| 1. |
- Rose, Linda M., et al.
(författare)
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Fatigue and recovery during and after static loading
- 2014
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Ingår i: Ergonomics. - : Informa UK Limited. - 0014-0139 .- 1366-5847. ; 57:11, s. 1696-1710
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Tidskriftsartikel (refereegranskat)abstract
- Subjectively assessed endurance time (ET), resumption time (RT) and perceived discomfort, pain or fatigue (PD), and objectively measured maximum force-exerting capacity were investigated for varying loads and durations of a pushing task with two repeated trials. Beyond the main results quantifying how the load scenario affected ET, RT and PD, three additional results are of note: (1) although the maximum pushing force did not change between trials, shorter ET, longer RT and higher PD indicated accumulation of fatigue in Trial 2; (2) the PD ratings showed a trend with a linear increase during loading and a curvilinear decrease during recovery; and (3) the RT and the load level for different relative loading times were found to have an unexpected U-shaped relationship, indicating lowest fatigue at the intermediate load level. These results can be used to model a more sustainable and productive work-recovery ratio.
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| 2. |
- Ahlin, Jane, et al.
(författare)
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Strategies to develop and strengthen human factors and ergonomics knowledge among stakeholders in Sweden
- 2015
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Ingår i: Proceedings 19th Triennial Congress of the IEA, Melbourne 9-14 August 2015. - Melbourne : International Ergonomics Association.
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Konferensbidrag (refereegranskat)abstract
- Knowledge and application of human factors and ergonomics (HFE) has significant potential as auseful tool and solution provider in the development, design and implementation of safe, efficient and sustainable artefacts and systems. Yet, it seems that this HFE knowledge is not utilised to its full potential. In a world of competing financial and commercial priorities, HFE specialists have apparently not succeeded in selling the systems approach as a tool towards improved overall systems performance and human well-being.The present paper describes the strategic and practical workperformed by the Swedish Ergonomics and Human Factors Society (EHSS) to strengthen the quality of human factors and ergonomics knowledge and practice among various stakeholders in Sweden. EHSS view human factors and ergonomics as a systems and design oriented discipline that extends across all aspects of human activity. Beyond the traditional domains of specialization within the discipline, the physical, cognitive and organisational ergonomics, EHSS has identified three focus areas; visual ergonomics, voice ergonomics and ergonomics design for all.Practitioner Summary: This paper presents the strategic and practical work performed by the Swedish Ergonomics and Human Factors Society (EHSS) in order to strengthen the quality of human factors and ergonomics knowledge and practice in Sweden. EHSS has identified three focus areas for its strategic work: visual ergonomics, voice ergonomics and ergonomics design for all.
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| 3. |
- Amid Hägg, Shadi, 1982-
(författare)
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Sleep disturbances : Consequences and comorbidities
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Sleep disorders are common in the general population, with insomnia and sleep-related breathing disorders being the most common disorders. Since sleep has many important functions, such as a role in consolidation of memories and learning, energy conservation, cardiovascular and immune system regulation, it is not surprising that the disruption of normal sleep may lead to negative health effects and various comorbidities. Aim: The overall aim of this thesis was to investigate the impact of disturbed sleep on various consequences and comorbidities. Methods and results: Papers I and II were based on the Sleep and Health in Women (SHE), a population-based prospective study of women, where a questionnaire was sent to women in 2000 and 2010. In paper I, the study cohort comprised 4,320 women <67 years of age who answered both questionnaires and had worked during the follow-up period. In women, having a long history of insomnia symptoms was associated with an increased risk of self-reported occupational accidents.In paper II, the 4,882 participants who answered the questions regarding nocturnal gastroesophageal reflux and snoring in both questionnaires were included in the study cohort. Women with nocturnal gastroesophageal reflux and snoring were at an increased risk of developing daytime sleepiness and to involuntarily fall asleep during the day. Paper III was based on the RHINE-cohort with participants from seven Northern European centers. The study cohort in paper III comprised the 2,568 smokers in the baseline study that also reported being smokers or former smokers in the follow-up study. It was found that having insomnia symptoms or excessive daytime sleepiness decreases the chance of long-term smoking cessation, and that smoking increases the risk of incident difficulties inducing sleep. Paper IV was the population-based, cross-sectional GA2LEN-survey which was conducted in four major Swedish cities. Paper IV included the 25,901 participants who answered questions regarding both snoring and insomnia symptoms. The combination of snoring and insomnia symptoms was associated with an increased risk of hypertension, asthma, chronic obstructive pulmonary disease, and daytime sleepiness. Conclusions: Disturbed sleep, due to varying causes, influences the risk of occupational accidents, on the chance of successful smoking cessation, on the risk of daytime sleepiness, hypertension, and obstructive lung disease. In clinical consultation, it is important to always inquire about disturbed sleep as it can have an impact on many aspects of health.
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| 4. |
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| 5. |
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| 6. |
- Antonsson, Ann-Beth, et al.
(författare)
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Belastningsarbetsskador vid städning. 17 städares berättelser om sina anmälda arbetsskador
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Inom ramen för ett aktionsprogram för optimal ergonomi och färre arbetsskador vid städning, har intervjuer gjorts med sjutton städare som anmält arbetsskada. Städarna har identifierats via Arbetsmiljöverkets register över arbetsskador, ISA, och anmälan är registrerad som belastningsskada. Syftet med detta delprojekt är att samla in arbetsskadade städares syn på vilka arbetsmoment de anser bidragit till deras arbetsskada Städarnas berättelser kommenteras av en städexpert och en ergonom. Städexpertens kommentarer belyser de belastningar städare har i relation till de städmetoder som används. Ofta verkar onödigt tunga och omoderna städmetoder ha bidragit till arbetsskadorna. Städning enligt modern och god praxis borde kunna minska skadorna. De skador som städarna beskriver är inte godkända som arbetsskador och tolkningen av de enskilda berättelserna bör därför göras med försiktighet. Ergonomens slutsatser är att för hela gruppen intervjuade städare är det sannolikt att städarbetet bidragit till den värk och andra skador som beskrivs i berättelserna. Städarnas berättelser visar att för att minska arbetsskadorna, krävs också att städarbetet organiseras så att det inte innebär tillfälliga och höga belastningar. Berättelserna visar att värken ofta utvecklats under lång tid. Det är därför viktigt med en medvetenhet om att värk och smärta ska tas på allvar och måste motarbetas, innan värken blivit kronisk. Vådan av de normalt sett positiva egenskaperna höga ambitioner och noggrannhet har också belysts av berättelserna. Mot bakgrund av städarnas berättelser samt städexpertens och ergonomens kommentarer, diskuteras flera tänkbara åtgärder för att minska risken för belastningsskador vid städning. Inom andra delprojekt i aktionsprogrammet kommer dessa och andra åtgärderar att studeras och utvärderas
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| 7. |
- Eklöf, Hampus, et al.
(författare)
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A prospective comparison of duplex ultrasonography, Captopril renography, MRA and CTA in assessing renal artery stenosis
- 2006
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Ingår i: Acta Radiologica. - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 47:8, s. 764-774
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To prospectively compare the diagnostic accuracy of duplex ultrasonography, captopril renography, computed tomography angiography (CTA), and 3D Gd magnetic resonance angiography (MRA) in diagnosing hemodynamically significant renal artery stenosis (RAS). Material and Methods: The standard of reference was measurement of transstenotic pressure gradient. Fifty-eight hypertensive patients with suspicion of RAS were evaluated, when possible, by all five techniques. Sensitivity and specificity to detect RAS were compared for each technique on both a patient and kidney basis. Discrepancies were evaluated separately and classified as borderline, method dependent, or operator dependent. Results: The prevalence of RAS was 77%. The sensitivity/specificity of ultrasonography, captopril renography, CTA, and MRA in detecting kidneys with RAS was 73/71%, 52/63%, 94/62%, and 93/91%, respectively. Ultrasonography had a significantly lower sensitivity than CTA and MRA (P < 0.001) but higher than captopril renography (P = 0.013). Borderline RAS was the main cause for discrepancies. Conclusion: MRA and CTA were significantly better than duplex ultrasonography and captopril renography in detecting hemodynamically significant RAS. The ultrasonography criteria for RAS based on the evaluation of renal peak systolic velocity and renal/aortic ratio are questionable. Captopril renography cannot be recommended for assessing RAS.
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| 8. |
- Holmer, Helene, et al.
(författare)
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Fracture incidence in GH-deficient patients on complete hormone replacement including GH
- 2007
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 0884-0431 .- 1523-4681. ; 22:12, s. 1842-1850
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Tidskriftsartikel (refereegranskat)abstract
- Fracture risk in GHD patients is not definitely established. Studying fracture incidence in 832 patients on GH therapy and 2581 matched population controls, we recorded a doubled fracture risk in CO GHD women, but a significantly lower fracture risk in AO GHD men. Introduction: The objective of this study was to evaluate fracture incidence in patients wilh confirmed growth hormone deficiency (GHD) on replacement therapy (including growth hormone [GH]) compared with population controls, while also taking potential confounders and effect modifiers into account. Materials and Methods: Eight hundred thirty-two patients with GHD and 2581 matched population controls answered a questionnaire about fractures and other background information. Incidence rate ratio (IRR) and 95% CI for first fracture were estimated. The median time on GH therapy for childhood onset (CO) GHD men and women was 15 and 12 yr, respectively, and 6 and 5 yr for adult onset (AO) GHD men and women, respectively. Results: A more than doubled risk (IRR, 2.29; 95% CI, 1.23-4.28) for nonosteoporotic fractures was recorded in women with CO GHD, whereas no risk increase was observed among CO GHD men (IRR. 0.61) and AO GHD women (IRR, 1.08). A significantly decreased incidence of fractures (IRR, 0.54; 95% CI 0.34-0.86) was recorded in AO GHD men. Conclusions: Increased fracture risk in CO GHD women can most likely be explained by interaction between oral estrogen and the GH-IGF-I axis. The adequate substitution rate of testosterone (90%) and GH (94%) may have resulted in significantly lower fracture risk in AO GHD men.
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| 9. |
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| 10. |
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| 11. |
- Hägg, Göran, et al.
(författare)
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Fysisk belastning
- 2008. - 1
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Ingår i: Arbete och teknik på människans villkor. - Stockholm : Prevent. - 9789173650373 ; , s. 129-188
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 12. |
- Hägg, Göran M., et al.
(författare)
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Adapting the force characteristics of a staple gun to the human hand
- 2015
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Ingår i: Applied Ergonomics. - : Elsevier. - 0003-6870 .- 1872-9126. ; 50, s. 133-138
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Tidskriftsartikel (refereegranskat)abstract
- Three prototype staple guns with modified force characteristics were compared with a commercially available standard staple gun with a linearly increasing force resistance during squeezing. The force characteristics of the prototypes were more or less adapted to the force characteristics of the human hand, and in one of the staple guns the general force level was also reduced by one third. Evaluation instruments were electromyography of the forearm flexors and extensors, subjective rating of forearm exertion and subjects' free comments about the four tools. Twelve professional craftsmen were recruited as test subjects. The results show significantly lower readings for two of the three prototypes compared with the standard gun in electromyography as well as subjective ratings. The squeezing times are also reduced for two of the prototypes. It is concluded that the choice of force characteristics of a staple gun is important both to minimize forearm muscular exertion and to increase tool efficiency.
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| 13. |
- Hägg, Göran M, et al.
(författare)
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Belastningar i städyrket - vilka är de och hur kan belastningen minskas?
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I storleksordningen 60 % av alla städare har ont varje vecka. Ytterligare i storleksordningen 20-25 % har ont ibland. Intervjuer med städare (se Bilaga 5) samt tidigare med arbetsskadade städare visar att besvären är vanliga och ofta uppkommer gradvis. Besvären märks mest efter arbetet, varför sambandet med arbetet inte alltid är tydligt. Om inget görs, kan besvären förvärras och leda till en mer bestående skada och/eller sjukfrånvaro. Rapporten beskriver belastningar vid olika arbetsmoment som förekommer vid städning samt vid städning av några vanliga lokaltyper som kontor, sjukhus och vårdcentraler, skolor och daghem, samt åtgärder som minskar belastningen. De åtgärder som krävs för att minska belastningen är: - Mer varierade arbetsuppgifter - Moderna städmetoder. Svabbning och våtmoppning är direkt olämpliga och bör användas endast i undantagsfall. - Bra städredskap, anpassade till arbetsuppgiften. - En organisation som inte överbelastar städare och som fördelar tunga arbetsuppgifter på flera. - Att städare har utbildning i och tillämpar god arbetsteknik. - Att lokalernas inredning är städvänlig. - Att lokalernas utformning är städvänlig - Att städare och deras arbetsledare och chefer uppmärksammar när någon börjar få ont och vidtar tidiga åtgärder för att minska belastningen Rapportens slutsats är att många aktörer behöver samverka för att minska städarnas belastning, bl a företag som upphandlar städtjänster, städarbetsgivare, städare, brukare av lokaler (som städas av städare), inredare och arkitekter.
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| 14. |
- Hägg, Göran M., et al.
(författare)
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How do different temperatures affect knife force?
- 2015
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Ingår i: The Ergonomics Open Journal. - : Bentham Open. - 1875-9343. ; :8, s. 27-31
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Tidskriftsartikel (refereegranskat)abstract
- Meat cutters have long since claimed that knife forces increase with lower meat temperatures. This study was performed to find out what effects the meat temperature has on cutting forces. In addition, the same issue was addressed for pure fat. One hundred and forty four samples of lean meat and of fat respectively were collected and put overnight inone of three refrigerators with temperatures 2, 7 and 12°C, 48 in each. These samples were cut while measuring cutting forces in an Anago KST Sharpness Analyzer machine. The results show that there were no significant differences in knife forces concerning lean meat at the three temperatures. However, the force in pure fat at 2°C was significantly increased by 30% compared to the other temperatures. The forces in fat were generally three times higher than for lean meat, regardlessof temperature.
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| 15. |
- Hägg, Göran M., et al.
(författare)
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Isotonic and isoelectric endurance tests for the upper trapezius muscle
- 1997
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Ingår i: European Journal of Applied Physiology and Occupational Physiology. - : Springer Science and Business Media LLC. - 0301-5548 .- 1432-1025 .- 1439-6319 .- 1439-6327. ; 75:3, s. 263-267
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Tidskriftsartikel (refereegranskat)abstract
- As an alternative to a conventional endurance electromyogram (EMG) test for assessment of muscle capacity in the upper trapezius muscle (isotonic test, IT), an isoelectric test (IE) has been investigated. Nine subjects performed the two endurance tests. The tests were performed with a straight horizontal arm in the plane of the scapula. In IE, EMG amplitude was fed back to the subject and the subject was instructed to maintain a constant EMG activity equal to the level with the arm unsupported. Subjective ratings of local fatigue were obtained during the experiments. The EMG recordings from both tests were analysed for the root mean square value as well as according to the mean power frequency (MPF) technique. All the subjects endured maximal 15 min IE while in IT the median endurance was 11.9 min. Average subjective ratings of perceived fatigue increased more in IT compared to IE. The average normalised MPF curve from IT increased while that from IE was unaffected. There was a significant difference between the MPF results at 6 and 8 min. It is noteworthy that the MPF was higher in IT in spite of a higher accumulated biomechanical load. It was concluded from these studies that the interpretation of decreased MPF as an indicator of increased local muscle fatigue is doubtful at low contraction levels. It is suggested that an IE is a more appropriate method for the functional evaluation of low threshold motor units of the upper trapezius muscle in research into occupational disorders.
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| 16. |
- Hägg, Göran M, et al.
(författare)
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Knife force differences when cutting meat at different temperatures
- 2012
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Ingår i: NES2012. - Stockholm : KTH Royal Institute of Technology. - 9789163711497
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Konferensbidrag (refereegranskat)abstract
- IntroductionMeat cutters in abattoirs is a group with high risks for musculoskeletal disorders. A major reason for this is that they exert high hand forces over a great part of the day when cutting meat. Though meat is refrigerated due to hygienic demands, meat temperature can vary. Meat cutters have claimed that knife forces increase with lower temperatures. This study was performed to find out what effects the meat temperature has on cutting forces. In addition, the same issue was addressed for pure fat.MethodTo be able to do cuts in meat under controlled conditions while measuring cutting forces, a machine, Anago KST Sharpness Analyzer, was used. The machine normally runs a knife at constant speed through a standardized textile ribbon while the force exerted on the ribbon is recorded over time. For this investigation, the ribbon was replaced by a wooden fixture with a 10 mm wide slot where the knife could pass and where meat samples could be fixed.Meat obtained from hind loin and fat tissue of pork was cut into 5 cm long, 4 cm wide and 2 cm thick samples. The meat fibre orientation was aligned with the long axis of the sample. When fixated in the fixture and the machine was started, the knife made a 4 cm long cut through 2 cm thick meat or fat.One hundred and forty four samples of meat and as many of fat were collected and put overnight in one of three refrigerators with temperatures 2, 7 and 12 °C, 48 in each. Well sharpened standard knifes were used for the tests. The knife was changed after 24 cuts. During the procedure samples were taken directly from the refrigerator and put into the fixture and tested immediately. The sample order was generally 2, 7, 12 °C to avoid systematic effects of a gradually blunter knife.ResultsThere were no significant differences in knife forces at the three meat temperatures. The forces for fat were in average about three times higher than the meat forces. There was no significant difference between forces in fat at 7 and 12 °C. However there was a strongly significant difference between these two groups and the 2 °C fat group. The force was about 30% higher compared to the forces at 7 and 12 °C in fat.ConclusionIn the range 2-12 °C there are no differences in meat. For fat there are no differences in the range 7-12 °C while the force increases about 30% when going from 7 to 2 °C.
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| 17. |
- Hägg, Göran M, et al.
(författare)
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Physical load
- 2009. - 1. uppl.
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Ingår i: Work and technology on human terms. - Stockholm : Prevent. - 9789173650588
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 18. |
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| 19. |
- Hägg, Göran, et al.
(författare)
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Metoder och arbetssätt för arbetsmiljöarbete
- 2006
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Ingår i: Arbete och Hälsa. - : Arbetslivsinstitutet. - 0346-7821. - 9170457948 ; , s. 24-42
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 20. |
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| 21. |
- Hägg, Göran, et al.
(författare)
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Physical load in cleaning work : a review of strenuous work tasks
- 2008
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Konferensbidrag (refereegranskat)abstract
- An action program with the aim to reduce work injuries and disorders among Swedish cleaners is presently carried out. Several sub-projects are accomplished within the project frame. In this paper, findings in several sub-projects regarding physical work load in cleaning work are summarized. Main data collection methods have been VIDAR-filming, interviews and questionnaires. Supplementary EMG measurements, biomechanical analysis with computer models and systematic observations with the OWAS method have also been performed. In total 61 cleaners have been studied in different ways encompassing all major types of cleaning work. The results show very few single tasks exhibit loads that from a strict biomechanical standpoint are injurious when performed a few times while repetitive monotonous tasks and awkward body postures are very frequent. Common repetitive tasks seen in most types of cleaning are mopping and dusting/wiping of various surfaces, often in awkward postures. Other common strenuous tasks are making beds in hotels, trains and cruise ships, handling of waste baskets and bags, cleaning of toilets and bathrooms and cleaning of stairs. The loads in some of these tasks are unnecessarily high due to the use of obsolete equipment and methods. Organizational issues are also important factors determining the total load on cleaners. Thorough cleaning campaigns on top of daily routines and gradual downsizing of staff with unchanged duties are examples of such issues. Obstacles caused by architecture, interior design and choice of furniture are also causing strenuous tasks.
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| 22. |
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| 23. |
- Hägg, Linus, et al.
(författare)
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Estimating the neutron yield in a deuterium plasma with the JET neutron camera
- 2023
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Ingår i: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 94:7
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Tidskriftsartikel (refereegranskat)abstract
- The JET neutron camera is a well-established detector system at JET, which has 19 sightlines each equipped with a liquid scintillator. The system measures a 2D profile of the neutron emission from the plasma. A first principle physics method is used to estimate the DD neutron yield that is based on JET neutron camera measurements and is independent of other neutron measurements. This paper details the data reduction techniques, models of the neutron camera, simulations of neutron transport, and detector responses used to this end. The estimate uses a simple parameterized model of the neutron emission profile. The method makes use of the JET neutron camera’s upgraded data acquisition system. It also accounts for neutron scattering near the detectors and transmission through the collimator. These components together contribute to 9% of the detected neutron rate above a 0.5 MeVee energy threshold. Despite the simplicity of the neutron emission profile model, the DD neutron yield estimate falls on average within 10% agreement with a corresponding estimate from the JET fission chambers. The method can be improved by considering more advanced neutron emission profiles. It can also be expanded to estimate the DT neutron yield with the same methodology.
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| 24. |
- Hägg, P Göran T
(författare)
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An Institutional Analysis of Insurance Regulation - The Case of Sweden
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis is a broad attempt to analyse economic forces behind, and economic rationales for, institutions that constrain the organisation and operation of insurance companies. The basic task is threefold: (i) to develop institutional theory by providing an outline of a transaction cost explanation of the origin of, and the rationale for, institutions that constrain the organisation and the operation of insurance organisations; (ii) to apply our institutional theory and explain recorded institutional structures in order to make them intelligible with respect to the contractual context in which they have been nested; and (iii) to appraise the explanatory power of our institutional theory with respect to conventional economic theories on the economics of public regulation. In the first part, we analyse the decision dilemma of consumers of whether to place trust in an insurer. The analytical tool has been a one-sided, dynamic Prisoner's Dilemma Game. One basic result is that there are contractual settings where spontaneous market mechanisms may fail to bring about an efficient level of transaction because of credibility problems of an industry. We have formally analysed the prime move dilemma and informally discussed incidents of misguided trust. The prime move dilemma refers to a situation where consumers, because of incomplete information, are unable to rank the quality of insurers and refrain from exchange because of a too low level of trust. The prime move problem may prevent the market from evolving. Misguided trust of consumers refers to the situation where consumers are unable to rank the quality of individual insurers but still find the category of companies trustworthy, Misguided trust is a contractual problem for an industry if incidents of failed performance by a few companies negatively affect consumers' average expectation about the trustworthiness of the entire industry. The market for insurance may, then, contract. The analysis creates a basis for novel hypotheses about the origin of insurance regulation. In the case of a prime move dilemma, public regulation may be requested by an industry because distrust prevents mutually beneficial exchange on risks. In the case of misguided trust, public regulation may be requested because the conduct of low quality comapnies damages the joint credibility of the industry. In the second part, we outline the evolution of recorded Swedish institutions of insurance starting in the late Middle Ages and ending in the early 20th century. We argue that our institutional analysis explains recorded developments to a high degree, as well as the core structure of today's regulatory system of insurance. Common rationales with the design of insurance institutions have been to invoke trust, protect relations involving trust, economise on transaction costs and promote further exchange on risks. Then, we contrast our institutional analysis with conventional economic theory - the public interest- and the special interest theory. We argue that the examined history lends strong support to our institutional theory, support to the special interest theory, and insignificante support to the special interest theory.
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| 25. |
- Hägg, Sara, et al.
(författare)
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Carotid Plaque Age Is a Feature of Plaque Stability Inversely Related to Levels of Plasma Insulin
- 2011
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:4, s. e18248-
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Tidskriftsartikel (refereegranskat)abstract
- Background: The stability of atherosclerotic plaques determines the risk for rupture, which may lead to thrombus formation and potentially severe clinical complications such as myocardial infarction and stroke. Although the rate of plaque formation may be important for plaque stability, this process is not well understood. We took advantage of the atmospheric C-14-declination curve (a result of the atomic bomb tests in the 1950s and 1960s) to determine the average biological age of carotid plaques. Methodology/Principal Finding: The cores of carotid plaques were dissected from 29 well-characterized, symptomatic patients with carotid stenosis and analyzed for C-14 content by accelerator mass spectrometry. The average plaque age (i.e. formation time) was 9.6+/-3.3 years. All but two plaques had formed within 5-15 years before surgery. Plaque age was not associated with the chronological ages of the patients but was inversely related to plasma insulin levels (p=0.0014). Most plaques were echo-lucent rather than echo-rich (2.2460.97, range 1-5). However, plaques in the lowest tercile of plaque age (most recently formed) were characterized by further instability with a higher content of lipids and macrophages (67.8+/-12.4 vs. 50.4+/-6.2, p=0.00005; 57.6+/-26.1 vs. 39.8+/-25.7, p<0.0005, respectively), less collagen (45.3+/-6.1 vs. 51.1+/-9.8, p<0.05), and fewer smooth muscle cells (130+/-31 vs. 141+/-21, p<0.05) than plaques in the highest tercile. Microarray analysis of plaques in the lowest tercile also showed increased activity of genes involved in immune responses and oxidative phosphorylation. Conclusions/Significance: Our results show, for the first time, that plaque age, as judge by relative incorporation of C-14, can improve our understanding of carotid plaque stability and therefore risk for clinical complications. Our results also suggest that levels of plasma insulin might be involved in determining carotid plaque age.
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| 26. |
- Hägg Samuelsson, Ulrika, 1973, et al.
(författare)
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Gene expression profile and aortic vessel distensibility in voluntarily exercised spontaneously hypertensive rats: potential role of heat shock proteins
- 2005
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Ingår i: Physiol Genomics. - 1531-2267 .- 1094-8341. ; 22:3, s. 319-26
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Tidskriftsartikel (refereegranskat)abstract
- Physical exercise is considered to be beneficial for cardiovascular health. Nevertheless, the underlying specific molecular mechanisms still remain unexplored. In this study, we aimed to investigate the effects of voluntary exercise on vascular mechanical properties and gene regulation patterns in spontaneously hypertensive rats. By using ultrasound biomicroscopy in an ex vivo perfusion chamber, we studied the distensibility of the thoracic aorta. Furthermore, exercise-induced gene regulation was studied in aortae, using microarray analysis and validated with real-time PCR. We found that distensibility was significantly improved in aortas from exercising compared with control rats (P < 0.0001). Exercising rats demonstrated a striking pattern of coordinated downregulation of genes belonging to the heat shock protein family. In conclusion, voluntary exercise leads to improved vessel wall distensibility and reduced gene expression of heat shock protein 60 and 70, which may indicate decreased oxidative stress in the aortic vascular wall.
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| 27. |
- Hägg Samuelsson, Ulrika, 1973, et al.
(författare)
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Physical exercise capacity is associated with coronary and peripheral vascular function in healthy young adults.
- 2005
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Ingår i: American journal of physiology. Heart and circulatory physiology. - : American Physiological Society. - 0363-6135 .- 1522-1539. ; 289:4
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Tidskriftsartikel (refereegranskat)abstract
- Short-term exercise training has been shown to improve cardiovascular function, whereas long-term effects of a physically active lifestyle, on coronary artery function in particular, are still not well studied. We explored possible relationships between physical exercise capacity and coronary and peripheral vascular function in healthy young adults. Twenty-nine healthy young male and female volunteers participated in the study. They underwent 1) basic clinical and echocardiographic characterization, 2) coronary flow velocity reserve (CFVR) measurement of the left anterior descending coronary artery (LAD), 3) common carotid artery (CCA) intima-media thickness (IMT) measurement, 4) assessment of CCA stiffness index (SI), 5) forearm flow-mediated vasodilation (FMD), and 6) submaximal exercise test. The calculated weight-adjusted maximal oxygen uptake capacity (Vo(2 max)(c)) was positively correlated to LAD CFVR and inversely correlated to IMT and SI. Also, subjects with high compared with moderate exercise capacity had higher FMD. In addition, subjects with LAD CFVR in the upper median had greater ratios between endothelium-dependent and -independent vasodilation in the forearm and lower SI in CCA. High exercise capacity due to a physically active lifestyle is associated with high coronary and peripheral artery function, indicating an early protective role of physical exercise for cardiovascular health.
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| 28. |
- Hägg Samuelsson, Ulrika, 1973, et al.
(författare)
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Voluntary physical exercise and coronary flow velocity reserve: a transthoracic colour Doppler echocardiography study in spontaneously hypertensive rats
- 2005
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Ingår i: Clin Sci (Lond). - 0143-5221. ; 109:3, s. 325-34
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, we have developed and demonstrated a coronary artery imaging protocol in rats using transthoracic high-frequency CDE (colour Doppler echocardiography) to investigate the potential direct effects of exercise on CFVR (coronary flow velocity reserve). SHR (spontaneously hypertensive rats) performed voluntary exercise for 6 weeks. Rats were then submitted to ultrasonographic examination and CFVR measurements. The LAD (left anterior descending coronary artery) was visualized using transthoracic CDE in a modified parasternal long-axis view. Doppler measurement was made in mid-LAD during baseline and adenosine-induced hyperaemic condition. Gene and protein expression in cardiac tissue were studied using real-time PCR and immunohistochemistry. Adenosine infusion significantly (P<0.001, as determined by ANOVA) decreased HR, without affecting blood pressure in anaesthetized SHR. A significantly greater adenosine dose-dependent response was seen in exercised rats compared with controls (P=0.02, as determined by ANOVA). The baseline flow velocity in mid-LAD was 0.33+/-0.06 and 0.41+/-0.14 m/s in the exercised and control animals respectively (P value was not significant). The maximum adenosine-induced response was reached at a dose of 140 microg.kg-1 of body weight.min-1, and CFVR averaged at 2.6+/-0.53 and 1.5+/-0.24 in exercised and control animals respectively (P<0.01). Gene expression of CuZnSOD was up-regulated by 21% in exercised animals compared with controls (1.1+/-0.16 compared with 0.89+/-0.09; P<0.01), whereas eNOS expression was unchanged. In conclusion, CFVR in rats can be non-invasively assessed using CDE with high feasibility. Physical exercise is associated with improved CFVR and antioxidative capacity in SHR.
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| 29. |
- Hägg Samuelsson, Ulrika, 1973, et al.
(författare)
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Voluntary physical exercise-induced vascular effects in spontaneously hypertensive rats
- 2004
-
Ingår i: Clin Sci (Lond). - 0143-5221. ; 107:6, s. 571-81
-
Tidskriftsartikel (refereegranskat)abstract
- Forced training has been shown to have beneficial vascular effects in various animal exercise models. In the present study, we explored possible physiological and molecular effects of voluntary physical exercise on various vascular beds. SHR (spontaneously hypertensive rats) performed voluntary exercise for 5 weeks in a computerized wheel cage facility. Ex vivo myograph studies revealed an increased sensitivity of the ACh (acetylcholine)-mediated vasodilation in resistance arteries of the exercised animals (ED50=15.0+/-3.5 nmol/l) compared with the controls (ED50=37.0+/-8.8 nmol/l; P=0.05). The exercise/control difference was abolished after scavenging reactive oxygen radicals. In conduit arteries, ACh induced a similar vasodilatory response in both groups. The in vivo aortic wall stiffness, assessed by means of Doppler tissue echography, was significantly lower in the exercising animals than in controls. This was demonstrated by significantly increased peak systolic aortic wall velocity (P=0.03) and the velocity time integral (P=0.01) in exercising animals compared with controls. The relative gene expression of eNOS (endothelial nitric oxide synthase) was similar in both groups of animals, whereas Cu/ZnSOD (copper/zinc superoxide dismutase) gene expression was significantly increased (+111%; P=0.0007) in the exercising animal compared with controls. In conclusion, voluntary physical exercise differentially improves vascular function in various vascular beds. Increased vascular compliance and antioxidative capacity may contribute to the atheroprotective effects associated with physical exercise in conduit vessels.
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| 30. |
- Johansson, Maria E, 1977, et al.
(författare)
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Haemodynamically significant plaque formation and regional endothelial dysfunction in cholesterol-fed ApoE-/- mice
- 2005
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Ingår i: Clinical Science. - 0143-5221 .- 1470-8736. ; 108:6, s. 531-8
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Tidskriftsartikel (refereegranskat)abstract
- Flow-mediated vasodilation is suggested as one of the mechanisms involved in arterial expansive remodelling, which is thought to be a defence mechanism in atherogenesis. In the present study, we tested the hypothesis that lumen obstructive plaque formation is associated with failure of NO (nitric oxide)-dependent vasodilation in conduit vessels. Cardiac function and aortic root flow velocities were assessed using high-resolution echocardiography and two-dimensional-guided pulsed Doppler in ApoE(-/-) (apolipoprotein E-deficient) mice fed a standard or high-cholesterol diet. Endothelial function in the proximal and mid-descending aortic regions was studied using a myograph technique. Flow velocity at the aortic root of cholesterol-fed ApoE(-/-) mice was significantly increased as a result of lumen narrowing, detected via histological analysis. NO-dependent vasodilatory responses were selectively impaired in the atherosclerosis-prone vascular regions in cholesterol-fed ApoE(-/-) mice. In conclusion, consumption of a high-cholesterol diet results in lumen obstructive plaque formation in ApoE(-/-) mice, which significantly alters aortic root haemodynamics. This phenomenon is associated with impaired NO-dependent vasodilation in vessel segments known to be prone to atherosclerosis.
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| 31. |
- Kihlberg, Steve, et al.
(författare)
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Arbete och Hälsa
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- En ergonomisk och teknisk utvärdering genomfördes av en förändring av produktionssystemet i ett elektronikföretag som innebar en ökad automatisering. Själva förändringsprocessen utvärderades också.Automatiseringen av den manuella monteringen och transporten minskade exponeringstiden för manuell montering på systemnivå samt ökade produktiviteten. För den kvarstående manuella monteringen ökade dock repetitiviteten och ensidigheten. Montörerna upplevde också att den psykiska arbetsbelastningen var större i det nya systemet jämfört med det gamla. De ansåg också att de manuella monteringsstationerna som helhet var dåliga arbetsuppgifter.I den studerade förändringsprocessen var bristen på kontinuitet i arbetsledning ett av avdelningens huvudproblem. Arbetsledaren fick också sätta sin prägel på hur produktionsmålen skulle uppfyllas och hur arbetsförhållandena skulle utformas. Därigenom blev det arbetsledaren och inte den handlingsplan med arbetsrotation som en arbetsorganisationsgrupp utformade som avgjorde hur arbetsorganisationen utformades.
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| 32. |
- Kihlberg, Steve, et al.
(författare)
-
Ett produktionssystem under förändring - ergonomisk och teknisk utvärdering
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- En ergonomisk och teknisk utvärdering genomfördes av en förändring av produktionssystemet i ett elektronikföretag som innebar en ökad automatisering. Själva förändringsprocessen utvärderades också. Automatiseringen av den manuella monteringen och transporten minskade exponeringstiden för manuell montering på systemnivå samt ökade produktiviteten. För den kvarstående manuella monteringen ökade dock repetitiviteten och ensidigheten. Montörerna upplevde också att den psykiska arbetsbelastningen var större i det nya systemet jämfört med det gamla. De ansåg också att de manuella monteringsstationerna som helhet var dåliga arbetsuppgifter. I den studerade förändringsprocessen var bristen på kontinuitet i arbetsledning ett av avdelningens huvudproblem. Arbetsledaren fick också sätta sin prägel på hur produktionsmålen skulle uppfyllas och hur arbetsförhållandena skulle utformas. Därigenom blev det arbetsledaren och inte den handlingsplan med arbetsrotation som en arbetsorganisationsgrupp utformade som avgjorde hur arbetsorganisationen utformades.
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| 33. |
- Kihlstedt, Annika, et al.
(författare)
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Checkout cashier work and counter design : Video movement analysis, musculoskeletal disorders and customer interaction
- 2011
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 41:3, s. 201-207
-
Tidskriftsartikel (refereegranskat)abstract
- This study was conducted in order to analyse checkout cashiers' movements at a checkout counter during interaction with customers and the prevalence of work-related stress and musculoskeletal disorders in checkout cashiers. In one shop, six cashiers were videotaped during the workday, and 50 cashiers from seven shops from the same chain of stores responded a questionnaire. Cashier activities and movements, customer interaction and counter design issues were analysed from the video data. Prevalence of work-related stress and musculoskeletal disorders was obtained from the questionnaire. It was found that 76% of all items were manually turned or angled. With a better adjustment of the scanner and a standardised positioning of the EAN-code, many of these movements could be avoided. Furthermore the prevalence of musculoskeletal disorders was quite high (68% for the neck). The questionnaire results showed that many cashiers experienced stress, giving a high percentage of cashiers in the "dedication under pressure" group. The behaviour of the customers was the major cause of stress. Other sources of stress arose from bad design or function of the computer system or other technical equipment. Relevance to industry: In this study several problems regarding cashier work were identified and solutions, relevant to counter and package designers, shop managers and cashiers are suggested. Data obtained on cashier movements and prevalence of musculoskeletal disorders are given.
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| 34. |
- Kumar, Rupesh, et al.
(författare)
-
Evaluation of muscular activity while mopping floor on two different types of floor
- 2008
-
Konferensbidrag (refereegranskat)abstract
- In cleaning occupations, about 80% of all cleaning tasks are done by manual cleaning tools, and about 30%-35% of working time is spent on mopping floors. Cleaning is considered as a physically demanding and strenuous job. This study examines the effects of mopping on polished and non-polished linoleum floors in school classrooms in terms of muscular activity and subjective awareness. Ten professional cleaners volunteered for this study and surface electromyography (sEMG) was recorded from six muscle groups; left and right wrist extensor, right and left anterior deltoid and right and left upper trapezius. The cleaners were randomly assigned a type of floor to be used in each test. The cleaners performed the mopping task for both polished and non-polished floors at their normal working rate. The results show no significant difference (p<0.05) in muscular activity while mopping on the polished floor compared to the non-polished floor; however, the cleaners rated the polished floor more comfortable to mop.
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| 35. |
- Kumar, Rupesh, et al.
(författare)
-
Muscular activity during staircase cleaning while using an easily adjustable and a non-adjustable mop stick
- 2008
-
Konferensbidrag (refereegranskat)abstract
- Professional cleaners are known to experience considerable musculoskeletal problems due to the static muscular work that have to be maintained throughout their working period as well as those due to highly repetitive movements of the arms and hands. About 80% of the cleaning job is done with the manual cleaning tool. In this study, staircase cleaning was studied and analyzed with special focus on muscular load differences resulting from using an easily adjustable as opposed to a non-adjustable mop stick. Thirteen professional cleaners participated in this study. Surface electromyography (sEMG) was recorded from six muscle groups (left and right wrist extensor, right and left middle deltoid and right and left upper trapezius) while cleaners performed the staircase cleaning task at their normal pace for about five minutes using the easily adjustable and the non adjustable mop stick in random order. At the end of each test the cleaners rated their perceived exertion on the Borg scale (0-10) for the upper part of the body. The results showed significantly higher mean sEMG activity recorded from the right middle deltoid and right upper trapezius while using the non-adjustable stick as compared to the easily adjustable stick (p<0.05). sEMG activity from the left middle deltoid and left upper trapezius showed no significant difference as all participating cleaners were right handed. The cleaners rated less exertion in the upper body parts while using the adjustable mop stick compared to the non-adjustable mop stick. The adjustable stick was also found to be more comfortable to use. It is concluded that while using a non-adjustable mop stick cleaners were compelled to adopt their right hand arm in abducted position in order to steer the mop while cleaning the staircase.
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| 36. |
- Mak, Jonathan K. L., et al.
(författare)
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Development of an Electronic Frailty Index for Hospitalized Older Adults in Sweden
- 2022
-
Ingår i: The journals of gerontology. Series A, Biological sciences and medical sciences. - : Oxford University Press. - 1079-5006 .- 1758-535X. ; 77:11, s. 2311-2319
-
Tidskriftsartikel (refereegranskat)abstract
- Background Frailty assessment in the Swedish health system relies on the Clinical Frailty Scale (CFS), but it requires training, in-person evaluation, and is often missing in medical records. We aimed to develop an electronic frailty index (eFI) from routinely collected electronic health records (EHRs) and assess its association with adverse outcomes in hospitalized older adults. Methods EHRs were extracted for 18 225 patients with unplanned admissions between 1 March 2020 and 17 June 2021 from 9 geriatric clinics in Stockholm, Sweden. A 48-item eFI was constructed using diagnostic codes, functioning and other health indicators, and laboratory data. The CFS, Hospital Frailty Risk Score, and Charlson Comorbidity Index were used for comparative assessment of the eFI. We modeled in-hospital mortality and 30-day readmission using logistic regression; 30-day and 6-month mortality using Cox regression; and length of stay using linear regression. Results Thirteen thousand one hundred and eighty-eight patients were included in analyses (mean age 83.1 years). A 0.03 increment in the eFI was associated with higher risks of in-hospital (odds ratio: 1.65; 95% confidence interval: 1.54-1.78), 30-day (hazard ratio [HR]: 1.43; 1.38-1.48), and 6-month mortality (HR: 1.34; 1.31-1.37) adjusted for age and sex. Of the frailty and comorbidity measures, the eFI had the highest area under receiver operating characteristic curve for in-hospital mortality of 0.813. Higher eFI was associated with longer length of stay, but had a rather poor discrimination for 30-day readmission. Conclusions An EHR-based eFI has robust associations with adverse outcomes, suggesting that it can be used in risk stratification in hospitalized older adults.
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| 37. |
- Mak, Jonathan K. L., et al.
(författare)
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Two Years with COVID-19 : The Electronic Frailty Index Identifies High-Risk Patients in the Stockholm GeroCovid Study
- 2023
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Ingår i: Gerontology. - : S. Karger. - 0304-324X .- 1423-0003. ; 69:4, s. 396-405
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: Frailty, a measure of biological aging, has been linked to worse COVID-19 outcomes. However, as the mortality differs across the COVID-19 waves, it is less clear whether a medical record-based electronic frailty index (eFI) that we have previously developed for older adults could be used for risk stratification in hospitalized COVID-19 patients. Objectives: The aim of the study was to examine the association of frailty with mortality, readmission, and length of stay in older COVID-19 patients and to compare the predictive accuracy of the eFI to other frailty and comorbidity measures. Methods: This was a retrospective cohort study using electronic health records (EHRs) from nine geriatric clinics in Stockholm, Sweden, comprising 3,980 COVID-19 patients (mean age 81.6 years) admitted between March 2020 and March 2022. Frailty was assessed using a 48-item eFI developed for Swedish geriatric patients, the Clinical Frailty Scale, and the Hospital Frailty Risk Score. Comorbidity was measured using the Charlson Comorbidity Index. We analyzed in-hospital mortality and 30-day readmission using logistic regression, 30-day and 6-month mortality using Cox regression, and the length of stay using linear regression. Predictive accuracy of the logistic regression and Cox models was evaluated by area under the receiver operating characteristic curve (AUC) and Harrell's C-statistic, respectively. Results: Across the study period, the in-hospital mortality rate decreased from 13.9% in the first wave to 3.6% in the latest (Omicron) wave. Controlling for age and sex, a 10% increment in the eFI was significantly associated with higher risks of in-hospital mortality (odds ratio = 2.95; 95% confidence interval = 2.42-3.62), 30-day mortality (hazard ratio [HR] = 2.39; 2.08-2.74), 6-month mortality (HR = 2.29; 2.04-2.56), and a longer length of stay (beta-coefficient = 2.00; 1.65-2.34) but not with 30-day readmission. The association between the eFI and in-hospital mortality remained robust across the waves, even after the vaccination rollout. Among all measures, the eFI had the best discrimination for in-hospital (AUC = 0.780), 30-day (Harrell's C = 0.733), and 6-month mortality (Harrell's C = 0.719). Conclusion: An eFI based on routinely collected EHRs can be applied in identifying high-risk older COVID-19 patients during the continuing pandemic.
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| 38. |
- Marcinkevicius, Benjaminas, et al.
(författare)
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Fuel ion ratio determination using the 14 MeV Tandem neutron spectrometer for JET DTE1 campaign discharges
- 2022
-
Ingår i: Fusion engineering and design. - : Elsevier. - 0920-3796 .- 1873-7196. ; 184
-
Tidskriftsartikel (refereegranskat)abstract
- This paper investigates the determination of the fuel ion ratio nT/ntot in fusion experiments using two different approaches. The methods are applied to plasma discharges from the deuterium-tritium campaign at the Joint European Torus (JET) in 1997. Multiple discharges have been analysed using data acquired with the Tandem (KM2) neutron spectrometer, using a new neutron spectrometer response function and improved line-of-sight information.The two different approaches were generally similar with the exception of the beam slowing down modelling, handled by two different particle transport codes, namely, TRANSP and PENCIL.The results show that nT/ntot can be determined using Tandem neutron spectrometer data; nT/ntot using both of the approaches are consistent and within the uncertainty for a range of studied discharges.The obtained results support previous studies on nT/ntot determination using neutron spectroscopy. In addition, we have shown that PENCIL can be used instead of TRANSP for a range of discharges which could simplify and speed up the estimation of nT/ntot. The possible limitations of the approach using PENCIL could be investigated using different neutron spectrometer data from the 2021 JET deuterium-tritium campaign.A similar spectrometer like Tandem is planned to be operational at ITER and the results of this paper form the first experimental verification of the capability for nT/ntot measurements with such spectrometers. Further research on this could lead to better understanding of these instruments and their limitations before the start of experiments at ITER.
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| 39. |
- Nocente, M., et al.
(författare)
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Fusion product measurements by nuclear diagnostics in the Joint European Torus deuterium-tritium 2 campaign (invited)
- 2022
-
Ingår i: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 93:9
-
Tidskriftsartikel (refereegranskat)abstract
- A new deuterium-tritium experimental, DTE2, campaign has been conducted at the Joint European Torus (JET) between August 2021 and late December 2021. Motivated by significant enhancements in the past decade at JET, such as the ITER-like wall and enhanced auxiliary heating power, the campaign achieved a new fusion energy world record and performed a broad range of fundamental experiments to inform ITER physics scenarios and operations. New capabilities in the area of fusion product measurements by nuclear diagnostics were available as a result of a decade long enhancement program. These have been tested for the first time in DTE2 and a concise overview is provided here. Confined alpha particle measurements by gamma-ray spectroscopy were successfully demonstrated, albeit with limitations at neutron rates higher than some 10(17) n/s. High resolution neutron spectroscopy measurements with the magnetic proton recoil instrument were complemented by novel data from a set of synthetic diamond detectors, which enabled studies of the supra-thermal contributions to the neutron emission. In the area of escaping fast ion diagnostics, a lost fast ion detector and a set of Faraday cups made it possible to determine information on the velocity space and poloidal distribution of the lost alpha particles for the first time. This extensive set of data provides unique information for fundamental physics studies and validation of the numerical models, which are key to inform the physics and scenarios of ITER. Published under an exclusive license by AIP Publishing.
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| 40. |
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| 41. |
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| 42. |
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| 43. |
- Rezagholi, Mahmoud
(författare)
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Cost-Efficient Designs for Assessing Work-Related Biomechanical Exposures
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Work-related disorders due to biomechanical exposures have been subject to extensive research. Studies addressing these exposures have, however, paid limited attention to an efficient use of resources in exposure assessment. The present thesis investigates cost-efficient procedures for assessment of work-related biomechanical exposures, i.e. procedures aiming at a proper balance between statistical and economic performance.Paper I is a systematic review of tools used in literature providing cost-efficient data collection designs. Two main approaches were identified in nine publications, i.e. comparing cost efficiency among alternative data collection designs, and optimizing resource allocation between different stages of data collection, e.g. subjects and samples within subjects. The studies presented, in general, simplified analyses, in particular with respect to economics.Paper II compared the cost-efficiency of four video-based techniques for assessing upper arm postures. The comparison was based both on a comprehensive model of cost and error and additionally on two simplified models. Labour costs were a dominant factor in the cost efficiency comparison. Measurement bias and costs other than labour cost influenced the rank and economic evaluation of the assessment techniques.Paper III compared the cost efficiency of different combinations of direct and indirect methods for exposure assessments. Although a combination of methods could significantly reduce the total cost of obtaining a desired level of precision, the total cost was, in the investigated scenario, lowest when only direct measurements were performed. However, when the total number of measurements was fixed, a combination was the most cost efficient choice.In Paper IV, demand functions were derived for a four-stage measurement strategy with the focus of either minimizing the cost for a required precision, or maximizing the precision for a predetermined budget. The paper presents algorithms for identifying optimal values of measurement inputs at all four stages, adjusted to integers, as necessary for practical application.In summary, the thesis shows that it is important to address all sources of costs and errors associated with alternative measurement designs in any particular study, and that an optimal determination of samples at different stages can be identified in several cases not previously addressed in the literature.
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| 44. |
- Sahlberg, Arne, et al.
(författare)
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Forward modeling of pile-up events in liquid scintillator detectors for neutron emission spectroscopy
- 2021
-
Ingår i: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 92:8
-
Tidskriftsartikel (refereegranskat)abstract
- When using liquid scintillator detectors to measure the neutron emission spectrum from fusion plasmas, the problem of pile-up distortion can be significant. Because of the large neutron rates encountered in many fusion experiments, some pile-up distortion can remain even after applying traditional pile-up elimination methods, which alters the shape of the measured light-yield spectrum and influences the spectroscopic analysis. Particularly, pile-up events appear as a high-energy tail in the measured light-yield spectrum, which obfuscates the contribution that supra-thermal ions make to the energy spectrum. It is important to understand the behavior of such “fast ions” in fusion plasmas, and it is hence desirable to be able to measure their contribution to the neutron spectrum as accurately as possible. This paper presents a technique for incorporating distortion from undetected pile-up events into the analysis of the light-yield spectrum, hence compensating for pile-up distortion. The spectral contribution from undetected pile-up events is determined using Monte Carlo methods and is included in the spectroscopic study as a pile-up component. The method is applied to data from an NE213 scintillator detector at JET and validated by comparing with results from the time-of-flight spectrometer TOFOR, which is not susceptible to pile-up distortion. Based on the results, we conclude that the suggested analysis method helps counteract the problem of pile-up effects and improves the possibilities for extracting accurate fast-ion information from the light-yield spectrum.
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| 45. |
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| 46. |
- Tapper, G, et al.
(författare)
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Reversing mouse buttons reduces finger extensor muscle static load
- 2007
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Ingår i: Proceedings of 39th Annual Congress of the Nordic Ergonomics Society.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper describes an evaluation of an alternative way to use an ordinary computer mouse. The function of the two mouse buttons were switched and the index finger operated the right button for normal clicking while the middle finger rested on the table directly to the right of the mouse. An electromyographic /EMG) evaluation of this alternative hand position in 29 subjects showed that the EMG activity in the extensor digitorum superficialis muscle was lower compared to a normal hand position both when the hand was resting on the mouse as well as during repeated clicking. All subjects showed a lower average EMG level during repeated clicking and 27 subjects reduced their activity when resting the hand on the mouse compared to a normal hand osition on the mouse.
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| 47. |
- Österman, Cecilia, 1971, et al.
(författare)
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Conceptual and Practical Strategy Work to Promote Ergonomics/Human Factors in Sweden
- 2019
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Ingår i: Advances in Intelligent Systems and Computing. - Cham : Springer International Publishing. - 2194-5365 .- 2194-5357. - 9783319960791 ; 821, s. 320-329
-
Konferensbidrag (refereegranskat)abstract
- This paper describes the results of the conceptual and practical strategy work performed by the Swedish Ergonomics and Human Factors Society (EHSS) today. The rationale of EHSS is to strengthen the quality of ergonomics/human factors knowledge and practice in Sweden and form a multidisciplinary platform across disciplines and professions for collaboration and for knowledge sharing. EHSS gathers about 350 members, representing different occupations in industry, academia and the public sector. Together, EHSS members hold knowledge and experience in physical, cognitive and organizational ergonomics and its application in working life and society. The overall aim of this paper is to inspire related societies and stakeholders to initiate discussions about strategies and future projects that allow for collaboration and knowledge sharing. Proposedly follow the EHSS model where we have formed a multidisciplinary platform for collaboration across disciplines and professions. The activities initiated and supported by EHSS are one step towards broadening the knowledge and application of HFE in Sweden, and to comprise new arenas of specialization. By participating in the key areas in society such as teaching, standardization, product development and occupational safety and health, the work of EHSS is one piece of the puzzle to improve human activities in the future. The vision is that together, we can improve safety, efficiency and well-being for all.
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