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1.	Alm, Erik, 1980-, et al. (författare) Automated annotation and quantification of metabolites in (1)H NMR data of biological origin 2012 Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 403:2, s. 443-455 Tidskriftsartikel (refereegranskat)abstract In 1H NMR metabolomic datasets, there are often over a thousand peaks per spectrum, many of which change position drastically between samples. Automatic alignment, annotation, and quantification of all the metabolites of interest in such datasets have not been feasible. In this work we propose a fully automated annotation and quantification procedure which requires annotation of metabolites only in a single spectrum. The reference database built from that single spectrum can be used for any number of 1H NMR datasets with a similar matrix. The procedure is based on the generalized fuzzy Hough transform (GFHT) for alignment and on Principal-components analysis (PCA) for peak selection and quantification. We show that we can establish quantities of 21 metabolites in several 1H NMR datasets and that the procedure is extendable to include any number of metabolites that can be identified in a single spectrum. The procedure speeds up the quantification of previously known metabolites and also returns a table containing the intensities and locations of all the peaks that were found and aligned but not assigned to a known metabolite. This enables both biopattern analysis of known metabolites and data mining for new potential biomarkers among the unknowns.
2.	Almqvist, Erik, et al. (författare) Solving the ADAPT Benchmark Problem - A Student Project Study 2010 Konferensbidrag (refereegranskat)abstract This paper describes a solution to the Advanced Diagnosis and Prognostics testbed (ADAPT) diagnosis benchmark problem. One main objective was to study and discuss how engineering students, with no diagnosis research background, would solve a challenging diagnosis problem. The study was performed within the framework of a final year project course for control engineering students. A main contribution of the work is the discussion on the development process used by the students. The solution is based on physical models of components and includes common techniques from control theory, like observers and parameter estimators, together with established algorithms for consistency based fault isolation. The system is fully implemented in C++ and evaluated, using the DXC software platform, with good diagnosis performance.
3.	Lindgren, Stig-Åke, 1950, et al. (författare) Coverage-dependent frequency for Li-atom vibrations on Cu(111) 1996 Ingår i: Physical Review B. - 2469-9969 .- 2469-9950. ; 54:15, s. 10912 - 10916 Tidskriftsartikel (refereegranskat)abstract Electron-energy-loss spectra recorded for monolayer amounts of Li adsorbed on Cu(111) show a loss peak associated with Li vibrations perpendicular to the substrate. The loss energy shifts from 38 meV at low coverage to 43 meV at 0.3 ML and remains constant for coverages between 0.3 and 0.5 ML. The loss intensity passes a maximum at a Li coverage of 0.15 ML and gradually decreases such that it is difficult to resolve a loss peak at coverages above 0.5 ML. The high loss energy indicates that the adatom resides on the surfaces rather than in substitutional sites. The frequency shift is much too large to be explained by dipole-dipole interactions. The above results are obtained with the evaporation source loaded with the natural Li isotope mixture (92.6% 7Li, 7.4% 6Li). Measurements with 6Li show that the increase of the vibration frequency with increasing coverage is not an isotope effect.
4.	Wahlström, Bengt Hjalmar, 1816-1893 (författare) Stemmata gentium Romanarum. Dissertatio quam ... p. p. B. Hjalm. Wahlström ... et Eric. Aug. Nyblæus ... In audit. Gustav. die XVIII Mart. MDCCCXL h. p. m. s. P. I 1840 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)
5.	Akansel, Serkan, 1983- (författare) Magnetization Dynamics in Ferromagnetic Thin Films : Evaluation of Different Contributions to Damping in Co2FeAl and FeCo Film Structures 2018 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Static and dynamic magnetic properties of Co2FeAl and Fe65Co35 alloys have been investigated. Co2FeAl films were deposited at different temperatures and the deposition parameters were optimized with respect to structural and magnetic properties. As a result, a film with B2 crystalline phase was obtained without any post-annealing process. A lowest magnetic damping parameter of was obtained for the film deposited at 573K. This obtained low value is comparable to the lowest values reported in research literature. After optimizing the deposition parameters of this alloy, different seed layers and capping layers were added adjacent to the Co2FeAl layer and the effect of these layers on the magnetic relaxation was investigated. In addition to adding nonmagnetic layers to Co2FeAl, the dependence of the magnetic damping parameter with respect to the thickness of Co2FeAl was investigated by depositing films with different thicknesses. A temperature dependent study of the magnetic damping parameter was also performed and the measured damping parameters were compared with theoretically calculated intrinsic Gilbert damping parameters. Different extrinsic contributions to the magnetic damping, such as two magnon scattering, spin pumping, eddy-current damping and radiative damping, were identified and subtracted from the experimentally obtained damping parameter. Hence, it was possible to obtain the intrinsic damping parameter, that is called the Gilbert damping parameter.In the second part of the thesis, Fe65Co35 alloys were investigated in terms of static and dynamic magnetic properties. Fe65Co35 films were deposited without and with different seed layers in order to first understand the effect of the seed layer on static magnetic properties of the films, such as the coercivity of the films. Then the films with seed layers yielding the lowest coercivity were investigated in terms of dynamic magnetic properties. Fe65Co35 films with different rhenium dopant concentrations and with ruthenium as the seed and capping layer were also investigated. The purpose of this study was to increase the damping parameter of the films and an increase of about ~230% was obtained by adding the dopant to the structure. This study was performed at different temperatures and after subtraction of the extrinsic contributions to the damping, the experimental values were compared with theoretically calculated values of the Gilbert damping parameter. During the thesis work, magnetic looper and superconducting quantum interference device magnetometers set-ups were used for static magnetic measurements and cavity, broadband in-plane and broadband out-of-plane ferromagnetic resonance set-ups were used for dynamic measurements.
6.	Banuazizi, Seyed Amir Hossein (författare) Determining and Optimizing the Current and Magnetic Field Dependence of Spin-Torque and Spin Hall Nano-Oscillators : Toward Next-Generation Nanoelectronic Devices and Systems 2018 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Spin-torque and spin Hall nano-oscillators are nanoscale devices (about 100 nm) capable of producing tunable broadband high-frequency microwave signals ranging from 0.1 GHz to over 65 GHz that several research groups trying to reach up to 200 - 300 GHz. Their development is ongoing for applications in high-frequency nanoelectronic devices and systems, such as mobile phones, wireless networks, base stations, vehicle radars, and even medical applications.This thesis covers a wide range of characterizations of spin-torque and spin Hall nano-oscillator devices that aim to investigate their current and magnetic field dependency, as well as to suggest improvements in these devices to optimize their application in spintronics and magnonics. The work is primarily based on experimental methods for characterizing these devices by building up new measurement systems, but it also includes numerical and micromagnetic simulations.Experimental techniques: In order to characterize the fabricated nanodevices in a detailed and accurate manner through their electrical and microwave responses, new measurement systems capable of full 3D control over the external magnetic fields will be described. In addition, a new method of probing an operational device using magnetic force microscopy (MFM) will be presented.Spin-torque nano-oscillators: We will describe remarkable improvements in the performance of spin-torque nano-oscillators (STNOs) that enhance their integration capability with applications in microwave systems. In nanocontact (NC-)STNOs made from a conventional spin-valve stack, though with thicker bottom electrodes, it is found the auto-oscillations can be excited with higher frequencies at lower threshold currents, and with higher output powers. We also find that this idea is useful for tuning spin-wave resonance and also controlling the thermal budget. Furthermore, a detailed study of magnetic droplet solitons and spin-wave dynamics in NC-STNOs will be described. Finally, we demonstrate ultra-high frequency tunability in low-current STNOs based on perpendicular magnetic tunnel junctions(p-MTJs).Spin Hall nano-oscillators: Characterizations of spin Hall nano-oscillator(SHNO) devices based on different structures and materials with both conventional and novel methods will be described. A detailed study of the current, temperature, and magnetic field profiles of nanogap SHNOs will be presented. In addition, we show the current and magnetic field dependence of nanoconstriction-based SHNOs.Moreover, it is shown that multiple SHNOs can be serially synchronized, thereby increasing their output power and enhancing the usage of these devices in applications such as neuromorphic computing. We show synchronization of multiple nanoconstriction SHNOs in the presence of a low in-plane magnetic field. Finally, there is a demonstration of the results of a novel method for probing an operationalSHNO using MFM.
7.	Bendix, Marie, 1971-, et al. (författare) Towards a Swedish identity in consultation-liaison (CL) psychiatry and psychosomatics : Re-foundation of the Swedish Association of CL Psychiatry 2018 Ingår i: Journal of Psychosomatic Research. - : Elsevier. - 0022-3999 .- 1879-1360. ; 108, s. 20-21 Tidskriftsartikel (refereegranskat)
8.	Brucas, Rimantas, 1965, et al. (författare) Magnetic and transport properties of Ni81Fe19/Al2O3 granular multilayers approaching the superparamagnetic limit 2007 Ingår i: Journal of Applied Physics. ; 101, s. 073907- Tidskriftsartikel (refereegranskat)
9.	Bärring, Maja, 1988, et al. (författare) Challenges of data acquisition for simulation models of production systems in need of standards 2018 Ingår i: Proceedings - Winter Simulation Conference. - : Institute of Electrical and Electronics Engineers Inc.. - 0891-7736. ; 2018-December, s. 691-702 Konferensbidrag (refereegranskat)abstract In this paper, we analyze the challenges in data acquisition for simulation models of production systems based on two cases from the robotics and aerospace industries. Unlike prior research, we focus not only on the challenges of data acquisition but also on how these challenges affect decisions in production systems. We examine this linkage using the concepts of strategic objectives, decision areas, and internal fit from operations management literature. Empirical findings show that for data acquisition to lead to improved production system performance it is necessary to develop standards. Standards should consider ownership of data by different functions within a manufacturing company, alignment of data to performance measurements, and the connection between data, information, and production decisions. Using these concepts, this paper proposes a set of guidelines that facilitate the standardization of data acquisition for simulation models in production systems. We conclude by discussing the managerial implications of our findings.
10.	Carlsson, Daniel, 1982- (författare) Effects of cold and hand-arm vibration on the peripheral neurosensory and vascular system : an occupational perspective 2017 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Background In Swedish working life, exposure to cold and exposure to hand-arm vibration (HAV) are two common health hazards. Health effects of HAV in the neurosensory, vascular and musculoskeletal systems are collectively denoted hand-arm vibration syndrome (HAVS), and have been thoroughly studied. Effects of cold exposure in terms of effects on the peripheral neurosensory and vascular system are on the contrary limited, especially in an occupational setting. Effects of cold exposure or cold injury have not previously been assessed with quantitative sensory testing (QST). Commonly reported symptoms after exposure to HAV and after cold injuries, includes cold sensitivity and sensation of cold. Cold sensitivity can also occur without previous exposure to vibration or cold and may have a major impact on quality of life. Other possible risk factors for cold sensitivity need to be assessed. Sensation of cold hands could theoretically imply an early manifestation of damage to the neurosensory or vascular system, and therefore be of importance to enable early detection of vascular and neurosensory HAVS. The purpose of this thesis was to increase the knowledge about health effects from cold and HAV on the peripheral neurosensory and vascular system, with an occupational perspective. The aims were: first, to identify and evaluate health effects and sequelae in the peripheral neurosensory and vascular system due to cold injury and cold exposure; second, to investigate if sensation of cold hands is a predictor for future onset of Raynaud's phenomenon or paresthesia; and third, to identify possible risk factors associated with cold sensitivity.Methods A case series on 15 military conscripts with local cold injuries in the hands or feet, involving QST and symptom descriptions, was conducted to investigate the hypothesis that cold injuries can result in similar neurosensory and vascular impairments as in HAVS. To assess health effects of cold exposure, a cohort study on 54 military conscripts in cold winter military training, with cold exposure assessments, was conducted. Possible health effects were assessed after 14 months of military training, containing considerable cold exposure, by means of QST, Finger systolic blood pressure after local cooling (FSBP) and a questionnaire. To investigate if sensation of cold hands is a predictor for vascular or neurosensory HAVS we investigated a cohort of 178 employees at a manufacturing company where HAV was a common exposure. The cohort was followed during 21 years and both vibration exposure and health outcomes were assessed regularly. Questionnaire items were used to assess sensations of cold hands as well as signs of Raynaud’s phenomenon and paresthesia. To identify risk factors for cold sensitivity a case-control study was conducted involving 997iiiparticipants from the general population in northern Sweden. The study was cross-sectional and explored possible risk factors for cold sensitivity.Results Cold injuries and cold exposure were associated with reduced sensibility in QST and increase severity and prevalence of neurosensory and vascular symptoms. Our results did not show any impairment in peripheral blood flow due to cold exposure, detectable by FSBP. The risk of developing Raynaud's phenomenon was increased for workers previously reporting sensation of cold hands (OR 6.3, 95% CI 2.3-17.0). No increased risk for paresthesia in relation to a sensation of cold hands was observed. The identified risk factors for cold sensitivity were frostbite in the hands, rheumatic disease, nerve injury in upper extremities or neck, migraine and vascular disease. When analysing women and men separately, women’s risk factors were frostbite in the hands, rheumatic disease, migraine and cold exposure. Men’s risk factors were frostbite in the hands, vibration exposure and nerve injury in upper extremities or neck. BMI > 25 was a protective factor for both men and women.Conclusion Cold injury and cold exposure are associated with impairments in the neurosensory system, detectable by QST. Symptoms such as sensation of cold hands and white fingers indicate vascular involvement, even though no vascular impairments due to cold exposure could be detected by objective measurements. A sensation of cold hands is a risk factor for development of Raynaud´s phenomenon, but not for paresthesia. At the individual level, reporting cold hands does not appear to be useful information when considering the possibility of a future development of Raynaud’s phenomenon. Frostbite in the hands is a risk factor for cold sensitivity among both women and men. For women rheumatic disease, migraine and cold exposure are also independent risk factors, and for men, exposure to HAV. Being overweight is a protective factor for both women and men.
11.	Carlsson, Daniel, et al. (författare) Neurosensory sequelae assessed by thermal and vibrotactile perception thresholds after local cold injury 2014 Ingår i: International Journal of Circumpolar Health. - : Informa UK Limited. - 1239-9736 .- 2242-3982. ; 73 Tidskriftsartikel (refereegranskat)abstract Background. Local freezing cold injuries are common in the north and sequelae to cold injury can persist many years. Quantitative sensory testing (QST) can be used to assess neurosensory symptoms but has previously not been used on cold injury patients.Objective. To evaluate neurosensory sequelae after local freezing cold injury by thermal and vibrotactile perception thresholds and by symptom descriptions.Design. Fifteen patients with a local freezing cold injury in the hands or feet, acquired during military training, were studied with QST by assessment of vibrotactile (VPT), warmth (WPT) and cold (CPT) perception thresholds 4 months post-injury. In addition, a follow-up questionnaire, focusing on neurovascular symptoms, was completed 4 months and 4 years post-injury.Results. QST demonstrated abnormal findings in one or both affected hands for VPT in 6 patients, for WPT in 4 patients and for CPT in 1 patient. In the feet, QST was abnormal for VPT in one or both affected feet in 8 patients, for WPT in 6 patients and for CPT in 4 patients. Freezing cold injury related symptoms, e. g. pain/discomfort when exposed to cold, cold sensation and white fingers were common at 4 months and persisted 4 years after the initial injury.Conclusions. Neurosensory sequelae after local freezing cold injury, in terms of abnormal thermal and/or vibration perception thresholds, may last at least 4 months after the initial injury. Symptoms such as pain/discomfort at cold exposure, cold sensations and white fingers may persist at least 4 years after the initial injury.
12.	Dahlblom, Mats, et al. (författare) Vertical temperature gradients in apartments with hydronic radiator heating 2019 Ingår i: Cold Climate HVAC 2018 : Sustainable Buildings in Cold Climates - Sustainable Buildings in Cold Climates. - Cham : Springer International Publishing. - 9783030006617 - 9783030006624 ; , s. 575-585 Konferensbidrag (refereegranskat)abstract A vertical temperature stratification normally exists in rooms during the heat-ing season in cold climates. An expression of the gradient in apartments heated by hydronic radiator heating systems with exhaust ventilation has ear-lier been developed assuming a dependency of the outdoor temperature. The expression was used by a public real estate owner when re-calculating meas-ured indoor temperature at 2.1 m above floor to 1.2 m above floor represent-ing the occupancy zone and used for individual metering and billing of space heating cost. To validate the suggested expression temperature measurements have been made at four heights in living rooms in apartments built in the 70’s. The heights includes 0.0, 0.1, 1.1 and 1.7 m above floor. The theoreti-cal expression has been compared to the full-scale measurements and in general the expression overestimates the vertical temperature gradient. The measured gradients are generally very low. The thermal comfort in the aspect of vertical temperature gradient is good for the studied period.
13.	Eklund, Anders, 1986- (författare) Microwave Frequency Stability and Spin Wave Mode Structure in Nano-Contact Spin Torque Oscillators 2016 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract The nano-contact spin torque oscillator (NC-STO) is an emerging device for highly tunable microwave frequency generation in the range from 0.1 GHz to above 65 GHz with an on-chip footprint on the scale of a few μm. The frequency is inherent to the magnetic material of the NC-STO and is excited by an electrical DC current by means of the spin torque transfer effect. Although the general operation is well understood, more detailed aspects such as a generally nonlinear frequency versus current relationship, mode-jumping and high device-to-device variability represent open questions. Further application-oriented questions are related to increasing the electrical output power through synchronization of multiple NC-STOs and integration with CMOS integrated circuits.This thesis consists of an experimental part and a simulation part. Experimentally, for the frequency stability it is found that the slow but strong 1/f-type frequency fluctuations are related to the degree of nonlinearity and the presence of perturbing, unexcited modes. It is also found that the NC-STO can exhibit up to three propagating spin wave oscillation modes with different frequencies and can randomly jump between them. These findings were made possible through the development of a specialized microwave time-domain measurement circuit. Another instrumental achievement was made with synchrotron X-rays, where we image dynamically the magnetic internals of an operating NC-STO device and reveal a spin wave mode structure with a complexity significantly higher than the one predicted by the present theory.In the simulations, we are able to reproduce the nonlinear current dependence by including spin wave-reflecting barriers in the nm-thick metallic, magnetic free layer. A physical model for the barriers is introduced in the form of metal grain boundaries with reduced magnetic exchange coupling. Using the experimentally measured average grain size of 30 nm, the spin wave mode structure resulting from the grain model is able to reproduce the experimentally found device nonlinearity and high device-to-device variability.In conclusion, the results point out microscopic material grains in the metallic free layer as the reason behind the nonlinear frequency versus current behavior and multiple propagating spin wave modes and thereby as a source of device-to-device variability and frequency instability.
14.	Flovik, Vegard, et al. (författare) Tailoring the magnetodynamic properties of nanomagnets using magnetocrystalline and shape anisotropies 2015 Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X .- 2469-9950 .- 2469-9969. ; 92:10 Tidskriftsartikel (refereegranskat)abstract Magnetodynamical properties of nanomagnets are affected by the demagnetizing fields created by the same nanoelements. In addition, magnetocrystalline anisotropy produces an effective field that also contributes to the spin dynamics. We show how the dimensions of magnetic elements can be used to balance crystalline and shape anisotropies, and that this can be used to tailor the magnetodynamic properties. We study ferromagnetic ellipses patterned from a 10-nm-thick epitaxial Fe film with dimensions ranging from 50x150 to 150x450 nm. The study combines ferromagnetic resonance (FMR) spectroscopy with analytical calculations and micromagnetic simulations, and proves that the dynamical properties can be effectively controlled by changing the size of the nanomagnets. We also show how edge defects in the samples influence the magnetization dynamics. Dynamical edge modes localized along the sample edges are strongly influenced by edge defects, and this needs to be taken into account in understanding the full FMR spectrum.
15.	Gustavsson, Erik (författare) Om skolvalsfrågans rättvisedimensioner : En pedagogisk-filosofisk analys 2022 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract This thesis explores how philosophical perspectives of justice can facilitate a critical discussion and a deepened understanding of the school choice issue and how it can be related to fundamental pedagogical ends of education, such as developing children´s autonomy and educating them to become democratic citizens. The methodological approach is based on John Dewey’s view of pragmatism, which argues for an experimental process of inquiry incorporating reflection on alternative lines of action. According to this approach, analyses of Swedish school choice policy are conducted based on three philosophical perspectives of justice: John Rawls’ justice as fairness, Nancy Fraser’s understanding of justice as three-dimensional and participative, and Amartya Sen’s capability approach. These perspectives clarify the relationship and meaning of three value premises that are prominent in the concept of school choice and foundational to liberal democratic societies: individual freedom, pluralism, and equality. Thus, the explorative approach highlights three answers to how the issue of school choice might be viewed from the perspective of justice. These answers are integrated into three criteria that serve as a pragmatistbased understanding of educational matters of justice, suggesting 1) that people should be viewed as active, social, and capable of intelligent change—individual and social—through reflective action; 2) that people should be given equal rights and opportunities to participate in and access influence over how they lead their lives; and 3) that societal organization (as well as the education system) should promote both people’s individual and common potential to act, which presupposes the striving toward full, free communication within and between social groups. Although the analyses of current Swedish school choice policy reveal increased criticism toward the contemporary system of school choice, the expressed policy strategies for dealing with injustice mainly aim to adjust the terms of choice within the realm of a market-based education, not critically examine the market structure, itself. The thesis argues for a renewed conversation about school choice, mirroring the pragmatic approach to inquiry while targeting the inherent democratic, communicative potential of schooling.
16.	Hallman, David, 1979-, et al. (författare) P09-09 Hybrid work and temporal patterns of sedentary behavior in a 24-hour compositional perspective 2022 Ingår i: European Journal of Public Health. - : Oxford Academic. - 1101-1262 .- 1464-360X. ; 32:Suppl2 Tidskriftsartikel (refereegranskat)abstract BackgroundDuring the COVID-19 pandemic, many white-collar workers were requested to exclusively work from home (WFH), which may have affected their sedentary behavior. In Sweden, having less severe restrictions than many other countries, workers were allowed to alternate between WFH and work at the office (WAO), so called hybrid work. Understanding how hybrid work influences total sedentary behavior and its temporal distribution is an important issue for future health promotion. This study aimed to investigate to what extent office workers changed their temporal pattern of sedentary behavior during days WFH compared to WAO, considering age and gender as potential moderators.MethodsData were collected from May to December 2020 in office workers (n = 199). Their mean age was 42 (SD 10) years and 55% were women. Physical behaviors were measured using a thigh-worn accelerometer (AxivityAX3) for seven consecutive days. A diary identified working hours, time-in-bed and days WFH or WAO. Time-use was classified as short (0-5 min), moderate (5-30 min) and long bouts (>30 min) of sedentary behavior (SB), non-SB, and time-in-bed during workdays (WAO and WFH) and non-workdays. We used Compositional data analysis to express data as 24-hour compositions and linear mixed models to estimate difference in 24-hour compositions between day types (within worker), including age and gender as covariates and moderators.ResultsWe found that workdays (WFH and WAO) were associated with proportionally less time-in-bed relative to time awake, more time SB relative to non-SB, and more time in longer relative to shorter sedentary bouts, compared to non-workdays (all p > 0.001). WFH was associated with more time-in-bed relative to awake and more SB relative to non-SB than WAO (p > 0.05), but the differences for sedentary bouts were not significant. Younger workers and women had more SB, and women accumulated more time than men in longer relative to shorter bouts of SB. However, age and gender did not affect differences between day types.ConclusionsWorking from home influenced 24-hour time-use in office workers by increasing sedentary behavior in total, while its temporal pattern was unchanged. Results contribute to evidence that can support organizational policies on hybrid work.
17.	Hallman, David, 1979-, et al. (författare) Symposium: Arbete, individ och nacksmärta : Forskning vid Forte-centret “Kroppen i arbete – från problem till potential” 2018 Ingår i: FALF KONFERENS 2018 Arbetet - problem eller potential för en hållbar livsmiljö? 10-12 juni 2018 i Gävle. - Gävle : Gävle University Press. - 9789188145284 ; , s. 102- Konferensbidrag (refereegranskat)abstract Besvär ifrån kroppens muskler och leder såsom nack- och ryggbesvär är fortfarande ett stort problem inom arbetslivet. Muskuloskeletal diagnos är den vanligaste orsaken till lång sjukfrånvaro inom privat sektor och näst vanligast inom kommuner och landsting. Orsakerna till dessa besvär kan vara relaterade till exponering både under arbete och på fritid, men även till individfaktorer. Vår forskargrupp har en bred ansats för att fylla kunskapsluckor inom detta område och kommer att presentera resultat från flera forskningsprojekt i symposiet Arbete, individ och nacksmärta.Långvarigt sittande har blivit alltmer vanligt förekommande i många yrkesgrupper. Långvarigt sittande och låg fysisk aktivitet har också uppmärksammats som ett betydande hälsoproblem i dagens arbetsliv och även som en möjlig riskfaktor för smärta i nacke-skuldra. Men forskningen om betydelsen av långvarigt sittande för smärta i nacke-skuldra är fortfarande begränsad. Likaså är det oklart om huvudets hållning vid sittandet och nackens funktion, exempelvis nackens rörelsefunktion och styrka, har betydelse för besvärsutveckling. Statiskt arbete med nacken i vridna och böjda positioner misstänks vara en riskfaktor för nack-skuldersmärta i yrken såsom tandläkare, men det är oklart varför vissa exponerade individer drabbas medan andra inte får ont. För de med långvarig smärta krävs ofta rehabiliterande åtgärder, och hur väl dessa åtgärder lyckas kan även det vara beroende av individens fysiska och psykosociala arbetsmiljö. Individens arbetsmiljö påverkar således inte bara risken för om man får besvär utan kan också ha betydelse för hur rehabiliteringen av besvären lyckas.Syftet med detta symposium är att presentera studier från Centrum för belastningsskadeforskning som handlar om nacksmärta i arbetslivet, sammanfatta kunskapsläget inom området och diskutera hur arbetet kan utformas för att bli hållbart och inkluderande. De forskningsexempel som presenteras berör stillasittande och hållning i arbetslivet och dess tänkbara konsekvenser för nacksmärta och hälsa, riskfaktorer för nacksmärta i tandläkaryrket och arbetsmiljöns betydelse för resultatet av rehabilitering vid nacksmärta. Symposiet avslutas med en frågestund och gemensam diskussion.
18.	Hanson, Maj, 1939, et al. (författare) Arrays of elliptical Fe(001) nanoparticles: Magnetization reversal, dipolar interactions, and effects of finite array sizes 2015 Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 2469-9950 .- 2469-9969 .- 1550-235X. ; 92:9 Tidskriftsartikel (refereegranskat)abstract The magnetic properties of arrays of nanoparticles are determined by the interplay between the individual particle properties and the dipolar interactions between them. Here we present a study of arrays of elliptical Fe(001) particles of thickness 10–50 nm. The aspect ratios of the ellipses are 1:3, their short axes a=50, 100, or 150 nm, and the periodicity of the rectangular arrays is either two or four times the corresponding axes of the ellipses. Magnetic measurements together with numerical and micromagnetic calculations yield a consistent picture of the arrays, comprising single-domain nanoparticles. We show that the magnetization reversal, occurring in the range 100–400 mT for fields applied along the long axis, is mainly determined by the properties of the corresponding single Fe ellipses. The interaction fields of the order of tens of mT can be tuned by the array configurations. For the actual arrays the interactions promote switching. For film thicknesses below the Bloch wall width parameter of Fe, lw=22 nm, magnetization reversal occurs without formation of domain walls or vortices. Within this range arrays may be tuned to obtain a well-defined switching field. Two general conclusions are drawn from the calculations: the character of the interaction, whether it promotes or delays magnetization reversal, is determined by the aspect ratio of the array grid, and the interaction strength saturates as the size of the array increases.
19.	Heiden, Marina, et al. (författare) A comparison of two strategies for building an exposure prediction model 2016 Ingår i: Annals of Occupational Hygiene. - : Oxford University Press (OUP). - 0003-4878 .- 1475-3162. ; 60:1, s. 74-89 Tidskriftsartikel (refereegranskat)abstract Cost-efficient assessments of job exposures in large populations may be obtained from models in which “true” exposures assessed by expensive measurement methods are estimated from easily accessible and cheap predictors. Typically, the models are built on the basis of a validation study comprising “true” exposure data as well as an extensive collection of candidate predictors from questionnaires or company data, which cannot all be included in the models due to restrictions in the degrees of freedom available for modeling. In these situations, predictors need to be selected using procedures that can identify the best possible subset of predictors among the candidates. The present study compares two strategies for selecting a set of predictor variables. One strategy relies on stepwise hypothesis testing of associations between predictors and exposure, while the other uses cluster analysis to reduce the number of predictors without relying on empirical information about the measured exposure. Both strategies were applied to the same dataset on biomechanical exposure and candidate predictors among computer users, and they were compared in terms of identified predictors of exposure as well as the resulting model fit using bootstrapped resamples of the original data. The identified predictors were, to a large part, different between the two strategies, and the initial model fit was better for the stepwise testing strategy than for the clustering approach. Internal validation of the models using bootstrap resampling with fixed predictors revealed an equally reduced model fit in resampled datasets for both strategies. However, when predictor selection was incorporated in the validation procedure for the stepwise testing strategy, the model fit was reduced to the extent that both strategies showed similar model fit. Thus, the two strategies would both be expected to perform poorly with respect to predicting biomechanical exposure in other samples of computer users.
20.	Iwarsson, Erik, et al. (författare) Analys av foster-DNA i kvinnans blod: icke-invasiv fosterdiagnostik för blodgrupps- eller könsbestämning 2011 Rapport (övrigt vetenskapligt/konstnärligt)
21.	Jackson, Jennie A., et al. (författare) Is what you see what you get? : Standard inclinometry of set upper arm elevation angles 2015 Ingår i: Applied Ergonomics. - : Elsevier BV. - 0003-6870 .- 1872-9126. ; 47, s. 242-252 Tidskriftsartikel (refereegranskat)abstract Previous research suggests inclinometers (INC) underestimate upper arm elevation. This study was designed to quantify possible bias in occupationally relevant postures, and test whether INC performance could be improved using calibration. Participants were meticulously positioned in set arm flexion and abduction angles between 0 degrees and 150 degrees. Different subject-specific and group-level regression models comprising linear and quadratic components describing the relationship between set and INC-registered elevation were developed using subsets of data, and validated using additional data. INC measured arm elevation showed a downward bias, particularly above 600. INC data adjusted using the regression models were superior to unadjusted data; a subject-specific, two-point calibration based on measurements at 0 and 900 gave results closest to the 'true' set angles. Thus, inclinometer measured arm elevation data required calibration to arrive at 'true' elevation angles. Calibration to a common measurement scale should be considered when comparing arm elevation data collected using different methods.
22.	Jackson, Jennie, et al. (författare) Digging deeper into the assessment of upper arm elevation angles using standard inclinometry 2015 Ingår i: Applied Ergonomics. - : Elsevier. - 0003-6870 .- 1872-9126. ; 51, s. 102-103 Tidskriftsartikel (refereegranskat)
23.	Jonasson, Jenni, et al. (författare) Evidence for a common Spinocerebellar ataxia type 7 (SCA7) founder mutation in Scandinavia 2000 Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 8, s. 918- Tidskriftsartikel (refereegranskat)abstract Spinocerebellar ataxia type 7 (SCA7) is a neuro-degenerative disorder characterised by progressive cerebellar ataxia and macular degeneration. SCA7 is one of the least common genetically verified autosomal dominant cerebellar ataxias (ADCAs) in the world (4.5 to 11.6%), but in Sweden and Finland SCA7 is the most commonly identified form of ADCA. In an inventory of hereditary ataxias in Scandinavia (Sweden, Norway, Denmark and Finland) we identified 15 SCA7 families, eight in Sweden and seven in Finland, while no cases of SCA7 could be found in Norway or Denmark. We examined whether the relatively high frequency of SCA7 families in Sweden and Finland was the result of a common founder effect. Only two out of 15 families could be connected genealogically. However, an extensive haplotype analysis over a 10.2 cM region surrounding the SCAI gene locus showed that all 15 families studied shared a common haplotype over at least 1.9 cM. This strongly suggests that all Scandinavian SCA7 families originate from a common founder pre-mutation.
24.	Le, Quang Tuan, 1976- (författare) Magnetodynamics in Spin Valves and Magnetic Tunnel Junctions with Perpendicular and Tilted Anisotropies 2016 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Spin-torque transfer (STT) effects have brought spintronics ever closer to practical electronic applications, such as MRAM and active broadband microwave spin-torque oscillator (STO), and have emerged as an increasingly attractive field of research in spin dynamics. Utilizing materials with perpendicular magnetic anisotropy (PMA) in such applications offers several great advantages such as low-current, low-field operation combined with high thermal stability. The exchange coupling that a PMA thin film exerts on an adjacent in-plane magnetic anisotropy (IMA) layer can tilt the IMA magnetization direction out of plane, thus creating a stack with an effective tilted magnetic anisotropy. The tilt angle can be engineered via both intrinsic material parameters, such as the PMA and the saturation magnetization, and extrinsic parameters, such as the layer thicknesses. STOs can be fabricated in one of a number of forms—as a nanocontact opening on a mesa from a deposited pseudospin-valve (PSV) structure, or as a nanopillar etching from magnetic tunneling junction (MTJ)—composed of highly reproducible PMA or predetermined tilted magnetic anisotropy layers. All-perpendicular CoFeB MTJ STOs showed high-frequency microwave generation with extremely high current tunability, all achieved at low applied biases. Spin-torque ferromagnetic resonance (ST-FMR) measurements and analysis revealed the bias dependence of spin-torque components, thus promise great potential for direct gate-voltage controlled STOs. In all-perpendicular PSV STOs, magnetic droplets were observed underneath the nanocontact area at a low drive current and low applied field. Furthermore, preliminary results for microwave auto-oscillation and droplet solitons were obtained from tilted-polarizer PSV STOs. These are promising and would be worth investigating in further studies of STT driven spin dynamics.
25.	Liv, Per, et al. (författare) Between- and within-observer variability in two methods for posture observations 2009 Ingår i: Proceedings of the IEA2009 conference. Konferensbidrag (refereegranskat)
26.	Liv, Per, 1979-, et al. (författare) Statistical power and measurement requirements in studies comparing observed postures between groups Annan publikation (övrigt vetenskapligt/konstnärligt)abstract Ergonomics studies comparing working postures and movements between independent groups are often based on observations. The present paper derives and exemplifies procedures for estimating the statistical power of such studies, addressing the effect of different strategies for allocating observations within and between observers. In the simple case of one observer rating the postures of all subjects in the study one or multiple times, a simple t-test is appropriate for testing the group difference, while statistical models acknowledging rating differences between observers are needed when multiple observers are involved. In the one-observer case, analytical power calculations are feasible, while a parametric bootstrapping approach is suggested and practiced in the paper for the multiple-observers case. Using empirical data from a previous study of postures among hairdressers observed from video recordings (percentages of time with the right upper arm elevated less than 15° and more than 90°), the study demonstrates that a considerable gain in power can be obtained by having one observer doing multiple repeated observations as compared to rating postures only once. Distributing a certain number of video recordings between multiple observers resulted in a loss of power when a simple t-test was used to test the group difference, but the comparison could be accomplished without loss of power if all observers were involved in rating both of the compared groups and the statistical model used to analyze data acknowledged variability in rating between observers. When different observers assessed the two compared groups, power decreased considerably. Thus, the study gives guidance for efficient design of posture observation studies comparing groups, as well as for appropriate statistical procedures for analyzing the data.
27.	Liv, Per, 1979-, et al. (författare) Uncertainties of calibrated exposure estimates, exemplified by working postures assessed by observation and inclinometry Annan publikation (övrigt vetenskapligt/konstnärligt)abstract Objectives: Many occupational exposure variables can be measured using different instruments, of which some can be considered inferior in terms of precision and/or accuracy while others have a superior performance. Thus, working postures can be assessed by observation, which is known to be associated with errors, while direct measurements using inclinometers are assumed to represent a “golden standard”. A possible bias in results obtained by the ”inferior” instrument can be corrected using regression calibration, but the statistical consequences of this procedure are not fully understood. This paper develops procedures for evaluating the precision of an estimate of “true” exposure after calibration, and illustrates them using data from a study of observed upper arm elevation versus corresponding inclinometer measurements.Methods: Three random coefficient models for estimating the relationship between inferior (observations) and superior (inclinometer) measurements were constructed, taking methodological (observer) variability into account to different extents. Expressions for estimating the uncertainty of a calibrated exposure (posture) mean value were derived, which identify the specific contributions from sample uncertainty and uncertainty associated with determining the calibration parameters.Results: In the example of posture observations, calibration introduced an uncertainty that outweighed the size of the observation bias. Thus, this proved to be an example of calibration not always being appropriate, i.e. in case the trade-off between bias correction and increased uncertainty is unfavorable.Conclusions: Calibration of inferior measurements can be a viable tool to correct for bias, but it may add a considerable uncertainty to the eventual mean exposure estimate. Thus, the trade-off between these two calibration effects needs to be considered in each specific case, and further research is needed on the determinants of the trade-off.
28.	Lovén, Jakob, et al. (författare) MYCN-regulated microRNAs repress estrogen receptor-alpha (ESR1) expression and neuronal differentiation in human neuroblastoma. 2010 Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 107:4, s. 1553-8 Tidskriftsartikel (refereegranskat)abstract MYCN, a proto-oncogene normally expressed in the migrating neural crest, is in its amplified state a key factor in the genesis of human neuroblastoma (NB). However, the mechanisms underlying MYCN-mediated NB progression are poorly understood. Here, we present a MYCN-induced miRNA signature in human NB involving the activation and transrepression of several miRNA genes from paralogous clusters. Several family members derived from the miR-17 approximately 92 cluster, including miR-18a and miR-19a, were among the up-regulated miRNAs. Expression analysis of these miRNAs in NB tumors confirmed increased levels in MYCN-amplified samples. Specifically, we show that miR-18a and miR-19a target and repress the expression of estrogen receptor-alpha (ESR1), a ligand-inducible transcription factor implicated in neuronal differentiation. Immunohistochemical staining demonstrated ESR1 expression in human fetal sympathetic ganglia, suggesting a role for ESR1 during sympathetic nervous system development. Concordantly, lentiviral restoration of ESR1 in NB cells resulted in growth arrest and neuronal differentiation. Moreover, lentiviral-mediated inhibition of miR-18a in NB cells led to severe growth retardation, outgrowth of varicosity-containing neurites, and induction of neuronal sympathetic differentiation markers. Bioinformatic analyses of microarray data from NB tumors revealed that high ESR1 expression correlates with increased event-free survival in NB patients and favorable disease outcome. Thus, MYCN amplification may disrupt estrogen signaling sensitivity in primitive sympathetic cells through deregulation of ESR1, thereby preventing the normal induction of neuroblast differentiation. Collectively, our findings demonstrate the molecular consequences of abnormal miRNA transcription in a MYCN-driven tumor and offer unique insights into the pathology underlying MYCN-amplified NB.
29.	Mathiassen, Svend Erik, et al. (författare) Arbetsmiljöns betydelse för besvär och sjukdom i nacke, axlar, armar och händer. En systematisk översikt 2022 Rapport (refereegranskat)
30.	Mathiassen, Svend Erik, et al. (författare) Bias and imprecision in posture percentile variables estimated from short exposure samples 2012 Ingår i: BMC Medical Research Methodology. - : BioMed Central. - 1471-2288. ; 12:1, s. 1-14 Tidskriftsartikel (refereegranskat)abstract BackgroundUpper arm postures are believed to be an important risk determinant for musculoskeletal disorder development in the neck and shoulders. The 10th and 90th percentiles of the angular elevation distribution have been reported in many studies as measures of neutral and extreme postural exposures, and variation has been quantified by the 10th-90th percentile range. Further, the 50th percentile is commonly reported as a measure of "average" exposure. These four variables have been estimated using samples of observed or directly measured postures, typically using sampling durations between 5 and 120 min.MethodsThe present study examined the statistical properties of estimated full-shift values of the 10th, 50th and 90th percentile and the 10th-90th percentile range of right upper arm elevation obtained from samples of seven different durations, ranging from 5 to 240 min. The sampling strategies were realized by simulation, using a parent data set of 73 full-shift, continuous inclinometer recordings among hairdressers. For each shift, sampling duration and exposure variable, the mean, standard deviation and sample dispersion limits (2.5% and 97.5%) of all possible sample estimates obtained at one minute intervals were calculated and compared to the true full-shift exposure value.ResultsEstimates of the 10th percentile proved to be upward biased with limited sampling, and those of the 90th percentile and the percentile range, downward biased. The 50th percentile was also slightly upwards biased. For all variables, bias was more severe with shorter sampling durations, and it correlated significantly with the true full-shift value for the 10th and 90th percentiles and the percentile range. As expected, shorter samples led to decreased precision of the estimate; sample standard deviations correlated strongly with true full-shift exposure values.ConclusionsThe documented risk of pronounced bias and low precision of percentile estimates obtained from short posture samples presents a concern in ergonomics research and practice, and suggests that alternative, unbiased exposure variables should be considered if data collection resources are restricted.
31.	Mathiassen, Svend Erik, et al. (författare) Cost-efficient measurement strategies for posture observations based on video recordings 2013 Ingår i: Applied Ergonomics. - : Elsevier. - 0003-6870 .- 1872-9126. ; 44:4, s. 609-617 Tidskriftsartikel (refereegranskat)abstract Assessment of working postures by observation is a common practice in ergonomics. The present study investigated whether monetary resources invested in a video-based posture observation study should preferably be spent in collecting many video recordings of the work and have them observed once by one observer, or in having multiple observers rate postures repeatedly from fewer videos. The study addressed this question from a practitioner's perspective by focusing two plausible scenarios: documenting the mean exposure of one individual, and of a specific occupational group. Using a data set of observed working postures among hairdressers, empirical values of posture variability, observer variability, and costs for recording and observing one video were entered into equations expressing the total cost of data collection and the information (defined as 1/SD) provided by the resulting estimates of two variables: percentage time with the arm elevated <15 degrees and >90 degrees. Sixteen measurement strategies involving 1-4 observers repeating their posture ratings 1-4 times were examined for budgets up to (sic)2000. For both posture variables and in both the individual and group scenario, the most cost-efficient strategy at any specific budget was to engage 3-4 observers and/or having observer(s) rate postures multiple times each. Between 17% and 34% less information was produced when using the commonly practiced approach of having one observer rate a number of video recordings one time each. We therefore recommend observational posture assessment to be based on video recordings of work, since this allows for multiple observations; and to allocate monetary resources to repeated observations rather than many video recordings. (C) 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.
32.	Mathiassen, Svend Erik, et al. (författare) Cost-efficient observation of working postures from video recordings : more videos, more observers or more views per observer? 2012 Ingår i: Work. - 1051-9815 .- 1875-9270. ; 41:Sup. 1, s. 2302-2306 Tidskriftsartikel (refereegranskat)abstract In ergonomics, assessing the working postures of an individual by observation is a very common practice. The present study investigated whether monetary resources devoted to an observational study should preferably be invested in collecting many video recordings of the work, or in having several observers estimate postures from available videos multiple times. On the basis of a data set of observed working postures among hairdressers, necessary information in terms of posture variability, observer variability, and costs for recording and observing videos was entered into equations providing the total cost of data collection and the precision (informative value) of the resulting estimates of two variables: percentages time with the arm elevated <15 degrees and >90 degrees. In all 160 data collection strategies, differing with respect to the number of video recordings and the number of repeated observations of each recording, were simulated and compared for cost and precision. For both posture variables, the most cost-efficient strategy for a given budget was to engage 4 observers to look at available video recordings, rather than to have one observer look at more recordings. Since the latter strategy is the more common in ergonomics practice, we recommend reconsidering standard practice in observational posture assessment.
33.	Mathiassen, Svend Erik, et al. (författare) Cost-efficient observation of working postures from video recordings – more videos, more observers or more views per observer? 2012 Ingår i: Work. - : IOS Press. - 1051-9815 .- 1875-9270. ; 41:Suppl. 1, s. 2302-2306 Tidskriftsartikel (refereegranskat)abstract In ergonomics, assessing the working postures of an individual by observation is a very common practice. The present study investigated whether monetary resources devoted to an observational study should preferably be invested in collecting many video recordings of the work, or in having several observers estimate postures from available videos multiple times. On the basis of a data set of observed working postures among hairdressers, necessary information in terms of posture variability, observer variability, and costs for recording and observing videos was entered into equations providing the total cost of data collection and the precision (informative value) of the resulting estimates of two variables: percentages time with the arm elevated 90 degrees. In all 160 data collection strategies, differing with respect to the number of video recordings and the number of repeated observations of each recording, were simulated and compared for cost and precision. For both posture variables, the most cost-efficient strategy for a given budget was to engage 4 observers to look at available video recordings, rather than to have one observer look at more recordings. Since the latter strategy is the more common in ergonomics practice, we recommend reconsidering standard practice in observational posture assessment.
34.	Norman, Mikael, et al. (författare) The Swedish Neonatal Quality Register - contents, completeness and validity 2019 Ingår i: Acta Paediatrica. - : WILEY. - 0803-5253 .- 1651-2227. ; 108:8, s. 1411-1418 Tidskriftsartikel (refereegranskat)abstract Aim: To describe the Swedish Neonatal Quality Register (SNQ) and to determine its completeness and agreement with other registers.Methods: SNQ collects data for infants admitted to neonatal units during the first four postnatal weeks. Completeness and registers' agreement were determined cross-linking SNQ data with Swedish population registers (the Inpatient, Medical Birth and Cause of Death Registers) for a study period of five years.Results: In total, 84 712 infants were hospitalised. A total of 52 806 infants occurred in both SNQ and the population registers; 28 692 were only found in the population registers, and 3214 infants were only found in SNQ. Between gestational weeks 24-34, completeness of SNQ was 98-99%. Below and above these gestational ages, completeness was lower. Infants missing in SNQ were term or near-term in 99% of the cases, and their diagnoses indicated conditions managed in maternity units, or re-admissions for acute infections, managed in paediatric units. For most diagnoses, the agreement between SNQ and population registers was high, but some (bronchopulmonary dysplasia and grade of hypoxic-ischaemic encephalopathy) were often missing in the population registers.Conclusion: SNQ completeness and agreement against other registers, especially for preterm infants, is excellent. SNQ is a valid tool for benchmarking, quality improvement and research.
35.	Nurbo, Johanna, et al. (författare) Design, synthesis and evaluation of peptide inhibitors of Mycobacterium tuberculosis ribonucleotide reductase 2007 Ingår i: Journal of Peptide Science. - : Wiley. - 1075-2617 .- 1099-1387. ; 13:12, s. 822-832 Tidskriftsartikel (refereegranskat)abstract Mycobacterium tuberculosis ribonucleotide reductase (RNR) is a potential target for new antitubercular drugs. Herein we describe the synthesis and evaluation of peptide inhibitors of RNR derived from the C-terminus of the small subunit of M. tuberculosis RNR. An N-terminal truncation, an alanine scan and a novel statistical molecular design (SMD) approach based on the heptapeptide Ac-Glu-Asp-Asp-Asp-Trp-Asp-Phe-OH were applied in this study. The alanine scan showed that TrP5 and Phe7 were important for inhibitory potency. A quantitative structure relationship (QSAR) model was developed based on the synthesized peptides which showed that a negative charge in positions 2, 3, and 6 is beneficial for inhibitory potency. Finally, in position 5 the model coefficients indicate that there is room for a larger side chain., as compared to Trp5.
36.	Pedersen, Eja, et al. (författare) Challenges in transdisciplinary research : Example from a study on people as part of energy and ventilation systems in residential buildings (PEIRE) 2019 Ingår i: Cold Climate HVAC 2018 : Sustainable Buildings in Cold Climates - Sustainable Buildings in Cold Climates. - 9783030006617 - 9783030006624 ; , s. 802-812 Konferensbidrag (refereegranskat)abstract Energy efficiency measures in residential buildings typically include changes in ventilation and heating systems, and increased thermal insulation of the building envelope. The expected energy efficiency is not always reached, despite large knowledge and professional implementation of each separate measure. Thereis a lack in understanding of how technical systems interact, and how the ocupants are influenced by and in turn influence the systems by their behaviour. A holistic view and a transdisciplinary research approach are needed to understand relevant interactions and propose integrated energy efficiency measures. The aim of this paper is to reveal challenges in transdisciplinary research projects that include real world studies on both humans and technical systems with measurements before and after renovation of multifamily housing. It is based on experiences from the PEIRE-project (People, Environment, Indoor, Renovation, Energy) carried out by a research team with expertise on environmental psychology, human behaviour, interaction design, universal design, building physics, building services, thermal comfort, aerosol technology, exposure assessment, acoustics, daylight, and complex thinking. Differences in theoretical bases and methodology needed to be dealt with. Metatheory building could help with the transition from a multi- to a transdisciplinary understanding.
37.	Rani, Parul (författare) Magnetic properties of hard-soft amorphous nanolaminates 2023 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Amorphous magnetic thin film heterostructures and multilayers are often used in data storage as well as spintronic devices. Spintronics will help the next generation of nano-electronic devices to increase their memory and processing power and reduce their power consumption. This thesis focuses on the developments of hard and soft amorphous thin films as well as soft/hard multilayers, with an emphasis on the optimization of these materials for use in, for example, spintronics applications. The key for optimization lies in the understanding of the fundamental relationships between structural disorder, composition, and macroscopic magnetic properties.The first part of thesis presents a systematic combinatorial study of composition-structure-property relationships in amorphous alloy thin films of SmCoTi and CoZr, with a particular emphasis on tuning the coercivity µ0Hc ordering temperature Tc, and saturation magnetization Ms with composition. It has been found that 5-7 at.% Ti increases the room temperature coercivity approximately by a factor of ~ 2 (maximum µ0Hc ≈ 0.2 T) compared to amorphous SmCo for Co content in the range 80-85 at.%. For CoZr, dilution of Co with Zr decreases the overall Co moment and the ordering temperature. In magnetic multilayered device architectures, these amorphous alloys might be appropriate for use as soft layers (CoZr) or tunable pinning layers (SmCoTi), depending on the application.This thesis also explores the combination of amorphous hard (SmCo or SmCoTi) and soft (CoAlZr) alloys in bilayer, trilayer, and multilayer structures. The sandwiched of hard and soft amorphous layers that are produced by magnetron sputtering exhibit well-defined interfaces without any lattice strain. First-order reversal curve measurements show that the amorphous hard and soft phases are rigidly exchange-coupled, i.e., the soft phase moment always follows the magnetization direction of the hard phase, for up to at least 20 nm thickness. It is easy to imprint uniaxial in-plane anisotropy in these samples. Both the coercivity and the anisotropy constant increase significantly, by a factor of approximately 4, with increased interface density in the case of CoAlZr/SmCoTi multilayers. In soft/hard/soft trilayers with the same materials, thermal stability is enhanced compared to a single hard layer. Experimental results presented in this thesis demonstrate the potential for tuning properties important to applications based on thin films and multilayers.
38.	Rodling Wahlström, Marie, 1960- (författare) Severe cerebral emergency : aspects of treatment and outcome in the intensive care patient 2009 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Severe Traumatic Brain Injury (TBI) and aneurysmal Subarachnoid Hemorrhage (SAH) are severe cerebral emergencies. They are common reasons for extensive morbidity and mortality in young people and adults in the western world. This thesis, based on five clinical studies in patients with severe TBI (I-IV) and SAH (V), is concentrated on examination of pathophysiological developments and of evaluation of therapeutic approaches in order to improve outcome after cerebral emergency. The treatment for severe TBI patients at Umeå University Hospital, Sweden is an intracranial pressure (ICP)-targeted therapy according to “the Lund-concept”. This therapy is based on physiological principles for cerebral volume regulation, in order to preserve a normal cerebral microcirculation and a normal ICP. The main goal is to avoid development of secondary brain injuries, thus avoiding brain oedema and worsened microcirculation. Study I is evaluating retrospectively 41 children with severe TBI, from 1993 to 2002. The boundaries of the ICP-targeted protocol were obtained in 90%. Survival rate was 93%, and favourable outcome (Glasgow Outcome Scale, score 4+5) was 80%. Study II is retrospectively analysing fluid administration and fluid balance in 93 adult patients with severe TBI, from 1998 to 2001.The ICP-targeted therapy used, have defined fluid strategies. The total fluid balance was positive day one to three, and negative day four to ten. Colloids constituted 40-60% of total fluids given/day. Severe organ failure was evident for respiratory insufficiency and observed in 29%. Mortality within 28 days was 11%. Study III is a prospective, randomised, double-blind, placebo-controlled clinical trial in 48 patients with severe TBI. In order to improve microcirculation and prevent oedema formation, prostacyclin treatment was added to the ICP-targeted therapy. Prostacyclin is endogenously produced, by the vascular endothelium, and has the ability to decrease capillary permeability and vasodilate cerebral capillaries. Prostacyclin is an inhibitor of leukocyte adhesion and platelet aggregation. There was no significant difference between prostacyclin or placebo groups in clinical outcome or in cerebral microdialysis markers such as lactatepyruvate ratio and brain glucose levels. Study IV is part of the third trial and focus on the systemic release of pro-inflammatory mediators that are rapidly activated by trauma. The systemically released pro-inflammatory mediators, interleukin-6 and CRP were significantly decreased in the prostacyclin group versus the placebo group. Study V is a prospective pilot study which analyses asymmetric dimethylarginine (ADMA) concentrations in serum from SAH patients. Acute SAH patients have cerebral vascular, systemic circulatory and inflammatory complications. ADMA is a marker in vascular diseases which is correlated to endothelial dysfunction. ADMA concentrations in serum were significantly elevated seven days after the SAH compared to admission and were still elevated at the three months follow-up. Our results show overall low mortality and high favourable outcome compared to international reports on outcome in severe TBI patients. Prostacyclin administration does not improve cerebral metabolism or outcome but significantly decreases the levels of pro-inflammatory mediators. SAH seems to induce long-lasting elevations of ADMA in serum, which indicates persistent endothelial dysfunction. Endothelial dysfunction may influence outcome after severe cerebral emergencies.
39.	Roos, Abraham, et al. (författare) Elevated Exhaled Nitric Oxide in Allergen-Provoked Asthma Is Associated with Airway Epithelial iNOS. 2014 Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:2 Tidskriftsartikel (refereegranskat)abstract Fractional exhaled nitric oxide is elevated in allergen-provoked asthma. The cellular and molecular source of the elevated fractional exhaled nitric oxide is, however, uncertain.
40.	Saxegaard, Magne, et al. (författare) Field and current-induced magnetization reversal studied through spatially resolved point-contacts 2010 Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 107:10, s. 103909- Tidskriftsartikel (refereegranskat)abstract ABSTRACT: We present results from scanning tunneling microscopy based point-contact measurements of the local resistance in octagon shaped, Co (20 nm )/ Cu (5 nm )/ Fe 19 Ni 81(2.5 nm ) spin-valve rings. Through this technique one can detect the magnetoresistance with spatial resolution, and link it to magnetic domain wall motion within the ring. Measurements with varying currents indicate current-induced effects leading to offsets in the magnetic fields required for magnetic switching. The offsets can be attributed to current-induced spin-transfer torque effects for the thin Fe 19 Ni 81 layer and to Oersted field effects for the thick Co layer.Full-text · Article · Jun 2010 · Journal of Applied Physics
41.	Schröder, Johan Henrik, 1791-1857 (författare) Uplandsdialekten. Akademisk afhandling, med vidtberömda filosofiska fakultetens i Upsala samtycke under inseende af Doct. Joh. Erik Wahlström af Uplands landskap, Acrelsk stipendiat och till offentlig granskning framställd på Gustavianska lärosalen den 10 juni 1848 p. v. t. f. m., I 1848 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)
42.	Singh, Suraj, et al. (författare) Magnetodynamic properties of dipole-coupled 1D magnonic crystals 2021 Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier. - 0304-8853 .- 1873-4766. ; 539 Tidskriftsartikel (refereegranskat)abstract Magnonic crystals are magnetic metamaterials, that provide a promising way to manipulate magnetodynamic properties by controlling the geometry of the patterned structures. Here, we study the magnetodynamic properties of 1D magnonic crystals consisting of parallel NiFe strips with different strip widths and separations. The strips couple via dipole-dipole interactions. As an alternative to experiments and/or micromagnetic simulations, we investigate the accuracy of a simple macrospin model. For the case of simple strips, a model with a single free parameter to account for an overestimation of the out of plane demagnetization of the magnonic lattice is described. By adjusting this parameter, a good fit with experimental as well as micromagnetic results is obtained. Moreover, the Gilbert damping is found independent of lattice constant however the inhomogeneous linewidth broadening found to increase with decreasing stripe separation.
43.	Strålin, Kristoffer, et al. (författare) Mortality in hospitalized COVID-19 patients was associated with the COVID-19 admission rate during the first year of the pandemic in Sweden 2022 Ingår i: Infectious Diseases. - : Taylor & Francis Ltd. - 2374-4235 .- 2374-4243. ; 54:2, s. 145-151 Tidskriftsartikel (refereegranskat)abstract Introduction Studies from the first pandemic wave found associations between COVID-19 hospital load and mortality. Here, we aimed to study if mortality of hospitalized COVID-19 patients was associated with the COVID-19 admission rate during a full year of the pandemic in Sweden. Method Observational review of all patients admitted to hospital with COVID-19 in Sweden between March 2020 and February 2021 (n = 42,017). Primary outcome was 60-day all-cause mortality related to number of COVID-19 hospital admissions per month/100,000 inhabitants. Poisson regression was used to estimate the relative risk for death by month of admission, adjusting for pre-existing factors. Results The overall mortality was 17.4%. Excluding March 2020, mortality was clearly correlated to the number of COVID-19 admissions per month (coefficient of correlation rho=.96; p<.0001). After adjustment for pre-existing factors, the correlation remained significant (rho=.75, p=.02). Patients admitted in December (high admission rate and high mortality) had more comorbidities and longer hospital stays, and patients treated in intensive care units (ICU) had longer pre-ICU hospital stays and worse respiratory status on ICU admission than those admitted in July to September (low admission rate and low mortality). Conclusion Mortality in hospitalized COVID-19 patients was clearly associated with the COVID-19 admission rate. Admission of healthier patients between pandemic waves and delayed ICU care during wave peaks could contribute to this pattern. The study supports measures to flatten-the-curve to reduce the number of COVID-19 patients admitted to hospital.
44.	Strålin, Kristoffer, et al. (författare) Mortality trends among hospitalised COVID-19 patients in Sweden : A nationwide observational cohort study 2021 Ingår i: The Lancet Regional Health. - : Elsevier. - 2666-7762. ; 4 Tidskriftsartikel (refereegranskat)abstract Background: It is important to know if mortality among hospitalised COVID-19 patients has changed as the pandemic has progressed. The aim of this study was to describe the dynamics over time of mortality among patients hospitalised for COVID-19 in Sweden, using nationwide data compiled by the Swedish National Board of Health and Welfare. Methods: Observational cohort study where all patients hospitalised in Sweden between March 1 and September 30, 2020, with SARS-CoV-2 RNA positivity 14 days before to 5 days after admission and a discharge code for COVID-19 were included. Outcome was 60-day all-cause mortality. Patients were categorised according to month of hospital admission. Poisson regression was used to estimate the relative risk of death by month of admission, adjusting for, age, sex, comorbidities, care dependency, country of birth, healthcare region, and Simplified Acute Physiology, version 3 (patients in intensive care units; ICU). Findings: A total of 17,140 patients were included, of which 2943 died within 60 days of admission. The overall 60-day mortality was thus 17.2% (95% CI, 16.6%-17.7%), and it decreased from 24.7% (95% CI, 23.0%-26.5%) in March to 10.4% (95% CI, 8.9%-12.1%) post-wave (July-September). Adjusted relative risk (RR) of death was 0.46 (95% CI, 0.39-0.54) post-wave, using March as reference. Corresponding RR for patients not admitted to ICU and those admitted to ICU were 0.49 (95% CI, 0.42-0.59) and 0.49 (95% CI, 0.33-0.72), respectively. The proportion of patients admitted to ICU decreased from 19.4% (95% CI, 17.9%-21.1%) in the March cohort to 8.9% (95% CI, 7.5%-10.6%) post-wave. Interpretation: There was a gradual decline in mortality during the spring of 2020 in Swedish hospitalised COVID-19 patients, independent of baseline patient characteristics. Future research is needed to explain the reasons for this decline. The changing COVID-19 mortality should be taken into account when management and results of studies from the first pandemic wave are evaluated. (C) 2021 The Authors. Published by Elsevier Ltd.
45.	Trask, Catherine, et al. (författare) Cost-efficient assessment of biomechanical exposure in occupational groups, exemplified by posture observation and inclinometry 2014 Ingår i: Scandinavian Journal of Work, Environment and Health. - : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 40:3, s. 252-265 Tidskriftsartikel (refereegranskat)abstract Objectives: This study compared the cost-efficiency of observation and inclinometer assessment of trunk and upper arm inclination in a population of flight baggage handlers, as an illustration of a general procedure for addressing the trade-off between resource consumption and statistical performance in occupational epidemiology.Methods: Trunk and upper arm inclination with respect to the line of gravity were assessed for 3 days on each of 27 airport baggage handlers using simultaneous recordings by inclinometers and video. Labour and equipment costs associated with data collection and data processing were tracked throughout. Statistical performance, in terms of the inverse of the standard deviation and root mean squared error of the group mean exposure, was computed from the variance components within and between workers, and bias (with inclinometer assumed to produce ‘correct’ inclination angles). The behavior of the trade-off between cost and efficiency with changed sample size, as well as with changed logistics for data collection and processing, was investigated using simulations.Results: At similar total costs, time spent at trunk and arm inclination angles greater than 60 degrees as well as 90th percentile arm inclination were estimated at higher precision using inclinometers, while median inclination and 90th percentile trunk inclination was determined more precisely using observation. This hierarchy persisted in a scenario where the study was immediately reproduced in another population, while inclinometry was more cost-efficient than observation for all three posture variables in a scenario where data were already collected and only needed to be processed. Observations showed to be biased relative to the –assumed to be correct – inclinometer data, and so inclinometry became the most cost-efficient option for all posture variables and irrespective of scenario when statistical performance was measured by bias and precision combined.Conclusions: Inclinometers were more cost-efficient in use than observation for two out of three posture metrics investigated when statistical performance was measured only in terms of precision. Since observations were biased, inclinometers consistently outperformed observation when both bias and precision were included in statistical performance. The presented general model for assessing cost-efficiency may be used for designing exposure assessment strategies with considerations not only to statistical criteria, but even to costs. The empirical data provide a specific basis for planning assessments of working postures in occupational groups.
46.	Trask, Catherine, et al. (författare) Data collection costs in industrial environments for three occupational posture exposure assessment methods 2012 Ingår i: BMC Medical Research Methodology. - : BioMed Central. - 1471-2288. ; 12:1, s. 89- Tidskriftsartikel (refereegranskat)abstract Background: Documentation of posture measurement costs is rare and cost models that do exist are generally nave. This paper provides a comprehensive cost model for biomechanical exposure assessment in occupational studies, documents the monetary costs of three exposure assessment methods for different stakeholders in data collection, and uses simulations to evaluate the relative importance of cost components. Methods: Trunk and shoulder posture variables were assessed for 27 aircraft baggage handlers for 3 full shifts each using three methods typical to ergonomic studies: self-report via questionnaire, observation via video film, and full-shift inclinometer registration. The cost model accounted for expenses related to meetings to plan the study, administration, recruitment, equipment, training of data collectors, travel, and onsite data collection. Sensitivity analyses were conducted using simulated study parameters and cost components to investigate the impact on total study cost. Results: Inclinometry was the most expensive method (with a total study cost of (sic) 66,657), followed by observation ((sic) 55,369) and then self report ((sic) 36,865). The majority of costs (90%) were borne by researchers. Study design parameters such as sample size, measurement scheduling and spacing, concurrent measurements, location and travel, and equipment acquisition were shown to have wide-ranging impacts on costs. Conclusions: This study provided a general cost modeling approach that can facilitate decision making and planning of data collection in future studies, as well as investigation into cost efficiency and cost efficient study design. Empirical cost data from a large field study demonstrated the usefulness of the proposed models.
47.	Trask, Catherine, et al. (författare) Data processing costs for three posture assessment methods 2013 Ingår i: BMC Medical Research Methodology. - : BioMed Central. - 1471-2288. ; 13 Tidskriftsartikel (refereegranskat)abstract BACKGROUND: Data processing contributes a non-trivial proportion to total research costs, but documentation of these costs is rare. This paper employed a priori cost tracking for three posture assessment methods (self-report, observation of video, and inclinometry), developed a model describing the fixed and variable cost components, and simulated additional study scenarios to demonstrate the utility of the model.METHODS: Trunk and shoulder postures of aircraft baggage handlers were assessed for 80 working days using all three methods. A model was developed to estimate data processing phase costs, including fixed and variable components related to study planning and administration, custom software development, training of analysts, and processing time.RESULTS: Observation of video was the most costly data processing method with total cost of € 30,630, and was 1.2-fold more costly than inclinometry (€ 26,255), and 2.5-fold more costly than self-reported data (€ 12,491). Simulated scenarios showed altering design strategy could substantially impact processing costs. This was shown for both fixed parameters, such as software development and training costs, and variable parameters, such as the number of work-shift files processed, as well as the sampling frequency for video observation. When data collection and data processing costs were combined, the cost difference between video and inclinometer methods was reduced to 7%; simulated data showed this difference could be diminished and, even, reversed at larger study sample sizes. Self-report remained substantially less costly under all design strategies, but produced alternate exposure metrics.CONCLUSIONS: These findings build on the previously published data collection phase cost model by reporting costs for post-collection data processing of the same data set. Together, these models permit empirically based study planning and identification of cost-efficient study designs.
48.	Trask, Catherine, et al. (författare) Getting what we pay for : comparing the cost efficiency of direct and observed trunk posture methods 2013 Ingår i: Eighth International Conference on Prevention of Work-related Musculoskeletal Disorders; abstracts. ; , s. 177- Konferensbidrag (refereegranskat)
49.	Trask, Catherine, et al. (författare) Modeling costs of exposure assessment methods in industrial environments 2012 Ingår i: Work. - 1051-9815 .- 1875-9270. ; 41:supplement 1, s. 6079-6086 Tidskriftsartikel (refereegranskat)abstract Documentation of posture measurement cost is rare and cost models that do exist are generally naive. This paper provides a comprehensive cost model for ergonomic research, documents the monetary costs of three exposure assessment methods (inclinometry, video observation, and self-report), and discusses cost components. Trunk and shoulder posture were assessed for 27 aircraft baggage handlers for 3 full shifts each using three methods typical to ergonomics: self-report via questionnaire, observation via video film, and full-shift inclinometer registration. The model accounted for costs related to meetings to plan the study, administration, recruitment, equipment, training of data collectors, travel, and onsite data collection. Findings show that inclinometer was the most expensive method, followed by observation and then self report; the majority of costs (90%) were borne by researchers. Study design parameters such as sample size, measurement scheduling and spacing, concurrent measurements, location and travel, and equipment acquisition were shown to have wide-ranging impacts on costs. This study provided empirical cost data for use in cost models that can facilitate decision making and planning of future studies, and can be used to investigate cost efficiency in future studies.
50.	Wahlström, B, et al. (författare) Association of ploidy and cell proliferation, Dukes' classification, and histopathological differentiation in adenocarcinomas of colon and rectum. 1992 Ingår i: The European journal of surgery = Acta chirurgica. - 1102-4151. ; 158:4 Tidskriftsartikel (refereegranskat)abstract OBJECTIVES--To find out if there is an association between DNA indexes and DNA synthesis (S) phase measurements and Dukes' classification and histopathological differentiation in colorectal cancers, and to investigate the interrelationship between DNA indexes and S phase measurements. DESIGN--Prospective open study. MATERIAL--182 colorectal carcinomas in 181 consecutive patients. INTERVENTION--Tumours biopsied immediately after resection or at rectoscopy or colonoscopy. RESULTS--One or more aneuploid cell populations were found in 113 of 182 carcinomas (62%). There was no correlation between Dukes' stage and either degree of differentiation or S phase measurements, but there were significant correlations between S phase measurements and histological grading (p less than 0.05), and between the percentage of cells in the S phase and the DNA index when values for both diploid and aneuploid tumours were included (p less than 0.001). CONCLUSION--The degree of aneuploidy indicates how far tumour cells have progressed in their cellular disarrangement, and information about a tumour's proliferative capacity is given by the S phase measurements.

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