Browsing by Subject "INSTRUMENT"

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  • Kokkonen, E.; Kaipio, M.; Nieminen, H. -E; Rehman, F.; Miikkulainen, V.; Putkonen, M.; Ritala, M.; Huotari, S.; Schnadt, J.; Urpelainen, S. (2022)
    An ambient pressure cell is described for conducting synchrotron-based x-ray photoelectron spectroscopy (XPS) measurements during atomic layer deposition (ALD) processes. The instrument is capable of true in situ and operando experiments in which it is possible to directly obtain elemental and chemical information from the sample surface using XPS as the deposition process is ongoing. The setup is based on the ambient pressure XPS technique, in which sample environments with high pressure (several mbar) can be created without compromising the ultrahigh vacuum requirements needed for the operation of the spectrometer and the synchrotron beamline. The setup is intended for chemical characterization of the surface intermediates during the initial stages of the deposition processes. The SPECIES beamline and the ALD cell provide a unique experimental platform for obtaining new information on the surface chemistry during ALD half-cycles at high temporal resolution. Such information is valuable for understanding the ALD reaction mechanisms and crucial in further developing and improving ALD processes. We demonstrate the capabilities of the setup by studying the deposition of TiO2 on a SiO2 surface by using titanium(IV) tetraisopropoxide and water as precursors. Multiple core levels and the valence band of the substrate surface were followed during the film deposition using ambient pressure XPS.
  • Karhu, Juho; Kuula, Joel; Virkkula, Aki; Timonen, Hilkka; Vainio, Markku; Hieta, Tuomas (2021)
    Photoacoustic detection is a sensitive method for measurement of light-absorbing particles directly in the aerosol phase. In this article, we demonstrate a new sensitive technique for photoacoustic aerosol absorption measurements using a cantilever microphone for the detection of the photoacoustic signal. Compared to conventional diaphragm microphones, a cantilever offers increased sensitivity by up to two orders of magnitude. The measurement setup uses a photoacoustic cell from Gasera PA201 gas measurement system, which we have adapted for aerosol measurements. Here we reached a noise level of 0.013 Mm(-1) (one standard deviation) with a sampling time of 20 s, using a simple single-pass design without a need for a resonant acoustic cell. The sampling time includes 10 s signal averaging time and 10 s sample exchange, since the photoacoustic cell is designed for closed cell operation. We demonstrate the method in measurements of size-selected nigrosin particles and ambient black carbon. Due to the exceptional sensitivity, the technique shows great potential for applications where low detection limits are required, for example size-selected absorption measurements and black carbon detection in ultra clean environments.
  • CORE Collaboration; Natoli, P.; Kiiveri, K.; Lindholm, V.; Keihänen, E.; Kurki-Suonio, H.; Väliviita, J. (2018)
    We present an analysis of the main systematic effects that could impact the measurement of CMB polarization with the proposed CORE space mission. We employ timeline to-map simulations to verify that the CORE instrumental set-up and scanning strategy allow us to measure sky polarization to a level of accuracy adequate to the mission science goals. We also show how the CORE observations can be processed to mitigate the level of contamination by potentially worrying systematics, including intensity-to-polarization leakage due to bandpass mismatch, asymmetric main beams, pointing errors and correlated noise. We use analysis techniques that are well validated on data from current missions such as Planck to demonstrate how the residual contamination of the measurements by these effects can be brought to a level low enough not to hamper the scientific capability of the mission, nor significantly increase the overall error budget. We also present a prototype of the CORE photometric calibration pipeline, based on that used for Planck, and discuss its robustness to systematics, showing how CORE can achieve its calibration requirements. While a fine-grained assessment of the impact of systematics requires a level of knowledge of the system that can only be achieved in a future study phase, the analysis presented here strongly suggests that the main areas of concern for the CORE mission can be addressed using existing knowledge, techniques and algorithms.
  • Moestl, C.; Amerstorfer, T.; Palmerio, E.; Isavnin, A.; Farrugia, C. J.; Lowder, C.; Winslow, R. M.; Donnerer, J. M.; Kilpua, E. K. J.; Boakes, P. D. (2018)
    Forecasting the geomagnetic effects of solar storms, known as coronal mass ejections (CMEs), is currently severely limited by our inability to predict the magnetic field configuration in the CME magnetic core and by observational effects of a single spacecraft trajectory through its 3-D structure. CME magnetic flux ropes can lead to continuous forcing of the energy input to the Earth's magnetosphere by strong and steady southward-pointing magnetic fields. Here we demonstrate in a proof-of-concept way a new approach to predict the southward field B-z in a CME flux rope. It combines a novel semiempirical model of CME flux rope magnetic fields (Three-Dimensional Coronal ROpe Ejection) with solar observations and in situ magnetic field data from along the Sun-Earth line. These are provided here by the MESSENGER spacecraft for a CME event on 9-13 July 2013. Three-Dimensional Coronal ROpe Ejection is the first such model that contains the interplanetary propagation and evolution of a 3-D flux rope magnetic field, the observation by a synthetic spacecraft, and the prediction of an index of geomagnetic activity. A counterclockwise rotation of the left-handed erupting CME flux rope in the corona of 30 degrees and a deflection angle of 20 degrees is evident from comparison of solar and coronal observations. The calculated Dst matches reasonably the observed Dst minimum and its time evolution, but the results are highly sensitive to the CME axis orientation. We discuss assumptions and limitations of the method prototype and its potential for real time space weather forecasting and heliospheric data interpretation.
  • Kask, Gilber; Uimonen, Mikko M.; Barner-Rasmussen, Ian; Tukiainen, Erkki J.; Blomqvist, Carl; Repo, Jussi P. (2021)
    The most widely used patient-reported outcome (PRO) measure for soft tissue sarcoma (STS) patients is the Toronto Extremity Salvage Score (TESS). The aim of the study was to validate and test the reliability of the TESS for patients with lower extremity STS based on Finnish population data. Patients were assessed using the TESS, the QLQ-C30 Function and Quality of life (QoL) modules, the 15D and the Musculoskeletal tumour Society (MSTS) score. The TESS was completed twice with a 2- to 4-week interval. The intraclass correlation coefficient (ICC) was used for test-retest reliability. Construct validity was tested for structural validity and convergent validity. Altogether 136 patients completed the TESS. A ceiling effect was noted as 21% of the patients scored maximum points. The ICC between first and second administration of the TESS was 0.96. The results of exploratory factor analysis together with high Cronbach's alpha (0.98) supported a unidimensional structure. The TESS correlated moderately with the MSTS score (rho = 0.59, p < 0.001) and strongly with the mobility dimension in the 15D HRQL instrument (rho = 0.76, p < 0.001) and the physical function in QLQ-C30 (rho = 0.83, p < 0.001). The TESS instrument is a comprehensive and reliable PRO measure. The TESS may be used as a validated single index score, for lower extremity STS patients for the measurement of a functional outcome. The TESS seems to reflect patients' HRQoL well after the treatment of lower extremity soft tissue sarcomas. (C) 2020 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
  • Janvier, Miho; Winslow, Reka; Good, Simon; Bonhomme, Elise; Démoulin, Pascal; Dasso, Sergio; Möstl, Christian; Lugaz, Noé; Amerstorfer, Tanja; Soubrié, Elie; Boakes, Peter D. (2019)
    We study interplanetary coronal mass ejections (ICMEs) measured by probes at different heliocentric distances (0.3-1 AU) to investigate the propagation of ICMEs in the inner heliosphere and determine how the generic features of ICMEs change with heliospheric distance. Using data from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER), Venus Express and ACE spacecraft, we analyze with the superposed epoch technique the profiles of ICME substructures, namely, the sheath and the magnetic ejecta. We determine that the median magnetic field magnitude in the sheath correlates well with ICME speeds at 1 AU, and we use this proxy to order the ICMEs at all spacecraft. We then investigate the typical ICME profiles for three categories equivalent to slow, intermediate, and fast ICMEs. Contrary to fast ICMEs, slow ICMEs have a weaker solar wind field at the front and a more symmetric magnetic field profile. We find the asymmetry to be less pronounced at Earth than at Mercury, indicating a relaxation taking place as ICMEs propagate. We also find that the magnetic field intensities in the wake region of the ICMEs do not go back to the pre-ICME solar wind intensities, suggesting that the effects of ICMEs on the ambient solar wind last longer than the duration of the transient event. Such results provide an indication of physical processes that need to be reproduced by numerical simulations of ICME propagation. The samples studied here will be greatly improved by future missions dedicated to the exploration of the inner heliosphere, such as Parker Solar Probe and Solar Orbiter.
  • Salo, J.; Repo, J. P.; Roine, R. P.; Sintonen, H.; Tukiainen, E. J. (2019)
    Objectives: There is limited information of the health-related quality of life (HRQoL) after surgical treatment of chest wall tumors. This cross-sectional study aimed to assess long-term HRQoL after chest wall reconstruction following oncological resection. Methods: Seventy-eight patients having undergone chest wall tumor resection and reconstruction during 1997-2015 were invited to complete the 15D and QLQ-C30 HRQoL instruments. Results: Altogether, 55 patients (17 men and 38 women), with a mean (SD) age of 68 (14) years, completed the questionnaires (response rate 71%). Patients had been operated due to soft tissue sarcoma (n=16), advanced breast cancer (n=15), osteo- or chondrosarcoma (n=14), or other tumor (n=10). Median time after primary surgery was 66 (IQR 38, 141) months. The resection was full thickness in 29/55 cases and partial thickness in 26/55 cases. Chest wall reconstruction was required for 47/55 cases (85%). Reconstruction was performed using soft-tissue flap in eight cases, skeletal stabilizations with mesh or mesh-cement-mesh (sandwich method) in 15 cases, and skeletal stabilizations and soft-tissue flap in 24 cases. Patients' mean 15D score (0.878, SD 0.111) was comparable to that of the age- and gender-standardized general population (0.891, SD 0.041). Limitations in breathing and usual activities were noted. The QLQ-C30 cancer-specific HRQoL was 72 points (maximum 100). Scores in the QLQ-C30 Functional scales ranged from 78 (Physical) to 91 (Social). Conclusions: Long-term HRQoL in patients after chest wall reconstruction following oncological resection is fair and comparable to that of the general population. Limitations in breathing and usual activities can occur. (C) 2019 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
  • Lehtomäki, Kaisa; Stedt, Hanna P.; Osterlund, Emerik; Muhonen, Timo; Soveri, Leena-Maija; Halonen, Päivi; Salminen, Tapio K.; Kononen, Juha; Kallio, Raija; Algars, Annika; Heerva, Eetu; Lamminmaki, Annamarja; Uutela, Aki; Nordin, Arno; Lehto, Juho; Saarto, Tiina; Sintonen, Harri; Kellokumpu-Lehtinen, Pirkko-Liisa; Ristamäki, Raija; Glimelius, Bengt; Isoniemi, Helena; Osterlund, Pia (2022)
    Simple Summary Metastatic colorectal cancer is the second most common cause of cancer death. Long-term survival and cure can be achieved after intensive treatments, including metastasectomy, i.e., the removal of all metastases. We wanted to clarify whether a patient health-related quality of life (HRQoL) was reduced by treatments that aimed to maximise metastasectomy rates, and whether HRQoL of treated patients is comparable to the general population. In a cross-sectional study of 444 patients (1751 questionnaires) in the RAXO-study population, we show that HRQoL of intensively treated patients, sometimes with multiple and multisite metastasectomies-usually combined with systemic therapy-remains at a high level during and after curative treatment and when compared with the general population. Good HRQoL was also seen during non-curative treatment from first- to later-lines, with an impaired HRQoL only at end-of-life. Thus, we should aim at maximising metastasectomies since they give long-term survival and sometimes cure with a high HRQoL. Metastasectomy and/or local ablative therapy in metastatic colorectal cancer (mCRC) patients often provide long-term survival. Health-related quality of life (HRQoL) data in curatively treated mCRC are limited. In the RAXO-study that evaluated repeated resectability, a multi-cross-sectional HRQoL substudy with 15D, EQ-5D-3L, QLQ-C30, and QLQ-CR29 questionnaires was conducted. Mean values of patients in different treatment groups were compared with age- and gender-standardized general Finnish populations. The questionnaire completion rate was 444/477 patients (93%, 1751 questionnaires). Mean HRQoL was 0.89-0.91 with the 15D, 0.85-0.87 with the EQ-5D, 68-80 with the EQ-5D-VAS, and 68-79 for global health status during curative treatment phases, with improvements in the remission phase (disease-free >18 months). In the remission phase, mean EQ-5D and 15D scores were similar to the general population. HRQoL remained stable during first- to later-line treatments, when the aim was no longer cure, and declined notably when tumour-controlling therapy was no longer meaningful. The symptom burden affecting mCRC survivors' well-being included insomnia, impotence, urinary frequency, and fatigue. Symptom burden was lower after treatment and slightly higher, though stable, through all phases of systemic therapy. HRQoL was high in curative treatment phases, further emphasizing the strategy of metastasectomy in mCRC when clinically meaningful.
  • Törmälehto, Soili; Mononen, Mika E.; Aarnio, Emma; Arokoski, Jari P. A.; Korhonen, Rami K.; Martikainen, Janne (2018)
    Background: The purpose was to quantify the decrement in health utility (referred as disutility) associated with knee osteoarthritis (OA) and different symptomatic and radiographic uni- and bilateral definitions of knee OA in a repeated measures design of persons with knee OA or at increased risk of developing knee OA. Methods: Data were obtained from the Osteoarthritis Initiative database. SF-12 health-related quality of life was converted into SF-6D utilities, and were then handled as the health utility loss by subtracting 1.000 from the utility score, yielding a negative value (disutility). Symptomatic OA was defined by radiographic findings (Kellgren-Lawrence, K-L, grade >= 2) and frequent knee pain in the same knee. Radiographic OA was defined by five different definitions (K-L >= 2 unilaterally / bilaterally, or the highest / mean / combination of K-L grades of both knees). Repeated measures generalized estimating equation (GEE) models were used to investigate disutility in relation to these different definitions. Results: Utility decreased with worsening of symptomatic or radiographic status of knee OA. The participants with bilateral and unilateral symptomatic knee OA had 0.03 (p <0.001) and 0.02 (p <0.001) points lower utility scores, respectively, compared with the reference group. The radiographic K-L grade 4 defined as the mean or the highest grade of both knees was related to a decrease of 0.04 (p <0.001) and 0.03 (p <0.001) points in utility scores, respectively, compared to the reference group. Conclusions: Knee OA is associated with diminished health-related quality of life. Health utility can be quantified in relation to both symptomatic and radiographic uni- and bilateral definitions of knee OA, and these definitions are associated with differing disutilities. The performance of symptomatic definition was better, indicating that pain experience is an important factor in knee OA related quality of life.
  • Suikkala, A; Timonen, L; Leino-Kilpi, H; Katajisto, J; Strandell-Laine, C (2021)
    Background Relationships with patients are seen as the core component of establishing the quality of patient-centred care and promoting patients' autonomy and relevant use of services. A clinical learning environment that emphasizes relationship-based healthcare is essential for encouraging future healthcare professionals to work in partnership with patients. There is also broad agreement that the insight of patients should be used actively in healthcare students' clinical learning. The aim of this study was to describe healthcare students' perceptions of their relationship with patients and the quality of the clinical learning environment and to identify factors associated with both of these. Methods A cross-sectional survey using an electronic questionnaire was applied to collect data from 1644 Finnish healthcare students, mostly nursing students, between January 2018 and May 2018. The data were analysed statistically using descriptive statistics, Spearman's correlation coefficients, and multifactor analysis of variance. Results Students perceived the level of the student-patient relationship and the role of the teacher as good while pedagogical atmosphere, premises of care, premises of learning, and supervisory relationship were perceived to be at very good level. The correlations between the student-patient relationship and all clinical learning environment dimensions were perceived as moderate. Furthermore, a number of student-related factors associated with the student-patient relationship and the quality of the clinical learning environment were detected. Conclusions In this study, the rarely explored perspective of the student-patient relationship within the context of the clinical learning environment was included. The student-patient relationship and the quality of the clinical learning environment were perceived as good by the students, with a number of determining factors affecting these perceptions. Giving the student-patient relationship a role in clinical education may be conducive to students' learning with the patient in focus, and may thus promote the competence needed in the rapidly evolving healthcare environment and the changing scope of clinical practice.
  • ESO Hlth Econ Working Grp; Cadilhac, Dominique A.; Kim, Joosup; Wilsno, Alastair; Meretoja, Atte; Lees, Kennedy R. (2020)
    Introduction Approaches to economic evaluations of stroke therapies are varied and inconsistently described. An objective of the European Stroke Organisation (ESO) Health Economics Working Group is to standardise and improve the economic evaluations of interventions for stroke. Methods The ESO Health Economics Working Group and additional experts were contacted to develop a protocol and a guidance document for data collection for economic evaluations of stroke therapies. A modified Delphi approach, including a survey and consensus processes, was used to agree on content. We also asked the participants about resources that could be shared to improve economic evaluations of interventions for stroke. Results Of 28 experts invited, 16 (57%) completed the initial survey, with representation from universities, government, and industry. More than half of the survey respondents endorsed 13 specific items to include in a standard resource use questionnaire. Preferred functional/quality of life outcome measures to use for economic evaluations were the modified Rankin Scale (14 respondents, 88%) and the EQ-5D instrument (11 respondents, 69%). Of the 12 respondents who had access to data used in economic evaluations, 10 (83%) indicated a willingness to share data. A protocol template and a guidance document for data collection were developed and are presented in this article. Conclusion The protocol template and guidance document for data collection will support a more standardised and transparent approach for economic evaluations of stroke care.
  • Rodriguez, E.; Kolmonen, P.; Virtanen, T. H.; Sogacheva, L.; Sundström, Anu-Maija; de Leeuw, G. (2015)
    The Advanced Along-Track Scanning Radiometer (AATSR) on board the ENVISAT satellite is used to study aerosol properties. The retrieval of aerosol properties from satellite data is based on the optimized fit of simulated and measured reflectances at the top of the atmosphere (TOA). The simulations are made using a radiative transfer model with a variety of representative aerosol properties. The retrieval process utilizes a combination of four aerosol components, each of which is defined by their (lognormal) size distribution and a complex refractive index: a weakly and a strongly absorbing fine-mode component, coarse mode sea salt aerosol and coarse mode desert dust aerosol). These components are externally mixed to provide the aerosol model which in turn is used to calculate the aerosol optical depth (AOD). In the AATSR aerosol retrieval algorithm, the mixing of these components is decided by minimizing the error function given by the sum of the differences between measured and calculated path radiances at 3-4 wavelengths, where the path radiances are varied by varying the aerosol component mixing ratios. The continuous variation of the fine-mode components allows for the continuous variation of the fine-mode aerosol absorption. Assuming that the correct aerosol model (i.e. the correct mixing fractions of the four components) is selected during the retrieval process, also other aerosol properties could be computed such as the single scattering albedo (SSA). Implications of this assumption regarding the ratio of the weakly/strongly absorbing fine-mode fraction are investigated in this paper by evaluating the validity of the SSA thus obtained. The SSA is indirectly estimated for aerosol plumes with moderate-to-high AOD resulting from wildfires in Russia in the summer of 2010. Together with the AOD, the SSA provides the aerosol absorbing optical depth (AAOD). The results are compared with AERONET data, i.e. AOD level 2.0 and SSA and AAOD inversion products. The RMSE (root mean square error) is 0.03 for SSA and 0.02 for AAOD lower than 0.05. The SSA is further evaluated by comparison with the SSA retrieved from the Ozone Monitoring Instrument (OMI). The SSA retrieved from both instruments show similar features, with generally lower AATSR-estimated SSA values over areas affected by wildfires.
  • Runov, Andrei; Grandin, Maxime; Palmroth, Minna; Battarbee, Markus; Ganse, Urs; Hietala, Heli; Hoilijoki, Sanni; Kilpua, Emilia; Pfau-Kempf, Yann; Toledo-Redondo, Sergio; Turc, Lucile; Turner, Drew (2021)
    We present results of noon-midnight meridional plane global hybrid-Vlasov simulations of the magnetotail ion dynamics under a steady southward interplanetary magnetic field using the Vlasiator model. The simulation results show magnetotail reconnection and formation of earthward and tailward fast plasma outflows. The hybrid-Vlasov approach allows us to study ion velocity distribution functions (VDFs) that are self-consistently formed during the magnetotail evolution. We examine the VDFs collected by virtual detectors placed along the equatorial magnetotail within earthward and tailward outflows and around the quasi-steady X line formed in the magnetotail at X approximate to -14 RE. This allows us to follow the evolution of VDFs during earthward and tailward motion of reconnected flux tubes as well as study signatures of unmagnetized ion motion in the weak magnetic field near the X line. The VDFs indicate actions of Fermi-type and betatron acceleration mechanisms, ion acceleration by the reconnection electric field, and Speiser-type motion of ions near the X line. The simulated VDFs are compared and show good agreement with VDFs observed in the magnetotail by the Time History of Events and Macroscale Interactions during Substorms (THEMIS) and Acceleration, Reconnection, Turbulence and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) spacecraft. We find that the VDFs become more gyrotropic but retain transverse anisotropy and counterstreaming ion beams when being convected earthward. The presented global hybrid-Vlasov simulation results are valuable for understanding physical processes of ion acceleration during magnetotail reconnection, interpretation of in situ observations, and for future mission development by setting requirements on pitch angle and energy resolution of upcoming instruments.
  • Möstl, C.; Isavnin, A.; Boakes, P. D.; Kilpua, E. K. J.; Davies, J. A.; Harrison, R. A.; Barnes, D.; Krupar, V.; Eastwood, J. P.; Good, S. W.; Forsyth, R. J.; Bothmer, V.; Reiss, M. A.; Amerstorfer, T.; Winslow, R. M.; Anderson, B. J.; Philpott, L. C.; Rodriguez, L.; Rouillard, A. P.; Gallagher, P.; Nieves-Chinchilla, T.; Zhang, T. L. (2017)
    We present an advance toward accurately predicting the arrivals of coronal mass ejections (CMEs) at the terrestrial planets, including Earth. For the first time, we are able to assess a CME prediction model using data over two thirds of a solar cycle of observations with the Heliophysics System Observatory. We validate modeling results of 1337 CMEs observed with the Solar Terrestrial Relations Observatory (STEREO) heliospheric imagers (HI) (science data) from 8 years of observations by five in situ observing spacecraft. We use the self-similar expansion model for CME fronts assuming 60 degrees longitudinal width, constant speed, and constant propagation direction. With these assumptions we find that 23%-35% of all CMEs that were predicted to hit a certain spacecraft lead to clear in situ signatures, so that for one correct prediction, two to three false alarms would have been issued. In addition, we find that the prediction accuracy does not degrade with the HI longitudinal separation from Earth. Predicted arrival times are on average within 2.6 +/- 16.6 h difference of the in situ arrival time, similar to analytical and numerical modeling, and a true skill statistic of 0.21. We also discuss various factors that may improve the accuracy of space weather forecasting using wide-angle heliospheric imager observations. These results form a first-order approximated baseline of the prediction accuracy that is possible with HI and other methods used for data by an operational space weather mission at the Sun-Earth L5 point. Plain Language Summary Solar storms are formed by incredibly powerful explosions on the Sun and travel as clouds of plasma threaded by magnetic fields through the solar system. Depending on their propagation direction, they may impact planets such as Earth, where they elicit colorful aurorae or, in very seldom cases, can lead to power failures with potentially tremendous economical and societal effects, thus posing a serious natural hazard. In this work, we have shown how well the solar storm impact can be forecasted when using a special type of instrument that can actually image the solar storms as they propagate toward the planets and even as they sweep over them. Our analysis includes two thirds of a solar cycle with 8 years of data, and spacecraft at Mercury, Venus, Earth, and in the solar wind to check on the correctness of our predictions. We could forecast the arrival time within +/- 16 h, and for one correct impact there are two to three false alarms. This forms a new baseline for the science of space weather prediction. Clearly, the modeling should be further improved to be used on a daily basis for a space weather mission to the Sun-Earth L5 point.
  • Kilpua, E. K. J.; Good, S. W.; Dresing, N.; Vainio, R.; Davies, E. E.; Forsyth, R. J.; Gieseler, J.; Lavraud, B.; Asvestari, E.; Morosan, D. E.; Pomoell, J.; Price, D. J.; Heyner, D.; Horbury, T. S.; Angelini, Corrado; O'Brien, H.; Evans, Bradley; Rodriguez-Pacheco, J.; Herrero, R. Gomez; Ho, G. C.; Kiel, University (2021)
    Context. Sheath regions ahead of coronal mass ejections (CMEs) are large-scale heliospheric structures that form gradually with CME expansion and propagation from the Sun. Turbulent and compressed sheaths could contribute to the acceleration of charged particles in the corona and in interplanetary space, but the relation of their internal structure to the particle energization process is still a relatively little studied subject. In particular, the role of sheaths in accelerating particles when the shock Mach number is low is a significant open research problem. Aims. This work seeks to provide new insights on the internal structure of CME-driven sheaths with regard to energetic particle enhancements. A good opportunity to achieve this aim was provided by multi-point, in-situ observations of a sheath region made by radially aligned spacecraft at 0.8 and similar to 1 AU (Solar Orbiter, the L1 spacecraft Wind and ACE, and BepiColombo) on April 19-21, 2020. The sheath was preceded by a weak and slowly propagating fast-mode shock. Methods. We apply a range of analysis techniques to in situ magnetic field, plasma and particle observations. The study focuses on smaller scale sheath structures and magnetic field fluctuations that coincide with energetic ion enhancements. Results. Energetic ion enhancements were identified in the sheath, but at different locations within the sheath structure at Solar Orbiter and L1. Magnetic fluctuation amplitudes at inertial-range scales increased in the sheath relative to the solar wind upstream of the shock, as is typically observed. However, when normalised to the local mean field, fluctuation amplitudes did not increase significantly; magnetic compressibility of fluctuation also did not increase within the sheath. Various substructures were found to be embedded within the sheath at the different spacecraft, including multiple heliospheric current sheet (HCS) crossings and a small-scale flux rope. At L1, the ion flux enhancement was associated with the HCS crossings, while at Solar Orbiter, the ion enhancement occurred within a compressed, small-scale flux rope. Conclusions. Several internal smaller-scale substructures and clear difference in their occurrence and properties between the used spacecraft was identified within the analyzed CME-driven sheath. These substructures are favourable locations for the energization of charged particles in interplanetary space. In particular, substructures that are swept from the upstream solar wind and compressed into the sheath can act as effective acceleration sites. A possible acceleration mechanism is betatron acceleration associated with a small-scale flux rope and warped HCS compressed in the sheath, while the contribution of shock acceleration to the latter cannot be excluded.
  • Scolini, C.; Rodriguez, L.; Mierla, M.; Pomoell, J.; Poedts, S. (2019)
    Context. Coronal mass ejections (CMEs) are the primary source of strong space weather disturbances at Earth. Their geo-effectiveness is largely determined by their dynamic pressure and internal magnetic fields, for which reliable predictions at Earth are not possible with traditional cone CME models. Aims. We study two well-observed Earth-directed CMEs using the EUropean Heliospheric FORecasting Information Asset (EUH-FORIA) model, testing for the first time the predictive capabilities of a linear force-free spheromak CME model initialised using parameters derived from remote-sensing observations. Methods. Using observation-based CME input parameters, we performed magnetohydrodynamic simulations of the events with EU-HFORIA, using the cone and spheromak CME models. Results. Simulations show that spheromak CMEs propagate faster than cone CMEs when initialised with the same kinematic parameters. We interpret these differences as the result of different Lorentz forces acting within cone and spheromak CMEs, which lead to different CME expansions in the heliosphere. Such discrepancies can be mitigated by initialising spheromak CMEs with a reduced speed corresponding to the radial speed only. Results at Earth provide evidence that the spheromak model improves the predictions of B (B-z) by up to 12-60 (22-40) percentage points compared to a cone model. Considering virtual spacecraft located within +/- 10 degrees around Earth, B (Bz) predictions reach 45-70% (58-78%) of the observed peak values. The spheromak model shows inaccurate predictions of the magnetic field parameters at Earth for CMEs propagating away from the Sun-Earth line. Conclusions. The spheromak model successfully predicts the CME properties and arrival time in the case of strictly Earth-directed events, while modelling CMEs propagating away from the Sun-Earth line requires extra care due to limitations related to the assumed spherical shape. The spatial variability of modelling results and the typical uncertainties in the reconstructed CME direction advocate the need to consider predictions at Earth and at virtual spacecraft located around it.
  • Sundstrom, A-M.; Arola, Antti; Kolmonen, Pekka; Xue, Yong; de Leeuw, G.; Kulmala, M. (2015)
  • Rauma, Ville; Salo, Jarmo; Sintonen, Harri; Räsänen, Jari Veli; Ilonen, Ilkka (2016)
    Background: This study presents a retrospective evaluation of patient, disease, and treatment features predicting long-term survival and health-related quality of life (HRQoL) among patients who underwent surgery for non-small cell lung cancer (NSCLC). Methods: Between January 2000 and June 2009, 586 patients underwent surgery at the Helsinki University Hospital. The 276 patients still alive in June 2011 received two validated quality of life questionnaires (QLQ): the generic 15D and the cancer-specific EORTC QLQ-C30 + QLQ-LC13. We used binary and linear regression analysis modeling to identify patient, disease, and treatment characteristics that predicted survival and long-term HRQoL. Results: When taking into account patient, disease, and treatment characteristics, long-term survival was quite predictable (69.5% correct), but no long-term HRQoL (R-2 between 0.041 and 0.119). Advanced age at the time of surgery, male gender, comorbidity (measured with the Charlson comorbidity index), clinical and pathological stages II-IV, and postoperative infectious complications predicted a lower survival rate. Features associated with poorer long-term HRQoL (measured with the 15D) were comorbidity, postoperative complications, and the use of the video-assisted thoracoscopic surgery (VATS) technique. Conclusions: Long-term HRQoL is only moderately predictable, while prediction of long-term survival is more reliable. Lower HRQoL is associated with comorbidities, complications, use of the VATS technique, and reduced pulmonary function, while adjuvant therapy is associated with higher HRQoL.
  • Ade, P. A. R.; Juvela, M.; Keihanen, E.; Kurki-Suonio, H.; Poutanen, T.; Suur-Uski, A. -S.; Valiviita, J.; Planck Collaboration (2014)
  • van Lier, Lisanne I.; van der Roest, Henriette G.; Oosten, Babette S. H.; Garms-Homolova, Vjenka; Onder, Graziano; Finne-Soveri, Harriet; Jonsson, Palmi V.; Ljunggren, Gunnar; Henrard, Jean-Claude; Topinkova, Eva; Sorbye, Liv Wergeland; Bernabei, Roberto; van Hout, Hein P. J.; Bosmans, Judith E. (2019)
    BACKGROUND: The objective was to identify predictors of societal costs covering formal and informal care utilization by older home care clients in 11 European countries. METHODS : Societal costs of 1907 older clients receiving home care for 12 months from the Aged in Home care (AdHoc) study were estimated using the InterRAI Minimum Data Set for Home Care's (MDS-HC) resource use items. Predictors (medical, functional, and psychosocial domains) of societal costs were identified by performing univariate and multivariate generalized linear model analyses. RESULTS : Mean societal costs per participant were (sic)36 442, ranging from (sic)14 865 in Denmark to (sic)78 836 in the United Kingdom. In the final multivariate model, country, being married, activities of daily living (ADL) dependency, cognitive impairment, limitations of going out, oral conditions, number of medications, arthritis, and cerebro vascular accident (CVA) were significantly associated with societal costs. CONCLUSIONS: Of the predictors, ADL dependency and limitations of going out may be modifiable. Developing interventions targeted at improving these conditions may create opportunities to curtail societal costs.