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- Hendriks, Hester S., et al.
(författare)
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Effects on neonatal exposure to the flame retardant tetrabrombisphenol-A, aluminum diethylphosphinate or zinc stannate on long-term, potentiation and synaptic protein levels in mice
- 2015
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Ingår i: Archives of Toxicology. - : Springer Nature. - 0340-5761 .- 1432-0738. ; 89:12, s. 2345-2354
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Tidskriftsartikel (refereegranskat)abstract
- Brominated flame retardants such as tetrabromobisphenol-A (TBBPA) may exert (developmental) neurotoxic effects. However, data on (neuro)toxicity of halogen-free flame retardants (HFFRs) are scarce. Recent in vitro studies indicated a high neurotoxic potential for some HFFRs, e.g., zinc stannate (ZS), whereas the neurotoxic potential of other HFFRs, such as aluminum diethylphosphinate (Alpi), appears low. However, the in vivo (neuro)toxicity of these compounds is largely unknown. We therefore investigated effects of neonatal exposure to TBBPA, Alpi or ZS on synaptic plasticity in mouse hippocampus. Male C57bl/6 mice received a single oral dose of 211 µmol/kg bw TBBPA, Alpi or ZS on postnatal day (PND) 10. On PND 17–19, effects on hippocampal synaptic plasticity were investigated using ex vivo extracellular field recordings. Additionally, we measured levels of postsynaptic proteins involved in long-term potentiation (LTP) as well as flame retardant concentrations in brain, muscle and liver tissues. All three flame retardants induced minor, but insignificant, effects on LTP. Additionally, TBBPA induced a minor decrease in post-tetanic potentiation. Despite these minor effects, expression of selected synaptic proteins involved in LTP was not affected. The flame retardants could not be measured in significant amounts in the brains, suggesting low bioavailability and/or rapid elimination/metabolism. We therefore conclude that a single neonatal exposure on PND 10 to TBBPA, Alpi or ZS does affect neurodevelopment and synaptic plasticity only to a small extent in mice. Additional data, in particular on persistence, bioaccumulation and (in vivo) toxicity, following prolonged (developmental) exposure are required for further (human) risk assessment.
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- Ražanskas, Petras, et al.
(författare)
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Predicting physiological parameters in fatiguing bicycling exercises using muscle activation timing
- 2017
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Ingår i: Biomedical Signal Processing and Control. - Amsterdam : Elsevier. - 1746-8094 .- 1746-8108. ; 35, s. 19-29
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Tidskriftsartikel (refereegranskat)abstract
- This article is concerned with a novel technique for prediction of blood lactate concentration level and oxygen uptake rate from multi-channel surface electromyography (sEMG) signals. The approach is built on predictive models exploiting a set of novel time-domain variables computed from sEMG signals. Signals from three muscles of each leg, namely, vastus lateralis, rectus femoris, and semitendinosus were used in this study. The feature set includes parameters reflecting asymmetry between legs, phase shifts between activation of different muscles, active time percentages, and sEMG amplitude. Prediction ability of both linear and non-linear (random forests-based) models was explored. The random forests models showed very good prediction accuracy and attained the coefficient of determination R2 = 0.962 for lactate concentration level and R2 = 0.980 for oxygen uptake rate. The linear models showed lower prediction accuracy. Comparable results were obtained also when sEMG amplitude data were removed from the training sets. A feature elimination algorithm allowed to build accurate random forests (R2 > 0.9) using just six (lactate concentration level) or four (oxygen uptake rate) time-domain variables. Models created to predict blood lactate concentration rate relied on variables reflecting interaction between front and back leg muscles, while parameters computed from front muscles and interactions between two legs were the most important variables for models created to predict oxygen uptake rate.© 2017 Elsevier Ltd.
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- Viberg, Bjarke, et al.
(författare)
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Poor relation between biomechanical and clinical studies for the proximal femoral locking compression plate : A systematic review
- 2017
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Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3674 .- 1745-3682. ; 88:4, s. 427-433
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Forskningsöversikt (refereegranskat)abstract
- Background and purpose — The proximal femur locking compression plate (PF-LCP) is a new concept in the treatment of hip fractures. When releasing new implants onto the market, biomechanical studies are conducted to evaluate performance of the implant. We investigated the relation between biomechanical and clinical studies on PF-LCP. Methods — A systematic literature search of relevant biomechanical and clinical studies was conducted in PubMed on December 1, 2015. 7 biomechanical studies and 15 clinical studies were included. Results — Even though the biomechanical studies showed equivalent or higher failure loads for femoral neck fracture, the clinical results were far worse, with a 37% complication rate. There were no biomechanical studies on pertrochanteric fractures. Biomechanical studies on subtrochanteric fractures showed that PF-LCP had a lower failure load than with proximal femoral nail, but higher than with angled blade plate. 4 clinical studies had complication rates less than 8% and 9 studies had complication rates between 15% and 53%. Interpretation — There was no clear relation between biomechanical and clinical studies. Biomechanical studies are generally inherently different from clinical studies, as they examine the best possible theoretical use of the implant without considering the long-term outcome in a clinical setting. Properly designed clinical studies are mandatory when introducing new implants, and they cannot be replaced by biomechanical studies.
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- Viberg Johansson, Jennifer, 1982-
(författare)
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INDIVIDUAL GENETIC RESEARCH RESULTS : Uncertainties, Conceptions, and Preferences
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis contributes to the ethical discussion on how to handle incidental findings in biomedical research using sequencing technologies from a theoretical and an empirical perspective. Study I and II are theoretical studies that used conceptual analysis. Study I demonstrates that the argument for disclosure based on the principle of beneficence ignores the complexity and uncertain predictive value of genetic risk information. The argument neglects the distinction between an incidentally discovered disease and an incidentally discovered risk for disease with unclear predictive value. Study II investigates the proposal to let participants express their preferences to incidental genetic findings in the consent form. The study argues that this freedom of choice is problematic because it is uncertain whether the opportunity to choose in the consent phase enables people to express what they truly prefer. Participants might be steered to a specific answer depending on mood, triggered feelings, and the framing of the question.The second part of the thesis is empirical and used both a qualitative and a quantitative approach. Study III investigates research participants’ understanding of genetic risk and used a phenomenographic approach and focus group interviews. One result was that participants understood genetic risk in binary terms. This understanding involved an either/or concept of genetic risk. Participants tend not to understand genetic risk as a probability. They also interpreted the information in terms of their past, present, and future life. Study IV used a questionnaire with a stated preference technique called Discrete Choice Experiments (DCE) to investigate participants’ preferences for genetic risk information. An effective preventive measure was the most important characteristic for research participants in their decision to be given genetic risk information. When the disease was life threatening, had a high penetrance probability, and had effective preventive measures, 98% of the participants wanted to know their incidental genetic risk information.As genetic risk information has many different characteristics and includes many uncertainties, ethical discussions and empirical studies of people’s attitudes and preferences need to explicitly engage the complexity of genetic incidental findings.
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- Viberg, Olga, et al.
(författare)
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Reducing Free Riding : CLASS–A System for Collaborative Learning Assessment
- 2019
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Ingår i: Methodologies and Intelligent Systems for Technology Enhanced Learning, 9th International Conference, Workshops. - Cham : Springer. - 9783030238834 ; , s. 132-138
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Konferensbidrag (refereegranskat)abstract
- In today’s era of digitalization of education, Computer Supported Collaborative Learning is becoming increasingly important in higher education. This type of learning has been frequently associated in the recent research literature with student regulation, feedback from peers and a student assessment schema which can incorporate both formative and summative assessment strategies. This work-in-progress paper presents the CLASS system which caters for all these aspects. Furthermore, the system supports mechanisms for the prevention of the free riding phenomenon, which has been reported in the literature as one of the most important disadvantages in group student work. The paper discusses the higher education context in which the CLASS system was developed and used, along with its design affordances and how these affordances can facilitate CSCL. The paper can be useful to designers and developers of CSCL systems as well as to practitioners that are interested in how they can exploit CSCL with their students working in groups.
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