| 1. |
- Andersson, Jan, 1965-, et al.
(författare)
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The proportions of severe and less severe bicycle crashes and how to avoid them
- 2024
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Ingår i: Transportation Research Part F. - : Elsevier. - 1369-8478 .- 1873-5517. ; 106:October, s. 169-178
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundIn collaboration with a bicycle airbag helmet company, data were collected to help explain events where head protections are deployed. The head protection records activations continuously, and when a head protection is deployed, this information is sent to the company. The company invited affected cyclists to (i) participate in a web survey, and (ii) share their data with researchers. The first aim of the study was to investigate the proportions between different severities of crashes, i.e., how many crashes with serious injuries occur for every crash with minor injuries, while the second aim was to predict when bicycle crashes will occur.Method A total of 196 cyclists completed the web survey. Participants were 20–76 years old (mean age 46 years) and consisted of 125 women and 55 men. The cyclists were highly educated, and 73 percent had completed a university or college education. In addition, head protection data were collected from 355 other cyclists, of which 264 had their helmet deployed.ResultsOne of the 182 (included events) cyclists ended up in hospital care. The data collected indicated the proportions of cyclists who needed hospital care (1 = severe injuries), cyclists with injuries (15), slight injures (85) and cyclists who could continue as before (81 = no injuries). The head protection data confirmed the web survey findings, but also demonstrated that the head protection, on journeys that ended with head protection deployment, had a higher degree of activations before the event) compared to journeys where it was not deployed. Furthermore, on trips made after deployment, the head protection had lower levels of activations, which can be understood as the cyclists adapting their behavior by, for example, riding more carefully (but not slower).ConclusionThis study highlights the proportions of events leading to minor injuries versus hospitalization. Activation measures (head protection conditions) can predict when events will occur, and cyclists will adjust their behavior accordingly following events.
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| 2. |
- Andersson, Jan, 1965-, et al.
(författare)
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Varför sker en cykelolycka egentligen : analys av händelser då Hövdingar har löst ut
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I samarbete med Hövding har en studie genomförts för att belysa hur olika aspekter bidrar till händelser där cykelhjälmen löser ut. Hjälmen registrerar kontinuerligt accelerationer och när en hjälm löser ut registreras denna information hos företaget. Företaget skickar då ut en inbjudan till cyklisten om att besvara en webbenkät som även inkluderar en inbjudan att medverka i en intervju. Studien bygger på data från tre olika källor –webbenkät, intervjuer och data från hjälmen – i syfte att öka förståelsen för varför en cykelolycka inträffar. Totalt var det 196 deltagare som besvarade enkäten och 50 deltagare som intervjuades. Dessutom samlades hjälmdata in från 355 cyklister, varav 264 cyklister hade varit inblandade i minst en händelse där hjälmen löst ut.Ett av huvudresultaten är att det är en helt vanlig dag, på en vanlig resa när en erfaren cyklist, med hög utbildning, väl medveten om trafikregler och om vad som sker runt omkring, cyklar till eller från jobbet – och ”plötsligt händer det” och inte förrän då inser cyklisten hur utsatt den är. Studien visar att en komplex bild växer fram från de tre datakällor som nyttjats för att förstå varför en olycka egentligen sker. Exempelvis ökar halka risken för en händelse där Hövdingen löser ut och är det dessutom mörkt ökar risken ytterligare. Hjälmdata kunde styrka resultaten från webbenkäten och intervjuerna men också visa på att hjälmen, på de resor som slutat med att den löste ut, haft en högre aktiveringsgrad (det har skakat mer) än på resor tidigare (då hjälmen inte har löst ut). Vidare har hjälmen på resor som gjorts efter att den löst ut, visat att cyklisten cyklar med en lägre aktiveringsgrad. Det innebär att cyklisten gjort någon form av anpassning så som att cykla försiktigare (men inte långsammare). Slutligen visar resultaten på skillnader mellan cyklister på konventionella cyklar jämfört med elcyklar vad gäller inblandning i händelser där hjälmen lösts ut.
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| 3. |
- Grillner, Sten, et al.
(författare)
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Neural basis of goal-directed locomotion : An overview
- 2007
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Ingår i: Brain Research Reviews. - : Elsevier BV. - 0165-0173 .- 1872-6321. ; 57:1, s. 2-12
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Tidskriftsartikel (refereegranskat)abstract
- The different neural control systems involved in goal-directed vertebrate locomotion are reviewed. They include not only the central pattern generator networks in the spinal cord that generate the basic locomotor synergy and the brainstem command systems for locomotion but also the control systems for steering and control of body orientation (posture) and finally the neural structures responsible for determining which motor programs should be turned on in a given instant. The role of the basal ganglia is considered in this context. The review summarizes the available information from a general vertebrate perspective, but specific examples are often derived from the lamprey, which provides the most detailed information when considering cellular and network perspectives.
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| 4. |
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| 5. |
- Huss, Mikael, et al.
(författare)
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Roles of ionic currents in lamprey CPG neurons : a modeling study
- 2007
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Ingår i: Journal of Neurophysiology. - : American Physiological Society. - 0022-3077 .- 1522-1598. ; 97:4, s. 2696-2711
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Tidskriftsartikel (refereegranskat)abstract
- The spinal network underlying locomotion in the lamprey consists of a core network of glutamatergic and glycinergic interneurons, previously studied experimentally and through mathematical modeling. We present a new and more detailed computational model of lamprey locomotor network neurons, based primarily on detailed electrophysiological measurements and incorporating new experimental findings. The model uses a Hodgkin Huxley-like formalism and consists of 86 membrane compartments containing 12 types of ion currents. One of the goals was to introduce a fast, transient potassium current (K-t) and two sodium-dependent potassium currents, one faster (K-NaF) and one slower (K-NaS), in the model. Not only has the model lent support to the interpretation of experimental results but it has also provided predictions for further experimental analysis of single-network neurons. For example, K-t was shown to be one critical factor for controlling action potential duration. In addition, the model has proved helpful in investigating the possible influence of the slow afterhyperpolarization on repetitive firing during ongoing activation. In particular, the balance between the simulated slow sodium-dependent and calcium-dependent potassium currents has been explored, as well as the possible involvement of dendritic conductances.
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| 6. |
- Kozlov, Alexander, et al.
(författare)
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Detailed reduced models excitatory hemi-cord locomotor network lamprey
- 2003
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Rhythmic locomotor-related activity can be induced in the isolated hemi-spinal cord of lamprey during bath application of D-glutamate or NMDA (Cangiano and Grillner, 2003). This bursting activity is not dependent on glycinergic inhibition but relies on mutual glutamatergic excitation among network interneurons. The possibility of such oscillatory activity was suggested by earlier simulations (Hellgren-Kotaleski et al. 1999). Here the underlying mechanisms are further examined using both detailed and reduced mathematical models. The detailed network model comprises a population of compartmental excitatory interneurones with Na+, K+, Ca2+, KCa channels as well as two Ca-pools. The synaptic interactions are mediated by AMPA receptors and voltage-dependent NMDA receptors, as established experimentally. This model reproduces the main experimental observations on both cell and network level, including the slow (NMDA/Mg2+ dependent) and the fast rhythm. Burst frequency can be modulated by changing the AMPA and/or NMDA drive, the latter providing only a narrow dynamic range. Further, the distributed network of the entire hemi-cord has been simulated. A weakly asymmetric rostro-caudal connectivity (stronger descending) could support a uniform intersegmental phase lag along most of the spinal cord, whereas a symmetric connectivity could not. The intersegmental phase lag is effectively controlled (forward and backward direction) by adding excitation or inhibition to the most rostral segments. The detailed model was progressively reduced until only the most important (slow) currents remained. The dynamics of the reduced model followed that of the detailed model. Ca influx and activation of KCa currents was shown to play a key role in the burst generation.
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| 7. |
- Lundström, Annika, et al.
(författare)
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Prognostic Value of Circulating Microvesicle Subpopulations in Ischemic Stroke and TIA
- 2020
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Ingår i: Translational Stroke Research. - : Springer Science and Business Media LLC. - 1868-4483 .- 1868-601X. ; 11:4, s. 708-719
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Tidskriftsartikel (refereegranskat)abstract
- Platelet microvesicles (PMV) have previously been found elevated in acute ischemic stroke (IS) and could be biomarkers for risk of recurrence. PMV surface antigens such as P-selectin and phosphatidylserine (PS) reflect platelet activation and procoagulance. Tissue factor-positive microvesicles (TF+MV) are considered procoagulant, in particular if co-expressing PS. We enumerated MV subpopulations with these surface antigens in a cohort of 211 patients with primarily non-cardioembolic IS or transient ischemic attack (TIA) and investigated their association with long-term outcome. MV concentrations were determined by flow cytometry in the acute and convalescent phase. Primary outcome was a composite of fatal and non-fatal recurrent IS or myocardial infarction. Secondary outcomes were recurrent IS and all-cause mortality. Outcome events were obtained from Swedish registers during a follow-up of 1100 patient years. Concentrations of PS-positive and PS-negative MV populations were elevated in patients compared with healthy controls in both the acute and convalescent phase. PS+TF+PMV displayed pronounced elevations, median fold change 77 in the acute phase (p < 0.0001) but were not associated with outcome, neither were PS+P-selectin(+)PMV. The only subpopulation positively associated with primary outcome was PS-TF+PMV, with adjusted hazard ratio of 1.86 (1.04-3.31,p = 0.036) by Cox regression. Unexpectedly, several MV subpopulations tended to be associated with reduced risk of poor long-term outcome. Our results suggest that PS+TF+PMV may be a promising marker for cerebral ischemia, and that the in vivo generation of PS-MV after IS/TIA warrants further study. Future MV studies should ideally enumerate PS(+)and PS-MV subpopulations separately.
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| 8. |
- Manfredi, L, et al.
(författare)
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A bioinspired autonomous swimming robot as a tool for studying goal-directed locomotion
- 2013
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Ingår i: Biological Cybernetics. - : Springer Science and Business Media LLC. - 0340-1200 .- 1432-0770. ; 107:5, s. 513-527
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Tidskriftsartikel (refereegranskat)abstract
- The bioinspired approach has been key in combining the disciplines of robotics with neuroscience in an effective and promising fashion. Indeed, certain aspects in the field of neuroscience, such as goal-directed locomotion and behaviour selection, can be validated through robotic artefacts. In particular, swimming is a functionally important behaviour where neuromuscular structures, neural control architecture and operation can be replicated artificially following models from biology and neuroscience. In this article, we present a biomimetic system inspired by the lamprey, an early vertebrate that locomotes using anguilliform swimming. The artefact possesses extra- and proprioceptive sensory receptors, muscle-like actuation, distributed embedded control and a vision system. Experiments on optimised swimming and on goal-directed locomotion are reported, as well as the assessment of the performance of the system,which shows high energy efficiency and adaptive behaviour. While the focus is on providing a robotic platform for testing biological models, the reported system can also be of major relevance for the development of engineering system applications.
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| 9. |
- Nyberg, Erik, 1992-, et al.
(författare)
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Impact of DAC on production personnel at marshalling yards : Deliverable D 5.1
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The current deliverable is an outcome of the EU-project titled DACcelerate part of WP4 (Infrastructure, capacity and modal shift/Green deal) in the European DAC Delivery Programme (EDDP, under the WP structure valid until end-2022). EDDP WP4 has been led by Trafikverket who is also in various leading positions/WPs in TRANS4M-R and EDDP neo. The overall objective DACcelerate WP5 is to investigate the changes in work environment at marshalling yards that a transition from screw couplers to Digital Automatic Couplers (DAC)entails. Production at the main marshalling yards of Sweden and Austria is analysed and compared. These two marshalling yards represent significant differences in terms of traffic throughput, physical design and organisation of production personnel. Job tasks performed by different professional roles at the marshalling yard has been surveyed as well as how personnel interact in accordance with current work processes. The research method applied in the current work has primarily involved workplace visits and interviews and hence the investigation has required a close collaboration with operators of marshalling yards. For the case studies in Sweden and Austria this has meant a comprehensive and trustful cooperation with the operator Green Cargo and the Austrian federal railways ÖBB. The current project has been integrated in WP4 of the EDDP programme as well as aligned with unions and other stakeholders through workshop sheld during the period when the project was carried out.
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| 10. |
- Olausson, Nina, et al.
(författare)
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Incidence of pulmonary and venous thromboembolism in pregnancies after in vitro fertilization with fresh respectively frozen-thawed embryo transfer : Nationwide cohort study
- 2020
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Ingår i: Journal of Thrombosis and Haemostasis. - : WILEY. - 1538-7933 .- 1538-7836. ; 18:8, s. 1965-1973
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Tidskriftsartikel (refereegranskat)abstract
- Background The assisted reproductive technique in vitro fertilization (IVF) is associated with an increased risk of venous thromboembolism (VTE) and pulmonary embolism (PE) during the first trimester. Objectives To compare the incidence of VTE and PE during the first trimester of IVF pregnancies using fresh or frozen-thawed embryo transfer to that during natural pregnancies. Patient/Methods Nationwide Swedish registry-based cohort study of women who gave birth (n = 902 891) at the age of 15-50 years to their first child from the 1st of January 1992 until the 31st of December 2012. Exposure groups were IVF with fresh respectively frozen-thawed embryo transfer. Incidences of VTE and PE were calculated, and time-varying hazard ratios estimated for all trimesters after fresh respectively frozen-thawed embryo transfer IVF and compared to natural conception. Results and Conclusion Women giving birth after fresh embryo transfer IVF had a more than eightfold increased incidence of venous thromboembolism (hazard ratio [HR] 8.96, 95% CI 6.33 to 12.67) and pulmonary embolism during the first trimester, (HR 8.69, 95% CI 3.83 to 19.71) compared to women giving birth after natural conception. The incidence of VTE in women giving birth after frozen-thawed embryo transfer was not increased during the first trimester. To conclude, fresh embryo transfer IVF was associated with a significantly increased incidence of VTE and PE during the first trimester. These results suggest that frozen-thawed embryo transfer could be a preferred method of IVF with a minimised maternal risk.
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