1,341 research outputs found
Lumbar muscle fatigue : analysis of electromyography, endurance time and subjective factors in patients with lumbar disc herniation and healthy subjects [Elektronisk resurs]
No full textThe overall aim of the thesis was to investigate the relation between objectively and subjectively assessed lumbar muscle fatigue and subjective factors in patients with lumbar disc herniation and in healthy subjects. Eighty healthy subjects and 43 patients undergoing surgery for lumbar disc herniation and selected consecutively for the study participated. Muscle fatigue in the lower back was assessed during a modified Sorensen test, an isometric prone holding test for the back extensors against gravity and until exhaustion, or a staircase protocol (20%, 40%, 60%, and 80% of maximum voluntary contraction). Concomitantly, EMG was detected from the lumbar extensor muscles and subjects rated their perceived fatigue - and the patients also their pain - on a Borg CR- 10 scale. Recovery was assessed after the modified Sorensen test during 5-second contractions at 1-5 minutes of recovery then examined using an exponential time dependence model. To measure activity, participation, self-efficacy and health, the patients also filled in questionnaires. The reliability of the modified Sorensen test was also assessed. The modified Sorensen test with concomitant measures of EMG provided useful reliability (ICC>0.60) for evaluation purposes. Borg scale ratings correlated highly (r>0.7) with endurance time. The EMG median frequency slopes correlated low-to-moderately (r<0.54). At Borg rating 3 (moderate fatigu'), 5 (strong fatigue), and 7 (very strong fatigue), the medians of median frequency and endurance time had changed by 28-37%, 48-69%, 63-89% at each time respectively. This relation can be used in clinical testing where maximum endurance tests are unsuitable: a fixed time performance until Borg rating 5 may be used. That healthy women's back muscles were more fatigue-resistant than healthy men's was shown in a smaller median frequency decrease. However the opposite was indicated for patients with lumbar disc herniation. Elimination of pain due to surgery reduced muscle fatigue with respect to a smaller median frequency decrease but not enough to increase endurance time. Patients could not fatigue their muscles as much as healthy subjects could, as shown by significantly shorter endurance time and smaller median frequency decrease than healthy subjects. The applicability of the exponential time dependence model was excellent to all healthy subjects except three. Of the patients, only 14 had an exponential recovery process both before and after surgery indicating that the recovery process had been impaired due to the disc herniation. Measurements of fatigue and recovery were associated with activity limitations, participation restrictions, self-efficacy and health in patients with lumbar disc herniation. These interactions were seen by correlation coefficients of 0.53-0.95 between endurance time and some of the questionnaire answers, especially for women. Patients with non-significant fatigue and an impaired recovery process scored significantly worse on the questionnaires than those with both fatigue and non-impaired recovery
Factors associated with pain and disability reduction following exercise interventions in chronic whiplash
No full textBackgroundSome studies support the prescription of exercise for people with whiplash-associated disorders (WAD); however, the response is highly variable. Further research is necessary to identify factors which predict response. MethodsThis is a secondary analysis of a randomized, multicentre controlled clinical trial of 202 volunteers with chronic WAD (grades 2 and 3). They received either neck-specific exercise with, or without a behavioural approach, or prescription of physical activity for 12weeks. Treatment response, defined as a clinical important reduction in pain or disability, was registered after 3 and 12months, and factors associated with treatment response were explored using logistic regression. ResultsParticipation in the neck-specific exercise group was the only significant factor associated with both neck pain and neck disability reduction both at 3 and 12months. Patients in this group had up to 5.3 times higher odds of disability reduction and 3.9 times higher odds of pain reduction compared to those in the physical activity group. Different baseline features were identified as predictors of response depending on the time point examined and the outcome measure selected (pain vs. disability). ConclusionFactors associated with treatment response after exercise interventions differ in the short and long term and differ depending on whether neck pain or disability is considered as the primary outcome. Participation in a neck-specific exercise intervention, in contrast to general physical activity, was the only factor that consistently indicated higher odds of treatment success. These results support the prescription of neck-specific exercise for individuals with chronic WAD.Funding Agencies|Swedish government through the REH-SAM Foundation; Clinical Research of Ostergotland Council; Clinical Research of Sormland County Council; Medical Research Council of Southeast Sweden; Uppsala-O rebro Regional Research Council Sweden; Swedish Research Council</p
Room temperature structures beyond 1.5 Å by serial femtosecond crystallography
No full textabstract: About 2.5 × 10[superscript 6] snapshots on microcrystals of photoactive yellow protein (PYP) from a recent serial femtosecond crystallographic (SFX) experiment were reanalyzed to maximum resolution. The resolution is pushed to 1.46 Å, and a PYP structural model is refined at that resolution. The result is compared to other PYP models determined at atomic resolution around 1 Å and better at the synchrotron. By comparing subtleties such as individual isotropic temperature factors and hydrogen bond lengths, we were able to assess the quality of the SFX data at that resolution. We also show that the determination of anisotropic temperature factor ellipsoids starts to become feasible with the SFX data at resolutions better than 1.5 Å.The final version of this article, as published in Structural Dynamics, can be viewed online at: http://aca.scitation.org/doi/10.1063/1.491990
EMG recovery and ratings after back extensor fatigue in patients with lumbar disc herniation and healthy subjects
No full textCorrelation between electromyographic spectral changes and subjective assessment of lumbar muscle fatigue in subjects without pain from the lower back
No full textLumbar muscle fatigue and recovery in patients with long-term low-back trouble - electromyography and health-related factors
No full textStudentaktive Læringsformer for å Fremme Dyplæring i Høyspenningsteknikk
No full textThe Nordic Journal of STEM Education licenses all content of the journal under a Creative Commons Attribution (CC-BY) licence. This means, among other things, that anyone is free to copy and distribute the content, as long as they give proper credit to the author(s) and the journal. For further information, see Creative Commons website for human readable or lawyer readable versions.Denne studien baserer seg på perspektiver rundt dyplæring. Det søkes å vise hvordan mer tudentaktive læringsformer kan skape mere robuste læringspraksiser som igjen muliggjør dyplæring. Studien søker å vise at en slik studentaktiv intensivering kan være en måte å gjøre undervisningen mer samstemt på. I studien har vi gjort tiltak for å gjøre undervisningen i emnet høyspenningsteknikk mer samstemt ved å inkludere nye, studentaktive læringsformer.Uttalelser fra studentene tyder på at varierte læringsformer var motiverende og at denne studentaktive læringsformen pekte i retning av dypere læring. Dette kunne imidlertid ikke dokumenteres på eksamensresultatene, noe som kan tyde på at neste skritt er å jobbe med vurderingsformen, slik at emnet blir ytterligere samstemt, og studentene i enda større grad blir
oppmuntret til å velge dyplæringsstrategier.publishedVersio
Å tegne i Naturfagsundervisningen
No full textHensikten med denne studien er å undersøke muligheter og utfordringer knyttet til det å tegne i naturfag. Dette blir studert i en undervisningsøkt som der elevene skal tegne en modell av drivhuseffekten. Undervisningsopplegget er blitt planlagt av meg og naturfagslæreren for klassen. Planleggingen av undervisningen tar utgangspunkt i Tytler et al. (2013) sine prinsipper for representasjonsbasert undervisning. Denne masteroppgaven har som mål å belyse problemstillingen: hvilke utfordringer og muligheter er det når elever arbeider med å tegne modeller i naturfagundervisningen? For å samle inn data er det blitt brukt video- og observasjon og elevproduktene fra timen er blitt samlet inn. Studien er en kvalitativ utviklingsstudiet, der to elevgrupper sitt arbeid med å tegne en modell blir studert. Det er videre blitt gjennomført en interaksjonsanalyse av samtalene elevene hadde og en analyse av elevene sin tegneprosess.
Funnene fra studien viser at elevene har en utvikling av forståelsen i arbeid med tegningen. Utover i tegneprosessen har elevene mer og mer fokus på den naturvitenskaplige forklaringen. Dette gjelder både i samtalene til elevene og hvordan tegningen utvikler seg. Denne utviklinger skjer ved at elevene interagere med hverandre og tegningen, og dette fungerer som en drivkraft for å få komme videre i arbeidet. Videre viser funnene at elevene har vansker med å vite hvor de skal starte med modellen og hva de skal inkludere i modellen. Flere av elevene bruker også mye tid til å fargelegge tegningen sin.This thesis aims to investigate the opportunities and challenges related to drawing in sciences. The research is conducted during a classroom activity where the students are asked to draw a model of the greenhouse effect. The teaching plan is planned by the author and the teacher of the natural science class and departs from Tytler et al. (2013) principles of teaching based on representations. This thesis aims to answer the following research question: which challenges and opportunities occurs when students work with drawing their own models in science classes? The empirical data gathering methods consist of video, observation, and the models made by the students during the class. The study is a qualitative development study, where the drawing of models by two different groups of students have been analyzed. Further, an interaction analysis of the conversations between students during the class and an analysis of the drawing process has been conducted.
The findings show that the students experience a development in their understanding when drawing. Furthermore, the study indicates that the students gain an increased focus on the scientific explanation. This development occurs through interaction between the students related to the drawing and acts as a driving force to move forward in their work. The study further shows that students experience struggles related to how they are supposed to start drawing the model and what they should include. A considerable portion of the students also spends a significant amount of time coloring their drawings
Pain related aspects of neck muscle performance, functioning and psychosocial factors in individuals with cervical radiculopathy
No full textAim: The overall aim of the work presented in this thesis was to describe and explore pain-related aspects of neck muscle performance, functioning and psychosocial factors in individuals with cervical radiculopathy (CR).Methods: Participants were 157 patients with CR. Also Study II included 33 asymptomatic age-and gender-matched controls. Study I, a prospective randomized controlled pilot trial, investigated outcomes after anterior cervical discectomy and fusion (ACDF) with interbody cage with (n=17) or without (n=16) cervical collar in CR. In Study II and III, ventral and dorsal neck muscle fatigue was recorded with surface electromyography (EMG) during isometric endurance (NME) tests. Study II compared a CR group (n=46) with healthy controls (n=34). In Study III, results after neck-specific training or prescribed physical activity (n=50) were analyzed. Pain was estimated using visual analogue scales (VAS) and perceived fatigue rated with Borg CR-10 scales before, during and after the tests. Cross-sectional, Study IV, identified dimensions underlying measures of impairments, disability, personal factors, and health status in patients with CR (n=124).Results: Study I, Both groups improved in all outcome measures, with a significant improvement from baseline to two years after surgery. Cervical collar worn for six weeks postoperatively, were associated with enhanced neck function and less neck pain even at long-term. Study II showed altered neck muscle endurance investigated with greater negative median frequency slope, variability, side imbalance, lower endurance time, and higher experience of fatigue among in the CR group compared to the healthy controls. Patients with CR had significantly shorter endurance time. In Study III, significant improvement in flexor NME was found after training, but with no difference between training groups. For the neck-specific training group only, there less activation of the splenius capitis during neck flexion after 14 weeks and one year, indicating reduced co-activation of the neck muscles. In Study IV, the PCA model provided three-components: Pain and functioning, Health, beliefs, and kinesiophobia, and Mood state and catastrophizing. These accounted for 73% of the cumulative percentages.Conclusions: Cervical collar post-surgery can help deal with initial post-operative pain and reduce disability. Shorter endurance and higher experience of fatigue was perceived among patients with CR compared to healthy subjects. Exercises increased flexor NME regardless of exercise group. The neck-specific group indicated reduced compensation of antagonist muscles during flexion contraction. To capture a broad picture of patients with CR pain, their functioning, fear avoidance beliefs, and anxiety are important factors in a clinical perspective.List of scientific papersI. Abbott A, Halvorsen M, Dedering Å. Is there a need for cervical collar usage post anterior cervical decompression and fusion using interbody cages? A randomized controlled pilot trial. Physiotherapy Theory and Practice. 29(4):290-300, 2013. https://doi.org/10.3109/09593985.2012.731627 II. Halvorsen M, Abbott A, Peolsson A, Dedering Å. Endurance and fatigue characteristics in the neck muscles during sub-maximal isometric test in patients with cervical radiculopathy. European Spine Journal. 23(3):590-8, 2014. https://doi.org/10.1007/s00586-013-3060-6 III. Halvorsen M, Falla D, Gizzi L, Harms-Ringdahl K, Peolsson A, Dedering Å. Short and long term effects of exercise on neck muscle function in patients with cervical radiculopathy. [Manuscript]IV. Halvorsen M, Kierkegaard M, Harms-Ringdahl K, Peolsson A, Dedering Å. Dimensions underlying measures of disability, personal factors and health status in cervical radiculopathy: a cross-sectional study. Medicine. 94(24):e999, 2015. https://doi.org/10.1097/MD.0000000000000999 </p
Using Author Profiling to Determine the Age Group of an Author
No full textDenne masteroppgaven utforsker hvordan fastslå aldersgruppen til en forfatter. I hovedsak om forfatteren er et barn, som vil si under 18 år, eller voksen, 25 år og oppover. Videre er målet å undersøke hvilke tekstlige trekk som best korrelerer med alderen til en forfatter, over flere genrer. Til slutt, vil vi utforske om det vil være tilstrekkelig å kun bruke en felles modell for å predikere alderen over flere domener, eller om hver enkelt genre trenger en individuell modell. For å få svar på disse spørsmålene, har datasett fra tidligere forsking innenfor feltet forfatterprofilering, blitt samlet inn. Disse datasettene inneholder bloggdata, sosial mediatekster og Twitterdata. Videre har flere eksperimenter blitt utført på disse datasettene, der vi brukte maskinlærings algoritmer ofte brukt til klassifisering, samt ofte brukte språkgjenkjennelsesmetoder. Eksperimentene som ble utført ble gjort på individuelle datasett, i tillegg til kombinerte datasett.
Resultatene viser at det er mulig å fastslå aldersgruppen til forfattere basert på hvordan de skriver, med relativ høy treffsikkerhet. Videre viser også resultatene fra eksperimentene at lineær kernel SVM (Support Vector Machine) produserte de beste resultatene, med tanke på treffsikkerhet, presisjon og recall score, og den kombinerte verdien. Det erflere tekstlige trekk som ernyttige til å skille tekstene fra de forskjellige aldersgruppene og genere fra hverandre. Noen av disse er TF-IDF (Term Frequency - Inverse Document Frequency), LIWC (Linguistic Inquiry and Word Count), n-grams, PoS (Part of Speech) tagging og frekvensen stilistiske språklige trekk. Til slutt, viser resultatene at modellene som er trent på kombinerte sett med genre, gjorde det betraktelig dårligere enn modeller som bare var trent på individuelle domener.This thesis investigates how to determine the age group of an author, mainly if the author is a child, below the age of 18, or an adult, above the age of 25. Furthermore, the goal is to explore which textual features across different genres best correlate with the age of an author. Lastly, we want to investigate if a single model would be sufficient to predict age across various genres, or if the different domains need an individual model. To answer these questions, several data sets, previously used in author profiling research, have been collected. The data sets gathered contain blog texts, social media data and Twitter data. Furthermore, numerous experiments are implemented using commonly used machine learning classification algorithms and language recognition methods. The experiments are performed on individual genre data sets, as well as combined domains.
The results showed that it is possible to determine the age group of authors with relative accuracy, based on how they write. Results also reveal that the linear kernel SVM (Support Vector Machine) produces the best results throughout the experiments, in regards to overall prediction accuracy, precision and recall score, and the combined measure. Moreover, some of the textual features that are effective in distinguishing text written by the different age groups across the genres are TF-IDF (Term Frequency - Inverse Document Frequency), LIWC (Linguistic Inquiry and Word Count), n-grams, PoS (Part of Speech) tagging and stylistic language frequencies. Additionally, the results show that the models that are trained on a combined set of genres underperformed compared to models that trained only on a single domain
- …
