RNs working in emergency care reported significantly better DNC ability, compared with RNs working in other areas of healthcare. Multiple linear regression analysis showed that working night shift and working in emergency care were positively associated with high self-reported overall DNC. The results indicate that workplace experience of serious events increase the readiness of registered nurses to handle violence, to act in accordance with safety regulations, and to apply principles of disaster medicine during serious events. (C) 2015 Elsevier Ltd. All rights reserved.
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| 4. |
- Theander, Kersti, et al.
(författare)
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Adjusting to future demands in healthcare : Curriculum changes and nursing students' self-reported professional competence
- 2016
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Ingår i: Nurse Education Today. - : Elsevier BV. - 0260-6917 .- 1532-2793. ; 37, s. 178-183
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Tidskriftsartikel (refereegranskat)abstract
- Background: Nursing competence is of significant importance for patient care. Newly graduated nursing students rate their competence as high. However, the impact of different designs of nursing curricula on nursing students' self-reported nursing competence areas is seldom reported. Objectives: To compare newly graduated nursing students' self-reported professional competence before and after the implementation of a new nursing curriculum. The study had a descriptive comparative design. Nursing students, who graduated in 2011, having studied according to an older curriculum, were compared with those who graduated in 2014, after a new nursing curriculum with more focus on person-centered nursing had been implemented. Setting: A higher education nursing program at a Swedish university. Participants: In total, 119 (2011 n = 69, 2014 n = 50) nursing students responded. Methods: Nursing students' self-reported professional competencies were assessed with the Nurse Professional Competence (NPC) scale. Results: There were no significant differences between the two groups of nursing students, who graduated in 2011 and 2014, respectively, with regard to age, sex, education, or work experience. Both groups rated their competencies as very high. Competence in value-based nursing was perceived to be significantly higher after the change in curriculum. The lowest competence, both in 2011 and 2014, was reported in education and supervision of staff and students. Conclusions: Our findings indicate that newly graduated nursing students- both those following the old curriculum and the first batch of students following the new one - perceive that their professional competence is high. Competence in value-based nursing, measured with the NPC scale, was reported higher after the implementation of a new curriculum, reflecting curriculum changes with more focus on person-centered nursing. (C) 2015 Elsevier Ltd. All rights reserved.
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| 5. |
- Amsallem, David, et al.
(författare)
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Energy Stable Model Reduction of Neurons by Non-negative Discrete Empirical Interpolation
- 2016
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Ingår i: SIAM Journal on Scientific Computing. - : SIAM publishing. - 1064-8275 .- 1095-7197. ; 38:2, s. B297-B326
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Tidskriftsartikel (refereegranskat)abstract
- The accurate and fast prediction of potential propagation in neuronal networks is of prime importance in neurosciences. This work develops a novel structure-preserving model reduction technique to address this problem based on Galerkin projection and nonnegative operator approximation. It is first shown that the corresponding reduced-order model is guaranteed to be energy stable, thanks to both the structure-preserving approach that constructs a distinct reduced-order basis for each cable in the network and the preservation of nonnegativity. Furthermore, a posteriori error estimates are provided, showing that the model reduction error can be bounded and controlled. Finally, the application to the model reduction of a large-scale neuronal network underlines the capability of the proposed approach to accurately predict the potential propagation in such networks while leading to important speedups.
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| 6. |
- Andersson, Martin O., et al.
(författare)
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Molecular detection of Babesia capreoli and Babesia venatorum in wild Swedish roe deer, Capreolus capreolus
- 2016
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Ingår i: Parasites & Vectors. - : Springer Science and Business Media LLC. - 1756-3305. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: The epidemiology of the zoonotic tick-transmitted parasite Babesia spp. and its occurrence in wild reservoir hosts in Sweden is unclear. In European deer, several parasite species, including Babesia capreoli and the zoonotic B. venatorum and B. divergens has been reported previously. The European roe deer, Capreolus capreolus, is an important and common part of the indigenous fauna in Europe, as well as an important host for Ixodes ricinus ticks, the vector of several Babesia spp. in Europe. Here, we aimed to investigate the occurrence of Babesia spp. in roe deer in Sweden. Findings: Roe deer (n = 77) were caught and sampled for blood. Babesia spp. was detected with a PCR assay targeting the 18S rRNA gene. The prevalence of Babesia spp. was 52 %, and two species were detected; B. capreoli and B. venatorum in 44 and 7.8 % of the individuals, respectively. Infection occurred both in summer and winter. Conclusions: We showed that roe deer in Sweden, close to the edge of their northern inland distributional range, are infected with Babesia spp. The occurrence of B. venatorum in roe deer imply that it is established in Sweden and the zoonotic implication of this finding should be regarded to a greater extent in future.
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| 7. |
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| 8. |
- Changfoot, Donovan M., et al.
(författare)
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Hybrid Computational-Fluid-Dynamics Platform to Investigate Aircraft Trailing Vortices
- 2019
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Ingår i: Journal of Aircraft. - 0021-8669 .- 1533-3868. ; 56:1, s. 344-355
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Tidskriftsartikel (refereegranskat)abstract
- This paper outlines the development of a parallel three-dimensional hybrid finite volume finite difference capability. The specific application area under consideration is modeling the trailing vortices shed from the wings of aircraft under transonic flight conditions. For this purpose, the Elemental finite volume code is employed in the vicinity of the aircraft, whereas the ESSENSE finite difference software is employed to accurately resolve the trailing vortices. The former method is spatially formally second-order, and the latter is set to sixth-order accuracy. The coupling of the two methods is achieved in a stable manner through the use of summation-by-parts operators and weak imposition of boundary conditions using simultaneous approximation terms. The developed hybrid solver is successfully validated against an analytical test case. This is followed by demonstrating the ability to model the flowfield, including trailing vortex structures, around the NASA Common Research Model under transonic flow conditions. The interface treatment is shown to describe the intersecting vortices in a smooth manner. In addition, insights gained in resolving the vortices include violation of underlying assumptions of analytical vortex modeling methods.
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| 9. |
- Delorme, Yann T., et al.
(författare)
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A simple and efficient incompressible Navier-Stokes solver for unsteady complex geometry flows on truncated domains
- 2017
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Ingår i: Computers & Fluids. - : Elsevier. - 0045-7930 .- 1879-0747. ; 150, s. 84-94
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Tidskriftsartikel (refereegranskat)abstract
- Incompressible Navier-Stokes solvers based on the projection method often require an expensive numerical solution of a Poisson equation for a pressure-like variable. This often involves linear system solvers based on iterative and multigrid methods which may limit the ability to scale to large numbers of processors. The artificial compressibility method (ACM) [6] introduces a time derivative of the pressure into the incompressible form of the continuity equation creating a coupled closed hyperbolic system that does not require a Poisson equation solution and allows for explicit time-marching and localized stencil numerical methods. Such a scheme should theoretically scale well on large numbers of CPUs, GPU'€™s, or hybrid CPU-GPU architectures. The original ACM was only valid for steady flows and dual-time stepping was often used for time-accurate simulations. Recently, Clausen [7] has proposed the entropically damped artificial compressibility (EDAC) method which is applicable to both steady and unsteady flows without the need for dual-time stepping. The EDAC scheme was successfully tested with both a finite-difference MacCormack'€™s method for the two-dimensional lid driven cavity and periodic double shear layer problem and a finite-element method for flow over a square cylinder, with scaling studies on the latter to large numbers of processors. In this study, we discretize the EDAC formulation with a new optimized high-order centered finite-difference scheme and an explicit fourth-order Runge-€“Kutta method. This is combined with an immersed boundary method to efficiently treat complex geometries and a new robust outflow boundary condition to enable higher Reynolds number simulations on truncated domains. Validation studies for the Taylor-€“Green Vortex problem and the lid driven cavity problem in both 2D and 3D are presented. An eddy viscosity subgrid-scale model is used to enable large eddy simulations for the 3D cases. Finally, an application to flow over a sphere is presented to highlight the boundary condition and performance comparisons to a traditional incompressible Navier-€“Stokes solver is shown for the 3D lid driven cavity. Overall, the combined EDAC formulation and discretization is shown to be both effective and affordable.
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| 10. |
- Elffers, Jan, et al.
(författare)
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Divide and conquer : Towards faster pseudo-boolean solving
- 2018
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Ingår i: IJCAI'18. - California : International Joint Conferences on Artificial Intelligence. ; , s. 1291-1299
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Konferensbidrag (refereegranskat)abstract
- The last 20 years have seen dramatic improvements in the performance of algorithms for Boolean satisfiability-so-called SAT solvers-and today conflict-driven clause learning (CDCL) solvers are routinely used in a wide range of application areas. One serious short-coming of CDCL, however, is that the underlying method of reasoning is quite weak. A tantalizing solution is to instead use stronger pseudo-Boolean (PB) reasoning, but so far the promise of exponential gains in performance has failed to materialize-the increased theoretical strength seems hard to harness algorithmically, and in many applications CDCL-based methods are still superior. We propose a modified approach to pseudo-Boolean solving based on division instead of the saturation rule used in [Chai and Kuehlmann'05] and other PB solvers. In addition to resulting in a stronger conflict analysis, this also improves performance by keeping integer coefficient sizes down, and yields a very competitive solver as shown by the results in the Pseudo-Boolean Competitions 2015 and 2016.
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